Combined Electrocardiography- and Respiratory-Triggered CT of the Lung to Reduce Respiratory Misregistration Artifacts between Imaging Slabs in Free-Breathing Children: Initial Experience.

PubMed

Goo, Hyun Woo; Allmendinger, Thomas

2017-01-01

Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. In total, 15 children (median age 19 months, range 6 months-8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children.

A proposed protocol for acceptance and constancy control of computed tomography systems: a Nordic Association for Clinical Physics (NACP) work group report.

PubMed

Kuttner, Samuel; Bujila, Robert; Kortesniemi, Mika; Andersson, Henrik; Kull, Love; Østerås, Bjørn Helge; Thygesen, Jesper; Tarp, Ivanka Sojat

2013-03-01

Quality assurance (QA) of computed tomography (CT) systems is one of the routine tasks for medical physicists in the Nordic countries. However, standardized QA protocols do not yet exist and the QA methods, as well as the applied tolerance levels, vary in scope and extent at different hospitals. To propose a standardized protocol for acceptance and constancy testing of CT scanners in the Nordic Region. Following a Nordic Association for Clinical Physics (NACP) initiative, a group of medical physicists, with representatives from four Nordic countries, was formed. Based on international literature and practical experience within the group, a comprehensive standardized test protocol was developed. The proposed protocol includes tests related to the mechanical functionality, X-ray tube, detector, and image quality for CT scanners. For each test, recommendations regarding the purpose, equipment needed, an outline of the test method, the measured parameter, tolerance levels, and the testing frequency are stated. In addition, a number of optional tests are briefly discussed that may provide further information about the CT system. Based on international references and medical physicists' practical experiences, a comprehensive QA protocol for CT systems is proposed, including both acceptance and constancy tests. The protocol may serve as a reference for medical physicists in the Nordic countries.

Cognitive training in Alzheimer's disease: a controlled randomized study.

PubMed

Giovagnoli, A R; Manfredi, V; Parente, A; Schifano, L; Oliveri, S; Avanzini, G

2017-08-01

This controlled randomized single-blind study evaluated the effects of cognitive training (CT), compared to active music therapy (AMT) and neuroeducation (NE), on initiative in patients with mild to moderate Alzheimer's disease (AD). Secondarily, we explored the effects of CT on episodic memory, mood, and social relationships. Thirty-nine AD patients were randomly assigned to CT, AMT, or NE. Each treatment lasted 3 months. Before, at the end, and 3 months after treatment, neuropsychological tests and self-rated scales assessed initiative, episodic memory, depression, anxiety, and social relationships. At the end of the CT, initiative significantly improved, whereas, at the end of AMT and NE, it was unchanged. Episodic memory showed no changes at the end of CT or AMT and a worsening after NE. The rates of the patients with clinically significant improvement of initiative were greater after CT (about 62%) than after AMT (about 8%) or NE (none). At the 3-month follow-up, initiative and episodic memory declined in all patients. Mood and social relationships improved in the three groups, with greater changes after AMT or NE. In patients with mild to moderate AD, CT can improve initiative and stabilize memory, while the non-cognitive treatments can ameliorate the psychosocial aspects. The combining of CT and non-cognitive treatments may have useful clinical implications.

[Virtual otoscopy--technique, indications and initial experiences with multislice spiral CT].

PubMed

Klingebiel, R; Bauknecht, H C; Lehmann, R; Rogalla, P; Werbs, M; Behrbohm, H; Kaschke, O

2000-11-01

We report the standardized postprocessing of high-resolution CT data acquired by incremental CT and multi-slice CT in patients with suspected middle ear disorders to generate three-dimensional endoluminal views known as virtual otoscopy. Subsequent to the definition of a postprocessing protocol, standardized endoluminal views of the middle ear were generated according to their otological relevance. The HRCT data sets of 26 ENT patients were transferred to a workstation and postprocessed to 52 virtual otoscopies. Generation of predefined endoluminal views from the HRCT data sets was possible in all patients. Virtual endoscopic views added meaningful information to the primary cross-sectional data in patients suffering from ossicular pathology, having contraindications for invasive tympanic endoscopy or being assessed for surgery of the tympanic cavity. Multi slice CT improved the visualization of subtle anatomic details such as the stapes suprastructure and reduced the scanning time. Virtual endoscopy allows for the non invasive endoluminal visualization of various tympanic lesions. Use of the multi-slice CT technique reduces the scanning time and improves image quality in terms of detail resolution.

Unenhanced Computed Tomography to Visualize Hollow Viscera and/or Mesenteric Injury After Blunt Abdominal Trauma: A Single-Institution Experience.

PubMed

Yang, Xu-Yang; Wei, Ming-Tian; Jin, Cheng-Wu; Wang, Meng; Wang, Zi-Qiang

2016-03-01

To identify and describe the major features of unenhanced computed tomography (CT) images of blunt hollow viscera and/or mesenteric injury (BHVI/MI) and to determine the value of unenhanced CT in the diagnosis of BHVI/MI. This retrospective study included 151 patients who underwent unenhanced CT before laparotomy for blunt abdominal trauma between January 2011 and December 2013. According to surgical observations, patients were classified as having BHVI/MI (n = 73) or not (n = 78). Sensitivity, specificity, P values, and likelihood ratios were calculated by comparing CT findings between the 2 groups. Six significant CT findings (P < 0.05) for BHVI/MI were identified and their sensitivity and specificity values determined, as follows: bowel wall thickening (39.7%, 96.2%), mesentery thickening (46.6%, 88.5%), mesenteric fat infiltration (12.3%, 98.7%), peritoneal fat infiltration (31.5%, 87.1%), parietal peritoneum thickening (30.1%, 85.9%), and intra- or retro-peritoneal air (34.2%, 96.2%). Unenhanced CT scan was useful as an initial assessment tool for BHVI/MI after blunt abdominal trauma. Six key features on CT were correlated with BHVI/MI.

Dynamic four-dimensional computed tomography (4D CT) imaging for re-entry risk assessment in re-do sternotomy - first experience.

PubMed

Narayanan, Harish; Viana, Fabiano F; Smith, Julian A; Roumeliotis, Nicholas K; Troupis, Christopher J; Crossett, Marcus P; Troupis, John M

2015-10-01

Repeat cardiac surgeries are well known to have higher rates of complications, one of the important reasons being injuries associated with re-do sternotomy. Routine imaging with CT can help to minimise this risk by pre-operatively assessing the anatomical relation between the sternum and the underlying cardiovascular structures, but is limited by its inability to determine the presence and severity of functional tethering and adhesions between these structures. However, with the evolution of wide area detector MD CT scanners, it is possible to assess the presence of tethering using the dynamic four-dimensional CT (4D CT) imaging technique. Nineteen patients undergoing re-do cardiac surgery were pre-operatively imaged using dynamic 4D CT during regulated respiration. The datasets were assessed in cine mode for presence of differential motion between sternum and underlying cardiovascular structures which indicates lack of significant tethering. Overall, there was excellent correlation between preoperative imaging and intraoperative findings. The technique enabled our surgeons to meticulously plan the procedures and to avoid re-entry related injuries. Our initial experience shows that dynamic 4D CT is useful in risk stratification prior to re-do sternotomy by determining the presence or absence of tethering between sternum and underlying structures based on assessment of differential motion. Furthermore we determined the technique to be superior to non-dynamic assessment of retrocardiac tethering. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Combined Electrocardiography- and Respiratory-Triggered CT of the Lung to Reduce Respiratory Misregistration Artifacts between Imaging Slabs in Free-Breathing Children: Initial Experience

PubMed Central

Allmendinger, Thomas

2017-01-01

Objective Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. Materials and Methods In total, 15 children (median age 19 months, range 6 months–8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Results Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Conclusion Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children. PMID:28860904

SU-F-T-261: Reconstruction of Initial Photon Fluence Based On EPID Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seliger, T; Engenhart-Cabillic, R; Czarnecki, D

2016-06-15

Purpose: Verifying an algorithm to reconstruct relative initial photon fluence for clinical use. Clinical EPID and CT images were acquired to reconstruct an external photon radiation treatment field. The reconstructed initial photon fluence could be used to verify the treatment or calculate the applied dose to the patient. Methods: The acquired EPID images were corrected for scatter caused by the patient and the EPID with an iterative reconstruction algorithm. The transmitted photon fluence behind the patient was calculated subsequently. Based on the transmitted fluence the initial photon fluence was calculated using a back-projection algorithm which takes the patient geometry andmore » its energy dependent linear attenuation into account. This attenuation was gained from the acquired cone-beam CT or the planning CT by calculating a water-equivalent radiological thickness for each irradiation direction. To verify the algorithm an inhomogeneous phantom consisting of three inhomogeneities was irradiated by a static 6 MV photon field and compared to a reference flood field image. Results: The mean deviation between the reconstructed relative photon fluence for the inhomogeneous phantom and the flood field EPID image was 3% rising up to 7% for off-axis fluence. This was probably caused by the used clinical EPID calibration, which flattens the inhomogeneous fluence profile of the beam. Conclusion: In this clinical experiment the algorithm achieved good results in the center of the field while it showed high deviation of the lateral fluence. This could be reduced by optimizing the EPID calibration, considering the off-axis differential energy response. In further progress this and other aspects of the EPID, eg. field size dependency, CT and dose calibration have to be studied to realize a clinical acceptable accuracy of 2%.« less

Palonosetron versus other 5-HT₃ receptor antagonists for prevention of chemotherapy-induced nausea and vomiting in patients with hematologic malignancies treated with emetogenic chemotherapy in a hospital outpatient setting in the United States.

PubMed

Craver, Chris; Gayle, Julie; Balu, Sanjeev; Buchner, Deborah

2011-01-01

This study evaluated the rate of uncontrolled chemotherapy-induced nausea and vomiting (CINV) after initiating antiemetic prophylaxis with palonosetron versus other 5-HT₃ receptor antagonists (RAs) in patients diagnosed with hematologic malignancies (lymphoma and leukemia) and receiving highly emetogenic chemotherapy (HEC) or moderately emetogenic chemotherapy (MEC) in a hospital outpatient setting. Patients aged ≥ 18 years and diagnosed with hematologic malignancies initiating HEC or MEC and antiemetic prophylaxis with palonosetron (Group 1) and other 5-HT₃ RAs (Group 2) for the first time in a hospital outpatient setting between 4/1/2007 and 3/31/2009 were identified from the Premier Perspective Database. Within each cycle, CINV events were identified (in the hospital outpatient, inpatient, and emergency room settings) through ICD-9 codes for nausea, vomiting, and/or volume depletion (from each CT administration day 1 until the end of the CT cycle), or use of rescue medications (day 2 until the end of the CT cycle). Negative binomial distribution generalized linear multivariate regression model estimating the CINV event rate on CT, specific CT cycles, and cancer diagnosis (leukemia/lymphoma)-matched groups in the follow-up period (first of 8 cycles or 6 months) was developed. Of 971 identified patients, 211 initiated palonosetron (Group 1). Group 1 patients comprised of more females [50.2 vs. 41.4%; p = 0.0226], Whites [74.4 vs. 70.4%, and Hispanics [7.6 vs. 6.3%; all races p = 0.0105], received more HEC treatments [89.6 vs. 84.2%; all CT types p = 0.0129], and had more lymphoma diagnosed patients [89.6 vs. 76.3%; all cancer types p = 0.0033] at baseline. After controlling for differences in several demographic and clinical variables, the regression model predicted a 20.4% decrease in CINV event rate per CT cycle for Group 1 versus Group 2 patients. Study limitations include potential lack of generalizability, absence of data on certain confounders including alcohol consumption and prior history of motion sickness, potential underestimation of incidence of uncontrolled CINV, and inability to draw conclusions pertaining to cause and effect relationship. In this retrospective hospital study, patients with hematologic malignancies treated with HEC or MEC and initiated on antiemetic prophylaxis with palonosetron in the hospital outpatient setting were more likely to experience significantly lower CINV event rates (in the hospital outpatient, inpatient, and emergency room settings) versus patients initiated on other 5-HT₃ RAs.

Role of 18F-fluoride PET/CT in the assessment of multiple myeloma: initial experience.

PubMed

Nishiyama, Yuji; Tateishi, Ukihide; Shizukuishi, Kazuya; Shishikura, Ayako; Yamazaki, Etsuko; Shibata, Hiroto; Yoneyama, Tomohiro; Ishigatsubo, Yoshiaki; Inoue, Tomio

2013-01-01

The aim of this study was to report our early experience with (18)F-fluoride PET/CT for detecting lesions and evaluate the usefulness of this modality in the assessment of multiple myeloma (MM). (18)F-fluoride PET/CT and (99m)Tc-MDP bone scintigraphy (BS) studies from 7 myeloma patients (4 male and 3 female, mean age 55 years) diagnosed according to standard criteria were reviewed retrospectively. Two reviewers visually and quantitatively analyzed the images and recorded their findings after reaching a consensus. Diagnostic certainty regarding the presence or absence of myeloma lesions was evaluated according to the reference standard consisting of whole-body magnetic resonance imaging and whole-body X-ray. A total of 93 affected areas were definite according to the reference standard. Of these, 83 affected areas (89 %) were identified on (18)F-fluoride PET/CT, whereas 54 affected areas (58 %) were found on BS. Mean SUVmax in the affected areas was 9.8 ± 3.2 (standard deviation) ranging from 5.0 to 21.2. A total of s17 lesions with bone fracture were also detected by (18)F-fluoride PET/CT and 2 lesions (12 %) were negative on BS. Our result showed that (18)F-fluoride PET was a possible modality to detect areas of lesions in patients with MM.

68Ga-PSMA-11 PET/CT Interobserver Agreement for Prostate Cancer Assessments: An International Multicenter Prospective Study.

PubMed

Fendler, Wolfgang Peter; Calais, Jeremie; Allen-Auerbach, Martin; Bluemel, Christina; Eberhardt, Nina; Emmett, Louise; Gupta, Pawan; Hartenbach, Markus; Hope, Thomas A; Okamoto, Shozo; Pfob, Christian Helmut; Pöppel, Thorsten D; Rischpler, Christoph; Schwarzenböck, Sarah; Stebner, Vanessa; Unterrainer, Marcus; Zacho, Helle D; Maurer, Tobias; Gratzke, Christian; Crispin, Alexander; Czernin, Johannes; Herrmann, Ken; Eiber, Matthias

2017-10-01

The interobserver agreement for 68 Ga-PSMA-11 PET/CT study interpretations in patients with prostate cancer is unknown. Methods: 68 Ga-PSMA-11 PET/CT was performed in 50 patients with prostate cancer for biochemical recurrence ( n = 25), primary diagnosis ( n = 10), biochemical persistence after primary therapy ( n = 5), or staging of known metastatic disease ( n = 10). Images were reviewed by 16 observers who used a standardized approach for interpretation of local (T), nodal (N), bone (Mb), or visceral (Mc) involvement. Observers were classified as having a low (<30 prior 68 Ga-PSMA-11 PET/CT studies; n = 5), intermediate (30-300 studies; n = 5), or high level of experience (>300 studies; n = 6). Histopathology ( n = 25, 50%), post-external-beam radiation therapy prostate-specific antigen response ( n = 15, 30%), or follow-up PET/CT ( n = 10, 20%) served as a standard of reference. Observer groups were compared by overall agreement (% patients matching the standard of reference) and Fleiss' κ with mean and corresponding 95% confidence interval (CI). Results: Agreement among all observers was substantial for T (κ = 0.62; 95% CI, 0.59-0.64) and N (κ = 0.74; 95% CI, 0.71-0.76) staging and almost perfect for Mb (κ = 0.88; 95% CI, 0.86-0.91) staging. Level of experience positively correlated with agreement for T (κ = 0.73/0.66/0.50 for high/intermediate/low experience, respectively), N (κ = 0.80/0.76/0.64, respectively), and Mc staging (κ = 0.61/0.46/0.36, respectively). Interobserver agreement for Mb was almost perfect irrespective of prior experience (κ = 0.87/0.91/0.88, respectively). Observers with low experience, when compared with intermediate and high experience, demonstrated significantly lower median overall agreement (54% vs. 66% and 76%, P = 0.041) and specificity for T staging (73% vs. 88% and 93%, P = 0.032). Conclusion: The interpretation of 68 Ga-PSMA-11 PET/CT for prostate cancer staging is highly consistent among observers with high levels of experience, especially for nodal and bone assessments. Initial training on at least 30 patient cases is recommended to ensure acceptable performance. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

PubMed

Reddy, T; McLaughlin, P D; Mallinson, P I; Reagan, A C; Munk, P L; Nicolaou, S; Ouellette, H A

2015-02-01

The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

Automated segmentation of murine lung tumors in x-ray micro-CT images

NASA Astrophysics Data System (ADS)

Swee, Joshua K. Y.; Sheridan, Clare; de Bruin, Elza; Downward, Julian; Lassailly, Francois; Pizarro, Luis

2014-03-01

Recent years have seen micro-CT emerge as a means of providing imaging analysis in pre-clinical study, with in-vivo micro-CT having been shown to be particularly applicable to the examination of murine lung tumors. Despite this, existing studies have involved substantial human intervention during the image analysis process, with the use of fully-automated aids found to be almost non-existent. We present a new approach to automate the segmentation of murine lung tumors designed specifically for in-vivo micro-CT-based pre-clinical lung cancer studies that addresses the specific requirements of such study, as well as the limitations human-centric segmentation approaches experience when applied to such micro-CT data. Our approach consists of three distinct stages, and begins by utilizing edge enhancing and vessel enhancing non-linear anisotropic diffusion filters to extract anatomy masks (lung/vessel structure) in a pre-processing stage. Initial candidate detection is then performed through ROI reduction utilizing obtained masks and a two-step automated segmentation approach that aims to extract all disconnected objects within the ROI, and consists of Otsu thresholding, mathematical morphology and marker-driven watershed. False positive reduction is finally performed on initial candidates through random-forest-driven classification using the shape, intensity, and spatial features of candidates. We provide validation of our approach using data from an associated lung cancer study, showing favorable results both in terms of detection (sensitivity=86%, specificity=89%) and structural recovery (Dice Similarity=0.88) when compared against manual specialist annotation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandapaka, A; Ghebremedhin, A; Farley, D

Purpose: To develop the methodology to evaluate the clinical performance of a Phase II Proton CT scanner Methods: Range errors on the order of 3%-5% constitute a major uncertainty in current charged particle treatment planning based on Hounsfield Unit (HU)-relative stopping power (RSP) calibration curves. Within our proton CT collaboration, we previously developed and built a Phase I proton CT scanner that provided a sensitive area of 9 cm (axial) × 18 cm (in-plane). This scanner served to get initial experience with this new treatment planning tool and to incorporate lessons learned into the next generation design. A Phase IImore » scanner was recently completed and is now undergoing initial performance testing. It will increase the proton acquisition rate and provide a larger detection area of 9 cm x 36 cm. We are now designing a comprehensive evaluation program to test the image quality, imaging dose, and range uncertainty associated with this scanner. The testing will be performed along the lines of AAPM TG 66. Results: In our discussion of the evaluation protocol we identified the following priorities. The image quality of proton CT images, in particular spatial resolution and low-density contrast discrimination, will be evaluated with the Catphan600 phantom. Initial testing showed that the Catphan uniformity phantom did not provide sufficient uniformity; it was thus replaced by a cylindrical water phantom. The imaging dose will be tested with a Catphan dose module, and compared to a typical cone beam CT dose for comparable image quality. Lastly, we developed a dedicated dosimetry range phantom based on the CIRS pediatric head phantom HN715. Conclusion: A formal evaluation of proton CT as a new tool for proton treatment planning is an important task. The availability of the new Phase II proton CT scanner will allow us to perform this task. This research is supported by the National Institute of Biomedical Imaging and Bioengineering of the NIH under award number R01EB013118. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.« less

Preoperative computed tomography-guided percutaneous hookwire localization of metallic marker clips in the breast with a radial approach: initial experience.

PubMed

Uematsu, T; Kasami, M; Uchida, Y; Sanuki, J; Kimura, K; Tanaka, K; Takahashi, K

2007-06-01

Hookwire localization is the current standard technique for radiological marking of nonpalpable breast lesions. Stereotactic directional vacuum-assisted breast biopsy (SVAB) is of sufficient sensitivity and specificity to replace surgical biopsy. Wire localization for metallic marker clips placed after SVAB is needed. To describe a method for performing computed tomography (CT)-guided hookwire localization using a radial approach for metallic marker clips placed percutaneously after SVAB. Nineteen women scheduled for SVAB with marker-clip placement, CT-guided wire localization of marker clips, and, eventually, surgical excision were prospectively entered into the study. CT-guided wire localization was performed with a radial approach, followed by placement of a localizing marker-clip surgical excision. Feasibility and reliability of the procedure and the incidence of complications were examined. CT-guided wire localization surgical excision was successfully performed in all 19 women without any complications. The mean total procedure time was 15 min. The median distance on CT image from marker clip to hookwire was 2 mm (range 0-3 mm). CT-guided preoperative hookwire localization with a radial approach for marker clips after SVAB is technically feasible.

Adult congenital heart disease imaging with second-generation dual-source computed tomography: initial experiences and findings.

PubMed

Ghoshhajra, Brian B; Sidhu, Manavjot S; El-Sherief, Ahmed; Rojas, Carlos; Yeh, Doreen Defaria; Engel, Leif-Christopher; Liberthson, Richard; Abbara, Suhny; Bhatt, Ami

2012-01-01

Adult congenital heart disease patients present a unique challenge to the cardiac imager. Patients may present with both acute and chronic manifestations of their complex congenital heart disease and also require surveillance for sequelae of their medical and surgical interventions. Multimodality imaging is often required to clarify their anatomy and physiology. Radiation dose is of particular concern in these patients with lifelong imaging needs for their chronic disease. The second-generation dual-source scanner is a recently available advanced clinical cardiac computed tomography (CT) scanner. It offers a combination of the high-spatial resolution of modern CT, the high-temporal resolution of dual-source technology, and the wide z-axis coverage of modern cone-beam geometry CT scanners. These advances in technology allow novel protocols that markedly reduce scan time, significantly reduce radiation exposure, and expand the physiologic imaging capabilities of cardiac CT. We present a case series of complicated adult congenital heart disease patients imaged by the second-generation dual-source CT scanner with extremely low-radiation doses and excellent image quality. © 2012 Wiley Periodicals, Inc.

Assessing Patients' Cognitive Therapy Skills: Initial Evaluation of the Competencies of Cognitive Therapy Scale.

PubMed

Strunk, Daniel R; Hollars, Shannon N; Adler, Abby D; Goldstein, Lizabeth A; Braun, Justin D

2014-10-01

In Cognitive Therapy (CT), therapists work to help patients develop skills to cope with negative affect. Most current methods of assessing patients' skills are cumbersome and impractical for clinical use. To address this issue, we developed and conducted an initial psychometric evaluation of self and therapist reported versions of a new measure of CT skills: the Competencies of Cognitive Therapy Scale (CCTS). We evaluated the CCTS at intake and post-treatment in a sample of 67 patients participating in CT. The CCTS correlated with a preexisting measure of CT skills (the Ways of Responding Questionnaire) and was also related to concurrent depressive symptoms. Across CT, self-reported improvements in CT competencies were associated with greater changes in depressive symptoms. These findings offer initial evidence for the validity of the CCTS. We discuss the CCTS in comparison with other measures of CT skills and suggest future research directions.

Assessing Patients’ Cognitive Therapy Skills: Initial Evaluation of the Competencies of Cognitive Therapy Scale

PubMed Central

Strunk, Daniel R.; Hollars, Shannon N.; Adler, Abby D.; Goldstein, Lizabeth A.; Braun, Justin D.

2014-01-01

In Cognitive Therapy (CT), therapists work to help patients develop skills to cope with negative affect. Most current methods of assessing patients’ skills are cumbersome and impractical for clinical use. To address this issue, we developed and conducted an initial psychometric evaluation of self and therapist reported versions of a new measure of CT skills: the Competencies of Cognitive Therapy Scale (CCTS). We evaluated the CCTS at intake and post-treatment in a sample of 67 patients participating in CT. The CCTS correlated with a preexisting measure of CT skills (the Ways of Responding Questionnaire) and was also related to concurrent depressive symptoms. Across CT, self-reported improvements in CT competencies were associated with greater changes in depressive symptoms. These findings offer initial evidence for the validity of the CCTS. We discuss the CCTS in comparison with other measures of CT skills and suggest future research directions. PMID:25408560

X-ray Computed Tomography Observation of Methane Hydrate Dissociation

USGS Publications Warehouse

Tomutsa, L.; Freifeld, B.; Kneafsey, T.J.; Stern, L.A.

2002-01-01

Deposits of naturally occurring methane hydrate have been identified in permafrost and deep oceanic environments with global reserves estimated to be twice the total amount of energy stored in fossil fuels. The fundamental behavior of methane hydrate in natural formations, while poorly understood, is of critical importance if the economic recovery of methane from hydrates is to be accomplished. In this study, computed X-ray tomography (CT) scanning is used to image an advancing dissociation front in a heterogeneous gas hydrate/sand sample at 0.1 MPa. The cylindrical methane hydrate and sand aggregate, 2.54 cm in diameter and 6.3 cm long, was contained in a PVC sample holder that was insulated on all but one end. At the uninsulated end, the dissociated gas was captured and the volume of gas monitored. The sample was initially imaged axially using X-ray CT scanning within the methane hydrate stability zone by keeping the sample temperature at 77??K. Subsequently, as the sample warmed through the methane hydrate dissociation point at 194??K and room pressure, gas was produced and the temperature at the bottom of the sample plug was monitored while CT images were acquired. The experiment showed that CT imaging can resolve the reduction in density (as seen by a reduction in beam attenuation) of the hydrate/sand aggregate due to the dissociation of methane hydrate. In addition, a comparison of CT images with gas flow and temperature measurements reveals that the CT scanner is able to resolve accurately and spatially the advancing dissociation front. Future experiments designed to better understand the thermodynamics of hydrate dissociation are planned to take advantage of the temporal and spatial resolution that the CT scanner provides.

Image Reconstruction for Hybrid True-Color Micro-CT

PubMed Central

Xu, Qiong; Yu, Hengyong; Bennett, James; He, Peng; Zainon, Rafidah; Doesburg, Robert; Opie, Alex; Walsh, Mike; Shen, Haiou; Butler, Anthony; Butler, Phillip; Mou, Xuanqin; Wang, Ge

2013-01-01

X-ray micro-CT is an important imaging tool for biomedical researchers. Our group has recently proposed a hybrid “true-color” micro-CT system to improve contrast resolution with lower system cost and radiation dose. The system incorporates an energy-resolved photon-counting true-color detector into a conventional micro-CT configuration, and can be used for material decomposition. In this paper, we demonstrate an interior color-CT image reconstruction algorithm developed for this hybrid true-color micro-CT system. A compressive sensing-based statistical interior tomography method is employed to reconstruct each channel in the local spectral imaging chain, where the reconstructed global gray-scale image from the conventional imaging chain served as the initial guess. Principal component analysis was used to map the spectral reconstructions into the color space. The proposed algorithm was evaluated by numerical simulations, physical phantom experiments, and animal studies. The results confirm the merits of the proposed algorithm, and demonstrate the feasibility of the hybrid true-color micro-CT system. Additionally, a “color diffusion” phenomenon was observed whereby high-quality true-color images are produced not only inside the region of interest, but also in neighboring regions. It appears harnessing that this phenomenon could potentially reduce the color detector size for a given ROI, further reducing system cost and radiation dose. PMID:22481806

Image Quality and Diagnostic Performance of a Digital PET Prototype in Patients with Oncologic Diseases: Initial Experience and Comparison with Analog PET.

PubMed

Nguyen, Nghi C; Vercher-Conejero, Jose L; Sattar, Abdus; Miller, Michael A; Maniawski, Piotr J; Jordan, David W; Muzic, Raymond F; Su, Kuan-Hao; O'Donnell, James K; Faulhaber, Peter F

2015-09-01

We report our initial clinical experience for image quality and diagnostic performance of a digital PET prototype scanner with time-of-flight (DigitalTF), compared with an analog PET scanner with time-of-flight (GeminiTF PET/CT). Twenty-one oncologic patients, mean age 58 y, first underwent clinical (18)F-FDG PET/CT on the GeminiTF. The scanner table was then withdrawn while the patient remained on the table, and the DigitalTF was inserted between the GeminiTF PET and CT scanner. The patients were scanned for a second time using the same PET field of view with CT from the GeminiTF for attenuation correction. Two interpreters reviewed the 2 sets of PET/CT images for overall image quality, lesion conspicuity, and sharpness. They counted the number of suggestive (18)F-FDG-avid lesions and provided the TNM staging for the 5 patients referred for initial staging. Standardized uptake values (SUVs) and SUV gradients as a measure of lesion sharpness were obtained. The DigitalTF showed better image quality than the GeminiTF. In a side-by-side comparison using a 5-point scale, lesion conspicuity (4.3 ± 0.6), lesion sharpness (4.3 ± 0.6), and diagnostic confidence (3.4 ± 0.7) were better with DigitalTF than with GeminiTF (P < 0.01). In 52 representative lesions, the lesion maximum SUV was 36% higher with DigitalTF than with GeminiTF, lesion-to-blood-pool SUV ratio was 59% higher, and SUV gradient was 51% higher, with good correlation between the 2 scanners. Lesions less than 1.5 cm showed a greater increase in SUV from GeminiTF to DigitalTF than those lesions 1.5 cm or greater. In 5 of 21 patients, DigitalTF showed an additional 8 suggestive lesions that were not seen using GeminiTF. In the 15 restaging patients, the true-negative rate was 100% and true-positive rate was 78% for both scanners. In the 5 patients for initial staging, DigitalTF led to upstaging in 2 patients and showed the same staging in the other 3 patients, compared with GeminiTF. DigitalTF provides better image quality, diagnostic confidence, and accuracy than GeminiTF. DigitalTF may be the most beneficial in detecting small tumor lesions and disease staging. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Exploring the relationship between nature sounds, connectedness to nature, mood and willingness to buy sustainable food: A retail field experiment.

PubMed

Spendrup, Sara; Hunter, Erik; Isgren, Ellinor

2016-05-01

Nature sounds are increasingly used by some food retailers to enhance in-store ambiance and potentially even influence sustainable food choices. An in-store, 2 × 3 between-subject full factorial experiment conducted on 627 customers over 12 days tested whether nature sound directly and indirectly influenced willingness to buy (WTB) sustainable foods. The results show that nature sounds positively and directly influence WTB organic foods in groups of customers (men) that have relatively low initial intentions to buy. Indirectly, we did not find support for the effect of nature sound on influencing mood or connectedness to nature (CtN). However, we show that information on the product's sustainability characteristics moderates the relationship between CtN and WTB in certain groups. Namely, when CtN is high, sustainability information positively moderated WTB both organic and climate friendly foods in men. Conversely, when CtN was low, men expressed lower WTB organic and climate friendly foods than identical, albeit conventionally labelled products. Consequently, our study concludes that nature sounds might be an effective, yet subtle in-store tool to use on groups of consumers who might otherwise respond negatively to more overt forms of sustainable food information. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ceiling art in a radiation therapy department: its effect on patient treatment experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonett, Jotham

A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art weremore » most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department.« less

CT brush and CancerZap!: two video games for computed tomography dose minimization.

PubMed

Alvare, Graham; Gordon, Richard

2015-05-12

X-ray dose from computed tomography (CT) scanners has become a significant public health concern. All CT scanners spray x-ray photons across a patient, including those using compressive sensing algorithms. New technologies make it possible to aim x-ray beams where they are most needed to form a diagnostic or screening image. We have designed a computer game, CT Brush, that takes advantage of this new flexibility. It uses a standard MART algorithm (Multiplicative Algebraic Reconstruction Technique), but with a user defined dynamically selected subset of the rays. The image appears as the player moves the CT brush over an initially blank scene, with dose accumulating with every "mouse down" move. The goal is to find the "tumor" with as few moves (least dose) as possible. We have successfully implemented CT Brush in Java and made it available publicly, requesting crowdsourced feedback on improving the open source code. With this experience, we also outline a "shoot 'em up game" CancerZap! for photon limited CT. We anticipate that human computing games like these, analyzed by methods similar to those used to understand eye tracking, will lead to new object dependent CT algorithms that will require significantly less dose than object independent nonlinear and compressive sensing algorithms that depend on sprayed photons. Preliminary results suggest substantial dose reduction is achievable.

Non-operative management of blunt splenic injuries in a paediatric population: a 12-year experience.

PubMed

Kirkegård, Jakob; Avlund, Tue Højslev; Amanavicius, Nerijus; Mortensen, Frank Viborg; Kissmeyer-Nielsen, Peter

2015-02-01

Non-operative management (NOM) is now the primary treatment for blunt splenic injuries in children. Only one study has examined the use of NOM in a Scandinavian population. Thus, the purpose of this study is to report our experience in treating children with blunt splenic injuries with NOM at a Danish university hospital. We conducted a retrospective observational study of 34 consecutive children (aged 16 years or less) admitted to our level 1-trauma centre with blunt splenic injury in the 12-year period from 1 January 2001 to 31 December 2012. Data on patients and procedures were obtained by review of all medical records and re-evaluation of all initial computed tomographies (CT). We included 34 children with a median age of 10.5 years (67.6% males) in this study. All patients were scheduled for NOM, and two (5.9%) patients underwent splenic artery embolisation (SAE). Two (5.9%) patients later needed surgical intervention. The NOM success rate was 88% (95% confidence interval (CI): 73-97%) without SAE and 94% (95% CI: 80-99%) with SAE. We found no difference in the American Association for the Surgery of Trauma grade when comparing the initial CT evaluation (mean 2.59 ± 1.1) with the CT re-evaluation (mean 2.71 ± 0.94); p = 0.226. We demonstrated a high degree of success and safety of non-operative treatment in children with blunt splenic injury in a Scandinavian setting. Our results are comparable to international findings.

Computed tomographic imaging in the pediatric patient with a seatbelt sign: still not good enough.

PubMed

Kopelman, Tammy R; Jamshidi, Ramin; Pieri, Paola G; Davis, Karole; Bogert, James; Vail, Sydney J; Gridley, Daniel; Singer Pressman, Melissa A

2018-02-01

Considering the improvements in CT over the past decade, this study aimed to determine whether CT can diagnose HVI in pediatric trauma patients with seatbelt signs (SBS). We retrospectively identified pediatric patients with SBS who had abdominopelvic CT performed on initial evaluation over 5 1/2years. Abnormal CT was defined by identification of any intra-abdominal abnormality possibly related to trauma. One hundred twenty patients met inclusion criteria. CT was abnormal in 38/120 (32%) patients: 34 scans had evidence of HVI and 6 showed solid organ injury (SOI). Of the 34 with suspicion for HVI, 15 (44%) had small amounts of isolated pelvic free fluid as the only abnormal CT finding; none required intervention. Ultimately, 16/120 (13%) patients suffered HVI and underwent celiotomy. Three patients initially had a normal CT but required celiotomy for clinical deterioration within 20h of presentation. False negative CT rate was 3.6%. The sensitivity, specificity and accuracy of CT to diagnose significant HVI in the presence of SBS were 81%, 80%, and 80%, respectively. Despite improvements in CT, pediatric patients with SBS may have HVI not evident on initial CT confirming the need to observation for delayed manifestation of HVI. Level II Study of a Diagnostic Test. Copyright © 2017 Elsevier Inc. All rights reserved.

Iterative reconstruction for CT perfusion with a prior-image induced hybrid nonlocal means regularization: Phantom studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Bin; Lyu, Qingwen; Ma, Jianhua

2016-04-15

Purpose: In computed tomography perfusion (CTP) imaging, an initial phase CT acquired with a high-dose protocol can be used to improve the image quality of later phase CT acquired with a low-dose protocol. For dynamic regions, signals in the later low-dose CT may not be completely recovered if the initial CT heavily regularizes the iterative reconstruction process. The authors propose a hybrid nonlocal means (hNLM) regularization model for iterative reconstruction of low-dose CTP to overcome the limitation of the conventional prior-image induced penalty. Methods: The hybrid penalty was constructed by combining the NLM of the initial phase high-dose CT inmore » the stationary region and later phase low-dose CT in the dynamic region. The stationary and dynamic regions were determined by the similarity between the initial high-dose scan and later low-dose scan. The similarity was defined as a Gaussian kernel-based distance between the patch-window of the same pixel in the two scans, and its measurement was then used to weigh the influence of the initial high-dose CT. For regions with high similarity (e.g., stationary region), initial high-dose CT played a dominant role for regularizing the solution. For regions with low similarity (e.g., dynamic region), the regularization relied on a low-dose scan itself. This new hNLM penalty was incorporated into the penalized weighted least-squares (PWLS) for CTP reconstruction. Digital and physical phantom studies were performed to evaluate the PWLS-hNLM algorithm. Results: Both phantom studies showed that the PWLS-hNLM algorithm is superior to the conventional prior-image induced penalty term without considering the signal changes within the dynamic region. In the dynamic region of the Catphan phantom, the reconstruction error measured by root mean square error was reduced by 42.9% in PWLS-hNLM reconstructed image. Conclusions: The PWLS-hNLM algorithm can effectively use the initial high-dose CT to reconstruct low-dose CTP in the stationary region while reducing its influence in the dynamic region.« less

Diagnostic value of CT, PET and combined PET/CT performed with low-dose unenhanced CT and full-dose enhanced CT in the initial staging of lymphoma.

PubMed

Pinilla, I; Gómez-León, N; Del Campo-Del Val, L; Hernandez-Maraver, D; Rodríguez-Vigil, B; Jover-Díaz, R; Coya, J

2011-10-01

The aim of this paper was to compare the accuracy of contrast-enhanced computed tomography (CT), positron emission tomography (PET), unenhanced low-dose PET/CT (LD-PET/CT) and full-dose enhanced PET/CT (FD-PET/CT) for the initial staging of lymphoma. One hundred and one lymphoma patients were examined by [18F]FDG-PET/CT including unenhanced low-dose CT and enhanced full-dose CT. Each modality of PET/CT was evaluated by a nuclear medicine physician and a radiologist unaware of the other modality, while the CT and PET images were interpreted separately by another independent radiologist and nuclear medicine physician respectively. The nodal and extranodal lesions detected by each technique were compared with a reference standard. For nodal assessment, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative LR (LR-) of LD-PET/CT were 97%, 96%, 98%, 95%, 26 and 0.02 respectively, and those of FD-PET/CT were 97%, 97%, 98%, 95%, 36 and 0.02. These results were significantly better than those of PET (sensitivity 82%, specificity 81%, PPV 88%, NPV 72%, LR+ 4.3, LR- 0.21). Likewise, both PET/CT displayed a higher sensitivity, NPV and LR- than CT (91%, 84%, 0.1 respectively). For organ evaluation, both modalities of PET/CT also had significantly better sensitivity and NPV than that of PET (LD-PET/CT: sensitivity 92%, NPV 90%; FD-PET/CT sensitivity 94%, NPV 92%; PET: sensitivity 70%, NPV 69%). The sensitivity, specificity, PPV and NPV for bone marrow involvement were 29%, 84%, 45% and 72% respectively for PET, and 29%, 90%, 56%, and 74% for both, LD-PET/CT, and FD-PET/CT. No significant differences were found between LD-PET/CT and FD-PET/CT, but FD-PET/CT detected important incidental findings in 5.9% of patients. PET/CT is an accurate technique for the initial staging of lymphomas without significant differences between LD-PET/CT and FD-PET/CT. FD-PET/CT detects relevant incidental findings that are missed on LD-PET/CT.

Translation initiation mediated by nuclear cap-binding protein complex.

PubMed

Ryu, Incheol; Kim, Yoon Ki

2017-04-01

In mammals, cap-dependent translation of mRNAs is initiated by two distinct mechanisms: cap-binding complex (CBC; a heterodimer of CBP80 and 20)-dependent translation (CT) and eIF4E-dependent translation (ET). Both translation initiation mechanisms share common features in driving cap- dependent translation; nevertheless, they can be distinguished from each other based on their molecular features and biological roles. CT is largely associated with mRNA surveillance such as nonsense-mediated mRNA decay (NMD), whereas ET is predominantly involved in the bulk of protein synthesis. However, several recent studies have demonstrated that CT and ET have similar roles in protein synthesis and mRNA surveillance. In a subset of mRNAs, CT preferentially drives the cap-dependent translation, as ET does, and ET is responsible for mRNA surveillance, as CT does. In this review, we summarize and compare the molecular features of CT and ET with a focus on the emerging roles of CT in translation. [BMB Reports 2017; 50(4): 186-193].

Prospective evaluation of 68 Ga-DOTATATE PET/CT in limited disease neuroendocrine tumors and/or elevated serum neuroendocrine biomarkers.

PubMed

Gabriel, Sophie; Garrigue, Philippe; Dahan, Laetitia; Castinetti, Frédéric; Sebag, Frédéric; Baumstark, Karine; Archange, Cendrine; Abhishek, Jha; Pacak, Karel; Guillet, Benjamin; Taïeb, David

2018-05-22

The 68 Ga-labelled somatostatin analogues ( 68 Ga-DOTA-SSAs) is becoming popular as an important diagnostic tool in neuroendocrine tumors as evidenced by a growing number of reports detailing institutional experience with various DOTA peptides. However, only few prospective studies have compared 68 Ga-DOTA-SSAs and somatostatin receptor scintigraphy (SRS) in gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and pulmonary neuroendocrine tumors. The aim of our prospective study was to perform head-to-head comparison between 68 Ga-DOTATATE PET/CT and standard imaging work-up (SI) that included multiphasic CT, liver MRI, and SRS using single photon emission computed tomography. In this prospective study, the patients were enrolled only if they met any of the following inclusion criteria were: i- initial staging of a NETs without distant metastases on SI or neuroendocrine tumor with unknown primary on SI; ii-restaging of NETs that could be treated by focused therapeutic interventions; iii- elevated serum neuroendocrine hormones or peptides. The exclusion criteria was grade 3 GEP-NETs. Thirty-two patients were enrolled in the study. Eleven patients (6 pancreas, 4 ileum, 1 duodenal) were included for initial evaluation and staging of NETs, 8 patients (5 pancreas, 1 ileal, 1 lung, 1 duodenal gastrinoma) for restaging, and 13 patients for elevated serum neuroendocrine biomarkers (5 ectopic Cushing's syndrome, 5 organic hypoglycemia, 1 patient each with elevated vasoactive inhibitory peptide, chromogranin A, and neuron-specific enolase). 68 Ga-DOTATATE PET/CT detected more primary tumors than SRS (15/18 vs 10/18: p=0.074). The missed tumors on 68 Ga-DOTATATE PET/CT were located in the lung in 2 cases and duodenum in 1 case. For other anatomical regions (nodal and distant metastasis), no statistical difference was observed between imaging modalities using 68 Ga-DOTATATE PET/CT and SRS. Overall, 68 Ga-DOTATATE PET/CT+CT+MRI detected 31/33 of the involved regions (including primaries) (29 and 22 for 68 Ga-DOTATATE and SRS, respectively). Our study shows that 68 Ga-DOTATATE PET/CT detected similar number of sites than combination of SRS, liver MRI and thoraco-abdominopelvic CT region-based analysis. 68 Ga-DOTATATE PET/CT missed half of primary lung carcinoids with ectopic Cushing's syndrome. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pulmonary Toxocariasis: Initial and Follow-Up CT Findings in 63 Patients.

PubMed

Lee, Kyung Hee; Kim, Tae Jung; Lee, Kyung Won

2015-06-01

The objective of our study was to describe the characteristic radiologic findings of pulmonary toxocariasis on initial and follow-up chest CT. Between June 2010 and May 2014, 63 patients with serologically proven, clinically diagnosed pulmonary toxocariasis and chest CT examinations performed within 2 months of an enzyme-linked immunosorbent assay for toxocariasis were identified. Two chest radiologists retrospectively analyzed the chest CT examinations in consensus; they focused on the distribution, location, number, and internal characteristics of the pulmonary lesions. The pulmonary lesions tended to involve three or more lobes (49% [31/63]) on the initial CT; predominance of the abnormalities in a subpleural location (81% [51/63]) and in the lower lung zone (98% [62/63]) was noted. The number of pulmonary lesions per patient were from two to five (46% [29/63]), more than five (32% [20/63]), or one (22% [14/63]). The radiologic findings of pulmonary toxocariasis could be categorized into four different patterns: ground-glass opacities (GGOs), solid nodules, consolidations, and linear opacities. The most common pattern was ill-defined GGOs with or without solid portions (84% [53/63]). The solid nodule and patchy consolidation patterns were found in 29% (18/63) and 21% (13/63) of patients, respectively. In addition, linear opacities (1-2 mm thick and 8-25 mm long) were present in 19% of patients (12/63); this finding is a subtle, yet novel, finding. On follow-up CT, the pulmonary lesions had either disappeared or migrated; when they had migrated, they revealed radiologic manifestations similar to the findings on the initial CT. Pulmonary toxocariasis manifested as multiple lesions in four radiologic patterns with subpleural and lower lung predominance on initial and follow-up CT. A linear opacity may be one of many clues in the diagnosis of pulmonary toxocariasis on CT.

Experimental study of teaching critical thinking in civic education in Taiwanese junior high school.

PubMed

Yang, Shu Ching; Chung, Tung-Yu

2009-03-01

To effectively respond to the need for greater CT (critical thinking) in the classroom, this study examines the effects of cultivating CT skills within civic education to maximize its potential. Despite realizing the importance of CT in education, schools do not tend to apply it. Furthermore, since students frequently do not raise questions or otherwise think critically, CT modules are incorporated into civic learning to encourage students to question facts, interpret and analyse evidence, make reasoned inferences regarding events, and independently develop informed opinions. These skills are fundamental to cultivating an informed and humane citizenry. This investigation examines how teaching critical thinking in civic education affects the CT skills and disposition of junior high school students. The participants were two classes of eighth grade students in southern Taiwan, and were distributed into experimental and control groups. Each group comprised 34 students, with the experimental group containing 16 boys and 18 girls and the control group containing 18 boys and 16 girls. The teaching experiment in this study was initiated and performed using equivalent pre-test and post-test group design. During the 10-week experiment, the experimental group was taught using CT instruction in civic education, while the control group was not taught with any CT programme. The data analysis included: quantitative statistics of the two main sets of instruments for measuring the CT ability and disposition of experimental treatment, qualitative analysis of learning sheets, and surveys of student perceptions of instruction in CT. Statistical analysis showed that the experimental group significantly outperformed the control group on the scales of CT skill and disposition, but did not perform well on certain subscales (e.g. recognition of assumptions and deductions, truth-seeking, analyticity, and inquisitiveness). Notably however, when triangulating with qualitative analysis of learner transcripts and surveys, learners attempted to perform various dimensions of CT skill and disposition to various degrees. Student surveys indicated that the CT programme fostered their active listening and respect for different ideas, and moreover they learned to tolerate divergent views and examine their ideas for possible bias. The programme boosted student learning interest and sense of accomplishment, and nurtured their teamwork/communicative skills. Furthermore, a few students experienced improvements in their speaking skills and courage as their confidence and ability to express themselves improved. Finally, limitations of this investigation and implications for further research are discussed.

Fully automatic segmentation of the femur from 3D-CT images using primitive shape recognition and statistical shape models.

PubMed

Ben Younes, Lassad; Nakajima, Yoshikazu; Saito, Toki

2014-03-01

Femur segmentation is well established and widely used in computer-assisted orthopedic surgery. However, most of the robust segmentation methods such as statistical shape models (SSM) require human intervention to provide an initial position for the SSM. In this paper, we propose to overcome this problem and provide a fully automatic femur segmentation method for CT images based on primitive shape recognition and SSM. Femur segmentation in CT scans was performed using primitive shape recognition based on a robust algorithm such as the Hough transform and RANdom SAmple Consensus. The proposed method is divided into 3 steps: (1) detection of the femoral head as sphere and the femoral shaft as cylinder in the SSM and the CT images, (2) rigid registration between primitives of SSM and CT image to initialize the SSM into the CT image, and (3) fitting of the SSM to the CT image edge using an affine transformation followed by a nonlinear fitting. The automated method provided good results even with a high number of outliers. The difference of segmentation error between the proposed automatic initialization method and a manual initialization method is less than 1 mm. The proposed method detects primitive shape position to initialize the SSM into the target image. Based on primitive shapes, this method overcomes the problem of inter-patient variability. Moreover, the results demonstrate that our method of primitive shape recognition can be used for 3D SSM initialization to achieve fully automatic segmentation of the femur.

The role of fluorine-18-fluorodeoxyglucose positron emission tomography in aggressive histological subtypes of thyroid cancer: an overview.

PubMed

Treglia, Giorgio; Annunziata, Salvatore; Muoio, Barbara; Salvatori, Massimo; Ceriani, Luca; Giovanella, Luca

2013-01-01

Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis.

A feasibility study of X-ray phase-contrast mammographic tomography at the Imaging and Medical beamline of the Australian Synchrotron.

PubMed

Nesterets, Yakov I; Gureyev, Timur E; Mayo, Sheridan C; Stevenson, Andrew W; Thompson, Darren; Brown, Jeremy M C; Kitchen, Marcus J; Pavlov, Konstantin M; Lockie, Darren; Brun, Francesco; Tromba, Giuliana

2015-11-01

Results are presented of a recent experiment at the Imaging and Medical beamline of the Australian Synchrotron intended to contribute to the implementation of low-dose high-sensitivity three-dimensional mammographic phase-contrast imaging, initially at synchrotrons and subsequently in hospitals and medical imaging clinics. The effect of such imaging parameters as X-ray energy, source size, detector resolution, sample-to-detector distance, scanning and data processing strategies in the case of propagation-based phase-contrast computed tomography (CT) have been tested, quantified, evaluated and optimized using a plastic phantom simulating relevant breast-tissue characteristics. Analysis of the data collected using a Hamamatsu CMOS Flat Panel Sensor, with a pixel size of 100 µm, revealed the presence of propagation-based phase contrast and demonstrated significant improvement of the quality of phase-contrast CT imaging compared with conventional (absorption-based) CT, at medically acceptable radiation doses.

18F-FDOPA PET/CT imaging of MAX-related pheochromocytoma.

PubMed

Taïeb, David; Jha, Abhishek; Guerin, Carole; Pang, Ying; Adams, Karen T; Chen, Clara C; Romanet, Pauline; Roche, Philippe; Essamet, Wassim; Ling, Alexander; Quezado, Martha M; Castinetti, Frédéric; Sebag, Fréderic; Pacak, Karel

2018-03-08

MYC associated factor X (MAX) has been recently described as a new susceptibility pheochromocytoma (PHEO) gene with a total of approximately 40 reported cases. At present, no study has specifically described the functional imaging phenotype of MAX-related PHEO. The objective of this study was to present our experience with contrast-enhanced CT and 18F-FDOPA PET/CT imaging in 6 consecutive patients (4 at initial diagnosis and 2 at follow-up evaluation) with rare but clinically important MAX-related PHEOs. In 5 patients, 18F-FDOPA was also compared to other radiopharmaceuticals. Patients had 5 different mutations in the MAX gene that caused disruption of Max/Myc interaction and/or abolished interaction with DNA based on in-silico analyses. All but one patient developed bilateral PHEOs during their lifetime. In all cases, 18F-FDOPA PET/CT accurately visualized PHEOs that were often multiple within the same gland or bilateral and detected more adrenal and extradrenal lesions than CT (per lesion sensitivity 90.5% vs 52.4% for CT/MRI). The 2 missed PHEO on 18F-FDOPA PET/CT were <1cm, corresponding to nodular adrenomedullary hyperplasia. 68Ga-DOTATATE PET/CT detected fewer lesions than 18F-FDOPA PET/CT in 1/3 patients and 18F-FDG PET/CT was only faintly positive in 2/4 patients with underestimation of extraadrenal lesions in 1 patient. MAX-related PHEO exihibit a marked 18F-FDOPA uptake, a finding that illustrates the common well-differentiated chromaffin pattern of PHEO associated with activation of kinase signaling pathways. 18F-FDOPA PET/CT should be considered as the first-line functional imaging modality for diagnostic or follow-up evaluation in these patients.

Generation of synthetic CT data using patient specific daily MR image data and image registration

NASA Astrophysics Data System (ADS)

Melanie Kraus, Kim; Jäkel, Oliver; Niebuhr, Nina I.; Pfaffenberger, Asja

2017-02-01

To fully exploit the advantages of magnetic resonance imaging (MRI) for radiotherapy (RT) treatment planning, a method is required to overcome the problem of lacking electron density information. We aim to establish and evaluate a new method for computed tomography (CT) data generation based on MRI and image registration. The thereby generated CT data is used for dose accumulation. We developed a process flow based on an initial pair of rigidly co-registered CT and T2-weighted MR image representing the same anatomical situation. Deformable image registration using anatomical landmarks is performed between the initial MRI data and daily MR images. The resulting transformation is applied to the initial CT, thus fractional CT data is generated. Furthermore, the dose for a photon intensity modulated RT (IMRT) or intensity modulated proton therapy (IMPT) plan is calculated on the generated fractional CT and accumulated on the initial CT via inverse transformation. The method is evaluated by the use of phantom CT and MRI data. Quantitative validation is performed by evaluation of the mean absolute error (MAE) between the measured and the generated CT. The effect on dose accumulation is examined by means of dose-volume parameters. One patient case is presented to demonstrate the applicability of the method introduced here. Overall, CT data derivation lead to MAEs with a median of 37.0 HU ranging from 29.9 to 66.6 HU for all investigated tissues. The accuracy of image registration showed to be limited in the case of unexpected air cavities and at tissue boundaries. The comparisons of dose distributions based on measured and generated CT data agree well with the published literature. Differences in dose volume parameters kept within 1.6% and 3.2% for photon and proton RT, respectively. The method presented here is particularly suited for application in adaptive RT in current clinical routine, since only minor additional technical equipment is required.

Ultra low-dose CT attenuation correction in PET SPM

NASA Astrophysics Data System (ADS)

Wang, Shyh-Jen; Yang, Bang-Hung; Tsai, Chia-Jung; Yang, Ching-Ching; Lee, Jason J. S.; Wu, Tung-Hsin

2010-07-01

The use of CT images for attenuation correction (CTAC) allows significantly shorter scanning time and a high quality noise-free attenuation map compared with conventional germanium-68 transmission scan because at least 10 4 times greater of photon flux would be generated from a CT scan under standard operating condition. However, this CTAC technique would potentially introduce more radiation risk to the patients owing to the higher radiation exposure from CT scan. Statistic parameters mapping (SPM) is a prominent technique in nuclear medicine community for the analysis of brain imaging data. The purpose of this study is to assess the feasibility of low-dose CT (LDCT) and ultra low-dose CT (UDCT) in PET SPM applications. The study was divided into two parts. The first part was to evaluate of tracer uptake distribution pattern and quantity analysis by using the striatal phantom to initially assess the feasibility of AC for clinical purpose. The second part was to examine the group SPM analysis using the Hoffman brain phantom. The phantom study is to simulate the human brain and to reduce the experimental uncertainty of real subjects. The initial studies show that the results of PET SPM analysis have no significant differences between LDCT and UDCT comparing to the current used default CTAC. Moreover, the dose of the LDCT is lower than that of the default CT by a factor of 9, and UDCT can even yield a 42 times dose reduction. We have demonstrated the SPM results while using LDCT and UDCT for PET AC is comparable to those using default CT setting, suggesting their feasibility in PET SPM applications. In addition, the necessity of UDCT in PET SPM studies to avoid excess radiation dose is also evident since most of the subjects involved are non-cancer patients or children and some normal subjects are even served as a comparison group in the experiment. It is our belief that additional attempts to decrease the radiation dose would be valuable, especially for children and normal volunteers, to work towards ALARA (as low as reasonably achievable) concept for PET SPM studies.

The role of CT-guided percutaneous drainage of loculated air collections: an institutional experience.

PubMed

Patel, Bhavik N; Morgan, Madeline; Tyler, Douglas; Paulson, Erik; Jaffe, Tracy A

2015-10-01

The purpose of this study is to describe our experience with the role of CT-guided percutaneous drainage of loculated intra-abdominal collections consisting entirely of gas. An IRB-approved retrospective study analyzing patients with air-only intra-abdominal collections over an 8-year period was undertaken. Seven patients referred for percutaneous drainage were included. Size of collections, subsequent development of fluid, and microbiological yield were determined. Clinical outcome was also analyzed. Out of 2835 patients referred for percutaneous drainage between 2004 and 2012, seven patients (5M, 2F; average age 63, range 54-85) met criteria for inclusion with CT showing air-only collections. Percutaneous drain placement (five 8 Fr, one 10 Fr, and one 12 Fr) using Seldinger technique was performed. Four patients (57%) had recently undergone surgery (2 Whipple, 1 colectomy, 1 hepatic resection) while two (29%) had a remote surgery (1 abdominoperineal resection, 1 sigmoidectomy). Despite the lack of detectable fluid on the original CT, 6 patients (86%) had air and fluid aspirated at drainage, 5 (83%) of the aspirates developed positive microbacterial cultures. Four patients (57%) presented with fever at the time of the initial scan, all of whom had positive cultures from aspirated fluid. Four patients (57%) had leukocytosis, all of whom had positive cultures from aspirated fluid. Although relatively rare in occurrence, patients with air-only intra-abdominal collections with signs of infection should be considered for percutaneous management similar to that of conventional infected fluid collections. Although fluid is not visible on CT, these collections can produce fluid that contains organisms.

Varying-energy CT imaging method based on EM-TV

NASA Astrophysics Data System (ADS)

Chen, Ping; Han, Yan

2016-11-01

For complicated structural components with wide x-ray attenuation ranges, conventional fixed-energy computed tomography (CT) imaging cannot obtain all the structural information. This limitation results in a shortage of CT information because the effective thickness of the components along the direction of x-ray penetration exceeds the limit of the dynamic range of the x-ray imaging system. To address this problem, a varying-energy x-ray CT imaging method is proposed. In this new method, the tube voltage is adjusted several times with the fixed lesser interval. Next, the fusion of grey consistency and logarithm demodulation are applied to obtain full and lower noise projection with a high dynamic range (HDR). In addition, for the noise suppression problem of the analytical method, EM-TV (expectation maximization-total Jvariation) iteration reconstruction is used. In the process of iteration, the reconstruction result obtained at one x-ray energy is used as the initial condition of the next iteration. An accompanying experiment demonstrates that this EM-TV reconstruction can also extend the dynamic range of x-ray imaging systems and provide a higher reconstruction quality relative to the fusion reconstruction method.

Determination of enoxaparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent.

PubMed

Schaden, Eva; Schober, Andreas; Hacker, Stefan; Spiss, Christian; Chiari, Astrid; Kozek-Langenecker, Sibylle

2010-04-01

Drug monitoring of low molecular weight heparin is generally not recommended, but could be reasonable in critically ill patients, whose risk for bleeding or thrombosis shows a high interpatient variability. Anti-Xa assays are not available around the clock even in central hospitals, whereas rotational thrombelastometry (ROTEM) becomes increasingly used at the bedside. Prothrombinase-induced clotting time (PiCT) reagent allows determination of factor Xa-inhibition in plasma. The aim of our study was to evaluate enoxaparin determination in whole blood with the ROTEM using specific test modifications, including PiCT. After ethics committee's approval, citrated whole blood obtained from overall 16 healthy volunteers was incubated with enoxaparin at 16 different anti-Xa concentrations. Main endpoint was the clotting time (CT) in ROTEM representing initial activation of clot formation. CT was determined in the new PiCT-ROTEM test, in a low-tissue factor-activated modification (LowTF-ROTEM) as well as in the commercially available heparin-sensitive ROTEM assays (HEPTEM and INTEM). In the absence of enoxaparin, CT values were 168.6 +/- 6.1 s (PiCT-ROTEM), 247.3 +/- 18.6 s (LowTF-ROTEM), and -6.2 +/- 7.9 s (INTEM-HEPTEM). A linear dependency (P < 0.01) between anti-Xa concentration and CT was found for PiCT-ROTEM, LowTF-ROTEM, and for INTEM-HEPTEM with correlation coefficients of 0.93 for PiCT-ROTEM, 0.94 for LowTF-ROTEM, and 0.81 for INTEM-HEPTEM. This in-vitro experiment demonstrates a strong correlation between enoxaparin anti-Xa concentrations and specific ROTEM tests. These promising assays should be further evaluated for monitoring anticoagulation in high-risk patients in clinical studies.

The origins of SPECT and SPECT/CT.

PubMed

Hutton, Brian F

2014-05-01

Single photon emission computed tomography (SPECT) has a long history of development since its initial demonstration by Kuhl and Edwards in 1963. Although clinical utility has been dominated by the rotating gamma camera, there have been many technological innovations with the recent popularity of organ-specific dedicated SPECT systems. The combination of SPECT and CT evolved from early transmission techniques used for attenuation correction with the initial commercial systems predating the release of PET/CT. The development and acceptance of SPECT/CT has been relatively slow with continuing debate as to what cost/performance ratio is justified. Increasingly, fully diagnostic CT is combined with SPECT so as to facilitate optimal clinical utility.

Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

PubMed

Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

2009-03-01

The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

Dual-contrast agent photon-counting computed tomography of the heart: initial experience.

PubMed

Symons, Rolf; Cork, Tyler E; Lakshmanan, Manu N; Evers, Robert; Davies-Venn, Cynthia; Rice, Kelly A; Thomas, Marvin L; Liu, Chia-Ying; Kappler, Steffen; Ulzheimer, Stefan; Sandfort, Veit; Bluemke, David A; Pourmorteza, Amir

2017-08-01

To determine the feasibility of dual-contrast agent imaging of the heart using photon-counting detector (PCD) computed tomography (CT) to simultaneously assess both first-pass and late enhancement of the myocardium. An occlusion-reperfusion canine model of myocardial infarction was used. Gadolinium-based contrast was injected 10 min prior to PCD CT. Iodinated contrast was infused immediately prior to PCD CT, thus capturing late gadolinium enhancement as well as first-pass iodine enhancement. Gadolinium and iodine maps were calculated using a linear material decomposition technique and compared to single-energy (conventional) images. PCD images were compared to in vivo and ex vivo magnetic resonance imaging (MRI) and histology. For infarct versus remote myocardium, contrast-to-noise ratio (CNR) was maximal on late enhancement gadolinium maps (CNR 9.0 ± 0.8, 6.6 ± 0.7, and 0.4 ± 0.4, p < 0.001 for gadolinium maps, single-energy images, and iodine maps, respectively). For infarct versus blood pool, CNR was maximum for iodine maps (CNR 11.8 ± 1.3, 3.8 ± 1.0, and 1.3 ± 0.4, p < 0.001 for iodine maps, gadolinium maps, and single-energy images, respectively). Combined first-pass iodine and late gadolinium maps allowed quantitative separation of blood pool, scar, and remote myocardium. MRI and histology analysis confirmed accurate PCD CT delineation of scar. Simultaneous multi-contrast agent cardiac imaging is feasible with photon-counting detector CT. These initial proof-of-concept results may provide incentives to develop new k-edge contrast agents, to investigate possible interactions between multiple simultaneously administered contrast agents, and to ultimately bring them to clinical practice.

Contribution of postmortem multidetector CT scanning to identification of the deceased in a mass disaster: Experience gained from the 2009 Victorian bushfires.

PubMed

O'Donnell, C; Iino, M; Mansharan, K; Leditscke, J; Woodford, N

2011-02-25

CT scanning of the deceased is an established technique performed on all individuals admitted to VIFM over the last 5 years. It is used primarily to assist pathologists in determining cause and manner of death but is also invaluable for identification of unknown deceased individuals where traditional methods are not possible. Based on this experience, CT scanning was incorporated into phase 2 of the Institute's DVI process for the 2009 Victorian bushfires. All deceased individuals and fragmented remains admitted to the mortuary were CT scanned in their body bags using established protocols. Images were reviewed by 2 teams of 2 radiologists experienced in forensic imaging and the findings transcribed onto a data sheet constructed specifically for the DVI exercise. The contents of 255 body bags were examined in the 28 days following the fires. 164 missing persons were included in the DVI process with 163 deceased individuals eventually identified. CT contributed to this identification in 161 persons. In 2 cases, radiologists were unable to recognize commingled remains. CT was utilized in the initial triage of each bag's contents. If radiological evaluation determined that bodies were incomplete then this information was provided to search teams who revisited the scenes of death. CT was helpful in differentiation of human from non-human remains in 8 bags, recognition of human/animal commingling in 10 bags and human commingling in 6 bags. In 61% of cases gender was able to be determined on CT using a novel technique of genitalia detection and in all but 2 cases this was correct. Age range was able to be determined on CT in 94% with an accuracy of 76%. Specific identification features detected on CT included the presence of disease (14 disease entities in 13 cases), medical devices (26 devices in 19 cases) and 274 everyday metallic items associated with the remains of 135 individuals. CT scanning provided useful information prior to autopsy by flagging likely findings including the presence of non-human remains, at the time of autopsy by assisting in the localization of identifying features in heavily disfigured bodies, and after autopsy by retrospective review of images for clarification of issues that arose at the time of pathologist case review. In view of the success of CT scanning in this mass disaster, DVI administrators should explore the incorporation of CT services into their disaster plans. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Post-operative re-bleeding in patients with hypertensive ICH is closely associated with the CT blend sign.

PubMed

Wu, Guofeng; Shen, Zhengkui; Wang, Likun; Sun, Shujie; Luo, Jinbiao; Mao, Yuanhong

2017-07-06

Intracranial post-operative re-haemorrhage is an important complication in patients with hypertensive intracerebral haemorrhage (ICH). The purpose of the present study was to determine the value of the computed tomography (CT) blend sign in predicting post-operative re-haemorrhage in patients with ICH. A total of 126 patients with ICH were included in the present study. All the patients underwent standard stereotactic minimally invasive surgery(MIS) to remove the ICH within 24 h following admission. There were 41 patients with a blend sign on initial CT and 85 patients without a blend sign on the initial CT. Multivariable logistic regression analyses were performed to assess the relationship between the presence of the blend sign on the non-enhanced admission CT scan and post-operative re-haemorrhage. Post-operative re-haemorrhage occurred in 24 of the 41 patients with the blend sign, and in 9 of the 85 patients without the blend sign. The incidence of re-haemorrhage was significantly different between the groups. The multivariate logistic regression analysis demonstrated that the initial Glasgow coma scale score (p = 0.002) and blend sign (P < 0.00) on the initial CT scan are independent predictors of post-operative re-haemorrhage. The sensitivity, specificity, and positive and negative predictive values of the blend sign for predicting post-operative re-haemorrhage were 72.7, 81.7, 58.5 and 89.4%, respectively. The presence of the blend sign on the initial CT scan is closely associated with post-operative re-haemorrhage in patients with ICH who undergo stereotactic MIS.

Use of the initial trauma CT scan to aid in diagnosis of open pelvic fractures.

PubMed

Scolaro, John A; Wilson, David J; Routt, Milton Lee Chip; Firoozabadi, Reza

2015-10-01

Open pelvic disruptions represent high-energy injuries. The prompt identification and management of these injuries decreases their associated morbidity and mortality. Computed tomography (CT) scans are routinely obtained in the initial evaluation of patients with pelvic injuries. The purpose of this study is to identify the incidence and source of air densities noted on computed tomography (CT) scans of the abdominal and pelvic region in patients with pelvic fractures and evaluate the use of initial CT imaging as an adjunctive diagnostic tool to identify open injuries. A retrospective review of a prospectively collected database was performed at a single institution. Seven hundred and twenty-two consecutive patients with a pelvic disruption over a two-year period were included. Review of initial injury CT scans was performed using bone and lung viewing algorithms to identify the presence of extra-luminal air. The primary outcome was the presence, location and source of air identified on pre-operative CT scans. Secondary measurements were identification of air by plain radiograph and correlation between identified air densities on CT and clinically diagnosed open pelvic fractures. Ninety-eight patients were identified as having extra-luminal air densities on CT scans. Eighty-one patients were included in the final analysis following application of inclusion and exclusion criteria. Air was noted by the radiologist in forty-five (55.6%) instances. Six patients (7.4%) were clinically diagnosed with an open pelvic ring disruption; in two patients (2.4%) this diagnosis was delayed. In all patients, the CT was able to track air from its origin. In patients with pelvic disruptions, the injury CT should also be evaluated for the presence and source of extra-luminal air. In some patients, this finding may represent an open pelvic ring disruption. A complete physical exam and CT evaluation should be used to decrease the missed or delayed diagnosis of an open pelvic ring injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dna2 initiates resection at clean DNA double-strand breaks

PubMed Central

Paudyal, Sharad C.; Li, Shan; Yan, Hong; Hunter, Tony

2017-01-01

Abstract Nucleolytic resection of DNA double-strand breaks (DSBs) is essential for both checkpoint activation and homology-mediated repair; however, the precise mechanism of resection, especially the initiation step, remains incompletely understood. Resection of blocked ends with protein or chemical adducts is believed to be initiated by the MRN complex in conjunction with CtIP through internal cleavage of the 5′ strand DNA. However, it is not clear whether resection of clean DSBs with free ends is also initiated by the same mechanism. Using the Xenopus nuclear extract system, here we show that the Dna2 nuclease directly initiates the resection of clean DSBs by cleaving the 5′ strand DNA ∼10–20 nucleotides away from the ends. In the absence of Dna2, MRN together with CtIP mediate an alternative resection initiation pathway where the nuclease activity of MRN apparently directly cleaves the 5′ strand DNA at more distal sites. MRN also facilitates resection initiation by promoting the recruitment of Dna2 and CtIP to the DNA substrate. The ssDNA-binding protein RPA promotes both Dna2- and CtIP–MRN-dependent resection initiation, but a RPA mutant can distinguish between these pathways. Our results strongly suggest that resection of blocked and clean DSBs is initiated via distinct mechanisms. PMID:28981724

The Role of Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Aggressive Histological Subtypes of Thyroid Cancer: An Overview

PubMed Central

Treglia, Giorgio; Annunziata, Salvatore; Muoio, Barbara; Salvatori, Massimo; Ceriani, Luca; Giovanella, Luca

2013-01-01

Aggressive histological subtypes of thyroid cancer are rare and have a poor prognosis. The most important aggressive subtypes of thyroid cancer are Hürthle cell carcinoma (HCTC) and anaplastic and poorly differentiated carcinoma (ATC and PDTC). The American Thyroid Association recently published guidelines for the management of patients with ATC, but no specific guidelines have been done about HCTC. We performed an overview of the literature about the role of Fluorine-18-Fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (FDG-PET or PET/CT) in aggressive histological subtypes of thyroid cancer. Only few original studies about the role of FDG-PET or PET/CT in HCTC, PDTC, and ATC have been published in the literature. FDG-PET or PET/CT seems to be useful in staging or followup of invasive and metastatic HCTC. FDG-PET or PET/CT should be used in patients with ATC in initial staging and in the followup after surgery to evaluate metastatic disease. Some authors suggest the use of FDG-PET/CT in staging of PDTC, but more studies are needed to define the diagnostic use of FDG-PET/CT in this setting. Limited experience suggests the usefulness of FDG-PET or PET/CT in patients with more aggressive histological subtypes of DTC. However, DTC presenting as radioiodine refractory and FDG-PET positive should be considered aggressive tumours with poor prognosis. PMID:23653645

Criteria for CT and Initial Management of Head Injured Infants: A Review

PubMed Central

SHIOMI, Naoto; ECHIGO, Tadashi; HINO, Akihiko; HASHIMOTO, Naoya; YAMAKI, Tarumi

2016-01-01

Criteria for computed tomography (CT) to head injured infants have not been established. Since the identification of neurological findings is difficult in infants, examination by CT may be necessary in some cases, but it may be difficult to perform CT because of problems with radiation exposure and body movement. Moreover, even though no intracranial abnormality was found immediately after injury, abnormal findings may appear after several hours. From this viewpoint, course observation after injury may be more important than CT in the initial treatment of head trauma in infants. The complaints and neurological manifestations of infants, particularly those aged 2 or younger, are frequently unclear; therefore, there is an opinion that CT is recommended for all pediatric patients. However, the appropriateness of its use should be determined after confirming the mechanism of injury, consciousness level, neurological findings, and presence/absence of a history of abuse. Among the currently available rules specifying criteria for CT of infants with head trauma, the Pediatric Emergency Care Applied Research Network (PECARN) study may be regarded as reliable at present. In Japan, where the majority of emergency hospitals are using CT, it may be necessary to develop criteria for CT in consideration of the actual situation. CT diagnosis for pediatric head trauma is not always necessary. When no imaging is performed, this should be fully explained at the initial treatment before selecting course observation at home. Checking on a state of the patients by telephone is useful for both patients and physicians. PMID:27194179

78 FR 19489 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-01

... announced below concerns Low Dose CT Lung Cancer Screening: Informed Decision Making and Smoking Cessation... include the initial review, discussion, and evaluation of ``Low Dose CT Lung Cancer Screening: Informed...

Effect of {sup 18}F-FDG PET/CT Imaging in Patients With Clinical Stage II and III Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groheux, David; Moretti, Jean-Luc; EAD Imagerie Moleculaire Diagnostique et Ciblage Therapeutique, IUH, University of Paris VII, Paris

2008-07-01

Purpose: To investigate the potential effect of using {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in the initial assessment of patients with clinical Stage II or III breast cancer. Methods and Materials: During 14 consecutive months, 39 patients (40 tumors) who presented with Stage II or III breast cancer on the basis of a routine extension assessment were prospectively included in this study. PET/CT was performed in addition to the initial assessment. Results: In 3 cases, PET/CT showed extra-axillary lymph node involvement that had not been demonstrated with conventional techniques. Two of these patients had hypermetabolic lymph nodes in themore » subpectoral and infraclavicular regions, and the third had a hypermetabolic internal mammary node. PET/CT showed distant uptake in 4 women. Of these 4 women, 1 had pleural involvement and 3 had bone metastasis. Overall, of the 39 women, the PET/CT results modified the initial stage in 7 (18%). The modified staging altered the treatment plan for 5 patients (13%). It led to radiotherapy in 4 patients (bone metastasis, pleural lesion, subpectoral lymph nodes, and internal mammary nodes) and excision of, and radiotherapy to, the infraclavicular lymph nodes in 1 patient. Conclusions: PET/CT can provide information on extra-axillary lymph node involvement and can uncover occult distant metastases in a significant percentage of patients. Therefore, initial PET/CT could enable better treatment planning for patients with Stage II and III breast cancer.« less

Characterizing Clinical Genetic Counselors' Countertransference Experiences: an Exploratory Study.

PubMed

Reeder, Rebecca; Veach, Patricia McCarthy; MacFarlane, Ian M; LeRoy, Bonnie S

2017-10-01

Countertransference (CT) refers to conscious and unconscious emotions, fantasies, behaviors, perceptions, and psychological defenses genetic counselors experience in response to any aspect of genetic counseling situations (Weil 2010). Some authors theorize about the importance of recognizing and managing CT, but no studies solely aim to explore genetic counselors' experiences of the phenomenon. This study examined the extent to which clinical genetic counselors' perceive themselves as inclined to experience CT, gathered examples of CT encountered in clinical situations, and assessed their CT management strategies. An anonymous online survey, sent to NSGC members, yielded 127 usable responses. Participants completed Likert-type items rating their CT propensities; 57 of these individuals also provided examples of CT they experienced in their practice. Factor analysis of CT propensities tentatively suggested four factors: Control, Conflict Avoidance, Directiveness, and Self-Regulation, accounting for 38.5% of response variance. Thematic analysis of CT examples yielded five common triggers: general similarity to patient, medical/genetic similarity, angry patients, patient behaves differently from counselor expectations, and disclosing bad news; six common manifestations: being self-focused, projecting feelings onto the patient, intense emotional reaction to patient, being overly invested, disengagement, and physical reaction; five CT effects: disruption in rapport building, repaired empathy, over-identification, conversation does not reach fullest potential, and counselor is drained emotionally; and three management strategies: recognizing CT as it occurs, self-reflection, and consultation. Results suggest CT is a common experience, occurring in both "routine" and emotionally complex cases. Training programs, continuing education, and peer supervision might include discussion of CT, informed by examples from the present study, to increase genetic counselor awareness and skills for managing the phenomenon.

Intelligent viewpoint selection for efficient CT to video registration in laparoscopic liver surgery.

PubMed

Robu, Maria R; Edwards, Philip; Ramalhinho, João; Thompson, Stephen; Davidson, Brian; Hawkes, David; Stoyanov, Danail; Clarkson, Matthew J

2017-07-01

Minimally invasive surgery offers advantages over open surgery due to a shorter recovery time, less pain and trauma for the patient. However, inherent challenges such as lack of tactile feedback and difficulty in controlling bleeding lower the percentage of suitable cases. Augmented reality can show a better visualisation of sub-surface structures and tumour locations by fusing pre-operative CT data with real-time laparoscopic video. Such augmented reality visualisation requires a fast and robust video to CT registration that minimises interruption to the surgical procedure. We propose to use view planning for efficient rigid registration. Given the trocar position, a set of camera positions are sampled and scored based on the corresponding liver surface properties. We implement a simulation framework to validate the proof of concept using a segmented CT model from a human patient. Furthermore, we apply the proposed method on clinical data acquired during a human liver resection. The first experiment motivates the viewpoint scoring strategy and investigates reliable liver regions for accurate registrations in an intuitive visualisation. The second experiment shows wider basins of convergence for higher scoring viewpoints. The third experiment shows that a comparable registration performance can be achieved by at least two merged high scoring views and four low scoring views. Hence, the focus could change from the acquisition of a large liver surface to a small number of distinctive patches, thereby giving a more explicit protocol for surface reconstruction. We discuss the application of the proposed method on clinical data and show initial results. The proposed simulation framework shows promising results to motivate more research into a comprehensive view planning method for efficient registration in laparoscopic liver surgery.

Dynamic volumetric computed tomographic assessment of the young paediatric airway: Initial experience of rapid, non-invasive, four-dimensional technique.

PubMed

Tan, Judith Zhi-Yie; Crossett, Marcus; Ditchfield, Michael

2013-04-01

The aim of this study was to evaluate the dynamic volumetric CT in the assessment of the paediatric airway. Ethics board approval was obtained for this retrospective review. Eight infants (median age 6 months, range 3 weeks to 1 year, 50% female) at a tertiary paediatric centre with complex clinical respiratory presentation underwent volumetric CT assessment of their airways. The entire lungs were examined over 1-2 respiratory cycles. In four patients, intravenous contrast was administered to assess for vascular airway compression. The patients were not intubated. CT findings were correlated with bronchography and bronchoscopy, where available. Two patients had diffuse tracheobronchomalacia associated with chronic lung disease. One patient demonstrated focal severe cervical tracheomalacia. One patient had a double aortic arch causing fixed narrowing with superimposed malacia of the distal trachea. Four patients had normal airways; one with chronic lung disease, one demonstrating air trapping. CT findings were concordant with bronchography (one case) and bronchoscopy (four cases) in all but one (CT negative, bronchoscopy positive) but did not alter patient management. The assessment of the paediatric airway, and in particular for tracheobronchomalacia, is difficult. Assessment with bronchography, bronchoscopy, helical CT and MR have issues with reliability, intubation, intratracheal/bronchial contrast administration and ionising radiation. Volumetric CT assesses the entire central airway in children at much lower radiation dose compared with previous dynamic CT imaging. This non-invasive, rapid assessment obviates the need for patient cooperation and enables evaluation of extratracheal intrathoracic structures. Volumetric CT enables four-dimensional assessment for paediatric tracheobronchomalacia without intubation or patient cooperation and at low radiation dose. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

Elimination of CT-detected gas bubbles derived from decompression illness with abdominal symptoms after a short hyperbaric oxygen treatment in a monoplace chamber: a case report.

PubMed

Oyaizu, Takuya; Enomoto, Mitsuhiro; Tsujimoto, Toshihide; Kojima, Yasushi; Okawa, Atsushi; Yagishita, Kazuyoshi

2017-01-01

We report the case of a 54-year-old male compressed-air worker with gas bubbles detected by computed tomography (CT). He had complained of strong abdominal pain 30 minutes after decompression after working at a pressure equivalent to 17 meters of sea water for three hours. The initial CT images revealed gas bubbles in the intrahepatic portal vein, pulmonary artery and bilateral femoral vein. After the first hyperbaric oxygen treatment (HBO₂ at 2.5 atmospheres absolute/ATA for 150 minutes), no bubbles were detected on repeat CT examination. The patient still exhibited abdominal distension, mild hypesthesia and slight muscle weakness in the upper extremities. Two sessions of U.S. Navy Treatment Table 6 (TT6) were performed on Days 6 and 7 after onset. The patient recovered completely on Day 7. This report describes the important role of CT imaging in evaluating intravascular gas bubbles as well as eliminating the diagnosis of other conditions when divers or compressed-air workers experience uncommon symptoms of decompression illness. In addition, a short treatment table of HBO₂ using non-TT6 HBO₂ treatment may be useful to reduce gas bubbles and the severity of decompression illness in emergent cases. Copyright© Undersea and Hyperbaric Medical Society.

Performance of FDG PET/CT in the clinical management of breast cancer.

PubMed

Groheux, David; Espié, Marc; Giacchetti, Sylvie; Hindié, Elif

2013-02-01

In this analysis, the role of metabolic imaging with fluorine 18 fluorodeoxyglucose (FDG) in breast cancer is reviewed. The analysis was limited to recent works by using state-of-the-art positron emission tomography (PET)/computed tomography (CT) technology. The strengths and limitations of FDG PET/CT are examined in various clinical settings, and the following questions are answered: Is FDG PET/CT useful to differentiate malignant from benign breast lesions? Can FDG PET/CT replace sentinel node biopsy for axillary staging? What is the role of FDG PET/CT in initial staging of inflammatory or locally advanced breast cancer? What is the role of FDG PET/CT in initial staging of clinical stage IIA and IIB and primary operable stage IIIA breast cancer? How does FDG PET/CT compare with conventional techniques in the restaging of cancer in patients who are suspected of having disease recurrence? What is the role of FDG PET/CT in the assessment of early response to neoadjuvant therapy and of response to therapy for metastatic disease? Some recommendations for clinical practice are given.

The utility of computed tomography as a screening tool for the evaluation of pediatric blunt chest trauma.

PubMed

Markel, Troy A; Kumar, Rajiv; Koontz, Nicholas A; Scherer, L R; Applegate, Kimberly E

2009-07-01

There is a growing concern that computed tomography (CT) is being unnecessarily overused for the evaluation of pediatric patients. The purpose of this study was to analyze the trends and utility of chest CT use compared with chest X-ray (CXR) for the evaluation of children with blunt chest trauma. A 4-year retrospective review was performed for pediatric patients who underwent chest CT within 24 hours of sustaining blunt trauma at a Level-I trauma center. Trends in the use of CT and CXR were documented, and results of radiology reports were analyzed and compared with clinical outcomes. Three hundred thirty-three children, mean age 11 years, had chest CTs, increasing from 5.5% in 2001-2002 to 10.5% in 2004-2005 (p < 0.001). Conversely, in those children who underwent chest CT, the rate of initial CXR use decreased from 84% to 56% during the same period (p < 0.001). Twenty percent of chest CTs had significant positive findings. Six patients underwent emergency surgery for cardiac or arterial injuries, and all demonstrated abnormal findings on CXR or CT scout imaging. When compared with the CT, only 5% of initial CXRs falsely reported normal findings that may have altered management. CT use in children has increased rapidly for the initial evaluation of chest trauma, whereas CXR use has decreased. Despite this trend, CXR remains an acceptable screening tool to analyze which patients may require CT evaluation. A multidisciplinary approach is warranted to develop guidelines that standardize the use of CT and thereby decreases unnecessary radiation exposure to pediatric patients.

Inter-observer variability in diagnosing radiological features of aneurysmal subarachnoid hemorrhage; a preliminary single centre study comparing observers from different specialties and levels of training.

PubMed

Siddiqui, Usman T; Khan, Anjum F; Shamim, Muhammad Shahzad; Hamid, Rana Shoaib; Alam, Muhammad Mehboob; Emaduddin, Muhammad

2014-01-01

A noncontrast computed tomography (CT) scan remains the initial radiological investigation of choice for a patient with suspected aneurysmal subarachnoid hemorrhage (aSAH). This initial scan may be used to derive key information about the underlying aneurysm which may aid in further management. The interpretation, however, is subject to the skill and experience of the interpreting individual. The authors here evaluate the interpretation of such CT scans by different individuals at different levels of training, and in two different specialties (Radiology and Neurosurgery). Initial nonontrast CT scan of 35 patients with aSAH was evaluated independently by four different observers. The observers selected for the study included two from Radiology and two from Neurosurgery at different levels of training; a resident currently in mid training and a resident who had recently graduated from training of each specialty. Measured variables included interpreter's suspicion of presence of subarachnoid blood, side of the subarachnoid hemorrhage, location of the aneurysm, the aneurysm's proximity to vessel bifurcation, number of aneurysm(s), contour of aneurysm(s), presence of intraventricular hemorrhage (IVH), intracerebral hemorrhage (ICH), infarction, hydrocephalus and midline shift. To determine the inter-observer variability (IOV), weighted kappa values were calculated. There was moderate agreement on most of the CT scan findings among all observers. Substantial agreement was found amongst all observers for hydrocephalus, IVH, and ICH. Lowest agreement rates were seen in the location of aneurysm being supra or infra tentorial. There were, however, some noteworthy exceptions. There was substantial to almost perfect agreement between the radiology graduate and radiology resident on most CT findings. The lowest agreement was found between the neurosurgery graduate and the radiology graduate. Our study suggests that although agreements were seen in the interpretation of some of the radiological features of aSAH, there is still considerable IOV in the interpretation of most features among physicians belonging to different levels of training and different specialties. Whether these might affect management or outcome is unclear.

The impact of diagnostic imaging wait times on the prognosis of lung cancer.

PubMed

Byrne, Suzanne C; Barrett, Brendan; Bhatia, Rick

2015-02-01

This study was performed to determine whether gaps in patient flow from initial lung imaging to computed tomography (CT) guided lung biopsy in patients with non-small cell lung cancer (NSCLC) was associated with a change in tumour size, stage, and thus prognosis. All patients who had a CT-guided lung biopsy in 2009 (phase I) and in 2011 (phase II) with a pathologic diagnosis of primary lung cancer (NSCLC) at Eastern Health, Newfoundland, were identified. Dates of initial abnormal imaging, confirmatory CT (if performed), and CT-guided biopsy were recorded, along with tumour size and resulting T stage at each time point. In 2010, wait times for diagnostic imaging at Eastern Health were reduced. The stage and prognosis of NSCLC in 2009 was compared with 2011. In phase 1, there was a statistically significant increase in tumour size (mean difference, 0.67 cm; P < .0001) and stage (P < .0001) from initial image to biopsy. There was a moderate correlation between the time (in days) between the images and change in size (r = 0.33, P = .008) or stage (r = 0.26, P = .036). In phase II, the median wait time from initial imaging to confirmatory CT was reduced to 7.5 days (from 19 days). At this reduced wait time, there was no statistically significant increase in tumour size (mean difference, 0.02; P > .05) or stage (P > .05) from initial imaging to confirmatory CT. Delays in patient flow through diagnostic imaging resulted in an increase in tumour size and stage, with a negative impact on prognosis of NSCLC. This information contributed to the hiring of additional CT technologists and extended CT hours to decrease the wait time for diagnostic imaging. With reduced wait times, the prognosis of NSCLC was not adversely impacted as patients navigated through diagnostic imaging. Copyright © 2015 Canadian Association of Radiologists. All rights reserved.

Estimation of critical end-test torque using neuromuscular electrical stimulation of the quadriceps in humans.

PubMed

Janzen, Natalie R; Hight, Robert E; Patel, Darshit S; Campbell, Jason A; Larson, Rebecca D; Black, Christopher D

2018-05-02

Characterization of critical power/torque (CP/CT) during voluntary exercise requires maximal effort, making difficult for those with neuromuscular impairments. To address this issue we sought to determine if electrically stimulated intermittent isometric exercise resulted in a critical end-test torque (ETT) that behaved similar to voluntary CT. In the first experiment participants (n = 9) completed four bouts of stimulated exercise at a 3:2 duty cycle, at frequencies of 100, 50, 25 Hz, and a low frequency below ETT (Sub-ETT; ≤ 15 Hz). The second experiment (n = 20) consisted of four bouts at a 2:2 duty cycle-two bouts at 100 Hz, one at an intermediate frequency (15-30 Hz), and one at Sub-ETT. The third experiment (n = 12) consisted of two bouts at 50 Hz at a 3:2 duty* cycle with proximal blood flow occlusion during one of the bouts. ETT torque was similar (p ≥ 0.43) within and among stimulation frequencies in experiment 1. No fatigue was observed during the Sub-ETT bouts (p > 0.05). For experiment 2, ETT was similar at 100 Hz and at the intermediate frequency (p ≥ 0.29). Again, Sub-ETT stimulation did not result in fatigue (p > 0.05). Altering oxygen delivery by altering the duty cycle (3:2 vs. 2:2; p = 0.02) and by occlusion (p < 0.001) resulted in lower ETT values. Stimulated exercise resulted in an ETT that was consistent from day-to-day and similar regardless of initial torque, as long as that torque exceeded ETT, and was sensitive to oxygen delivery. As such we propose it represents a parameter similar to voluntary CT.

Comparison of Intralaminar and Interlaminar Mode-I Fracture Toughness of Unidirectional IM7/8552 Graphite/Epoxy Composite

NASA Technical Reports Server (NTRS)

Czabaj, Michael W.; Ratcliffe, James

2012-01-01

The intralaminar and interlaminar mode-I fracture-toughness of a unidirectional IM7/8552 graphite/epoxy composite were measured using compact tension (CT) and double cantilever beam (DCB) test specimens, respectively. Two starter crack geometries were considered for both the CT and DCB specimen configurations. In the first case, starter cracks were produced by 12.5 micron thick, Teflon film inserts. In the second case, considerably sharper starter cracks were produced by fatigue precracking. For each specimen configuration, use of the Teflon film starter cracks resulted in initially unstable crack growth and artificially high initiation fracture-toughness values. Conversely, specimens with fatigue precracks exhibited stable growth onset and lower initiation fracture toughness. For CT and DCB specimens with fatigue precracks, the intralaminar and interlaminar initiation fracture toughnesses were approximately equal. However, during propagation, the CT specimens exhibited more extensive fiber bridging, and rapidly increasing R-curve behavior as compared to the DCB specimens. Observations of initiation and propagation of intralaminar and interlaminar fracture, and the measurements of fracture toughness, were supported by fractographic analysis using scanning electron microscopy.

Results of subscale MTF compression experiments

NASA Astrophysics Data System (ADS)

Howard, Stephen; Mossman, A.; Donaldson, M.; Fusion Team, General

2016-10-01

In magnetized target fusion (MTF) a magnetized plasma torus is compressed in a time shorter than its own energy confinement time, thereby heating to fusion conditions. Understanding plasma behavior and scaling laws is needed to advance toward a reactor-scale demonstration. General Fusion is conducting a sequence of subscale experiments of compact toroid (CT) plasmas being compressed by chemically driven implosion of an aluminum liner, providing data on several key questions. CT plasmas are formed by a coaxial Marshall gun, with magnetic fields supported by internal plasma currents and eddy currents in the wall. Configurations that have been compressed so far include decaying and sustained spheromaks and an ST that is formed into a pre-existing toroidal field. Diagnostics measure B, ne, visible and x-ray emission, Ti and Te. Before compression the CT has an energy of 10kJ magnetic, 1 kJ thermal, with Te of 100 - 200 eV, ne 5x1020 m-3. Plasma was stable during a compression factor R0/R >3 on best shots. A reactor scale demonstration would require 10x higher initial B and ne but similar Te. Liner improvements have minimized ripple, tearing and ejection of micro-debris. Plasma facing surfaces have included plasma-sprayed tungsten, bare Cu and Al, and gettering with Ti and Li.

Routine repeat head CT may not be necessary for patients with mild TBI

PubMed Central

Rosen, Claire B; Luy, Diego D; Deane, Molly R; Scalea, Thomas M; Stein, Deborah M

2018-01-01

Background Routine repeat cranial CT (RHCT) is standard of care for CT-verified traumatic brain injury (TBI). Despite mixed evidence, those with mild TBI are subject to radiation and expense from serial CT scans. Thus, we investigated the necessity and utility of RHCT for patients with mild TBI. We hypothesized that repeat head CT in these patients would not alter patient care or outcomes. Methods We retrospectively studied patients suffering from mild TBI (Glasgow Coma Scale (GCS) score 13–15) and treated at the R Adams Cowley Shock Trauma Center from November 2014 through January 2015. The primary outcome was the need for surgical intervention. Outcomes were compared using paired Student’s t-test, and stratified by injury on initial CT, GCS change, demographics, and presenting vital signs (mean ± SD). Results Eighty-five patients met inclusion criteria with an average initial GCS score=14.6±0.57. Our center sees about 2800 patients with TBI per year, or about 230 per month. This includes patients with concussions. This sample represents about 30% of patients with TBI seen during the study period. Ten patients required operation (four based on initial CT and others for worsening GCS, headaches, large unresolving injury). There was progression of injury on repeat CT scan in only two patients that required operation, and this accompanied clinical deterioration. The mean brain Abbreviated Injury Scale (AIS) score was 4.8±0.3 for surgical patients on initial CT scan compared with 3.4±0.6 (P<0.001) for non-surgical patients. Initial CT subdural hematoma size was 1.1±0.6 cm for surgical patients compared with 0.49±0.3 cm (P=0.05) for non-surgical patients. There was no significant difference between intervention groups in terms of other intracranial injuries, demographics, vital signs, or change in GCS. Overall, 75 patients that did not require surgical intervention received RHCT. At $340 per CT, $51 000 was spent on unnecessary imaging ($367 000/year, extrapolated). Discussion In an environment of increased scrutiny on healthcare expenditures, it is necessary to question dogma and eliminate unnecessary cost. Our data questions the use of routine repeat head CT scans in every patient with anatomic TBI and suggests that clinically stable patients with small injury can simply be followed clinically. Level of evidence Level III. PMID:29766124

Reductive Dechlorination of Carbon Tetrachloride by Tetrachloroethene and Trichloroethene Respiring Anaerobic Mixed Cultures

NASA Astrophysics Data System (ADS)

Vickstrom, K. E.; Azizian, M.; Semprini, L.

2015-12-01

Carbon tetrachloride (CT) is a toxic and recalcitrant groundwater contaminant with the potential to form a broad range of transformation products. Of the possible biochemical pathways through which CT can be degraded, reductive dehalogenation to less chlorinated compounds and mineralization to carbon dioxide (CO2) appear to be the most frequently utilized pathways by anaerobic organisms. Results will be presented from batch experiments of CT degradation by the Evanite (EV), Victoria Strain (VS) and Point Mugu (PM) anaerobic dechlorinating cultures. The cultures are grown in chemostats and are capable of transforming tetrachloroethene (PCE) or trichloroethene (TCE) to ethene by halorespiration via reductive dehalogenase enzymes. For the batch CT transformation tests, the cells along with supernatant were harvested from chemostats fed PCE or TCE, but never CT. The batch reactors were initially fed 0.0085 mM CT and an excess of formate (EV and VS) or lactate (PM) as electron donor. Transformation of CT was 100% with about 20% converted to chloroform (CF) and undetected products. Multiple additions of CT showed a slowing of pseudo first-order CT transformation rates across all cultures. Batch reactors were then established and fed 0.085 mM CT with an excess of electron donor in order to better quantify the reductive pathway. CT was transformed to CF and dichloromethane (DCM), with trace amounts of chloromethane (CM) detected. Between 60-90% of the mass added to the system was accounted for, showing that the majority of the carbon tetrachloride present is being reductively dehalogenated. Results from batch reactors that were poisoned using sodium azide, and from reactors not provided electron donor will be presented to distinguish between biotic and abiotic reactions. Furthermore, results from reactors prepared with acetylene (a potent, reversible inhibitor of reductive dehalogenases (1)) will be presented as a means of identifying the enzymes involved in the transformation of CT. The results clearly demonstrate that reductive dechlorination of CT can be promoted by anaerobic cultures not previously acclimated to CT. 1. G. Pon, M. R. Hyman, L. Semprini, Environ. Sci. Technol. 37, 3181-3188 (2003).

The effectiveness of using WebCT in distance learning programmes in MACE, the University of Manchester

NASA Astrophysics Data System (ADS)

Ahmad, Rosman

The World Wide Web impacted the educational model and became part of distance education early in this century. There were many changes taking place in higher education for political, economic and educational reasons." New goals and educational objectives were being set within educational institutions. There were particular emphases to produce a more effective delivery of learning methods for distance learning students. The use of Internet was seen as an important issue in the development of an understanding of the complex process of instilling knowledge to post graduates students. Well-established universities were re-examining their missions and looking for different ways of providing lifelong education. The School of Mechanical, Aerospace and Civil Engineering (MACE) was particularly keen to increase the use of web-based learning in its courses, which will increase the amount of students enrolled into these programmes and help them learn in a flexible and workable manner. This approach was reinforced by responses from a survey of MSc. degree students which suggested that the current distance learning programme were not being operated efficiently and did not develop adequate personal skills in relation to the requirements of prospective employers. One way of improving these programmes was to make use of the Virtual Learning Environment (VLE). A study was made and WebCT was found to be suitable. Five WebCT units were initially produced. The experience of designing and running the units was very useful in determining the effective use of the WebCT. From the analysis of students and staff surveys it has been demonstrated that these WebCT units are much more effective in achieving the project objectives in a wide number of areas which relate to students satisfaction, skills development and enhancing their interest into learning experience. The success of the WebCT units has stimulated interest in overseas establishments. It is hope that the success will follow in the author's home country, Malaysia.

Timing of Radiation Therapy and Chemotherapy After Breast-Conserving Surgery for Node-Positive Breast Cancer: Long-Term Results From International Breast Cancer Study Group Trials VI and VII

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karlsson, Per, E-mail: per.karlsson@oncology.gu.se; Cole, Bernard F.; Price, Karen N.

Purpose: To update the previous report from 2 randomized clinical trials, now with a median follow-up of 16 years, to analyze the effect of radiation therapy timing on local failure and disease-free survival. Patients and Methods: From July 1986 to April 1993, International Breast Cancer Study Group trial VI randomly assigned 1475 pre-/perimenopausal women with node-positive breast cancer to receive 3 or 6 cycles of initial chemotherapy (CT). International Breast Cancer Study Group trial VII randomly assigned 1212 postmenopausal women with node-positive breast cancer to receive tamoxifen for 5 years, or tamoxifen for 5 years with 3 early cycles of initial CT. Formore » patients who received breast-conserving surgery (BCS), radiation therapy (RT) was delayed until initial CT was completed; 4 or 7 months after BCS for trial VI and 2 or 4 months for trial VII. We compared RT timing groups among 433 patients on trial VI and 285 patients on trial VII who received BCS plus RT. Endpoints were local failure, regional/distant failure, and disease-free survival (DFS). Results: Among pre-/perimenopausal patients there were no significant differences in disease-related outcomes. The 15-year DFS was 48.2% in the group allocated 3 months initial CT and 44.9% in the group allocated 6 months initial CT (hazard ratio [HR] 1.12; 95% confidence interval [CI] 0.87-1.45). Among postmenopausal patients, the 15-year DFS was 46.1% in the no-initial-CT group and 43.3% in the group allocated 3 months initial CT (HR 1.11; 95% CI 0.82-1.51). Corresponding HRs for local failures were 0.94 (95% CI 0.61-1.46) in trial VI and 1.51 (95% CI 0.77-2.97) in trial VII. For regional/distant failures, the respective HRs were 1.15 (95% CI 0.80-1.63) and 1.08 (95% CI 0.69-1.68). Conclusions: This study confirms that, after more than 15 years of follow-up, it is reasonable to delay radiation therapy until after the completion of standard CT.« less

[Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

PubMed

Kirchner, J; Laufer, U; Jendreck, M; Kickuth, R; Schilling, E M; Liermann, D

2000-01-01

Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

Initial experience of using an iron-containing fiducial marker for radiotherapy of prostate cancer: Advantages in the visualization of markers in Computed Tomography and Magnetic Resonance Imaging

NASA Astrophysics Data System (ADS)

Tanaka, Osamu; Iida, Takayoshi; Komeda, Hisao; Tamaki, Masayoshi; Seike, Kensaku; Kato, Daiki; Yokoyama, Takamasa; Hirose, Shigeki; Kawaguchi, Daisuke

2016-12-01

Visualization of markers is critical for imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). However, the size of the marker varies according to the imaging technique. While a large-sized marker is more useful for visualization in MRI, it results in artifacts on CT and causes substantial pain on administration. In contrast, a small-sized marker reduces the artifacts on CT but hampers MRI detection. Herein, we report a new ironcontaining marker and compare its utility with that of non-iron-containing markers. Five patients underwent CT/MRI fusion-based intensity-modulated radiotherapy, and the markers were placed by urologists. A Gold Anchor™ (GA; diameter, 0.28 mm; length, 10 mm) was placed using a 22G needle on the right side of the prostate. A VISICOIL™ (VIS; diameter, 0.35 mm; length, 10 mm) was placed using a 19G needle on the left side. MRI was performed using T2*-weighted imaging. Three observers evaluated and scored the visual qualities of the acquired images. The mean score of visualization was almost identical between the GA and VIS in radiography and cone-beam CT (Novalis Tx). The artifacts in planning CT were slightly larger using the GA than using the VIS. The visualization of the marker on MRI using the GA was superior to that using the VIS. In conclusion, the visualization quality of radiography, conebeam CT, and planning CT was roughly equal between the GA and VIS. However, the GA was more strongly visualized than was the VIS on MRI due to iron containing.

CT perfusion for determination of pharmacologically mediated blood flow changes in an animal tumor model.

PubMed

Hakimé, Antoine; Peddi, Himaja; Hines-Peralta, Andrew U; Wilcox, Carol J; Kruskal, Jonathan; Lin, Shezhang; de Baere, Thierry; Raptopoulos, Vassilios D; Goldberg, S Nahum

2007-06-01

To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). Multisection CT perfusion techniques may provide an accurate and more reproducible method of tumor perfusion surveillance than comparison of single representative tumor sections. (c) RSNA, 2007.

Percutaneous CT and Fluoroscopy-Guided Screw Fixation of Pathological Fractures in the Shoulder Girdle: Technical Report of 3 Cases.

PubMed

Garnon, Julien; Koch, Guillaume; Ramamurthy, Nitin; Caudrelier, Jean; Rao, Pramod; Tsoumakidou, Georgia; Cazzato, Roberto Luigi; Gangi, Afshin

2016-09-01

To review our initial experience with percutaneous CT and fluoroscopy-guided screw fixation of pathological shoulder-girdle fractures. Between May 2014 and June 2015, three consecutive oncologic patients (mean age 65 years; range 57-75 years) with symptomatic pathological shoulder-girdle fractures unsuitable for surgery and radiotherapy underwent percutaneous image-guided screw fixation. Fractures occurred through metastases (n = 2) or a post-ablation cavity (n = 1). Mechanical properties of osteosynthesis were adjudged superior to stand-alone cementoplasty in each case. Cannulated screws were placed under combined CT and fluoroscopic guidance with complementary radiofrequency ablation or cementoplasty to optimise local palliation and secure screw fixation, respectively, in two cases. Follow-up was undertaken every few weeks until mortality or most recent appointment. Four pathological fractures were treated in three patients (2 acromion, 1 clavicular, 1 coracoid). Mean size of associated lesion was 2.6 cm (range 1-4.5 cm). Technical success was achieved in all cases (100 %), without complications. Good palliation and restoration of mobility were observed in two cases at 2-3 months; one case could not be followed due to early post-procedural oncologic mortality. Percutaneous image-guided shoulder-girdle osteosynthesis appears technically feasible with good short-term efficacy in this complex patient subset. Further studies are warranted to confirm these promising initial results.

Impact of soil structure heterogeneity on the degradation of organic pollutants at the centimeter scale : 3D Modeling using graph based method

NASA Astrophysics Data System (ADS)

Sinclair Yemini, Francis; Chenu, Claire; Monga, Olivier; Vieuble Gonond, Laure; Juarez, Sabrina; Pihneiro, Marc; otten, Wilfred; Garnier, Patricia

2014-05-01

Contaminant degradation by microorganisms is very variable in soils because of the very heterogeneous spatial relationship of contaminant/degraders. Repacked Soil columns were carried out to study the degradation of 2,4D pesticide labelled with C14 for different scenarios of microorganisms and pesticide initial location. Measurements of global C14-CO2 emission and C14 distribution in the soil column showed that the initial location play a crucial rule on the dissipation of the pollutant. Experiments were simulated using a 3D model able to model microbial degradation and substrate diffusion between aggregates by considering explicitly the 3D structure of soil from CT images. The initial version of the model (Monga et al., 2008) was improved in order to simulate diffusion in samples of large size. Partial differential equations were implemented using freefem++ solver. The model simulates properly the dynamics of 2,4D in the column for the different initial situations. CT images of the same soil but using undisturbed structure instead of repacked aggregates were also carried out. Significant differences of the simulated results were observed between the repacked and the undisturbed soil. The conclusion of our work is that the heterogeneity of the soil structure and location of pollutants and decomposers has a very strong influence on the dissipation of pollutants.

Patient participation in cancer clinical trials: A pilot test of lay navigation.

PubMed

Cartmell, Kathleen B; Bonilha, Heather S; Matson, Terri; Bryant, Debbie C; Zapka, Jane G; Bentz, Tricia A; Ford, Marvella E; Hughes-Halbert, Chanita; Simpson, Kit N; Alberg, Anthony J

2016-08-15

Clinical trials (CT) represent an important treatment option for cancer patients. Unfortunately, patients face challenges to enrolling in CTs, such as logistical barriers, poor CT understanding and complex clinical regimens. Patient navigation is a strategy that may help to improve the delivery of CT education and support services. We examined the feasibility and initial effect of one navigation strategy, use of lay navigators. A lay CT navigation intervention was evaluated in a prospective cohort study among 40 lung and esophageal cancer patients. The intervention was delivered by a trained lay navigator who viewed a 17-minute CT educational video with each patient, assessed and answered their questions about CT participation and addressed reported barriers to care and trial participation. During this 12-month pilot project, 85% (95% CI: 72%-93%) of patients eligible for a therapeutic CT consented to participate in the CT navigation intervention. Among navigated patients, CT understanding improved between pre- and post-test (means 3.54 and 4.40, respectively; p-value 0.004), and 95% (95% CI: 82%-98%) of navigated patients consented to participate in a CT. Navigated patients reported being satisfied with patient navigation services and CT participation. In this formative single-arm pilot project, initial evidence was found for the potential effect of a lay navigation intervention on CT understanding and enrollment. A randomized controlled trial is needed to examine the efficacy of the intervention for improving CT education and enrollment.

MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems.

PubMed

Avanesov, Maxim; Weinrich, Julius M; Kraus, Thomas; Derlin, Thorsten; Adam, Gerhard; Yamamura, Jin; Karul, Murat

2016-11-01

The purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. In this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48-64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. In neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p=0.25; mCTSI: 4.0 vs. 4.0, p=0.10; EPIC: 2.0 vs. 2.0, p=0.41; NP: CTSI: 8.0 vs. 7.0, p=0.64; mCTSI: 8.0 vs. 8.0, p=0.10; EPIC: 3.0 vs. 3.0, p=0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. An initial dual-phase abdominal CT after ≥72h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a single-phase protocol. Copyright © 2016. Published by Elsevier Ireland Ltd.

Effect of clinical decision rules, patient cost and malpractice information on clinician brain CT image ordering: a randomized controlled trial.

PubMed

Gimbel, Ronald W; Pirrallo, Ronald G; Lowe, Steven C; Wright, David W; Zhang, Lu; Woo, Min-Jae; Fontelo, Paul; Liu, Fang; Connor, Zachary

2018-03-12

The frequency of head computed tomography (CT) imaging for mild head trauma patients has raised safety and cost concerns. Validated clinical decision rules exist in the published literature and on-line sources to guide medical image ordering but are often not used by emergency department (ED) clinicians. Using simulation, we explored whether the presentation of a clinical decision rule (i.e. Canadian CT Head Rule - CCHR), findings from malpractice cases related to clinicians not ordering CT imaging in mild head trauma cases, and estimated patient out-of-pocket cost might influence clinician brain CT ordering. Understanding what type and how information may influence clinical decision making in the ordering advanced medical imaging is important in shaping the optimal design and implementation of related clinical decision support systems. Multi-center, double-blinded simulation-based randomized controlled trial. Following standardized clinical vignette presentation, clinicians made an initial imaging decision for the patient. This was followed by additional information on decision support rules, malpractice outcome review, and patient cost; each with opportunity to modify their initial order. The malpractice and cost information differed by assigned group to test the any temporal relationship. The simulation closed with a second vignette and an imaging decision. One hundred sixteen of the 167 participants (66.9%) initially ordered a brain CT scan. After CCHR presentation, the number of clinicians ordering a CT dropped to 76 (45.8%), representing a 21.1% reduction in CT ordering (P = 0.002). This reduction in CT ordering was maintained, in comparison to initial imaging orders, when presented with malpractice review information (p = 0.002) and patient cost information (p = 0.002). About 57% of clinicians changed their order during study, while 43% never modified their imaging order. This study suggests that ED clinician brain CT imaging decisions may be influenced by clinical decision support rules, patient out-of-pocket cost information and findings from malpractice case review. NCT03449862 , February 27, 2018, Retrospectively registered.

Fixed, object-specific intensity compensation for cone beam optical CT radiation dosimetry

NASA Astrophysics Data System (ADS)

Dekker, Kurtis H.; Hazarika, Rubin; Silveira, Matheus A.; Jordan, Kevin J.

2018-03-01

Optical cone beam computed tomography (CT) scanning of radiochromic gel dosimeters, using a CCD camera and a low stray light convergent source, provides fast, truly 3D radiation dosimetry with high accuracy. However, a key limiting factor in radiochromic gel dosimetry at large (⩾10 cm diameter) volumes is the initial attenuation of the dosimeters. It is not unusual to observe a 5–10×  difference in signal intensity through the dosimeter center versus through the surrounding medium in pre-irradiation images. Thus, all dosimetric information in a typical experiment is measured within the lower 10%–20% of the camera sensor’s range, and re-use of gels is often not possible due to a lack of transmission. To counteract this, in this note we describe a simple method to create source compensators by printing on transparent films. This technique, which is easily implemented and inexpensive, is an optical analogue to the bowtie filter in x-ray CT. We present transmission images and solution phantom reconstructions to demonstrate that (1) placing compensators beyond the focal zone of the imaging lens prevents high spatial frequency features of the printed films from generating reconstruction artifacts, and (2) object-specific compensation considerably reduces the range of intensities measured in projection images. This will improve the measurable dose range in optical CT dosimetry, and will enable imaging of larger gel volumes (∼15 cm diameter). Additionally, it should enable re-use of dosimeters by printing a new compensator for a second experiment.

Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

PubMed

Li, Liang; Wang, Bigong; Wang, Ge

2016-01-01

In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

Propulsion and Power Supplies for Unmanned Vehicles. Volume I. Engines for Small Propeller-Driven RPVS

DTIC Science & Technology

1977-11-01

residual unbaiance. Mass production experience and availability of rotary piston engines -type WANKEL- refer basically to the automobile industry...production air cooled automobile engine in standard form can be ruled out on a specific weight basis. 4. In modified form, as used in many light aircr: Ct...the air cooled automobile engine appears to be a possibility. Availability, lcw initial cost; and good specific fuel consumption could make the unit

Translation initiation on mRNAs bound by nuclear cap-binding protein complex CBP80/20 requires interaction between CBP80/20-dependent translation initiation factor and eukaryotic translation initiation factor 3g.

PubMed

Choe, Junho; Oh, Nara; Park, Sungjin; Lee, Ye Kyung; Song, Ok-Kyu; Locker, Nicolas; Chi, Sung-Gil; Kim, Yoon Ki

2012-05-25

In the cytoplasm of mammalian cells, either cap-binding proteins 80 and 20 (CBP80/20) or eukaryotic translation initiation factor (eIF) 4E can direct the initiation of translation. Although the recruitment of ribosomes to mRNAs during eIF4E-dependent translation (ET) is well characterized, the molecular mechanism for CBP80/20-dependent translation (CT) remains obscure. Here, we show that CBP80/20-dependent translation initiation factor (CTIF), which has been shown to be preferentially involved in CT but not ET, specifically interacts with eIF3g, a component of the eIF3 complex involved in ribosome recruitment. By interacting with eIF3g, CTIF serves as an adaptor protein to bridge the CBP80/20 and the eIF3 complex, leading to efficient ribosome recruitment during CT. Accordingly, down-regulation of CTIF using a small interfering RNA causes a redistribution of CBP80 from polysome fractions to subpolysome fractions, without significant consequence to eIF4E distribution. In addition, down-regulation of eIF3g inhibits the efficiency of nonsense-mediated mRNA decay, which is tightly coupled to CT but not to ET. Moreover, the artificial tethering of CTIF to an intercistronic region of dicistronic mRNA results in translation of the downstream cistron in an eIF3-dependent manner. These findings support the idea that CT mechanistically differs from ET.

SU-F-T-626: Intracranial SRS Re-Treatment Without Acquisition of New CT Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiant, D; Manning, M; Liu, H

Purpose: Linear accelerator based stereotactic radiosurgery (SRS) for multiple intracranial lesions with frequent surveillance is becoming a popular treatment option. This strategy leads to retreatment with SRS as new lesions arise. Currently, each course of treatment uses magnetic resonance (MR) and computed tomography (CT) images for treatment planning. We propose that new MR images, with course 1 CT images, may be used for future treatment plans with negligible loss of dosimetric accuracy. Methods: Ten patients that received multiple courses of SRS were retrospectively reviewed. The treatment plans and contours from non-initial courses were copied to the initial CTs and recalculated.more » Doses metrics for the plans calculated on the initial CTs and later CTs were compared. All CT scans were acquired on a Philips CT scanner with a 600 mm field of view and 1 mm slice thickness (Philips Healthcare, Andover, MA). All targets were planned to 20 Gy and calculated in Eclipse V. 13.6 (Varian, Palo Alto, CA) using analytic anisotropic algorithm with 1 mm calculation grid. Results: Sixteen lesions were evaluated. The mean time between courses was 250 +/− 215 days (range 103–979). The mean target volume was 2.0 +/− 2.9 cc (range 0.1–10.1). The average difference in mean target dose between the two calculations was 0.2 +/− 0.3 Gy (range 0.0 – 1.0). The mean conformity index (CI) was 1.28 +/− 0.14 (range 1.07 – 1.82). The average difference in CI was 0.03 +/− 0.16 (range 0.00 – 0.44). Targets volumes < 0.5 cc showed the largest changes in both metrics. Conclusion: Continued treatment based on initial CT images is feasible. Dose calculation on the initial CT for future treatments provides reasonable dosimetric accuracy. Changes in dose metrics are largest for small volumes, and are likely dominated by partial volume effects in target definition.« less

SU-E-J-267: Change in Mean CT Intensity of Lung Tumors During Radiation Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahon, R; Tennyson, N; Weiss, E

2015-06-15

Purpose: To evaluate CT intensity change of lung tumors during radiation therapy. Methods: Repeated 4D CT images were acquired on a CT simulator during the course of therapy for 27 lung cancer patients on IRB approved protocols. All subjects received definitive radiation treatment ± chemotherapy. CT scans were completed prior to treatment, and 2–7 times during the treatment course. Primary tumor was delineated by an experienced Radiation Oncologist. Contours were thresholded between −100 HU and 200 HU to remove airways and bone. Correlations between the change in the mean tumor intensity and initial tumor intensity, SUVmax, and tumor volume changemore » rate were investigated. Reproducibility was assessed by evaluating the variation in mean intensity over all phases in 4DCT, for a subgroup of 19 subjects. Results: Reproducibility of tumor intensity between phases as characterized by the root mean square of standard deviation across 19 subjects was 1.8 HU. Subjects had a mean initial tumor intensity of 16.5 ± 11.6 HU and an overall reduction in HU by 10.3 ± 8.5 HU. Evaluation of the changes in tumor intensity during treatment showed a decrease of 0.3 ± 0.3 HU/day for all subjects, except three. No significant correlation was found between change in HU/day and initial HU intensity (p=0.53), initial PET SUVmax (p=0.69), or initial tumor volume (p=0.70). The rate of tumor volume change was weakly correlated (R{sup 2}=0.05) with HU change (p=0.01). Conclusion: Most lung cancer subjects showed a marked trend of decreasing mean tumor CT intensity throughout radiotherapy, including early in the treatment course. Change in HU/day is not correlated with other potential early predictors for response, such as SUV and tumor volume change. This Result supports future studies to evaluate change in tumor intensity on CT as an early predictor of response.« less

NUT Midline Carcinoma in Elderly Patients: Usefulness of 18F-FDG PET/CT for Treatment Assessment.

PubMed

Kawase, Takatsugu; Naka, Go; Kubota, Kazuo; Sakashita, Baku; Takeda, Yuichiro

2015-09-01

Nuclear protein in testis (NUT) midline carcinoma is a rare disease that generally arises in adolescents and young adults. However, we encountered a rare NUT midline carcinoma case in an elderly patient. F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (PET/CT) studies were performed before and during the treatment course. In this case, the initial PET/CT study revealed locoregional hypermetabolism in the mediastinal lesion. After then, the interim PET/CT study indicated a clear diminishing response to the initial treatment, whereas the residual masses were morphologically observable. Nuclear imaging may allow visualization of the therapeutic effect of antineoplastic therapies in both young and elderly patients.

18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging.

PubMed

Caresia Aroztegui, Ana Paula; García Vicente, Ana María; Alvarez Ruiz, Soledad; Delgado Bolton, Roberto Carlos; Orcajo Rincon, Javier; Garcia Garzon, Jose Ramon; de Arcocha Torres, Maria; Garcia-Velloso, Maria Jose

2017-10-01

Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced breast cancer. Baseline tumor glycolytic activity is associated with tumor biology and prognosis.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: I. Acute pain.

PubMed

Meléndez, D M; Marti, S; Pajor, E A; Moya, D; Heuston, C E M; Gellatly, D; Janzen, E D; Schwartzkopf-Genswein, K S

2017-10-01

Three experiments evaluated the effect of band and knife castration on acute pain for the first 7 d after the procedure on 1-wk-, 2-mo-, and 4-mo-old calves. All calves were blocked by age and weight and randomly assigned to 1 of 3 treatments: sham castration (control, CT), band castration (BA), and knife castration (KN). Experiment 1 evaluated 1-wk-old Angus bull calves ( = 34; 43.0 ± 6.61 kg BW), Exp. 2 evaluated 2-mo-old Angus bull calves ( = 34; 91.5 ± 11.93 kg BW), and Exp. 3 evaluated 4-mo-old Angus bull calves ( = 35; 157.6 ± 22.52 kg BW). For all experiments, physiological and behavioral parameters were collected before (d -1 and immediately before castration [T0]) and after (60 and 120 min and on d 7) castration to assess acute pain. Physiological measures included complete blood cell count, cortisol, substance P, and scrotal temperature. Behavioral measures consisted of a visual analog scale, stride length, and time and frequency budgets for walking, standing, lying, tail flicking, foot stamping, and head turning. Performance parameters included initial and final BW and ADG. In Exp. 1, tail flicking was greater ( = 0.02) in KN calves compared to BA calves 2 to 4 h after castration, although no differences were seen between BA and KN compared to CT calves. In Exp. 2, a treatment × time interaction ( = 0.02) was observed for cortisol, where KN calves had greater cortisol concentrations 120 min after castration compared to BA and CT calves; KN calves also lay down and ate less ( < 0.01; = 0.02) and stood and walked more ( < 0.01; = 0.05) compared to BA and CT calves 2 to 4 h after castration. In Exp. 3, a treatment × time interaction ( < 0.01) was observed for cortisol concentrations in which all treatments were different from one another at 60 and 120 min, with BA calves having the greatest concentrations, KN calves being intermediate, and CT having the lowest concentrations. Overall, KN and BA castrated calves presented physiological and behavioral changes associated with acute pain; however, 2-mo-old BA calves presented the fewest behavioral changes and no physiological changes associated with acute pain compared to CT calves.

Direct comparison of (68)Ga-DOTA-TOC and (18)F-FDG PET/CT in the follow-up of patients with neuroendocrine tumour treated with the first full peptide receptor radionuclide therapy cycle.

PubMed

Nilica, Bernhard; Waitz, Dietmar; Stevanovic, Vlado; Uprimny, Christian; Kendler, Dorota; Buxbaum, Sabine; Warwitz, Boris; Gerardo, Llanos; Henninger, Benjamin; Virgolini, Irene; Rodrigues, Margarida

2016-08-01

To determine the value of (68)Ga-DOTA-TOC and (18)F-FDG PET/CT for initial and follow-up evaluation of patients with neuroendocrine tumour (NET) treated with peptide receptor radionuclide therapy (PRRT). We evaluated 66 patients who had histologically proven NET and underwent both PRRT and three combined (68)Ga-DOTA-TOC and (18)F-FDG PET/CT studies. (68)Ga-DOTA-TOC PET/CT was performed before PRRT, 3 months after completion of PRRT and after a further 6 - 9 months. (18)F-FDG PET/CT was done within 2 months of (68)Ga-DOTA-TOC PET/CT. Follow-up ranged from 11.8 to 80.0 months (mean 34.5 months). All patients were (68)Ga-DOTA-TOC PET-positive initially and at follow-up after the first full PRRT cycle. Overall, 62 of the 198 (18)F-FDG PET studies (31 %) were true-positive in 38 of the 66 patients (58 %). Of the 66 patients, 28 (5 grade 1, 23 grade 2) were (18)F-FDG-negative initially and during follow-up (group 1), 24 (5 grade 1, 13 grade 2, 6 grade 3) were (18)F-FDG-positive initially and during follow-up (group 2), 9 patients (2 grade 1, 6 grade 2, 1 grade 3) were (18)F-FDG-negative initially but (18)F-FDG-positive during follow-up (group 3), and 5 patients (all grade 2) were (18)F-FDG-positive initially but (18)F-FDG-negative during follow-up (group 4).(18)F-FDG PET showed more and/or larger metastases than (68)Ga-DOTA-TOC PET in five patients of group 2 and four patients of group 3, all with progressive disease. In three patients with progressive disease who died during follow-up tumour SUVmax increased by 41 - 82 % from the first to the last follow-up investigation. In NET patients, the presence of (18)F-FDG-positive tumours correlates strongly with a higher risk of progression. Initially, patients with (18)F-FDG-negative NET may show (18)F-FDG-positive tumours during follow-up. Also patients with grade 1 and grade 2 NET may have (18)F-FDG-positive tumours. Therefore, (18)F-FDG PET/CT is a complementary tool to (68)Ga-DOTA-TOC PET/CT with clinical relevance for molecular investigation.

Non-target effect of continuous application of chlorpyrifos on soil microbes, nematodes and its persistence under sub-humid tropical rice-rice cropping system.

PubMed

Kumar, Upendra; Berliner, J; Adak, Totan; Rath, Prakash C; Dey, Avro; Pokhare, Somnath S; Jambhulkar, Nitiprasad N; Panneerselvam, P; Kumar, Anjani; Mohapatra, Shyamranjan D

2017-01-01

Application of pesticide in agricultural fields is "unnecessary evil" for non-target microflora and fauna. Hence, to identify the safer pesticide molecules against non-target microbes, a long-term pesticide experiment was initiated at National Rice Research Institute, Cuttack, India. In the present study, the effect of continuous application of chlorpyrifos (0.5kgha -1 ) in rice fields on non-target groups of soil microbes and nematodes was studied for seven seasons (four wet and three dry seasons) during 2009-2013. Treatments were arranged in a randomized complete block design with four replications of chlorpyrifos-treated (0.5kg a.i. ha -1 ) (CT) and untreated control (UT) plots. During seven seasons of experimentation, regular application of chlorpyrifos had no significant effect on population of heterotrophic aerobic, anaerobic, oligotrophic and copiotrophic bacteria in CT compared to UT, whereas, population of asymbiotic aerobic nitrogen fixer, nitrifiers, denitrifiers, gram positive and spore-forming bacteria were significantly reduced by nearly 0.25-2 fold in CT than UT. However, comparatively less deviation in population of actinomycetes, fungi, phosphate solubilizing and sulfur oxidizing bacteria were observed in CT than UT. Significant interactions were found between effects of chlorpyrifos with time in population dynamics of microbes. In plant parasitic nematode species, Meloidogyne graminicola (RRKN) and Hirschmanniella spp. (RRN), were significantly lower (p<0.01) in CT compared to UT after first year onwards. The overall observation of five years data indicated that the RRKN population showed a decreasing trend (R 2 =0.644) whereas RRN showed increasing trend (R 2 =0.932) in CT. The drastic chlorpyrifos dissipation was noticed after 15 days of application from the initial residue of 0.25mgkg -1 soil, which indicated that chlorpyrifos residue in rice field soil was not persistent and its half-life was found to be 4.02 days. Overall, the present findings revealed that non-target effect of repetitive application of chloropyrifos (0.5kgha -1 ) on soil microbes and nematodes was found less under rice-rice cropping system. Copyright © 2016 Elsevier Inc. All rights reserved.

Space Shuttle Crawler Transporter Vibration Analysis in Support of Rollout Fatigue Load Spectra Verification Program

NASA Technical Reports Server (NTRS)

Margasahayam, Ravi N.; Meyer, Karl A.; Nerolich, Shaun M.; Burton, Roy C.; Gosselin, Armand M.

2004-01-01

The Crawler Transporter (CT), designed and built for the Apollo Program in the 1960's and surpassing its initial operational life, has become an integral part of the Space Shuttle Program (SSP). The CT transports the Space Shuttle Vehicle (SSV) stack, atop the Mobile Launch Platform (MLP), from the Vehicle Assembly Building (VAB) to the launch pad. This support structure provides hydraulic jacking, leveling and load equalization for the 12 million pound stack on its 3.5-5.0 mile rollout to the launch pad. Major elements of the SSV, consisting of the orbiter, solid rocket boosters (SRB) and external tank (ET) have required fatigue analyses as part of the mission life certification. Compared to rollout vibration, the SSV sees relatively high vibration loads during launch, ascent, descent and landing phases of the mission. Although preliminary measured SRB vibration levels during rollout were of low amplitude and frequency, the duration of the rollout phase is typically high, from 5-6 hours. As part of an expanded mission life assessment, additional certification effort was initiated to define fatigue load spectra for rollout. This study addresses the CT vibration analyses in support of the rollout fatigue study. Structural models developed for modal and vibration analyses were used to identify unique CT, CT/MLP and CT/MLP/SRB vibration characteristics for comparison to instrumented rollout tests. Whereas the main structural and vibration characteristics of the SSV are well defined, minimum analytical and vibration test data on the Crawler Transporter were available. Unique vibration characteristics of the CT are attributable to the drive mechanism, hydraulic jacking system, structural framing and the CT-to-MLP support pad restraints. Initial tests performed on the CT/MLP/SRB configuration showed reasonable correlation with predicted mode shapes and frequencies.

Robust 3D-2D image registration: application to spine interventions and vertebral labeling in the presence of anatomical deformation

NASA Astrophysics Data System (ADS)

Otake, Yoshito; Wang, Adam S.; Webster Stayman, J.; Uneri, Ali; Kleinszig, Gerhard; Vogt, Sebastian; Khanna, A. Jay; Gokaslan, Ziya L.; Siewerdsen, Jeffrey H.

2013-12-01

We present a framework for robustly estimating registration between a 3D volume image and a 2D projection image and evaluate its precision and robustness in spine interventions for vertebral localization in the presence of anatomical deformation. The framework employs a normalized gradient information similarity metric and multi-start covariance matrix adaptation evolution strategy optimization with local-restarts, which provided improved robustness against deformation and content mismatch. The parallelized implementation allowed orders-of-magnitude acceleration in computation time and improved the robustness of registration via multi-start global optimization. Experiments involved a cadaver specimen and two CT datasets (supine and prone) and 36 C-arm fluoroscopy images acquired with the specimen in four positions (supine, prone, supine with lordosis, prone with kyphosis), three regions (thoracic, abdominal, and lumbar), and three levels of geometric magnification (1.7, 2.0, 2.4). Registration accuracy was evaluated in terms of projection distance error (PDE) between the estimated and true target points in the projection image, including 14 400 random trials (200 trials on the 72 registration scenarios) with initialization error up to ±200 mm and ±10°. The resulting median PDE was better than 0.1 mm in all cases, depending somewhat on the resolution of input CT and fluoroscopy images. The cadaver experiments illustrated the tradeoff between robustness and computation time, yielding a success rate of 99.993% in vertebral labeling (with ‘success’ defined as PDE <5 mm) using 1,718 664 ± 96 582 function evaluations computed in 54.0 ± 3.5 s on a mid-range GPU (nVidia, GeForce GTX690). Parameters yielding a faster search (e.g., fewer multi-starts) reduced robustness under conditions of large deformation and poor initialization (99.535% success for the same data registered in 13.1 s), but given good initialization (e.g., ±5 mm, assuming a robust initial run) the same registration could be solved with 99.993% success in 6.3 s. The ability to register CT to fluoroscopy in a manner robust to patient deformation could be valuable in applications such as radiation therapy, interventional radiology, and an assistant to target localization (e.g., vertebral labeling) in image-guided spine surgery.

Usage of CT data in biomechanical research

NASA Astrophysics Data System (ADS)

Safonov, Roman A.; Golyadkina, Anastasiya A.; Kirillova, Irina V.; Kossovich, Leonid Y.

2017-02-01

Object of study: The investigation is focused on development of personalized medicine. The determination of mechanical properties of bone tissues based on in vivo data was considered. Methods: CT, MRI, natural experiments on versatile test machine Instron 5944, numerical experiments using Python programs. Results: The medical diagnostics methods, which allows determination of mechanical properties of bone tissues based on in vivo data. The series of experiments to define the values of mechanical parameters of bone tissues. For one and the same sample, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonic investigations and mechanical experiments on single-column test machine Instron 5944 were carried out. The computer program for comparison of CT and MRI images was created. The grayscale values in the same points of the samples were determined on both CT and MRI images. The Haunsfield grayscale values were used to determine rigidity (Young module) and tensile strength of the samples. The obtained data was compared to natural experiments results for verification.

Compact Torus Fueling of the STOR-M Tokamak

NASA Astrophysics Data System (ADS)

Xiao, C.; Hirose, A.; Zawalski, W.; White, D.; Raman, R.; Decoste, R.; Gregory, B. C.; Martin, F.

1996-11-01

Tangential injection of accelerated compact torus (CT) has been performed on the STOR-M tokamak (R/a=46/12 cm, B_t<1 T, I_p<= 50 kA, barn_e=(0.5 - 1)×10^13 cm-3) using the University of Saskatchewan Compact Torus Injector (USCTI). The CT parameters are: m~=1 μg, v=120 km/sec, B=0.1 T and n=(2 - 4)×10^15 cm-3. After CT injection, the electron density in tokamak doubles and the poloidal β-value increases. Indications of reduction in the loop voltage and H_α emission level have also been observed. Currently, following efforts are being made: (a) to coat chromium on the electrode surface, (b) to increase the on-line baking temperature, and (c) to reduce the neutral gas load which follows the CT plasma. In addition, numerical calculation of CT motion in a tokamak magnetic field has been carried out. For horizontal injection, the initial CT magnetic dipole direction should be aligned with the CT velocity for deeper penetration. In the case of vertical injection, the CT trajectory is independent of the initial magnetic dipole direction and central penetration is facilitated by off-axis injection.

Dosimetric consequences of the parotid glands using CT-to-CBCT deformable registration during IMRT for late stage head and neck cancers

NASA Astrophysics Data System (ADS)

Conill, Annette L.

Patients receiving Intensity Modulated Radiation Therapy (IMRT) for late stage head and neck (HN) cancer often experience anatomical changes due to weight loss, tumor regression, and positional changes of normal anatomy (1). As a result, the actual dose delivered may vary from the original treatment plan. The purpose of this study was (a) to evaluate the dosimetric consequences of the parotid glands during the course of treatment, and (b) to determine if there would be an optimal timeframe for replanning. Nineteen locally advanced HN cancer patients underwent definitive IMRT. Each patient received an initial computerized tomography simulation (CT-SIM) scan and weekly cone beam computerized tomography (CBCT) scans. A Deformable Image Registration (DIR) was performed between the CT-SIM and CBCT of the parotid glands and Planning Target Volumes (PTVs) using the Eclipse treatment planning system (TPS) and the Velocity deformation software. A recalculation of the dose was performed on the weekly CBCTs using the original monitor units. The parameters for evaluation of our method were: the changes in volume of the PTVs and parotid glands, the dose coverage of the PTVs, the lateral displacement in the Center of Mass (COM), the mean dose, and Normal Tissue Complication Probability (NTCP) of the parotid glands. The studies showed a reduction of the volume in the PTVs and parotids, a medial displacement in COM, and alterations of the mean dose to the parotid glands as compared to the initial plans. Differences were observed for the dose volume coverage of the PTVs and NTCP of the parotid gland values between the initial plan and our proposed method utilizing deformable registration-based dose calculations.

New bone post-processing tools in forensic imaging: a multi-reader feasibility study to evaluate detection time and diagnostic accuracy in rib fracture assessment.

PubMed

Glemser, Philip A; Pfleiderer, Michael; Heger, Anna; Tremper, Jan; Krauskopf, Astrid; Schlemmer, Heinz-Peter; Yen, Kathrin; Simons, David

2017-03-01

The aim of this multi-reader feasibility study was to evaluate new post-processing CT imaging tools in rib fracture assessment of forensic cases by analyzing detection time and diagnostic accuracy. Thirty autopsy cases (20 with and 10 without rib fractures in autopsy) were randomly selected and included in this study. All cases received a native whole body CT scan prior to the autopsy procedure, which included dissection and careful evaluation of each rib. In addition to standard transverse sections (modality A), CT images were subjected to a reconstruction algorithm to compute axial labelling of the ribs (modality B) as well as "unfolding" visualizations of the rib cage (modality C, "eagle tool"). Three radiologists with different clinical and forensic experience who were blinded to autopsy results evaluated all cases in a random manner of modality and case. Rib fracture assessment of each reader was evaluated compared to autopsy and a CT consensus read as radiologic reference. A detailed evaluation of relevant test parameters revealed a better accordance to the CT consensus read as to the autopsy. Modality C was the significantly quickest rib fracture detection modality despite slightly reduced statistic test parameters compared to modalities A and B. Modern CT post-processing software is able to shorten reading time and to increase sensitivity and specificity compared to standard autopsy alone. The eagle tool as an easy to use tool is suited for an initial rib fracture screening prior to autopsy and can therefore be beneficial for forensic pathologists.

CT-Guided Interventions Using a Free-Hand, Optical Tracking System: Initial Clinical Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schubert, Tilman, E-mail: TSchubert@uhbs.ch; Jacob, Augustinus L.; Pansini, Michele

2013-08-01

PurposeThe present study was designed to evaluate the geometrical accuracy and clinical applicability of a new, free-hand, CT-guided, optical navigation system.MethodsFifteen procedures in 14 consecutive patients were retrospectively analyzed. The navigation system was applied for interventional procedures on small target lesions, in cases with long needle paths, narrow access windows, or when an out-of-plane access was expected. Mean lesion volume was 27.9 ml, and mean distance to target measured was 107.5 mm. Eleven of 15 needle trajectories were planned as out-of-plane approaches regarding the axial CT plane.ResultsNinety-one percent of the biopsies were diagnostic. All therapeutic interventions were technically successful. Targetingmore » precision was high with a mean distance of the needle tip from planned target of 1.98 mm. Mean intervention time was 1:12 h. A statistically significant correlation between angular needle deviation and intervention time (p = 0.007), respiratory movement of the target (p = 0.008), and body mass index (p = 0.02) was detected. None of the evaluated parameters correlated significantly with the distance from the needle tip to the planned target.ConclusionsThe application of a navigation system for complex CT-guided procedures provided safe and effective targeting within a reasonable intervention time in our series.« less

18F-FDG PET/CT for Monitoring Response of Merkel Cell Carcinoma to the Novel Programmed Cell Death Ligand 1 Inhibitor Avelumab.

PubMed

Eshghi, Naghmehossadat; Lundeen, Tamara F; MacKinnon, Lea; Avery, Ryan; Kuo, Phillip H

2018-05-01

An 85-year-old man with stage IIIA Merkel cell carcinoma of the left arm was initially treated with local excision and axillary node dissection followed by radiation therapy. Eight months after surgery, whole-body FDG PET/CT demonstrated intensely hypermetabolic hepatic metastases and abdominal lymphadenopathy. Given his age and comorbidities, he was considered a poor candidate for chemotherapy, and therefore the novel programmed cell death ligand 1 inhibitor avelumab was initiated. FDG PET/CT after 4 cycles showed complete resolution of hepatic and nodal metastases. Whole-body FDG PET/CT can be used for monitoring response of multisystem metastases from Merkel cell carcinoma to active immunotherapy.

Lung Cancer Screening With Low-Dose CT: Implementation Amid Changing Public Policy at One Health Care System.

PubMed

Begnaud, Abbie; Hall, Thomas; Allen, Tadashi

2016-01-01

Screening for lung cancer with low-dose CT has evolved rapidly in recent years since the National Lung Screening Trial (NLST) results. Subsequent professional and governmental organization guidelines have shaped policy and reimbursement for the service. Increasingly available guidance describes eligible patients and components necessary for a high-quality lung cancer screening program; however, practical instruction and implementation experience is not widely reported. We launched a lung cancer screening program in the face of reimbursement and guideline uncertainties at a large academic health center. We report our experience with implementation, including challenges and proposed solutions. Initially, we saw less referrals than expected for screening, and many patients referred for screening did not clearly meet eligibility guidelines. We educated primary care providers and implemented system tools to encourage referral of eligible patients. Moreover, in response to the Centers for Medicare & Medicaid Services (CMS) final coverage determination, we report our programmatic adaptation to meet these requirements. In addition to the components common to all quality programs, individual health delivery systems will face unique barriers related to patient population, available resources, and referral patterns.

Five Years of Cyclotron Radioisotope Production Experiences at the First PET-CT in Venezuela

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colmenter, L.; Coelho, D.; Esteves, L. M.

2007-10-26

Five years operation of a compact cyclotron installed at PET-CT facility in Caracas, Venezuela is given. Production rate of {sup 18}F labeled FDG, operation and radiation monitoring experience are included. We conclude that {sup 18}FDG CT-PET is the most effective technique for patient diagnosis.

Contribution of CT scan and CT-guided aspiration in the management of retropharyngeal abscess in children based on a series of 18 cases.

PubMed

Martin, C A; Gabrillargues, J; Louvrier, C; Saroul, N; Mom, T; Gilain, L

2014-11-01

This study was designed to analyse the contribution of CT scan to the management of retropharyngeal abscess in children and the place of CT-guided percutaneous aspiration as an alternative to surgical drainage. Retrospective study including 18 children with a mean age of 38 months [range: 5-67 months] presenting with retropharyngeal infection between 2006 and 2011. All cases were initially assessed by contrast-enhanced CT scan of the neck. Clinical, radiological treatment and bacteriological data were collected. Radiological results were correlated with surgical and percutaneous aspiration findings (presence or absence of an abscess). The initial CT scan detected 14 abscesses, 3 cases of non-suppurative lymphadenitis and one case of retropharyngeal oedema. One case of non-suppurative lymphadenitis progressed to abscess after failure of antibiotic therapy and was treated surgically. Surgical drainage revealed a purulent collection in 11 cases and no collection in 3 cases. Four CT-guided percutaneous aspirations were successfully performed. Three cases were treated by antibiotics alone (2 cases of lymphadenitis and 1 case of retropharyngeal oedema). Bacteriological examinations revealed the presence of Streptococcus pyogenes in 78.5% of cases. The positive predictive value of the initial CT scan was 78.8% in our series. Contrast-enhanced neck CT scan confirmed the diagnosis of retropharyngeal abscess and the indication for surgical drainage. It must be performed urgently, on admission. When it is decided to treat the patient with antibiotics alone, follow-up imaging should be performed in the absence of improvement 24 to 48 hours after starting antibiotics. CT-guided percutaneous aspiration is both a diagnostic modality confirming abscess formation of an inflammatory lesion of the retropharyngeal space as well as a therapeutic tool, sometimes avoiding the need for surgical drainage. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Radiation dose in 320-slice multidetector cardiac CT: a single center experience of evolving dose minimization.

PubMed

Tung, Matthew K; Cameron, James D; Casan, Joshua M; Crossett, Marcus; Troupis, John M; Meredith, Ian T; Seneviratne, Sujith K

2013-01-01

Minimization of radiation exposure remains an important subject that occurs in parallel with advances in scanner technology. We report our experience of evolving radiation dose and its determinants after the introduction of 320-multidetector row cardiac CT within a single tertiary cardiology referral service. Four cohorts of consecutive patients (total 525 scans), who underwent cardiac CT at defined time points as early as 2008, are described. These include a cohort just after scanner installation, after 2 upgrades of the operating system, and after introduction of an adaptive iterative image reconstruction algorithm. The proportions of nondiagnostic coronary artery segments and studies with nondiagnostic segments were compared between cohorts. Significant reductions were observed in median radiation doses in all cohorts compared with the initial cohort (P < .001). Median dose-length product fell from 944 mGy · cm (interquartile range [IQR], 567.3-1426.5 mGy · cm) to 156 mGy · cm (IQR, 99.2-265.0 mGy · cm). Although the proportion of prospectively triggered scans has increased, reductions in radiation dose have occurred independently of distribution of scan formats. In multiple regression that combined all groups, determinants of dose-length product were tube output, the number of cardiac cycles scanned, tube voltage, scan length, scan format, body mass index, phase width, and heart rate (adjusted R(2) = 0.85, P < .001). The proportion of nondiagnostic coronary artery segments was slightly increased in group 4 (2.9%; P < .01). While maintaining diagnostic quality in 320-multidetector row cardiac CT, the radiation dose has decreased substantially because of a combination of dose-reduction protocols and technical improvements. Continued minimization of radiation dose will increase the potential for cardiac CT to expand as a cardiac imaging modality. Copyright © 2013 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Percutaneous CT and Fluoroscopy-Guided Screw Fixation of Pathological Fractures in the Shoulder Girdle: Technical Report of 3 Cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garnon, Julien, E-mail: juliengarnon@gmail.com; Koch, Guillaume, E-mail: Guillaume.koch@gmail.com; Ramamurthy, Nitin, E-mail: Nitin-ramamurthy@hotmail.com

ObjectiveTo review our initial experience with percutaneous CT and fluoroscopy-guided screw fixation of pathological shoulder-girdle fractures.Materials and MethodsBetween May 2014 and June 2015, three consecutive oncologic patients (mean age 65 years; range 57–75 years) with symptomatic pathological shoulder-girdle fractures unsuitable for surgery and radiotherapy underwent percutaneous image-guided screw fixation. Fractures occurred through metastases (n = 2) or a post-ablation cavity (n = 1). Mechanical properties of osteosynthesis were adjudged superior to stand-alone cementoplasty in each case. Cannulated screws were placed under combined CT and fluoroscopic guidance with complementary radiofrequency ablation or cementoplasty to optimise local palliation and secure screw fixation, respectively, in two cases. Follow-up wasmore » undertaken every few weeks until mortality or most recent appointment.ResultsFour pathological fractures were treated in three patients (2 acromion, 1 clavicular, 1 coracoid). Mean size of associated lesion was 2.6 cm (range 1–4.5 cm). Technical success was achieved in all cases (100 %), without complications. Good palliation and restoration of mobility were observed in two cases at 2–3 months; one case could not be followed due to early post-procedural oncologic mortality.ConclusionPercutaneous image-guided shoulder-girdle osteosynthesis appears technically feasible with good short-term efficacy in this complex patient subset. Further studies are warranted to confirm these promising initial results.« less

Reduction in Chemotherapy Mixing Errors Using Six Sigma: Illinois CancerCare Experience.

PubMed

Heard, Bridgette; Miller, Laura; Kumar, Pankaj

2012-03-01

Chemotherapy mixing errors (CTMRs), although rare, have serious consequences. Illinois CancerCare is a large practice with multiple satellite offices. The goal of this study was to reduce the number of CTMRs using Six Sigma methods. A Six Sigma team consisting of five participants (registered nurses and pharmacy technicians [PTs]) was formed. The team had 10 hours of Six Sigma training in the DMAIC (ie, Define, Measure, Analyze, Improve, Control) process. Measurement of errors started from the time the CT order was verified by the PT to the time of CT administration by the nurse. Data collection included retrospective error tracking software, system audits, and staff surveys. Root causes of CTMRs included inadequate knowledge of CT mixing protocol, inconsistencies in checking methods, and frequent changes in staffing of clinics. Initial CTMRs (n = 33,259) constituted 0.050%, with 77% of these errors affecting patients. The action plan included checklists, education, and competency testing. The postimplementation error rate (n = 33,376, annualized) over a 3-month period was reduced to 0.019%, with only 15% of errors affecting patients. Initial Sigma was calculated at 4.2; this process resulted in the improvement of Sigma to 5.2, representing a 100-fold reduction. Financial analysis demonstrated a reduction in annualized loss of revenue (administration charges and drug wastage) from $11,537.95 (Medicare Average Sales Price) before the start of the project to $1,262.40. The Six Sigma process is a powerful technique in the reduction of CTMRs.

18F-FDG PET/CT Imaging of Hidradenocarcinoma Arising From Preexisting Hidradenoma of the Knee.

PubMed

Patel, Tirth V; Oldan, Jorge

2018-01-01

Malignant tumors of the sweat glands are exceedingly rare and aggressive tumors. We present here a case of a 60-year-old man with a malignant hidradenocarcinoma that developed in a background of preexisting benign hidradenoma on the lateral aspect of the knee that was initially resected, but rapidly recurred with associated inguinal lymphadenopathy. F-FDG PET/CT was performed as part of preoperative staging, which demonstrated abnormal inguinal lymph nodes and metastatic disease to the lungs. FDG PET/CT can play an invaluable role in the initial staging and follow-up of this rare malignancy.

IMPACT Observatory: tracking the evolution of clinical trial data sharing and research integrity.

PubMed

Krleža-Jerić, Karmela; Gabelica, Mirko; Banzi, Rita; Martinić, Marina Krnić; Pulido, Bibiana; Mahmić-Kaknjo, Mersiha; Reveiz, Ludovic; Šimić, Josip; Utrobičić, Ana; Hrgović, Irena

2016-10-15

The opening of research data is emerging thanks to the increasing possibilities of digital technology. The opening of clinical trial (CT) data is a part of this process, expected to have positive scientific, ethical, health, and economic impacts thus contributing to research integrity. The January 2016 proposal by the International Council of Medical Journal Editors triggered ample discussion about CT data sharing and reconfirmed the need for an ongoing assessment of its dynamics. The IMProving Access to Clinical Trials data (IMPACT) Observatory aims to play such a role, and assess the data sharing culture, policies, and practices of key players, the impact of their interventions on CTs, and contribute to a transformation of research. The objective of this paper is to present the IMPACT Observatory as well as share some of its preliminary findings. Methods include a scoping study of research, surveys, interviews, and an environmental scan of research data repositories. Our preliminary findings indicate that although opening of CT data has not yet been achieved, its evolution is encouraging. Initiatives by key players contribute to increasing of CT data sharing, and many barriers are shrinking or disappearing. The major barrier is the lack of data sharing standards, from preparing data for public sharing to its curatorship, findability and access. However, experiences accumulated by sharing CT data according to "upon request" or "open" mechanisms could inform the development of such standards. The Vivli, CORBEL-ECRIN and Open Trials projects are currently working in this direction.

A Cinematic Magnetic Resonance Imaging Study of Milk of Magnesia Laxative and an Antiflatulent Diet to Reduce Intrafraction Prostate Motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichol, Alan M.; Warde, Padraig R.; Lockwood, Gina A.

Purpose: To determine the reduction of prostate motion during a typical radiotherapy (RT) fraction from a bowel regimen comprising an antiflatulent diet and daily milk of magnesia. Methods and Materials: Forty-two patients with T1c-T2c prostate cancer voided the bladder and rectum before three cinematic magnetic resonance imaging scans obtained every 9 s for 9 min in a vacuum immobilization device. The MRIs were at baseline without bowel regimen (MRI-BL), before CT planning with bowel regimen (MRI-CT), and before a randomly assigned RT fraction (1-42) with bowel regimen (MRI-RT). A single observer tracked displacement of the posterior midpoint (PM) of themore » prostate. The primary endpoints were comparisons of the proportion of time that the PM was displaced >3 mm (PTPM3) from its initial position, and the secondary endpoints were comparisons of the reduction of initial rectal area, with and without the bowel regimen. Results: The mean rectal area was: 13.5 cm{sup 2} at MRI-BL, 12.7 cm{sup 2} at MRI-CT, and 12.3 cm{sup 2} at MRI-RT (MRI-BL vs. MRI-CT, p = 0.11; MRI-BL vs. MRI-CT, p = 0.07). Moving rectal gas alone (56%) and moving gas and stool (18%) caused 74% of intrafraction prostate motion. The PTPM3 was 11.3% at MRI-BL, 4.8% at MRI-CT, and 12.0% at MRI-RT (MRI-BL vs. MRI-CT, p = 0.12; MRI-BL vs. MRI-RT, p = 0.89). Conclusion: For subjects voiding their rectum before imaging, an antiflatulent diet and milk of magnesia laxative did not significantly reduce initial rectal area or intrafraction prostate motion.« less

Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by 18F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience.

PubMed

Masala, Salvatore; Schillaci, Orazio; Bartolucci, Alberto D; Calabria, Ferdinando; Mammucari, Matteo; Simonetti, Giovanni

2011-02-01

Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. (18)F-FDG positron emission tomography/computed tomography ((18)F-FDG PET/CT) is a single technique of imaging that provides in a "single step" both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUV(max)) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUV(max) value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation.

Evaluation of Prostate Cancer with 11C- and 18F-Choline PET/CT: Diagnosis and Initial Staging.

PubMed

Nitsch, Sascha; Hakenberg, Oliver W; Heuschkel, Martin; Dräger, Desiree; Hildebrandt, Guido; Krause, Bernd J; Schwarzenböck, Sarah M

2016-10-01

Early diagnosis and adequate staging are crucial for the choice of adequate treatment in prostate cancer (PC). Morphologic and functional imaging modalities, such as CT and MRI, have had limited accuracy in the diagnosis and nodal staging of PC. Molecular PET/CT imaging with 11 C- or 18 F-choline-labeled derivatives is increasingly being used, but its role in the diagnosis and initial staging of PC is controversial because of limitations in sensitivity and specificity for the detection of primary PC. For T staging, functional MRI is superior to 11 C- or 18 F-choline PET/CT. For N staging, 11 C- or 18 F-choline PET/CT can provide potentially useful information that may influence treatment planning. For the detection of bone metastases, 11 C- or 18 F-choline PET/CT has had promising results; however, in terms of cost-effectiveness, the routine use of 11 C- or 18 F-choline PET/CT is still debatable. 11 C- or 18 F-choline PET/CT might be used in high-risk PC before radiation treatment planning, potentially affecting this planning (e.g., regarding dose escalation). This review provides an overview of the diagnostic accuracy and limitations of 11 C- or 18 F-choline PET/CT in the diagnosis and staging of PC. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Abdomen/pelvis computed tomography in staging of pediatric Hodgkin Lymphoma: is it always necessary?

PubMed

Farruggia, Piero; Puccio, Giuseppe; Sala, Alessandra; Todesco, Alessandra; Terenziani, Monica; Mura, Rosamaria; D'Amico, Salvatore; Casini, Tommaso; Mosa, Clara; Pillon, Marta; Boaro, Maria Paola; Bottigliero, Gaetano; Burnelli, Roberta; Consarino, Caterina; Fedeli, Fausto; Mascarin, Maurizio; Perruccio, Katia; Schiavello, Elisabetta; Trizzino, Angela; Ficola, Umberto; Garaventa, Alberto; Rossello, Mario

2016-09-01

The purpose of the study was to determine if abdomen/pelvis computed tomography (CT) can be safety omitted in the initial staging of a subgroup of children affected by Hodgkin Lymphoma (HL). Every participating center of A.I.E.O.P (Associazione Italiana di Ematologia ed Oncologia Pediatrica) sent local staging reports of 18F-fluorodeoxyglucose positron emission tomography (PET) and abdominal ultrasound (US) along with digital images of staging abdomen/pelvis CT to the investigation center where the CT scans were evaluated by an experienced pediatric radiologist. The local radiologist who performed the US was unaware of local CT and PET reports (both carried out after US), and the reviewer radiologist examining the CT images was unaware of local US, PET and CT reports. A new abdominal staging of 123 patients performed on the basis of local US report, local PET report, and centralized CT report was then compared to a simpler staging based on local US and PET. No additional lesion was discovered by CT in patients with abdomen/pelvis negativity in both US and PET or isolated spleen positivity in US (or US and PET), and so it seems that in the initial staging, abdomen/pelvis CT can be safety omitted in about 1/2 to 2/3 of children diagnosed with HL. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Imaging infection with 18F-FDG-labeled leukocyte PET/CT: initial experience in 21 patients.

PubMed

Dumarey, Nicolas; Egrise, Dominique; Blocklet, Didier; Stallenberg, Bernard; Remmelink, Myriam; del Marmol, Véronique; Van Simaeys, Gaëtan; Jacobs, Frédérique; Goldman, Serge

2006-04-01

The aim of this study was to assess the feasibility and the potential role of PET/CT with (18)F-FDG-labeled autologous leukocytes in the diagnosis and localization of infectious lesions. Twenty-one consecutive patients with suspected or documented infection were prospectively evaluated with whole-body PET/CT 3 h after injection of autologous (18)F-FDG-labeled leukocytes. Two experienced nuclear medicine physicians who were unaware of the clinical end-diagnosis reviewed all PET/CT studies. A visual score (0-3)-according to uptake intensity-was used to assess studies. The results of PET/CT with (18)F-FDG-labeled white blood cell ((18)F-FDG-WBC) assessment were compared with histologic or biologic diagnosis in 15 patients and with clinical end-diagnosis after complete clinical work-up in 6 patients. Nine patients had fever of unknown etiology, 6 patients had documented infection but with unknown extension of the infectious disease, 4 patients had a documented infection with unfavorable evolution, and 2 patients had a documented infection with known extension. The best trade-off between sensitivity and specificity was obtained when a visual score of >or=2 was chosen to identify increased tracer uptake as infection. With this threshold, sensitivity, specificity, and accuracy were each 86% on a patient-per-patient basis and 91%, 85%, and 90% on a lesion-per-lesion basis. In this small group of patients, the absence of areas with increased WBC uptake on WBC PET/CT had a 100% negative predictive value. Hybrid (18)F-FDG-WBC PET/CT was found to have a high sensitivity and specificity for the diagnosis of infection. It located infectious lesions with a high precision. In this small series, absence of areas with increased uptake virtually ruled out the presence of infection. (18)F-FDG-WBC PET/CT for infection detection deserves further investigation in a larger prospective series.

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

PubMed Central

Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Results Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Conclusion Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung. PMID:21228937

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

PubMed

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Pediatric CT Scans

Cancer.gov

The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

The impact of 18 F-FET PET-CT on target definition in image-guided stereotactic radiotherapy in patients with skull base lesions.

PubMed

Badakhshi, Harun; Graf, Reinhold; Prasad, Vikas; Budach, Volker

2014-06-25

18 F-fluoro-ethyl-tyrosine PET is gaining more indications in the field of oncology. We investigated the potentials of usage of FET-PET/CT in addition to MRI for definition of gross tumor volume (GTV) in stereotactic radiotherapy of lesions of skull base. We included in a prospective setting 21 cases. An MRI was performed, completed by FET PET/CT. Different GTV's were defined based on respective imaging tools: 1. GTVMRI, 2. GTV MRI /CT, 3. GTV composit (1 + 2), and GTVPET = GTV Boost. Lesions could be visualised by MRI and FET-PET/CT in all patients. FET tracer enhancement was found in all cases. Skull base infiltration by these lesions was observed by MRI, CT (PET/CT) and FET-PET (PET/CT) in all patients. Totally, brain tissue infiltration was seen in 10 patients. While, in 7 (out 10) cases, MRI and CT (from PET/CT) were indicating brain infiltration, FET-PET could add additional information regarding infiltrative behaviour: in 3 (out 10) patients, infiltration of the brain was displayed merely in FET-PET. An enlargement of GTVMRI/CT due to the FET-PET driven information, which revealed GTVcomposite , was necessary in 7 cases,. This enlargement was significant by definition (> 10% of GTVMRI/CT). The mean PET-effect on GTV counted for 1 ± 4 cm3. The restricted boost fields were based mainly on the GTVPET volume. In mean, about 8.5 cm3 of GTVMRI/CT, which showed no FET uptake, were excluded from target volume. GTV boost driven by only-PET-activity, was in mean by 33% smaller than the initial large treatment field, GTV composite, for those cases received boost treatment. FET-PET lead to significant (>10%) changes in the initial treatment fields in 11/21 patients and showed additional tumour volume relevant for radiation planning in 6/21 cases, and led to a subsequent decrease of more than 10% of the initial volumes for the boost fields. The implementation of FET PET into the planning procedures showed a benefit in terms of accurate definition of skull base lesions as targets for Image-guided stereotactic Radiotherapy. This has to be investigated prospectively in larger cohorts.

Management of large primary spontaneous pneumothorax in children: radiological guidance, surgical intervention and proposed guideline.

PubMed

Soccorso, Giampiero; Anbarasan, Ravindar; Singh, Michael; Lindley, Richard M; Marven, Sean S; Parikh, Dakshesh H

2015-12-01

Primary spontaneous pneumothorax (PSP) is managed in accordance with the adult British Thoracic Society (BTS) guidelines due to lack of paediatric evidence and consensus. We aim to highlight the differences and provide a best practice surgical management strategy for PSP based on experience of two major paediatric surgical centres. Retrospective review of PSP management and outcomes from two UK Tertiary Paediatric hospitals between 2004 and 2015. Fifty children with 55 PSP (5 bilateral) were referred to our Thoracic Surgical Services after initial management: 53% of the needle aspirations failed. Nine children (20%) were associated with visible bullae on the initial chest X-ray. Forty-nine children were assessed with computed tomography scan (CT). Apical emphysematous-like changes (ELC) were identified in 37 children (75%). Ten children had also bullae in the asymptomatic contralateral lungs (20%). In two children (4%), CT demonstrated other lung lesions: a tumour of the left main bronchus in one child; a multi-cystic lesion of the right middle lobe in keeping with a congenital lung malformation in another child. Contralateral asymptomatic ELC were detected in 20% of the children: of those 40% developed pneumothorax within 6 months. Best surgical management was thoracoscopic staple bullectomy and pleurectomy with 11% risk of recurrence. Histology confirmed ELC in 100% of the apical lung wedge resections even in those apexes apparently normal at the time of thoracoscopy. Our experience suggests that adult BTS guidelines are not applicable to children with large PSP. Needle aspiration is ineffective. We advocate early referral to a Paediatric Thoracic Service. We suggest early chest CT scan to identify ELC, for counselling regarding contralateral asymptomatic ELC and to rule out secondary pathological conditions causing pneumothorax. In rare instance if bulla is visible on presenting chest X-ray, thoracoscopy could be offered as primary option.

Effects of psychotherapies for posttraumatic stress disorder on sleep disturbances: Results from a randomized clinical trial.

PubMed

Woodward, Elizabeth; Hackmann, Ann; Wild, Jennifer; Grey, Nick; Clark, David M; Ehlers, Anke

2017-10-01

The effectiveness and mechanisms of psychotherapies for posttraumatic stress disorder (PTSD) in treating sleep problems is of interest. This study compared the effects of a trauma-focused and a non-trauma-focused psychotherapy on sleep, to investigate whether 1) sleep improves with psychotherapy for PTSD; 2) the degree of sleep improvement depends on whether the intervention is trauma or nontrauma-focused; 3) the memory-updating procedure in cognitive therapy for PTSD (CT-PTSD) is associated with sleep improvements; 4) initial sleep duration affects PTSD treatment outcome; and 5) which symptom changes are associated with sleep duration improvements. Self-reported sleep was assessed during a randomized controlled trial (Ehlers et al., 2014) comparing CT-PTSD (delivered weekly or intensively over 7-days) with emotion-focused supportive therapy, and a waitlist. Sleep duration was reported daily in sleep diaries during intensive CT-PTSD. CT-PTSD led to greater increases in sleep duration (55.2 min) and reductions in insomnia symptoms and nightmares than supportive therapy and the waitlist. In intensive CT-PTSD, sleep duration improved within 7 days, and sleep diaries indicated a 40-min sleep duration increase after updating trauma memories. Initial sleep duration was not related to CT-PTSD treatment outcome when initial PTSD symptom severity was controlled. The results suggest that trauma-focused psychotherapy for PTSD is more effective than nontrauma-focused therapy in improving self-reported sleep, and that CT-PTSD can still be effective in the presence of reduced sleep duration. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Impact of initial FDG-PET/CT and serum-free light chain on transformation of conventionally defined solitary plasmacytoma to multiple myeloma.

PubMed

Fouquet, Guillemette; Guidez, Stéphanie; Herbaux, Charles; Van de Wyngaert, Zoé; Bonnet, Sarah; Beauvais, David; Demarquette, Hélène; Adib, Salim; Hivert, Bénédicte; Wemeau, Mathieu; Berthon, Céline; Terriou, Louis; Coiteux, Valérie; Macro, Margaret; Decaux, Olivier; Facon, Thierry; Huglo, Damien; Leleu, Xavier

2014-06-15

Solitary plasmacytoma (SP) is a localized proliferation of monoclonal plasma cells in either bone or soft tissue, without evidence of multiple myeloma (MM), and whose prognosis is marked by a high risk of transformation to MM. We studied the impact of FDG-PET/CT (2[18F]fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography) on the risk of transformation of SP to overt MM among other markers in a series of 43 patients diagnosed with SP. Median age was 57.5 years; 48% of patients had an abnormal involved serum-free light chain (sFLC) value, and 64% had an abnormal sFLC ratio at diagnosis. Thirty-three percent had two or more hypermetabolic lesions on initial PET/CT, and 20% had two or more focal lesions on initial MRI. With a median follow-up of 50 months, 14 patients transformed to MM with a median time (TTMM) of 71 months. The risk factors that significantly shortened TTMM at diagnosis were two or more hypermetabolic lesions on PET/CT, abnormal sFLC ratio and involved sFLC, and to a lesser extent at completion of treatment, absence of normalized involved sFLC and PET/CT or MRI. In a multivariate analysis, abnormal initial involved sFLC [OR = 10; 95% confidence interval (CI), 1-87; P = 0.008] and PET/CT (OR = 5; 95% CI, 0-9; P = 0.032) independently shortened TTMM. An abnormal involved sFLC value and the presence of at least two hypermetabolic lesions on PET/CT at diagnosis of SP were the two predictors of early evolution to myeloma in our series. This data analysis will need confirmation in a larger study, and the study of these two risk factors may lead to a different management of patients with SP in the future. . ©2014 American Association for Cancer Research.

Radiological Findings in a case of Advance staged Mesothelioma

PubMed Central

Aziz, Fahad

2009-01-01

Chest X Ray is the initial screening test for the mesothelioma like all other the chest diseases. But computed tomography (CT) is the imaging technique of choice for charactering pleural masses. CT also gives important information regarding invasion of the chest wall and surrounding structures. Certain CT features help differentiate benign from malignant processes. This short article highlights the salient CT appearance of mesothelioma; the most common pleural tumor. PMID:22263002

EPA Initiates Rulemaking to Revise Certain Aspects of the Agricultural Worker Protection Standard (WPS) and the Certification and Training (C&T) Rule; Implementation Dates for WPS and C&T Remain In Effect

EPA Pesticide Factsheets

EPA has initiated a process to revise certain requirements in the WPS. By the end of FY2018, EPA expects to publish a Notice of Proposed Rulemaking to solicit public input on proposed revisions to the WPS requirements for minimum ages, designated represen

The effect of initial resident fluid saturation on the interaction between resident and infiltrating fluids in porous media

NASA Astrophysics Data System (ADS)

Hsu, S. Y.; Chen, H.; Huang, Q. Z.; Lee, T. Y.; Chiu, Y.; Chang, L. C.; Lamorski, K.; Sławiński, C.; Tsao, C. W.

2017-12-01

The interplay between resident ("old") fluid already in the vadose zone and infiltrating ("new") fluid was examined with micromodel experiments. The geometric patterns of the micromodels are based on a pore doublet and a 2D pore geometry of a sand-packing soil scanned by Micro X-Ray CT. We studied the old and new fluid interaction during imbibition process subject to different evaporation times (different the initial old fluid saturations). The results found that, in the pore-doublet micromodel experiment, the old fluid was mixed and displaced by the new fluid, and an increase in the initial old fluid saturation led to a decrease in the amount of old fluid displaced by the new fluid. On the other hand, the most of the old fluid in the micromodel of 2D sand-packing pore geometry was displaced by and mixed with the new fluid. However, a small amount of the initial old fluid that occupied pore throats remained untouched by the new fluid due to the air blockage. The amount of untouched old fluid increased as the initial old fluid saturation decreased. Our finding reveals the effect of pore geometry and inital old fluid distribution on the interaction between resident and infiltrating fluids.

SU-G-TeP2-11: Initial Evaluation of a Novel Split-Filter Dual-Energy CT for Use in Radiation Oncology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, J; Huang, J; Szczykutowicz, T

2016-06-15

Purpose: To perform an initial evaluation of a novel split-filter dual-energy CT (DECT) system with the goal of understanding the clinical utility and limitations of the system for radiation therapy. Methods: Several phantoms were imaged using the split-filter DECT technique on the Siemens Edge CT scanner using a range of clinically-relevant doses. The optimum-contrast reconstruction, the mixed reconstruction, and the monoenergetic reconstructions (ranging from 40 keV to 190 keV) were evaluated. Each image was analyzed for CT number accuracy, uniformity, noise, low-contrast visibility (LCV), spatial resolution and geometric distortion. For comparison purposes, all parameters were evaluated on 120 kVp single-energymore » CT (SECT) scans used for treatment planning, as well as, a sequential-scan DECT technique for corresponding doses. Results: For all DECT reconstructions no observable geometric distortion was found. Both the optimal-contrast and mixed images demonstrated slight improvements in LCV and noise when compared to the SECT, and slight reductions in CT number accuracy and spatial resolution. The CT numbers trended as expected for the monoenergetic reconstructions, with CT number accuracy within 50 HU for materials of density <2 g/cm3. Spatial resolution increased with energy, and for monoenergetic reconstructions >70 keV the spatial resolution exceeded that of the SECT. The noise in the monoenergetic reconstructions increased with decreasing energy. Thus, the image uniformity, signal-to-noise ratio and LCV were diminished at lower energies (70 keV). Applying iterative reconstruction techniques to the low-energy images reduced noise and improved LCV. The signal-to-noise ratio was stable for energies >100 keV. Conclusion: The initial commissioning of the novel split-filter DECT technology demonstrated favorable results for clinical implementation. The mixed reconstruction showed potential as a replacement for the treatment planning SECT. The image parameters for the monoenergetic reconstructions varied appropriately with energy. This work provides an initial understanding of the limitations and potential applications for monoenergetic imaging.« less

Results of initial low-dose computed tomographic screening for lung cancer.

PubMed

Church, Timothy R; Black, William C; Aberle, Denise R; Berg, Christine D; Clingan, Kathy L; Duan, Fenghai; Fagerstrom, Richard M; Gareen, Ilana F; Gierada, David S; Jones, Gordon C; Mahon, Irene; Marcus, Pamela M; Sicks, JoRean D; Jain, Amanda; Baum, Sarah

2013-05-23

Lung cancer is the largest contributor to mortality from cancer. The National Lung Screening Trial (NLST) showed that screening with low-dose helical computed tomography (CT) rather than with chest radiography reduced mortality from lung cancer. We describe the screening, diagnosis, and limited treatment results from the initial round of screening in the NLST to inform and improve lung-cancer-screening programs. At 33 U.S. centers, from August 2002 through April 2004, we enrolled asymptomatic participants, 55 to 74 years of age, with a history of at least 30 pack-years of smoking. The participants were randomly assigned to undergo annual screening, with the use of either low-dose CT or chest radiography, for 3 years. Nodules or other suspicious findings were classified as positive results. This article reports findings from the initial screening examination. A total of 53,439 eligible participants were randomly assigned to a study group (26,715 to low-dose CT and 26,724 to chest radiography); 26,309 participants (98.5%) and 26,035 (97.4%), respectively, underwent screening. A total of 7191 participants (27.3%) in the low-dose CT group and 2387 (9.2%) in the radiography group had a positive screening result; in the respective groups, 6369 participants (90.4%) and 2176 (92.7%) had at least one follow-up diagnostic procedure, including imaging in 5717 (81.1%) and 2010 (85.6%) and surgery in 297 (4.2%) and 121 (5.2%). Lung cancer was diagnosed in 292 participants (1.1%) in the low-dose CT group versus 190 (0.7%) in the radiography group (stage 1 in 158 vs. 70 participants and stage IIB to IV in 120 vs. 112). Sensitivity and specificity were 93.8% and 73.4% for low-dose CT and 73.5% and 91.3% for chest radiography, respectively. The NLST initial screening results are consistent with the existing literature on screening by means of low-dose CT and chest radiography, suggesting that a reduction in mortality from lung cancer is achievable at U.S. screening centers that have staff experienced in chest CT. (Funded by the National Cancer Institute; NLST ClinicalTrials.gov number, NCT00047385.).

Organic soil production from urban soil, spent mushroom substrate, and other additives

NASA Astrophysics Data System (ADS)

Pham, Nhung Thi Ha

2017-09-01

In recent years, spent mushroom substrate (SMS) is becoming the huge problem in environmental pollution issues from mushroom production. However, SMS is also a nutrient-rich ogranic material with available nutrients and high porosity. Therefore, the value of products made from SMS should be exploited to take full advantage of agricultural by-product, support organic agriculture development without environmental pollution. The research has built 5 experimental formulas (4 mixed formulas and 1 control formulas with only urban soil). The analysis results of soil samples from mixed formulas and the control formula witness a significant increase in moisture and OM of mixed formulas (moisture from 36-42%, OM from 5.5-6.9%) after 20 treatment days, and N-P-K contents are also improved remarkably. 60 days later, soil nutrients in mixed formulas continue to rise, with highest OM (8.679%) at CT1; N (0.154%) at CT4; K2O (0,698%) and P2O5 (0,172%) at CT3, in addition, heavy metal contents in all formulas are under standard limit. Synthetic assessment of all norms indicates that the best organic soil product comes from CT3. The pak choi planting experiments are performed show that the growth of plants cultivated on organic soil products made from mixed formulas are much better than plants are grown on initially soil, and they also have no pestilent insect. Specially, pak choi planted on organic soil from CT3 have sharp developing with excellent tolerance ability, quantity and area of leaves are high. Thus, CT3 is the most suitable formula to increase soil nutrients, to solve spent mushroom subtrate streament problems after harvest, and for sustainable agricultural development.

Real-time intraprocedural 18F-FDG PET/CT-guided biopsy using automated robopsy arm (ARA) in the diagnostic evaluation of thoracic lesions with prior inconclusive biopsy results: initial experience from a tertiary health care centre.

PubMed

Radhakrishnan, Renjith Kalathoorakathu; Mittal, Bhagwant Rai; Gorla, Arun Kumar Reddy; Basher, Rajender Kumar; Sood, Ashwani; Bal, Amanjit; Kalra, Naveen; Khandelwal, Niranjan; Singh, Navneet; Behera, Digambar

2017-12-01

The aim of this study was to assess the feasibility and appraise the diagnostic utility of real time 18 F-FDG PET/CT-guided biopsy under automated robopsy arm (ARA) guidance for the evaluation of thoracic lesions with prior inconclusive biopsy results. PET/CT-guided biopsy of thoracic lesions was performed in patients who had at least one previous inconclusive biopsy. A total of 25 patients (male:female-18 males, 7 females; age: range, 13-75; mean, 53.7) were included in this study. All these patients underwent percutaneous needle biopsies under real-time PET/CT guidance using ARA (ROBIO-EX, Perfint healthcare Pvt Ltd, Chennai, India) needle navigation technique. Histopathology and clinical follow-up results were reviewed for assessing the accuracy of procedures. Adequate representative tissue sample could be retrieved in all the patients. No major procedure-related complications were encountered in any patient. Of the 25 procedures, 21 lesions were positive for malignancy and benign findings were observed in the other 4 lesions on histopathology. None of the patients required further biopsy in arriving at a final diagnosis. Overall diagnostic yield of the procedure was 100%. Real time 18 F-FDG PET/CT guidance for percutaneous biopsies of lung and mediastinal lesions is a feasible technique with potential utility in patients with previous inconclusive biopsy results. Advances in knowledge: 18 F-FDG PET/CT guidance reduces the sampling errors by specifically targeting areas of viability and avoiding necrosis/atelectasis. A navigational tool like ARA is thought to help in accurately targeting these areas.

Can SNOMED CT be squeezed without losing its shape?

PubMed

López-García, Pablo; Schulz, Stefan

2016-09-21

In biomedical applications where the size and complexity of SNOMED CT become problematic, using a smaller subset that can act as a reasonable substitute is usually preferred. In a special class of use cases-like ontology-based quality assurance, or when performing scaling experiments for real-time performance-it is essential that modules show a similar shape than SNOMED CT in terms of concept distribution per sub-hierarchy. Exactly how to extract such balanced modules remains unclear, as most previous work on ontology modularization has focused on other problems. In this study, we investigate to what extent extracting balanced modules that preserve the original shape of SNOMED CT is possible, by presenting and evaluating an iterative algorithm. We used a graph-traversal modularization approach based on an input signature. To conform to our definition of a balanced module, we implemented an iterative algorithm that carefully bootstraped and dynamically adjusted the signature at each step. We measured the error for each sub-hierarchy and defined convergence as a residual sum of squares <1. Using 2000 concepts as an initial signature, our algorithm converged after seven iterations and extracted a module 4.7 % the size of SNOMED CT. Seven sub-hierarhies were either over or under-represented within a range of 1-8 %. Our study shows that balanced modules from large terminologies can be extracted using ontology graph-traversal modularization techniques under certain conditions: that the process is repeated a number of times, the input signature is dynamically adjusted in each iteration, and a moderate under/over-representation of some hierarchies is tolerated. In the case of SNOMED CT, our results conclusively show that it can be squeezed to less than 5 % of its size without any sub-hierarchy losing its shape more than 8 %, which is likely sufficient in most use cases.

Combined endeavor of Neutrosophic Set and Chan-Vese model to extract accurate liver image from CT scan.

PubMed

Siri, Sangeeta K; Latte, Mrityunjaya V

2017-11-01

Many different diseases can occur in the liver, including infections such as hepatitis, cirrhosis, cancer and over effect of medication or toxins. The foremost stage for computer-aided diagnosis of liver is the identification of liver region. Liver segmentation algorithms extract liver image from scan images which helps in virtual surgery simulation, speedup the diagnosis, accurate investigation and surgery planning. The existing liver segmentation algorithms try to extort exact liver image from abdominal Computed Tomography (CT) scan images. It is an open problem because of ambiguous boundaries, large variation in intensity distribution, variability of liver geometry from patient to patient and presence of noise. A novel approach is proposed to meet challenges in extracting the exact liver image from abdominal CT scan images. The proposed approach consists of three phases: (1) Pre-processing (2) CT scan image transformation to Neutrosophic Set (NS) and (3) Post-processing. In pre-processing, the noise is removed by median filter. The "new structure" is designed to transform a CT scan image into neutrosophic domain which is expressed using three membership subset: True subset (T), False subset (F) and Indeterminacy subset (I). This transform approximately extracts the liver image structure. In post processing phase, morphological operation is performed on indeterminacy subset (I) and apply Chan-Vese (C-V) model with detection of initial contour within liver without user intervention. This resulted in liver boundary identification with high accuracy. Experiments show that, the proposed method is effective, robust and comparable with existing algorithm for liver segmentation of CT scan images. Copyright © 2017 Elsevier B.V. All rights reserved.

Anteroposterior chest radiograph vs. chest CT scan in early detection of pneumothorax in trauma patients.

PubMed

Omar, Hesham R; Mangar, Devanand; Khetarpal, Suneel; Shapiro, David H; Kolla, Jaya; Rashad, Rania; Helal, Engy; Camporesi, Enrico M

2011-09-27

Pneumothorax is a common complication following blunt chest wall trauma. In these patients, because of the restrictions regarding immobilization of the cervical spine, Anteroposterior (AP) chest radiograph is usually the most feasible initial study which is not as sensitive as the erect chest X-ray or CT chest for detection of a pneumothorax. We will present 3 case reports which serve for better understanding of the entity of occult pneumothorax. The first case is an example of a true occult pneumothorax where an initial AP chest X-ray revealed no evidence of pneumothorax and a CT chest immediately performed revealed evidence of pneumothorax. The second case represents an example of a missed rather than a truly occult pneumothorax where the initial chest radiograph revealed clues suggesting the presence of pneumothorax which were missed by the reading radiologist. The third case emphasizes the fact that "occult pneumothorax is predictable". The presence of subcutaneous emphesema and pulmonary contusion should call for further imaging with CT chest to rule out pneumothorax. Thoracic CT scan is therefore the "gold standard" for early detection of a pneumothorax in trauma patients. This report aims to sensitize readers to the entity of occult pneumothorax and create awareness among intensivists and ER physicians regarding the proper diagnosis and management.

The Beck Initiative: Training School-Based Mental Health Staff in Cognitive Therapy

ERIC Educational Resources Information Center

Creed, Torrey A.; Jager-Hyman, Shari; Pontoski, Kristin; Feinberg, Betsy; Rosenberg, Zachary; Evans, Arthur; Hurford, Matthew O.; Beck, Aaron T.

2013-01-01

A growing literature supports cognitive therapy (CT) as an efficacious treatment for youth struggling with emotional or behavioral problems. Recently, work in this area has extended the dissemination of CT to school-based settings. The current study has two aims: 1) to examine the development of therapists' knowledge and skills in CT, an…

[Tuberculous otomastoiditis: advantage of MRI in the treatment survey].

PubMed

Moya, Plana A; Malinvaud, D; Mimoun, M; Huart, J; Bonfils, P

2008-01-01

Mycobacterium tuberculosis is a rare cause of otomastoiditis, accounting for less than a percent of chronic otitis media. The diagnosis is difficult and typically delayed because most physicians are unfamiliar with its presenting features and special laboratory requirements. Such delayed diagnosis leads to delayed treatment onset, and thus, increases complications frequency as irreversible hearing loss, facial palsy or meningo-encephalitis complications. Moreover non specific CT findings do not allow any accurate evaluation of inner ear lesions initially and under treatment. We described the first case of MRI of tuberculous mastoiditis and the evolution over a 2-years follow-up period. A patient with a clinical history of chronic otorrhea, resistant to conventional therapy, was referred to our department. CT and MRI permitted to describe the initial lesions and to appreciate the medical treatment efficiency (in order to perform surgery in case of failure or complications). Under medical treatment, MRI showed abscess volume decrease at three months while CT was still unchanged. Remineralization only was observed on CT at 12 months. The patient's healing was obtained after 15 months of antituberculous medication. MRI has the advantage over CT to demonstrate directly abscess collections that superimposed to areas of bone destructions within the temporal bone. Initially, MRI allows an accurate evaluation of abscess collections and possible meningo-encephalitis complications. Moreover, MRI precises earlier than CT the improvement of lesions and the efficacy of medical treatment, and thus, permitting us to postpone surgery where it is unnecessary.

PET/CT versus bone marrow biopsy in the initial evaluation of bone marrow infiltration in various pediatric malignancies.

PubMed

Zapata, Claudia P; Cuglievan, Branko; Zapata, Catalina M; Olavarrieta, Raquel; Raskin, Scott; Desai, Kavita; De Angulo, Guillermo

2018-02-01

Accurate staging is essential in the prognosis and management of pediatric malignancies. Current protocols require screening for marrow infiltration with bone marrow biopsy (BMB) as the gold standard. Positron emission tomography-computed tomography (PET-CT) is commonly used to complete the staging process and can also be used to evaluate marrow infiltration. To compare PET-CT and BMB in the initial evaluation of bone marrow infiltration in pediatric cancers. We retrospectively reviewed new cases of EWS, rhabdomyosarcoma, neuroblastoma, and lymphoma diagnosed between January 2009 and October 2014. Each case had undergone both PET-CT and BMB within 4 weeks without treatment in the interval between screening modalities. We reviewed 69 cases. Bone marrow infiltration was demonstrated in 34 cases by PET-CT and in 18 cases by BMB. The sensitivity and negative predictive value of PET-CT were both 100%. Interestingly, the cases in which infiltration was not detected on BMB had an abnormal marrow signal on PET-CT focal or distant to iliac crest. PET-CT has a high sensitivity when assessing marrow infiltration in pediatric malignancies. Advances in radiologic modalities may obviate the use of invasive, painful, and costly procedures like BMB. Furthermore, biopsy results are limited by insufficient tissue or the degree of marrow infiltration (diffuse vs. focal disease). PET-CT can improve the precision of biopsy when used as a guiding tool. This study proposes the use of PET-CT as first-line screening for bone marrow infiltration to improve the accuracy of staging in new diagnoses. © 2017 Wiley Periodicals, Inc.

CT-Guided Percutaneous Drainage of Infected Collections Due to Gastric Leak After Sleeve Gastrectomy for Morbid Obesity: Initial Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelogrigoris, M., E-mail: kelogre.mic@hotmail.com; Sotiropoulou, E.; Stathopoulos, K.

This study was designed to evaluate the efficacy and safety of computed tomography (CT)-guided drainage in treating infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity. From January 2007 to June 2009, 21 patients (9 men and 12 women; mean age, 39.2 (range, 26-52) years) with infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity underwent image-guided percutaneous drainage. All procedures were performed using CT guidance and 8- to 12-Fr pigtail drainage catheters. Immediate technical success was achieved in all 21 infected collections. In 18 of 21 collections, we obtained progressive shrinkagemore » of the collection with consequent clinical success (success rate 86%). In three cases, the abdominal fluid collection was not resolved, and the patients were reoperated. Among the 18 patients who avoided surgery, 2 needed replacement of the catheter due to obstruction. No major complications occurred during the procedure. The results of our study support that CT-guided percutaneous drainage is an effective and safe method to treat infected abdominal fluid collections due to gastric leak in patients who had previously underwent laparoscopic sleeve gastrectomy for morbid obesity. It may be considered both as a preparatory step for surgery and a valuable alternative to open surgery. Failure of the procedure does not, however, preclude a subsequent surgical operation.« less

Lung cancer screening with low-dose helical CT in Korea: experiences at the Samsung Medical Center.

PubMed

Chong, Semin; Lee, Kyung Soo; Chung, Myung Jin; Kim, Tae Sung; Kim, Hojoong; Kwon, O Jung; Choi, Yoon-Ho; Rhee, Chong H

2005-06-01

To determine overall detection rates of lung cancer by low-dose CT (LDCT) screening and to compare histopathologic and imaging differences of detected cancers between high- and low-risk groups, this study included 6,406 asymptomatic Korean adults with >or=45 yr of age who underwent LDCT for lung cancer screening. All were classified into high- (>or=20 pack-year smoking; 3,353) and low-risk (3,053; <20 pack-yr smoking and non-smokers) groups. We compared CT findings of detected cancers and detection rates between high- and low-risk. At initial CT, 35% (2,255 of 6,406) had at least one or more non-calcified nodule. Lung cancer detection rates were 0.36% (23 of 6,406). Twenty-one non-small cell lung cancers appeared as solid (n=14) or ground-glass opacity (GGO) (n=7) nodules. Cancer likelihood was higher in GGO nodules than in solid nodules (p<0.01). Fifteen of 23 cancers occurred in high-risk group and 8 in low-risk group (p=0.215). Therefore, LDCT screening help detect early stage of lung cancer in asymptomatic Korean population with detection rate of 0.36% on a population basis and may be useful for discovering early lung cancer in low-risk group as well as in high-risk group.

False Positive Positron Emission Tomography / Computed Tomography Scans in Treated Head and Neck Cancers

PubMed Central

Cheung, Michael K; Ong, Shawn Y; Goyal, Uma; Wertheim, Betsy C; Hsu, Charles C

2017-01-01

Objective Positron emission tomography/computed tomography (PET/CT) imaging for head and neck cancers (HNC) is commonly utilized for post-treatment assessment. Though PET/CT in this setting has been reported to have high negative predictive values (> 90%), positive predictive values have been reported at approximately 50%, leading to high rates of false positivity (FP) and troubling management decisions for both patient and practitioner. The objective of this study was to identify patient, disease, treatment and imaging factors that might be associated with a higher likelihood of FP on initial post-treatment PET/CT imaging for patients treated for HNC.  Materials and methods A retrospective chart review was performed on 84 patients treated for HNC who received radiation therapy (RT) as part of their overall management from October 2005 to August 2013. Of the patients screened, 19 were found to have mucosally based squamous cell carcinoma (SCC) with positive initial post-treatment PET/CT studies (23%). Fisher’s exact test was used to analyze the association between categorical variables and FP, including patient's gender, disease laterality, primary tumor site and stage, nodal and overall stage, high dose RT fraction size, number of RT fractions completed, total RT dose, biologically effective dose and timing of PET/CT acquisition. Wilcoxon rank-sum test was used to analyze the association between continuous variables and FP, including patient age, total elapsed days of RT, an amount of infused fluorodeoxyglucose 18F-FDG, pre-PET/CT serum glucose levels, and maximum standardized uptake value SUVmax. Statistically significant findings were those that were deemed p <0.05. Results Among patients with positive initial post-treatment PET/CT scans for treated HNC, there was a lower proportion of higher primary disease stage associated with FP versus true positivity (T-stage 3-4: 20 vs 78%, respectively, p=0.023). We also discovered that 50% of patients that underwent confirmation for FP findings suffered serious complications as a direct consequence of invasive exploratory procedures. Conclusions Although PET/CT is known for its exceptional negative predictive value (> 90%) in the post-treatment setting for HNC, high rates of FP remains a clinical challenge. Our study suggests that tumor stage (T-stage) may impact FP rates in positive initial post-treatment PET/CT scans. We recommend careful multidisciplinary discussion regarding positive PET/CT studies in the post-treatment setting for HNC, particularly if invasive intervention is considered. PMID:28497009

Characteristics of Rib Fractures in Child Abuse-The Role of Low-Dose Chest Computed Tomography.

PubMed

Sanchez, Thomas R; Grasparil, Angelo D; Chaudhari, Ruchir; Coulter, Kevin P; Wootton-Gorges, Sandra L

2018-02-01

Our aim is to describe the radiologic characteristics of rib fractures in clinically diagnosed cases of child abuse and suggest a complementary imaging for radiographically occult injuries in highly suspicious cases of child abuse. Retrospective analysis of initial and follow-up skeletal surveys and computed tomography (CT) scans of 16 patients younger than 12 months were reviewed after obtaining approval from our institutional review board. The number, location, displacement, and age of the rib fractures were recorded. Out of a total 105 rib fractures, 84% (87/105) were detected on the initial skeletal survey. Seventeen percent (18/105) were seen only after follow-up imaging, more than half of which (11/18) were detected on a subsequent CT. Majority of the fractures were posterior (43%) and anterior (30%) in location. An overwhelming majority (96%) of the fractures are nondisplaced. Seventeen percent of rib fractures analyzed in the study were not documented on the initial skeletal survey. Majority of fractures are nondisplaced and located posteriorly or anteriorly, areas that are often difficult to assess especially in the acute stage. The CT scan is more sensitive in evaluating these types of fractures. Low-dose chest CT can be an important imaging modality for suspicious cases of child abuse when initial radiographic findings are inconclusive.

Mutual influences between partners' hormones shape conflict dialog and relationship duration at the initiation of romantic love.

PubMed

Schneiderman, Inna; Kanat-Maymon, Yaniv; Zagoory-Sharon, Orna; Feldman, Ruth

2014-01-01

Early-stage romantic love involves reorganization of neurohormonal systems and behavioral patterns marked by mutual influences between the partners' physiology and behavior. Guided by the biobehavioral synchrony conceptual frame, we tested bidirectional influences between the partners' hormones and conflict behavior at the initiation of romantic love. Participants included 120 new lovers (60 couples) and 40 singles. Plasma levels of five affiliation and stress-related hormones were assessed: oxytocin (OT), prolactin (PRL), testosterone (T), cortisol (CT), and dehydroepiandrosterone sulfate (DHEAS). Couples were observed in conflict interaction coded for empathy and hostility. CT and DHEAS showed direct actor effects: higher CT and DHEAS predicted greater hostility. OT showed direct partner effects: individuals whose partners had higher OT showed greater empathy. T and CT showed combined actor-partner effects. High T predicted greater hostility only when partner also had high T, but lower hostility when partner had low T. Similarly, CT predicted low empathy only in the context of high partner's CT. Mediational analysis indicated that combined high CT in both partners was associated with relationship breakup as mediated by decrease in empathy. Findings demonstrate the mutual influences between hormones and behavior within an attachment bond and underscore the dynamic, co-regulated, and systemic nature of pair-bond formation in humans.

Automatic co-segmentation of lung tumor based on random forest in PET-CT images

NASA Astrophysics Data System (ADS)

Jiang, Xueqing; Xiang, Dehui; Zhang, Bin; Zhu, Weifang; Shi, Fei; Chen, Xinjian

2016-03-01

In this paper, a fully automatic method is proposed to segment the lung tumor in clinical 3D PET-CT images. The proposed method effectively combines PET and CT information to make full use of the high contrast of PET images and superior spatial resolution of CT images. Our approach consists of three main parts: (1) initial segmentation, in which spines are removed in CT images and initial connected regions achieved by thresholding based segmentation in PET images; (2) coarse segmentation, in which monotonic downhill function is applied to rule out structures which have similar standardized uptake values (SUV) to the lung tumor but do not satisfy a monotonic property in PET images; (3) fine segmentation, random forests method is applied to accurately segment the lung tumor by extracting effective features from PET and CT images simultaneously. We validated our algorithm on a dataset which consists of 24 3D PET-CT images from different patients with non-small cell lung cancer (NSCLC). The average TPVF, FPVF and accuracy rate (ACC) were 83.65%, 0.05% and 99.93%, respectively. The correlation analysis shows our segmented lung tumor volumes has strong correlation ( average 0.985) with the ground truth 1 and ground truth 2 labeled by a clinical expert.

Second cancers discovered by (18)FDG PET/CT imaging for choroidal melanoma.

PubMed

Chin, Kimberly; Finger, Paul T; Kurli, Madhavi; Tena, Lawrence B; Reddy, Shantan

2007-08-01

Positron-emission tomography/computed tomography (PET/CT) is a unique imaging tool that aids in the detection of cancerous lesions. It is currently and widely used for cancer staging (both initial and follow-up). Here we report our findings of second primary cancers incidentally discovered during PET/CT staging of patients with choroidal melanomas. We performed a retrospective case review of 139 patients with uveal melanoma who were subsequently evaluated by whole-body [18-fluorine-labeled] 2-deoxy-2-fluoro-D-glucose ((18)FDG) PET/CT imaging. In this series, 93 were scanned before treatment and 46 during the course of their follow-up systemic examinations. Their mean follow-up was 50.9 months. Six patients (4.3%) had second primary cancers revealed by PET/CT imaging. Three patients (50%) were synchronous (found at initial staging), and the remaining 3 patients (50%) were metachronous (found at follow-up staging). Second primary cancers were found in the lung, breast, uterus, colon, and thyroid. Although whole-body PET/CT scans were ordered as part of the staging process of patients with diagnosed choroidal melanoma, both synchronous and metachronous second primary cancers were found. PET/CT has become an indispensable tool for staging, diagnosis, and treatment planning for choroidal melanoma. The possibility of detecting second primary cancers should also be considered valuable.

Psychobiology of cumulative trauma: hair cortisol as a risk marker for stress exposure in women.

PubMed

Morris, Matthew C; Abelson, James L; Mielock, Alyssa S; Rao, Uma

2017-07-01

Childhood trauma (CT) is associated with long-lasting alterations of the hypothalamic-pituitary-adrenal (HPA) axis and elevated risk for stress exposure in adulthood. Although HPA alterations are present in the early aftermath of trauma, it remains unclear how initial HPA activity is associated with subsequent stress exposure and whether CT exposure influences the strength and direction of this association. The present study examined prospective associations between hair cortisol content (HCC) and stress exposure from baseline to 3-month follow-up in young adult women with recent (i.e. past 3 months) exposure to interpersonal violence (IPV; i.e. physical or sexual assault) and non-traumatized controls. History of significant CT abuse or neglect was determined based on clinical cutoffs for a self-report CT measure: 12 women had abuse or neglect and recent IPV exposure (CT + IPV); 7 women had abuse or neglect but no IPV exposure (CT); 15 women had no history of trauma (NTC). HCC was computed for 3 cm sections reflecting cortisol secretion during the 3 months preceding the baseline assessment. The interaction of cumulative trauma and HCC predicted stress exposure over 3-month follow-up, controlling for baseline stress exposure and depressive symptoms. Simple slopes analyses revealed that lower baseline HCC predicted greater stress exposure in the CT + IPV group compared to the CT group; HCC was not associated with stress exposure in the NTC group. The present findings highlight the potential utility of HCC as a predictor of stress exposure for women with a history of childhood abuse or neglect, particularly in the context of recent IPV. Lay summary Adults with a history of CT show long-lasting alterations in major stress response systems, including the HPA axis. They are also more likely to experience stressful life events in adulthood. However, it is not clear how altered HPA activity influences risk for stress exposure and whether CT affects their relationship. The results from this study show that lower HPA activity (measured with hair cortisol) predicted greater stress exposure in women with CT - particularly for women who also experienced recent incidents involving physical or sexual assault.

A First Look at Oxygen and Silicon Isotope Variations in Diatom Silica from a Pliocene Antarctic Marine Sediment Core

NASA Astrophysics Data System (ADS)

Abbott, T.; Dodd, J. P.; Hackett, H.; Scherer, R. P.

2016-02-01

Coupled oxygen (δ18O) and silicon (δ30Si) isotope variations in diatom silica (opal-A) are increasingly used as a proxy to reconstruct paleoenvironmental conditions (water temperatures, water mass mixing, nutrient cycling) in marine environments. Diatom silica is a particularly significant paleoenvironmental proxy in high latitude environments, such as the Southern Ocean, where diatom blooms are abundant and diatom frustules are well preserved in the sediment. The Andrill-1B (AND-1B) sediment core from the Ross Sea (Antarctica) preserves several Pliocene ( 4.5 Ma) age diatomite units. Here we present preliminary δ18O and δ30Si values for a diatomite subunit in the AND-1B sediment core. Initial isotope values for the AND-1B diatoms silica record relatively high variability (range δ18O: 36.3‰ to 39.9‰) that could be interpreted as large-scale changes in the water temperature and/or freshwater mixing in the Ross Sea; however, a significant concern with marine sediment of this age is isotope fractionation during diagenesis and the potential formation of opal-CT lepispheres. The effects of clay contamination on the diatom silica δ18O values have been addressed through sample purification and quantified through chemical and physical analyses of the diatom silica. The isotopic effects of opal-CT are not as clearly understood and more difficult to physically separate from the primary diatom silica. In order to better understand the isotope variations in the AND-1B diatoms, we also evaluated silicon and oxygen isotope fractionation during the transition from opal-A to opal-CT in a controlled laboratory experiment. Opal-A from cultured marine diatoms (Thalassiosira weissflogii) was subjected to elevated temperatures (150°C) in acid digestion vessels for 4 weeks to initiate opal-CT precipitation. Quantifying the effects of opal-CT formation on δ18O and δ30Si variations in biogenic silica improves our understanding of the use of diatom silica isotope values a paleoenvironmental proxy throughout the Cenozoic.

Traumatic midline subarachnoid hemorrhage on initial computed tomography as a marker of severe diffuse axonal injury.

PubMed

Mata-Mbemba, Daddy; Mugikura, Shunji; Nakagawa, Atsuhiro; Murata, Takaki; Ishii, Kiyoshi; Kushimoto, Shigeki; Tominaga, Teiji; Takahashi, Shoki; Takase, Kei

2018-01-05

OBJECTIVE The objective of this study was to test the hypothesis that midline (interhemispheric or perimesencephalic) traumatic subarachnoid hemorrhage (tSAH) on initial CT may implicate the same shearing mechanism that underlies severe diffuse axonal injury (DAI). METHODS The authors enrolled 270 consecutive patients (mean age [± SD] 43 ± 23.3 years) with a history of head trauma who had undergone initial CT within 24 hours and brain MRI within 30 days. Six initial CT findings, including intraventricular hemorrhage (IVH) and tSAH, were used as candidate predictors of DAI. The presence of tSAH was determined at the cerebral convexities, sylvian fissures, sylvian vallecula, cerebellar folia, interhemispheric fissure, and perimesencephalic cisterns. Following MRI, patients were divided into negative and positive DAI groups, and were assigned to a DAI stage: 1) stage 0, negative DAI; 2) stage 1, DAI in lobar white matter or cerebellum; 3) stage 2, DAI involving the corpus callosum; and 4) stage 3, DAI involving the brainstem. Glasgow Outcome Scale-Extended (GOSE) scores were obtained in 232 patients. RESULTS Of 270 patients, 77 (28.5%) had DAI; tSAH and IVH were independently associated with DAI (p < 0.05). Of tSAH locations, midline tSAH was independently associated with both overall DAI and DAI stage 2 or 3 (severe DAI; p < 0.05). The midline tSAH on initial CT had sensitivity of 60.8%, specificity of 81.7%, and positive and negative predictive values of 43.7% and 89.9%, respectively, for severe DAI. When adjusted for admission Glasgow Coma Score, the midline tSAH independently predicted poor GOSE score at both hospital discharge and after 6 months. CONCLUSIONS Midline tSAH could implicate the same shearing mechanism that underlies severe DAI, for which midline tSAH on initial CT is a probable surrogate.

Delayed diagnosis of injuries in pediatric trauma: the role of radiographic ordering practices.

PubMed

Willner, Emily L; Jackson, Hollie A; Nager, Alan L

2012-01-01

We sought to describe the use of radiographic studies in pediatric major trauma patients and determine the extent to which a selective, clinically guided use of imaging contributes to delayed diagnosis of injury (DDI). We conducted a retrospective chart review of 324 consecutive pediatric major trauma patients at our level 1 trauma center. One radiologist reviewed all imaging. Delayed diagnosis of injury was defined as detection after more than 12 hours. Equivalency testing was performed to compare radiology use in patients with and without DDI. Twenty-six (8%) of 324 patients had 36 DDI; 27 (75%) of 36 were orthopedic injuries. Median time to DDI detection was 20.5 hours (interquartile range, 15-60.5). During initial evaluation, DDI patients had similar numbers of plain radiographs (3.5 vs 3, P = .54) but more computed tomographic (CT) scans (4 vs 3, P = .03) compared with patients without DDI. Sixteen percent of all patients received CT thorax; 55%, CT cervical spine; and 56%, CT abdomen. Only 1 clinically important DDI was detected solely on the basis of a later CT scan (0.3%; 95% confidence interval, 0-1.5). No cervical spine, intrathoracic, or intraabdominal DDI was attributable to failure to obtain a CT during initial evaluation. Patients with DDI had higher injury severity scores, intubation rates, and pediatric intensive care unit admission rates than those without DDI. Patients with DDI had similar initial plain x-ray evaluations to patients without DDI, despite DDI patients being more severely injured. Delayed diagnosis of injury was not attributable to inadequate CT use. Most DDIs were orthopedic, highlighting the importance of a tertiary survey and a low threshold for skeletal radiographs. Copyright © 2012 Elsevier Inc. All rights reserved.

Does social defeat mediate the association between childhood trauma and psychosis? Evidence from the NEMESIS-2 Study.

PubMed

van Nierop, M; van Os, J; Gunther, N; van Zelst, C; de Graaf, R; ten Have, M; van Dorsselaer, S; Bak, M; Myin-Germeys, I; van Winkel, R

2014-06-01

Based on theoretical considerations and animal studies, mediation of 'social defeat' (SD) in the association between childhood trauma (CT) and psychosis was investigated. Trained interviewers administered a structured interview assessing CT, psychotic experiences and other psychopathology in 6646 participants in the second Netherlands Mental Health Survey and Incidence Study (NEMESIS-2). Childhood trauma was associated with psychotic experiences making up the extended psychosis phenotype (EPP), as well as with a diagnosis of psychotic disorder (PD). Similarly, CT was associated with a priori selected items indexing SD (discouraged, hopeless, worthless, loss of self-confidence, low self-esteem, better off dead, suicidal thoughts) and with a measure of affective dysregulation (AD), which in turn were also associated with psychosis. While SD and AD individually acted as mediators in the association between CT and EPP, only SD acted as a mediator in the association between CT and PD. Cannabis use did not mediate the association between CT and EPP or PD. The present results suggest a developmental model implicating SD as an important mediator in the link between childhood adverse experiences and later development of psychotic experiences. The combined mediation by SD and AD is compatible with an 'affective pathway' to early psychosis. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Randomized controlled trial of relaxation music to reduce heart rate in patients undergoing cardiac CT.

PubMed

Ng, Ming Yen; Karimzad, Yasser; Menezes, Ravi J; Wintersperger, Bernd J; Li, Qin; Forero, Julian; Paul, Narinder S; Nguyen, Elsie T

2016-10-01

To evaluate the heart rate lowering effect of relaxation music in patients undergoing coronary CT angiography (CCTA), pulmonary vein CT (PVCT) and coronary calcium score CT (CCS). Patients were randomised to a control group (i.e. standard of care protocol) or to a relaxation music group (ie. standard of care protocol with music). The groups were compared for heart rate, radiation dose, image quality and dose of IV metoprolol. Both groups completed State-Trait Anxiety Inventory anxiety questionnaires to assess patient experience. One hundred and ninety-seven patients were recruited (61.9 % males); mean age 56y (19-86 y); 127 CCTA, 17 PVCT, 53 CCS. No significant difference in heart rate, radiation dose, image quality, metoprolol dose and anxiety scores. 86 % of patients enjoyed the music. 90 % of patients in the music group expressed a strong preference to have music for future examinations. The patient cohort demonstrated low anxiety levels prior to CT. Relaxation music in CCTA, PVCT and CCS does not reduce heart rate or IV metoprolol use. Patients showed low levels of anxiety indicating that anxiolytics may not have a significant role in lowering heart rate. Music can be used in cardiac CT to improve patient experience. • Relaxation music does not reduce heart rate in cardiac CT • Relaxation music does not reduce beta-blocker use in cardiac CT • Relaxation music has no effect on cardiac CT image quality • Low levels of anxiety are present in patients prior to cardiac CT • Patients enjoyed the relaxation music and this results in improved patient experience.

Chlamydia trachomatis OmpA genotyping as a tool for studying the natural history of genital chlamydial infection.

PubMed

Geisler, W M; Black, C M; Bandea, C I; Morrison, S G

2008-12-01

To investigate the relationship of Chlamydia trachomatis (CT) outer membrane protein A (OmpA) type to the clearance of CT infection before treatment. CT OmpA genotyping, with amplification and sequencing of ompA, was utilised to study the natural history of CT infection (spontaneous resolution vs persistence) in 102 individuals with chlamydia-positive screening tests returning for treatment. CT OmpA distribution was associated with spontaneous resolution of CT, most notably with CT OmpA genotype J/Ja detected more often from the initial screening CT test than other genotypes in those who then had spontaneous resolution of CT noted at the time of treatment. Five individuals with presumed persisting CT infection had discordant CT OmpA genotypes at the screening and treatment visits, suggesting possible new interval CT infection. Clearance of chlamydia by the host before treatment may be influenced by the CT OmpA genotype infecting the host. CT OmpA genotyping may be a valuable tool in understanding the natural history of chlamydial infections.

IMPACT Observatory: tracking the evolution of clinical trial data sharing and research integrity

PubMed Central

Krleža-Jerić, Karmela; Gabelica, Mirko; Banzi, Rita; Martinić, Marina Krnić; Pulido, Bibiana; Mahmić-Kaknjo, Mersiha; Reveiz, Ludovic; Šimić, Josip; Utrobičić, Ana; Hrgović, Irena

2016-01-01

Introduction The opening of research data is emerging thanks to the increasing possibilities of digital technology. The opening of clinical trial (CT) data is a part of this process, expected to have positive scientific, ethical, health, and economic impacts thus contributing to research integrity. The January 2016 proposal by the International Council of Medical Journal Editors triggered ample discussion about CT data sharing and reconfirmed the need for an ongoing assessment of its dynamics. The IMProving Access to Clinical Trials data (IMPACT) Observatory aims to play such a role, and assess the data sharing culture, policies, and practices of key players, the impact of their interventions on CTs, and contribute to a transformation of research. The objective of this paper is to present the IMPACT Observatory as well as share some of its preliminary findings. Materials and methods Methods include a scoping study of research, surveys, interviews, and an environmental scan of research data repositories. Results Our preliminary findings indicate that although opening of CT data has not yet been achieved, its evolution is encouraging. Initiatives by key players contribute to increasing of CT data sharing, and many barriers are shrinking or disappearing. Conclusions The major barrier is the lack of data sharing standards, from preparing data for public sharing to its curatorship, findability and access. However, experiences accumulated by sharing CT data according to “upon request” or “open” mechanisms could inform the development of such standards. The Vivli, CORBEL-ECRIN and Open Trials projects are currently working in this direction. PMID:27812300

Use of Computed X-ray Tomographic Data for Analyzing the Thermodynamics of a Dissociating Porous Sand/Hydrate Mixture

DOE R&D Accomplishments Database

Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Stern, Laura A.; Kirby, Stephen H.

2002-02-28

X-ray computed tomography (CT) is a method that has been used extensively in laboratory experiments for measuring rock properties and fluid transport behavior. More recently, CT scanning has been applied successfully to detect the presence and study the behavior of naturally occurring hydrates. In this study, we used a modified medical CT scanner to image and analyze the progression of a dissociation front in a synthetic methane hydrate/sand mixture. The sample was initially scanned under conditions at which the hydrate is stable (atmospheric pressure and liquid nitrogen temperature, 77 K). The end of the sample holder was then exposed to the ambient air, and the core was continuously scanned as dissociation occurred in response to the rising temperature. CT imaging captured the advancing dissociation front clearly and accurately. The evolved gas volume was monitored as a function of time. Measured by CT, the advancing hydrate dissociation front was modeled as a thermal conduction problem explicitly incorporating the enthalpy of dissociation, using the Stefan moving-boundary-value approach. The assumptions needed to perform the analysis consisted of temperatures at the model boundaries. The estimated value for thermal conductivity of 2.6 W/m K for the remaining water ice/sand mixture is higher than expected based on conduction alone; this high value may represent a lumped parameter that incorporates the processes of heat conduction, methane gas convection, and any kinetic effects that occur during dissociation. The technique presented here has broad implications for future laboratory and field testing that incorporates geophysical techniques to monitor gas hydrate dissociation.

Approaches to inspecting computed tomographic and magnetic resonance studies.

PubMed

Lamb, Christopher R; Dale, Vicki H M

2013-01-01

There is a need to better understand how to optimally inspect large image datasets. The aim of the present study was to complement experimental studies of visual perception by using an online questionnaire to collect opinions of practicing veterinary radiologists about the approaches they use when inspecting clinical computed X-ray tomography (CT) and/or magnetic resonance (MR) studies, and to test associations between radiologist's approaches and their training, experience, or caseload. Questionnaires were received from 90/454 (20%) American College of Veterinary Radiology (ACVR) Diplomates and 58/156 (37%) European College of Veterinary Diagnostic Imaging (ECVDI) Diplomates, providing 139 complete responses for CT studies and 116 for MR. Questionnaire responses differed for the following variables: specialty college, years since Board Certification, CT and MR caseload, and type of practice. ACVR Diplomates more frequently inspected multiple anatomic structures in CT and MR images before moving on to the next image, and ECVDI Diplomates more frequently inspected a specific anatomic structure through a series, then went back and checked another structure. A significant number of radiologists indicated that they initially ignore the history, adopt relatively rigid search patterns with emphasis on viewing images in a predetermined order with minimal deviation, and arrange series of images to facilitate comparisons between images, such as pre- and postcontrast images. Radiologists tended to adopt similar approaches for both CT and MR studies. Findings from this study could be used as foci for teaching novices how to approach large imaging studies, and provide guidance for case-based assessment of trainees. © 2013 Veterinary Radiology & Ultrasound.

Design of the Women's Health Initiative clinical trial and observational study. The Women's Health Initiative Study Group.

PubMed

1998-02-01

The Women's Health Initiative (WHI) is a large and complex clinical investigation of strategies for the prevention and control of some of the most common causes of morbidity and mortality among postmenopausal women, including cancer, cardiovascular disease, and osteoporotic fractures. The WHI was initiated in 1992, with a planned completion date of 2007. Postmenopausal women ranging in age from 50 to 79 are enrolled at one of 40 WHI clinical centers nationwide into either a clinical trial (CT) that will include about 64,500 women or an observational study (OS) that will include about 100,000 women. The CT is designed to allow randomized controlled evaluation of three distinct interventions: a low-fat eating pattern, hypothesized to prevent breast cancer and colorectal cancer and, secondarily, coronary heart disease; hormone replacement therapy, hypothesized to reduce the risk of coronary heart disease and other cardiovascular diseases and, secondarily, to reduce the risk of hip and other fractures, with increased breast cancer risk as a possible adverse outcome; and calcium and vitamin D supplementation, hypothesized to prevent hip fractures and, secondarily, other fractures and colorectal cancer. Overall benefit-versus-risk assessment is a central focus in each of the three CT components. Women are screened for participation in one or both of the components--dietary modification (DM) or hormone replacement therapy (HRT)--of the CT, which will randomize 48,000 and 27,500 women, respectively. Women who prove to be ineligible for, or who are unwilling to enroll in, these CT components are invited to enroll in the OS. At their 1-year anniversary of randomization, CT women are invited to be further randomized into the calcium and vitamin D (CaD) trial component, which is projected to include 45,000 women. The average follow-up for women in either CT or OS is approximately 9 years. Concerted efforts are made to enroll women of racial and ethnic minority groups, with a target of 20% of overall enrollment in both the CT and OS. This article gives a brief description of the rationale for the interventions being studied in each of the CT components and for the inclusion of the OS component. Some detail is provided on specific study design choices, including eligibility criteria, recruitment strategy, and sample size, with attention to the partial factorial design of the CT. Some aspects of the CT monitoring approach are also outlined. The scientific and logistic complexity of the WHI implies particular leadership and management challenges. The WHI organization and committee structure employed to respond to these challenges is also briefly described.

An evaluation on CT image acquisition method for medical VR applications

NASA Astrophysics Data System (ADS)

Jang, Seong-wook; Ko, Junho; Yoo, Yon-sik; Kim, Yoonsang

2017-02-01

Recent medical virtual reality (VR) applications to minimize re-operations are being studied for improvements in surgical efficiency and reduction of operation error. The CT image acquisition method considering three-dimensional (3D) modeling for medical VR applications is important, because the realistic model is required for the actual human organ. However, the research for medical VR applications has focused on 3D modeling techniques and utilized 3D models. In addition, research on a CT image acquisition method considering 3D modeling has never been reported. The conventional CT image acquisition method involves scanning a limited area of the lesion for the diagnosis of doctors once or twice. However, the medical VR application is required to acquire the CT image considering patients' various postures and a wider area than the lesion. A wider area than the lesion is required because of the necessary process of comparing bilateral sides for dyskinesia diagnosis of the shoulder, pelvis, and leg. Moreover, patients' various postures are required due to the different effects on the musculoskeletal system. Therefore, in this paper, we perform a comparative experiment on the acquired CT images considering image area (unilateral/bilateral) and patients' postures (neutral/abducted). CT images are acquired from 10 patients for the experiments, and the acquired CT images are evaluated based on the length per pixel and the morphological deviation. Finally, by comparing the experiment results, we evaluate the CT image acquisition method for medical VR applications.

A novel computer-aided detection system for pulmonary nodule identification in CT images

NASA Astrophysics Data System (ADS)

Han, Hao; Li, Lihong; Wang, Huafeng; Zhang, Hao; Moore, William; Liang, Zhengrong

2014-03-01

Computer-aided detection (CADe) of pulmonary nodules from computer tomography (CT) scans is critical for assisting radiologists to identify lung lesions at an early stage. In this paper, we propose a novel approach for CADe of lung nodules using a two-stage vector quantization (VQ) scheme. The first-stage VQ aims to extract lung from the chest volume, while the second-stage VQ is designed to extract initial nodule candidates (INCs) within the lung volume. Then rule-based expert filtering is employed to prune obvious FPs from INCs, and the commonly-used support vector machine (SVM) classifier is adopted to further reduce the FPs. The proposed system was validated on 100 CT scans randomly selected from the 262 scans that have at least one juxta-pleural nodule annotation in the publicly available database - Lung Image Database Consortium and Image Database Resource Initiative (LIDC-IDRI). The two-stage VQ only missed 2 out of the 207 nodules at agreement level 1, and the INCs detection for each scan took about 30 seconds in average. Expert filtering reduced FPs more than 18 times, while maintaining a sensitivity of 93.24%. As it is trivial to distinguish INCs attached to pleural wall versus not on wall, we investigated the feasibility of training different SVM classifiers to further reduce FPs from these two kinds of INCs. Experiment results indicated that SVM classification over the entire set of INCs was in favor of, where the optimal operating of our CADe system achieved a sensitivity of 89.4% at a specificity of 86.8%.

Differentiation between diverticulitis and colorectal cancer: quantitative CT perfusion measurements versus morphologic criteria--initial experience.

PubMed

Goh, Vicky; Halligan, Steve; Taylor, Stuart A; Burling, David; Bassett, Paul; Bartram, Clive I

2007-02-01

To determine whether computed tomographic (CT) perfusion measurements in prospectively recruited patients can be used to differentiate between diverticulitis and colorectal cancer and to compare this discrimination with that of standard morphologic criteria. After institutional review board approval and written informed consent were obtained, 60 patients (24 men, 36 women; mean age, 69 years; range, 33.5-90.4 years; 20 patients with cancer, 20 with diverticulitis, and 20 with inactive diverticular disease) underwent CT perfusion imaging at the level of the colonic abnormality, and perfusion parameters were calculated. Analysis of variance was used to investigate any differences in perfusion between the patient groups. Two independent observers also analyzed an abdominopelvic CT study obtained immediately after the CT perfusion study and noted standard morphologic criteria for differential diagnosis. The sensitivity and specificity of CT perfusion measurements for determining the diagnostic category were compared with morphologic criteria by means of multivariate analysis to identify the most discriminatory criteria. Mean blood volume, blood flow, transit time, and permeability were significantly different between patients with cancer and those with diverticulitis (P < .0001); patients with cancer had the highest blood volume, blood flow, and permeability and the shortest transit time. The most discriminatory criteria for determining diagnostic category were blood volume, transit time, permeability, and presence of pericolonic nodes (P = .05, .02, .04, and .02, respectively). Blood volume and blood flow each had a sensitivity of 80% and had specificity of 70% and 75%, respectively, for cancer in comparison with standard morphologic criteria: less than 5 cm of bowel involvement (45% sensitivity, 95% specificity), presence of a mass (85% sensitivity, 90% specificity), pericolonic inflammation (75% sensitivity, 5% specificity), and pericolonic nodes (90% sensitivity, 45% specificity). CT perfusion measurements enable differentiation and better discrimination, in comparison with morphologic criteria, between cancer and diverticulitis. (c) RSNA, 2007.

Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Zaki, Mohammed; Yamashita, Tomio; Seto, Aska; Matsumoto, Tsuneo; Matsunaga, Naofumi

2004-02-01

In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n = 15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 degrees for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9 +/- 3.1 mm vs 19.0 +/- 9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases.

Shaping Networked Theatre: Experience Architectures, Behaviours and Creative Pedagogies

ERIC Educational Resources Information Center

Sutton, Paul

2012-01-01

Since 2006 the UK based applied theatre company C&T has been using its experience and expertise in mixing drama, learning and digital media to create a new online utility for shaping collaborative educational drama experiences. C&T describes this practice as "Networked Theatre". This article describes both the motivations for…

Tomotherapy as a tool in image-guided radiation therapy (IGRT): current clinical experience and outcomes

PubMed Central

Yartsev, S; Kron, T; Van Dyk, J

2007-01-01

Modern radiotherapy is characterised by a better target definition through medical imaging accompanied by significantly improved radiation delivery methods, most notably Intensity-Modulate Radiation Therapy (IMRT). However, the treatment can only be as accurate as the positioning of patients for their daily radiotherapy fraction. It is in this context that a number of imaging modalities - ranging from ultrasound to on-board kilovoltage imaging and computed tomography (CT) - have found their way into the treatment room where they verify accurate patient positioning prior to or even during delivery of radiation. Helical tomotherapy (HT) combines IMRT delivery with in-built image guidance using megavoltage CT scanning. This paper discusses the initial experience of different centres with IGRT using HT illustrated by a number of clinical examples from the installation in London in Ontario, Canada, one of the world’s first HT sites. We found that HT allows the delivery of highly conformal radiation dose distributions combined with adequate daily image acquisition. An important feature of this unit is its seamless integration, which also includes a customised inverse treatment planning system and a quality assurance module for individual patients. PMID:21614258

Real-time CT-video registration for continuous endoscopic guidance

NASA Astrophysics Data System (ADS)

Merritt, Scott A.; Rai, Lav; Higgins, William E.

2006-03-01

Previous research has shown that CT-image-based guidance could be useful for the bronchoscopic assessment of lung cancer. This research drew upon the registration of bronchoscopic video images to CT-based endoluminal renderings of the airway tree. The proposed methods either were restricted to discrete single-frame registration, which took several seconds to complete, or required non-real-time buffering and processing of video sequences. We have devised a fast 2D/3D image registration method that performs single-frame CT-Video registration in under 1/15th of a second. This allows the method to be used for real-time registration at full video frame rates without significantly altering the physician's behavior. The method achieves its speed through a gradient-based optimization method that allows most of the computation to be performed off-line. During live registration, the optimization iteratively steps toward the locally optimal viewpoint at which a CT-based endoluminal view is most similar to a current bronchoscopic video frame. After an initial registration to begin the process (generally done in the trachea for bronchoscopy), subsequent registrations are performed in real-time on each incoming video frame. As each new bronchoscopic video frame becomes available, the current optimization is initialized using the previous frame's optimization result, allowing continuous guidance to proceed without manual re-initialization. Tests were performed using both synthetic and pre-recorded bronchoscopic video. The results show that the method is robust to initialization errors, that registration accuracy is high, and that continuous registration can proceed on real-time video at >15 frames per sec. with minimal user-intervention.

Structure and Protein-Protein Interaction Studies on Chlamydia trachomatis Protein CT670 (YscO Homolog)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenzini, Emily; Singer, Alexander; Singh, Bhag

2010-07-28

Comparative genomic studies have identified many proteins that are found only in various Chlamydiae species and exhibit no significant sequence similarity to any protein in organisms that do not belong to this group. The CT670 protein of Chlamydia trachomatis is one of the proteins whose genes are in one of the type III secretion gene clusters but whose cellular functions are not known. CT670 shares several characteristics with the YscO protein of Yersinia pestis, including the neighboring genes, size, charge, and secondary structure, but the structures and/or functions of these proteins remain to be determined. Although a BLAST search withmore » CT670 did not identify YscO as a related protein, our analysis indicated that these two proteins exhibit significant sequence similarity. In this paper, we report that the CT670 crystal, solved at a resolution of 2 {angstrom}, consists of a single coiled coil containing just two long helices. Gel filtration and analytical ultracentrifugation studies showed that in solution CT670 exists in both monomeric and dimeric forms and that the monomer predominates at lower protein concentrations. We examined the interaction of CT670 with many type III secretion system-related proteins (viz., CT091, CT665, CT666, CT667, CT668, CT669, CT671, CT672, and CT673) by performing bacterial two-hybrid assays. In these experiments, CT670 was found to interact only with the CT671 protein (YscP homolog), whose gene is immediately downstream of ct670. A specific interaction between CT670 and CT671 was also observed when affinity chromatography pull-down experiments were performed. These results suggest that CT670 and CT671 are putative homologs of the YcoO and YscP proteins, respectively, and that they likely form a chaperone-effector pair.« less

Gastrointestinal motor inhibition by exogenous human, salmon, and eel calcitonin in conscious dogs.

PubMed

Nakamura, H; Asano, T; Haruta, K; Takeda, K

1995-01-01

Effects of synthetic eel (E-), salmon (S-), and human (H-) calcitonin (CT) on gastrointestinal motility were studied in conscious beagle dogs, which had been implanted with strain gauge force transducers. Intramuscular administration of E-, S-, or H-CT interrupted gastric migrating motor complexes, digestive pattern, and gastric emptying. The order of potency was E-CT = S-CT > H-CT. Motor inhibition induced by CT occurred independently of plasma immunoreactive motilin levels or hypocalcemia. In addition, E-CT and S-CT induced vomiting without a retrograde giant contraction (RGC) during the postprandial state. Apomorphine or CuSO4 initiated RGC prior to vomiting. RGC induced by apomorphine was inhibited by pretreatment with E-CT as well as hexamethonium, atropine, or surgical vagotomy. E-CT showed no inhibitory effect on nicotine stimulated contraction of isolated guinea-pig ileum. These results suggest that peripherally administered CT inhibits canine gastrointestinal motility at the central nervous system level by lowering vagal activity.

Risk stratification and staging in prostate cancer with prostatic specific membrane antigen PET/CTObjective: A one-stop-shop.

PubMed

Gupta, Manoj; Choudhury, Partha Sarathi; Rawal, Sudhir; Goel, Harish Chandra; Singh, Amitabh; Talwar, Vineet; Sahoo, Saroj Kumar

2017-01-01

Current imaging modalities for prostate cancer (PC) had limitations for risk stratification and staging. Magnetic resonance imaging (MRI) frequently underestimated lymphatic metastasis while bone scintigraphy often had diagnostic dilemmas. Prostatic specific membrane antigen (PSMA) positron emission tomography-computed tomography (PET/CT) has been remarkable in diagnosing PC recurrence and staging. We hypothesized it can become one-stop-shop for initial risk stratification and staging. Ninety seven PSMA PET-CT studies were re analysed for tumor node metastases (TNM) staging and risk stratification of lymphatic and distant metastases proportion. The histopathology of 23/97 patients was available as gold standard. Chi-square test was used for proportion comparison. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), over-estimation, under-estimation and correct-estimation of T and N stages were calculated. Cohen's kappa coefficient (k) was derived for inter-rater agreement. Lymphic or distant metastases detection on PSMA PET/CT increased significantly with increase in risk category. PSMA PET/CT sensitivity, specificity, PPV and NPV for extra prostatic extension (EPE), seminal vesicle invasion (SVI) and lymphatic metastases were 63.16%, 100%, 100%, 36.36% & 55%, 100%, 100%, 25% and 65.62%, 99.31%, 87.50%, 97.53%, respectively. Cohen's kappa coefficient showed substantial agreement between PSMA PET/CT and histopathological lymphic metastases (κ 0.734) however, it was just in fair agreement (κ 0.277) with T stage. PSMA PET/CT over-estimated, under-estimated and correct-estimated T and N stages in 8.71%, 39.13%, 52.17% and 8.71%, 4.35%, 86.96% cases, respectively. We found that PSMA PET/CT has potential for initial risk stratifications with reasonable correct estimation for N stage. However, it can underestimate T stage. Hence, we suggest that PSMA PET/CT should be used for staging and initial risk stratification of PC as one-stop-shop with regional MRI in surgically resectable cases.

GAUGING THE EXTENT OF THYROIDECTOMY FOR INDETERMINATE THYROID NODULES: AN ONCOLOGIC PERSPECTIVE.

PubMed

Schneider, David F; Cherney Stafford, Linda M; Brys, Nicole; Greenberg, Caprice C; Balentine, Courtney J; Elfenbein, Dawn M; Pitt, Susan C

2017-04-02

Increasing emphasis is being placed on appropriateness of care and avoidance of over- and under-treatment. Indeterminate thyroid nodules (ITNs) present a particular risk for this problem because cancer found via diagnostic lobectomy (DL) often requires a completion thyroidectomy (CT). However, initial total thyroidectomy (TT) for benign ITN results in lifelong thyroid hormone replacement. We sought to measure the accuracy and factors associated with the extent of initial thyroidectomy for ITN. We queried a single institution thyroid surgery database for all adult patients undergoing an initial operation for ITN. Multivariate logistic regression identified factors associated with either oncologic under- or overtreatment at initial operation. There were 639 patients with ITN. The median age was 52 (range, 18 to 93) years, 78.4% were female, and final pathology revealed a cancer >1 cm in 24.7%. The most common cytology was follicular neoplasm (45.1%) followed by Hürthle cell neoplasm (20.2%). CT or initial oncologic undertreatment was required in 58 patients (9.3%). Excluding those with goiters, 19.0% were treated with TT for benign final pathology. Multivariate analysis failed to identify any factor that independently predicted the need for CT. Female gender was associated with TT in benign disease (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.0 to 4.5; P = .05). Age >45 years predicted correct initial use of DL (OR, 2.6; 95% CI, 1.2 to 5.7; P = .02). Suspicious for papillary thyroid carcinoma (OR, 5.7; 95% CI, 2.1 to 15.3; P<.01) and frozen section (OR, 9.7; 95% CI, 2.5 to 38.6; P<.01) were associated with oncologically appropriate initial TT. The highest frequency of CT occurred in patients with follicular lesion of undetermined significance (11.6%). TT for benign final pathology occurred most frequently in patients with a Hürthle cell neoplasm (24.8%). In patients with ITN, nearly 30% received an inappropriate extent of initial thyroidectomy from an oncologic standpoint. Tools to pre-operatively identify both benign and malignant disease can assist in the complex decision making to gauge the proper extent of initial surgery for ITN. ATA = American Thyroid Association AUS = atypia of undetermined significance CI = confidence interval CT = completion thyroidectomy FLUS = follicular lesion of undetermined significance ITN = indeterminate thyroid nodule OR = odds ratio PTC = papillary thyroid carcinoma TT = total thyroidectomy.

[Initial experience of percutaneous coronary intervention guided by computed tomography coronary angiography derived roadmap and magnetic navigation system].

PubMed

Zhang, Qiu; Kong, De-yu; Li, Chun-jian; Chen, Bo; Jia, En-zhi; Chen, Lei-Lei; Jia, Qing-zhe; Dai, Zhen-hua; Zhu, Tian-tian; Chen, Jun; Liu, Jie; Zhu, Tie-bing; Yang, Zhi-jian; Cao, Ke-jiang

2013-02-01

To evaluate the feasibility, efficacy and safety of the percutaneous coronary intervention (PCI)guided by computed tomography (CT) coronary angiography derived roadmap and magnetic navigation system (MNS). During June 2011 and May 2012, thirty consecutive patients receiving elective PCI were enrolled, coronary artery disease was primarily diagnosed by dual-source CT coronary angiography (DSCT-CA) at outpatient clinic and successively proved by coronary artery angiography in the hospital. Target vessels from pre-procedure DSCT-CA were transferred to the magnetic navigation system, and consequently edited, reconstructed, and projected onto the live fluoroscopic screen as roadmap. Parameters including characters of the target lesions, time, contrast volume, radiation dosage for guidewire crossing, and complications of the procedure were recorded. Thirty patients with 36 lesions were recruited and intervened by PCI. Among the target lesions, sixteen were classified as type A, 11 as type B1, 8 as type B2, 1 as type C. The average length of the target lesions was (22.0 ± 9.8) mm, and the average stenosis of the target lesions was (81.3 ± 10.3)%. Under the guidance of CT roadmap and MNS, 36 target lesions were crossed by the magnetic guidewires, with a lesion crossing ratio of 100%. The time of placement of the magnetic guidewires was 92.5 (56.6 - 131.3) seconds. The contrast volume and the radiation dosage for guidewire placement were 0.0 (0.0 - 3.0) ml and 235.0 (123.5 - 395.1) µGym(2)/36.5 (21.3 - 67.8) mGy, respectively. Guidewires were successfully placed in 21 (58.3%) lesions without contrast agent. All enrolled vessels were successfully treated, and there were no MNS associated complications. It is feasible, effective and safe to initiate PCI under the guidance of CT derived roadmap and MNS. This method might be helpful for the guidewire placement in the treatment of total occlusions.

SU-E-T-217: Intrinsic Respiratory Gating in Small Animal CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Y; Smith, M; Mistry, N

Purpose: Preclinical animal models of lung cancer can provide a controlled test-bed for testing dose escalation or function-based-treatment-planning studies. However, to extract lung function, i.e. ventilation, one needs to be able to image the lung at different phases of ventilation (in-hale / ex-hale). Most respiratory-gated imaging using micro-CT involves using an external ventilator and surgical intervention limiting the utility in longitudinal studies. A new intrinsic respiratory retrospective gating method was developed and tested in mice. Methods: A fixed region of interest (ROI) that covers the diaphragm was selected on all projection images to estimate the mean intensity (M). The meanmore » intensity depends on the projection angle and diaphragm position. A 3-point moving average (A) of consecutive M values: Mpre, Mcurrent and Mpost, was calculated to be subtracted from Mcurrent. A fixed threshold was used to enable amplitude based sorting into 4 different phases of respiration. Images at full-inhale and end-exhale phases of respiration were reconstructed using the open source OSCaR. Lung volumes estimated at the 2 phases of respiration were validated against literature values. Results: Intrinsic retrospective gating was accomplished without the use of any external breathing waveform. While projection images were acquired at 360 different angles. Only 138 and 104 projections were used to reconstruct images at full-inhale and end-exhale. This often results in non-uniform under-sampled angular projections leading to some minor streaking artifacts. The calculated expiratory, inspiratory and tidal lung volumes correlated well with the values known from the literature. Conclusion: Our initial result demonstrates an intrinsic gating method that is suitable for flat panel cone beam small animal CT systems. Reduction in streaking artifacts can be accomplished by oversampling the data or using iterative reconstruction methods. This initial experience will enable freebreathing small animal micro-CT imaging to fuel longitudinal studies of lung function.« less

Femoral head avascular necrosis: a frequently missed incidental finding on multidetector CT.

PubMed

Barille, M F; Wu, Jim S; McMahon, Colm J

2014-03-01

To determine the incidence of missed femoral head avascular necrosis (AVN) on pelvic computed tomography (CT) performed for clinical indications other than assessment for AVN. The study was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. The picture archiving and communication system (PACS) database was queried for patients with diagnosis of femoral head AVN on magnetic resonance imaging (MRI), who also underwent pelvic multidetector CT after or <30 days before the MRI examination. The MRI and CT images of 144 hips of 72 patients (39 patients with reported AVN on MRI and 33 age-matched controls; mean age = 60 years, 28 male, 44 female), were reviewed in consensus by two readers in a randomized, blinded manner. Using MRI-proven CT-visible AVN as a reference standard, the incidence of missed AVN on initial CT interpretation was determined. Readers confirmed AVN in 33 patients on the MRI images. Nine hips with AVN underwent joint replacement of the affected joint(s) prior to subsequent CT and were excluded. Forty-three MRI-proven AVN cases in 28 patients (15 bilateral, 13 unilateral) were available for analysis. The study readers diagnosed 35/43 (81%) MRI-proven AVN cases in 22/28 (79%) patients. Four of the 35 (11%) cases of MRI-proven, CT-visible AVN were prospectively reported in 3/22 (14%) patients at initial clinical interpretation, with a miss rate of 89% per hip and 86% per patient. Multidetector CT has high accuracy for detection of AVN; however, this is frequently missed as an incidental finding (89% missed in the present study). Assessment for signs of femoral AVN should be part of routine search pattern in interpretation of pelvic CT. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Comparison between esophagography and chest computed tomography for evaluation of leaks after esophagectomy and gastric pull-through.

PubMed

Lantos, Joshua E; Levine, Marc S; Rubesin, Stephen E; Lau, Charles T; Torigian, Drew A

2013-03-01

To assess the diagnostic performance of esophagography and chest computed tomography (CT) for detecting leaks after esophagectomy and gastric pull-through. Our database revealed 29 patients who had undergone esophagography and chest CT after esophagectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for postoperative leaks were determined for esophagography and CT, separately and combined, on the basis of a retrospective image review. Patients were also stratified for esophagograms with water-soluble contrast alone versus water-soluble contrast and high-density barium and for CT with and without oral contrast. Our findings were retrospectively compared with those reported at initial image interpretation. Clinically relevant leaks were present in 14 (48%) of 29 patients after esophagectomy. Esophagography had a sensitivity of 79%, specificity of 73%, PPV of 73%, and NPV of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, PPV of 55%, and NPV of 71% and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, PPV of 56%, and NPV of 100%. The sensitivity of esophagography increased with high-density barium, whereas the sensitivity of CT was the same with and without oral contrast agent. Finally, esophagography and CT were seen to have a higher sensitivity and lower specificity on retrospective review compared with the results reported at initial image interpretation. Esophagography had a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy, whereas esophagography and CT combined had a sensitivity of 100% for detecting leaks. Therefore, postoperative leaks can be excluded with confidence after esophagectomy when both tests are negative.

Improvement of portable computed tomography system for on-field applications

NASA Astrophysics Data System (ADS)

Sukrod, K.; Khoonkamjorn, P.; Tippayakul, C.

2015-05-01

In 2010, Thailand Institute of Nuclear Technology (TINT) received a portable Computed Tomography (CT) system from the IAEA as part of the Regional Cooperative Agreement (RCA) program. This portable CT system has been used as the prototype for development of portable CT system intended for industrial applications since then. This paper discusses the improvements in the attempt to utilize the CT system for on-field applications. The system is foreseen to visualize the amount of agarwood in the live tree trunk. The experiments adopting Am-241 as the radiation source were conducted. The Am-241 source was selected since it emits low energy gamma which should better distinguish small density differences of wood types. Test specimens made of timbers with different densities were prepared and used in the experiments. The cross sectional views of the test specimens were obtained from the CT system using different scanning parameters. It is found from the experiments that the results are promising as the picture can clearly differentiate wood types according to their densities. Also, the optimum scanning parameters were determined from the experiments. The results from this work encourage the research team to advance into the next phase which is to experiment with the real tree on the field.

Studies on Plasmoid Merging using Compact Toroid Injectors

NASA Astrophysics Data System (ADS)

Allfrey, Ian; Matsumoto, Tadafumi; Roche, Thomas; Gota, Hiroshi; Edo, Takahiro; Asai, Tomohiko; Sheftman, Daniel; Osin Team; Dima Team

2017-10-01

C-2 and C-2U experiments have used magnetized coaxial plasma guns (MCPG) to inject compact toroids (CTs) for refueling the long-lived advanced beam-driven field-reversed configuration (FRC) plasma. This refueling method will also be used for the C-2W experiment. To minimize momentum transfer from the CT to the FRC two CTs are injected radially, diametrically opposed and coincident in time. To improve understanding of the CT characteristics TAE has a dedicated test bed for the development of CT injectors (CTI), where plasmoid merging experiments are performed. The test bed has two CTIs on axis with both axial and transverse magnetic fields. The 1 kG magnetic fields, intended to approximate the magnetic field strength and injection angle on C-2W, allow studies of cross-field transport and merging. Both CTIs are capable of injecting multiple CTs at up to 1 kHz. The resulting merged CT lives >100 μs with a radius of 25 cm. More detailed results of CT parameters will be presented.

The diagnostic challenge of the sequelae of acute pancreatitis on CT imaging: a pictorial essay.

PubMed

Hughey, Mark; Taffel, Myles; Zeman, Robert K; Patel, Smita; Hill, Michael C

2017-04-01

The purpose of the study was to present a pictorial review of the long-term sequelae of acute pancreatitis on CT imaging as these findings can cause diagnostic confusion in the absence of a proper clinical history and/or prior CT imaging. We retrospectively identified 81 patients who had an episode of acute pancreatitis with diagnostic findings on CT and also underwent one or more follow-up CT scans at least 1 month beyond the acute episode. The residual findings on all follow-up CT scans were tabulated, including the time interval since the initial bout of acute pancreatitis. Residual inflammatory changes were present in 19.8% of cases, with a median time period lasting 86 days since the initial episode of acute pancreatitis. Residual fluid collections were seen in 27.2% and persisted for a median of 132 days. Three patients had residual solid-appearing inflammatory masses, which could be mistaken for neoplasms. Other long-term sequelae were also tabulated, including pancreatic ductal dilatation, pancreatic atrophy, new or increased pancreatic calcifications, biliary tract dilatation, central portal venous occlusion, and pseudoaneurysm formation. These residual findings and long-term complications are presented as a pictorial essay. Recognizing the spectrum of residual findings of acute pancreatitis, some of which can be long term, is important in the correct interpretation of a pancreatic CT. These findings can mimic acute pancreatitis or a pancreatic/peripancreatic neoplasm and often cause diagnostic confusion, especially in the absence of prior CT imaging.

Low-dose CT image reconstruction using gain intervention-based dictionary learning

NASA Astrophysics Data System (ADS)

Pathak, Yadunath; Arya, K. V.; Tiwari, Shailendra

2018-05-01

Computed tomography (CT) approach is extensively utilized in clinical diagnoses. However, X-ray residue in human body may introduce somatic damage such as cancer. Owing to radiation risk, research has focused on the radiation exposure distributed to patients through CT investigations. Therefore, low-dose CT has become a significant research area. Many researchers have proposed different low-dose CT reconstruction techniques. But, these techniques suffer from various issues such as over smoothing, artifacts, noise, etc. Therefore, in this paper, we have proposed a novel integrated low-dose CT reconstruction technique. The proposed technique utilizes global dictionary-based statistical iterative reconstruction (GDSIR) and adaptive dictionary-based statistical iterative reconstruction (ADSIR)-based reconstruction techniques. In case the dictionary (D) is predetermined, then GDSIR can be used and if D is adaptively defined then ADSIR is appropriate choice. The gain intervention-based filter is also used as a post-processing technique for removing the artifacts from low-dose CT reconstructed images. Experiments have been done by considering the proposed and other low-dose CT reconstruction techniques on well-known benchmark CT images. Extensive experiments have shown that the proposed technique outperforms the available approaches.

A Missing Piece in Clinical Trial Inspections in Latin America: Interviews With Research Subjects in Peru.

PubMed

Minaya, Gabriela E; Fuentes-Delgado, Duilio J; Ugalde, Antonio; Homedes, Núria

2017-10-01

Most regulatory agencies conduct clinical trial (CT) site inspections, but the experiences and behaviors of research subjects and their knowledge of the rights and obligations that ensue from participating in a CT are seldom explored. The authors assessed the technical feasibility of incorporating interviews with participants in CT inspections. This article analyzes the responses of 13 CT participants, 14% ( n = 96) of those included in three tuberculosis (TB) CTs. Participants did not object to being interviewed and provided information not obtained during regular inspections. Participants were appreciative of the agency's concern for the integrity of the CT process. Most interviewees did not understand the consent form and were unaware that they were participating in an experiment with unapproved new drugs. Participants' decision to enroll in CT related to undue inducement and therapeutic misconception. Some patients' behaviors, undisclosed to researchers, could have compromised the integrity of the data collected.

Comparison of (68)Ga-DOTA-Tyr(3)-octreotide and (18)F-fluoro-L-dihydroxyphenylalanine positron emission tomography in neuroendocrine tumor patients.

PubMed

Putzer, D; Gabriel, M; Kendler, D; Henninger, B; Knoflach, M; Kroiss, A; Vonguggenberg, E; Warwitz, B; Virgolini, I J

2010-02-01

(68)Ga-DOTA-Tyr3-octreotide positron emission tomography ((68)Ga-DOTA-TOC PET) and (18)F-fluoro-L-dihydroxyphenylalanine PET ((18)F-DOPA PET) are emerging modalities for imaging of neuroendocrine tumors. This study reports our initial experiences with these two PET modalities on initial diagnosis, staging and restaging in NET patients. Fifteen patients with NET underwent both (68)Ga-DOTA-TOC and (18)F-DOPA PET as well as computed tomography (CT). Image findings were compared on a patient-basis (pathological uptake: yes/no) as well as on a lesion-basis. Contrast-enhanced CT and histological follow-up served as gold standard. Furthermore, imaging results were matched with tumor marker levels and quantitative tracer uptake by the tumor lesions. When comparing (68)Ga-DOTA-TOC and (18)F-DOPA PET, each modality showed a sensitivity of 64% and a specificity of 100% on a patient-based analysis. (68)Ga-DOTA-TOC PET and (18)F-DOPA PET showed equal findings in 7 out of 15 patients and disagreement in 8 patients. (68)Ga-DOTA-TOC revealed more metastases than (18)F-DOPA PET in 6 patients, while (18)F-DOPA PET detected more metastases than (68)Ga-DOTA-TOC in 4 patients. By (68)Ga-DOTA-TOC PET, 208 malignant lesions were detected, while by (18)F-DOPA only 86 lesions were found, and in CT 124, respectively. (68)Ga-DOTA-TOC and (18)F-DOPA PET are useful tools in the detection and staging of NET lesions. Our initial results allow the conclusion that (68)Ga-DOTA-TOC PET may have a stronger clinical impact in NET patients, as it does not only offer diagnostic information, but is decisive for the further treatment management, i. e. PRRT, as well.

The adaptive statistical iterative reconstruction-V technique for radiation dose reduction in abdominal CT: comparison with the adaptive statistical iterative reconstruction technique.

PubMed

Kwon, Heejin; Cho, Jinhan; Oh, Jongyeong; Kim, Dongwon; Cho, Junghyun; Kim, Sanghyun; Lee, Sangyun; Lee, Jihyun

2015-10-01

To investigate whether reduced radiation dose abdominal CT images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V) compromise the depiction of clinically competent features when compared with the currently used routine radiation dose CT images reconstructed with ASIR. 27 consecutive patients (mean body mass index: 23.55 kg m(-2) underwent CT of the abdomen at two time points. At the first time point, abdominal CT was scanned at 21.45 noise index levels of automatic current modulation at 120 kV. Images were reconstructed with 40% ASIR, the routine protocol of Dong-A University Hospital. At the second time point, follow-up scans were performed at 30 noise index levels. Images were reconstructed with filtered back projection (FBP), 40% ASIR, 30% ASIR-V, 50% ASIR-V and 70% ASIR-V for the reduced radiation dose. Both quantitative and qualitative analyses of image quality were conducted. The CT dose index was also recorded. At the follow-up study, the mean dose reduction relative to the currently used common radiation dose was 35.37% (range: 19-49%). The overall subjective image quality and diagnostic acceptability of the 50% ASIR-V scores at the reduced radiation dose were nearly identical to those recorded when using the initial routine-dose CT with 40% ASIR. Subjective ratings of the qualitative analysis revealed that of all reduced radiation dose CT series reconstructed, 30% ASIR-V and 50% ASIR-V were associated with higher image quality with lower noise and artefacts as well as good sharpness when compared with 40% ASIR and FBP. However, the sharpness score at 70% ASIR-V was considered to be worse than that at 40% ASIR. Objective image noise for 50% ASIR-V was 34.24% and 46.34% which was lower than 40% ASIR and FBP. Abdominal CT images reconstructed with ASIR-V facilitate radiation dose reductions of to 35% when compared with the ASIR. This study represents the first clinical research experiment to use ASIR-V, the newest version of iterative reconstruction. Use of the ASIR-V algorithm decreased image noise and increased image quality when compared with the ASIR and FBP methods. These results suggest that high-quality low-dose CT may represent a new clinical option.

The adaptive statistical iterative reconstruction-V technique for radiation dose reduction in abdominal CT: comparison with the adaptive statistical iterative reconstruction technique

PubMed Central

Cho, Jinhan; Oh, Jongyeong; Kim, Dongwon; Cho, Junghyun; Kim, Sanghyun; Lee, Sangyun; Lee, Jihyun

2015-01-01

Objective: To investigate whether reduced radiation dose abdominal CT images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V) compromise the depiction of clinically competent features when compared with the currently used routine radiation dose CT images reconstructed with ASIR. Methods: 27 consecutive patients (mean body mass index: 23.55 kg m−2 underwent CT of the abdomen at two time points. At the first time point, abdominal CT was scanned at 21.45 noise index levels of automatic current modulation at 120 kV. Images were reconstructed with 40% ASIR, the routine protocol of Dong-A University Hospital. At the second time point, follow-up scans were performed at 30 noise index levels. Images were reconstructed with filtered back projection (FBP), 40% ASIR, 30% ASIR-V, 50% ASIR-V and 70% ASIR-V for the reduced radiation dose. Both quantitative and qualitative analyses of image quality were conducted. The CT dose index was also recorded. Results: At the follow-up study, the mean dose reduction relative to the currently used common radiation dose was 35.37% (range: 19–49%). The overall subjective image quality and diagnostic acceptability of the 50% ASIR-V scores at the reduced radiation dose were nearly identical to those recorded when using the initial routine-dose CT with 40% ASIR. Subjective ratings of the qualitative analysis revealed that of all reduced radiation dose CT series reconstructed, 30% ASIR-V and 50% ASIR-V were associated with higher image quality with lower noise and artefacts as well as good sharpness when compared with 40% ASIR and FBP. However, the sharpness score at 70% ASIR-V was considered to be worse than that at 40% ASIR. Objective image noise for 50% ASIR-V was 34.24% and 46.34% which was lower than 40% ASIR and FBP. Conclusion: Abdominal CT images reconstructed with ASIR-V facilitate radiation dose reductions of to 35% when compared with the ASIR. Advances in knowledge: This study represents the first clinical research experiment to use ASIR-V, the newest version of iterative reconstruction. Use of the ASIR-V algorithm decreased image noise and increased image quality when compared with the ASIR and FBP methods. These results suggest that high-quality low-dose CT may represent a new clinical option. PMID:26234823

Minor head injury in children.

PubMed

Klig, Jean E; Kaplan, Carl P

2010-06-01

This review will examine mild closed head injury (CHI) and the current evidence on head computed tomography (CT) imaging risks in children, prediction rules to guide decisions on CT scan use, and issues of concussion after initial evaluation. The current literature offers preliminary evidence on the risks of radiation exposure from CT scans in children. A recent study introduces a validated prediction rule for use in mild CHI, to limit the number of CT scans performed. Concurrent with this progress, fast (or short sequence) MRI represents an emerging technology that may prove to be a viable alternative to CT scan use in certain cases of mild CHI where imaging is desired. The initial emergency department evaluation for mild CHI is the start point for a sequence of follow-up to assure that postconcussive symptoms fully resolve. The literature on sports-related concussion offers some information that may be used for patients with non-sports-related concussion. It is clear that CT scan use should be as safe and limited in scope as possible for children. Common decisions on the use of CT imaging for mild head injury can now be guided by a prediction rule for clinically important traumatic brain injury. Parameters for the follow-up care of patients with mild CHI after emergency department discharge are needed in the future to assure that postconcussive symptoms are adequately screened for full resolution.

Evaluation of the Diagnostic Accuracy of Conventional 2-Dimensional and 3-Dimensional Computed Tomography for Assessing Canine Sacral and Pelvic Fractures by Radiologists, Orthopedic Surgeons, and Veterinary Medical Students.

PubMed

Stieger-Vanegas, Susanne M; Senthirajah, Sri Kumar Jamie; Nemanic, Sarah; Baltzer, Wendy; Warnock, Jennifer; Hollars, Katelyn; Lee, Scott S; Bobe, Gerd

2015-08-01

To determine, using 3 groups of evaluators of varying experience reading orthopedic CT studies, if 3-dimensional computed tomography (3D-CT) provides a more accurate and time efficient method for diagnosis of canine sacral and pelvic fractures, and displacements of the sacroiliac and coxofemoral joints compared with 2-dimensional computed tomography (2D-CT). Retrospective clinical and prospective study. Dogs (n = 23): 12 dogs with traumatic pelvic fractures, 11 canine cadavers with pelvic trauma induced by a lateral impactor. All dogs had a 2D-CT exam of the pelvis and subsequent 3D-CT reconstructions from the 2D-CT images. Both 2D-CT and 3D-CT studies were anonymized and randomly presented to 2 veterinary radiologists, 2 veterinary orthopedic surgeons, and 2 veterinary medical students. Evaluators classified fractures using a confidence scale and recorded the duration of evaluation for each modality and case. 3D-CT was a more time-efficient technique for evaluation of traumatic sacral and pelvic injuries compared with 2D-CT in all evaluator groups irrespective of experience level reading orthopedic CT studies. However, for radiologists and surgeons, 2D-CT was the more accurate technique for evaluating sacral and pelvic fractures. 3D-CT improves sacral and pelvic fracture diagnosis when added to 2D-CT; however, 3D-CT has a reduced accuracy for evaluation of sacral and pelvic fractures if used without concurrent evaluation of 2D-CT images. © Copyright 2014 by The American College of Veterinary Surgeons.

Experimental and Numerical Observations of Hydrate Reformation during Depressurization in a Core-Scale Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seol, Yongkoo; Myshakin, Evgeniy

2011-01-01

Gas hydrate has been predicted to reform around a wellbore during depressurization-based gas production from gas hydrate-bearing reservoirs. This process has an adverse effect on gas production rates and it requires time and sometimes special measures to resume gas flow to producing wells. Due to lack of applicable field data, laboratory scale experiments remain a valuable source of information to study hydrate reformation. In this work, we report laboratory experiments and complementary numerical simulations executed to investigate the hydrate reformation phenomenon. Gas production from a pressure vessel filled with hydrate-bearing sand was induced by depressurization with and without heat fluxmore » through the boundaries. Hydrate decomposition was monitored with a medical X-ray CT scanner and pressure and temperature measurements. CT images of the hydrate-bearing sample were processed to provide 3-dimensional data of heterogeneous porosity and phase saturations suitable for numerical simulations. In the experiments, gas hydrate reformation was observed only in the case of no-heat supply from surroundings, a finding consistent with numerical simulation. By allowing gas production on either side of the core, numerical simulations showed that initial hydrate distribution patterns affect gas distribution and flow inside the sample. This is a direct consequence of the heterogeneous pore network resulting in varying hydraulic properties of the hydrate-bearing sediment.« less

Initial clinical experience with a sac-anchoring endoprosthesis for aortic aneurysm repair.

PubMed

Donayre, Carlos E; Zarins, Christopher K; Krievins, Dainis K; Holden, Andrew; Hill, Andrew; Calderas, Carlos; Velez, Jaime; White, Rodney A

2011-03-01

All current aortic endografts depend on proximal and distal fixation to prevent migration. However, migration and rupture can occur, particularly in patients with aortic necks that are short or angulated, or both. We present our initial clinical experience with a new sac-anchoring endoprosthesis designed to anchor and seal the device within the aneurysm sac. The initial worldwide experience using a new endoprosthesis for the treatment of aortic aneurysms (Nellix Endovascular, Palo Alto, Calif) was reviewed. The endoprosthesis consists of dual balloon-expandable endoframes surrounded by polymer-filled endobags designed to obliterate the aneurysm sac and maintain endograft position. Clinical results and follow-up contrast computed tomography (CT) scans at 30 days and 6 and 12 months were reviewed. The endograft was successfully deployed in 21 patients with infrarenal aortic aneurysms measuring 5.7 ± 0.7 cm (range, 4.3-7.4 cm). Two patients with common iliac aneurysms were treated with sac-anchoring extenders that maintained patency of the internal iliac artery. Infusion of 71 ± 37 mL of polymer (range, 19-158 mL) into the aortic endobags resulted in complete aneurysm exclusion in all patients. Mean implant time was 76 ± 35 minutes, with 33 ± 17 minutes of fluoroscopy time and 180 ± 81 mL of contrast; estimated blood loss was 174 ± 116 mL. One patient died during the postoperative period (30-day mortality, 4.8%), and one died at 10 months from non-device-related causes. During a mean follow-up of 8.7 ± 3.1 months and a median of 6.3 months, there were no late aneurysm- or device-related adverse events and no secondary procedures. CT imaging studies at 6 months and 1 year revealed no increase in aneurysm size, no device migration, and no new endoleaks. One patient had a limited proximal type I endoleak at 30 days that resolved at 60 days and remained sealed. One patient has an ongoing distal type I endoleak near the iliac bifurcation, with no change in aneurysm size at 12 months. Initial clinical experience with this novel intrasac anchoring prosthesis is promising, with successful aneurysm exclusion and good short-term results. This new device platform has the potential to address the anatomic restrictions and limitations of current endografts. Further studies with a longer follow-up time are needed. Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Value of C-Arm Cone Beam Computed Tomography Image Fusion in Maximizing the Versatility of Endovascular Robotics.

PubMed

Chinnadurai, Ponraj; Duran, Cassidy; Al-Jabbari, Odeaa; Abu Saleh, Walid K; Lumsden, Alan; Bismuth, Jean

2016-01-01

To report our initial experience and highlight the value of using intraoperative C-arm cone beam computed tomography (CT; DynaCT(®)) image fusion guidance along with steerable robotic endovascular catheter navigation to optimize vessel cannulation. Between May 2013 and January 2015, all patients who underwent endovascular procedures using DynaCT image fusion technique along with Hansen Magellan vascular robotic catheter were included in this study. As a part of preoperative planning, relevant vessel landmarks were electronically marked in contrast-enhanced multi-slice computed tomography images and stored. At the beginning of procedure, an intraoperative noncontrast C-arm cone beam CT (syngo DynaCT(®), Siemens Medical Solutions USA Inc.) was acquired in the hybrid suite. Preoperative images were then coregistered to intraoperative DynaCT images using aortic wall calcifications and bone landmarks. Stored landmarks were then overlaid on 2-dimensional (2D) live fluoroscopic images as virtual markers that are updated in real-time with C-arm, table movements and image zoom. Vascular access and robotic catheter (Magellan(®), Hansen Medical) was setup per standard. Vessel cannulation was performed based on electronic virtual markers on live fluoroscopy using robotic catheter. The impact of 3-dimensional (3D) image fusion guidance on robotic vessel cannulation was evaluated retrospectively, by assessing quantitative parameters like number of angiograms acquired before vessel cannulation and qualitative parameters like accuracy of vessel ostium and centerline markers. All 17 vessels were cannulated successfully in 14 patients' attempted using robotic catheter and image fusion guidance. Median vessel diameter at origin was 5.4 mm (range, 2.3-13 mm), whereas 12 of 17 (70.6%) vessels had either calcified and/or stenosed origin from parent vessel. Nine of 17 vessels (52.9 %) were cannulated without any contrast injection. Median number of angiograms required before cannulation was 0 (range, 0-2). On qualitative assessment, 14 of 15 vessels (93.3%) had grade = 1 accuracy (guidewire inside virtual ostial marker). Fourteen of 14 vessels had grade = 1 accuracy (virtual centerlines that matched with the actual vessel trajectory during cannulation). In this small series, the experience of using DynaCT image fusion guidance together with a steerable endovascular robotic catheter indicates that such image fusion strategies can enhance intraoperative 2D fluoroscopy by bringing preoperative 3D information about vascular stenosis and/or calcification, angulation, and take off from main vessel thereby facilitating ultimate vessel cannulation. Copyright © 2016 Elsevier Inc. All rights reserved.

Four-Dimensional CT of the Diaphragm in Children: Initial Experience

PubMed Central

2018-01-01

Objective To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. Materials and Methods In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. Results Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p < 0.0001), while the normal diaphragm motion was significantly smaller than the motion of the contralateral normal diaphragm in paralysis (4.5 ± 2.1 mm vs. 7.6 ± 3.8 mm, p = 0.01). Basal lung density change of the affected side was significantly smaller than that of the contralateral side in diaphragm paralysis (89 ± 73 Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). Conclusion The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children. PMID:29354007

A Novel ¹¹¹In-Labeled Anti-Prostate-Specific Membrane Antigen Nanobody for Targeted SPECT/CT Imaging of Prostate Cancer.

PubMed

Chatalic, Kristell L S; Veldhoven-Zweistra, Joke; Bolkestein, Michiel; Hoeben, Sander; Koning, Gerben A; Boerman, Otto C; de Jong, Marion; van Weerden, Wytske M

2015-07-01

Prostate-specific membrane antigen (PSMA) is overexpressed in prostate cancer (PCa) and a promising target for molecular imaging and therapy. Nanobodies (single-domain antibodies, VHH) are the smallest antibody-based fragments possessing ideal molecular imaging properties, such as high target specificity and rapid background clearance. We developed a novel anti-PSMA Nanobody (JVZ-007) for targeted imaging and therapy of PCa. Here, we report on the application of the (111)In-radiolabeled Nanobody for SPECT/CT imaging of PCa. A Nanobody library was generated by immunization of a llama with 4 human PCa cell lines. Anti-PSMA Nanobodies were captured by biopanning on PSMA-overexpressing cells. JVZ-007 was selected for evaluation as an imaging probe. JVZ-007 was initially produced with a c-myc-hexahistidine (his) tag allowing purification and detection. The c-myc-his tag was subsequently replaced by a single cysteine at the C terminus, allowing site-specific conjugation of chelates for radiolabeling. JVZ-007-c-myc-his was conjugated to 2-(4-isothiocyanatobenzyl)-diethylenetriaminepentaacetic acid (p-SCN-DTPA) via the lysines, whereas JVZ-007-cys was conjugated to maleimide-DTPA via the C-terminal cysteine. PSMA targeting was analyzed in vitro by cell-binding experiments using flow cytometry, autoradiography, and internalization assays with various PCa cell lines and patient-derived xenografts (PDXs). The targeting properties of radiolabeled Nanobodies were evaluated in vivo in biodistribution and SPECT/CT imaging experiments, using nude mice bearing PSMA-positive PC-310 and PSMA-negative PC-3 tumors. JVZ-007 was successfully conjugated to DTPA for radiolabeling with (111)In at room temperature. (111)In-JVZ007-c-myc-his and (111)In-JVZ007-cys internalized in LNCaP cells and bound to PSMA-expressing PDXs and, importantly, not to PSMA-negative PDXs and human kidneys. Good tumor targeting and fast blood clearance were observed for (111)In-JVZ-007-c-myc-his and (111)In-JVZ-007-cys. Renal uptake of (111)In-JVZ-007-c-myc-his was initially high but was efficiently reduced by coinjection of gelofusine and lysine. The replacement of the c-myc-his tag by the cysteine contributed to a further reduction of renal uptake without loss of targeting. PC-310 tumors were clearly visualized by SPECT/CT with both tracers, with low renal uptake (<4 percentage injected dose per gram) for (111)In-JVZ-007-cys already at 3 h after injection. We developed an (111)In-radiolabeled anti-PSMA Nanobody, showing good tumor targeting, low uptake in nontarget tissues, and low renal retention, allowing excellent SPECT/CT imaging of PCa within a few hours after injection. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

The Beatles, the Nobel Prize, and CT scanning of the chest.

PubMed

Goodman, Lawrence R

2010-01-01

From its first test scan on a mouse, in 1967, to current medical practice, the CT scanner has become a core imaging tool in thoracic diagnosis. Initially financed by money from Beatles' record sales, the first patient scan was performed in 1971. Only 8 years later, a Nobel Prize in Physics and Medicine was awarded to Hounsfield and Cormack for their discovery. This article traces the history of CT scanner development and how each technical advance expanded chest diagnostic frontiers. Chest imaging now accounts for 30% of all CT scanning.

Stone orientation affects the mechanism of failure in artificial kidney stones subject to shock waves

NASA Astrophysics Data System (ADS)

van Cauwelaert, Javier; Cleveland, Robin O.

2003-10-01

Micro computed tomography (CT) imaging was used to follow the progressive development of cracks in artificial kidney stones. The artificial stones were made from U30 cement with a cylindrical shape (6.5 mm diameter and 8.5 mm long). The stones were held within a polypropylene vial in one of three orientations: vertical, horizontal, and angled at 45 deg. The stones were treated with an electromagnetic lithotripter and the initiation and growth of cracks was observed using microCT. The images show that the orientation of the stones with respect to the shock changes the dominant mechanism for fragmentation. Vertical stones developed a spall-like crack near the distal surface, which propagated from the surface to the interior of the stone. Initiation of a secondary spall-like crack was observed proximal to the first crack. Little surface damage was observed. Horizontal stones presented pitting in the proximal surface and erosion in lateral faces, indicating the action of cavitation. Angled stones presented both spall-like fracture in either the leading or the distal corners and surface damage (pitting) in the proximal surface. Experiments are being performed to follow the development of cracks in human kidney stones. [Work supported by the Whitaker Foundation.

Kinetic analysis of Legionella inactivation using ozone in wastewater.

PubMed

Li, Jun; Li, Kunquan; Zhou, Yan; Li, Xuebin; Tao, Tao

2017-02-01

Legionella inactivation using ozone was studied in wastewater using kinetic analysis and modeling. The experimental results indicate that the relationship between the ozone concentration, germ concentration, and chemical oxygen demand (COD) can be used to predict variations in germ and COD concentrations. The ozone reaction with COD and inactivation of Legionella occurred simultaneously, but the reaction with COD likely occurred at a higher rate than the inactivation, as COD is more easily oxidized by ozone than Legionella. Higher initial COD concentrations resulted in a lower inactivation rate and higher lnN/N 0 . Higher temperature led to a higher inactivation efficiency. The relationship of the initial O 3 concentration and Legionella inactivation rate was not linear, and thus, the Ct value required for a 99.99% reduction was not constant. The initial O 3 concentration was more important than the contact time, and a reduction of the initial O 3 concentration could not be compensated by increasing the contact time. The Ct values were compared over a narrow range of initial concentrations; the Ct values could only be contrasted when the initial O 3 concentrations were very similar. A higher initial O 3 concentration led to a higher inflection point value for the lnN/N 0 vs C 0 t curve. Energy consumption using a plasma corona was lower than when using boron-doped diamond electrodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Incidence of Brain Metastases on Follow-up 18F-FDG PET/CT Scans of Non-Small Cell Lung Cancer Patients: Should We Include the Brain?

PubMed

Nia, Emily S; Garland, Linda L; Eshghi, Naghmehossadat; Nia, Benjamin B; Avery, Ryan J; Kuo, Phillip H

2017-09-01

The brain is the most common site of distant metastasis from lung cancer. Thus, MRI of the brain at initial staging is routinely performed, but if this examination is negative a follow-up examination is often not performed. This study evaluates the incidence of asymptomatic brain metastases in non-small cell lung cancer patients detected on follow-up 18 F-FDG PET/CT scans. Methods: In this Institutional Review Board-approved retrospective review, all vertex to thigh 18 F-FDG PET/CT scans in patients with all subtypes of lung cancer from August 2014 to August 2016 were reviewed. A total of 1,175 18 F-FDG PET/CT examinations in 363 patients were reviewed. Exclusion criteria included brain metastases on initial staging, histologic subtype of small-cell lung cancer, and no follow-up 18 F-FDG PET/CT examinations. After our exclusion criteria were applied, a total of 809 follow-up 18 F-FDG PET/CT scans in 227 patients were included in the final analysis. The original report of each 18 F-FDG PET/CT study was reviewed for the finding of brain metastasis. The finding of a new brain metastasis prompted a brain MRI, which was reviewed to determine the accuracy of the 18 F-FDG PET/CT. Results: Five of 227 patients with 809 follow-up 18 F-FDG PET/CT scans reviewed were found to have incidental brain metastases. The mean age of the patients with incidental brain metastasis was 68 y (range, 60-77 y). The mean time from initial diagnosis to time of detection of incidental brain metastasis was 36 mo (range, 15-66 mo). When MRI was used as the gold standard, our false-positive rate was zero. Conclusion: By including the entire head during follow-up 18 F-FDG PET/CT scans of patients with non-small cell lung cancer, brain metastases can be detected earlier while still asymptomatic. But, given the additional scan time, radiation, and low incidence of new brain metastases in asymptomatic patients, the cost-to-benefit ratio should be weighed by each institution. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

The Impact of Health Education Counseling on Rate of Recurrent Sexually Transmitted Infections in Adolescents.

PubMed

In-Iw, Supinya; Braverman, Paula K; Bates, Justin R; Biro, Frank M

2015-12-01

To evaluate the effectiveness of a sexually transmitted infection (STI) intervention by a health educator that included partner notification, condom use, and retesting within 3 months. Retrospective chart review was conducted, and data were collected from 274 sexually active adolescent girls, aged 15 to 19 years, who were diagnosed with gonorrhea (GC), Chlamydia (CT), and Trichomonas (TV) infection, during a 9-month span in an urban hospital-based adolescent medicine clinic. Data regarding recurrent STIs (GC, CT, and TV) were collected for 12 months following the incident infection. There were 161 in the intervention group (health educator counseling), and 113 controls who received usual care. Differences between groups were analyzed using χ(2) and survival analyses. There were no significant differences in age, gender, or race between the intervention and control groups at baseline. The majority in both groups were diagnosed initially with CT infection (57% CT, 16% GC, and 5% TV in the intervention group; 46% CT, 21% GC, and 12% TV in the control group). There was a significantly lower rate of STI in the intervention group for those retested within 12 months of the initial diagnosis (P = .002). The median (SD) time to recurrence in the intervention group was greater: 134 (14.7) days versus 116 (12.1) days (P = .034). Health education counseling, initial diagnosis with TV, and duration of time from initial diagnosis to retest (interval to retest) were significant protective factors for recurrent STI. Health education counseling in an urban adolescent clinic is effective in reducing recurrent infection at 12-month follow-up and can serve as an important component in reducing STI recidivism. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Longitudinal Assessment of Synovial, Lymph Node, and Bone Volumes in Inflammatory Arthritis in Mice using in vivo MRI and micro-CT

PubMed Central

Proulx, Steven T.; Kwok, Edmund; You, Zhigang; Papuga, M. Owen; Beck, Christopher A.; Shealy, David J.; Ritchlin, Christopher T.; Awad, Hani A.; Boyce, Brendan F.; Xing, Lianping; Schwarz, Edward M.

2009-01-01

Objective Development of longitudinal 3D outcomes of inflammation and bone erosion in murine arthritis using contrast enhanced (CE) MRI and in vivo micro-CT; and in a pilot study, to determine the value of entrance criteria by age versus synovial volume in therapeutic intervention studies. Methods CE-MRI and in vivo micro-CT was performed on TNF-Tg and WT littermates to quantify the synovial and popliteal lymph node (LN) volumes and patella and talus bone volumes, respectively, which were validated with histology. These longitudinal outcome measures were used to assess the natural history of inflammatory-erosive arthritis. We also performed anti-TNF versus placebo efficacy studies in TNF-Tg mice in which treatment was initiated either by age (4–5 months) or synovial volume (3mm3 as detected by CE-MRI). Linear regression was performed to analyze the correlation between synovitis and focal erosion. Results CE-MRI demonstrated the highly variable nature of TNF-induced joint inflammation. Initiation of treatment by synovial volume produced significantly larger treatment effects on synovial volume (p=0.04) and lymph node volume (p<0.01) than initiation by age. By correlating the MRI and microCT data we were able to demonstrate a significant relationship between changes in synovial and patellar volumes (R2 =0.75; p<0.01). Conclusion In vivo CE-MRI and micro-CT 3D outcome measures are powerful tools that accurately demonstrate the progression of inflammatory-erosive arthritis in mice. These methods can be used to identify mice with arthritis of similar severity before intervention studies are initiated and thus minimize heterogeneity in outcome studies of chronic arthritis seen between genetically identical littermates. PMID:18050199

68Ga-Labeled Anti-Prostate-Specific Membrane Antigen Peptide as Marker for Androgen Deprivation Therapy Response in Prostate Cancer.

PubMed

Schlenkhoff, Carl Diedrich; Gaertner, Florian; Essler, Markus; Hauser, Stefan; Ahmadzadehfar, Hojjat

2016-05-01

Prostate cancer was diagnosed in a 71-year-old man with an elevated prostate-specific antigen. The CT of the abdomen showed multiple para-aortal lymph nodes, and thus, a Ga anti-prostate-specific membrane antigen (PSMA-11) PET/CT was initiated, which showed, aside from the prostate cancer and multiple iliacal and para-aortal lymph node metastases, an increased tracer uptake in a lymph node left cervical. According to this advanced disease, a palliative therapy with GnRH agonist was initiated. A second PSMA-11 PET/CT was performed 4 months later, which showed a very good response; thus, additional radiation of the pelvis and the draining lymphatic system was performed.

Association between Smoking and the Progression of Computed Tomography Findings in Chronic Pancreatitis.

PubMed

Lee, Jeong Woo; Kim, Ho Gak; Lee, Dong Wook; Han, Jimin; Kwon, Hyuk Yong; Seo, Chang Jin; Oh, Ji Hye; Lee, Joo Hyoung; Jung, Jin Tae; Kwon, Joong Goo; Kim, Eun Young

2016-05-23

Smoking and alcohol intake are two wellknown risk factors for chronic pancreatitis. However, there are few studies examining the association between smoking and changes in computed tomography (CT) findings in chronic pancreatitis. The authors evaluated associations between smoking, drinking and the progression of calcification on CT in chronic pancreatitis. In this retrospective study, 59 patients with chronic pancreatitis who had undergone initial and follow-up CT between January 2002 and September 2010 were included. Progression of calcification among CT findings was compared according to the amount of alcohol intake and smoking. The median duration of followup was 51.6 months (range, 17.1 to 112.7 months). At initial CT findings, there was pancreatic calcification in 35 patients (59.3%). In the follow-up CT, progression of calcification was observed in 37 patients (62.7%). Progression of calcification was more common in smokers according to the multivariate analysis (odds ratio [OR], 9.987; p=0.006). The amount of smoking was a significant predictor for progression of calcification in the multivariate analysis (OR, 6.051 in less than 1 pack per day smokers; OR, 36.562 in more than 1 pack per day smokers; p=0.008). Continued smoking accelerates pancreatic calcification, and the amount of smoking is associated with the progression of calcification in chronic pancreatitis.

Reaction-induced porosity fingering: Replacement dynamic and porosity evolution in the KBr-KCl system

NASA Astrophysics Data System (ADS)

Beaudoin, Nicolas; Hamilton, Andrea; Koehn, Daniel; Shipton, Zoe Kai; Kelka, Ulrich

2018-07-01

In this contribution, we use X-ray computed micro-tomography (X-CT) to observe and quantify dynamic pattern and porosity formation in a fluid-mediated replacement reaction. The evolution of connected porosity distribution helps to understand how fluid can migrate through a transforming rock, for example during dolomitization, a phenomenon extensively reported in sedimentary basins. Two types of experiment were carried out, in both cases a single crystal of KBr was immersed in a static bath of saturated aqueous KCl at room temperature and atmospheric pressure, and in both cases the replacement process was monitored in 3D using X-CT. In the first type of experiment a crystal of KBr was taken out, scanned, and returned to the solution in cycles (discontinuous replacement). In the second type of experiment, 3 samples of KBr were continuously reacted for 15, 55 min and 5.5 h respectively, with the latter being replaced completely (continuous replacement). X-CT of KBr-KCl replacement offers new insights into dynamic porosity development and transport mechanisms during replacement. As the reaction progresses the sample composition changes from KBr to KCl via a K(Br, Cl) solid solution series which generates porosity in the form of fingers that account for a final molar volume reduction of 13% when pure KCl is formed. These fingers form during an initial and transient advection regime followed by a diffusion dominated system, which is reflected by the reaction propagation, front morphology, and mass evolution. The porosity develops as fingers perpendicular to the sample walls, which allow a faster transport of reactant than in the rest of the crystal, before fingers coarsen and connect laterally. In the continuous experiment, finger coarsening has a dynamic behaviour consistent with fingering processes observed in nature. In the discontinuous experiment, which can be compared to rock weathering or to replacement driven by intermittent fluid contact, the pore structure changes from well-organized parallel fingers to a complex 3D connected network, shedding light on the alteration of reservoir properties during weathering.

Comprehensive CT Evaluation in Acute Ischemic Stroke: Impact on Diagnosis and Treatment Decisions

PubMed Central

Löve, Askell; Siemund, Roger; Andsberg, Gunnar; Cronqvist, Mats; Holtås, Stig; Björkman-Burtscher, Isabella

2011-01-01

Background. With modern CT imaging a comprehensive overview of cerebral macro- and microcirculation can be obtained within minutes in acute ischemic stroke. This opens for patient stratification and individualized treatment. Methods. Four patients with acute ischemic stroke of different aetiologies and/or treatments were chosen for illustration of the comprehensive CT protocol and its value in subsequent treatment decisions. The patients were clinically evaluated according to the NIHSS-scale, examined with the comprehensive CT protocol including both CT angiography and CT perfusion, and followed up by MRI. Results. The comprehensive CT examination protocol increased the examination time but did not delay treatment initiation. In some cases CT angiography revealed the cause of stroke while CT perfusion located and graded the perfusion defect with reasonable accuracy, confirmed by follow-up MR-diffusion. In the presented cases findings of the comprehensive CT examination influenced the treatment strategy. Conclusions. The comprehensive CT examination is a fast and safe method allowing accurate diagnosis and making way for individualized treatment in acute ischemic stroke. PMID:21603175

How to use PET/CT in the evaluation of response to radiotherapy.

PubMed

Decazes, Pierre; Thureau, Sébastien; Dubray, Bernard; Vera, Pierre

2018-06-01

Radiotherapy is a major treatment modality for many cancers. Tumor response after radiotherapy determines the subsequent steps of the patient's management (surveillance, adjuvant or salvage treatment and palliative care). Tumor response assessed during radiotherapy offers a promising opportunity to adapt the treatment plan to reduced or increased target volume, to specifically target sub-volumes with relevant biological characteristics (metabolism, hypoxia, proliferation, etc.) and to further spare the organs at risk. In addition to its role in the diagnosis and the initial staging, Positron Emission Tomography combined with a Computed Tomography (PET/CT) provides functional information and is therefore attractive to evaluate tumor response. The aim of this paper is to review the published data addressing PET/CT as an evaluation tool in irradiated tumors. Reports on PET/CT acquired at various times (during radiotherapy, after initial (chemo-) radiotherapy, after definitive radiotherapy and during posttreatment follow-up) in solid tumors (lung, head-and-neck, cervix, esophagus, prostate and rectum) were collected and reviewed. Various tracers and technical aspects are also discussed. 18F-FDG PET/CT has a well-established role in clinical routine after definitive chemo-radiotherapy for locally advanced head-and-neck cancers. 18F-choline PET/CT is indicated in prostate cancer patients with biochemical failure. 18F-FDG PET/CT is optional in many other circumstances and the clinical benefits of assessing tumor response with PET/CT remain a field of very active research. The combination of PET with Magnetic Resonance Imaging (PET/MRI) may prove to be valuable in irradiated rectal and cervix cancers. Tumor response can be evaluated by PET/CT with clinical consequences in multiple situations, notably in head and neck and prostate cancers, after radiotherapy. Further clinical evaluation for most cancers is still needed, possibly in association to MRI.

Chronic Obstructive Pulmonary Disease Exacerbations in the COPDGene Study: Associated Radiologic Phenotypes

PubMed Central

Kazerooni, Ella A.; Lynch, David A.; Liu, Lyrica X.; Murray, Susan; Curtis, Jeffrey L.; Criner, Gerard J.; Kim, Victor; Bowler, Russell P.; Hanania, Nicola A.; Anzueto, Antonio R.; Make, Barry J.; Hokanson, John E.; Crapo, James D.; Silverman, Edwin K.; Martinez, Fernando J.; Washko, George R.

2011-01-01

Purpose: To test the hypothesis—given the increasing emphasis on quantitative computed tomographic (CT) phenotypes of chronic obstructive pulmonary disease (COPD)—that a relationship exists between COPD exacerbation frequency and quantitative CT measures of emphysema and airway disease. Materials and Methods: This research protocol was approved by the institutional review board of each participating institution, and all participants provided written informed consent. One thousand two subjects who were enrolled in the COPDGene Study and met the GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria for COPD with quantitative CT analysis were included. Total lung emphysema percentage was measured by using the attenuation mask technique with a −950-HU threshold. An automated program measured the mean wall thickness and mean wall area percentage in six segmental bronchi. The frequency of COPD exacerbation in the prior year was determined by using a questionnaire. Statistical analysis was performed to examine the relationship of exacerbation frequency with lung function and quantitative CT measurements. Results: In a multivariate analysis adjusted for lung function, bronchial wall thickness and total lung emphysema percentage were associated with COPD exacerbation frequency. Each 1-mm increase in bronchial wall thickness was associated with a 1.84-fold increase in annual exacerbation rate (P = .004). For patients with 35% or greater total emphysema, each 5% increase in emphysema was associated with a 1.18-fold increase in this rate (P = .047). Conclusion: Greater lung emphysema and airway wall thickness were associated with COPD exacerbations, independent of the severity of airflow obstruction. Quantitative CT can help identify subgroups of patients with COPD who experience exacerbations for targeted research and therapy development for individual phenotypes. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110173/-/DC1 PMID:21788524

Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom.

PubMed

Yamashiro, Tsuneo; Tsubakimoto, Maho; Nagatani, Yukihiro; Moriya, Hiroshi; Sakuma, Kotaro; Tsukagoshi, Shinsuke; Inokawa, Hiroyasu; Kimoto, Tatsuya; Teramoto, Ryuichi; Murayama, Sadayuki

2015-01-01

The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software. A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale. It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%. It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases.

Utility of the PET-CT in the evaluation of early response to treatment in the diffuse large B-cell lymphoma. Preliminary results.

PubMed

Cortés Romera, M; Gámez Cenzano, C; Caresia Aróztegui, A P; Martín-Comín, J; González-Barca, E; Ricart Brulles, Y; Palacios Abufón, A; Robles Barba, J; Rodríguez-Bel, L; Rossi Seoane, S; Fernández de Sevilla, A

2012-01-01

To assess the role of FDG-PET/CT performed after the first cycles of chemotherapy in the prediction of response to treatment in patients with diffuse large B-cell lymphoma. Twenty patients (mean age: 48 years) were included, 16 initial staging and 4 relapse. All patients underwent PET/CT at 3 times: 1) Baseline, 2) After 1-3 cycles of chemotherapy (early response assessment), and 3) End of treatment (evaluation of final response). Early PET/CT findings were correlated to the end-treatment PET/CT and follow-up. The evaluation of the response was established according to the decrease in uptake of the lesions (SUVmax). In the early assessment, a good response indicator (GRI) was obtained when the lesion disappeared or had more than 50% reduction in SUVmax. At the end of the treatment, a complete metabolic response (CMR) was determined in negative PET scans. Follow-up was superior to 19 months and final outcome was established as progression/relapse or no evidence of disease (NED). At the early treatment evaluation, 16/16 patients of initial staging (100%) and 2/4 of relapse (50%) achieved GRI. At the end of treatment evaluation, 14/16 patients of initial staging with GRI achieved CMR and 1/16 PMR: 14 were alive with NED in the follow-up while 1 relapsed. In the second group, 2/2 patients with GRI achieved CMR (100%): 1 continued with NED in the follow-up and another relapsed. FDG-PET/CT after the first cycles of chemotherapy is useful to monitor treatment due to its high negative predictive value (87.5%), using it to modify treatment early in the non-responders. Copyright © 2011 Elsevier España, S.L. y SEMNIM. All rights reserved.

Attenuation-emission alignment in cardiac PET∕CT based on consistency conditions

PubMed Central

Alessio, Adam M.; Kinahan, Paul E.; Champley, Kyle M.; Caldwell, James H.

2010-01-01

Purpose: In cardiac PET and PET∕CT imaging, misaligned transmission and emission images are a common problem due to respiratory and cardiac motion. This misalignment leads to erroneous attenuation correction and can cause errors in perfusion mapping and quantification. This study develops and tests a method for automated alignment of attenuation and emission data. Methods: The CT-based attenuation map is iteratively transformed until the attenuation corrected emission data minimize an objective function based on the Radon consistency conditions. The alignment process is derived from previous work by Welch et al. [“Attenuation correction in PET using consistency information,” IEEE Trans. Nucl. Sci. 45, 3134–3141 (1998)] for stand-alone PET imaging. The process was evaluated with the simulated data and measured patient data from multiple cardiac ammonia PET∕CT exams. The alignment procedure was applied to simulations of five different noise levels with three different initial attenuation maps. For the measured patient data, the alignment procedure was applied to eight attenuation-emission combinations with initially acceptable alignment and eight combinations with unacceptable alignment. The initially acceptable alignment studies were forced out of alignment a known amount and quantitatively evaluated for alignment and perfusion accuracy. The initially unacceptable studies were compared to the proposed aligned images in a blinded side-by-side review. Results: The proposed automatic alignment procedure reduced errors in the simulated data and iteratively approaches global minimum solutions with the patient data. In simulations, the alignment procedure reduced the root mean square error to less than 5 mm and reduces the axial translation error to less than 1 mm. In patient studies, the procedure reduced the translation error by >50% and resolved perfusion artifacts after a known misalignment for the eight initially acceptable patient combinations. The side-by-side review of the proposed aligned attenuation-emission maps and initially misaligned attenuation-emission maps revealed that reviewers preferred the proposed aligned maps in all cases, except one inconclusive case. Conclusions: The proposed alignment procedure offers an automatic method to reduce attenuation correction artifacts in cardiac PET∕CT and provides a viable supplement to subjective manual realignment tools. PMID:20384256

Evaluation of an imaging protocol using ultrasound as the primary diagnostic modality in pediatric patients with superficial soft tissue infections of the face and neck.

PubMed

Sethia, Rishabh; Mahida, Justin B; Subbarayan, Rahul A; Deans, Katherine J; Minneci, Peter C; Elmaraghy, Charles A; Essig, Garth F

2017-05-01

To determine the clinical impact of an initiative to use ultrasound (US) as the primary diagnostic modality for children with superficial face and neck infections versus use of computed tomography (CT). Children with a diagnosis of lymphadenitis, face or neck abscess, or face and neck cellulitis were retrospectively evaluated by the otolaryngology service. Patients were separated into two groups based on implementation of a departmental initiative to use US as the primary diagnostic modality. The pre-implementation cohort consisted of patients treated prior to the initiative (2006-2009) and the current protocol cohort consisted of patients treated after the initiative was started (2010-2013). Demographics, use of US or CT, necessity of surgical intervention, and failure of medical management were compared. Three hundred seventy three children were evaluated; 114 patients were included in the pre-implementation cohort and 259 patients were included in the current protocol cohort for comparison. Patients presenting during the current protocol period were more likely to undergo US (pre-implementation vs. current protocol, p-value) (12% vs. 49%, p < 0.0001) and less likely to undergo CT (66% vs. 41%, p < 0.0001) for their initial evaluation. There were no differences in the percentage of children who underwent prompt surgical drainage, prompt discharge without surgery, or trial inpatient observation. There were also no differences in the rate of treatment failure for patients undergoing prompt surgery or prompt discharge on antibiotics. For those patients who underwent repeat evaluation following trial medical management, US was used more frequently in the current protocol period (4% vs. 20%, p = 0.002) with no difference in CT use, selected treatment strategy, or treatment failure rates. Increased use of US on initial evaluation of children with superficial face and neck infections resulted in decreased CT utilization, without negatively impacting outcome. Decreasing pediatric radiation exposure and potential long-term effects is of primary importance. Copyright © 2017. Published by Elsevier B.V.

Quantitative CT Evaluation of Small Pulmonary Vessels in Patients with Acute Pulmonary Embolism.

PubMed

Matsuoka, Shin; Kotoku, Akiyuki; Yamashiro, Tsuneo; Matsushita, Shoichiro; Fujikawa, Atsuko; Yagihashi, Kunihiro; Nakajima, Yasuo

2018-05-01

The objective of this study was to investigate the correlation between the computed tomography (CT) cross-sectional area (CSA) of small pulmonary vessels and the CT obstruction index in patients with acute pulmonary embolism (PE) and the correlation between the changes in these measurements after anticoagulant therapy. Fifty-two patients with acute PE were selected for this study. We measured the CSA less than 5 mm 2 on coronal reconstructed images to obtain the percentage of the CSA (%CSA < 5). CT angiographic index was obtained based on the Qanadli method for the evaluation of the degree of pulmonary arterial obstruction. Spearman rank correlation analysis was used to evaluate the relationship between the initial and the follow-up values and changes in the %CSA < 5 and the CT obstruction index. There was no significant correlation between the %CSA < 5 and CT obstruction index on both initial (ρ = -0.03, P = 0.84) and follow-up (ρ = -0.03, P = 0.82) assessments. In contrast, there was a significant negative correlation between the changes in %CSA < 5 and the CT obstruction index (ρ = -0.59, P < 0.0001). Although the absolute %CSA < 5 and CT obstruction index were not significantly correlated, the changes in the values of the two parameters had a significant correlation. Changes in %CSA < 5, which can be obtained easily, can be used as biomarker of therapeutic response in patients with acute PE. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Impact of creatine kinase correction on the predictive value of S-100B after mild traumatic brain injury.

PubMed

Bazarian, Jeffrey J; Beck, Christopher; Blyth, Brian; von Ahsen, Nicolas; Hasselblatt, Martin

2006-01-01

To validate a correction factor for the extracranial release of the astroglial protein, S-100B, based on concomitant creatine kinase (CK) levels. The CK- S-100B relationship in non-head injured marathon runners was used to derive a correction factor for the extracranial release of S-100B. This factor was then applied to a separate cohort of 96 mild traumatic brain injury (TBI) patients in whom both CK and S-100B levels were measured. Corrected S-100B was compared to uncorrected S-100B for the prediction of initial head CT, three-month headache and three-month post concussive syndrome (PCS). Corrected S-100B resulted in a statistically significant improvement in the prediction of 3-month headache (area under curve [AUC] 0.46 vs 0.52, p=0.02), but not PCS or initial head CT. Using a cutoff that maximizes sensitivity (> or = 90%), corrected S-100B improved the prediction of initial head CT scan (negative predictive value from 75% [95% CI, 2.6%, 67.0%] to 96% [95% CI: 83.5%, 99.8%]). Although S-100B is overall poorly predictive of outcome, a correction factor using CK is a valid means of accounting for extracranial release. By increasing the proportion of mild TBI patients correctly categorized as low risk for abnormal head CT, CK-corrected S100-B can further reduce the number of unnecessary brain CT scans performed after this injury.

Effects of vitamin K2 (menatetrenone) and alendronate on bone mineral density and bone strength in rats fed a low-magnesium diet.

PubMed

Kobayashi, M; Hara, K; Akiyama, Y

2004-11-01

In this study, we examined changes in bone parameters and bone strength in rats fed low-Mg diets (experiment 1) and the effects of vitamin K2 (MK-4, experiment 3) and alendronate (ALN, experiment 2) in this model. In experiment 1, 5-week-old male Wistar rats were fed three low-Mg diets (Mg 9, 6, 3 mg/100 g diet) for 4 weeks. Although the cortical bone mineral content (CtBMC) and cortical thickness (CtTh) of the femoral diaphysis in all low-Mg-diet groups were the same as or greater than those in the intact group (Mg: 90 mg/100 g diet), the maximum load and elastic modulus were significantly reduced in the 3-mg-Mg group. In experiment 2, 4-week-old Wistar rats were fed a 6-mg-Mg diet for 8 weeks, and the effect of ALN (2, 20, and 200 microg/kg twice a week) was evaluated. The administration of ALN at 200 microg/kg increased the cortical bone mineral content (CtBMC), CtTh, and maximum load, but had no effect on the elastic modulus, as compared with the low-Mg-control group. In experiment 3, the effect of MK-4 was evaluated under the same conditions as in experiment 2. The administration of MK-4 had no effect on CtBMC, CtTh, or bone components of the femoral diaphysis. However, MK-4 inhibited the decreases in maximum load and elastic modulus due to the low-Mg diet. Since there is no other experimental model in which there is a decrease in bone mechanical properties without a decrease in bone mineral content, the low-Mg diet model is considered to be an excellent model for examining bone quality. Our results from this model suggest that MK-4 and ALN affect bone mechanical properties by different mechanisms.

High-performance C-arm cone-beam CT guidance of thoracic surgery

NASA Astrophysics Data System (ADS)

Schafer, Sebastian; Otake, Yoshito; Uneri, Ali; Mirota, Daniel J.; Nithiananthan, Sajendra; Stayman, J. W.; Zbijewski, Wojciech; Kleinszig, Gerhard; Graumann, Rainer; Sussman, Marc; Siewerdsen, Jeffrey H.

2012-02-01

Localizing sub-palpable nodules in minimally invasive video-assisted thoracic surgery (VATS) presents a significant challenge. To overcome inherent problems of preoperative nodule tagging using CT fluoroscopic guidance, an intraoperative C-arm cone-beam CT (CBCT) image-guidance system has been developed for direct localization of subpalpable tumors in the OR, including real-time tracking of surgical tools (including thoracoscope), and video-CBCT registration for augmentation of the thoracoscopic scene. Acquisition protocols for nodule visibility in the inflated and deflated lung were delineated in phantom and animal/cadaver studies. Motion compensated reconstruction was implemented to account for motion induced by the ventilated contralateral lung. Experience in CBCT-guided targeting of simulated lung nodules included phantoms, porcine models, and cadavers. Phantom studies defined low-dose acquisition protocols providing contrast-to-noise ratio sufficient for lung nodule visualization, confirmed in porcine specimens with simulated nodules (3-6mm diameter PE spheres, ~100-150HU contrast, 2.1mGy). Nodule visibility in CBCT of the collapsed lung, with reduced contrast according to air volume retention, was more challenging, but initial studies confirmed visibility using scan protocols at slightly increased dose (~4.6-11.1mGy). Motion compensated reconstruction employing a 4D deformation map in the backprojection process reduced artifacts associated with motion blur. Augmentation of thoracoscopic video with renderings of the target and critical structures (e.g., pulmonary artery) showed geometric accuracy consistent with camera calibration and the tracking system (2.4mm registration error). Initial results suggest a potentially valuable role for CBCT guidance in VATS, improving precision in minimally invasive, lungconserving surgeries, avoid critical structures, obviate the burdens of preoperative localization, and improve patient safety.

Dissolution-induced preferential flow in a limestone fracture.

PubMed

Liu, Jishan; Polak, Amir; Elsworth, Derek; Grader, Avrami

2005-06-01

Flow in a rock fracture is surprisingly sensitive to the evolution of flow paths that develop as a result of dissolution. Net dissolution may either increase or decrease permeability uniformly within the fracture, or may form a preferential flow path through which most of the injected fluid flows, depending on the prevailing ambient mechanical and chemical conditions. A flow-through test was completed on an artificial fracture in limestone at room temperature under ambient confining stress of 3.5 MPa. The sample was sequentially circulated by water of two different compositions through the 1500 h duration of the experiment; the first 935 h by tap groundwater, followed by 555 h of distilled water. Measurements of differential pressures between the inlet and the outlet, fluid and dissolved mass fluxes, and concurrent X-ray CT imaging and sectioning were used to characterize the evolution of flow paths within the limestone fracture. During the initial circulation of groundwater, the differential pressure increased almost threefold, and was interpreted as a net reduction in permeability as the contacting asperities across the fracture are removed, and the fracture closes. With the circulation of distilled water, permeability initially reduces threefold, and ultimately increases by two orders of magnitude. This spontaneous switch from net decrease in permeability, to net increase occurred with no change in flow rate or applied effective stress, and is attributed to the evolving localization of flow path as evidenced by CT images. Based on the X-ray CT characterizations, a flow path-dependent flow model was developed to simulate the evolution of flow paths within the fracture and its influence on the overall flow behaviors of the injected fluid in the fracture.

Facilitating Intellectual Liberation, Engaging the Null Curriculum, and WebCT

ERIC Educational Resources Information Center

Wojcik, Teresa G.; Titone, Connie

2015-01-01

College professors seek to create intellectual experiences that free students from false perceptions and incomplete truths. This article explores one curricular decision and an accompanying pedagogical approach which, the authors argue, facilitates such a liberating experience. In the online environment of WebCT, students post their reactions to…

Perfusion CT helps decision making for thrombolysis when there is no clear time of onset

PubMed Central

Hellier, K D; Hampton, J L; Guadagno, J V; Higgins, N P; Antoun, N M; Day, D J; Gillard, J H; Warburton, E A; Baron, J‐C

2006-01-01

Current guidelines on thrombolysis post stroke with recombinant tissue plasminogen activator (rt‐PA) exclude its use where time of onset is unknown, thus denying some patients potentially beneficial treatment. Contrast enhanced perfusion computed tomography (pCT) imaging can be used together with plain CT and information on clinical deficits to decide whether or not thrombolysis should be initiated even though the exact time of stroke onset is unknown. Based on the results of pCT and CT, rt‐PA was administered to two patients with unknown time of stroke onset; one of the patients also underwent suction thrombectomy. Results in both cases were excellent. PMID:16484659

Stress-Induced Fracturing of Reservoir Rocks: Acoustic Monitoring and μCT Image Analysis

NASA Astrophysics Data System (ADS)

Pradhan, Srutarshi; Stroisz, Anna M.; Fjær, Erling; Stenebråten, Jørn F.; Lund, Hans K.; Sønstebø, Eyvind F.

2015-11-01

Stress-induced fracturing in reservoir rocks is an important issue for the petroleum industry. While productivity can be enhanced by a controlled fracturing operation, it can trigger borehole instability problems by reactivating existing fractures/faults in a reservoir. However, safe fracturing can improve the quality of operations during CO2 storage, geothermal installation and gas production at and from the reservoir rocks. Therefore, understanding the fracturing behavior of different types of reservoir rocks is a basic need for planning field operations toward these activities. In our study, stress-induced fracturing of rock samples has been monitored by acoustic emission (AE) and post-experiment computer tomography (CT) scans. We have used hollow cylinder cores of sandstones and chalks, which are representatives of reservoir rocks. The fracture-triggering stress has been measured for different rocks and compared with theoretical estimates. The population of AE events shows the location of main fracture arms which is in a good agreement with post-test CT image analysis, and the fracture patterns inside the samples are visualized through 3D image reconstructions. The amplitudes and energies of acoustic events clearly indicate initiation and propagation of the main fractures. Time evolution of the radial strain measured in the fracturing tests will later be compared to model predictions of fracture size.

A Method for Extracting Suspected Parotid Lesions in CT Images using Feature-based Segmentation and Active Contours based on Stationary Wavelet Transform

NASA Astrophysics Data System (ADS)

Wu, T. Y.; Lin, S. F.

2013-10-01

Automatic suspected lesion extraction is an important application in computer-aided diagnosis (CAD). In this paper, we propose a method to automatically extract the suspected parotid regions for clinical evaluation in head and neck CT images. The suspected lesion tissues in low contrast tissue regions can be localized with feature-based segmentation (FBS) based on local texture features, and can be delineated with accuracy by modified active contour models (ACM). At first, stationary wavelet transform (SWT) is introduced. The derived wavelet coefficients are applied to derive the local features for FBS, and to generate enhanced energy maps for ACM computation. Geometric shape features (GSFs) are proposed to analyze each soft tissue region segmented by FBS; the regions with higher similarity GSFs with the lesions are extracted and the information is also applied as the initial conditions for fine delineation computation. Consequently, the suspected lesions can be automatically localized and accurately delineated for aiding clinical diagnosis. The performance of the proposed method is evaluated by comparing with the results outlined by clinical experts. The experiments on 20 pathological CT data sets show that the true-positive (TP) rate on recognizing parotid lesions is about 94%, and the dimension accuracy of delineation results can also approach over 93%.

Recent Developments and Applications of Radiation/Detection Technology in Tsinghua University

NASA Astrophysics Data System (ADS)

Kang, Ke-Jun

2010-03-01

Nuclear technology applications have been very important research fields in Tsinghua University (THU) for more than 50 years. This paper describes two major directions and related projects running in THU concerning nuclear technology applications for radiation imaging and nuclear technology applications for astrophysics. Radiation imaging is a significant application of nuclear technology for all kinds of real world needs including security inspections, anti-smuggling operations, and medicine. The current improved imaging systems give much higher quality radiation images. THU has produced accelerating tubes for both industrial and medical accelerators with energy levels ranging from 2.5˜20Mev. Detectors have been produced for medical and industrial imaging as well as for high energy physics experiments such as the MRPC with fast time and position resolutions. DR and CT systems for radiation imaging systems have been continuously improved with new system designs and improved algorithms for image reconstruction and processing. Two important new key initiatives are the dual-energy radiography and dual-energy CT systems. Dual-energy CT imaging improves material discrimination by providing both the electron density and the atomic number distribution of scanned objects. Finally, this paper also introduces recent developments related to the hard X-ray modulation telescope (HXMT) provided by THU.

Diagnostic Value of 18F-FDG PET/CT Versus MRI in the Setting of Antibody-Specific Autoimmune Encephalitis.

PubMed

Solnes, Lilja B; Jones, Krystyna M; Rowe, Steven P; Pattanayak, Puskar; Nalluri, Abhinav; Venkatesan, Arun; Probasco, John C; Javadi, Mehrbod S

2017-08-01

Diagnosis of autoimmune encephalitis presents some challenges in the clinical setting because of varied clinical presentations and delay in obtaining antibody panel results. We examined the role of neuroimaging in the setting of autoimmune encephalitides, comparing the utility of 18 F-FDG PET/CT versus conventional brain imaging with MRI. Methods: A retrospective study was performed assessing the positivity rate of MRI versus 18 F-FDG PET/CT during the initial workup of 23 patients proven to have antibody-positive autoimmune encephalitis. 18 F-FDG PET/CT studies were analyzed both qualitatively and semiquantitatively. Areas of cortical lobar hypo (hyper)-metabolism in the cerebrum that were 2 SDx from the mean were recorded as abnormal. Results: On visual inspection, all patients were identified as having an abnormal pattern of 18 F-FDG uptake. In semiquantitative analysis, at least 1 region of interest with metabolic change was identified in 22 of 23 (95.6%) patients using a discriminating z score of 2. Overall, 18 F-FDG PET/CT was more often abnormal during the diagnostic period than MRI (10/23, 43% of patients). The predominant finding on brain 18 F-FDG PET/CT imaging was lobar hypometabolism, being observed in 21 of 23 (91.3%) patients. Hypometabolism was most commonly observed in the parietal lobe followed by the occipital lobe. An entire subset of antibody-positive patients, anti- N -methyl-d-aspartate receptor (5 patients), had normal MRI results and abnormal 18 F-FDG PET/CT findings whereas the other subsets demonstrated a greater heterogeneity. Conclusion: Brain 18 F-FDG PET/CT may play a significant role in the initial evaluation of patients with clinically suspected antibody-mediated autoimmune encephalitis. Given that it is more often abnormal when compared with MRI in the acute setting, this molecular imaging technique may be better positioned as an early biomarker of disease so that treatment may be initiated earlier, resulting in improved patient outcomes. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed.

PubMed

Haeussler, Silvia; Luepke, Matthias; Seifert, Hermann; Staszyk, Carsten

2014-02-21

In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity.To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp.

Intra-pulp temperature increase of equine cheek teeth during treatment with motorized grinding systems: influence of grinding head position and rotational speed

PubMed Central

2014-01-01

Background In equine practice, teeth corrections by means of motorized grinding systems are standard procedure. The heat resulting from that treatment may cause irreparable damage to the dental pulp. It has been shown that a 5.5°C temperature rise may cause severe destruction in pulp cells. Hence, the capability to continuously form secondary dentine is lost, and may lead, due to equine-typical occlusal tooth abrasion, to an opening of the pulp cavity. To obtain reliable data on the intra-pulp increase in temperature during corrective treatments, equine cheek teeth (CT) were modified in a way (occlusal surface smoothed, apical parts detached, pulp horns standardized) that had been qualified in own former published studies. All parameters influencing the grinding process were standardized (force applied, initial temperatures, dimensions of pulp horns, positioning of grinding disk, rotational speed). During grinding experiments, imitating real dental treatments, the time span for an intra-pulp temperature increase of 5.5°C was determined. Results The minimum time recorded for an intra-pulp temperature increase of 5.5°C was 38 s in mandibular CT (buccal grinding, 12,000 rpm) and 70 s in maxillary CT (flat occlusal grinding, 12,000 rpm). The data obtained showed that doubling the rotational speed of the disk results in halving the time span after which the critical intra-pulp temperature increase in maxillary CT is reached. For mandibular CT, the time span even drops by two thirds. Conclusion The use of standardized hypsodont CT enabled comparative studies of intra-pulp heating during the grinding of occlusal tooth surfaces using different tools and techniques. The anatomical structure of the natural vital hypsodont tooth must be kept in mind, so that the findings of this study do not create a deceptive sense of security with regard to the time-dependent heating of the native pulp. PMID:24559121

SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, J S; Ma, C

2014-06-01

Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system wasmore » used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use.« less

Spontaneous rectus sheath hematoma: The utility of CT angiography.

PubMed

Pierro, Antonio; Cilla, Savino; Modugno, Pietro; Centritto, Enrico Maria; De Filippo, Carlo Maria; Sallustio, Giuseppina

2018-04-01

We described the utility of computed tomography (CT) angiography in detection of bleeding vessels for a rapid percutaneous arterial embolization of the spontaneous rectus sheath hematoma. A 70-year-old woman comes to our attention with acute abdominal pain and a low hemoglobin level. An unenhanced CT was performed demonstrating a large rectus sheath hematoma. A conservative management was initially established. Despite this therapy, the abdominal pain increased together with a further decrease of hemoglobin values. A CT angiography was then performed, demonstrating an active bleeding within the hematoma and addressing the patient to a rapid percutaneous arterial embolization.

Common Postmortem Computed Tomography Findings Following Atraumatic Death: Differentiation between Normal Postmortem Changes and Pathologic Lesions

PubMed Central

Gonoi, Wataru; Okuma, Hidemi; Shirota, Go; Shintani, Yukako; Abe, Hiroyuki; Takazawa, Yutaka; Fukayama, Masashi; Ohtomo, Kuni

2015-01-01

Computed tomography (CT) is widely used in postmortem investigations as an adjunct to the traditional autopsy in forensic medicine. To date, several studies have described postmortem CT findings as being caused by normal postmortem changes. However, on interpretation, postmortem CT findings that are seemingly due to normal postmortem changes initially, may not have been mere postmortem artifacts. In this pictorial essay, we describe the common postmortem CT findings in cases of atraumatic in-hospital death and describe the diagnostic pitfalls of normal postmortem changes that can mimic real pathologic lesions. PMID:26175579

Robotically Driven CT-guided Needle Insertion: Preliminary Results in Phantom and Animal Experiments.

PubMed

Hiraki, Takao; Kamegawa, Tetsushi; Matsuno, Takayuki; Sakurai, Jun; Kirita, Yasuzo; Matsuura, Ryutaro; Yamaguchi, Takuya; Sasaki, Takanori; Mitsuhashi, Toshiharu; Komaki, Toshiyuki; Masaoka, Yoshihisa; Matsui, Yusuke; Fujiwara, Hiroyasu; Iguchi, Toshihiro; Gobara, Hideo; Kanazawa, Susumu

2017-11-01

Purpose To evaluate the accuracy of the remote-controlled robotic computed tomography (CT)-guided needle insertion in phantom and animal experiments. Materials and Methods In a phantom experiment, 18 robotic and manual insertions each were performed with 19-gauge needles by using CT fluoroscopic guidance for the evaluation of the equivalence of accuracy of insertion between the two groups with a 1.0-mm margin. Needle insertion time, CT fluoroscopy time, and radiation exposure were compared by using the Student t test. The animal experiments were approved by the institutional animal care and use committee. In the animal experiment, five robotic insertions each were attempted toward targets in the liver, kidneys, lungs, and hip muscle of three swine by using 19-gauge or 17-gauge needles and by using conventional CT guidance. The feasibility, safety, and accuracy of robotic insertion were evaluated. Results The mean accuracies of robotic and manual insertion in phantoms were 1.6 and 1.4 mm, respectively. The 95% confidence interval of the mean difference was -0.3 to 0.6 mm. There were no significant differences in needle insertion time, CT fluoroscopy time, or radiation exposure to the phantom between the two methods. Effective dose to the physician during robotic insertion was always 0 μSv, while that during manual insertion was 5.7 μSv on average (P < .001). Robotic insertion was feasible in the animals, with an overall mean accuracy of 3.2 mm and three minor procedure-related complications. Conclusion Robotic insertion exhibited equivalent accuracy as manual insertion in phantoms, without radiation exposure to the physician. It was also found to be accurate in an in vivo procedure in animals. © RSNA, 2017 Online supplemental material is available for this article.

Automatic lung nodule matching for the follow-up in temporal chest CT scans

NASA Astrophysics Data System (ADS)

Hong, Helen; Lee, Jeongjin; Shin, Yeong Gil

2006-03-01

We propose a fast and robust registration method for matching lung nodules of temporal chest CT scans. Our method is composed of four stages. First, the lungs are extracted from chest CT scans by the automatic segmentation method. Second, the gross translational mismatch is corrected by the optimal cube registration. This initial registration does not require extracting any anatomical landmarks. Third, initial alignment is step by step refined by the iterative surface registration. To evaluate the distance measure between surface boundary points, a 3D distance map is generated by the narrow-band distance propagation, which drives fast and robust convergence to the optimal location. Fourth, nodule correspondences are established by the pairs with the smallest Euclidean distances. The results of pulmonary nodule alignment of twenty patients are reported on a per-center-of mass point basis using the average Euclidean distance (AED) error between corresponding nodules of initial and follow-up scans. The average AED error of twenty patients is significantly reduced to 4.7mm from 30.0mm by our registration. Experimental results show that our registration method aligns the lung nodules much faster than the conventional ones using a distance measure. Accurate and fast result of our method would be more useful for the radiologist's evaluation of pulmonary nodules on chest CT scans.

A Hybrid Method for Pancreas Extraction from CT Image Based on Level Set Methods

PubMed Central

Tan, Hanqing; Fujita, Hiroshi

2013-01-01

This paper proposes a novel semiautomatic method to extract the pancreas from abdominal CT images. Traditional level set and region growing methods that request locating initial contour near the final boundary of object have problem of leakage to nearby tissues of pancreas region. The proposed method consists of a customized fast-marching level set method which generates an optimal initial pancreas region to solve the problem that the level set method is sensitive to the initial contour location and a modified distance regularized level set method which extracts accurate pancreas. The novelty in our method is the proper selection and combination of level set methods, furthermore an energy-decrement algorithm and an energy-tune algorithm are proposed to reduce the negative impact of bonding force caused by connected tissue whose intensity is similar with pancreas. As a result, our method overcomes the shortages of oversegmentation at weak boundary and can accurately extract pancreas from CT images. The proposed method is compared to other five state-of-the-art medical image segmentation methods based on a CT image dataset which contains abdominal images from 10 patients. The evaluated results demonstrate that our method outperforms other methods by achieving higher accuracy and making less false segmentation in pancreas extraction. PMID:24066016

[Analysis of 163 rib fractures by imaging examination].

PubMed

Song, Tian-fu; Wang, Chao-chao

2014-12-01

To explore the applications of imaging examination on rib fracture sites in forensic identification. Features including the sites, numbers of the processed imaging examination and the first radiological technology at diagnosis in 56 cases of rib fractures from 163 injuries were retrospectively analyzed. The detection rate of the rib fractures within 14 days was 65.6%. The initial detection rate of anterior rib fracture proceeded by X-ray was 76.2%, then 90.5% detected at a second time X-ray, while the detection rate of CT was 66.7% and 80.0%, respectively. The initial detec- tion rate of rib fracture in axillary section proceeded by X-ray was 27.6%, then 58.6% detected at a second time X-ray, while the detection rate of CT was 54.3% and 80.4%, respectively. The initial detection rate of posterior rib fracture proceeded by X-ray was 63.6%, then 81.8% detected at a second time X-ray, while the detection rate of CT was 50.0% and 70.0%, respectively. It is important to pay attention to the use of combined imaging examinations and the follow-up results. In the cases of suspicious for rib fracture in axillary section, CT examination is suggested in such false X-ray negative cases.

Postoperative Evaluation of Reduction Loss in Proximal Humeral Fractures: A Comparison of Plain Radiographs and Computed Tomography.

PubMed

Jia, Xiao-Yang; Chen, Yan-Xi; Qiang, Min-Fei; Zhang, Kun; Li, Hao-Bo; Jiang, Yu-Chen; Zhang, Yi-Jie

2017-05-01

To compare postoperative CT images with plain radiographs for measuring prognostic factors of reduction loss of fractures of the proximal part of the humerus. A total of 65 patients who sustained fractures of the proximal humerus treated with locking plates from June 2012 to October 2015 were retrospectively analyzed. There were 24 men and 41 women, with a mean age of 60.0 years (range, 22-76 years). According to the Neer classification system of proximal humeral fracture, there were 26 two-part, 27 three-part and 12 four-part fractures of the proximal part of the humerus, and all fractures were treated with open reduction and internal fixation (ORIF) using locked plating. All postoperative CT images and plain radiographs of the patients were obtained. Prognostic factors of the reduction loss were the change of neck shaft angle (NSA) and the change of humeral head height (HHH). The change of NSA and HHH were evaluated by the difference between postoperative initial and final follow-up measurement. Reduction loss was defined as the change ≥10° for NSA or ≥5 mm for HHH. The NSA and HHH were measured using plain radiographs and 3-D CT images, both initially and at final follow-up. The paired t-test was used for comparison of NSA, change of NSA, HHH, and change of HHH between two image modalities. The differences between two image modalities in the assessment of reduction loss were examined using the χ 2 -test (McNemar test). Intraclass correlation coefficients (ICC) were used to assess the intra-observer and inter-observer reliability. 3-D CT images (ICC range, 0.834-0.967) were more reliable in all parameters when compared with plain radiographs (ICC range, 0.598-0.915). Significant differences were found between the two image modalities in all parameters (plain radiographs: initial NSA = 133.6° ± 3.8°, final NSA = 130.0° ± 1.9°, initial HHH = 17.9 ± 0.9 mm, final HHH = 15.8 ± 1.5 mm; 3-D CT: initial NSA = 131.4° ± 3.4°, final NSA = 128.8° ± 1.7°, initial HHH = 16.8 ± 1.2 mm, final HHH = 14.5 ± 1.1 mm; all P < 0.05). In the assessment of reduction loss, the percentage was 16.9% (11/65) for the plain radiographs and 7.7% (5/65) for the 3-D CT scans (P < 0.05). For the 5 patients with reduction loss, which were observed by two imaging modalities, the mean Constant-Murley score was 61.0 ± 1.6. The patients with reduction loss, observed only in plain radiographs but not CT images, had good shoulder function (Constant-Murley score: 82.7 ± 1.0). Our data reveal that 3-D CT images are more reliable than plain radiographs in the assessment of the prognostic factors of reduction loss of fractures of the proximal part of the humerus with treatment of locking plates; this reliable CT technique can serve as an effective guideline for the subsequent clinical management of patients. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

CT of schistosomal calcification of the intestine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fataar, S.; Bassiony, H.; Satyanath, S.

1985-01-01

The spectrum of schistosomal colonic calcification on abdominal radiographs has been described. The appearance on computed tomography (CT) is equally distinctive and occurs with varying degrees of genitourinary calcification. The authors have experience in three cases with the appearance on CT of intestinal calcification due to schistosomiasis.

Contrast-enhanced small-animal PET/CT in cancer research: strong improvement of diagnostic accuracy without significant alteration of quantitative accuracy and NEMA NU 4-2008 image quality parameters.

PubMed

Lasnon, Charline; Quak, Elske; Briand, Mélanie; Gu, Zheng; Louis, Marie-Hélène; Aide, Nicolas

2013-01-17

The use of iodinated contrast media in small-animal positron emission tomography (PET)/computed tomography (CT) could improve anatomic referencing and tumor delineation but may introduce inaccuracies in the attenuation correction of the PET images. This study evaluated the diagnostic performance and accuracy of quantitative values in contrast-enhanced small-animal PET/CT (CEPET/CT) as compared to unenhanced small animal PET/CT (UEPET/CT). Firstly, a NEMA NU 4-2008 phantom (filled with 18F-FDG or 18F-FDG plus contrast media) and a homemade phantom, mimicking an abdominal tumor surrounded by water or contrast media, were used to evaluate the impact of iodinated contrast media on the image quality parameters and accuracy of quantitative values for a pertinent-sized target. Secondly, two studies in 22 abdominal tumor-bearing mice and rats were performed. The first animal experiment studied the impact of a dual-contrast media protocol, comprising the intravenous injection of a long-lasting contrast agent mixed with 18F-FDG and the intraperitoneal injection of contrast media, on tumor delineation and the accuracy of quantitative values. The second animal experiment compared the diagnostic performance and quantitative values of CEPET/CT versus UEPET/CT by sacrificing the animals after the tracer uptake period and imaging them before and after intraperitoneal injection of contrast media. There was minimal impact on IQ parameters (%SDunif and spillover ratios in air and water) when the NEMA NU 4-2008 phantom was filled with 18F-FDG plus contrast media. In the homemade phantom, measured activity was similar to true activity (-0.02%) and overestimated by 10.30% when vials were surrounded by water or by an iodine solution, respectively. The first animal experiment showed excellent tumor delineation and a good correlation between small-animal (SA)-PET and ex vivo quantification (r2 = 0.87, P < 0.0001). The second animal experiment showed a good correlation between CEPET/CT and UEPET/CT quantitative values (r2 = 0.99, P < 0.0001). Receiver operating characteristic analysis demonstrated better diagnostic accuracy of CEPET/CT versus UEPET/CT (senior researcher, area under the curve (AUC) 0.96 versus 0.77, P = 0.004; junior researcher, AUC 0.78 versus 0.58, P = 0.004). The use of iodinated contrast media for small-animal PET imaging significantly improves tumor delineation and diagnostic performance, without significant alteration of SA-PET quantitative accuracy and NEMA NU 4-2008 IQ parameters.

Predictive value of abdominal CT in evaluating internal herniation after bariatric laparoscopic Roux-en-Y gastric bypass.

PubMed

Ederveen, J C; van Berckel, M M G; Nienhuijs, S W; Weber, R J P; Nederend, J

2018-06-04

Internal herniation, a serious complication after bariatric surgery, is challenging to diagnose. The aim of this study was to determine the accuracy of abdominal CT in diagnosing internal herniation. The study included consecutive patients who had undergone laparoscopic gastric bypass surgery between 1 January 2011 and 1 January 2015 at a bariatric centre of excellence. To select patients suspected of having internal herniation, reports of abdominal CT and reoperations up to 1 January 2017 were screened. CT was presumed negative for internal herniation if no follow-up CT or reoperation was performed within 90 days after the initial CT, or no internal herniation was found during reoperation. The accuracy of abdominal CT in diagnosing internal herniation was calculated using two-way contingency tables. A total of 1475 patients were included (84·7 per cent women, mean age 46·5 years, median initial BMI 41·8 kg/m 2 ). CT and/or reoperation was performed in 192 patients (13·0 per cent) in whom internal herniation was suspected. Internal herniation was proven laparoscopically in 37 of these patients. The incidence of internal herniation was 2·5 per cent. An analysis by complaint included a total of 265 episodes, for which 247 CT scans were undertaken. CT was not used to investigate 18 episodes, but internal herniation was encountered in one-third of these during reoperation. Combining the follow-up and intraoperative findings, the accuracy of CT for internal herniation had a sensitivity of 83·8 (95 per cent c.i. 67·3 to 93·2) per cent, a specificity of 87·1 (81·7 to 91·2) per cent, a positive predictive value of 53·4 (40·0 to 66·5) per cent and a negative predictive value of 96·8 (92·9 to 98·7) per cent. Abdominal CT is an important tool in diagnosing internal herniation, with a high specificity and a high negative predictive value. © 2018 BJS Society Ltd Published by John Wiley & Sons Ltd.

Reading the mind in the touch: Neurophysiological specificity in the communication of emotions by touch.

PubMed

Kirsch, Louise P; Krahé, Charlotte; Blom, Nadia; Crucianelli, Laura; Moro, Valentina; Jenkinson, Paul M; Fotopoulou, Aikaterini

2017-05-29

Touch is central to interpersonal interactions. Touch conveys specific emotions about the touch provider, but it is not clear whether this is a purely socially learned function or whether it has neurophysiological specificity. In two experiments with healthy participants (N = 76 and 61) and one neuropsychological single case study, we investigated whether a type of touch characterised by peripheral and central neurophysiological specificity, namely the C tactile (CT) system, can communicate specific emotions and mental states. We examined the specificity of emotions elicited by touch delivered at CT-optimal (3cm/s) and CT-suboptimal (18cm/s) velocities (Experiment 1) at different body sites which contain (forearm) vs. do not contain (palm of the hand) CT fibres (Experiment 2). Blindfolded participants were touched without any contextual cues, and were asked to identify the touch provider's emotion and intention. Overall, CT-optimal touch (slow, gentle touch on the forearm) was significantly more likely than other types of touch to convey arousal, lust or desire. Affiliative emotions such as love and related intentions such as social support were instead reliably elicited by gentle touch, irrespective of CT-optimality, suggesting that other top-down factors contribute to these aspects of tactile social communication. To explore the neural basis of this communication, we also tested this paradigm in a stroke patient with right perisylvian damage, including the posterior insular cortex, which is considered as the primary cortical target of CT afferents, but excluding temporal cortex involvement that has been linked to more affiliative aspects of CT-optimal touch. His performance suggested an impairment in 'reading' emotions based on CT-optimal touch. Taken together, our results suggest that the CT system can add specificity to emotional and social communication, particularly with regards to feelings of desire and arousal. On the basis of these findings, we speculate that its primary functional role may be to enhance the 'sensual salience' of tactile interactions. Copyright © 2017. Published by Elsevier Ltd.

Ground deformation monitoring using small baseline DInSAR technique: A case study in Taiyuan City from 2003 to 2009

USGS Publications Warehouse

Wu, H.-A.; Zhang, Y.-H.; Chen, X.-Y.; Lu, T.; Du, J.; Sun, Z.-H.; Sun, G.-T.

2011-01-01

DInSAR technique based on time series of SAR images has been very popular to monitor ground stow deformation in recent years such as permanent scatterers (PS) method small baseline subsets (SBAS) method and coherent targets (CT) method. By taking advantage of PS method and CT method in this paper small baseline DTnSAR technique is used to investigate the ground deformation of Taiyuan City Shanxi Province from 2003 to 2009 by using 23 ENVISAT ASAR images. The experiment results demonstrate that: (1) during this period four significant subsidence centers have been developed in Taiyuan namely Xiayuan Wujiabu Xiaodian Sunjiazhai. The largest subsidence center is Sunjiazhai with an average subsidence rate of -77. 28 mm/a; (2) The subsidence of the old center Wanbolin has sHowed down. And the subsidence in the northern region has stopped and some areas even rebounded. (3) The change of subsidence centers indicates that the control measures of "closing wells and reducing exploitation" taken by the Taiyuan government has achieved initial effects. (4) The experiment results have been validated with leveling data and the acouracy is 2. 90 mm which shows that the small baseline DInSAR technique can be used to monitor urban ground deformation.

Dose Optimization in TOF-PET/MR Compared to TOF-PET/CT

PubMed Central

Queiroz, Marcelo A.; Delso, Gaspar; Wollenweber, Scott; Deller, Timothy; Zeimpekis, Konstantinos; Huellner, Martin; de Galiza Barbosa, Felipe; von Schulthess, Gustav; Veit-Haibach, Patrick

2015-01-01

Purpose To evaluate the possible activity reduction in FDG-imaging in a Time-of-Flight (TOF) PET/MR, based on cross-evaluation of patient-based NECR (noise equivalent count rate) measurements in PET/CT, cross referencing with phantom-based NECR curves as well as initial evaluation of TOF-PET/MR with reduced activity. Materials and Methods A total of 75 consecutive patients were evaluated in this study. PET/CT imaging was performed on a PET/CT (time-of-flight (TOF) Discovery D 690 PET/CT). Initial PET/MR imaging was performed on a newly available simultaneous TOF-PET/MR (Signa PET/MR). An optimal NECR for diagnostic purposes was defined in clinical patients (NECRP) in PET/CT. Subsequent optimal activity concentration at the acquisition time ([A]0) and target NECR (NECRT) were obtained. These data were used to predict the theoretical FDG activity requirement of the new TOF-PET/MR system. Twenty-five initial patients were acquired with (retrospectively reconstructed) different imaging times equivalent for different activities on the simultaneous PET/MR for the evaluation of clinically realistic FDG-activities. Results The obtained values for NECRP, [A]0 and NECRT were 114.6 (± 14.2) kcps (Kilocounts per second), 4.0 (± 0.7) kBq/mL and 45 kcps, respectively. Evaluating the NECRT together with the phantom curve of the TOF-PET/MR device, the theoretical optimal activity concentration was found to be approximately 1.3 kBq/mL, which represents 35% of the activity concentration required by the TOF-PET/CT. Initial evaluation on patients in the simultaneous TOF-PET/MR shows clinically realistic activities of 1.8 kBq/mL, which represent 44% of the required activity. Conclusion The new TOF-PET/MR device requires significantly less activity to generate PET-images with good-to-excellent image quality, due to improvements in detector geometry and detector technologies. The theoretically achievable dose reduction accounts for up to 65% but cannot be fully translated into clinical routine based on the coils within the FOV and MR-sequences applied at the same time. The clinically realistic reduction in activity is slightly more than 50%. Further studies in a larger number of patients are needed to confirm our findings. PMID:26147919

In vivo 3D PIXE-micron-CT imaging of Drosophila melanogaster using a contrast agent

NASA Astrophysics Data System (ADS)

Matsuyama, Shigeo; Hamada, Naoki; Ishii, Keizo; Nozawa, Yuichiro; Ohkura, Satoru; Terakawa, Atsuki; Hatori, Yoshinobu; Fujiki, Kota; Fujiwara, Mitsuhiro; Toyama, Sho

2015-04-01

In this study, we developed a three-dimensional (3D) computed tomography (CT) in vivo imaging system for imaging small insects with micrometer resolution. The 3D CT imaging system, referred to as 3D PIXE-micron-CT (PIXEμCT), uses characteristic X-rays produced by ion microbeam bombardment of a metal target. PIXEμCT was used to observe the body organs and internal structure of a living Drosophila melanogaster. Although the organs of the thorax were clearly imaged, the digestive organs in the abdominal cavity could not be clearly discerned initially, with the exception of the rectum and the Malpighian tubule. To enhance the abdominal images, a barium sulfate powder radiocontrast agent was added. For the first time, 3D images of the ventriculus of a living D. melanogaster were obtained. Our results showed that PIXEμCT can provide in vivo 3D-CT images that reflect correctly the structure of individual living organs, which is expected to be very useful in biological research.

Doctor-patient communication and cancer patients' choice of alternative therapies as supplement or alternative to conventional care.

PubMed

Salamonsen, Anita

2013-03-01

Cancer patients' use of complementary and alternative medicine (CAM) is widespread, despite the fact that clinical studies validating the efficacy of CAM remain sparse in the Nordic countries. The purpose of this study was to explore possible connections between cancer patients' communication experiences with doctors and the decision to use CAM as either supplement or alternative to conventional treatment (CT). The Regional Committee for Medical and Health Research Ethics and the Norwegian Data Inspectorate approved the study. From a group of 52 cancer patients with self-reported positive experiences from use of CAM, 13 were selected for qualitative interviews. Six used CAM as supplement, and seven as alternative to CT, periodically or permanently. Communication experiences with 46 doctors were described. The analysis revealed three connections between doctor-patient communication and patients' treatment decisions: (i) negative communication experiences because of the use of CAM; (ii) negative communication experiences resulted in the decision to use CAM, and in some cases to decline CT; and (iii) positive communication experiences led to the decision to use CAM as supplement, not alternative to CT. The patients, including the decliners of CT, wanted to discuss treatment decisions in well-functioning interpersonal processes with supportive doctors. In doctors' practices and education of doctors, a greater awareness of potential positive and negative outcomes of doctor-patient communication that concern CAM issues could be of importance. More research is needed to safeguard CAM users' treatment decisions and their relationship to conventional health care. © 2012 The Author. Scandinavian Journal of Caring Sciences © 2012 Nordic College of Caring Science.

VISIBILITY OF STRUCTURES OF RELEVANCE FOR PATIENTS WITH CYSTIC FIBROSIS IN CHEST TOMOSYNTHESIS: INFLUENCE OF ANATOMICAL LOCATION AND OBSERVER EXPERIENCE.

PubMed

Meltzer, Carin; Båth, Magnus; Kheddache, Susanne; Ásgeirsdóttir, Helga; Gilljam, Marita; Johnsson, Åse Allansdotter

2016-06-01

The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in 14 % of the ratings. Central and peripheral lateral structures received higher visibility ratings compared with peripheral structures anteriorly, posteriorly and surrounding the diaphragm (p ≤ 0.001). Reported visibility was significantly higher for the most experienced observer (p ≤ 0.01). The results indicate that minor pathology can be difficult to visualise with DTS depending on location and observer experience. Central and peripheral lateral structures are generally well depicted. © The Author 2016. Published by Oxford University Press.

VISIBILITY OF STRUCTURES OF RELEVANCE FOR PATIENTS WITH CYSTIC FIBROSIS IN CHEST TOMOSYNTHESIS: INFLUENCE OF ANATOMICAL LOCATION AND OBSERVER EXPERIENCE

PubMed Central

Meltzer, Carin; Båth, Magnus; Kheddache, Susanne; Ásgeirsdóttir, Helga; Gilljam, Marita; Johnsson, Åse Allansdotter

2016-01-01

The aims of this study were to assess the visibility of pulmonary structures in patients with cystic fibrosis (CF) in digital tomosynthesis (DTS) using computed tomography (CT) as reference and to investigate the dependency on anatomical location and observer experience. Anatomical structures in predefined regions of CT images from 21 patients were identified. Three observers with different levels of experience rated the visibility of the structures in DTS by performing a head-to-head comparison with visibility in CT. Visibility of the structures in DTS was reported as equal to CT in 34 %, inferior in 52 % and superior in 14 % of the ratings. Central and peripheral lateral structures received higher visibility ratings compared with peripheral structures anteriorly, posteriorly and surrounding the diaphragm (p ≤ 0.001). Reported visibility was significantly higher for the most experienced observer (p ≤ 0.01). The results indicate that minor pathology can be difficult to visualise with DTS depending on location and observer experience. Central and peripheral lateral structures are generally well depicted. PMID:26842827

Association between Smoking and the Progression of Computed Tomography Findings in Chronic Pancreatitis

PubMed Central

Lee, Jeong Woo; Kim, Ho Gak; Lee, Dong Wook; Han, Jimin; Kwon, Hyuk Yong; Seo, Chang Jin; Oh, Ji Hye; Lee, Joo Hyoung; Jung, Jin Tae; Kwon, Joong Goo; Kim, Eun Young

2016-01-01

Background/Aims Smoking and alcohol intake are two well-known risk factors for chronic pancreatitis. However, there are few studies examining the association between smoking and changes in computed tomography (CT) findings in chronic pancreatitis. The authors evaluated associations between smoking, drinking and the progression of calcification on CT in chronic pancreatitis. Methods In this retrospective study, 59 patients with chronic pancreatitis who had undergone initial and follow-up CT between January 2002 and September 2010 were included. Progression of calcification among CT findings was compared according to the amount of alcohol intake and smoking. Results The median duration of follow-up was 51.6 months (range, 17.1 to 112.7 months). At initial CT findings, there was pancreatic calcification in 35 patients (59.3%). In the follow-up CT, progression of calcification was observed in 37 patients (62.7%). Progression of calcification was more common in smokers according to the multivariate analysis (odds ratio [OR], 9.987; p=0.006). The amount of smoking was a significant predictor for progression of calcification in the multivariate analysis (OR, 6.051 in less than 1 pack per day smokers; OR, 36.562 in more than 1 pack per day smokers; p=0.008). Conclusions Continued smoking accelerates pancreatic calcification, and the amount of smoking is associated with the progression of calcification in chronic pancreatitis. PMID:26601825

Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bloch, B. Nicolas; Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna; Lenkinski, Robert E.

2007-09-01

Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of datamore » read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moignier, Alexandra, E-mail: alexandra.moignier@irsn.fr; Derreumaux, Sylvie; Broggio, David

Purpose: Current retrospective cardiovascular dosimetry studies are based on a representative patient or simple mathematic phantoms. Here, a process of patient modeling was developed to personalize the anatomy of the thorax and to include a heart model with coronary arteries. Methods and Materials: The patient models were hybrid computational phantoms (HCPs) with an inserted detailed heart model. A computed tomography (CT) acquisition (pseudo-CT) was derived from HCP and imported into a treatment planning system where treatment conditions were reproduced. Six current patients were selected: 3 were modeled from their CT images (A patients) and the others were modelled from 2more » orthogonal radiographs (B patients). The method performance and limitation were investigated by quantitative comparison between the initial CT and the pseudo-CT, namely, the morphology and the dose calculation were compared. For the B patients, a comparison with 2 kinds of representative patients was also conducted. Finally, dose assessment was focused on the whole coronary artery tree and the left anterior descending coronary. Results: When 3-dimensional anatomic information was available, the dose calculations performed on the initial CT and the pseudo-CT were in good agreement. For the B patients, comparison of doses derived from HCP and representative patients showed that the HCP doses were either better or equivalent. In the left breast radiation therapy context and for the studied cases, coronary mean doses were at least 5-fold higher than heart mean doses. Conclusions: For retrospective dose studies, it is suggested that HCP offers a better surrogate, in terms of dose accuracy, than representative patients. The use of a detailed heart model eliminates the problem of identifying the coronaries on the patient's CT.« less

Post-infectious bronchiolitis obliterans in children: CT features that predict responsiveness to pulse methylprednisolone.

PubMed

Yoon, H M; Lee, J S; Hwang, J-Y; Cho, Y A; Yoon, H-K; Yu, J; Hong, S-J; Yoon, C H

2015-05-01

Intravenous pulse methylprednisolone therapy (IPMT) is an important treatment option for post-infectious obliterative bronchiolitis (OB), although it must be used carefully and only in selected patients because of its drawbacks. This study evaluated whether CT and clinical features of children with post-infectious OB can predict their responsiveness to IPMT. We searched the medical records for patients (less than 18 years of age) who were diagnosed with post-infectious OB between January 2000 and December 2011. 17 children who received IPMT were included in this study. All underwent chest CT before and after IPMT. The radiological features seen on pre-treatment CT were recorded. The air-trapping area percentages on pre- and post-treatment CT images were determined. The nine patients who exhibited decreased air trapping on post-treatment CT scans relative to pre-treatment scans were classed as responders. The patient ages and time from initial pneumonia to IPMT were recorded. All responders and only four non-responders had thickened bronchial walls before treatment (p = 0.029). The two groups did not differ significantly in terms of bronchiolitis, bronchiectasis or the extent of air trapping, although the responders had a significantly shorter median interval between initial pneumonia and IPMT (4 vs 50 months; p = 0.005) and were significantly younger (median, 2.0 vs 7.5 years; p = 0.048). Immediate IPMT may improve the degree of air trapping in children with post-infectious OB if they show a thickened bronchial wall on CT. Children with post-infectious OB may respond favourably to IPMT when pre-treatment CT indicates bronchial-wall thickening.

Serial changes and prognostic implications of CT findings in combined pulmonary fibrosis and emphysema: comparison with fibrotic idiopathic interstitial pneumonias alone.

PubMed

Lee, Geewon; Kim, Ki Uk; Lee, Ji Won; Suh, Young Ju; Jeong, Yeon Joo

2017-05-01

Background Although fibrotic idiopathic interstitial pneumonias (IIPs) alone and those combined with pulmonary emphysema are naturally progressive diseases, the process of deterioration and outcomes are variable. Purpose To evaluate and compare serial changes of computed tomography (CT) abnormalities and prognostic predictive factors in fibrotic IIPs alone and those combined with pulmonary emphysema. Material and Methods A total of 148 patients with fibrotic IIPs alone (82 patients) and those combined with pulmonary emphysema (66 patients) were enrolled. Semi-quantitative CT analysis was used to assess the extents of CT characteristics which were evaluated on initial and follow-up CT images. Univariate and multivariate analyses were performed to assess the effects of clinical and CT variables on survival. Results Significant differences were noted between fibrotic scores, as determined using initial CT scans, in the fibrotic IIPs alone (21.22 ± 9.83) and those combined with pulmonary emphysema groups (14.70 ± 7.28) ( P < 0.001). At follow-up CT scans, changes in the extent of ground glass opacities (GGO) were greater ( P = 0.031) and lung cancer was more prevalent ( P = 0.001) in the fibrotic IIPs combined with pulmonary emphysema group. Multivariate Cox proportional hazards analysis showed changes in the extent of GGO (hazard ratio, 1.056) and the presence of lung cancer (hazard ratio, 4.631) were predictive factors of poor survivals. Conclusion Although patients with fibrotic IIPs alone and those combined with pulmonary emphysema have similar mortalities, lung cancer was more prevalent in patients with fibrotic IIPs combined with pulmonary emphysema. Furthermore, changes in the extent of GGO and the presence of lung cancer were independent prognostic factors of poor survivals.

Ultrasonography versus computed tomography for suspected nephrolithiasis.

PubMed

Smith-Bindman, Rebecca; Aubin, Chandra; Bailitz, John; Bengiamin, Rimon N; Camargo, Carlos A; Corbo, Jill; Dean, Anthony J; Goldstein, Ruth B; Griffey, Richard T; Jay, Gregory D; Kang, Tarina L; Kriesel, Dana R; Ma, O John; Mallin, Michael; Manson, William; Melnikow, Joy; Miglioretti, Diana L; Miller, Sara K; Mills, Lisa D; Miner, James R; Moghadassi, Michelle; Noble, Vicki E; Press, Gregory M; Stoller, Marshall L; Valencia, Victoria E; Wang, Jessica; Wang, Ralph C; Cummings, Steven R

2014-09-18

There is a lack of consensus about whether the initial imaging method for patients with suspected nephrolithiasis should be computed tomography (CT) or ultrasonography. In this multicenter, pragmatic, comparative effectiveness trial, we randomly assigned patients 18 to 76 years of age who presented to the emergency department with suspected nephrolithiasis to undergo initial diagnostic ultrasonography performed by an emergency physician (point-of-care ultrasonography), ultrasonography performed by a radiologist (radiology ultrasonography), or abdominal CT. Subsequent management, including additional imaging, was at the discretion of the physician. We compared the three groups with respect to the 30-day incidence of high-risk diagnoses with complications that could be related to missed or delayed diagnosis and the 6-month cumulative radiation exposure. Secondary outcomes were serious adverse events, related serious adverse events (deemed attributable to study participation), pain (assessed on an 11-point visual-analogue scale, with higher scores indicating more severe pain), return emergency department visits, hospitalizations, and diagnostic accuracy. A total of 2759 patients underwent randomization: 908 to point-of-care ultrasonography, 893 to radiology ultrasonography, and 958 to CT. The incidence of high-risk diagnoses with complications in the first 30 days was low (0.4%) and did not vary according to imaging method. The mean 6-month cumulative radiation exposure was significantly lower in the ultrasonography groups than in the CT group (P<0.001). Serious adverse events occurred in 12.4% of the patients assigned to point-of-care ultrasonography, 10.8% of those assigned to radiology ultrasonography, and 11.2% of those assigned to CT (P=0.50). Related adverse events were infrequent (incidence, 0.4%) and similar across groups. By 7 days, the average pain score was 2.0 in each group (P=0.84). Return emergency department visits, hospitalizations, and diagnostic accuracy did not differ significantly among the groups. Initial ultrasonography was associated with lower cumulative radiation exposure than initial CT, without significant differences in high-risk diagnoses with complications, serious adverse events, pain scores, return emergency department visits, or hospitalizations. (Funded by the Agency for Healthcare Research and Quality.).

Low-dose head computed tomography in children: a single institutional experience in pediatric radiation risk reduction: clinical article.

PubMed

Morton, Ryan P; Reynolds, Renee M; Ramakrishna, Rohan; Levitt, Michael R; Hopper, Richard A; Lee, Amy; Browd, Samuel R

2013-10-01

In this study, the authors describe their experience with a low-dose head CT protocol for a preselected neurosurgical population at a dedicated pediatric hospital (Seattle Children's Hospital), the largest number of patients with this protocol reported to date. All low-dose head CT scans between October 2011 and November 2012 were reviewed. Two different low-dose radiation dosages were used, at one-half or one-quarter the dose of a standard head CT scan, based on patient characteristics agreed upon by the neurosurgery and radiology departments. Patient information was also recorded, including diagnosis and indication for CT scan. Six hundred twenty-four low-dose head CT procedures were performed within the 12-month study period. Although indications for the CT scans varied, the most common reason was to evaluate the ventricles and catheter placement in hydrocephalic patients with shunts (70%), followed by postoperative craniosynostosis imaging (12%). These scans provided adequate diagnostic imaging, and no patient required a follow-up full-dose CT scan as a result of poor image quality on a low-dose CT scan. Overall physician comfort and satisfaction with interpretation of the images was high. An additional 2150 full-dose head CT scans were performed during the same 12-month time period, making the total number of CT scans 2774. This value compares to 3730 full-dose head CT scans obtained during the year prior to the study when low-dose CT and rapid-sequence MRI was not a reliable option at Seattle Children's Hospital. Thus, over a 1-year period, 22% of the total CT scans were able to be converted to low-dose scans, and full-dose CT scans were able to be reduced by 42%. The implementation of a low-dose head CT protocol substantially reduced the amount of ionizing radiation exposure in a preselected population of pediatric neurosurgical patients. Image quality and diagnostic utility were not significantly compromised.

SU-C-207A-03: Development of Proton CT Imaging System Using Thick Scintillator and CCD Camera

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, S; Uesaka, M; Nishio, T

2016-06-15

Purpose: In the treatment planning of proton therapy, Water Equivalent Length (WEL), which is the parameter for the calculation of dose and the range of proton, is derived by X-ray CT (xCT) image and xCT-WEL conversion. However, about a few percent error in the accuracy of proton range calculation through this conversion has been reported. The purpose of this study is to construct a proton CT (pCT) imaging system for an evaluation of the error. Methods: The pCT imaging system was constructed with a thick scintillator and a cooled CCD camera, which acquires the two-dimensional image of integrated value ofmore » the scintillation light toward the beam direction. The pCT image is reconstructed by FBP method using a correction between the light intensity and residual range of proton beam. An experiment for the demonstration of this system was performed with 70-MeV proton beam provided by NIRS cyclotron. The pCT image of several objects reconstructed from the experimental data was evaluated quantitatively. Results: Three-dimensional pCT images of several objects were reconstructed experimentally. A finestructure of approximately 1 mm was clearly observed. The position resolution of pCT image was almost the same as that of xCT image. And the error of proton CT pixel value was up to 4%. The deterioration of image quality was caused mainly by the effect of multiple Coulomb scattering. Conclusion: We designed and constructed the pCT imaging system using a thick scintillator and a CCD camera. And the system was evaluated with the experiment by use of 70-MeV proton beam. Three-dimensional pCT images of several objects were acquired by the system. This work was supported by JST SENTAN Grant Number 13A1101 and JSPS KAKENHI Grant Number 15H04912.« less

Medically Treated Diverticular Abscess Associated With High Risk of Recurrence and Disease Complications.

PubMed

Devaraj, Bikash; Liu, Wendy; Tatum, James; Cologne, Kyle; Kaiser, Andreas M

2016-03-01

The best management for diverticulitis with abscess formation remains unknown. The purpose of this study was to determine the natural course and outcomes of patients with medically treated diverticular abscess. We conducted a retrospective review of all patients at our institution with diverticular abscess confirmed by CT from 2004 to 2014. This study was conducted in a tertiary referral hospital. A total of 1194 patients were treated for acute diverticulitis in 10 years; 210 patients with CT-documented diverticular abscess were analyzed (140 men (66.7%) and 70 women (33.3%); median age 45 years; range, 23-84 years). Overall recurrence and disease complication rates, as well as the need for subsequent operation after initial successful nonsurgical management, were measured, along with analysis of the whole cohort and the subgroup of patients with percutaneous drainage for diverticular abscess. During the initial presentation, 25 patients failed nonoperative management and required an urgent operation. A total of 185 patients were initially successfully managed without surgery and were discharged from the hospital. Of these, recurrent diverticulitis developed in 112 (60.5%) after an average time interval of 5.3 months (range, 0.8-20.0 months); 47 patients (42%) experienced more than 1 episode. The modified Hinchey stage at time of recurrence (compared with index stay) increased in 51 patients (45.6%). Seventy one (63%) of 112 recurrences showed local disease complications (recurrent abscess, fistula, stricture, or peritonitis). Fistula formation (colovesicular/colovaginal/colocutaneous) and recurrent abscess were the 2 most frequent complications. Twenty nine (26%) of 112 recurrences required an urgent operation; overall, 66 (59%) of 112 patients eventually underwent surgery at our institution. The original abscess size in patients who later developed recurrences was significantly larger than in patients who did not develop recurrence (5.3 vs 3.2 cm; p < 0.001). Paradoxically, larger abscesses also had a higher chance of successful CT-guided drainage (average size, 6.5 cm; range, 1.1-14 cm), yet CT-guided drainage did not change the overall outcome. Of 65 (31.0%) of 210 patients with CT-guided drainage, 45 (73.8%) of 61 after initial success experienced a recurrence. Furthermore, local disease complications at the time of recurrence were noted in 32 of 61 patients (52.5% of all CT-guided drainage, 71.1% of post-CT-guided drainage recurrences), and 13 (29.2%) of 45 patients with recurrence after successful CT-guided drainage subsequently required an urgent operation. The study was limited by its retrospective noncomparative design. Diverticular abscesses represent complicated diverticulitis and are associated with a high risk of recurrences and disease complications. Recurrences (contrary to other series) were often more severe than the index presentation. The successful CT-guided drainage of a diverticular abscess does not appear to lower the risks of future recurrence or complication rates and frequently is only a bridge to surgery. After initial successful nonoperative management, patients with diverticular abscess should be offered interval elective colectomy (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A216).

Sci—Thur PM: Imaging — 06: Canada's National Computed Tomography (CT) Survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wardlaw, GM; Martel, N; Blackler, W

2014-08-15

The value of computed tomography (CT) in medical imaging is reflected in its' increased use and availability since the early 1990's; however, given CT's relatively larger exposures (vs. planar x-ray) greater care must be taken to ensure that CT procedures are optimised in terms of providing the smallest dose possible while maintaining sufficient diagnostic image quality. The development of CT Diagnostic Reference Levels (DRLs) supports this process. DRLs have been suggested/supported by international/national bodies since the early 1990's and widely adopted elsewhere, but not on a national basis in Canada. Essentially, CT DRLs provide guidance on what is considered goodmore » practice for common CT exams, but require a representative sample of CT examination data to make any recommendations. Canada's National CT Survey project, in collaboration with provincial/territorial authorities, has collected a large national sample of CT practice data for 7 common examinations (with associated clinical indications) of both adult and pediatric patients. Following completion of data entry into a common database, a survey summary report and recommendations will be made on CT DRLs from this data. It is hoped that these can then be used by local regions to promote CT practice optimisation and support any dose reduction initiatives.« less

Enantioselective binding of L, D-phenylalanine to ct DNA

NASA Astrophysics Data System (ADS)

Zhang, Lijin; Xu, Jianhua; Huang, Yan; Min, Shungeng

2009-10-01

The enantioselective binding of L, D-phenylalanine to calf thymus DNA was studied by absorption, circular dichroism, fluorescence quenching, viscosity, salt effect and emission experiments. The results obtained from absorption, circular dichroism, fluorescence quenching and viscosity experiments excluded the intercalative binding and salt effect experiments did not support electrostatic binding. So the binding of L, D-phenylalanine to ct DNA should be groove binding. Furthermore, the emission spectra revealed that the binding is enantioselective.

Enantioselective binding of L,D-phenylalanine to ct DNA.

PubMed

Zhang, Lijin; Xu, Jianhua; Huang, Yan; Min, Shungeng

2009-10-15

The enantioselective binding of L,D-phenylalanine to calf thymus DNA was studied by absorption, circular dichroism, fluorescence quenching, viscosity, salt effect and emission experiments. The results obtained from absorption, circular dichroism, fluorescence quenching and viscosity experiments excluded the intercalative binding and salt effect experiments did not support electrostatic binding. So the binding of l,d-phenylalanine to ct DNA should be groove binding. Furthermore, the emission spectra revealed that the binding is enantioselective.

CT liver volumetry using geodesic active contour segmentation with a level-set algorithm

NASA Astrophysics Data System (ADS)

Suzuki, Kenji; Epstein, Mark L.; Kohlbrenner, Ryan; Obajuluwa, Ademola; Xu, Jianwu; Hori, Masatoshi; Baron, Richard

2010-03-01

Automatic liver segmentation on CT images is challenging because the liver often abuts other organs of a similar density. Our purpose was to develop an accurate automated liver segmentation scheme for measuring liver volumes. We developed an automated volumetry scheme for the liver in CT based on a 5 step schema. First, an anisotropic smoothing filter was applied to portal-venous phase CT images to remove noise while preserving the liver structure, followed by an edge enhancer to enhance the liver boundary. By using the boundary-enhanced image as a speed function, a fastmarching algorithm generated an initial surface that roughly estimated the liver shape. A geodesic-active-contour segmentation algorithm coupled with level-set contour-evolution refined the initial surface so as to more precisely fit the liver boundary. The liver volume was calculated based on the refined liver surface. Hepatic CT scans of eighteen prospective liver donors were obtained under a liver transplant protocol with a multi-detector CT system. Automated liver volumes obtained were compared with those manually traced by a radiologist, used as "gold standard." The mean liver volume obtained with our scheme was 1,520 cc, whereas the mean manual volume was 1,486 cc, with the mean absolute difference of 104 cc (7.0%). CT liver volumetrics based on an automated scheme agreed excellently with "goldstandard" manual volumetrics (intra-class correlation coefficient was 0.95) with no statistically significant difference (p(F<=f)=0.32), and required substantially less completion time. Our automated scheme provides an efficient and accurate way of measuring liver volumes.

Intensity Modulated Radiation Treatment of Prostate Cancer Guided by High Field MR Spectroscopic Imaging

DTIC Science & Technology

2006-05-01

d). (e) In the histogram analysis eld units are observed initially for voxels located on the d to 250 Hounsfield units.ses (a) el the tration...CT10, CT20, and CT30. Histogram ximum difference of 250 Hounsfield units . Only 0.01% d units.d imag ts a mand finite-element model. The fluid flow...cause Hounsfield unit calibration problems. While this does not seem to influence the image registration, the use of CBCT for dose calculation should

Prostate-Specific Membrane Antigen Expression in Adrenocortical Carcinoma on 68Ga-Prostate-Specific Membrane Antigen PET/CT.

PubMed

Arora, Saurabh; Damle, Nishikant Avinash; Aggarwal, Sameer; Passah, Averilicia; Behera, Abhishek; Arora, Geetanjali; Bal, Chandrasekhar; Tripathi, Madhavi

2018-06-01

We present here a case of metastatic adrenocortical carcinoma with bilateral lung nodules. The patient had been treated with mitotane therapy initially and then was later referred for chemotherapy. There was progression of disease noted on the F-FDG PET/CT. Ga prostate-specific membrane antigen (PSMA) PET/CT was planned to explore the possibility of future treatment with Lu-DKFZ-PSMA-617. It revealed peripheral increased uptake of Ga-HBED-CC-PSMA equal to liver uptake.

Clinical importance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography in the management of patients with bronchoalveolar carcinoma: Role in the detection of recurrence.

PubMed

Skoura, Evangelia; Datseris, Ioannis E; Exarhos, Dimitrios; Chatziioannou, Sophia; Oikonomopoulos, Georgios; Samartzis, Alexandros; Giannopoulou, Chariklia; Syrigos, Konstantinos N

2013-05-01

[ 18 F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been reported to have a low sensitivity in the initial diagnosis of bronchoalveolar carcinoma (BAC) due to BAC's low metabolic activity. The aim of this study was to assess the value of [ 18 F]FDG-PET/CT in the detection of BAC recurrence. Between February 2007 and September 2011, the [ 18 F]FDG-PET/CT scans that were performed on patients with known, histologically proven BAC were studied. A total of 24 [ 18 F]FDG-PET/CT scans were performed in 22 patients, including 16 males and 6 females, with a mean age of 65±9 years. Among the scans, 15 were performed to assess for possible recurrence with equivocal findings in conventional imaging methods and 9 for restaging post-therapy. In all cases conventional imaging studies (CT and MRI) were performed 5-30 days prior to PET/CT. Among the 24 [ 18 F]FDG-PET/CT scans, 18 were positive and 6 negative. Among the 15 [ 18 F]FDG-PET/CT scans performed for suspected recurrence, 34 lesions were detected and the mean maximum standardized uptake value (SUVmax) was 6.8±3.26. In nine scans, upstaging was observed, while two were in agreement with the findings of the conventional modalities. A greater number of lesions were detected in two scans and fewer lesions were detected in one, with no change in staging. Only one scan was negative. By contrast, in patients examined for restaging, there were only five lesions with a mean SUVmax of 4.86±3.18. Agreement between the findings of [ 18 F]FDG-PET/CT and the conventional modalities was observed in 8 out of 9 cases. Although [ 18 F]FDG-PET/CT has been reported to have a low sensitivity in the initial diagnosis of BAC, the present results indicate that when there is recurrence, the lesions become [ 18 F]FDG avid. [ 18 F]FDG-PET/CT may provide further information in patients evaluated for recurrence and thus improve patient management.

Whole-body MRI versus 18F-FDG PET/CT for pretherapeutic assessment and staging of lymphoma: a meta-analysis.

PubMed

Wang, Danyang; Huo, Yanlei; Chen, Suyun; Wang, Hui; Ding, Yingli; Zhu, Xiaochun; Ma, Chao

2018-01-01

18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) is the reference standard in staging of 18 F-FDG-avid lymphomas; however, there is no recommended functional imaging modality for indolent lymphomas. Therefore, we aimed to compare the performance of whole-body magnetic resonance imaging (WB-MRI) with that of 18 F-FDG PET/CT for lesion detection and initial staging in patients with aggressive or indolent lymphoma. We searched the MEDLINE, EMBASE, and CENTRAL databases for studies that compared WB-MRI with 18 F-FDG PET/CT for lymphoma staging or lesion detection. The methodological quality of the studies was assessed using version 2 of the "Quality Assessment of Diagnostic Accuracy Studies" tool. The pooled staging accuracy ( μ ) of WB-MRI and 18 F-FDG PET/CT for initial staging and for assessing possible heterogeneity ( χ 2 ) across studies were calculated using commercially available software. Eight studies comprising 338 patients were included. In terms of staging, the meta-analytic staging accuracies of WB-MRI and 18 F-FDG PET/CT for Hodgkin lymphoma and aggressive non-Hodgkin lymphoma (NHL) were 98% (95% CI, 94%-100%) and 98% (95% CI, 94%-100%), respectively. The pooled staging accuracy of 18 F-FDG PET/CT dropped to 87% (95% CI, 72%-97%) for staging in patients with indolent lymphoma, whereas that of WB-MRI remained 96% (95% CI, 91%-100%). Subgroup analysis indicated an even lower staging accuracy of 18 F-FDG PET/CT for staging of less FDG-avid indolent NHLs (60%; 95% CI, 23%-92%), in contrast to the superior performance of WB-MRI (98%; 95% CI, 88%-100%). WB-MRI is a promising radiation-free imaging technique that may serve as a viable alternative to 18 F-FDG PET/CT for staging of 18 FDG-avid lymphomas, where 18 F-FDG PET/CT remains the standard of care. Additionally, WB-MRI seems a less histology-dependent functional imaging test than 18 F-FDG PET/CT and may be the imaging test of choice for staging of indolent NHLs with low 18 F-FDG avidity.

Diversity and Collegiate Experiences Affecting Self-Perceived Gains in Critical Thinking: Which Works, and Who Benefits?

ERIC Educational Resources Information Center

Cole, Darnell; Zhou, Ji

2014-01-01

This study is grounded in the theoretical and conceptual frameworks that postulate diversity and collegiate experiences as triggers for the cognitive disequilibrium that fosters critical thinking (CT). With the assumption that CT is both a general and a discipline-specific facility, this longitudinal, single-institution study of 447 students…

Changing Conspiracy Beliefs through Rationality and Ridiculing.

PubMed

Orosz, Gábor; Krekó, Péter; Paskuj, Benedek; Tóth-Király, István; Bőthe, Beáta; Roland-Lévy, Christine

2016-01-01

Conspiracy theory (CT) beliefs can be harmful. How is it possible to reduce them effectively? Three reduction strategies were tested in an online experiment using general and well-known CT beliefs on a comprehensive randomly assigned Hungarian sample ( N = 813): exposing rational counter CT arguments, ridiculing those who hold CT beliefs, and empathizing with the targets of CT beliefs. Several relevant individual differences were measured. Rational and ridiculing arguments were effective in reducing CT, whereas empathizing with the targets of CTs had no effect. Individual differences played no role in CT reduction, but the perceived intelligence and competence of the individual who conveyed the CT belief-reduction information contributed to the success of the CT belief reduction. Rational arguments targeting the link between the object of belief and its characteristics appear to be an effective tool in fighting conspiracy theory beliefs.

Micro X-ray CT imaging of pore-scale changes in unconsolidated sediment under confining pressure

NASA Astrophysics Data System (ADS)

Schindler, M.; Prasad, M.

2017-12-01

Micro X-ray computed tomography was used to image confining-pressure induced changes in a dry, unconsolidated quartz sand pack while simultaneously recording ultrasonic P-wave velocities. The experiments were performed under in-situ pressure of up to 4000 psi. The majority of digital rock physics studies rely on micro CT images obtained under ambient pressure and temperature conditions although effective rock properties strongly depend on in situ conditions. Goal of this work is to be able to obtain micro CT images of rock samples while pore and confining pressure is applied. Simultaneously we recorded ultrasonic P-wave velocities. The combination of imaging and velocity measurements provides insight in pore-scale changes in the rock and their influence on elastic properties. We visually observed a reduction in porosity by more than a third of the initial value as well as extensive grain damage, changes in pore and grain size distribution and an increase in contact number and contact radius with increasing confining pressure. An increase in measured ultrasonic P-wave velocities with increasing pressure was observed. We used porosity, contact number and contact radius obtained from micro CT images to model P-wave velocity with the contact-radius model by Bachrach et al. (1998). Our observations showed that the frame of unconsolidated sediments is significantly altered starting at pressures of only 1000 psi. This finding indicates that common assumptions in rock physics models (the solid frame remains unchanged) are violated for unconsolidated sediments. The effects on the solid frame should be taken into account when modeling the pressure dependence of elastic rock properties.

Cortical thickness estimation of the proximal femur from multi-view dual-energy X-ray absorptiometry (DXA)

NASA Astrophysics Data System (ADS)

Tsaousis, N.; Gee, A. H.; Treece, G. M.; Poole, K. E. S.

2013-02-01

Hip fracture is the leading cause of acute orthopaedic hospital admission amongst the elderly, with around a third of patients not surviving one year post-fracture. Although various preventative therapies are available, patient selection is difficult. The current state-of-the-art risk assessment tool (FRAX) ignores focal structural defects, such as cortical bone thinning, a critical component in characterizing hip fragility. Cortical thickness can be measured using CT, but this is expensive and involves a significant radiation dose. Instead, Dual-Energy X-ray Absorptiometry (DXA) is currently the preferred imaging modality for assessing hip fracture risk and is used routinely in clinical practice. Our ambition is to develop a tool to measure cortical thickness using multi-view DXA instead of CT. In this initial study, we work with digitally reconstructed radiographs (DRRs) derived from CT data as a surrogate for DXA scans: this enables us to compare directly the thickness estimates with the gold standard CT results. Our approach involves a model-based femoral shape reconstruction followed by a data-driven algorithm to extract numerous cortical thickness point estimates. In a series of experiments on the shaft and trochanteric regions of 48 proximal femurs, we validated our algorithm and established its performance limits using 20 views in the range 0°-171°: estimation errors were 0:19 +/- 0:53mm (mean +/- one standard deviation). In a more clinically viable protocol using four views in the range 0°-51°, where no other bony structures obstruct the projection of the femur, measurement errors were -0:07 +/- 0:79 mm.

Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience.

PubMed

Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang

2017-01-01

To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80 each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. • Automatic spectral imaging protocol selection provides appropriate scan protocols. • Abdominal CT is feasible using spectral imaging and 300 mgI/kg contrast agent. • 50-keV monochromatic images with 50 % ASIR provide optimal image quality.

Circle Time for Social and Emotional Learning in Primary School

ERIC Educational Resources Information Center

Cefai, Carmel; Ferrario, Erika; Cavioni, Valeria; Carter, Audrey; Grech, Tracy

2014-01-01

This paper discusses the findings and implications of a semi-randomised control trial study on the effectiveness of circle time (CT) on primary school students' social and emotional learning, as well as classroom teachers' and students' experience of CT. A social and emotional learning programme was delivered through CT by trained classroom…

Sudden Gains in Cognitive Therapy of Depression and Depression Relapse/Recurrence

ERIC Educational Resources Information Center

Tang, Tony Z.; DeRubeis, Robert J.; Hollon, Steven D.; Amsterdam, Jay; Shelton, Richard

2007-01-01

Cognitive therapy (CT) may have significant advantages over antidepressants in preventing depression relapses. Many CT patients experience sudden gains: large symptom improvement in 1 between-session interval. Past studies have associated CT sudden gains with in-session cognitive changes but not with life events. This study examined sudden gains…

Simulation With Debriefing and Guided Reflective Journaling to Stimulate Critical Thinking in Prelicensure Baccalaureate Degree Nursing Students.

PubMed

Padden-Denmead, Mary L; Scaffidi, Rose M; Kerley, Regina M; Farside, Amy Lee

2016-11-01

Simulation and guided reflective journaling have been identified as effective teaching and learning methods to develop critical thinking (CT) and clinical reasoning skills in nursing students. A descriptive correlational design was used to determine the relationship between CT and level of reflection using the Holistic Critical Thinking Skills Rubric (HCTSR) and the level of reflection on action assessment (LORAA), respectively, to evaluate 23 baccalaureate student-guided reflective journal entries after a simulation exercise with guided debriefing and after two subsequent clinical experiences. A statistically significant positive relationship (p < .01) was found between mean HCTSR and LORAA scores on all three journal entries, but no relationship to CT during simulation or on standardized test scores. The results also indicated support for use of the guided reflection after significant learning experiences. The LORAA and the HCTSR are effective measures of level of reflection and CT to evaluate learning from simulation and clinical experiences. [J Nurs Educ. 2016;55(11):645-650.]. Copyright 2016, SLACK Incorporated.

A Delphi study and ranking exercise to support commissioning services: future delivery of Thrombectomy services in England.

PubMed

Halvorsrud, Kristoffer; Flynn, Darren; Ford, Gary A; McMeekin, Peter; Bhalla, Ajay; Balami, Joyce; Craig, Dawn; White, Phil

2018-02-22

Intra-arterial thrombectomy is the gold standard treatment for large artery occlusive stroke. However, the evidence of its benefits is almost entirely based on trials delivered by experienced neurointerventionists working in established teams in neuroscience centres. Those responsible for the design and prospective reconfiguration of services need access to a comprehensive and complementary array of information on which to base their decisions. This will help to ensure the demonstrated effects from trials may be realised in practice and account for regional/local variations in resources and skill-sets. One approach to elucidate the implementation preferences and considerations of key experts is a Delphi survey. In order to support commissioning decisions, we aimed using an electronic Delphi survey to establish consensus on the options for future organisation of thrombectomy services among physicians with clinical experience in managing large artery occlusive stroke. A Delphi survey was developed with 12 options for future organisation of thrombectomy services in England. A purposive sampling strategy established an expert panel of stroke physicians from the British Association of Stroke Physicians (BASP) Clinical Standards and/or Executive Membership that deliver 24/7 intravenous thrombolysis. Options with aggregate scores falling within the lowest quartile were removed from the subsequent Delphi round. Options reaching consensus following the two Delphi rounds were then ranked in a final exercise by both the wider BASP membership and the British Society of Neuroradiologists (BSNR). Eleven stroke physicians from BASP completed the initial two Delphi rounds. Three options achieved consensus, with subsequently wider BASP (97%, n = 43) and BSNR members (86%, n = 21) assigning the highest approval rankings in the final exercise for transferring large artery occlusive stroke patients to nearest neuroscience centre for thrombectomy based on local CT/CT Angiography. The initial Delphi rounds ensured optimal reduction of options by an expert panel of stroke physicians, while subsequent ranking exercises allowed remaining options to be ranked by a wider group of experts within stroke to reach consensus. The preferred implementation option for thrombectomy is investigating suspected acute stroke patients by CT/CT Angiography and secondary transfer of large artery occlusive stroke patients to the nearest neuroscience (thrombectomy) centre.

Natural Course of Initially Non-Operated Cases of Acute Subdural Hematoma : The Risk Factors of Hematoma Progression

PubMed Central

Son, Seong; Lee, Sang Gu; Kim, Eun Young; Park, Chan Woo; Kim, Woo Kyung

2013-01-01

Objective The objectives of the present study were to characterize the natural course of initially non-operated traumatic acute subdural hematoma (ASDH) and to identify the risk factors of hematoma progression. Methods Retrospective analysis was performed using sequential computed tomography (CT) images maintained in a prospective observational database containing 177 ASDH cases treated from 2005 to 2011. Patients were allocated to four groups as followings; 136 (76.8%) patients to the spontaneous resolution group, 12 (6.8%) who underwent operation between 4 hours and 7 days to the rapid worsening group (RWG), 24 (13.6%) who experienced an increase of hematoma and that underwent operation between 7 and 28 days to the subacute worsening group (SWG), and 5 (2.8%) who developed delayed aggravation requiring surgery from one month after onset to the delayed worsening group (DWG). Groups were compared with respect to various factors. Results No significant intergroup difference was found with respect to age, mechanism of injury, or initial Glasgow Coma Scale. The presence of combined cerebral contusion or subarachnoid hemorrhage was found to be a significant prognostic factor. Regarding CT findings, mixed density was common in the RWG and the SWG. Midline shifting, hematoma thickness, and numbers of CT slices containing hematoma were significant prognostic factors of the RWG and the SWG. Brain atrophy was more severe in the SWG and the DWG. Conclusion A large proportion of initially non-operated ASDHs worsen in the acute or subacute phase. Patients with risk factors should be monitored carefully for progression by repeat CT imaging. PMID:24278650

Redesigning Instruction through Web-based Course Authoring Tools.

ERIC Educational Resources Information Center

Dabbagh, Nada H.; Schmitt, Jeff

1998-01-01

Examines the pedagogical implications of redesigning instruction for Web-based delivery through a case study of an undergraduate computer science course. Initially designed for a traditional learning environment, this course transformed to a Web-based course using WebCT, a Web-based course authoring tool. Discusses the specific features of WebCT.…

Molecular Dynamics Simulations of Insulin: Elucidating the Conformational Changes that Enable Its Binding.

PubMed

Papaioannou, Anastasios; Kuyucak, Serdar; Kuncic, Zdenka

2015-01-01

A sequence of complex conformational changes is required for insulin to bind to the insulin receptor. Recent experimental evidence points to the B chain C-terminal (BC-CT) as the location of these changes in insulin. Here, we present molecular dynamics simulations of insulin that reveal new insights into the structural changes occurring in the BC-CT. We find three key results: 1) The opening of the BC-CT is inherently stochastic and progresses through an open and then a "wide-open" conformation--the wide-open conformation is essential for receptor binding, but occurs only rarely. 2) The BC-CT opens with a zipper-like mechanism, with a hinge at the Phe24 residue, and is maintained in the dominant closed/inactive state by hydrophobic interactions of the neighboring Tyr26, the critical residue where opening of the BC-CT (activation of insulin) is initiated. 3) The mutation Y26N is a potential candidate as a therapeutic insulin analogue. Overall, our results suggest that the binding of insulin to its receptor is a highly dynamic and stochastic process, where initial docking occurs in an open conformation and full binding is facilitated through interactions of insulin receptor residues with insulin in its wide-open conformation.

A Complete System for Automatic Extraction of Left Ventricular Myocardium From CT Images Using Shape Segmentation and Contour Evolution

PubMed Central

Zhu, Liangjia; Gao, Yi; Appia, Vikram; Yezzi, Anthony; Arepalli, Chesnal; Faber, Tracy; Stillman, Arthur; Tannenbaum, Allen

2014-01-01

The left ventricular myocardium plays a key role in the entire circulation system and an automatic delineation of the myocardium is a prerequisite for most of the subsequent functional analysis. In this paper, we present a complete system for an automatic segmentation of the left ventricular myocardium from cardiac computed tomography (CT) images using the shape information from images to be segmented. The system follows a coarse-to-fine strategy by first localizing the left ventricle and then deforming the myocardial surfaces of the left ventricle to refine the segmentation. In particular, the blood pool of a CT image is extracted and represented as a triangulated surface. Then, the left ventricle is localized as a salient component on this surface using geometric and anatomical characteristics. After that, the myocardial surfaces are initialized from the localization result and evolved by applying forces from the image intensities with a constraint based on the initial myocardial surface locations. The proposed framework has been validated on 34-human and 12-pig CT images, and the robustness and accuracy are demonstrated. PMID:24723531

Screening CT Colonography: Multicenter Survey of Patient Experience, Preference, and Potential Impact on Adherence

DTIC Science & Technology

2012-06-21

June 21. N IH -PA Author M anuscript N IH -PA Author M anuscript N IH -PA Author M anuscript this sizeable group . Although nearly 70% indicated on ...Screening CT Colonography: Multicenter Survey of Patient Experience, Preference, and Potential Impact on Adherence B. Dustin Pooler1, Mark J. Baumel2...MATERIALS AND METHODS—A 12-question survey instrument measuring pretest choice, experience, and satisfaction was given to a consecutive cohort of

Using injectable hydrogel markers to assess resimulation for boost target volume definition in a patient undergoing whole-breast radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Henal; Goyal, Sharad; Kim, Leonard, E-mail: kimlh@rutgers.edu

Several publications have recommended that patients undergoing whole-breast radiotherapy be resimulated for boost planning. The rationale for this is that the seroma may be smaller when compared with the initial simulation. However, the decision remains whether to use the earlier or later images to define an appropriate boost target volume. A patient undergoing whole-breast radiotherapy had new, injectable, temporary hydrogel fiducial markers placed 1 to 3 cm from the seroma at the time of initial simulation. The patient was resimulated 4.5 weeks later for conformal photon boost planning. Computed tomography (CT) scans acquired at the beginning and the end ofmore » whole-breast radiotherapy showed that shrinkage of the lumpectomy cavity was not matched by a corresponding reduction in the surrounding tissue volume, as demarcated by hydrogel markers. This observation called into question the usual interpretation of cavity shrinkage for boost target definition. For this patient, it was decided to define the boost target volume on the initial planning CT instead of the new CT.« less

Initial FDG-PET/CT predicts survival in adults Ewing sarcoma family of tumors

PubMed Central

Jamet, Bastien; Carlier, Thomas; Campion, Loic; Bompas, Emmanuelle; Girault, Sylvie; Borrely, Fanny; Ferrer, Ludovic; Rousseau, Maxime; Venel, Yann; Kraeber-Bodéré, Françoise; Rousseau, Caroline

2017-01-01

Purpose The aim of this retrospective study was to determine, at baseline, the prognostic value of different FDG-PET/CT quantitative parameters in a homogenous Ewing Sarcoma Family of Tumors (ESFT) adult population, compared with clinically relevant prognostic factors. Methods Adult patients from 3 oncological centers, all with proved ESFT, were retrospectively included. Quantitative FDG-PET/CT parameters (SUV (maximum, peak and mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion of each patient were recorded before treatment, as well as usual clinical prognostic factors (stage of disease, location, tumor size, gender and age). Then, their relation with progression free survival (PFS) and overall survival (OS) was evaluated. Results 32 patients were included. Median age was 21 years (range, 15 to 61). Nineteen patients (59%) were initially metastatic. On multivariate analysis, high SUVmax remained independent predictor of worst OS (p=0.02) and PFS (p=0.019), metastatic disease of worst PFS (p=0.01) and high SUVpeak of worst OS (p=0.01). Optimal prognostic cut-off of SUVpeak was found at 12.5 in multivariate analyses for PFS and OS (p=0.0001). Conclusions FDG-PET/CT, recommended at ESFT diagnosis for initial staging, can be a useful tool for predicting long-term adult patients outcome through semi-quantitative parameters. PMID:29100369

Optimization of the protocols for the use of contrast agents in PET/CT studies.

PubMed

Pelegrí Martínez, L; Kohan, A A; Vercher Conejero, J L

The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Gleason score at diagnosis predicts the rate of detection of 18F-choline PET/CT performed when biochemical evidence indicates recurrence of prostate cancer: experience with 1,000 patients.

PubMed

Cimitan, Marino; Evangelista, Laura; Hodolič, Marina; Mariani, Giuliano; Baseric, Tanja; Bodanza, Valentina; Saladini, Giorgio; Volterrani, Duccio; Cervino, Anna Rita; Gregianin, Michele; Puccini, Giulia; Guidoccio, Federica; Fettich, Jure; Borsatti, Eugenio

2015-02-01

The objective of this study was to explore the ability of the initial Gleason score (GS) to predict the rate of detection of recurrent prostate cancer (PCa) with (18)F-choline PET/CT in a large cohort of patients. Data from 1,000 patients who had undergone (18)F-choline PET/CT because of biochemical evidence of relapse of PCa between 2004 and 2013 were retrieved from databases at 4 centers. Continuous data were compared by the Student t test or ANOVA, and categoric variables were compared by the χ(2) test. Univariable and multivariable analyses were performed by logistic regression. The GS at diagnosis was less than or equal to 6 in 257 patients, 7 in 347 patients, and greater than 7 in 396 patients. The results of 645 PET/CT scans were positive for PCa recurrence. Eighty-one percent of the positive PET/CT results were found in patients with a PSA level of greater than or equal to 2 ng/mL, 43% were found in patients with a PSA level of 1-2 ng/mL, and 31% were found in patients with a PSA level of less than or equal to 1 ng/mL; 78.8% of patients with positive PET/CT results had a GS of greater than 7. The results of (18)F-choline PET/CT scans were negative in 300 patients; 44% had a GS of less than or equal to 6, 35% had a GS of 7, and 17% had a GS of greater than 7. PET/CT results were rated as doubtful in only 5.5% of patients (median PSA, 1.8 ng/mL). When the GS was greater than 7, the rates of detection of (18)F-choline PET/CT were 51%, 65%, and 91% for a PSA level of less than 1 ng/mL, 1-2 ng/mL, and greater than 2 ng/mL, respectively. In univariable and multivariable analyses, both a GS of 7 and a GS of greater than 7 were independent predictors for positive (18)F-choline PET/CT results (odds ratios, 0.226 and 0.330, respectively; P values for both, <0.001). A high GS at diagnosis is a strong predictive factor for positive (18)F-choline PET/CT scan results for recurrent PCa, even when the PSA level is low (i.e., ≤1 ng/mL). © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Normal cross-sectional anatomy of the bovine digit: comparison of computed tomography and limb anatomy.

PubMed

Raji, A R; Sardari, K; Mohammadi, H R

2008-06-01

The purpose of this study was to define the structures of the digits and hoof in Holstein dairy cattle by using computed tomography scan (CT scan). Transverse, sagittal and dorsoplantar CT images of two isolated cattle cadaver digits were obtained using a Siemens ARTX2 Somatom. The CT images were compared to corresponding frozen cross-sections. Relevant anatomical structures were identified and labelled at each level. The CT images provided anatomical detail of the digits and hoof in Holstein dairy cattle. Transversal images provided excellent depiction of anatomical structures when compared to corresponding frozen cross-sections. The information presented in this paper would serve as an initial reference to the evaluation of CT images of the digits and hoof in Holstein dairy cattle.

The effect of dental artifacts, contrast media, and experience on interobserver contouring variations in head and neck anatomy.

PubMed

O'Daniel, Jennifer C; Rosenthal, David I; Garden, Adam S; Barker, Jerry L; Ahamad, Anesa; Ang, K Kian; Asper, Joshua A; Blanco, Angel I; de Crevoisier, Renaud; Holsinger, F Christopher; Patel, Chirag B; Schwartz, David L; Wang, He; Dong, Lei

2007-04-01

To investigate interobserver variability in the delineation of head-and-neck (H&N) anatomic structures on CT images, including the effects of image artifacts and observer experience. Nine observers (7 radiation oncologists, 1 surgeon, and 1 physician assistant) with varying levels of H&N delineation experience independently contoured H&N gross tumor volumes and critical structures on radiation therapy treatment planning CT images alongside reference diagnostic CT images for 4 patients with oropharynx cancer. Image artifacts from dental fillings partially obstructed 3 images. Differences in the structure volumes, center-of-volume positions, and boundary positions (1 SD) were measured. In-house software created three-dimensional overlap distributions, including all observers. The effects of dental artifacts and observer experience on contouring precision were investigated, and the need for contrast media was assessed. In the absence of artifacts, all 9 participants achieved reasonable precision (1 SD < or =3 mm all boundaries). The structures obscured by dental image artifacts had larger variations when measured by the 3 metrics (1 SD = 8 mm cranial/caudal boundary). Experience improved the interobserver consistency of contouring for structures obscured by artifacts (1 SD = 2 mm cranial/caudal boundary). Interobserver contouring variability for anatomic H&N structures, specifically oropharyngeal gross tumor volumes and parotid glands, was acceptable in the absence of artifacts. Dental artifacts increased the contouring variability, but experienced participants achieved reasonable precision even with artifacts present. With a staging contrast CT image as a reference, delineation on a noncontrast treatment planning CT image can achieve acceptable precision.

Light-Induced resetting of the circadian pacemaker: quantitative analysis of transient versus steady-state phase shifts.

PubMed

Watanabe, K; Deboer, T; Meijer, J H

2001-12-01

The suprachiasmatic nuclei of the hypothalamus contain the major circadian pacemaker in mammals, driving circadian rhythms in behavioral and physiological functions. This circadian pacemaker's responsiveness to light allows synchronization to the light-dark cycle. Phase shifting by light often involves several transient cycles in which the behavioral activity rhythm gradually shifts to its steady-state position. In this article, the authors investigate in Syrian hamsters whether a phase-advancing light pulse results in immediate shifts of the PRC at the next circadian cycle. In a first series of experiments, the authors aimed a light pulse at CT 19 to induce a phase advance. It appeared that the steady-state phase advances were highly correlated with activity onset in the first and second transient cycle. This enabled them to make a reliable estimate of the steady-state phase shift induced by a phase-advancing light pulse on the basis of activity onset in the first transient cycle. In the next series of experiments, they presented a light pulse at CT 19, which was followed by a second light pulse aimed at the delay zone of the PRC on the next circadian cycle. The immediate and steady-state phase delays induced by the second light pulse were compared with data from a third experiment in which animals received a phase-delaying light pulse only. The authors observed that the waveform of the phase-delay part of the PRC (CT 12-16) obtained in Experiment 2 was virtually identical to the phase-delay part of the PRC for a single light pulse (obtained in Experiment 3). This finding allowed for a quantitative assessment of the data. The analysis indicates that the delay part of the PRC-between CT 12 and CT 16-is rapidly reset following a light pulse at CT 19. These findings complement earlier findings in the hamster showing that after a light pulse at CT 19, the phase-advancing part of the PRC is immediately shifted. Together, the data indicate that the basis for phase advancing involves rapid resetting of both advance and delay components of the PRC.

Evaluation of PET and laparoscopy in STagIng advanced gastric cancer: a multicenter prospective study (PLASTIC-study).

PubMed

Brenkman, H J F; Gertsen, E C; Vegt, E; van Hillegersberg, R; van Berge Henegouwen, M I; Gisbertz, S S; Luyer, M D P; Nieuwenhuijzen, G A P; van Lanschot, J J B; Lagarde, S M; de Steur, W O; Hartgrink, H H; Stoot, J H M B; Hulsewe, K W E; Spillenaar Bilgen, E J; van Det, M J; Kouwenhoven, E A; van der Peet, D L; Daams, F; van Sandick, J W; van Grieken, N C T; Heisterkamp, J; van Etten, B; Haveman, J W; Pierie, J P; Jonker, F; Thijssen, A Y; Belt, E J T; van Duijvendijk, P; Wassenaar, E; van Laarhoven, H W M; Wessels, F J; Haj Mohammad, N; van Stel, H F; Frederix, G W J; Siersema, P D; Ruurda, J P

2018-04-20

Initial staging of gastric cancer consists of computed tomography (CT) and gastroscopy. In locally advanced (cT3-4) gastric cancer, fluorodeoxyglucose positron emission tomography with CT (FDG-PET/CT or PET) and staging laparoscopy (SL) may have a role in staging, but evidence is scarce. The aim of this study is to evaluate the impact and cost-effectiveness of PET and SL in addition to initial staging in patients with locally advanced gastric cancer. This prospective observational cohort study will include all patients with a surgically resectable, advanced gastric adenocarcinoma (cT3-4b, N0-3, M0), that are scheduled for treatment with curative intent after initial staging with gastroscopy and CT. The modalities to be investigated in this study is the addition of PET and SL. The primary outcome of this study is the proportion of patients in whom the PET or SL lead to a change in treatment strategy. Secondary outcome parameters are: diagnostic performance, morbidity and mortality, quality of life, and cost-effectiveness of these additional diagnostic modalities. The study recently started in August 2017 with a duration of 36 months. At least 239 patients need to be included in this study to demonstrate that the diagnostic modalities are break-even. Based on the annual number of gastrectomies in the participating centers, it is estimated that approximately 543 patients are included in this study. In this study, it is hypothesized that performing PET and SL for locally advanced gastric adenocarcinomas results in a change of treatment strategy in 27% of patients and an annual cost-reduction in the Netherlands of €916.438 in this patient group by reducing futile treatment. The results of this study may be applicable to all countries with comparable treatment algorithms and health care systems. NCT03208621 . This trial was registered prospectively on June 30, 2017.

Delayed Enhancement of Ascites After IV Contrast Material Administration at CT: Time Course and Clinical Correlation

PubMed Central

Benedetti, Nancy; Aslam, Rizwan; Wang, Zhen J.; Joe, Bonnie N.; Fu, Yanjun; Yee, Judy; Yeh, Benjamin M.

2010-01-01

OBJECTIVE The objective of our study was to determine the prevalence and clinical predictors of delayed contrast enhancement of ascites. MATERIALS AND METHODS In this retrospective study, 132 consecutive patients with ascites who underwent repeated abdominopelvic CT examinations performed within 7 days of each other were identified. These patients included 112 patients who received and 20 who did not receive IV contrast material at the initial CT examination. For each examination, we recorded the CT attenuation of the ascites. For the follow-up scan, the presence of delayed enhancement of ascites was defined as an increase in CT attenuation > 10 HU over baseline. The Fisher’s exact test, unpaired Student’s t test, and logistic regression were used to determine predictors of delayed enhancement of ascites. RESULTS A threshold increase in the attenuation of ascites by > 10 HU or more between the initial and follow-up CT examinations occurred only when IV contrast material was given with the initial examination. The increased attenuation was due to delayed contrast enhancement of ascites and occurred in 15 of the 112 patients (13%). Of the 16 patients scanned less than 1 day apart, 10 (63%) showed delayed enhancement of ascites. Delayed enhancement was not observed 3 or more days after IV contrast material administration. For each 1 mg/dL increase in serum creatinine level, the likelihood of delayed enhancement of ascites increased (odds ratio, 2.02; 95% CI, 1.11–3.69). Multivariate logistic regression showed that a short time interval between examinations (p < 0.001), increased serum creatinine level (p < 0.001), and presence of loculated ascites (p = < 0.01) were independent predictors of the magnitude of delayed enhancement of ascites. CONCLUSION Delayed contrast enhancement of ascites occurs commonly after recent prior IV contrast material administration and should not be mistaken for hemoperitoneum or proteinaceous fluid such as pus. PMID:19696286

Intracellular Signal Triggered by Cholera Toxin in Saccharomyces boulardii and Saccharomyces cerevisiae

PubMed Central

Brandão, Rogelio L.; Castro, Ieso M.; Bambirra, Eduardo A.; Amaral, Sheila C.; Fietto, Luciano G.; Tropia, Maria José M.; Neves, Maria José; Dos Santos, Raquel G.; Gomes, Newton C. M.; Nicoli, Jacques R.

1998-01-01

As is the case for Saccharomyces boulardii, Saccharomyces cerevisiae W303 protects Fisher rats against cholera toxin (CT). The addition of glucose or dinitrophenol to cells of S. boulardii grown on a nonfermentable carbon source activated trehalase in a manner similar to that observed for S. cerevisiae. The addition of CT to the same cells also resulted in trehalase activation. Experiments performed separately on the A and B subunits of CT showed that both are necessary for activation. Similarly, the addition of CT but not of its separate subunits led to a cyclic AMP (cAMP) signal in both S. boulardii and S. cerevisiae. These data suggest that trehalase stimulation by CT probably occurred through the cAMP-mediated protein phosphorylation cascade. The requirement of CT subunit B for both the cAMP signal and trehalase activation indicates the presence of a specific receptor on the yeasts able to bind to the toxin, a situation similar to that observed for mammalian cells. This hypothesis was reinforced by experiments with 125I-labeled CT showing specific binding of the toxin to yeast cells. The adhesion of CT to a receptor on the yeast surface through the B subunit and internalization of the A subunit (necessary for the cAMP signal and trehalase activation) could be one more mechanism explaining protection against the toxin observed for rats treated with yeasts. PMID:9464394

Development of an Ex Vivo, Beating Heart Model for CT Myocardial Perfusion

PubMed Central

Das, Marco; Haberland, Ulrike; Slump, Cees; Handayani, Astri; van Tuijl, Sjoerd; Stijnen, Marco; Oudkerk, Matthijs; Wildberger, Joachim E.; Vliegenthart, Rozemarijn

2015-01-01

Objective. To test the feasibility of a CT-compatible, ex vivo, perfused porcine heart model for myocardial perfusion CT imaging. Methods. One porcine heart was perfused according to Langendorff. Dynamic perfusion scanning was performed with a second-generation dual source CT scanner. Circulatory parameters like blood flow, aortic pressure, and heart rate were monitored throughout the experiment. Stenosis was induced in the circumflex artery, controlled by a fractional flow reserve (FFR) pressure wire. CT-derived myocardial perfusion parameters were analysed at FFR of 1 to 0.10/0.0. Results. CT images did not show major artefacts due to interference of the model setup. The pacemaker-induced heart rhythm was generally stable at 70 beats per minute. During most of the experiment, blood flow was 0.9–1.0 L/min, and arterial pressure varied between 80 and 95 mm/Hg. Blood flow decreased and arterial pressure increased by approximately 10% after inducing a stenosis with FFR ≤ 0.50. Dynamic perfusion scanning was possible across the range of stenosis grades. Perfusion parameters of circumflex-perfused myocardial segments were affected at increasing stenosis grades. Conclusion. An adapted Langendorff porcine heart model is feasible in a CT environment. This model provides control over physiological parameters and may allow in-depth validation of quantitative CT perfusion techniques. PMID:26185756

F-18 fluoride positron emission tomography/computed tomography in the diagnosis of avascular necrosis of the femoral head: Comparison with magnetic resonance imaging

PubMed Central

Gayana, Shankaramurthy; Bhattacharya, Anish; Sen, Ramesh Kumar; Singh, Paramjeet; Prakash, Mahesh; Mittal, Bhagwant Rai

2016-01-01

Objective: Femoral head avascular necrosis (FHAVN) is one of the increasingly common causes of musculoskeletal disability and poses a major diagnostic and therapeutic challenge. Although radiography, scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) have been widely used in the diagnosis of FHAVN, positron emission tomography (PET) has recently been evaluated to assess vascularity of the femoral head. In this study, the authors compared F-18 fluoride PET/CT with MRI in the initial diagnosis of FHAVN. Patients and Methods: We prospectively studied 51 consecutive patients with a high clinical suspicion of FHAVN. All patients underwent MRI and F-18 fluoride PET/CT, the time interval between the two scans being 4–10 (mean 8) days. Two nuclear medicine physicians blinded to the MRI report read the PET/CT scans. Clinical assessment was also done. Final diagnoses were made by surgical pathology or clinical and radiologic follow-up. Results: A final diagnosis of avascular necrosis (AVN) was made in 40 patients. MRI was 96.5% sensitive, 100% specific, and 98.03% accurate while PET/CT was 100% sensitive, specific, and accurate in diagnosing FHAVN. The agreement between the two imaging modalities for the diagnosis of AVN was 96.07%. Conclusion: F-18 fluoride PET/CT showed good agreement with MRI in the initial diagnosis of FHAVN and can be better than MRI in detecting early disease. PMID:26917886

Geodesic Distance Algorithm for Extracting the Ascending Aorta from 3D CT Images

PubMed Central

Jang, Yeonggul; Jung, Ho Yub; Hong, Youngtaek; Cho, Iksung; Shim, Hackjoon; Chang, Hyuk-Jae

2016-01-01

This paper presents a method for the automatic 3D segmentation of the ascending aorta from coronary computed tomography angiography (CCTA). The segmentation is performed in three steps. First, the initial seed points are selected by minimizing a newly proposed energy function across the Hough circles. Second, the ascending aorta is segmented by geodesic distance transformation. Third, the seed points are effectively transferred through the next axial slice by a novel transfer function. Experiments are performed using a database composed of 10 patients' CCTA images. For the experiment, the ground truths are annotated manually on the axial image slices by a medical expert. A comparative evaluation with state-of-the-art commercial aorta segmentation algorithms shows that our approach is computationally more efficient and accurate under the DSC (Dice Similarity Coefficient) measurements. PMID:26904151

Which Test? Whose Scores? Comparing Standardized Critical Thinking Tests

ERIC Educational Resources Information Center

Hatcher, Donald L.

2011-01-01

In this article, after describing one approach for teaching critical thinking (CT) that was in place at Baker University from 1990 to 2008, the author describes their experience assessing CT using three standardized exams and shows why the choice of a standardized CT test can be problematic and the results misleading. These results can be…

Quantifying multiscale porosity and fracture aperture distribution in granite cores using computed tomography

NASA Astrophysics Data System (ADS)

Wenning, Quinn; Madonna, Claudio; Joss, Lisa; Pini, Ronny

2017-04-01

Knowledge of porosity and fracture (aperture) distribution is key towards a sound description of fluid transport in low-permeability rocks. In the context of geothermal energy development, the ability to quantify the transport properties of fractures is needed to in turn quantify the rate of heat transfer, and, accordingly, to optimize the engineering design of the operation. In this context, core-flooding experiments coupled with non-invasive imaging techniques (e.g., X-Ray Computed Tomography - X-Ray CT) represent a powerful tool for making direct observations of these properties under representative geologic conditions. This study focuses on quantifying porosity and fracture aperture distribution in a fractured westerly granite core by using two recently developed experimental protocols. The latter include the use of a highly attenuating gas [Vega et al., 2014] and the application of the so-called missing CT attenuation method [Huo et al., 2016] to produce multidimensional maps of the pore space and of the fractures. Prior to the imaging experiments, the westerly granite core (diameter: 5 cm, length: 10 cm) was thermally shocked to induce micro-fractured pore space; this was followed by the application of the so-called Brazilian method to induce a macroscopic fracture along the length of the core. The sample was then mounted in a high-pressure aluminum core-holder, exposed to a confining pressure and placed inside a medical CT scanner for imaging. An initial compressive pressure cycle was performed to remove weak asperities and reduce the hysteretic behavior of the fracture with respect to effective pressure. The CT scans were acquired at room temperature and 0.5, 5, 7, and 10 MPa effective pressure under loading and unloading conditions. During scanning the pore fluid pressure was undrained and constant, and the confining pressure was regulated at the desired pressure with a high precision pump. Highly transmissible krypton and helium gases were used as saturating fluids to obtain a sufficiently high contrast in the acquired CT images (˜ 474 HU). 3D reconstructions of the sample have been prepared in terms of porosity at a maximum resolution of (0.24×0.24×1) mm3 . Porosity is estimated via the X-ray saturation technique, where porosity is a function of the difference between CT numbers of pure helium and krypton and the difference between the CT numbers of an individual voxel saturated with helium and krypton, respectively. Applying this method with krypton and helium is advantageous for low permeable samples where achieving complete water saturation is difficult. This allows for quantification of voxel-by-voxel-porosity distribution where the whole core porosity is less than 2%. The fracture aperture is assessed using the measured missing CT attenuation method. Use of the medical CT scanner to estimate intrinsic rock properties requires careful voxel-by-voxel consideration and appraisal of the uncertainty, which can be reduced by subtracting multiple slices taken at the exact same location. These results show that core-scale porosity and fracture distribution heterogeneity play an important role in fluid saturation and heat extraction potential in geothermal systems. Huo, D., Pini, R., and Benson, S.M., 2016, A calibration-free approach for measuring fracture aperture distributions using X-ray computed tomography: Geosphere, v. 12, no. 2, p. 558-571, doi:10.1130/GES01175.1. Vega, B., Dutta, A., and Kovscek, A.R., 2014, CT imaging of low-permeability, dual-porosity systems using high X-ray contrast gas: Transport in Porous Media, v. 101, p. 81-97, doi:10.1007/s11242-013-0232-0.

Neurocognitive assessment in patients with a minor traumatic brain injury and an abnormal initial CT scan: Can cognitive evaluation assist in identifying patients who require surveillance CT brain imaging?

PubMed

Clements, Thomas W; Dunham, Michael; Kirkpatrick, Andrew; Rajakumar, Ruphus; Gratton, Carolyn; Lall, Rohan; McBeth, Paul; Ball, Chad G

2018-05-01

Evidence for repeat computed tomography (CT) in minor traumatic brain injury (mTBI) patients with intracranial pathology is scarce. The aim of this study was to investigate the utility of clinical cognitive assessment (COG) in defining the need for repeat imaging. COG performance was compared with findings on subsequent CT, and need for neurosurgery in mTBI patients (GCS 13-15 and positive CT findings). Of 152 patients, 65.8% received a COG (53.0% passed). Patients with passed COG underwent fewer repeat CT (43.4% vs. 78.7%; p = .001) and had shorter LOS (8.7 vs. 19.5; p < .05). Only 1 patient required neurosurgery after a passed COG. The negative predictive value of a normal COG was 90.6% (95%CI = 81.8%-95.4%). mTBI patients with an abnormal index CT who pass COG are less likely to undergo repeat CT head, and rarely require neurosurgery. The COG warrants further investigation to determine its role in omitting repeat head CT. Copyright © 2018 Elsevier Inc. All rights reserved.

SU-F-J-188: Clinical Implementation of in Room Mobile CT for Image Guided Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, H; Wu, R; Poenisch, F

Purpose: To implement soft-tissue image-guided proton therapy using inroom mobile CT. Methods: Anthropomorphic phantom was first used to determine the setup accuracy using in- room mobile CT. Laser and bbs were used for the initial setup (marked isocenter). CT data was then acquired with in-room mobile CT (daily CT). The shift between the marked isocenter and the planned isocenter (final isocenter) was determined from the daily CT using in-house Computer Assisted Targeting (CAT) software. Orthogonal DRRs of the day was also generated from the daily CT. The phantom was then transferred on the treatment couch top to the treatment machinemore » using a transportation system, and again aligned to the marked isocenter. Couch shifts were made to align the phantom to the final isocenter using the shifts as determined using the CAT software, and verified using orthogonal X-ray images with the daily DRRs. Results: Phantom data suggests that following the setup procedure as described above, targeting accuracy could be within 1 mm. Patient data are being acquired and analyzed. Conclusion: In-room mobile CT is capable of providing soft-tissue image-guided proton therapy.« less

[Application of computed tomography (CT) examination for forensic medicine].

PubMed

Urbanik, Andrzej; Chrzan, Robert

2013-01-01

The aim of the study is to present a own experiences in usage of post mortem CT examination for forensic medicine. With the help of 16-slice CT scanner 181 corpses were examined. Obtained during acquisition imaging data are later developed with dedicated programmes. Analyzed images were extracted from axial sections, multiplanar reconstructions as well as 3D reconstructions. Gained information helped greatly when classical autopsy was performed by making it more accurate. A CT scan images recorded digitally enable to evaluate corpses at any time, despite processes of putrefaction or cremation. If possible CT examination should precede classical autopsy.

Contextual convolutional neural networks for lung nodule classification using Gaussian-weighted average image patches

NASA Astrophysics Data System (ADS)

Lee, Haeil; Lee, Hansang; Park, Minseok; Kim, Junmo

2017-03-01

Lung cancer is the most common cause of cancer-related death. To diagnose lung cancers in early stages, numerous studies and approaches have been developed for cancer screening with computed tomography (CT) imaging. In recent years, convolutional neural networks (CNN) have become one of the most common and reliable techniques in computer aided detection (CADe) and diagnosis (CADx) by achieving state-of-the-art-level performances for various tasks. In this study, we propose a CNN classification system for false positive reduction of initially detected lung nodule candidates. First, image patches of lung nodule candidates are extracted from CT scans to train a CNN classifier. To reflect the volumetric contextual information of lung nodules to 2D image patch, we propose a weighted average image patch (WAIP) generation by averaging multiple slice images of lung nodule candidates. Moreover, to emphasize central slices of lung nodules, slice images are locally weighted according to Gaussian distribution and averaged to generate the 2D WAIP. With these extracted patches, 2D CNN is trained to achieve the classification of WAIPs of lung nodule candidates into positive and negative labels. We used LUNA 2016 public challenge database to validate the performance of our approach for false positive reduction in lung CT nodule classification. Experiments show our approach improves the classification accuracy of lung nodules compared to the baseline 2D CNN with patches from single slice image.

Repeat neuroimaging of mild traumatic brain-injured patients with acute traumatic intracranial hemorrhage: clinical outcomes and radiographic features.

PubMed

Kreitzer, Natalie; Lyons, Michael S; Hart, Kim; Lindsell, Cristopher J; Chung, Sora; Yick, Andrew; Bonomo, Jordan

2014-10-01

Emergency department (ED) management of mild traumatic brain injury (TBI) patients with any form of traumatic intracranial hemorrhage (ICH) is variable. Since 2000, our center's standard practice has been to obtain a repeat head computed tomography (CT) at least 6 hours after initial imaging. Patients are eligible for discharge if clinical and CT findings are stable. Whether this practice is safe is unknown. This study characterized clinical outcomes in mild TBI patients with acute traumatic ICH seen on initial ED neuroimaging. This retrospective cohort study included patients presenting to the ED with blunt mild TBI with Glasgow Coma Scale (GCS) scores of 14 or 15 and stable vital signs, during the period from January 2001 to January 2010. Patients with any ICH on initial head CT and repeat head CT within 24 hours were eligible. Cases were excluded for initial GCS < 14, injury > 24 hours old, pregnancy, concomitant nonminor injuries, and coagulopathy. A single investigator abstracted data from records using a standardized case report form and data dictionary. Primary endpoints included death, neurosurgical procedures, and for discharged patients, return to the ED within 7 days. Differences in proportions were computed with 95% confidence intervals (CIs). Of 1,011 patients who presented to the ED and had two head CTs within 24 hours, 323 (32%) met inclusion criteria. The median time between CT scans was 6 hours (interquartile range = 5 to 7 hours). A total of 153 (47%) patients had subarachnoid hemorrhage, 132 (41%) patients had subdural hemorrhage, 11 (3%) patients had epidural hemorrhage, 78 (24%) patients had cerebral contusions, and 59 (18%) patients had intraparenchymal hemorrhage. Four of 323 (1.2%, 95% CI = 0.3% to 3.2%) patients died within 2 weeks of injury. Three of the patients who died had been admitted from the ED on their initial visits, and one had been discharged home. There were 206 patients (64%) discharged from the ED, 28 (13.6%) of whom returned to the ED within 1 week. Of the 92 who were hospitalized, three (0.9%, 95% CI = 0.2% to 2.7%) required neurosurgical intervention. Discharge after a repeat head CT and brief period of observation in the ED allowed early discharge of a cohort of mild TBI patients with traumatic ICH without delayed adverse outcomes. Whether this justifies the cost and radiation exposure involved with this pattern of practice requires further study. © 2014 by the Society for Academic Emergency Medicine.

Local Failure in Parameningeal Rhabdomyosarcoma Correlates With Poor Response to Induction Chemotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ladra, Matthew M.; Mandeville, Henry C.; Niemierko, Andrzej

2015-06-01

Background: Local control remains a challenge in pediatric parameningeal rhabdomyosarcoma (PM-RMS), and survival after local failure (LF) is poor. Identifying patients with a high risk of LF is of great interest to clinicians. In this study, we examined whether tumor response to induction chemotherapy (CT) could predict LF in embryonal PM-RMS. Methods: We identified 24 patients with embryonal PM-RMS, age 2 to 18 years, with complete magnetic resonance imaging and gross residual disease after surgical resection. All patients received proton radiation therapy (RT), median dose 50.4 Gy{sub RBE} (50.4-55.8 Gy{sub RBE}). Tumor size was measured before initial CT and before RT. Results:more » With a median follow-up time of 4.1 years for survivors, LF was seen in 9 patients (37.5%). The median time from the initiation of CT to the start of RT was 4.8 weeks. Patients with LF had a similar initial (pre-CT) tumor volume compared with patients with local controlled (LC) (54 cm{sup 3} vs 43 cm{sup 3}, P=.9) but a greater median volume before RT (pre-RT) (40 cm{sup 3} vs 7 cm{sup 3}, P=.009) and a smaller median relative percent volume reduction (RPVR) in tumor size (0.4% vs 78%, P<.001). Older age (P=.05), larger pre-RT tumor volume (P=.03), and smaller RPVR (P=.003) were significantly associated with actuarial LF on univariate Cox analysis. Conclusions: Poor response to induction CT appears to be associated with an increased risk of LF in pediatric embryonal PM-RMS.« less

[Renal angiomyolipomas without fat component: tomodensitometric and histologic characteristics, clinical course].

PubMed

Negre, T; Faure, A; Andre, M; Daniel, L; Coulange, C; Lechevallier, E

2011-11-01

Angiomyolipoma is the most frequent benign renal solid tumor. Because of the lack of fat component on the CT scan, diagnosis of this tumor is hard and can require percutaneous biopsy of unknown renal tumor. The follow-up of the poor fat CT scan component AML (PFCT AML) is uncertain. Five hundred percutaneous renal biopsy under tomodenstitometry have been realised between 1998 and 2008. There was 41 PFCT AML on the 500 biopsy. By definition, a PFCT AML is an AML where the diagnosis is done on a percutaneous biopsy but where there was no fat component on the first CT scan. We studied and compared clinical, tomodensitometric and histologic parameters of these 41 patients (mean age: 56, 9±11.04; sexe rate M/F: 6/35) where renal AML was diagnosed on percutaneous renal biopsy but without fat component on CT scan. Average size was 26.44±14.68mm. We phone-called 16 patients for the long-term follow-up. Average follow-up was 41±28.3 months. For four patients on 16, initial diagnosis was done in front of local symptoms, for one of the 16 diagnosis was done in front of general symptoms, for one of the diagnosis was done during Bourneville tuberous sclerosis evolution and 10 of the 16 was done fortuitously. After review of the initial CT scan, fat density was found on 24% of them. Ten percent was epithelioid angiomyolipoma. Four renal biopsy on 41 (10%) was epithelioid AML. No epithelioid AML had fat component after the second look of the CT scan. Among the 16 patients who were phone-called, three (19%) underwent a complication. Two had abdominal pain and was treated medically. Initial sizes were 26 and 30mm. Only one patient must be operated by radical nephrectomy for acute hemorrhage. Initial size was 45mm. No neoplasic degeneration was identified for those 16 patients. In our study, the PFCT AML rate was 8.2%. In 25% cases, CT scan read-through shown a fat component and could help for the diagnosis. PFCT AML evolution seems to be the same as a classic AML. Conservative treatment had a good covering because there was no death and no malignant evolution. However, we found 10% of epithelioid angiomyolipoma in which malignant risk is high. PFCT AML diagnosed on renal percutaneous biopsy of unknown renal tumor requires the same management than the classic AML. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

SU-C-9A-06: The Impact of CT Image Used for Attenuation Correction in 4D-PET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Y; Bowsher, J; Yan, S

2014-06-01

Purpose: To evaluate the appropriateness of using 3D non-gated CT image for attenuation correction (AC) in a 4D-PET (gated PET) imaging protocol used in radiotherapy treatment planning simulation. Methods: The 4D-PET imaging protocol in a Siemens PET/CT simulator (Biograph mCT, Siemens Medical Solutions, Hoffman Estates, IL) was evaluated. CIRS Dynamic Thorax Phantom (CIRS Inc., Norfolk, VA) with a moving glass sphere (8 mL) in the middle of its thorax portion was used in the experiments. The glass was filled with {sup 18}F-FDG and was in a longitudinal motion derived from a real patient breathing pattern. Varian RPM system (Varian Medicalmore » Systems, Palo Alto, CA) was used for respiratory gating. Both phase-gating and amplitude-gating methods were tested. The clinical imaging protocol was modified to use three different CT images for AC in 4D-PET reconstruction: first is to use a single-phase CT image to mimic actual clinical protocol (single-CT-PET); second is to use the average intensity projection CT (AveIP-CT) derived from 4D-CT scanning (AveIP-CT-PET); third is to use 4D-CT image to do the phase-matched AC (phase-matching- PET). Maximum SUV (SUVmax) and volume of the moving target (glass sphere) with threshold of 40% SUVmax were calculated for comparison between 4D-PET images derived with different AC methods. Results: The SUVmax varied 7.3%±6.9% over the breathing cycle in single-CT-PET, compared to 2.5%±2.8% in AveIP-CT-PET and 1.3%±1.2% in phasematching PET. The SUVmax in single-CT-PET differed by up to 15% from those in phase-matching-PET. The target volumes measured from single- CT-PET images also presented variations up to 10% among different phases of 4D PET in both phase-gating and amplitude-gating experiments. Conclusion: Attenuation correction using non-gated CT in 4D-PET imaging is not optimal process for quantitative analysis. Clinical 4D-PET imaging protocols should consider phase-matched 4D-CT image if available to achieve better accuracy.« less

One-Year Longitudinal Study of Fatigue, Cognitive Functions, and Quality of Life After Adjuvant Radiotherapy for Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noal, Sabine; Clinical Research Department, Centre Francois Baclesse, Caen; Levy, Christelle

Purpose: Most patients with localized breast cancer (LBC) who take adjuvant chemotherapy (CT) complain of fatigue and a decrease in quality of life during or after radiotherapy (RT). The aim of this longitudinal study was to compare the impact of RT alone with that occurring after previous CT on quality of life. Methods and Materials: Fatigue (the main endpoint) and cognitive impairment were assessed in 161 CT-RT and 141 RT patients during RT and 1 year later. Fatigue was assessed with Functional Assessment of Cancer Therapy-General questionnaires, including breast and fatigue modules. Results: At baseline, 60% of the CT-RT patientsmore » expressed fatigue vs. 33% of the RT patients (p <0.001). Corresponding values at the end of RT were statistically similar (61% and 53%), and fatigue was still reported at 1 year by more than 40% of patients in both groups. Risk factors for long-term fatigue included depression (odds ratio [OR] = 6), which was less frequent in the RT group at baseline (16% vs. 28 %, respectively, p = 0.01) but reached a similar value at the end of RT (25% in both groups). Initial mild cognitive impairments were reported by RT (34 %) patients and CT-RT (24 %) patients and were persistent at 1 year for half of them. No biological disorders were associated with fatigue or cognitive impairment. Conclusions: Fatigue was the main symptom in LBC patients treated with RT, whether they received CT previously or not. The correlation of persistent fatigue with initial depressive status favors administering medical and psychological programs for LBC patients treated with CT and/or RT, to identify and manage this main quality-of-life-related symptom.« less

Pulmonary tularaemia: all that looks like cancer is not necessarily cancer - case report of four consecutive cases.

PubMed

Fachinger, Patrick; Tini, Gabrielo Mauro; Grobholz, Rainer; Gambazzi, Franco; Fankhauser, Hans; Irani, Sarosh

2015-03-26

Pulmonary tularaemia is a very rare disease with only a small number of cases described in the literature. So far, to our knowledge, there exists no case report of pulmonary tularaemia where PET-CT scans and follow up CT scans are available. We present four consecutive cases of pulmonary tularaemia. All patients suffered from non-specific symptoms. All patients were referred to our institution with strong suspicions of malignancy, particularly lung cancer. Diagnosis of tularaemia was made by typical findings in the aspirate of EBUS guided fine needle aspiration (necrosis, epithelioid cell aggregation) and surgical biopsy respectively, and a positive serology. In three of the four cases, the diagnosis was confirmed by positive PCR results of the tissue. PET-CT scans obtained in all four cases were indistinguishable from lesions typically seen in patients suffering from lung cancer. One of the four patients suffered from recurrence of the disease after antibiotic treatment; also this patient finally recovered after initiation of a second antibiotic regimen. One case became asymptomatic spontaneously, but this patient still received an antibiotic treatment. In one case, a follow up CT scan was unchanged compared to the initial PET-CT scan; in all other cases, the lesions disappeared almost completely. Symptoms of patients suffering from pulmonary tularaemia are non-specific and can be of prolonged character. PET-CT scans in these cases are indistinguishable from lung cancer. The diagnosis can be established when typical findings in EBUS guided fine needle aspirates or surgical biopsies are found in combination with a positive serology. In most cases the lesions disappear in follow up CT scans after clinically successful treatment.

Computed tomography in the evaluation of penetrating neck trauma: a preliminary study.

PubMed

Gracias, V H; Reilly, P M; Philpott, J; Klein, W P; Lee, S Y; Singer, M; Schwab, C W

2001-11-01

Penetrating neck trauma has traditionally been evaluated by surgical exploration and/or invasive diagnostic studies. We hypothesized that computed tomography (CT), used as an early diagnostic tool to accurately determine trajectory, would direct or eliminate further studies or procedures in stable patients with penetrating neck trauma. Retrospective case series. Academic, urban, level I trauma center. Hemodynamically stable patients without hard signs of vascular injury or aerodigestive violation who had sustained penetrating trauma to the neck. Patients underwent a spiral CT as an initial diagnostic study after initial evaluation in the trauma bay. Further invasive studies were directed by CT findings. Number of invasive studies performed. Twenty-three patients were identified during the 30-month period. Nineteen patients sustained gunshot wounds; 3, shotgun wounds; and 1, a stab wound. One patient died of a cranial gunshot wound. Three isolated zone I, 1 isolated zone II, 9 isolated zone III, and 10 multiple neck zone trajectories were evaluated. Thirteen patients were identified by CT to have trajectories remote from vital structures and required no further evaluation. Ten patients underwent angiography. Only 2 underwent bronchoscopy and esophagoscopy. Four patients were discharged from the emergency department; 7 other patients were discharged within 24 hours. No adverse patient events occurred before, during, or after CT scan. Computed tomography in stable selected patients with penetrating neck trauma appears safe. Invasive studies can often be eliminated from the diagnostic algorithm when CT demonstrates trajectories remote from vital structures. As a result, efficient evaluation and early discharge from the trauma bay or emergency department can be realized. Further prospective study of CT scan after penetrating neck trauma is needed.

Exploring Issues about Computational Thinking in Higher Education

ERIC Educational Resources Information Center

Czerkawski, Betul C.; Lyman, Eugene W., III

2015-01-01

The term computational thinking (CT) has been in academic discourse for decades, but gained new currency in 2006, when Jeanette Wing used it to describe a set of thinking skills that students in all fields may require in order to succeed. Wing's initial article and subsequent writings on CT have been broadly influential; experts in…

Tangential scanning of hardwood logs: developing an industrial computer tomography scanner

Treesearch

Nand K. Gupta; Daniel L. Schmoldt; Bruce Isaacson

1999-01-01

It is generally believed that noninvasive scanning of hardwood logs such as computer tomography (CT) scanning prior to initial breakdown will greatly improve the processing of logs into lumber. This belief, however, has not translated into rapid development and widespread installation of industrial CT scanners for log processing. The roadblock has been more operational...

CT Imaging, Data Reduction, and Visualization of Hardwood Logs

Treesearch

Daniel L. Schmoldt

1996-01-01

Computer tomography (CT) is a mathematical technique that, combined with noninvasive scanning such as x-ray imaging, has become a powerful tool to nondestructively test materials prior to use or to evaluate materials prior to processing. In the current context, hardwood lumber processing can benefit greatly by knowing what a log looks like prior to initial breakdown....

Time to gain trust and change—Experiences of attachment and mindfulness-based cognitive therapy among patients with chronic pain and psychiatric co-morbidity

PubMed Central

Peilot, Birgitta; Andréll, Paulin; Samuelsson, Anita; Mannheimer, Clas; Frodi, Ann; Sundler, Annelie J.

2014-01-01

The treatment of patients with chronic pain disorders is complex. In the rehabilitation of these patients, coping with chronic pain is seen as important. The aim of this study was to explore the meaning of attachment and mindfulness-based cognitive therapy (CT) among patients with chronic pain and psychiatric co-morbidity. A phenomenological approach within a lifeworld perspective was used. In total, 10 patients were interviewed after completion of 7- to 13-month therapy. The findings reveal that the therapy and the process of interaction with the therapist were meaningful for the patients’ well-being and for a better management of pain. During the therapy, the patients were able to initiate a movement of change. Thus, CT with focus on attachment and mindfulness seems to be of value for these patients. The therapy used in this study was adjusted to the patients’ special needs, and a trained psychotherapist with a special knowledge of patients with chronic pain might be required. PMID:25138653

Enhancing Cognitive Training Through Aerobic Exercise After a First Schizophrenia Episode: Theoretical Conception and Pilot Study

PubMed Central

Nuechterlein, Keith H.; Ventura, Joseph; McEwen, Sarah C.; Gretchen-Doorly, Denise; Vinogradov, Sophia; Subotnik, Kenneth L.

2016-01-01

Cognitive training (CT) and aerobic exercise have separately shown promise for improving cognitive deficits in schizophrenia. Aerobic exercise releases brain-derived neurotrophic factor, which promotes synaptic plasticity and neurogenesis. Thus, aerobic exercise provides a neurotrophic platform for neuroplasticity-based CT. The combination of aerobic exercise and CT may yield more robust effects than CT alone, particularly in the initial course of schizophrenia. In a pilot study, 7 patients with a recent onset of schizophrenia were assigned to Cognitive Training & Exercise (CT&E) and 9 to CT alone for a 10-week period. Posit Science programs were used for CT. Neurocognitive training focused on tuning neural circuits related to perceptual processing and verbal learning and memory. Social cognitive training used the same learning principles with social and affective stimuli. Both groups participated in these training sessions 2d/wk, 2h/d. The CT&E group also participated in an aerobic conditioning program for 30 minutes at our clinic 2d/wk and at home 2d/wk. The effect size for improvement in the MATRICS Consensus Cognitive Battery Overall Composite score for CT&E patients relative to CT patients was large. Functional outcome, particularly independent living skills, also tended to improve more in the CT&E than in the CT group. Muscular endurance, cardiovascular fitness, and diastolic blood pressure also showed relative improvement in the CT&E compared to the CT group. These encouraging pilot study findings support the promise of combining CT and aerobic exercise to improve the early course of schizophrenia. PMID:27460618

Radiotherapy treatment planning: benefits of CT-MR image registration and fusion in tumor volume delineation.

PubMed

Djan, Igor; Petrović, Borislava; Erak, Marko; Nikolić, Ivan; Lucić, Silvija

2013-08-01

Development of imaging techniques, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), made great impact on radiotherapy treatment planning by improving the localization of target volumes. Improved localization allows better local control of tumor volumes, but also minimizes geographical misses. Mutual information is obtained by registration and fusion of images achieved manually or automatically. The aim of this study was to validate the CT-MRI image fusion method and compare delineation obtained by CT versus CT-MRI image fusion. The image fusion software (XIO CMS 4.50.0) was applied to delineate 16 patients. The patients were scanned on CT and MRI in the treatment position within an immobilization device before the initial treatment. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated on CT alone and on CT+MRI images consecutively and image fusion was obtained. Image fusion showed that CTV delineated on a CT image study set is mainly inadequate for treatment planning, in comparison with CTV delineated on CT-MRI fused image study set. Fusion of different modalities enables the most accurate target volume delineation. This study shows that registration and image fusion allows precise target localization in terms of GTV and CTV and local disease control.

[Secondary Splenic Rupture after Initially Inconspicuous CAT Scan].

PubMed

Prokop, A; Koll, S; Chmielnicki, M

2016-04-01

Splenic injuries occur in 1-5 % of blunt abdominal trauma cases. After initial haemorrhagic compression, secondary delayed spleen rupture can occur with a latency of one day to a month or longer. Mortality is then up to 15 %. The spleen injury is almost always recognisable on CT or ultrasound. In one case from our clinic, secondary splenic rupture occurred in a patient after discharge from hospitalisation, even though the initial CT and ultrasound were unremarkable. The patient survived, and underwent emergent splenectomy 8 days after the trauma. An expert review of the case identified no errors in treatment. No case of secondary splenic rupture after initially unremarkable diagnostic studies and clinical course has previously been published. Secondary splenic rupture has a high mortality rate. Patients should be advised of potential complications after hospital discharge, and should return to the hospital immediately in case of symptoms. Georg Thieme Verlag KG Stuttgart · New York.

[Role of 18FDG-PET/CT in the management and gross tumor volume definition for radiotherapy of head and neck cancer; single institution experiences based on long-term follow-up].

PubMed

Hideghéty, Katalin; Cserháti, Adrienne; Besenyi, Zsuzsanna; Zag, Levente; Gaál, Szilvia; Együd, Zsófia; Mózes, Petra; Szántó, Erika; Csenki, Melinda; Rusz, Orsolya; Varga, Zoltán; Dobi, Ágnes; Maráz, Anikó; Pávics, László; Lengyel, Zsolt

2015-06-01

The purpose of our work is evaluation of the impact of 18FDG-PET/CT on the complex management of locoregionally advanced (T3-4N1-3) head and neck squamous cell cancer (LAHNSC), and on the target definition for 3D conformal (3DCRT) and intensity-modulated radiotherapy (IMRT). 18FDG-PET/CT were performed on 185 patients with LAHNSC prior to radiotherapy/chemoradiation in the treatment position between 2006 and 2011. Prior to it 91 patients received induction chemotherapy (in 20 cases of these, baseline PET/CT was also available). The independently delineated CT-based gross tumor volume (GTVct) and PET/CT based ones (GTVpet) were compared. Impact of PET/CT on the treatment strategy, on tumor response evaluation to ICT, on GTV definition furthermore on overall and disease-specific survival (OS, DSS) was analysed. PET/CT revealed 10 head and neck, 2 lung cancers for 15 patients with carcinoma of unknown primary (CUP) while 3 remained unknown. Second tumors were detected in 8 (4.4%), distant metastasis in 15 (8.2%) cases. The difference between GTVct and GTVpet was significant (p=0.001). In 16 patients (14%) the GTVpet were larger than GTVct due to multifocal manifestations in the laryngo-pharyngeal regions (4 cases) or lymph node metastases (12 cases). In the majority of the cases (82 pts, 72%) PET/CT-based conturing resulted in remarkable decrease in the volume (15-20%: 4 cases, 20-50%: 46 cases, >50%: 32 cases). On the basis of the initial and post-ICT PET/CT comparison in 15/20 patients more than 50% volume reduction and in 6/20 cases complete response were achieved. After an average of 6.4 years of follow-up the OS (median: 18.3±2.6 months) and DSS (median: 25.0±4.0 months) exhibited close correlation (p=0.0001) to the GTVpet. In cases with GTVpet <10 cm3 prior to RT, DSS did not reach the median, the mean is 82.1±6.1 months, while in cases with GTVpet 10-40 cm3 the median of the DSS was 28.8±4.9 months (HR = 3.57; 95% CI: 1.5-8.3), and in those with GTVpet >40 cm3 the median DSS was 8.4±0.96 months (HR= 11.48; 95% CI: 5.3-24.9). Our results suggest that 18FDG-PET/CT plays an important role for patient with LAHNSC, by modifying the treatment concept and improving the target definition for selective RT modalities. Volumetric PET/CT-based assessment of the tumor response after ICT gives valuable contribution to further therapy planning.

CT14QED parton distribution functions from isolated photon production in deep inelastic scattering

NASA Astrophysics Data System (ADS)

Schmidt, Carl; Pumplin, Jon; Stump, Daniel; Yuan, C.-P.

2016-06-01

We describe the implementation of quantum electrodynamic (QED) evolution at leading order (LO) along with quantum chromodynamic (QCD) evolution at next-to-leading order (NLO) in the CTEQ-TEA global analysis package. The inelastic contribution to the photon parton distribution function (PDF) is described by a two-parameter ansatz, coming from radiation off the valence quarks, and based on the CT14 NLO PDFs. Setting the two parameters to be equal allows us to completely specify the inelastic photon PDF in terms of the inelastic momentum fraction carried by the photon, p0γ, at the initial scale Q0=1.295 GeV . We obtain constraints on the photon PDF by comparing with ZEUS data [S. Chekanov et al. (ZEUS Collaboration), Phys. Lett. B 687, 16 (2010)] on the production of isolated photons in deep inelastic scattering, e p →e γ +X . For this comparison we present a new perturbative calculation of the process that consistently combines the photon-initiated contribution with the quark-initiated contribution. Comparison with the data allows us to put a constraint at the 90% confidence level of p0γ≲0.14 % for the inelastic photon PDF at the initial scale of Q0=1.295 GeV in the one-parameter radiative ansatz. The resulting inelastic CT14QED PDFs will be made available to the public. In addition, we also provide CT14QEDinc PDFs, in which the inclusive photon PDF at the scale Q0 is defined by the sum of the inelastic photon PDF and the elastic photon distribution obtained from the equivalent photon approximation.

Results of a prospective clinical study on the diagnostic performance of standard magnetic resonance imaging in comparison to a combination of 3T MRI and additional CT imaging in Kienböck's disease.

PubMed

Stahl, Stephane; Hentschel, Pascal; Ketelsen, Dominik; Grosse, Ulrich; Held, Manuel; Wahler, Theodora; Syha, Roland; Schaller, Hans-Eberhard; Nikolaou, Konstantin; Grözinger, Gerd

2017-05-01

This prospective clinical study examined standard wrist magnetic resonance imaging (MRI) examinations and the incremental value of computed tomography (CT) in the diagnosis of Kienböck's disease (KD) with regard to reliability and precision in the different diagnostic steps during diagnostic work-up. Sixty-four consecutive patients referred between January 2009 and January 2014 with positive initial suspicion of KD according to external standard wrist MRI were prospectively included (step one). Institutional review board approval was obtained. Clinical examination by two handsurgeons were followed by wrist radiographs (step two), ultrathin-section CT, and 3T contrast-enhanced MRI (step three). Final diagnosis was established in a consensus conference involving all examiners and all examinations results available from step three. In 12/64 patients, initial suspicion was discarded at step two and in 34/64 patients, the initial suspicion of KD was finally discarded at step three. The final external MRI positive predictive value was 47%. The most common differential diagnoses at step three were intraosseous cysts (n=15), lunate pseudarthrosis (n=13), and ulnar impaction syndrome (n=5). A correlation between radiograph-based diagnoses (step two) with final diagnosis (step three) showed that initial suspicion of stage I KD had the lowest sensitivity for correct diagnosis (2/11). Technical factors associated with a false positive external MRI KD diagnosis were not found. Standard wrist MRI should be complemented with thin-section CT, and interdisciplinary interpretation of images and clinical data, to increase diagnostic accuracy in patients with suspected KD. Copyright © 2017. Published by Elsevier B.V.

Initial Experience With Gallium-68 DOTA-Octreotate PET/CT and Peptide Receptor Radionuclide Therapy for Pediatric Patients With Refractory Metastatic Neuroblastoma.

PubMed

Kong, Grace; Hofman, Michael S; Murray, William K; Wilson, Sharyn; Wood, Paul; Downie, Peter; Super, Leanne; Hogg, Annette; Eu, Peter; Hicks, Rodney J

2016-03-01

Pediatric patients with refractory neuroblastoma have limited therapeutic options. Neuroblastoma may express somatostatin receptors (SSTRs) allowing imaging with 68Ga-DOTA-Octreotate (GaTATE) positron emission tomography/computed tomography (PET/CT) and peptide receptor radionuclide therapy (PRRT). We reviewed our experience with this theranostic combination. GaTATE studies (8 patients; 2 to 9 years old) were reviewed and compared with 123I-MIBG or posttreatment 131I-MIBG studies. Immunohistochemistry (IHC) for SSTR subtype 2 was performed in 5 patients. Four patients received PRRT. GaTATE PET showed additional disease in 38% (3/8 patients), and upstaged 1 patient by detecting marrow involvement. IHC detected SSTR 2 in all patients assessed. Six patients were deemed suitable for PRRT on imaging. Four patients received 17 cycles of palliative PRRT (10 111In-DOTATATE; 5 177Lu-DOTATATE; 1 combined 111In and 177Lu-DOTATATE; 1 combined 177Lu and 90Y-DOTATATE) with no significant toxicity attributed to PRRT. All had objective responses. Two survivors are now 40 and 56 months from PRRT commencement. GaTATE PET was positive in a high proportion of patients with refractory neuroblastoma, correlating with SSTR 2 on IHC, with additional disease identified compared with MIBG imaging. PRRT seems safe, feasible, with responses observed in patients with progression despite multimodality treatment. These data support ongoing clinical trials in such patients.

Improved surgical procedure using intraoperative navigation for the implantation of the SPG microstimulator in patients with chronic cluster headache.

PubMed

Kohlmeier, Carsten; Behrens, Peter; Böger, Andreas; Ramachandran, Brinda; Caparso, Anthony; Schulze, Dirk; Stude, Philipp; Heiland, Max; Assaf, Alexandre T

2017-12-01

The ATI SPG microstimulator is designed to be fixed on the posterior maxilla, with the integrated lead extending into the pterygopalatine fossa to electrically stimulate the sphenopalatine ganglion (SPG) as a treatment for cluster headache. Preoperative surgical planning to ensure the placement of the microstimulator in close proximity (within 5 mm) to the SPG is critical for treatment efficacy. The aim of this study was to improve the surgical procedure by navigating the initial dissection prior to implantation using a passive optical navigation system and to match the post-operative CBCT images with the preoperative treatment plan to verify the accuracy of the intraoperative placement of the microstimulator. Custom methods and software were used that result in a 3D rotatable digitally reconstructed fluoroscopic image illustrating the patient-specific placement with the ATI SPG microstimulator. Those software tools were preoperatively integrated with the planning software of the navigation system to be used intraoperatively for navigated placement. Intraoperatively, the SPG microstimulator was implanted by completing the initial dissection with CT navigation, while the final position of the stimulator was verified by 3D CBCT. Those reconstructed images were then immediately matched with the preoperative CT scans with the digitally inserted SPG microstimulator. This method allowed for visual comparison of both CT scans and verified correct positioning of the SPG microstimulator. Twenty-four surgeries were performed using this new method of CT navigated assistance during SPG microstimulator implantation. Those results were compared to results of 21 patients previously implanted without the assistance of CT navigation. Using CT navigation during the initial dissection, an average distance reduction of 1.2 mm between the target point and electrode tip of the SPG microstimulator was achieved. Using the navigation software for navigated implantation and matching the preoperative planned scans with those performed post-operatively, the average distance was 2.17 mm with navigation, compared to 3.37 mm in the 28 surgeries without navigation. Results from this new procedure showed a significant reduction (p = 0.009) in the average distance from the SPG microstimulator to the desired target point. Therefore, a distinct improvement could be achieved in positioning of the SPG microstimulator through the use of intraoperative navigation during the initial dissection and by post-operative matching of pre- and post-operatively performed CBCT scans.

Correlation of X-ray computed tomography with quantitative nuclear magnetic resonance methods for pre-clinical measurement of adipose and lean tissues in living mice.

PubMed

Metzinger, Matthew N; Miramontes, Bernadette; Zhou, Peng; Liu, Yueying; Chapman, Sarah; Sun, Lucy; Sasser, Todd A; Duffield, Giles E; Stack, M Sharon; Leevy, W Matthew

2014-10-08

Numerous obesity studies have coupled murine models with non-invasive methods to quantify body composition in longitudinal experiments, including X-ray computed tomography (CT) or quantitative nuclear magnetic resonance (QMR). Both microCT and QMR have been separately validated with invasive techniques of adipose tissue quantification, like post-mortem fat extraction and measurement. Here we report a head-to-head study of both protocols using oil phantoms and mouse populations to determine the parameters that best align CT data with that from QMR. First, an in vitro analysis of oil/water mixtures was used to calibrate and assess the overall accuracy of microCT vs. QMR data. Next, experiments were conducted with two cohorts of living mice (either homogenous or heterogeneous by sex, age and genetic backgrounds) to assess the microCT imaging technique for adipose tissue segmentation and quantification relative to QMR. Adipose mass values were obtained from microCT data with three different resolutions, after which the data were analyzed with different filter and segmentation settings. Strong linearity was noted between the adipose mass values obtained with microCT and QMR, with optimal parameters and scan conditions reported herein. Lean tissue (muscle, internal organs) was also segmented and quantified using the microCT method relative to the analogous QMR values. Overall, the rigorous calibration and validation of the microCT method for murine body composition, relative to QMR, ensures its validity for segmentation, quantification and visualization of both adipose and lean tissues.

Influence of Air Discontinuity and Wall Effects on the Measurements of Hydraulic Parameters Under Dynamic Conditions

NASA Astrophysics Data System (ADS)

Looms, M. C.; Jensen, K. H.; Wildenschild, D.; Christensen, B. S.; Gudbjerg, J.

2003-12-01

Both dynamic (one-step) and semi-static (syringe pump) outflow experiments were carried out in the lab to test whether the resulting retention characteristics differed according to experiment type. Three sands of varying uniformity and coarseness were packed in a cylindrical sample holder. Compressed air was used to control the air phase pressure, while water was allowed to drain at atmospheric pressure from the outlet at the bottom of the sample. During the outflow experiments the capillary pressure was measured within the sample holder using a tensiometer connected to a pressure transducer. A medical CT-scanner was used to visualize and quantify the outflow patterns within the sand matrix during selected outflow experiments. Positive vertical shifts in capillary pressure during dynamic experiments were found in all three sand types at saturations close to porosity. The size and shape of the shifts corresponded with the dynamic effects found in previous work on the topic. Furthermore, the shifts were slightly greater in the coarsest and most uniform sand type. Numerical simulations of the one-step experiments using HYDRUS1D and T2VOC showed, however, that one of the basic assumptions when calculating the capillary pressure was most likely violated. The air phase could not be considered to be continuous at all times, and assuming this to be the case would result in positive shifts of the retention curves when running T2VOC. The results of using the CT-scanner showed the importance of achieving a homogeneous packing, since the investigated sand packing turned out to have an area at the edge of the sample holder with a higher porosity. This caused the edge to control the initial drainage. Therefore, the data collected at high saturations could not be expected to adequately describe the hydraulic properties of the inner sand. We also found that the time at which the inner sand commenced drainage coincided with a jump in capillary pressure for the resulting measured retention curve.

[Usefulness of stratigraphy and computerized tomography in the initial staging of osteosarcoma of the extremities. Retrospective study of 217 cases].

PubMed

Pelotti, P; Ciminari, R; Bacci, G; Avella, M; Briccoli, A

1988-01-01

The value of stratigraphy and pulmonary CT in the initial work-up of osteosarcoma of the extremities is assessed with reference to 217 patients encountered in the Bone Tumour Centre of Rizzoli Orthopaedic Institute in May 1983-May 1986. Stratigraphy revealed lung metastases not identified by standard radiography in 4 patients (1.8%), while CT revealed metastases not identified by either standard X-rays or stratigraphy in a further 6 cases (2.7%). It is concluded that the increase in the percentage of cures (about 30%) reported in the last 10 years in osteosarcoma cases given adjuvant chemotherapy cannot be explained by any difference in initial selection due to the use of these techniques that were not adopted in the historical series.

Treatment response assessment of radiofrequency ablation for hepatocellular carcinoma: usefulness of virtual CT sonography with magnetic navigation.

PubMed

Minami, Yasunori; Kitai, Satoshi; Kudo, Masatoshi

2012-03-01

Virtual CT sonography using magnetic navigation provides cross sectional images of CT volume data corresponding to the angle of the transducer in the magnetic field in real-time. The purpose of this study was to clarify the value of this virtual CT sonography for treatment response of radiofrequency ablation for hepatocellular carcinoma. Sixty-one patients with 88 HCCs measuring 0.5-1.3 cm (mean±SD, 1.0±0.3 cm) were treated by radiofrequency ablation. For early treatment response, dynamic CT was performed 1-5 days (median, 2 days). We compared early treatment response between axial CT images and multi-angle CT images using virtual CT sonography. Residual tumor stains on axial CT images and multi-angle CT images were detected in 11.4% (10/88) and 13.6% (12/88) after the first session of RFA, respectively (P=0.65). Two patients were diagnosed as showing hyperemia enhancement after the initial radiofrequency ablation on axial CT images and showed local tumor progression shortly because of unnoticed residual tumors. Only virtual CT sonography with magnetic navigation retrospectively showed the residual tumor as circular enhancement. In safety margin analysis, 10 patients were excluded because of residual tumors. The safety margin more than 5 mm by virtual CT sonographic images and transverse CT images were determined in 71.8% (56/78) and 82.1% (64/78), respectively (P=0.13). The safety margin should be overestimated on axial CT images in 8 nodules. Virtual CT sonography with magnetic navigation was useful in evaluating the treatment response of radiofrequency ablation therapy for hepatocellular carcinoma. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Lifetime interpersonal violence and self-reported chlamydia trachomatis diagnosis among California women.

PubMed

Alvarez, Jennifer; Pavao, Joanne; Mack, Katelyn P; Chow, Joan M; Baumrind, Nikki; Kimerling, Rachel

2009-01-01

To examine the relationship between cumulative exposure to various types of interpersonal violence throughout the life span and self-reported history of Chlamydia trachomatis (CT) diagnosis in a population-based sample of California women. This was a cross-sectional analysis of a population-based survey of California women aged 18-44 years (n = 3521). Participants reported their experience of multiple types of interpersonal violence: physical or sexual abuse in childhood or adulthood and intimate partner violence (IPV) in the past 12 months. Current posttraumatic stress disorder (PTSD) and depressive symptoms were also reported. Separate logistic regression models assessed the association between experiencing each type of interpersonal violence, as well as women's cumulative exposure to violence, and past CT diagnosis, adjusting for age, race/ethnicity, and poverty, as well as mental health problems. Six percent of women reported a past diagnosis of CT, and 40.8% reported experiencing at least one type of interpersonal violence in their lifetime. All types of violence were significantly associated with higher odds of having a past CT diagnosis even after controlling for sociodemographics. Women who reported experiencing four or more types of violence experiences had over five times the odds of reporting a lifetime CT diagnosis compared with women who never experienced interpersonal violence (adjusted odds ratio = 5.71, 95% CI 3.27-9.58). Current PTSD and depressive symptoms did not significantly affect the relationship between a woman's cumulative experience of violence and her risk of past CT diagnosis. There is a robust association between experiencing multiple forms of violence and having been diagnosed with CT. Women who seek treatment for sexually transmitted diseases (STDs), such as CT, should be assessed for their lifetime history of violence, especially violence in their current intimate relationships. Sexual risk reduction counseling may also be important for women who have a history of risky sexual behaviors and who are likely to be reinfected.

PET/CT incidental detection of second tumor in patients investigated for pancreatic neoplasms.

PubMed

Moletta, Lucia; Bissoli, Sergio; Fantin, Alberto; Passuello, Nicola; Valmasoni, Michele; Sperti, Cosimo

2018-05-04

Positron Emission Tomography/computed tomography (PET/CT) is an imaging technique which has a role in the detection and staging malignancies (both in first diagnosis and follow-up). The finding of an unexpected region of FDG (Fluorodeoxyglucose) uptake can occur when performing whole-body FDG-PET, raising the possibility of a second primary tumor. The aim of this study was to evaluate our experience of second primary cancer incidentally discovered during PET/CT examination performed for pancreatic diseases, during the initial work-up or follow-up after surgical resection. In this study, a retrospective evaluation of a prospectively collected data base was performed. Three hundred ninety- nine patients with pancreatic pathology were evaluated by whole body PET/CT imaging from January 2004 to December 2014. Among them, 348 patients were scanned before surgical resection and 51 during the course of their follow-up (pancreatic cancer). Median follow-up time was 29 months (range 14-124). Fifty-six patients (14%) had incidental uptake of FDG in their organs: 31 patients had focal uptake and 25 showed diffuse with or without focal uptake. All patients with focal uptake were investigated, and invasive malignancy was diagnosed in 22 patients: 14 colon, 4 lung, 1 larynx, 1 urothelial, 1 breast cancer, and 1 colon metastasis from pancreatic cancer. Twenty patients underwent resection, and 6 endoscopic removal of colonic polyps. Three patients were not operated for advanced disease, and two patients did not show any pathology (PET/CT false positive). Of the 10 patients investigated for diffuse uptake, no malignancy was found; none of these patients developed a second cancer during the follow-up. As in other malignancies, unexpected FDG uptake can occur in patients having PET/CT investigation for pancreatic diseases. Focal uptake is likely to be a malignancy and deserves further investigations, although the stage and the poor prognosis of primary pancreatic cancer should be kept in mind. Some selected patients may benefit from the aggressive treatment of incidental lesions and show survival benefit.

Premonitory acoustic emissions and stick-slip in natural and smooth-faulted Westerly granite

USGS Publications Warehouse

Thompson, B.D.; Young, R.P.; Lockner, David A.

2009-01-01

A stick-slip event was induced in a cylindrical sample of Westerly granite containing a preexisting natural fault by loading at constant confining pressure of 150 MPa. Continuously recorded acoustic emission (AE) data and computer tomography (CT)-generated images of the fault plane were combined to provide a detailed examination of microscale processes operating on the fault. The dynamic stick-slip event, considered to be a laboratory analog of an earthquake, generated an ultrasonic signal that was recorded as a large-amplitude AE event. First arrivals of this event were inverted to determine the nucleation site of slip, which is associated with a geometric asperity on the fault surface. CT images and AE locations suggest that a variety of asperities existed in the sample because of the intersection of branch or splay faults with the main fault. This experiment is compared with a stick-slip experiment on a sample prepared with a smooth, artificial saw-cut fault surface. Nearly a thousand times more AE were observed for the natural fault, which has a higher friction coefficient (0.78 compared to 0.53) and larger shear stress drop (140 compared to 68 MPa). However at the measured resolution, the ultrasonic signal emitted during slip initiation does not vary significantly between the two experiments, suggesting a similar dynamic rupture process. We propose that the natural faulted sample under triaxial compression provides a good laboratory analogue for a field-scale fault system in terms of the presence of asperities, fault surface heterogeneity, and interaction of branching faults. ?? 2009.

Clinical experience with a computer-aided diagnosis system for automatic detection of pulmonary nodules at spiral CT of the chest

NASA Astrophysics Data System (ADS)

Wormanns, Dag; Fiebich, Martin; Saidi, Mustafa; Diederich, Stefan; Heindel, Walter

2001-05-01

The purpose of the study was to evaluate a computer aided diagnosis (CAD) workstation with automatic detection of pulmonary nodules at low-dose spiral CT in a clinical setting for early detection of lung cancer. Two radiologists in consensus reported 88 consecutive spiral CT examinations. All examinations were reviewed using a UNIX-based CAD workstation with a self-developed algorithm for automatic detection of pulmonary nodules. The algorithm was designed to detect nodules with at least 5 mm diameter. The results of automatic nodule detection were compared to the consensus reporting of two radiologists as gold standard. Additional CAD findings were regarded as nodules initially missed by the radiologists or as false positive results. A total of 153 nodules were detected with all modalities (diameter: 85 nodules <5mm, 63 nodules 5-9 mm, 5 nodules >= 10 mm). Reasons for failure of automatic nodule detection were assessed. Sensitivity of radiologists for nodules >=5 mm was 85%, sensitivity of CAD was 38%. For nodules >=5 mm without pleural contact sensitivity was 84% for radiologists at 45% for CAD. CAD detected 15 (10%) nodules not mentioned in the radiologist's report but representing real nodules, among them 10 (15%) nodules with a diameter $GREW5 mm. Reasons for nodules missed by CAD include: exclusion because of morphological features during region analysis (33%), nodule density below the detection threshold (26%), pleural contact (33%), segmentation errors (5%) and other reasons (2%). CAD improves detection of pulmonary nodules at spiral CT significantly and is a valuable second opinion in a clinical setting for lung cancer screening. Optimization of region analysis and an appropriate density threshold have a potential for further improvement of automatic nodule detection.

Results of early thyroidectomy for medullary thyroid carcinoma in children with multiple endocrine neoplasia type 2.

PubMed

Telander, R L; Zimmerman, D; van Heerden, J A; Sizemore, G W

1986-12-01

Children with multiple endocrine neoplasia type 2 (MEN2) often develop medullary carcinoma of the thyroid (MCT) or its precursor, C-cell hyperplasia. Survival results are improved if malignancy is diagnosed early from the results of plasma immunoreactive calcitonin (iCT) measurement. The effect of early detection and thyroidectomy in children with MEN2 syndrome was determined by reviewing the experience between 1975 and 1985. Seventeen children with MEN2 who were 12 years old or younger underwent a total thyroidectomy for MCT or C-cell hyperplasia. iCT was measured in all patients preoperatively and postoperatively. Of the 17 children, 14 (82%) had MEN2a and 3 (18%) had MEN2b. There were 14 (82%) female and three (18%) male patients; their mean age was 6.97 years (range 1.5 to 12 years). In all patients, the diagnosis of MCT was made from initial elevated levels of iCT after stimulation with pentagastrin. Three patients had clinical evidence of disease preoperatively. All patients underwent a total thyroidectomy and lymph nodes were removed from the central zone; a neck dissection was performed in the three with clinically obvious disease. MCT with C-cell hyperplasia was found in 11 children and C-cell hyperplasia alone in six. Of the 11 with carcinoma, eight had bilateral disease and three unilateral. Six children had bilateral C-cell hyperplasia. All 17 children were alive and feeling well at the time of this report; however, three had evidence of metastatic disease according to iCT measurements. None of the children had recurrent nerve injuries; one had evidence of hypoparathyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Radium-223 IN metastatic hormone-sensitive high-grade prostate cancer: initial experience.

PubMed

Osvaldo, García-Pérez Francisco; Salvador, Medina-Ornelas Sevastián; Zael, Santana-Ríos; Nora, Sobrevilla-Moreno

2017-01-01

Our study evaluates the feasibility of compassionate exemption of Radium-223 ( 223 Ra) treatment in metastatic hormone-sensitive high-grade prostate cancer (mHSHGPC) patients with concomitant androgen deprivation-therapy (ADT). Seven patients with mHSHGPC, were treated with six cycles of 223 Ra plus ADT. All patients had undergone to 18 F-NaF-PET/CT. A qualitative analyses of the 18 F-NaF-PET/CT was performed in conjunction with Alkaline Phosphatase (ALP), Lactate-dehydrogenase (LDH) and Prostatic-Specific Antigen (PSA) values. The mean of SUVmax values were used as a quantitative measure of tumoral burden. Changes in PSA, ALP, LDH from baseline were evaluated, and were defined as increase or decrease of at least 30%. Clinical response was achieved if there was pain reduction using visual analogic scale. Four patients showed a significant reduction in mean SUVmax after 3 cycles of 223 Ra, and one after 6 cycles. Patients who showed reductions in mean SUVmax after Ra-223 also showed reductions in PSA, ALP and LDH. Four weeks after the last cycle of 223 Ra all patients had decreased total PSA, ALP and LDH values ≥ 30% also significant improvement on pain. No progress disease was documented after 14 ± 4 weeks. We found slight to moderate decreases in neutrophils and hemoglobin in two patients. We concluded that 223 Ra plus ADT can be useful in mHSHGPC; the semi-quantitative 18 F-NaF-PET/CT as a method effective to monitor the treatment response. Due to concomitant administration of ADT, 18 F-NaF-PET/CT cannot differentiate whether the findings were due to androgen blockade or the 223 Ra; nevertheless, data supporting the efficacy of 223 Ra is the significant improvement on pain.

Cumulative effective dose associated with radiography and CT of adolescents with spinal injuries.

PubMed

Lemburg, Stefan P; Peters, Soeren A; Roggenland, Daniela; Nicolas, Volkmar; Heyer, Christoph M

2010-12-01

The purpose of this study was to analyze the quantity and distribution of cumulative effective doses in diagnostic imaging of adolescents with spinal injuries. At a level 1 trauma center from July 2003 through June 2009, imaging procedures during initial evaluation and hospitalization and after discharge of all patients 10-20 years old with spinal fractures were retrospectively analyzed. The cumulative effective doses for all imaging studies were calculated, and the doses to patients with spinal injuries who had multiple traumatic injuries were compared with the doses to patients with spinal injuries but without multiple injuries. The significance level was set at 5%. Imaging studies of 72 patients (32 with multiple injuries; average age, 17.5 years) entailed a median cumulative effective dose of 18.89 mSv. Patients with multiple injuries had a significantly higher total cumulative effective dose (29.70 versus 10.86 mSv, p < 0.001) mainly owing to the significantly higher CT-related cumulative effective dose to multiple injury patients during the initial evaluation (18.39 versus 2.83 mSv, p < 0.001). Overall, CT accounted for 86% of the total cumulative effective dose. Adolescents with spinal injuries receive a cumulative effective dose equal to that of adult trauma patients and nearly three times that of pediatric trauma patients. Areas of focus in lowering cumulative effective dose should be appropriate initial estimation of trauma severity and careful selection of CT scan parameters.

The BIG (brain injury guidelines) project: defining the management of traumatic brain injury by acute care surgeons.

PubMed

Joseph, Bellal; Friese, Randall S; Sadoun, Moutamn; Aziz, Hassan; Kulvatunyou, Narong; Pandit, Viraj; Wynne, Julie; Tang, Andrew; O'Keeffe, Terence; Rhee, Peter

2014-04-01

It is becoming a standard practice that any "positive" identification of a radiographic intracranial injury requires transfer of the patient to a trauma center for observation and repeat head computed tomography (RHCT). The purpose of this study was to define guidelines-based on each patient's history, physical examination, and initial head CT findings-regarding which patients require a period of observation, RHCT, or neurosurgical consultation. In our retrospective cohort analysis, we reviewed the records of 3,803 blunt traumatic brain injury patients during a 4-year period. We classified patients according to neurologic examination results, use of intoxicants, anticoagulation status, and initial head CT findings. We then developed brain injury guidelines (BIG) based on the individual patient's need for observation or hospitalization, RHCT, or neurosurgical consultation. A total of 1,232 patients had an abnormal head CT finding. In the BIG 1 category, no patients worsened clinically or radiographically or required any intervention. BIG 2 category had radiographic worsening in 2.6% of the patients. All patients who required neurosurgical intervention (13%) were in BIG 3. There was excellent agreement between assigned BIG and verified BIG. κ statistic is equal to 0.98. We have proposed BIG based on patient's history, neurologic examination, and findings of initial head CT scan. These guidelines must be used as supplement to good clinical examination while managing patients with traumatic brain injury. Prospective validation of the BIG is warranted before its widespread implementation. Epidemiologic study, level III.

Maternal depression across the first years of life compromises child psychosocial adjustment; relations to child HPA-axis functioning.

PubMed

Apter-Levi, Yael; Pratt, Maayan; Vakart, Adam; Feldman, Michal; Zagoory-Sharon, Orna; Feldman, Ruth

2016-02-01

Maternal depression across the first years of life negatively impacts children's development. One pathway of vulnerability may involve functioning of the hypothalamic-pituitary-adrenal (HPA) axis. We utilize a community cohort of 1983 women with no comorbid risk repeatedly assessed for depression from birth to six years to form two groups; chronically depressed (N=40) and non-depressed (N=91) women. At six years, mother and child underwent psychiatric diagnosis, child salivary cortisol (CT) was assessed three times during a home-visit, mother-child interaction was videotaped, and child empathy was coded from behavioral paradigms. Latent Growth curve Model using Structural Equation Modeling (SEM) estimated the links between maternal depression and mother's negative parenting and three child outcomes; psychopathology, social withdrawal, and empathy as related to child CT baseline and variability. Depressed mothers displayed more negative parenting and their children showed more Axis-I psychopathology and social withdrawal. SEM analysis revealed that maternal depression was associated with reduced CT variability, which predicted higher child psychopathology and social withdrawal. Whereas all children exhibited similar initial levels of CT, children of controls reduced CT levels over time while children of depressed mothers maintained high, non-flexible levels. Mother negativity was related to lower initial CT levels, which predicted decreased empathy. Findings suggest that chronic maternal depression may compromise children's social-emotional adjustment by diminishing HPA-system flexibility as well as limiting the mother's capacity to provide attuned and predictable caregiving. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of Osteoporosis in Injured Older Women Admitted to a Safety-Net Level One Trauma Center: A Unique Opportunity to Fulfill an Unmet Need

PubMed Central

Young, Elisabeth S.; Reed, May J.; Pham, Tam N.; Gross, Joel A.; Taitsman, Lisa A.

2017-01-01

Background Older trauma patients often undergo computed tomography (CT) as part of the initial work-up. CT imaging can also be used opportunistically to measure bone density and assess osteoporosis. Methods In this retrospective cohort study, osteoporosis was ascertained from admission CT scans in women aged ≥65 admitted to the ICU for traumatic injury during a 3-year period at a single, safety-net, level 1 trauma center. Osteoporosis was defined by established CT-based criteria of average L1 vertebral body Hounsfield units <110. Evidence of diagnosis and/or treatment of osteoporosis was the primary outcome. Results The study cohort consisted of 215 women over a 3-year study period, of which 101 (47%) had evidence of osteoporosis by CT scan criteria. There were no differences in injury severity score, hospital length of stay, cost, or discharge disposition between groups with and without evidence of osteoporosis. Only 55 (59%) of the 94 patients with osteoporosis who survived to discharge had a documented osteoporosis diagnosis and/or corresponding evaluation/treatment plan. Conclusion Nearly half of older women admitted with traumatic injuries had underlying osteoporosis, but 41% had neither clinical recognition of this finding nor a treatment plan for osteoporosis. Admission for traumatic injury is an opportunity to assess osteoporosis, initiate appropriate intervention, and coordinate follow-up care. Trauma and acute care teams should consider assessment of osteoporosis in women who undergo CT imaging and provide a bridge to outpatient services. PMID:29234352

New prospective 4D-CT for mitigating the effects of irregular respiratory motion

NASA Astrophysics Data System (ADS)

Pan, Tinsu; Martin, Rachael M.; Luo, Dershan

2017-08-01

Artifact caused by irregular respiration is a major source of error in 4D-CT imaging. We propose a new prospective 4D-CT to mitigate this source of error without new hardware, software or off-line data-processing on the GE CT scanner. We utilize the cine CT scan in the design of the new prospective 4D-CT. The cine CT scan at each position can be stopped by the operator when an irregular respiration occurs, and resumed when the respiration becomes regular. This process can be repeated at one or multiple scan positions. After the scan, a retrospective reconstruction is initiated on the CT console to reconstruct only the images corresponding to the regular respiratory cycles. The end result is a 4D-CT free of irregular respiration. To prove feasibility, we conducted a phantom and six patient studies. The artifacts associated with the irregular respiratory cycles could be removed from both the phantom and patient studies. A new prospective 4D-CT scanning and processing technique to mitigate the impact of irregular respiration in 4D-CT has been demonstrated. This technique can save radiation dose because the repeat scans are only at the scan positions where an irregular respiration occurs. Current practice is to repeat the scans at all positions. There is no cost to apply this technique because it is applicable on the GE CT scanner without new hardware, software or off-line data-processing.

Factors influencing residual pleural opacity in tuberculous pleural effusion.

PubMed

Kwon, Jee Sook; Cha, Seung-Ick; Jeon, Kyung-Nyeo; Kim, Young-Joo; Kim, Eun-Jin; Kim, Chang-Ho; Park, Jae-Yong; Jung, Tae-Hoon

2008-08-01

Tuberculous pleural effusion (TPE) leads to residual pleural opacity (RPO) in a significant proportion of cases. The aim of this study was to investigate which TPE patients would have RPO following the treatment. This study was performed prospectively for a total of 60 TPE patients, who underwent pleural fluid analysis on the initial visit and chest radiographs and computed tomography (CT) scans before and after the administration of antituberculous medication. At the end of antituberculous medication, the incidence of RPO was 68.3% (41/60) on CT with a range of 2-50 mm. Compared with the non-RPO group, the RPO group had a longer symptom duration and lower pleural fluid glucose level. On initial CT, loculation, extrapleural fat proliferation, increased attenuation of extrapleural fat, and pleura-adjacent atelectasis were more frequent, and parietal pleura was thicker in the RPO group compared with the non-RPO group. By multivariate analysis, extrapleural fat proliferation, loculated effusion, and symptom duration were found to be predictors of RPO in TPE. In conclusion, RPO in TPE may be predicted by the clinico-radiologic parameters related to the chronicity of the effusion, such as symptom duration and extrapleural fat proliferation and loculated effusion on CT.

The Emergent Landscape of Detecting EGFR Mutations Using Circulating Tumor DNA in Lung Cancer

PubMed Central

Wei, Fang; Wong, David T.; Su, Wu-Chou

2015-01-01

The advances in targeted therapies for lung cancer are based on the evaluation of specific gene mutations especially the epidermal growth factor receptor (EGFR). The assays largely depend on the acquisition of tumor tissue via biopsy before the initiation of therapy or after the onset of acquired resistance. However, the limitations of tissue biopsy including tumor heterogeneity and insufficient tissues for molecular testing are impotent clinical obstacles for mutation analysis and lung cancer treatment. Due to the invasive procedure of tissue biopsy and the progressive development of drug-resistant EGFR mutations, the effective initial detection and continuous monitoring of EGFR mutations are still unmet requirements. Circulating tumor DNA (ctDNA) detection is a promising biomarker for noninvasive assessment of cancer burden. Recent advancement of sensitive techniques in detecting EGFR mutations using ctDNA enables a broad range of clinical applications, including early detection of disease, prediction of treatment responses, and disease progression. This review not only introduces the biology and clinical implementations of ctDNA but also includes the updating information of recent advancement of techniques for detecting EGFR mutation using ctDNA in lung cancer. PMID:26448936

Simultaneous CT-MRI Reconstruction for Constrained Imaging Geometries using Structural Coupling and Compressive Sensing

PubMed Central

Xi, Yan; Zhao, Jun; Bennett, James R.; Stacy, Mitchel R.; Sinusas, Albert J.; Wang, Ge

2016-01-01

Objective A unified reconstruction framework is presented for simultaneous CT-MRI reconstruction. Significance Combined CT-MRI imaging has the potential for improved results in existing preclinical and clinical applications, as well as opening novel research directions for future applications. Methods In an ideal CT-MRI scanner, CT and MRI acquisitions would occur simultaneously, and hence would be inherently registered in space and time. Alternatively, separately acquired CT and MRI scans can be fused to simulate an instantaneous acquisition. In this study, structural coupling and compressive sensing techniques are combined to unify CT and MRI reconstructions. A bidirectional image estimation method was proposed to connect images from different modalities. Hence, CT and MRI data serve as prior knowledge to each other for better CT and MRI image reconstruction than what could be achieved with separate reconstruction. Results Our integrated reconstruction methodology is demonstrated with numerical phantom and real-dataset based experiments, and has yielded promising results. PMID:26672028

Postoperative PET/CT and target delineation before adjuvant radiotherapy in patients with oral cavity squamous cell carcinoma.

PubMed

Dutta, Pinaki R; Riaz, Nadeem; McBride, Sean; Morris, Luc G; Patel, Snehal; Ganly, Ian; Wong, Richard J; Palmer, Frank; Schöder, Heiko; Lee, Nancy

2016-04-01

The purpose of this study was for us to present our evaluation of the effectiveness of positron emission tomography (PET)/CT imaging in postoperative patients with oral cavity squamous cell carcinoma (SCC) before initiating adjuvant radiation therapy. Treatment planning PET/CT scans were obtained in 44 patients with oral cavity SCC receiving adjuvant radiation. We identified target areas harboring macroscopic disease requiring higher radiation doses or additional surgery. Fourteen PET/CT scans were abnormal. Thirteen patients underwent surgery and/or biopsy, increased radiation dose, and/or addition of chemotherapy. Eleven patients received higher radiation doses. Patients undergoing imaging >8 weeks were more likely to have abnormal results (p = .01). One-year distant metastases-free survival was significantly worse in patients with positive PET/CT scans (61.5% vs 92.7%; p = .01). The estimated positive predictive value (PPV) was 38% for postoperative PET/CT scanning. We demonstrated that 32% of patients have abnormal PET/CT scans resulting in management changes. Patients may benefit from postoperative PET/CT imaging to optimize adjuvant radiation treatment planning. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1285-E1293, 2016. © 2015 Wiley Periodicals, Inc.

Likelihood of aneurysmal subarachnoid haemorrhage in patients with normal unenhanced CT, CSF xanthochromia on spectrophotometry and negative CT angiography.

PubMed

Rana, A K; Turner, H E; Deans, K A

2013-01-01

Patients with suspected subarachnoid haemorrhage, a normal noncontrast computed tomography (CT) and cerebrospinal fluid (CSF) evidence of haemoglobin breakdown products often undergo CT angiography (CTA). If this is normal, then invasive catheter angiography may be offered. In current clinical practice, haemoglobin breakdown products are detected by spectrophotometry rather than visible xanthochromia, and CTA is performed on multidetector scanners. The aim of this study was to determine if such patients should still have a catheter angiography, given the associated risks. Patients positive for CSF spectrophotometry (n=26) were retrospectively identified from the clinical biochemistry information system and imaging data from the electronic radiology records were reviewed. Discharge letters were consulted to relate the biochemistry and radiology results to the final diagnosis. 15 patients with CT angiography were found. Nine patients had normal CT angiography. No causative aneurysms had been missed. One patient had small, coincidental aneurysms missed on initial reading of the CTA. The likelihood of a clinically significant aneurysm in a patient who is CT negative, lumbar puncture positive and CTA negative is low. Double reporting of negative CT angiograms may be advisable.

Scenes from the past: initial investigation of early jurassic vertebrate fossils with multidetector CT.

PubMed

Bolliger, Stephan A; Ross, Steffen; Thali, Michael J; Hostettler, Bernhard; Menkveld-Gfeller, Ursula

2012-01-01

The study of fossils permits the reconstruction of past life on our planet and enhances our understanding of evolutionary processes. However, many fossils are difficult to recognize, being encased in a lithified matrix whose tedious removal is required before examination is possible. The authors describe the use of multidetector computed tomography (CT) in locating, identifying, and examining fossil remains of crocodilians (Mesosuchia) embedded in hard shale, all without removing the matrix. In addition, they describe how three-dimensional (3D) reformatted CT images provided details that were helpful for extraction and preparation. Multidetector CT can help experienced paleontologists localize and characterize fossils in the matrix of a promising rock specimen in a nondestructive manner. Moreover, with its capacity to generate highly accurate 3D images, multidetector CT can help determine whether the fossils warrant extraction and can assist in planning the extraction process. Thus, multidetector CT may well become an invaluable tool in the field of paleoradiology.

Development of a semi-automated combined PET and CT lung lesion segmentation framework

NASA Astrophysics Data System (ADS)

Rossi, Farli; Mokri, Siti Salasiah; Rahni, Ashrani Aizzuddin Abd.

2017-03-01

Segmentation is one of the most important steps in automated medical diagnosis applications, which affects the accuracy of the overall system. In this paper, we propose a semi-automated segmentation method for extracting lung lesions from thoracic PET/CT images by combining low level processing and active contour techniques. The lesions are first segmented in PET images which are first converted to standardised uptake values (SUVs). The segmented PET images then serve as an initial contour for subsequent active contour segmentation of corresponding CT images. To evaluate its accuracy, the Jaccard Index (JI) was used as a measure of the accuracy of the segmented lesion compared to alternative segmentations from the QIN lung CT segmentation challenge, which is possible by registering the whole body PET/CT images to the corresponding thoracic CT images. The results show that our proposed technique has acceptable accuracy in lung lesion segmentation with JI values of around 0.8, especially when considering the variability of the alternative segmentations.

Extracting atomic numbers and electron densities from a dual source dual energy CT scanner: experiments and a simulation model.

PubMed

Landry, Guillaume; Reniers, Brigitte; Granton, Patrick Vincent; van Rooijen, Bart; Beaulieu, Luc; Wildberger, Joachim E; Verhaegen, Frank

2011-09-01

Dual energy CT (DECT) imaging can provide both the electron density ρ(e) and effective atomic number Z(eff), thus facilitating tissue type identification. This paper investigates the accuracy of a dual source DECT scanner by means of measurements and simulations. Previous simulation work suggested improved Monte Carlo dose calculation accuracy when compared to single energy CT for low energy photon brachytherapy, but lacked validation. As such, we aim to validate our DECT simulation model in this work. A cylindrical phantom containing tissue mimicking inserts was scanned with a second generation dual source scanner (SOMATOM Definition FLASH) to obtain Z(eff) and ρ(e). A model of the scanner was designed in ImaSim, a CT simulation program, and was used to simulate the experiment. Accuracy of measured Z(eff) (labelled Z) was found to vary from -10% to 10% from low to high Z tissue substitutes while the accuracy on ρ(e) from DECT was about 2.5%. Our simulation reproduced the experiments within ±5% for both Z and ρ(e). A clinical DECT scanner was able to extract Z and ρ(e) of tissue substitutes. Our simulation tool replicates the experiments within a reasonable accuracy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Importance of Second-look Endoscopy on an Empty Stomach for Finding Gastric Bezoars in Patients with Gastric Ulcers.

PubMed

Iwamuro, Masaya; Tanaka, Shouichi; Moritou, Yuki; Inaba, Tomoki; Higashi, Reiji; Kusumoto, Chiaki; Yunoki, Naoko; Ishikawa, Shin; Okamoto, Yuko; Kawai, Yoshinari; Kitada, Ken-Ichi; Takenaka, Ryuta; Toyokawa, Tatsuya; Okada, Hiroyuki

2017-06-01

　Most gastric bezoars can be treated with endoscopic fragmentation combined with or without cola dissolution, whereas laparotomy or laparoscopic surgery is generally inevitable for small intestinal bezoars because they cause small bowel obstruction. Therefore, early diagnosis and management of gastric bezoars are necessary to prevent bezoar-induced ileus. To investigate the incidence of overlooked gastric bezoars during the initial esophagogastroduodenoscopy, we retrospectively reviewed the cases of 27 patients diagnosed with gastrointestinal bezoars. The bezoars were diagnosed using esophagogastroduodenoscopy (n=25), abdominal ultrasonography (n=1), and barium follow-through examination (n=1). Bezoars were overlooked in 9/25 patients (36.0%) during the initial endoscopy examination because the bezoars were covered with debris in the stomach. Of the 9 patients, 8 had concomitant gastric ulcers, and the other patient had gastric lymphoma. Although a computed tomography (CT) scan was performed before the second-look endoscopy in 8 of the 9 patients, the bezoars were mistaken as food debris on CT findings and were overlooked in these patients. In conclusion, gastric bezoars may not be discovered during the initial esophagogastroduodenoscopy and CT scan. In cases with debris in the stomach, second-look endoscopy is essential to detect bezoars.

Thoracoabdominal Computed Tomography in Trauma Patients: A Cost-Consequences Analysis

PubMed Central

van Vugt, Raoul; Kool, Digna R.; Brink, Monique; Dekker, Helena M.; Deunk, Jaap; Edwards, Michael J.

2014-01-01

Background: CT is increasingly used during the initial evaluation of blunt trauma patients. In this era of increasing cost-awareness, the pros and cons of CT have to be assessed. Objectives: This study was performed to evaluate cost-consequences of different diagnostic algorithms that use thoracoabdominal CT in primary evaluation of adult patients with high-energy blunt trauma. Materials and Methods: We compared three different algorithms in which CT was applied as an immediate diagnostic tool (rush CT), a diagnostic tool after limited conventional work-up (routine CT), and a selective tool (selective CT). Probabilities of detecting and missing clinically relevant injuries were retrospectively derived. We collected data on radiation exposure and performed a micro-cost analysis on a reference case-based approach. Results: Both rush and routine CT detected all thoracoabdominal injuries in 99.1% of the patients during primary evaluation (n = 1040). Selective CT missed one or more diagnoses in 11% of the patients in which a change of treatment was necessary in 4.8%. Rush CT algorithm costed € 2676 (US$ 3660) per patient with a mean radiation dose of 26.40 mSv per patient. Routine CT costed € 2815 (US$ 3850) and resulted in the same radiation exposure. Selective CT resulted in less radiation dose (23.23 mSv) and costed € 2771 (US$ 3790). Conclusions: Rush CT seems to result in the least costs and is comparable in terms of radiation dose exposure and diagnostic certainty with routine CT after a limited conventional work-up. However, selective CT results in less radiation dose exposure but a slightly higher cost and less certainty. PMID:25337521

Enhancing Cognitive Training Through Aerobic Exercise After a First Schizophrenia Episode: Theoretical Conception and Pilot Study.

PubMed

Nuechterlein, Keith H; Ventura, Joseph; McEwen, Sarah C; Gretchen-Doorly, Denise; Vinogradov, Sophia; Subotnik, Kenneth L

2016-07-01

Cognitive training (CT) and aerobic exercise have separately shown promise for improving cognitive deficits in schizophrenia. Aerobic exercise releases brain-derived neurotrophic factor, which promotes synaptic plasticity and neurogenesis. Thus, aerobic exercise provides a neurotrophic platform for neuroplasticity-based CT. The combination of aerobic exercise and CT may yield more robust effects than CT alone, particularly in the initial course of schizophrenia. In a pilot study, 7 patients with a recent onset of schizophrenia were assigned to Cognitive Training & Exercise (CT&E) and 9 to CT alone for a 10-week period. Posit Science programs were used for CT. Neurocognitive training focused on tuning neural circuits related to perceptual processing and verbal learning and memory. Social cognitive training used the same learning principles with social and affective stimuli. Both groups participated in these training sessions 2d/wk, 2h/d. The CT&E group also participated in an aerobic conditioning program for 30 minutes at our clinic 2d/wk and at home 2d/wk. The effect size for improvement in the MATRICS Consensus Cognitive Battery Overall Composite score for CT&E patients relative to CT patients was large. Functional outcome, particularly independent living skills, also tended to improve more in the CT&E than in the CT group. Muscular endurance, cardiovascular fitness, and diastolic blood pressure also showed relative improvement in the CT&E compared to the CT group. These encouraging pilot study findings support the promise of combining CT and aerobic exercise to improve the early course of schizophrenia. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Pediatric and adolescent lymphoma: comparison of whole-body STIR half-Fourier RARE MR imaging with an enhanced PET/CT reference for initial staging.

PubMed

Punwani, Shonit; Taylor, Stuart A; Bainbridge, Alan; Prakash, Vineet; Bandula, Steven; De Vita, Enrico; Olsen, Oystein E; Hain, Sharon F; Stevens, Nicola; Daw, Stephen; Shankar, Ananth; Bomanji, Jamshed B; Humphries, Paul D

2010-04-01

To compare the diagnostic performance of rapid whole-body anatomic magnetic resonance (MR) staging of pediatric and adolescent lymphoma to an enhanced positron emission tomographic (PET)/computed tomographic (CT) reference standard. Ethical permission was given by the University College London Hospital ethics committee, and informed written consent was obtained from all participants and/or parents or guardians. Thirty-one subjects (age range, 7.3-18.0 years; 18 male, 11 female) with histologically proved lymphoma were prospectively recruited. Pretreatment staging was performed with whole-body short inversion time inversion-recovery (STIR) half-Fourier rapid acquisition with relaxation enhancement (RARE) MR imaging, fluorine 18 fluorodeoxyglucose PET/CT, and contrast agent-enhanced chest CT. Twenty-six subjects had posttreatment PET/CT and compromised our final cohort. Eleven nodal and 11 extranodal sites per patient were assessed on MR imaging by two radiologists in consensus, with a nodal short-axis threshold of >1 cm and predefined extranodal positivity criteria. The same sites were independantly evaluated by two nuclear medicine physicians on PET/CT images. Disease positivity was defined as a maximum standardized uptake value >2.5 or nodal size >1 cm. An unblinded expert panel reevaluated the imaging findings, removing perceptual errors, and derived an enhanced PET/CT reference standard (taking into account chest CT and 3-month follow-up imaging) against which the reported and intrinsic performance of MR imaging was assessed by using the kappa statistic. There was very good agreement between MR imaging and the enhanced PET/CT reference standard for nodal and extranodal staging (kappa = 0.96 and 0.86, respectively) which improved following elimination of perceptual errors (kappa = 0.97 and 0.91, respectively). The sensitivity and specificity of MR imaging (following removal of perceptual error) were 98% and 99%, respectively, for nodal disease and 91% and 99%, respectively, for extranodal disease. Whole-body STIR half-Fourier RARE MR imaging of pediatric and adolescent lymphoma can accurately depict nodal and extranodal disease and may provide an alternative nonionizing imaging method for anatomic disease assessment at initial staging. RSNA, 2010

Everolimus use and associated factors among post-menopausal women with hormonal receptor positive/human epidermal growth factor receptor 2 negative metastatic breast cancer.

PubMed

Li, Nanxin; Hao, Yanni; Xie, Jipan; Lin, Peggy L; Zhou, Zhou; Zhong, Yichen; Signorovitch, James E; Wu, Eric Q

2015-08-01

Everolimus has been shown to be an effective HR+/HER2- mBC treatment in both clinical trials and real-world practice. The current study aims at understanding factors associated with everolimus use and how it is used in the real world. A retrospective chart review was conducted among postmenopausal HR+/HER2- mBC women who received everolimus, endocrine therapy (ET), or chemotherapy (CT) for mBC between 1 July 2012 and 15 April 2013 after an NSAI failure. Factors associated with everolimus use versus ET or CT were identified using multivariable logistic regressions. Reasons for prescribing everolimus and everolimus treatment patterns were described. Liver metastasis and high tumor volume were associated with a higher likelihood of everolimus use versus ET (OR = 1.67, OR = 1.62) but a lower likelihood of everolimus use versus CT (OR = 0.43, OR = 0.30). Medicare-only insurance (OR = 0.30) as well as ECOG ≥2 (OR = 3.72) and prior CT in mBC (OR = 2.76) were associated with a lower and higher likelihood of everolimus use versus CT, respectively. The top reason for prescribing everolimus was efficacy (69-85%). About 15% and 29% of everolimus users in second line and third line or above received prior CT for mBC. Exemestane was the most common concomitant therapy with everolimus (56-87%). The majority of patients initiated everolimus at the labeled dose of 10 mg daily (>80%) and maintained this dose (>80%). In the real world, everolimus was used in more severe patients than ET but less severe patients than CT based on visceral metastasis, tumor volume, and performance status. The top reason for prescribing everolimus was efficacy. A large proportion of patients received first or second line CT before everolimus initiation. The majority of patients used everolimus according to the labeled combination and dose. Future studies are needed to determine optimal sequencing of everolimus, ET, and CT for HR+/HER2- mBC.

Hepatic CT image query using Gabor features

NASA Astrophysics Data System (ADS)

Zhao, Chenguang; Cheng, Hongyan; Zhuang, Tiange

2004-07-01

A retrieval scheme for liver computerize tomography (CT) images based on Gabor texture is presented. For each hepatic CT image, we manually delineate abnormal regions within liver area. Then, a continuous Gabor transform is utilized to analyze the texture of the pathology bearing region and extract the corresponding feature vectors. For a given sample image, we compare its feature vector with those of other images. Similar images with the highest rank are retrieved. In experiments, 45 liver CT images are collected, and the effectiveness of Gabor texture for content based retrieval is verified.

The effect of simulation courseware on critical thinking in undergraduate nursing students: multi-site pre-post study.

PubMed

Shin, Hyunsook; Ma, Hyunhee; Park, Jiyoung; Ji, Eun Sun; Kim, Dong Hee

2015-04-01

The use of simulations has been considered as opportunities for students to enhance their critical thinking (CT), but previous studies were limited because they did not provide in-depth information on the working dynamics of simulation or on the effects of the number of simulation exposures on CT. This study examined the effect of an integrated pediatric nursing simulation used in a nursing practicum on students' CT abilities and identified the effects of differing numbers of simulation exposures on CT in a multi-site environment. The study used a multi-site, pre-test, post-test design. A total of 237 nursing students at three universities enrolled in a pediatric practicum participated in this study from February to December 2013. All three schools used the same simulation courseware, including the same simulation scenarios, evaluation tools, and simulation equipment. The courseware incorporated high-fidelity simulators and standardized patients. Students at school A completed one simulation session, whereas students at schools B and C completed two and three simulation sessions, respectively. Yoon's Critical Thinking Disposition tool (2008) was used to measure students' CT abilities. The gains in students' CT scores varied according to their numbers of exposures to the simulation courseware. With a single exposure, there were no statistically significant gains in CT, whereas three exposures to the courseware produced significant gains in CT. In seven subcategories of critical thinking, three exposures to the simulation courseware produced CT gains in the prudence and intellectual eagerness subcategories, and the overall simulation experience produced CT gains in the prudence, systematicity, healthy skepticism, and intellectual eagerness subcategories. Simulation courseware may produce positive learning outcomes for prudence in nursing education. In addition, the findings from the multi-site comparative study may contribute to greater understanding of how patient simulation experiences impact students' CT abilities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Knowledge of medical imaging radiation dose and risk among doctors.

PubMed

Brown, Nicholas; Jones, Lee

2013-02-01

The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

PET/MRI: Where Might It Replace PET/CT?

PubMed Central

Ehman, Eric C.; Johnson, Geoffrey B.; Villanueva-Meyer, Javier E.; Cha, Soonmee; Leynes, Andrew Palmera; Larson, Peder Eric Zufall; Hope, Thomas A.

2017-01-01

Simultaneous positron emission tomography and MRI (PET/MRI) is a technology that combines the anatomic and quantitative strengths of MR imaging with physiologic information obtained from PET. PET and computed tomography (PET/ CT) performed in a single scanning session is an established technology already in widespread and accepted use worldwide. Given the higher cost and complexity of operating and interpreting the studies obtained on a PET/MRI system, there has been question as to which patients would benefit most from imaging with PET/MRI versus PET/CT. In this article, we compare PET/MRI with PET/CT, detail the applications for which PET/MRI has shown promise and discuss impediments to future adoption. It is our hope that future work will prove the benefit of PET/MRI to specific groups of patients, initially those in which PET/CT and MRI are already performed, leveraging simultaneity and allowing for greater degrees of multiparametric evaluation. PMID:28370695

Correlation Between Findings of Multislice Helical Computed Tomography (CT), Endoscopic Examinations, Endovascular Procedures, and Surgery in Patients with Symptoms of Acute Gastrointestinal Bleeding.

PubMed

Konecki, Dariusz; Grabowska-Derlatka, Laretta; Pacho, Ryszard; Rowiński, Olgierd

2017-01-01

Endoscopic methods (gastroscopy and colonoscopy) are considered fundamental for the diagnosis of gastrointestinal bleeding. In recent years, multidetector computed tomography (MDCT) has also gained importance in diagnosing gastrointestinal bleeding, particularly in hemodynamically unstable patients and in cases with suspected lower gastrointestinal tract bleeding. CT can detect both the source and the cause of active gastrointestinal bleeding, thereby expediting treatment initiation. The study group consisted of 16 patients with clinical symptoms of gastrointestinal bleeding in whom features of active bleeding were observed on CT. In all patients, bleeding was verified by means of other methods such as endoscopic examinations, endovascular procedures, or surgery. The bleeding source was identified on CT in all 16 patients. In 14 cases (87.5%), bleeding was confirmed by other methods. CT is an efficient, fast, and readily available tool for detecting the location of acute gastrointestinal bleeding.

THE PATHOMECHANICAL ETIOLOGY OF POST-TRAUMATIC OSTEOARTHRITIS FOLLOWING INTRAARTICULAR FRACTURES

PubMed Central

Anderson, Donald D; Marsh, J Lawrence; Brown, Thomas D

2011-01-01

Many intra-articular fracture patients eventually experience significant functional deficits, pain, and stiffness from post-traumatic osteoarthritis (PTOA). Over the last several decades, continued refinement of surgical reconstruction techniques has failed to markedly improve patient outcomes. New treatment paradigms are needed - ideally, bio/pharmaceutical. Progress in that direction has been impeded because the pathomechanical etiol-ogy of PTOA development is poorly understood. In particular, the relative roles and pathomechanisms of acute joint injury (from the initial trauma) versus chronic contact stress elevation (from residual incongruity) are unknown, primarily because there have been no objective methods for reliably quantifying either of these insult entities. Over the past decade, novel enabling technologies have been developed that provide objective biomechanical indices of injury severity and of chronic contact stress challenge to fractured joint surfaces. The severity of the initial joint injury is indexed primarily on the basis of the energy released in fracture, obtained from validated digital image analysis of CT scans. Chronic contact stress elevations are indexed by patient-specific finite element stress analysis, using models derived from post-reduction CT scans. These new measures, conceived in the laboratory, have been taken through the stage of validation, and then have been applied in studies of intra-articular fracture patients, to relate these biomechanical indices of cartilage insult to the incidence and severity of PTOA This body of work has provided a novel framework for developing and testing new approaches to forestall PTOA following intra-articular fractures. PMID:22096414

The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2011-02-15

Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process.more » Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule{>=}3 mm,''''nodule<3 mm,'' and ''non-nodule{>=}3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked ''nodule{>=}3 mm'' by at least one radiologist, of which 928 (34.7%) received such marks from all four radiologists. These 2669 lesions include nodule outlines and subjective nodule characteristic ratings. Conclusions: The LIDC/IDRI Database is expected to provide an essential medical imaging research resource to spur CAD development, validation, and dissemination in clinical practice.« less

Costs of testing for ocular Chlamydia trachomatis infection compared to mass drug administration for trachoma in the Gambia: application of results from the PRET study.

PubMed

Harding-Esch, Emma; Jofre-Bonet, Mireia; Dhanjal, Jaskiran K; Burr, Sarah; Edwards, Tansy; Holland, Martin; Sillah, Ansumana; West, Sheila; Lietman, Tom; Keenan, Jeremy; Mabey, David; Bailey, Robin

2015-04-01

Mass drug administration (MDA) treatment of active trachoma with antibiotic is recommended to be initiated in any district where the prevalence of trachoma inflammation, follicular (TF) is ≥ 10% in children aged 1-9 years, and then to continue for at least three annual rounds before resurvey. In The Gambia the PRET study found that discontinuing MDA based on testing a sample of children for ocular Chlamydia trachomatis(Ct) infection after one MDA round had similar effects to continuing MDA for three rounds. Moreover, one round of MDA reduced disease below the 5% TF threshold. We compared the costs of examining a sample of children for TF, and of testing them for Ct, with those of MDA rounds. The implementation unit in PRET The Gambia was a census enumeration area (EA) of 600-800 people. Personnel, fuel, equipment, consumables, data entry and supervision costs were collected for census and treatment of a sample of EAs and for the examination, sampling and testing for Ct infection of 100 individuals within them. Programme costs and resource savings from testing and treatment strategies were inferred for the 102 EAs in the study area, and compared. Census costs were $103.24 per EA plus initial costs of $108.79. MDA with donated azithromycin cost $227.23 per EA. The mean cost of examining and testing 100 children was $796.90 per EA, with Ct testing kits costing $4.80 per result. A strategy of testing each EA for infection is more expensive than two annual rounds of MDA unless the kit cost is less than $1.38 per result. However stopping or deciding not to initiate treatment in the study area based on testing a sample of EAs for Ct infection (or examining children in a sample of EAs) creates savings relative to further unnecessary treatments. Resources may be saved by using tests for chlamydial infection or clinical examination to determine that initial or subsequent rounds of MDA for trachoma are unnecessary.

Costs of Testing for Ocular Chlamydia trachomatis Infection Compared to Mass Drug Administration for Trachoma in The Gambia: Application of Results from the PRET Study

PubMed Central

Harding-Esch, Emma; Jofre-Bonet, Mireia; Dhanjal, Jaskiran K.; Burr, Sarah; Edwards, Tansy; Holland, Martin; Sillah, Ansumana; West, Sheila; Lietman, Tom; Keenan, Jeremy; Mabey, David; Bailey, Robin

2015-01-01

Background Mass drug administration (MDA) treatment of active trachoma with antibiotic is recommended to be initiated in any district where the prevalence of trachoma inflammation, follicular (TF) is ≥10% in children aged 1–9 years, and then to continue for at least three annual rounds before resurvey. In The Gambia the PRET study found that discontinuing MDA based on testing a sample of children for ocular Chlamydia trachomatis(Ct) infection after one MDA round had similar effects to continuing MDA for three rounds. Moreover, one round of MDA reduced disease below the 5% TF threshold. We compared the costs of examining a sample of children for TF, and of testing them for Ct, with those of MDA rounds. Methods The implementation unit in PRET The Gambia was a census enumeration area (EA) of 600–800 people. Personnel, fuel, equipment, consumables, data entry and supervision costs were collected for census and treatment of a sample of EAs and for the examination, sampling and testing for Ct infection of 100 individuals within them. Programme costs and resource savings from testing and treatment strategies were inferred for the 102 EAs in the study area, and compared. Results Census costs were $103.24 per EA plus initial costs of $108.79. MDA with donated azithromycin cost $227.23 per EA. The mean cost of examining and testing 100 children was $796.90 per EA, with Ct testing kits costing $4.80 per result. A strategy of testing each EA for infection is more expensive than two annual rounds of MDA unless the kit cost is less than $1.38 per result. However stopping or deciding not to initiate treatment in the study area based on testing a sample of EAs for Ct infection (or examining children in a sample of EAs) creates savings relative to further unnecessary treatments. Conclusion Resources may be saved by using tests for chlamydial infection or clinical examination to determine that initial or subsequent rounds of MDA for trachoma are unnecessary. PMID:25901349

Personalized Circulating Tumor DNA Biomarkers Dynamically Predict Treatment Response and Survival In Gynecologic Cancers.

PubMed

Pereira, Elena; Camacho-Vanegas, Olga; Anand, Sanya; Sebra, Robert; Catalina Camacho, Sandra; Garnar-Wortzel, Leopold; Nair, Navya; Moshier, Erin; Wooten, Melissa; Uzilov, Andrew; Chen, Rong; Prasad-Hayes, Monica; Zakashansky, Konstantin; Beddoe, Ann Marie; Schadt, Eric; Dottino, Peter; Martignetti, John A

2015-01-01

High-grade serous ovarian and endometrial cancers are the most lethal female reproductive tract malignancies worldwide. In part, failure to treat these two aggressive cancers successfully centers on the fact that while the majority of patients are diagnosed based on current surveillance strategies as having a complete clinical response to their primary therapy, nearly half will develop disease recurrence within 18 months and the majority will die from disease recurrence within 5 years. Moreover, no currently used biomarkers or imaging studies can predict outcome following initial treatment. Circulating tumor DNA (ctDNA) represents a theoretically powerful biomarker for detecting otherwise occult disease. We therefore explored the use of personalized ctDNA markers as both a surveillance and prognostic biomarker in gynecologic cancers and compared this to current FDA-approved surveillance tools. Tumor and serum samples were collected at time of surgery and then throughout treatment course for 44 patients with gynecologic cancers, representing 22 ovarian cancer cases, 17 uterine cancer cases, one peritoneal, three fallopian tube, and one patient with synchronous fallopian tube and uterine cancer. Patient/tumor-specific mutations were identified using whole-exome and targeted gene sequencing and ctDNA levels quantified using droplet digital PCR. CtDNA was detected in 93.8% of patients for whom probes were designed and levels were highly correlated with CA-125 serum and computed tomography (CT) scanning results. In six patients, ctDNA detected the presence of cancer even when CT scanning was negative and, on average, had a predictive lead time of seven months over CT imaging. Most notably, undetectable levels of ctDNA at six months following initial treatment was associated with markedly improved progression free and overall survival. Detection of residual disease in gynecologic, and indeed all cancers, represents a diagnostic dilemma and a potential critical inflection point in precision medicine. This study suggests that the use of personalized ctDNA biomarkers in gynecologic cancers can identify the presence of residual tumor while also more dynamically predicting response to treatment relative to currently used serum and imaging studies. Of particular interest, ctDNA was an independent predictor of survival in patients with ovarian and endometrial cancers. Earlier recognition of disease persistence and/or recurrence and the ability to stratify into better and worse outcome groups through ctDNA surveillance may open the window for improved survival and quality and life in these cancers.

Initial nitrous oxide, carbon dioxide, and methane costs of converting conservation reserve program grassland to row crops under no-till vs. conventional tillage.

PubMed

Ruan, Leilei; Philip Robertson, G

2013-08-01

Around 4.4 million ha of land in USDA Conservation Reserve Program (CRP) contracts will expire between 2013 and 2018 and some will likely return to crop production. No-till (NT) management offers the potential to reduce the global warming costs of CO2 , CH4 , and N2 O emissions during CRP conversion, but to date there have been no CRP conversion tillage comparisons. In 2009, we converted portions of three 9-21 ha CRP fields in Michigan to conventional tillage (CT) or NT soybean production and reserved a fourth field for reference. Both CO2 and N2 O fluxes increased following herbicide application in all converted fields, but in the CT treatment substantial and immediate N2 O and CO2 fluxes occurred after tillage. For the initial 201-day conversion period, average daily N2 O fluxes (g N2 O-N ha(-1)  d(-1) ) were significantly different in the order: CT (47.5 ± 6.31, n = 6) ≫ NT (16.7 ± 2.45, n = 6) ≫ reference (2.51 ± 0.73, n = 4). Similarly, soil CO2 fluxes in CT were 1.2 times those in NT and 3.1 times those in the unconverted CRP reference field. All treatments were minor sinks for CH4 (-0.69 ± 0.42 to -1.86 ± 0.37 g CH4 -C ha(-1)  d(-1) ) with no significant differences among treatments. The positive global warming impact (GWI) of converted soybean fields under both CT (11.5 Mg CO2 e ha(-1) ) and NT (2.87 Mg CO2 e ha(-1) ) was in contrast to the negative GWI of the unconverted reference field (-3.5 Mg CO2 e ha(-1) ) with on-going greenhouse gas (GHG) mitigation. N2 O contributed 39.3% and 55.0% of the GWI under CT and NT systems with the remainder contributed by CO2 (60.7% and 45.0%, respectively). Including foregone mitigation, we conclude that NT management can reduce GHG costs by ~60% compared to CT during initial CRP conversion. © 2013 John Wiley & Sons Ltd.

Transformation of carbon tetrachloride and chloroform by trichloroethene respiring anaerobic mixed cultures and supernatant.

PubMed

Vickstrom, Kyle E; Azizian, Mohammad F; Semprini, Lewis

2017-09-01

Carbon tetrachloride (CT) and chloroform (CF) were transformed in batch reactor experiments conducted with anaerobic dechlorinating cultures and supernatant (ADC + S) harvested from continuous flow reactors. The Evanite (EV) and Victoria/Stanford (VS) cultures, capable of respiring trichloroethene (TCE), 1,2-cis-dichloroethene (cDCE), and vinyl chloride (VC) to ethene (ETH), were grown in continuous flow reactors receiving an influent feed of saturated TCE (10 mM; 60 mEq) and formate (45 mM; 90 mEq) but no CT or CF. Cells and supernatant were harvested from the chemostats and inoculated into batch reactors at the onset of each experiment. CT transformation was complete following first order kinetics with CF, DCM and CS 2 as the measurable transformation products, representing 20-40% of the original mass of CT, with CO 2 likely the unknown transformation product. CF was transformed to DCM and likely CO 2 at an order of magnitude rate lower than CT, while DCM was not further transformed. An analytical first order model including multiple key reactions effectively simulated CT transformation, product formation and transformation, and provided reasonable estimates of transformation rate coefficients. Biotic and abiotic treatments indicated that CT was mainly transformed via abiotic processes. However, the presence of live cells was associated with the transformation of CF to DCM. In biotic tests both TCE and CT were simultaneously transformed, with TCE transformed to ETH and approximately 15-53% less CF formed via CT transformation. A 14-day exposure to CF (CF max  = 1.4 μM) reduced all rates of chlorinated ethene respiration by a factor of 10 or greater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic resonance force microscopy with a paramagnetic probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

Here, we consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Magnetic resonance force microscopy with a paramagnetic probe

NASA Astrophysics Data System (ADS)

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

2017-04-01

We consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Magnetic resonance force microscopy with a paramagnetic probe

DOE PAGES

Berman, G. P.; Gorshkov, V. N.; Tsifrinovich, V. I.

2017-04-01

Here, we consider theoretically extension of magnetic resonance force microscopy (MRFM) replacing a ferromagnetic probe on a cantilever tip (CT) with a paramagnetic one (PMRFM). The dynamics of the interaction between the paramagnetic probe and a local magnetic moment in a sample is analyzed, using a quasi-classical approach. We show that the application of a proper sequence of electromagnetic pulses provides a significant deflection of the CT from the initial equilibrium position. Periodic application of these sequences of pulses results in quasi-periodic CT deflections from the equilibrium, which can be used for detection of the magnetic moment in a sample.

Analysis of manual segmentation in paranasal CT images.

PubMed

Tingelhoff, Kathrin; Eichhorn, Klaus W G; Wagner, Ingo; Kunkel, Maria E; Moral, Analia I; Rilk, Markus E; Wahl, Friedrich M; Bootz, Friedrich

2008-09-01

Manual segmentation is often used for evaluation of automatic or semi-automatic segmentation. The purpose of this paper is to describe the inter and intraindividual variability, the dubiety of manual segmentation as a gold standard and to find reasons for the discrepancy. We realized two experiments. In the first one ten ENT surgeons, ten medical students and one engineer outlined the right maxillary sinus and ethmoid sinuses manually on a standard CT dataset of a human head. In the second experiment two participants outlined maxillary sinus and ethmoid sinuses five times consecutively. Manual segmentation was accomplished with custom software using a line segmentation tool. The first experiment shows the interindividual variability of manual segmentation which is higher for ethmoidal sinuses than for maxillary sinuses. The variability can be caused by the level of experience, different interpretation of the CT data or different levels of accuracy. The second experiment shows intraindividual variability which is lower than interindividual variability. Most variances in both experiments appear during segmentation of ethmoidal sinuses and outlining hiatus semilunaris. Concerning the inter and intraindividual variances the segmentation result of one manual segmenter could not directly be used as gold standard for the evaluation of automatic segmentation algorithms.

Trends in CT scan rates in children and pregnant women: teaching, private, public and nonprofit facilities.

PubMed

Hoshiko, Sumi; Smith, Daniel; Fan, Cathyn; Jones, Carrie R; McNeel, Sandra V; Cohen, Ronald A

2014-05-01

Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution. We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions. We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005-2012. We modeled trends overall and by facility type. CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities. CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care.

The Necessity of Follow-Up Brain Computed-Tomography Scans: Is It the Pathology Itself Or Our Fear that We Should Overcome?

PubMed Central

Öğrenci, Ahmet; Koban, Orkun; Ekşi, Murat; Yaman, Onur; Dalbayrak, Sedat

2017-01-01

AIM: This study aimed to make a retrospective analysis of pediatric patients with head traumas that were admitted to one hospital setting and to make an analysis of the patients for whom follow-up CT scans were obtained. METHODS: Pediatric head trauma cases were retrospectively retrieved from the hospital’s electronic database. Patients’ charts, CT scans and surgical notes were evaluated by one of the authors. Repeat CT scans for operated patients were excluded from the total number of repeat CT scans. RESULTS: One thousand one hundred and thirty-eight pediatric patients were admitted to the clinic due to head traumas. Brain CT scan was requested in 863 patients (76%) in the cohort. Follow-up brain CT scans were obtained in 102 patients. Additional abnormal finding requiring surgical intervention was observed in only one patient (isolated 4th ventricle hematoma) on the control CTs (1% of repeat CT scans), who developed obstructive hydrocephalus. None of the patients with no more than 1 cm epidural hematoma in its widest dimension and repeat CT scans obtained 1.5 hours after the trauma necessitated surgery. CONCLUSION: Follow-up CT scans changed clinical approach in only one patient in the present series. When ordering CT scan in the follow-up of pediatric traumas, benefits and harms should be weighted based upon time interval from trauma onset to initial CT scan and underlying pathology. PMID:29104682

BASE (Broadening Access to Science Education): A Research and Mentoring Focused Summer STEM Camp Serving Underrepresented High School Girls

ERIC Educational Resources Information Center

Phelan, Shelley A.; Harding, Shannon M.; Harper-Leatherman, Amanda S.

2017-01-01

BASE (Broadening Access to Science Education) Camp is a hands-on, two-week residential summer science experience on the Fairfield University campus in Fairfield CT, USA. The annual program targets 24 young women who attend high school in the neighboring city of Bridgeport, CT, the most economically depressed city in CT. The camp, which is free to…

Performance improvement of magnetized coaxial plasma gun by magnetic circuit on a bias coil

NASA Astrophysics Data System (ADS)

Edo, Takahiro; Matsumoto, Tadafumi; Asai, Tomohiko; Kamino, Yasuhiro; Inomoto, Michiaki; Gota, Hiroshi

2016-10-01

A magnetized coaxial plasmoid accelerator has been utilized for compact torus (CT) injection to refuel into fusion reactor core plasma. Recently, CT injection experiments have been conducted on the C-2/C-2U facility at Tri Alpha Energy. In the series of experiments successful refueling, i.e. increased particle inventory of field-reversed configuration (FRC) plasma, has been observed. In order to improve the performance of CT injector and to refuel in the upgraded FRC device, called C-2W, with higher confinement magnetic field, magnetic circuit consisting of magnetic material onto a bias magnetic coil is currently being tested at Nihon University. Numerical work suggests that the optimized bias magnetic field distribution realizes the increased injection velocity because of higher conversion efficiency of Lorenz self force to kinetic energy. Details of the magnetic circuit design as well as results of the test experiment and field calculations will be presented and discussed.

Ab Initio Analysis of Auger-Assisted Electron Transfer.

PubMed

Hyeon-Deuk, Kim; Kim, Joonghan; Prezhdo, Oleg V

2015-01-15

Quantum confinement in nanoscale materials allows Auger-type electron-hole energy exchange. We show by direct time-domain atomistic simulation and analytic theory that Auger processes give rise to a new mechanism of charge transfer (CT) on the nanoscale. Auger-assisted CT eliminates the renown Marcus inverted regime, rationalizing recent experiments on CT from quantum dots to molecular adsorbates. The ab initio simulation reveals a complex interplay of the electron-hole and charge-phonon channels of energy exchange, demonstrating a variety of CT scenarios. The developed Marcus rate theory for Auger-assisted CT describes, without adjustable parameters, the experimental plateau of the CT rate in the region of large donor-acceptor energy gap. The analytic theory and atomistic insights apply broadly to charge and energy transfer in nanoscale systems.

Integrated image presentation of transmission and fluorescent X-ray CT using synchrotron radiation

NASA Astrophysics Data System (ADS)

Zeniya, T.; Takeda, T.; Yu, Q.; Hasegawa, Y.; Hyodo, K.; Yuasa, T.; Hiranaka, Y.; Itai, Y.; Akatsuka, T.

2001-07-01

We have developed a computed tomography (CT) system with synchrotron radiation (SR) to detect fluorescent X-rays and transmitted X-rays simultaneously. Both SR transmission X-ray CT (SR-TXCT) and SR fluorescent X-ray CT (SR-FXCT) can describe cross-sectional images with high spatial and contrast resolutions as compared to conventional CT. TXCT gives morphological information and FXCT gives functional information of organs. So, superposed display system for SR-FXCT and SR-TXCT images has been developed for clinical diagnosis with higher reliability. Preliminary experiment with brain phantom was carried out and the superposition of both images was performed. The superposed SR-CT image gave us both functional and morphological information easily with high reliability, thus demonstrating the usefulness of this system.

Effect of Different Loading Conditions on the Nucleation and Development of Shear Zones Around Material Heterogeneities

NASA Astrophysics Data System (ADS)

Rybacki, E.; Nardini, L.; Morales, L. F.; Dresen, G.

2017-12-01

Rock deformation at depths in the Earth's crust is often localized in high temperature shear zones, which occur in the field at different scales and in a variety of lithologies. The presence of material heterogeneities has long been recognized to be an important cause for shear zones evolution, but the mechanisms controlling initiation and development of localization are not fully understood, and the question of which loading conditions (constant stress or constant deformation rate) are most favourable is still open. To better understand the effect of boundary conditions on shear zone nucleation around heterogeneities, we performed a series of torsion experiments under constant twist rate (CTR) and constant torque (CT) conditions in a Paterson-type deformation apparatus. The sample assemblage consisted of copper-jacketed Carrara marble hollow cylinders with one weak inclusion of Solnhofen limestone. The CTR experiments were performed at maximum bulk strain rates of 1.8-1.9*10-4 s-1, yielding shear stresses of 19-20 MPa. CT tests were conducted at shear stresses between 18.4 and 19.8 MPa resulting in shear strain rates of 1-2*10-4 s-1. All experiments were run at 900 °C temperature and 400 MPa confining pressure. Maximum bulk shear strains (γ) were ca. 0.3 and 1. Strain localized within the host marble in front of the inclusion in an area termed process zone. Here grain size reduction is intense and local shear strain (estimated from markers on the jackets) is up to 8 times higher than the applied bulk strain, rapidly dropping to 2 times higher at larger distance from the inclusion. The evolution of key microstructural parameters such as average grain size and average grain orientation spread (GOS, a measure of lattice distortion) within the process zone, determined by electron backscatter diffraction analysis, differs significantly as a function of loading conditions. Both parameters indicate that, independent of bulk strain and distance from the inclusion, the contribution of small strain-free recrystallized grains is larger in CTR than in CT samples. Our results suggest that loading conditions substantially affect material heterogeneity-induced localization in its nucleation and transient stages.

Classifying features in CT imagery: accuracy for some single- and multiple-species classifiers

Treesearch

Daniel L. Schmoldt; Jing He; A. Lynn Abbott

1998-01-01

Our current approach to automatically label features in CT images of hardwood logs classifies each pixel of an image individually. These feature classifiers use a back-propagation artificial neural network (ANN) and feature vectors that include a small, local neighborhood of pixels and the distance of the target pixel to the center of the log. Initially, this type of...

Radiological review of pleural tumors

PubMed Central

Sureka, Binit; Thukral, Brij Bhushan; Mittal, Mahesh Kumar; Mittal, Aliza; Sinha, Mukul

2013-01-01

Tumors of the pleura are not uncommon and diagnosis is clinched by combined imaging and clinical correlation. Malignant tumors are more common than benign tumors. Initial imaging modalities are chest radiography and Computed Tomography (CT). Further characterization may be required using Ultrasoundgraphy (USG), Magnetic resonance Imaging (MRI) and PET-CT. Biopsy remains gold standard. This article highlights various common and uncommon tumors of pleura and characteristic imaging findings. PMID:24604935

Optimization of the scan protocols for CT-based material extraction in small animal PET/CT studies

NASA Astrophysics Data System (ADS)

Yang, Ching-Ching; Yu, Jhih-An; Yang, Bang-Hung; Wu, Tung-Hsin

2013-12-01

We investigated the effects of scan protocols on CT-based material extraction to minimize radiation dose while maintaining sufficient image information in small animal studies. The phantom simulation experiments were performed with the high dose (HD), medium dose (MD) and low dose (LD) protocols at 50, 70 and 80 kVp with varying mA s. The reconstructed CT images were segmented based on Hounsfield unit (HU)-physical density (ρ) calibration curves and the dual-energy CT-based (DECT) method. Compared to the (HU;ρ) method performed on CT images acquired with the 80 kVp HD protocol, a 2-fold improvement in segmentation accuracy and a 7.5-fold reduction in radiation dose were observed when the DECT method was performed on CT images acquired with the 50/80 kVp LD protocol, showing the possibility to reduce radiation dose while achieving high segmentation accuracy.

Development of proton CT imaging system using plastic scintillator and CCD camera

NASA Astrophysics Data System (ADS)

Tanaka, Sodai; Nishio, Teiji; Matsushita, Keiichiro; Tsuneda, Masato; Kabuki, Shigeto; Uesaka, Mitsuru

2016-06-01

A proton computed tomography (pCT) imaging system was constructed for evaluation of the error of an x-ray CT (xCT)-to-WEL (water-equivalent length) conversion in treatment planning for proton therapy. In this system, the scintillation light integrated along the beam direction is obtained by photography using the CCD camera, which enables fast and easy data acquisition. The light intensity is converted to the range of the proton beam using a light-to-range conversion table made beforehand, and a pCT image is reconstructed. An experiment for demonstration of the pCT system was performed using a 70 MeV proton beam provided by the AVF930 cyclotron at the National Institute of Radiological Sciences. Three-dimensional pCT images were reconstructed from the experimental data. A thin structure of approximately 1 mm was clearly observed, with spatial resolution of pCT images at the same level as that of xCT images. The pCT images of various substances were reconstructed to evaluate the pixel value of pCT images. The image quality was investigated with regard to deterioration including multiple Coulomb scattering.

Ab initio study on the formation of triiodide CT complex from the reaction of iodine with 2,3-diaminopyridine.

PubMed

Al-Hashimi, Nessreen A; Hussein, Yasser H A

2010-01-01

The charge transfer (CT) interaction between iodine and 2,3-diaminopyridine (DAPY) has been thoroughly investigated via theoretical calculations. A Hartree-Fock, 3-21G level of theory was used to optimize and calculate the Mullican charge distribution scheme as well as the vibrational frequencies of DAPY alone and both its CT complexes with one and two iodine molecules. A very good agreement was found between experiment and theory. New illustrations were concluded with a deep analysis and description for the vibrational frequencies of the formed CT complexes. The two-step CT complex formation mechanism published earlier was supported. Copyright 2009 Elsevier B.V. All rights reserved.

Whole-body diffusion-weighted magnetic resonance imaging (WB-DW-MRI) vs choline-positron emission tomography-computed tomography (choline-PET/CT) for selecting treatments in recurrent prostate cancer.

PubMed

Conde-Moreno, A J; Herrando-Parreño, G; Muelas-Soria, R; Ferrer-Rebolleda, J; Broseta-Torres, R; Cozar-Santiago, M P; García-Piñón, F; Ferrer-Albiach, C

2017-05-01

To determine the effectiveness of whole-body diffusion-weighted magnetic resonance imaging (WB-DW-MRI) in detecting metastases by comparing the results with those from choline-positron emission tomography-computed tomography (choline-PET/CT) in patients with biochemical relapse after primary treatment, and no metastases in bone scintigraphy, CT and/or pelvic MRI, or metastatic/oligometastatic prostate cancer (PCa). Patients with this disease profile who could benefit from treatment with stereotactic body radiation therapy (SBRT) were selected and their responses to these techniques were rated. This was a prospective, controlled, unicentric study, involving 46 consecutive patients from our centre who presented biochemical relapse after adjuvant, salvage or radical treatment with external beam radiotherapy, or brachytherapy. After initial tests (bone scintigraphy, CT, pelvic MRI), 35 patients with oligometastases or without them were selected. 11 patients with multiple metastases were excluded from the study. WB-DW-MRI and choline-PET/CT was then performed on each patient within 1 week. The results were interpreted by specialists in nuclear medicine and MRI. If they were candidates for treatment with ablative SBRT (SABR), they were then evaluated every three months with both tests. Choline-PET/CT detected lesions in 16 patients that were not observable using WB-DW-MRI. The results were consistent in seven patients and in three cases, a lesion was observed using WB-DW-MRI that was not detected with choline-PET/CT. The Kappa value obtained was 0.133 (p = 0.089); the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of WB-DW-MRI were estimated at 44.93, 64.29, 86.11, and 19.15%, respectively. For choline-PET/CT patients, the sensitivity, specificity, PPV, and NPV were 97.10, 58.33, 93.06, and 77.78%, respectively. Choline-PET/CT has a high global sensitivity while WB-DW-MRI has a high specificity, and so they are complementary techniques. Future studies with more enrolled patients and a longer follow-up period will be required to confirm these data. The initial data show that the best technique for evaluating response after SBRT is choline-PET/CT. Trial registration number NCT02858128.

Optical CT scanning of PRESAGETM polyurethane samples with a CCD-based readout system

NASA Astrophysics Data System (ADS)

Doran, S. J.; Krstajic, N.; Adamovics, J.; Jenneson, P. M.

2004-01-01

This article demonstrates the resolution capabilities of the CCD scanner under ideal circumstances and describes the first CCD-based optical CT experiments on a new class of dosimeter, known as PRESAGETM (Heuris Pharma, Skillman, NJ).

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose

PubMed Central

Wenz, Holger; Maros, Máté E.; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O.; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

2015-01-01

Objectives To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. Methods 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Results Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Conclusion Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels. PMID:26288186

Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

PubMed

Wenz, Holger; Maros, Máté E; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

2015-01-01

To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (p<0.05). Mean SNR was significantly higher in all spiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05<0.0024). Subjective image quality improved with increasing IR levels. Combination of 3rd-generation DSCT spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

Magnetic Compression Experiment at General Fusion with Simulation Results

NASA Astrophysics Data System (ADS)

Dunlea, Carl; Khalzov, Ivan; Hirose, Akira; Xiao, Chijin; Fusion Team, General

2017-10-01

The magnetic compression experiment at GF was a repetitive non-destructive test to study plasma physics applicable to Magnetic Target Fusion compression. A spheromak compact torus (CT) is formed with a co-axial gun into a containment region with an hour-glass shaped inner flux conserver, and an insulating outer wall. External coil currents keep the CT off the outer wall (levitation) and then rapidly compress it inwards. The optimal external coil configuration greatly improved both the levitated CT lifetime and the rate of shots with good compressional flux conservation. As confirmed by spectrometer data, the improved levitation field profile reduced plasma impurity levels by suppressing the interaction between plasma and the insulating outer wall during the formation process. We developed an energy and toroidal flux conserving finite element axisymmetric MHD code to study CT formation and compression. The Braginskii MHD equations with anisotropic heat conduction were implemented. To simulate plasma / insulating wall interaction, we couple the vacuum field solution in the insulating region to the full MHD solution in the remainder of the domain. We see good agreement between simulation and experiment results. Partly funded by NSERC and MITACS Accelerate.

Initial experience of intraoperative three-dimensional navigation for liver resection using real-time virtual sonography.

PubMed

Satou, Shouichi; Aoki, Taku; Kaneko, Junichi; Sakamoto, Yoshihiro; Hasegawa, Kiyoshi; Sugawara, Yasuhiko; Arai, Osamu; Mitake, Tsuyoshi; Miura, Koui; Kokudo, Norihiro

2014-02-01

Real-time virtual sonography is an innovative imaging technology that detects the spatial position of an ultrasound probe and immediately reconstructs a section of computed tomography (CT) and/or magnetic resonance in accordance with the ultrasound image, thereby allowing a real-time comparison of those modalities. A novel intraoperative navigation system for liver resection using real-time virtual sonography has been devised for the detection of tumors and navigation of the resection plane. Sixteen patients with hepatic malignancies (26 tumors in total) were involved in this study, and the system was used intraoperatively. The tumor size ranged 2 to 140 mm (23 mm in median). By the navigation system, operators could refer intraoperative ultrasound image displayed on the television monitor side-by-side with corresponding images of CT and/or magnetic resonance. In addition, the system overlaid preoperative simulation on the CT image and highlighted the extent of resection so as to navigate the resection plane. Because the system used electromagnetic power in the operation room, the feasibility and safety of the system was investigated as well as its validity. The system could be used uneventfully in each operation. All of the 26 tumors scheduled to be resected were detected by the navigation system. The weight of the resected specimen correlated with the preoperatively simulated volume (R = 0.995, P < .0001). The feasibility and safety of the navigation system were confirmed. The system should be helpful for intraoperative tumor detection and navigation of liver resection.

Initial experience with visualizing hand and foot tendons by dual-energy computed tomography.

PubMed

Deng, Kai; Sun, Cong; Liu, Cheng; Ma, Rui

2009-01-01

To assess the feasibility of visualizing hand and foot tendons by dual-energy computed tomography (CT). Twenty patients who suffered from hand or feet pains were scanned on dual-source CT (Definition, Forchheim, Germany) with dual-energy mode at tube voltages of 140 and 80 kV and a corresponding ratio of 1:4 between tube currents. The reconstructed images were postprocessed by volume rendering techniques (VRT) and multiplanar reconstruction (MPR). All of the suspected lesions were confirmed by surgery or follow-up studies. Twelve patients (total of 24 hands and feet, respectively) were found to be normal and the other eight patients (total of nine hands and feet, respectively) were found abnormal. Dual-energy techniques are very useful in visualizing tendons of the hands and feet, such as flexor pollicis longus tendon, flexor digitorum superficialis/profundus tendon, Achilles tendon, extensor hallucis longus tendon, and extensor digitorum longus tendon, etc. It can depict the whole shape of the tendons and their fixation points clearly. Peroneus longus tendon in the sole of the foot was not displayed very well. The distal ends of metacarpophalangeal joints with extensor digitoium tendon and extensor pollicis longus tendon were poorly shown. The lesions of tendons such as the circuitry, thickening, and adherence were also shown clearly. Dual-energy CT offers a new method to visualize tendons of the hand and foot. It could clearly display both anatomical structures and pathologic changes of hand and foot tendons.

[Successful treatment of locally advanced squamous cell carcinoma of the esophagus by combination chemotherapy with 5-fluorouracil plus nedaplatin following tracheal stent tube placement-a case report].

PubMed

Nishimura, Junya; Kubo, Naoshi; Lee, Tomohiro; Shinto, Osamu; Sakurai, Katsunobu; Toyokawa, Takahiro; Tanaka, Hiroaki; Muguruma, Kazuya; Shibutani, Masatsune; Yamazoe, Sadaaki; Nagahara, Hisashi; Kimura, Kenjiro; Amano, Ryosuke; Ohtani, Hiroshi; Yashiro, Masakazu; Maeda, Kiyoshi; Ohira, Masaichi; Hirakawa, Kosei

2013-11-01

The patient was a 68-year-old man who complained of hoarseness and dyspnea. Upper gastrointestinal endoscopy revealed a type 3 tumor located in the middle thoracic esophagus at 30 cm from the incisor tooth that involved one-fourth of the circumference of the esophagus. Histopathological examination revealed moderately differentiated squamous cell carcinoma. Chest computed tomography( CT) revealed severe tracheal stenosis due to compression by a metastatic lymph node along the left recurrent laryngeal nerve. The patient was diagnosed as having cT4( 106recL-trachea), N2( 101L, 106recL, 106recR), M0, Stage IVa unresectable esophageal carcinoma. After insertion of a tracheal stent tube( spiral Z stent: diameter, 18 mm; length, 80 mm) to improve dyspnea, combination chemotherapy with 5-fluorouracil( 5-FU) plus nedaplatin was administered. Subsequent CT and endoscopy showed that the main tumor and the metastatic lymph node had significantly reduced in size and that complete response (CR) had been achieved. Thirty months after the initial treatment, the patient showed no sign of disease recurrence, after completion of 19 cycles of chemotherapy. The patient did not experience any severe adverse events. We report a case of a patient with locally advanced squamous cell carcinoma of the esophagus successfully treated with 5-FU/nedaplatin combination chemotherapy following tracheal stent tube placement.

Computed Tomography Support for Microgravity Materials Science Experiments

NASA Technical Reports Server (NTRS)

Gillies, Donald C.; Engel, H. Peter; Whitaker, Ann F. (Technical Monitor)

2001-01-01

The accurate measurement of density in both liquid and solid samples is of considerable interest to Principal Investigators with materials science experiments slated for the ISS. The work to be described is an innovative application of a conventional industrial nondestructive evaluation instrument. Traditional applications of industrial computed tomography (CT) rely on reconstructing cross sections of large structures to provide two-dimensional planar views which can identify defects such as porosity, or other material anomalies. This has been done on microgravity materials science experiments to check the integrity of ampoule-cartridge assemblies for safety purposes. With a substantially monoenergetic flux, as can be obtained with a radioactive cobalt source, there will be a direct correlation between absorption and density. Under such conditions it then becomes possible to make accurate measurements of density throughout a sample, and even when the sample itself is enclosed within a furnace and a safety required cartridge. Such a system has been installed at Kennedy Space Center (KSC) and is available to PIs to examine samples before and after flight. The CT system is being used to provide density information for two purposes. Firstly, the determination of density changes from liquid to solid is vital information to the PI for purposes of modeling the solidification behavior of his sample, and to engineers who have to design containment ampoules and must allow for shrinkage and other volume changes that may occur during processing. While such information can be obtained by pycnometric measurements, the possibility of using a furnace installed on the CT system enables one to examine potentially dangerous materials having high vapor pressures, while not needing visible access to the material. In addition, uniform temperature can readily be obtained, and the system can be controlled to ramp up, hold, and ramp down while collecting data over a wide range of parameters automatically. Results of initial tests on low melting point elements such as gallium, indium and tin will be presented, and the intent is to proceed to compounds such as InSb, HgCdTe and CdTe. Alloys such as Pb-Sb (PI - Poirier, U AZ) and Cu-Al (PI - Trivedi, Ames Lab.), which are the subjects of flight experiments, will also be examined. The second application is the conversion of measured density values directly to composition. This was successfully done with the mercury cadmium telluride alloys grown on the second and fourth United States Microgravity Payload (USMP-2 and USMP-4) missions by Lehoczky. CdTe values along the length of the boules were obtained at KSC prior to cutting the sample, and could have been obtained prior to its removal from the cartridge and ampoule. Examples of the data obtained will be shown. It is anticipated that several of the materials science PIs will avail themselves of the technique described, initially for determining densities prior to flight, and then to acquire early quantitative data on the compositional variation within their samples.

Dedicated Cone-Beam CT System for Extremity Imaging

PubMed Central

Al Muhit, Abdullah; Zbijewski, Wojciech; Thawait, Gaurav K.; Stayman, J. Webster; Packard, Nathan; Senn, Robert; Yang, Dong; Foos, David H.; Yorkston, John; Siewerdsen, Jeffrey H.

2014-01-01

Purpose To provide initial assessment of image quality and dose for a cone-beam computed tomographic (CT) scanner dedicated to extremity imaging. Materials and Methods A prototype cone-beam CT scanner has been developed for imaging the extremities, including the weight-bearing lower extremities. Initial technical assessment included evaluation of radiation dose measured as a function of kilovolt peak and tube output (in milliampere seconds), contrast resolution assessed in terms of the signal difference–to-noise ratio (SDNR), spatial resolution semiquantitatively assessed by using a line-pair module from a phantom, and qualitative evaluation of cadaver images for potential diagnostic value and image artifacts by an expert CT observer (musculoskeletal radiologist). Results The dose for a nominal scan protocol (80 kVp, 108 mAs) was 9 mGy (absolute dose measured at the center of a CT dose index phantom). SDNR was maximized with the 80-kVp scan technique, and contrast resolution was sufficient for visualization of muscle, fat, ligaments and/or tendons, cartilage joint space, and bone. Spatial resolution in the axial plane exceeded 15 line pairs per centimeter. Streaks associated with x-ray scatter (in thicker regions of the patient—eg, the knee), beam hardening (about cortical bone—eg, the femoral shaft), and cone-beam artifacts (at joint space surfaces oriented along the scanning plane—eg, the interphalangeal joints) presented a slight impediment to visualization. Cadaver images (elbow, hand, knee, and foot) demonstrated excellent visibility of bone detail and good soft-tissue visibility suitable to a broad spectrum of musculoskeletal indications. Conclusion A dedicated extremity cone-beam CT scanner capable of imaging upper and lower extremities (including weight-bearing examinations) provides sufficient image quality and favorable dose characteristics to warrant further evaluation for clinical use. © RSNA, 2013 Online supplemental material is available for this article. PMID:24475803

Determination of a Testing Threshold for Lumbar Puncture in the Diagnosis of Subarachnoid Hemorrhage after a Negative Head Computed Tomography: A Decision Analysis.

PubMed

Taylor, Richard Andrew; Singh Gill, Harman; Marcolini, Evie G; Meyers, H Pendell; Faust, Jeremy Samuel; Newman, David H

2016-10-01

The objective was to determine the testing threshold for lumbar puncture (LP) in the evaluation of aneurysmal subarachnoid hemorrhage (SAH) after a negative head computed tomography (CT). As a secondary aim we sought to identify clinical variables that have the greatest impact on this threshold. A decision analytic model was developed to estimate the testing threshold for patients with normal neurologic findings, being evaluated for SAH, after a negative CT of the head. The testing threshold was calculated as the pretest probability of disease where the two strategies (LP or no LP) are balanced in terms of quality-adjusted life-years. Two-way and probabilistic sensitivity analyses (PSAs) were performed. For the base-case scenario the testing threshold for performing an LP after negative head CT was 4.3%. Results for the two-way sensitivity analyses demonstrated that the test threshold ranged from 1.9% to 15.6%, dominated by the uncertainty in the probability of death from initial missed SAH. In the PSA the mean testing threshold was 4.3% (95% confidence interval = 1.4% to 9.3%). Other significant variables in the model included probability of aneurysmal versus nonaneurysmal SAH after negative head CT, probability of long-term morbidity from initial missed SAH, and probability of renal failure from contrast-induced nephropathy. Our decision analysis results suggest a testing threshold for LP after negative CT to be approximately 4.3%, with a range of 1.4% to 9.3% on robust PSA. In light of these data, and considering the low probability of aneurysmal SAH after a negative CT, classical teaching and current guidelines addressing testing for SAH should be revisited. © 2016 by the Society for Academic Emergency Medicine.

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

PubMed

Cho, S H; Sung, Y M; Kim, M S

2012-10-01

The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

Gray Matter-White Matter De-Differentiation on Brain Computed Tomography Predicts Brain Death Occurrence.

PubMed

Vigneron, C; Labeye, V; Cour, M; Hannoun, S; Grember, A; Rampon, F; Cotton, F

2016-01-01

Previous studies have shown that a loss of distinction between gray matter (GM) and white matter (WM) on unenhanced CT scans was predictive of poor outcome after cardiac arrest. The aim of this study was to identify a marker/predictor of imminent brain death. In this retrospective study, 15 brain-dead patients after anoxia and cardiac arrest were included. Patients were paired (1:1) with normal control subjects. Only patients' unenhanced CT scans performed before brain death and during the 24 hours after initial signs were analyzed. WM and GM densities were measured in predefined regions of interest (basal ganglia level, centrum semi-ovale level, high convexity level, brainstem level). At each level, GM and WM density and GM/WM ratio for brain-dead patients and normal control subjects were compared using the Wilcoxon signed-rank test. At each level, a lower GM/WM ratio and decreased GM and WM densities were observed in brain-dead patients' CT scans when compared with normal control subject CT scans. A cut-off value of 1.21 at the basal ganglia level was identified, below which brain death systematically occurred. GM/WM dedifferentiation on unenhanced CT scan is measurable before the occurrence of brain death, highlighting its importance in brain death prediction. The mechanism of GM/WM differentiation loss could be explained by the lack of oxygen caused by ischemia initially affecting the mitochondrial system. Copyright © 2016 Elsevier Inc. All rights reserved.

Signal Transduction in Receptor for Advanced Glycation End Products (RAGE)

PubMed Central

Rai, Vivek; Maldonado, Andres Y.; Burz, David S.; Reverdatto, Sergey; Schmidt, Ann Marie; Shekhtman, Alexander

2012-01-01

The receptor for advanced glycation end products (RAGE) is a multiligand cell surface macromolecule that plays a central role in the etiology of diabetes complications, inflammation, and neurodegeneration. The cytoplasmic domain of RAGE (C-terminal RAGE; ctRAGE) is critical for RAGE-dependent signal transduction. As the most membrane-proximal event, mDia1 binds to ctRAGE, and it is essential for RAGE ligand-stimulated phosphorylation of AKT and cell proliferation/migration. We show that ctRAGE contains an unusual α-turn that mediates the mDia1-ctRAGE interaction and is required for RAGE-dependent signaling. The results establish a novel mechanism through which an extracellular signal initiated by RAGE ligands regulates RAGE signaling in a manner requiring mDia1. PMID:22194616

Component extraction on CT volumes of assembled products using geometric template matching

NASA Astrophysics Data System (ADS)

Muramatsu, Katsutoshi; Ohtake, Yutaka; Suzuki, Hiromasa; Nagai, Yukie

2017-03-01

As a method of non-destructive internal inspection, X-ray computed tomography (CT) is used not only in medical applications but also for product inspection. Some assembled products can be divided into separate components based on density, which is known to be approximately proportional to CT values. However, components whose densities are similar cannot be distinguished using the CT value driven approach. In this study, we proposed a new component extraction algorithm from the CT volume, using a set of voxels with an assigned CT value with the surface mesh as the template rather than the density. The method has two main stages: rough matching and fine matching. At the rough matching stage, the position of candidate targets is identified roughly from the CT volume, using the template of the target component. At the fine matching stage, these candidates are precisely matched with the templates, allowing the correct position of the components to be detected from the CT volume. The results of two computational experiments showed that the proposed algorithm is able to extract components with similar density within the assembled products on CT volumes.

Exploring User Learnability and Learning Performance in an App for Depression: Usability Study

PubMed Central

Montague, Enid; Lattie, Emily G; Schueller, Stephen M; Kwasny, Mary J; Mohr, David C

2017-01-01

Background Mental health apps tend to be narrow in their functioning, with their focus mostly being on tracking, management, or psychoeducation. It is unclear what capability such apps have to facilitate a change in users, particularly in terms of learning key constructs relating to behavioral interventions. Thought Challenger (CBITs, Chicago) is a skill-building app that engages users in cognitive restructuring, a core component of cognitive therapy (CT) for depression. Objective The purpose of this study was to evaluate the learnability and learning performance of users following initial use of Thought Challenger. Methods Twenty adults completed in-lab usability testing of Thought Challenger, which comprised two interactions with the app. Learnability was measured via completion times, error rates, and psychologist ratings of user entries in the app; learning performance was measured via a test of CT knowledge and skills. Nonparametric tests were conducted to evaluate the difference between individuals with no or mild depression to those with moderate to severe depression, as well as differences in completion times and pre- and posttests. Results Across the two interactions, the majority of completion times were found to be acceptable (5 min or less), with minimal errors (1.2%, 10/840) and successful completion of CT thought records. Furthermore, CT knowledge and skills significantly improved after the initial use of Thought Challenger (P=.009). Conclusions The learning objectives for Thought Challenger during initial uses were successfully met in an evaluation with likely end users. The findings therefore suggest that apps are capable of providing users with opportunities for learning of intervention skills. PMID:28801301

Using three-dimensional-computerized tomography as a diagnostic tool for temporo-mandibular joint ankylosis: a case report.

PubMed

Kao, S Y; Chou, J; Lo, J; Yang, J; Chou, A P; Joe, C J; Chang, R C

1999-04-01

Roentgenographic examination has long been a useful diagnostic tool for temporo-mandibular joint (TMJ) disease. The methods include TMJ tomography, panoramic radiography and computerized tomography (CT) scan with or without injection of contrast media. Recently, three-dimensional CT (3D-CT), reconstructed from the two-dimensional image of a CT scan to simulate the soft tissue or bony structure of the real target, was proposed. In this report, a case of TMJ ankylosis due to traumatic injury is presented. 3D-CT was employed as one of the presurgical roentgenographic diagnostic tools. The conventional radiographic examination including panoramic radiography and tomography showed lesions in both sides of the mandible. CT scanning further suggested that the right-sided lesion was more severe than that on the left. With 3D-CT image reconstruction the size and extent of the lesions were clearly observable. The decision was made to proceed with an initial surgical approach on the right side. With condylectomy and condylar replacement using an autogenous costochondral graft on the right side, the range of mouth opening improved significantly. In this case report, 3D-CT demonstrates its advantages as a tool for the correct and precise diagnosis of TMJ ankylosis.

Biomechanical aspects of initial intraosseous stability and implant design: a quantitative micro-morphometric analysis.

PubMed

Akça, Kivanç; Chang, Ting-Ling; Tekdemir, Ibrahim; Fanuscu, Mete I

2006-08-01

The objective of this biomechanical study was to explore the effect of bone micro-morphology on initial intraosseous stability of implants with different designs. Straumann and Astra Tech dental implants were placed into anterior and posterior regions of completely edentulous maxilla and mandible of a human cadaver. Experiments were undertaken to quantify initial implant stability and bone micro-morphology. Installation torque values (ITVs) and implant stability quotients (ISQs) were measured to determine initial intraosseous implant stability. For quantification of relative bone volume and micro-architecture, sectioned implant-bone and bone core specimens of each implant placement site were consecutively scanned and trabecular bone was analyzed in a micro-computed tomography (micro-CT) unit. Experimental outcomes were evaluated for correlations among implant designs, initial intraosseous implant stability and bone micro-structural parameters. ITVs correlated higher with bone volume fraction (BV/TV) than ISQs, at 88.1% and 68.9% levels, respectively. Correlations between ITVs and micro-morphometric parameters were significant at the 95% confidence level (P<0.05) while ISQs were not. Differences in ITVs, ISQs and BV/TV data in regards to implant designs used were not significant at the 95% confidence level (P>0.05). Bone micro-morphology has a prevailing effect over implant design on intraosseus initial implant stability, and ITV is more sensitive in terms of revealing biomechanical properties at the bone-implant interface in comparison with ISQ.

[A case of intragastric wall abscess formation during bevacizumab combined chemotherapy].

PubMed

Mori, Ayano; Kogawa, Takahiro; Arihara, Youhei; Abe, Masakazu; Tamura, Fumito; Abe, Seiichirou; Kukitsu, Takehiro; Ihara, Hideyuki; Sumiyoshi, Tetsuya; Yoshizaki, Naoto; Kondou, Hitoshi; Tsuji, Yasushi

2013-05-01

A 38-year-old man was given a diagnosis of as sigmoid colon cancer and underwent sigmoid colectomy. Post-operative pathological staging was stage IIIb. He then underwent adjuvant chemotherapy. One year and 4 months after the surgery, CT scans revealed multiple liver and lung metastases. He was given mFOLFOX6+bevacizumab, which was changed later to FOLFIRI+bevacizumab. After these chemotherapies, he was admitted to the hospital due to sudden abdominal pain and high grade fever. Obstructive jaundice was initially diagnosed, but detailed study of initial CT revealed intragastric wall abscess. After the drainage of the abscess, his conditions improved. We speculated that the abscess formation was caused by mucosal damage due to bevacizumab.

A Low Salinity Mystery in a Turbidity Current Measured During the Monterey Coordinated Canyon Experiment

NASA Astrophysics Data System (ADS)

Xu, J.; Wang, Z.; Wang, C.; Li, J.; Gwiazda, R.; Paull, C. K.; Maier, K. L.

2016-12-01

Conductivity-Temperature (CT) sensors are one of the most common instruments in oceanographic research that record water conductivity and temperature, two most important parameters of ocean waters from which salinity is computed. When used in super-high turbid water or flows (e.g. turbidity currents or slurries), however, the working principle of CT sensors suggests possibility of bias in conductivity measurements. In this study, a series of lab experiments were conducted to investigate how the presence of high-concentrated sediment particles influences the conductivity readings from an inductive CT sensor. The results provided evidence to challenge a long-held notion that the reduced conductivity often seen inside turbidity currents is an indication of fresh water presence.

Lung cancer mimicking lung abscess formation on CT images.

PubMed

Taira, Naohiro; Kawabata, Tsutomu; Gabe, Atsushi; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawasaki, Hidenori; Yamashiro, Toshimitsu; Ishikawa, Kiyoshi

2014-01-01

Male, 64 FINAL DIAGNOSIS: Lung pleomorphic carcinoma Symptoms: Cough • fever - Clinical Procedure: - Specialty: Oncology. Unusual clinical course. The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resembled a lung abscess on CT. We herein describe the case of 64-year-old male who was diagnosed with lung cancer using surgery. In this case, it was quite difficult to distinguish between the lung cancer and a lung abscess on CT images, and a lung abscess was initially suspected due to symptoms, such as fever and coughing, contrast-enhanced CT image findings showing a ring-enhancing mass in the right upper lobe and the patient's laboratory test results. However, a pathological diagnosis of lung cancer was confirmed according to the results of a rapid frozen section biopsy of the lesion. This case suggests that physicians should not suspect both a lung abscesses and malignancy in cases involving masses presenting as ring-enhancing lesions on contrast-enhanced CT.

Clinical impact of 18 F-FDG positron emission tomography/CT on adenoid cystic carcinoma of the head and neck.

PubMed

Jung, Ji-Hoon; Lee, Sang-Woo; Son, Seung Hyun; Kim, Choon-Young; Lee, Chang-Hee; Jeong, Ju Hye; Jeong, Shin Young; Ahn, Byeong-Cheol; Lee, Jaetae

2017-03-01

The purpose of this retrospective study was to assess the diagnostic value of 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT and the prognostic value of metabolic PET parameters in patients with adenoid cystic carcinoma of the head and neck (ACCHN). Forty patients with newly diagnosed ACCHN were enrolled in this study. We investigated the diagnostic value of 18 F-FDG PET/CT for detecting and staging compared to conventional CT. Kaplan-Meier survival analysis for progression-free survival (PFS) was performed with clinicopathological factors and metabolic PET parameters. The 18 F-FDG PET/CT showed comparable sensitivity (92.3%) to conventional CT for lesion detection, and changed staging and management plan in 6 patients (15.0%). Lower PFS rates were associated with advanced T classification, advanced TNM classification, high maximum standardized uptake value (SUVmax; >5.1), and high total lesion glycolysis (>40.1) of the primary tumor. The 18 F-FDG PET/CT can provide additional information for initial staging, and metabolic PET parameters may serve as prognostic factors of ACCHN. © 2016 Wiley Periodicals, Inc. Head Neck 39: 447-455, 2017. © 2016 Wiley Periodicals, Inc.

Evaluation of a new imaging tool for use with major trauma cases in the emergency department.

PubMed

Crönlein, Moritz; Holzapfel, Konstantin; Beirer, Marc; Postl, Lukas; Kanz, Karl-Georg; Pförringer, Dominik; Huber-Wagner, Stefan; Biberthaler, Peter; Kirchhoff, Chlodwig

2016-11-17

The aim of this study was to evaluate potential benefits of a new diagnostic software prototype (Trauma Viewer, TV) automatically reformatting computed tomography (CT) data on diagnostic speed and quality, compared to CT-image data evaluation using a conventional CT console. Multiple trauma CT data sets were analysed by one expert radiology and one expert traumatology fellow independently twice, once using the TV and once using the secondary conventional CT console placed in the CT control room. Actual analysis time and precision of diagnoses assessment were evaluated. The TV and CT-console results were compared respectively, but also a comparison to the initial multiple trauma CT reports assessed by emergency radiology fellows considered as the gold standard was performed. Finally, design and function of the Trauma Viewer were evaluated in a descriptive manner. CT data sets of 30 multiple trauma patients were enrolled. Mean time needed for analysis of one CT dataset was 2.43 min using the CT console and 3.58 min using the TV respectively. Thus, secondary conventional CT console analysis was on average 1.15 min shorter compared to the TV analysis. Both readers missed a total of 11 diagnoses using the secondary conventional CT console compared to 12 missed diagnoses using the TV. However, none of these overlooked diagnoses resulted in an Abbreviated Injury Scale (AIS) > 2 corresponding to life threatening injuries. Even though it took the two expert fellows a little longer to analyse the CT scans on the prototype TV compared to the CT console, which can be explained by the new user interface of the TV, our preliminary results demonstrate that, after further development, the TV might serve as a new diagnostic feature in the trauma room management. Its high potential to improve time and quality of CT-based diagnoses might help in fast decision making regarding treatment of severely injured patients.

Peripheral Quantitative CT (pQCT) Using a Dedicated Extremity Cone-Beam CT Scanner

PubMed Central

Muhit, A. A.; Arora, S.; Ogawa, M.; Ding, Y.; Zbijewski, W.; Stayman, J. W.; Thawait, G.; Packard, N.; Senn, R.; Yang, D.; Yorkston, J.; Bingham, C.O.; Means, K.; Carrino, J. A.; Siewerdsen, J. H.

2014-01-01

Purpose We describe the initial assessment of the peripheral quantitative CT (pQCT) imaging capabilities of a cone-beam CT (CBCT) scanner dedicated to musculoskeletal extremity imaging. The aim is to accurately measure and quantify bone and joint morphology using information automatically acquired with each CBCT scan, thereby reducing the need for a separate pQCT exam. Methods A prototype CBCT scanner providing isotropic, sub-millimeter spatial resolution and soft-tissue contrast resolution comparable or superior to standard multi-detector CT (MDCT) has been developed for extremity imaging, including the capability for weight-bearing exams and multi-mode (radiography, fluoroscopy, and volumetric) imaging. Assessment of pQCT performance included measurement of bone mineral density (BMD), morphometric parameters of subchondral bone architecture, and joint space analysis. Measurements employed phantoms, cadavers, and patients from an ongoing pilot study imaged with the CBCT prototype (at various acquisition, calibration, and reconstruction techniques) in comparison to MDCT (using pQCT protocols for analysis of BMD) and micro-CT (for analysis of subchondral morphometry). Results The CBCT extremity scanner yielded BMD measurement within ±2–3% error in both phantom studies and cadaver extremity specimens. Subchondral bone architecture (bone volume fraction, trabecular thickness, degree of anisotropy, and structure model index) exhibited good correlation with gold standard micro-CT (error ~5%), surpassing the conventional limitations of spatial resolution in clinical MDCT scanners. Joint space analysis demonstrated the potential for sensitive 3D joint space mapping beyond that of qualitative radiographic scores in application to non-weight-bearing versus weight-bearing lower extremities and assessment of phalangeal joint space integrity in the upper extremities. Conclusion The CBCT extremity scanner demonstrated promising initial results in accurate pQCT analysis from images acquired with each CBCT scan. Future studies will include improved x-ray scatter correction and image reconstruction techniques to further improve accuracy and to correlate pQCT metrics with known pathology. PMID:25076823

Computed tomography and clinical outcome in patients with severe traumatic brain injury.

PubMed

Stenberg, Maud; Koskinen, Lars-Owe D; Jonasson, Per; Levi, Richard; Stålnacke, Britt-Marie

2017-01-01

To study: (i) acute computed tomography (CT) characteristics and clinical outcome; (ii) clinical course and (iii) Corticosteroid Randomisation after Significant Head Injury acute calculator protocol (CRASH) model and clinical outcome in patients with severe traumatic brain injury (sTBI). Initial CT (CT i ) and CT 24 hours post-trauma (CT 24 ) were evaluated according to Marshall and Rotterdam classifications. Rancho Los Amigos Cognitive Scale-Revised (RLAS-R) and Glasgow Outcome Scale Extended (GOSE) were assessed at three months and one year post-trauma. The prognostic value of the CRASH model was evaluated. Thirty-seven patients were included. Marshall CT i and CT 24 were significantly correlated with RLAS-R at three months. Rotterdam CT 24 was significantly correlated with GOSE at three months. RLAS-R and the GOSE improved significantly from three months to one year. CRASH predicted unfavourable outcome at six months for 81% of patients with bad outcome and for 85% of patients with favourable outcome according to GOSE at one year. Neither CT nor CRASH yielded clinically useful predictions of outcome at one year post-injury. The study showed encouragingly many instances of significant recovery in this population of sTBI. The combination of lack of reliable prognostic indicators and favourable outcomes supports the case for intensive acute management and rehabilitation as the default protocol in the cases of sTBI.

The influence of interpreters' professional background and experience on the interpretation of multimodality imaging of pulmonary lesions using 18F-3'-deoxy-fluorothymidine and 18F-fluorodeoxyglucose PET/CT.

PubMed

Xu, Bai-xuan; Liu, Chang-bin; Wang, Rui-min; Shao, Ming-zhe; Fu, Li-ping; Li, Yun-gang; Tian, Jia-he

2013-01-01

Based on the results of a recently accomplished multicenter clinical trial for the incremental value of a dual-tracer (18F-FDG and 18F-FLT), dual-modality (PET and CT) imaging in the differential diagnosis of pulmonary lesions, we investigate some issues that might affect the image interpretation and result reporting. The images were read in two separate sessions. Firstly the images were read and reported by physician(s) of the imaging center on completion of each PET/CT scanning. By the end of MCCT, all images collected during the trial were re-read by a collective of readers in an isolated, blinded, and independent way. One hundred sixty two patients successfully passed the data verification and entered into the final analysis. The primary reporting result showed adding 18F-FDG image information did not change the clinical performance much in sensitivity, specifity and accuracy, but the ratio between SUVFLT and SUVFDG did help the differentiation efficacy among the three subgroups of patients. The collective reviewing result showed the diagnostic achievement varied with reading strategies. ANOVA indicated significant differences among (18)F-FDG, (18)F-FLT in SUV (F = 14.239, p = 0.004). CT had almost the same diagnostic performance as 18F-FLT. When the 18F-FDG, 18F-FLT and CT images read in pair, both diagnostic sensitivity and specificity improved. The best diagnostic figures were obtained in full-modality strategy, when dual-tracer PET worked in combination with CT. With certain experience and training both radiologists and nuclear physicians are qualified to read and to achieve the similar diagnostic accuracy in PET/CT study. Making full use of modality combination and selecting right criteria seems more practical than professional back ground and personal experience in the new hybrid imaging technology, at least when novel tracer or application is concerned.

Iatrogenic radiation exposure to patients with early onset spine and chest wall deformities.

PubMed

Khorsand, Derek; Song, Kit M; Swanson, Jonathan; Alessio, Adam; Redding, Gregory; Waldhausen, John

2013-08-01

Retrospective cohort series. Characterize average iatrogenic radiation dose to a cohort of children with thoracic insufficiency syndrome (TIS) during assessment and treatment at a single center with vertically expandable prosthetic titanium rib. Children with TIS undergo extensive evaluations to characterize their deformity. No standardized radiographical evaluation exists, but all reports use extensive imaging. The source and level of radiation these patients receive is not currently known. We evaluated a retrospective consecutive cohort of 62 children who had surgical treatment of TIS at our center from 2001-2011. Typical care included obtaining serial radiographs, spine and chest computed tomographic (CT) scans, ventilation/perfusion scans, and magnetic resonance images. Epochs of treatment were divided into time of initial evaluation to the end of initial vertically expandable prosthetic titanium rib implantation with each subsequent epoch delineated by the next surgical intervention. The effective dose for each examination was estimated within millisieverts (mSv). Plain radiographs were calculated from references. Effective dose was directly estimated for CT scans since 2007 and an average of effective dose from 2007-2011 was used for scans before 2007. Effective dose from fluoroscopy was directly estimated. All doses were reported in mSv. A cohort of 62 children had a total of 447 procedures. There were a total of 290 CT scans, 4293 radiographs, 147 magnetic resonance images, and 134 ventilation/perfusion scans. The average accumulated effective dose was 59.6 mSv for children who had completed all treatment, 13.0 mSv up to initial surgery, and 3.2 mSv for each subsequent epoch of treatment. CT scans accounted for 74% of total radiation dose. Children managed for TIS using a consistent protocol received iatrogenic radiation doses that were on average 4 times the estimated average US background radiation exposure of 3 mSv/yr. CT scans comprised 74% of the total dose. 3.

Study of CT Scan Flooding System at High Temperature and Pressure

NASA Astrophysics Data System (ADS)

Chen, X. Y.

2017-12-01

CT scan flooding experiment can scan micro-pore in different flooding stages by the use of CT scan technology, without changing the external morphology and internal structure of the core, and observe the distribution characterization in pore medium of different flooding fluid under different pressure.thus,it can rebuilt the distribution images of oil-water distribution in different flooding stages. However,under extreme high pressure and temperature conditions,the CT scan system can not meet the requirements. Container of low density materials or thin shell can not resist high pressure,while high density materials or thick shell will cause attenuation and scattering of X-ray. The experiment uses a simple Ct scanning systems.X ray from a point light source passing trough a micro beryllium shell on High pressure stainless steal container,continuously irradiates the core holder that can continuously 360° rotate along the core axis. A rare earth intensifying screen behind the core holder emitting light when irradiated with X ray can show the core X ray section image. An optical camera record the core X ray images through a transparency high pressure glazing that placed on the High pressure stainless steal container.Thus,multiple core X ray section images can reconstruct the 3D core reconstruction after a series of data processing.The experiment shows that both the micro beryllium shell and rare earth intensifying screen can work in high temperature and high pressure environment in the stainless steal container. This way that X-ray passes through a thin layer of micro beryllium shell , not high pressure stainless steal shell,avoid the attenuation and scattering of X-ray from the container shell,while improving the high-pressure experiment requirements.

Low-voltage chest CT: another way to reduce the radiation dose in asbestos-exposed patients.

PubMed

Macía-Suárez, D; Sánchez-Rodríguez, E; Lopez-Calviño, B; Diego, C; Pombar, M

2017-09-01

To assess whether low voltage chest computed tomography (CT) can be used to successfully diagnose disease in patients with asbestos exposure. Fifty-six former employees of the shipbuilding industry, who were candidates to receive a standard-dose chest CT due to their occupational exposure to asbestos, underwent a routine CT. Immediately after this initial CT, they underwent a second acquisition using low-dose chest CT parameters, based on a low potential (80 kV) and limited tube current. The findings of the two CT protocols were compared based on typical diseases associated with asbestos exposure. The kappa coefficient for each parameter and for an overall rating (grouping them based on mediastinal, pleural, and pulmonary findings) were calculated in order to test for correlations between the two protocols. A good correlation between routine and low-dose CT was demonstrated for most parameters with a mean radiation dose reduction of up to 83% of the effective dose based on the dose-length product between protocols. Low-dose chest CT, based on a limited tube potential, is useful for patients with an asbestos exposure background. Low-dose chest CT can be successfully used to minimise the radiation dose received by patients, as this protocol produced an estimated mean effective dose similar to that of an abdominal or pelvis plain film. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

CTEQ-TEA parton distribution functions and HERA Run I and II combined data

NASA Astrophysics Data System (ADS)

Hou, Tie-Jiun; Dulat, Sayipjamal; Gao, Jun; Guzzi, Marco; Huston, Joey; Nadolsky, Pavel; Pumplin, Jon; Schmidt, Carl; Stump, Daniel; Yuan, C.-P.

2017-02-01

We analyze the impact of the recent HERA Run I +II combination of inclusive deep inelastic scattering cross-section data on the CT14 global analysis of parton distribution functions (PDFs). New PDFs at next-to-leading order and next-to-next-to-leading order, called CT14 HERA 2 , are obtained by a refit of the CT14 data ensembles, in which the HERA Run I combined measurements are replaced by the new HERA Run I +II combination. The CT14 functional parametrization of PDFs is flexible enough to allow good descriptions of different flavor combinations, so we use the same parametrization for CT14 HERA 2 but with an additional shape parameter for describing the strange quark PDF. We find that the HERA I +II data can be fit reasonably well, and both CT14 and CT14 HERA 2 PDFs can describe equally well the non-HERA data included in our global analysis. Because the CT14 and CT14 HERA 2 PDFs agree well within the PDF errors, we continue to recommend CT14 PDFs for the analysis of LHC Run 2 experiments.

Dissecting aneurysm of arch and descending thoracic aorta presenting as a left sided hemorrhagic pleural effusion

PubMed Central

Shamim, Shelley; Thakur, Sumitra Basu; Sengupta, Amitava; Bhattacharyya, Sujit Kumar; Sit, Niranjan

2010-01-01

The most common cause of massive hemorrhagic effusion is malignancy. Herein we present a case of dissecting aneurysm of descending thoracic aorta presenting initially with shortness of breath due to left sided massive pleural effusion. Effusion was hemorrhagic in nature with high hematocrit value. CT scan of thorax with CT angiogram was done and that revealed the diagnosis. PMID:21139725

(68)Ga-PSMA-11 PET/CT: a new technique with high potential for the radiotherapeutic management of prostate cancer patients.

PubMed

Sterzing, Florian; Kratochwil, Clemens; Fiedler, Hannah; Katayama, Sonja; Habl, Gregor; Kopka, Klaus; Afshar-Oromieh, Ali; Debus, Jürgen; Haberkorn, Uwe; Giesel, Frederik L

2016-01-01

Radiotherapy is the main therapeutic approach besides surgery of localized prostate cancer. It relies on risk stratification and exact staging. This report analyses the potential of [(68)Ga]Glu-urea-Lys(Ahx)-HBED-CC ((68)Ga-PSMA-11), a new positron emission tomography (PET) tracer targeting prostate-specific membrane antigen (PSMA) for prostate cancer staging and individualized radiotherapy planning. A cohort of 57 patients with prostate cancer scanned with (68)Ga-PSMA-11 PET/CT for radiotherapy planning was retrospectively reviewed; 15 patients were at initial diagnosis and 42 patients at time of biochemical recurrence. Staging results of conventional imaging, including bone scintigraphy, CT or MRI, were compared with (68)Ga-PSMA ligand PET/CT results and the influence on radiotherapeutic management was quantified. (68)Ga-PSMA ligand PET/CT had a dramatic impact on radiotherapy application in the presented cohort. In 50.8 % of the cases therapy was changed. The presented imaging technique of (68)Ga-PSMA PET/CT could be a key technology for individualized radiotherapy management in prostate cancer.

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (FDG PET/CT) Findings in an Unusual Case of Multiple Myeloma Presenting with a Large Extra-Axial Intracranial Mass.

PubMed

Ayaz, Sevin; Ayaz, Ümit Yaşar

2016-01-01

We aimed to present unusual cranial FDG PET/CT findings of a 56-year-old female with multiple myeloma (MM). Plain CT images revealed a lytic lesion in the right parietal bone, filled with an oval-shaped, large, extra-axial, extradural, intracranial mass which measured 75×75×40 mm and had smooth borders. The right parietal lobe was compressed by the mass. The maximum standardized uptake value (SUV max ) of the mass lesion was 8.94 on FDG PET/CT images. Multiple lytic lesions with an increased uptake were also detected in other calvarial bones, in several vertebras and in the proximal left femur. After seven months, a control FDG PET/CT following radiotherapy and chemotherapy revealed almost complete regression of the right parietal extra-axial mass lesion. The number, size and metabolism of lytic lesions in other bones also decreased. FDG PET/CT was useful for an initial evaluation of MM lesions and was effective in monitoring the response of these lesions to therapy.

Development of Compact Toroid Injector for C-2 FRCs

NASA Astrophysics Data System (ADS)

Matsumoto, Tadafumi; Sekiguchi, Junichi; Asai, Tomohiko; Gota, Hiroshi; Garate, Eusebio; Allfrey, Ian; Valentine, Travis; Smith, Brett; Morehouse, Mark; TAE Team

2014-10-01

Collaborative research project with Tri Alpha Energy has been started and we have developed a new compact toroid (CT) injector for the C-2 device, mainly for fueling field-reversed configurations (FRCs). The CT is formed by a magnetized coaxial plasma-gun (MCPG), which consists of coaxial cylinder electrodes; a spheromak-like plasma is generated by discharge and pushed out from the gun by Lorentz force. The inner diameter of outer electrode is 83.1 mm and the outer diameter of inner electrode is 54.0 mm. The surface of the inner electrode is coated with tungsten in order to reduce impurities coming out from the electrode. The bias coil is mounted inside of the inner electrode. We have recently conducted test experiments and achieved a supersonic CT translation speed of up to ~100 km/s. Other typical plasma parameters are as follows: electron density ~ 5 × 1021 m-3, electron temperature ~ 40 eV, and the number of particles ~0.5-1.0 × 1019. The CT injector is now planned to be installed on C-2 and the first CT injection experiment will be conducted in the near future. The detailed MCPG design as well as the test experimental results will be presented.

The Power of Computer-aided Tomography to Investigate Marine Benthic Communities

EPA Science Inventory

Utilization of Computer-aided-Tomography (CT) technology is a powerful tool to investigate benthic communities in aquatic systems. In this presentation, we will attempt to summarize our 15 years of experience in developing specific CT methods and applications to marine benthic co...

Feasibility study using MRI and two optical CT scanners for readout of polymer gel and PresageTM

NASA Astrophysics Data System (ADS)

Svensson, H.; Skyt, P. S.; Ceberg, S.; Doran, S.; Muren, L. P.; Balling, P.; Petersen, J. B. B.; Bäck, S. Å. J.

2013-06-01

The aim of this study was to compare the conventional combination of three-dimensional dosimeter (nPAG gel) and readout method (MRI) with other combinations of three-dimensional dosimeters (nPAG gel/PresageTM) and readout methods (optical CT scanners). In the first experiment, the dose readout of a gel irradiated with a four field-box technique was performed with both an Octopus IQ scanner and MRI. It was seen that the MRI readout agreed slightly better to the TPS. In another experiment, a gel and a PresageTM sample were irradiated with a VMAT field and read out using MRI and a fast laser scanner, respectively. A comparison between the TPS and the volumes revealed that the MRI/gel readout had closer resemblance to the TPS than the optical CT/PresageTM readout. There are clearly potential in the evaluated optical CT scanners, but more time has to be invested in the particular scanning scenario than was possible in this study.

Paediatric CT protocol optimisation: a design of experiments to support the modelling and optimisation process.

PubMed

Rani, K; Jahnen, A; Noel, A; Wolf, D

2015-07-01

In the last decade, several studies have emphasised the need to understand and optimise the computed tomography (CT) procedures in order to reduce the radiation dose applied to paediatric patients. To evaluate the influence of the technical parameters on the radiation dose and the image quality, a statistical model has been developed using the design of experiments (DOE) method that has been successfully used in various fields (industry, biology and finance) applied to CT procedures for the abdomen of paediatric patients. A Box-Behnken DOE was used in this study. Three mathematical models (contrast-to-noise ratio, noise and CTDI vol) depending on three factors (tube current, tube voltage and level of iterative reconstruction) were developed and validated. They will serve as a basis for the development of a CT protocol optimisation model. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

TH-B-207B-01: Optimizing Pediatric CT in the Emergency Department

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dodge, C.

This imaging educational program will focus on solutions to common pediatric image quality optimization challenges. The speakers will present collective knowledge on best practices in pediatric imaging from their experience at dedicated children’s hospitals. One of the most commonly encountered pediatric imaging requirements for the non-specialist hospital is pediatric CT in the emergency room setting. Thus, this educational program will begin with optimization of pediatric CT in the emergency department. Though pediatric cardiovascular MRI may be less common in the non-specialist hospitals, low pediatric volumes and unique cardiovascular anatomy make optimization of these techniques difficult. Therefore, our second speaker willmore » review best practices in pediatric cardiovascular MRI based on experiences from a children’s hospital with a large volume of cardiac patients. Learning Objectives: To learn techniques for optimizing radiation dose and image quality for CT of children in the emergency room setting. To learn solutions for consistently high quality cardiovascular MRI of children.« less

200 MeV Proton Radiography Studies with a Hand Phantom Using a Prototype Proton CT Scanner

PubMed Central

Plautz, Tia; Bashkirov, V.; Feng, V.; Hurley, F.; Johnson, R.P.; Leary, C.; Macafee, S.; Plumb, A.; Rykalin, V.; Sadrozinski, H.F.-W.; Schubert, K.; Schulte, R.; Schultze, B.; Steinberg, D.; Witt, M.; Zatserklyaniy, A.

2014-01-01

Proton radiography has applications in patient alignment and verification procedures for proton beam radiation therapy. In this paper, we report an experiment which used 200 MeV protons to generate proton energy-loss and scattering radiographs of a hand phantom. The experiment used the first-generation proton CT scanner prototype, which was installed on the research beam line of the clinical proton synchrotron at Loma Linda University Medical Center (LLUMC). It was found that while both radiographs displayed anatomical details of the hand phantom, the energy-loss radiograph had a noticeably higher resolution. Nonetheless, scattering radiography may yield more contrast between soft and bone tissue than energy-loss radiography, however, this requires further study. This study contributes to the optimization of the performance of the next-generation of clinical proton CT scanners. Furthermore, it demonstrates the potential of proton imaging (proton radiography and CT), which is now within reach of becoming available as a new, potentially low-dose medical imaging modality. PMID:24710156

Clinical utility of FDG PET/CT in acute complicated pyelonephritis-results from an observational study.

PubMed

Wan, Chih-Hsing; Tseng, Jing-Ren; Lee, Ming-Hsun; Yang, Lan-Yan; Yen, Tzu-Chen

2018-03-01

Acute complicated pyelonephritis (ACP) is an upper urinary tract infection associated with coexisting urinary tract abnormalities or medical conditions that could predispose to serious outcomes or treatment failures. Although CT and magnetic resonance imaging (MRI) are frequently used in patients with ACP, the clinical value of 18 F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG PET/CT) has not been systematically investigated. This single-center retrospective study was designed to evaluate the potential usefulness of FDG PET/CT in patients with ACP. Thirty-one adult patients with ACP who underwent FDG PET/CT were examined. FDG PET/CT imaging characteristics, including tracer uptake patterns, kidney volumes, and extrarenal imaging findings, were reviewed in combination with clinical data and conventional imaging results. Of the 31 patients, 19 (61%) showed focal FDG uptake. The remaining 12 study participants showed a diffuse FDG uptake pattern. After volumetric approximation, the affected kidneys were found to be significantly enlarged. Patients who showed a focal uptake pattern had a higher frequency of abscess formation requiring drainage. ACP patients showing diffuse tracer uptake patterns had a more benign clinical course. Seven patients had suspected extrarenal coinfections, and FDG PET/CT successfully confirmed the clinical suspicion in five cases. FDG PET/CT was as sensitive as CT in identifying the six patients (19%) who developed abscesses. Notably, FDG PET/CT findings caused a modification to the initial antibiotic regimen in nine patients (29%). FDG PET/CT may be clinically useful in the assessment of patients with ACP who have a progressive disease course.

3D intrathoracic region definition and its application to PET-CT analysis

NASA Astrophysics Data System (ADS)

Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W.; Higgins, William E.

2014-03-01

Recently developed integrated PET-CT scanners give co-registered multimodal data sets that offer complementary three-dimensional (3D) digital images of the chest. PET (positron emission tomography) imaging gives highly specific functional information of suspect cancer sites, while CT (X-ray computed tomography) gives associated anatomical detail. Because the 3D CT and PET scans generally span the body from the eyes to the knees, accurate definition of the intrathoracic region is vital for focusing attention to the central-chest region. In this way, diagnostically important regions of interest (ROIs), such as central-chest lymph nodes and cancer nodules, can be more efficiently isolated. We propose a method for automatic segmentation of the intrathoracic region from a given co-registered 3D PET-CT study. Using the 3D CT scan as input, the method begins by finding an initial intrathoracic region boundary for a given 2D CT section. Next, active contour analysis, driven by a cost function depending on local image gradient, gradient-direction, and contour shape features, iteratively estimates the contours spanning the intrathoracic region on neighboring 2D CT sections. This process continues until the complete region is defined. We next present an interactive system that employs the segmentation method for focused 3D PET-CT chest image analysis. A validation study over a series of PET-CT studies reveals that the segmentation method gives a Dice index accuracy of less than 98%. In addition, further results demonstrate the utility of the method for focused 3D PET-CT chest image analysis, ROI definition, and visualization.

Assessment of Lymph Nodes and Prostate Status Using Early Dynamic Curves with (18)F-Choline PET/CT in Prostate Cancer.

PubMed

Mathieu, Cédric; Ferrer, Ludovic; Carlier, Thomas; Colombié, Mathilde; Rusu, Daniela; Kraeber-Bodéré, Françoise; Campion, Loic; Rousseau, Caroline

2015-01-01

Dynamic image acquisition with (18)F-Choline [fluorocholine (FCH)] PET/CT in prostate cancer is mostly used to overcome the bladder repletion, which could obstruct the loco-regional analysis. The aim of our study was to analyze early dynamic FCH acquisitions to define pelvic lymph node or prostate pathological status. Retrospective analysis was performed on 39 patients for initial staging (n = 18), or after initial treatment (n = 21). Patients underwent 10-min dynamic acquisitions centered on the pelvis, after injection of 3-4 MBq/kg of FCH. Whole-body images were acquired about 1 h after injection using a PET/CT GE Discovery LS (GE-LS) or Siemens Biograph mCT (mCT). Maximum and mean SUV according to time were measured on nodal and prostatic lesions. SUVmean was corrected for partial volume effect (PVEC) with suitable recovery coefficients. The status of each lesion was based on histological results or patient follow-up (>6 months). A Mann-Whitney test and ANOVA were used to compare mean and receiver operating characteristic (ROC) curve analysis. The median PSA was 8.46 ng/mL and the median Gleason score was 3 + 4. Ninety-two lesions (43 lymph nodes and 49 prostate lesions) were analyzed, including 63 malignant lesions. In early dynamic acquisitions, the maximum and mean SUV were significantly higher, respectively, on mCT and GE-LS, in malignant versus benign lesions (p < 0.001, p < 0.001). Mean SUV without PVEC, allowed better discrimination of benign from malignant lesions, in comparison with maximum and mean SUV (with PVEC), for both early and late acquisitions. For patients acquired on mCT, area under the ROC curve showed a trend to better sensitivity and specificity for early acquisitions, compared with late acquisitions (SUVmax AUC 0.92 versus 0.85, respectively). Assessment of lymph nodes and prostate pathological status with early dynamic imaging using PET/CT FCH allowed prostate cancer detection in situations where proof of malignancy is difficult to obtain.

Computed tomography of the abnormal thymus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baron, R.L.; Lee, J.K.T.; Sagel, S.S.

1982-01-01

Computed tomography (CT) should be the imaging method of choice following plain chest radiographs when a suspected thymic abnormality requires further evaluation. Based upon a six-year experience, including the evaluation of 25 patients with thymic pathology, CT was found useful in suggesting or excluding a diagnosis of thymoma and in distinguishing thymic hyperplasis from thymoma in patients with myasthenia gravis. The thickness of the thymic lobes determined by CT was found to be a more accurate indicator of infiltrative disease (thymic hyperplasia and lymphoma) than the width. CT was helpful in differentiating benign thymic cysts from solid tumors, and inmore » defining the extent of a thymic neoplasms. On occasion, CT may suggest the specific histologic nature of a thymic lesion.« less

Trauma of the upper cervical spine: focus on vertical atlantoaxial dislocation.

PubMed

Pissonnier, M L; Lazennec, J Y; Renoux, J; Rousseau, M A

2013-10-01

Traumatic ligament injuries of the craniovertebral junction, either isolated or associated with bone avulsion or fracture, often lead to death. These injuries are rare and underrated but are increasingly seen in emergency departments due to the improvement in initial on-scene management of accidents. Vertical atlantoaxial dislocation (AAD) is a specific lesion that was barely reported. Based on our experience, our goal was to systematically investigate the prevalence and prognosis of traumatic vertical AAD and discuss its management. All cervical CT scans performed at our institution between 2006 and 2010 for cervical trauma in adults were retrospectively reviewed. Based on the measurement of lateral mass index (LMI), defined as the gap between C1 and C2 articular facets, we identified three cases of traumatic vertical AAD in 300 CT scans. Their medical records were investigated. The incidence of vertical AAD was 1% in the exposed population. One case was an isolated vertical AAD and two were associated with a type II odontoid fracture. We report the first case in the literature of unilateral vertical AAD. Two patients died rapidly; the survivor was treated with occipitocervical fixation. Specific maneuvers were used for immobilization and reduction. This study found a not insignificant incidence of vertical AAD and a high lethality rate. LMI appears to be a relevant radiological criterion for this diagnosis, for which traction is contraindicated. Associated neurological or vascular damage should be suspected and investigated. In our experience, spinal surgical fixation is required because of major instability.

Life-threatening gastrointestinal system bleeding in Hodgkin disease: multidetector CT findings and review of the literature.

PubMed

Akpinar, Erhan; Türkbey, Bariş; Cil, Barbaros Erhan; Canyiğit, Murat; Dündar, Ziya; Balkanci, Ferhun

2007-06-01

Acute lower gastrointestinal system (GIS) bleeding is a life-threatening condition. Immediate determination of the origin of the bleeding is crucial, since hemostatic management must be initiated as rapidly as possible. Colonoscopy, radionuclide studies, and conventional angiography are considered the most important methods for assessing the origin of the bleeding. There are few published reports about the feasibility of computed tomography (CT) in acute GIS bleeding. We present multidetector CT (MDCT) findings in a case of Hodgkin disease status one month post-chemotherapy (CHOP protocol; cyclophosphamide, doxorubicin, vincristine, prednisone) that presented with acute lower GIS bleeding.

Somatostatin receptor positron emission tomography/computed tomography (PET/CT) in the evaluation of opsoclonus-myoclonus ataxia syndrome.

PubMed

Joshi, Prathamesh; Lele, Vikram

2013-04-01

Opsoclonus-myoclonus ataxia (OMA) syndrome is the most common paraneoplastic neurological syndrome of childhood, associated with occult neuroblastoma in 20%-50% of all cases. OMA is the initial presentation of neuroblastoma in 1%-3% of children. Conventional radiological imaging approaches include chest radiography and abdominal computed tomography (CT). Nuclear medicine techniques, in form of (123)I/(131)I-metaiodobenzylguanidine (MIBG) scintigraphy have been incorporated in various diagnostic algorithms for evaluation of OMA. We describe use of somatostatin receptor PET/CT with (68)Gallium- DOTA-DPhe(1), Tyr(3)-octreotate (DOTATATE) in diagnosis of neuroblastoma in two cases of OMA.

The Potential for Conservation Tillage Adoption in the San Joaquin Valley, California: A Qualitative Study of Farmer Perspectives and Opportunities for Extension

PubMed Central

Bossange, Anne V.; Knudson, Kandace M.; Shrestha, Anil; Harben, Ronald; Mitchell, Jeffrey P.

2016-01-01

Conservation tillage (CT) systems have a number of potential benefits including lower crop production costs and the ability to reduce soil erosion that have made them common in several regions of the world. Although CT systems have been researched and successfully implemented on some farms in California’s San Joaquin Valley (SJV), overall adoption is low and the reasons for the region’s comparatively low rates of adoption are not known. In 2011, we conducted written surveys and interviews with SJV farmers to identify characteristics of farmers who adopt or do not adopt CT, to determine reasons for non-adoption of CT, and to learn how successful CT adoption takes place in the SJV. We found that a universally acceptable definition of CT needs to be developed in order for effective research, outreach and communication on CT. Our research, which examined CT adoption within the expected progression of the diffusion of innovation model, suggested that larger and less diverse farms were more likely to use CT. Most farmers expressed transition to CT as a continuous learning process. Further, we conclude that gaining meaningful experience with CT practices by researchers in the local context is also a large component of successful adoption. PMID:27907196

Pediatric pancreatic trauma: trending toward nonoperative management?

PubMed

Cuenca, Alex G; Islam, Saleem

2012-11-01

Pancreatic trauma is rare in children and optimal care has not been defined. We undertook this study to review the cumulative experience from three centers. After obtaining Institutional Review Board approval at each site, the trauma registries of three institutions were searched for pancreatic injuries. The charts were reviewed and data pertaining to demographics, hospital course, and outcome were obtained and analyzed. During the study period, a total of 79 pancreatic injuries were noted. The most common mechanism of injury was motor vehicle crash (44%) followed by child abuse (11%) and bicycle crashes (11%). Computed tomographic (CT) scans were obtained in 95 per cent with peripancreatic fluid the most common finding. Median Injury Severity Score (ISS) was 9, whereas median organ injury score was 2, and a higher grade correlated with need for operation (P = 0.001). Pancreatic operations were performed in 32 patients, whereas nonoperative management was noted in 47 cases. We noted no differences in length of stay, age, ISS, or initial blood pressure in operative versus nonoperatively managed cases. Pancreatic injuries were rare in children with trauma. CT scans were the most common method of diagnosis. Nonoperative management appeared to be safe and was more common, especially for the lower grade injuries.

A strain energy filter for 3D vessel enhancement with application to pulmonary CT images.

PubMed

Xiao, Changyan; Staring, Marius; Shamonin, Denis; Reiber, Johan H C; Stolk, Jan; Stoel, Berend C

2011-02-01

The traditional Hessian-related vessel filters often suffer from detecting complex structures like bifurcations due to an over-simplified cylindrical model. To solve this problem, we present a shape-tuned strain energy density function to measure vessel likelihood in 3D medical images. This method is initially inspired by established stress-strain principles in mechanics. By considering the Hessian matrix as a stress tensor, the three invariants from orthogonal tensor decomposition are used independently or combined to formulate distinctive functions for vascular shape discrimination, brightness contrast and structure strength measuring. Moreover, a mathematical description of Hessian eigenvalues for general vessel shapes is obtained, based on an intensity continuity assumption, and a relative Hessian strength term is presented to ensure the dominance of second-order derivatives as well as suppress undesired step-edges. Finally, we adopt the multi-scale scheme to find an optimal solution through scale space. The proposed method is validated in experiments with a digital phantom and non-contrast-enhanced pulmonary CT data. It is shown that our model performed more effectively in enhancing vessel bifurcations and preserving details, compared to three existing filters. Copyright © 2010 Elsevier B.V. All rights reserved.

Implementation of a CT Scan Practice Guideline for Pediatric Trauma Patients Reduces Unnecessary Scans Without Impacting Outcomes.

PubMed

McGrew, Patrick R; Chestovich, Paul J; Fisher, Jay D; Kuhls, Deborah A; Fraser, Douglas R; Patel, Purvi P; Katona, Chad W; Saquib, Syed; Fildes, John J

2018-05-04

Computed Tomography (CT) scans are useful in the evaluation of trauma patients, but are costly and pose risks from ionizing radiation in children. Recent literature has demonstrated the utility of CT scan guidelines in the management of pediatric trauma. This study objective is to review our treatment of pediatric blunt trauma patients and evaluate CT utilization before and after CT-guideline implementation. Our Pediatric Level 2 Trauma Center (TC) implemented a CT scan practice guideline for pediatric trauma patients in March 2014. The guideline recommended for or against CT of the head and abdomen/pelvis utilizing published criteria from the Pediatric Emergency Care and Research Network (PECARN). There was no chest CT guideline. We reviewed all pediatric trauma patients for CT scans obtained during initial evaluation before and after guideline implementation, excluding inpatient scans. The Trauma Registry Database was queried to include all pediatric (age<15) trauma patients seen in our TC from 2010-2016, excluding penetrating mechanism and deaths in the TC. Scans were considered positive if organ injury was detected. Primary outcome was the proportion of patients undergoing CT and percent positive CTs. Secondary outcomes were hospital length of stay (LOS), readmissions, and mortality. Categorical and continuous variables were analyzed with Chi-square and Wilcoxon rank-sum tests, respectively. P<0.05 was considered significant. We identified 1934 patients: 1106 pre- and 828 post-guideline. Absolute reductions in head, chest, and abdomen/pelvis CT scans were 17.7%, 11.5%, and 18.8% respectively (p<0.001). Percent positive head CTs were equivalent, but percent positive chest and abdomen CT increased after implementation. Secondary outcomes were unchanged. Implementation of a pediatric CT guideline significantly decreases CT utilization, reducing the radiation exposure without a difference in outcome. Trauma centers treating pediatric patients should adopt similar guidelines to decrease unnecessary CT scans in children. Level IV, Therapeutic Study.

Robot-Assisted Mckeown Esophagectomy is Feasible After Neoadjuvant Chemoradiation. Our Initial Experience.

PubMed

Goel, Ashish; Shah, Swati H; Selvakumar, Veda Padma Priya; Garg, Shubha; Kumar, Kapil

2018-02-01

Neoadjuvant chemoradiation has become the standard of care for esophageal cancer, especially for middle third esophageal lesions and those with squamous histology. Although more and more thoracic surgeons and surgical oncologists have now shifted to video-assisted and robot-assisted thoracoscopic esophagectomy; there is still limited experience for the use of minimal-assisted approaches in patients undergoing surgery after neoadjuvant chemoradiation. Most surgeons have concerns of feasibility, safety, and oncological outcomes as well as issues related to difficult learning curve in adopting robotic esophagectomy in patients after chemoradiation. We present our initial experience of Robot-Assisted Mckeown Esophagectomy in 27 patients after neoadjuvant chemoradiation, from May 2013 to October 2014. All patients underwent neoadjuvant chemoradiation to a dose of 50.4 Gy/25Fr with concurrent weekly cisplatin, followed by reassessment with clinical examination and repeat FDG PET/CT 6 weeks after completion of chemoradiation. Patients with progressive disease underwent palliative chemotherapy while patients with either partial or significant response to chemoradiation underwent Robot-Assisted Mckeown Esophagectomy with esophageal replacement by gastric conduit and esophagogastric anastomosis in the left neck. Out of 27 patients, 92.5 % patients had stage cT3/T4 tumours and node-positive disease in 48.1 % on imaging. Most patients were middle thoracic esophageal cancers (23/27), with squamous histology in all except for one. All patients received neoadjuvant chemoradiation and subsequently underwent Robot Assisted Mckeown Esophagectomy. The average time for robot docking, thoracic mobilization and total surgical procedure was 13.2, 108.4 and 342.7 min, respectively. The procedure was well tolerated by all patients with only one case of peri-operative mortality. Average ICU stay was 6.35 days (range 3-9 days). R0 resection rate of 96.3 % and average lymph node yield of 18 could be achieved. Pathological node negativity rate (pN0) and complete response (pCR) were 66.6 and 44.4 %, respectively. In the initial cases, four patients had to be converted to open due technical reasons or intraoperative complications. The present study, with shorter operative times, similar ICU stay, overall low morbidity, and mortality and optimal oncological outcomes suggest that robot-assisted thoracic mobilization of esophagus in patients with prior chemoradiation is feasible and safe with acceptable oncological outcomes. It has a shorter learning curve and hence allows for a transthoracic minimally invasive transthoracic esophagectomy to more and more patients, otherwise unfit for conventional approach.

A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Lorraine; Cox, Jennifer; Faculty of Health Sciences, University of Sydney, Sydney, New South Wales

2015-09-15

The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 daysmore » post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm{sup 3} (4–118) and CT2ch: median 16 cm{sup 3}, (2–99), (P = 0.01), but no significant volume reduction thereafter. Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence.« less

The Swedish new variant of Chlamydia trachomatis: genome sequence, morphology, cell tropism and phenotypic characterization

PubMed Central

Unemo, Magnus; Seth-Smith, Helena M. B.; Cutcliffe, Lesley T.; Skilton, Rachel J.; Barlow, David; Goulding, David; Persson, Kenneth; Harris, Simon R.; Kelly, Anne; Bjartling, Carina; Fredlund, Hans; Olcén, Per; Thomson, Nicholas R.; Clarke, Ian N.

2010-01-01

Chlamydia trachomatis is a major cause of bacterial sexually transmitted infections worldwide. In 2006, a new variant of C. trachomatis (nvCT), carrying a 377 bp deletion within the plasmid, was reported in Sweden. This deletion included the targets used by the commercial diagnostic systems from Roche and Abbott. The nvCT is clonal (serovar/genovar E) and it spread rapidly in Sweden, undiagnosed by these systems. The degree of spread may also indicate an increased biological fitness of nvCT. The aims of this study were to describe the genome of nvCT, to compare the nvCT genome to all available C. trachomatis genome sequences and to investigate the biological properties of nvCT. An early nvCT isolate (Sweden2) was analysed by genome sequencing, growth kinetics, microscopy, cell tropism assay and antimicrobial susceptibility testing. It was compared with relevant C. trachomatis isolates, including a similar serovar E C. trachomatis wild-type strain that circulated in Sweden prior to the initially undetected expansion of nvCT. The nvCT genome does not contain any major genetic polymorphisms – the genes for central metabolism, development cycle and virulence are conserved – or phenotypic characteristics that indicate any altered biological fitness. This is supported by the observations that the nvCT and wild-type C. trachomatis infections are very similar in terms of epidemiological distribution, and that differences in clinical signs are only described, in one study, in women. In conclusion, the nvCT does not appear to have any altered biological fitness. Therefore, the rapid transmission of nvCT in Sweden was due to the strong diagnostic selective advantage and its introduction into a high-frequency transmitting population. PMID:20093289

PET/CT-guided interventions: Indications, advantages, disadvantages and the state of the art.

PubMed

Cazzato, Roberto Luigi; Garnon, Julien; Shaygi, Behnam; Koch, Guillaume; Tsoumakidou, Georgia; Caudrelier, Jean; Addeo, Pietro; Bachellier, Philippe; Namer, Izzie Jacques; Gangi, Afshin

2018-02-01

Positron emission tomography/computed tomography (PET/CT) represents an emerging imaging guidance modality that has been applied to successfully guide percutaneous procedures such as biopsies and tumour ablations. The aim of the present narrative review is to report the indications, advantages and disadvantages of PET/CT-guided procedures in the field of interventional oncology and to briefly describe the experience gained with this new emerging technique while performing biopsies and tumor ablations.

Clinical experience with infliximab biosimilar Remsima (CT-P13) in inflammatory bowel disease patients

PubMed Central

Jahnsen, Jørgen

2016-01-01

Many reference biological therapies have now reached or are near to patent expiry, and therefore a number of biosimilars have been or will be developed. The term biosimilar can be defined as a biotherapeutic product that is similar in efficacy, safety and quality to the licensed reference product. Biosimilars may lead to a reduced price and significant cost savings for the health community and hopefully more patients globally will have easier access to biological therapy when indicated. CT-P13, which is a TNF-alfa inhibitor, is the first monoclonal antibody biosimilar being used in clinical practice. The drug is approved for all indications as an innovator product although clinical efficacy has only been demonstrated in rheumatic diseases. Until now the number of patients with inflammatory bowel disease (IBD) treated with CT-P13 is confined, but experience is continuously growing. Based on current data, CT-P13 seems to be efficacious and generally well tolerated in IBD especially in patients who are naïve to biological therapy. Knowledge with regard to interchangeability between CT-P13 and the originator infliximab is however, still rather sparse and more data are desired. Immunogenicity and long-term safety related to CT-P13 are other areas of great importance and good and reliable postmarketing pharmacovigilance is therefore required in the coming years. PMID:27134662

Mechanisms of Radiation-Induced Bone Loss and Effect on Prostate Cancer Bone Metastases

DTIC Science & Technology

2012-06-01

Develop intravital multiphoton fluorescence microscopy (IVFM) for real-time imaging of osteocytes in calvariae of transgenic mice using i) GFP to...OT, OB counting) and in vivo bone imaging (months 6-10) 8 20 week old female C57Bl/6 mice (n=30) were used in this experiment. The mice were...divided into 2 groups. One group (group A, n=15) was imaged twice by microCT during the experiment that included a baseline microCT that was given 2 days

Expanding the Scope of an Automated Radiology Recommendation-Tracking Engine: Initial Experiences and Lessons Learned.

PubMed

Licurse, Mindy Y; Lalevic, Darco; Zafar, Hanna M; Schnall, Mitchell D; Cook, Tessa S

2017-04-01

An automated radiology recommendation-tracking engine for incidental focal masses in the liver, pancreas, kidneys, and adrenal glands was launched within our institution in July 2013. For 2 years, the majority of CT, MR, and US examination reports generated within our health system were mined by the engine. However, the need to expand the system beyond the initial four organs was soon identified. In July 2015, the second phase of the system was implemented and expanded to include additional anatomic structures in the abdomen and pelvis, as well as to provide non-radiology and non-imaging options for follow-up. The most frequent organs with incidental findings, outside of the original four, included the ovaries and the endometrium, which also correlated to the most frequently ordered imaging follow-up study of pelvic ultrasound and non-imaging follow-up study of endometrial biopsies, respectively. The second phase expansion has demonstrated new venues for augmenting and improving radiologist roles in optimal communication and management of incidental findings.

Malignant external otitis: the role of computed tomography and radionuclides in evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendelson, D.S.; Som, P.M.; Mendelson, M.H.

1983-12-01

Nine patients with malignant external otitis (MEO) were evaluated with Tc-99m bone scans, Ga-67 citrate scans, pluridirectional tomography, and computed tomographic (CT) scans in order to assess the role of each in the diagnosis and management of MEO. The Tc-99m and Ga-67 citrate scans were the most accurate studies in the initial identification of disease activity, while the return to normal or improvement of the Ga-67 citrate scan has been shown to correlate best with clinical resolution of MEO. CT demonstrated soft-tissue disease and central skull base osteomyelitis better than pluridirectional tomography. CT is excellent for localizing and following themore » progression of bone disease; however, because reossification of the skull base is a very slow process, CT cannot be used to follow accurately regression or inactivity of MEO affecting this area. CT is the best modality for following soft-tissue extension of MEO.« less

Deformable anatomical templates for brachytherapy treatment planning in radiotherapy of cervical cancer

NASA Astrophysics Data System (ADS)

Christensen, Gary E.; Williamson, Jeffrey F.; Chao, K. S. C.; Miller, Michael I.; So, F. B.; Vannier, Michael W.

1997-10-01

This paper describes a new method to register serial, volumetric x-ray computed tomography (CT) data sets for tracking soft-tissue deformation caused by insertion of intracavity brachytherapy applicators to treat cervical cancer. 3D CT scans collected from the same patient with and without a brachytherapy applicator are registered to aid in computation of the radiation dose to tumor and normal tissue. The 3D CT image volume of pelvic anatomy with the applicator. Initial registration is accomplished by rigid alignment of the pelvic bones and non-rigid alignment of gray scale CT data and hand segmentations of the vagina, cervix, bladder, and rectum. A viscous fluid transformation model is used for non-rigid registration to allow for local, non-linear registration of the vagina, cervix, bladder, and rectum without disturbing the rigid registration of the bony pelvis and adjacent structures. Results are presented in which two 3D CT data sets of the same patient - imaged with and without a brachytherapy applicator - are registered.

Correlation Between Findings of Multislice Helical Computed Tomography (CT), Endoscopic Examinations, Endovascular Procedures, and Surgery in Patients with Symptoms of Acute Gastrointestinal Bleeding

PubMed Central

Konecki, Dariusz; Pacho, Ryszard; Rowiński, Olgierd

2017-01-01

Summary Background Endoscopic methods (gastroscopy and colonoscopy) are considered fundamental for the diagnosis of gastrointestinal bleeding. In recent years, multidetector computed tomography (MDCT) has also gained importance in diagnosing gastrointestinal bleeding, particularly in hemodynamically unstable patients and in cases with suspected lower gastrointestinal tract bleeding. CT can detect both the source and the cause of active gastrointestinal bleeding, thereby expediting treatment initiation. Material/Methods The study group consisted of 16 patients with clinical symptoms of gastrointestinal bleeding in whom features of active bleeding were observed on CT. In all patients, bleeding was verified by means of other methods such as endoscopic examinations, endovascular procedures, or surgery. Results The bleeding source was identified on CT in all 16 patients. In 14 cases (87.5%), bleeding was confirmed by other methods. Conclusions CT is an efficient, fast, and readily available tool for detecting the location of acute gastrointestinal bleeding. PMID:29662594

Ultrasound-Guided Abrams Pleural Biopsy vs CT-Guided Tru-Cut Pleural Biopsy in Malignant Pleural Disease, a 3-Year Follow-up Study.

PubMed

Sivakumar, Parthipan; Jayaram, Deepak; Rao, Deepak; Dhileepan, Vignesh; Ahmed, Irfan; Ahmed, Liju

2016-12-01

Conventional Abrams biopsy shows low sensitivity in suspected malignant pleural disease. There are limited data on the improvement in sensitivity by adding in image guidance. This retrospective study compares the diagnostic sensitivity of Abrams biopsy using ultrasound guidance with CT-guided Tru-Cut biopsy in suspected malignant pleural disease. Data were collected from 2006 to 2012 of patients who underwent image-guided biopsies for suspected non-tuberculous pleural disease. Data were collected on the result of the initial biopsy and final patient diagnosis as of June 2015. Sixty-three patients underwent image-guided Abrams biopsy and 29 underwent CT-guided Tru-Cut biopsies. The sensitivity of Abrams was 71.43 % compared to 75 % in the CT-guided Tru-Cut group. Specificity was 100 % in both groups. Image-guided Abrams biopsies demonstrate comparable diagnostic sensitivity in malignant pleural disease to CT-guided Tru-Cut biopsy.

Contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) 2017 – a review of important differences compared to the CT/MRI system

PubMed Central

Noh, Seung Yeon; Wilson, Stephanie R; Kono, Yuko; Piscaglia, Fabio; Jang, Hyun-Jung; Lyshchik, Andrej; Dietrich, Christoph F.; Willmann, Juergen K.; Vezeridis, Alexander; Sirlin, Claude B

2017-01-01

Medical imaging plays an important role in the diagnosis and management of hepatocellular carcinoma (HCC). The Liver Imaging Reporting and Data System (LI-RADS) was initially created to standardize the reporting and data collection of CT and MR imaging for patients at risk for HCC. As contrast-enhanced ultrasound (CEUS) has been widely used in clinical practice, it has recently been added to the LI-RADS. While CEUS LI-RADS shares fundamental concepts with CT/MRI LI-RADS, there are key differences between the modalities reflecting dissimilarities in the underlying methods of image acquisition and types of contrast material. This review introduces a recent update of CEUS LI-RADS and explains the key differences from CT/MRI LI-RADS. PMID:28911220

Diagnosis and management of solitary pulmonary nodules.

PubMed

Jeong, Yeon Joo; Lee, Kyung Soo; Kwon, O Jung

2008-12-01

The advent of computed tomography (CT) screening with or without the help of computer-aided detection systems has increased the detection rate of solitary pulmonary nodules (SPNs), including that of early peripheral lung cancer. Helical dynamic (HD)CT, providing the information on morphologic and hemodynamic characteristics with high specificity and reasonably high accuracy, can be used for the initial assessment of SPNs. (18)F-fluorodeoxyglucose PET/CT is more sensitive at detecting malignancy than HDCT. Therefore, PET/CT may be selectively performed to characterize SPNs when HDCT gives an inconclusive diagnosis. Serial volume measurements are currently the most reliable methods for the tissue characterization of subcentimeter nodules. When malignant nodule is highly suspected for subcentimeter nodules, video-assisted thoracoscopic surgery nodule removal after nodule localization using the pulmonary nodule-marker system may be performed for diagnosis and treatment.

PET/CT and MRI of intra-osseous haemangioma of the tibia

PubMed Central

Cha, J G; Yoo, J H; Kim, H K; Park, J M; Paik, S H; Park, S J

2012-01-01

Intra-osseous haemangioma is a rare, benign neoplasm that usually involves the vertebrae and craniofacial bones. Furthermore, its occurrence in the long bones is extremely rare. We report the findings of fluorine-18-fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT and MRI in a patient with intra-osseous haemangioma in the proximal tibia, who was initially misdiagnosed as having a malignancy based on 18F-FDG PET/CT. 18F-FDG PET/CT showed a well-marginated osteolytic lesion with abnormal FDG uptake. The mass demonstrated low signal intensity on T1 weighted MRI. On T2 weighted images, the lesion appeared as a cluster of high signal intensity lobules and showed strong enhancement on contrast-enhanced T1 weighted images. Surgical curettage was performed and histopathological examination of the excised tissue confirmed a cavernous haemangioma. PMID:22457416

[Computer aided diagnosis model for lung tumor based on ensemble convolutional neural network].

PubMed

Wang, Yuanyuan; Zhou, Tao; Lu, Huiling; Wu, Cuiying; Yang, Pengfei

2017-08-01

The convolutional neural network (CNN) could be used on computer-aided diagnosis of lung tumor with positron emission tomography (PET)/computed tomography (CT), which can provide accurate quantitative analysis to compensate for visual inertia and defects in gray-scale sensitivity, and help doctors diagnose accurately. Firstly, parameter migration method is used to build three CNNs (CT-CNN, PET-CNN, and PET/CT-CNN) for lung tumor recognition in CT, PET, and PET/CT image, respectively. Then, we aimed at CT-CNN to obtain the appropriate model parameters for CNN training through analysis the influence of model parameters such as epochs, batchsize and image scale on recognition rate and training time. Finally, three single CNNs are used to construct ensemble CNN, and then lung tumor PET/CT recognition was completed through relative majority vote method and the performance between ensemble CNN and single CNN was compared. The experiment results show that the ensemble CNN is better than single CNN on computer-aided diagnosis of lung tumor.

1975 Memorial Award Paper. Image generation and display techniques for CT scan data. Thin transverse and reconstructed coronal and sagittal planes.

PubMed

Glenn, W V; Johnston, R J; Morton, P E; Dwyer, S J

1975-01-01

The various limitations to computerized axial tomographic (CT) interpretation are due in part to the 8-13 mm standard tissue plane thickness and in part to the absence of alternative planes of view, such as coronal or sagittal images. This paper describes a method for gathering multiple overlapped 8 mm transverse sections, subjecting these data to a deconvolution process, and then displaying thin (1 mm) transverse as well as reconstructed coronal and sagittal CT images. Verification of the deconvolution technique with phantom experiments is described. Application of the phantom results to human post mortem CT scan data illustrates this method's faithful reconstruction of coronal and sagittal tissue densities when correlated with actual specimen photographs of a sectioned brain. A special CT procedure, limited basal overlap scanning, is proposed for use on current first generation CT scanners without hardware modification.

Critical thinking skills of basic baccalaureate and Accelerated second-degree nursing students.

PubMed

Newton, Sarah E; Moore, Gary

2013-01-01

The purpose of this study was to describe the critical thinking (CT) skills of basic baccalaureate (basic-BSN) and accelerated second-degree (ASD) nursing students at nursing program entry. Many authors propose that CT in nursing should be viewed as a developmental process that increases as students' experiences with it change. However, there is a dearth of literature that describes basic-BSN and ASD students' CT skills from an evolutionary perspective. The study design was exploratory descriptive. The results indicated thatASD students had higher CT scores on a quantitative critical thinking assessment at program entry than basic-BSN students. CT data are needed across the nursing curriculum from basic-BSN and ASD students in order for nurse educators to develop cohort-specific pedagogical approaches that facilitate critical thinking in nursing and produce nurses with good CT skills for the future.

Energy-Discriminative Performance of a Spectral Micro-CT System

PubMed Central

He, Peng; Yu, Hengyong; Bennett, James; Ronaldson, Paul; Zainon, Rafidah; Butler, Anthony; Butler, Phil; Wei, Biao; Wang, Ge

2013-01-01

Experiments were performed to evaluate the energy-discriminative performance of a spectral (multi-energy) micro-CT system. The system, designed by MARS (Medipix All Resolution System) Bio-Imaging Ltd. (Christchurch, New Zealand), employs a photon-counting energy-discriminative detector technology developed by CERN (European Organization for Nuclear Research). We used the K-edge attenuation characteristic of some known materials to calibrate the detector’s photon energy discrimination. For tomographic analysis, we used the compressed sensing (CS) based ordered-subset simultaneous algebraic reconstruction techniques (OS-SART) to reconstruct sample images, which is effective to reduce noise and suppress artifacts. Unlike conventional CT, the principal component analysis (PCA) method can be applied to extract and quantify additional attenuation information from a spectral CT dataset. Our results show that the spectral CT has a good energy-discriminative performance and provides more attenuation information than the conventional CT. PMID:24004864

A method of semi-quantifying β-AP in brain PET-CT 11C-PiB images.

PubMed

Jiang, Jiehui; Lin, Xiaoman; Wen, Junlin; Huang, Zhemin; Yan, Zhuangzhi

2014-01-01

Alzheimer's disease (AD) is a common health problem for elderly populations. Positron emission tomography-computed tomography (PET-CT)11C-PiB for beta-P (amyloid-β peptide, β-AP) imaging is an advanced method to diagnose AD in early stage. However, in practice radiologists lack a standardized value to semi-quantify β-AP. This paper proposes such a standardized value: SVβ-AP. This standardized value measures the mean ratio between the dimension of β-AP areas in PET and CT images. A computer aided diagnosis approach is also proposed to achieve SVβ-AP. A simulation experiment was carried out to pre-test the technical feasibility of the CAD approach and SVβ-AP. The experiment results showed that it is technically feasible.

Quality control of CT systems by automated monitoring of key performance indicators: a two-year study.

PubMed

Nowik, Patrik; Bujila, Robert; Poludniowski, Gavin; Fransson, Annette

2015-07-08

The purpose of this study was to develop a method of performing routine periodical quality controls (QC) of CT systems by automatically analyzing key performance indicators (KPIs), obtainable from images of manufacturers' quality assurance (QA) phantoms. A KPI pertains to a measurable or determinable QC parameter that is influenced by other underlying fundamental QC parameters. The established KPIs are based on relationships between existing QC parameters used in the annual testing program of CT scanners at the Karolinska University Hospital in Stockholm, Sweden. The KPIs include positioning, image noise, uniformity, homogeneity, the CT number of water, and the CT number of air. An application (MonitorCT) was developed to automatically evaluate phantom images in terms of the established KPIs. The developed methodology has been used for two years in clinical routine, where CT technologists perform daily scans of the manufacturer's QA phantom and automatically send the images to MonitorCT for KPI evaluation. In the cases where results were out of tolerance, actions could be initiated in less than 10 min. 900 QC scans from two CT scanners have been collected and analyzed over the two-year period that MonitorCT has been active. Two types of errors have been registered in this period: a ring artifact was discovered with the image noise test, and a calibration error was detected multiple times with the CT number test. In both cases, results were outside the tolerances defined for MonitorCT, as well as by the vendor. Automated monitoring of KPIs is a powerful tool that can be used to supplement established QC methodologies. Medical physicists and other professionals concerned with the performance of a CT system will, using such methods, have access to comprehensive data on the current and historical (trend) status of the system such that swift actions can be taken in order to ensure the quality of the CT examinations, patient safety, and minimal disruption of service.

Brown Adipose Reporting Criteria in Imaging STudies (BARCIST 1.0): Recommendations for Standardized FDG-PET/CT Experiments in Humans

PubMed Central

Chen, Kong Y.; Laughlin, Maren R.; Haft, Carol R.; Hu, Houchun Harry; Bredella, Miriam A.; Enerbäck, Sven; Kinahan, Paul E.; van Marken Lichtenbelt, Wouter; Lin, Frank I.; Sunderland, John J.; Virtanen, Kirsi A.; Wahl, Richard L.

2016-01-01

Human brown adipose tissue (BAT) presence, metabolic activity and estimated mass are typically measured by imaging [18F]fluorodeoxyglucose (FDG) uptake in response to cold exposure in regions of the body expected to contain BAT, using positron emission tomography combined with x-ray computed tomography (FDG-PET/CT). Efforts to describe the epidemiology and biology of human BAT are hampered by diverse experimental practices, making it difficult to directly compare results among laboratories. An expert panel was assembled by the National Institute of Diabetes and Digestive and Kidney Diseases on November 4, 2014 to discuss minimal requirements for conducting FDG-PET/CT experiments of human BAT, data analysis, and publication of results. This resulted in Brown Adipose Reporting Criteria in Imaging STudies (BARCIST 1.0). Since there are no fully-validated best practices at this time, panel recommendations are meant to enhance comparability across experiments, but not to constrain experimental design or the questions that can be asked. PMID:27508870

Initial evaluation of the Celesteion large-bore PET/CT scanner in accordance with the NEMA NU2-2012 standard and the Japanese guideline for oncology FDG PET/CT data acquisition protocol version 2.0.

PubMed

Kaneta, Tomohiro; Ogawa, Matsuyoshi; Motomura, Nobutoku; Iizuka, Hitoshi; Arisawa, Tetsu; Hino-Shishikura, Ayako; Yoshida, Keisuke; Inoue, Tomio

2017-10-11

The goal of this study was to evaluate the performance of the Celesteion positron emission tomography/computed tomography (PET/CT) scanner, which is characterized by a large-bore and time-of-flight (TOF) function, in accordance with the NEMA NU-2 2012 standard and version 2.0 of the Japanese guideline for oncology fluorodeoxyglucose PET/CT data acquisition protocol. Spatial resolution, sensitivity, count rate characteristic, scatter fraction, energy resolution, TOF timing resolution, and image quality were evaluated according to the NEMA NU-2 2012 standard. Phantom experiments were performed using 18 F-solution and an IEC body phantom of the type described in the NEMA NU-2 2012 standard. The minimum scanning time required for the detection of a 10-mm hot sphere with a 4:1 target-to-background ratio, the phantom noise equivalent count (NEC phantom ), % background variability (N 10mm ), % contrast (Q H,10mm ), and recovery coefficient (RC) were calculated according to the Japanese guideline. The measured spatial resolution ranged from 4.5- to 5-mm full width at half maximum (FWHM). The sensitivity and scatter fraction were 3.8 cps/kBq and 37.3%, respectively. The peak noise-equivalent count rate was 70 kcps in the presence of 29.6 kBq mL -1 in the phantom. The system energy resolution was 12.4% and the TOF timing resolution was 411 ps at FWHM. Minimum scanning times of 2, 7, 6, and 2 min per bed position, respectively, are recommended for visual score, noise-equivalent count (NEC) phantom , N 10mm , and the Q H,10mm to N 10mm ratio (QNR) by the Japanese guideline. The RC of a 10-mm-diameter sphere was 0.49, which exceeded the minimum recommended value. The Celesteion large-bore PET/CT system had low sensitivity and NEC, but good spatial and time resolution when compared to other PET/CT scanners. The QNR met the recommended values of the Japanese guideline even at 2 min. The Celesteion is therefore thought to provide acceptable image quality with 2 min/bed position acquisition, which is the most common scan protocol in Japan.

A 5-Year Prospective Follow-Up Study of Lipid-Rich Adrenal Incidentalomas: No Tumor Growth or Development of Hormonal Hypersecretion

PubMed Central

Raade, Merja; Hämäläinen, Esa; Sane, Timo

2015-01-01

Background Current guidelines for follow-up of adrenal incidentalomas are extensive and hampered by lack of follow-up studies. We tested the hypothesis that small lipid-rich adrenal incidentalomas, initially characterized by tumor size <40 mm and <10 Hounsfield units (HUs) on unenhanced computed tomography (CT) may not demonstrate excessive growth/hormonal hypersecretion on follow-up. Methods Sixty-nine incidentalomas in 56 patients were restudied with unenhanced CT and screening for hypercortisolism (dexamethasone suppression test [DST], plasma adrenocorticotropic hormone) and pheochromocytoma (24-hour urinary metanephrines and normetanephrines) 5 years later. Primary hyperaldosteronism was excluded at base-line. Results Tumor (n=69) size was similar before and after 5 years follow-up (19±6 mm vs. 20±7 mm). Mean tumor growth was 1±2 mm. Largest increase in tumor size was 8 mm, this tumor was surgically removed and histopathology confirmed cortical adenoma. DST was normal in 54 patients and two patients (3.6%) were still characterized by subclinical hypercortisolism. Initial tumor size was >20 mm for the patient with largest tumor growth and those with subclinical hypercortisolism. All patients had normal 24-hour urinary metanephrines and normetanephrines. Low attenuation (<10 HU) was demonstrated in 97% of 67 masses re-evaluated with unenhanced CT. Conclusion None of the patients developed clinically relevant tumor growth or new subclinical hypercortisolism. Biochemical screening for pheochromocytoma in incidentalomas demonstrating <10 HU on unenhanced CT is not needed. For such incidentalomas <40 mm, it seems sufficient to perform control CT and screen for hypercortisolism after 5 years. PMID:26354488

A 5-Year Prospective Follow-Up Study of Lipid-Rich Adrenal Incidentalomas: No Tumor Growth or Development of Hormonal Hypersecretion.

PubMed

Schalin-Jäntti, Camilla; Raade, Merja; Hämäläinen, Esa; Sane, Timo

2015-12-01

Current guidelines for follow-up of adrenal incidentalomas are extensive and hampered by lack of follow-up studies. We tested the hypothesis that small lipid-rich adrenal incidentalomas, initially characterized by tumor size <40 mm and <10 Hounsfield units (HUs) on unenhanced computed tomography (CT) may not demonstrate excessive growth/hormonal hypersecretion on follow-up. Sixty-nine incidentalomas in 56 patients were restudied with unenhanced CT and screening for hypercortisolism (dexamethasone suppression test [DST], plasma adrenocorticotropic hormone) and pheochromocytoma (24-hour urinary metanephrines and normetanephrines) 5 years later. Primary hyperaldosteronism was excluded at base-line. Tumor (n=69) size was similar before and after 5 years follow-up (19±6 mm vs. 20±7 mm). Mean tumor growth was 1±2 mm. Largest increase in tumor size was 8 mm, this tumor was surgically removed and histopathology confirmed cortical adenoma. DST was normal in 54 patients and two patients (3.6%) were still characterized by subclinical hypercortisolism. Initial tumor size was >20 mm for the patient with largest tumor growth and those with subclinical hypercortisolism. All patients had normal 24-hour urinary metanephrines and normetanephrines. Low attenuation (<10 HU) was demonstrated in 97% of 67 masses re-evaluated with unenhanced CT. None of the patients developed clinically relevant tumor growth or new subclinical hypercortisolism. Biochemical screening for pheochromocytoma in incidentalomas demonstrating <10 HU on unenhanced CT is not needed. For such incidentalomas <40 mm, it seems sufficient to perform control CT and screen for hypercortisolism after 5 years.

Lung cancer perfusion: can we measure pulmonary and bronchial circulation simultaneously?

PubMed

Yuan, Xiaodong; Zhang, Jing; Ao, Guokun; Quan, Changbin; Tian, Yuan; Li, Hong

2012-08-01

To describe a new CT perfusion technique for assessing the dual blood supply in lung cancer and present the initial results. This study was approved by the institutional review board. A CT protocol was developed, and a dual-input CT perfusion (DI-CTP) analysis model was applied and evaluated regarding the blood flow fractions in lung tumours. The pulmonary trunk and the descending aorta were selected as the input arteries for the pulmonary circulation and the bronchial circulation respectively. Pulmonary flow (PF), bronchial flow (BF), and a perfusion index (PI, = PF/ (PF + BF)) were calculated using the maximum slope method. After written informed consent was obtained, 13 consecutive subjects with primary lung cancer underwent DI-CTP. Perfusion results are as follows: PF, 13.45 ± 10.97 ml/min/100 ml; BF, 48.67 ± 28.87 ml/min/100 ml; PI, 21 % ± 11 %. BF is significantly larger than PF, P < 0.001. There is a negative correlation between the tumour volume and perfusion index (r = 0.671, P = 0.012). The dual-input CT perfusion analysis method can be applied successfully to lung tumours. Initial results demonstrate a dual blood supply in primary lung cancer, in which the systemic circulation is dominant, and that the proportion of the two circulation systems is moderately dependent on tumour size. A new CT perfusion technique can assess lung cancer's dual blood supply. A dual blood supply was confirmed with dominant bronchial circulation in lung cancer. The proportion of the two circulations is moderately dependent on tumour size. This new technique may benefit the management of lung cancer.

Prognosis estimation under the light of metabolic tumor parameters on initial FDG-PET/CT in patients with primary extranodal lymphoma

PubMed Central

Okuyucu, Kursat; Ozaydın, Sukru; Alagoz, Engin; Ozgur, Gokhan; Oysul, Fahrettin Guven; Ozmen, Ozlem; Tuncel, Murat; Ozturk, Mustafa; Arslan, Nuri

2016-01-01

Abstract Background Non-Hodgkin’s lymphomas arising from the tissues other than primary lymphatic organs are named primary extranodal lymphoma. Most of the studies evaluated metabolic tumor parameters in different organs and histopathologic variants of this disease generally for treatment response. We aimed to evaluate the prognostic value of metabolic tumor parameters derived from initial FDG-PET/CT in patients with a medley of primary extranodal lymphoma in this study. Patients and methods There were 67 patients with primary extranodal lymphoma for whom FDG-PET/CT was requested for primary staging. Quantitative PET/CT parameters: maximum standardized uptake value (SUVmax), average standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to estimate disease-free survival and overall survival. Results SUVmean, MTV and TLG were found statistically significant after multivariate analysis. SUVmean remained significant after ROC curve analysis. Sensitivity and specificity were calculated as 88% and 64%, respectively, when the cut-off value of SUVmean was chosen as 5.15. After the investigation of primary presentation sites and histo-pathological variants according to recurrence, there is no difference amongst the variants. Primary site of extranodal lymphomas however, is statistically important (p = 0.014). Testis and central nervous system lymphomas have higher recurrence rate (62.5%, 73%, respectively). Conclusions High SUVmean, MTV and TLG values obtained from primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in primary extranodal lymphoma. SUVmean is the most significant one amongst them for estimating recurrence/metastasis. PMID:27904443

A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

NASA Astrophysics Data System (ADS)

Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K.; Yashar, Catheryn M.; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

2015-04-01

Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images.

PubMed

Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K; Yashar, Catheryn M; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

2015-04-07

Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based 'thin-plate-spline robust point matching' algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT

PubMed Central

Cho, S H; Sung, Y M; Kim, M S

2012-01-01

Objective The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. Methods 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. Results 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Conclusion Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images. PMID:22514102

CT fluoroscopy-guided renal tumour cutting needle biopsy: retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure.

PubMed

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

2018-01-01

To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. • CT fluoroscopy-guided renal tumour biopsy has a high diagnostic yield. • CT fluoroscopy-guided renal tumour biopsy is safe. • Small tumour size (≤1.5 cm) is a risk factor for diagnostic failure.

Withdrawal of long-term epoprostenol therapy in pulmonary arterial hypertension (PAH).

PubMed

Calcaianu, George; Calcaianu, Mihaela; Canuet, Matthieu; Enache, Irina; Kessler, Romain

2017-01-01

Once initiated for pulmonary arterial hypertension (PAH), epoprostenol treatment usually needs to be delivered for an indefinite duration. It is possible that some participants could be transitioned from epoprostenol to oral therapies. We retrospectively evaluated eight PAH participants transitioned from epoprostenol to PAH oral drugs. The criteria for epoprostenol withdrawal were: (1) persistent improvement of clinic and hemodynamic status; (2) stable dose of epoprostenol for the last three months; and (3) the participant's preference for oral therapy after evaluation of risk-benefit. We evaluated the clinical, functional, and hemodynamic status at baseline, at withdrawal, and after the transition to oral PAH therapy. The transition was completed in all eight participants. Four participants had a complete successful transition (CT) with a stable clinical and hemodynamic course and four participants had a partial successful transition (PT) remaining stable clinically, with a mild hemodynamic worsening, but without need to re-initiate epoprostenol therapy. The four CT participants were treated with epoprostenol for a shorter period of time (CT group: 35 ± 30 versus PT group: 79 ± 49 months, P = 0.08). Mean epoprostenol dosage was lower in the CT group (CT group: 15 ± 1.5 ng/kg/min versus PT group: 24 ± 11 ng/kg/min, P = 0.09). Safe withdrawal of epoprostenol treatment and transition to oral PAH therapy was possible in a small and highly selected group of participants. The majority of these participants had a porto-pulmonary PAH or PAH associated to HIV infection.

Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors

PubMed Central

Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

2017-01-01

Background: Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Methods: Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images <60 keV in Group A. The total radiation dose, total iodine load, contrast injection speed, and maximum injection pressure were compared between the two groups. The 40 keV and 60 keV spectral CT images of Group A were compared with the images of Group B to evaluate overall image quality. Results: The total radiation dose, total iodine load, injection speed, and maximum injection pressure for Group A were decreased by 19%, 15%, 34.4%, and 18.3%, respectively. The optimal energy level in spectral CT for displaying the abdominal vessels was 40 keV. At this level, the CT values in the abdominal aorta and its three branches, the portal vein and its two branches, and the inferior vena cava were all greater than 340 hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and −1.716 for liver, −0.153 and −1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P > 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = −8.11 for liver, −7.83 for pancreas, and −5.38 for renal cortex, all P < 0.05). However, the subjective scores for the 40 keV (FBP) and 60 keV (40% ASiR) spectral CT images determined by two radiologists were all >3, indicating clinically acceptable image quality. Conclusions: Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality. PMID:28345547

Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors.

PubMed

Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

2017-04-05

Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images <60 keV in Group A. The total radiation dose, total iodine load, contrast injection speed, and maximum injection pressure were compared between the two groups. The 40 keV and 60 keV spectral CT images of Group A were compared with the images of Group B to evaluate overall image quality. The total radiation dose, total iodine load, injection speed, and maximum injection pressure for Group A were decreased by 19%, 15%, 34.4%, and 18.3%, respectively. The optimal energy level in spectral CT for displaying the abdominal vessels was 40 keV. At this level, the CT values in the abdominal aorta and its three branches, the portal vein and its two branches, and the inferior vena cava were all greater than 340 hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and -1.716 for liver, -0.153 and -1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P> 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = -8.11 for liver, -7.83 for pancreas, and -5.38 for renal cortex, all P< 0.05). However, the subjective scores for the 40 keV (FBP) and 60 keV (40% ASiR) spectral CT images determined by two radiologists were all> 3, indicating clinically acceptable image quality. Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

Atlas-based whole-body segmentation of mice from low-contrast Micro-CT data.

PubMed

Baiker, Martin; Milles, Julien; Dijkstra, Jouke; Henning, Tobias D; Weber, Axel W; Que, Ivo; Kaijzel, Eric L; Löwik, Clemens W G M; Reiber, Johan H C; Lelieveldt, Boudewijn P F

2010-12-01

This paper presents a fully automated method for atlas-based whole-body segmentation in non-contrast-enhanced Micro-CT data of mice. The position and posture of mice in such studies may vary to a large extent, complicating data comparison in cross-sectional and follow-up studies. Moreover, Micro-CT typically yields only poor soft-tissue contrast for abdominal organs. To overcome these challenges, we propose a method that divides the problem into an atlas constrained registration based on high-contrast organs in Micro-CT (skeleton, lungs and skin), and a soft tissue approximation step for low-contrast organs. We first present a modification of the MOBY mouse atlas (Segars et al., 2004) by partitioning the skeleton into individual bones, by adding anatomically realistic joint types and by defining a hierarchical atlas tree description. The individual bones as well as the lungs of this adapted MOBY atlas are then registered one by one traversing the model tree hierarchy. To this end, we employ the Iterative Closest Point method and constrain the Degrees of Freedom of the local registration, dependent on the joint type and motion range. This atlas-based strategy renders the method highly robust to exceptionally large postural differences among scans and to moderate pathological bone deformations. The skin of the torso is registered by employing a novel method for matching distributions of geodesic distances locally, constrained by the registered skeleton. Because of the absence of image contrast between abdominal organs, they are interpolated from the atlas to the subject domain using Thin-Plate-Spline approximation, defined by correspondences on the already established registration of high-contrast structures (bones, lungs and skin). We extensively evaluate the proposed registration method, using 26 non-contrast-enhanced Micro-CT datasets of mice, and the skin registration and organ interpolation, using contrast-enhanced Micro-CT datasets of 15 mice. The posture and shape varied significantly among the animals and the data was acquired in vivo. After registration, the mean Euclidean distance was less than two voxel dimensions for the skeleton and the lungs respectively and less than one voxel dimension for the skin. Dice coefficients of volume overlap between manually segmented and interpolated skeleton and organs vary between 0.47+/-0.08 for the kidneys and 0.73+/-0.04 for the brain. These experiments demonstrate the method's effectiveness for overcoming exceptionally large variations in posture, yielding acceptable approximation accuracy even in the absence of soft-tissue contrast in in vivo Micro-CT data without requiring user initialization. Copyright 2010 Elsevier B.V. All rights reserved.

Initial Experience of the Application of Automated Tube Potential Selection Technique in High-pitch Dual-source CT Angiography of Whole Aorta Using Third-generation Dual-source CT Scanner.

PubMed

Kong, Lingyan; Liang, Jixiang; Xue, Huadan; Wang, Yining; Wang, Yun; Jin, Zhengyu; Zhang, Daming; Chen, Jin

2017-02-20

Objective To evaluate the application of automated tube potential selection technique in high-pitch dual-source CT aortic angiography on a third-generation dual-source CT scanner. Methods Whole aorta angiography were indiated in 59 patients,who were divided into 2 groups using a simple random method:in group 1 there were 31 patients who underwent the examination with automated tube potential selection using a vascular setting with a preferred image quality of 288 mA/100 kV;in group 2 there were 28 patients who underwent the examination with a tube voltage of 100 kV and automated tube current modulation using a reference tube current of 288 mA. Both groups were scanned on a third generation dual-source CT device operated in dual-source high-pitch ECG-gating mode with a pitch of 3.0,collimation of 2×192×0.6 mm,and a rotation time of 0.25 s. Iterative reconstruction algorithm was used. For group 1,the volume and flow of contrast medium and chasing saline were adapted to the tube voltage. For group 2,a contrast material bolus of 45 ml with a flow of 4.5 ml/s followed by a 50 ml saline chaser at 5 ml/s was used. CTA scan was automatically started using a bolus tracking technique at the level of the original part of aorta after a trigger threshold of 100 HU was reached. The start delay was set to 6 s in both groups. Effective dose (ED),signal to noise ratio (SNR),contrast to noise ratio (CNR),and subjective diagnostic quality of both groups were evaluated. Results The mean ED were 21.3% lower (t=-3.099,P=0.000) in group 1 [(2.48±0.80) mSv] than in group 2 [(3.15±0.86) mSv]. Two groups showed no significant difference in attenuation,SD,SNR,or CNR at all evaluational parts of aorta (ascending aorta,aortic arch,diaphragmatic aorta,or iliac bifurcation)(all P>0.05). There was no significant difference in subjective diagnostic quality values of two groups [(1.41±0.50) scores vs. (1.39±0.50) scores;W=828.5,P=0.837]. Conclusion Compared with automated tube current modulation,the automated tube potential selection technique in aorta CT angiography on a third-generation dual-source CT can dramatically reduce radiation dose without affecting image quality.

1236 C/T and 3435 C/T polymorphisms of the ABCB1 gene in Mexican breast cancer patients.

PubMed

Gutierrez-Rubio, S A; Quintero-Ramos, A; Durán-Cárdenas, A; Franco-Topete, R A; Castro-Cervantes, J M; Oceguera-Villanueva, A; Jiménez-Pérez, L M; Balderas-Peña, L M A; Morgan-Villela, G; Del-Toro-Arreola, A; Daneri-Navarro, A

2015-02-13

MDR1, which is encoded by the ABCB1 gene, is involved in multidrug resistance (hydrophobic), as well as the elimination of xenotoxic agents. The association between ABCB1 gene polymorphisms and breast cancer risk in different populations has been described previously; however, the results have been inconclusive. In this study, we examined the association between polymorphisms 3435 C/T and 1236 C/T in the ABCB1 gene and breast cancer development in Mexican women according to their menopausal status and molecular classification. Molecular subtypes as well as allele and genotype frequencies were analyzed. A total of 248 women with initial breast cancer diagnosis and 180 ethnically matched, healthy, unrelated individuals were enrolled. Polymerase chain reaction-restriction fragment length polymorphism was performed to detect polymorphisms 3435 C/T and 1236 C/T in the ABCB1 gene. Premenopausal T allele carriers of the 3435 C/T polymorphism showed a 2-fold increased risk of breast cancer with respect to the reference and postmenopausal groups, as well as triple-negative expression regarding the luminal A/B molecular subrogated subtypes. In contrast, the CT genotype of the 1236 polymorphism was a protective factor against breast cancer. We conclude that the T allele carrier of the 3435 C/T polymorphism in the ABCB1 gene in combination with an estrogen receptor-negative status may be an important risk factor for breast cancer development in premenopausal women.

Prevalence of genital Chlamydia trachomatis infections in Russia: systematic literature review and multicenter study.

PubMed

Smelov, Vitaly; Thomas, Pierre; Ouburg, Sander; Morré, Servaas A

2017-09-29

A reliable overview of data on the prevalence of Chlamydia trachomatis (CT) in Russia is lacking and needed. All the available data on CT prevalence were analyzed in a systematic literature review on CT prevalence in Russia, strengthened with data from the multicenter study among 1263 people in the second-largest Russian megalopolis, St. Petersburg, testing for CT DNA in urethral, anal, cervical and prostate samples. A total of 10 articles met the inclusion criteria. The overall average prevalence of genital CT infections in Russian populations ranged from 2.9% to 33%. Risk factors included being symptomatic (P = 0.004; in men P < 0.001), being younger than 30 years (P = 0.001) and being a man who has sex with men (MSM) (P = 0.0084). Main limitations included the lack of studies in MSM. CT prevalence was higher in the groups where urethral and prostate secretion samples were pooled (5.2%-7.3% vs 3.2% in the urethra only). The data on CT prevalence in a range of Russian populations are analyzed and reported. Prostate secretions represent an additional sampling material for the study of CT infection in men. CT detection in some settings in St. Petersburg yielded levels of reliability comparable with internationally available tests. The initiation of screening programs for Chlamydia infections in Russia should be considered. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Rib fractures induced by coughing: an unusual cause of acute chest pain.

PubMed

De Maeseneer, M; De Mey, J; Debaere, C; Meysman, M; Osteaux, M

2000-03-01

We report three patients with stress fractures of the ribs induced by coughing. Standard radiographs of the chest and ribs did not reveal evidence of rib fractures in any of the patients. Bone scintigraphy, performed 1 to 2 weeks after initial onset of symptoms, showed a focal area of increased uptake along the chest wall in all cases. Thin section angulated helical CT directly visualized the subtle rib fractures. Initial diagnosis of a cough-induced fracture of the rib may be difficult because of the associated underlying disorder, and unnecessary examinations are commonly performed. Identification of a cough-induced fracture of the rib using helical CT may be clinically important to avoid unnecessary concern and additional examinations.

Non-perforated peptic ulcer disease: multidetector CT findings, complications, and differential diagnosis.

PubMed

Tonolini, Massimo; Ierardi, Anna Maria; Bracchi, Elena; Magistrelli, Paolo; Vella, Adriana; Carrafiello, Gianpaolo

2017-10-01

Despite availability of effective therapies, peptic ulcer disease (PUD) remains a major global disease, resulting from a combination of persistent Helicobacter pylori infection and widespread use of nonsteroidal anti-inflammatory drugs. Albeit endoscopy definitely represents the mainstay diagnostic technique, patients presenting to emergency departments with unexplained abdominal pain generally undergo multidetector CT as an initial investigation. Although superficial ulcers generally remain inconspicuous, careful multiplanar CT interpretation may allow to detect deep ulcers, secondary mural and extraluminal signs of peptic gastroduodenitis, thereby allowing timely endoscopic verification and appropriate treatment. This pictorial essay aims to provide radiologists with an increased familiarity with CT diagnosis of non-perforated PUD, with emphasis on differential diagnosis. Following an overview of current disease epidemiology and complications, it explains the appropriate CT acquisition and interpretation techniques, and reviews with several examples the cross-sectional findings of uncomplicated PUD. Afterwards, the CT features of PUD complications such as ulcer haemorrhage, gastric outlet obstruction, biliary and pancreatic fistulisation are presented. • Gastric and duodenal peptic ulcers are increasingly caused by nonsteroidal anti-inflammatory drugs • Multiplanar CT interpretation allows detecting deep ulcers and secondary signs of gastroduodenitis • CT diagnosis of uncomplicated peptic disease relies on direct and indirect signs • Currently the commonest complication, haemorrhage may be treated with transarterial embolisation • Other uncommon complications include gastric outlet obstruction and biliopancreatic fistulisation.

Utilization of head CT during injury visits to United States emergency departments: 2012-2015.

PubMed

Yun, Brian J; Borczuk, Pierre; Zachrison, Kori S; Goldstein, Joshua N; Berlyand, Yosef; Raja, Ali S

2018-05-18

Studies have shown increasing utilization of head computed tomography (CT) imaging of emergency department (ED) patients presenting with an injury-related visit. Multiple initiatives, including the Choosing Wisely™ campaign and evidence-based clinical decision support based on validated decision rules, have targeted head CT use in patients with injuries. Therefore, we investigated national trends in the use of head CT during injury-related ED visits from 2012 to 2015. This was a secondary analysis of data from the annual United States (U.S.) National Hospital Ambulatory Medical Care Survey from 2012 to 2015. The study population was defined as injury-related ED visits, and we sought to determine the percentage in which a head CT was ordered and, secondarily, to determine both the diagnostic yield of clinically significant intracranial findings and hospital characteristics associated with increased head CT utilization. Between 2012 and 2015, 12.25% (95% confidence interval [CI] 11.48-13.02%) of injury-related visits received at least one head CT. Overall head CT utilization showed an increased trend during the study period (2012: 11.7%, 2015: 13.23%, p = 0.09), but the results were not statistically significant. The diagnostic yield of head CT for a significant intracranial injury over the period of four years was 7.4% (9.68% in 2012 vs. 7.67% in 2015, p = 0.23). Head CT use along with diagnostic yield has remained stable from 2012 to 2015 among patients presenting to the ED for an injury-related visit. Copyright © 2017 Elsevier Inc. All rights reserved.

Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

PubMed

Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

2005-03-01

The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

Blunt trauma of bone structures of the chest--computed tomography vs multidetector computed tomography.

PubMed

Petrović, Kosta; Turkalj, Ivan; Stojanović, Sanja; Vucaj-Cirilović, Viktorija; Nikolić, Olivera; Stojiljković, Dragana

2013-08-01

Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists inde pendently and separately described the findings for 5-mm-thick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thin-slice examination together which was ultimately considered as a real, true finding. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.

A 30-Min Nucleic Acid Amplification Point-of-Care Test for Genital Chlamydia trachomatis Infection in Women: A Prospective, Multi-center Study of Diagnostic Accuracy.

PubMed

Harding-Esch, E M; Cousins, E C; Chow, S-L C; Phillips, L T; Hall, C L; Cooper, N; Fuller, S S; Nori, A V; Patel, R; Thomas-William, S; Whitlock, G; Edwards, S J E; Green, M; Clarkson, J; Arlett, B; Dunbar, J K; Lowndes, C M; Sadiq, S T

2018-02-01

Rapid Point-Of-Care Tests for Chlamydia trachomatis (CT) may reduce onward transmission and reproductive sexual health (RSH) sequelae by reducing turnaround times between diagnosis and treatment. The io® single module system (Atlas Genetics Ltd.) runs clinical samples through a nucleic acid amplification test (NAAT)-based CT cartridge, delivering results in 30min. Prospective diagnostic accuracy study of the io® CT-assay in four UK Genito-Urinary Medicine (GUM)/RSH clinics on additional-to-routine self-collected vulvovaginal swabs. Samples were tested "fresh" within 10days of collection, or "frozen" at -80°C for later testing. Participant characteristics were collected to assess risk factors associated with CT infection. CT prevalence was 7.2% (51/709) overall. Sensitivity, specificity, positive and negative predictive values of the io® CT assay were, respectively, 96.1% (95% Confidence Interval (CI): 86.5-99.5), 97.7% (95%CI: 96.3-98.7), 76.6% (95%CI: 64.3-86.2) and 99.7% (95%CI: 98.9-100). The only risk factor associated with CT infection was being a sexual contact of an individual with CT. The io® CT-assay is a 30-min, fully automated, high-performing NAAT currently CE-marked for CT diagnosis in women, making it a highly promising diagnostic to enable specific treatment, initiation of partner notification and appropriately intensive health promotion at the point of care. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of C-arm computed tomography and on-site quick cortisol assay for adrenal venous sampling: A retrospective study of 178 patients.

PubMed

Chang, Chin-Chen; Lee, Bo-Ching; Chang, Yeun-Chung; Wu, Vin-Cent; Huang, Kuo-How; Liu, Kao-Lang

2017-12-01

To compare the performance of on-site quick cortisol assay (QCA) and C-arm computed tomography (CT) assistance on adrenal venous sampling (AVS) without adrenocorticotropic hormone stimulation. The institutional review board at our hospital approved this retrospective study, which included 178 consecutive patients with primary aldosteronism. During AVS, we used C-arm CT to confirm right adrenal cannulation between May 2012 and June 2015 (n = 100) and QCA for bilateral adrenal cannulation between July 2015 and September 2016 (n = 78). Successful AVS required a selectivity index (cortisol adrenal vein /cortisol peripheral ) of ≥ 2.0 bilaterally. The overall success rate of C-arm CT-assisted AVS was 87%, which increased to 97.4% under QCA (P = .013). The procedure time (C-arm CT, 49.5 ± 21.3 min; QCA, 37.5 ± 15.6 min; P < .001) and radiation dose (C-arm CT, 673.9 ± 613.8 mGy; QCA, 346.4 ± 387.8 mGy; P < .001) were also improved. The resampling rate was 16% and 21.8% for C-arm CT and QCA, respectively. The initial success rate of the performing radiologist remained stable during the study period (C-arm CT 75%; QCA, 82.1%, P = .259). QCA might be superior to C-arm CT for improving the performance of AVS. • Adrenal venous sampling (AVS) is a technically challenging procedure. • C-arm CT and quick cortisol assay (QCA) are efficient for assisting AVS. • QCA might outperform C-arm CT in enhancing AVS performance.

Simultaneous biodegradation of phenol and carbon tetrachloride mediated by humic acids.

PubMed

Martínez, Claudia M; Alvarez, Luis H; Cervantes, Francisco J

2012-09-01

The capacity of an anaerobic sediment to achieve the simultaneous biodegradation of phenol and carbon tetrachloride (CT) was evaluated, using humic acids (HA) as redox mediator. The presence of HA in sediment incubations increased the rate of biodegradation of phenol and the rate of dehalogenation (2.5-fold) of CT compared to controls lacking HA. Further experiments revealed that the electron-accepting capacity of HA derived from different organic-rich environments was not associated with their reducing capacity to achieve CT dechlorination. The collected kinetic data suggest that the reduction of CT by reduced HA was the rate-limiting step during the simultaneous biodegradation of phenol and CT. To our knowledge, the present study constitutes the first demonstration of the simultaneous biodegradation of two priority pollutants mediated by HA.

[Spiral CT angiography in practice].

PubMed

Pavcec, Zlatko; Zokalj, Ivan; Rumboldt, Zoran; Pal, Andrej; Saghir, Hussein; Ozretić, David; Latin, Branko; Perhoć, Zeljka; Marotti, Miljenko

2005-01-01

Incidence of vascular diseases and development of new radiologic techniques in the last three decades has given strong impuls for introduction of non-invasive vascular diagnostic methods. Thanks to the introduction of Doppler ultrasound, new types of computed tomography (CT) and magnetic resonance (MR) scanners, non-invasive vascular diagnostic methods are replacing conventional invasive (catheter) angiographic methods. Computed tomographic angiography (CTA) is a noninvasive vascular diagnostic method based on continuous scanning with CT scanner during intravenous application of contrast material. Performing of CTA is possible after introduction of spiral CT technique whose characteristics are short imaging time and volumetric data acquisition. The main goal of this article, based on our experiences, is to review the role of CTA, performed on single-slice CT scanner, in managment of patients with vascular pathology.

Cost Analysis of the STONE Randomized Trial: Can Health Care Costs be Reduced One Test at a Time?

PubMed

Melnikow, Joy; Xing, Guibo; Cox, Ginger; Leigh, Paul; Mills, Lisa; Miglioretti, Diana L; Moghadassi, Michelle; Smith-Bindman, Rebecca

2016-04-01

Decreasing the use of high-cost tests may reduce health care costs. To compare costs of care for patients presenting to the emergency department (ED) with suspected kidney stones randomized to 1 of 3 initial imaging tests. Patients were randomized to point-of-care ultrasound (POC US, least costly), radiology ultrasound (RAD US), or computed tomography (CT, most costly). Subsequent testing and treatment were the choice of the treating physician. A total of 2759 patients at 15 EDs were randomized to POC US (n=908), RAD US, (n=893), or CT (n=958). Mean age was 40.4 years; 51.8% were male. All medical care documented in the trial database in the 7 days following enrollment was abstracted and coded to estimate costs using national average 2012 Medicare reimbursements. Costs for initial ED care and total 7-day costs were compared using nonparametric bootstrap to account for clustering of patients within medical centers. Initial ED visit costs were modestly lower for patients assigned to RAD US: $423 ($411, $434) compared with patients assigned to CT: $448 ($438, $459) (P<0.0001). Total costs were not significantly different between groups: $1014 ($912, $1129) for POC US, $970 ($878, $1078) for RAD US, and $959 ($870, $1044) for CT. Hospital admissions contributed over 50% of total costs, though only 11% of patients were admitted. Mean total costs (and admission rates) varied substantially by site from $749 to $1239. Assignment to a less costly test had no impact on overall health care costs for ED patients. System-level interventions addressing variation in admission rates from the ED might have greater impact on costs.

Transient transcriptional activation of the Vibrio cholerae El Tor virulence regulator toxT in response to culture conditions.

PubMed

Medrano, A I; DiRita, V J; Castillo, G; Sanchez, J

1999-05-01

Vibrio cholerae El Tor require special in vitro culture conditions, consisting of an initial static growth period followed by shift to shaking (AKI conditions), for expression of cholera toxin (CT) and toxin coregulated pili (TCP). ToxT, a regulator whose initial transcription depends on the ToxR regulator, positively modulates expression of CT and TCP. To help understand control of CT and TCP in El Tor vibrios, we monitored ctxAB and ToxR-dependent toxT transcription by time course primer extension assays. AKI conditions stimulated CT synthesis with an absence of ctxAB transcription during static growth followed by induction upon shaking. ToxR-dependent toxT transcription was induced at the end of the static growth period but was transient, stopping shortly after shaking was initiated but, interestingly, also if the static phase was prolonged. Immunoblot assays showed that ToxR protein levels were not coincidentally transient, implying a protein on/off switch mechanism for ToxR. Despite the transient activation by ToxR, transcription of ctxAB was maintained during shaking. This finding suggested continued toxT expression, possibly through relay transcription from another promoter. The 12.6-kb distant upstream tcpA promoter responsible for expression of the TCP operon has been proposed to provide an alternate toxT message by readthrough transcription. Activation of the tcpA promoter is supported by increased expression of TcpA protein during the shaking phase of the culture. Readthrough transcription of toxT from tcpA would be compatible with reverse transcription-PCR evidence for a toxT mRNA at times when ToxR-dependent transcription was no longer detectable by primer extension.

Muscle fatigue in frog semitendinosus: alterations in contractile function

NASA Technical Reports Server (NTRS)

Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

1992-01-01

The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

Radiation dose reduction with chest computed tomography using adaptive statistical iterative reconstruction technique: initial experience.

PubMed

Prakash, Priyanka; Kalra, Mannudeep K; Digumarthy, Subba R; Hsieh, Jiang; Pien, Homer; Singh, Sarabjeet; Gilman, Matthew D; Shepard, Jo-Anne O

2010-01-01

To assess radiation dose reduction and image quality for weight-based chest computed tomographic (CT) examination results reconstructed using adaptive statistical iterative reconstruction (ASIR) technique. With local ethical committee approval, weight-adjusted chest CT examinations were performed using ASIR in 98 patients and filtered backprojection (FBP) in 54 weight-matched patients on a 64-slice multidetector CT. Patients were categorized into 3 groups: 60 kg or less (n = 32), 61 to 90 kg (n = 77), and 91 kg or more (n = 43) for weight-based adjustment of noise indices for automatic exposure control (Auto mA; GE Healthcare, Waukesha, Wis). Remaining scan parameters were held constant at 0.984:1 pitch, 120 kilovolts (peak), 40-mm table feed per rotation, and 2.5-mm section thickness. Patients' weight, scanning parameters, and CT dose index volume were recorded. Effective doses (EDs) were estimated. Image noise was measured in the descending thoracic aorta at the level of the carina. Data were analyzed using analysis of variance. Compared with FBP, ASIR was associated with an overall mean (SD) decrease of 27.6% in ED (ASIR, 8.8 [2.3] mSv; FBP, 12.2 [2.1] mSv; P < 0.0001). With the use of ASIR, the ED values were 6.5 (1.8) mSv (28.8% decrease), 7.3 (1.6) mSv (27.3% decrease), and 12.8 (2.3) mSv (26.8% decrease) for the weight groups of 60 kg or less, 61 to 90 kg, and 91 kg or more, respectively, compared with 9.2 (2.3) mSv, 10.0 (2.0) mSv, and 17.4 (2.1) mSv with FBP (P < 0.0001). Despite dose reduction, there was less noise with ASIR (12.6 [2.9] mSv) than with FBP (16.6 [6.2] mSv; P < 0.0001). Adaptive statistical iterative reconstruction helps reduce chest CT radiation dose and improve image quality compared with the conventionally used FBP image reconstruction.

18F-FDG PET/CT in gastric MALT lymphoma: a bicentric experience.

PubMed

Albano, Domenico; Bertoli, Mattia; Ferro, Paola; Fallanca, Federico; Gianolli, Luigi; Picchio, Maria; Giubbini, Raffaele; Bertagna, Francesco

2017-04-01

The role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma. Sixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics. Thirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage (p=0.010), and Ki67 index (p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index (p=0.047; p=0.012; p=0.042). 18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio are correlated only with Ki-67 index, and only lesion-to-liver SUVmax ratio was independently associated with Ki-67 score.

Citalopram and escitalopram plasma drug and metabolite concentrations: genome-wide associations

PubMed Central

Ji, Yuan; Schaid, Daniel J; Desta, Zeruesenay; Kubo, Michiaki; Batzler, Anthony J; Snyder, Karen; Mushiroda, Taisei; Kamatani, Naoyuki; Ogburn, Evan; Hall-Flavin, Daniel; Flockhart, David; Nakamura, Yusuke; Mrazek, David A; Weinshilboum, Richard M

2014-01-01

Aims Citalopram (CT) and escitalopram (S-CT) are among the most widely prescribed selective serotonin reuptake inhibitors used to treat major depressive disorder (MDD). We applied a genome-wide association study to identify genetic factors that contribute to variation in plasma concentrations of CT or S-CT and their metabolites in MDD patients treated with CT or S-CT. Methods Our genome-wide association study was performed using samples from 435 MDD patients. Linear mixed models were used to account for within-subject correlations of longitudinal measures of plasma drug/metabolite concentrations (4 and 8 weeks after the initiation of drug therapy), and single-nucleotide polymorphisms (SNPs) were modelled as additive allelic effects. Results Genome-wide significant associations were observed for S-CT concentration with SNPs in or near the CYP2C19 gene on chromosome 10 (rs1074145, P = 4.1 × 10−9) and with S-didesmethylcitalopram concentration for SNPs near the CYP2D6 locus on chromosome 22 (rs1065852, P = 2.0 × 10−16), supporting the important role of these cytochrome P450 (CYP) enzymes in biotransformation of citalopram. After adjustment for the effect of CYP2C19 functional alleles, the analyses also identified novel loci that will require future replication and functional validation. Conclusions In vitro and in vivo studies have suggested that the biotransformation of CT to monodesmethylcitalopram and didesmethylcitalopram is mediated by CYP isozymes. The results of our genome-wide association study performed in MDD patients treated with CT or S-CT have confirmed those observations but also identified novel genomic loci that might play a role in variation in plasma levels of CT or its metabolites during the treatment of MDD patients with these selective serotonin reuptake inhibitors. PMID:24528284

Citalopram and escitalopram plasma drug and metabolite concentrations: genome-wide associations.

PubMed

Ji, Yuan; Schaid, Daniel J; Desta, Zeruesenay; Kubo, Michiaki; Batzler, Anthony J; Snyder, Karen; Mushiroda, Taisei; Kamatani, Naoyuki; Ogburn, Evan; Hall-Flavin, Daniel; Flockhart, David; Nakamura, Yusuke; Mrazek, David A; Weinshilboum, Richard M

2014-08-01

Citalopram (CT) and escitalopram (S-CT) are among the most widely prescribed selective serotonin reuptake inhibitors used to treat major depressive disorder (MDD). We applied a genome-wide association study to identify genetic factors that contribute to variation in plasma concentrations of CT or S-CT and their metabolites in MDD patients treated with CT or S-CT. Our genome-wide association study was performed using samples from 435 MDD patients. Linear mixed models were used to account for within-subject correlations of longitudinal measures of plasma drug/metabolite concentrations (4 and 8 weeks after the initiation of drug therapy), and single-nucleotide polymorphisms (SNPs) were modelled as additive allelic effects. Genome-wide significant associations were observed for S-CT concentration with SNPs in or near the CYP2C19 gene on chromosome 10 (rs1074145, P = 4.1 × 10(-9) ) and with S-didesmethylcitalopram concentration for SNPs near the CYP2D6 locus on chromosome 22 (rs1065852, P = 2.0 × 10(-16) ), supporting the important role of these cytochrome P450 (CYP) enzymes in biotransformation of citalopram. After adjustment for the effect of CYP2C19 functional alleles, the analyses also identified novel loci that will require future replication and functional validation. In vitro and in vivo studies have suggested that the biotransformation of CT to monodesmethylcitalopram and didesmethylcitalopram is mediated by CYP isozymes. The results of our genome-wide association study performed in MDD patients treated with CT or S-CT have confirmed those observations but also identified novel genomic loci that might play a role in variation in plasma levels of CT or its metabolites during the treatment of MDD patients with these selective serotonin reuptake inhibitors. © 2014 The British Pharmacological Society.

Comparison of 68Ga-PSMA-11 and 18F-Fluciclovine PET/CT in a Case Series of 10 Patients with Prostate Cancer Recurrence.

PubMed

Calais, Jeremie; Fendler, Wolfgang P; Herrmann, Ken; Eiber, Matthias; Ceci, Francesco

2018-05-01

This was a head-to-head comparison between 68 Ga-labeled prostate-specific membrane antigen (PSMA)-11 and 18 F-fluciclovine PET/CT in a series of 10 patients with prostate cancer (PCa) recurrence. Methods: In total, 288 patients with PCa recurrence were enrolled in a prospective study of 68 Ga-PSMA-11 PET/CT imaging for recurrent disease localization (ClinicalTrials.gov identifier NCT02940262). We retrospectively identified 10 patients who underwent clinically indicated 18 F-fluciclovine PET/CT prior to enrollment. Results: The median time between the 2 scans was 2.2 mo (range, 0.2-4.2 mo). The median prostate-specific antigen (PSA) value was 1.0 ng/mL (mean, 4.7 ng/mL; range, 0.13-18.1 ng/mL) and 1.1 ng/mL (mean, 6.2 ng/mL; range, 0.24-31.3 ng/mL) at the time of 18 F-fluciclovine and 68 Ga-PSMA-11 PET/CT, respectively. Five of 10 patients (50%) were negative with 18 F-fluciclovine but positive with 68 Ga-PSMA-11 PET/CT. Two of 10 patients (20%) were positive with both 18 F-fluciclovine and 68 Ga-PSMA-11 PET/CT, but 68 Ga-PSMA-11 PET/CT showed additional lymph nodes metastasis. Three of 10 patients (30%) were negative with both 18 F-fluciclovine and 68 Ga-PSMA-11 PET/CT. Conclusion: This case series suggests improved detection rates for 68 Ga-PSMA-11 PET/CT when compared with 18 F-fluciclovine PET/CT in patients with recurrent PCa. Prospective trials designed to directly compare the two should be initiated. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

CT versus MR Techniques in the Detection of Cervical Artery Dissection.

PubMed

Hanning, Uta; Sporns, Peter B; Schmiedel, Meilin; Ringelstein, Erich B; Heindel, Walter; Wiendl, Heinz; Niederstadt, Thomas; Dittrich, Ralf

2017-11-01

Spontaneous cervical artery dissection (sCAD) is an important etiology of juvenile stroke. The gold standard for the diagnosis of sCAD is convential angiography. However, magnetic resonance imaging (MRI)/MR angiography (MRA) and computed tomography (CT)/CT angiography (CTA) are frequently used alternatives. New developments such as multislice CT/CTA have enabled routine acquisition of thinner sections with rapid imaging times. The goal of this study was to compare the capability of recent developed 128-slice CT/CTA to MRI/MRA to detect radiologic features of sCAD. Retrospective review of patients with suspected sCAD (n = 188) in a database of our Stroke center (2008-2014), who underwent CT/CTA and MRI/MRA on initial clinical work-up. A control group of 26 patients was added. All Images were evaluated concerning specific and sensitive radiological features for dissection by two experienced neuroradiologists. Imaging features were compared between the two modalities. Forty patients with 43 dissected arteries received both modalities (29 internal carotid arteries [ICAs] and 14 vertebral arteries [VAs]). All CADs were identified in CT/CTA and MRI/MRA. The features intimal flap, stenosis, and lumen irregularity appeared in both modalities. One high-grade stenosis was identified by CT/CTA that was expected occluded on MRI/MRA. Two MRI/MRA-confirmed pseudoaneurysms were missed by CT/CTA. None of the controls evidenced specific imaging signs for dissection. CT/CTA is a reliable and better available alternative to MRI/MRA for diagnosis of sCAD. CT/CTA should be used to complement MRI/MRA in cases where MRI/MRA suggests occlusion. Copyright © 2017 by the American Society of Neuroimaging.

The value of FDG PET/CT for follow-up of patients with melanoma: a retrospective analysis

PubMed Central

Vensby, Philip H; Schmidt, Grethe; Kjær, Andreas; Fischer, Barbara M

2017-01-01

The incidence of melanoma (MM) is among the fastest rising cancers in the western countries. Positron Emission Tomography with Computed Tomography (PET/CT) is a valuable non-invasive tool for the diagnosis and staging of patients with MM. However, research on the value of PET/CT in follow-up of melanoma patients is limited. This study assesses the diagnostic value of PET/CT for follow-up after melanoma surgery. This retrospective study includes patients with MM who performed at least one PET/CT scan after initial surgery and staging. PET/CT findings were compared to histology, MRI or fine needle aspiration (FNA) to estimate the diagnostic accuracy. The diagnostic performance of PET/CT performed in patients with and without a clinical suspicion of relapse was compared. 238 patients (526 scans) were included. Of the 526 scans 130 (25%) scans were PET-positive, 365 (69%) PET-negative, and 28 (5%) had equivocal findings. Sensitivity was 89% [0.82-0.94], specificity 92% [0.89-0.95], positive and negative predictive values of 78% [0.70-0.84] and 97% [0.94-0.98] respectively. When stratified for reason of referral there was no statistical significant difference in the diagnostic accuracy of PET/CT between patients referred with or without a clinical suspicion of relapse. This study demonstrates that PET/CT despite a moderate sensitivity has a high negative predictive value in the follow-up of melanoma patients. Thus, a negative PET/CT-scan essentially rules out relapse. However, the frequency of false positive findings is relatively high, especially among patients undergoing a “routine” PET/CT with no clinical suspicion of relapse, potentially causing anxiety and leading to further diagnostic procedures. PMID:29348980

The value of FDG PET/CT for follow-up of patients with melanoma: a retrospective analysis.

PubMed

Vensby, Philip H; Schmidt, Grethe; Kjær, Andreas; Fischer, Barbara M

2017-01-01

The incidence of melanoma (MM) is among the fastest rising cancers in the western countries. Positron Emission Tomography with Computed Tomography (PET/CT) is a valuable non-invasive tool for the diagnosis and staging of patients with MM. However, research on the value of PET/CT in follow-up of melanoma patients is limited. This study assesses the diagnostic value of PET/CT for follow-up after melanoma surgery. This retrospective study includes patients with MM who performed at least one PET/CT scan after initial surgery and staging. PET/CT findings were compared to histology, MRI or fine needle aspiration (FNA) to estimate the diagnostic accuracy. The diagnostic performance of PET/CT performed in patients with and without a clinical suspicion of relapse was compared. 238 patients (526 scans) were included. Of the 526 scans 130 (25%) scans were PET-positive, 365 (69%) PET-negative, and 28 (5%) had equivocal findings. Sensitivity was 89% [0.82-0.94], specificity 92% [0.89-0.95], positive and negative predictive values of 78% [0.70-0.84] and 97% [0.94-0.98] respectively. When stratified for reason of referral there was no statistical significant difference in the diagnostic accuracy of PET/CT between patients referred with or without a clinical suspicion of relapse. This study demonstrates that PET/CT despite a moderate sensitivity has a high negative predictive value in the follow-up of melanoma patients. Thus, a negative PET/CT-scan essentially rules out relapse. However, the frequency of false positive findings is relatively high, especially among patients undergoing a "routine" PET/CT with no clinical suspicion of relapse, potentially causing anxiety and leading to further diagnostic procedures.

Blind CT image quality assessment via deep learning strategy: initial study

NASA Astrophysics Data System (ADS)

Li, Sui; He, Ji; Wang, Yongbo; Liao, Yuting; Zeng, Dong; Bian, Zhaoying; Ma, Jianhua

2018-03-01

Computed Tomography (CT) is one of the most important medical imaging modality. CT images can be used to assist in the detection and diagnosis of lesions and to facilitate follow-up treatment. However, CT images are vulnerable to noise. Actually, there are two major source intrinsically causing the CT data noise, i.e., the X-ray photo statistics and the electronic noise background. Therefore, it is necessary to doing image quality assessment (IQA) in CT imaging before diagnosis and treatment. Most of existing CT images IQA methods are based on human observer study. However, these methods are impractical in clinical for their complex and time-consuming. In this paper, we presented a blind CT image quality assessment via deep learning strategy. A database of 1500 CT images is constructed, containing 300 high-quality images and 1200 corresponding noisy images. Specifically, the high-quality images were used to simulate the corresponding noisy images at four different doses. Then, the images are scored by the experienced radiologists by the following attributes: image noise, artifacts, edge and structure, overall image quality, and tumor size and boundary estimation with five-point scale. We trained a network for learning the non-liner map from CT images to subjective evaluation scores. Then, we load the pre-trained model to yield predicted score from the test image. To demonstrate the performance of the deep learning network in IQA, correlation coefficients: Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are utilized. And the experimental result demonstrate that the presented deep learning based IQA strategy can be used in the CT image quality assessment.

Circulating Tumor DNA Measurement by Picoliter Droplet-Based Digital PCR and Vemurafenib Plasma Concentrations in Patients with Advanced BRAF-Mutated Melanoma.

PubMed

Garlan, Fanny; Blanchet, Benoit; Kramkimel, Nora; Puszkiel, Alicja; Golmard, Jean-Louis; Noe, Gaelle; Dupin, Nicolas; Laurent-Puig, Pierre; Vidal, Michel; Taly, Valerie; Thomas-Schoemann, Audrey

2017-06-01

Circulating tumor DNA (ctDNA) has been reported as a prognostic marker in melanoma. In BRAF V600-mutant melanoma, a plasma under-exposure to vemurafenib could favor emerging resistance but no biological data are available to support this hypothesis. We aimed to investigate the relationship between vemurafenib plasma concentrations and the ctDNA plasma concentration during follow-up of BRAF-mutated melanoma patients. Eleven patients treated with single-agent vemurafenib for advanced BRAF V600-mutant melanoma were analyzed in an exploratory monocentric study. The vemurafenib plasma concentration was measured by liquid chromatography. ctDNA was extracted from plasma samples and the ctDNA concentration was evaluated using picoliter droplet-based digital PCR with Taqman ® detection probes targeting the BRAF p.V600E/K mutation and wild-type BRAF sequences. At baseline, plasma ctDNA was detectable in 72% (n = 8/11) of patients and the ctDNA concentration decreased in 88% of these patients (n = 7/8) from day (D) 0 to D15 after vemurafenib initiation. During follow-up, an increased ctDNA concentration was detected in nine patients: in five patients, the first increase in ctDNA concentrations followed a decrease in vemurafenib concentrations. More interestingly, an inverse correlation between vemurafenib concentration and ctDNA concentrations was demonstrated (p = 0.026). The ctDNA concentration at baseline was associated with overall survival (hazard ratio = 2.61, 95% CI 1.04-6.56; p = 0.04). This study demonstrates the relevance of vemurafenib plasma monitoring during the follow-up of metastatic melanoma patients. Plasma drug monitoring and ctDNA concentrations could be combined to monitor tumor evolution in melanoma patients treated with anti-BRAF therapies.

Are CT scans obtained at referring institutions justified prior to transfer to a pediatric trauma center?

PubMed

Benedict, Leo Andrew; Paulus, Jessica K; Rideout, Leslie; Chwals, Walter J

2014-01-01

To assess whether pediatric trauma patients initially evaluated at referring institutions met Massachusetts statewide trauma field triage criteria for stabilization and immediate transfer to a Pediatric Trauma Center (PTC) without pre-transfer CT imaging. A 3-year retrospective cohort study was completed at our level 1 PTC. Patients with CT imaging at referring institutions were classified according to a triage scheme based on Massachusetts statewide trauma field triage criteria. Demographic data and injury profile characteristics were abstracted from patient medical records and our pediatric trauma registry. A total of 262 patients with 413 CT scans were reviewed from 2008 to 2011. 172 patients scanned (66%, 95% CI: 60%, 71%) met criteria for immediate transfer to a pediatric trauma center. Notably, 110 scans (27% of the total performed at referring institutions) were duplicated within four hours upon arrival to our PTC. GCS score <14 (45%) was the most common requirement for transfer, and CT scan of the head was the most frequent scan obtained (53%). The majority of pediatric trauma patients were subjected to CT scans at referring institutions despite meeting Massachusetts trauma triage guidelines that call for stabilization and immediate transfer to a pediatric trauma center without any CT imaging. © 2014.

[Clinical decision to perform cranial computed tomography in children with non-severe head injury].

PubMed

Franco-Koehrlen, Celine Alicia; Iglesias-Leboreiro, José; Bernárdez-Zapata, Isabel; Rendón-Macías, Mario Enrique

The main goal of this article was to evaluate if the decision to perform cranial computed tomography (CT) in children with minor head injury is determined by the presence or absence of the physician during assessment in the emergency room. Clinical files of 92 patients from 8 months to 4 years of age were selected. Those children were evaluated at the emergency department of the Spanish Hospital of Mexico due to non-severe traumatic brain injury. Glasgow Coma Scale (GCS) score was determined in all patients. Groups of patients were compared: 1) patients having CT, 2) patients with a physician who attended the initial assessment, 3) patients whose attending physician did not arrive to assess the patient and 4) patients assessed by the emergency room staff. 38% of patients with non-severe brain injury underwent CT, 8.6% had a brain injury visible on the CT. Moderate intensity impacts were greater in patients with CT. Regarding the ECG, it was found that most children scored 15 points (p=0.03). In patients without a physician, a greater trend was demonstrated for performing CT. Patients with minor head injury but without neurological signs should undergo a detailed clinical evaluation in order to avoid unwarranted CT. Copyright © 2015. Publicado por Masson Doyma México S.A.

Relationship between solitary pulmonary nodule lung cancer and CT image features based on gradual clustering

NASA Astrophysics Data System (ADS)

Zhang, Weipeng

2017-06-01

The relationship between the medical characteristics of lung cancers and computer tomography (CT) images are explored so as to improve the early diagnosis rate of lung cancers. This research collected CT images of patients with solitary pulmonary nodule lung cancer, and used gradual clustering methodology to classify them. Preliminary classifications were made, followed by continuous modification and iteration to determine the optimal condensation point, until iteration stability was achieved. Reasonable classification results were obtained. the clustering results fell into 3 categories. The first type of patients was mostly female, with ages between 50 and 65 years. CT images of solitary pulmonary nodule lung cancer for this group contain complete lobulation and burr, with pleural indentation; The second type of patients was mostly male with ages between 50 and 80 years. CT images of solitary pulmonary nodule lung cancer for this group contain complete lobulation and burr, but with no pleural indentation; The third type of patients was also mostly male with ages between 50 and 80 years. CT images for this group showed no abnormalities. the application of gradual clustering methodology can scientifically classify CT image features of patients with lung cancer in the initial lesion stage. These findings provide the basis for early detection and treatment of malignant lesions in patients with lung cancer.

Computed tomography is not justified in every pediatric blunt trauma patient with a suspicious mechanism of injury.

PubMed

Hershkovitz, Yehuda; Zoarets, Itai; Stepansky, Albert; Kozer, Eran; Shapira, Zahar; Klin, Baruch; Halevy, Ariel; Jeroukhimov, Igor

2014-07-01

Computed tomography (CT) has become an important tool for the diagnosis of intra-abdominal and chest injuries in patients with blunt trauma. The role of CT in conscious asymptomatic patients with a suspicious mechanism of injury remains controversial. This controversy intensifies in the management of pediatric blunt trauma patients, who are much more susceptible to radiation exposure. The objective of this study was to evaluate the role of abdominal and chest CT imaging in asymptomatic pediatric patients with a suspicious mechanism of injury. Forty-two pediatric patients up to 15 years old were prospectively enrolled. All patients presented with a suspicious mechanism of blunt trauma and multisystem injury. They were neurologically intact and had no signs of injury to the abdomen or chest. Patients underwent CT imaging of the chest and abdomen as part of the initial evaluation. Thirty-one patients (74%) had a normal CT scan. Two patients of 11 with an abnormal CT scan required a change in management and were referred for observation in the Intensive Care Unit. None of the patients required surgical intervention. The routine use of CT in asymptomatic pediatric patients with a suspicious mechanism of blunt trauma injury is not justified. Copyright © 2014 Elsevier Inc. All rights reserved.

A Compact Torus Fusion Reactor Utilizing a Continuously Generated Strings of CT's. The CT String Reactor, CTSR.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, C W; Reisman, D B; McLean, H S

2007-05-30

A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal fieldmore » opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.« less

Non-stimulated adrenal venous sampling using Dyna computed tomography in patients with primary aldosteronism

PubMed Central

Chang, Chin-Chen; Lee, Bo-Ching; Liu, Kao-Lang; Chang, Yeun-Chung; Wu, Vin-Cent; Huang, Kuo-How

2016-01-01

In this retrospective study, we aimed to examine the effect of applying Dyna computed tomography (CT) on the success rate of adrenal venous sampling (AVS) without adrenocorticotropic hormone stimulation. A total of 100 consecutive patients with primary aldosteronism who underwent AVS between May 2012 and July 2015 were enrolled. In all the cases, Dyna CT was used in AVS to validate catheter position in the right adrenal vein. A selectivity index (cortisoladrenal vein /cortisolinferior vena cava) of ≥2.0 of both adrenal veins were required for successful AVS. Dyna CT indicated misplaced catheters in 16 patients; of these patients, 75% (12/16) eventually had successful right AVS after catheter repositioning. The success rate of initial sampling at the right adrenal vein was 76% (76/100), which increased to 88% (88/100) after Dyna CT was applied (p < 0.001). The most common inadvertently catheterised vessels detected using Dyna CT were the accessory hepatic veins (56.3%, 9/16), followed by the renal capsular veins (37.5%, 6/16). The overall success rate of non-stimulated AVS using Dyna CT was 87% (87/100). Thus, the application of Dyna CT further increased the success rate of non-stimulated AVS. PMID:27876824

Mastoid bone fracture presenting as unusual delayed onset of facial nerve palsy.

PubMed

Hsu, Ko-Chiang; Wang, Ann-Ching; Chen, Shyi-Jou

2008-03-01

Delayed-onset facial nerve paralysis is a rather uncommon complication of a mastoid bone fracture for children younger than 10 years. We routinely arrange a cranial computed tomography (CT) for patients encountering initial loss of consciousness, severe headache, intractable vomiting, and/or any neurologic deficit arising from trauma to the head. However, minor symptomatic cranial nerve damage may be missed and the presenting symptom diagnosed as being a peripheral nerve problem. Herein, we report a case of a young boy who presented at our emergency department (ED) 3 days subsequent to his accident, complaining of hearing loss in the right ear and paralysis of the ipsilateral face. Unpredictably, we observed his cranial CT scan revealing a linear fracture of the skull over the right temporal bone involving the right mastoid air cells. The patient was treated conservatively and recovered well without any adverse neurologic consequences. We emphasize that ED physicians should arrange a cranial CT scan for a head-injured child with symptomatic facial nerve palsy, even if there are no symptoms such as severe headache, vomiting, Battle sign, and/or initial loss of consciousness.

Generative Adversarial Networks for Noise Reduction in Low-Dose CT.

PubMed

Wolterink, Jelmer M; Leiner, Tim; Viergever, Max A; Isgum, Ivana

2017-12-01

Noise is inherent to low-dose CT acquisition. We propose to train a convolutional neural network (CNN) jointly with an adversarial CNN to estimate routine-dose CT images from low-dose CT images and hence reduce noise. A generator CNN was trained to transform low-dose CT images into routine-dose CT images using voxelwise loss minimization. An adversarial discriminator CNN was simultaneously trained to distinguish the output of the generator from routine-dose CT images. The performance of this discriminator was used as an adversarial loss for the generator. Experiments were performed using CT images of an anthropomorphic phantom containing calcium inserts, as well as patient non-contrast-enhanced cardiac CT images. The phantom and patients were scanned at 20% and 100% routine clinical dose. Three training strategies were compared: the first used only voxelwise loss, the second combined voxelwise loss and adversarial loss, and the third used only adversarial loss. The results showed that training with only voxelwise loss resulted in the highest peak signal-to-noise ratio with respect to reference routine-dose images. However, CNNs trained with adversarial loss captured image statistics of routine-dose images better. Noise reduction improved quantification of low-density calcified inserts in phantom CT images and allowed coronary calcium scoring in low-dose patient CT images with high noise levels. Testing took less than 10 s per CT volume. CNN-based low-dose CT noise reduction in the image domain is feasible. Training with an adversarial network improves the CNNs ability to generate images with an appearance similar to that of reference routine-dose CT images.

68Ga-DOTATATE PET/CT interobserver agreement for neuroendocrine tumor assessments: results from a prospective study on 50 patients

PubMed Central

Fendler, Wolfgang Peter; Barrio, Martin; Spick, Claudio; Allen-Auerbach, Martin; Ambrosini, Valentina; Benz, Matthias; Bluemel, Christina; Grewal, Ravinder Kaur; Lapa, Constantin; Miederer, Matthias; Nicolas, Guillaume; Schuster, Tibor; Czernin, Johannes; Herrmann, Ken

2016-01-01

We evaluated the observer agreement for 68Ga-DOTATATE PET/CT study interpretations in patients with neuroendocrine tumors (NET). Methods 68Ga-DOTATATE PET/CT was performed in 50 patients with known or suspected NET of the small bowel (n = 19), pancreas (n = 14), lung (n = 4) or other location (n = 13). Images were reviewed by seven observers who used a standardized approach for image interpretation. Observers were classified as having low (<500 scans or <5 years experience with 68Ga-DOTATATE PET/CT; n = 4) or high level of experience (≥500 scans and ≥5 years experience with 68Ga-DOTATATE PET/CT; n = 3). Interpretation by the primary nuclear medicine physician un-blinded to all clinical and imaging data served as reference standard. Interobserver agreement was determined by Cohen's κ and intraclass correlation coefficient (ICC) with corresponding 95% confidence interval (CI). Results Interobserver agreement was substantial and the median number of false findings (FF) was low for the overall scan result; i.e. positive versus negative study (κ = 0.80, 95%CI 0.74–0.86; FF = 3), organ involvement (κ = 0.70, 95%CI 0.64–0.76; FF = 5), and lymph node involvement (κ = 0.71, 95%CI 0.65–0.78; FF = 6). The interobserver agreement was substantial to almost-perfect and the average absolute difference (Δ) to the reference reader was low for number of organ and lymph node metastases (ICC = 0.84, 95%CI 0.77–0.89, Δ = 0.45 and ICC = 0.77, 95%CI 0.69–0.84, Δ = 0.45), tumor SUVmax (ICC = 0.99, 95%CI 0.97–0.99; Δ = 0.44) and reference SUV (SUVmean spleen: ICC = 0.81, Δ = 1.10; SUVmax liver ICC = 0.79, Δ = 0.62). Interpretations of the appropriateness for peptide-receptor radionuclide therapy (PRRT) varied more significantly among observers (κ = 0.64, 95%CI 0.57–0.70) and a higher frequency of false positive recommendations for PRRT occurred in observers with low versus high levels of experience (range, 7–12 versus 4–8). Conclusion The interpretation of 68Ga-DOTATATE PET/CT for NET staging is consistent among readers with low and high levels of experience. However, image based recommendations for or against PRRT require experience and training. PMID:27539839

Image Guided Planning for Prostate Carcinomas With Incorporation of Anti-3-[18F]FACBC (Fluciclovine) Positron Emission Tomography: Workflow and Initial Findings From a Randomized Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schreibmann, Eduard, E-mail: eschre2@emory.edu; Schuster, David M.; Rossi, Peter J.

Purpose: {sup 18}F-Fluciclovine (anti-1-amino-3-[{sup 18}F]fluorocyclobutane-1-carboxylic acid) is a novel positron emission tomography (PET)/computed tomography (CT) radiotracer that has demonstrated utility for detection of prostate cancer. Our goal is to report the initial results from a randomized controlled trial of the integration of {sup 18}F-fluciclovine PET-CT into treatment planning for defining prostate bed and lymph node target volumes. Methods and Materials: We report our initial findings from a cohort of 41 patients, of the first enrolled on a randomized controlled trial, who were randomized to the {sup 18}F-fluciclovine arm. All patients underwent {sup 18}F-fluciclovine PET-CT for the detection of metabolic abnormalitiesmore » and high-resolution CT for treatment planning. The 2 datasets were registered first by use of a rigid registration. If soft tissue displacement was observable, the rigid registration was improved with a deformable registration. Each {sup 18}F-fluciclovine abnormality was segmented as a percentage of the maximum standard uptake value (SUV) within a small region of interest around the lesion. The percentage best describing the SUV falloff was integrated in planning by expanding standard target volumes with the PET abnormality. Results: In 21 of 55 abnormalities, a deformable registration was needed to map the {sup 18}F-fluciclovine activity into the simulation CT. The most selected percentage was 50% of maximum SUV, although values ranging from 15% to 70% were used for specific patients, illustrating the need for a per-patient selection of a threshold SUV value. The inclusion of {sup 18}F-fluciclovine changed the planning volumes for 46 abnormalities (83%) of the total 55, with 28 (51%) located in the lymph nodes, 11 (20%) in the prostate bed, 10 (18%) in the prostate, and 6 (11%) in the seminal vesicles. Only 9 PET abnormalities were fully contained in the standard target volumes based on the CT-based segmentations and did not necessitate expansion. Conclusions: The use of {sup 18}F-fluciclovine in postprostatectomy radiation therapy planning was feasible and led to augmentation of the target volumes in the majority (30 of 41) of the patients studied.« less

Application of fluence field modulation to proton computed tomography for proton therapy imaging.

PubMed

Dedes, G; De Angelis, L; Rit, S; Hansen, D; Belka, C; Bashkirov, V; Johnson, R P; Coutrakon, G; Schubert, K E; Schulte, R W; Parodi, K; Landry, G

2017-07-12

This simulation study presents the application of fluence field modulated computed tomography, initially developed for x-ray CT, to proton computed tomography (pCT). By using pencil beam (PB) scanning, fluence modulated pCT (FMpCT) may achieve variable image quality in a pCT image and imaging dose reduction. Three virtual phantoms, a uniform cylinder and two patients, were studied using Monte Carlo simulations of an ideal list-mode pCT scanner. Regions of interest (ROI) were selected for high image quality and only PBs intercepting them preserved full fluence (FF). Image quality was investigated in terms of accuracy (mean) and noise (standard deviation) of the reconstructed proton relative stopping power compared to reference values. Dose calculation accuracy on FMpCT images was evaluated in terms of dose volume histograms (DVH), range difference (RD) for beam-eye-view (BEV) dose profiles and gamma evaluation. Pseudo FMpCT scans were created from broad beam experimental data acquired with a list-mode pCT prototype. FMpCT noise in ROIs was equivalent to FF images and accuracy better than  -1.3%(-0.7%) by using 1% of FF for the cylinder (patients). Integral imaging dose reduction of 37% and 56% was achieved for the two patients for that level of modulation. Corresponding DVHs from proton dose calculation on FMpCT images agreed to those from reference images and 96% of BEV profiles had RD below 2 mm, compared to only 1% for uniform 1% of FF. Gamma pass rates (2%, 2 mm) were 98% for FMpCT while for uniform 1% of FF they were as low as 59%. Applying FMpCT to preliminary experimental data showed that low noise levels and accuracy could be preserved in a ROI, down to 30% modulation. We have shown, using both virtual and experimental pCT scans, that FMpCT is potentially feasible and may allow a means of imaging dose reduction for a pCT scanner operating in PB scanning mode. This may be of particular importance to proton therapy given the low integral dose found outside the target.

TU-AB-BRA-03: Atlas-Based Algorithms with Local Registration-Goodness Weighting for MRI-Driven Electron Density Mapping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farjam, R; Tyagi, N; Veeraraghavan, H

Purpose: To develop image-analysis algorithms to synthesize CT with accurate electron densities for MR-only radiotherapy of head & neck (H&N) and pelvis anatomies. Methods: CT and 3T-MRI (Philips, mDixon sequence) scans were randomly selected from a pool of H&N (n=11) and pelvis (n=12) anatomies to form an atlas. All MRIs were pre-processed to eliminate scanner and patient-induced intensity inhomogeneities and standardize their intensity histograms. CT and MRI for each patient were then co-registered to construct CT-MRI atlases. For more accurate CT-MR fusion, bone intensities in CT were suppressed to improve the similarity between CT and MRI. For a new patient,more » all CT-MRI atlases are deformed onto the new patients’ MRI initially. A newly-developed generalized registration error (GRE) metric was then calculated as a measure of local registration accuracy. The synthetic CT value at each point is a 1/GRE-weighted average of CTs from all CT-MR atlases. For evaluation, the mean absolute error (MAE) between the original and synthetic CT (generated in a leave-one-out scheme) was computed. The planning dose from the original and synthetic CT was also compared. Results: For H&N patients, MAE was 67±9, 114±22, and 116±9 HU over the entire-CT, air and bone regions, respectively. For pelvis anatomy, MAE was 47±5 and 146±14 for the entire and bone regions. In comparison with MIRADA medical, an FDA-approved registration tool, we found that our proposed registration strategy reduces MAE by ∼30% and ∼50% over the entire and bone regions, respectively. GRE-weighted strategy further lowers MAE by ∼15% to ∼40%. Our primary dose calculation also showed highly consistent results between the original and synthetic CT. Conclusion: We’ve developed a novel image-analysis technique to synthesize CT for H&N and pelvis anatomies. Our proposed image fusion strategy and GRE metric help generate more accurate synthetic CT using locally more similar atlases (Support: Philips Healthcare). The research is supported by Philips HealthCare.« less

Intraprocedural yttrium-90 positron emission tomography/CT for treatment optimization of yttrium-90 radioembolization.

PubMed

Bourgeois, Austin C; Chang, Ted T; Bradley, Yong C; Acuff, Shelley N; Pasciak, Alexander S

2014-02-01

Radioembolization with yttrium-90 ((90)Y) microspheres relies on delivery of appropriate treatment activity to ensure patient safety and optimize treatment efficacy. We report a case in which (90)Y positron emission tomography (PET)/computed tomography (CT) was performed to optimize treatment planning during a same-day, three-part treatment session. This treatment consisted of (i) an initial (90)Y infusion with a dosage determined using an empiric treatment planning model, (ii) quantitative (90)Y PET/CT imaging, and (iii) a secondary infusion with treatment planning based on quantitative imaging data with the goal of delivering a specific total tumor absorbed dose. © 2014 SIR Published by SIR All rights reserved.

Pseudoaneurysm of the thoracic aorta sustained during exposure to a tornado diagnosed with ECG-synchronized CT aortography.

PubMed

Chakraborty, Amit; von Herrmann, Paul F; Embertson, Ryan E; Landwehr, Kevin P; Winkler, Michael A

2016-01-01

A case of a tornado victim with a delayed presentation of injury to the aortic isthmus is discussed. Tornado forces resemble the forces of high energy explosions, and the injuries that can occur as a result of these forces can be bizarre. The patient presented with the unique computed tomography (CT) findings of isolated pseudoaneurysm of the thoracic aorta in the absence of other traumatic injury to the thorax. Equivocal results of the initial CT aortogram (CTA) were confirmed with ECG-synchronized CTA (ECG-CTA), demonstrating the superiority of ECG-CTA as compared to standard CTA. Copyright © 2016 Elsevier Inc. All rights reserved.

IgG4-Related Disease Simulating Carcinoma Colon With Diffuse Peritoneal Carcinomatosis on 18F-FDG PET/CT.

PubMed

Vadi, Shelvin Kumar; Parihar, Ashwin Singh; Kumar, Rajender; Singh, Harmandeep; Mittal, Bhagwant Rai; Bal, Amanjit; Sinha, Saroj Kumar

2018-05-14

IgG4-related disease (IgG4-RD) continues to be a diagnostic challenge and a great mimicker of malignancies. We report here a case of young man who presented with subacute intestinal obstruction with initial imaging and clinical features suggestive of carcinoma colon. 18F-FDG PET/CT showed diffuse peritoneal carcinomatosis pattern typically seen with abdominal malignancies. However, the histopathology and the raised IgG4 levels diagnosed it to be IgG4-RD. Although 18F-FDG PET/CT has typical patterns corresponding to the multisystemic involvement of IgG4-RD, the index case did not show any such findings.

Factors in the Spread of Continuing Training in the European Community.

ERIC Educational Resources Information Center

Aventur, Francois; Campo, Christian; Moebus, Martine

1999-01-01

A study compared 17 European countries' initial and continuing vocational training systems. Two kinds of continuing training (CT)--that which is initiated by the employer and that which is intiated by the individual--provide an indicator for comparing the different situations observed throughout the European Community. The two forms are mutually…

CT imaging, then and now: a 30-year review of the economics of computed tomography.

PubMed

Stockburger, Wayne T

2004-01-01

The first computed tomography (CT) scanner in the US was installed in June 1973 at the Mayo Clinic in Rochester, MN. By the end of 1974, 44 similar systems had been installed at medical facilities around the country. Less than 4 years after the introduction of CT imaging in the US, at least 400 CT systems had been installed. The practice of pneumoencephalography was eliminated. The use of nuclear medicine brain scans significantly diminished. At the time, CT imaging was limited to head studies, but with the introduction of contrast agents and full body CT systems the changes in the practice of medicine became even more significant. CT imaging was hailed by the US medical community as the greatest advance in radiology since the discovery of x-rays. But the rapid spread of CT systems, their frequency of use, and the associated increase in healthcare costs combined to draw the attention of decision-makers within the federal and state governments, specifically to establish policies regarding the acquisition and use of diagnostic technologies. Initially, CT imaging was limited to neurological applications, but in the 30 years since its inception, capabilities and applications have been expanded as a result of the advancements in technology and software development. While neurological disorders are still a common reason for CT imaging, many other medical disciplines (oncology, emergency medicine, orthopedics, etc.) have found CT imaging to be the definitive tool for diagnostic information. As such, the clinical demand for CT imaging has steadily increased. Economically, the development of CT imaging has been one of success, even in the face of governmental action to restrict its acquisition and utilization by healthcare facilities. CTimaging has increased the cost of healthcare, but in turn has added unquantifiable value to the practice of medicine in the US.

Echocardiography as an indication of continuous-time cardiac quiescence

NASA Astrophysics Data System (ADS)

Wick, C. A.; Auffermann, W. F.; Shah, A. J.; Inan, O. T.; Bhatti, P. T.; Tridandapani, S.

2016-07-01

Cardiac computed tomography (CT) angiography using prospective gating requires that data be acquired during intervals of minimal cardiac motion to obtain diagnostic images of the coronary vessels free of motion artifacts. This work is intended to assess B-mode echocardiography as a continuous-time indication of these quiescent periods to determine if echocardiography can be used as a cost-efficient, non-ionizing modality to develop new prospective gating techniques for cardiac CT. These new prospective gating approaches will not be based on echocardiography itself but on CT-compatible modalities derived from the mechanics of the heart (e.g. seismocardiography and impedance cardiography), unlike the current standard electrocardiogram. To this end, echocardiography and retrospectively-gated CT data were obtained from ten patients with varied cardiac conditions. CT reconstructions were made throughout the cardiac cycle. Motion of the interventricular septum (IVS) was calculated from both echocardiography and CT reconstructions using correlation-based, deviation techniques. The IVS was chosen because it (1) is visible in echocardiography images, whereas the coronary vessels generally are not, and (2) has been shown to be a suitable indicator of cardiac quiescence. Quiescent phases were calculated as the minima of IVS motion and CT volumes were reconstructed for these phases. The diagnostic quality of the CT reconstructions from phases calculated from echocardiography and CT data was graded on a four-point Likert scale by a board-certified radiologist fellowship-trained in cardiothoracic radiology. Using a Wilcoxon signed-rank test, no significant difference in the diagnostic quality of the coronary vessels was found between CT volumes reconstructed from echocardiography- and CT-selected phases. Additionally, there was a correlation of 0.956 between the echocardiography- and CT-selected phases. This initial work suggests that B-mode echocardiography can be used as a tool to develop CT-compatible gating techniques based on modalities derived from cardiac mechanics rather than relying on the ECG alone.

Microstructural examination of

NASA Astrophysics Data System (ADS)

Fukuoka, C.; Yoshizawa, H.; Nakagawa, Y. G.; Lapides, M. E.

1993-10-01

Fatigue tests were performed to examine how microstructural conditioning influences crack initiation and propagation in SA508 class 3 low-carbon steel. A 3-mm-long crack was introduced in compact tension (CT) fatigue test specimens under four different loads in order to obtain crack tip plastic zones at different stress intensity factor ranges, ΔK = 18, 36, 54, and 72 MPa√m. The microstructure of the plastic zones around the crack tip were examined by trans- mission electron microscopy (TEM) and selected area electron diffraction (SAD). Micro- orientation of the dislocation cells in the plastic zones of all of the CT samples increased to 4 deg from the level of an as-received sample. Four-point bending fatigue tests were performed for plate shape samples with a large cyclic strain range. The SAD value of the bending samples was also 4 deg in the damaged area where cracks already initiated at an early stage of the fatigue process. These test results indicate that the microstructural conditioning is a prerequisite for the fatigue crack initiation and propagation in SA508. These observations may lead to better under- standing of how fatigue initiation processes transit to cracks.

It's a question of endurance - Patients with head and neck cancer experiences of 18F-FDG PET/CT in a fixation mask.

PubMed

Andersson, Camilla; Röing, Marta; Tiblom Ehrsson, Ylva; Johansson, Birgitta

2017-08-01

This study aimed to explore how patients with head and neck cancer experienced undergoing an 18 F-fluoro-deoxy-glucose positrons emissions tomography/computed tomography ( 18 F-FDG PET/CT) examination in a fixation mask. Interviews were conducted with nine patients with known or suspected head and neck cancer who were scheduled for the examination for the first time. The phenomenological method according to van Manen and his four lifeworld existentials; lived space, lived body, lived time, and lived relation was used to analyse the interviews. The thoughts and feelings of the patients during the PET/CT examination varied, some found it very difficult, while others did not. However, for all the patients, it was an experience that required some form of coping to maintain composure for example distraction. PET/CT examnation in a fixation mask may be strenuous for some patients. Patients need more detailed information, including suggestions for coping behaviours, prior to the examination, as well as higher level of support during and after the examination. The results of this study may be used to improve patient care and optimize the procedure of PET/CT examination in a fixation mask. Copyright © 2017 Elsevier Ltd. All rights reserved.

Feature-based US to CT registration of the aortic root

NASA Astrophysics Data System (ADS)

Lang, Pencilla; Chen, Elvis C. S.; Guiraudon, Gerard M.; Jones, Doug L.; Bainbridge, Daniel; Chu, Michael W.; Drangova, Maria; Hata, Noby; Jain, Ameet; Peters, Terry M.

2011-03-01

A feature-based registration was developed to align biplane and tracked ultrasound images of the aortic root with a preoperative CT volume. In transcatheter aortic valve replacement, a prosthetic valve is inserted into the aortic annulus via a catheter. Poor anatomical visualization of the aortic root region can result in incorrect positioning, leading to significant morbidity and mortality. Registration of pre-operative CT to transesophageal ultrasound and fluoroscopy images is a major step towards providing augmented image guidance for this procedure. The proposed registration approach uses an iterative closest point algorithm to register a surface mesh generated from CT to 3D US points reconstructed from a single biplane US acquisition, or multiple tracked US images. The use of a single simultaneous acquisition biplane image eliminates reconstruction error introduced by cardiac gating and TEE probe tracking, creating potential for real-time intra-operative registration. A simple initialization procedure is used to minimize changes to operating room workflow. The algorithm is tested on images acquired from excised porcine hearts. Results demonstrate a clinically acceptable accuracy of 2.6mm and 5mm for tracked US to CT and biplane US to CT registration respectively.

Role of fluorine-18 fluorodeoxyglucose PET/CT in head and neck oncology: the point of view of the radiation oncologist

PubMed Central

Navarro, Arturo; del Hoyo, Olga; Gomez-Iturriaga, Alfonso; Alongi, Filippo; Medina, Jose A; Elicin, Olgun; Skanjeti, Andrea; Giammarile, Francesco; Bilbao, Pedro; Casquero, Francisco; de Bari, Berardino; Dal Pra, Alan

2016-01-01

Squamous cell carcinoma is the most common malignant tumour of the head and neck. The initial TNM staging, the evaluation of the tumour response during treatment, and the long-term surveillance are crucial moments in the approach to head and neck squamous cell carcinoma (HNSCC). Thus, at each of these moments, the choice of the best diagnostic tool providing the more precise and larger information is crucial. Positron emission tomography with fluorine-18 fludeoxyglucose integrated with CT (18F-FDG-PET/CT) rapidly gained clinical acceptance, and it has become an important imaging tool in routine clinical oncology. However, controversial data are currently available, for example, on the role of 18F-FDG-PET/CT imaging during radiotherapy planning, the prognostic value or its real clinical impact on treatment decisions. In this article, the role of 18F-FDG-PET/CT imaging in HNSCC during pre-treatment staging, radiotherapy planning, treatment response assessment, prognosis and follow-up is reviewed focusing on current evidence and controversial issues. A proposal on how to integrate 18F-FDG-PET/CT in daily clinical practice is also described. PMID:27416996

Blunt pancreatic trauma: A persistent diagnostic conundrum?

PubMed Central

Kumar, Atin; Panda, Ananya; Gamanagatti, Shivanand

2016-01-01

Blunt pancreatic trauma is an uncommon injury but has high morbidity and mortality. In modern era of trauma care, pancreatic trauma remains a persistent challenge to radiologists and surgeons alike. Early detection of pancreatic trauma is essential to prevent subsequent complications. However early pancreatic injury is often subtle on computed tomography (CT) and can be missed unless specifically looked for. Signs of pancreatic injury on CT include laceration, transection, bulky pancreas, heterogeneous enhancement, peripancreatic fluid and signs of pancreatitis. Pan-creatic ductal injury is a vital decision-making parameter as ductal injury is an indication for laparotomy. While lacerations involving more than half of pancreatic parenchyma are suggestive of ductal injury on CT, ductal injuries can be directly assessed on magnetic resonance imaging (MRI) or encoscopic retrograde cholangio-pancreatography. Pancreatic trauma also shows temporal evolution with increase in extent of injury with time. Hence early CT scans may underestimate the extent of injures and sequential imaging with CT or MRI is important in pancreatic trauma. Sequential imaging is also needed for successful non-operative management of pancreatic injury. Accurate early detection on initial CT and adopting a multimodality and sequential imaging strategy can improve outcome in pancreatic trauma. PMID:26981225

Relationship of brain imaging with radionuclides and with x-ray computed tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, D.E.

1981-03-03

Because of high sensitivity and specificity for altered local cerebral structure, x-ray computed tomography (CT) is the preferred initial diagnostic imaging study under most circumstances when cerebral disease is suspected. CT has no competitor for detecting fresh intracerebral hemorrhage. Radionuclide imaging (RN) scan is preferred when relative perfusion is to be assessed, in patients allergic to contrast media, and when an adequate CT study is not technically possible. (RN) plays an important complementary role to CT, especially for patients suspected of subacute or chronic subdura hematoma, cerebral infarction, arteriovenous malformations, meningitis, encephalitis, normal pressure hydrocephalus, or when CT findings aremore » inconclusive. When CT is not available, RN serves as a good screening study for suspected cerebral tumor, infection, recent infarction, arteriovenous malformation, and chronic subdural hematoma. Future improvement in radionuclide imaging by means of emission composition potential. The compound plating approacl threshold for all the investigated transistors and fast neutron spectra lies within the raal. The value of the potential slightly changes with the coordinate change in this region, i.e. the charge on a collecting electrode is not practically guided up to a certain moment of time during the movement of nonequilibrium carriers.« less