Virtual Reality Therapy for the Treatment of Alcohol Dependence: A Preliminary Investigation With Positron Emission Tomography/Computerized Tomography.

PubMed

Son, Ji Hyun; Lee, Sang Hoon; Seok, Ju Won; Kee, Baik Seok; Lee, Hyun Woong; Kim, Hyung Joon; Lee, Tae Kyung; Han, Doug Hyun

2015-07-01

Virtual reality therapy (VRT) uses multimodal stimulation that includes visual, auditory, olfactory, and gustatory stimuli. The aim of this study was to assess the effectiveness of VRT in treating subjects with alcohol dependence (AD) by evaluating changes in brain metabolism. The VRT protocol consisted of three steps: relaxation, presentation of a high-risk situation, and presentation of an aversive situation. Twelve alcohol-dependent subjects underwent 10 sessions of VRT. The alcohol-dependent subjects were assessed with 18F-fluorodeoxyglucose positron emission tomography images before and after VRT, whereas the control group underwent imaging according to the same protocol only at baseline. Compared with the healthy control group, AD subjects showed higher metabolism in the right lentiform nucleus and right temporal lobe (BA20) at baseline (P(FDR < .05) = .026). In addition, the metabolism in the left anterior cingulate was lower in subjects with AD (P(uncorr) = .001). After VRT, alcohol-dependent subjects showed decreased brain metabolism in the right lentiform nucleus (P(FDR < .05) = .026) and right temporal lobe (BA38, P(FDR < .05) = .032) relative to that at baseline. Our results suggest a neurobiological imbalance, notably, a high sensitivity to stimuli, in the limbic system in subjects with AD. Furthermore, we determined that metabolism decreased in the basal ganglia after VRT, which may explain the limbic-regulated responses of reward and regulation. Therefore, we tentatively recommend VRT to treat AD through its regulating effect on limbic circuits.

Otolaryngology and ophthalmology

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

Hanafee, W.N.

A literature review with 227 references of the diagnostic use of computerized tomography for head and neck problems is presented. The anatomy, congenital malformations, infectious diseases, and nioplasms of the auditory organs, paranasal sinuses, pharynx, larynx and salivary glands are examined in detail. A major impetus to the use of computerized tomography has been the realization by the health care industry that CT scanning offers details of tumors in the head and neck area that are not available by other modalities. (KRM)

Extension of the Gladstone-Dale equation for flame flow field diagnosis by optical computerized tomography

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

Chen Yunyun; Li Zhenhua; Song Yang

2009-05-01

An extended model of the original Gladstone-Dale (G-D) equation is proposed for optical computerized tomography (OCT) diagnosis of flame flow fields. For the purpose of verifying the newly established model, propane combustion is used as a practical example for experiment, and moire deflection tomography is introduced with the probe wavelength 808 nm. The results indicate that the temperature based on the extended model is more accurate than that based on the original G-D equation. In a word, the extended model can be suitable for all kinds of flame flow fields whatever the components, temperature, and ionization are.

Computerized tomography using video recorded fluoroscopic images

NASA Technical Reports Server (NTRS)

Kak, A. C.; Jakowatz, C. V., Jr.; Baily, N. A.; Keller, R. A.

1975-01-01

A computerized tomographic imaging system is examined which employs video-recorded fluoroscopic images as input data. By hooking the video recorder to a digital computer through a suitable interface, such a system permits very rapid construction of tomograms.

Technology in the Assessment of Learning Disability.

ERIC Educational Resources Information Center

Bigler, Erin D.; Lajiness-O'Neill, Renee; Howes, Nancy-Louise

1998-01-01

Reviews recent neuroradiologic and brain imaging techniques in the assessment of learning disability. Technologies reviewed include computerized tomography; magnetic resonance imaging; electrophysiological and metabolic imaging; computerized electroencepholographic studies of evoked potentials, event-related potentials, spectral analysis, and…

Computerized tomography platform using beta rays

NASA Astrophysics Data System (ADS)

Paetkau, Owen; Parsons, Zachary; Paetkau, Mark

2017-12-01

A computerized tomography (CT) system using a 0.1 μCi Sr-90 beta source, Geiger counter, and low density foam samples was developed. A simple algorithm was used to construct images from the data collected with the beta CT scanner. The beta CT system is analogous to X-ray CT as both types of radiation are sensitive to density variations. This system offers a platform for learning opportunities in an undergraduate laboratory, covering topics such as image reconstruction algorithms, radiation exposure, and the energy dependence of absorption.

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

PubMed

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, <0.001 and 0.0002, respectively). When comparing measurement errors between stones of different composition in vitro, the error for calcium oxalate calculi was significantly different from the gold standard for all methods except bone window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x magnified bone windows was superior to 4.0x magnified soft tissue windows in measurement accuracy. Magnified bone window measurements were not statistically different from digital caliper measurements (mean underestimation vs digital caliper 0.3 mm, p = 0.4), while magnified soft tissue windows were statistically distinct (mean underestimation 1.4 mm, p = 0.001). In this study magnified bone windows were the most accurate method of stone measurements in vitro and in vivo. Therefore, we recommend the routine use of magnified bone windows for computerized tomography measurement of stones. In vitro the measurement error in calcium oxalate stones was greater than that in uric acid stones, suggesting that stone composition may be responsible for measurement inaccuracies.

Computerized tomography tailored for the assessment of microscopic hematuria.

PubMed

Lang, Erich K; Macchia, Richard J; Thomas, Raju; Ruiz-Deya, Gilberto; Watson, Richard A; Richter, Frank; Irwin R, Robert; Marberger, Michael; Mydlo, Jack; Lechner, Gerhard; Cho, Kyunghee C; Gayle, Brian

2002-02-01

We report the results of a multicenter study of arterial, corticomedullary, nephrographic and excretory phase helical computerized tomography (CT) for detecting and characterizing abnormalities causing asymptomatic microscopic hematuria. We evaluated 350 consecutive patients, including 216 men and 134 women 23 to 88 years old, with asymptomatic microscopic hematuria of undetermined cause at 4 medical centers. Patients with known urological pathology were excluded from study. We performed 4 helical CT sequences, including pre-enhancement phase imaging from kidney to symphysis pubis, arterial phase imaging of the kidney and lower pelvis, corticomedullary nephrographic phase imaging of the kidney and lower pelvis, and excretory phase imaging from kidney to symphysis pubis with 2 to 5 mm. collimation and 1 to 1.5 pitch. Of 171 proved lesions 158 were correctly diagnosed. There were 10 false-positive and 13 false-negative diagnoses, indicating 0.9239 sensitivity, 0.9441 specificity, 0.9404 positive and 0.9285 negative predictive values, (p <0.001). All cases of congenital renal lesions, calculous disease, ureteral lesion and neoplastic lesion of the bladder were correctly diagnosed, as were 40 of 41 inflammatory renal, 21 of 23 renal masses and 13 of 16 inflammatory bladder lesions. In 27 patients with renal calculi the study was limited to pre-enhancement spiral CT. A positive diagnosis rate of 45.1% (158 of 350 cases) for the causes of heretofore refractory cases of hematuria with high sensitivity and specificity attest to the effectiveness of our hematuria CT protocol and support its use.

Non-Conventional Applications of Computerized Tomography: Analysis of Solid Dosage Forms Produced by Pharmaceutical Industry

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

Martins de Oliveira, Jose Jr.; Germano Martins, Antonio Cesar

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe a non-conventional application of computerized tomography: visualization and improvements in the understanding of some internal structural features of solid dosage forms. A micro-CT X-ray scanner, with a minimum resolution of 30 mum was used to characterize some pharmaceutical tablets, granules, controlled-release osmotic tablet and liquid-filled soft-gelatin capsules. The analysis presented in this work are essentially qualitative, but quantitative parameters, such as porosity, density distribution, tablets dimensions, etc. could also be obtained using the related CT techniques.

Asymptomatic Emphysematous Pyelonephritis - Positron Emission Tomography Computerized Tomography Aided Diagnostic and Therapeutic Elucidation

PubMed Central

Pathapati, Deepti; Shinkar, Pawan Gulabrao; kumar, Satya Awadhesh; Jha; Dattatreya, Palanki Satya; Chigurupati, Namrata; Chigurupati, Mohana Vamsy; Rao, Vatturi Venkata Satya Prabhakar

2017-01-01

The authors report an interesting coincidental unearthing by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of a potentially serious medical condition of emphysematous pyelonephritis in a case of nasopharyngeal carcinoma. The management by conservative ureteric stenting and antibiotics was done with gratifying clinical outcome. PMID:28242985

Health technology assessment review: Computerized glucose regulation in the intensive care unit - how to create artificial control

PubMed Central

2009-01-01

Current care guidelines recommend glucose control (GC) in critically ill patients. To achieve GC, many ICUs have implemented a (nurse-based) protocol on paper. However, such protocols are often complex, time-consuming, and can cause iatrogenic hypoglycemia. Computerized glucose regulation protocols may improve patient safety, efficiency, and nurse compliance. Such computerized clinical decision support systems (Cuss) use more complex logic to provide an insulin infusion rate based on previous blood glucose levels and other parameters. A computerized CDSS for glucose control has the potential to reduce overall workload, reduce the chance of human cognitive failure, and improve glucose control. Several computer-assisted glucose regulation programs have been published recently. In order of increasing complexity, the three main types of algorithms used are computerized flowcharts, Proportional-Integral-Derivative (PID), and Model Predictive Control (MPC). PID is essentially a closed-loop feedback system, whereas MPC models the behavior of glucose and insulin in ICU patients. Although the best approach has not yet been determined, it should be noted that PID controllers are generally thought to be more robust than MPC systems. The computerized Cuss that are most likely to emerge are those that are fully a part of the routine workflow, use patient-specific characteristics and apply variable sampling intervals. PMID:19849827

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance

Science.gov Websites

Radiopharmaceuticals, DOE Technical Report, 1977 Emission Computed Tomography: A New Technique for the Quantitative Extending the Power of Nuclear Magnetic Resonance Techniques Magnetic Resonance Imaging Research Top Some

Research on ionospheric tomography based on variable pixel height

NASA Astrophysics Data System (ADS)

Zheng, Dunyong; Li, Peiqing; He, Jie; Hu, Wusheng; Li, Chaokui

2016-05-01

A novel ionospheric tomography technique based on variable pixel height was developed for the tomographic reconstruction of the ionospheric electron density distribution. The method considers the height of each pixel as an unknown variable, which is retrieved during the inversion process together with the electron density values. In contrast to conventional computerized ionospheric tomography (CIT), which parameterizes the model with a fixed pixel height, the variable-pixel-height computerized ionospheric tomography (VHCIT) model applies a disturbance to the height of each pixel. In comparison with conventional CIT models, the VHCIT technique achieved superior results in a numerical simulation. A careful validation of the reliability and superiority of VHCIT was performed. According to the results of the statistical analysis of the average root mean square errors, the proposed model offers an improvement by 15% compared with conventional CIT models.

Computerized tomography calibrator

NASA Technical Reports Server (NTRS)

Engel, Herbert P. (Inventor)

1991-01-01

A set of interchangeable pieces comprising a computerized tomography calibrator, and a method of use thereof, permits focusing of a computerized tomographic (CT) system. The interchangeable pieces include a plurality of nestable, generally planar mother rings, adapted for the receipt of planar inserts of predetermined sizes, and of predetermined material densities. The inserts further define openings therein for receipt of plural sub-inserts. All pieces are of known sizes and densities, permitting the assembling of different configurations of materials of known sizes and combinations of densities, for calibration (i.e., focusing) of a computerized tomographic system through variation of operating variables thereof. Rather than serving as a phanton, which is intended to be representative of a particular workpiece to be tested, the set of interchangeable pieces permits simple and easy standardized calibration of a CT system. The calibrator and its related method of use further includes use of air or of particular fluids for filling various openings, as part of a selected configuration of the set of pieces.

Computerized N-acetylcysteine physician order entry by template protocol for acetaminophen toxicity.

PubMed

Thompson, Trevonne M; Lu, Jenny J; Blackwood, Louisa; Leikin, Jerrold B

2011-01-01

Some medication dosing protocols are logistically complex for traditional physician ordering. The use of computerized physician order entry (CPOE) with templates, or order sets, may be useful to reduce medication administration errors. This study evaluated the rate of medication administration errors using CPOE order sets for N-acetylcysteine (NAC) use in treating acetaminophen poisoning. An 18-month retrospective review of computerized inpatient pharmacy records for NAC use was performed. All patients who received NAC for the treatment of acetaminophen poisoning were included. Each record was analyzed to determine the form of NAC given and whether an administration error occurred. In the 82 cases of acetaminophen poisoning in which NAC was given, no medication administration errors were identified. Oral NAC was given in 31 (38%) cases; intravenous NAC was given in 51 (62%) cases. In this retrospective analysis of N-acetylcysteine administration using computerized physician order entry and order sets, no medication administration errors occurred. CPOE is an effective tool in safely executing complicated protocols in an inpatient setting.

Radionuclide and Fluorescence Imaging of Clear Cell Renal Cell Carcinoma Using Dual Labeled Anti-Carbonic Anhydrase IX Antibody G250.

PubMed

Muselaers, Constantijn H J; Rijpkema, Mark; Bos, Desirée L; Langenhuijsen, Johan F; Oyen, Wim J G; Mulders, Peter F A; Oosterwijk, Egbert; Boerman, Otto C

2015-08-01

Tumor targeted optical imaging using antibodies labeled with near infrared fluorophores is a sensitive imaging modality that might be used during surgery to assure complete removal of malignant tissue. We evaluated the feasibility of dual modality imaging and image guided surgery with the dual labeled anti-carbonic anhydrase IX antibody preparation (111)In-DTPA-G250-IRDye800CW in mice with intraperitoneal clear cell renal cell carcinoma. BALB/c nu/nu mice with intraperitoneal SK-RC-52 lesions received 10 μg DTPA-G250-IRDye800CW labeled with 15 MBq (111)In or 10 μg of the dual labeled irrelevant control antibody NUH-82 (20 mice each). To evaluate when tumors could be detected, 4 mice per group were imaged weekly during 5 weeks with single photon emission computerized tomography/computerized tomography and the fluorescence imaging followed by ex vivo biodistribution studies. As early as 1 week after tumor cell inoculation single photon emission computerized tomography and fluorescence images showed clear delineation of intraperitoneal clear cell renal cell carcinoma with good concordance between single photon emission computerized tomography/computerized tomography and fluorescence images. The high and specific accumulation of the dual labeled antibody conjugate in tumors was confirmed in the biodistribution studies. Maximum tumor uptake was observed 1 week after inoculation (mean ± SD 58.5% ± 18.7% vs 5.6% ± 2.3% injected dose per gm for DTPA-G250-IRDye800CW vs NUH-82, respectively). High tumor uptake was also observed at other time points. This study demonstrates the feasibility of dual modality imaging with dual labeled antibody (111)In-DTPA-G250-IRDye800CW in a clear cell renal cell carcinoma model. Results indicate that preoperative and intraoperative detection of carbonic anhydrase IX expressing tumors, positive resection margins and metastasis might be feasible with this approach. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The poppy seed test for colovesical fistula: big bang, little bucks!

PubMed

Kwon, Eric O; Armenakas, Noel A; Scharf, Stephen C; Panagopoulos, Georgia; Fracchia, John A

2008-04-01

Diagnosis of a colovesical fistula is often challenging, and usually involves numerous invasive and expensive tests and procedures. The poppy seed test stands out as an exception to this rule. We evaluated the accuracy and cost-effectiveness of various established diagnostic tests used to evaluate a suspected colovesical fistula. We identified 20 prospectively entered patients with surgically confirmed colovesical fistulas between 2000 and 2006. Each patient was evaluated preoperatively with a (51)chromium nuclear study, computerized tomography of the abdomen and pelvis with oral and intravenous contrast medium, and the poppy seed test. Costs were calculated using institutional charges, 2006 Medicare limiting approved charges and the market price, respectively. The z test was used to compare the proportion of patients who tested positive for a fistula with each of these modalities. The chromium study was positive in 16 of 20 patients (80%) at a cost of $490.83 per study. Computerized tomography was positive in 14 of 20 patients (70%) at a cost of $652.92 per study. The poppy seed test was positive in 20 of 20 patients (100%) at a cost of $5.37 per study. The difference in the proportion of patients who tested positive for a fistula on computerized tomography and the poppy seed test was statistically significant (p = 0.03). There was no difference between the chromium group and the computerized tomography or poppy seed group (p = 0.72 and 0.12, respectively). The poppy seed test is an accurate, convenient and inexpensive diagnostic test. It is an ideal initial consideration for evaluating a suspected colovesical fistula.

Positron emission tomography/computerized tomography in lung cancer

PubMed Central

Vural, Gulin Ucmak

2014-01-01

Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer. PMID:24914421

The role of preoperative CT scan in patients with tracheoesophageal fistula: a review.

PubMed

Garge, Saurabh; Rao, K L N; Bawa, Monika

2013-09-01

The morbidity and mortality associated with esophageal atresia with or without a fistula make it a challenging congenital abnormality for the pediatric surgeon. Anatomic factors like inter-pouch gap and origin of fistula are not taken into consideration in various prognostic classifications. The preoperative evaluation of these cases with computerized tomography (CT) has been used by various investigators to delineate these factors. We reviewed these studies to evaluate the usefulness of this investigation in the intra operative and post operative period. A literature search was done on all peer-reviewed articles published on preoperative computed tomography (CT) in cases of tracheoesophageal fistula using the PUBMED and MEDLINE search engines. Key words included tracheoesophageal fistula, computerized tomography, virtual bronchoscopy, and 3D computerized tomography reconstruction. Further, additional articles were selected from the list of references obtained from the retrieved publications. A total of 8 articles were selected for analysis. In most of the studies, comprising 96 patients, observations noted in preoperative CT were confirmed during surgery. In a study by Mahalik et al [Mahalik SK, Sodhi KS, Narasimhan KL, Rao KL. Role of preoperative 3D CT reconstruction for evaluation of patients with esophageal atresia and tracheoesophageal fistula. Pediatr Surg Int. 2012 Jun 22. [Epub ahead of print

Semi-automatic forensic approach using mandibular midline lingual structures as fingerprint: a pilot study.

PubMed

Shaheen, E; Mowafy, B; Politis, C; Jacobs, R

2017-12-01

Previous research proposed the use of the mandibular midline neurovascular canal structures as a forensic finger print. In their observer study, an average correct identification of 95% was reached which triggered this study. To present a semi-automatic computer recognition approach to replace the observers and to validate the accuracy of this newly proposed method. Imaging data from Computer Tomography (CT) and Cone Beam Computer Tomography (CBCT) of mandibles scanned at two different moments were collected to simulate an AM and PM situation where the first scan presented AM and the second scan was used to simulate PM. Ten cases with 20 scans were used to build a classifier which relies on voxel based matching and results with classification into one of two groups: "Unmatched" and "Matched". This protocol was then tested using five other scans out of the database. Unpaired t-testing was applied and accuracy of the computerized approach was determined. A significant difference was found between the "Unmatched" and "Matched" classes with means of 0.41 and 0.86 respectively. Furthermore, the testing phase showed an accuracy of 100%. The validation of this method pushes this protocol further to a fully automatic identification procedure for victim identification based on the mandibular midline canals structures only in cases with available AM and PM CBCT/CT data.

Development of a method for measuring femoral torsion using real-time ultrasound.

PubMed

Hafiz, Eliza; Hiller, Claire E; Nicholson, Leslie L; Nightingale, E Jean; Clarke, Jillian L; Grimaldi, Alison; Eisenhuth, John P; Refshauge, Kathryn M

2014-07-01

Excessive femoral torsion has been associated with various musculoskeletal and neurological problems. To explore this relationship, it is essential to be able to measure femoral torsion in the clinic accurately. Computerized tomography (CT) and magnetic resonance imaging (MRI) are thought to provide the most accurate measurements but CT involves significant radiation exposure and MRI is expensive. The aim of this study was to design a method for measuring femoral torsion in the clinic, and to determine the reliability of this method. Details of design process, including construction of a jig, the protocol developed and the reliability of the method are presented. The protocol developed used ultrasound to image a ridge on the greater trochanter, and a customized jig placed on the femoral condyles as reference points. An inclinometer attached to the customized jig allowed quantification of the degree of femoral torsion. Measurements taken with this protocol had excellent intra- and inter-rater reliability (ICC2,1 = 0.98 and 0.97, respectively). This method of measuring femoral torsion also permitted measurement of femoral torsion with a high degree of accuracy. This method is applicable to the research setting and, with minor adjustments, will be applicable to the clinical setting.

[The role of multidetector computer tomography in diagnosis of acute pancreatitis].

PubMed

Lohanikhina, K Iu; Hordiienko, K P; Kozarenko, T M

2014-10-01

With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%.

Detection of drugs and explosives using neutron computerized tomography and artificial intelligence techniques.

PubMed

Ferreira, F J O; Crispim, V R; Silva, A X

2010-06-01

In this study the development of a methodology to detect illicit drugs and plastic explosives is described with the objective of being applied in the realm of public security. For this end, non-destructive assay with neutrons was used and the technique applied was the real time neutron radiography together with computerized tomography. The system is endowed with automatic responses based upon the application of an artificial intelligence technique. In previous tests using real samples, the system proved capable of identifying 97% of the inspected materials. Copyright 2010 Elsevier Ltd. All rights reserved.

An Analysis of the Need for a Whole-Body CT Scanner at US Darnall Army Community Hospital

DTIC Science & Technology

1980-05-01

TASK IWORK UNIT ELEMENT NO. I NO.JC NO. rSSION NO. Ij6T’,WAM ’"Aa1W% A WHOLE BODY CT SCANNER AT DARNALL ARMY COMUNITY HOSPITAL 16PTR3OAL tUTHOR(S)* a...computerized axial tomography or CT. Computerized tomography experiments "were conducted by Godfrey Hounsfield at Central Research Laboratories, EMI, Ltd. in...remained the same, with clinical and nursing unit facilities to support a one division post. Presently, Fort Hood is the home of the III US Army Corps, the

Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

NASA Astrophysics Data System (ADS)

Guo, J.; Bücherl, T.; Zou, Y.; Guo, Z.

2011-09-01

Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

Ionospheric tomography using ADS-B signals

NASA Astrophysics Data System (ADS)

Cushley, A. C.; Noël, J.-M.

2014-07-01

Numerical modeling has demonstrated that Automatic Dependent Surveillance Broadcast (ADS-B) signals can be used to reconstruct two-dimensional (2-D) electron density maps of the ionosphere using techniques for computerized tomography. Ray tracing techniques were used to determine the characteristics of individual waves, including the wave path and the state of polarization at the satellite receiver. The modeled Faraday rotation was computed and converted to total electron content (TEC) along the raypaths. The resulting TEC was used as input for computerized ionospheric tomography (CIT) using algebraic reconstruction technique. This study concentrated on reconstructing mesoscale structures 25-100 km in horizontal extent. The primary scientific interest of this study was to show that ADS-B signals can be used as a new source of data for CIT to image the ionosphere and to obtain a better understanding of magneto-ionic wave propagation.

Technological Advances in the Study of Reading: An Introduction.

ERIC Educational Resources Information Center

Henk, William A.

1991-01-01

Describes the purpose and functional operation of new computer-driven technologies such as computerized axial tomography, positron emissions transaxial tomography, regional cerebral blood flow monitoring, magnetic resonance imaging, and brain electrical activity mapping. Outlines their current contribution to the knowledge base. Speculates on the…

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

PubMed

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

Feasibility and Efficacy of Nurse-Driven Acute Stroke Care.

PubMed

Mainali, Shraddha; Stutzman, Sonja; Sengupta, Samarpita; Dirickson, Amanda; Riise, Laura; Jones, Donald; Yang, Julian; Olson, DaiWai M

2017-05-01

Acute stroke care requires rapid assessment and intervention. Replacing traditional sequential algorithms in stroke care with parallel processing using telestroke consultation could be useful in the management of acute stroke patients. The purpose of this study was to assess the feasibility of a nurse-driven acute stroke protocol using a parallel processing model. This is a prospective, nonrandomized, feasibility study of a quality improvement initiative. Stroke team members had a 1-month training phase, and then the protocol was implemented for 6 months and data were collected on a "run-sheet." The primary outcome of this study was to determine if a nurse-driven acute stroke protocol is feasible and assists in decreasing door to needle (intravenous tissue plasminogen activator [IV-tPA]) times. Of the 153 stroke patients seen during the protocol implementation phase, 57 were designated as "level 1" (symptom onset <4.5 hours) strokes requiring acute stroke management. Among these strokes, 78% were nurse-driven, and 75% of the telestroke encounters were also nurse-driven. The average door to computerized tomography time was significantly reduced in nurse-driven codes (38.9 minutes versus 24.4 minutes; P < .04). The use of a nurse-driven protocol is feasible and effective. When used in conjunction with a telestroke specialist, it may be of value in improving patient outcomes by decreasing the time for door to decision for IV-tPA. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Primary Malignant Lymphoma in a Spinal Cord Presenting as an Epidural Mass with Myelopathy: A Case Report

PubMed Central

Cho, Jae-Hoon; Cho, Dae-Chul; Sung, Joo-Kyung

2012-01-01

We report the case of a 47-year-old man who presented with progressive paraparesis and sphincter changes over 2 weeks. Magnetic resonance imaging revealed a spinal epidural mass from T9 to L2. We performed a decompressive laminectomy and mass removal. The histopathology was consistent with a small lymphocytic lymphoma. No metastatic lesion was noted in the chest and abdomen-pelvic computerized tomography (CT) and positron emission tomography computerized tomography (PET-CT) scan. The final diagnosis was primary spinal lymphoma, so we performed chemotherapy combined with radiotherapy. At one year follow-up, he had no neurological deficit and no recurrence on neurologic and radiologic exams. Primary spinal cord lymphomas should be considered in the differential diagnosis of spinal cord tumors. Early surgical management is mandatory to achieve a recovery of neurologic function, especially if the patient has a neurological deficit. PMID:25983828

Fiber Optic Communication System For Medical Images

NASA Astrophysics Data System (ADS)

Arenson, Ronald L.; Morton, Dan E.; London, Jack W.

1982-01-01

This paper discusses a fiber optic communication system linking ultrasound devices, Computerized tomography scanners, Nuclear Medicine computer system, and a digital fluoro-graphic system to a central radiology research computer. These centrally archived images are available for near instantaneous recall at various display consoles. When a suitable laser optical disk is available for mass storage, more extensive image archiving will be added to the network including digitized images of standard radiographs for comparison purposes and for remote display in such areas as the intensive care units, the operating room, and selected outpatient departments. This fiber optic system allows for a transfer of high resolution images in less than a second over distances exceeding 2,000 feet. The advantages of using fiber optic cables instead of typical parallel or serial communication techniques will be described. The switching methodology and communication protocols will also be discussed.

Evaluation of Hospitalized Intractable Epileptic Children with SPECT Scan in Ahvaz, South West of Iran

PubMed Central

Ahmadi, Faramarz; Malekian, Arash; Davoodzadeh, Hannaneh; Kabirinia, Hossein

2016-01-01

Introduction Seizures are the most frequent neurologic disorder seen in childhood. Epilepsy is a group of disorders that includes an abnormally increased susceptibility to seizures. Aim To examine the effectiveness of SPECT (Single Photon Emission Computerized Tomography) in detecting seizure foci in 21 Iranian children who had medically refractory epilepsy. Materials and Methods Children between 2 to 15 years of age with uncontrolled seizures were investigated using SPECT scan as a standardized protocol. Results In 16 cases (76.2%), likely seizure foci were evident, as were seen in the form of decreased regional blood flow, while in 5 cases (23.8%), SPECT scan results were normal. Left temporal lobe was the most common area which had decreased regional blood flow. Conclusion SPECT scan can potentially be used to investigate children with uncontrolled seizures. PMID:27891419

Congenital Anomaly of Single Dominant Right Coronary Artery with Hypoplastic Left Coronary Artery.

PubMed

Chuang, Cheng-Yen; Chen, Yen-Chou; Cheng, Ho-Shun; Hsieh, Ming-Hsiung

2015-11-01

With the popularization of new imaging technology, more people are deciding to undergo non-invasive studies such as multidetector computerized tomography (MDCT) before receiving coronary angiography. For this reason, coronary anomalies of coronary artery are being encountered more frequently. We here report a 68-year-old male presenting with typical angina. The MDCT images suggested chronic total occlusion of the left anterior descending (LAD) artery with collateral circulation from the right coronary artery (RCA). The patient's coronary angiography showed a congenital coronary anomaly with a single dominant RCA supplying the entire coronary circulation of the heart with both LAD and left circumflex artery hypoplasia. Angiography; Anomaly; Computerized tomography; Coronary artery.

[The importance of neurological examinations in the age of the technological revolution].

PubMed

Berbel-García, A; González-Spínola, J; Martínez-Salio, A; Porta-Etessam, J; Pérez-Martínez, D A; de Toledo, M; Sáiz-Díaz, R A

Neurologic practice and care have been modified in many important ways during the past ten years, to adapt to the explosion of new information and new technology. Students, residents and practicing physicians have been continuing programs to a model that focuses almost exclusively on the applications to neurologic disorders of the new knowledge obtained from biomedical research. On the other hand high demand for outpatient neurologic care prevents adequate patient's evaluation. Case 1: 65 years old female. Occipital headache diagnosed of tensional origin (normal computerized tomography). Two months later is re-evaluated due to intractable pain and hypoglossal lesion. An amplified computerized tomography revealed a occipital condyle metastasis. Case 2: 21 years old female. Clinical suspicion of demyelinating disease due to repeated facial paresis and sensitive disorder. General exploration and computerized tomography revealed temporo-mandibular joint. Case 3: 60 years old female. Valuation of anticoagulant therapy due to repeated transient ischemic attacks. She suffered from peripheral facial palsy related to auditory cholesteatoma. Neurologic education is nowadays orientated to new technologies. On the other hand, excessive demand prevents adequate valuation and a minute exploration is substituted by complementary evaluations. These situations generate diagnostic mistakes or iatrogenic. It would be important a consideration of the neurologic education profiles and fulfillment of consultations time recommendations for outpatients care.

Computer versus paper system for recognition and management of sepsis in surgical intensive care.

PubMed

Croft, Chasen A; Moore, Frederick A; Efron, Philip A; Marker, Peggy S; Gabrielli, Andrea; Westhoff, Lynn S; Lottenberg, Lawrence; Jordan, Janeen; Klink, Victoria; Sailors, R Matthew; McKinley, Bruce A

2014-02-01

A system to provide surveillance, diagnosis, and protocolized management of surgical intensive care unit (SICU) sepsis was undertaken as a performance improvement project. A system for sepsis management was implemented for SICU patients using paper followed by a computerized system. The hypothesis was that the computerized system would be associated with improved process and outcomes. A system was designed to provide early recognition and guide patient-specific management of sepsis including (1) modified early warning signs-sepsis recognition score (MEWS-SRS; summative point score of ranges of vital signs, mental status, white blood cell count; after every 4 hours) by bedside nurse; (2) suspected site assessment (vascular access, lung, abdomen, urinary tract, soft tissue, other) at bedside by physician or extender; (3) sepsis management protocol (replicable, point-of-care decisions) at bedside by nurse, physician, and extender. The system was implemented first using paper and then a computerized system. Sepsis severity was defined using standard criteria. In January to May 2012, a paper system was used to manage 77 consecutive sepsis encounters (3.9 ± 0.5 cases per week) in 65 patients (77% male; age, 53 ± 2 years). In June to December 2012, a computerized system was used to manage 132 consecutive sepsis encounters (4.4 ± 0.4 cases per week) in 119 patients (63% male; age, 58 ± 2 years). MEWS-SRS elicited 683 site assessments, and 201 had sepsis diagnosis and protocol management. The predominant site of infection was abdomen (paper, 58%; computer, 53%). Recognition of early sepsis tended to occur more using the computerized system (paper, 23%; computer, 35%). Hospital mortality rate for surgical ICU sepsis (paper, 20%; computer, 14%) was less with the computerized system. A computerized sepsis management system improves care process and outcome. Early sepsis is recognized and managed with greater frequency compared with severe sepsis or septic shock. The system has a beneficial effect as a clinical standard of care for SICU patients. Therapeutic study, level III.

Motion Estimation and Compensation Strategies in Dynamic Computerized Tomography

NASA Astrophysics Data System (ADS)

Hahn, Bernadette N.

2017-12-01

A main challenge in computerized tomography consists in imaging moving objects. Temporal changes during the measuring process lead to inconsistent data sets, and applying standard reconstruction techniques causes motion artefacts which can severely impose a reliable diagnostics. Therefore, novel reconstruction techniques are required which compensate for the dynamic behavior. This article builds on recent results from a microlocal analysis of the dynamic setting, which enable us to formulate efficient analytic motion compensation algorithms for contour extraction. Since these methods require information about the dynamic behavior, we further introduce a motion estimation approach which determines parameters of affine and certain non-affine deformations directly from measured motion-corrupted Radon-data. Our methods are illustrated with numerical examples for both types of motion.

Strut fracture and disc embolization of a Björk-Shiley mitral valve prosthesis: localization of embolized disc by computerized axial tomography.

PubMed

Larrieu, A J; Puglia, E; Allen, P

1982-08-01

The case of a patient who survived strut fracture and embolization of a Björk-Shiley mitral prosthetic disc is presented. Prompt surgical treatment was directly responsible for survival. In addition, computerized axial tomography of the abdomen aided in localizing and retrieving the embolized disc, which was lodged at the origin of the superior mesenteric artery. A review of similar case reports from the literature supports our conclusions that the development of acute heart failure and absent or muffled prosthetic heart sounds in a patient with a Björk-Shiley prosthetic heart valve inserted prior to 1978 should raise the possibility of valve dysfunction and lead to early reoperation.

Quantum Tomography Protocols with Positivity are Compressed Sensing Protocols (Open Access)

DTIC Science & Technology

2015-12-08

ARTICLE OPEN Quantum tomography protocols with positivity are compressed sensing protocols Amir Kalev1, Robert L Kosut2 and Ivan H Deutsch1...Characterising complex quantum systems is a vital task in quantum information science. Quantum tomography, the standard tool used for this purpose, uses a well...designed measurement record to reconstruct quantum states and processes. It is, however, notoriously inefficient. Recently, the classical signal

[Computerized protocol for functional exploration of the stomatognathic system].

PubMed

Salsench, J; Torrent, J; Ferrer, J

1988-11-01

In making a protocol it is necessary that all members of the team who are going to collect information have the same unity of criterion about the different variables that compose it. The drawing up of this document is as much or more necessary than the protocol itself.

Preoperative Computerized Tomography and Magnetic Resonance Imaging of the Pancreas Predicts Pancreatic Mass and Functional Outcomes After Total Pancreatectomy and Islet Autotransplant.

PubMed

Young, Michael C; Theis, Jake R; Hodges, James S; Dunn, Ty B; Pruett, Timothy L; Chinnakotla, Srinath; Walker, Sidney P; Freeman, Martin L; Trikudanathan, Guru; Arain, Mustafa; Robertson, Paul R; Wilhelm, Joshua J; Schwarzenberg, Sarah J; Bland, Barbara; Beilman, Gregory J; Bellin, Melena D

2016-08-01

Approximately two thirds of patients will remain on insulin therapy after total pancreatectomy with islet autotransplant (TPIAT) for chronic pancreatitis. We investigated the relationship between measured pancreas volume on computerized tomography or magnetic resonance imaging and features of chronic pancreatitis on imaging, with subsequent islet isolation and diabetes outcomes. Computerized tomography or magnetic resonance imaging was reviewed for pancreas volume (Vitrea software) and presence or absence of calcifications, atrophy, and dilated pancreatic duct in 97 patients undergoing TPIAT. Relationship between these features and (1) islet mass isolated and (2) diabetes status at 1-year post-TPIAT were evaluated. Pancreas volume correlated with islet mass measured as total islet equivalents (r = 0.50, P < 0.0001). Mean islet equivalents were reduced by more than half if any one of calcifications, atrophy, or ductal dilatation were observed. Pancreatic calcifications increased the odds of insulin dependence 4.0 fold (1.1, 15). Collectively, the pancreas volume and 3 imaging features strongly associated with 1-year insulin use (P = 0.07), islet graft failure (P = 0.003), hemoglobin A1c (P = 0.0004), fasting glucose (P = 0.027), and fasting C-peptide level (P = 0.008). Measures of pancreatic parenchymal destruction on imaging, including smaller pancreas volume and calcifications, associate strongly with impaired islet mass and 1-year diabetes outcomes.

Computerized tomography-guided sphenopalatine ganglion pulsed radiofrequency treatment in 16 patients with refractory cluster headaches: Twelve- to 30-month follow-up evaluations.

PubMed

Fang, Luo; Jingjing, Lu; Ying, Shen; Lan, Meng; Tao, Wang; Nan, Ji

2016-02-01

Sphenopalatine ganglion percutaneous radiofrequency thermocoagulation treatment can improve the symptoms of cluster headaches to some extent. However, as an ablation treatment, radiofrequency thermocoagulation treatment also has side effects. To preliminarily evaluate the efficacy and safety of a non-ablative computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion in patients with refractory cluster headaches. We included and analysed 16 consecutive cluster headache patients who failed to respond to conservative therapy from the Pain Management Center at the Beijing Tiantan Hospital between April 2012 and September 2013 treated with pulsed radiofrequency treatment of sphenopalatine ganglion. Eleven of 13 episodic cluster headaches patients and one of three chronic cluster headaches patient were completely relieved of the headache within an average of 6.3 ± 6.0 days following the treatment. Two episodic cluster headache patients and two chronic cluster headache patients showed no pain relief following the treatment. The mean follow-up time was 17.0 ± 5.5 months. All patients enrolled in this study showed no treatment-related side effects or complications. Our data show that patients with refractory episodic cluster headaches were quickly, effectively and safely relieved from the cluster period after computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion, suggesting that it may be a therapeutic option if conservative treatments fail. © International Headache Society 2015.

Identifying and classifying hyperostosis frontalis interna via computerized tomography.

PubMed

May, Hila; Peled, Nathan; Dar, Gali; Hay, Ori; Abbas, Janan; Masharawi, Youssef; Hershkovitz, Israel

2010-12-01

The aim of this study was to recognize the radiological characteristics of hyperostosis frontalis interna (HFI) and to establish a valid and reliable method for its identification and classification. A reliability test was carried out on 27 individuals who had undergone a head computerized tomography (CT) scan. Intra-observer reliability was obtained by examining the images three times, by the same researcher, with a 2-week interval between each sample ranking. The inter-observer test was performed by three independent researchers. A validity test was carried out using two methods for identifying and classifying HFI: 46 cadaver skullcaps were ranked twice via computerized tomography scans and then by direct observation. Reliability and validity were calculated using Kappa test (SPSS 15.0). Reliability tests of ranking HFI via CT scans demonstrated good results (K > 0.7). As for validity, a very good consensus was obtained between the CT and direct observation, when moderate and advanced types of HFI were present (K = 0.82). The suggested classification method for HFI, using CT, demonstrated a sensitivity of 84%, specificity of 90.5%, and positive predictive value of 91.3%. In conclusion, volume rendering is a reliable and valid tool for identifying HFI. The suggested three-scale classification is most suitable for radiological diagnosis of the phenomena. Considering the increasing awareness of HFI as an early indicator of a developing malady, this study may assist radiologists in identifying and classifying the phenomena.

Computerized tomography in neuro-ophthalmology

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

Moseley, I.F.; Sanders, M.D.

This highly specialized text is organized into sections that cover anatomy, diseases of the orbit, visual loss, optic nerve disease, disorders of eye movement, and heredofamilial, developmental, and metabolic disorders.

Computerized PET/CT image analysis in the evaluation of tumour response to therapy

PubMed Central

Wang, J; Zhang, H H

2015-01-01

Current cancer therapy strategy is mostly population based, however, there are large differences in tumour response among patients. It is therefore important for treating physicians to know individual tumour response. In recent years, many studies proposed the use of computerized positron emission tomography/CT image analysis in the evaluation of tumour response. Results showed that computerized analysis overcame some major limitations of current qualitative and semiquantitative analysis and led to improved accuracy. In this review, we summarize these studies in four steps of the analysis: image registration, tumour segmentation, image feature extraction and response evaluation. Future works are proposed and challenges described. PMID:25723599

Preoperative predictive model of cervical lymph node metastasis combining fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography findings and clinical factors in patients with oral or oropharyngeal squamous cell carcinoma.

PubMed

Mochizuki, Yumi; Omura, Ken; Nakamura, Shin; Harada, Hiroyuki; Shibuya, Hitoshi; Kurabayashi, Toru

2012-02-01

This study aimed to construct a preoperative predictive model of cervical lymph node metastasis using fluorine-18 fluorodeoxyglucose positron-emission tomography/computerized tomography ((18)F-FDG PET/CT) findings in patients with oral or oropharyngeal squamous cell carcinoma (SCC). Forty-nine such patients undergoing preoperative (18)F-FDG PET/CT and neck dissection or lymph node biopsy were enrolled. Retrospective comparisons with spatial correlation between PET/CT and the anatomical sites based on histopathological examinations of surgical specimens were performed. We calculated a logistic regression model, including the SUVmax-related variable. When using the optimal cutoff point criterion of probabilities calculated from the model that included either clinical factors and delayed-phase SUVmax ≥0.087 or clinical factors and maximum standardized uptake (SUV) increasing rate (SUV-IR) ≥ 0.100, it significantly increased the sensitivity, specificity, and accuracy (87.5%, 65.7%, and 75.2%, respectively). The use of predictive models that include clinical factors and delayed-phase SUVmax and SUV-IR improve preoperative nodal diagnosis. Copyright © 2012 Elsevier Inc. All rights reserved.

Epilepsy Surgery

MedlinePlus

... monitor the brain's activity and detect abnormalities. Single-photon emission computerized tomography (SPECT). The scan image varies ... off anti-seizure drugs after a year or two. By Mayo Clinic Staff . Mayo Clinic Footer Legal ...

Bone Scan

MedlinePlus

... your doctor might order additional imaging called single-photon emission computerized tomography (SPECT). This imaging can help ... radioactivity from the tracers is usually completely eliminated two days after the scan. Results A doctor who ...

[Computerized clinical protocol for occlusion].

PubMed

Salsench, J; Ferrer, J; Nogueras, J

1988-11-01

In making a protocol it is necessary that all members of the team who are going to collect information have the same unity of criterion about the different variables that compose it. The drawing up of this document is as much or more necessary than the protocol itself. In this work we all data collected in the protocol and we give the explanations of each concept.

Brain Lesions

MedlinePlus

... seen on a brain-imaging test, such as magnetic resonance imaging (MRI) or computerized tomography (CT). On ... A cohort study. PLOS One. 2013;8:e71467. Magnetic resonance imaging (MRI). National Multiple Sclerosis Society. http:// ...

Methanol poisoning

MedlinePlus

... tests Chest x-ray CT (computerized tomography, or advanced imaging) scan EKG (electrocardiogram, or heart tracing) Fluids ... Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; ...

CT scan (image)

MedlinePlus

CT stands for computerized tomography. In this procedure, a thin X-ray beam is rotated around the ... D image of a section through the body. CT scans are very detailed and provide excellent information ...

Head CT (image)

MedlinePlus

CT stands for computerized tomography. In this procedure, a thin X-ray beam is rotated around the ... D image of a section through the body. CT scans are very detailed and provide excellent information ...

Carotid Angioplasty and Stenting

MedlinePlus

... and of the blood flow to the brain. Magnetic resonance angiography (MRA) or computerized tomography angiography (CTA). ... vessels by using either radiofrequency waves in a magnetic field or by using X-rays with contrast ...

Windshield washer fluid

MedlinePlus

... tests Chest x-ray CT (computerized tomography, or advanced imaging) scan EKG (electrocardiogram, or heart tracing) Fluids ... Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; ...

Coping with Memory Loss

MedlinePlus

... either using computerized axial tomography (CAT) scans or magnetic resonance imaging (MRI) – can help to identify strokes and tumors, which can sometimes cause memory loss. “The goal is to rule out factors ...

Recurrent Urinary Tract Infections Due to Bacterial Persistence or Reinfection in Women-Does This Factor Impact Upper Tract Imaging Findings?

PubMed

Wu, Yuefeng Rose; Rego, Lauren L; Christie, Alana L; Lavelle, Rebecca S; Alhalabi, Feras; Zimmern, Philippe E

2016-08-01

We compared the rates of upper tract imaging abnormalities of recurrent urinary tract infections due to bacterial persistence or reinfection. Following institutional review board approval we reviewed a prospectively maintained database of women with documented recurrent urinary tract infections (3 or more per year) and trigonitis. We searched for demographic data, urine culture findings and findings on radiology interpreted upper tract imaging, including renal ultrasound, computerized tomography or excretory urogram. Patients with irretrievable images, absent or incomplete urine culture results for review, no imaging performed, an obvious source of recurrent urinary tract infections or a history of pyelonephritis were excluded from analysis. Of 289 women from 2006 to 2014 with symptomatic recurrent urinary tract infections 116 met study inclusion criteria. Mean ± SD age was 65.0 ± 14.4 years. Of the women 95% were white and 81% were postmenopausal. Almost a third were sexually active and none had prolapse stage 2 or greater. Of the 116 women 48 (41%) had persistent and 68 (59%) had reinfection recurrent urinary tract infection. Imaging included ultrasound in 52 patients, computerized tomography in 26, ultrasound and computerized tomography in 31, and excretory urogram with ultrasound/computerized tomography in 7. Of the total of 58 imaging findings in 55 women 57 (98%) were noncontributory. One case (0.9%) of mild hydronephrosis was noted in the persistent recurrent urinary tract infection group but it was not related to any clinical parameters. Escherichia coli was the dominant bacteria in 71% of persistent and 47% of reinfection recurrent urinary tract infections in the most recently reported urine culture. This study reaffirms that upper tract imaging is not indicated for bacterial reinfection, recurrent urinary tract infections. However, the same conclusion can be extended to recurrent urinary tract infections secondary to bacterial persistence, thus, questioning the routine practice of upper tract studies in white postmenopausal women with recurrent urinary tract infections and trigonitis. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Computed Tomography Status

DOE R&D Accomplishments Database

Hansche, B. D.

1983-01-01

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Evaluation of a continuous-rotation, high-speed scanning protocol for micro-computed tomography.

PubMed

Kerl, Hans Ulrich; Isaza, Cristina T; Boll, Hanne; Schambach, Sebastian J; Nolte, Ingo S; Groden, Christoph; Brockmann, Marc A

2011-01-01

Micro-computed tomography is used frequently in preclinical in vivo research. Limiting factors are radiation dose and long scan times. The purpose of the study was to compare a standard step-and-shoot to a continuous-rotation, high-speed scanning protocol. Micro-computed tomography of a lead grid phantom and a rat femur was performed using a step-and-shoot and a continuous-rotation protocol. Detail discriminability and image quality were assessed by 3 radiologists. The signal-to-noise ratio and the modulation transfer function were calculated, and volumetric analyses of the femur were performed. The radiation dose of the scan protocols was measured using thermoluminescence dosimeters. The 40-second continuous-rotation protocol allowed a detail discriminability comparable to the step-and-shoot protocol at significantly lower radiation doses. No marked differences in volumetric or qualitative analyses were observed. Continuous-rotation micro-computed tomography significantly reduces scanning time and radiation dose without relevantly reducing image quality compared with a normal step-and-shoot protocol.

Few CT Scan Abnormalities Found Even in Neurologically Impaired Learning Disabled Children.

ERIC Educational Resources Information Center

Denckla, Martha Bridge; And Others

1985-01-01

Most of 32 learning disabled children (seven to 14 years old) with neurological lateralization characteristics marked by right and left hemispheres had a normal CT (computerized tomography) scan. (CL)

Prostate Enlargement: Benign Prostatic Hyperplasia (BPH)

MedlinePlus

... such as ultrasound, a computerized tomography scan, or magnetic resonance imaging to guide the biopsy needle into ... heats and destroys selected portions of prostate tissue. Shields protect the urethra from heat damage. Transurethral microwave ...

SPECT (Single-Photon Emission Computerized Tomography) Scan

MedlinePlus

... can become damaged or even die. Reduced pumping efficiency. SPECT can show how completely your heart chambers ... radioactive tracer SPECT scans aren't safe for women who are pregnant or breast-feeding because the ...

Non-Hodgkin Lymphoma (For Parents)

MedlinePlus

... chest X-ray a computerized tomography (CT or CAT) scan , which rotates around the patient and creates an ... ray (Video) Getting an MRI (Video) Getting a CAT Scan (Video) Chemotherapy Hodgkin Lymphoma Stem Cell Transplants Can ...

The mobile hospital technology industry: focus on the computerized tomography scanner.

PubMed

Hartley, D; Moscovice, I

1996-01-01

This study of firms offering mobile hospital technology to rural hospitals in eight northwestern states found that several permanently parked computerized tomography (CT) units were found where mobile routes had atrophied due to the purchase of fixed units by former mobile CT hospital clients. Based on a criterion of 140 scans per month per unit as a threshold of profitable production, units owned by larger firms (those that operate five or more units) were more likely to be profitable than units owned by smaller firms (71% versus 20%, P = 0.03). A substantial number of rural hospitals lose money on mobile CT due to low Medicare reimbursement. In some areas, mobile hospital technology is a highly competitive industry. Evidence was found that several firms compete in some geographic areas and that some firms have lost hospital clients to competing vendors.

Magnetic resonance imaging and computerized tomography in malignant external otitis

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

Gherini, S.G.; Brackmann, D.E.; Bradley, W.G.

1986-05-01

In malignant external otitis (MEO), determining the anatomic extent of disease and evaluating the physiologic response to therapy remain a problem. Magnetic resonance imaging (MRI) has recently become available in limited clinical settings. Four patients with MEO were evaluated using MRI, computerized tomography (CT), technetium-99 (Tc-99) bone scanning, and gallium-67 citrate (Ga-67 citrate) scanning. MRI is superior to CT, Tc-99 bone scanning, and Ga-67 citrate scanning in evaluating the anatomic extent of soft tissue changes in MEO. MRI alone cannot be relied upon to determine the physiologic response to therapy. MRI can, however, serve as a valuable guide to themore » interpretation of Tc-99 bone and Ga-67 citrate scans, and in this respect, MRI is extremely useful in the treatment of MEO.« less

Uroradiographic manifestations of Burkitt's lymphoma in children

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

Fernbach, S.K.; Glass, R.B.

1986-05-01

The radiological studies of 18 children with biopsy proved Burkitt's lymphoma were analyzed retrospectively. Before therapy the genitourinary tract was evaluated in 15 children by excretory urography, sonography, computerized tomography and/or gallium citrate scintigraphy. Genitourinary abnormalities were detected in 9 children. Changes due to tumor included renal or ureteral displacement in 4 children, hydronephrosis in 3 and intraparenchymal masses in 4. Extrinsic compression of the bladder causing no compromise of function was seen in only 2 children. Gonadal involvement occurred in 2 boys and 1 girl. The modality of choice for evaluating the genitourinary tract in patients with Burkitt's lymphomamore » has been excretory urography. Since ultrasound and computerized tomography provide more direct information about tumor deposits within the kidney and retroperitoneum, either should be performed in this population before initiation of chemotherapy.« less

Rectus sheath hematoma: three case reports

PubMed Central

Kapan, Selin; Turhan, Ahmet N; Alis, Halil; Kalayci, Mustafa U; Hatipoglu, Sinan; Yigitbas, Hakan; Aygun, Ersan

2008-01-01

Introduction Rectus sheath hematoma is an uncommon cause of acute abdominal pain. It is an accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear. It could occur spontaneously or after trauma. They are usually located infraumblically and often misdiagnosed as acute abdomen, inflammatory diseases or tumours of the abdomen. Case presentation We reported three cases of rectus sheath hematoma presenting with a mass in the abdomen and diagnosed by computerized tomography. The patients recovered uneventfully after bed rest, intravenous fluid replacement, blood transfusion and analgesic treatment. Conclusion Rectus sheath hematoma is a rarely seen pathology often misdiagnosed as acute abdomen that may lead to unnecessary laparotomies. Computerized tomography must be chosen for definitive diagnosis since ultrasonography is subject to error due to misinterpretation of the images. Main therapy is conservative management. PMID:18221529

Properties of an ideal PET perfusion tracer: new PET tracer cases and data.

PubMed

Maddahi, Jamshid

2012-02-01

An ideal positron emission tomography (PET) tracer should be highly extractable by the myocardium and able to provide high-resolution images, should enable quantification of absolute myocardial blood flow (MBF), should be compatible with both pharmacologically induced and exercise-induced stress imaging, and should not require an on-site cyclotron. The PET radionuclides nitrogen-13 ammonia and oxygen-15 water require an on-site cyclotron. Rubidium-82 may be available locally due to the generator source, but greater utilization is limited because of its relatively low myocardial extraction fraction, long positron range, and generator cost. Flurpiridaz F 18, a novel PET tracer in development, has a high-extraction fraction, short positron range, and relatively long half-life (as compared to currently available tracers), and may be produced at regional cyclotrons. Results of early clinical trials suggest that both pharmacologically and exercise-induced stress PET imaging protocols can be completed more rapidly and with lower patient radiation exposure than with single-photon emission computerized tomography (SPECT) tracers. As compared to SPECT images in the same patients, flurpiridaz F 18 PET images showed better defect contrast. Flurpiridaz F 18 is a potentially promising tracer for assessment of myocardial perfusion, measurement of absolute MBF, calculation of coronary flow reserves, and assessment of cardiac function at the peak of the stress response.

Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples

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

Hullar, Ted; Anastasio, Cort, E-mail: canastasio@ucdavis.edu; Paige, David F.

2014-04-15

High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as −25 °Cmore » ± 0.2 °C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.« less

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars.

PubMed

Acar, Buket; Kamburoğlu, Kıvanç; Tatar, İlkan; Arıkan, Volkan; Çelik, Hakan Hamdi; Yüksel, Selcen; Özen, Tuncer

2015-12-01

This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

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.

Preoperative N Staging of Gastric Cancer by Stomach Protocol Computed Tomography

PubMed Central

Kim, Se Hoon; Kim, Jeong Jae; Lee, Jeong Sub; Kim, Seung Hyoung; Kim, Bong Soo; Maeng, Young Hee; Hyun, Chang Lim; Kim, Min Jeong

2013-01-01

Purpose Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. Materials and Methods Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. Results The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). Conclusions Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment. PMID:24156034

Mini-Stroke vs. Regular Stroke: What's the Difference?

MedlinePlus

... may need various diagnostic tests, such as a magnetic resonance imaging (MRI) scan or a computerized tomography ( ... org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation ...

Mineral & Bone Disorder in Chronic Kidney Disease

MedlinePlus

... stages of CKD. Slowed bone growth leads to short stature, which may remain with a child into adulthood. ... and local anesthetic. The health care provider uses imaging techniques such as ultrasound or a computerized tomography ...

Biopsy: Types of Biopsy Procedures Used to Diagnose Cancer

MedlinePlus

... procedure — such as X-ray, computerized tomography (CT), magnetic resonance imaging (MRI) or ultrasound — with a needle ... org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation ...

Intravenous leiomyomatosis of the uterus with extension to the right heart

PubMed Central

2011-01-01

A 42-year-old woman admitted with debilitation and engorgement both lower extremities. Transthoracic two-dimensional echocardiography, abdominal ultrasound and computerized tomography revealed a lobulated pelvic mass, a mass within right internal iliac vein, both common iliac vein, as well as the inferior vena cava, extending into the right atrium. In addition, echocardiography and abdominal ultrasound showed the tumor of right atrium and inferior vena cave has no stalk and has well-demarcated borders with the wall of right atrium and inferior vena cave. Hence, the presumptive diagnosis of IVL was made by echocardiography and abdominal ultrasound and the presumptive diagnosis of sarcoma with invasion in right internal iliac vein, both common iliac vein, the inferior vena cava, as well as the right atrium was made by multi-detector-row computerized tomography. The patient underwent a one-stage combined multidisciplinary thoraco-abdominal operation under general anaesthetic. Subsequently the pathologic report confirmed IVL. PMID:21943238

Comparisons of ionospheric electron density distributions reconstructed by GPS computerized tomography, backscatter ionograms, and vertical ionograms

NASA Astrophysics Data System (ADS)

Zhou, Chen; Lei, Yong; Li, Bofeng; An, Jiachun; Zhu, Peng; Jiang, Chunhua; Zhao, Zhengyu; Zhang, Yuannong; Ni, Binbin; Wang, Zemin; Zhou, Xuhua

2015-12-01

Global Positioning System (GPS) computerized ionosphere tomography (CIT) and ionospheric sky wave ground backscatter radar are both capable of measuring the large-scale, two-dimensional (2-D) distributions of ionospheric electron density (IED). Here we report the spatial and temporal electron density results obtained by GPS CIT and backscatter ionogram (BSI) inversion for three individual experiments. Both the GPS CIT and BSI inversion techniques demonstrate the capability and the consistency of reconstructing large-scale IED distributions. To validate the results, electron density profiles obtained from GPS CIT and BSI inversion are quantitatively compared to the vertical ionosonde data, which clearly manifests that both methods output accurate information of ionopsheric electron density and thereby provide reliable approaches to ionospheric soundings. Our study can improve current understanding of the capability and insufficiency of these two methods on the large-scale IED reconstruction.

A motion artefact study and locally deforming objects in computerized tomography

NASA Astrophysics Data System (ADS)

Hahn, Bernadette N.

2017-11-01

Movements of the object during the data collection in computerized tomography can introduce motion artefacts in the reconstructed image. They can be reduced by employing information about the dynamic behaviour within the reconstruction step. However, inaccuracies concerning the movement are inevitable in practice. In this article, we give an explicit characterization of what is visible in an image obtained by a reconstruction algorithm with incorrect motion information. Then, we use this result to study in detail the situation of locally deforming objects, i.e. individual parts of the object have a different dynamic behaviour. In this context, we prove that additional artefacts arise due to the global nature of the Radon transform, even if the motion is exactly known. Based on our analysis, we propose a numerical scheme to reduce these artefacts in the reconstructed image. All our results are illustrated by numerical examples.

Radiation Hard Sensors for Surveillance.

DTIC Science & Technology

1988-03-11

track position measurements were noted. E. Heijne (CERN) reported on the degradation of silicon detectors for doses larger than 2x10 11 muons /cm 2...Workshop on Transmission and Emission Computerized Tomography , July 1978, Seoul, Korea Nahmias C., Kenyon D.B., Garnett E.S.: Optimization of...crystal size in emission computed tomography . IEEE Trans ,.-.e Nucl Sci NS-27: 529-532, 1980. Mullani N.A., Ficke D.C., Ter-Pogossian M.M.: Cesium Fluoride

Computer-assisted surgery in the lower jaw: double surgical guide for immediately loaded implants in postextractive sites-technical notes and a case report.

PubMed

De Santis, Daniele; Canton, Luciano Claudio; Cucchi, Alessandro; Zanotti, Guglielmo; Pistoia, Enrico; Nocini, Pier Francesco

2010-01-01

Computer-assisted surgery is based on computerized tomography (CT) scan technology to plan the placement of dental implants and a computer-aided design/computer-aided manufacturing (CAD-CAM) technology to create a custom surgical template. It provides guidance for insertion implants after analysis of existing alveolar bone and planning of implant position, which can be immediately loaded, therefore achieving esthetic and functional results in a surgical stage. The absence of guidelines to treat dentulous areas is often due to a lack of computer-assisted surgery. The authors have attempted to use this surgical methodology to replace residual teeth with an immediate implantoprosthetic restoration. The aim of this case report is to show the possibility of treating a dentulous patient by applying a computer-assisted surgical protocol associated with the use of a double surgical template: one before extraction and a second one after extraction of selected teeth.

Computerized Tomography Measures During and After Artificial Lengthening of the Vocal Tract in Subjects With Voice Disorders.

PubMed

Guzman, Marco; Miranda, Gonzalo; Olavarria, Christian; Madrid, Sofia; Muñoz, Daniel; Leiva, Miguel; Lopez, Lorena; Bortnem, Cori

2017-01-01

The present study aimed to observe the effect of two types of tubes on vocal tract bidimensional and tridimensional images. Ten participants with hyperfunctional dysphonia were included. Computerized tomography was performed during production of sustained [a:], followed by sustained phonation into a drinking straw, and then repetition of sustained [a:]. A similar procedure was performed with a stirring straw after 15 minutes of vocal rest. Anatomic distances and area measures were obtained from computerized tomography midsagittal and transversal images. Vocal tract total volume was also calculated. During tube phonation, increases were measured in the vertical length of the vocal tract, oropharyngeal area, hypopharyngeal area, outlet of the epilaryngeal tube, and inlet to the lower pharynx. Also, the larynx was lower, and more closure was noted between the velum and the nasal passage. Tube phonation causes an increased total vocal tract volume, mostly because of the increased cross-sectional areas in the pharyngeal region. This change is more prominent when the tube offers more airflow resistance (stirring straw) compared with less airflow resistance (drinking straw). Based on our data and previous studies, it seems that vocal tract changes are not dependent on the voice condition (vocally trained, untrained, or disordered voices), but on the exercise itself and the type of instructions given to subjects. Tube phonation is a good option to reach therapeutic goals (eg, wide pharynx and low larynx) without giving biomechanical instructions, but only asking patients to feel easy voice and vibratory sensations. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Three-Dimensional Planning in Maxillofacial Fracture Surgery: Computer-Aided Design/Computer-Aided Manufacture Surgical Splints by Integrating Cone Beam Computerized Tomography Images Into Multislice Computerized Tomography Images.

PubMed

Ren, Jiayin; Zhou, Zhongwei; Li, Peng; Tang, Wei; Guo, Jixiang; Wang, Hu; Tian, Weidong

2016-09-01

This study aimed to evaluate an innovative workflow for maxillofacial fracture surgery planning and surgical splint designing. The maxillofacial multislice computerized tomography (MSCT) data and dental cone beam computerized tomography (CBCT) data both were obtained from 40 normal adults and 58 adults who suffered fractures. The each part of the CBCT dentition image was registered into MSCT image by the use of the iterative closest point algorithm. Volume evaluation of the virtual splints that were designed by the registered MSCT images and MSCT images of the same object was performed. Eighteen patients (group 1) were operated without any splint. Twenty-one (group 2) and 19 patients (group 3) used the splints designed according to the MSCT images and registered MSCT images, respectively. The authors' results showed that the mean errors between the 2 models ranged from 0.53 to 0.92 mm and the RMS errors ranged from 0.38 to 0.69 mm in fracture patients. The mean errors between the 2 models ranged from 0.47 to 0.85 mm and the RMS errors ranged from 0.33 to 0.71 mm in normal adults. 72.22% patients in group 1 recovered occlusion. 85.71% patients in group 2, and 94.73% patients in group 3 reconstructed occlusion. There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients (P <0.05). The MSCT images based splints' volume was statistically significantly distinct from the registered MSCT splints' volume in normal adults (P <0.05). There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients and normal adults (P <0.05). The occlusion recovery rate of group 3 was better than that of group 1 and group 2. The way of integrating CBCT images into MSCT images for splints designing was feasible. The volume of the splints designed by MSCT images tended to be smaller than the splints designed by the integrated MSCT images. The patients operated with splints tended to regain occlusion. The patients who were operated with the splints which were designed according to registered MSCT images tended to get occlusal recovered.

Evaluation of effects of anterior palatoplasty operation on upper airway parameters in computed tomography in patients with pure snoring and obstructive sleep apnea syndrome.

PubMed

Selcuk, Adin; Ozer, Tulay; Esen, Erkan; Ozdogan, Fatih; Ozel, Halil Erdem; Yuce, Turgut; Caliskan, Sebla; Dasli, Sinem; Bilal, Nagihan; Genc, Gulden; Genc, Selahattin

2017-05-01

To investigate changes in upper airway volume parameters measured by computerized tomography scans in patients with surgically treated by anterior palatoplasty of whom having pure snoring and mild-moderate obstructive sleep apnea. A prospective study on consecutively anterior palatoplasty performed pure snoring and obstructive sleep apnea patients. Computerized tomography scans were obtained preoperatively and following anterior palatoplasty procedure to measure changes in upper airway volume. Patients underwent diagnostic drug induced sleep endoscopy to assess the site of obstruction. Preoperative and postoperative measurements were compared using student's t test and Chi-square test. Twenty-two patients (16 men and 6 women, age 48.22 ± 9.23, body mass index 25.85 ± 2.57) completed the trial. Anterior palatoplasty was associated with an increase in total upper airway volume from 4.81 ± 1.73 cm 3 before treatment to 6.57 ± 2.03 cm 3 after treatment (p < 0.005). Change in soft palate thickness did not vary significantly (p < 0.039). The mean soft palate length has changed from 4.13 ± 0.41 to 3.93 ± 0.51 cm (p < 0.001). The preoperative and postoperative measurements of cross-sectional areas and volumes all showed significant difference except velopharynx minimal lateral airway dimension. The operational procedure increased the total upper airway volume much more in men than in women (p < 0.05). Results of this study indicate that anterior palatoplasty operation appears to produce significant increase in upper airway volume and cross sectional area. It does not seem to have an effect on lateral airway dimension. Computerized tomography is a quick and noninvasive imaging technique that allows for quantitative assessment of the velopharyngeal patency changes.

Pathophysiologic study of chronic infarcts with I-123 isopropyl iodo-amphetamine (IMP): the importance of periinfarct area

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

Raynaud, C.; Rancurel, G.; Samson, Y.

1987-01-01

Seventeen chronic cerebral infarcts were investigated by a highly sensitive, dedicated brain single photon emission computerized tomography system using /sup 123/I-isopropyl iodoamphetamine (IMP) and /sup 133/Xe. IMP uptake was measured 10 minutes, 2 hours, and 5 hours after injection, and regional cerebral blood flow was measured with 133Xe. In 4 cases a positron emission tomography system was used to measure the rCBF and the regional metabolic rate of oxygen with C15O2 and 15O2. The results obtained allowed us to identify 2 abnormal zones. One, the central area, was characterized by a severe decrease in IMP uptake and rCBF averaging 34%more » and 46% respectively and by a hypodense image on the x-ray computerized tomography scan. The second, the periinfarct or ''peripheral area'' was characterized by a moderate decrease in IMP uptake and regional cerebral blood flow averaging 13 and 19% respectively; this area extended around the central area and had a normal density on computerized tomography scan. The IMP hypofixation of the peripheral area observed at the 10th minute tended to disappear at the 5th hour. The volume of this area was often found to be quite large, covering more than 30% of a hemisphere whereas the central area did not exceed 25%. Volume appeared to be correlated with the neurological status of the patient. The nature of the peripheral area is not established with certainty. It may be caused by deafferentation of areas not directly affected by the ischemic insult and/or selective ischemic neuronal loss. The results stress the important role played by the peripheral area, which may be useful in establishing the prognosis and evaluating the efficacy of therapy in individual stroke cases.« less

The Supraclavicular Artery Perforator Flap: A Comparative Study of Imaging Techniques Used in Preoperative Mapping.

PubMed

Sheriff, Hemin Oathman; Mahmood, Kawa Abdullah; Hamawandi, Nzar; Mirza, Aram Jamal; Hawas, Jawad; Moreno, Esther Granell; Clavero, Juan Antonio; Hankins, Christopher; Masia, Jaume

2018-05-18

 The supraclavicular artery flap is an excellent flap for head and neck reconstruction. The aim of this study is to assess imaging techniques to define the precise vascular boundaries of this flap.  Six imaging techniques were used for supraclavicular artery mapping in 65 cases; handheld Doppler, triplex ultrasound, computed tomography angiography, magnetic resonance angiography, digital subtraction angiography, and indocyanine green angiography. We checked the site of the perforators, the course of a supraclavicular artery, and anatomical mapping of the supraclavicular artery.  Handheld Doppler identified perforators' sites in 80% of the cases but showed no results for the course of the vessel. Triplex ultrasound identified the site of perforators in 52.9%, and partial mapping of the course of a supraclavicular artery in 64.7% of the cases. Computerized tomography angiography showed the site of perforators in 60%, and the course of supraclavicular artery completely in 45%, and partially in an additional 30%of the cases examined. Magnetic resonance angiography showed negative results for all parameters. Digital subtraction angiography showed the partial course of a supraclavicular artery in 62.5%, but showed no perforators. Indocyanine green angiography showed the site of perforators in 60% and a partial course of supraclavicular artery distal to perforators in 60%.Anatomical mapping of the vessel was possible with computerized tomography angiogram completely in 45%, and partially in 30%, and was also possible with indocyanine green angiography partially in 60%.  Computerized tomography angiography showed best results in the mapping of the supraclavicular artery, but with an inability to define the perforator perfusion territories, and also with risks of irradiation, while indocyanine green angiography is a good alternative as it could precisely map the superficial course of the artery and angiosomes, with no radiation exposure. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Reliability, validity and sensitivity of a computerized visual analog scale measuring state anxiety.

PubMed

Abend, Rany; Dan, Orrie; Maoz, Keren; Raz, Sivan; Bar-Haim, Yair

2014-12-01

Assessment of state anxiety is frequently required in clinical and research settings, but its measurement using standard multi-item inventories entails practical challenges. Such inventories are increasingly complemented by paper-and-pencil, single-item visual analog scales measuring state anxiety (VAS-A), which allow rapid assessment of current anxiety states. Computerized versions of VAS-A offer additional advantages, including facilitated and accurate data collection and analysis, and applicability to computer-based protocols. Here, we establish the psychometric properties of a computerized VAS-A. Experiment 1 assessed the reliability, convergent validity, and discriminant validity of the computerized VAS-A in a non-selected sample. Experiment 2 assessed its sensitivity to increase in state anxiety following social stress induction, in participants with high levels of social anxiety. Experiment 1 demonstrated the computerized VAS-A's test-retest reliability (r = .44, p < .001); convergent validity with the State-Trait Anxiety Inventory's state subscale (STAI-State; r = .60, p < .001); and discriminant validity as indicated by significantly lower correlations between VAS-A and different psychological measures relative to the correlation between VAS-A and STAI-State. Experiment 2 demonstrated the VAS-A's sensitivity to changes in state anxiety via a significant pre- to during-stressor rise in VAS-A scores (F(1,48) = 25.13, p < .001). Set-order administration of measures, absence of clinically-anxious population, and gender-unbalanced samples. The adequate psychometric characteristics, combined with simple and rapid administration, make the computerized VAS-A a valuable self-rating tool for state anxiety. It may prove particularly useful for clinical and research settings where multi-item inventories are less applicable, including computer-based treatment and assessment protocols. The VAS-A is freely available: http://people.socsci.tau.ac.il/mu/anxietytrauma/visual-analog-scale/. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of computed tomography numbers for treatment planning of lung cancer

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

Mira, J.G.; Fullerton, G.D.; Ezekiel, J.

1982-09-01

Computerized tomography numbers (CTN) were evaluated in 32 computerized tomography scans performed on patients with carcinoma of the lung, with the aim of evaluating CTN in normal (lung, blood, muscle, etc) and pathologic tissues (tumor, atelectasis, effusion, post-radiation fibrosis). Our main findings are: 1. Large individual CTN variations are encountered in both normal and pathologic tissues, above and below mean values. Hence, absolute numbers are meaningless. Measurements of any abnormal intrathoracic structure should be compared in relation to normal tissue CTN values in the same scan. 2. Tumor and complete atelectasis have CTN basically similar to soft tissue. Hence, thesemore » numbers are not useful for differential diagnosis. 3. Effusions usually have lower CTN and can be distinguished from previous situations. 4. Dosimetry based on uniform lung density assumptions (i.e., 300 mg/cm/sup 3/) might produce substantial dose errors as lung CTN exhibit variations indicating densities well above and below this value. 5. Preliminary information indicates that partial atelectasis and incipient post-radiation fibrosis can have very low CTN. Hence, they can be differentiated from solid tumors in certain cases, and help in differential diagnosis of post radiation recurrence within the radiotherapy field versus fibrosis.« less

Sarcoidosis Occurring After Lymphoma

PubMed Central

London, Jonathan; Grados, Aurélie; Fermé, Christophe; Charmillon, Alexandre; Maurier, François; Deau, Bénédicte; Crickx, Etienne; Brice, Pauline; Chapelon-Abric, Catherine; Haioun, Corinne; Burroni, Barbara; Alifano, Marco; Le Jeunne, Claire; Guillevin, Loïc; Costedoat-Chalumeau, Nathalie; Schleinitz, Nicolas; Mouthon, Luc; Terrier, Benjamin

2014-01-01

Abstract Sarcoidosis is a granulomatous disease that most frequently affects the lungs with pulmonary infiltrates and/or bilateral hilar and mediastinal lymphadenopathy. An association of sarcoidosis and lymphoproliferative disease has previously been reported as the sarcoidosis-lymphoma syndrome. Although this syndrome is characterized by sarcoidosis preceding lymphoma, very few cases of sarcoidosis following lymphoma have been reported. We describe the clinical, biological, and radiological characteristics and outcome of 39 patients presenting with sarcoidosis following lymphoproliferative disease, including 14 previously unreported cases and 25 additional patients, after performing a literature review. Hodgkin lymphoma and non-Hodgkin lymphoma were equally represented. The median delay between lymphoma and sarcoidosis was 18 months. Only 16 patients (41%) required treatment. Sarcoidosis was of mild intensity or self-healing in most cases, and overall clinical response to sarcoidosis was excellent with complete clinical response in 91% of patients. Sarcoidosis was identified after a follow-up computerized tomography scan (CT-scan) or 18fluorodeoxyglucose-positron emission tomography/computerized tomography (18FDG-PET/CT) evaluation in 18/34 patients (53%). Sarcoidosis is therefore a differential diagnosis to consider when lymphoma relapse is suspected on a CT-scan or 18FDG-PET/CT, emphasizing the necessity to rely on histological confirmation of lymphoma relapse. PMID:25380084

Use of Noncontrast Computed Tomography and Computed Tomographic Perfusion in Predicting Intracerebral Hemorrhage After Intravenous Alteplase Therapy.

PubMed

Batchelor, Connor; Pordeli, Pooneh; d'Esterre, Christopher D; Najm, Mohamed; Al-Ajlan, Fahad S; Boesen, Mari E; McDougall, Connor; Hur, Lisa; Fainardi, Enrico; Shankar, Jai Jai Shiva; Rubiera, Marta; Khaw, Alexander V; Hill, Michael D; Demchuk, Andrew M; Sajobi, Tolulope T; Goyal, Mayank; Lee, Ting-Yim; Aviv, Richard I; Menon, Bijoy K

2017-06-01

Intracerebral hemorrhage is a feared complication of intravenous alteplase therapy in patients with acute ischemic stroke. We explore the use of multimodal computed tomography in predicting this complication. All patients were administered intravenous alteplase with/without intra-arterial therapy. An age- and sex-matched case-control design with classic and conditional logistic regression techniques was chosen for analyses. Outcome was parenchymal hemorrhage on 24- to 48-hour imaging. Exposure variables were imaging (noncontrast computed tomography hypoattenuation degree, relative volume of very low cerebral blood volume, relative volume of cerebral blood flow ≤7 mL/min·per 100 g, relative volume of T max ≥16 s with all volumes standardized to z axis coverage, mean permeability surface area product values within T max ≥8 s volume, and mean permeability surface area product values within ipsilesional hemisphere) and clinical variables (NIHSS [National Institutes of Health Stroke Scale], onset to imaging time, baseline systolic blood pressure, blood glucose, serum creatinine, treatment type, and reperfusion status). One-hundred eighteen subjects (22 patients with parenchymal hemorrhage versus 96 without, median baseline NIHSS score of 15) were included in the final analysis. In multivariable regression, noncontrast computed tomography hypoattenuation grade ( P <0.006) and computerized tomography perfusion white matter relative volume of very low cerebral blood volume ( P =0.04) were the only significant variables associated with parenchymal hemorrhage on follow-up imaging (area under the curve, 0.73; 95% confidence interval, 0.63-0.83). Interrater reliability for noncontrast computed tomography hypoattenuation grade was moderate (κ=0.6). Baseline hypoattenuation on noncontrast computed tomography and very low cerebral blood volume on computerized tomography perfusion are associated with development of parenchymal hemorrhage in patients with acute ischemic stroke receiving intravenous alteplase. © 2017 American Heart Association, Inc.

The potential of positron emission tomography/computerized tomography (PET/CT) scanning as a detector of high-risk patients with oral infection during preoperative staging.

PubMed

Yamashiro, Keisuke; Nakano, Makoto; Sawaki, Koichi; Okazaki, Fumihiko; Hirata, Yasuhisa; Takashiba, Shogo

2016-08-01

It is sometimes difficult to determine during the preoperative period whether patients have oral infections; these patients need treatment to prevent oral infection-related complications from arising during medical therapies, such as cancer therapy and surgery. One of the reasons for this difficulty is that basic medical tests do not identify oral infections, including periodontitis and periapical periodontitis. In this report, we investigated the potential of positron emission tomography/computerized tomography (PET/CT) as a diagnostic tool in these patients. We evaluated eight patients during the preoperative period. All patients underwent PET/CT scanning and were identified as having the signs of oral infection, as evidenced by (18)F-fludeoxyglucose (FDG) localization in the oral regions. Periodontal examination and orthopantomogram evaluation showed severe infection or bone resorption in the oral regions. (18)F-FDG was localized in oral lesions, such as severe periodontitis, apical periodontitis, and pericoronitis of the third molar. The densities of (18)F-FDG were proportional to the degree of inflammation. PET/CT is a potential diagnostic tool for oral infections. It may be particularly useful in patients during preoperative staging, as they frequently undergo scanning at this time, and those identified as having oral infections at this time require treatment before cancer therapy or surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of microtomography and optical coherence tomography on apical endodontic filling analysis.

PubMed

Suassuna, Fernanda Clotilde Mariz; Maia, Ana Marly Araújo; Melo, Daniela Pita; Antonino, Antônio Celso Dantas; Gomes, Anderson Stevens Leônidas; Bento, Patrícia Meira

2018-02-01

To comparein vitro differences in the apical filling regarding working length (WL) change and presence of voids and to validate optical coherence tomography (OCT) in comparison with computerized microtomography (µCT) for the detection of failures in the apical filling. Forty-five uniradicular teeth with round canals, divided into groups (n = 15) following the obturation protocols: LC (lateral condensation), TMC (thermomechanical compaction) and SC (single cone). Samples were scanned using µCT (parameters: 80 kV, 222 µA, and resolution of 11 µm), OCT (parameters: SSOCT, 1300 nm and axial resolution of 12 µm), and periapical digital radiography. The images were analyzsed by two blind and calibrated observers using ImageJ software to measure the boundary of the obturation WL and voids presence. Categorical and metric data were submitted to inferential analysis, and the validity of the OCT as a diagnostic test was assessed with performance and reliability tests. The WL average remained constant for all obturation techniques and image methods. OCT showed adequate sensitivity and specificity to detect voids in the WL of apical obturations in vitro in comparison with µCT. Both image methods found a higher number of voids for LC technique (µCT p = 0.011/OCT p = 0.002). OCT can be used in apical obturation voids assessment and the LC technique revealed more voids with larger dimensions.

Neurologic applications of positron emission tomography.

PubMed

Lenzi, G L; Pantano, P

1984-11-01

The impact of computerized neuroimaging in the neurologic sciences has been so dramatic that it has completely changed our approach to the individual patient. Further changes may be expected from the newborn positron emission tomography (PET) and nuclear magnetic resonance (NMR) in order to help the reader digest a large bulk of data and fully realize the present state of the art of PET, the authors have shaped this review mainly on results rather than on methods and on published reports rather than on future potential.

Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

PubMed

McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R

To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations. Copyright © 2017 Elsevier Inc. All rights reserved.

Renal calyceal anatomy characterization with 3-dimensional in vivo computerized tomography imaging.

PubMed

Miller, Joe; Durack, Jeremy C; Sorensen, Mathew D; Wang, James H; Stoller, Marshall L

2013-02-01

Calyceal selection for percutaneous renal access is critical for safe, effective performance of percutaneous nephrolithotomy. Available anatomical evidence is contradictory and incomplete. We present detailed renal calyceal anatomy obtained from in vivo 3-dimentional computerized tomography renderings. A total of 60 computerized tomography urograms were randomly selected. The renal collecting system was isolated and 3-dimensional renderings were constructed. The primary plane of each calyceal group of 100 kidneys was determined. A coronal maximum intensity projection was used for simulated percutaneous access. The most inferior calyx was designated calyx 1. Moving superiorly, the subsequent calyces were designated calyx 2 and, when present, calyx 3. The surface rendering was rotated to assess the primary plane of the calyceal group and the orientation of the select calyx. The primary plane of the upper pole calyceal group was mediolateral in 95% of kidneys and the primary plane of the lower pole calyceal group was anteroposterior in 95%. Calyx 2 was chosen in 90 of 97 simulations and it was appropriate in 92%. Calyx 3 was chosen in 7 simulations but it was appropriate in only 57%. Calyx 1 was not selected in any simulation and it was anteriorly oriented in 75% of kidneys. Appropriate lower pole calyceal access can be reliably accomplished with an understanding of the anatomical relationship between individual calyceal orientation and the primary plane of the calyceal group. Calyx 2 is most often appropriate for accessing the anteroposterior primary plane of the lower pole. Calyx 1 is most commonly oriented anterior. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Childhood Psychosis and Computed Tomographic Brain Scan Findings.

ERIC Educational Resources Information Center

Gillberg, Christopher; Svendsen, Pal

1983-01-01

Computerized tomography (CT) of the brain was used to examine 27 infantile autistic children, 9 children with other kinds of childhood psychoses, 23 children with mental retardation, and 16 normal children. Gross abnormalities were seen in 26 percent of the autism cases. (Author/SEW)

Checking the possibility of controlling fuel element by X-ray computerized tomography

NASA Astrophysics Data System (ADS)

Trinh, V. B.; Zhong, Y.; Osipov, S. P.; Batranin, A. V.

2017-08-01

The article considers the possibility of checking fuel elements by X-ray computerized tomography. The checking tasks are based on the detection of particles of active material, evaluation of the heterogeneity of the distribution of uranium salts and the detection of clusters of uranium particles. First of all, scheme of scanning improve the performance and quality of the resulting three-dimensional images of the internal structure is determined. Further, the possibility of detecting clusters of uranium particles having the size of 1 mm3 and measuring the coordinates of clusters of uranium particles in the middle layer with the accuracy of within a voxel size (for the considered experiments of about 80 μm) is experimentally proved in the main part. The problem of estimating the heterogeneity of the distribution of the active material in the middle layer and the detection of particles of active material with a nominal diameter of 0.1 mm in the “blank” is solved.

Skeletal maturity assessment with the use of cone-beam computerized tomography.

PubMed

Joshi, Vajendra; Yamaguchi, Tetsutaro; Matsuda, Yukiko; Kaneko, Norikazu; Maki, Kotarou; Okano, Tomohiro

2012-06-01

The aim of the study was to compare cervical vertebrae maturity assessed with the use of cone-beam computerized tomography (CBCT) with the hand-wrist maturation method and cervical vertebrae maturation assessed with the use of lateral cephalography for the assessment of skeletal maturity. Assessment of skeletal maturation was done using skeletal maturity indicators (SMI) from hand-wrist radiography, cervical vertebrae maturity index (CVMI) from CBCT and lateral cephalography (cephalo-CVMI). The Spearman correlation coefficient was used for statistical analysis. We observed a significant relationship between CBCT-CVMI and cephalo-CVMI as well as between CBCT-CVMI and SMI stages. The Spearman correlation coefficient value between CBCT-CVMI and cephalo-CVMI was 0.975 (P < .0001) and between CBCT-CVMI and SMI was 0.961(P < .0001). Cervical vertebrae maturity assessment with CBCT provided a reliable assessment of pubertal growth spurt, and therefore CBCT can be used to assess skeletal maturity. Copyright © 2012 Elsevier Inc. All rights reserved.

Contrast-enhanced multidetector computerized tomography for odontogenic cysts and cystic-appearing tumors of the jaws: is it useful?

PubMed

Kakimoto, Naoya; Chindasombatjaroen, Jira; Tomita, Seiki; Shimamoto, Hiroaki; Uchiyama, Yuka; Hasegawa, Yoko; Kishino, Mitsunobu; Murakami, Shumei; Furukawa, Souhei

2013-01-01

The purpose of this study was to investigate the usefulness of computerized tomography (CT), particularly contrast-enhanced CT, in differentiation of jaw cysts and cystic-appearing tumors. We retrospectively analyzed contrast-enhanced CT images of 90 patients with odontogenic jaw cysts or cystic-appearing tumors. The lesion size and CT values were measured and the short axis to long axis (S/L) ratio, contrast enhancement (CE) ratio, and standard deviation ratio were calculated. The lesion size and the S/L ratio of keratocystic odontogenic tumors were significantly different from those of radicular cysts and follicular cysts. There were no significant differences in the CE ratio among the lesions. Multidetector CT provided diagnostic information about the size of odontogenic cysts and cystic-appearing tumors of the jaws that was related to the lesion type, but showed no relation between CE ratio and the type of these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison between multislice and cone-beam computerized tomography in the volumetric assessment of cleft palate.

PubMed

Albuquerque, Marco Antonio; Gaia, Bruno Felipe; Cavalcanti, Marcelo Gusmão Paraíso

2011-08-01

The aim of this study was to determine the applicability of multislice and cone-beam computerized tomography (CT) in the assessment of bone defects in patients with oral clefts. Bone defects were produced in 9 dry skulls to mimic oral clefts. All defects were modeled with wax. The skulls were submitted to multislice and cone-beam CT. Subsequently, physical measurements were obtained by the Archimedes principle of water displacement of wax models. The results demonstrated that multislice and cone-beam CT showed a high efficiency rate and were considered to be effective for volumetric assessment of bone defects. It was also observed that both CT modalities showed excellent results with high reliability in the study of the volume of bone defects, with no difference in performance between them. The clinical applicability of our research has shown these CT modalities to be immediate and direct, and they is important for the diagnosis and therapeutic process of patients with oral cleft. Copyright © 2011 Mosby, Inc. All rights reserved.

Sarcoidosis Occurring After Solid Cancer: A Nonfortuitous Association

PubMed Central

Grados, Aurélie; Ebbo, Mikael; Bernit, Emmanuelle; Veit, Véronique; Mazodier, Karin; Jean, Rodolphe; Coso, Diane; Aurran-Schleinitz, Thérèse; Broussais, Florence; Bouabdallah, Reda; Gravis, Gwenaelle; Goncalves, Anthony; Giovaninni, Marc; Sève, Pascal; Chetaille, Bruno; Gavet-Bongo, Florence; Weitten, Thierry; Pavic, Michel; Harlé, Jean-Robert; Schleinitz, Nicolas

2015-01-01

Abstract The association between cancer and sarcoidosis is controversial. Some epidemiological studies show an increase of the incidence of cancer in patients with sarcoidosis but only few cases of sarcoidosis following cancer treatment have been reported. We conducted a retrospective case study from internal medicine and oncology departments for patients presenting sarcoidosis after solid cancer treatment. We also performed a literature review to search for patients who developed sarcoidosis after solid cancer. We describe the clinical, biological, and radiological characteristics and outcome of these patients. Twelve patients were included in our study. Various cancers were observed with a predominance of breast cancer. Development of sarcoidosis appeared in the 3 years following cancer and was asymptomatic in half of the patients. The disease was frequently identified after a follow-up positron emission tomography computerized tomography evaluation. Various manifestations were observed but all patients presented lymph node involvement. Half of the patients required systemic therapy. With a median follow-up of 73 months, no patient developed cancer relapse. Review of the literature identified 61 other patients for which the characteristics of both solid cancer and sarcoidosis were similar to those observed in our series. This report demonstrates that sarcoidosis must be considered in the differential diagnosis of patients with a history of malignancy who have developed lymphadenopathy or other lesions on positron emission tomography computerized tomography. Histological confirmation of cancer relapse is mandatory in order to avoid unjustified treatments. This association should be consider as a protective factor against cancer relapse. PMID:26181571

The effect of different exercise protocols and regression-based algorithms on the assessment of the anaerobic threshold.

PubMed

Zuniga, Jorge M; Housh, Terry J; Camic, Clayton L; Bergstrom, Haley C; Schmidt, Richard J; Johnson, Glen O

2014-09-01

The purpose of this study was to examine the effect of ramp and step incremental cycle ergometer tests on the assessment of the anaerobic threshold (AT) using 3 different computerized regression-based algorithms. Thirteen healthy adults (mean age and body mass [SD] = 23.4 [3.3] years and body mass = 71.7 [11.1] kg) visited the laboratory on separate occasions. Two-way repeated measures analyses of variance with appropriate follow-up procedures were used to analyze the data. The step protocol resulted in greater mean values across algorithms than the ramp protocol for the V[Combining Dot Above]O2 (step = 1.7 [0.6] L·min and ramp = 1.5 [0.4] L·min) and heart rate (HR) (step = 133 [21] b·min and ramp = 124 [15] b·min) at the AT. There were no significant mean differences, however, in power outputs at the AT between the step (115.2 [44.3] W) and the ramp (112.2 [31.2] W) protocols. Furthermore, there were no significant mean differences for V[Combining Dot Above]O2, HR, or power output across protocols among the 3 computerized regression-based algorithms used to estimate the AT. The current findings suggested that the protocol selection, but not the regression-based algorithms can affect the assessment of the V[Combining Dot Above]O2 and HR at the AT.

Biometric correspondence between reface computerized facial approximations and CT-derived ground truth skin surface models objectively examined using an automated facial recognition system.

PubMed

Parks, Connie L; Monson, Keith L

2018-05-01

This study employed an automated facial recognition system as a means of objectively evaluating biometric correspondence between a ReFace facial approximation and the computed tomography (CT) derived ground truth skin surface of the same individual. High rates of biometric correspondence were observed, irrespective of rank class (R k ) or demographic cohort examined. Overall, 48% of the test subjects' ReFace approximation probes (n=96) were matched to his or her corresponding ground truth skin surface image at R 1 , a rank indicating a high degree of biometric correspondence and a potential positive identification. Identification rates improved with each successively broader rank class (R 10 =85%, R 25 =96%, and R 50 =99%), with 100% identification by R 57 . A sharp increase (39% mean increase) in identification rates was observed between R 1 and R 10 across most rank classes and demographic cohorts. In contrast, significantly lower (p<0.01) increases in identification rates were observed between R 10 and R 25 (8% mean increase) and R 25 and R 50 (3% mean increase). No significant (p>0.05) performance differences were observed across demographic cohorts or CT scan protocols. Performance measures observed in this research suggest that ReFace approximations are biometrically similar to the actual faces of the approximated individuals and, therefore, may have potential operational utility in contexts in which computerized approximations are utilized as probes in automated facial recognition systems. Copyright © 2018. Published by Elsevier B.V.

Cost-Effective and High-Resolution Subsurface Characterization Using Hydraulic Tomography

DTIC Science & Technology

2017-08-28

implementation and compare costs associated with HT and conventional methods. TECHNOLOGY DESCRIPTION The HT concept is analogous to the Computerized...develop guidance for HT field implementation and compare costs associated with HT and conventional methods. 15. SUBJECT TERMS Subsurface...3  2.1  TECHNOLOGY DESCRIPTION

32 CFR Appendix A to Part 199 - Acronyms

Code of Federal Regulations, 2014 CFR

2014-07-01

... 199—Acronyms AFR—Air Force Regulation AR—Army Regulation ASD (HA)—Assistant Secretary of Defense... Renal Disease CT—Computerized Tomography DASD (A)—Deputy Assistant Secretary of Defense (Administration....—Licensed Practical Nurse L.V.N.—Licensed Vocational Nurse MBD—Minimal Brain Dysfunction MCO—Marine Corps...

32 CFR Appendix A to Part 199 - Acronyms

Code of Federal Regulations, 2013 CFR

2013-07-01

... 199—Acronyms AFR—Air Force Regulation AR—Army Regulation ASD (HA)—Assistant Secretary of Defense... Renal Disease CT—Computerized Tomography DASD (A)—Deputy Assistant Secretary of Defense (Administration....—Licensed Practical Nurse L.V.N.—Licensed Vocational Nurse MBD—Minimal Brain Dysfunction MCO—Marine Corps...

32 CFR Appendix A to Part 199 - Acronyms

Code of Federal Regulations, 2012 CFR

2012-07-01

... 199—Acronyms AFR—Air Force Regulation AR—Army Regulation ASD (HA)—Assistant Secretary of Defense... Renal Disease CT—Computerized Tomography DASD (A)—Deputy Assistant Secretary of Defense (Administration....—Licensed Practical Nurse L.V.N.—Licensed Vocational Nurse MBD—Minimal Brain Dysfunction MCO—Marine Corps...

Non-Invasive Visualization and Quantitation of Cardiovascular Structure and Function.

ERIC Educational Resources Information Center

Ritman, E. L.; And Others

1979-01-01

Described is a new approach to investigative physiology based on computerized transaxial tomography, in which visualization and measurement of the internal structure of the cardiopulmonary system is possible without postmortem, biopsy, or vivisection procedures. Examples are given for application of the Dynamic Spatial Reconstructor (DSR). (CS)

Estimating Tissue Iron Burden: Current Status and Future Prospects

PubMed Central

Wood, John C.

2015-01-01

SUMMARY Iron overload is becoming an increasing problem as haemoglobinopathy patients gain greater access to good medical care and as therapies for myelodysplastic syndromes improve. Therapeutic options for iron chelation therapy have increased and many patients now receive combination therapies. However, optimal utilization of iron chelation therapy requires knowledge not only of the total body iron burden but the relative iron distribution among the different organs. The physiological basis for extrahepatic iron deposition is presented in order to help identify patients at highest risk for cardiac and endocrine complications. This manuscript reviews the current state of the art for monitoring global iron overload status as well as its compartmentalization. Plasma markers, computerized tomography, liver biopsy, magnetic susceptibility devices and magnetic resonance imaging (MRI) techniques are all discussed but MRI has come to dominate clinical practice. The potential impact of recent pancreatic and pituitary MRI studies on clinical practice are discussed as well as other works-in-progress. Clinical protocols are derived from experience in haemoglobinopathies but may provide useful guiding principles for other iron overload disorders, such as myelodysplastic syndromes. PMID:25765344

Neuroimaging in pediatric traumatic head injury: diagnostic considerations and relationships to neurobehavioral outcome.

PubMed

Bigler, E D

1999-08-01

Contemporary neuorimaging techniques in child traumatic brain injury are reviewed, with an emphasis on computerized tomography (CT) and magnetic resonance (MR) imaging. A brief overview of MR spectroscopy (MRS), functional MR imaging (fMRI), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) is also provided because these techniques will likely constitute important neuroimaging techniques of the future. Numerous figures are provided to illustrate the multifaceted manner in which traumatic deficits can be imaged and the role of neuroimaging information as it relates to TBI outcome.

Neurosurgical applications of ion beams

NASA Astrophysics Data System (ADS)

Fabrikant, Jacob I.; Levy, Richard P.; Phillips, Mark H.; Frankel, Kenneth A.; Lyman, John T.

1989-04-01

The program at Donner Pavilion has applied nuclear medicine research to the diagnosis and radiosurgical treatment of life-threatening intracranial vascular disorders that affect more than half a million Americans. Stereotactic heavy-charged-particle Bragg peak radiosurgery, using narrow beams of heavy ions, demonstrates superior biological and physical characteristics in brain over X-and γ-rays, viz., improved dose distribution in the Bragg peak and sharp lateral and distal borders and less scattering of the beam. Examination of CNS tissue response and alteration of cerebral blood-flow dynamics related to heavy-ion Bragg peak radiosurgery is carried out using three-dimensional treatment planning and quantitative imaging utilizing cerebral angiography, computerized tomography (CT), magnetic resonance imaging (MRI), cine-CT, xenon X-ray CT and positron emission tomography (PET). Also under examination are the physical properties of narrow heavy-ion beams for improving methods of dose delivery and dose distribution and for establishing clinical RBE/LET and dose-response relationships for human CNS tissues. Based on the evaluation and treatment with stereotactically directed narrow beams of heavy charged particles of over 300 patients, with cerebral angiography, CT scanning and MRI and PET scanning of selected patients, plus extensive clinical and neuroradiological followup, it appears that Stereotactic charged-particle Bragg peak radiosurgery obliterates intracranial arteriovenous malformations or protects against rebleeding with reduced morbidity and no mortality. Discussion will include the method of evaluation, the clinical research protocol, the Stereotactic neuroradiological preparation, treatment planning, the radiosurgery procedure and the protocol for followup. Emphasis will be placed on the neurological results, including the neuroradiological and clinical response and early and late delayed injury in brain leading to complications (including vasogenic edema, arterial occlusion, venous thrombosis and radiation necrosis). Clinical results in both children and adults will be illustrated and health outcome will be related to the advantages of charged-particle treatment planning, the radiosurgical procedure, dose distribution and dose localization.

The development and role of megavoltage cone beam computerized tomography in radiation oncology

NASA Astrophysics Data System (ADS)

Morin, Olivier

External beam radiation therapy has now the ability to deliver doses that conform tightly to a tumor volume. The steep dose gradients planned in these treatments make it increasingly important to reproduce the patient position and anatomy at each treatment fraction. For this reason, considerable research now focuses on in-room three-dimensional imaging. This thesis describes the first clinical megavoltage cone beam computed tomography (MVCBCT) system, which utilizes a conventional linear accelerator equipped with an amorphous silicon flat panel detector. The document covers the system development and investigation of its clinical applications over the last 4-5 years. The physical performance of the system was evaluated and optimized for soft-tissue contrast resolution leading to recommendations of imaging protocols to use for specific clinical applications and body sites. MVCBCT images can resolve differences of 5% in electron density for a mean dose of 9 cGy. Hence, the image quality of this system is sufficient to differentiate some soft-tissue structures. The absolute positioning accuracy with MVCBCT is better than 1 mm. The accuracy of isodose lines calculated using MVCBCT images of head and neck patients is within 3% and 3 mm. The system shows excellent stability in image quality, CT# calibration, radiation exposure and absolute positioning over a period of 8 months. A procedure for MVCBCT quality assurance was developed. In our clinic, MVCBCT has been used to detect non rigid spinal cord distortions, to position a patient with a paraspinous tumor close to metallic hardware, to position prostate cancer patients using gold markers or soft-tissue landmarks, to monitor head and neck anatomical changes and their dosimetric consequences, and to complement the convention CT for treatment planning in presence of metallic implants. MVCBCT imaging is changing the clinical practice of our department by increasingly revealing patient-specific errors. New verification protocols are being developed to minimize those errors thus moving the practice of radiation therapy one step closer to personalized medicine.

Rare Forms of Castleman Disease Mimicking Malignancy: Mesenteric and Pancreatic Involvement.

PubMed

Ozsoy, Mustafa; Ozsoy, Zehra; Sahin, Suleyman; Arıkan, Yuksel

2018-03-12

Castleman disease is a lymphoproliferative disorder with unknown etiology and pathogenesis. While the disease may involve all parts of the body, the mediastinum appears to be the most common part of involvement. In this study, we present two cases of Castleman disease with different localizations that mimicked malignancy. A 62-year-old female patient presented with jaundice. Laboratory analysis indicated aspartate aminotransferase: 250 U/L, total bilirubin: 4 mg/dl, and carbohydrate antigen (CA) 19-9: 900 U/ml. Computerized tomography (CT) of the abdomen showed a mass originating from the pancreas head which resulted in a biliary tract obstruction. A positron emission tomography-computed tomography (PET/CT) showed that the only site of involvement was the pancreas head. A decision was made to perform pancreaticoduodenectomy. During intra-abdominal exploration, lymphadenopathies were identified in the surroundings of the retropancreatic portal vein and the hepatic artery. Histopathological investigation of the dissected lymph nodes demonstrated findings consistent with granulomatous plasma-cell-rich Castleman disease. A 55-year-old female patient presented with abdominal pain, nausea, and vomiting. Computerized tomography of the abdomen showed an abdominal mass of 7 cm, originating from the mesenterium, with high-contrast uptake in the mesenterium in the lower abdominal quadrant. The mesenteric mass was resected along with segmentary small intestine resection. Histopathological investigation of the mass showed a giant granulomatous structure that consisted of plasma cells consistent with Castleman disease. Castleman disease should be kept in mind during differential diagnosis of locally advanced lymph nodes observed during preoperative investigations and intraoperative exploration.

Robust Spatial Autoregressive Modeling for Hardwood Log Inspection

Treesearch

Dongping Zhu; A.A. Beex

1994-01-01

We explore the application of a stochastic texture modeling method toward a machine vision system for log inspection in the forest products industry. This machine vision system uses computerized tomography (CT) imaging to locate and identify internal defects in hardwood logs. The application of CT to such industrial vision problems requires efficient and robust image...

Letter to the Editor: Use of Publicly Available Image Resources

DOE PAGES

Armato, Samuel G.; Drukker, Karen; Li, Feng; ...

2017-05-11

Here we write with regard to the Academic Radiology article entitled, “Computer-aided Diagnosis for Lung Cancer: Usefulness of Nodule Heterogeneity” by Drs. Nishio and Nagashima (1). The authors also report on a computerized method to classify as benign or malignant lung nodules present in computed tomography (CT) scans.

PubMed Central

FOUNTOULAKIS, E.N.; PAPADAKI, E.; PANAGIOTAKI, I.; GIANNIKAKI, E.; LAGOUDIANAKIS, G.; BIZAKIS, J.

2011-01-01

SUMMARY Haemangiopericytoma is a rare soft tissue tumour, with great histological variability and unpredictable clinical and biological behaviour. The precise cell type origin is uncertain. One third of haemangiopericytomas occur in the head and neck area, but only a few cases have been reported regarding localization at the parapharyngeal space. Herewith, case is presented of a 54-year-old female, referred to our Department due to a parapharyngeal space tumour with non-specific imaging characteristics. The patient underwent radical excision of the tumour with a trans-cervical sub-mandibular approach. The histolopathologic examination revealed a neoplasm with the characteristic features of haemangiopericytoma. One year later, during the scheduled follow-up, the computerized tomography scan showed no evidence of recurrence or residual disease. The pre-operative evaluation of a haemangiopericytoma must include a thorough imaging evaluation with computerized tomography and magnetic resonance imaging, even if results may not be specific for haemangiopericytoma. Angiography and pre-operative embolization may be performed in cases of large tumours with significant vascularity. The treatment of choice is radical excision. The follow-up includes clinical evaluation every 6 months and annual magnetic resonance imaging for at least 3 years. PMID:22058597

Application of Micromirror in Microsurgical Clipping to the Intracranial Aneurysms.

PubMed

Zhao, Chao; Ma, Zhiguo; Zhang, Yuhai; Mou, Shanling; Yang, Yunxue; Yang, Yonglin; Sun, Guoqing; Yao, Weicheng

2018-05-01

The aim of the study was to explore the values and disadvantages of micromirror in the intracranial aneurysm clipping surgery. Micromirror was used to assist microsurgical clipping to 36 intracranial aneurysms in 31 patients, of which 3 were carotid-ophthalmic artery aneurysms, 3 were anterior choroidal artery aneurysms, 11 were posterior communicating artery aneurysms, 7 were middle cerebral artery aneurysms, 10 were anterior communicating artery or anterior cerebral artery aneurysms, and the rest were a posterior cerebral artery aneurysm and a posterior inferior cerebellar artery aneurysm. The micromirror was used before and after clipping to observe the anatomic features of necks hidden behind and medial to aneurysms, to visualize surrounding neurovascular structures, and to verify the optimal clipping position. Intraoperative indocyanine green fluorescein angiography, postoperative computerized tomography angiography, and digital subtraction angiography confirmed the success of sufficient clipping. Intraoperative indocyanine green angiography, postoperative computerized tomography angiography , or digital subtraction angiography were performed and showed no case of wrong or insufficient clipping of aneurysm. Micromirror-assisted microsurgical clipping to the intracranial aneurysm is safe, sufficient, convenient, and practical.

[Quantitative analysis method based on fractal theory for medical imaging of normal brain development in infants].

PubMed

Li, Heheng; Luo, Liangping; Huang, Li

2011-02-01

The present paper is aimed to study the fractal spectrum of the cerebral computerized tomography in 158 normal infants of different age groups, based on the calculation of chaotic theory. The distribution range of neonatal period was 1.88-1.90 (mean = 1.8913 +/- 0.0064); It reached a stable condition at the level of 1.89-1.90 during 1-12 months old (mean = 1.8927 +/- 0.0045); The normal range of 1-2 years old infants was 1.86-1.90 (mean = 1.8863 +/- 4 0.0085); It kept the invariance of the quantitative value among 1.88-1.91(mean = 1.8958 +/- 0.0083) during 2-3 years of age. ANOVA indicated there's no significant difference between boys and girls (F = 0.243, P > 0.05), but the difference of age groups was significant (F = 8.947, P < 0.001). The fractal dimension of cerebral computerized tomography in normal infants computed by box methods was maintained at an efficient stability from 1.86 to 1.91. It indicated that there exit some attractor modes in pediatric brain development.

The application of compressive sampling in rapid ultrasonic computerized tomography (UCT) technique of steel tube slab (STS).

PubMed

Jiang, Baofeng; Jia, Pengjiao; Zhao, Wen; Wang, Wentao

2018-01-01

This paper explores a new method for rapid structural damage inspection of steel tube slab (STS) structures along randomly measured paths based on a combination of compressive sampling (CS) and ultrasonic computerized tomography (UCT). In the measurement stage, using fewer randomly selected paths rather than the whole measurement net is proposed to detect the underlying damage of a concrete-filled steel tube. In the imaging stage, the ℓ1-minimization algorithm is employed to recover the information of the microstructures based on the measurement data related to the internal situation of the STS structure. A numerical concrete tube model, with the various level of damage, was studied to demonstrate the performance of the rapid UCT technique. Real-world concrete-filled steel tubes in the Shenyang Metro stations were detected using the proposed UCT technique in a CS framework. Both the numerical and experimental results show the rapid UCT technique has the capability of damage detection in an STS structure with a high level of accuracy and with fewer required measurements, which is more convenient and efficient than the traditional UCT technique.

Indication-Based Ordering: A New Paradigm for Glycemic Control in Hospitalized Inpatients

PubMed Central

Lee, Joshua; Clay, Brian; Zelazny, Ziband; Maynard, Gregory

2008-01-01

Background Inpatient glycemic control is a constant challenge. Institutional insulin management protocols and structured order sets are commonly advocated but poorly studied. Effective and validated methods to integrate algorithmic protocol guidance into the insulin ordering process are needed. Methods We introduced a basic structured set of computerized insulin orders (Version 1), and later introduced a paper insulin management protocol, to assist users with the order set. Metrics were devised to assess the impact of the protocol on insulin use, glycemic control, and hypoglycemia using pharmacy data and point of care glucose tests. When incremental improvement was seen (as described in the results), Version 2 of the insulin orders was created to further streamline the process. Results The percentage of regimens containing basal insulin improved with Version 1. The percentage of patient days with hypoglycemia improved from 3.68% at baseline to 2.59% with Version 1 plus the paper insulin management protocol, representing a relative risk for hypoglycemic day of 0.70 [confidence interval (CI) 0.62, 0.80]. The relative risk of an uncontrolled (mean glucose over 180 mg/dl) patient stay was reduced to 0.84 (CI 0.77, 0.91) with Version 1 and was reduced further to 0.73 (CI 0.66, 0.81) with the paper protocol. Version 2 used clinician-entered patient parameters to guide protocol-based insulin ordering and simultaneously improved the flexibility and ease of ordering over Version 1. Conclusion Patient parameter and protocol-based clinical decision support, added to computerized provider order entry, has a track record of improving glycemic control indices. This justifies the incorporation of these algorithms into online order management. PMID:19885198

Evaluation of dose from kV cone-beam computed tomography during radiotherapy: a comparison of methodologies

NASA Astrophysics Data System (ADS)

Buckley, J.; Wilkinson, D.; Malaroda, A.; Metcalfe, P.

2017-01-01

Three alternative methodologies to the Computed-Tomography Dose Index for the evaluation of Cone-Beam Computed Tomography dose are compared, the Cone-Beam Dose Index, IAEA Human Health Report No. 5 recommended methodology and the AAPM Task Group 111 recommended methodology. The protocols were evaluated for Pelvis and Thorax scan modes on Varian® On-Board Imager and Truebeam kV XI imaging systems. The weighted planar average dose was highest for the AAPM methodology across all scans, with the CBDI being the second highest overall. A 17.96% and 1.14% decrease from the TG-111 protocol to the IAEA and CBDI protocols for the Pelvis mode and 18.15% and 13.10% decrease for the Thorax mode were observed for the XI system. For the OBI system, the variation was 16.46% and 7.14% for Pelvis mode and 15.93% to the CBDI protocol in Thorax mode respectively.

An in vitro study of the accuracy of a new protocol for planning distraction osteogenesis of the mandible.

PubMed

Gateno, J; Allen, M E; Teichgraeber, J F; Messersmith, M L

2000-09-01

The purpose of this study was to determine the in vitro accuracy of a new protocol for distraction osteogenesis of the mandible that involves a planning process and a surgical technique. An experimental design was developed to simulate distraction osteogenesis on stereolithographic models of patients with craniofacial deformities. All patients had previously undergone 3-dimensional computerized scans of the craniofacial skeleton. The data from these scans were used to generate stereolithographic models. Before the fabrication of the models, the computed tomography (CT) data were manipulated to add a series of rulers and markers to the models. The 3-dimensional computerized scans were also used as the basis of the planning process. They were imported into an animation software (3D-Studio Max; Discreet, Montreal, Canada), and a virtual distractor was built and installed on the model, and the osteotomies and distraction processes were simulated. Finally, a recipe for sequencing the linear and angular changes of the distractor were calculated. A surgical technique was developed to facilitate the precise installation of the distractor as indicated in the presurgical plan. The transfer of information regarding pin position and orientation from the computer model to the patient was accomplished by creating a surgical template. This template was designed in the computer and fabricated by use of stereolithography. Mock surgery was performed on the stereolithographic models, and the results were compared with those predicted by the computer. The difference between the actual position and the predicted position was recorded. On the X-axis, the difference between the predicted position for the condylar marker and the actual position of the marker on the stereolithographic models was 0.6 +/- 1.1 mm. On the Y-axis, the difference between the predicted position for the condylar marker and the actual position of the marker on the stereolithographic models was -0.9 +/- 2.6. On the Z-axis, the difference between the predicted position for the condylar marker and the actual position of the marker on the stereolithographic models was 0.04 +/- 0.8 mm. There was excellent correlation between the predicted and the actual measurements for the X, Y, and Z axes: 0.98, 0.93, and 0.98, respectively. The results indicate that the combination of this planning process and surgical technique was very accurate. This in vitro study is the first step in determining the clinical usefulness of this protocol. If the results of this study are validated in clinical practice, this protocol will allow clinicians to improve the clinical outcomes of patients treated with distraction osteogenesis.

Computerized Cognitive Rehabilitation of Attention and Executive Function in Acquired Brain Injury: A Systematic Review.

PubMed

Bogdanova, Yelena; Yee, Megan K; Ho, Vivian T; Cicerone, Keith D

Comprehensive review of the use of computerized treatment as a rehabilitation tool for attention and executive function in adults (aged 18 years or older) who suffered an acquired brain injury. Systematic review of empirical research. Two reviewers independently assessed articles using the methodological quality criteria of Cicerone et al. Data extracted included sample size, diagnosis, intervention information, treatment schedule, assessment methods, and outcome measures. A literature review (PubMed, EMBASE, Ovid, Cochrane, PsychINFO, CINAHL) generated a total of 4931 publications. Twenty-eight studies using computerized cognitive interventions targeting attention and executive functions were included in this review. In 23 studies, significant improvements in attention and executive function subsequent to training were reported; in the remaining 5, promising trends were observed. Preliminary evidence suggests improvements in cognitive function following computerized rehabilitation for acquired brain injury populations including traumatic brain injury and stroke. Further studies are needed to address methodological issues (eg, small sample size, inadequate control groups) and to inform development of guidelines and standardized protocols.

Are flexion extension films necessary for cervical spine clearance in patients with neck pain after negative cervical CT scan?

PubMed

Tran, Baotram; Saxe, Jonathan M; Ekeh, Akpofure Peter

2013-09-01

There are variations in cervical spine (CS) clearance protocols in neurologically intact blunt trauma patients with negative radiological imaging but persistent neck pain. Current guidelines from the current Eastern Association for the Surgery of Trauma include options of maintaining the cervical collar or obtaining either magnetic resonance imaging (MRI) or flexion-extension films (FEF). We evaluated the utility of FEF in the current era of routine computerized tomography (CT) for imaging the CS in trauma. All neurologically intact, awake, nonintoxicated patients who underwent FEF for persistent neck pain after negative CT scan of the CS at our level I trauma center over a 13-mo period were identified. Their charts were reviewed and demographic data obtained. There were 354 patients (58.5% male) with negative cervical CS CT scans who had FEF for residual neck pain. Incidental degenerative changes were seen in 37%--which did not affect their acute management. FEF were positive for possible ligamentous injury in 5 patients (1.4%). Two of these patients had negative magnetic resonance images and the other three had collars removed within 3 wk as the findings were ultimately determined to be degenerative. In the current era, where cervical CT has universally supplanted initial plain films, FEF appear to be of little value in the evaluation of persistent neck pain. Their use should be excluded from cervical spine clearance protocols in neurologically intact, awake patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Processing And Display Of Medical Three Dimensional Arrays Of Numerical Data Using Octree Encoding

NASA Astrophysics Data System (ADS)

Amans, Jean-Louis; Darier, Pierre

1986-05-01

imaging modalities such as X-Ray computerized Tomography (CT), Nuclear Medecine and Nuclear Magnetic Resonance can produce three-dimensional (3-D) arrays of numerical data of medical object internal structures. The analysis of 3-D data by synthetic generation of realistic images is an important area of computer graphics and imaging.

[Two cases of severe eye and cranial injuries due to firework explosions].

PubMed

Saunte, J P; Trojaborg, N S; Nielsen, O A; Thygesen, J

1999-12-20

Two patients who sustained serious facial, cranial and eye trauma secondary to recreational fireworks injuries are reported. Initial assessment included axial and coronary computerized tomography, control of haemorrhage, debridement of wound and brain, and in one patient bilateral excenteration of the globe. Both patients suffered from intracranial haemorrhage, but both recovered without severe neurological sequelae.

The New Approach to Sport Medicine: 3-D Reconstruction

ERIC Educational Resources Information Center

Ince, Alparslan

2015-01-01

The aim of this study is to present a new approach to sport medicine. Comparative analysis of the Vertebrae Lumbales was done in sedentary group and Muay Thai athletes. It was done by acquiring three dimensional (3-D) data and models through photogrammetric methods from the Multi-detector Computerized Tomography (MDCT) images of the Vertebrae…

Augmented Quadruple-Phase Contrast Media Administration and Triphasic Scan Protocol Increases Image Quality at Reduced Radiation Dose During Computed Tomography Urography.

PubMed

Saade, Charbel; Mohamad, May; Kerek, Racha; Hamieh, Nadine; Alsheikh Deeb, Ibrahim; El-Achkar, Bassam; Tamim, Hani; Abdul Razzak, Farah; Haddad, Maurice; Abi-Ghanem, Alain S; El-Merhi, Fadi

The aim of this article was to investigate the opacification of the renal vasculature and the urogenital system during computed tomography urography by using a quadruple-phase contrast media in a triphasic scan protocol. A total of 200 patients with possible urinary tract abnormalities were equally divided between 2 protocols. Protocol A used the conventional single bolus and quadruple-phase scan protocol (pre, arterial, venous, and delayed), retrospectively. Protocol B included a quadruple-phase contrast media injection with a triphasic scan protocol (pre, arterial and combined venous, and delayed), prospectively. Each protocol used 100 mL contrast and saline at a flow rate of 4.5 mL. Attenuation profiles and contrast-to-noise ratio of the renal arteries, veins, and urogenital tract were measured. Effective radiation dose calculation, data analysis by independent sample t test, receiver operating characteristic, and visual grading characteristic analyses were performed. In arterial circulation, only the inferior interlobular arteries in both protocols showed a statistical significance (P < 0.05). Venously, the inferior vena cava, proximal and distal renal veins demonstrated a significant opacification reduction in protocol B than in protocol A (P < 0.001). Protocol B showed a significantly higher mean contrast-to-noise ratio than protocol A (protocol B: 22.68 ± 13.72; protocol A: 14.75 ± 5.76; P < 0.001). Radiation dose was significantly reduced in protocol B (7.38 ± 2.22 mSv) than in protocol A (12.28 ± 2.72 mSv) (P < 0.001). Visual grading characteristic (P < 0.027) and receiver operating characteristic (P < 0.0001) analyses demonstrated a significant preference for protocol B. In computed tomography urography, augmented quadruple-phase contrast media and triphasic scan protocol usage increases the image quality at a reduced radiation dose.

Effective Heart Disease Detection Based on Quantitative Computerized Traditional Chinese Medicine Using Representation Based Classifiers.

PubMed

Shu, Ting; Zhang, Bob; Tang, Yuan Yan

2017-01-01

At present, heart disease is the number one cause of death worldwide. Traditionally, heart disease is commonly detected using blood tests, electrocardiogram, cardiac computerized tomography scan, cardiac magnetic resonance imaging, and so on. However, these traditional diagnostic methods are time consuming and/or invasive. In this paper, we propose an effective noninvasive computerized method based on facial images to quantitatively detect heart disease. Specifically, facial key block color features are extracted from facial images and analyzed using the Probabilistic Collaborative Representation Based Classifier. The idea of facial key block color analysis is founded in Traditional Chinese Medicine. A new dataset consisting of 581 heart disease and 581 healthy samples was experimented by the proposed method. In order to optimize the Probabilistic Collaborative Representation Based Classifier, an analysis of its parameters was performed. According to the experimental results, the proposed method obtains the highest accuracy compared with other classifiers and is proven to be effective at heart disease detection.

Use of Flowchart for Automation of Clinical Protocols in mHealth.

PubMed

Dias, Karine Nóra; Welfer, Daniel; Cordeiro d'Ornellas, Marcos; Pereira Haygert, Carlos Jesus; Dotto, Gustavo Nogara

2017-01-01

For healthcare professionals to use mobile applications we need someone who knows software development, provide them. In healthcare institutions, health professionals use clinical protocols to govern care, and sometimes these documents are computerized through mobile applications to assist them. This work aims to present a proposal of an application of flow as a way of describing clinical protocols for automatic generation of mobile applications to assist health professionals. The purpose of this research is to enable health professionals to develop applications from the description of their own clinical protocols. As a result, we developed a web system that automates clinical protocols for an Android platform, and we validated with two clinical protocols used in a Brazilian hospital. Preliminary results of the developed architecture demonstrate the feasibility of this study.

Optimal Adenosine Stress for Maximum Stress Perfusion, Coronary Flow Reserve, and Pixel Distribution of Coronary Flow Capacity by Kolmogorov-Smirnov Analysis.

PubMed

Kitkungvan, Danai; Lai, Dejian; Zhu, Hongjian; Roby, Amanda E; Johnson, Nils P; Steptoe, Derek D; Patel, Monica B; Kirkeeide, Richard; Gould, K Lance

2017-02-01

Different adenosine stress imaging protocols have not been systemically validated for absolute myocardial perfusion and coronary flow reserve (CFR) by positron emission tomography, where submaximal stress precludes assessing physiological severity of coronary artery disease. In 127 volunteers, serial rest-stress positron emission tomography scans using rubidium-82 with various adenosine infusion protocols identified (1) the protocol with maximum stress perfusion and CFR, (2) test-retest precision in same subject, (3) stress perfusion and CFR after adenosine compared with dipyridamole, (4) heterogeneity of coronary flow capacity combining stress perfusion and CFR, and (5) potential relevance for patients with risk factors or coronary artery disease. The adenosine 6-minute infusion with rubidium-82 injection at 3 minutes caused CFR that was significantly 15.7% higher than the 4-minute adenosine infusion with rubidium-82 injection at 2 minutes and significantly more homogeneous by Kolmogorov-Smirnov analysis for histograms of 1344 pixel range of perfusion in paired positron emission tomographies. In a coronary artery disease cohort separate from volunteers of this study, compared with the 3/6-minute protocol, the 2/4-minute adenosine protocol would potentially have changed 332 of 1732 (19%) positron emission tomographies at low-risk physiological severity CFR ≥2.3 to CFR <2.0, thereby implying high-risk quantitative severity potentially appropriate for interventions but because of suboptimal stress of the 2/4 protocol in some patients. The 6-minute adenosine infusion with rubidium-82 activation at 3 minutes produced CFR that averaged 15.7% higher than that in the 2/4-minute protocol, thereby potentially providing essential information for personalized management in some patients. © 2017 American Heart Association, Inc.

Practical considerations for optimizing cardiac computed tomography protocols for comprehensive acquisition prior to transcatheter aortic valve replacement.

PubMed

Khalique, Omar K; Pulerwitz, Todd C; Halliburton, Sandra S; Kodali, Susheel K; Hahn, Rebecca T; Nazif, Tamim M; Vahl, Torsten P; George, Isaac; Leon, Martin B; D'Souza, Belinda; Einstein, Andrew J

2016-01-01

Transcatheter aortic valve replacement (TAVR) is performed frequently in patients with severe, symptomatic aortic stenosis who are at high risk or inoperable for open surgical aortic valve replacement. Computed tomography angiography (CTA) has become the gold standard imaging modality for pre-TAVR cardiac anatomic and vascular access assessment. Traditionally, cardiac CTA has been most frequently used for assessment of coronary artery stenosis, and scanning protocols have generally been tailored for this purpose. Pre-TAVR CTA has different goals than coronary CTA and the high prevalence of chronic kidney disease in the TAVR patient population creates a particular need to optimize protocols for a reduction in iodinated contrast volume. This document reviews details which allow the physician to tailor CTA examinations to maximize image quality and minimize harm, while factoring in multiple patient and scanner variables which must be considered in customizing a pre-TAVR protocol. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Ionospheric Tomography Using Faraday Rotation of Automatic Dependant Surveillance Broadcast UHF Signals

NASA Astrophysics Data System (ADS)

Cushley, A. C.

2013-12-01

The proposed launch of a satellite carrying the first space-borne ADS-B receiver by the Royal Military College of Canada (RMCC) will create a unique opportunity to study the modification of the 1090 MHz radio waves following propagation through the ionosphere from the transmitting aircraft to the passive satellite receiver(s). Experimental work successfully demonstrated that ADS-B data can be used to reconstruct two dimensional (2D) electron density maps of the ionosphere using computerized tomography (CT). The goal of this work is to evaluate the feasibility of CT reconstruction. The data is modelled using Ray-tracing techniques. This allows us to determine the characteristics of individual waves, including the wave path and the state of polarization at the satellite receiver. The modelled Faraday rotation (FR) is determined and converted to total electron content (TEC) along the ray-paths. The resulting TEC is used as input for computerized ionospheric tomography (CIT) using algebraic reconstruction technique (ART). This study concentrated on meso-scale structures 100-1000 km in horizontal extent. The primary scientific interest of this thesis was to show the feasibility of a new method to image the ionosphere and obtain a better understanding of magneto-ionic wave propagation. Multiple feature input electron density profile to ray-tracing program. Top: reconstructed relative electron density map of ray-trace input (Fig. 1) using TEC measurements and line-of-sight path. Bottom: reconstructed electron density map of ray-trace input using quiet background a priori estimate.

Osteochondrosis of the inferior pole of the scapula (Roca disease).

PubMed

Skaf, Abdalla; Taneja, Atul K

2014-03-01

We report a rare case of osteochondrosis of the inferior pole of the scapula in a 14-year-old boy, an amateur swimmer, that was diagnosed by a combination of clinical and imaging findings. Also known as Roca disease, this is the first article to report this entity in the English literature and demonstrates its computerized tomography and MRI features.

Predicting internal red oak (Quercus rubra) log defect features using surface defect defect measurements

Treesearch

R. Edward Thomas

2013-01-01

Determining the defects located within a log is crucial to understanding the tree/log resource for efficient processing. However, existing means of doing this non-destructively requires the use of expensive x-ray/CT (computerized tomography), MRI (magnetic resonance imaging), or microwave technology. These methods do not lend themselves to fast, efficient, and cost-...

The application of compressive sampling in rapid ultrasonic computerized tomography (UCT) technique of steel tube slab (STS)

PubMed Central

Jiang, Baofeng; Jia, Pengjiao; Zhao, Wen; Wang, Wentao

2018-01-01

This paper explores a new method for rapid structural damage inspection of steel tube slab (STS) structures along randomly measured paths based on a combination of compressive sampling (CS) and ultrasonic computerized tomography (UCT). In the measurement stage, using fewer randomly selected paths rather than the whole measurement net is proposed to detect the underlying damage of a concrete-filled steel tube. In the imaging stage, the ℓ1-minimization algorithm is employed to recover the information of the microstructures based on the measurement data related to the internal situation of the STS structure. A numerical concrete tube model, with the various level of damage, was studied to demonstrate the performance of the rapid UCT technique. Real-world concrete-filled steel tubes in the Shenyang Metro stations were detected using the proposed UCT technique in a CS framework. Both the numerical and experimental results show the rapid UCT technique has the capability of damage detection in an STS structure with a high level of accuracy and with fewer required measurements, which is more convenient and efficient than the traditional UCT technique. PMID:29293593

Classification and Current Management of Inner Ear Malformations.

PubMed

Sennaroğlu, Levent; Bajin, Münir Demir

2017-09-29

Morphologically congenital sensorineural hearing loss can be investigated under two categories. The majority of congenital hearing loss causes (80%) are membranous malformations. Here, the pathology involves inner ear hair cells. There is no gross bony abnormality and, therefore, in these cases high-resolution computerized tomography and magnetic resonance imaging of the temporal bone reveal normal findings. The remaining 20% have various malformations involving the bony labyrinth and, therefore, can be radiologically demonstrated by computerized tomography and magnetic resonance imaging. The latter group involves surgical challenges as well as problems in decision-making. Some cases may be managed by a hearing aid, others need cochlear implantation, and some cases are candidates for an auditory brainstem implantation (ABI). During cochlear implantation, there may be facial nerve abnormalities, cerebrospinal fluid leakage, electrode misplacement or difficulty in finding the cochlea itself. During surgery for inner ear malformations, the surgeon must be ready to modify the surgical approach or choose special electrodes for surgery. In the present review article, inner ear malformations are classified according to the differences observed in the cochlea. Hearing and language outcomes after various implantation methods are closely related to the status of the cochlear nerve, and a practical classification of the cochlear nerve deficiency is also provided.

Analysis of rocket beacon transmissions for computerized reconstruction of ionospheric densities

NASA Technical Reports Server (NTRS)

Bernhardt, P. A.; Huba, J. D.; Chaturvedi, P. K.; Fulford, J. A.; Forsyth, P. A.; Anderson, D. N.; Zalesak, S. T.

1993-01-01

Three methods are described to obtain ionospheric electron densities from transionospheric, rocket-beacon TEC data. First, when the line-of-sight from a ground receiver to the rocket beacon is tangent to the flight trajectory, the electron concentration can be obtained by differentiating the TEC with respect to the distance to the rocket. A similar method may be used to obtain the electron-density profile if the layer is horizontally stratified. Second, TEC data obtained during chemical release experiments may be interpreted with the aid of physical models of the disturbed ionosphere to yield spatial maps of the modified regions. Third, computerized tomography (CT) can be used to analyze TEC data obtained along a chain of ground-based receivers aligned along the plane of the rocket trajectory. CT analysis of TEC data is used to reconstruct a 2D image of a simulated equatorial plume. TEC data is computed for a linear chain of nine receivers with adjacent spacings of either 100 or 200 km. The simulation data are analyzed to provide an F region reconstruction on a grid with 15 x 15 km pixels. Ionospheric rocket tomography may also be applied to rocket-assisted measurements of amplitude and phase scintillations and airglow intensities.

Clinical technique for invasive cervical root resorption

PubMed Central

Silveira, Luiz Fernando Machado; Silveira, Carina Folgearini; Martos, Josué; Piovesan, Edno Moacir; César Neto, João Batista

2011-01-01

This clinical case report describes the diagnosis and treatment of an external invasive cervical resorption. A 17-year-old female patient had a confirmed diagnosis of invasive cervical resorption class 4 by cone beam computerized tomography. Although, there was no communication with the root canal, the invasive resorption process was extending into the cervical and middle third of the root. The treatment of the cervical resorption of the lateral incisor interrupted the resorptive process and restored the damaged root surface and the dental functions without any esthetic sequelae. Both the radiographic examination and computed tomography are imperative to reveal the extent of the defect in the differential diagnosis. PMID:22144822

An analysis of regional cerebral blood flow in impulsive murderers using single photon emission computed tomography.

PubMed

Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa

2007-01-01

The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.

Screening and Biosensor-Based Approaches for Lung Cancer Detection

PubMed Central

Wang, Lulu

2017-01-01

Early diagnosis of lung cancer helps to reduce the cancer death rate significantly. Over the years, investigators worldwide have extensively investigated many screening modalities for lung cancer detection, including computerized tomography, chest X-ray, positron emission tomography, sputum cytology, magnetic resonance imaging and biopsy. However, these techniques are not suitable for patients with other pathologies. Developing a rapid and sensitive technique for early diagnosis of lung cancer is urgently needed. Biosensor-based techniques have been recently recommended as a rapid and cost-effective tool for early diagnosis of lung tumor markers. This paper reviews the recent development in screening and biosensor-based techniques for early lung cancer detection. PMID:29065541

Helical computerized tomography and NT-proBNP for screening of right ventricular overload on admission and at long term follow-up of acute pulmonary embolism.

PubMed

Laiho, Mia K; Harjola, Veli-Pekka; Graner, Marit; Piilonen, Anneli; Raade, Merja; Mustonen, Pirjo

2012-05-04

Right ventricular dysfunction (RVD) in acute pulmonary embolism (APE) can be assessed with helical computerized tomography (CT) and transthoracic echocardiography (TTE). Signs of RVD and elevated natriuretic peptides like NT-proBNP and cardiac troponin (TnT) are associated with increased risk of mortality. However, the prognostic role of both initial diagnostic strategy and the use of NT-proBNP and TnT for screening for long-term probability of RVD remains unknown. The aim of the study was to determine the role of helical CT and NT-proBNP in detection of RVD in the acute phase. In addition, the value of NT-proBNP for ruling out RVD at long-term follow-up was assessed. Sixty-three non-high risk APE patients were studied. RVD was assessed at admission in the emergency department by CT and TTE, and both NT-proBNP and TnT samples were taken. These, excepting CT, were repeated seven months later. At admission RVD was detected by CT in 37 (59 %) patients. RVD in CT correlated strongly with RVD in TTE (p < 0.0001). NT-proBNP was elevated (≥ 350 ng/l) in 32 (86 %) patients with RVD but in only seven (27 %) patients without RVD (p < 0.0001). All the patients survived until the 7-month follow-up. TTE showed persistent RVD in 6 of 63 (10 %) patients who all had RVD in CT at admission. All of them had elevated NT-proBNP levels in the follow-up compared with 5 (9 %) of patients without RVD (p < 0.0001). TTE does not confer further benefit when helical CT is used for screening for RVD in non-high risk APE. All the patients who were found to have RVD in TTE at seven months follow-up had had RVD in the acute phase CT as well. Thus, patients without RVD in diagnostic CT do not seem to require further routine follow-up to screen for RVD later. On the other hand, persistent RVD and thus need for TTE control can be ruled out by assessment of NT-proBNP at follow-up. A follow-up protocol based on these findings is suggested.

Helical computerized tomography and NT-proBNP for screening of right ventricular overload on admission and at long term follow-up of acute pulmonary embolism

PubMed Central

2012-01-01

Background Right ventricular dysfunction (RVD) in acute pulmonary embolism (APE) can be assessed with helical computerized tomography (CT) and transthoracic echocardiography (TTE). Signs of RVD and elevated natriuretic peptides like NT-proBNP and cardiac troponin (TnT) are associated with increased risk of mortality. However, the prognostic role of both initial diagnostic strategy and the use of NT-proBNP and TnT for screening for long-term probability of RVD remains unknown. The aim of the study was to determine the role of helical CT and NT-proBNP in detection of RVD in the acute phase. In addition, the value of NT-proBNP for ruling out RVD at long-term follow-up was assessed. Methods Sixty-three non-high risk APE patients were studied. RVD was assessed at admission in the emergency department by CT and TTE, and both NT-proBNP and TnT samples were taken. These, excepting CT, were repeated seven months later. Results At admission RVD was detected by CT in 37 (59 %) patients. RVD in CT correlated strongly with RVD in TTE (p < 0.0001). NT-proBNP was elevated (≥ 350 ng/l) in 32 (86 %) patients with RVD but in only seven (27 %) patients without RVD (p < 0.0001). All the patients survived until the 7-month follow-up. TTE showed persistent RVD in 6 of 63 (10 %) patients who all had RVD in CT at admission. All of them had elevated NT-proBNP levels in the follow-up compared with 5 (9 %) of patients without RVD (p < 0.0001). Conclusions TTE does not confer further benefit when helical CT is used for screening for RVD in non-high risk APE. All the patients who were found to have RVD in TTE at seven months follow-up had had RVD in the acute phase CT as well. Thus, patients without RVD in diagnostic CT do not seem to require further routine follow-up to screen for RVD later. On the other hand, persistent RVD and thus need for TTE control can be ruled out by assessment of NT-proBNP at follow-up. A follow-up protocol based on these findings is suggested. PMID:22559861

256 Slice Multi-detector Computed Tomography Thoracic Aorta Computed Tomography Angiography: Improved Luminal Opacification Using a Patient-Specific Contrast Protocol and Caudocranial Scan Acquisition.

PubMed

Saade, Charbel; El-Merhi, Fadi; El-Achkar, Bassam; Kerek, Racha; Vogl, Thomas J; Maroun, Gilbert Georges; Jamjoom, Lamia; Al-Mohiy, Hussain; Naffaa, Lena

Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve arterial and aneurysmal opacification and reduce both contrast and radiation dose in the assessment of thoracic aortic aneurysms (TAA) using helical thoracic computed tomography angiography (CTA). To investigate opacification of the thoracic aorta and TAA using a caudocranial scan direction and a patient-specific contrast protocol. Thoracic aortic CTA was performed in 160 consecutive patients with suspected TAA using a 256-slice computed tomography scanner and a dual barrel contrast injector. Patients were subjected in equal numbers to one of two contrast protocols. Patient age and sex were equally distributed across both groups. Protocol A, the department's standard protocol, consisted of a craniocaudal scan direction with 100 mL of contrast, intravenously injected at a flow rate of 4.5 mL/s. Protocol B involved a caudocranial scan direction and a novel contrast formula based on patient cardiovascular dynamics, followed by 100 mL of saline at 4.5 mL/s. Each scan acquisition comprised of 120 kVp, 200 mA with modulation, temporal resolution 0.27 seconds, and pitch 0.889:1. The dose length product was measured between each protocol and data generated were compared using Mann-Whitney U nonparametric statistics. Receiver operating characteristic analysis, visual grading characteristic (VGC), and κ analyses were performed. Mean opacification in the thoracic aorta and aneurysm measured was 24 % and 55%, respectively. The mean contrast volume was significantly lower in protocol B (73 ± 10 mL) compared with A (100 ± 1 mL) (P<0.001). The contrast-to-noise ratio demonstrated significant differences between the protocols (protocol A, 18.2 ± 12.9; protocol B, 29.7 ± 0.61; P < 0.003). Mean effective dose in protocol B (2.6 ± 0.4 mSv) was reduced by 19% compared with A (3.2 ± 0.8 mSv) (P < 0.004). Aneurysmal detectability demonstrated significant increases by receiver operating characteristic and visual grading characteristic analysis for protocol B compared with A (P < 0.02), and reader agreement increased from poor to excellent. Significant increase in the visualization of TAAs following a caudocranial scan direction during helical thoracic CTA can be achieved using low-contrast volume based on patient-specific contrast formula.

[The importance of axial computer tomography of the neurocranium in neurotraumatology (1) (author's transl)].

PubMed

Gustorf, R

1979-07-01

Computer tomography enables exact diagnostic clarification of intracranial lesions in trauma of the neurocranium. Subdural or epidural as well as intracerebral haemorrhages can be localised, and a circumscribed contusion and cerebral oedema become tangible. The article reports on 90 patients subjected to computerized tomography following trauma of the neurocranium. In about 50% of the cases, the trauma had been caused by a traffic accident. About 27% of the accident victims were children and adolescents. In about one-half of the examined persons, subdural or epidural haemorrhages were found, whereas in about 20% of the cases, contusions, partly with mild haemorrhages, were seen. In about 10% of the cases a more or less severe oedema was seen. About 20% of the patients yielded no abnormal finding by CT in accordance with the age of the patient.

LUNGx Challenge for computerized lung nodule classification

DOE PAGES

Armato, Samuel G.; Drukker, Karen; Li, Feng; ...

2016-12-19

The purpose of this work is to describe the LUNGx Challenge for the computerized classification of lung nodules on diagnostic computed tomography (CT) scans as benign or malignant and report the performance of participants’ computerized methods along with that of six radiologists who participated in an observer study performing the same Challenge task on the same dataset. The Challenge provided sets of calibration and testing scans, established a performance assessment process, and created an infrastructure for case dissemination and result submission. We present ten groups that applied their own methods to 73 lung nodules (37 benign and 36 malignant) thatmore » were selected to achieve approximate size matching between the two cohorts. Area under the receiver operating characteristic curve (AUC) values for these methods ranged from 0.50 to 0.68; only three methods performed statistically better than random guessing. The radiologists’ AUC values ranged from 0.70 to 0.85; three radiologists performed statistically better than the best-performing computer method. The LUNGx Challenge compared the performance of computerized methods in the task of differentiating benign from malignant lung nodules on CT scans, placed in the context of the performance of radiologists on the same task. Lastly, the continued public availability of the Challenge cases will provide a valuable resource for the medical imaging research community.« less

LUNGx Challenge for computerized lung nodule classification

PubMed Central

Armato, Samuel G.; Drukker, Karen; Li, Feng; Hadjiiski, Lubomir; Tourassi, Georgia D.; Engelmann, Roger M.; Giger, Maryellen L.; Redmond, George; Farahani, Keyvan; Kirby, Justin S.; Clarke, Laurence P.

2016-01-01

Abstract. The purpose of this work is to describe the LUNGx Challenge for the computerized classification of lung nodules on diagnostic computed tomography (CT) scans as benign or malignant and report the performance of participants’ computerized methods along with that of six radiologists who participated in an observer study performing the same Challenge task on the same dataset. The Challenge provided sets of calibration and testing scans, established a performance assessment process, and created an infrastructure for case dissemination and result submission. Ten groups applied their own methods to 73 lung nodules (37 benign and 36 malignant) that were selected to achieve approximate size matching between the two cohorts. Area under the receiver operating characteristic curve (AUC) values for these methods ranged from 0.50 to 0.68; only three methods performed statistically better than random guessing. The radiologists’ AUC values ranged from 0.70 to 0.85; three radiologists performed statistically better than the best-performing computer method. The LUNGx Challenge compared the performance of computerized methods in the task of differentiating benign from malignant lung nodules on CT scans, placed in the context of the performance of radiologists on the same task. The continued public availability of the Challenge cases will provide a valuable resource for the medical imaging research community. PMID:28018939

LUNGx Challenge for computerized lung nodule classification

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

Armato, Samuel G.; Drukker, Karen; Li, Feng

The purpose of this work is to describe the LUNGx Challenge for the computerized classification of lung nodules on diagnostic computed tomography (CT) scans as benign or malignant and report the performance of participants’ computerized methods along with that of six radiologists who participated in an observer study performing the same Challenge task on the same dataset. The Challenge provided sets of calibration and testing scans, established a performance assessment process, and created an infrastructure for case dissemination and result submission. We present ten groups that applied their own methods to 73 lung nodules (37 benign and 36 malignant) thatmore » were selected to achieve approximate size matching between the two cohorts. Area under the receiver operating characteristic curve (AUC) values for these methods ranged from 0.50 to 0.68; only three methods performed statistically better than random guessing. The radiologists’ AUC values ranged from 0.70 to 0.85; three radiologists performed statistically better than the best-performing computer method. The LUNGx Challenge compared the performance of computerized methods in the task of differentiating benign from malignant lung nodules on CT scans, placed in the context of the performance of radiologists on the same task. Lastly, the continued public availability of the Challenge cases will provide a valuable resource for the medical imaging research community.« less

Use of sonic tomography to detect and quantify wood decay in living trees1

PubMed Central

Gilbert, Gregory S.; Ballesteros, Javier O.; Barrios-Rodriguez, Cesar A.; Bonadies, Ernesto F.; Cedeño-Sánchez, Marjorie L.; Fossatti-Caballero, Nohely J.; Trejos-Rodríguez, Mariam M.; Pérez-Suñiga, José Moises; Holub-Young, Katharine S.; Henn, Laura A. W.; Thompson, Jennifer B.; García-López, Cesar G.; Romo, Amanda C.; Johnston, Daniel C.; Barrick, Pablo P.; Jordan, Fulvia A.; Hershcovich, Shiran; Russo, Natalie; Sánchez, Juan David; Fábrega, Juan Pablo; Lumpkin, Raleigh; McWilliams, Hunter A.; Chester, Kathleen N.; Burgos, Alana C.; Wong, E. Beatriz; Diab, Jonathan H.; Renteria, Sonia A.; Harrower, Jennifer T.; Hooton, Douglas A.; Glenn, Travis C.; Faircloth, Brant C.; Hubbell, Stephen P.

2016-01-01

Premise of the study: Field methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes. Methods and Results: Living trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness. Conclusions: Sonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees. PMID:28101433

A novel permeabilization protocol to obtain intracellular 3D immunolabeling for electron tomography.

PubMed

Jiménez, Nuria; Post, Jan A

2014-01-01

Electron tomography (ET) is a very important high-resolution tool for 3D imaging in cell biology. By combining the technique with immunolabeling, ET can provide essential insights into both cellular architecture and dynamics. We recently developed a protocol to achieve 3D immunolabeling of intracellular antigens without the need for uncontrolled permeabilization steps that cause random, extensive cell membrane disruption. Here we describe this novel method based on well-controlled permeabilization by targeted laser cell perforation. Mechanical permeabilization of the plasma membrane can be applied at specific sites without affecting other parts of the plasma membrane and intracellular membranes. Despite the relatively small opening created in the plasma membrane, the method allows specific 3D immunolocalization of cytoplasmic antigens in cultured cells by a pre-embedment protocol. The approach is unique and leads to a superior ultrastructural preservation for transmission electron microscopy and electron tomography.

Mid-Frequency Sonar Interactions with Beaked Whales

DTIC Science & Technology

2011-06-30

Beaked Whale, was not completed. However, several other goals were achieved, including synthesis of a morphometric model of a beaked whale. This and work...induced acoustic fields inside beaked whales and other marine mammals. Another high-level goal was to acquire new high-resolution morphometric and...range 1-10 kHz; collecting high-resolution morphometric data through computerized tomography (CT) scans on marine mammal specimens, and constructing

CMT for materials science

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

Kinney, J.

This session is comprised of two articles by John Kinney describing biomedical and other uses for computerized tomography. In the first article, Kinney describes the use of a three-dimensional x-ray tomographic microscope to image the trabecular bone architecture of the proximal tibias of rats in vivo. Research in this field may help to detect the earliest stages of hypoestrogenemic bone loss and may help to more rapidly test the effectiveness of new clinical treatments for this major public health problem. The second article describes recent advances in X-ray tomography using synchrotron radiation to evaluate microstructures in ceramic matrix composites, bonemore » loss in osteoporosis, and the development of carries lesions in teeth.« less

Heidelberg Retina Tomography Analysis in Optic Disks with Anatomic Particularities

PubMed Central

Alexandrescu, C; Pascu, R; Ilinca, R; Popescu, V; Ciuluvica, R; Voinea, L; Celea, C

2010-01-01

Due to its objectivity, reproducibility and predictive value confirmed by many large scale statistical clinical studies, Heidelberg Retina Tomography has become one of the most used computerized image analysis of the optic disc in glaucoma. It has been signaled, though, that the diagnostic value of Moorfieds Regression Analyses and Glaucoma Probability Score decreases when analyzing optic discs with extreme sizes. The number of false positive results increases in cases of megalopapilllae and the number of false negative results increases in cases of small size optic discs. The present paper is a review of the aspects one should take into account when analyzing a HRT result of an optic disc with anatomic particularities. PMID:21254731

PROTOCOL - A COMPUTERIZED SOLID WASTE QUANTITY AND COMPOSITION ESTIMATION SYSTEM: OPERATIONAL MANUAL

EPA Science Inventory

The assumptions of traditional sampling theory often do not fit the circumstances when estimating the quantity and composition of solid waste arriving at a given location, such as a landfill site, or at a specific point in an industrial or commercial process. The investigator oft...

Discrimination of correlated and entangling quantum channels with selective process tomography

DOE PAGES

Dumitrescu, Eugene; Humble, Travis S.

2016-10-10

The accurate and reliable characterization of quantum dynamical processes underlies efforts to validate quantum technologies, where discrimination between competing models of observed behaviors inform efforts to fabricate and operate qubit devices. We present a protocol for quantum channel discrimination that leverages advances in direct characterization of quantum dynamics (DCQD) codes. We demonstrate that DCQD codes enable selective process tomography to improve discrimination between entangling and correlated quantum dynamics. Numerical simulations show selective process tomography requires only a few measurement configurations to achieve a low false alarm rate and that the DCQD encoding improves the resilience of the protocol to hiddenmore » sources of noise. Lastly, our results show that selective process tomography with DCQD codes is useful for efficiently distinguishing sources of correlated crosstalk from uncorrelated noise in current and future experimental platforms.« less

Early prosthetic aortic valve infection identified with the use of positron emission tomography in a patient with lead endocarditis.

PubMed

Amraoui, Sana; Tlili, Ghoufrane; Sohal, Manav; Bordenave, Laurence; Bordachar, Pierre

2016-12-01

18-Fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT) scanning has recently been proposed as a diagnostic tool for lead endocarditis (LE). FDG PET/CT might be also useful to localize associated septic emboli in patients with LE. We report an interesting case of a LE patient with a prosthetic aortic valve in whom a trans-esophageal echocardiogram did not show associated aortic endocarditis. FDG PET/CT revealed prosthetic aortic valve infection. A second TEE performed 2 weeks after identified aortic vegetation. A longer duration of antimicrobial therapy with serial follow-up echocardiography was initiated. There was also increased uptake in the sigmoid colon, corresponding to focal polyps resected during a colonoscopy. FDG PET/CT scanning seems to be highly sensitive for prosthetic aortic valve endocarditis diagnosis. This promising diagnostic tool may be beneficial in LE patients, by identifying septic emboli and potential sites of pathogen entry.

The effects of an 8-week computerized cognitive training program in older adults: a study protocol for a randomized controlled trial.

PubMed

Ten Brinke, Lisanne F; Best, John R; Crockett, Rachel A; Liu-Ambrose, Teresa

2018-01-30

Given the world's aging population, it is important to identify strategies that promote healthy cognitive aging and minimize cognitive decline. Currently, no curative pharmaceutical therapy exists for cognitive impairment and dementia. As a result, there is much interest in lifestyle approaches. Specifically, complex mental activity, such as cognitive training, may be a promising method to combat cognitive decline in older adults. As such, the industry of commercial computerized cognitive training (CCT) applications has rapidly grown in the last decade. However, the efficacy of these commercial products is largely not established. Moreover, exercise is a recognized strategy for promoting cognitive outcomes in older adults and may augment the efficacy of computerized cognitive training applications. Therefore, we propose a proof-of-concept randomized controlled trial (RCT) to examine the effect of a commercial CCT program in community-dwelling older adults. An 8-week RCT to examine the effect of a commercial CCT program, alone and preceded by a 15-min brisk walk, on cognitive function and explore the underlying neural mechanisms in adults aged 65-85 years old. Participants will be randomized to one of three intervention groups: 1) Computerized cognitive training (FBT); 2) A 15-min brisk walk followed by computerized cognitive training (Ex-FBT); or 3) A combination of educational classes, sham cognitive training, and balanced and tone exercises (active control, BAT). Participants in all intervention groups will attend three one-hour classes per week over the course of the intervention. Participants will be assessed at baseline, trial completion, and 1-year post study completion (1-year follow-up). If results from this study show benefits for cognition at trial completion, CCT programs, alone or in combination with walking, might be a strategy to promote healthy cognitive aging in older adults. In addition, results from the 1-year follow-up measurement could provide important information regarding the long-term benefits of these CCT programs. ClinicalTrials.gov Protocol Registration System: NCT02564809; registered September 1, 2015.

How to evaluate and compare maintenance contracts: a checklist.

PubMed

Gustine, S M; Young, P

1986-07-01

Several factors need to be considered when comparing computerized tomography (CT) maintenance contracts. Five areas in particular require careful review to ensure that an institution is getting maximum value for its contract dollars: the credibility of the servicing company; the servicing engineer's qualifications and commitments; a thorough understanding of contract terminology; accurate analysis standards; and professionalism. The following article examines each of these areas in closer detail.

Ruptured intracranial dermoid: an unusual cause of headache in an older patient.

PubMed

Rajapakse, Anoja; Diack, Alison

2008-02-01

A 76-year-old woman with a history of migraine presented with worsening headache. Computerized tomography brain scan and magnetic resonance imaging brain scan showed the presence of fat globules in the cerebrospinal fluid space. This appearance was suggestive of ruptured intracranial dermoid. She recovered spontaneously. While headache is a known presentation of ruptured intracranial dermoid, the condition is unusual to present in older people.

Phenylpropanolamine and cerebral hemorrhage

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

McDowell, J.R.; LeBlanc, H.J.

1985-05-01

Computerized tomography, carotid angiograms, and arteriography were used to diagnose several cases of cerebral hemorrhage following the use of phenylpropanolamine. The angiographic picture in one of the three cases was similar to that previously described in association with amphetamine abuse and pseudoephedrine overdose, both substances being chemically and pharmacologically similar to phenylpropanolamine. The study suggests that the arterial change responsible for symptoms may be due to spasm rather than arteriopathy. 14 references, 5 figures.

Mid-Frequency Sonar Interactions With Beaked Whales

DTIC Science & Technology

2009-09-30

to acquire new high-resolution morphometric and physical-property data on beaked whales for use in the model. It is hoped that the availability of such... morphometric and physical-property data on beaked whales for use in the model. It is hoped that the availability of such a system, together with high-quality... morphometric data through computerized tomography (CT) scans on marine mammal carcasses, and constructing finite-element models of the anatomy

Use Case Analysis: The Ambulatory EEG in Navy Medicine for Traumatic Brain Injuries

DTIC Science & Technology

2016-12-01

best uses of the device for naval medicine. 14. SUBJECT TERMS traumatic brain injuries, electroencephalography, EEG, use case study 15. NUMBER OF...Traumatic Brain Injury NCS Non-Convulsive Seizures PD Parkinson’s Disease QEEG Quantitative EEG SPECT Single-Photon Emission Computerized Tomography...INTENTIONALLY LEFT BLANK 1 I. INTRODUCTION This study examines the diagnosis of traumatic brain injuries (TBI). Early detection and diagnosis is

Dual scan CT image recovery from truncated projections

NASA Astrophysics Data System (ADS)

Sarkar, Shubhabrata; Wahi, Pankaj; Munshi, Prabhat

2017-12-01

There are computerized tomography (CT) scanners available commercially for imaging small objects and they are often categorized as mini-CT X-ray machines. One major limitation of these machines is their inability to scan large objects with good image quality because of the truncation of projection data. An algorithm is proposed in this work which enables such machines to scan large objects while maintaining the quality of the recovered image.

A modified conjugate gradient method based on the Tikhonov system for computerized tomography (CT).

PubMed

Wang, Qi; Wang, Huaxiang

2011-04-01

During the past few decades, computerized tomography (CT) was widely used for non-destructive testing (NDT) and non-destructive examination (NDE) in the industrial area because of its characteristics of non-invasiveness and visibility. Recently, CT technology has been applied to multi-phase flow measurement. Using the principle of radiation attenuation measurements along different directions through the investigated object with a special reconstruction algorithm, cross-sectional information of the scanned object can be worked out. It is a typical inverse problem and has always been a challenge for its nonlinearity and ill-conditions. The Tikhonov regulation method is widely used for similar ill-posed problems. However, the conventional Tikhonov method does not provide reconstructions with qualities good enough, the relative errors between the reconstructed images and the real distribution should be further reduced. In this paper, a modified conjugate gradient (CG) method is applied to a Tikhonov system (MCGT method) for reconstructing CT images. The computational load is dominated by the number of independent measurements m, and a preconditioner is imported to lower the condition number of the Tikhonov system. Both simulation and experiment results indicate that the proposed method can reduce the computational time and improve the quality of image reconstruction. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Brachytherapy of prostate cancer after colectomy for colorectal cancer: pilot experience.

PubMed

Koutrouvelis, Panos G; Theodorescu, Dan; Katz, Stuart; Lailas, Niko; Hendricks, Fred

2005-01-01

We present a method of brachytherapy for prostate cancer using a 3-dimensional stereotactic system and computerized tomography guidance in patients without a rectum due to previous treatment for colorectal cancer. From June 1994 to November 2003 a cohort of 800 patients were treated with brachytherapy for prostate cancer. Four patients had previously been treated for colorectal cancer with 4,500 cGy external beam radiation therapy, abdominoperineal resection and chemotherapy, while 1 underwent abdominoperineal resection alone for ulcerative colitis. Because of previous radiation therapy, these patients were not candidates for salvage external beam radiation therapy or radical prostatectomy and they had no rectum for transrectal ultrasound guided transperineal brachytherapy or cryotherapy. A previously described, 3-dimensional stereotactic system was used for brachytherapy in these patients. The prescribed radiation dose was 120 to 144 Gy with iodine seeds in rapid strand format. Patient followup included clinical examination and serum prostate specific antigen measurement. Average followup was 18.6 months. Four patients had excellent biochemical control, while 1 had biochemical failure. Patients did not experience any gastrointestinal morbidity. One patient had a stricture of the distal ureter, requiring a stent. Three-dimensional computerized tomography guided brachytherapy for prostate cancer in patients with a history of colorectal cancer who have no rectum is a feasible method of treatment.

Computerized tomography and pulmonary diffusing capacity in highly trained athletes after performing a triathlon.

PubMed

Caillaud, C; Serre-Cousiné, O; Anselme, F; Capdevilla, X; Préfaut, C

1995-10-01

We investigated the computerized tomographies (CTs) of the thorax and the pulmonary diffusing capacity for CO (DLCO) in eight male athletes before and after a triathlon. DLCO and alveolar volume (VA) were simultaneously measured during 9 s of breath holding. The transfer coefficient (KCO = DLCO/VA) was then calculated. CT scanning was performed during breath holding with the subjects in the supine position. Scanner analysis was done by 1) counting the linear and polygonal opacities (index of interstitial fluid accumulation) and 2) calculating the physical mean lung density and the mean slice mass. Results showed a significant reduction in DLCO (44.9 +/- 2.3 vs. 42.9 +/- 1.7 ml.min-1.mmHg-1; P < 0.05) and KCO (6.0 +/- 0.3 vs. 5.6 +/- 0.3 ml.min-1.mmHg-1.l of VA-1; P < 0.05) after the triathlon and an increase in mean lung density (0.21 +/- 0.009 vs. 0.25 +/- 0.01 g/cm3; P < 0.0001). The number of polygonal and linear opacities increased after the race (P < 0.001). This study confirmed that DLCO and KCO decrease in elite athletes after a long-distance race and showed a concomitant increase in CT lung density and in the number of opacities.

Experience with single photon emission computerized tomography (SPECT) in follow-up of sternotomy healing.

PubMed

Harjula, A; Järvinen, A; Mattila, S; Porkka, L

1985-01-01

Single photon emission computerized tomography (SPECT) was performed thrice in ten patients undergoing open-heart surgery--preoperatively and 2 and 12 weeks postoperatively. The operations were done for ischemic heart disease (5), aortic valvular stenosis (2), aortic valvular insufficiency (1), leaking mitral prosthetic valve (1) and combined aortic and mitral valvular stenosis and insufficiency (1). The healing process in the longitudinally divided sternum was evaluated from the SPECT study. Four conventional static images in two dimensions were registered in anteroposterior, posteroanterior and left and right lateral projections. A tomographic study was done. Quantitative analyses were performed. The ratio of the sternal counts to the counts from a thoracic vertebra was calculated for use as a reference. The activity ratios showed a similar pattern in six cases, with initial increases and at 12 weeks slight decrease compared with the preoperative values. In two cases the activity was still increasing after 12 postoperative weeks. One patient, with sternotomy also one year previously, showed only slightly increased activity. The activity at the areas of the sternal wires was increased in six cases. The study thus revealed differing patterns of isotope uptake, although recovery was uneventful in all patients. The differences may reflect the possibility that the operative course and the preoperative clinical status can influence the healing mechanisms.

Parametric electrical impedance tomography for measuring bone mineral density in the pelvis using a computational model.

PubMed

Kimel-Naor, Shani; Abboud, Shimon; Arad, Marina

2016-08-01

Osteoporosis is defined as bone microstructure deterioration resulting a decrease of bone's strength. Measured bone mineral density (BMD) constitutes the main tool for Osteoporosis diagnosis, management, and defines patient's fracture risk. In the present study, parametric electrical impedance tomography (pEIT) method was examined for monitoring BMD, using a computerized simulation model and preliminary real measurements. A numerical solver was developed to simulate surface potentials measured over a 3D computerized pelvis model. Varying cortical and cancellous BMD were simulated by changing bone conductivity and permittivity. Up to 35% and 16% change was found in the real and imaginary modules of the calculated potential, respectively, while BMD changes from 100% (normal) to 60% (Osteoporosis). Negligible BMD relative error was obtained with SNR>60 [dB]. Position changes errors indicate that for long term monitoring, measurement should be taken at the same geometrical configuration with great accuracy. The numerical simulations were compared to actual measurements that were acquired from a healthy male subject using a five electrodes belt bioimpedance device. The results suggest that pEIT may provide an inexpensive easy to use tool for frequent monitoring BMD in small clinics during pharmacological treatment, as a complementary method to DEXA test. Copyright © 2016. Published by Elsevier Ltd.

The reliability of Cavalier's principle of stereological method in determining volumes of enchondromas using the computerized tomography tools.

PubMed

Acar, Nihat; Karakasli, Ahmet; Karaarslan, Ahmet; Mas, Nermin Ng; Hapa, Onur

2017-01-01

Volumetric measurements of benign tumors enable surgeons to trace volume changes during follow-up periods. For a volumetric measurement technique to be applicable, it should be easy, rapid, and inexpensive and should carry a high interobserver reliability. We aimed to assess the interobserver reliability of a volumetric measurement technique using the Cavalier's principle of stereological methods. The computerized tomography (CT) of 15 patients with a histopathologically confirmed diagnosis of enchondroma with variant tumor sizes and localizations was retrospectively reviewed for interobserver reliability evaluation of the volumetric stereological measurement with the Cavalier's principle, V = t × [((SU) × d) /SL]2 × Σ P. The volumes of the 15 tumors collected by the observers are demonstrated in Table 1. There was no statistical significance between the first and second observers ( p = 0.000 and intraclass correlation coefficient = 0.970) and between the first and third observers ( p = 0.000 and intraclass correlation coefficient = 0.981). No statistical significance was detected between the second and third observers ( p = 0.000 and intraclass correlation coefficient = 0.976). The Cavalier's principle with the stereological technique using the CT scans is an easy, rapid, and inexpensive technique in volumetric evaluation of enchondromas with a trustable interobserver reliability.

Assessment of radiation exposure in dental cone-beam computerized tomography with the use of metal-oxide semiconductor field-effect transistor (MOSFET) dosimeters and Monte Carlo simulations.

PubMed

Koivisto, J; Kiljunen, T; Tapiovaara, M; Wolff, J; Kortesniemi, M

2012-09-01

The aims of this study were to assess the organ and effective dose (International Commission on Radiological Protection (ICRP) 103) resulting from dental cone-beam computerized tomography (CBCT) imaging using a novel metal-oxide semiconductor field-effect transistor (MOSFET) dosimeter device, and to assess the reliability of the MOSFET measurements by comparing the results with Monte Carlo PCXMC simulations. Organ dose measurements were performed using 20 MOSFET dosimeters that were embedded in the 8 most radiosensitive organs in the maxillofacial and neck area. The dose-area product (DAP) values attained from CBCT scans were used for PCXMC simulations. The acquired MOSFET doses were then compared with the Monte Carlo simulations. The effective dose measurements using MOSFET dosimeters yielded, using 0.5-cm steps, a value of 153 μSv and the PCXMC simulations resulted in a value of 136 μSv. The MOSFET dosimeters placed in a head phantom gave results similar to Monte Carlo simulations. Minor vertical changes in the positioning of the phantom had a substantial affect on the overall effective dose. Therefore, the MOSFET dosimeters constitute a feasible method for dose assessment of CBCT units in the maxillofacial region. Copyright © 2012 Elsevier Inc. All rights reserved.

Successful Treatment of Lung Calciphylaxis With Sodium Thiosulfate in a Patient With Sickle Cell Disease

PubMed Central

Arrestier, Romain; Dudreuilh, Caroline; Remy, Philippe; Boulahia, Ghada; Bentaarit, Bouteina; Leibler, Claire; Adedjouma, Amir; Kofman, Tomek; Matignon, Marie; Sahali, Dil; Dufresne, Roger; Deux, Jean-Francois; Colin, Charlotte; Grimbert, Philippe; Lang, Philippe; Bartolucci, Pablo; Maitre, Bernard; Tran Van Nhieu, Jeanne; Audard, Vincent

2016-01-01

Abstract Calciphylaxis is a small vessel vasculopathy, characterized by medial wall calcification that develops in a few patients with chronic renal failure. The prognosis of skin calciphylaxis has improved considerably since the introduction of sodium thiosulfate (STS), but it remains unclear whether this therapy is effective against organ lesions related to calciphylaxis. Pulmonary calciphylaxis is a usually fatal medical condition that may occur in association with skin involvement in patients with end-stage renal disease. We report here the case of a 49-year-old woman homozygous sickle cell disease patient on chronic hemodialysis with biopsy-proven systemic calciphylaxis involving the lungs and skin. On admission, ulcerative skin lesions on the lower limbs and bilateral pulmonary infiltrates on chest computerized tomography scan were the main clinical and radiological findings. Skin and bronchial biopsies demonstrated calciphylaxis lesions. The intravenous administration of STS in association with cinacalcet for 8 consecutive months led to a clear improvement in skin lesions and thoracic lesions on chest computerized tomography scan. This case suggests for the first time that organ lesions related to calciphylaxis, and particularly lung injury, are potentially reversible. This improvement probably resulted from the combination of 3 interventions (more frequent dialysis, cinacalcet, and STS), rather than the administration of STS alone. PMID:26871829

ART 3.5D: an algorithm to label arteries and veins from three-dimensional angiography.

PubMed

Barra, Beatrice; De Momi, Elena; Ferrigno, Giancarlo; Pero, Guglielmo; Cardinale, Francesco; Baselli, Giuseppe

2016-10-01

Preoperative three-dimensional (3-D) visualization of brain vasculature by digital subtraction angiography from computerized tomography (CT) in neurosurgery is gaining more and more importance, since vessels are the primary landmarks both for organs at risk and for navigation. Surgical embolization of cerebral aneurysms and arteriovenous malformations, epilepsy surgery, and stereoelectroencephalography are a few examples. Contrast-enhanced cone-beam computed tomography (CE-CBCT) represents a powerful facility, since it is capable of acquiring images in the operation room, shortly before surgery. However, standard 3-D reconstructions do not provide a direct distinction between arteries and veins, which is of utmost importance and is left to the surgeon's inference so far. Pioneering attempts by true four-dimensional (4-D) CT perfusion scans were already described, though at the expense of longer acquisition protocols, higher dosages, and sensible resolution losses. Hence, space is open to approaches attempting to recover the contrast dynamics from standard CE-CBCT, on the basis of anomalies overlooked in the standard 3-D approach. This paper aims at presenting algebraic reconstruction technique (ART) 3.5D, a method that overcomes the clinical limitations of 4-D CT, from standard 3-D CE-CBCT scans. The strategy works on the 3-D angiography, previously segmented in the standard way, and reprocesses the dynamics hidden in the raw data to recover an approximate dynamics in each segmented voxel. Next, a classification algorithm labels the angiographic voxels and artery or vein. Numerical simulations were performed on a digital phantom of a simplified 3-D vasculature with contrast transit. CE-CBCT projections were simulated and used for ART 3.5D testing. We achieved up to 90% classification accuracy in simulations, proving the feasibility of the presented approach for dynamic information recovery for arteries and veins segmentation.

Computerized macular pathology diagnosis in spectral domain optical coherence tomography scans based on multiscale texture and shape features.

PubMed

Liu, Yu-Ying; Ishikawa, Hiroshi; Chen, Mei; Wollstein, Gadi; Duker, Jay S; Fujimoto, James G; Schuman, Joel S; Rehg, James M

2011-10-21

To develop an automated method to identify the normal macula and three macular pathologies (macular hole [MH], macular edema [ME], and age-related macular degeneration [AMD]) from the fovea-centered cross sections in three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) images. A sample of SD-OCT macular scans (macular cube 200 × 200 or 512 × 128 scan protocol; Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA) was obtained from healthy subjects and subjects with MH, ME, and/or AMD (dataset for development: 326 scans from 136 subjects [193 eyes], and dataset for testing: 131 scans from 37 subjects [58 eyes]). A fovea-centered cross-sectional slice for each of the SD-OCT images was encoded using spatially distributed multiscale texture and shape features. Three ophthalmologists labeled each fovea-centered slice independently, and the majority opinion for each pathology was used as the ground truth. Machine learning algorithms were used to identify the discriminative features automatically. Two-class support vector machine classifiers were trained to identify the presence of normal macula and each of the three pathologies separately. The area under the receiver operating characteristic curve (AUC) was calculated to assess the performance. The cross-validation AUC result on the development dataset was 0.976, 0.931, 0939, and 0.938, and the AUC result on the holdout testing set was 0.978, 0.969, 0.941, and 0.975, for identifying normal macula, MH, ME, and AMD, respectively. The proposed automated data-driven method successfully identified various macular pathologies (all AUC > 0.94). This method may effectively identify the discriminative features without relying on a potentially error-prone segmentation module.

Computerized Macular Pathology Diagnosis in Spectral Domain Optical Coherence Tomography Scans Based on Multiscale Texture and Shape Features

PubMed Central

Liu, Yu-Ying; Chen, Mei; Wollstein, Gadi; Duker, Jay S.; Fujimoto, James G.; Schuman, Joel S.; Rehg, James M.

2011-01-01

Purpose. To develop an automated method to identify the normal macula and three macular pathologies (macular hole [MH], macular edema [ME], and age-related macular degeneration [AMD]) from the fovea-centered cross sections in three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) images. Methods. A sample of SD-OCT macular scans (macular cube 200 × 200 or 512 × 128 scan protocol; Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA) was obtained from healthy subjects and subjects with MH, ME, and/or AMD (dataset for development: 326 scans from 136 subjects [193 eyes], and dataset for testing: 131 scans from 37 subjects [58 eyes]). A fovea-centered cross-sectional slice for each of the SD-OCT images was encoded using spatially distributed multiscale texture and shape features. Three ophthalmologists labeled each fovea-centered slice independently, and the majority opinion for each pathology was used as the ground truth. Machine learning algorithms were used to identify the discriminative features automatically. Two-class support vector machine classifiers were trained to identify the presence of normal macula and each of the three pathologies separately. The area under the receiver operating characteristic curve (AUC) was calculated to assess the performance. Results. The cross-validation AUC result on the development dataset was 0.976, 0.931, 0939, and 0.938, and the AUC result on the holdout testing set was 0.978, 0.969, 0.941, and 0.975, for identifying normal macula, MH, ME, and AMD, respectively. Conclusions. The proposed automated data-driven method successfully identified various macular pathologies (all AUC > 0.94). This method may effectively identify the discriminative features without relying on a potentially error-prone segmentation module. PMID:21911579

Obtaining 3D Chemical Maps by Energy Filtered Transmission Electron Microscopy Tomography.

PubMed

Roiban, Lucian; Sorbier, Loïc; Hirlimann, Charles; Ersen, Ovidiu

2018-06-09

Energy filtered transmission electron microscopy tomography (EFTEM tomography) can provide three-dimensional (3D) chemical maps of materials at a nanometric scale. EFTEM tomography can separate chemical elements that are very difficult to distinguish using other imaging techniques. The experimental protocol described here shows how to create 3D chemical maps to understand the chemical distribution and morphology of a material. Sample preparation steps for data segmentation are presented. This protocol permits the 3D distribution analysis of chemical elements in a nanometric sample. However, it should be noted that currently, the 3D chemical maps can only be generated for samples that are not beam sensitive, since the recording of filtered images requires long exposure times to an intense electron beam. The protocol was applied to quantify the chemical distribution of the components of two different heterogeneous catalyst supports. In the first study, the chemical distribution of aluminum and titanium in titania-alumina supports was analyzed. The samples were prepared using the swing-pH method. In the second, the chemical distribution of aluminum and silicon in silica-alumina supports that were prepared using the sol-powder and mechanical mixture methods was examined.

Benchmarking a quantum teleportation protocol in superconducting circuits using tomography and an entanglement witness.

PubMed

Baur, M; Fedorov, A; Steffen, L; Filipp, S; da Silva, M P; Wallraff, A

2012-01-27

Teleportation of a quantum state may be used for distributing entanglement between distant qubits in quantum communication and for quantum computation. Here we demonstrate the implementation of a teleportation protocol, up to the single-shot measurement step, with superconducting qubits coupled to a microwave resonator. Using full quantum state tomography and evaluating an entanglement witness, we show that the protocol generates a genuine tripartite entangled state of all three qubits. Calculating the projection of the measured density matrix onto the basis states of two qubits allows us to reconstruct the teleported state. Repeating this procedure for a complete set of input states we find an average output state fidelity of 86%.

Optimization of coronary attenuation in coronary computed tomography angiography using diluted contrast material.

PubMed

Kawaguchi, Naoto; Kurata, Akira; Kido, Teruhito; Nishiyama, Yoshiko; Kido, Tomoyuki; Miyagawa, Masao; Ogimoto, Akiyoshi; Mochizuki, Teruhito

2014-01-01

The purpose of this study was to evaluate a personalized protocol with diluted contrast material (CM) for coronary computed tomography angiography (CTA). One hundred patients with suspected coronary artery disease underwent retrospective electrocardiogram-gated coronary CTA on a 256-slice multidetector-row CT scanner. In the diluted CM protocol (n=50), the optimal scan timing and CM dilution rate were determined by the timing bolus scan, with 20% CM dilution (5ml/s during 10s) being considered suitable to achieve the target arterial attenuation of 350 Hounsfield units (HU). In the body weight (BW)-adjusted protocol (n=50, 222mg iodine/kg), only the optimal scan timing was determined by the timing bolus scan. The injection rate and volume in the timing bolus scan and real scan were identical between the 2 protocols. We compared the means and variations in coronary attenuation between the 2 protocols. Coronary attenuation (mean±SD) in the diluted CM and BW-adjusted protocols was 346.1±23.9 HU and 298.8±45.2 HU, respectively. The diluted CM protocol provided significantly higher coronary attenuation and lower variance than did the BW-adjusted protocol (P<0.05, in each). The diluted CM protocol facilitates more uniform attenuation on coronary CTA in comparison with the BW-adjusted protocol.  

Computerized Doppler Tomography and Spectrum Analysis of Carotid Artery Flow

PubMed Central

Morton, Paul; Goldman, Dave; Nichols, W. Kirt

1981-01-01

Contrast angiography remains the definitive study in the evaluation of atherosclerotic occlusive vascular disease. However, a safer technique for serial screening of symptomatic patients and for routine follow up is necessary. Computerized pulsed Doppler ultrasonic arteriography is a noninvasive technique developed by Miles6 for imaging lateral, antero-posterior and transverse sections of the carotid artery. We [ill] this system with new software and hardware to analyze the three-dimensional blood flow data. The system now provides information about the location of the occlusive process in the artery and a semi-quantitative evaluation of the degree of obstruction. In addition, we interfaced a digital signal analyzer to the system which permits spectrum analysis of the pulsed Doppler signal. This addition has allowed us to identify lesions which are not yet hemodynamically significant. ImagesFig. 2bFig. 2c

PROTOCOL - A COMPUTERIZED SOLID WASTE QUANTITY AND COMPOSITION ESTIMATION SYSTEM. Project Summary (EPA/600/S2-91/005)

EPA Science Inventory

The assumptions of traditional sampling theory often do not fit the circumstances when estimating the quantity and composition of solid waste arriving at a given location, such as a landfill site, or at a specific point in an industrial or commercial process. The investigator oft...

Exponentially Decelerated Contrast Media Injection Rate Combined With a Novel Patient-Specific Contrast Formula Reduces Contrast Volume Administration and Radiation Dose During Computed Tomography Pulmonary Angiography.

PubMed

Saade, Charbel; Mayat, Ahmad; El-Merhi, Fadi

2016-01-01

Matching contrast injection timing with vessel dynamics significantly improves vessel opacification and reduces contrast dose in the assessment of pulmonary embolism during computed tomography (CT) pulmonary angiography. The aim of this study was to investigate opacification of the pulmonary vasculature (PV) during CT pulmonary angiography using a patient-specific contrast formula (PSCF) and exponentially decelerated contrast media (EDCM) injection rate. Institutional review board approved this retrospective study. Computed tomography pulmonary angiography was performed on 200 patients with suspected pulmonary embolism using a 64-channel CT scanner. Patient demographics were equally distributed. Patients were randomly assigned to 2 equal protocol groups: protocol A used a PSCF, and protocol B involved the use of a PSCF combined with EDCM. The mean cross-sectional opacification profile of 8 central and 11 peripheral PVs were measured for each patient, and arteriovenous contrast ratio was calculated. Protocols were compared using Mann-Whitney U nonparametric statistics. Jackknife alternative free-response receiver operating characteristic analyses were used to assess diagnostic efficacy. Interobserver variations were investigated using kappa methods. A number of pulmonary arteries demonstrated increases in opacification (P < 0.02) for protocol B compared with A, whereas opacification in all veins was reduced in protocol B (P < 0.03). Subsequently, increased arteriovenous contrast ratio in protocol B compared with A was observed at all anatomic locations (P < 0.0002). An increase in jackknife alternative free-response receiver operating characteristic figure of merit (P < 0.0002) and interobserver variation was observed with protocol B compared with protocol A (κ = 0.3-0.73). Mean contrast volume was reduced in protocol B (29 [4] mL) compared with protocol A (33 [9] mL). Mean effective radiation dose in protocol B (1.2 [0.4] mSv) was reduced by 14% compared with protocol A (1.4 [0.6] mSv). Significant improvements in visualization of the PV can be achieved with a low contrast volume using an EDCM and PSCF. The reduced risk of cancer induction is highlighted.

Optimized tomography of continuous variable systems using excitation counting

NASA Astrophysics Data System (ADS)

Shen, Chao; Heeres, Reinier W.; Reinhold, Philip; Jiang, Luyao; Liu, Yi-Kai; Schoelkopf, Robert J.; Jiang, Liang

2016-11-01

We propose a systematic procedure to optimize quantum state tomography protocols for continuous variable systems based on excitation counting preceded by a displacement operation. Compared with conventional tomography based on Husimi or Wigner function measurement, the excitation counting approach can significantly reduce the number of measurement settings. We investigate both informational completeness and robustness, and provide a bound of reconstruction error involving the condition number of the sensing map. We also identify the measurement settings that optimize this error bound, and demonstrate that the improved reconstruction robustness can lead to an order-of-magnitude reduction of estimation error with given resources. This optimization procedure is general and can incorporate prior information of the unknown state to further simplify the protocol.

Discriminative feature representation: an effective postprocessing solution to low dose CT imaging

NASA Astrophysics Data System (ADS)

Chen, Yang; Liu, Jin; Hu, Yining; Yang, Jian; Shi, Luyao; Shu, Huazhong; Gui, Zhiguo; Coatrieux, Gouenou; Luo, Limin

2017-03-01

This paper proposes a concise and effective approach termed discriminative feature representation (DFR) for low dose computerized tomography (LDCT) image processing, which is currently a challenging problem in medical imaging field. This DFR method assumes LDCT images as the superposition of desirable high dose CT (HDCT) 3D features and undesirable noise-artifact 3D features (the combined term of noise and artifact features induced by low dose scan protocols), and the decomposed HDCT features are used to provide the processed LDCT images with higher quality. The target HDCT features are solved via the DFR algorithm using a featured dictionary composed by atoms representing HDCT features and noise-artifact features. In this study, the featured dictionary is efficiently built using physical phantom images collected from the same CT scanner as the target clinical LDCT images to process. The proposed DFR method also has good robustness in parameter setting for different CT scanner types. This DFR method can be directly applied to process DICOM formatted LDCT images, and has good applicability to current CT systems. Comparative experiments with abdomen LDCT data validate the good performance of the proposed approach. This research was supported by National Natural Science Foundation under grants (81370040, 81530060), the Fundamental Research Funds for the Central Universities, and the Qing Lan Project in Jiangsu Province.

Telestroke Imaging: A Review.

PubMed

Laghari, Fahad J; Hammer, Maxim D

2017-01-01

The use of telecommunications technology to provide the healthcare services, telemedicine, has been in use since the 1860s. The use of technology has ranged from providing medical care to far-off places during wartimes to monitoring physiological measurements of astronauts in space. Since the 1990s, reports have been published on diagnoses of neurological diseases with the use of video links. Studies confirm that the neurological examinations, including the National Institutes of Health Stroke Scale, performed during teleneurology are dependable. The transfer of stroke patients in rural hospitals to bigger medical centers delays treatment while there exists current and projected shortage of neurologists. Telestroke provides the solution. Patients suspected of acute stroke need a noncontrast computerized tomography (CT) scan for tissue plasminogen activator administration. Vascular imaging such as CT angiography, magnetic resonance angiography, and digital subtraction angiography can help show large-vessel occlusion or critical stenosis responsive to endovascular therapy. A standard protocol can be followed to decide a vascular modality of choice, considering advantages and disadvantages of each imaging modality. Telestroke solves the problems of distance and of shortage of neurologists. Neuroimaging plays a vital role in the delivery of telestroke, and the telestroke doctor should be comfortable with making a decision on selecting an appropriate vascular imaging modality. Copyright © 2016 by the American Society of Neuroimaging.

Can PET-CT imaging and radiokinetic analyses provide useful clinical information on atypical femoral shaft fracture in osteoporotic patients?

PubMed

Chesnut, C Haile; Chesnut, Charles H

2012-03-01

Atypical femoral shaft fractures are associated with the extended usage of nitrogen-containing bisphosphonates as therapy for osteoporosis. For such fractures, the positron emission tomography (PET) procedure, coupled with computerized tomography (CT), provides a potential imaging modality for defining aspects of the pathogenesis, site specificity, and possible prodromal abnormalities prior to fracture. PET-CT may assess the radiokinetic variables K1 (a putative marker for skeletal blood flow) and Ki (a putative marker for skeletal bone formation), and when combined with PET imaging modalities and CT skeletal site localization, may define the site of such radiokinetic findings. Further studies into the clinical usage of PET-CT in patients with atypical femoral shaft fractures are warranted.

[Mobile CT at neurointensive sections--it is possible].

PubMed

Frost, Majbritt; Stenkær, Susanne; Kellenberger, Simone; Ehlers, Lars

2011-01-24

Intrahospital transportation can be complicated and hazardous. Mobile computerized tomography (CT) of the head performed at the neurointensive care unit is a new technique that minimizes the need for transportation of unstable patients. Even small changes in physiological parameters can be detrimental for these patients and cause secondary injury and thus affect their prognoses. The portable CT scanner in the neurointensive care unit holds great potential, but the high price level may limit its use.

Hypomelanosis of Ito. Case report with involvement of the central nervous system and review of the literature.

PubMed

Rosemberg, S; Arita, F N; Campos, C; Alonso, F

1984-02-01

A case of hypomelanosis of Ito in a ten-year-old black boy with mental retardation, epilepsy and abnormalities of the white matter of the cerebral hemispheres revealed by a computerized tomography is presented. This is the 41st reported case on this disease, a number of which have shown neurological signs. A review of the literature with emphasis on the neurological manifestations is performed.

Multiprofissional electronic protocol in ophtalmology with enfasis in strabismus.

PubMed

Ribeiro, Christie Graf; Moreira, Ana Tereza Ramos; Pinto, José Simão DE Paula; Malafaia, Osvaldo

2016-01-01

to create and validate an electronic database in ophthalmology focused on strabismus, to computerize this database in the form of a systematic data collection software named Electronic Protocol, and to incorporate this protocol into the Integrated System of Electronic Protocols (SINPE(c)). this is a descriptive study, with the methodology divided into three phases: (1) development of a theoretical ophthalmologic database with emphasis on strabismus; (2) computerization of this theoretical ophthalmologic database using SINPE(c) and (3) interpretation of the information with demonstration of results to validate the protocol. We inputed data from the charts of fifty patients with known strabismus through the Electronic Protocol for testing and validation. the new electronic protocol was able to store information regarding patient history, physical examination, laboratory exams, imaging results, diagnosis and treatment of patients with ophthalmologic diseases, with emphasis on strabismus. We included 2,141 items in this master protocol and created 20 new specific electronic protocols for strabismus, each with its own specifics. Validation was achieved through correlation and corroboration of the symptoms and confirmed diagnoses of the fifty included patients with the diagnostic criteria for the twenty new strabismus protocols. a new, validated electronic database focusing on ophthalmology, with emphasis on strabismus, was successfully created through the standardized collection of information, and computerization of the database using proprietary software. This protocol is ready for deployment to facilitate data collection, sorting and application for practitioners and researchers in numerous specialties. criar uma base eletrônica de dados em oftalmologia com ênfase em estrabismo através da coleta padronizada de informações. Informatizar esta base sob a forma de software para a coleta sistemática de dados chamado "Protocolo Eletrônico" e incorporar este "Protocolo Eletrônico" da Oftalmologia ao Sistema Integrado de Protocolos Eletrônicos (SINPE(c)). este é um estudo descritivo e a metodologia aplicada em seu desenvolvimento está didaticamente dividida em três fases: 1) criação da base teórica de dados clínicos de oftalmologia com ênfase em estrabismo; 2) informatização da base teórica dos dados utilizando o SINPE(c); e 3) interpretação das informações com demonstração dos resultados. A informatização da base de dados foi realizada pela utilização da concessão de uso do SINPE(c). Foram incluídos neste protocolo 50 pacientes com estrabismo para validação do protocolo. o protocolo eletrônico desenvolvido permitiu armazenar informações relacionadas à anamnese, exame físico, exames complementares, diagnóstico e tratamento de pacientes com doenças oftalmológicas, com ênfase em estrabismo. Foram incluídos neste trabalho 2141 itens no protocolo mestre e foram criados 20 protocolos específicos de estrabismo, cada um com suas particularidades. Os 50 pacientes que foram incluídos nos protocolos específicos demonstraram a eficácia do método empregado. foi criada uma base eletrônica de dados em oftalmologia com ênfase em estrabismo através da coleta padronizada de informações. Esta base de dados foi informatizada sob a forma de software onde os futuros usuários poderão utilizar o protocolo eletrônico multiprofissional de doenças oftalmológicas com ênfase em estrabismo para a coleta de seus dados.

Clinical anatomy of the orbitomeningeal foramina: variational anatomy of the canals connecting the orbit with the cranial cavity.

PubMed

Macchi, Veronica; Regoli, Marì; Bracco, Sandra; Nicoletti, Claudio; Morra, Aldo; Porzionato, Andrea; De Caro, Raffaele; Bertelli, Eugenio

2016-03-01

In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice. Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen. Orbitomeningeal foramina were detected in 59.46% of skulls and in 54% of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17% of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina. Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.

Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis.

PubMed

O'Neill, Marisol; Huang, Gene O; Lamb, Dolores J

2017-12-01

The murine penis model has enriched our understanding of anomalous penile development. The morphologic characterization of the murine penis using conventional serial sectioning methods is labor intensive and prone to errors. To develop a novel application of micro-computerized tomography (micro-CT) with iodine staining for rapid, non-destructive morphologic study of murine penis structure. Penises were dissected from 10 adult wild-type mice and imaged using micro-CT with iodine staining. Images were acquired at 5-μm spatial resolution on a Bruker SkyScan 1272 micro-CT system. After images were acquired, the specimens were washed of any remaining iodine and embedded in paraffin for conventional histologic examination. Histologic and micro-CT measurements for all specimens were made by 2 independent observers. Measurements of penile structures were made on virtual micro-CT sections and histologic slides. The Lin concordance correlation coefficient demonstrated almost perfect strength of agreement for interobserver variability for histologic section (0.9995, 95% CI = 0.9990-0.9997) and micro-CT section (0.9982, 95% CI = 0.9963-0.9991) measurements. Bland-Altman analysis for agreement between the 2 modalities of measurement demonstrated mean differences of -0.029, 0.022, and -0.068 mm for male urogenital mating protuberance, baculum, and penile glans length, respectively. There did not appear to be a bias for overestimation or underestimation of measured lengths and limits of agreement were narrow. The enhanced ability offered by micro-CT to phenotype the murine penis has the potential to improve translational studies examining the molecular pathways contributing to anomalous penile development. The present study describes the first reported use of micro-CT with iodine staining for imaging the murine penis. Producing repeated histologic sections of identical orientation was limited by inherent imperfections in mounting and tissue sectioning, but this was compensated for by using micro-CT reconstructions to identify matching virtual sections. This study demonstrates the successful use of micro-CT with iodine staining, which has the potential for submicron spatial resolution, as a non-destructive method of characterizing murine penile morphology. O'Neill M, Huang GO, Lamb DJ. Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis. J Sex Med 2017;14:1533-1539. Copyright © 2017. Published by Elsevier Inc.

Impact of renal anatomy on shock wave lithotripsy outcomes for lower pole kidney stones: results of a prospective multifactorial analysis controlled by computerized tomography.

PubMed

Torricelli, Fabio C M; Marchini, Giovanni S; Yamauchi, Fernando I; Danilovic, Alexandre; Vicentini, Fabio C; Srougi, Miguel; Monga, Manoj; Mazzucchi, Eduardo

2015-06-01

We evaluated which variables impact fragmentation and clearance of lower pole calculi after shock wave lithotripsy. We prospectively evaluated patients undergoing shock wave lithotripsy for a solitary 5 to 20 mm lower pole kidney stone between June 2012 and August 2014. Patient body mass index and abdominal waist circumference were recorded. One radiologist blinded to shock wave lithotripsy outcomes measured stone size, area and density, stone-to-skin distance, infundibular length, width and height, and infundibulopelvic angle based on baseline noncontrast computerized tomography. Fragmentation, success (defined as residual fragments less than 4 mm in asymptomatic patients) and the stone-free rate were evaluated by noncontrast computerized tomography 12 weeks postoperatively. Univariate and multivariate analysis was performed. A total of 100 patients were enrolled in the study. Mean stone size was 9.1 mm. Overall fragmentation, success and stone-free rates were 76%, 54% and 37%, respectively. On logistic regression body mass index (OR 1.27, 95% CI 1.11-1.49, p = 0.004) and stone density (OR 1.0026, 95% CI 1.0008-1.0046, p = 0.005) significantly impacted fragmentation. Stone size (OR 1.24, 95% CI 1.07-1.48, p = 0.039) and stone density (OR 1.0021, 95% CI 1.0007-1.0037, p = 0.012) impacted the success rate while stone size (OR 1.24, 95% CI 1.04-1.50, p = 0.029), stone density (OR 1.0015, 95% CI 1.0001-1.0032, p = 0.046) and infundibular length (OR 1.1035, 95% CI 1.015-1.217, p = 0.015) impacted the stone-free rate. The best outcomes were found in patients with a body mass index of 30 kg/m(2) or less, stones 10 mm or less and 900 HU or less, and an infundibular length of 25 mm or less. The coexistence of significant unfavorable variables led to a stone-free rate of less than 20%. Obese patients with higher than 10 mm density stones (greater than 900 HU) in the lower pole of the kidney with an infundibular length of greater than 25 mm should be discouraged from undergoing shock wave lithotripsy. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

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

Dumitrescu, Eugene; Humble, Travis S.

The accurate and reliable characterization of quantum dynamical processes underlies efforts to validate quantum technologies, where discrimination between competing models of observed behaviors inform efforts to fabricate and operate qubit devices. We present a protocol for quantum channel discrimination that leverages advances in direct characterization of quantum dynamics (DCQD) codes. We demonstrate that DCQD codes enable selective process tomography to improve discrimination between entangling and correlated quantum dynamics. Numerical simulations show selective process tomography requires only a few measurement configurations to achieve a low false alarm rate and that the DCQD encoding improves the resilience of the protocol to hiddenmore » sources of noise. Lastly, our results show that selective process tomography with DCQD codes is useful for efficiently distinguishing sources of correlated crosstalk from uncorrelated noise in current and future experimental platforms.« less

Qualification of computerized monitoring systems in a cell therapy facility compliant with the good manufacturing practices.

PubMed

Del Mazo-Barbara, Anna; Mirabel, Clémentine; Nieto, Valentín; Reyes, Blanca; García-López, Joan; Oliver-Vila, Irene; Vives, Joaquim

2016-09-01

Computerized systems (CS) are essential in the development and manufacture of cell-based medicines and must comply with good manufacturing practice, thus pushing academic developers to implement methods that are typically found within pharmaceutical industry environments. Qualitative and quantitative risk analyses were performed by Ishikawa and Failure Mode and Effects Analysis, respectively. A process for qualification of a CS that keeps track of environmental conditions was designed and executed. The simplicity of the Ishikawa analysis permitted to identify critical parameters that were subsequently quantified by Failure Mode Effects Analysis, resulting in a list of test included in the qualification protocols. The approach presented here contributes to simplify and streamline the qualification of CS in compliance with pharmaceutical quality standards.

Vestibular rehabilitation outcomes in chronic vertiginous patients through computerized dynamic visual acuity and Gaze stabilization test.

PubMed

Badaracco, Carlo; Labini, Francesca Sylos; Meli, Annalisa; De Angelis, Ezio; Tufarelli, Davide

2007-09-01

To evaluate the efficiency of the rehabilitative protocols in patients with labyrinthine hypofunction, focusing on computerized dynamic visual acuity test (DVAt) and Gaze stabilization test (GST) specifically evaluating the vestibulo-oculomotor reflex (VOR) changes due to vestibular rehabilitation. Consecutive sample study. Day hospital in Ears, Nose, and Throat Rehabilitation Unit. Thirty-two patients with chronic dizziness with a mean age of 60.74 years. Patients performed one cycle of 12 daily rehabilitation sessions (2 h each) consisting of exercises aimed at improving VOR gain. The rehabilitation program included substitutional and/or habitudinal exercises, exercises on a stability platform, and exercises on a moving footpath with rehabilitative software. Dizziness Handicap Inventory and Activities-specific Balance Confidence Scale. Computerized dynamic posturography, computerized DVAt, and GST. The patients significantly improved in all the tests. Vestibular rehabilitation improved the quality of life by reducing the handicap index and improving the ability in everyday tasks. The recovery of the vestibular-ocular reflex and vestibular-spinal reflex efficiency was objectively proven by instrumental testing. The DVAt and the GST allow to objectively quantify the fixation ability at higher frequencies and speeds (main VOR function). Moreover, these new parameters permit to completely evaluate vestibular rehabilitation outcomes, adding new information to the generally used tests that only assess vestibulospinal reflex.

Cerebral infarction in association with Ecstasy abuse.

PubMed Central

Manchanda, S.; Connolly, M. J.

1993-01-01

A previously fit 35 year old man presented with a right hemiparesis and dysphasia 36 hours after abuse of Ecstasy (3,4-methylenedioxymethamphetamine). Computerized axial tomography scan demonstrated an extensive acute left cerebral infarction and carotid digital subtraction angiogram, 2 days after admission, revealed left middle cerebral artery occlusion. There were no other known risk factors and all other investigations were negative. The patient made a partial recovery. We propose an association between Ecstasy abuse and cerebral infarction. PMID:7904748

Cerebral infarction in association with Ecstasy abuse.

PubMed

Manchanda, S; Connolly, M J

1993-11-01

A previously fit 35 year old man presented with a right hemiparesis and dysphasia 36 hours after abuse of Ecstasy (3,4-methylenedioxymethamphetamine). Computerized axial tomography scan demonstrated an extensive acute left cerebral infarction and carotid digital subtraction angiogram, 2 days after admission, revealed left middle cerebral artery occlusion. There were no other known risk factors and all other investigations were negative. The patient made a partial recovery. We propose an association between Ecstasy abuse and cerebral infarction.

Keeping the Edge. Air Force Materiel Command Cold War Context (1945-1991). Volume 2: Installations and Facilities

DTIC Science & Technology

2003-08-01

connector increased the strength of the joints by spreading the load more equally over the cross section of the wood, and in fact made the "all-wood...strength of the timber joints by spreading the load more equally over the cross section of the wood. The Timber Engineering Company established a...Laboratory Computerized Axial Tomography Columbia Broadcasting System Comprehensive Display System Corps of Engineers Ballistic Missile Construction

A novel three-dimensional image reconstruction method for near-field coded aperture single photon emission computerized tomography

PubMed Central

Mu, Zhiping; Hong, Baoming; Li, Shimin; Liu, Yi-Hwa

2009-01-01

Coded aperture imaging for two-dimensional (2D) planar objects has been investigated extensively in the past, whereas little success has been achieved in imaging 3D objects using this technique. In this article, the authors present a novel method of 3D single photon emission computerized tomography (SPECT) reconstruction for near-field coded aperture imaging. Multiangular coded aperture projections are acquired and a stack of 2D images is reconstructed separately from each of the projections. Secondary projections are subsequently generated from the reconstructed image stacks based on the geometry of parallel-hole collimation and the variable magnification of near-field coded aperture imaging. Sinograms of cross-sectional slices of 3D objects are assembled from the secondary projections, and the ordered subset expectation and maximization algorithm is employed to reconstruct the cross-sectional image slices from the sinograms. Experiments were conducted using a customized capillary tube phantom and a micro hot rod phantom. Imaged at approximately 50 cm from the detector, hot rods in the phantom with diameters as small as 2.4 mm could be discerned in the reconstructed SPECT images. These results have demonstrated the feasibility of the authors’ 3D coded aperture image reconstruction algorithm for SPECT, representing an important step in their effort to develop a high sensitivity and high resolution SPECT imaging system. PMID:19544769

An Anatomical Study of Maxillary-Zygomatic Complex Using Three-Dimensional Computerized Tomography-Based Zygomatic Implantation

PubMed Central

Zhao, Shijie; Liu, Hui; Sun, Zhipeng; Wang, Jianwei

2017-01-01

Objective To obtain anatomical data of maxillary-zygomatic complex based on simulating the zygomatic implantation using cadaver heads and three-dimensional computerized tomography (3D-CT). Methods Simulating zygomatic implantation was performed using seven cadaver heads and 3D-CT images from forty-eight adults. After measuring the maxillary-zygomatic complex, we analyzed the position between the implantation path and the maxillary sinus cavity as well as the distance between the implantation path and the zygomatic nerve. Results The distance from the starting point to the endpoint of the implant was 56.85 ± 5.35 mm in cadaver heads and 58.15 ± 7.37 mm in 3D-CT images. For the most common implantation path (80.20%), the implant went through the maxillary sinus cavity completely. The projecting points of the implant axis (IA) on the surface of zygoma were mainly located in the region of frontal process of zygomatic bone close to the lateral orbital wall. The distances between IA and zygomatic nerve in 53 sides were shorter than 2 mm. Conclusion The simulating zygomatic implantation on cadaver skulls and 3D-CT imaging provided useful anatomical data of the maxillary-zygomatic complex. It is necessary to take care to avoid the zygomatic nerve injury during implantation, because it frequently appears on the route of implantation. PMID:29376077

Preoperative Computerized Tomography and Magnetic Resonance Imaging of the Pancreas Predicts Pancreatic Mass and Functional Outcomes After Total Pancreatectomy and Islet Autotransplant

PubMed Central

Young, Michael C.; Theis, Jake R.; Hodges, James S.; Dunn, Ty B.; Pruett, Timothy L.; Chinnakotla, Srinath; Walker, Sidney P.; Freeman, Martin L.; Trikudanathan, Guru; Arain, Mustafa; Robertson, R. Paul; Wilhelm, Joshua J.; Schwarzenberg, Sarah J.; Bland, Barbara; Beilman, Gregory J.; Bellin, Melena D.

2015-01-01

Objectives About two-thirds of patients will remain on insulin therapy after total pancreatectomy with islet autotransplant (TPIAT) for chronic pancreatitis. We investigated the relationship between measured pancreas volume on computerized tomography (CT) or magnetic resonance imaging (MRI), and features of chronic pancreatiits on imaging, with subsequent islet isolation and diabetes outcomes. Methods CT or MRI was reviewed for pancreas volume (Vitrea software), and presence or absence of calcifications, atrophy, and dilated pancreatic duct in 97 patients undergoing TPIAT. Relationship between these features and: (1) islet mass isolated and (2) diabetes status at 1 year post-TPAIT were evaluated. Results Pancreas volume correlated with islet mass measured as total islet equivalents (r=0.50, p<0.0001). Mean islet equivalents was reduced by more than half if any one of calcifications, atrophy, or ductal dilatation were observed. Pancreatic calcifications increased the odds of insulin dependence 4.0 fold (1.1, 15). Collectively, the pancreas volume and 3 imaging features strongly associated with 1 year insulin use (p=0.07), islet graft failure (p=0.003), Hemoglobin A1c (p=0.0004), fasting glucose (p=0.027), and fasting C-peptide level (p=0.008). Conclusions Measures of pancreatic parenchymal destruction on imaging, including smaller pancreas volume and calcifications associate strongly with impaired islet mass and 1 year diabetes outcomes. PMID:26745861

Color intensity projections: A rapid approach for evaluating four-dimensional CT scans in treatment planning

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

Cover, Keith S.; Lagerwaard, Frank J.; Senan, Suresh

2006-03-01

Purpose: Four-dimensional computerized tomography scans (4DCT) enable intrafractional motion to be determined. Because more than 1500 images can be generated with each 4DCT study, tools for efficient data visualization and evaluation are needed. We describe the use of color intensity projections (CIP) for visualizing mobility. Methods: Four-dimensional computerized tomography images of each patient slice were combined into a CIP composite image. Pixels largely unchanged over the component images appear unchanged in the CIP image. However, pixels whose intensity changes over the phases of the 4DCT appear in the CIP image as colored pixels, and the hue encodes the percentage ofmore » time the tissue was in each location. CIPs of 18 patients were used to study tumor and surrogate markers, namely the diaphragm and an abdominal marker block. Results: Color intensity projections permitted mobility of high-contrast features to be quickly visualized and measured. In three selected expiratory phases ('gating phases') that were reviewed in the sagittal plane, gating would have reduced mean tumor mobility from 6.3 {+-} 2.0 mm to 1.4 {+-} 0.5 mm. Residual tumor mobility in gating phases better correlated with residual mobility of the marker block than that of the diaphragm. Conclusion: CIPs permit immediate visualization of mobility in 4DCT images and simplify the selection of appropriate surrogates for gated radiotherapy.« less

The potential for non-invasive study of mummies: validation of the use of computerized tomography by post factum dissection and histological examination of a 17th century female Korean mummy

PubMed Central

Lim, Do-Seon; Lee, In Sun; Choi, Ki-Ju; Lee, Soong Deok; Oh, Chang Seok; Kim, Yi-Suk; Bok, Gi Dae; Kim, Myeung Ju; Yi, Yang Su; Lee, Eun-Joo; Shin, Dong Hoon

2008-01-01

The socio-cultural antipathies of some descendants with regard to invasive examinations of age-old human remains make permission for dissection of Korean mummies of the Joseon Dynasty (1392–1910) difficult to obtain. Overcoming this obstacle necessitated the use of non-invasive techniques, such as multi-detector computerized tomography (MDCT) and endoscopic examination, enabling determination of the preservation status of internal organs of mummies without significantly damaging the mummies themselves. However, MDCT alone cannot clearly differentiate specific mummified organs. Therefore, in much the same way as diagnostic radiologists make their MDCT readings on living patients more reliable by means of comparison with accumulated post-factum data from autopsies or histological studies, examinations of mummies by invasive techniques should not be decried as mere destruction of age-old human remains. Rather, providing that due permission from descendants and/or other relevant authorities can be obtained, dissection and histological examination should be performed whenever opportunities arise. Therefore, in this study, we compared the radiological data acquired from a 17th century mummy with our dissection results for the same subject. As accumulation of this kind of data could be very crucial for correct interpretation of MDCT findings on Korean mummies, we will perform similar trials on other Korean mummies found in forthcoming days if conditions permit. PMID:19014355

Computerized ionospheric tomography based on geosynchronous SAR

NASA Astrophysics Data System (ADS)

Hu, Cheng; Tian, Ye; Dong, Xichao; Wang, Rui; Long, Teng

2017-02-01

Computerized ionospheric tomography (CIT) based on spaceborne synthetic aperture radar (SAR) is an emerging technique to construct the three-dimensional (3-D) image of ionosphere. The current studies are all based on the Low Earth Orbit synthetic aperture radar (LEO SAR) which is limited by long repeat period and small coverage. In this paper, a novel ionospheric 3-D CIT technique based on geosynchronous SAR (GEO SAR) is put forward. First, several influences of complex atmospheric environment on GEO SAR focusing are detailedly analyzed, including background ionosphere and multiple scattering effects (induced by turbulent ionosphere), tropospheric effects, and random noises. Then the corresponding GEO SAR signal model is constructed with consideration of the temporal-variant background ionosphere within the GEO SAR long integration time (typically 100 s to 1000 s level). Concurrently, an accurate total electron content (TEC) retrieval method based on GEO SAR data is put forward through subband division in range and subaperture division in azimuth, obtaining variant TEC value with respect to the azimuth time. The processing steps of GEO SAR CIT are given and discussed. Owing to the short repeat period and large coverage area, GEO SAR CIT has potentials of covering the specific space continuously and completely and resultantly has excellent real-time performance. Finally, the TEC retrieval and GEO SAR CIT construction are performed by employing a numerical study based on the meteorological data. The feasibility and correctness of the proposed methods are verified.

Vertebral sarcoidosis: demonstration of bone involvement by computerized axial tomography

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

Dinerstein, S.L.; Kovarsky, J.

1984-08-01

A report is given of a rare case of vertebral sarcoidosis with negative conventional spinal x-ray films, yet with typical cystic lesions of the spine found incidentally during abdominal computerized axial tomography (CAT). The patient was a 28-year-old black man, who was admitted for evaluation of a 1 1/2-year history of diffuse myalgias, intermittent fever to 102 F orally, bilateral hilar adenopathy, and leukopenia. A technetium polyphosphate bone scan revealed diffuse areas of increased uptake over the sternum, entire vertebral column, and pelvis. Conventional x-ray films of the cervical, thoracic, and lumbar spine, and an AP view of the pelvismore » were all normal. Chest x-ray film revealed only bilateral hilar adenopathy. During the course of an extensive negative evaluation for infection, an abdominal CAT scan was done, showing multiple, small, sclerotic-rimmed cysts at multiple levels of the lower thoracic and lumbar spine. Bone marrow biopsy revealed only changes consistent with anemia of chronic disease. Mediastinal lymph node biopsy revealed noncaseating granulomas. A tentative diagnosis of sarcoidosis was made, and treatment with prednisone, isoniazid and rifampin was begun. Within two weeks of initiation of prednisone therapy, the patient was symptom-free. A repeat technetium polyphosphate bone scan revealed only a small residual area of mildly increased uptake over the upper thoracic vertebrae.« less

Discrepancies between leg-to-leg bioelectrical Impedance analysis and computerized tomography in abdominal visceral fat measurement.

PubMed

Lu, Hsueh-Kuan; Chen, Yu-Yawn; Yeh, Chinagwen; Chuang, Chih-Lin; Chiang, Li-Ming; Lai, Chung-Liang; Casebolt, Kevin M; Huang, Ai-Chun; Lin, Wen-Long; Hsieh, Kuen-Chang

2017-08-22

The aim of this study was to evaluate leg-to-leg bioelectrical impedance analysis (LBIA) using a four-contact electrode system for measuring abdominal visceral fat area (VFA). The present study recruited 381 (240 male and 141 female) Chinese participants to compare VFA measurements estimated by a standing LBIA system (VFALBIA) with computerized tomography (CT) scanned at the L4-L5 vertebrae (VFA CT ). The total mean body mass index (BMI) was 24.7 ± 4.2 kg/m 2 . Correlation analysis, regression analysis, Bland-Altman plot, and paired sample t-tests were used to analyze the accuracy of the VFA LBIA . For the total subjects, the regression line was VFA LBIA  = 0.698 VFA CT  + 29.521, (correlation coefficient (r) = 0.789, standard estimate of error (SEE) = 24.470 cm 2 , p < 0.001), Lin's correlation coefficient (CCC) was 0.785; and the limit of agreement (LOA; mean difference ±2 standard deviation) ranged from -43.950 to 67.951 cm 2 , LOA% (given as a percentage of mean value measured by the CT) was 48.2%. VFA LBIA and VFA CT showed significant difference (p < 0.001). Collectively, the current study indicates that LBIA has limited potential to accurately estimate visceral fat in a clinical setting.

Dental status of three Egyptian mummies: radiological investigation by multislice computerized tomography.

PubMed

Gerloni, Alessandro; Cavalli, Fabio; Costantinides, Fulvio; Costantinides, Fulvia; Bonetti, Stefano; Paganelli, Corrado

2009-06-01

The aim of the study was to provide a paleopathologic and radiologic overview of the jaws and teeth of 3 Egyptian mummies preserved in the Civic Museum of History and Art in Trieste. Computerized tomography (CT) imaging and postprocessing techniques were used to examine the oral structures. A 16-slice CT scanner was used (Aquilion 16; Toshiba Medical Systems Europe, Zoetermeer, The Netherlands). Scans were obtained at high resolution. Orthogonal-plane and 3-dimensional (3D) reconstructions were created along with curved reconstructions of the lower and upper jaws. Determination of decayed/missing teeth (DMT) and decayed/missing/tooth surfaces (DMTs) were made with 3D images. Analyses revealed differences in the embalming techniques and state of preservation of the bodies. Marked wear of the occlusal surfaces was a characteristic finding in all of the mummies. The DMT and DMTs were low compared with values for contemporary populations. Two mummies had fully erupted third molars. All mummies exhibited bone changes consistent with periodontitis. The CT evaluations of the oral structures of the mummies provided insight into the dental status and oral diseases of these ancient Egyptians. The low DMT and DMTs values and indications of periodontitis may be associated with the lifestyle of these Egyptians. The fully erupted and well aligned third molars may represent a morphologic adaptation of the arches to the muscular activity associated with grinding tough foods.

Early-Dynamic Positron Emission Tomography (PET)/Computed Tomography and PET Angiography for Endoleak Detection After Endovascular Aneurysm Repair.

PubMed

Drescher, Robert; Gühne, Falk; Freesmeyer, Martin

2017-06-01

To propose a positron emission tomography (PET)/computed tomography (CT) protocol including early-dynamic and late-phase acquisitions to evaluate graft patency and aneurysm diameter, detect endoleaks, and rule out graft or vessel wall inflammation after endovascular aneurysm repair (EVAR) in one examination without intravenous contrast medium. Early-dynamic PET/CT of the endovascular prosthesis is performed for 180 seconds immediately after intravenous injection of F-18-fluorodeoxyglucose. Data are reconstructed in variable time frames (time periods after tracer injection) to visualize the arterial anatomy and are displayed as PET angiography or fused with CT images. Images are evaluated in view of vascular abnormalities, graft configuration, and tracer accumulation in the aneurysm sac. Whole-body PET/CT is performed 90 to 120 minutes after tracer injection. This protocol for early-dynamic PET/CT and PET angiography has the potential to evaluate vascular diseases, including the diagnosis of complications after endovascular procedures.

Quantum tomography enhanced through parametric amplification

NASA Astrophysics Data System (ADS)

Knyazev, E.; Spasibko, K. Yu; Chekhova, M. V.; Khalili, F. Ya

2018-01-01

Quantum tomography is the standard method of reconstructing the Wigner function of quantum states of light by means of balanced homodyne detection. The reconstruction quality strongly depends on the photodetectors quantum efficiency and other losses in the measurement setup. In this article we analyze in detail a protocol of enhanced quantum tomography, proposed by Leonhardt and Paul [1] which allows one to reduce the degrading effect of detection losses. It is based on phase-sensitive parametric amplification, with the phase of the amplified quadrature being scanned synchronously with the local oscillator phase. Although with sufficiently strong amplification the protocol enables overcoming any detection inefficiency, it was so far not implemented in the experiment, probably due to the losses in the amplifier. Here we discuss a possible proof-of-principle experiment with a traveling-wave parametric amplifier. We show that with the state-of-the-art optical elements, the protocol enables high fidelity tomographic reconstruction of bright non-classical states of light. We consider two examples: bright squeezed vacuum and squeezed single-photon state, with the latter being a non-Gaussian state and both strongly affected by the losses.

Overall evaluability of low dose protocol for computed tomography angiography of thoracic aorta using 80 kV and iterative reconstruction algorithm using different concentration contrast media.

PubMed

Annoni, Andrea Daniele; Mancini, Maria E; Andreini, Daniele; Formenti, Alberto; Mushtaq, Saima; Nobili, Enrica; Guglielmo, Marco; Baggiano, Andrea; Conte, Edoardo; Pepi, Mauro

2017-10-01

Multidetector Computed Tomography Angiography (MDCTA) is presently the imaging modality of choice for aortic disease. However, the effective radiation dose and the risk related to the use of contrast agents associated with MDCTA is an issue of concern. Aim of this study was to assess image quality of a low dose ECG-gated MDCTA of thoracic aorta using different concentration contrast media without tailored injection protocol. Two-hundred patients were randomised into four different scan protocols: Group A (Iodixanol 320 and 80 Kvp tube voltage), Group B (Iodixanol 320 and 100 Kvp tube voltage), Group C (Iomeprol 400 and 80 Kvp tube voltage) and Group D (Iomeprol 400 and 100 Kvp tube voltage). Image quality, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and effective dose (ED) were compared among groups. No significant differences in image noise, SNR and CNR between groups with the same tube voltage. Significant differences in SNR and CNR were found among groups with 80 kV versus groups using 100 kV but without differences in terms of image quality. ED was significantly lower in groups with 80 kV. Multidetector Computed Tomography Angiography protocols using 80 kV and low concentration contrast media are feasible without need of tailored injection protocols. © 2017 The Royal Australian and New Zealand College of Radiologists.

Peri-implant assessment via cone beam computed tomography and digital periapical radiography: an ex vivo study.

PubMed

Silveira-Neto, Nicolau; Flores, Mateus Ericson; De Carli, João Paulo; Costa, Max Dória; Matos, Felipe de Souza; Paranhos, Luiz Renato; Linden, Maria Salete Sandini

2017-11-01

This research evaluated detail registration in peri-implant bone using two different cone beam computer tomography systems and a digital periapical radiograph. Three different image acquisition protocols were established for each cone beam computer tomography apparatus, and three clinical situations were simulated in an ex vivo fresh pig mandible: buccal bone defect, peri-implant bone defect, and bone contact. Data were subjected to two analyses: quantitative and qualitative. The quantitative analyses involved a comparison of real specimen measures using a digital caliper in three regions of the preserved buccal bone - A, B and E (control group) - to cone beam computer tomography images obtained with different protocols (kp1, kp2, kp3, ip1, ip2, and ip3). In the qualitative analyses, the ability to register peri-implant details via tomography and digital periapical radiography was verified, as indicated by twelve evaluators. Data were analyzed with ANOVA and Tukey's test (α=0.05). The quantitative assessment showed means statistically equal to those of the control group under the following conditions: buccal bone defect B and E with kp1 and ip1, peri-implant bone defect E with kp2 and kp3, and bone contact A with kp1, kp2, kp3, and ip2. Qualitatively, only bone contacts were significantly different among the assessments, and the p3 results differed from the p1 and p2 results. The other results were statistically equivalent. The registration of peri-implant details was influenced by the image acquisition protocol, although metal artifacts were produced in all situations. The evaluators preferred the Kodak 9000 3D cone beam computer tomography in most cases. The evaluators identified buccal bone defects better with cone beam computer tomography and identified peri-implant bone defects better with digital periapical radiography.

Differentiation of benign from malignant cervical lymph nodes in patients with head and neck cancer using PET/CT imaging.

PubMed

Payabvash, Seyedmehdi; Meric, Kaan; Cayci, Zuzan

2016-01-01

To differentiate malignant from benign cervical lymph nodes in patients with head/neck cancer. In this retrospective study, 39 patients with primary head/neck cancer who underwent Positron Emission Tomography (PET)/Computerized Tomography (CT) and image-guided lymph node biopsy were included. Overall, 23 (59%) patients had biopsy-proven malignant cervical lymphadenopathy. Malignant lymph nodes had higher maximum standardized uptake (SUV-max) value (P<.001) and short-axis diameter (P=.015) compared to benign nodes. An SUV-max of ≥2.5 was 100% sensitive, and an SUV-max ≥5.5 was 100% specific for malignant lymphadenopathy. The PET/CT SUV-max value can help with differentiation of malignant cervical lymph nodes in patients with head/neck cancer. Published by Elsevier Inc.

The use of microtomography in bone tissue and biomaterial three-dimensional analysis.

PubMed

Bedini, Rossella; Meleo, Deborah; Pecci, Raffaella; Pacifici, Luciano

2009-01-01

X-ray computed microtomography (micro-CT, microComputerised Tomography) is a miniaturized form of conventional computerized axial tomography (CAT ). This sophisticated technology enables 3D riconstruction of the internal structure of small X-ray opaque objects without sample destruction or preparation. The aim of this study is to show the possible applications of micro-CT in the analysis of bone graft materials of different origins (i.e. homologous, heterologous, alloplastic) in order to define their morphometric properties by means of SkyScan 1072 3D microtomography system. Since there is a close relationship between the properties of the materials and their microstructure, it is necessary to examine them using the highest levels of resolution before being able to improve existing materials or create new products.

Automation in an Addiction Treatment Research Clinic: Computerized Contingency Management, Ecological Momentary Assessment, and a Protocol Workflow System

PubMed Central

Vahabzadeh, Massoud; Lin, Jia-Ling; Mezghanni, Mustapha; Epstein, David H.; Preston, Kenzie L.

2009-01-01

Issues A challenge in treatment research is the necessity of adhering to protocol and regulatory strictures while maintaining flexibility to meet patients’ treatment needs and accommodate variations among protocols. Another challenge is the acquisition of large amounts of data in an occasionally hectic environment, along with provision of seamless methods for exporting, mining, and querying the data. Approach We have automated several major functions of our outpatient treatment research clinic for studies in drug abuse and dependence. Here we describe three such specialized applications: the Automated Contingency Management (ACM) system for delivery of behavioral interventions, the Transactional Electronic Diary (TED) system for management of behavioral assessments, and the Protocol Workflow System (PWS) for computerized workflow automation and guidance of each participant’s daily clinic activities. These modules are integrated into our larger information system to enable data sharing in real time among authorized staff. Key Findings ACM and TED have each permitted us to conduct research that was not previously possible. In addition, the time to data analysis at the end of each study is substantially shorter. With the implementation of the PWS, we have been able to manage a research clinic with an 80-patient capacity having an annual average of 18,000 patient-visits and 7,300 urine collections with a research staff of five. Finally, automated data management has considerably enhanced our ability to monitor and summarize participant-safety data for research oversight. Implications and conclusion When developed in consultation with end users, automation in treatment-research clinics can enable more efficient operations, better communication among staff, and expansions in research methods. PMID:19320669

High-pressure freezing for scanning transmission electron tomography analysis of cellular organelles.

PubMed

Walther, Paul; Schmid, Eberhard; Höhn, Katharina

2013-01-01

Using an electron microscope's scanning transmission mode (STEM) for collection of tomographic datasets is advantageous compared to bright field transmission electron microscopic (TEM). For image formation, inelastic scattering does not cause chromatic aberration, since in STEM mode no image forming lenses are used after the beam has passed the sample, in contrast to regular TEM. Therefore, thicker samples can be imaged. It has been experimentally demonstrated that STEM is superior to TEM and energy filtered TEM for tomography of samples as thick as 1 μm. Even when using the best electron microscope, adequate sample preparation is the key for interpretable results. We adapted protocols for high-pressure freezing of cultivated cells from a physiological state. In this chapter, we describe optimized high-pressure freezing and freeze substitution protocols for STEM tomography in order to obtain high membrane contrast.

[Multidisciplinary protocol for computed tomography imaging and angiographic embolization of splenic injury due to trauma: assessment of pre-protocol and post-protocol outcomes].

PubMed

Koo, M; Sabaté, A; Magalló, P; García, M A; Domínguez, J; de Lama, M E; López, S

2011-11-01

To assess conservative treatment of splenic injury due to trauma, following a protocol for computed tomography (CT) and angiographic embolization. To quantify the predictive value of CT for detecting bleeding and need for embolization. The care protocol developed by the multidisciplinary team consisted of angiography with embolization of lesions revealed by contrast extravasation under CT as well as embolization of grade III-V injuries observed, or grade I-II injuries causing hemodynamic instability and/or need for blood transfusion. We collected data on demographic variables, injury severity score (ISS), angiographic findings, and injuries revealed by CT. Pre-protocol and post-protocol outcomes were compared. The sensitivity and specificity of CT findings were calculated for all patients who required angiographic embolization. Forty-four and 30 angiographies were performed in the pre- and post-protocol periods, respectively. The mean (SD) ISSs in the two periods were 25 (11) and 26 (12), respectively. A total of 24 (54%) embolizations were performed in the pre-protocol period and 28 (98%) after implementation of the protocol. Two and 7 embolizations involved the spleen in the 2 periods, respectively; abdominal laparotomies numbered 32 and 25, respectively, and 10 (31%) vs 4 (16%) splenectomies were performed. The specificity and sensitivity values for contrast extravasation found on CT and followed by embolization were 77.7% and 79.5%. The implementation of this multidisciplinary protocol using CT imaging and angiographic embolization led to a decrease in the number of splenectomies. The protocol allows us to take a more conservative treatment approach.

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.

Phantom dosimetry and image quality of i-CAT FLX cone-beam computed tomography

PubMed Central

Ludlow, John B.; Walker, Cameron

2013-01-01

Introduction Increasing use of cone-beam computed tomography in orthodontics has been coupled with heightened concern with the long-term risks of x-ray exposure in orthodontic populations. An industry response to this has been to offer low-exposure alternative scanning options in newer cone-beam computed tomography models. Methods Effective doses resulting from various combinations of field size, and field location comparing child and adult anthropomorphic phantoms using the recently introduced i-CAT FLX cone-beam computed tomography unit were measured with Optical Stimulated Dosimetry using previously validated protocols. Scan protocols included High Resolution (360° rotation, 600 image frames, 120 kVp, 5 mA, 7.4 sec), Standard (360°, 300 frames, 120 kVp, 5 mA, 3.7 sec), QuickScan (180°, 160 frames, 120 kVp, 5 mA, 2 sec) and QuickScan+ (180°, 160 frames, 90 kVp, 3 mA, 2 sec). Contrast-to-noise ratio (CNR) was calculated as a quantitative measure of image quality for the various exposure options using the QUART DVT phantom. Results Child phantom doses were on average 36% greater than Adult phantom doses. QuickScan+ protocols resulted in significantly lower doses than Standard protocols for child (p=0.0167) and adult (p=0.0055) phantoms. 13×16 cm cephalometric fields of view ranged from 11–85 μSv in the adult phantom and 18–120 μSv in the child for QuickScan+ and Standard protocols respectively. CNR was reduced by approximately 2/3rds comparing QuickScan+ to Standard exposure parameters. Conclusions QuickScan+ effective doses are comparable to conventional panoramic examinations. Significant dose reductions are accompanied by significant reductions in image quality. However, this trade-off may be acceptable for certain diagnostic tasks such as interim assessment of treatment results. PMID:24286904

Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT.

PubMed

Yang, Ching-Ching; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin; Liu, Shu-Hsin

2017-06-01

This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.

CT diagnosis of a clinically unsuspected acute appendicitis complicating infectious mononucleosis.

PubMed

Zissin, R; Brautbar, O; Shapiro-Feinberg, M

2001-01-01

Acute appendicitis is a rare complication of infectious mononucleosis (IM). We describe a patient with IM and splenic rupture with a computerized tomography (CT) diagnosis of acute appendicitis during the acute phase of the infectious disease. Diagnostic imaging features of acute appendicitis were found on an abdominal CT performed for the evaluation of postoperative fever. Histologic examination confirmed the CT diagnosis of the clinically unsuspected acute appendicitis. Our case is unique both for the rarity of this complication and the lack of clinical symptoms.

Spontaneous thrombosis of congenital extrahepatic portosystemic shunt (Abernethy malformation) simulating inguinal hernia incarceration.

PubMed

Afzal, Samara; Nair, Amit; Grainger, Jennie; Latif, Sherif; Rehman, Atiq-ur

2010-08-01

Tender lumps in the inguinal region are often explored emergently to treat suspected hernial strangulation. We discuss the case of an adult male who presented acutely with a tender inguinal swelling and raised inflammatory markers and was therefore deemed as requiring surgical exploration. However preoperative abdominal computerized tomography (CT) revealed an extensive thrombosing congenital venous malformation of portosystemic origin with extension into the symptomatic inguinal canal. A potentially lethal exsanguination from surgery was thus avoided.

Subdural abscess secondary to covert dental sepsis

PubMed Central

Sprott, Mae S.; Hall, K.; Newman, P. K.; Welbury, R. R.; Ingham, H. R.

1981-01-01

The bacterial flora of a subdural abscess in a 17-year-old male, with radiological evidence of unilateral infection of the maxillary and frontal air sinuses, was typical of that encountered in the dental sulcus. Extensive examination revealed no primary focus of infection other than apical infection in the 2 upper first molar teeth, which were extracted. Treatment with ampicillin, gentamicin and metronidazole rapidly controlled the subdural infection, and resolution, as evidenced by computerized tomography, was complete at 10 months. PMID:7335566

MODERN BEAMS FOR ANCIENT MUMMIES COMPUTERIZED TOMOGRAPHY OF THE HOLOCENE MUMMIFIED REMAINS FROM WADI TAKARKORI (ACACUS, SOUTH-WESTERN LIBYA; MIDDLE PASTORAL).

PubMed

Di Vincenzo, Fabio; Carbone, Iacopo; Ottini, Laura; Profico, Antonio; Ricci, Francesca; Tafuri, Mary Anne; Fornaciari, Gino; Manzi, Giorgio

2015-01-01

The Middle Pastoral human remains from Wadi Takarkori in the Libyan Acacus mountains (Fezzan) are exceptionally preserved partial mummies ranging between 6100 and 5000 uncal years BP; this small sample represents the most ancient of its kind ever found. In this report, we present a survey of the skeletal anatomy of these mummifed corpses, based on high resolution CT-scan data, including a preliminary phenetic interpretation of their cranial morphology.

Endoscopic drainage and cystoduodedonstomy in a child with pancreatic pseudocyst.

PubMed

Ateş, Ufuk; Küçük, Gönül; Çınar, Kubilay; Bahadır, Berktuğ; Bektaş, Mehmet; Göllü, Gülnur; Bingöl Koloğlu, Meltem

2017-11-01

An 11-year-old morbidly obese boy was diagnosed with pancreatic pseudocyst. Following fine needle aspiration, the cyst recurred in 1-month follow-up. Therefore, endoscopic drainage and cystoduodenostomy was performed following endosonography. Control ultrasonography (USG) revealed a completely shrunken cyst. During the 3 years of follow-up, the patient was asymptomatic with no evidence of cyst on computerized tomography scans. Endoscopic drainage and cystoduodenostomy is a minimally invasive, effective, and safe approach in the management of pancreatic pseudocysts in children.

The impact of different cone beam computed tomography and multi-slice computed tomography scan parameters on virtual three-dimensional model accuracy using a highly precise ex vivo evaluation method.

PubMed

Matta, Ragai-Edward; von Wilmowsky, Cornelius; Neuhuber, Winfried; Lell, Michael; Neukam, Friedrich W; Adler, Werner; Wichmann, Manfred; Bergauer, Bastian

2016-05-01

Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Low-Contrast and Low-Radiation Dose Protocol in Cardiac Computed Tomography: Usefulness of Low Tube Voltage and Knowledge-Based Iterative Model Reconstruction Algorithm.

PubMed

Iyama, Yuji; Nakaura, Takeshi; Yokoyama, Koichi; Kidoh, Masafumi; Harada, Kazunori; Oda, Seitaro; Tokuyasu, Shinichi; Yamashita, Yasuyuki

This study aimed to evaluate the feasibility of a low contrast, low-radiation dose protocol of 80-peak kilovoltage (kVp) with prospective electrocardiography-gated cardiac computed tomography (CT) using knowledge-based iterative model reconstruction (IMR). Thirty patients underwent an 80-kVp prospective electrocardiography-gated cardiac CT with low-contrast agent (222-mg iodine per kilogram of body weight) dose. We also enrolled 30 consecutive patients who were scanned with a 120-kVp cardiac CT with filtered back projection using the standard contrast agent dose (370-mg iodine per kilogram of body weight) as a historical control group. We evaluated the radiation dose for the 2 groups. The 80-kVp images were reconstructed with filtered back projection (protocol A), hybrid iterative reconstruction (HIR, protocol B), and IMR (protocol C). We compared CT numbers, image noise, and contrast-to-noise ratio among 120-kVp protocol, protocol A, protocol B, and protocol C. In addition, we compared the noise reduction rate between HIR and IMR. Two independent readers compared image contrast, image noise, image sharpness, unfamiliar image texture, and overall image quality among the 4 protocols. The estimated effective dose (ED) of the 80-kVp protocol was 74% lower than that of the 120-kVp protocol (1.4 vs 5.4 mSv). The contrast-to-noise ratio of protocol C was significantly higher than that of protocol A. The noise reduction rate of IMR was significantly higher than that of HIR (P < 0.01). There was no significant difference in almost all qualitative image quality between 120-kVp protocol and protocol C except for image contrast. A 80-kVp protocol with IMR yields higher image quality with 74% decreased radiation dose and 40% decreased contrast agent dose as compared with a 120-kVp protocol, while decreasing more image noise compared with the 80-kVp protocol with HIR.

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block.

PubMed

Cabeda, Estêvan Vieira; Falcão, Andréa Maria Gomes; Soares, José; Rochitte, Carlos Eduardo; Nomura, César Higa; Ávila, Luiz Francisco Rodrigues; Parga, José Rodrigues

2015-12-01

Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution's ethics committee. The patients' mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001). The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Effectiveness of Computerized Oculomotor Vision Screening in a Military Population: Pilot Study

DTIC Science & Technology

2012-01-01

Medical Center, Bethesda, MD; 3Clinical Services, Illinois College of Optometry, Chicago, IL Abstract—The prevalence of oculomotor dysfunctions associ - ated...vergence and their associated recovery as well as for the monocular accommodative facility measurements. This study demonstrated that non- eye -care...comprehensive eye examination without dilation on all subjects. The optometrists used the identi- cal testing protocol to determine manifest refraction

Experimental validation of a linear model for data reduction in chirp-pulse microwave CT.

PubMed

Miyakawa, M; Orikasa, K; Bertero, M; Boccacci, P; Conte, F; Piana, M

2002-04-01

Chirp-pulse microwave computerized tomography (CP-MCT) is an imaging modality developed at the Department of Biocybernetics, University of Niigata (Niigata, Japan), which intends to reduce the microwave-tomography problem to an X-ray-like situation. We have recently shown that data acquisition in CP-MCT can be described in terms of a linear model derived from scattering theory. In this paper, we validate this model by showing that the theoretically computed response function is in good agreement with the one obtained from a regularized multiple deconvolution of three data sets measured with the prototype of CP-MCT. Furthermore, the reliability of the model as far as image restoration in concerned, is tested in the case of space-invariant conditions by considering the reconstruction of simple on-axis cylindrical phantoms.

Influence of basis images and skull position on evaluation of cortical bone thickness in cone beam computed tomography.

PubMed

Nascimento, Monikelly do Carmo Chagas; Boscolo, Solange Maria de Almeida; Haiter-Neto, Francisco; Santos, Emanuela Carla Dos; Lambrichts, Ivo; Pauwels, Ruben; Jacobs, Reinhilde

2017-06-01

The aim of this study was to assess the influence of the number of basis images and the orientation of the skull on the evaluation of cortical alveolar bone in cone beam computed tomography (CBCT). Eleven skulls with a total of 59 anterior teeth were selected. CBCT images were acquired by using 4 protocols, by varying the rotation of the tube-detector arm and the orientation of the skull (protocol 1: 360°/0°; protocol 2: 180°/0°; protocol 3: 180°/90°; protocol 4: 180°/180°). Observers evaluated cortical bone as absent, thin, or thick. Direct observation of the skulls was used as the gold standard. Intra- and interobserver agreement, as well as agreement of scoring between the 3 bone thickness classifications, were calculated by using the κ statistic. The Wilcoxon signed-rank test was used to compare the 4 protocols. For lingual cortical bone, protocol 1 showed no statistical difference from the gold standard. Higher reliability was found in protocol 3 for absent (κ = 0.80) and thin (κ = 0.47) cortices, whereas for thick cortical bone, protocol 2 was more consistent (κ = 0.60). In buccal cortical bone, protocol 1 obtained the highest agreement for absent cortices (κ = 0.61), whereas protocol 4 was better for thin cortical plates (κ = 0.38) and protocol 2 for thick cortical plates (κ = 0.40). No consistent effect of the number of basis images or head orientation for visual detection of alveolar bone was detected, except for lingual cortical bone, for which full rotation scanning showed improved visualization. Copyright © 2017 Elsevier Inc. All rights reserved.

Lifelong physical activity in maintaining bone strength in older men and women of the Age, Gene/Environment Susceptibility-Reykjavik Study.

PubMed

Rianon, N J; Lang, T F; Sigurdsson, G; Eiriksdottir, G; Sigurdsson, S; Garcia, M; Pajala, S; Koster, A; Yu, B; Selwyn, B J; Taylor, W C; Kapadia, A S; Gudnason, V; Launer, L J; Harris, T B

2012-09-01

We examined if lifelong physical activity is important for maintaining bone strength in the elderly. Associations of quantitative computerized tomography-acquired bone measures (vertebral and femoral) and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study. Results conclude lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health later in life. Skeletal loading is thought to modulate the loss of bone in later life, and physical activity is a chief means of affecting bone strength by skeletal loading. Despite much discussion regarding lifelong versus early adulthood physical activity for preventing bone loss later in life, inconsistency still exists regarding how to maintain bone mass later in life (≥65 years). We examined if lifelong physical activity is important for maintaining bone strength in the elderly. The associations of quantitative computerized tomography-acquired vertebral and femoral bone measures and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study. Our findings conclude that lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health in the elderly.

Percutaneous nephrolithotomy in pediatric patients: is computerized tomography a must?

PubMed

Gedik, Abdullah; Tutus, Ali; Kayan, Devrim; Yılmaz, Yakup; Bircan, Kamuran

2011-02-01

The aim of this study was to retrospectively evaluate the results of pediatric percutaneous nephrolithotomy (PNL) cases, and discuss the results and necessity of non-contrast computerized tomography (CT) in these cases. In all, 48 pediatric patients who underwent PNL were retrospectively evaluated. Before PNL, either intravenous urography or CT was performed. In all patients, we evaluated the PNL time, scopy time with stone burden, and complications. During the PNL procedure, we switched to open surgery in two cases: in one because of renal pelvis perforation and in the other because of transcolonic access. In one patient who was scheduled to undergo PNL, we performed open surgery, primarily because we detected a retrorenal colon with CT. The stone burden in 45 patients who underwent PNL was 445 ± 225 mm(2), the PNL time was 51 ± 23 min, and the scopy time was 6.1 ± 2.7 min. We removed nephrostomy tubes 1-4 days after the procedure. In two patients, 24 h after removal of nephrostomy tubes, we inserted double J stents because of prolonged urine extravasation from the tract. In all, 34 of the 45 patients were stone-free, 5 patients had clinically insignificant stone fragments, and 6 patients had residual stones. PNL is a safe and effective method in the treatment of pediatric patients with kidney stones. Clinical experience is the most important factor in obtaining stone-free results. CT should be performed in all pediatric patients in order to prevent colon perforation.

[Utility of methoxy isobutyl isonitrile (MIBI) scintigraphy, ultrasound and computerized axial tomography in preoperative topographic diagnosis of hiperparathyroidism].

PubMed

Gómez Palacios, Angel; Gómez Zábala, Jesús; Gutiérrez, María Teresa; Expósito, Amaya; Barrios, Borja; Zorraquino, Angel; Taibo, Miguel Angel; Iturburu, Ignacio

2006-12-01

1. To assess the sensitivity of scintigraphy using methoxy isobutyl isonitrile (MIBI). 2. To compare its resolution with that of ultrasound (US) and computerized axial tomography (CAT). 3. To use its diagnostic reliability to determine whether selective approaches can be used to treat hyperparathyroidism (HPT). A study of 76 patients who underwent surgery for HPT between 1996 and 2005 was performed. MIBI scintigraphy and cervical US were used for whole-body scanning in all patients; CAT was used in 47 patients. Intraoperative and postoperative biopsies were used for final evaluation of the tests, after visualization and surgical extirpation. The results of scintigraphy were positive in 65 patients (85.52%). The diagnosis was correct in all of the single images. Multiple images were due to hyperplasia and parathyroid adenomas with thyroid disease (5.2%). Three images, incorrectly classified as negative (3.94%), were positive. The sensitivity of US was 63% and allowed detection of three MIBI-negative adenomas (4%). CAT was less sensitive (55%), but detected a further three MIBI-negative adenomas (4%). 1. The sensitivity of MIBI reached 89.46%. In the absence of thyroid nodules, MIBI diagnosed 100% of single lesions. Pathological thyroid processes produced false-positive results (5.2%) and there were diagnostic errors (4%). 2. MIBI scintigraphy was more sensitive than US and CAT. 3. Positive, single image scintigraphy allows a selective cervical approach. US and CAT may help to save a further 8% of patients (with negative scintigraphy).

Prevalence of Extracochlear Electrodes: Computerized Tomography Scans, Cochlear Implant Maps, and Operative Reports.

PubMed

Holder, Jourdan T; Kessler, David M; Noble, Jack H; Gifford, René H; Labadie, Robert F

2018-06-01

To quantify and compare the number of cochlear implant (CI) electrodes found to be extracochlear on postoperative computerized tomography (CT) scans, the number of basal electrodes deactivated during standard CI mapping (without knowledge of the postoperative CT scan), and the extent of electrode insertion noted by the surgeon. Retrospective. Academic Medical Center. Two hundred sixty-two patients underwent standard cochlear implantation and postoperative temporal bone CT scanning. Scans were analyzed to determine the number of extracochlear electrodes. Standard CI programming had been completed without knowledge of the extracochlear electrodes identified on the CT. These standard CI maps were reviewed to record the number of deactivated basal electrodes. Lastly, each operative report was reviewed to record the extent of reported electrode insertion. 13.4% (n = 35) of CIs were found to have at least one electrode outside of the cochlea on the CT scan. Review of CI mapping indicated that audiologists had deactivated extracochlear electrodes in 60% (21) of these cases. Review of operative reports revealed that surgeons correctly indicated the number of extracochlear electrodes in 6% (2) of these cases. Extracochlear electrodes were correctly identified audiologically in 60% of cases and in surgical reports in 6% of cases; however, it is possible that at least a portion of these cases involved postoperative electrode migration. Given these findings, postoperative CT scans can provide information regarding basal electrode location, which could help improve programming accuracy, associated frequency allocation, and audibility with appropriate deactivation of extracochlear electrodes.

Staphylococcus caprae native mitral valve infective endocarditis.

PubMed

Kwok, T'ng Choong; Poyner, Jennifer; Olson, Ewan; Henriksen, Peter; Koch, Oliver

2016-10-01

Staphylococcus caprae is a rare cause of infective endocarditis. Here, we report a case involving the native mitral valve in the absence of an implantable cardiac electronic device. A 76-year-old man presented with a 2 week history of confusion and pyrexia. His past medical history included an open reduction and internal fixation of a humeral fracture 17 years previously, which remained non-united despite further revision 4 years later. There was no history of immunocompromise or farm-animal contact. Two sets of blood culture bottles, more than 12 h apart, were positive for S. caprae . Trans-thoracic echocardiography revealed a 1×1.2 cm vegetation on the mitral valve, with moderate mitral regurgitation. Due to ongoing confusion, he had a magnetic resonance imaging brain scan, which showed a subacute small vessel infarct consistent with a thromboembolic source. A humeral SPECT-CT (single-photon emission computerized tomography-computerized tomography) scan showed no clear evidence of acute osteomyelitis. Surgical vegetectomy and mitral-valve repair were considered to reduce the risk of further systemic embolism and progressive valve infection. However, the potential risks of surgery to this patient led to a decision to pursue a cure with antibiotic therapy alone. He remained well 3 months after discharge, with repeat echocardiography demonstrating a reduction in the size of the vegetation (0.9 cm). Management of this infection was challenging due to its rarity and its unclear progression, complicated by the dilemma surrounding surgical intervention in a patient with a complex medical background.

To Find a Better Dosimetric Parameter in the Predicting of Radiation-Induced Lung Toxicity Individually: Ventilation, Perfusion or CT based.

PubMed

Xiao, Lin-Lin; Yang, Guoren; Chen, Jinhu; Wang, Xiaohui; Wu, Qingwei; Huo, Zongwei; Yu, Qingxi; Yu, Jinming; Yuan, Shuanghu

2017-03-15

This study aimed to find a better dosimetric parameter in predicting of radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) individually: ventilation(V), perfusion (Q) or computerized tomography (CT) based. V/Q single-photon emission computerized tomography (SPECT) was performed within 1 week prior to radiotherapy (RT). All V/Q imaging data was integrated into RT planning system, generating functional parameters based on V/Q SPECT. Fifty-seven NSCLC patients were enrolled in this prospective study. Fifteen (26.3%) patients underwent grade ≥2 RILT, the remaining forty-two (73.7%) patients didn't. Q-MLD, Q-V20, V-MLD, V-V20 of functional parameters correlated more significantly with the occurrence of RILT compared to V20, MLD of anatomical parameters (r = 0.630; r = 0.644; r = 0.617; r = 0.651 vs. r = 0.424; r = 0.520 p < 0.05, respectively). In patients with chronic obstructive pulmonary diseases (COPD), V functional parameters reflected significant advantage in predicting RILT; while in patients without COPD, Q functional parameters reflected significant advantage. Analogous results were existed in fractimal analysis of global pulmonary function test (PFT). In patients with central-type NSCLC, V parameters were better than Q parameters; while in patients with peripheral-type NSCLC, the results were inverse. Therefore, this study demonstrated that choosing a suitable dosimetric parameter individually can help us predict RILT accurately.

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

PubMed

Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

2008-01-01

Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

Computerized tomography with 3-dimensional reconstruction for the evaluation of renal size and arterial anatomy in the living kidney donor.

PubMed

Janoff, Daniel M; Davol, Patrick; Hazzard, James; Lemmers, Michael J; Paduch, Darius A; Barry, John M

2004-01-01

Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes. Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions. The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%. CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

Association between gamma-glutamyltransferase and coronary artery calcification.

PubMed

Atar, Asli I; Yilmaz, Omer C; Akin, Kayihan; Selcoki, Yusuf; Er, Okan; Eryonucu, Beyhan

2013-08-20

The exact mechanisms behind the association between atherosclerosis and gamma-glutamyltransferase (GGT) are unclear. Coronary artery calcification (CAC) detected by computerized tomography is an important marker of atherosclerosis and its severity correlates with coronary plaque burden. The aim of this study was to investigate if serum GGT levels are associated with CAC in patients without known coronary heart disease (CHD) who had low-intermediate risk for CHD. Two hundred and seventy two patients who had low-intermediate risk for coronary artery disease were included in the study. Serum GGT levels were measured spectrophotometrically. CACS (Agatston method) were performed using a 64-slice computerized tomography scanner. The patients were grouped according to their GGT values in four quartiles. Patients in higher GGT quartiles had elevated CAC score (P<0.001). Patients in higher GGT quartiles were predominantly males (P<0.001) and were more likely to be smoking (P=0.004), and have elevated uric acid (P<0.001), fasting blood glucose (P<0.001), CRP levels (P=0.003) and 10-year total cardiovascular risk (P=0.007) and low HDL levels (P<0.001). Positive correlations were found between log GGT and CAC (r=0.233, P<0.001). In the multivariate analysis GGT, age, smoking and serum uric acid levels appeared as independent factors predictive of presence of CAC. We demonstrated a significant correlation between serum GGT levels and CAC and CHD risk factors. Serum GGT level was an independent marker of CAC. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Variability in Cobb angle measurements using reformatted computerized tomography scans.

PubMed

Adam, Clayton J; Izatt, Maree T; Harvey, Jason R; Askin, Geoffrey N

2005-07-15

Survey of intraobserver and interobserver measurement variability. To assess the use of reformatted computerized tomography (CT) images for manual measurement of coronal Cobb angles in idiopathic scoliosis. Cobb angle measurements in idiopathic scoliosis are traditionally made from standing radiographs, whereas CT is often used for assessment of vertebral rotation. Correlating Cobb angles from standing radiographs with vertebral rotations from supine CT is problematic because the geometry of the spine changes significantly from standing to supine positions, and 2 different imaging methods are involved. We assessed the use of reformatted thoracolumbar CT images for Cobb angle measurement. Preoperative CT of 12 patients with idiopathic scoliosis were used to generate reformatted coronal images. Five observers measured coronal Cobb angles on 3 occasions from each of the images. Intraobserver and interobserver variability associated with Cobb measurement from reformatted CT scans was assessed and compared with previous studies of measurement variability using plain radiographs. For major curves, 95% confidence intervals for intraobserver and interobserver variability were +/-6.6 degrees and +/-7.7 degrees, respectively. For minor curves, the intervals were +/-7.5 degrees and +/-8.2 degrees, respectively. Intraobserver and interobserver technical error of measurement was 2.4 degrees and 2.7 degrees, with reliability coefficients of 88% and 84%, respectively. There was no correlation between measurement variability and curve severity. Reformatted CT images may be used for manual measurement of coronal Cobb angles in idiopathic scoliosis with similar variability to manual measurement of plain radiographs.

Effects of anesthetic protocol on normal canine brain uptake of 18F-FDG assessed by PET/CT.

PubMed

Lee, Min Su; Ko, Jeff; Lee, Ah Ra; Lee, In Hye; Jung, Mi Ae; Austin, Brenda; Chung, Hyunwoo; Nahm, Sangsoep; Eom, Kidong

2010-01-01

The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine-zolazepam in a randomized cross-over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P < 0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine-zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain.

Camera calibration for multidirectional flame chemiluminescence tomography

NASA Astrophysics Data System (ADS)

Wang, Jia; Zhang, Weiguang; Zhang, Yuhong; Yu, Xun

2017-04-01

Flame chemiluminescence tomography (FCT), which combines computerized tomography theory and multidirectional chemiluminescence emission measurements, can realize instantaneous three-dimensional (3-D) diagnostics for flames with high spatial and temporal resolutions. One critical step of FCT is to record the projections by multiple cameras from different view angles. For high accuracy reconstructions, it requires that extrinsic parameters (the positions and orientations) and intrinsic parameters (especially the image distances) of cameras be accurately calibrated first. Taking the focus effect of the camera into account, a modified camera calibration method was presented for FCT, and a 3-D calibration pattern was designed to solve the parameters. The precision of the method was evaluated by reprojections of feature points to cameras with the calibration results. The maximum root mean square error of the feature points' position is 1.42 pixels and 0.0064 mm for the image distance. An FCT system with 12 cameras was calibrated by the proposed method and the 3-D CH* intensity of a propane flame was measured. The results showed that the FCT system provides reasonable reconstruction accuracy using the camera's calibration results.

Imaging lung perfusion

PubMed Central

Wielpütz, Mark O.; Kauczor, Hans-Ulrich

2012-01-01

From the first measurements of the distribution of pulmonary blood flow using radioactive tracers by West and colleagues (J Clin Invest 40: 1–12, 1961) allowing gravitational differences in pulmonary blood flow to be described, the imaging of pulmonary blood flow has made considerable progress. The researcher employing modern imaging techniques now has the choice of several techniques, including magnetic resonance imaging (MRI), computerized tomography (CT), positron emission tomography (PET), and single photon emission computed tomography (SPECT). These techniques differ in several important ways: the resolution of the measurement, the type of contrast or tag used to image flow, and the amount of ionizing radiation associated with each measurement. In addition, the techniques vary in what is actually measured, whether it is capillary perfusion such as with PET and SPECT, or larger vessel information in addition to capillary perfusion such as with MRI and CT. Combined, these issues affect quantification and interpretation of data as well as the type of experiments possible using different techniques. The goal of this review is to give an overview of the techniques most commonly in use for physiological experiments along with the issues unique to each technique. PMID:22604884

Nuclear medicine in clinical neurology: an update

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

Oldendorf, W.H.

1981-01-01

Isotope scanning using technetium 99m pertechnetate has fallen into disuse since the advent of x-ray computerized tomography. Regional brain blood flow studies have been pursued on a research basis. Increased regional blood flow during focal seizure activity has been demonstrated and is of use in localizing such foci. Cisternography as a predictive tool in normal pressure hydrocephalus is falling into disuse. Positron tomographic scanning is a potent research tool that can demonstrate both regional glycolysis and blood flow. Unfortunately, it is extremely expensive and complex to apply in a clinical setting. With support from the National Institutes of Health, sevenmore » extramural centers have been funded to develop positron tomographic capabilities, and they will greatly advance our knowledge of stroke pathophysiology, seizure disorders, brain tumors, and various degenerative diseases. Nuclear magnetic resonance imaging is a potentially valuable tool since it creates tomographic images representing the distribution of brain water. No tissue ionization is produced, and images comparable to second-generation computerized tomographic scans are already being produced in humans.« less

Comprehensive Clinical Staging for Resectable Lung Cancer: Clinicopathological Correlations and the Role of Brain MRI.

PubMed

Vernon, Jordyn; Andruszkiewicz, Nicole; Schneider, Laura; Schieman, Colin; Finley, Christian J; Shargall, Yaron; Fahim, Christine; Farrokhyar, Forough; Hanna, Waël C

2016-11-01

In our model of comprehensive clinical staging (CCS) for lung cancer, patients with a computerized tomography scan of the chest and upper abdomen not showing distant metastases will then routinely undergo whole body positron emission tomography/computerized tomography and magnetic resonance imaging (MRI) of the brain before any therapeutic decision. Our aim was to determine the accuracy of CCS and the value of brain MRI in this population. A retrospective analysis of a prospectively entered database was performed for all patients who underwent lung cancer resection from January 2012 to June 2014. Demographics, clinical and pathological stage (seventh edition of the American Joint Committee on Cancer/Union for International Cancer Control tumor, node, and metastasis staging manual), and costs of staging were collected. Correlation between clinical and pathological stage was determined. Of 315 patients with primary lung cancer, 55.6% were female and the mean age was 70 ± 9.6 years. When correlation was analyzed without consideration for substages A and B, 49.8% of patients (158 of 315) were staged accurately, 39.7% (125 of 315) were overstaged, and 10.5% (32 of 315) were understaged. Only 4.7% of patients (15 of 315) underwent surgery without appropriate neoadjuvant treatment. Preoperative brain MRI detected asymptomatic metastases in four of 315 patients (1.3%). At a median postoperative follow-up of 19 months (range 6-43), symptomatic brain metastases developed in seven additional patients. The total cost of CCS in Canadian dollars was $367,292 over the study period, with $117,272 (31.9%) going toward brain MRI. CCS is effective for patients with resectable lung cancer, with less than 5% of patients being denied appropriate systemic treatment before surgery. Brain MRI is a low-yield and high-cost intervention in this population, and its routine use should be questioned. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Variable pixel size ionospheric tomography

NASA Astrophysics Data System (ADS)

Zheng, Dunyong; Zheng, Hongwei; Wang, Yanjun; Nie, Wenfeng; Li, Chaokui; Ao, Minsi; Hu, Wusheng; Zhou, Wei

2017-06-01

A novel ionospheric tomography technique based on variable pixel size was developed for the tomographic reconstruction of the ionospheric electron density (IED) distribution. In variable pixel size computerized ionospheric tomography (VPSCIT) model, the IED distribution is parameterized by a decomposition of the lower and upper ionosphere with different pixel sizes. Thus, the lower and upper IED distribution may be very differently determined by the available data. The variable pixel size ionospheric tomography and constant pixel size tomography are similar in most other aspects. There are some differences between two kinds of models with constant and variable pixel size respectively, one is that the segments of GPS signal pay should be assigned to the different kinds of pixel in inversion; the other is smoothness constraint factor need to make the appropriate modified where the pixel change in size. For a real dataset, the variable pixel size method distinguishes different electron density distribution zones better than the constant pixel size method. Furthermore, it can be non-chided that when the effort is spent to identify the regions in a model with best data coverage. The variable pixel size method can not only greatly improve the efficiency of inversion, but also produce IED images with high fidelity which are the same as a used uniform pixel size method. In addition, variable pixel size tomography can reduce the underdetermined problem in an ill-posed inverse problem when the data coverage is irregular or less by adjusting quantitative proportion of pixels with different sizes. In comparison with constant pixel size tomography models, the variable pixel size ionospheric tomography technique achieved relatively good results in a numerical simulation. A careful validation of the reliability and superiority of variable pixel size ionospheric tomography was performed. Finally, according to the results of the statistical analysis and quantitative comparison, the proposed method offers an improvement of 8% compared with conventional constant pixel size tomography models in the forward modeling.

Radiological Assessment of Bioengineered Bone in a Muscle Flap for the Reconstruction of Critical-Size Mandibular Defect

PubMed Central

Al-Fotawei, Randa; Ayoub, Ashraf F.; Heath, Neil; Naudi, Kurt B.; Tanner, K. Elizabeth; Dalby, Matthew J.; McMahon, Jeremy

2014-01-01

This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicled muscle flap for the reconstruction of critical size mandibular defect. The surgical defect (20 mm×15 mm) was created in the mandible of ten experimental rabbits. The masseter muscle was adapted to fill the surgical defect, a combination of calcium sulphate/hydroxyapatite cement (CERAMENT™ |SPINE SUPPORT), BMP-7 and rabbit mesenchymal stromal cells (rMSCs) was injected inside the muscle tissue. Radiographic assessment was carried out on the day of surgery and at 4, 8, and 12 weeks postoperatively. At 12 weeks, the animals were sacrificed and cone beam computerized tomography (CBCT) scanning and micro-computed tomography (µ-CT) were carried out. Clinically, a clear layer of bone tissue was identified closely adherent to the border of the surgical defect. Sporadic radio-opaque areas within the surgical defect were detected radiographically. In comparison with the opposite non operated control side, the estimated quantitative scoring of the radio-opacity was 46.6% ±15, the mean volume of the radio-opaque areas was 63.4% ±20. Areas of a bone density higher than that of the mandibular bone (+35% ±25%) were detected at the borders of the surgical defect. The micro-CT analysis revealed thinner trabeculae of the regenerated bone with a more condensed trabecular pattern than the surrounding native bone. These findings suggest a rapid deposition rate of the mineralised tissue and an active remodelling process of the newly regenerated bone within the muscle flap. The novel surgical model of this study has potential clinical application; the assessment of bone regeneration using the presented radiolographic protocol is descriptive and comprehensive. The findings of this research confirm the remarkable potential of local muscle flaps as local bioreactors to induce bone formation for reconstruction of maxillofacial bony defects. PMID:25226170

[Comparative evaluation of ultrasonography, computerized tomography, angiography and lipiodol CT in defining extent of hepatocarcinoma. A multicenter study].

PubMed

Dalla Palma, L; Pozzi Mucelli, R; Sponza, M; Bartolozzi, C; De Santis, M; Gandini, G; Mannella, P; Matricardi, L; Rossi, C; Simonetti, G

1995-03-01

The authors report the results of a multicentric trial on hepatocellular carcinoma (HCC) patients, whose lesions were confirmed with biopsy or by high (> 400 ng/ml) alpha-fetoprotein levels. The series consisted of 149 patients examined in 8 different centers and submitted to ultrasonography (US), Computed Tomography (CT) before and after contrast agent administration, angiography and Lipiodol CT. According to lesion size and number, the patients were divided with each imaging modality into three groups: a) group 1: unifocal HCC < 5 cm diameter; b) group 2: multifocal HCC with 2-3 nodules and/or tumor mass < 80 ml; c) multifocal HCC with more than 3 nodules (with total tumor mass not exceeding 40% of liver volume) or with total tumor mass > 80 ml. In 77 patients all the examinations were available for comparison. US and CT diagnosed more patients as belonging to group 1 than angiography and Lipiodol CT, while more patients were classified as groups 2 and 3 with angiography and Lipiodol CT, meaning that US and CT may understage some HCC cases (about 15%) because they show a lower number of nodules. This observation was confirmed by the direct comparison between US and Lipiodol CT (in 114 patients), CT and Lipiodol CT (in 103 patients) and angiography and Lipiodol CT (in 116 patients). US and Lipiodol CT were in disagreement in 18 cases, CT and Lipiodol CT in 16 cases and angiography and Lipiodol CT in 13 cases. In most of these cases, Lipiodol CT showed more lesions than the other techniques. The size of the undetected lesions was small, ranging few mm to 2 cm in nearly all cases. To conclude, the results of this multicentric trial show that Lipiodol CT is a fundamental tool to evaluate HCC extent. In contrast, conventional CT appeared not to add any significant piece of information and can therefore be excluded from the diagnostic protocol of HCC.

Performance analysis of routing protocols for IoT

NASA Astrophysics Data System (ADS)

Manda, Sridhar; Nalini, N.

2018-04-01

Internet of Things (IoT) is an arrangement of advancements that are between disciplinary. It is utilized to have compelling combination of both physical and computerized things. With IoT physical things can have personal virtual identities and participate in distributed computing. Realization of IoT needs the usage of sensors based on the sector for which IoT is integrated. For instance, in healthcare domain, IoT needs to have integration with wearable sensors used by patients. As sensor devices produce huge amount of data, often called big data, there should be efficient routing protocols in place. To the extent remote systems is worried there are some current protocols, for example, OLSR, DSR and AODV. It additionally tosses light into Trust based routing protocol for low-power and lossy systems (TRPL) for IoT. These are broadly utilized remote directing protocols. As IoT is developing round the corner, it is basic to investigate routing protocols that and evaluate their execution regarding throughput, end to end delay, and directing overhead. The execution experiences can help in settling on very much educated choices while incorporating remote systems with IoT. In this paper, we analyzed different routing protocols and their performance is compared. It is found that AODV showed better performance than other routing protocols aforementioned.

Electronic data collection for the analysis of surgical maneuvers on patients submitted to rhinoplasty

PubMed Central

Berger, Cezar; Freitas, Renato; Malafaia, Osvaldo; Pinto, José Simão de Paula; Mocellin, Marcos; Macedo, Evaldo; Fagundes, Marina Serrato Coelho

2012-01-01

Summary Introduction: In the health field, computerization has become increasingly necessary in professional practice, since it facilitates data recovery and assists in the development of research with greater scientific rigor. Objective: the present work aimed to develop, apply, and validate specific electronic protocols for patients referred for rhinoplasty. Methods: The prospective research had 3 stages: (1) preparation of theoretical data bases; (2) creation of a master protocol using Integrated System of Electronic Protocol (SINPE©); and (3) elaboration, application, and validation of a specific protocol for the nose and sinuses regarding rhinoplasty. Results: After the preparation of the master protocol, which dealt with the entire field of otorhinolaryngology, we idealized a specific protocol containing all matters related to the patient. In particular, the aesthetic and functional nasal complaints referred for surgical treatment (i.e., rhinoplasty) were organized into 6 main hierarchical categories: anamnesis, physical examination, complementary exams, diagnosis, treatment, and outcome. This protocol utilized these categories and their sub-items: finality; access; surgical maneuvers on the nasal dorsum, tip, and base; clinical evolution after 3, 6, and 12 months; revisional surgery; and quantitative and qualitative evaluations. Conclusion: The developed electronic-specific protocol is feasible and important for information registration from patients referred to rhinoplasty. PMID:25991979

Treatment algorithms and protocolized care.

PubMed

Morris, Alan H

2003-06-01

Excess information in complex ICU environments exceeds human decision-making limits and likely contributes to unnecessary variation in clinical care, increasing the likelihood of clinical errors. I reviewed recent critical care clinical trials searching for information about the impact of protocol use on clinically pertinent outcomes. Several recently published clinical trials illustrate the importance of distinguishing efficacy and effectiveness trials. One of these trials illustrates the danger of conducting effectiveness trials before the efficacy of an intervention is established. The trials also illustrate the importance of distinguishing guidelines and inadequately explicit protocols from adequately explicit protocols. Only adequately explicit protocols contain enough detail to lead different clinicians to the same decision when faced with the same clinical scenario. Differences between guidelines and protocols are important. Guidelines lack detail and provide general guidance that requires clinicians to fill in many gaps. Computerized or paper-based protocols are detailed and, when used for complex clinical ICU problems, can generate patient-specific, evidence-based therapy instructions that can be carried out by different clinicians with almost no interclinician variability. Individualization of patient therapy can be preserved by these protocols when they are driven by individual patient data. Explicit decision-support tools (eg, guidelines and protocols) have favorable effects on clinician and patient outcomes and can reduce the variation in clinical practice. Guidelines and protocols that aid ICU decision makers should be more widely distributed.

Impact of reduced-radiation dual-energy protocols using 320-detector row computed tomography for analyzing urinary calculus components: initial in vitro evaluation.

PubMed

Cai, Xiangran; Zhou, Qingchun; Yu, Juan; Xian, Zhaohui; Feng, Youzhen; Yang, Wencai; Mo, Xukai

2014-10-01

To evaluate the impact of reduced-radiation dual-energy (DE) protocols using 320-detector row computed tomography on the differentiation of urinary calculus components. A total of 58 urinary calculi were placed into the same phantom and underwent DE scanning with 320-detector row computed tomography. Each calculus was scanned 4 times with the DE protocols using 135 kV and 80 kV tube voltage and different tube current combinations, including 100 mA and 570 mA (group A), 50 mA and 290 mA (group B), 30 mA and 170 mA (group C), and 10 mA and 60 mA (group D). The acquisition data of all 4 groups were then analyzed by stone DE analysis software, and the results were compared with x-ray diffraction analysis. Noise, contrast-to-noise ratio, and radiation dose were compared. Calculi were correctly identified in 56 of 58 stones (96.6%) using group A and B protocols. However, only 35 stones (60.3%) and 16 stones (27.6%) were correctly diagnosed using group C and D protocols, respectively. Mean noise increased significantly and mean contrast-to-noise ratio decreased significantly from groups A to D (P <.05). In addition, the effective dose decreased markedly from groups A to D at 3.78, 1.81, 1.07, and 0.37 mSv, respectively. Decreasing the DE tube currents from 100 mA and 570 mA to 50 mA and 290 mA resulted in 96.6% accuracy for urinary calculus component analysis while reducing patient radiation exposure to 1.81 mSv. Further reduction of tube currents may compromise diagnostic accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.

Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

PubMed

Scripes, Paola G; Yaparpalvi, Ravindra

2012-09-01

The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

Imaging anatomy of the vestibular and visual systems.

PubMed

Gunny, Roxana; Yousry, Tarek A

2007-02-01

This review will outline the imaging anatomy of the vestibular and visual pathways, using computed tomography and magnetic resonance imaging, with emphasis on the more recent developments in neuroimaging. Technical advances in computed tomography and magnetic resonance imaging, such as the advent of multislice computed tomography and newer magnetic resonance imaging techniques such as T2-weighted magnetic resonance cisternography, have improved the imaging of the vestibular and visual pathways, allowing better visualization of the end organs and peripheral nerves. Higher field strength magnetic resonance imaging is a promising tool, which has been used to evaluate and resolve fine anatomic detail in vitro, as in the labyrinth. Advanced magnetic resonance imaging techniques such as functional magnetic resonance imaging and diffusion tractography have been used to identify cortical areas of activation and associated white matter pathways, and show potential for the future identification of complex neuronal relays involved in integrating these pathways. The assessment of the various components of the vestibular and the visual systems has improved with more detailed research on the imaging anatomy of these systems, the advent of high field magnetic resonance scanners and multislice computerized tomography, and the wider use of specific techniques such as tractography which displays white matter tracts not directly accessible until now.

Relatively Long Survival in Hepatocellular Carcinoma Presenting With Carcinoid Syndrome

PubMed Central

Nwokediuko, Sylvester Chuks; Uchenna, Ijoma; Esther, Ofoegbu; Okechukwu, Okafor; Augustine, Onuh; Charity, Ajuyah

2010-01-01

Hepatocelluar carcinoma is one of the commonest cancers in Nigeria. Some patients may manifest a variety of paraneoplastic syndromes. Carcinoid syndrome is an extremely rare presentation of hepatocellular carcinoma. A 57-year old man presented with recurrent facial flushing and diarrhea, tricuspid regurgitation, and very high level of urinary hydroxyindoleacetic acid (HIAA) as the first manifestation of a multicentric hepatic lesion which proved histologically to be hepatocellular carcinoma. The lesions also exhibited arterial hypervascularization on contrast enhanced computerized tomography. The patient is still alive after 6 years of symptoms. PMID:27956985

A case report of a spontaneous oesophageal pleural fistula.

PubMed

Kumar, Sanjeev; Singh, Arshdeep; Matreja, Prithpal S; Kler, Sanjiv Kumar

2013-03-01

We are reporting a case of an asthmatic patient who presented to us with retrosternal chest pain, constipation, and shortness of breath, with features which were suggestive of a hydropneumothorax and shock. On recovery from the shock, the patient was found to have increased chest tube drainage, which was suggestive of an oesophageal rupture. The Computerized Tomography (CT) scan showed a fistulous track. The patient was diagnosed as a case of a spontaneous oesophageal pleural fistula (Spontaneous EPF) on the basis of her clinical and radiological findings.

A Case Report of a Spontaneous Oesophageal Pleural Fistula

PubMed Central

Kumar, Sanjeev; Singh, Arshdeep; Matreja, Prithpal S; Kler, Sanjiv Kumar

2013-01-01

We are reporting a case of an asthmatic patient who presented to us with retrosternal chest pain, constipation, and shortness of breath, with features which were suggestive of a hydropneumothorax and shock. On recovery from the shock, the patient was found to have increased chest tube drainage, which was suggestive of an oesophageal rupture. The Computerized Tomography (CT) scan showed a fistulous track. The patient was diagnosed as a case of a spontaneous oesophageal pleural fistula (Spontaneous EPF) on the basis of her clinical and radiological findings. PMID:23634410

Xeroradiography and ultrasonography in the evaluation of a penile injury.

PubMed

Oesterling, J E; Bromberg, W D; Albertsen, P C

1986-04-01

A 34-year-old white man presented with severe penile cellulitis following injection of epoxy glue into the shaft of the penis. Preoperative xeroradiography and ultrasonography localized the hardened masses of glue to the left corpus cavernosum and subcutaneous tissues. Under the guidance of intraoperative ultrasonography this foreign material was removed surgically. Postoperatively, the cellulitis resolved promptly and xeroradiography demonstrated no residual fragments. Although various modalities, including computerized tomography and roentgenography, are available to detect foreign bodies in soft tissues, xeroradiography and ultrasonography are ideally suited for use in the male external genitalia.

Current Trends in the Management of Blunt Solid Organ Injuries.

PubMed

Taviloglu, Korhan; Yanar, Hakan

2009-04-01

The management of patients with solid organ injuries has changed since the introduction of technically advanced imaging tools, such as ultrasonography and multiple scan computerized tomography, interventional radiological techniques and modern intensive care units. In spite of this development in the management of these patients, major solid organ traumas can still be challenging. There has been great improvement in the non-operative management (NOM) of intra-abdominal solid organ injury in recent decades. In most cases treatment of injuries has shifted from early surgical treatment to NOM.

Nuclear cardiology

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

Willerson, J.T.

1979-01-01

Nuclear Cardiology is a well-written, concise compendium of chapters that covers a wide range of topics in nuclear cardiology. Each chapter has been contributed by one or more recognized experts in the field, and the work is thoroughly referened. The physics and physiology of nuclear cardiology, myocardial imaging with /sup 201/Tl and /sup 99m/Tc pyrophosphate, left ventricular and right ventricular function, measurement of coronary blood flow with /sup 133/Xe, and microspheres are discussed, and there are chapters on metabolic imaging with positron emitters and on transmission computerized tomography of the heart.

Neural network and its application to CT imaging

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

Nikravesh, M.; Kovscek, A.R.; Patzek, T.W.

We present an integrated approach to imaging the progress of air displacement by spontaneous imbibition of oil into sandstone. We combine Computerized Tomography (CT) scanning and neural network image processing. The main aspects of our approach are (I) visualization of the distribution of oil and air saturation by CT, (II) interpretation of CT scans using neural networks, and (III) reconstruction of 3-D images of oil saturation from the CT scans with a neural network model. Excellent agreement between the actual images and the neural network predictions is found.

Nuclear magnetic resonance diagnosis of an anaplastic astrocytoma.

PubMed

Jackson, J A; Derman, H S; Harper, R L; Willcott, M R; Ford, J J; Schneiders, N J; McCrary, J A; Kelly, A; Bryan, R N

1984-01-01

A patient presented with an 8-month history of a progressive left homonymous visual field deficit, left hemiparesis, and a left thalamocortical sensory deficit that was not detectable by repeated conventional neurodiagnostic evaluations. Proton nuclear magnetic resonance (NMR) imaging revealed a right parietal lesion characterized by a prolonged T2 (spin-spin relaxation time). At surgery, the mass proved to be an anaplastic astrocytoma. NMR appears to be more sensitive than x-ray computerized tomography scanning in some patients with malignant gliomas and offers the clinician an additional probe with which to evaluate these patients.

Appendiceal hemorrhage -- an uncommon cause of lower gastrointestinal bleeding.

PubMed

Chiang, Ching-Chung; Tu, Chi-Wen; Liao, Chi-Szu; Shieh, Min-Chieh; Sung, Tien-Chou

2011-06-01

Lower gastrointestinal bleeding is a common disease among elderly patients. The common sources of lower gastrointestinal bleeding include vascular disease, Crohn's disease, neoplasms, inflammatory bowel disease, hemorrhoids, and ischemic colitis. Lower gastrointestinal bleeding arising from the appendix is an extremely rare condition. We report a case of appendiceal hemorrhage in a young male. Diagnosis was made by multidetector computerized tomography during survey for hematochezia. The patient recovered well after appendectomy. The histological finding revealed focal erosion of appendix mucosa with bleeding. Copyright © 2011. Published by Elsevier B.V.

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.

An interesting case of angiogenesis in cavernous hemangioma.

PubMed

Das, Dipankar; Bhattacharjee, Kasturi; Deka, Panna; Bhattacharjee, Harsha; Misra, Diva Kant; Koul, Akanksha; Kapoor, Deepika; Deka, Apurba

2016-10-01

Cavernous hemangioma is the most common orbital tumor in adult. There is lot of literatures for clinicopathological features of this tumor. These tumors had been studied for the model of angiogenesis in many of the experimental setups. We present a case of 34-year-old male with this tumor in the left eye with computerized tomography evidence. Postsurgical laboratory findings gave interesting evidence of tumor angiogenesis with tumor endothelial cells and sprouting of the small vessels endothelial cells. Podosome rosette could be conceptualized from the characteristic patterns seen in the tumor.

Assessment of phantom dosimetry and image quality of i-CAT FLX cone-beam computed tomography.

PubMed

Ludlow, John B; Walker, Cameron

2013-12-01

The increasing use of cone-beam computed tomography in orthodontics has been coupled with heightened concern about the long-term risks of x-ray exposure in orthodontic populations. An industry response to this has been to offer low-exposure alternative scanning options in newer cone-beam computed tomography models. Effective doses resulting from various combinations of field of view size and field location comparing child and adult anthropomorphic phantoms with the recently introduced i-CAT FLX cone-beam computed tomography unit (Imaging Sciences, Hatfield, Pa) were measured with optical stimulated dosimetry using previously validated protocols. Scan protocols included high resolution (360° rotation, 600 image frames, 120 kV[p], 5 mA, 7.4 seconds), standard (360°, 300 frames, 120 kV[p], 5 mA, 3.7 seconds), QuickScan (180°, 160 frames, 120 kV[p], 5 mA, 2 seconds), and QuickScan+ (180°, 160 frames, 90 kV[p], 3 mA, 2 seconds). Contrast-to-noise ratio was calculated as a quantitative measure of image quality for the various exposure options using the QUART DVT phantom. Child phantom doses were on average 36% greater than adult phantom doses. QuickScan+ protocols resulted in significantly lower doses than standard protocols for the child (P = 0.0167) and adult (P = 0.0055) phantoms. The 13 × 16-cm cephalometric fields of view ranged from 11 to 85 μSv in the adult phantom and 18 to 120 μSv in the child phantom for the QuickScan+ and standard protocols, respectively. The contrast-to-noise ratio was reduced by approximately two thirds when comparing QuickScan+ with standard exposure parameters. QuickScan+ effective doses are comparable with conventional panoramic examinations. Significant dose reductions are accompanied by significant reductions in image quality. However, this trade-off might be acceptable for certain diagnostic tasks such as interim assessment of treatment results. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Unified Digital Image Display And Processing System

NASA Astrophysics Data System (ADS)

Horii, Steven C.; Maguire, Gerald Q.; Noz, Marilyn E.; Schimpf, James H.

1981-11-01

Our institution like many others, is faced with a proliferation of medical imaging techniques. Many of these methods give rise to digital images (e.g. digital radiography, computerized tomography (CT) , nuclear medicine and ultrasound). We feel that a unified, digital system approach to image management (storage, transmission and retrieval), image processing and image display will help in integrating these new modalities into the present diagnostic radiology operations. Future techniques are likely to employ digital images, so such a system could readily be expanded to include other image sources. We presently have the core of such a system. We can both view and process digital nuclear medicine (conventional gamma camera) images, positron emission tomography (PET) and CT images on a single system. Images from our recently installed digital radiographic unit can be added. Our paper describes our present system, explains the rationale for its configuration, and describes the directions in which it will expand.

Paravertebral masses in blue-tailed monitor, Varanus dorianus, indicative of soft-tissue infection with associated osteomyelitis.

PubMed

Rothschild, Bruce M

2014-03-01

Paravertebral osseous masses in reptiles have been attributed to Paget's disease on the basis of histology. Histologically recognized mosaic architecture and cement lines, however, lack specificity. A Varanus dorianus with this condition was subjected to standard and computerized tomography. Because the masses were extraskeletal in nature, Paget's disease could be excluded. Although interpretation of the computed tomography suggested the process to be entirely extraskeletal, standard radiographs revealed disorganized vertebral architecture characteristic of osteomyelitis, crossing intervertebral spaces. Posttraumatic myositis ossificans and calcified hematoma were confidently excluded as diagnoses. The etiology of paraspinal masses in this V. dorianus appears attributable to infection, with infection of a puncture wound hypothesized as the underlying process. If one extrapolates the findings in this one animal, it seems reasonable to suggest that consideration be given to investigating the possibility of an infectious origin when similar masses are recognized in other reptiles.

Early Diagnosis of Breast Cancer.

PubMed

Wang, Lulu

2017-07-05

Early-stage cancer detection could reduce breast cancer death rates significantly in the long-term. The most critical point for best prognosis is to identify early-stage cancer cells. Investigators have studied many breast diagnostic approaches, including mammography, magnetic resonance imaging, ultrasound, computerized tomography, positron emission tomography and biopsy. However, these techniques have some limitations such as being expensive, time consuming and not suitable for young women. Developing a high-sensitive and rapid early-stage breast cancer diagnostic method is urgent. In recent years, investigators have paid their attention in the development of biosensors to detect breast cancer using different biomarkers. Apart from biosensors and biomarkers, microwave imaging techniques have also been intensely studied as a promising diagnostic tool for rapid and cost-effective early-stage breast cancer detection. This paper aims to provide an overview on recent important achievements in breast screening methods (particularly on microwave imaging) and breast biomarkers along with biosensors for rapidly diagnosing breast cancer.

Integration of healthcare information: from enterprise PACS to patient centered multimedia health record.

PubMed

Soriano, Enrique; Plazzotta, Fernando; Campos, Fernando; Kaminker, Diego; Cancio, Alfredo; Aguilera Díaz, Jerónimo; Luna, Daniel; Seehaus, Alberto; Carcía Mónaco, Ricardo; de Quirós, Fernán González Bernaldo

2010-01-01

Every single piece of healthcare information should be fully integrated and transparent within the electronic health record. The Italian Hospital of Buenos Aires initiated the project Multimedia Health Record with the goal to achieve this integration while maintaining a holistic view of current structure of the systems of the Hospital, where the axis remains are the patient and longitudinal history, commencing with section Computed Tomography. Was implemented DICOM standard for communication and image storage and bought a PACS. It was necessary adapt our generic reporting system for live up to the commercial RIS. The Computerized Tomography (CT) Scanners of our hospital were easily integrated into the DICOM network and all the CT Scans generated by our radiology service were stored in the PACS, reported using the Structured Reporting System (we installed diagnostic terminals equipped with 3 monitors) and displayed in the EHR at any point of HIBA's healthcare network.

A combination of physical activity and computerized brain training improves verbal memory and increases cerebral glucose metabolism in the elderly.

PubMed

Shah, T; Verdile, G; Sohrabi, H; Campbell, A; Putland, E; Cheetham, C; Dhaliwal, S; Weinborn, M; Maruff, P; Darby, D; Martins, R N

2014-12-02

Physical exercise interventions and cognitive training programs have individually been reported to improve cognition in the healthy elderly population; however, the clinical significance of using a combined approach is currently lacking. This study evaluated whether physical activity (PA), computerized cognitive training and/or a combination of both could improve cognition. In this nonrandomized study, 224 healthy community-dwelling older adults (60-85 years) were assigned to 16 weeks home-based PA (n=64), computerized cognitive stimulation (n=62), a combination of both (combined, n=51) or a control group (n=47). Cognition was assessed using the Rey Auditory Verbal Learning Test, Controlled Oral Word Association Test and the CogState computerized battery at baseline, 8 and 16 weeks post intervention. Physical fitness assessments were performed at all time points. A subset (total n=45) of participants underwent [(18)F] fluorodeoxyglucose positron emission tomography scans at 16 weeks (post-intervention). One hundred and ninety-one participants completed the study and the data of 172 participants were included in the final analysis. Compared with the control group, the combined group showed improved verbal episodic memory and significantly higher brain glucose metabolism in the left sensorimotor cortex after controlling for age, sex, premorbid IQ, apolipoprotein E (APOE) status and history of head injury. The higher cerebral glucose metabolism in this brain region was positively associated with improved verbal memory seen in the combined group only. Our study provides evidence that a specific combination of physical and mental exercises for 16 weeks can improve cognition and increase cerebral glucose metabolism in cognitively intact healthy older adults.

A combination of physical activity and computerized brain training improves verbal memory and increases cerebral glucose metabolism in the elderly

PubMed Central

Shah, T; Verdile, G; Sohrabi, H; Campbell, A; Putland, E; Cheetham, C; Dhaliwal, S; Weinborn, M; Maruff, P; Darby, D; Martins, R N

2014-01-01

Physical exercise interventions and cognitive training programs have individually been reported to improve cognition in the healthy elderly population; however, the clinical significance of using a combined approach is currently lacking. This study evaluated whether physical activity (PA), computerized cognitive training and/or a combination of both could improve cognition. In this nonrandomized study, 224 healthy community-dwelling older adults (60–85 years) were assigned to 16 weeks home-based PA (n=64), computerized cognitive stimulation (n=62), a combination of both (combined, n=51) or a control group (n=47). Cognition was assessed using the Rey Auditory Verbal Learning Test, Controlled Oral Word Association Test and the CogState computerized battery at baseline, 8 and 16 weeks post intervention. Physical fitness assessments were performed at all time points. A subset (total n=45) of participants underwent [18F] fluorodeoxyglucose positron emission tomography scans at 16 weeks (post-intervention). One hundred and ninety-one participants completed the study and the data of 172 participants were included in the final analysis. Compared with the control group, the combined group showed improved verbal episodic memory and significantly higher brain glucose metabolism in the left sensorimotor cortex after controlling for age, sex, premorbid IQ, apolipoprotein E (APOE) status and history of head injury. The higher cerebral glucose metabolism in this brain region was positively associated with improved verbal memory seen in the combined group only. Our study provides evidence that a specific combination of physical and mental exercises for 16 weeks can improve cognition and increase cerebral glucose metabolism in cognitively intact healthy older adults. PMID:25463973

Comparison of orbital volume obtained by tomography and rapid prototyping.

PubMed

Roça, Guilherme Berto; Foggiatto, José Aguiomar; Ono, Maria Cecilia Closs; Ono, Sergio Eiji; da Silva Freitas, Renato

2013-11-01

This study aims to compare orbital volume obtained by helical tomography and rapid prototyping. The study sample was composed of 6 helical tomography scans. Eleven healthy orbits were identified to have their volumes measured. The volumetric analysis with the helical tomography utilized the same protocol developed by the Plastic Surgery Unit of the Federal University of Paraná. From the CT images, 11 prototypes were created, and their respective volumes were analyzed in 2 ways: using software by SolidWorks and by direct analysis, when the prototype was filled with saline solution. For statistical analysis, the results of the volumes of the 11 orbits were considered independent. The average orbital volume measurements obtained by the method of Ono et al was 20.51 cm, the average obtained by the SolidWorks program was 20.64 cm, and the average measured using the prototype method was 21.81 cm. The 3 methods demonstrated a strong correlation between the measurements. The right and left orbits of each patient had similar volumes. The tomographic method for the analysis of orbital volume using the Ono protocol yielded consistent values, and by combining this method with rapid prototyping, both reliability validations of results were enhanced.

3D Imaging with Holographic Tomography

NASA Astrophysics Data System (ADS)

Sheppard, Colin J. R.; Kou, Shan Shan

2010-04-01

There are two main types of tomography that enable the 3D internal structures of objects to be reconstructed from scattered data. The commonly known computerized tomography (CT) give good results in the x-ray wavelength range where the filtered back-projection theorem and Radon transform can be used. These techniques rely on the Fourier projection-slice theorem where rays are considered to propagate straight through the object. Another type of tomography called `diffraction tomography' applies in applications in optics and acoustics where diffraction and scattering effects must be taken into account. The latter proves to be a more difficult problem, as light no longer travels straight through the sample. Holographic tomography is a popular way of performing diffraction tomography and there has been active experimental research on reconstructing complex refractive index data using this approach recently. However, there are two distinct ways of doing tomography: either by rotation of the object or by rotation of the illumination while fixing the detector. The difference between these two setups is intuitive but needs to be quantified. From Fourier optics and information transformation point of view, we use 3D transfer function analysis to quantitatively describe how spatial frequencies of the object are mapped to the Fourier domain. We first employ a paraxial treatment by calculating the Fourier transform of the defocused OTF. The shape of the calculated 3D CTF for tomography, by scanning the illumination in one direction only, takes on a form that we might call a 'peanut,' compared to the case of object rotation, where a diablo is formed, the peanut exhibiting significant differences and non-isotropy. In particular, there is a line singularity along one transverse direction. Under high numerical aperture conditions, the paraxial treatment is not accurate, and so we make use of 3D analytical geometry to calculate the behaviour in the non-paraxial case. This time, we obtain a similar peanut, but without the line singularity.

Surface radiation dose comparison of a dedicated extremity cone beam computed tomography (CBCT) device and a multidetector computed tomography (MDCT) machine in pediatric ankle and wrist phantoms

PubMed Central

Nagy, Eszter; Apfaltrer, Georg; Riccabona, Michael; Singer, Georg; Stücklschweiger, Georg; Guss, Helmuth; Sorantin, Erich

2017-01-01

Objectives To evaluate and compare surface doses of a cone beam computed tomography (CBCT) and a multidetector computed tomography (MDCT) device in pediatric ankle and wrist phantoms. Methods Thermoluminescent dosimeters (TLD) were used to measure and compare surface doses between CBCT and MDCT in a left ankle and a right wrist pediatric phantom. In both modalities adapted pediatric dose protocols were utilized to achieve realistic imaging conditions. All measurements were repeated three times to prove test-retest reliability. Additionally, objective and subjective image quality parameters were assessed. Results Average surface doses were 3.8 ±2.1 mGy for the ankle, and 2.2 ±1.3 mGy for the wrist in CBCT. The corresponding surface doses in optimized MDCT were 4.5 ±1.3 mGy for the ankle, and 3.4 ±0.7 mGy for the wrist. Overall, mean surface dose was significantly lower in CBCT (3.0 ±1.9 mGy vs. 3.9 ±1.2 mGy, p<0.001). Subjectively rated general image quality was not significantly different between the study protocols (p = 0.421), whereas objectively measured image quality parameters were in favor of CBCT (p<0.001). Conclusions Adapted extremity CBCT imaging protocols have the potential to fall below optimized pediatric ankle and wrist MDCT doses at comparable image qualities. These possible dose savings warrant further development and research in pediatric extremity CBCT applications. PMID:28570626

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

Blume-Kohout, Robin J.; Gamble, John King; Nielsen, Erik

Quantum tomography is used to characterize quantum operations implemented in quantum information processing (QIP) hardware. Traditionally, state tomography has been used to characterize the quantum state prepared in an initialization procedure, while quantum process tomography is used to characterize dynamical operations on a QIP system. As such, tomography is critical to the development of QIP hardware (since it is necessary both for debugging and validating as-built devices, and its results are used to influence the next generation of devices). But tomography suffers from several critical drawbacks. In this report, we present new research that resolves several of these flaws. Wemore » describe a new form of tomography called gate set tomography (GST), which unifies state and process tomography, avoids prior methods critical reliance on precalibrated operations that are not generally available, and can achieve unprecedented accuracies. We report on theory and experimental development of adaptive tomography protocols that achieve far higher fidelity in state reconstruction than non-adaptive methods. Finally, we present a new theoretical and experimental analysis of process tomography on multispin systems, and demonstrate how to more effectively detect and characterize quantum noise using carefully tailored ensembles of input states.« less

Cardiopulmonary data-acquisition system

NASA Technical Reports Server (NTRS)

Crosier, W. G.; Reed, R. A.

1981-01-01

Computerized system controls and monitors bicycle and treadmill cardiovascular stress tests. It acquires and reduces stress data and displays heart rate, blood pressure, workload, respiratory rate, exhaled-gas composition, and other variables. Data are printed on hard-copy terminal every 30 seconds for quick operator response to patient. Ergometer workload is controlled in real time according to experimental protocol. Collected data are stored directly on tape in analog form and on floppy disks in digital form for later processing.

[Use of computerized stabylometric footboard in evaluation of work suitability at height work in building firms].

PubMed

D'Orso, M I; Garaguso, M; Ferrari, G; Riva, M A; Gallamini, M; Cesana, G

2012-01-01

A relevant part of deadly work accidents and of severe work accidents reported in national specific statistics coming from INAIL is until today caused by workers' falls during their at height work activities. Medical evaluation of eventual workers' hyper susceptibility to fall caused by balance alterations, if included in medical surveillance, is frequently carried out by medical doctors using different subjective tests included in different clinical protocols. Use of a computerized stabylometric footboard on the contrary allows to obtain objective and reproducible data concerning vestibular function which, associated with traditional clinical medical evaluation, seem to better detect eventual presence of balance disturbances, especially those non clinically perceivable by workers and therefore more dangerous. We report results evidenced in a research carried out in a group of 185 workers engaged in building firms and having work tasks including phases of at height work.

Dietary magnesium reduction to 25% of nutrient requirement disrupts bone and mineral metabolism in the rat.

PubMed

Rude, Robert K; Gruber, Helen E; Norton, H James; Wei, Livia Y; Frausto, Angelica; Kilburn, Jeremy

2005-08-01

Low dietary magnesium (Mg) may be a risk factor for osteoporosis. In animals, severe Mg deficiency (0.04% of nutrient requirement [NR]) results in bone loss. We have also found that a more moderate dietary Mg restriction (10% of NR) also resulted in loss of bone. We now report the effect of Mg intake of 25% NR on bone and mineral metabolism in the rat. Serum Mg, Ca, PTH, 1,25(OH)2-vitamin D, alkaline phosphatase, osteocalcin, and pyridinoline were measured at 2, 4, and 6 months in control and Mg-deficient animals. Femurs and tibias were collected for mineral content, micro-computerized tomography, histomorphometry, and immunocytochemical localization. Profound Mg deficiency developed as assessed by marked hypomagnesemia and 27% reduction in bone Mg content. Serum calcium was not significantly different between groups. Mg depletion resulted in a significantly lower serum PTH concentrations. Serum 1,25(OH)2-vitamin D was also significantly lower. No difference was noted in markers of bone turnover. Histomorphometry and micro-computerized tomography demonstrated decreased bone volume and trabecular thickness. No difference was observed for osteoclast or osteoblast number. Inflammatory cytokines may contribute to bone loss. We found that immunocytochemical localization of TNFalpha in osteoclasts was increased 138-150%. This increase in TNFalpha may be due to increased substance P as it was found to be elevated from 179% to 432%. These data demonstrate that Mg intake of 25% NR in the rat causes lower bone mass which may be related to increased release of substance P and TNFalpha.

Research diagnostic criteria for temporomandibular disorders (RDC/TMD): development of image analysis criteria and examiner reliability for image analysis.

PubMed

Ahmad, Mansur; Hollender, Lars; Anderson, Quentin; Kartha, Krishnan; Ohrbach, Richard; Truelove, Edmond L; John, Mike T; Schiffman, Eric L

2009-06-01

As part of the Multisite Research Diagnostic Criteria For Temporomandibular Disorders (RDC/TMD) Validation Project, comprehensive temporomandibular joint diagnostic criteria were developed for image analysis using panoramic radiography, magnetic resonance imaging (MRI), and computerized tomography (CT). Interexaminer reliability was estimated using the kappa (kappa) statistic, and agreement between rater pairs was characterized by overall, positive, and negative percent agreement. Computerized tomography was the reference standard for assessing validity of other imaging modalities for detecting osteoarthritis (OA). For the radiologic diagnosis of OA, reliability of the 3 examiners was poor for panoramic radiography (kappa = 0.16), fair for MRI (kappa = 0.46), and close to the threshold for excellent for CT (kappa = 0.71). Using MRI, reliability was excellent for diagnosing disc displacements (DD) with reduction (kappa = 0.78) and for DD without reduction (kappa = 0.94) and good for effusion (kappa = 0.64). Overall percent agreement for pairwise ratings was >or=82% for all conditions. Positive percent agreement for diagnosing OA was 19% for panoramic radiography, 59% for MRI, and 84% for CT. Using MRI, positive percent agreement for diagnoses of any DD was 95% and of effusion was 81%. Negative percent agreement was >or=88% for all conditions. Compared with CT, panoramic radiography and MRI had poor and marginal sensitivity, respectively, but excellent specificity in detecting OA. Comprehensive image analysis criteria for the RDC/TMD Validation Project were developed, which can reliably be used for assessing OA using CT and for disc position and effusion using MRI.

In Vivo Evaluation of Chemical Composition of Eight Types of Urinary Calculi Using Spiral Computerized Tomography in a Chinese Population.

PubMed

Huo, Jun; Liu, Zhong-Yuan; Wang, Ke-Feng; Xu, Zhen-Qun

2015-09-01

This study was conducted to evaluate the chemical composition of eight types of urinary calculi using spiral computerized tomography (CT) in vivo. From October 2011 to February 2013, upper urinary tract calculi were obtained from 122 patients in the department of urinary surgery of the First Affiliated Hospital of Soochow University. All patients were scanned with a 64-detector row helical CT scanner using 6.50 mm collimation before ureterorenoscopy. Data from the preoperative spiral CT scans and postoperative chemical composition of urinary calculi were collected. The chemical composition analysis indicates that there were five types of pure calculi and three types of mixed calculi, including 39 calcium oxalate calculi, 12 calcium phosphate calculi, 10 calcium carbonate calculi, 8 magnesium ammonium phosphate calculi, 6 carbonated apatite, 21 uric acid/ammonium urate calculi, 10 uric acid/calcium oxalate calculi, and 16 calcium oxalate/calcium phosphate calculi. There were significant differences in the mean CT values among the five types of pure calculi (P < 0.001). Furthermore, we also observed significant differences in the mean CT values among three types of mixed calculi (P < 0.001). Significant differences in the mean CT values were also found among eight types of urinary calculi (P < 0.001). However, no statistically significant difference was observed between the mean CT values of magnesium ammonium phosphate calculi and uric acid/calcium oxalate calculi (P = 0.262). Our findings suggest that spiral CT could be a promising tool for determining the chemical composition of upper urinary tract calculi. © 2014 Wiley Periodicals, Inc.

Planning guidelines for computerized transaxial tomography (CT)

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

Not Available

1976-11-23

Guidelines to assist local communities in review and decisionmaking related to computerized tomography (CT) 'head' and 'whole body' scanner needs and placement are presented. Although medical benefits for head scanning are well established, the proper role of whole body scanning in relation to other diagnostic procedures has not been determined. It is recommended that a 20 percent weighted consideration could be given to a potential CT scanner applicant's present capabilities in diagnostic 'body' work. The following guidelines for CT are recommended for use in assessing work qualifications of potential CT scanner applicants: (1) The facility must have an active neurosurgicalmore » service, with a geographically full-time board - certified neurosurgeon and at least 50 intracranial procedures performed annually. (2) The facility must have an active neurological service, with a geographically full-time board - certified neurologist. (3) The facility must have on staff a qualified neuroradiologist. It is recommended that the CT scanner utilization level be a minimum of 3,000 examinations per year per unit of new equipment. The applicant must submit financial data and must be committed to providing care to all patients, independent of ability to pay. The applicant must submit letters from area hospitals agreeing to utilize the scanner services. Additional criteria are given for body scanning work and for the number of scanners in a specific area. Detailed information is presented about scanner development and use in southeastern Pennsylvania and neighboring planning areas, and the cost of scanner operations is compared with revenues. The CT scanner committee membership is included.« less

A simple objective method to assess the radiopacity of urinary calculi and its use to predict extracorporeal shock wave lithotripsy outcomes.

PubMed

el-Gamal, Osama; el-Badry, Amr

2009-07-01

We describe an objective method to evaluate kidney stone radiopacity for use in selection of cases suitable for ESWL. We recruited 76 adult patients with a solitary 1 to 2 cm renal pelvic stone. All patients underwent routine plain x-ray of the urinary tract but an aluminum step wedge (Gammex) was adapted to the cassette before x-ray exposure. This x-ray was then digitized and analyzed by histogram to calculate the gray level of the stone and of each step of the aluminum step wedge. This allowed radiographic stone density to be expressed in mm aluminum equivalent. All patients also underwent abdominopelvic computerized tomography and then ESWL was started. Stone density on plain x-ray was 1.83 to 5.93 mm aluminum equivalent. There was a positive correlation between these values and stone attenuation values on computerized tomography (r(2) 0.83, p <0.005). The 12 patients in whom ESWL failed were found to have stones of significantly higher density than stones in patients with complete stone fragmentation (mean +/- SD 4.8 +/- 0.74 vs 3.35 +/- 0.88 mm aluminum equivalent, p <0.005). There was also a positive correlation between stone radiopacity in mm aluminum equivalent and the total number of shock waves required to achieve complete fragmentation (r(2) 0.66, p <0.005). The aluminum step wedge with plain x-ray of the urinary tract provides a good reference for objectively assessing the radiopacity of renal calculi.

A Computerized Tomography Study of Vocal Tract Setting in Hyperfunctional Dysphonia and in Belting.

PubMed

Saldias, Marcelo; Guzman, Marco; Miranda, Gonzalo; Laukkanen, Anne-Maria

2018-04-03

Vocal tract setting in hyperfunctional patients is characterized by a high larynx and narrowing of the epilaryngeal and pharyngeal region. Similar observations have been made for various singing styles, eg, belting. The voice quality in belting has been described to be loud, speech like, and high pitched. It is also often described as sounding "pressed" or "tense". The above mentioned has led to the hypothesis that belting may be strenuous to the vocal folds. However, singers and teachers of belting do not regard belting as particularly strenuous. This study investigates possible similarities and differences between hyperfunctional voice production and belting. This study concerns vocal tract setting. Four male patients with hyperfunctional dysphonia and one male contemporary commercial music singer were registered with computerized tomography while phonating on [a:] in their habitual speaking pitch. Additionally, the singer used the pitch G4 in belting. The scannings were studied in sagittal and transversal dimensions by measuring lengths, widths, and areas. Various similarities were found between belting and hyperfunction: high vertical larynx position, small hypopharyngeal width, and epilaryngeal outlet. On the other hand, belting differed from dysphonia (in addition to higher pitch) by a wider lip and jaw opening, and larger volumes of the oral cavity. Belting takes advantage of "megaphone shape" of the vocal tract. Future studies should focus on modeling and simulation to address sound energy transfer. Also, they should consider aerodynamic variables and vocal fold vibration to evaluate the "price of decibels" in these phonation types. Copyright © 2018. Published by Elsevier Inc.

A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: an in vitro study.

PubMed

Gaurav, Vivek; Srivastava, Nikhil; Rana, Vivek; Adlakha, Vivek Kumar

2013-01-01

Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

Computerized tomography of the otic capsule and otoliths in the oyster toadfish, Opsanus tau.

PubMed

Edds-Walton, Peggy L; Arruda, Julie; Fay, Richard R; Ketten, Darlene R

2015-02-01

The neurocranium of the toadfish (Opsanus tau) exhibits a distinct translucent region in the otic capsule (OC) that may have functional significance for the auditory pathway. This study used ultrahigh resolution computerized tomography (100 µm voxels) to compare the relative density of three sites along the OC (dorsolateral, midlateral, and ventromedial) and two reference sites (dorsal: supraoccipital crest; ventral: parasphenoid bone) in the neurocranium. Higher attenuation occurs where structural density is greater; thus, we compared the X-ray attenuations measured, which provided a measure of relative density. The maximum attenuation value was recorded for each of the five sites (x and y) on consecutive sections throughout the OC and for each of the three calcareous otoliths associated with the sensory maculae (lagena, saccule, and utricle) in the OC. All three otoliths had higher attenuations than any sites in the neurocranium. Both dorsal and ventral reference sites (supraoccipital crest and parasphenoid bone, respectively) had attenuation levels consistent with calcified bone and had relatively small, irregular variations along the length of the OC in all individuals. The lowest relative attenuations (lowest densities) occurred consistently at the three sites along the OC. In addition, the lowest attenuations measured along the OC occurred at the ventromedial site around the saccular otolith for all seven fish. The decrease in bone density along the OC is consistent with the hypothesis that there is a low-density channel in the skull to facilitate transmission of acoustic stimuli to the auditory endorgans of the ear. © 2014 Wiley Periodicals, Inc.

[Use of Digital Health Records and "WebMovil" corporate service in the communication management of critical results of Microbiology, in the context of a primary health care area].

PubMed

Guzmán-González, A F; Navajas-Luque, F; de la Torre-Fernández, J

2014-03-01

The objective was to describe and evaluate a new communication protocol of reporting critical results applied to Microbiology in a health area of Andalusia. The size and type of the critical values of Microbiology are analyzed for primary care patients. A new computerized reporting system was analyzed, in real time, through Diraya Digital Health Records, which integrates the analytical test module (MPA). The protocol is complemented, in collaboration with the Information Technology (IT), with the Junta de Andalucía short message service (SMS) "WebMovil". The total number of notices of critical results by the new protocol in 2012 was 817. The number of critical values for primary care was 570, of which 90 were for Microbiology. The most frequent notice was by isolation in the stool culture (n = 51; 56.67%). The prevalence of the critical values of Microbiology in primary care was 0.45/100. The average time of notifications was 13 minutes. The success rate of notifications was 97.7% and 0% obtained in the number of withdrawals. In 99.93% of cases the contact with the patient was stated and in 98.55% the medical intervention was also confirmed. Communication by a computerized system linked to the SMS technology showed a reduction in the time of notification, and produced additional benefits, such as eliminating the risk of error when there is no repetition of information from the recipient received by the laboratory. Furthermore, the use of SMS messages ensures that doctors on duty always receive information immediately.

[Isolation of Scedosporium apiospermum (teleomorph: Pseudallescheria apiosperma) from an acute myeloid leukemia patient].

PubMed

Ergin, Cağrı; Kutlu, Murat; Arıkan Akdağlı, Sevtap; Sarıbaş, Zeynep; Aydeniz Ozansoy, Fatma; Sarı, Ismail; Dursunoğlu, Neşe

2013-04-01

Scedosporium apiospermum is an emerging opportunistic pathogen that may lead to life-threatening infections especially in immunosuppressive individuals. In this report, S.apiospermum infection in a 62 year old male patient with acute myeloid leukemia was presented. During remission-induction chemotherapy, piperacillin-tazobactam therapy was started for febrile neutropenia. Since fever had continued, treatment was switched to imipenem and also amphotericin B deoxycholate was added to the treatment protocol. Because of allergic reaction to amphotericin B, caspofungin was started at the fifth day of neutropenic fever. Following imaging studies with high resolution computerized thorasic tomography, antifungal therapy was changed to voriconazole due to findings suggestive of invasive aspergillosis. Since galactomannan antigen was found negative at the first day of voriconazole therapy, bronchoalveolar lavage material from apical segment of the left lower lobe was cultured onto various microbiologic media. S.apiospermum (Teleomorph: Pseudallescheria apiosperma) was isolated on the fourth day of cultivation. According to CLSI M38-A2 microdilution procedure, minimum inhibitory concentrations (MIC) of voriconazole, caspofungin, amphotericin B and posaconazole were found as 0.06, 2, 8 and 4 µg/ml, respectively. Since neutropenia was resolved, the patient was discharged with continued voriconazole therapy. It was concluded that antifungal susceptibility tests should be performed for Scedosporium species and the results should be compared to the clinical response. The determination of MIC breakpoints may provide useful information for the recommendation and use of optimal choices for the treatment of Scedosporium infections.

[Analysis of a series pheochromocytoma cases over 15 years].

PubMed

Rojo Alvaro, J; Toni, M; Ollero, Md; Pineda, Jj; Munárriz, P; Anda, E

2012-01-01

The pheochromocytoma is a catecholamine secreting tumour derived from chromaffin cells of the sympathetic nervous system. Eighty to eighty-five percent of these tumours are localized in the adrenal medulla. When pheocromocytomas are found outside the adrenal gland they are referred to as extra-adrenal pheochromocytomas or paragangliomas. The diagnosis is confirmed by elevation of catecholamines and the metanephrines in blood plasma and urine. Localization of the tumour should be done following biochemical diagnosis by means of CT scan and/or MRI. The treatment of choice is tumour resection by laparoscopic surgery. A review was made of all patient medical histories diagnosed with pheochromocytoma confirmed by the pathology reports of Pathological anatomy of the Navarre hospital Complex (Anatomía patológica del Complejo hospitalario de Navarra A y B) between 1996 to 2010. Descriptive analysis was made using the IBM SPSS statistics program. Our series consists of 43 patients diagnosed with pheochromocytoma over a span of 15 years. The average age on presentation was 47 years. Among the younger patients specific genetic syndromes were found. Computerized tomography was the most widely used method of localization. Contradictory results were found regarding perioperative medical management protocols. All pheocromocytoma tumours in this series were benign. It is advisable to carry out a genetic study on patients under twenty. The biochemical indicators with the greatest diagnostic sensitivity were the levels of normetanephrine and metanephrine in urine. Surgery was the only treatment option.

Safety of Microbubbles and Transcranial Ultrasound in Rabbits

NASA Astrophysics Data System (ADS)

Culp, William C.; Brown, Aliza T.; Hennings, Leah; Lowery, John; Culp, Benjamin C.; Erdem, Eren; Roberson, Paula; Matsunaga, Terry O.

2007-05-01

The object of this study was to evaluate the safety of large doses of microbubbles and ultrasound administered to the head of rabbits as if they were receiving acute stroke therapy of a similar nature. Materials and Methods: Female New Zealand White rabbits were used, N=24, in three groups 1] n=4 control (no treatment), 2] n=10 bubble control (ultrasound plus aspirin), and 3] n=10 target group (ultrasound plus aspirin plus MRX-815 microbubbles). Group 3 was infused with IV bubbles over 1 hour at 0.16cc/kg. Ultrasound was delivered to the dehaired side of the head during bubble infusion and for 1 additional hour at 0.8 W/cm2 20% pulsed wave. Rabbits survived for 22 to 24 hours, were imaged with computerized tomography and 3 Tesla magnetic resonance imaging including contrast studies, and sacrificed. Tetrazolium (TTC) and Hematoxylin and Eosin (H&E) sections were made for pathological examination. Results: All 24 animals showed absence of bleeding, endothelial damage, EKG abnormalities, stroke, blood-brain-barrier breakdown, or other acute abnormalities. CT and MRI showed no bleeding or signs of stroke, but two animals had mild hydrocephalus. The EKGs showed normal variation in QTc. Rabbit behavior was normal in all. Minimal chronic inflammation unrelated to the study was seen in 5. Two animals were excluded because of protocol violations and replaced during the study. Conclusion: The administered dose of microbubbles and ultrasound demonstrated no detrimental effects on the healthy rabbit animal model.

An interactive Bayesian geostatistical inverse protocol for hydraulic tomography

USGS Publications Warehouse

Fienen, Michael N.; Clemo, Tom; Kitanidis, Peter K.

2008-01-01

Hydraulic tomography is a powerful technique for characterizing heterogeneous hydrogeologic parameters. An explicit trade-off between characterization based on measurement misfit and subjective characterization using prior information is presented. We apply a Bayesian geostatistical inverse approach that is well suited to accommodate a flexible model with the level of complexity driven by the data and explicitly considering uncertainty. Prior information is incorporated through the selection of a parameter covariance model characterizing continuity and providing stability. Often, discontinuities in the parameter field, typically caused by geologic contacts between contrasting lithologic units, necessitate subdivision into zones across which there is no correlation among hydraulic parameters. We propose an interactive protocol in which zonation candidates are implied from the data and are evaluated using cross validation and expert knowledge. Uncertainty introduced by limited knowledge of dynamic regional conditions is mitigated by using drawdown rather than native head values. An adjoint state formulation of MODFLOW-2000 is used to calculate sensitivities which are used both for the solution to the inverse problem and to guide protocol decisions. The protocol is tested using synthetic two-dimensional steady state examples in which the wells are located at the edge of the region of interest.

Whole-body computed tomography in trauma patients: optimization of the patient scanning position significantly shortens examination time while maintaining diagnostic image quality.

PubMed

Hickethier, Tilman; Mammadov, Kamal; Baeßler, Bettina; Lichtenstein, Thorsten; Hinkelbein, Jochen; Smith, Lucy; Plum, Patrick Sven; Chon, Seung-Hun; Maintz, David; Chang, De-Hua

2018-01-01

The study was conducted to compare examination time and artifact vulnerability of whole-body computed tomographies (wbCTs) for trauma patients using conventional or optimized patient positioning. Examination time was measured in 100 patients scanned with conventional protocol (Group A: arms positioned alongside the body for head and neck imaging and over the head for trunk imaging) and 100 patients scanned with optimized protocol (Group B: arms flexed on a chest pillow without repositioning). Additionally, influence of two different scanning protocols on image quality in the most relevant body regions was assessed by two blinded readers. Total wbCT duration was about 35% or 3:46 min shorter in B than in A. Artifacts in aorta (27 vs 6%), liver (40 vs 8%) and spleen (27 vs 5%) occurred significantly more often in B than in A. No incident of non-diagnostic image quality was reported, and no significant differences for lungs and spine were found. An optimized wbCT positioning protocol for trauma patients allows a significant reduction of examination time while still maintaining diagnostic image quality.

A Semi-Discrete Landweber-Kaczmarz Method for Cone Beam Tomography and Laminography Exploiting Geometric Prior Information

NASA Astrophysics Data System (ADS)

Vogelgesang, Jonas; Schorr, Christian

2016-12-01

We present a semi-discrete Landweber-Kaczmarz method for solving linear ill-posed problems and its application to Cone Beam tomography and laminography. Using a basis function-type discretization in the image domain, we derive a semi-discrete model of the underlying scanning system. Based on this model, the proposed method provides an approximate solution of the reconstruction problem, i.e. reconstructing the density function of a given object from its projections, in suitable subspaces equipped with basis function-dependent weights. This approach intuitively allows the incorporation of additional information about the inspected object leading to a more accurate model of the X-rays through the object. Also, physical conditions of the scanning geometry, like flat detectors in computerized tomography as used in non-destructive testing applications as well as non-regular scanning curves e.g. appearing in computed laminography (CL) applications, are directly taken into account during the modeling process. Finally, numerical experiments of a typical CL application in three dimensions are provided to verify the proposed method. The introduction of geometric prior information leads to a significantly increased image quality and superior reconstructions compared to standard iterative methods.

Computed tomography of the lacrimal drainage system: retrospective study of 107 cases of dacryostenosis.

PubMed

Francis, I C; Kappagoda, M B; Cole, I E; Bank, L; Dunn, G D

1999-05-01

To evaluate the role of computed tomography in patients with dacryostenosis. One hundred seven cases of dacryostenosis (94 patients) were assessed by thorough clinical and lacrimal history and examination, and lacrimal region computerized tomography (CT). The lacrimal drainage system examination included the state and position of the puncta; Jones testing; lacrimal syringing; and, in the latter half of the study, telescopic nasal endoscopy. The patients were drawn from the hospital outpatients and private office of the operating lacrimal surgeon in this series (I.C.F.). Of the 107 cases, 79 either underwent dacryocystorhinostomy surgery or had this planned. In 14 of the 107 cases (12 patients), preoperative CT led to an alteration of patient management, usually referral to an otolaryngologist for further evaluation or treatment. In addition to the detection of two tumors extrinsic to the sac, conditions such as ethmoiditis, lacrimal sac mucoceles, soft tissue opacity in the nasolacrimal duct, gross nasal polyposis, fungal sinusitis, and a dacryolith were observed by CT. Similar to the role of functional endoscopic sinus surgery in otolaryngology, CT imaging will become increasingly important in the assessment of many patients with symptoms of lacrimal drainage obstruction.

Great Ears: Low-Frequency Sensitivity Correlates in Land and Marine Leviathans.

PubMed

Ketten, D R; Arruda, J; Cramer, S; Yamato, M

2016-01-01

Like elephants, baleen whales produce low-frequency (LF) and even infrasonic (IF) signals, suggesting they may be particularly susceptible to underwater anthropogenic sound impacts. Analyses of computerized tomography scans and histologies of the ears in five baleen whale and two elephant species revealed that LF thresholds correlate with basilar membrane thickness/width and cochlear radii ratios. These factors are consistent with high-mass, low-stiffness membranes and broad spiral curvatures, suggesting that Mysticeti and Proboscidea evolved common inner ear adaptations over similar time scales for processing IF/LF sounds despite operating in different media.

Procedural-support music therapy in the healthcare setting: a cost-effectiveness analysis.

PubMed

DeLoach Walworth, Darcy

2005-08-01

This comparative analysis examined the cost-effectiveness of music therapy as a procedural support in the pediatric healthcare setting. Many healthcare organizations are actively attempting to reduce the amount of sedation for pediatric patients undergoing various procedures. Patients receiving music therapy-assisted computerized tomography scans ( n = 57), echocardiograms ( n = 92), and other procedures ( n = 17) were included in the analysis. Results of music therapy-assisted procedures indicate successful elimination of patient sedation, reduction in procedural times, and decrease in the number of staff members present for procedures. Implications for nurses and music therapists in the healthcare setting are discussed.

A look at 15 years of planar thallium-201 imaging

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

Kaul, S.

1989-09-01

Extensive experience has been accumulated over the past 15 years regarding planar thallium-201 imaging. Quantitation of technically superior images provides a high sensitivity and specificity for the detection of CAD. In addition, planar thallium-201 images provide very important prognostic information in different clinical situations. Although single photon emission computerized tomography offers potential theoretical advantages over planar imaging, because of the problems involved in reconstruction, specifically the creation of artifacts, it may not be the ideal imaging modality in all situations. Good quality planar thallium-201 imaging still has an important role in clinical cardiology today. 144 references.

Liesegang Rings in Xanthogranulomatous Pyelonephritis: A Case Report

PubMed Central

Pegas, Karla Laís; Edelweiss, Maria Isabel; Cambruzzi, Eduardo; Zettler, Cláudio Galleano

2010-01-01

Liesegang rings are concentric noncellular lamellar structures, rarely seen in vivo, occurring as a consequence of the accumulation of insoluble products in a colloidal matrix. These characteristic structures are a rare phenomenon usually found in association with cystic or inflammatory lesions and may be mistaken for parasites. The authors examined Liesegang rings from an inflammatory kidney lesion identified previously as a tumoral lesion on computerized tomography. On microscopic evaluation, Liesegang rings can be mistaken for eggs and larvae of parasites, psammoma bodies and calcification. Special stains like PAS, Grocott, von Kossa and Masson's trichrome facilitate the diagnosis. PMID:21151725

CMT for biomedical and other applications

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

Spanne, P.

This session includes two presentations describing applications for x-ray tomography using synchrotron radiation for biomedical uses and fluid flow modeling, and outlines advantages for using monoenergetic x-rays. Contrast mechanisms are briefly described and several graphs of absorbed doses and scattering of x-rays are included. Also presented are schematic diagrams of computerized tomographic instrumentation with camera head. A brief description of goals for a real time tomographic system and expected improvements to the system are described. Color photomicrographs of the Berea Sandstone and human bone are provided, as well as a 3-D microtomographic reconstruction of a human vertebra sample.

Splenic infarction at low altitude in a child with hemoglobin S-C disease.

PubMed

Alvarado, C S; Wyly, B; Buchanan, I; Fajman, W A

1988-08-01

We describe a 15-year-old black boy with hemoglobin S-C disease living in Atlanta (altitude 1,034 ft), with no prior history of aircraft or mountain travel, who developed splenic infarction. The clinical picture was characterized by severe left upper quadrant abdominal pain, fever, splenomegaly, and hematologic and scintigraphic evidence of functional asplenia. The diagnosis was suggested by liver/spleen scintigraphy and further confirmed by ultrasonography and computerized tomography (CT) of the spleen. Treatment consisted of analgesics, intravenous fluids, and short-term antibiotic therapy. The child recovered without sequelae.

High resolution collimator system for X-ray detector

DOEpatents

Eberhard, Jeffrey W.; Cain, Dallas E.

1987-01-01

High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

A case of mycotic aneurysm due to Burkholderia pseudomallei.

PubMed

Ding, C H; Hussin, S; Tzar, M N; Rahman, M M; Ramli, S R

2013-04-01

Burkholderia pseudomallei is an free-living gram-negative bacterium causing melioidosis and is endemic in Southeast Asia. A 56-year-old diabetic construction worker with a 1-month history of abdominal pain and 1-day history of high-grade fever was found to have a left non-dissecting infrarenal mycotic aortic aneurysm by abdominal computerized tomography scan. Bacteriological examination of his blood yielded Burkholderia pseudomallei. The patient was treated with right axillo-bifemoral bypass with excision of aneurysm and high-dose intravenous ceftazidime for two weeks, followed by oral trimethoprim/sulfamethoxazole and oral doxycycline for a minimum of five months.

Exertional headache as unusual presentation of the syndrome of an elongated styloid process.

PubMed

Maggioni, Ferdinando; Marchese-Ragona, Rosario; Mampreso, Edoardo; Mainardi, Federico; Zanchin, Giorgio

2009-05-01

We present the case of a 34-year-old man with a 2-year history of pain related to efforts in heavy lifting, beginning in the right ear and radiating to the neck and to the vertex. He underwent multiple negative neuroimaging examinations, until a 3-dimensional computerized tomography scan of the pharyngeal region evidenced an elongated styloid process. A diagnosis of Eagle's syndrome was made. The excision of the elongated styloid process was performed, resulting in complete and lasting pain relief. We focus on Eagle's syndrome and in particular on this atypical presentation.

Secondary signet-ring cell adenocarcinoma of urinary bladder from a gastric primary.

PubMed

Sharma, Pramod K; Vijay, Mukesh K; Das, Ranjit K; Chatterjee, Uttara

2011-05-01

Primary bladder tumor is a frequent urological malignancy, whereas the incidence of secondary bladder tumor from a distant organ is quite rare. Secondary bladder neoplasms represent 1% of all malignant bladder tumors, of which distant metastases from stomach account for about 4% of cases. We present the case of a 30-year-old male who underwent partial gastrectomy for Signet-ring cell carcinoma of the stomach and presented 2 years later with hematuria. On computerized tomography scan, a bladder tumor was found which was resected cystoscopically. The histopathological examination revealed secondary Signet-ring cell adenocarcinoma of the urinary bladder.

Radiographic evidence of disuse osteoporosis in the monkey /M. nemestrina/

NASA Technical Reports Server (NTRS)

Young, D. R.; Schneider, V. S.

1981-01-01

Radiological techniques were utilized for monitoring progressive changes in compact bone in the tibia of monkeys during experimentally induced osteopenia. Bone mass loss in the tibia during restraint was evaluated from radiographs, from bone mineral analysis, and from images reconstructed from gamma ray computerized tomography. The losses during 6 months of restraint tended to occur predominantly in the proximal tibia and were characterized by subperiosteal bone loss, intracortical striations, and scalloped endosteal surfaces. Bone mineral content in the cross section of the tibia declined 17-21%. In 6 months of recovery, the mineral content of the proximal tibia remained depressed.

Magnetic resonance imaging for the ophthalmologist: A primer

PubMed Central

Simha, Arathi; Irodi, Aparna; David, Sarada

2012-01-01

Magnetic resonance imaging (MRI) and computerized tomography (CT) have added a new dimension in the diagnosis and management of ocular and orbital diseases. Although CT is more widely used, MRI is the modality of choice in select conditions and can be complimentary to CT in certain situations. The diagnostic yield is best when the ophthalmologist and radiologist work together. Ophthalmologists should be able to interpret these complex imaging modalities as better clinical correlation is then possible. In this article, we attempt to describe the basic principles of MRI and its interpretation, avoiding confusing technical terms. PMID:22824600

Superior mesenteric vein thrombosis complicating appendicular masses.

PubMed

Echtibi, Salma S; Bashir, Masoud O; Ahmed, Misbah U; Branicki, Frank J; Abu-Zidan, Fikri M

2003-09-01

Mesenteric vein thrombosis (MVT) is rare. Its diagnosis is usually difficult and delayed. Herein, we report 2 patients who developed MVT as a complication of an appendicular mass. One of them had appendectomy and developed fever 10 days postoperatively. The other was treated conservatively. An abdominal computerized tomography (CT) scan with intravenous contrast was helpful in diagnosing the superior MVT in both patients, which were not suspected. Intravenous contrast should be used when performing CT of an appendicular mass. Special interest should be directed at studying the superior mesenteric vein. Early diagnosis of our patients helped to start early medical treatment with anticoagulation.

Measurement of eye lens dose for Varian On-Board Imaging with different cone-beam computed tomography acquisition techniques

PubMed Central

Deshpande, Sudesh; Dhote, Deepak; Thakur, Kalpna; Pawar, Amol; Kumar, Rajesh; Kumar, Munish; Kulkarni, M. S.; Sharma, S. D.; Kannan, V.

2016-01-01

The objective of this work was to measure patient eye lens dose for different cone-beam computed tomography (CBCT) acquisition protocols of Varian's On-Board Imaging (OBI) system using optically stimulated luminescence dosimeter (OSLD) and to study the variation in eye lens dose with patient geometry and distance of isocenter to the eye lens. During the experimental measurements, OSLD was placed on the patient between the eyebrows of both eyes in line of nose during CBCT image acquisition to measure eye lens doses. The eye lens dose measurements were carried out for three different cone-beam acquisition protocols (standard dose head, low-dose head [LDH], and high-quality head [HQH]) of Varian OBI. Measured doses were correlated with patient geometry and distance between isocenter and eye lens. Measured eye lens doses for standard head and HQH protocols were in the range of 1.8–3.2 mGy and 4.5–9.9 mGy, respectively. However, the measured eye lens dose for the LDH protocol was in the range of 0.3–0.7 mGy. The measured data indicate that eye lens dose to patient depends on the selected imaging protocol. It was also observed that eye lens dose does not depend on patient geometry but strongly depends on distance between eye lens and treatment field isocenter. However, undoubted advantages of imaging system should not be counterbalanced by inappropriate selection of imaging protocol, especially for very intense imaging protocol. PMID:27651564

Reproducibility of three-dimensional cephalometric landmarks in cone-beam and low-dose computed tomography.

PubMed

Olszewski, R; Frison, L; Wisniewski, M; Denis, J M; Vynckier, S; Cosnard, G; Zech, F; Reychler, H

2013-01-01

The purpose of this study is to compare the reproducibility of three-dimensional cephalometric landmarks on three-dimensional computed tomography (3D-CT) surface rendering using clinical protocols based on low-dose (35-mAs) spiral CT and cone-beam CT (I-CAT). The absorbed dose levels for radiosensitive organs in the maxillofacial region during exposure in both 3D-CT protocols were also assessed. The study population consisted of ten human dry skulls examined with low-dose CT and cone-beam CT. Two independent observers identified 24 cephalometric anatomic landmarks at 13 sites on the 3D-CT surface renderings using both protocols, with each observer repeating the identification 1 month later. A total of 1,920 imaging measurements were performed. Thermoluminescent dosimeters were placed at six sites around the thyroid gland, the submandibular glands, and the eyes in an Alderson phantom to measure the absorbed dose levels. When comparing low-dose CT and cone-beam CT protocols, the cone-beam CT protocol proved to be significantly more reproducible for four of the 13 anatomical sites. There was no significant difference between the protocols for the other nine anatomical sites. Both low-dose and cone-beam CT protocols were equivalent in dose absorption to the eyes and submandibular glands. However, thyroid glands were more irradiated with low-dose CT. Cone-beam CT was more reproducible and procured less irradiation to the thyroid gland than low-dose CT. Cone-beam CT should be preferred over low-dose CT for developing three-dimensional bony cephalometric analyses.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson's disease.

PubMed

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C; Mackay, Clare E; Hu, Michele T M

2016-08-01

SEE POSTUMA DOI101093/AWW131 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson's disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson's disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson's disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson's disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson's disease and 10 control subjects received (123)I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson's disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson's disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson's disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson's disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson's disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson’s disease

PubMed Central

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A.; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A.; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C.; Mackay, Clare E.

2016-01-01

Abstract See Postuma (doi:10.1093/aww131) for a scientific commentary on this article. Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson’s disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson’s disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson’s disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson’s disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson’s disease and 10 control subjects received 123I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson’s disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson’s disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson’s disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson’s disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson’s disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. PMID:27297241

Automated detection of pulmonary nodules in CT images with support vector machines

NASA Astrophysics Data System (ADS)

Liu, Lu; Liu, Wanyu; Sun, Xiaoming

2008-10-01

Many methods have been proposed to avoid radiologists fail to diagnose small pulmonary nodules. Recently, support vector machines (SVMs) had received an increasing attention for pattern recognition. In this paper, we present a computerized system aimed at pulmonary nodules detection; it identifies the lung field, extracts a set of candidate regions with a high sensitivity ratio and then classifies candidates by the use of SVMs. The Computer Aided Diagnosis (CAD) system presented in this paper supports the diagnosis of pulmonary nodules from Computed Tomography (CT) images as inflammation, tuberculoma, granuloma..sclerosing hemangioma, and malignant tumor. Five texture feature sets were extracted for each lesion, while a genetic algorithm based feature selection method was applied to identify the most robust features. The selected feature set was fed into an ensemble of SVMs classifiers. The achieved classification performance was 100%, 92.75% and 90.23% in the training, validation and testing set, respectively. It is concluded that computerized analysis of medical images in combination with artificial intelligence can be used in clinical practice and may contribute to more efficient diagnosis.

Optical coherence tomography: A guide to interpretation of common macular diseases

PubMed Central

Bhende, Muna; Shetty, Sharan; Parthasarathy, Mohana Kuppuswamy; Ramya, S

2018-01-01

Optical coherence tomography is a quick, non invasive and reproducible imaging tool for macular lesions and has become an essential part of retina practice. This review address the common protocols for imaging the macula, basics of image interpretation, features of common macular disorders with clues to differentiate mimickers and an introduction to choroidal imaging. It includes case examples and also a practical algorithm for interpretation. PMID:29283118

Detection of Acute and Long-Term Effects of Concussion: Dual-Task Gait Balance Control Versus Computerized Neurocognitive Test.

PubMed

Howell, David R; Osternig, Louis R; Chou, Li-Shan

2018-02-16

To examine the acute (within 72h of injury) and long-term (2mo postinjury) independent associations between objective dual-task gait balance and neurocognitive measurements among adolescents and young adults with a concussion and matched controls. Longitudinal case-control. Motion analysis laboratory. A total of 95 participants completed the study: 51 who sustained a concussion (mean age, 17.5±3.3y; 71% men) and 44 controls (mean age, 17.7±2.9y; 72% men). Participants who sustained a concussion underwent a dual-task gait analysis and computerized neurocognitive testing within 72 hours of injury and again 2 months later. Uninjured controls also completed the same test protocol in similar time increments. Not applicable. We compared dual-task gait balance control and computerized neurocognitive test performance between groups using independent samples t tests. Multivariable binary logistic regression models were then constructed for each testing time to determine the association between group membership (concussion vs control), dual-task gait balance control, and neurocognitive function. Medial-lateral center-of-mass displacement during dual-task gait was independently associated with group membership at the initial test (adjusted odds ratio [aOR], 2.432; 95% confidence interval [CI], 1.269-4.661) and 2-month follow-up test (aOR, 1.817; 95% CI, 1.014-3.256) tests. Visual memory composite scores were significantly associated with group membership at the initial hour postinjury time point (aOR, .953; 95% CI, .833-.998). However, the combination of computerized neurocognitive test variables did not predict dual-task gait balance control for participants with concussion, and no single neurocognitive variable was associated with dual-task gait balance control at either testing time. Dual-task assessments concurrently evaluating gait and cognitive performance may allow for the detection of persistent deficits beyond those detected by computerized neurocognitive deficits alone. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

How to implement a clinical pathway for intensive glucose regulation in acute coronary syndromes.

PubMed

de Mulder, Maarten; Zwaan, Esther; Wielinga, Yvonne; Stam, Frank; Umans, Victor A W M

2009-06-01

Hyperglycemia upon admission of myocardial infarction patients predicts inferior clinical outcomes. Current strategies investigating hyperglycemia correction mostly use glucose-driven protocols. Implementation of these often labor-intensive protocols might be facilitated with the approach of a clinical pathway. Therefore, we evaluated the implementation of our glucose-driven protocol.We adapted a protocol for use in our coronary care unit (CCU), which was implemented according to the steps of a clinical pathway. To compensate for carbohydrates in meals we additionally developed a regimen of subcutaneous insulin.Protocol adherence was facilitated with a Web-based insulin calculator. All hyperglycemic patients admitted to the CCU were eligible for treatment according to this protocol.In a 4-month period, 643 glucose measurements were obtained in hyperglycemic patients admitted to our CCU. Patients were treated intensively with IV insulin for 35 hours and had 23 glucose measurements in this time span on average. This regimen achieved a median glucose of 6.2 mmol/L. Severe hypoglycemia occurred in only 1.1% of measurements and was without severe clinical side effects.Introduction of new intensive insulin protocol according to the steps of a clinical pathway is safe and feasible. The presence of a clinical pathway coordinator and sound communication are important conditions for successful introduction, which can be further aided with a computerized calculator.

Quantitative assessment on coronary computed tomography angiography (CCTA) image quality: comparisons between genders and different tube voltage settings.

PubMed

Chian, Teo Chee; Nassir, Norziana Mat; Ibrahim, Mohd Izuan; Yusof, Ahmad Khairuddin Md; Sabarudin, Akmal

2017-02-01

This study was carried out to quantify and compare the quantitative image quality of coronary computed tomography angiography (CCTA) between genders as well as between different tube voltages scan protocols. Fifty-five cases of CCTA were collected retrospectively and all images including reformatted axial images at systolic and diastolic phases as well as images with curved multi planar reformation (cMPR) were obtained. Quantitative image quality including signal intensity, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of right coronary artery (RCA), left anterior descending artery (LAD), left circumflex artery (LCx) and left main artery (LM) were quantified using Analyze 12.0 software. Six hundred and fifty-seven coronary arteries were evaluated. There were no significant differences in any quantitative image quality parameters between genders. 100 kilovoltage peak (kVp) scanning protocol produced images with significantly higher signal intensity compared to 120 kVp scanning protocol (P<0.001) in all coronary arteries in all types of images. Higher SNR was also observed in 100 kVp scan protocol in all coronary arteries except in LCx where 120 kVp showed better SNR than 100 kVp. There were no significant differences in image quality of CCTA between genders and different tube voltages. Lower tube voltage (100 kVp) scanning protocol is recommended in clinical practice to reduce the radiation dose to patient.

Comparison of low- and ultralow-dose computed tomography protocols for quantitative lung and airway assessment.

PubMed

Hammond, Emily; Sloan, Chelsea; Newell, John D; Sieren, Jered P; Saylor, Melissa; Vidal, Craig; Hogue, Shayna; De Stefano, Frank; Sieren, Alexa; Hoffman, Eric A; Sieren, Jessica C

2017-09-01

Quantitative computed tomography (CT) measures are increasingly being developed and used to characterize lung disease. With recent advances in CT technologies, we sought to evaluate the quantitative accuracy of lung imaging at low- and ultralow-radiation doses with the use of iterative reconstruction (IR), tube current modulation (TCM), and spectral shaping. We investigated the effect of five independent CT protocols reconstructed with IR on quantitative airway measures and global lung measures using an in vivo large animal model as a human subject surrogate. A control protocol was chosen (NIH-SPIROMICS + TCM) and five independent protocols investigating TCM, low- and ultralow-radiation dose, and spectral shaping. For all scans, quantitative global parenchymal measurements (mean, median and standard deviation of the parenchymal HU, along with measures of emphysema) and global airway measurements (number of segmented airways and pi10) were generated. In addition, selected individual airway measurements (minor and major inner diameter, wall thickness, inner and outer area, inner and outer perimeter, wall area fraction, and inner equivalent circle diameter) were evaluated. Comparisons were made between control and target protocols using difference and repeatability measures. Estimated CT volume dose index (CTDIvol) across all protocols ranged from 7.32 mGy to 0.32 mGy. Low- and ultralow-dose protocols required more manual editing and resolved fewer airway branches; yet, comparable pi10 whole lung measures were observed across all protocols. Similar trends in acquired parenchymal and airway measurements were observed across all protocols, with increased measurement differences using the ultralow-dose protocols. However, for small airways (1.9 ± 0.2 mm) and medium airways (5.7 ± 0.4 mm), the measurement differences across all protocols were comparable to the control protocol repeatability across breath holds. Diameters, wall thickness, wall area fraction, and equivalent diameter had smaller measurement differences than area and perimeter measurements. In conclusion, the use of IR with low- and ultralow-dose CT protocols with CT volume dose indices down to 0.32 mGy maintains selected quantitative parenchymal and airway measurements relevant to pulmonary disease characterization. © 2017 American Association of Physicists in Medicine.

Very low intravenous contrast volume protocol for computed tomography angiography providing comprehensive cardiac and vascular assessment prior to transcatheter aortic valve replacement in patients with chronic kidney disease.

PubMed

Pulerwitz, Todd C; Khalique, Omar K; Nazif, Tamim N; Rozenshtein, Anna; Pearson, Gregory D N; Hahn, Rebecca T; Vahl, Torsten P; Kodali, Susheel K; George, Isaac; Leon, Martin B; D'Souza, Belinda; Po, Ming Jack; Einstein, Andrew J

2016-01-01

Transcatheter aortic valve replacement (TAVR) is a lifesaving procedure for many patients high risk for surgical aortic valve replacement. The prevalence of chronic kidney disease (CKD) is high in this population, and thus a very low contrast volume (VLCV) computed tomography angiography (CTA) protocol providing comprehensive cardiac and vascular imaging would be valuable. 52 patients with severe, symptomatic aortic valve disease, undergoing pre-TAVR CTA assessment from 2013-4 at Columbia University Medical Center were studied, including all 26 patients with CKD (eGFR<30 mL/min) who underwent a novel VLCV protocol (20 mL of iohexol at 2.5 mL/s), and 26 standard-contrast-volume (SCV) protocol patients. Using a 320-slice volumetric scanner, the protocol included ECG-gated volume scanning of the aortic root followed by medium-pitch helical vascular scanning through the femoral arteries. Two experienced cardiologists performed aortic annulus and root measurements. Vascular image quality was assessed by two radiologists using a 4-point scale. VLCV patients had mean (±SD) age 86 ± 6.5, BMI 23.9 ± 3.4 kg/m(2) with 54% men; SCV patients age 83 ± 8.8, BMI 28.7 ± 5.3 kg/m(2), 65% men. There was excellent intra- and inter-observer agreement for annular and root measurements, and excellent agreement with 3D-transesophageal echocardiographic measurements. Both radiologists found diagnostic-quality vascular imaging in 96% of VLCV and 100% of SCV cases, with excellent inter-observer agreement. This study is the first of its kind to report the feasibility and reproducibility of measurements for a VLCV protocol for comprehensive pre-TAVR CTA. There was excellent agreement of cardiac measurements and almost all studies were diagnostic quality for vascular access assessment. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Comparison of Radiation Dose and Image Quality of Triple-Rule-Out Computed Tomography Angiography Between Conventional Helical Scanning and a Strategy Incorporating Sequential Scanning

PubMed Central

Manheimer, Eric D.; Peters, M. Robert; Wolff, Steven D.; Qureshi, Mehreen A.; Atluri, Prashanth; Pearson, Gregory D.N.; Einstein, Andrew J.

2011-01-01

Triple-rule-out computed tomography angiography (TRO CTA), performed to evaluate the coronary arteries, pulmonary arteries, and thoracic aorta, has been associated with high radiation exposure. Utilization of sequential scanning for coronary computed tomography angiography (CCTA) reduces radiation dose. The application of sequential scanning to TRO CTA is much less well defined. We analyzed radiation dose and image quality from TRO CTA performed in a single outpatient center, comparing scans from a period during which helical scanning with electrocardiographically controlled tube current modulation was used for all patients (n=35) and after adoption of a strategy incorporating sequential scanning whenever appropriate (n=35). Sequential scanning was able to be employed in 86% of cases. The sequential-if-appropriate strategy, compared to the helical-only strategy, was associated with a 61.6% dose decrease (mean dose-length product [DLP] of 439 mGy×cm vs 1144 mGy×cm and mean effective dose of 7.5 mSv vs 19.4 mSv, respectively, p<0.0001). Similarly, there was a 71.5% dose reduction among 30 patients scanned with the sequential protocol compared to 40 patients scanned with the helical protocol under either strategy (326 mGy×cm vs 1141 mGy×cm and 5.5 mSv vs 19.4 mSv, respectively, p<0.0001). Although image quality did not differ between strategies, there was a non-statistically significant trend towards better quality in the sequential protocol compared to the helical protocol. In conclusion, approaching TRO CTA with a diagnostic strategy of sequential scanning as appropriate offers a marked reduction in radiation dose while maintaining image quality. PMID:21306693

Migrainous aura as stroke-mimic: The role of perfusion-computed tomography.

PubMed

Ridolfi, Mariana; Granato, Antonio; Polverino, Paola; Furlanis, Giovanni; Ukmar, Maja; Zorzenon, Irene; Manganotti, Paolo

2018-03-01

The acute-onset of migrainuos aura (MA) can be erroneously diagnosed in Emergency Department (ED) as acute stroke (AS) and it can be classified as "stroke mimic" (SM). Perfusion computer tomography (PCT) may be useful to improve detection of infarcts. The aim of the study was to investigate the role in ED of PCT in improving diagnosis of migrainous aura. Data were compared with the well-defined perfusion patterns in patients with acute ischemic stroke. A standardized Stroke Protocol was planned. The protocol consisted in centralizing in ED all the patients with acute-onset of neurological symptoms compatible with cerebrovascular disease and in performing a general and neurological examination, hematological tests, brain non-contrast computed tomography (NCCT), CT angiography (CTA) of the supra-aortic and intracranial arteries and cerebral PCT. Patients with diagnosis of definite or probable acute stroke were hospitalized in Stroke Unit (SU). A six-months retrospective analysis of all the patients included in the Stroke Protocol and discharged from ED or from SU with a diagnosis of migraine with aura was performed. 172 patients were included in the Stroke Protocol and 6 patients were enrolled. NCCT, CTA and PCT were performed after 60-90 min from symptoms onset and revealed normal perfusion. Intravenous thrombolysis was performed only in one patient. Patients with acute-onset of neurological symptoms, who have rapid progressive improvement of symptoms, normal neuroimaging, in particular PCT, and preceding episodes of migraine with aura, may be considered as suffering from MA. In these cases, even if thrombolysis is safe, clinicians may defer a prompt aggressive treatment. Copyright © 2018 Elsevier B.V. All rights reserved.

The Aerospace Energy Systems Laboratory: A BITBUS networking application

NASA Technical Reports Server (NTRS)

Glover, Richard D.; Oneill-Rood, Nora

1989-01-01

The NASA Ames-Dryden Flight Research Facility developed a computerized aircraft battery servicing facility called the Aerospace Energy Systems Laboratory (AESL). This system employs distributed processing with communications provided by a 2.4-megabit BITBUS local area network. Customized handlers provide real time status, remote command, and file transfer protocols between a central system running the iRMX-II operating system and ten slave stations running the iRMX-I operating system. The hardware configuration and software components required to implement this BITBUS application are required.

Cognitive impairment in systemic lupus erythematosus women with elevated autoantibodies and normal single photon emission computerized tomography.

PubMed

Peretti, Charles-Siegfried; Peretti, Charles Roger; Kozora, Elizabeth; Papathanassiou, Dimitri; Chouinard, Virginie-Anne; Chouinard, Guy

2012-01-01

Systemic lupus erythematosus (SLE) is known to induce psychiatric disorders, from psychoses to maladaptive coping. Brain autoantibodies were proposed to explain SLE neuropsychiatric disorders and found to be elevated before the onset of clinical symptoms. We assessed cognition in Caucasian SLE women with elevated autoantibodies without overt neuropsychiatric syndromes, in conjunction with single photon emission computerized tomography (SPECT). 31 women meeting SLE criteria of the American College of Rheumatology (ACR) were included. Patients who met the ACR neuropsychiatric definition were excluded. Matched controls were 23 healthy women from the Champagne-Ardenne region, France. Participants completed neuropsychological and autoantibodies measurements, and 19 completed SPECT. 61% (19/31) of women with SLE and 53% (9/17) of those with normal SPECT had significant global cognitive impairment defined as 4 T-scores <40 in cognitive tests, compared to 0% (0/23) of controls. SLE women also had significantly greater cognitive dysfunction (mean T-score) on the Wechsler Adult Intelligence Scale (WAIS) visual backspan, Trail Making Test A and B, WAIS Digit Symbol Substitution Test and Stroop Interference, compared to controls. Elevated antinuclear antibody correlated with impairment in the WAIS visual span, WAIS visual backspan, and cancellation task; elevated anti-double-stranded DNA antibody and anticardiolipin correlated respectively with impairment in the Trail Making Test A and WAIS auditive backspan. Two SLE women had abnormal SPECT. A high prevalence of cognitive deficits was found in Caucasian SLE women compared to normal women, which included impairment in cognitive domains important for daily activities. Elevated autoantibodies tended to correlate with cognitive dysfunction. Copyright © 2012 S. Karger AG, Basel.

The Difficult Ureter: Clinical and Radiographic Characteristics Associated With Upper Urinary Tract Access at the Time of Ureteroscopic Stone Treatment.

PubMed

Viers, Boyd R; Viers, Lyndsay D; Hull, Nathan C; Hanson, Theodore J; Mehta, Ramila A; Bergstralh, Eric J; Vrtiska, Terri J; Krambeck, Amy E

2015-11-01

To evaluate the association between clinicoradiographic features and need for prestenting (PS) because of inability of the ureter to accommodate the ureteroscope, or ureteral access sheath, at the time of stone treatment. From 2009 to 2013, 120 consecutive nonstented patients underwent ureteroscopic stone treatment with preoperative computerized tomography urogram. Acute stone events with obstruction or infection were excluded. Preoperative radiographic imaging underwent radiologist review. Clinicoradiographic features were characterized, and multivariable logistic regression models were used to identify covariates independently associated with need for PS. Of the 154 renal units treated, 25 (16%) required PS for failed primary access. PS ureters were less likely to have a history of prior ipsilateral ureteral stent (4% vs 31%) or surgery (8% vs 36%; P <.05). Radiographically, PS ureters had a narrower ureteropelvic junction (4 mm vs 5 mm) and were more likely to have <50% ureteral opacification on computerized tomography urogram (32% vs 9%; P <.05). On multivariable analysis, prior ipsilateral ureteral stent (odds ratio [OR] = 0.11) and stone surgery (OR = 0.15) reduced the need for PS; meanwhile, <50% ureteral opacification (OR = 4.41) was independently associated with an increased risk of access failure. We report a 16% incidence of access failure requiring PS at time of ureteroscopy. Clinically, there was an 89% and 85% risk reduction in the need for PS with prior history of ipsilateral ureteral stent or surgery. Radiographically, there was a 4.4-fold increased risk of PS with <50% ureteral opacification. Accordingly, our findings may assist in counseling and operative management of the difficult ureter. Copyright © 2015 Elsevier Inc. All rights reserved.

Combining ultrasonography and noncontrast helical computerized tomography to evaluate Holmium laser lithotripsy

PubMed Central

Mi, Jia; Li, Jie; Zhang, Qinglu; Wang, Xing; Liu, Hongyu; Cao, Yanlu; Liu, Xiaoyan; Sun, Xiao; Shang, Mengmeng; Liu, Qing

2016-01-01

Abstract The purpose of the study was to establish a mathematical model for correlating the combination of ultrasonography and noncontrast helical computerized tomography (NCHCT) with the total energy of Holmium laser lithotripsy. In this study, from March 2013 to February 2014, 180 patients with single urinary calculus were examined using ultrasonography and NCHCT before Holmium laser lithotripsy. The calculus location and size, acoustic shadowing (AS) level, twinkling artifact intensity (TAI), and CT value were all documented. The total energy of lithotripsy (TEL) and the calculus composition were also recorded postoperatively. Data were analyzed using Spearman's rank correlation coefficient, with the SPSS 17.0 software package. Multiple linear regression was also used for further statistical analysis. A significant difference in the TEL was observed between renal calculi and ureteral calculi (r = –0.565, P < 0.001), and there was a strong correlation between the calculus size and the TEL (r = 0.675, P < 0.001). The difference in the TEL between the calculi with and without AS was highly significant (r = 0.325, P < 0.001). The CT value of the calculi was significantly correlated with the TEL (r = 0.386, P < 0.001). A correlation between the TAI and TEL was also observed (r = 0.391, P < 0.001). Multiple linear regression analysis revealed that the location, size, and TAI of the calculi were related to the TEL, and the location and size were statistically significant predictors (adjusted r2 = 0.498, P < 0.001). A mathematical model correlating the combination of ultrasonography and NCHCT with TEL was established; this model may provide a foundation to guide the use of energy in Holmium laser lithotripsy. The TEL can be estimated by the location, size, and TAI of the calculus. PMID:27930563

Is Routine Use of High Resolution Computerized Tomography of Temporal Bone in Patients of Atticoantral Chronic Suppurative Otitis Media without Intracranial Complications Justified?

PubMed

Bathla, Meeta; Doshi, Hiren; Kansara, Atul

2018-03-01

Role of high resolution computerized tomography (HRCT) of temporal bone is established in cases of atticoantral chronic suppurative otitis media (CSOM) with intracranial complications. Routine use of HRCT in management of patients of atticoantral CSOM without intracranial complications has been an issue of debate. The aim of this study was to evaluate the routine use of HRCT of temporal bone in such cases. This study was a prospective study done at LG hospital, AMC MET Medical College, Ahmedabad to evaluate and compare the temporal bone findings in HRCT and intraoperative findings in 100 patients with atticoantral CSOM. All patients underwent HRCT screening followed by surgical exploration of middle ear cleft. In extent of disease HRCT showed very high sensitivity and specificity for epitympanum (100, 94%) and mesotympanum (98, 98%) areas. It gave valuable information of disease extent in hidden areas like sinus tympani and facial recess of mesotympanum. HRCT satisfactorily delineated malleus and incus erosion but had 75% sensitivity for detecting erosion of stapes suprastructure, though specificity was of 97%. For bony anatomical landmarks HRCT showed very high sensitivity and specificity for detecting erosion of lateral semicircular canal, tegmen tympani and sinus plate. Detection of facial canal erosion on HRCT had moderate sensitivity of 75%. We concluded that routine use of HRCT is justified as a reliable preoperative tool in patients with atticoantral CSOM without intracranial complications and it helps to plan type of surgical intervention. HRCT has limited role to distinguish between granulations and cholesteatoma and also to delineate stapes supra structure and facial nerve canal.

Thirteen-Year Evaluation of Highly Cross-Linked Polyethylene Articulating With Either 28-mm or 36-mm Femoral Heads Using Radiostereometric Analysis and Computerized Tomography.

PubMed

Nebergall, Audrey K; Greene, Meridith E; Rubash, Harry; Malchau, Henrik; Troelsen, Anders; Rolfson, Ola

2016-09-01

The objective of this 13-year prospective evaluation of highly cross-linked ultra high molecular weight polyethylene (HXLPE) was to (1) assess the long-term wear of HXLPE articulating with 2 femoral head sizes using radiostereometric analysis (RSA) and to (2) determine if osteolysis is a concern with this material through the use of plain radiographs and computerized tomography (CT). All patients received a Longevity HXLPE liner with tantalum beads and either a 28-mm or 36-mm femoral head. Twelve patients (6 in each head size group) agreed to return for 13-year RSA, plain radiograph, and CT follow-up. The 1-year and 13-year plain radiographs as well as the CT scans were analyzed for the presence of osteolysis. The 13-year mean ± standard error steady-state wear was 0.05 ± 0.02 mm with no significant increase over time or between the 2 head size groups. Two patients' CT scans showed radiolucent regions in the acetabulum of 4.51 cm(3) and 11.25 cm(3), respectively. In one patient, this area corresponded to a partially healed degenerative cyst treated with autograft during surgery. The second patient had an acetabular protrusio treated with autograft, and the CT scan revealed areas of remodeling of this graft. One patient's 13-year plain radiographs showed evidence of cup loosening and linear radiolucencies in zones 2 and 3. There was no evidence of significant wear over time using RSA. The CT scans did not show evidence of osteolysis due to wear particles. These results suggest that this material has reduced wear compared to conventional polyethylene, irrespective of head size. Copyright © 2016 Elsevier Inc. All rights reserved.

Low osmolar (non-ionic) contrast media versus high osmolar (ionic) contrast media in intravenous urography and enhanced computerized tomography: a cost-effectiveness analysis.

PubMed

Wangsuphachart, S

1991-12-01

The cost-effectiveness of three alternative policies for the use of intravenous contrast media for urography and enhanced computerized tomography (CT) are analyzed. Alternative #1 is to use high osmolar contrast media (HOCM) in all patients, the historical policy. Alternative #2 is to replace it with low osmolar contrast media (LOCM) in all patients. Alternative #3 is to use LOCM only in the high risk patients. Data on the 6,242 patients who underwent intravenous urography and enhanced CT at the Department of Radiology, Chulalongkorn Hospital in 1989 were used. Both societal and hospital viewpoints were analyzed. The incremental cost-effectiveness (ICE) between #2 and #1 was 26,739 Baht (US$1,070) per healthy day saved (HDS), while the ICE between #3 and #1 was 12,057 Baht (US$482) per HDS. For fatal cases only, ICE between #2 and #1 was 35,111 Baht (US$1,404) per HDS, while the ICE between #3 and #1 was 18,266 Baht (US$731) per HDS. The incremental cost (IC) per patient was 2,341 Baht (US$94) and 681 Baht (US$27) respectively. For the hospital viewpoint the ICE between #2 and #1 was 13,744 (US$550) and between #3 and #1 was 6,127 Baht (US$245) per HDS. The IC per patient was 1,203 Baht (US$48) and 346 Baht (US$14), respectively. From the sensitivity analysis, #3 should be used if the LOCM price is reduced more than 75% (equal to 626 Baht or less) and more than 80% of the patients are able to pay for the contrast media.

Imaging-based assessment of the mineral composition of urinary stones: an in vitro study of the combination of hounsfield unit measurement in noncontrast helical computerized tomography and the twinkling artifact in color Doppler ultrasound.

PubMed

Hassani, Hakim; Raynal, Gauthier; Spie, Romain; Daudon, Michel; Vallée, Jean-Noël

2012-05-01

We evaluated the value of combining noncontrast helical computerized tomography (NCHCT) and color Doppler ultrasound in the assessment of the composition of urinary stones. In vitro, we studied 120 stones of known composition, that separate into the five main types: 18 calcium oxalate monohydrate (COM) stones, 41 calcium oxalate dihydrate (COD) stones, 24 uric acid stones, 25 calcium phosphate stones and 12 cystine calculi. Stones were characterized in terms of their Hounsfield density (HU) in NCHCT and the presence of a twinkling artifact (TA) in color Doppler ultrasound. There were statistically significant HU differences between calcium and non-calcium stones (p < 0.001), calcium oxalate stones and calcium phosphate stones (p < 0.001) and uric acid stones and cystine calculi (p < 0.001) but not between COM and COD stones (p = 0.786). Hence, the HU was a predictive factor of the composition of all types of stones, other than for COM and COD stones within the calcium oxalate class (p > 0.05). We found that the TA does not enable differentiation between calcium and non-calcium stones (p > 0.999), calcium oxalate stones and calcium phosphate stones (p = 0.15), or uric acid stones and cystine calculi (p = 0.079). However, it did reveal a significant difference between COM and COD stones (p = 0.002). The absence of a TA is a predictive factor for the presence of COM stones (p = 0.008). Hence, the association of NCHCT and Doppler enables the accurate classification of the five types of stones in vitro. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

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.

Computerized tomography assessment of cranial and mid-facial fractures in patients following road traffic accident in South-West Nigeria.

PubMed

Abiodun, Adeyinka; Atinuke, Agunloye; Yvonne, Osuagwu

2012-01-01

Globally, the most common cause of cranio-facial fractures is road traffic accident (RTA) with computerized tomography (CT) scan as the gold standard in the diagnosis of patients with cranial and facial fractures. The purpose of this study is to assess the pattern of cranial and facial fractures on CT in head injured patients following RTA. Using CT, detailed analyses of 236 patients with head injury following RTA were performed between 2006 and 2008, Data recorded included cause of injury, age and gender distribution, cranial and mid-facial fractures sustained, associated intracranial and soft tissue injury and the types of vehicular accident. The peak age of the patients was between 30 and 39 years. RTA was more common in males than females. Motor-vehicle was the most common cause of RTA in the present study (66.9%). More passengers were involved in the motor vehicle (87.3%) and motorcycle (52.0%) accidents than their corresponding drivers, and they were predominantly males. Majority of the patients involved in pedestrian road traffic accident (PRTA) were motor vehicle victims (93.3%). There were more patients with cranial (59.8%) than mid-facial fractures (40.2%). Majority of the patients had temporal bone cranial fracture (31.1%) and combined or mixed type of mid-facial fractures (41.3%). Intracranial bleeding (31.7%) was the most common associated intracranial finding. RTAs continue to be a menace and are the main cause of craniofacial injury in Nigeria. This pattern of etiologic factors is in accordance with data from most developing countries. Special attention should be paid to reinforcement of legislation and enactment of laws aimed at the reduction of head injury and provision for easy access to CT for the head injured patient.

Computerized tomography-assisted calculation of sinus augmentation volume.

PubMed

Krennmair, Gerald; Krainhöfner, Martin; Maier, Harald; Weinländer, Michael; Piehslinger, Eva

2006-01-01

This study was intended to calculate the augmentation volume for a sinus lift procedure based on cross-sectional computerized tomography (CT) scans for 2 different augmentation heights. Based on area calculations of cross-sectional CT scans, the volume of additional bone needed was calculated for 44 sinus lift procedures. The amount of bone volume needed to raise the sinus floor to heights of both 12 and 17 mm was calculated. To achieve a sinus floor height of 12 mm, it was necessary to increase the height by a mean of 7.2+/-2.1 mm (range, 3.0 to 10.5 mm), depending on the residual ridge height; to achieve a height of 17 mm, a mean of 12.4+/-2.0 mm (range, 8.5 to 15.5 mm) was required (P < .01). The calculated augmentation volume for an augmentation height of 12 mm was 1.7+/-.9 cm3; for an augmentation height of 17 mm, the volume required was 3.6+/-1.5 cm3. Increasing the height of the sinus lift by 5 mm, ie, from 12 mm to 17 mm augmentation height, increased the augmentation volume by 100%. A significant correlation was found between augmentation height and the calculated sinus lift augmentation volume (r = 0. 78, P < .01). Detailed preoperative knowledge of sinus lift augmentation volume is helpful as a predictive value in deciding on a donor site for harvesting autogenous bone and on the ratio of bone to bone substitute to use. Calculation of the augmentation size can help determine the surgical approach and thus perioperative treatment and the costs of the surgery for both patients and clinicians.

Computerized tomography attenuation values can be used to differentiate hydronephrosis from pyonephrosis.

PubMed

Yuruk, Emrah; Tuken, Murat; Sulejman, Suhejb; Colakerol, Aykut; Serefoglu, Ege Can; Sarica, Kemal; Muslumanoglu, Ahmet Yaser

2017-03-01

To determine the diagnostic value of computerized tomography (CT) in differentiating pyonephrosis from hydronephrosis on the basis of attenuation values (Hounsfield unit-HU). Data of the patients with grades 1-3 hydronephrosis on abdominopelvic CT, who underwent nephrostomy tube placement for decompression of the collecting system, were retrospectively analyzed. Patient demographics and CT findings were recorded along with the first access urine culture results. Three physicians calculated the surface areas and the attenuation values of the dilated collecting systems using the system software. Mean HU of pyonephrosis and hydronephrosis cases was compared. A total of 105 patients with the mean age of 47.7 ± 15.5 (range 20-80) were included. The interclass correlation coefficient of three physicians was 0.981 for HU measurement and 0.999 for calculation of collecting system surface area. Of the patients, 47 (44.8 %) had pyonephrosis. Mean surface areas of the collecting system were similar in patients with pyonephrosis and hydronephrosis (1481.13 ± 1562.94 vs. 1612.94 ± 2261.4 mm 2 , p = 0.735). Urine cultures were positive in all patients with pyonephrosis, whereas 12.7 % of hydronephrosis cases had bacterial in first access urine culture. The HU of the patients with pyonephrosis was significantly higher that that of patients with hydronephrosis (13.51 ± 13.29 vs. 4.67 ± 5.37, p = 0.0001). Having a HU of 9.21 or over diagnosed pyonephrosis accurately with 65.96 % sensitivity and 87.93 % specificity. Measuring attenuation values of the collecting system may be useful to differentiate pyonephrosis from hydronephrosis. Diagnosing pyonephrosis accurately may avoid septic complications.

Baseline Characteristics of Participants in the Randomized National Lung Screening Trial

PubMed Central

Aberle, Denise R.; Adams, Amanda M.; Berg, Christine D.; Clapp, Jonathan D.; Clingan, Kathy L.; Gareen, Ilana F.; Marcus, Pamela M.; Pinsky, Paul F.

2010-01-01

Background The National Lung Screening Trial (NLST), a randomized study conducted at 33 US sites, is comparing lung cancer mortality among persons screened with reduced dose helical computerized tomography and among persons screened with chest radiograph. In this article, we present characteristics of the study population. Methods Eligible participants were aged 55–74 years and were current or former smokers with a cigarette smoking history of at least 30 pack-years. Randomization was stratified by site, sex, and age. To assess representativeness of the study population, demographic characteristics of individuals from the general population who met NLST age and smoking history inclusion criteria were obtained from the Tobacco Use Supplement of the US Census Bureau Current Population Surveys. Results The NLST enrolled 53 456 persons, with 26 733 randomly assigned to chest radiograph screening and 26 723 to computerized tomography screening. Characteristics of the participants were as follows: 31 533 (59%) were men, 39 234 (73%) were younger than 65 years, 25 779 (48%) were current smokers, and 16 839 (32%) had a college or higher degree. Median cigarette exposure was 48 pack-years. Among Tobacco Use Supplement respondents who met NLST age and smoking history criteria, 59% were men, 65% were younger than 65 years, and 57% were current smokers. Median cigarette exposure among this group was 47 pack-years, and 14% had a college degree or higher. Conclusion The NLST cohort has a distribution of sex and pack-year history that is similar to the component of the general US population that meets the major NLST eligibility criteria; however, NLST participants are younger, better educated, and less likely to be current smokers. PMID:21119104

Fractional flow reserve by computerized tomography and subsequent coronary revascularization

PubMed Central

Packard, René R. Sevag; Li, Dong; Budoff, Matthew J.; Karlsberg, Ronald P.

2017-01-01

Aims Fractional flow reserve by computerized tomography (FFR-CT) provides non-invasive functional assessment of the hemodynamic significance of coronary artery stenosis. We determined the FFR-CT values, receiver operator characteristic (ROC) curves, and predictive ability of FFR-CT for actual standard of care guided coronary revascularization. Methods and results Consecutive outpatients who underwent coronary CT angiography (coronary CTA) followed by invasive angiography over a 24-month period from 2012 to 2014 were identified. Studies that fit inclusion criteria (n = 75 patients, mean age 66, 75% males) were sent for FFR-CT analysis, and results stratified by coronary artery calcium (CAC) scores. Coronary CTA studies were re-interpreted in a blinded manner, and baseline FFR-CT values were obtained retrospectively. Therefore, results did not interfere with clinical decision-making. Median FFR-CT values were 0.70 in revascularized (n = 69) and 0.86 in not revascularized (n = 138) coronary arteries (P < 0.001). Using clinically established significance cut-offs of FFR-CT ≤0.80 and coronary CTA ≥70% stenosis for the prediction of clinical decision-making and subsequent coronary revascularization, the positive predictive values were 74 and 88% and negative predictive values were 96 and 84%, respectively. The area under the curve (AUC) for all studied territories was 0.904 for coronary CTA, 0.920 for FFR-CT, and 0.941 for coronary CTA combined with FFR-CT (P = 0.001). With increasing CAC scores, the AUC decreased for coronary CTA but remained higher for FFR-CT (P < 0.05). Conclusion The addition of FFR-CT provides a complementary role to coronary CTA and increases the ability of a CT-based approach to identify subsequent standard of care guided coronary revascularization. PMID:27469588

Peripancreatic collections in acute pancreatitis: Correlation between computerized tomography and operative findings

PubMed Central

Vege, Santhi Swaroop; Fletcher, Joel G; Talukdar, Rupjyoti; Sarr, Michael G

2010-01-01

AIM: To evaluate the ability of contrast-enhanced computerized tomography (CECT) to characterize the nature of peripancreatic collections. METHODS: Twenty five patients with peripancreatic collections on CECT and who underwent operative intervention for severe acute pancreatitis were retrospectively studied. The collections were classified into (1) necrosis without frank pus; (2) necrosis with pus; and (3) fluid without necrosis. A blinded radiologist assessed the preoperative CTs of each patient for necrosis and peripancreatic fluid collections. Peripancreatic collections were described in terms of volume, location, number, heterogeneity, fluid attenuation, wall perceptibility, wall enhancement, presence of extraluminal gas, and vascular compromise. RESULTS: Fifty-four collections were identified at operation, of which 45 (83%) were identified on CECT. Of these, 25/26 (96%) had necrosis without pus, 16/19 (84%) had necrosis with pus, and 4/9 (44%) had fluid without necrosis. Among the study characteristics, fluid heterogeneity was seen in a greater proportion of collections in the group with necrosis and pus, compared to the other two groups (94% vs 48% and 25%, P = 0.002 and 0.003, respectively). Among the wall characteristics, irregularity was seen in a greater proportion of collections in the groups with necrosis with and without pus, when compared to the group with fluid without necrosis (88% and 71% vs 25%, P = 0.06 and P < 0.01, respectively). The combination of heterogeneity and presence of extraluminal gas had a specificity and positive likelihood ratio of 92% and 5.9, respectively, in detecting pus. CONCLUSION: Most of the peripancreatic collections seen on CECT in patients with severe acute pancreatitis who require operative intervention contain necrotic tissue. CECT has a somewhat limited role in differentiating the different types of collections. PMID:20818812

Calculating the number of shock waves, expulsion time, and optimum stone parameters based on noncontrast computerized tomography characteristics.

PubMed

Foda, Khaled; Abdeldaeim, Hussein; Youssif, Mohamed; Assem, Akram

2013-11-01

To define the parameters that accompanied a successful extracorporeal shock wave lithotripsy (ESWL), namely the number of shock waves (SWs), expulsion time (ET), mean stone density (MSD), and the skin-to-stone distance (SSD). A total of 368 patients diagnosed with renal calculi using noncontrast computerized tomography had their MSD, diameter, and SSD recorded. All patients were treated using a Siemens lithotripter. ESWL success meant a stone-free status or presence of residual fragments <3 mm, ET was the time in days for the successful clearance of stone fragments. Correlation was performed between the stone characteristics, number of SWs, and ET. Two multiple regression analysis models defined the number of SWs and ET. Two receiver operating characteristic curves plotted the best MSD cutoff value and optimum SSD for a successful ESWL. Three hundred one patients were ESWL successes. A significant positive correlation was elicited between number of SWs and stone diameter, density and SSD; between ET and stone diameter and density. Multiple regressions concluded 2 equations: Number of SWs = 265.108 + 5.103 x1 + 22.39 x2 + 10.931 x3 ET (days) = -10.85 + 0.031 x1 + 2.11 x2 x1 = stone density (Hounsfield unit [HUs]), x2 = stone diameter (mm), and x3 = SSD (mm). Receiver operating characteristic curves demonstrated a cutoff value of ≤ 934 HUs with 94.4% sensitivity and 66.7% specificity and P = .0211. The SSD curve showed that a distance ≤ 99 mm was 85.7% sensitive, 87.5% specific, P <.0001. Stone disintegration is not recommended if MSD is >934 HUs and SSD >99 mm. The required number of SWs and the expected ET can be anticipated. Copyright © 2013 Elsevier Inc. All rights reserved.

Model-based registration for assessment of spinal deformities in idiopathic scoliosis

NASA Astrophysics Data System (ADS)

Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Knutsson, Hans

2014-01-01

Detailed analysis of spinal deformity is important within orthopaedic healthcare, in particular for assessment of idiopathic scoliosis. This paper addresses this challenge by proposing an image analysis method, capable of providing a full three-dimensional spine characterization. The proposed method is based on the registration of a highly detailed spine model to image data from computed tomography. The registration process provides an accurate segmentation of each individual vertebra and the ability to derive various measures describing the spinal deformity. The derived measures are estimated from landmarks attached to the spine model and transferred to the patient data according to the registration result. Evaluation of the method provides an average point-to-surface error of 0.9 mm ± 0.9 (comparing segmentations), and an average target registration error of 2.3 mm ± 1.7 (comparing landmarks). Comparing automatic and manual measurements of axial vertebral rotation provides a mean absolute difference of 2.5° ± 1.8, which is on a par with other computerized methods for assessing axial vertebral rotation. A significant advantage of our method, compared to other computerized methods for rotational measurements, is that it does not rely on vertebral symmetry for computing the rotational measures. The proposed method is fully automatic and computationally efficient, only requiring three to four minutes to process an entire image volume covering vertebrae L5 to T1. Given the use of landmarks, the method can be readily adapted to estimate other measures describing a spinal deformity by changing the set of employed landmarks. In addition, the method has the potential to be utilized for accurate segmentations of the vertebrae in routine computed tomography examinations, given the relatively low point-to-surface error.

A 10-Year Retrospective Review of Nephrolithiasis in the Navy and Navy Pilots.

PubMed

Masterson, James H; Phillips, Christopher J; Crum-Cianflone, Nancy F; Krause, Robert J; Sur, Roger L; L'Esperance, James O

2017-08-01

Little is known about the incidence of nephrolithiasis in the United States Navy. Navy pilots must be kidney stone-free and are often referred for treatment of small asymptomatic stones. The primary objectives of this study were to determine the incidence of nephrolithiasis and computerized tomography, proportion undergoing treatment and incidence of stone related mishaps in Navy pilots compared with other Navy personnel. We retrospectively studied the records of all Navy service members from 2002 to 2011 for nephrolithiasis based on ICD-9 stone codes to determine the mentioned rates. We also reviewed NSC (Naval Safety Center) data for a history of accidents associated with nephrolithiasis. Rates of disease were calculated using person-years of followup and inferential statistics were done using univariable and multivariable analyses. We evaluated 667,840 Navy personnel with a total of 3,238,331 person-years of followup. The annual incidence of nephrolithiasis was 240/100,000 person-years with a 5-year recurrence rate of 35.3%. On multivariable analysis pilots had nephrolithiasis incidence and treatment rates similar to those of the overall Navy population. Women had a higher incidence of nephrolithiasis compared with men (OR 1.17, p <0.0001). The rate of computerized tomography was lower in pilots than in the rest of the Navy (39 vs 66/10,000 person-years, p <0.0001). No recorded accidents were associated with kidney stones. Navy pilots had a similar incidence of nephrolithiasis and were no more likely to undergo a surgical procedure. Given that no accidents were associated with nephrolithiasis, this study suggests reconsidering current military policies necessitating pilots to be completely stone-free. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Relations between age, weight, refractive error and eye shape by computerized tomography in children.

PubMed

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung; Moon, Yeon Sung

2007-09-01

To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths/axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years.

Relations between Age, Weight, Refractive Error and Eye Shape by Computerized Tomography in Children

PubMed Central

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung

2007-01-01

Purpose To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Methods Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Results Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths / axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. Conclusions The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years. PMID:17804923

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT AT 2-MONTH INTERVALS REDUCES FOVEAL AVASCULAR ZONE ENLARGEMENT AND VISION LOSS IN RADIATION MACULOPATHY: A Pilot Study.

PubMed

Daruich, Alejandra; Matet, Alexandre; Schalenbourg, Ann; Zografos, Leonidas

2018-05-03

To evaluate, in eyes with radiation maculopathy, the effect of 2-month-interval anti-vascular endothelial growth factor therapy on best-corrected visual acuity and foveal avascular zone (FAZ) enlargement using optical coherence tomography angiography. Consecutive treatment-naive patients with radiation maculopathy after proton beam irradiation for choroidal melanoma were retrospectively included. Clinical and optical coherence tomography angiography data at baseline and the 6-month visit were recorded. Two independent observers measured FAZ area manually on 3 × 3-mm optical coherence tomography angiography images of the superficial capillary plexus and deep capillary plexus. Patients were encouraged to follow strictly a 2-month-interval intravitreal anti-vascular endothelial growth factor treatment by either bevacizumab or ranibizumab. Findings were analyzed based on the adherence to the treatment scheme. According to the adherence to the bimonthly anti-vascular endothelial growth factor treatment protocol, patients were categorized into 3 groups: treatment protocol (n = 19, strict adherence), variable intervals (n = 11, intervals other than 2 months), and no treatment (n = 11). The estimated radiation dose to the foveola in each group was 49 ± 16, 46 ± 17, and 46 ± 18 cobalt gray equivalent, respectively (P = 0.85). For the entire cohort, best-corrected visual acuity loss (P < 0.02) and FAZ enlargement (P < 0.0001) were observed over 6 months. Best-corrected visual acuity loss was significantly less pronounced in the treatment-protocol group than in the variable-interval and no-treatment groups (P = 0.007 and P = 0.004). The FAZ enlargement was lower in the treatment-protocol group compared with the variable-interval group for both superficial capillary plexus (P = 0.029) and deep capillary plexus (P = 0.03), and to the no-treatment group for the deep capillary plexus only (P = 0.016). Decrease in best-corrected visual acuity and FAZ enlargement on optical coherence tomography angiography occurred over 6 months in eyes with radiation maculopathy and were significantly reduced under 2-month-interval anti-vascular endothelial growth factor therapy.

Single photon emission computed tomography (SPECT) in epilepsy

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

Leroy, R.F.

1991-12-31

Epilepsy is a common neurologic disorder which has just begun to be studied with single photon emission computerized tomography (SPECT). Epilepsy usually is studied with electroencephalographic (EEG) techniques that demonstrate the physiologic changes that occur during seizures, and with neuroimaging techniques that show the brain structures where seizures originate. Neither method alone has been adequate to describe the pathophysiology of the patient with epilepsy. EEG techniques lack anatomic sensitivity, and there are no structural abnormalities shown by neuroimaging which are specific for epilepsy. Functional imaging (FI) has developed as a physiologic tool with anatomic sensitivity, and SPECT has been promotedmore » as a FI technique because of its potentially wide availability. However, SPECT is early in its development and its clinical utility for epilepsy still has to be demonstrated. To understand this role of SPECT, consideration must be given to the pathophysiology of epilepsy, brain physiology, types of seizure, epileptic syndromes, and the SPECT technique itself. 44 refs., 2 tabs.« less

NECTAR—A fission neutron radiography and tomography facility

NASA Astrophysics Data System (ADS)

Bücherl, T.; Lierse von Gostomski, Ch.; Breitkreutz, H.; Jungwirth, M.; Wagner, F. M.

2011-09-01

NECTAR (Neutron Computerized Tomography and Radiography) is a versatile facility for radiographic and tomographic investigations as well as for neutron activation experiments using fission neutrons. The radiation sources for this facility are two plates of highly enriched uranium situated in the moderator vessel in FRM II. Thermal neutrons originating from the main fuel element of the reactor generate in these plates fast neutrons. These can escape through a horizontal beam tube without moderation. The beam can be filtered and manipulated in order to reduce the accompanying gamma radiation and to match the specific experimental tasks. A summary of the main parameters required for experimental set-up and (quantitative) data evaluation is presented. The (measured) spectra of the neutron and gamma radiations are shown along with the effect of different filters on their behavior. The neutron and gamma fluxes, dose rates, L/ D-ratios, etc. and the main parameters of the actually used detection systems for neutron imaging are given, too.

Radiosynovectomy of Proximal Interphalangeal Joint Synovitis in Rheumatoid Arthritis Treated with Rhenium-188 Labeled Tin-colloid and Imaging with Single-photon Emission Computerized Tomography/Computed Tomography: A First Case Report.

PubMed

Kamaleshwaran, Koramadai Karuppusamy; Rajamani, Venkataraman; Krishnan, Boopathi; Mallia, Madhav; Kalarikal, Radhakrishnan; Mohanan, Vyshakh; Shinto, Ajit Sugunan

2015-01-01

Rheumatoid arthritis (RA) is a chronic disease that is mainly characterized by the asymmetric erosive synovitis, particularly affecting peripheral joints. Radiation synovectomy or radiosynovectomy (RSV), also known as radiosynoviorthesis was first described in 1950's as an adjuvant treatment for RA. RSV is based on the irradiation of the joint synovium by the intra-articular administration of various β-emitting radiopharmaceuticals. As a generator-produced β-emitting radionuclide, the importance of rhenium-188 (Re-188) for radionuclide therapy is increasing rapidly. There are previous reports which used Re-188 tin colloid in knee joint synovitis, but use of Re-188 tin colloid in small joint is not yet reported. We describe the use of Re-188 tin colloid in a 45-year-old female who presented with right 4(th) proximal interphalangeal joint synovitis due to rheumatoid arthritis.

[Usefulness of computed tomography and magnetic resonance in the preoperative diagnosis for hyperparathyroidism].

PubMed

Pino Rivero, V; Pantoja Hernández, C G; González Palomino, A; Trinidad Ruíz, G; Marcos García, M; Keituqwa Yáñez, T; Pardo Romero, G; Blasco Huelva, A

2005-01-01

Sonnography and Tc-99m sestamibi scintigraphy are the most requested preoperative imaging tests nowdays in the surgery of hyperparathyroidism. The aim of our article is to know if Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) are useful as a location study and in which cases it would be more justified to ask these radiologic techniques. For that we report our results with 29 patients at all diagnosed as hyperparathyroidism (26 primary forms and 3 secondary ones) and operated by our E.N.T. Department later. On 20 of them a cervical CT was asked before the parathyroidectomy and on the rest 9, a MRI with sensitivities of 65% and 88.9% respectively. We think both complementary explorations must not be solicited by routine but they can represent a help in the cases in that sonnography and scintigraphy are not able to show the possible adenoma or hiperplasia, particularly in recurrent hyperparathyroidisms, reinterventions or suspect of parathyroid glands in an atypical location.

Brain imaging and behavioral outcome in traumatic brain injury.

PubMed

Bigler, E D

1996-09-01

Brain imaging studies have become an essential diagnostic assessment procedure in evaluating the effects of traumatic brain injury (TBI). Such imaging studies provide a wealth of information about structural and functional deficits following TBI. But how pathologic changes identified by brain imaging methods relate to neurobehavioral outcome is not as well known. Thus, the focus of this article is on brain imaging findings and outcome following TBI. The article starts with an overview of current research dealing with the cellular pathology associated with TBI. Understanding the cellular elements of pathology permits extrapolation to what is observed with brain imaging. Next, this article reviews the relationship of brain imaging findings to underlying pathology and how that pathology relates to neurobehavioral outcome. The brain imaging techniques of magnetic resonance imaging, computerized tomography, and single photon emission computed tomography are reviewed. Various image analysis procedures, and how such findings relate to neuropsychological testing, are discussed. The importance of brain imaging in evaluating neurobehavioral deficits following brain injury is stressed.

[Human neurocysticercosis in Baixada Fluminense, Rio de Janeiro State, Brazil].

PubMed

Mendes, Ernani Costa; da Silva, Scintilla Santos; Fonseca, Edson Alexandre La' Terza; de Souza, Hilana Regina Ribeiro; de Carvalho, Raimundo Wilson

2005-12-01

The objective of this manuscript was to know the neurocysticercosis prevalence and some epidemiological aspects in Baixada Fluminense, State of Rio de Janeiro, Brazil. The data came from the service of computerized tomography of the Nova Iguaçu General Hospital from 1996 to 2002 and from neuroimage "D'IMAGEM" Center from 1992 to 2002. We analyzed 36,379 tomographies identifying 72 cases of the parasitoses, the majority in women (62.5%, p>0.05) and in the chronic phase (93.1%). The neurocysticercosis had occurred in all age groups and increase with age (r=0.84, p<0.05), being that 45.8% of them up to 50 years. The 20 interviewed cases were origin from several municipal districts of Baixada Fluminense, the monthly per capita income was 366 R dollars. The growing urbanization, deficient sanitary vigilance, absence of sewage systems and sanitary education are the main factors that potentially the transmission of cysticercosis and taeniasis in the Baixada Fluminense.

Atelectasis observed by computerized tomography after Caesarean section.

PubMed

Meira, M N C; Carvalho, C R R; Galizia, M S; Borges, J B; Kondo, M M; Zugaib, M; Vieira, J E

2010-06-01

Atelectasis after either vaginal or Caesarean delivery has not been adequately quantified. This study addresses the hypothesis that atelectasis may be worse in women who undergo Caesarean section when compared with vaginal delivery under regional anaesthesia. Twenty healthy non-smoking women submitted to a chest computed tomography (CT) 2 h after delivery in a University Hospital, who had experienced vaginal delivery (n=10) under combined spinal-epidural analgesia or a Caesarean section (n=10) under spinal anaesthesia, were evaluated. The percentage cross-sectional area of atelectasis in dependent lung regions were measured from the CT images obtained at cross-section of the xiphoid process and the top of the diaphragm. The percentage cross-sectional area of atelectasis was 3.95% in the vaginal delivery group and 14.1% in the Caesarean group (P<0.001, Mann-Whitney rank sum test). These results suggested that pulmonary atelectasis is greater after Caesarean section delivery under spinal anaesthesia than after vaginal delivery with combined spinal-epidural analgesia.

High Resolution Chest Computerized Tomography in the Diagnosis of Ocular Sarcoidosis in a High TB Endemic Population.

PubMed

Babu, Kalpana; Shukla, Sai Bhakti; Philips, Mariamma

2017-04-01

To review the role of high resolution chest computed tomography (HRCT) in ocular sarcoidosis in a high TB endemic population. This was a retrospective study. Out of 140 cases, 54 had ocular sarcoidosis, while 86 cases had ocular tuberculosis. Abnormal HRCT findings was noted in 52 cases (96.3%) of ocular sarcoidosis compared with 55 cases (64.7%) of ocular tuberculosis (p = 0.001). Mediastinal lymphadenopathy was the most common finding in both groups (p = 0.544). Hilar lymphadenopathy and fissural nodules were significantly seen in ocular sarcoidosis (p = 0.001). Necrosis was seen in three cases of ocular sarcoidosis. In nearly half of the cases, it was not possible to differentiate between sarcoidosis and tuberculosis on HRCT. HRCT is a useful diagnostic tool in ocular sarcoidosis. Bilateral hilar lymphadenopathy and fissural nodules are significant findings in ocular sarcoidosis. A confident diagnosis of ocular sarcoidosis is made by the amalgamation of results of clinical, radiologic, and other laboratory investigations.

Orientation-dependent tensile deformation and damage of a T700 carbon fiber/epoxy composite: A synchrotron-based study

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

Bie, B. X.; Huang, J. Y.; Fan, D.

Uniaxial tensile experiments are conducted on a T700 carbon fiber/epoxy composite along various offaxis angles. Stressestrain curves are measured along with strain fields mapped via synchrotron x-ray digital image correlation, as well as computerized tomography. Elastic modulus and tensile strength decrease with increasing off-axis angles, while fracture strain exhibits a nonmonotonic trend as a combined result of tensile strength decrease and fracture mode transition. At high off-axis angles, strain field mapping demonstrates distinct tensile and shear strain localizations and deformation bands approximately along the fiber directions, while deformation is mainly achieved via continuous growth of tensile strain at low off-axismore » angles. Roughness of fracture planes decreases exponentially as the off-axis angle increases. The stressestrain curves, strain fields, tomography and fractographs show consistent features, and reveal a fracture mode transition from mainly tension (fiber fracture) to in-plane shear (interface debonding).« less

Separation of left and right lungs using 3-dimensional information of sequential computed tomography images and a guided dynamic programming algorithm.

PubMed

Park, Sang Cheol; Leader, Joseph Ken; Tan, Jun; Lee, Guee Sang; Kim, Soo Hyung; Na, In Seop; Zheng, Bin

2011-01-01

This article presents a new computerized scheme that aims to accurately and robustly separate left and right lungs on computed tomography (CT) examinations. We developed and tested a method to separate the left and right lungs using sequential CT information and a guided dynamic programming algorithm using adaptively and automatically selected start point and end point with especially severe and multiple connections. The scheme successfully identified and separated all 827 connections on the total 4034 CT images in an independent testing data set of CT examinations. The proposed scheme separated multiple connections regardless of their locations, and the guided dynamic programming algorithm reduced the computation time to approximately 4.6% in comparison with the traditional dynamic programming and avoided the permeation of the separation boundary into normal lung tissue. The proposed method is able to robustly and accurately disconnect all connections between left and right lungs, and the guided dynamic programming algorithm is able to remove redundant processing.

Technology transfer opportunities: new development: computerized field manual provides valuable resource for hydrologic investigations

USGS Publications Warehouse

Chapel, Paul

1996-01-01

The U.S. Geological Survey (USGS) is known throughout the world for conducting quality scientific investigation is hydrologic environments. Proper and consistent field techniques have been an integral part of this good research. Over the past few decades, the USGS has developed and published detailed, standard protocols for conducting studies in most aspects of the hydrologic environment. These protocols have been published in a number of diverse documents. The wealth of information contained in these diverse documents can benefit other scientists in industry, government, and academia that are involved in conducting hydrologic studies. Scientists at the USGS have brought together many of the most important of the field protocols in a user-friendly, graphical-interfaced field manual that will be useful in both the field and in the office. This electronic field manual can assist hydrologists and other scientists in conducting and documenting their field activities in a manner that is recognized standard throughout the hydrologic community.

Comparison of in vivo 3D cone-beam computed tomography tooth volume measurement protocols.

PubMed

Forst, Darren; Nijjar, Simrit; Flores-Mir, Carlos; Carey, Jason; Secanell, Marc; Lagravere, Manuel

2014-12-23

The objective of this study is to analyze a set of previously developed and proposed image segmentation protocols for precision in both intra- and inter-rater reliability for in vivo tooth volume measurements using cone-beam computed tomography (CBCT) images. Six 3D volume segmentation procedures were proposed and tested for intra- and inter-rater reliability to quantify maxillary first molar volumes. Ten randomly selected maxillary first molars were measured in vivo in random order three times with 10 days separation between measurements. Intra- and inter-rater agreement for all segmentation procedures was attained using intra-class correlation coefficient (ICC). The highest precision was for automated thresholding with manual refinements. A tooth volume measurement protocol for CBCT images employing automated segmentation with manual human refinement on a 2D slice-by-slice basis in all three planes of space possessed excellent intra- and inter-rater reliability. Three-dimensional volume measurements of the entire tooth structure are more precise than 3D volume measurements of only the dental roots apical to the cemento-enamel junction (CEJ).

Optimization of a solid-state electron spin qubit using Gate Set Tomography

DOE PAGES

Dehollain, Juan P.; Muhonen, Juha T.; Blume-Kohout, Robin J.; ...

2016-10-13

Here, state of the art qubit systems are reaching the gate fidelities required for scalable quantum computation architectures. Further improvements in the fidelity of quantum gates demands characterization and benchmarking protocols that are efficient, reliable and extremely accurate. Ideally, a benchmarking protocol should also provide information on how to rectify residual errors. Gate Set Tomography (GST) is one such protocol designed to give detailed characterization of as-built qubits. We implemented GST on a high-fidelity electron-spin qubit confined by a single 31P atom in 28Si. The results reveal systematic errors that a randomized benchmarking analysis could measure but not identify, whereasmore » GST indicated the need for improved calibration of the length of the control pulses. After introducing this modification, we measured a new benchmark average gate fidelity of 99.942(8)%, an improvement on the previous value of 99.90(2)%. Furthermore, GST revealed high levels of non-Markovian noise in the system, which will need to be understood and addressed when the qubit is used within a fault-tolerant quantum computation scheme.« less

The APOSTEL recommendations for reporting quantitative optical coherence tomography studies.

PubMed

Cruz-Herranz, Andrés; Balk, Lisanne J; Oberwahrenbrock, Timm; Saidha, Shiv; Martinez-Lapiscina, Elena H; Lagreze, Wolf A; Schuman, Joel S; Villoslada, Pablo; Calabresi, Peter; Balcer, Laura; Petzold, Axel; Green, Ari J; Paul, Friedemann; Brandt, Alexander U; Albrecht, Philipp

2016-06-14

To develop consensus recommendations for reporting of quantitative optical coherence tomography (OCT) study results. A panel of experienced OCT researchers (including 11 neurologists, 2 ophthalmologists, and 2 neuroscientists) discussed requirements for performing and reporting quantitative analyses of retinal morphology and developed a list of initial recommendations based on experience and previous studies. The list of recommendations was subsequently revised during several meetings of the coordinating group. We provide a 9-point checklist encompassing aspects deemed relevant when reporting quantitative OCT studies. The areas covered are study protocol, acquisition device, acquisition settings, scanning protocol, funduscopic imaging, postacquisition data selection, postacquisition data analysis, recommended nomenclature, and statistical analysis. The Advised Protocol for OCT Study Terminology and Elements recommendations include core items to standardize and improve quality of reporting in quantitative OCT studies. The recommendations will make reporting of quantitative OCT studies more consistent and in line with existing standards for reporting research in other biomedical areas. The recommendations originated from expert consensus and thus represent Class IV evidence. They will need to be regularly adjusted according to new insights and practices. © 2016 American Academy of Neurology.

Review of cardiovascular imaging in the Journal of Nuclear Cardiology in 2017. Part 2 of 2: Myocardial perfusion imaging.

PubMed

Hage, Fadi G; AlJaroudi, Wael A

2018-04-16

In 2017, the Journal of Nuclear Cardiology published many high-quality articles. In this review, we will summarize a selection of these articles to provide a concise review of the main advancements that have recently occurred in the field. In the first article of this 2-part series, we focused on publications dealing with positron emission tomography, computed tomography, and magnetic resonance. This review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography summarizing advances in the field including prognosis, safety and tolerability, the impact of imaging on management, and the use of novel imaging protocols.

Quantum gate-set tomography

NASA Astrophysics Data System (ADS)

Blume-Kohout, Robin

2014-03-01

Quantum information technology is built on (1) physical qubits and (2) precise, accurate quantum logic gates that transform their states. Developing quantum logic gates requires good characterization - both in the development phase, where we need to identify a device's flaws so as to fix them, and in the production phase, where we need to make sure that the device works within specs and predict residual error rates and types. This task falls to quantum state and process tomography. But until recently, protocols for tomography relied on a pre-existing and perfectly calibrated reference frame comprising the measurements (and, for process tomography, input states) used to characterize the device. In practice, these measurements are neither independent nor perfectly known - they are usually implemented via exactly the same gates that we are trying to characterize! In the past year, several partial solutions to this self-consistency problem have been proposed. I will present a framework (gate set tomography, or GST) that addresses and resolves this problem, by self-consistently characterizing an entire set of quantum logic gates on a black-box quantum device. In particular, it contains an explicit closed-form protocol for linear-inversion gate set tomography (LGST), which is immune to both calibration error and technical pathologies like local maxima of the likelihood (which plagued earlier methods). GST also demonstrates significant (multiple orders of magnitude) improvements in efficiency over standard tomography by using data derived from long sequences of gates (much like randomized benchmarking). GST has now been applied to qubit devices in multiple technologies. I will present and discuss results of GST experiments in technologies including a single trapped-ion qubit and a silicon quantum dot qubit. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL850.

Computerized Dead-Space Volume Measurement of Face Masks Applied to Simulated Faces.

PubMed

Amirav, Israel; Luder, Anthony S; Halamish, Asaf; Marzuk, Chatib; Daitzchman, Marcelo; Newhouse, Michael T

2015-09-01

The dead-space volume (VD) of face masks for metered-dose inhaler treatments is particularly important in infants and young children with asthma, who have relatively low tidal volumes. Data about VD have been traditionally obtained from water displacement measurements, in which masks are held against a flat surface. Because, in real life, masks are placed against the face, VD is likely to differ considerably between masks depending upon their contour and fit. The aim of this study was to develop an accurate and reliable way to measure VD electronically and to apply this technique by comparing the electronic VD of commonly available face masks. Average digital faces were obtained from 3-dimensional images of 270 infants and children. Commonly used face masks (small and medium) from various manufacturers (Monaghan Medical, Pari Respiratory Equipment, Philips Respironics, and InspiRx) were scanned and digitized by means of computed tomography. Each mask was electronically applied to its respective digital face, and the VD enclosed (mL) was computerized and precisely measured. VD varied between 22.6 mL (SootherMask, InspiRx) and 43.1 mL (Vortex, Pari) for small masks and between 41.7 mL (SootherMask) and 71.5 mL (AeroChamber, Monaghan Medical) for medium masks. These values were significantly lower and less variable than measurements obtained by water displacement. Computerized techniques provide an innovative and relatively simple way of accurately measuring the VD of face masks applied to digital faces. As determined by computerized measurement using average-size virtual faces, the InspiRx masks had a significantly smaller VD for both small and medium masks compared with the other masks. This is of considerable importance with respect to aerosol dose and delivery time, particularly in young children. (ClinicalTrials.gov registration NCT01274299.). Copyright © 2015 by Daedalus Enterprises.

Detection of the source of hemorrhage using postmortem computerized tomographic angiography in a case of a giant juvenile nasopharyngeal angiofibroma after surgical treatment.

PubMed

do Nascimento, Felipe Barjud Pereira; dos Santos, Glaucia Aparecida Bento; Melo, Nelson Almeida d'Ávila; Damasceno, Eduarda Bittencourt; Mauad, Thais

2015-09-01

Postmortem computerized tomographic angiography (PMCTA) has been increasingly used in forensic medicine to detect and locate the source of bleeding in cases of fatal acute hemorrhage. In this paper, we report a case of postoperative complication in a patient with a giant juvenile nasopharyngeal angiofibroma in which the source of bleeding was detected by PMCTA. A case description and evaluations of the pre- and postoperative exams, postmortem CT angiogram, and conventional autopsy results are provided. The source of bleeding was identified by postmortem CT angiography but not by conventional autopsy. The established protocol, injecting contrast medium into the femoral artery, was effective in identifying the source of bleeding. Postoperative bleeding is a rare and frequently fatal complication of juvenile nasopharyngeal angiofibroma. As a complement to conventional autopsy, postmortem angiography is a valuable tool for the detection of lethal acute hemorrhagic foci, and establishing a routine procedure for PMCTA may improve its efficiency.

Role of tDCS in potentiating poststroke computerized cognitive rehabilitation: Lessons learned from a case study.

PubMed

Leo, Antonino; De Luca, Rosario; Russo, Margherita; Naro, Antonino; Bramanti, Placido; Calabrò, Rocco S

2016-01-01

Cognitive impairment after stroke is quite common and can cause important disability with a relevant impact on quality of life. Cognitive rehabilitation (CR) and related assistive technology may improve functional outcomes. A 30-year-old woman came to our research institute for an intensive CR cycle following a right parieto-temporal stroke. Because the patient was in the chronic phase, we decided to use 3 different rehabilitative protocols: (a) traditional cognitive training (TCT), (b) computerized cognitive training (CCT), and (c) CCT combined with transcranial direct stimulation (CCT plus) with a 2-week interval separating each session. Cognitive and language deficits were investigated using an ad-hoc psychometric battery at baseline (T0), post-TCT (T1), post-CCT (T2), and post-CCT plus (T3). Our patient showed the best neuropsychological improvement, with regard to attention processes and language domain, after T3. Our data showed that CCT plus should be considered a promising tool in the treatment of poststroke neuropsychological deficits.

USE OF COMPUTED TOMOGRAPHY FOR INVESTIGATION OF HEPATIC LIPIDOSIS IN CAPTIVE CHELONOIDIS CARBONARIA (SPIX, 1824).

PubMed

Marchiori, Adriano; da Silva, Ieverton Cleiton Correia; de Albuquerque Bonelli, Marília; de Albuquerque Zanotti, Luciana Carla Rameh; Siqueira, Daniel B; Zanotti, Alexandre Pinheiro; Costa, Fabiano Séllos

2015-06-01

Computed tomography is a sensitive and highly applicable technique for determining the degree of radiographic attenuation of the hepatic parenchyma. Radiodensity measurements of the liver can help in the diagnosis of hepatic lipidosis in humans and animals. The objective was to investigate the presence of hepatic lipidosis in captive red-footed tortoises (Chelonoidis carbonaria) using computed tomography. Computed tomography was performed in 10 male red-footed tortoises. Mean radiographic attenuation values for the hepatic parenchyma were 11.2±3.0 Hounsfield units (HU). Seven red-footed tortoises had values lower than 20 HU, which is compatible with C. carbonaria hepatic lipidosis. These results allowed an early diagnosis of the hepatic changes and suggested corrective measures regarding feeding and management protocols.

Optimal Verification of Entangled States with Local Measurements

NASA Astrophysics Data System (ADS)

Pallister, Sam; Linden, Noah; Montanaro, Ashley

2018-04-01

Consider the task of verifying that a given quantum device, designed to produce a particular entangled state, does indeed produce that state. One natural approach would be to characterize the output state by quantum state tomography, or alternatively, to perform some kind of Bell test, tailored to the state of interest. We show here that neither approach is optimal among local verification strategies for 2-qubit states. We find the optimal strategy in this case and show that quadratically fewer total measurements are needed to verify to within a given fidelity than in published results for quantum state tomography, Bell test, or fidelity estimation protocols. We also give efficient verification protocols for any stabilizer state. Additionally, we show that requiring that the strategy be constructed from local, nonadaptive, and noncollective measurements only incurs a constant-factor penalty over a strategy without these restrictions.

Comparison of retinal thickness by Fourier-domain optical coherence tomography and OCT retinal image analysis software segmentation analysis derived from Stratus optical coherence tomography images

NASA Astrophysics Data System (ADS)

Tátrai, Erika; Ranganathan, Sudarshan; Ferencz, Mária; Debuc, Delia Cabrera; Somfai, Gábor Márk

2011-05-01

Purpose: To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). Methods: Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. Results: A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 +/- 8 μm compared to OCTRIMA, and 42 +/- 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. Conclusion: High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device.

MDCT for computerized volumetry of pneumothoraces in pediatric patients.

PubMed

Cai, Wenli; Lee, Edward Y; Vij, Abhinav; Mahmood, Soran A; Yoshida, Hiroyuki

2011-03-01

Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f), respectively. Our automated CAV scheme provides an accurate measurement of pneumothorax volume in MDCT images of pediatric patients. For accurate volumetric quantification of pneumothorax in children in MDCT images by use of the automated CAV scheme, we recommended reconstruction parameters based on a slice thickness ≤1.5 mm and the reconstruction kernel B70f. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

First Branchial Cleft Malformation with Duplication of External Auditory Canal

PubMed Central

Parida, Pradipta Kumar; Raja, Kalairasi; Surianarayanan, Gopalakrishnan; Ganeshan, Sivaraman

2013-01-01

First branchial cleft anomalies are uncommon, accounting for less than 10% of all branchial abnormalities. Their rare occurrence and varied presentation have frequently led to misdiagnosis and inadequate and inappropriate treatment of these conditions leading to repeated recurrences and secondary infection. In this paper, a case of 11-year girl with type 2 first branchial cleft defect is described. She first presented with a nonhealing ulcer of upper neck from childhood. Diagnosis had previously been missed and treated as tubercular ulcer. We confirmed the correct diagnosis by history and computerized tomography fistulogram. The lesion was completely excised with no further recurrence. PMID:24312740

Thyroid tuberculosis: presenting symptom of mediastinal tuberculous lymphadenitis--an unusual case.

PubMed

Chandanwale, Shirish S; Buch, Archana C; Vimal, Shruti S; Sachdeva, Punita

2014-01-01

Tuberculosis of thyroid gland is extremely rare. It spreads to thyroid by lymphogenous or heamatogenous route or from adjacent focus, either from larynx or cervical and mediastinal adenitis. We report an unusual case of a 33-year-old male with thyroid swelling. Fine needle aspiration (FNA) smears showed epithelioid cells without necrosis and acid fast bacilli (AFB). Subsequent investigation revealed mediastinal tuberculous lymphadenitis on Computerized Tomography (CT) scan. FNA confirmed the diagnosis of mediastinal tuberculous lymphadenitis. We conclude, when epithelioid cells are seen on FNA thyroid, tuberculosis must be ruled out especially in regions where there is high prevalence of tuberculosis.

[Bronchogenic esophageal cysts in the adult. Four cases].

PubMed

Fékété, F; Rongère, C; Foulon, J P; Molas, G

1988-05-07

Bronchogenic oesophageal cysts possess a mucosa of the airway type but are unconnected to the tracheobronchial tree; they are in close anatomical relation with the oesophageal wall. These characteristics are explained by the fact that the respiratory and digestive tract share the same embryonic development. Four cases of bronchogenic oesophageal cyst are reported, and 21 well-documented cases from the literature are reviewed. The lesion is extremely rare in adults, often complicated and responsible for gastrointestinal, respiratory and sometimes even cardiac symptoms. Its features at radiology, endoscopy and computerized tomography are suggestive of the diagnosis. Treatment consists of excision by enucleation. Excision must be complete for recurrences to be avoided.

An Unusual Reason for Gastric Variceal Hemorrhage: Wandering Spleen.

PubMed

Köseoğlu, Hüseyin; Atalay, Roni; Büyükaşık, Naciye Şemnur; Canyiğit, Murat; Özer, Mehmet; Solakoğlu, Tevfik; Akın, Fatma Ebru; Bolat, Aylin Demirezer; Yürekli, Öykü Tayfur; Ersoy, Osman

2015-12-01

Wandering spleen is the displacement of the spleen due to the loss or weakening of the ligaments of the spleen and is seen very rarely with an incidence of less than 0.5 %. It can cause portal hypertension, but gastric variceal hemorrhage is a quite rare condition within the spectrum of this uncommon disease. We report a 22-year-old woman with wandering spleen presenting with life-threatening gastric variceal hemorrhage. Her diagnosis was made by computerized tomography. Endoscopic therapy was not adequate to stop the bleeding, and urgent splenectomy was performed. After surgery she has been well with no symptoms until now.

Acoustic beam control in biomimetic projector via velocity gradient

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

Gao, Xiaowei; Dong, Erqian; Song, Zhongchang

A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

Acoustic beam control in biomimetic projector via velocity gradient

NASA Astrophysics Data System (ADS)

Gao, Xiaowei; Zhang, Yu; Cao, Wenwu; Dong, Erqian; Song, Zhongchang; Li, Songhai; Tang, Liguo; Zhang, Sai

2016-07-01

A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

Significance of postshunt ventricular asymmetries.

PubMed

Linder, M; Diehl, J T; Sklar, F H

1981-08-01

Ventricular asymmetries after shunt surgery were studied. Right and left ventricular areas from pre-and postoperative computerized tomography scans were measured with a computer digitizing technique, and the respective areas were expressed as a ratio. Measurements were made from the scans of 15 hydrocephalic children selected at random. Ages at surgery ranged from 1 to 101 weeks. The results indicate a significantly greater decrease in ventricular size on the side of the ventricular shunt catheter. Multiple regression analysis showed no relationship between the magnitude of change in ventricular size and either the patients' age orn the time intervals between surgery and follow-up scans. Possible mechanisms for these postshunt ventricular asymmetries are discussed.

Secondary signet-ring cell adenocarcinoma of urinary bladder from a gastric primary

PubMed Central

Sharma, Pramod K.; Vijay, Mukesh K.; Das, Ranjit K.; Chatterjee, Uttara

2011-01-01

Primary bladder tumor is a frequent urological malignancy, whereas the incidence of secondary bladder tumor from a distant organ is quite rare. Secondary bladder neoplasms represent 1% of all malignant bladder tumors, of which distant metastases from stomach account for about 4% of cases. We present the case of a 30-year-old male who underwent partial gastrectomy for Signet-ring cell carcinoma of the stomach and presented 2 years later with hematuria. On computerized tomography scan, a bladder tumor was found which was resected cystoscopically. The histopathological examination revealed secondary Signet-ring cell adenocarcinoma of the urinary bladder. PMID:21747602

Endodontic management of a mandibular first molar with six root canal systems.

PubMed

Jain, Dilip; Reddy, Smitha; Venigalla, Bhuvan Shome; Kamishetty, Shekhar

2015-01-01

Internal anatomy of pulp is complex. The first mandibular molars typically have two roots, one mesial with two root canals and another distal root, which contains one or two canals. A 20-year-old female patient reported with intermittent pain and incomplete root canal treatment in left lower back region since 1-week. Refined access cavity revealed initially two canals in mesial and two canals in the distal root. With operating microscope and cone beam computerized tomography, two additional canals (L-mesio-buccal and B-mesio-lingual) were identified in mesial root. One-year follow-up showed patient was asymptomatic and complete healing of periapical radiolucency.

[Imaging of temporo-mandibular disorders].

PubMed

Felizardo, Rufino; Foucart, Jean-Michel; Pizelle, Christophe

2012-03-01

Dominated for years by standard films (tomographic mouth open and mouth closed X-rays, MRI) radiographs of the TMJ have progressively lost their usefulness to diagnosticians who have progressively increased their reliance on well codified clinical examinations, which suffice in a great majority of cases.The indications for and diagnostic worth of radiological studies and the impact they have on the management of TMJ disorders are today quite low especially when the high cost of procedures like MRI, computerized tomography, and CBCT is taken into account. In this article we discuss the various maladies that dentists might encounter and the situations in which radiological examinations are still indicated. © EDP Sciences, SFODF, 2012.

Cerebral edema, mass effects, and regional blood volume in man.

PubMed

Penn, R D; Kurtz, D

1977-03-01

The authors conducted quantitative analysis of computerized tomography (CT) scans to measure tumor size, cerebral edema, and regional blood volume in man. Mass lesions without edema caused a local reduction in blood volume. Cerebral edema also reduced blood volume in proportion to its severity. Consideration of the electrolyte changes and water shifts in white-matter edema suggested that the decrease in absorption coefficient seen in CT scans was due to the increase in water content. Thus, in cerebral edema separation of blood vessels as well as increased interstitial pressure decrease blood volume, and the regional differences in turn reflect pressure gradients within the brain.

Evaluation with stabilometric platform of balance disorders in osteoporosis patients. A proposal for a diagnostic protocol.

PubMed

Cultrera, Pina; Pratelli, Elisa; Petrai, Veronica; Postiglione, Marco; Zambelan, Giulia; Pasquetti, Pietro

2010-05-01

Osteoporosis is a systemic disease with reduced bone mass and qualitative alterations of the bone, associated to increased risk of fracture. Pathogenesis of osteoporosis fractures is multifactorial. Main risk factor is falls (except for vertebral fragility fractures which occurs often in absence of trauma). Aging by itself produces physiological changes: muscular hypotrophy with asthenia, deficit of visus and hearing together with associated pathologies and multi-drug therapies. In osteoporosis patients with vertebral fractures posture change occurs which reduces balance. After clinical postural evaluation it is possible to carry out instrumental evaluation of posture with computerized methods such as stabilometry, baropodometry, dynanometry and gait analysis. Examination carried out with use of stabilometric computerized platform allows stabilometric (body sway assessment) as well as posturometric examination (center of pressure assessment during quiet standing). Fundamental parameters obtained are: position of the body center of gravity, area and shape of sway density curve and velocity variables. Protocol of evaluation includes assessment of examination in standard condition and in condition of temporary sensorial deprivation (to investigate the influence of various afferent systems on the maintenance of posture and balance). Accurate evaluation of postural control in osteoporosis patients constitutes a fundamental tool in fracture risk evaluation due to fall and in identification and correction of modifiable factors responsible for balance defect. This approach, together with adequate drug therapy, may lead to significant reduction of fractures in osteoporosis patients with subsequent reduction of hospitalization and residual consequent disabilities.

Quantitative assessment on coronary computed tomography angiography (CCTA) image quality: comparisons between genders and different tube voltage settings

PubMed Central

Chian, Teo Chee; Nassir, Norziana Mat; Ibrahim, Mohd Izuan; Yusof, Ahmad Khairuddin Md

2017-01-01

Background This study was carried out to quantify and compare the quantitative image quality of coronary computed tomography angiography (CCTA) between genders as well as between different tube voltages scan protocols. Methods Fifty-five cases of CCTA were collected retrospectively and all images including reformatted axial images at systolic and diastolic phases as well as images with curved multi planar reformation (cMPR) were obtained. Quantitative image quality including signal intensity, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of right coronary artery (RCA), left anterior descending artery (LAD), left circumflex artery (LCx) and left main artery (LM) were quantified using Analyze 12.0 software. Results Six hundred and fifty-seven coronary arteries were evaluated. There were no significant differences in any quantitative image quality parameters between genders. 100 kilovoltage peak (kVp) scanning protocol produced images with significantly higher signal intensity compared to 120 kVp scanning protocol (P<0.001) in all coronary arteries in all types of images. Higher SNR was also observed in 100 kVp scan protocol in all coronary arteries except in LCx where 120 kVp showed better SNR than 100 kVp. Conclusions There were no significant differences in image quality of CCTA between genders and different tube voltages. Lower tube voltage (100 kVp) scanning protocol is recommended in clinical practice to reduce the radiation dose to patient. PMID:28275559

Dense concentric circle scanning protocol for measuring pulsatile retinal blood flow in rats with Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Tan, Bingyao; Hosseinaee, Zohreh; Bizheva, Kostadinka

2017-11-01

The variability in the spatial orientation of retinal blood vessels near the optic nerve head (ONH) results in imprecision of the measured Doppler angle and therefore the pulsatile blood flow (BF), when those parameters are evaluated using Doppler OCT imaging protocols based on dual-concentric circular scans. Here, we utilized a dense concentric circle scanning protocol and evaluated its precision for measuring pulsatile retinal BF in rats for different numbers of the circular scans. An spectral domain optical coherence tomography (SD-OCT) system operating in the 1060-nm spectral range with image acquisition rate of 47,000 A-scans/s was used to acquire concentric circular scans centered at the rat's ONH, with diameters ranging from 0.8 to 1.0 mm. A custom, automatic blood vessel segmentation algorithm was used to track the spatial orientation of the retinal blood vessels in three dimensions, evaluate the spatially dependent Doppler angle and calculate more accurately the axial BF for each major retinal blood vessel. Metrics such as retinal BF, pulsatility index, and resistance index were evaluated for each and all of the major retinal blood vessels. The performance of the proposed dense concentric circle scanning protocols was compared with that of the dual-circle scanning protocol. Results showed a 3.8±2.2 deg difference in the Doppler angle calculation between the two approaches, which resulted in ˜7% difference in the calculated retinal BF.

3.0Tesla magnetic resonance angiography (MRA) for comprehensive renal evaluation of living renal donors: pilot study with computerized tomography angiography (CTA) comparison.

PubMed

Gulati, Mittul; Dermendjian, Harout; Gómez, Ana M; Tan, Nelly; Margolis, Daniel J; Lu, David S; Gritsch, H Albin; Raman, Steven S

2016-01-01

Most living related donor (LRD) kidneys are harvested laparoscopically. Renal vascular anatomy helps determine donor suitability for laparoscopic nephrectomy. Computed tomography angiography (CTA) is the current gold standard for preoperative imaging; magnetic resonance angiography (MRA) offers advantages including lack of ionizing radiation and lower incidence of contrast reactions. We evaluated 3.0T MRA for assessing renal anatomy of LRDs. Thirty consecutive LRDs underwent CTA followed by 3.0T MRA. Data points included number and branching of vessels, incidental findings, and urothelial opacification. Studies were individually evaluated by three readers blinded to patient data. Studies were reevaluated in consensus with discrepancies revealed, and final consensus results were labeled "truth". Compared with consensus "truth", both computed tomography (CT) and magnetic resonance imaging were highly accurate for assessment of arterial and venous anatomy, although CT was superior for detection of late venous confluence as well as detection of renal stones. Both modalities were comparable in opacification of lower ureters and bladder; MRA underperformed CTA for opacification of upper urinary tracts. 3.0T MRA enabled excellent detection of comprehensive renal anatomy compared to CTA in LRDs. Copyright © 2016 Elsevier Inc. All rights reserved.

A method for volume determination of the orbit and its contents by high resolution axial tomography and quantitative digital image analysis.

PubMed Central

Cooper, W C

1985-01-01

The various congenital and acquired conditions which alter orbital volume are reviewed. Previous investigative work to determine orbital capacity is summarized. Since these studies were confined to postmortem evaluations, the need for a technique to measure orbital volume in the living state is presented. A method for volume determination of the orbit and its contents by high-resolution axial tomography and quantitative digital image analysis is reported. This procedure has proven to be accurate (the discrepancy between direct and computed measurements ranged from 0.2% to 4%) and reproducible (greater than 98%). The application of this method to representative clinical problems is presented and discussed. The establishment of a diagnostic system versatile enough to expand the usefulness of computerized axial tomography and polytomography should add a new dimension to ophthalmic investigation and treatment. Images FIGURE 8 FIGURE 9 FIGURE 10 A FIGURE 10 B FIGURE 11 A FIGURE 11 B FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 15 FIGURE 16 FIGURE 17 FIGURE 18 FIGURE 19 FIGURE 20 FIGURE 21 FIGURE 22 FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 26 A FIGURE 26 B FIGURE 27 FIGURE 28 FIGURE 29 FIGURE 30 FIGURE 31 FIGURE 32 PMID:3938582

Ionospheric tomography using Faraday rotation of Automatic Dependent Surveillance Broadcast (UHF) signals Ionospheric Measurement From ADS-B Signals

NASA Astrophysics Data System (ADS)

Cushley, Alex Clay

The proposed launch of a CubeSat carrying the first space-borne ADS-B receiver by RMCC will create a unique opportunity to study the modification of radio waves following propagation through the ionosphere as the signals propagate from the transmitting aircraft to the passive satellite receiver(s). Experimental work is described which successfully demonstrated that ADS-B data can be used to reconstruct two-dimensional electron density maps of the ionosphere using techniques from computerized tomography. Ray-tracing techniques are used to determine the characteristics of individual waves, including the wave path and the state of polarization at the satellite receiver. The modelled Faraday rotation is determined and converted to TEC along the ray-paths. The resulting TEC is used as input for CIT using ART. This study concentrated on meso-scale structures 100--1000 km in horizontal extent. The primary scientific interest of this thesis was to show the feasibility of a new method to image the ionosphere and obtain a better understanding of magneto-ionic wave propagation. Keywords: Automatic Dependent Surveillance-Broadcast (ADS-B), Faraday rotation, electromagnetic (EM) waves, radio frequency (RF) propagation, ionosphere (auroral, irregularities, instruments and techniques), electron density profile, total electron content (TEC), computer ionospheric tomography (CIT), algebraic reconstruction technique (ART).

The early detection of antral malignancy in the postmaxillectomy patient

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

Som, P.M.; Shugar, J.M.; Biller, H.F.

1982-05-01

A protocol was developed for the radiographic evaluation of the postmaxillectomy patient that called for a six- to eight-week postoperative, baseline computed tomography (CT) scan, followed by CT scans at four- to six-month intervals for at least three years. This protocol allowed for an early, more complete assessment of clinically discovered recurrences and the detection of clinically occult recurrences in three out of 18 patients who followed the protocol. The CT appearance of the normal partial and total maxillectomy is discussed, as well as the focal nodular soft-tissue findings suggestive of recurrent disease.

Epidemiological study of a von Hippel-Lindau family in northwest China.

PubMed

Zhang, Jingyao; Wu, Dapeng; Ai, Hong; Bai, Jigang; Dong, Shunbin; Yang, Qinling; Qu, Kai; Zhou, Lei; Xu, Xinsen; Liu, Chang

2013-09-01

von Hippel-Lindau (VHL) disease is a rare, inherited neoplastic disease characterized by hemangioblastomas (HBL) of the central nervous system (CNS), retinal angiomas, renal cell carcinomas (RCC), pancreatic endocrine tumors (PETs), pheochromocytomas, paragangliomas, and visceral cysts. We encountered a large VHL family in northwest China and conducted a systematic screening of the family members based on their epidemiological and clinical characteristics. A self-designed questionnaire was used to collect the general sociodemographic and health information of the family members. For the preliminary family screening, physical examination and abdomen B ultrasonography were performed. The suspected patients were subjected to cranial computerized tomography and fundus examination. The clinical data of the patients with confirmed VHL disease were collected from hospital records. A total of 63 lineal descendants in six generations were observed in the family (generations O, A, B, C, D, E), including 9 dead suspected cases (6 males, 3 females) and 10 living cases (2 males, 8 females). Among the 10 living cases, 4, 2, 1, 3, 4, 8, and 2 manifested HBLs of the CNS, PETs, RCC, pancreatic cysts, renal cysts, pheochromocytomas (4 hemi and 4 bilateral), and paragangliomas, respectively. Data showed that the morbidity of VHL disease in generation C was lower than that in generation B, but the age of onset was younger. This study is the first to report VHL disease in northwest China and VHL-associated PET cases in Chinese. Therefore, follow-up checkups of the family should be focused on younger generations. Proper family screening protocols should be followed for the treatment of patients with VHL disease.

Neuroblastoma: treatment outcome after incomplete resection of primary tumors.

PubMed

Moon, Suk-Bae; Park, Kwi-Won; Jung, Sung-Eun; Youn, Woong-Jae

2009-09-01

For International Neuroblastoma Staging System (INSS) stages III or IV neuroblastoma (intermediate or high risk), complete excision of the primary tumor is not always feasible. Most current studies on the treatment outcome of these patients have reported on the complete excision status. The aim of this study is to review the treatment outcome after the incomplete resection. The medical records of 37 patients that underwent incomplete resection between January 1986 and December 2005 were reviewed retrospectively. Incomplete resection was assessed by review of the operative notes and postoperative computerized tomography. Age, gender, tumor location, INSS stage, N-myc gene copy number, pre- and postoperative therapy, and treatment outcome were reviewed. The treatment outcome was evaluated according to the postoperative treatment protocol in the high-risk group. Intermediate-risk patients were treated with conventional chemotherapy, isotretinoin (ITT) and interleukin-2 (IL-2). High-risk patients were treated with peripheral blood stem cell transplantation (PBSCT), ITT, and IL-2 (N = 11). Before the introduction of PBSCT, the high-risk patients were also treated with the conventional chemotherapy (N = 19). Intermediate-risk patients (N = 5) currently have no evidence of disease (NED). For the high-risk patients (N = 32), 19 patients were treated with chemotherapy alone; 15 patients died of their disease while four patients currently have an NED status. Eight of 11 patients that underwent PBSCT are currently alive. For intermediate risk, conventional chemotherapy appears to be acceptable treatment. However, for high-risk patients, every effort should be made to control residual disease including the use of myeloablative chemotherapy, differentiating agents and immune-modulating agents.

Low tube voltage computed tomography urography using low-concentration contrast media: Comparison of image quality in conventional computed tomography urography.

PubMed

Hwang, Inpyeong; Cho, Jeong Yeon; Kim, Sang Youn; Oh, Seung-June; Ku, Ja Hyeon; Lee, Joongyup; Kim, Seung Hyup

2015-12-01

The aim of the present study was to investigate the feasibility and image quality of excretory CT urography performed using low iodine-concentration contrast media and low tube voltage. This prospective study enrolled 63 patients who undergoing CT urography. The subjects were randomized into two groups of an excretory phase CT urography protocol and received either 240 mg I/mL of contrast media and 80 kVp of tube voltage (low-concentration protocol, n=32) or 350 mg I/mL and 120 kVp (conventional protocol, n=31). Two readers qualitatively evaluated images for sharpness of the urinary tract, image noise, streak artifact and overall diagnostic acceptability. The mean attenuation, signal-to-noise ratio, contrast-to-noise ratio and figure of merit were measured in the urinary tract. The non-inferiority test assessed the diagnostic acceptability between the two protocol groups. The low-concentration protocol showed a significantly lower effective radiation dose (3.44 vs. 5.70 mSv, P<.001). The diagnostic acceptability was significantly lower in the low-concentration protocol with iterative reconstruction algorithm than in the conventional protocol (4.06±0.45 vs. 4.50±0.37, P<.001), however, all subjects showed at least more than standard diagnostic acceptability and the difference resided in the predefined non-inferiority margin. The signal-to-noise ratio, contrast-to-noise ratio and figure of merit were significantly higher in the low-concentration protocol along the entire urinary tract (P<.001). CT urography using 240 mg I/mL iodine contrast media, 80 kVp tube voltage and an iterative reconstruction algorithm is beneficial to reduce radiation dose and iodine load, and its objective image quality and subjective diagnostic acceptability is not inferior to that of conventional CT urography. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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.

Tomographic quantum cryptography

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

Liang, Yeong Cherng; Kaszlikowski, Dagomir; Englert, Berthold-Georg

2003-08-01

We present a protocol for quantum cryptography in which the data obtained for mismatched bases are used in full for the purpose of quantum state tomography. Eavesdropping on the quantum channel is seriously impeded by requiring that the outcome of the tomography is consistent with unbiased noise in the channel. We study the incoherent eavesdropping attacks that are still permissible and establish under which conditions a secure cryptographic key can be generated. The whole analysis is carried out for channels that transmit quantum systems of any finite dimension.

Improved algorithm for computerized detection and quantification of pulmonary emphysema at high-resolution computed tomography (HRCT)

NASA Astrophysics Data System (ADS)

Tylen, Ulf; Friman, Ola; Borga, Magnus; Angelhed, Jan-Erik

2001-05-01

Emphysema is characterized by destruction of lung tissue with development of small or large holes within the lung. These areas will have Hounsfield values (HU) approaching -1000. It is possible to detect and quantificate such areas using simple density mask technique. The edge enhancement reconstruction algorithm, gravity and motion of the heart and vessels during scanning causes artefacts, however. The purpose of our work was to construct an algorithm that detects such image artefacts and corrects them. The first step is to apply inverse filtering to the image removing much of the effect of the edge enhancement reconstruction algorithm. The next step implies computation of the antero-posterior density gradient caused by gravity and correction for that. Motion artefacts are in a third step corrected for by use of normalized averaging, thresholding and region growing. Twenty healthy volunteers were investigated, 10 with slight emphysema and 10 without. Using simple density mask technique it was not possible to separate persons with disease from those without. Our algorithm improved separation of the two groups considerably. Our algorithm needs further refinement, but may form a basis for further development of methods for computerized diagnosis and quantification of emphysema by HRCT.

The association of malocclusion and trumpet performance.

PubMed

Kula, Katherine; Cilingir, H Zeynep; Eckert, George; Dagg, Jack; Ghoneima, Ahmed

2016-01-01

To determine whether trumpet performance skills are associated with malocclusion. Following institutional review board approval, 70 university trumpet students (54 male, 16 female; aged 20-38.9 years) were consented. After completing a survey, the students were evaluated while playing a scripted performance skills test (flexibility, articulation, range, and endurance exercises) on their instrument in a soundproof music practice room. One investigator (trumpet teacher) used a computerized metronome and a decibel meter during evaluation. A three-dimensional (3D) cone-beam computerized tomography scan (CBCT) was taken of each student the same day as the skills test. Following reliability studies, multiple dental parameters were measured on the 3D CBCT. Nonparametric correlations (Spearman), accepting P < .05 as significant, were used to determine if there were significant associations between dental parameters and the performance skills. Intrarater reliability was excellent (intraclass correlations; all r values > .94). Although associations were weak to moderate, significant negative associations (r ≤ -.32) were found between Little's irregularity index, interincisal inclination, maxillary central incisor rotation, and various flexibility and articulation performance skills, whereas significant positive associations (r ≤ .49) were found between arch widths and various skills. Specific malocclusions are associated with trumpet performance of experienced young musicians.

Bringing Standardized Processes in Atom-Probe Tomography: I Establishing Standardized Terminology

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

Anderson, Ian M; Danoix, F; Forbes, Richard

2011-01-01

Defining standardized methods requires careful consideration of the entire field and its applications. The International Field Emission Society (IFES) has elected a Standards Committee, whose task is to determine the needed steps to establish atom-probe tomography as an accepted metrology technique. Specific tasks include developing protocols or standards for: terminology and nomenclature; metrology and instrumentation, including specifications for reference materials; test methodologies; modeling and simulations; and science-based health, safety, and environmental practices. The Committee is currently working on defining terminology related to atom-probe tomography with the goal to include terms into a document published by the International Organization for Standardsmore » (ISO). A lot of terms also used in other disciplines have already been defined) and will be discussed for adoption in the context of atom-probe tomography.« less

Radiation dose to the eyes and parotids during CT of the sinuses.

PubMed

Bassim, Marc K; Ebert, Charles S; Sit, Roger C; Senior, Brent A

2005-10-01

To measure the radiation dose to the lens and parotid during high-resolution computed tomography scan of the sinuses. Nine cadaver heads were scanned in the axial plane by means of a fine-cut (0.75 mm) protocol. Images were then reconstructed in the coronal and sagittal planes for use with the image guidance software. Thermoluminescent dosimeters were taped over the eyes and parotids and used to measure the radiation dose absorbed by these organs. Doses obtained were 29.5 mGy for the lens and around 30 mGy for the parotid. The measured doses are lower than the reported acute thresholds of 500-2000 mGy for lens opacities and well below the threshold of 2500 mGy for damage to the parotid. These results demonstrate minimal risk from radiation through the use of high-resolution computed tomography and support the use of such a protocol for diagnosis and preoperative planning.

Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET.

PubMed

Dantas, Roberto Nery; Assuncao, Antonildes Nascimento; Marques, Ismar Aguiar; Fahel, Mateus Guimaraes; Nomura, Cesar Higa; Avila, Luiz Francisco Rodrigues; Giorgi, Maria Clementina Pinto; Soares, Jose; Meneghetti, Jose Claudio; Parga, Jose Rodrigues

2018-06-01

Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography ( 82 RbPET) MPI. Thus, this study aimed to evaluate agreement between 82 RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients. Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress 82 RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software. There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv). There was a significant agreement between dipyridamole stress 320-CT MPI and 82 RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure. • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

A novel ultrafast-low-dose computed tomography protocol allows concomitant coronary artery evaluation and lung cancer screening.

PubMed

Gaudio, Carlo; Petriello, Gennaro; Pelliccia, Francesco; Tanzilli, Alessandra; Bandiera, Alberto; Tanzilli, Gaetano; Barillà, Francesco; Paravati, Vincenzo; Pellegrini, Massimo; Mangieri, Enrico; Barillari, Paolo

2018-05-08

Cardiac computed tomography (CT) is often performed in patients who are at high risk for lung cancer in whom screening is currently recommended. We tested diagnostic ability and radiation exposure of a novel ultra-low-dose CT protocol that allows concomitant coronary artery evaluation and lung screening. We studied 30 current or former heavy smoker subjects with suspected or known coronary artery disease who underwent CT assessment of both coronary arteries and thoracic area (Revolution CT, General Electric). A new ultrafast-low-dose single protocol was used for ECG-gated helical acquisition of the heart and the whole chest. A single IV iodine bolus (70-90 ml) was used. All patients with CT evidence of coronary stenosis underwent also invasive coronary angiography. All the coronary segments were assessable in 28/30 (93%) patients. Only 8 coronary segments were not assessable in 2 patients due to motion artefacts (assessability: 98%; 477/485 segments). In the assessable segments, 20/21 significant stenoses (> 70% reduction of vessel diameter) were correctly diagnosed. Pulmonary nodules were detected in 5 patients, thus requiring to schedule follow-up surveillance CT thorax. Effective dose was 1.3 ± 0.9 mSv (range: 0.8-3.2 mSv). Noteworthy, no contrast or radiation dose increment was required with the new protocol as compared to conventional coronary CT protocol. The novel ultrafast-low-dose CT protocol allows lung cancer screening at time of coronary artery evaluation. The new approach might enhance the cost-effectiveness of coronary CT in heavy smokers with suspected or known coronary artery disease.

Diagnostic performance of a streamlined 18F-choline PET-CT protocol for the detection of prostate carcinoma recurrence in combination with appropriate-use criteria.

PubMed

Frood, R; Baren, J; McDermott, G; Bottomley, D; Patel, C; Scarsbrook, A

2018-04-30

To evaluate the efficacy of single time-point half-body (skull base to thighs) fluorine-18 choline positron emission tomography-computed tomography (PET-CT) compared to a triple-phase acquisition protocol in the detection of prostate carcinoma recurrence. Consecutive choline PET-CT studies performed at a single tertiary referral centre in patients with biochemical recurrence of prostate carcinoma between September 2012 and March 2017 were reviewed retrospectively. The indication for the study, imaging protocol used, imaging findings, whether management was influenced by the PET-CT, and subsequent patient outcome were recorded. Ninety-one examinations were performed during the study period; 42 were carried out using a triple-phase protocol (dynamic pelvic imaging for 20 minutes after tracer injection, half-body acquisition at 60 minutes and delayed pelvic scan at 90 minutes) between 2012 and August 2015. Subsequently following interim review of diagnostic performance, a streamlined protocol and appropriate-use criteria were introduced. Forty-nine examinations were carried out using the single-phase protocol between 2015 and 2017. Twenty-nine (69%) of the triple-phase studies were positive for recurrence compared to 38 (78%) of the single-phase studies. Only one patient who had a single-phase study would have benefited from a dynamic acquisition, they have required no further treatment or imaging and are currently under prostate-specific antigen (PSA) surveillance. Choline PET-CT remains a useful tool for the detection of prostate recurrence when used in combination with appropriate-use criteria. Removal of dynamic and delayed acquisition phases reduces study time without adversely affecting accuracy. Benefits include shorter imaging time which improves patient comfort, reduced cost, and improved scanner efficiency. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Ejection fraction in myocardial perfusion imaging assessed with a dynamic phantom: comparison between IQ-SPECT and LEHR.

PubMed

Hippeläinen, Eero; Mäkelä, Teemu; Kaasalainen, Touko; Kaleva, Erna

2017-12-01

Developments in single photon emission tomography instrumentation and reconstruction methods present a potential for decreasing acquisition times. One of such recent options for myocardial perfusion imaging (MPI) is IQ-SPECT. This study was motivated by the inconsistency in the reported ejection fraction (EF) and left ventricular (LV) volume results between IQ-SPECT and more conventional low-energy high-resolution (LEHR) collimation protocols. IQ-SPECT and LEHR quantitative results were compared while the equivalent number of iterations (EI) was varied. The end-diastolic (EDV) and end-systolic volumes (ESV) and the derived EF values were investigated. A dynamic heart phantom was used to produce repeatable ESVs, EDVs and EFs. Phantom performance was verified by comparing the set EF values to those measured from a gated multi-slice X-ray computed tomography (CT) scan (EF True ). The phantom with an EF setting of 45, 55, 65 and 70% was imaged with both IQ-SPECT and LEHR protocols. The data were reconstructed with different EI, and two commonly used clinical myocardium delineation software were used to evaluate the LV volumes. The CT verification showed that the phantom EF settings were repeatable and accurate with the EF True being within 1% point from the manufacture's nominal value. Depending on EI both MPI protocols can be made to produce correct EF estimates, but IQ-SPECT protocol produced on average 41 and 42% smaller EDV and ESV when compared to the phantom's volumes, while LEHR protocol underestimated volumes by 24 and 21%, respectively. The volume results were largely similar between the delineation methods used. The reconstruction parameters can greatly affect the volume estimates obtained from perfusion studies. IQ-SPECT produces systematically smaller LV volumes than the conventional LEHR MPI protocol. The volume estimates are also software dependent.

Development of a patient simulator for teaching and evaluation of the basic cardio-pulmonary reanimation protocol.

PubMed

Villagómez, C; Suarez, F; Gómez, S; Dávila, A; Vega-Gonzalez, A; Gómez-González, J

2011-01-01

Providing appropriate cardio-pulmonary reanimation after cardio-pulmonary arrest is paramount for survival. An effective and low-cost approach to learn and practice the cardio-pulmonary reanimation is through a computerized life-size patient simulator. The present work describes the development of a patient simulator for the Centre of Education and Certification of Medical Aptitudes (CECAM) from the UNAM's Faculty of Medicine. This patient simulator has many new and innovative features, such real-time feedback to the medical student, which improves the whole teaching/learning experience.

CAD/CAM guided surgery in implant dentistry. A review of software packages and step-by-step protocols for planning surgical guides.

PubMed

Scherer, Michael D; Kattadiyil, Mathew T; Parciak, Ewa; Puri, Shweta

2014-01-01

Three-dimensional radiographic imaging for dental implant treatment planning is gaining widespread interest and popularity. However, application of the data from 30 imaging can be a complex and daunting process initially. The purpose of this article is to describe features of three software packages and the respective computerized guided surgical templates (GST) fabricated from them. A step-by-step method of interpreting and ordering a GST to simplify the process of the surgical planning and implant placement is discussed.

Decision aid on radioactive iodine treatment for early stage papillary thyroid cancer: update to study protocol with follow-up extension.

PubMed

Sawka, Anna M; Straus, Sharon; Rodin, Gary; Thorpe, Kevin E; Ezzat, Shereen; Gafni, Amiram; Goldstein, David P

2015-07-14

Patient decision aids (P-DAs) are used to inform patients about healthcare choices, but there is limited knowledge about their longer term effects, beyond the time period of decision-making. We developed a computerized P-DA that explains the choice of radioactive iodine (RAI) adjuvant treatment or no RAI, for patients with low risk papillary thyroid cancer after total thyroidectomy. The original protocol for a randomized controlled trial, comparing the use of the P-DA (with usual care) to usual care alone, has been published in Trials http://www.trialsjournal.com/content/11/1/81. We found that P-DA (with usual care) significantly improved patients' medical knowledge at the time of decision-making (primary outcome) compared to usual care alone (control). In this update, we present the protocol for an extended follow-up study (15 to 23 months post-randomization), including qualitative and quantitative methods. The patient outcomes evaluated using quantitative questionnaires include: the degree to which patients feel well-informed about their RAI treatment choice, decision satisfaction, decision regret, cancer-related worry, mood, and trust in the treating physician. The qualitative component explores the experiences of RAI treatment decision-making, treatment satisfaction, and trial participation in a representative subgroup of patients. Extended follow-up study results will be described for the entire study population, and data will be compared between the P-DA and control groups. This mixed methods extended follow-up study will provide data on long term outcomes, relating to the use of a computerized P-DA in decision-making about adjuvant RAI treatment in early stage papillary thyroid cancer. Our results are intended to inform future research in this area, particularly relating to long term effects of the use of P-DAs in making healthcare choices. Clinicaltrials.gov identifier NCT01083550, registered 24 February 2010 and last updated 5 January 2015.

Measuring outcomes in children's rehabilitation: a decision protocol.

PubMed

Law, M; King, G; Russell, D; MacKinnon, E; Hurley, P; Murphy, C

1999-06-01

To develop and test the feasibility and clinical utility of a computerized self-directed software program designed to enable service providers in children's rehabilitation to make decisions about the most appropriate outcome measures to use in client and program evaluation. A before-and-after design was used to test the feasibility and initial impact of the decision-making outcome software in improving knowledge and use of clinical outcome measures. A children's rehabilitation center in a city of 50,000. All service providers in the children's rehabilitation center. Disciplines represented included early childhood education, occupational therapy, physical therapy, speech and language pathology, audiology, social work, and psychology. Using a conceptual framework based on the International Classification of Impairment, Disability, and Handicap (ICIDH), an outcome measurement decision-making protocol was developed. The decision-making protocol was computerized in an educational software program with an attached database of critically appraised measures. Participants learned about outcome measures through the program and selected outcome measures that met their specifications. The computer software was tested for feasibility in the children's rehabilitation center for 6 months. Knowledge and use of clinical outcome measures were determined before and after the feasibility testing using a survey of all service providers currently at the centre and audits of 30 randomly selected rehabilitation records (at pretest, posttest, and follow-up). Service providers indicated that the outcomes software was easy to follow and believed that the use of the ICIDH framework helped them in making decisions about selecting outcome measures. Results of the survey indicated that there were significant changes in the service providers' level of comfort with selecting measures and knowing what measures were available. Use of outcome measures as identified through the audit did not change. The "All About Outcomes" software is clinically useful. Further research should evaluate whether using the software affects the use of outcome measures in clinical practice.

Quality Assessment of Process Measures in Antimicrobial Stewardship: Concordance of Valacyclovir Indication and Automatic Prospective Approval in Computerized Provider Order Entry

PubMed Central

Lee, Tiffany; McCoy, Christopher; Mahoney, Monica V

2017-01-01

Abstract Background The Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) recommend computerized decision support at the time of prescribing as an antimicrobial stewardship (AST) tool. Providing antimicrobial indications during prescribing can optimize infection-specific therapy through appropriate antimicrobial selection, dosing, and frequency. The Leapfrog group identifies this as a quality measure for their report card system. At Beth Israel Deaconess Medical Center (BIDMC), indication-based dosing has been incorporated in the computerized provider order entry (CPOE) system since 2006. At BIDMC, valacyclovir is only approved for the treatment of varicella zoster (VZV) infection or prophylaxis of solid organ transplant (SOT) patients at low risk for cytomegalovirus. These indications bypass the need for AST approval. Accuracy validation of the selected indications has not been formally performed. Methods A retrospective chart review was performed in patients prescribed valacyclovir during an 8-month period in 2016. Electronic medical records, laboratory reports, and pharmacy records were reviewed to identify the suspected/confirmed infection. The primary outcome was the concordance rate of selected CPOE valacyclovir indication compared with suspected/confirmed infection at the time of ordering. The secondary outcome was the proportion of valacyclovir use per institutional protocol. Results Overall, 117 patients were included, with a median age of 57.9 years, 51 (43.6%) were male, and 4 (3.4%) were located in an intensive care unit. Fifty-nine orders (50.4%) selected VZV as the indication, followed by 21 orders (17.9%) for SOT prophylaxis. Of orders with any CPOE indication, only 59/101 (58.4%) were concordant with suspected/confirmed infection. Of the valacyclovir orders with a VZV indication, 37 (62.7%) were concordant. Of the orders with SOT prophylaxis indications, 5 (23.8%) were concordant. Furthermore, only 46 orders (39.3%) were per BIDMC-protocol. Conclusion Concordance of CPOE indication selection and suspected/confirmed infection for valacyclovir was low. Using CPOE to grant automatic prospective approval must be monitored and audited for accuracy if employed as an AST tool. Disclosures All authors: No reported disclosures.

Characterizing EPR-mediated passive drug targeting using contrast-enhanced functional ultrasound imaging.

PubMed

Theek, Benjamin; Gremse, Felix; Kunjachan, Sijumon; Fokong, Stanley; Pola, Robert; Pechar, Michal; Deckers, Roel; Storm, Gert; Ehling, Josef; Kiessling, Fabian; Lammers, Twan

2014-05-28

The Enhanced Permeability and Retention (EPR) effect is extensively used in drug delivery research. Taking into account that EPR is a highly variable phenomenon, we have here set out to evaluate if contrast-enhanced functional ultrasound (ceUS) imaging can be employed to characterize EPR-mediated passive drug targeting to tumors. Using standard fluorescence molecular tomography (FMT) and two different protocols for hybrid computed tomography-fluorescence molecular tomography (CT-FMT), the tumor accumulation of a ~10 nm-sized near-infrared-fluorophore-labeled polymeric drug carrier (pHPMA-Dy750) was evaluated in CT26 tumor-bearing mice. In the same set of animals, two different ceUS techniques (2D MIOT and 3D B-mode imaging) were employed to assess tumor vascularization. Subsequently, the degree of tumor vascularization was correlated with the degree of EPR-mediated drug targeting. Depending on the optical imaging protocol used, the tumor accumulation of the polymeric drug carrier ranged from 5 to 12% of the injected dose. The degree of tumor vascularization, determined using ceUS, varied from 4 to 11%. For both hybrid CT-FMT protocols, a good correlation between the degree of tumor vascularization and the degree of tumor accumulation was observed, within the case of reconstructed CT-FMT, correlation coefficients of ~0.8 and p-values of <0.02. These findings indicate that ceUS can be used to characterize and predict EPR, and potentially also to pre-select patients likely to respond to passively tumor-targeted nanomedicine treatments. Copyright © 2014 Elsevier B.V. All rights reserved.

Detection of periimplant fenestration and dehiscence with the use of two scan modes and the smallest voxel sizes of a cone-beam computed tomography device.

PubMed

de-Azevedo-Vaz, Sergio Lins; Vasconcelos, Karla de Faria; Neves, Frederico Sampaio; Melo, Saulo Leonardo Sousa; Campos, Paulo Sérgio Flores; Haiter-Neto, Francisco

2013-01-01

To assess the accuracy of cone-beam computed tomography (CBCT) in periimplant fenestration and dehiscence detection, and to determine the effects of 2 voxel sizes and scan modes. One hundred titanium implants were placed in bovine ribs in which periimplant fenestration and dehiscence were simulated. CBCT images were acquired with the use of 3 protocols of the i-CAT NG unit: A) 0.2 mm voxel size half-scan (180°); B) 0.2 mm voxel size full-scan (360°); and C) 0.12 mm voxel size full scan (360°). Receiver operating characteristic curves and diagnostic values were obtained. The Az values were compared with the use of analysis of variance. The Az value for dehiscence in protocol A was significantly lower than those of B or C (P < .01). They did not statistically differ for fenestration (P > .05). Protocol B yielded the highest values. The voxel sizes did not affect fenestration and dehiscence detection, and for dehiscence full-scan performed better than half-scan. Copyright © 2013 Elsevier Inc. All rights reserved.

Estimation of patient radiation dose from whole body 18F- FDG PET/CT examination in cancer imaging: a preliminary study

NASA Astrophysics Data System (ADS)

Mahmud, M. H.; Nordin, A. J.; Saad, F. F. Ahmad; Fattah Azman, A. Z.

2014-11-01

This study aims to estimate the radiation effective dose resulting from whole body fluorine-18 flourodeoxyglucose Positron Emission Tomography (18F-FDG PET) scanning as compared to conservative Computed Tomography (CT) techniques in evaluating oncology patients. We reviewed 19 oncology patients who underwent 18F-FDG PET/CT at our centre for cancer staging. Internal and external doses were estimated using radioactivity of injected FDG and volume CT Dose Index (CTDIvol), respectively with employment of the published and modified dose coefficients. The median differences of dose among the conservative CT and PET protocols were determined using Kruskal Wallis test with p < 0.05 considered as significant. The median (interquartile range, IQR) effective doses of non-contrasted CT, contrasted CT and PET scanning protocols were 7.50 (9.35) mSv, 9.76 (3.67) mSv and 6.30 (1.20) mSv, respectively, resulting in the total dose of 21.46 (8.58) mSv. Statistically significant difference was observed in the median effective dose between the three protocols (p < 0.01). The effective doses of whole body 18F-FDG PET technique may be effective the lowest amongst the conventional CT imaging techniques.

A time and imaging cost analysis of low-risk ED observation patients: a conservative 64-section computed tomography coronary angiography "triple rule-out" compared to nuclear stress test strategy.

PubMed

Takakuwa, Kevin M; Halpern, Ethan J; Shofer, Frances S

2011-02-01

The study aimed to examine time and imaging costs of 2 different imaging strategies for low-risk emergency department (ED) observation patients with acute chest pain or symptoms suggestive of acute coronary syndrome. We compared a "triple rule-out" (TRO) 64-section multidetector computed tomography protocol with nuclear stress testing. This was a prospective observational cohort study of consecutive ED patients who were enrolled in our chest pain observation protocol during a 16-month period. Our standard observation protocol included a minimum of 2 sets of cardiac enzymes at least 6 hours apart followed by a nuclear stress test. Once a week, observation patients were offered a TRO (to evaluate for coronary artery disease, thoracic dissection, and pulmonary embolus) multidetector computed tomography with the option of further stress testing for those patients found to have evidence of coronary artery disease. We analyzed 832 consecutive observation patients including 214 patients who underwent the TRO protocol. Mean total length of stay was 16.1 hours for TRO patients, 16.3 hours for TRO plus other imaging test, 22.6 hours for nuclear stress testing, 23.3 hours for nuclear stress testing plus other imaging tests, and 23.7 hours for nuclear stress testing plus TRO (P < .0001 for TRO and TRO + other test compared to stress test ± other test). Mean imaging times were 3.6, 4.4, 5.9, 7.5, and 6.6 hours, respectively (P < .05 for TRO and TRO + other test compared to stress test ± other test). Mean imaging costs were $1307 for TRO patients vs $945 for nuclear stress testing. Triple rule-out reduced total length of stay and imaging time but incurred higher imaging costs. A per-hospital analysis would be needed to determine if patient time savings justify the higher imaging costs. Copyright © 2011 Elsevier Inc. All rights reserved.

Renal Shielding and Dosimetry for Patients With Severe Systemic Sclerosis Receiving Immunoablation With Total Body Irradiation in the Scleroderma: Cyclophosphamide or Transplantation Trial

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

Craciunescu, Oana I., E-mail: oana.craciunescu@duke.ed; Steffey, Beverly A.; Kelsey, Chris R.

2011-03-15

Purpose: To describe renal shielding techniques and dosimetry in delivering total body irradiation (TBI) to patients with severe systemic sclerosis (SSc) enrolled in a hematopoietic stem cell transplant protocol. Methods and Materials: The Scleroderma: Cyclophosphamide or Transplantation (SCOT) protocol uses a lymphoablative preparative regimen including 800 cGy TBI delivered in two 200-cGy fractions twice a day before CD34{sup +} selected autologous hematopoietic stem cell transplantation. Lung and kidney doses are limited to 200 cGy to protect organs damaged by SSc. Kidney block proximity to the spinal cord was investigated, and guidelines were developed for acceptable lumbar area TBI dosing. Informationmore » about kidney size and the organ shifts from supine to standing positions were recorded using diagnostic ultrasound (US). Minimum distance between the kidney blocks (dkB) and the lumbar spine region dose was recorded, and in vivo dosimetry was performed at several locations to determine the radiation doses delivered. Results: Eleven patients were treated at our center with an anteroposterior (AP)/posteroanterior (PA) TBI technique. A 10% to 20% dose inhomogeneity in the lumbar spine region was achieved with a minimum kidney block separation of 4 to 5 cm. The average lumbar spine dose was 179.6 {+-} 18.1 cGy, with an average dkB of 5.0 {+-} 1.0 cm. Kidney block shield design was accomplished using a combination of US and noncontrast computerized tomography (CT) or CT imaging alone. The renal US revealed a wide range of kidney displacement from upright to supine positions. Overall, the average in vivo dose for the kidney prescription point was 193.4 {+-} 5.1 cGy. Conclusions: The dose to the kidneys can be attenuated while maintaining a 10% to 20% dose inhomogeneity in the lumbar spine area. Kidneys were localized more accurately using both US and CT imaging. With this technique, renal function has been preserved, and the study continues to enroll patients.« less

Linked Orders Improve Safety in Scheduling and Administration of Chemotherapeutic Agents

PubMed Central

Whipple, Nancy; Boulware, Joy; Danca, Kala; Boyarin, Kirill; Ginsberg, Eliot; Poon, Eric; Sweet, Micheal; Schade, Sue; Rogala, Jennifer

2010-01-01

The pharmacologic treatment for cancer must adhere to complex, finely orchestrated treatment plans, including not only chemotherapy medications, but pre/post-hydration, anti-emetics, anti-anxiety, and other medications that are given before, during and after chemotherapy doses. The treatment plans specify the medications and dictate precise dosing, frequency, and timing. This is a challenge to most Computerized Physician Order Entry (CPOE), Pharmacy and Electronic Medication Administration record (eMAR) Systems. Medications are scheduled on specific dates, referred to as chemo days, from the onset of the treatment, and precisely timed on the designated chemo day. For patients enrolled in research protocols, the adherence to the defined schedule takes on additional import, since variation is a violation of the protocol. If the oncologist determines that medications must be administered outside the defined constraints, the patient must be un-enrolled from the protocol and the course of therapy is re-written. Pharmacy and eMAR systems utilized in processing chemotherapy medications must be able to support the intricate relationships between each drug defined in the treatment plans. PMID:21347104

Cystic lung disease in birt-hogg-dubé syndrome: a case series of three patients.

PubMed

Kilincer, Abidin; Ariyurek, Orhan Macit; Karabulut, Nevzat

2014-06-01

Birt-Hogg-Dubé syndrome is characterized by clinical manifestations such as hamartomas of the skin, renal tumors and lung cysts with spontaneous pneumothoraces. Patients with Birt-Hogg-Dubé syndrome may present with only multiple lung cysts. We report the chest computerized tomography (CT) features of three patients with Birt-Hogg-Dubé syndrome. Each patient had multiple lung cysts of various sizes according to chest CT evaluation, most of which were located in lower lobes and related to pleura. The identification of unique characteristics in the chest CT of patients with Birt-Hogg-Dubé syndrome may provide an efficient mechanism for diagnosis.

Sickle cell-induced ischemic colitis.

PubMed

Stewart, Camille L; Ménard, Geraldine E

2009-07-01

Sickle cell-induced ischemic colitis is a rare yet potentially fatal complication of sickle cell anemia. Frequent pain crises with heavy analgesia may obscure and prolong this important diagnosis. Our patient was a 29-year-old female with sickle cell disease who was admitted with left lower quadrant abdominal pain. A diagnostic workup, including chemistries, complete blood count, blood cultures, chest x-ray, computerized tomography scanning, and colonoscopy, was performed to identify the etiology of her symptoms. This case highlights the importance of differentiating simple pain crisis from more serious and life-threatening ischemic bowel. A review of the literature compares this case to others reported and gives a method for diagnosing and treating this complication of sickle cell disease.

Ultrasound in the Diagnosis & Management of Pleural Effusions

PubMed Central

Soni, Nilam J.; Franco, Ricardo; Velez, Maria I.; Schnobrich, Daniel; Dancel, Ria; Restrepo, Marcos I.; Mayo, Paul H.

2015-01-01

We review the literature on the use of point-of-care ultrasound to evaluate and manage pleural effusions. Point-of-care ultrasound is more sensitive than physical exam and chest radiography to detect and characterize pleural fluid, and avoids many negative aspects of computerized tomography (CT). Additionally, point-of-care ultrasound can be used to assess pleural fluid volume and character, revealing possible underlying pathologies and guiding management. Thoracentesis performed with ultrasound guidance has lower risk of pneumothorax and bleeding complications. Future research should focus on the clinical-effectiveness of point-of-care ultrasound in the routine management of pleural effusions and how new technologies may expand its clinical utility. PMID:26218493

The holographic display of three-dimensional medical objects through the usage of a shiftable cylindrical lens

NASA Astrophysics Data System (ADS)

Teng, Dongdong; Liu, Lilin; Zhang, Yueli; Pang, Zhiyong; Wang, Biao

2014-09-01

Through the creative usage of a shiftable cylindrical lens, a wide-view-angle holographic display system is developed for medical object display in real three-dimensional (3D) space based on a time-multiplexing method. The two-dimensional (2D) source images for all computer generated holograms (CGHs) needed by the display system are only one group of computerized tomography (CT) or magnetic resonance imaging (MRI) slices from the scanning device. Complicated 3D message reconstruction on the computer is not necessary. A pelvis is taken as the target medical object to demonstrate this method and the obtained horizontal viewing angle reaches 28°.

A case report of esophageal perforation: Complication of nasogastric tube placement

PubMed Central

Isik, Arda; Firat, Deniz; Peker, Kemal; Sayar, Ilyas; Idiz, Oguz; Soytürk, Mehmet

2014-01-01

Patient: Male, 70 Final Diagnosis: Esophageal perforation Symptoms: Abdominal pain • nausea • vomiting Medication: — Clinical Procedure: — Specialty: Surgery Objective: Unusual clinical course Background: Esophageal perforation is a well-defined and severe clinical condition. There are several etiologies of esophagus perforation. Case Report: We report the case of a 70-year-old Caucasian man who underwent an emergency cholecystectomy due to acute cholecystitis. Two days after surgery, his condition deteriorated. Thorax computerized tomography revealed an esophageal perforation. Conclusions: Esophageal perforation due to nasogastric application is relatively rare but the consequences are potentially serious. The anatomy of the upper gastrointestinal system should be understood by all healthcare professionals involved in the treatment. PMID:24803977

How We Manage Patients with Plasmacytomas.

PubMed

Fotiou, Despina; Dimopoulos, Meletios A; Kastritis, Efstathios

2018-04-17

To discuss the diagnostic approach, treatment options, and future considerations in the management of plasmacytomas, either solitary or in the context of overt multiple myeloma (MM). Advanced imaging techniques such as whole-body magnetic resonance imaging and positron emission tomography/computerized tomography are essential for the diagnostic workup of solitary plasmacytomas (SP) to rule out the presence of other disease foci. The role of flow cytometry and clonal plasma cell detection is currently under study together with other prognostic factors for the identification of patients with SP at high risk of progression to overt MM. Solitary plasmacytomas are treated effectively with local radiotherapy whereas systemic therapy is required at relapse. Clonal plasma cells that accumulate at extramedullary sites have distinct biological characteristics. Patients with MM and soft tissue involvement have poor outcomes and should be treated as ultra-high risk. A revised definition of SP that distinguishes between true solitary clonal PC accumulations and SP with minimal bone marrow involvement should be considered to guide an appropriate therapeutic and follow-up approach. Future studies should be conducted to determine optimum treatment approaches for patients with MM and paraskeletal or extramedullary disease.

Evaluative studies in nuclear medicine research: emission computed tomography assessment. Final report, January 1-December 31, 1981

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

Potchen, E.J.; Harris, G.I.; Gift, D.A.

The report provides information on an assessment of the potential short and long term benefits of emission computed tomography (ECT) in biomedical research and patient care. Work during the past year has been augmented by the development and use of an opinion survey instrument to reach a wider representation of knowledgeable investigators and users of this technology. This survey instrument is reproduced in an appendix. Information derived from analysis of the opinion survey, and used in conjunction with results of independent staff studies of available sources, provides the basis for the discussions given in following sections of PET applications inmore » the brain, of technical factors, and of economic implications. Projections of capital and operating costs on a per study basis were obtained from a computerized, pro forma accounting model and are compared with the survey cost estimates for both research and clinical modes of application. The results of a cash-flow model analysis of the relationship between projected economic benefit of PET research to disease management and the costs associated with such research are presented and discussed.« less

Residual FDG-PET metabolic activity in metastatic melanoma patients with prolonged response to anti-PD-1 therapy.

PubMed

Kong, Benjamin Y; Menzies, Alexander M; Saunders, Catherine A B; Liniker, Elizabeth; Ramanujam, Sangeetha; Guminski, Alex; Kefford, Richard F; Long, Georgina V; Carlino, Matteo S

2016-09-01

18-Fluorodeoxyglucose positron emission tomography (FDG-PET) scans were performed on 27 patients with unresectable stage IIIC or IV melanoma after prolonged treatment with anti-PD-1 antibodies to examine the hypothesis that patients with prolonged response to treatment may have metabolically inactive lesions by FDG-PET. Scans were performed at a median of 15.2 months (range 12-29 months) after starting treatment. Overall, 15 of 27 (56%) patients had a positive FDG-PET scan. Eight patients with positive scans underwent biopsy; 5 of 8 (62%) were melanoma and 3 of 8 (38%) were immune cell infiltrates. Of the 12 patients with negative FDG-PET scans, six had residual computerized tomography-visible lesions, five have ceased treatment, and none have recurred with follow-up of 6-10 months. Patients with residual metastases after a prolonged period without progression on anti-PD-1 therapy may have metabolically inactive lesions. Isolated metabolically active lesions in clinically well patients may reveal immune cell infiltrates rather than melanoma. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Texture classification of lung computed tomography images

NASA Astrophysics Data System (ADS)

Pheng, Hang See; Shamsuddin, Siti M.

2013-03-01

Current development of algorithms in computer-aided diagnosis (CAD) scheme is growing rapidly to assist the radiologist in medical image interpretation. Texture analysis of computed tomography (CT) scans is one of important preliminary stage in the computerized detection system and classification for lung cancer. Among different types of images features analysis, Haralick texture with variety of statistical measures has been used widely in image texture description. The extraction of texture feature values is essential to be used by a CAD especially in classification of the normal and abnormal tissue on the cross sectional CT images. This paper aims to compare experimental results using texture extraction and different machine leaning methods in the classification normal and abnormal tissues through lung CT images. The machine learning methods involve in this assessment are Artificial Immune Recognition System (AIRS), Naive Bayes, Decision Tree (J48) and Backpropagation Neural Network. AIRS is found to provide high accuracy (99.2%) and sensitivity (98.0%) in the assessment. For experiments and testing purpose, publicly available datasets in the Reference Image Database to Evaluate Therapy Response (RIDER) are used as study cases.

Fulminant clostridium difficile colitis: comparing computed tomography with histopathology: are they concordant?

PubMed

Felder, Seth I; Larson, Brent; Balzer, Bonnie; Wachsman, Ashley; Haker, Katherine; Fleshner, Phillip; Annamalai, Alagappan; Margulies, Daniel R

2014-10-01

A Total abdominal colectomy (TAC) is recommended for fulminant Clostridium difficile colitis (FCDC) because intraoperative assessment of diseased segments is inaccurate. To determine whether computerized tomography (CT) provides an accurate assessment of disease, we examined the concordance between CT and histopathologic colitis distribution in patients undergoing TAC for FCDC. The ileocolon was divided into seven distinct segments. Of 20 patients meeting criteria, the median interval between preoperative CT and TAC was 1.5 days (range, 0 to 23 days), and mortality was 65 per cent. The CT distribution of colitis was pancolitis in 12 patients and segmental in eight. Nine of the 12 patients with CT pancolitis had histologic pancolitis (75% concordance). Four of the eight patients with CT-diagnosed segmental disease had histologic segmental disease (50% concordance). For patients with FCDC, the distribution of colitis on CT agrees with the histopathologic extent of disease in the majority of patients. However, discordance between CT and histologic extent of disease was present in 25 to 50 per cent of patients. Therefore, the recommendation for TAC rather than segmental resection for FCDC remains justified.

F-18 FDG PET/CT findings in a patient with bilateral orbital and gastric mucosa-associated lymphoid tissue lymphomas.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Hiyama, Atsuto; Takeda, Koumei; Matsunaga, Naofumi

2009-09-01

Orbital mucosa-associated lymphoid tissue (MALT) lymphoma is an uncommon disease, while the incidence is recently increasing. We describe the F-18 fluorodeoxyglucose positron emission tomography computerized tomography (FDG PET/CT) findings in a case of bilateral orbital MALT lymphomas with a coexisting gastric lesion. Although only the lesion in the left orbit was initially identified on MR imaging, FDG PET/CT scan unexpectedly and additionally could identify the tiny lesion of the contralateral orbit and the gastric lesion. This patient received radiotherapy to all these lesions, with a combination of rituximab monoclonal antibody therapy. The follow-up PET/CT studies at 3, 6, and 9 months and 1.5 years after treatment showed regression or disappearance of all these FDG-avid lesions. Accurate localization and staging are crucial to select an adequate treatment in MALT lymphoma at any location. This case indicates the feasibility of FDG PET/CT scan for accurate localization and staging and also for monitoring treatment in patients with orbital MALT lymphoma.

The influence of body mass index, age, implants, and dental restorations on image quality of cone beam computed tomography.

PubMed

Ritter, Lutz; Mischkowski, Robert A; Neugebauer, Jörg; Dreiseidler, Timo; Scheer, Martin; Keeve, Erwin; Zöller, Joachim E

2009-09-01

The aim was to determine the influence of patient age, gender, body mass index (BMI), amount of dental restorations, and implants on image quality of cone-beam computerized tomography (CBCT). Fifty CBCT scans of a preretail version of Galileos (Sirona, Germany) were investigated retrospectively by 4 observers regarding image quality of 6 anatomic structures, pathologic findings detection, subjective exposure quality, and artifacts. Patient age, BMI, gender, amount of dental restorations, and implants were recorded and statistically tested for correlations to image quality. A negative effect on image quality was found statistically significantly correlated with age and the amount of dental restorations. None of the investigated image features were garbled by any of the investigated influence factors. Age and the amount of dental restorations appear to have a negative impact on CBCT image quality, whereas gender and BMI do not. Image quality of mental foramen, mandibular canal, and nasal floor are affected negatively by age but not by the amount of dental restorations. Further studies are required to elucidate influence factors on CBCT image quality.

Application of generalized singular value decomposition to ionospheric tomography

NASA Astrophysics Data System (ADS)

Bhuyan, K.; Singh, S.; Bhuyan, P.

2004-10-01

The electron density distribution of the low- and mid-latitude ionosphere has been investigated by the computerized tomography technique using a Generalized Singular Value Decomposition (GSVD) based algorithm. Model ionospheric total electron content (TEC) data obtained from the International Reference Ionosphere 2001 and slant relative TEC data measured at a chain of three stations receiving transit satellite transmissions in Alaska, USA are used in this analysis. The issue of optimum efficiency of the GSVD algorithm in the reconstruction of ionospheric structures is being addressed through simulation of the equatorial ionization anomaly (EIA), in addition to its application to investigate complicated ionospheric density irregularities. Results show that the Generalized Cross Validation approach to find the regularization parameter and the corresponding solution gives a very good reconstructed image of the low-latitude ionosphere and the EIA within it. Provided that some minimum norm is fulfilled, the GSVD solution is found to be least affected by considerations, such as pixel size and number of ray paths. The method has also been used to investigate the behaviour of the mid-latitude ionosphere under magnetically quiet and disturbed conditions.

Impact of Contrast Media Concentration on Low-Kilovolt Computed Tomography Angiography: A Systematic Preclinical Approach.

PubMed

Fleischmann, Ulrike; Pietsch, Hubertus; Korporaal, Johannes G; Flohr, Thomas G; Uder, Michael; Jost, Gregor; Lell, Michael M

2018-05-01

Low peak kilovoltage (kVp) protocols in computed tomography angiography (CTA) demand a review of contrast media (CM) administration practices. The aim of this study was to systematically evaluate different iodine concentrations of CM in a porcine model. Dynamic 70 kVp CTA was performed on 7 pigs using a third-generation dual-source CT system. Three CM injection protocols (A-C) with an identical total iodine dose and iodine delivery rate (150 mg I/kg, 12 s, 0.75 g I/s) differed in iodine concentration and flow rate (protocol A: 400 mg I/mL, 1.9 mL/s; B: 300 mg I/mL, 2.5 mL/s; C: 150 mg I/mL, 5 mL/s). All protocols were applied in a randomized order and compared intraindividually. Arterial enhancement at different locations in the pulmonary artery, the aorta, and aortic branches was measured over time. Time attenuation curves, peak enhancement, time to peak, and bolus tracking delay times needed for static CTA were calculated. The reproducibility of optimal parameters was tested in single-phase CTA. The heart rates of the pigs were comparable for all protocols (P > 0.7). The injection pressure was significantly higher for protocol A (64 ± 5 psi) and protocol C (55 ± 3 psi) compared with protocol B (39 ± 2 psi) (P < 0.001). Average arterial peak enhancement in the dynamic scans was 359 ± 51 HU (protocol A), 382 ± 36 HU (B), and 382 ± 60 HU (C) (A compared with B and C: P < 0.01; B compared with C: P = 0.995). Time to peak enhancement decreased with increasing injection rate. The delay time for bolus tracking depended on the injection rate as well and was highest for protocol A (4.7 seconds) and lowest for protocol C (3.9 seconds) (P = 0.038). The peak enhancement values of the dynamic scans highly correlated with those of the single-phase CTA scans. In 70 kVp CTA, 300 mg I/mL iodine concentrations showed to be superior to high-concentration CM when keeping the iodine delivery rate constant. Besides, iodine concentrations as low as 150 mg I/mL can be administered without compromising vascular enhancement. This opens up new possibilities in CM administration.

Computerized cognitive training in children and adolescents with attention deficit/hyperactivity disorder as add-on treatment to stimulants: feasibility study and protocol description.

PubMed

Rosa, Virginia de Oliveira; Schmitz, Marcelo; Moreira-Maia, Carlos Roberto; Wagner, Flavia; Londero, Igor; Bassotto, Caroline de Fraga; Moritz, Guilherme; de Souza, Caroline Dos Santos; Rohde, Luis Augusto Paim

2017-01-01

Cognitive training has received increasing attention as a non-pharmacological approach for the treatment of attention deficit/hyperactivity disorder (ADHD) in children and adolescents. Few studies have assessed cognitive training as add-on treatment to medication in randomized placebo controlled trials. The purpose of this preliminary study was to explore the feasibility of implementing a computerized cognitive training program for ADHD in our environment, describe its main characteristics and potential efficacy in a small pilot study. Six ADHD patients aged 10-12-years old receiving stimulants and presenting residual symptoms were enrolled in a randomized clinical trial to either a standard cognitive training program or a controlled placebo condition for 12 weeks. The primary outcome was core ADHD symptoms measured using the Swanson, Nolan and Pelham Questionnaire (SNAP-IV scale). We faced higher resistance than expected to patient enrollment due to logistic issues to attend face-to-face sessions in the hospital and to fill the requirement of medication status and absence of some comorbidities. Both groups showed decrease in parent reported ADHD symptoms without statistical difference between them. In addition, improvements on neuropsychological tests were observed in both groups - mainly on trained tasks. This protocol revealed the need for new strategies to better assess the effectiveness of cognitive training such as the need to implement the intervention in a school environment to have an assessment with more external validity. Given the small sample size of this pilot study, definitive conclusions on the effects of cognitive training as add-on treatment to stimulants would be premature.

Positron Emission Tomography: Principles, Technology, and Recent Developments

NASA Astrophysics Data System (ADS)

Ziegler, Sibylle I.

2005-04-01

Positron emission tomography (PET) is a nuclear medical imaging technique for quantitative measurement of physiologic parameters in vivo (an overview of principles and applications can be found in [P.E. Valk, et al., eds. Positron Emission Tomography. Basic Science and Clinical Practice. 2003, Springer: Heidelberg]), based on the detection of small amounts of posi-tron-emitter-labelled biologic molecules. Various radiotracers are available for neuro-logical, cardiological, and oncological applications in the clinic and in research proto-cols. This overview describes the basic principles, technology, and recent develop-ments in PET, followed by a section on the development of a tomograph with ava-lanche photodiodes dedicated for small animal imaging as an example of efforts in the domain of high resolution tomographs.

Patient Safety and Quality Improvement in Otolaryngology Education: A Systematic Review.

PubMed

Gettelfinger, John D; Paulk, P Barrett; Schmalbach, Cecelia E

2017-06-01

Objective The breadth and depth of patient safety/quality improvement (PS/QI) research dedicated to otolaryngology-head and neck surgery (OHNS) education remains unknown. This systematic review aims to define this scope and to identify knowledge gaps as well as potential areas of future study to improved PS/QI education and training in OHNS. Data Sources A computerized Ovid/Medline database search was conducted (January 1, 1965, to May 15, 2015). Similar computerized searches were conducted using Cochrane Database, PubMed, and Google Scholar. Review Methods The study protocol was developed a priori using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Articles were classified by year, subspecialty, Institute of Medicine (IOM) Crossing the Chasm categories, and World Health Organization (WHO) subclass. Results Computerized searches yielded 8743 eligible articles, 267 (3.4%) of which met otolaryngology PS/QI inclusion criteria; 51 (19%) were dedicated to resident/fellow education and training. Simulation studies (39%) and performance/competency evaluation (23.5%) were the most common focus. Most projects involved general otolaryngology (47%), rhinology (18%), and otology (16%). Classification by the IOM included effective care (45%), safety/effective care (41%), and effective and efficient care (7.8%). Most research fell into the WHO category of "identifying solutions" (61%). Conclusion Nineteen percent of OHNS PS/QI articles are dedicated to education, the majority of which are simulation and focus on effective care. Knowledges gaps for future research include facial plastics PS/QI and the WHO category of "studies translating evidence into safer care."

Sensitive Quantitative Assessment of Balance Disorders

NASA Technical Reports Server (NTRS)

Paloski, Willilam H.

2007-01-01

Computerized dynamic posturography (CDP) has become a standard technique for objectively quantifying balance control performance, diagnosing the nature of functional impairments underlying balance disorders, and monitoring clinical treatment outcomes. We have long used CDP protocols to assess recovery of sensory-motor function in astronauts following space flight. The most reliable indicators of post-flight crew performance are the sensory organization tests (SOTs), particularly SOTs 5 and 6, which are sensitive to changes in availability and/or utilization of vestibular cues. We have noted, however, that some astronauts exhibiting obvious signs of balance impairment after flight are able to score within clinical norms on these tests, perhaps as a result of adopting competitive strategies or by their natural skills at substituting alternate sensory information sources. This insensitivity of the CDP protocol could underestimate of the degree of impairment and, perhaps, lead to premature release of those crewmembers to normal duties. To improve the sensitivity of the CDP protocol we have introduced static and dynamic head tilt SOT trials into our protocol. The pattern of postflight recovery quantified by the enhanced CDP protocol appears to more aptly track the re-integration of sensory-motor function, with recovery time increasing as the complexity of sensory-motor/biomechanical task increases. The new CDP protocol therefore seems more suitable for monitoring post-flight sensory-motor recovery and for indicating to crewmembers and flight surgeons fitness for return to duty and/or activities of daily living. There may be classes of patients (e.g., athletes, pilots) having motivation and/or performance characteristics similar to astronauts whose sensory-motor treatment outcomes would also be more accurately monitored using the enhanced CDP protocol. Furthermore, the enhanced protocol may be useful in early detection of age-related balance disorders.

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

Nielsen, Erik; Blume-Kohout, Robin; Rudinger, Kenneth

PyGSTi is an implementation of Gate Set Tomography in the python programming language. Gate Set Tomography (GST) is a theory and protocol for simultaneously estimating the state preparation, gate operations, and measurement effects of a physical system of one or many quantum bits (qubits). These estimates are based entirely on the statistics of experimental measurements, and their interpretation and analysis can provide a detailed understanding of the types of errors/imperfections in the physical system. In this way, GST provides not only a means of certifying the "goodness" of qubits but also a means of debugging (i.e. improving) them.

Implementation of real-time digital endoscopic image processing system

NASA Astrophysics Data System (ADS)

Song, Chul Gyu; Lee, Young Mook; Lee, Sang Min; Kim, Won Ky; Lee, Jae Ho; Lee, Myoung Ho

1997-10-01

Endoscopy has become a crucial diagnostic and therapeutic procedure in clinical areas. Over the past four years, we have developed a computerized system to record and store clinical data pertaining to endoscopic surgery of laparascopic cholecystectomy, pelviscopic endometriosis, and surgical arthroscopy. In this study, we developed a computer system, which is composed of a frame grabber, a sound board, a VCR control board, a LAN card and EDMS. Also, computer system controls peripheral instruments such as a color video printer, a video cassette recorder, and endoscopic input/output signals. Digital endoscopic data management system is based on open architecture and a set of widely available industry standards; namely Microsoft Windows as an operating system, TCP/IP as a network protocol and a time sequential database that handles both images and speech. For the purpose of data storage, we used MOD and CD- R. Digital endoscopic system was designed to be able to store, recreate, change, and compress signals and medical images. Computerized endoscopy enables us to generate and manipulate the original visual document, making it accessible to a virtually unlimited number of physicians.

Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures

NASA Astrophysics Data System (ADS)

Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon

2017-02-01

We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography.

PubMed

Trépout, Sylvain; Bastin, Philippe; Marco, Sergio

2017-03-12

This report describes a protocol for preparing thick biological specimens for further observation using a scanning transmission electron microscope. It also describes an imaging method for studying the 3D structure of thick biological specimens by scanning transmission electron tomography. The sample preparation protocol is based on conventional methods in which the sample is fixed using chemical agents, treated with a heavy atom salt contrasting agent, dehydrated in a series of ethanol baths, and embedded in resin. The specific imaging conditions for observing thick samples by scanning transmission electron microscopy are then described. Sections of the sample are observed using a through-focus method involving the collection of several images at various focal planes. This enables the recovery of in-focus information at various heights throughout the sample. This particular collection pattern is performed at each tilt angle during tomography data collection. A single image is then generated, merging the in-focus information from all the different focal planes. A classic tilt-series dataset is then generated. The advantage of the method is that the tilt-series alignment and reconstruction can be performed using standard tools. The collection of through-focal images allows the reconstruction of a 3D volume that contains all of the structural details of the sample in focus.

A New Dual-purpose Quality Control Dosimetry Protocol for Diagnostic Reference-level Determination in Computed Tomography.

PubMed

Sohrabi, Mehdi; Parsi, Masoumeh; Sina, Sedigheh

2018-05-17

A diagnostic reference level is an advisory dose level set by a regulatory authority in a country as an efficient criterion for protection of patients from unwanted medical exposure. In computed tomography, the direct dose measurement and data collection methods are commonly applied for determination of diagnostic reference levels. Recently, a new quality-control-based dose survey method was proposed by the authors to simplify the diagnostic reference-level determination using a retrospective quality control database usually available at a regulatory authority in a country. In line with such a development, a prospective dual-purpose quality control dosimetry protocol is proposed for determination of diagnostic reference levels in a country, which can be simply applied by quality control service providers. This new proposed method was applied to five computed tomography scanners in Shiraz, Iran, and diagnostic reference levels for head, abdomen/pelvis, sinus, chest, and lumbar spine examinations were determined. The results were compared to those obtained by the data collection and quality-control-based dose survey methods, carried out in parallel in this study, and were found to agree well within approximately 6%. This is highly acceptable for quality-control-based methods according to International Atomic Energy Agency tolerance levels (±20%).

Dual tracer imaging of SPECT and PET probes in living mice using a sequential protocol

PubMed Central

Chapman, Sarah E; Diener, Justin M; Sasser, Todd A; Correcher, Carlos; González, Antonio J; Avermaete, Tony Van; Leevy, W Matthew

2012-01-01

Over the past 20 years, multimodal imaging strategies have motivated the fusion of Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scans with an X-ray computed tomography (CT) image to provide anatomical information, as well as a framework with which molecular and functional images may be co-registered. Recently, pre-clinical nuclear imaging technology has evolved to capture multiple SPECT or multiple PET tracers to further enhance the information content gathered within an imaging experiment. However, the use of SPECT and PET probes together, in the same animal, has remained a challenge. Here we describe a straightforward method using an integrated trimodal imaging system and a sequential dosing/acquisition protocol to achieve dual tracer imaging with 99mTc and 18F isotopes, along with anatomical CT, on an individual specimen. Dosing and imaging is completed so that minimal animal manipulations are required, full trimodal fusion is conserved, and tracer crosstalk including down-scatter of the PET tracer in SPECT mode is avoided. This technique will enhance the ability of preclinical researchers to detect multiple disease targets and perform functional, molecular, and anatomical imaging on individual specimens to increase the information content gathered within longitudinal in vivo studies. PMID:23145357

Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.

PubMed

Gomes, Manuel; Aldridge, Robert W; Wylie, Peter; Bell, James; Epstein, Owen

2013-04-01

When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown. The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS. We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions. 3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained. 3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.

Feasibility and utility of an integrated medical imaging and informatics smartphone system for management of acute stroke.

PubMed

Shkirkova, Kristina; Akam, Eftitan Y; Huang, Josephine; Sheth, Sunil A; Nour, May; Liang, Conrad W; McManus, Michael; Trinh, Van; Duckwiler, Gary; Tarpley, Jason; Vinuela, Fernando; Saver, Jeffrey L

2017-12-01

Background Rapid dissemination and coordination of clinical and imaging data among multidisciplinary team members are essential for optimal acute stroke care. Aim To characterize the feasibility and utility of the Synapse Emergency Room mobile (Synapse ERm) informatics system. Methods We implemented the Synapse ERm system for integration of clinical data, computerized tomography, magnetic resonance, and catheter angiographic imaging, and real-time stroke team communications, in consecutive acute neurovascular patients at a Comprehensive Stroke Center. Results From May 2014 to October 2014, the Synapse ERm application was used by 33 stroke team members in 84 Code Stroke alerts. Patient age was 69.6 (±17.1), with 41.5% female. Final diagnosis was: ischemic stroke 64.6%, transient ischemic attack 7.3%, intracerebral hemorrhage 6.1%, and cerebrovascular-mimic 22.0%. Each patient Synapse ERm record was viewed by a median of 10 (interquartile range 6-18) times by a median of 3 (interquartile range 2-4) team members. The most used feature was computerized tomography, magnetic resonance, and catheter angiography image display. In-app tweet team, communications were sent by median 1 (interquartile range 0-1, range 0-13) users per case and viewed by median 1 (interquartile range 0-3, range 0-44) team members. Use of the system was associated with rapid treatment times, faster than national guidelines, including median door-to-needle 51.0 min (interquartile range 40.5-69.5) and median door-to-groin 94.5 min (interquartile range 85.5-121.3). In user surveys, the mobile information platform was judged easy to employ in 91% (95% confidence interval 65%-99%) of uses and of added help in stroke management in 50% (95% confidence interval 22%-78%). Conclusion The Synapse ERm mobile platform for stroke team distribution and integration of clinical and imaging data was feasible to implement, showed high ease of use, and moderate perceived added utility in therapeutic management.

SU-F-T-270: A Technique for Modeling a Diode Array Into the TPS for Lung SBRT Patient Specific QA

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

Curley, C; Leventouri, T; Ouhib, Z

2016-06-15

Purpose: To accurately match the treatment planning system (TPS) with the measurement environment, where quality assurance (QA) devices are used to collect data, for lung Stereotactic Body Radiation Therapy (SBRT) patient specific QA. Incorporation of heterogeneities is also studied. Methods: Dual energy computerized tomography (DECT) and single energy computerized tomography (SECT) were used to model phantoms incorporating a 2-D diode array into the TPS. A water-equivalent and a heterogeneous phantom (simulating the thoracic region of a patient) were studied. Monte Carlo and pencil beam planar dose distributions were compared to measured distributions. Composite and individual fields were analyzed for normallymore » incident and planned gantry angle deliveries. γ- analysis was used with criteria 3% 3mm, 2% 2mm, and 1% 1mm. Results: The Monte Carlo calculations for the DECT resulted in improved agreements with the diode array for 46.4% of the fields at 3% 3mm, 85.7% at 2% 2mm, and 92.9% at 1% 1mm.For the SECT, the Monte Carlo calculations gave no agreement for the same γ-analysis criteria. Pencil beam calculations resulted in lower agreements with the diode array in the TPS. The DECT showed improvements for 14.3% of the fields at 3% 3mm and 2% 2mm, and 28.6% at 1% 1mm.In SECT comparisons, 7.1% of the fields at 3% 3mm, 10.7% at 2% 2mm, and 17.9% at 1% 1mm showed improved agreements with the diode array. Conclusion: This study demonstrates that modeling the diode array in the TPS is viable using DECT with Monte Carlo for patient specific lung SBRT QA. As recommended by task groups (e.g. TG 65, TG 101, TG 244) of the American Association of Physicists in Medicine (AAPM), pencil beam algorithms should be avoided in the presence of heterogeneous materials, including a diode array.« less

Three-dimensional Cross-Platform Planning for Complex Spinal Procedures: A New Method Adaptive to Different Navigation Systems.

PubMed

Kosterhon, Michael; Gutenberg, Angelika; Kantelhardt, Sven R; Conrad, Jens; Nimer Amr, Amr; Gawehn, Joachim; Giese, Alf

2017-08-01

A feasibility study. To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures. There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software. Patients computerized tomography and/or magnetic resonance volume data sets of the affected spinal segments were imported to Amira software, reconstructed to 3D images and fused with magnetic resonance data for soft-tissue visualization, resulting in a virtual patient model. Objects needed for surgical plans or surgical procedures such as trajectories, implants or surgical instruments were either digitally constructed or computerized tomography scanned and virtually positioned within the 3D model as required. As crucial step of this method these objects were fused with the patient's original diagnostic image data, resulting in a single DICOM sequence, containing all preplanned information necessary for the operation. By this step it was possible to import complex surgical plans into any navigation system. We applied this method not only to intraoperatively adjustable implants and objects under experimental settings, but also planned and successfully performed surgical procedures, such as the percutaneous lateral approach to the lumbar spine following preplanned trajectories and a thoracic tumor resection including intervertebral body replacement using an optical navigation system. To demonstrate the versatility and compatibility of the method with an entirely different navigation system, virtually preplanned lumbar transpedicular screw placement was performed with a robotic guidance system. The presented method not only allows virtual planning of complex surgical procedures, but to export objects and surgical plans to any navigation or guidance system able to read DICOM data sets, expanding the possibilities of embedded planning software.

[Cerebellar infarction in vascular teritorry of arteria cerebelli superior].

PubMed

Savić, Dejan; Savić, Ljiljana

2010-01-01

Cerebellar vascular diseases are focal cerebrovascular diseases in posterior circulation--vertebrobasilar system. The cerebellum is supplied by three main arteries arising from the vertebrobasilar system: arteria cerebelli inferior posterior, arteria cerebelli inferior anterior and arteria cerebelli superior. Cerebelar infarctions are rare but unpredictable disorders. The aim of this study was determination of main risk factors, clinical presentation and prognosis of the cerebellar infarctions in distal vascular teritorry of the arteria cerebelli superior. We evaluated 60 patients hospitalized after acute cerebellar infarction among other hospitalized patients in five year period. In 18 patients computerized tomography demonstrated infarction in distal vascular teritorry of the arteria cerebelli superior. All patients underwent clinical and other diagnostic investigations (computerized tomography, electrocardyography and standard blood tests) and were questioned by phone after finishing hospital treatment. Cerebellar infarcts in distal vascular teritorry of arteria cerebell superior was 30% of all cerebellar infarcts. The most frequent risk factor was hypertension (66.7%). Symptomatology and clinical signs were heterogenous but the most frequent were instability (77.8%), vertigo (72.2%) and vomiting (55.6%) followed by ataxia of the limbs (77.8%) and the body (61.1%), nystagmus (55.6%) and disarthria (33.3%) in clinical presentation. All patients had good recovery in hospital and one year afterwards. Infarctions in distribution of arteria cerebelli superior are rare and have multiple risk factors and various clinical features in majority of other studies as in this one. Mass effects are present in several studies but none in this one which reflects contraversions present in other published investigations. Cerebellar infarctions in vascular teritorry of arteria cerebelli superior have multiple risk factors, mostly heterogenous clinical presentations with predominance of instability, vertigo and vomiting with ataxia of the limbs and the body as well as nystagmus and disarthria in clinical presentation. The outcome and prognosis of disease is good despite the large amount of arteria cerebelli superior vascular teritorry.

Abbreviated injury scale scoring in traffic fatalities: comparison of computerized tomography and autopsy.

PubMed

Leth, Peter Mygind; Ibsen, Marlene

2010-06-01

The purpose of this investigation is to evaluate the value of postmortem computerized tomography (CT) for Abbreviated Injury Scale (AIS) scoring and Injury Severity Scoring (ISS) of traffic fatalities. This is a prospective investigation of a consecutive series of 52 traffic fatalities from Southern Denmark that were CT scanned and autopsied. The AIS and ISS scores based on CT and autopsy (AU) were registered in a computer database and compared. Kappa values for reproducibility of AIS-severity scores and ISS scores were calculated. On an average, there was a 94% agreement between AU and CT in detecting the presence or absence of lesions in the various anatomic regions, and the severity scores were the same in 90% of all cases (range, 75-100%). When different severity scoring was obtained, CT detected more lesions with a high severity score in the facial skeleton, pelvis, and extremities, whereas AU detected more lesions with high scores in the soft tissues (especially in the aorta), cranium, and ribs. The kappa value for reproducibility of AIS scores confirmed that the agreement between the two methods was good. The lowest kappa values (>0.6) were found for the facial skeleton, cerebellum, meninges, neck organs, lungs, kidneys, and gastrointestinal tract. In these areas, the kappa value provided moderate agreement between CT and AU. For all other areas, there was a substantial agreement between the two methods. The ISS scores obtained by CT and by AU were calculated and were found to be with no or moderate variation in 85%. Rupture of the aorta was often overlooked by CT, resulting in too low ISS scoring. The most precise postmortem AIS and ISS scorings of traffic fatalities was obtained by a combination of AU and CT. If it is not possible to perform an AU, then CT may be used as an acceptable alternative for AIS scoring. We have identified one important obstacle for postmortem ISS scoring, namely that aorta ruptures are not easily detected by post mortem CT.

Computerized tomography with total variation and with shearlets

NASA Astrophysics Data System (ADS)

Garduño, Edgar; Herman, Gabor T.

2017-04-01

To reduce the x-ray dose in computerized tomography (CT), many constrained optimization approaches have been proposed aiming at minimizing a regularizing function that measures a lack of consistency with some prior knowledge about the object that is being imaged, subject to a (predetermined) level of consistency with the detected attenuation of x-rays. One commonly investigated regularizing function is total variation (TV), while other publications advocate the use of some type of multiscale geometric transform in the definition of the regularizing function, a particular recent choice for this is the shearlet transform. Proponents of the shearlet transform in the regularizing function claim that the reconstructions so obtained are better than those produced using TV for texture preservation (but may be worse for noise reduction). In this paper we report results related to this claim. In our reported experiments using simulated CT data collection of the head, reconstructions whose shearlet transform has a small ℓ 1-norm are not more efficacious than reconstructions that have a small TV value. Our experiments for making such comparisons use the recently-developed superiorization methodology for both regularizing functions. Superiorization is an automated procedure for turning an iterative algorithm for producing images that satisfy a primary criterion (such as consistency with the observed measurements) into its superiorized version that will produce results that, according to the primary criterion are as good as those produced by the original algorithm, but in addition are superior to them according to a secondary (regularizing) criterion. The method presented for superiorization involving the ℓ 1-norm of the shearlet transform is novel and is quite general: It can be used for any regularizing function that is defined as the ℓ 1-norm of a transform specified by the application of a matrix. Because in the previous literature the split Bregman algorithm is used for similar purposes, a section is included comparing the results of the superiorization algorithm with the split Bregman algorithm.

Technetium-99m-HMPAO labeled leukocyte single photon emission computerized tomography (SPECT) for assessing Crohn's disease extent and intestinal infiltration.

PubMed

Biancone, L; Schillaci, O; Capoccetti, F; Bozzi, R M; Fina, D; Petruzziello, C; Geremia, A; Simonetti, G; Pallone, F

2005-02-01

Scintigraphy using radiolabeled leukocytes is a useful technique for assessing intestinal infiltration in Crohn's disease (CD). However, limits of planar images include overlapping activity in other organs and low specificity. To investigate the usefulness of (99m)Tc-HMPAO (hexametyl propylene amine oxime) labeled leukocyte single photon emission computerized tomography (SPECT) for assessing CD lesions, in comparison with planar images. Twenty-two inflammatory bowel disease patients (19 CD; 2 ulcerative colitis, UC; 1 ileal pouch) assessed by conventional endoscopy or radiology were enrolled. Leukocytes were labeled with (99m)Tc-HMPAO. SPECT images were acquired at 2 h and planar images at 30 min and 2 h. Bowel uptake was quantitated in nine regions (score 0-3). Both SPECT and planar images detected a negative scintigraphy (score 0) in the UC patient with no pouchitis and a positive scintigraphy (score 1-3) in the 21 patients showing active inflammation by conventional techniques. SPECT showed a higher global score than planar images (0.71 +/- 0.09 vs 0.30 +/- 0.05; p < 0.001), and in particular in the right iliac fossa (p= 0.003), right and left flank (p < 0.001; p= 0.02), hypogastrium (p= 0.002), and mesogastrium (p < 0.001). SPECT provided a better visualization and a higher uptake than planar images in patients with ileal and ileocolonic CD (6.45 +/- 0.82 vs 2.8 +/- 0.55, p < 0.001; 5.5 +/- 1.6 vs 2.6 +/- 0.7, p= 0.03), and with perianal CD (6.6 +/- 1.6 vs 3.4 +/- 1.2; p= 0.03). (99m)Tc-HMPAO labeled leukocyte SPECT provides a more detailed visualization of CD lesions than planar images. This technique may better discriminate between intestinal and bone marrow uptake, thus being useful for assessing CD lesions within the pelvis, including perianal disease.

Usefulness of fluorodeoxyglucose positron emission tomography/computed tomography for detection of a neuroblastic nodule in a ganglioneuroblastoma: a case report.

PubMed

Takeda, Yuka; Sano, Hideki; Kawano, Asuka; Mochizuki, Kazuhiro; Takahashi, Nobuhisa; Kobayashi, Shogo; Ohara, Yoshihiro; Tasaki, Kazuhiro; Hosoya, Mitusuaki; Kikuta, Atsushi

2018-05-03

Ganglioneuroblastoma, nodular is defined as a composite tumor of biologically distinct clones. The peripheral neuroblastic tumors in this category are characterized by the presence of grossly visible neuroblastoma nodules coexisting with ganglioneuroblastoma, intermixed, or with ganglioneuroma. Making a correct diagnosis of ganglioneuroblastoma, nodular is often difficult by biopsy or partial tumor resection, because the neuroblastic nodule could be hidden and not sampled for pathological examination. We report a case of a Japanese boy aged 3 years, 8 months, with an unresectable abdominal tumor and elevated vanillylmandelic acid and homovanillic acid levels. The initial biopsy was ganglioneuroma. However, after the second biopsy from a hidden neuroblastoma nodule that was clearly highlighted by fluorodeoxyglucose positron emission tomography/computed tomography, we reached the diagnosis of ganglioneuroblastoma, nodular. Because the nodule demonstrated neuroblastoma, differentiating subtype, with a low mitosis-karyorrhexis index (favorable histology) and nonamplified MYCN, the boy was treated according to the intermediate-risk protocol and is now alive and well 4 years after the diagnosis. This case illustrates the critical role of fluorodeoxyglucose positron emission tomography/computed tomography for detecting a neuroblastoma nodule in a ganglioneuroblastoma.

Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

PubMed

Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

2017-06-01

The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO® phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500®, ProMax® 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax® 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500®, the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of an ontology-based system for computerized cognitive rehabilitation.

PubMed

Alloni, Anna; Quaglini, Silvana; Panzarasa, Silvia; Sinforiani, Elena; Bernini, Sara

2018-07-01

This paper describes the results of a randomized clinical trial about the effectiveness of a computerized rehabilitation treatment on a sample of 31 patients affected by Parkinson disease. Computerized exercises were administered by the therapists to the intervention group (n = 17) through the CoRe tool, which automatically generates a big variety of exercises leveraging on a stimuli set (words, sounds and images) organized into a dedicated ontology. A battery of standard neuropsychological tests was performed for patients' assessment at baseline, after the treatment (that lasted 1 month), and after 6 months from the treatment stop. The control group underwent a sham intervention. Results show a statistically significant clinical benefit from computerized rehabilitation with respect to sham treatment. For the intervention group, response time and response accuracy were integrated into a weighted score that accounts also for the specific cognitive burden of each exercise. Differently from the control group, the majority of patients in the intervention group showed an improvement in that score, more marked in the first week of treatment, and which lasts for the entire treatment period, which could account both for a quick learning effect and for an improvement of cognitive conditions. Good usability of CoRe, already observed in previous studies, was confirmed by the present trial, where the percentage of protocol completion in the intervention group is very high (all but one patient are above 90%). The CoRe system showed to be effective to improve some cognitive abilities in patients with Parkinson disease. However, after the end of the training, the benefit is hardly maintained over time. These findings support the implementation of CoRe in the clinical routine and the continuation of the treatment after discharge through the use of a homecare version of the system. Copyright © 2018 Elsevier B.V. All rights reserved.

Treatment Protocol for High Velocity/High Energy Gunshot Injuries to the Face

PubMed Central

Peled, Micha; Leiser, Yoav; Emodi, Omri; Krausz, Amir

2011-01-01

Major causes of facial combat injuries include blasts, high-velocity/high-energy missiles, and low-velocity missiles. High-velocity bullets fired from assault rifles encompass special ballistic properties, creating a transient cavitation space with a small entrance wound and a much larger exit wound. There is no dispute regarding the fact that primary emergency treatment of ballistic injuries to the face commences in accordance with the current advanced trauma life support (ATLS) recommendations; the main areas in which disputes do exist concern the question of the timing, sequence, and modes of surgical treatment. The aim of the present study is to present the treatment outcome of high-velocity/high-energy gunshot injuries to the face, using a protocol based on the experience of a single level I trauma center. A group of 23 injured combat soldiers who sustained bullet and shrapnel injuries to the maxillofacial region during a 3-week regional military conflict were evaluated in this study. Nine patients met the inclusion criteria (high-velocity/high-energy injuries) and were included in the study. According to our protocol, upon arrival patients underwent endotracheal intubation and were hemodynamically stabilized in the shock-trauma unit and underwent total-body computed tomography with 3-D reconstruction of the head and neck and computed tomography angiography. All patients underwent maxillofacial surgery upon the day of arrival according to the protocol we present. In view of our treatment outcomes, results, and low complication rates, we conclude that strict adherence to a well-founded and structured treatment protocol based on clinical experience is mandatory in providing efficient, appropriate, and successful treatment to a relatively large group of patients who sustain various degrees of maxillofacial injuries during a short period of time. PMID:23449809

Cost Analysis of the Addition of Hyperacute Magnetic Resonance Imaging for Selection of Patients for Endovascular Stroke Therapy.

PubMed

John, Seby; Thompson, Nicolas R; Lesko, Terry; Papesh, Nancy; Obuchowski, Nancy; Tomic, Dan; Wisco, Dolora; Khawaja, Zeshaun; Uchino, Ken; Man, Shumei; Cheng-Ching, Esteban; Toth, Gabor; Masaryk, Thomas; Ruggieri, Paul; Modic, Michael; Hussain, Muhammad Shazam

2017-10-01

Patient selection is important to determine the best candidates for endovascular stroke therapy. In application of a hyperacute magnetic resonance imaging (MRI) protocol for patient selection, we have shown decreased utilization with improved outcomes. A cost analysis comparing the pre- and post-MRI protocol time periods was performed to determine if the previous findings translated into cost opportunities. We retrospectively identified individuals considered for endovascular stroke therapy from January 2008 to August 2012 who were ≤8 h from stroke symptoms onset. Patients prior to April 30, 2010 were selected based on results of the computed tomography/computed tomography angiography alone (pre-hyperacute), whereas patients after April 30, 2010 were selected based on results of MRI (post-hyperacute MRI). Demographic, outcome, and financial information was collected. Log-transformed average daily direct costs were regressed on time period. The regression model included demographic and clinical covariates as potential confounders. Multiple imputation was used to account for missing data. We identified 267 patients in our database (88 patients in pre-hyperacute MRI period, 179 in hyperacute MRI protocol period). Patient length of stay was not significantly different in the hyperacute MRI protocol period as compared to the pre-hyperacute MRI period (10.6 vs. 9.9 days, p < 0.42). The median of average daily direct costs was reduced by 24.5% (95% confidence interval 14.1-33.7%, p < 0.001). Use of the hyperacute MRI protocol translated into reduced costs, in addition to reduced utilization and better outcomes. MRI selection of patients is an effective strategy, both for patients and hospital systems.

High dose microCT does not contribute towards improved microPET/CT image quantitative accuracy and can limit longitudinal scanning of small animals

NASA Astrophysics Data System (ADS)

McDougald, Wendy A.; Collins, Richard; Green, Mark; Tavares, Adriana A. S.

2017-10-01

Obtaining accurate quantitative measurements in preclinical Positron Emission Tomography/Computed Tomography (PET/CT) imaging is of paramount importance in biomedical research and helps supporting efficient translation of preclinical results to the clinic. The purpose of this study was two-fold: (1) to investigate the effects of different CT acquisition protocols on PET/CT image quality and data quantification; and (2) to evaluate the absorbed dose associated with varying CT parameters. Methods: An air/water quality control CT phantom, tissue equivalent material phantom, an in-house 3D printed phantom and an image quality PET/CT phantom were imaged using a Mediso nanoPET/CT scanner. Collected data was analyzed using PMOD software, VivoQuant software and National Electric Manufactures Association (NEMA) software implemented by Mediso. Measured Hounsfield Unit (HU) in collected CT images were compared to the known HU values and image noise was quantified. PET recovery coefficients (RC), uniformity and quantitative bias were also measured. Results: Only less than 2% and 1% of CT acquisition protocols yielded water HU values < -80 and air HU values < -840, respectively. Four out of eleven CT protocols resulted in more than 100 mGy absorbed dose. Different CT protocols did not impact PET uniformity and RC, and resulted in <4% overall bias relative to expected radioactive concentration. Conclusion: Preclinical CT protocols with increased exposure times can result in high absorbed doses to the small animals. These should be avoided, as they do not contributed towards improved microPET/CT image quantitative accuracy and could limit longitudinal scanning of small animals.

Standardization and Optimization of Computed Tomography Protocols to Achieve Low-Dose

PubMed Central

Chin, Cynthia; Cody, Dianna D.; Gupta, Rajiv; Hess, Christopher P.; Kalra, Mannudeep K.; Kofler, James M.; Krishnam, Mayil S.; Einstein, Andrew J.

2014-01-01

The increase in radiation exposure due to CT scans has been of growing concern in recent years. CT scanners differ in their capabilities and various indications require unique protocols, but there remains room for standardization and optimization. In this paper we summarize approaches to reduce dose, as discussed in lectures comprising the first session of the 2013 UCSF Virtual Symposium on Radiation Safety in Computed Tomography. The experience of scanning at low dose in different body regions, for both diagnostic and interventional CT procedures, is addressed. An essential primary step is justifying the medical need for each scan. General guiding principles for reducing dose include tailoring a scan to a patient, minimizing scan length, use of tube current modulation and minimizing tube current, minimizing-tube potential, iterative reconstruction, and periodic review of CT studies. Organized efforts for standardization have been spearheaded by professional societies such as the American Association of Physicists in Medicine. Finally, all team members should demonstrate an awareness of the importance of minimizing dose. PMID:24589403

Experimental adaptive quantum tomography of two-qubit states

NASA Astrophysics Data System (ADS)

Struchalin, G. I.; Pogorelov, I. A.; Straupe, S. S.; Kravtsov, K. S.; Radchenko, I. V.; Kulik, S. P.

2016-01-01

We report an experimental realization of adaptive Bayesian quantum state tomography for two-qubit states. Our implementation is based on the adaptive experimental design strategy proposed in the work by Huszár and Houlsby [F. Huszár and N. M. T. Houlsby, Phys. Rev. A 85, 052120 (2012)., 10.1103/PhysRevA.85.052120] and provides an optimal measurement approach in terms of the information gain. We address the practical questions which one faces in any experimental application: the influence of technical noise and the behavior of the tomographic algorithm for an easy-to-implement class of factorized measurements. In an experiment with polarization states of entangled photon pairs, we observe a lower instrumental noise floor and superior reconstruction accuracy for nearly pure states of the adaptive protocol compared to a nonadaptive protocol. At the same time, we show that for the mixed states, the restriction to factorized measurements results in no advantage for adaptive measurements, so general measurements have to be used.

A novel color vision test for detection of diabetic macular edema.

PubMed

Shin, Young Joo; Park, Kyu Hyung; Hwang, Jeong-Min; Wee, Won Ryang; Lee, Jin Hak; Lee, In Bum; Hyon, Joon Young

2014-01-02

To determine the sensitivity of the Seoul National University (SNU) computerized color vision test for detecting diabetic macular edema. From May to September 2003, a total of 73 eyes of 73 patients with diabetes mellitus were examined using the SNU computerized color vision test and optical coherence tomography (OCT). Color deficiency was quantified as the total error score on the SNU test and as error scores for each of four color quadrants corresponding to yellows (Q1), greens (Q2), blues (Q3), and reds (Q4). SNU error scores were assessed as a function of OCT foveal thickness and total macular volume (TMV). The error scores in Q1, Q2, Q3, and Q4 measured by the SNU color vision test increased with foveal thickness (P < 0.05), whereas they were not correlated with TMV. Total error scores, the summation of Q1 and Q3, the summation of Q2 and Q4, and blue-yellow (B-Y) error scores were significantly correlated with foveal thickness (P < 0.05), but not with TMV. The observed correlation between SNU color test error scores and foveal thickness indicates that the SNU test may be useful for detection and monitoring of diabetic macular edema.

The association of malocclusion and trumpet performance.

PubMed

Kula, Katherine; Cilingir, H Zeynep; Eckert, George; Dagg, Jack; Ghoneima, Ahmed

2015-04-20

  To determine whether trumpet performance skills are associated with malocclusion.   Following institutional review board approval, 70 university trumpet students (54 male, 16 female; aged 20-38.9 years) were consented. After completing a survey, the students were evaluated while playing a scripted performance skills test (flexibility, articulation, range, and endurance exercises) on their instrument in a soundproof music practice room. One investigator (trumpet teacher) used a computerized metronome and a decibel meter during evaluation. A three-dimensional (3D) cone-beam computerized tomography scan (CBCT) was taken of each student the same day as the skills test. Following reliability studies, multiple dental parameters were measured on the 3D CBCT. Nonparametric correlations (Spearman), accepting P < .05 as significant, were used to determine if there were significant associations between dental parameters and the performance skills.   Intrarater reliability was excellent (intraclass correlations; all r values > .94). Although associations were weak to moderate, significant negative associations (r ≤ -.32) were found between Little's irregularity index, interincisal inclination, maxillary central incisor rotation, and various flexibility and articulation performance skills, whereas significant positive associations (r ≤ .49) were found between arch widths and various skills.   Specific malocclusions are associated with trumpet performance of experienced young musicians. (Angle Orthod. 0000;00:000-000.).

Improving perceptions of empathy in patients undergoing low-yield computerized tomographic imaging in the emergency department.

PubMed

Lin, Michelle P; Probst, Marc A; Puskarich, Michael A; Dehon, Erin; Kuehl, Damon R; Wang, Ralph C; Hess, Erik P; Butler, Katie; Runyon, Michael S; Wang, Hao; Courtney, D Mark; Muckley, Brandon; Hobgood, Cherri D; Hall, Cassandra L; Kline, Jeffrey A

2018-04-01

We assessed emergency department (ED) patient perceptions of how physicians can improve their language to determine patient preferences for 11 phrases to enhance physician empathy toward the goal of reducing low-value advanced imaging. Multi-center survey study of low-risk ED patients undergoing computerized tomography (CT) scanning. We enroled 305 participants across nine sites. The statement "I have carefully considered what you told me about what brought you here today" was most frequently rated as important (88%). The statement "I have thought about the cost of your medical care to you today" was least frequently rated as important (59%). Participants preferred statements indicating physicians had considered their "vital signs and physical examination" (86%), "past medical history" (84%), and "what prior research tells me about your condition" (79%). Participants also valued statements conveying risks of testing, including potential kidney injury (78%) and radiation (77%). The majority of phrases were identified as important. Participants preferred statements conveying cognitive reassurance, medical knowledge and risks of testing. Our findings suggest specific phrases have the potential to enhance ED patient perceptions of physician empathy. Further research is needed to determine whether statements to convey empathy affect diagnostic testing rates. Copyright © 2017 Elsevier B.V. All rights reserved.

Small Vessel Disease/White Matter Disease of the Brain and Its Association With Osteoporosis

PubMed Central

Alagiakrishnan, Kannayiram; Hsueh, Jenny; Zhang, Edwin; Khan, Khurshid; Senthilselvan, Ambikaipakan

2015-01-01

Background Evidence now suggests the role of neural effect on bone mass control. The effect of small vessel disease of the brain on osteoporosis has not been studied. The aim of this study was to investigate the association of white matter disease (WMD) of the brain with osteoporosis in the elderly. Methods In this retrospective cross-sectional study, 780 consecutive patient charts between 2010 and 2011 were reviewed in the Senior’s Outpatient Clinic at the University of Alberta Hospital. Subjects with brain computerized tomography (CT) were included in the study. Subjects with incomplete information, intracranial hemorrhage, acute stroke, cerebral edema, and/or normal pressure hydrocephalus on the CT were excluded. WMD was quantified on CT using Wahlund’s scoring protocol. Osteoporosis information was obtained from the chart, which has been diagnosed based on bone mineral density (BMD) information. Logistic regression analysis was done to determine the association of WMD severity with osteoporosis after controlling for confounding vascular risk factors. Results Of the 505 subjects who were included in the study, 188 (37%) had osteoporosis and 171 (91%) of these osteoporotic subjects were females. The mean age was 79.8 ± 7.04 years. The prevalence of WMD in osteoporosis subjects was 73%. In the unadjusted logistic regression analysis, there was a significant association between WMD severity and osteoporosis (odds ratio (OR): 1.10; 95% confidence interval (CI): 1.05 - 1.14; P < 0.001) and the significance remained in the adjusted model, after correcting for age, sex and all vascular risk factors (OR: 1.11; 95% CI: 1.05 - 1.18; P < 0.001). Conclusion WMD severity of the brain was associated with osteoporosis in the elderly. PMID:25780476

Mycobacterium tuberculosis dysregulates MMP/TIMP balance to drive rapid cavitation and unrestrained bacterial proliferation

PubMed Central

Kübler, André; Luna, Brian; Larsson, Christer; Ammerman, Nicole C.; Andrade, Bruno B.; Orandle, Marlene; Bock, Kevin W.; Xu, Ziyue; Bagci, Ulas; Molura, Daniel J.; Marshall, John; Burns, Jay; Winglee, Kathryn; Ahidjo, Bintou Ahmadou; Cheung, Laurene S.; Klunk, Mariah; Jain, Sanjay K.; Kumar, Nathella Pavan; Babu, Subash; Sher, Alan; Friedland, Jon S.; Elkington, Paul T. G.; Bishai, William R.

2014-01-01

Active tuberculosis (TB) often presents with advanced pulmonary disease, including irreversible lung damage and cavities. Cavitary pathology contributes to antibiotic failure, transmission, morbidity and mortality. Matrix metalloproteinases (MMPs), in particular MMP-1 are implicated in TB pathogenesis. We explored the mechanisms relating MMP/TIMP imbalance to cavity formation in a modified rabbit model of cavitary TB. Our model results in consistent progression of consolidation to human-like cavities (100% by day 28) with resultant bacillary burdens (>107 CFU/g) far greater than those found in matched granulomatous tissue (105 CFU/g). Using a novel, breath-hold computerized tomography scanning and image analysis protocol. We show that cavities develop rapidly from areas of densely consolidated tissue. Radiological change correlated with a decrease in functional lung tissue as estimated by changes in lung density during controlled pulmonary expansion (R2=0.6356, p<0.0001). We demonstrated that the expression of interstitial collagenase (MMP-1) is specifically greater in cavitary compared to granulomatous lesions (p<0.01), and that TIMP-3 significantly decreases at the cavity surface. Our findings demonstrate that an MMP-1/TIMP imbalance, is associated with the progression of consolidated regions to cavities containing very high bacterial burdens. Our model provided mechanistic insight, correlating with human disease at the pathological, microbiological and molecular levels,. It also provides a strategy to investigate therapeutics in the context of complex TB pathology. We used these findings to predict a MMP/TIMP balance in active TB; and confirmed this in human plasma, revealing the potential of MMP/TIMP levels as key components of a diagnostic matrix aimed at distinguishing active from latent TB (PPV=92.9%; 95%CI 66.1–99.8%, NPV=85.6%; 95%CI 77.0–91.9%). PMID:25186281

A three-dimensional thermal and electromagnetic model of whole limb heating with a MAPA.

PubMed

Charny, C K; Levin, R L

1991-10-01

Previous studies by the authors have shown that if properly implemented, the Pennes assumptions can be applied to quantify bioheat transfer during extremity heating. Given its relative numerical simplicity and its ability to predict temperatures in thermoregulated tissue, the Pennes model of bioheat transfer was utilized in a three-dimensional thermal model of limb heating. While the arterial blood temperature was assumed to be radially uniform within a cross section of the limb, axial gradients in the arterial and venous blood temperatures were computed with this three-dimensional model. A realistically shaped, three-dimensional finite element model of a tumor-bearing human lower leg was constructed and was "attached" mathematically to the whole body thermal model of man described in previous studies by the authors. The central as well as local thermoregulatory feedback control mechanisms which determine blood perfusion to the various tissues and rate of evaporation by sweating were input into the limb model. In addition, the temperature of the arterial blood which feeds into the most proximal section of the lower leg was computed by the whole body thermal model. The variations in the shape of the tissues which comprise the limb were obtained from computerized tomography scans. Axial variations in the energy deposition patterns along the length of the limb exposed to a miniannular phased array (MAPA) applicator were also input into this model of limb heating. Results indicate that proper positioning of the limb relative to the MAPA is a significant factor in determining the effectiveness of the treatment. A patient-specific hyperthermia protocol can be designed using this coupled electromagnetic and thermal model.

COBRA: A prospective multimodal imaging study of dopamine, brain structure and function, and cognition.

PubMed

Nevalainen, N; Riklund, K; Andersson, M; Axelsson, J; Ögren, M; Lövdén, M; Lindenberger, U; Bäckman, L; Nyberg, L

2015-07-01

Cognitive decline is a characteristic feature of normal human aging. Previous work has demonstrated marked interindividual variability in onset and rate of decline. Such variability has been linked to factors such as maintenance of functional and structural brain integrity, genetics, and lifestyle. Still, few, if any, studies have combined a longitudinal design with repeated multimodal imaging and a comprehensive assessment of cognition as well as genetic and lifestyle factors. The present paper introduces the Cognition, Brain, and Aging (COBRA) study, in which cognitive performance and brain structure and function are measured in a cohort of 181 older adults aged 64 to 68 years at baseline. Participants will be followed longitudinally over a 10-year period, resulting in a total of three equally spaced measurement occasions. The measurement protocol at each occasion comprises a comprehensive set of behavioral and imaging measures. Cognitive performance is evaluated via computerized testing of working memory, episodic memory, perceptual speed, motor speed, implicit sequence learning, and vocabulary. Brain imaging is performed using positron emission tomography with [(11)C]-raclopride to assess dopamine D2/D3 receptor availability. Structural magnetic resonance imaging (MRI) is used for assessment of white and gray-matter integrity and cerebrovascular perfusion, and functional MRI maps brain activation during rest and active task conditions. Lifestyle descriptives are collected, and blood samples are obtained and stored for future evaluation. Here, we present selected results from the baseline assessment along with a discussion of sample characteristics and methodological considerations that determined the design of the study. This article is part of a Special Issue entitled SI: Memory & Aging. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Optimizing multimodality treatment for head and neck cancer in rural India.

PubMed

Trivedi, N P; Trivedi, P; Trivedi, H; Trivedi, S; Trivedi, N

2012-01-01

Multimodality treatment of head and neck cancer in rural India is not always feasible due to lack of infrastructure and logistics. To demonstrate the feasibility of multimodality treatment for head and neck cancer in a community setting in rural India. Community cancer center, retrospective review. This article focuses on practice environment in a cancer clinic in rural India. We evaluated patient profile, treatment protocols, infrastructure availability, factors impacting treatment decisions, cost estimations, completion of treatment, and major treatment-related complications for the patient population treated in our clinic for a 2-year period. A total of 230 head and neck cancer patients were treated with curative intent. Infrastructure support included basic operating room facility (cautery machine, suction, drill system, microscope, and anesthesia machine without ventilator support), blood bank, histopathology laboratory, and computerized tomography machine. Radiation therapy (RT) facility was available in a nearby city, about 75 km away. One hundred and fifty-four (67%) patients presented at an advanced stage, with 138 (60%) receiving multimodality treatment. One hundred and eighty-four (80%) patients underwent primary surgery and 167 (73%) received radiotherapy. Two hundred and twelve (92%) patients completed the treatment, 60 (26%) were lost to follow-up at 18-month median follow-up (range 12-26 months), with 112 patients (66%) being alive, disease free. Totally 142 were major head neck surgeries with 25 free flap reconstructions and 41 regional flaps. There were 15 (6%) major post-op complications and two perioperative mortalities. Average cost of treatment for single modality treatment was approximately 40,000 INR and for multimodality treatment was 80,000 INR. This study demonstrates that it is feasible to provide basic multimodality treatment to head and neck cancer patients in the community.

Impact of Image Filters and Observations Parameters in CBCT for Identification of Mandibular Osteolytic Lesions

PubMed Central

Monteiro, Bruna Moraes; Nobrega Filho, Denys Silveira; Lopes, Patrícia de Medeiros Loureiro; de Sales, Marcelo Augusto Oliveira

2012-01-01

The aim of this study was to analyze the influence of filters (algorithms) to improve the image of Cone Beam Computed Tomography (CBCT) in diagnosis of osteolytic lesions of the mandible, in order to establish the protocols for viewing images more suitable for CBCT diagnostics. 15 dry mandibles in which perforations were performed, simulating lesions, were submitted to CBCT examination. Two examiners analyzed the images, using filters to improve image Hard, Normal, and Very Sharp, contained in the iCAT Vision software, and protocols for assessment: axial; sagittal and coronal; and axial, sagittal and coronal planes simultaneously (MPR), on two occasions. The sensitivity and specificity (validity) of the cone beam computed tomography (CBCT) have been demonstrated as the values achieved were above 75% for sensitivity and above 85% for specificity, reaching around 95.5% of sensitivity and 99% of specificity when we used the appropriate observation protocol. It was concluded that the use of filters (algorithms) to improve the CBCT image influences the diagnosis, due to the fact that all measured values were correspondingly higher when it was used the filter Very Sharp, which justifies its use for clinical activities, followed by Hard and Normal filters, in order of decreasing values. PMID:22956955

Impact of Image Filters and Observations Parameters in CBCT for Identification of Mandibular Osteolytic Lesions.

PubMed

Monteiro, Bruna Moraes; Nobrega Filho, Denys Silveira; Lopes, Patrícia de Medeiros Loureiro; de Sales, Marcelo Augusto Oliveira

2012-01-01

The aim of this study was to analyze the influence of filters (algorithms) to improve the image of Cone Beam Computed Tomography (CBCT) in diagnosis of osteolytic lesions of the mandible, in order to establish the protocols for viewing images more suitable for CBCT diagnostics. 15 dry mandibles in which perforations were performed, simulating lesions, were submitted to CBCT examination. Two examiners analyzed the images, using filters to improve image Hard, Normal, and Very Sharp, contained in the iCAT Vision software, and protocols for assessment: axial; sagittal and coronal; and axial, sagittal and coronal planes simultaneously (MPR), on two occasions. The sensitivity and specificity (validity) of the cone beam computed tomography (CBCT) have been demonstrated as the values achieved were above 75% for sensitivity and above 85% for specificity, reaching around 95.5% of sensitivity and 99% of specificity when we used the appropriate observation protocol. It was concluded that the use of filters (algorithms) to improve the CBCT image influences the diagnosis, due to the fact that all measured values were correspondingly higher when it was used the filter Very Sharp, which justifies its use for clinical activities, followed by Hard and Normal filters, in order of decreasing values.

Image Quality and Radiation Exposure Comparison of a Double High-Pitch Acquisition for Coronary Computed Tomography Angiography Versus Standard Retrospective Spiral Acquisition in Patients With Atrial Fibrillation.

PubMed

Prazeres, Carlos Eduardo Elias Dos; Magalhães, Tiago Augusto; de Castro Carneiro, Adriano Camargo; Cury, Roberto Caldeira; de Melo Moreira, Valéria; Bello, Juliana Hiromi Silva Matsumoto; Rochitte, Carlos Eduardo

The aim of this study was to compare image quality and radiation dose of coronary computed tomography (CT) angiography performed with dual-source CT scanner using 2 different protocols in patients with atrial fibrillation. Forty-seven patients with AF underwent 2 different acquisition protocols: double high-pitch (DHP) spiral acquisition and retrospective spiral acquisition. The image quality was ranked according to a qualitative score by 2 experts: 1, no evident motion; 2, minimal motion not influencing coronary artery luminal evaluation; and 3, motion with impaired luminal evaluation. A third expert solved any disagreement. A total of 732 segments were evaluated. The DHP group (24 patients, 374 segments) showed more segments classified as score 1 than the retrospective spiral acquisition group (71.3% vs 37.4%). Image quality evaluation agreement was high between observers (κ = 0.8). There was significantly lower radiation exposure for the DHP group (3.65 [1.29] vs 23.57 [10.32] mSv). In this original direct comparison, a DHP spiral protocol for coronary CT angiography acquisition in patients with atrial fibrillation resulted in lower radiation exposure and superior image quality compared with conventional spiral retrospective acquisition.

Dose reduction in whole-body computed tomography of multiple injuries (DoReMI): protocol for a prospective cohort study

PubMed Central

2014-01-01

Background Single-pass, contrast-enhanced whole body multidetector computed tomography (MDCT) emerged as the diagnostic standard for evaluating patients with major trauma. Modern iterative image algorithms showed high image quality at a much lower radiation dose in the non-trauma setting. This study aims at investigating whether the radiation dose can safely be reduced in trauma patients without compromising the diagnostic accuracy and image quality. Methods/Design Prospective observational study with two consecutive cohorts of patients. Setting: A high-volume, academic, supra-regional trauma centre in Germany. Study population: Consecutive male and female patients who 1. had been exposed to a high-velocity trauma mechanism, 2. present with clinical evidence or high suspicion of multiple trauma (predicted Injury Severity Score [ISS] ≥16) and 3. are scheduled for primary MDCT based on the decision of the trauma leader on call. Imaging protocols: In a before/after design, a consecutive series of 500 patients will undergo single-pass, whole-body 128-row multi-detector computed tomography (MDCT) with a standard, as low as possible radiation dose. This will be followed by a consecutive series of 500 patients undergoing an approved ultra-low dose MDCT protocol using an image processing algorithm. Data: Routine administrative data and electronic patient records, as well as digital images stored in a picture archiving and communications system will serve as the primary data source. The protocol was approved by the institutional review board. Main outcomes: (1) incidence of delayed diagnoses, (2) diagnostic accuracy, as correlated to the reference standard of a synopsis of all subsequent clinical, imaging, surgical and autopsy findings, (3) patients’ safety, (4) radiation exposure (e.g. effective dose), (5) subjective image quality (assessed independently radiologists and trauma surgeons on a 100-mm visual analogue scale), (6) objective image quality (e.g., contrast-to-noise ratio). Analysis: Multivariate regression will be employed to adjust and correct the findings for time and cohort effects. An exploratory interim analysis halfway after introduction of low-dose MDCT will be conducted to assess whether this protocol is clearly inferior or superior to the current standard. Discussion Although non-experimental, this study will generate first large-scale data on the utility of imaging-enhancing algorithms in whole-body MDCT for major blunt trauma. Trial registration Current Controlled Trials ISRCTN74557102. PMID:24589310

Comparison of the pharmacokinetics between L-BPA and L-FBPA using the same administration dose and protocol: a validation study for the theranostic approach using [18F]-L-FBPA positron emission tomography in boron neutron capture therapy.

PubMed

Watanabe, Tsubasa; Hattori, Yoshihide; Ohta, Youichiro; Ishimura, Miki; Nakagawa, Yosuke; Sanada, Yu; Tanaka, Hiroki; Fukutani, Satoshi; Masunaga, Shin-Ichiro; Hiraoka, Masahiro; Ono, Koji; Suzuki, Minoru; Kirihata, Mitsunori

2016-11-08

Boron neutron capture therapy (BNCT) is a cellular-level particle radiation therapy that combines the selective delivery of boron compounds to tumour tissue with neutron irradiation. L-p-Boronophenylalanine (L-BPA) is a boron compound now widely used in clinical situations. Determination of the boron distribution is required for successful BNCT prior to neutron irradiation. Thus, positron emission tomography with [ 18 F]-L-FBPA, an 18 F-labelled radiopharmaceutical analogue of L-BPA, was developed. However, several differences between L-BPA and [ 18 F]-L-FBPA have been highlighted, including the different injection doses and administration protocols. The purpose of this study was to clarify the equivalence between L-BPA and [ 19 F]-L-FBPA as alternatives to [ 18 F]-L-FBPA. SCC-VII was subcutaneously inoculated into the legs of C3H/He mice. The same dose of L-BPA or [ 19 F]-L-FBPA was subcutaneously injected. The time courses of the boron concentrations in blood, tumour tissue, and normal tissue were compared between the groups. Next, we administered the therapeutic dose of L-BPA or the same dose of [ 19 F]-L-FBPA by continuous infusion and compared the effects of the administration protocol on boron accumulation in tissues. There were no differences between L-BPA and [ 19 F]-L-FBPA in the transition of boron concentrations in blood, tumour tissue, and normal tissue using the same administration protocol. However, the normal tissue to blood ratio of the boron concentrations in the continuous-infusion group was lower than that in the subcutaneous injection group. No difference was noted in the time course of the boron concentrations in tumour tissue and normal tissues between L-BPA and [ 19 F]-L-FBPA. However, the administration protocol had effects on the normal tissue to blood ratio of the boron concentration. In estimating the BNCT dose in normal tissue by positron emission tomography (PET), we should consider the possible overestimation of the normal tissue to blood ratio of the boron concentrations derived from the values measured by PET on dose calculation.

Comparison and usefulness of cardiac magnetic resonance versus computed tomography in infants six months of age or younger with aortic arch anomalies without deep sedation or anesthesia.

PubMed

Fogel, Mark A; Pawlowski, Thomas W; Harris, Matthew A; Whitehead, Kevin K; Keller, Marc S; Wilson, Justine; Tipton, Deanna; Harris, Christine

2011-07-01

The present project investigated whether cardiac magnetic resonance (CMR) of aortic arch anomalies can be performed successfully in infants <6 months of age without the use of cardiac anesthesia or deep sedation. We performed a retrospective review of infants ≤6 months old from 2005 to 2009 who underwent either CMR or computed tomography angiography to investigate aortic arch abnormalities. The CMR procedure used a "feed and swaddle" protocol without deep sedation or cardiac anesthesia. Of the 52 infants referred for CMR, 24 underwent the feed and swaddle protocol (aged 2.6 ± 1.4 months). One patient awoke during the study, and examination of the remaining 23 yielded a definitive diagnosis (success rate 96%). The scanning time was 6.2 ± 3.1 minutes, with the large airways evaluation accounting for 1/2 the time. Single-shot axial steady-state free precession, in which the definitive diagnosis was made, accounted for 0.59 ± 0.3 minutes. Fifteen infants were diagnosed with a vascular ring. Of the 8 infants who underwent surgery, the diagnostic accuracy was 100%. During the same period, 19 patients, who had undergone computed tomography angiography (aged 1.67 ± 1.20 months), were referred for aortic arch evaluation. Of these 19 patients, 6 (32%) underwent sedation or anesthesia. The imaging time was 0.08 ± 0.06 minutes, significantly different from the CMR times (p <0.01). However, the overall room times (31.3 ± 22.3 and 35.8 ± 3.86 minutes, respectively) were not different between the CMR and angiographic groups. The radiation dose was 1.41 ± 1.03 mSv. In conclusion, CMR evaluation of aortic arch anomalies in children <6 months old can be successfully completed quickly using a feed and swaddle approach with high diagnostic accuracy. This protocol avoids the risks of sedation, as well as the radiation associated with computed tomography angiography. Copyright © 2011 Elsevier Inc. All rights reserved.

Very Low Intravenous Contrast Volume Protocol for Computed Tomography Angiography Providing Comprehensive Cardiac and Vascular Assessment Prior to Transcatheter Aortic Valve Replacement in Patients with Chronic Kidney Disease

PubMed Central

Pulerwitz, Todd C.; Khalique, Omar K.; Nazif, Tamim N.; Rozenshtein, Anna; Pearson, Gregory D.N.; Hahn, Rebecca T.; Vahl, Torsten P.; Kodali, Susheel K.; George, Isaac; Leon, Martin B.; D'Souza, Belinda; Po, Ming Jack; Einstein, Andrew J.

2016-01-01

Background Transcatheter aortic valve replacement (TAVR) is a lifesaving procedure for many patients high risk for surgical aortic valve replacement. The prevalence of chronic kidney disease (CKD) is high in this population, and thus a very low contrast volume (VLCV) computed tomography angiography (CTA) protocol providing comprehensive cardiac and vascular imaging would be valuable. Methods 52 patients with severe, symptomatic aortic valve disease, undergoing pre-TAVR CTA assessment from 2013-4 at Columbia University Medical Center were studied, including all 26 patients with CKD (eGFR<30mL/min) who underwent a novel VLCV protocol (20mL of iohexol at 2.5mL/s), and 26 standard-contrast-volume (SCV) protocol patients. Using a 320-slice volumetric scanner, the protocol included ECG-gated volume scanning of the aortic root followed by medium-pitch helical vascular scanning through the femoral arteries. Two experienced cardiologists performed aortic annulus and root measurements. Vascular image quality was assessed by two radiologists using a 4-point scale. Results VLCV patients had mean(±SD) age 86±6.5, BMI 23.9±3.4 kg/m2 with 54% men; SCV patients age 83±8.8, BMI 28.7±5.3 kg/m2, 65% men. There was excellent intra- and inter-observer agreement for annular and root measurements, and excellent agreement with 3D-transesophageal echocardiographic measurements. Both radiologists found diagnostic-quality vascular imaging in 96% of VLCV and 100% of SCV cases, with excellent inter-observer agreement. Conclusions This study is the first of its kind to report the feasibility and reproducibility of measurements for a VLCV protocol for comprehensive pre-TAVR CTA. There was excellent agreement of cardiac measurements and almost all studies were diagnostic quality for vascular access assessment. PMID:27061253

Experimental Demonstration of a Cheap and Accurate Phase Estimation

DOE PAGES

Rudinger, Kenneth; Kimmel, Shelby; Lobser, Daniel; ...

2017-05-11

We demonstrate an experimental implementation of robust phase estimation (RPE) to learn the phase of a single-qubit rotation on a trapped Yb + ion qubit. Here, we show this phase can be estimated with an uncertainty below 4 × 10 -4 rad using as few as 176 total experimental samples, and our estimates exhibit Heisenberg scaling. Unlike standard phase estimation protocols, RPE neither assumes perfect state preparation and measurement, nor requires access to ancillae. We crossvalidate the results of RPE with the more resource-intensive protocol of gate set tomography.

An anencephalic monocephalus diprosopus "headed twin": postmortem and CT findings with emphasis on the cranial bones.

PubMed

Ekinci, Gazanfer; Balci, Sevim; Erzen, Canan

2005-01-01

Monocephalus diprosopus is a form of conjoined twinning characterized by a single body, one unusual head and two faces or a spectrum of duplication of the craniofacial structures. Such cases have been mainly described according to postmortem pathologic examination. This presented case is a 26-week-stillborn female fetus, with unusual facial appearance with four eyes, two mouths, two noses, two ears and a defective cranial vault. To our knowledge, a detailed computerized tomography (CT) examination of the aberrant facial and cranial bones of such a case has not been reported to date. In this reported case, we present an anencephalic monocephalus diprosopus "headed twin", and describe the CT findings with emphasis on the cranial bones.

Chronic pulmonary interstitial fibrosis in a blue-fronted Amazon parrot (Amazona aestiva aestiva).

PubMed

Amann, Olga; Kik, Marja J L; Passon-Vastenburg, Maartje H A C; Westerhof, Ineke; Lumeij, Johannes T; Schoemaker, Nico J

2007-03-01

A 30-yr-old blue-fronted Amazon parrot (Amazon aestiva aestiva) was presented to the clinic with a history of sneezing more often during the last 2 mo. Physical examination revealed only a mild nasal discharge. Complete hematologic and plasma biochemical examination showed no abnormalities. Computerized tomography (CT) of the complete bird showed generalized lung alterations consistent with lung fibrosis. Two lung biopsies were taken. The results of the histologic examination of the biopsies confirmed the tentative CT diagnosis of pulmonary interstitial fibrosis. To our knowledge this is the first reported case of chronic pulmonary interstitial fibrosis diagnosed by means of a lung biopsy in an avian species. The histologic characteristics are discussed and compared with those of human idiopathic pulmonary fibrosis.

[Treatment of inflammatory complications of colic diverticular disease at the emergency surgical care hospital].

PubMed

Reznitsky, P A; Yartsev, P A; Shavrina, N V

To assess an effectiveness of minimally invasive and laparoscopic technologies in treatment of inflammatory complications of colic diverticular disease. The study included 150 patients who were divided into control and main groups. Survey included ultrasound, X-ray examination and abdominal computerized tomography. In the main group standardized treatment algorithm including minimally invasive and laparoscopic technologies was used. In the main group 79 patients underwent conservative treatment, minimally invasive (ultrasound-assisted percutaneous drainage of abscesses) and laparoscopic surgery that was successful in 78 (98.7%) patients. Standardized algorithm reduces time of treatment, incidence of postoperative complications, mortality and the risk of recurrent inflammatory complications of colic diverticular disease. Also postoperative quality of life was improved.

Manubriosternal dislocation with spinal fracture: A rare cause for delayed haemothorax.

PubMed

Kothari, Manish; Saini, Pramod; Shethna, Sunny; Dalvie, Samir

2015-01-01

Type 2 manubriosternal dislocations with concomitant spinal fracture are rare and may be associated with thoracic visceral injuries. The complication of delayed haemothorax has not been reported yet. We report a case of a young male who suffered manubriosternal dislocation with chance type thoracic spine fracture due to fall of a tree branch over his back. The haemothorax presented late on day three. The possible injury mechanism is discussed along with review of literature. We conclude that a lateral chest radiograph is indicated in spinal fracture patients complaining of midsternal pain. Computerized axial tomography scan of chest with contrast is indicated to rule out visceral injuries and a chest radiograph should be repeated before the patient is discharged to look for delayed haemothorax.

Distributed nuclear medicine applications using World Wide Web and Java technology.

PubMed

Knoll, P; Höll, K; Mirzaei, S; Koriska, K; Köhn, H

2000-01-01

At present, medical applications applying World Wide Web (WWW) technology are mainly used to view static images and to retrieve some information. The Java platform is a relative new way of computing, especially designed for network computing and distributed applications which enables interactive connection between user and information via the WWW. The Java 2 Software Development Kit (SDK) including Java2D API, Java Remote Method Invocation (RMI) technology, Object Serialization and the Java Advanced Imaging (JAI) extension was used to achieve a robust, platform independent and network centric solution. Medical image processing software based on this technology is presented and adequate performance capability of Java is demonstrated by an iterative reconstruction algorithm for single photon emission computerized tomography (SPECT).

Reconstruction of a three-dimensional, transonic rotor flow field from holographic interferogram data

NASA Technical Reports Server (NTRS)

Kittleson, John K.; Yu, Yung H.

1987-01-01

Holographic interferometry and computerized aided tomography (CAT) are used to determine the transonic velocity field of a model rotor blade in hover. A pulsed ruby laser recorded 40 interferograms with a 2 ft dia view field near the model rotor blade tip operating at a tip Mach number of 0.90. After digitizing the interferograms and extracting the fringe order functions, the data are transferred to a CAT code. The CAT code then calculates the perturbation velocity in several planes above the blade surface. The values from the holography-CAT method compare favorably with previously obtained numerical computations in most locations near the blade tip. The results demonstrate the technique's potential for three dimensional transonic rotor flow studies.

Herniation of unruptured tuberculous lung abscess into chest wall without pleural or bronchial spillage

PubMed Central

Magazine, Rahul; Mohapatra, Aswini K.; Manu, Mohan K.; Srivastava, Rajendra K.

2011-01-01

A 22-year-old unmarried man presented to the chest outpatient department with a history of productive cough of two-month duration. He also complained of pain and swelling on the anterior aspect of right side of chest of one-month duration. Imaging studies of the thorax, including chest roentgenography and computerized tomography, revealed an unruptured lung abscess which had herniated into the chest wall. Culture of pus aspirated from the chest wall swelling grew Mycobacterium tuberculosis. He was diagnosed to have a tuberculous lung abscess which had extended into the chest wall, without spillage into the pleural cavity or the bronchial tree. Antituberculosis drugs were prescribed, and he responded to the treatment with complete resolution of the lesion. PMID:22084547

Brief cognitive and behavioral screening in children with new-onset epilepsy: a pilot feasibility trial.

PubMed

Triplett, Regina L; Asato, Miya R

2015-01-01

Minimal work has used psychometrically robust measures in a systematic fashion to identify and monitor children at risk for cognitive and behavioral comorbidities in current epilepsy care. We piloted a computerized cognitive battery and behavioral questionnaire for children with newly diagnosed epilepsy to determine clinical feasibility and acceptability to parents and patients. We recruited medication-naïve children (ages 8-17 years) with recent-onset seizures and typical developmental history from an outpatient child neurology clinic. Children completed the CNS Vital Signs computerized battery, whereas parents completed the Strengths and Difficulties Questionnaire. Post-test interviews with parents and patients were completed regarding the acceptability of the assessment procedures. Forty-four families were eligible, and 39 agreed to participate (89%). All assessments were completed in less than 45 minutes. Parents rated testing in clinic as convenient and important, expressing strong interest in the cognitive and behavioral impact of epilepsy and medication. Children also rated the testing procedure as acceptable and agreed that they would recommend it to peers. Our brief battery was tolerated and well received by children and their parents. Computerized testing of children along with a parent questionnaire is a psychometrically viable approach that is acceptable to families. Our protocol is time efficient for clinical use with the potential to detect early cognitive and behavioral difficulties related to epilepsy. Ongoing longitudinal study will provide further information regarding the success of our screening methods in monitoring for disease- or treatment-related changes. Copyright © 2015 Elsevier Inc. All rights reserved.

Denver screening protocol for blunt cerebrovascular injury reduces the use of multi-detector computed tomography angiography.

PubMed

Beliaev, Andrei M; Barber, P Alan; Marshall, Roger J; Civil, Ian

2014-06-01

Blunt cerebrovascular injury (BCVI) occurs in 0.2-2.7% of blunt trauma patients and has up to 30% mortality. Conventional screening does not recognize up to 20% of BCVI patients. To improve diagnosis of BCVI, both an expanded battery of screening criteria and a multi-detector computed tomography angiography (CTA) have been suggested. The aim of this study is to investigate whether the use of CTA restricted to the Denver protocol screen-positive patients would reduce the unnecessary use of CTA as a pre-emptive screening tool. This is a registry-based study of blunt trauma patients admitted to Auckland City Hospital from 1998 to 2012. The diagnosis of BCVI was confirmed or excluded with CTA, magnetic resonance angiography and, if these imaging were non-conclusive, four-vessel digital subtraction angiography. Thirty (61%) BCVI and 19 (39%) non-BCVI patients met eligibility criteria. The Denver protocol applied to our cohort of patients had a sensitivity of 97% (95% confidence interval (CI): 83-100%) and a specificity of 42% (95% CI: 20-67%). With a prevalence of BCVI in blunt trauma patients of 0.2% and 2.7%, post-test odds of a screen-positive test were 0.03 (95% CI: 0.002-0.005) and 0.046 (95% CI: 0.314-0.068), respectively. Application of the CTA to the Denver protocol screen-positive trauma patients can decrease the use of CTA as a pre-emptive screening tool by 95-97% and reduces its hazards. © 2013 Royal Australasian College of Surgeons.

128 slice computed tomography dose profile measurement using thermoluminescent dosimeter

NASA Astrophysics Data System (ADS)

Salehhon, N.; Hashim, S.; Karim, M. K. A.; Ang, W. C.; Musa, Y.; Bahruddin, N. A.

2017-05-01

The increasing use of computed tomography (CT) in clinical practice marks the needs to understand the dose descriptor and dose profile. The purposes of the current study were to determine the CT dose index free-in-air (CTDIair) in 128 slice CT scanner and to evaluate the single scan dose profile (SSDP). Thermoluminescent dosimeters (TLD-100) were used to measure the dose profile of the scanner. There were three sets of CT protocols where the tube potential (kV) setting was manipulated for each protocol while the rest of parameters were kept constant. These protocols were based from routine CT abdominal examinations for male adult abdomen. It was found that the increase of kV settings made the values of CTDIair increased as well. When the kV setting was changed from 80 kV to 120 kV and from 120 kV to 140 kV, the CTDIair values were increased as much as 147.9% and 53.9% respectively. The highest kV setting (140 kV) led to the highest CTDIair value (13.585 mGy). The p-value of less than 0.05 indicated that the results were statistically different. The SSDP showed that when the kV settings were varied, the peak sharpness and height of Gaussian function profiles were affected. The full width at half maximum (FWHM) of dose profiles for all protocols were coincided with the nominal beam width set for the measurements. The findings of the study revealed much information on the characterization and performance of 128 slice CT scanner.

Orbital flourine-18-fluorodeoxyglucose positron emission tomography in patients with Graves' disease for evaluation of active inflammation.

PubMed

Uslu-Beşli, Lebriz; Kabasakal, Levent; Sağer, Sait; Cicik, Erdoğan; Asa, Sertaç; Sönmezoğlu, Kerim

2017-11-01

Prediction and early diagnosis of orbitopathy is needed in patients with Graves' disease, especially when radioiodine therapy is planned. Positron emission tomography/computerized tomography (PET/CT) using flourine-18-fluorodeoxyglucose (FDG) is an effective imaging modality in detection of inflammation, however, its ability to detect orbital inflammation has not been well studied. The aim of our study is to determine the ability of FDG PET/CT to detect orbital inflammation related with Graves' disease, identify active orbitopathy, predict the radioiodine-triggered orbitopathy, and find out the effects of radioiodine on orbital inflammation. Total 31 Graves' disease patients and 17 controls were included. All Graves' disease patients underwent cranial FDG PET/CT imaging prior therapy. Radioiodine therapy and post-treatment PET/CT study was applied to 21 patients. PET/CT images of all examinees were evaluated, measuring extraocular muscle maximum standard uptake value (SUVmax) and muscle thickness. FDG uptake was increased in the majority of extraocular muscles in Graves' disease patients in comparison to controls and this increase was found to be irrelevant from muscle thickness. Extraocular muscle SUVmax values did not increase in Graves' orbitopathy patients who received radioiodine under corticosteroid prophylaxis. SUVmax level of all orbital rectus muscles were increased after radioiodine therapy in nonsmokers, whereas no increase was detected in smokers. FDG PET/CT may be helpful in detection of extraocular muscle inflammation and it may show ongoing orbitopathy in early stages of inflammation before anatomical changes occur.

A prospective evaluation of the impact of 18-F-fluoro-deoxy-D-glucose positron emission tomography staging on survival for patients with locally advanced esophageal cancer

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

Blackstock, A. William; Farmer, Michael R.; Lovato, James

2006-02-01

Purpose: To determine the impact of 18-F-fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) in the staging and prognosis of patients with locally advanced esophageal cancer (LAEC). Methods and Materials: Between January 2000 and October 2004, all patients with LAEC evaluated in the Department of Radiation Oncology were considered for enrollment into a Phase II trial of preoperative chemoradiation. Entry required a staging whole-body FDG-PET scan. Results: One hundred ten consecutive patients were evaluated; 38 were ineligible for reasons including treatment elsewhere, prior malignancy, or refusal of treatment. After conventional staging (clinical examination, endoscopic ultrasound, and chest/abdominal computerized tomography), 33 patients were ineligiblemore » because of metastatic disease or poor performance status. Of the remaining 39 patients, 23 were confirmed to have LAEC after FDG-PET staging and were treated in the Phase II trial (Cohort I). Sixteen patients, however, had FDG-PET findings consistent with occult metastatic disease and were deemed ineligible for the trial but were treated with curative intent (Cohort II). The 2-year survival rate for the 23 patients in Cohort I was 64%, compared with 17% (p = 0.003) for patients in Cohort II (FDG-PET positive). Conclusions: More than one-third of patients determined to have LAEC with conventional staging were upstaged with the use of FDG-PET. Despite comparable therapy, upstaging with FDG-PET predicts poor 2-year survival.« less

Patient doses from CT examinations in Turkey.

PubMed

Ataç, Gökçe Kaan; Parmaksız, Aydın; İnal, Tolga; Bulur, Emine; Bulgurlu, Figen; Öncü, Tolga; Gündoğdu, Sadi

2015-01-01

We aimed to establish the first diagnostic reference levels (DRLs) for computed tomography (CT) examinations in adult and pediatric patients in Turkey and compare these with international DRLs. CT performance information and examination parameters (for head, chest, high-resolution CT of the chest [HRCT-chest], abdominal, and pelvic protocols) from 1607 hospitals were collected via a survey. Dose length products and effective doses for standard patient sizes were calculated from the reported volume CT dose index (CTDIvol). The median number of protocols reported from the 167 responding hospitals (10% response rate) was 102 across five different age groups. Third quartile CTDIvol values for adult pelvic and all pediatric body protocols were higher than the European Commission standards but were comparable to studies conducted in other countries. The radiation dose indicators for adult patients were similar to those reported in the literature, except for those associated with head protocols. CT protocol optimization is necessary for adult head and pediatric chest, HRCT-chest, abdominal, and pelvic protocols. The findings from this study are recommended for use as national DRLs in Turkey.

The Long-Term Survival of a Patient With Stage IV Renal Cell Carcinoma Following an Integrative Treatment Approach Including the Intravenous α-Lipoic Acid/Low-Dose Naltrexone Protocol.

PubMed

Berkson, Burton M; Calvo Riera, Francisco

2017-12-01

In this case report, we describe the treatment of a 64-year-old male patient diagnosed with metastatic renal cell carcinoma (RCC) in June of 2008. In spite of a left nephrectomy and the standard oncological protocols, the patient developed a solitary left lung metastasis that continued to grow. He was informed that given his diagnosis and poor response to conventional therapy, any further treatment would, at best, be palliative. The patient arrived at the Integrative Medical Center of New Mexico in August of 2010. He was in very poor health, weak, and cachectic. An integrative program-developed by one of the authors using intravenous (IV) α-lipoic acid, IV vitamin C, low-dose naltrexone, and hydroxycitrate, and a healthy life style program-was initiated. From August 2010 to August 2015, the patient's RCC with left lung metastasis was followed closely using computed tomography and positron emission tomography/computed tomography imaging. His most recent positron emission tomography scan demonstrated no residual increased glucose uptake in his left lung. After only a few treatments of IV α-lipoic acid and IV vitamin C, his symptoms began to improve, and the patient regained his baseline weight. His energy and outlook improved, and he returned to work. The patient had stable disease with disappearance of the signs and symptoms of stage IV RCC, a full 9 years following diagnosis, with a gentle integrative program, which is essentially free of side effects. As of November 2017 the patient feels well and is working at his full-time job.

Diagnostic reference levels of paediatric computed tomography examinations performed at a dedicated Australian paediatric hospital.

PubMed

Bibbo, Giovanni; Brown, Scott; Linke, Rebecca

2016-08-01

Diagnostic Reference Levels (DRL) of procedures involving ionizing radiation are important tools to optimizing radiation doses delivered to patients and in identifying cases where the levels of doses are unusually high. This is particularly important for paediatric patients undergoing computed tomography (CT) examinations as these examinations are associated with relatively high-dose. Paediatric CT studies, performed at our institution from January 2010 to March 2014, have been retrospectively analysed to determine the 75th and 95th percentiles of both the volume computed tomography dose index (CTDIvol ) and dose-length product (DLP) for the most commonly performed studies to: establish local diagnostic reference levels for paediatric computed tomography examinations performed at our institution, benchmark our DRL with national and international published paediatric values, and determine the compliance of CT radiographer with established protocols. The derived local 75th percentile DRL have been found to be acceptable when compared with those published by the Australian National Radiation Dose Register and two national children's hospitals, and at the international level with the National Reference Doses for the UK. The 95th percentiles of CTDIvol for the various CT examinations have been found to be acceptable values for the CT scanner Dose-Check Notification. Benchmarking CT radiographers shows that they follow the set protocols for the various examinations without significant variations in the machine setting factors. The derivation of DRL has given us the tool to evaluate and improve the performance of our CT service by improved compliance and a reduction in radiation dose to our paediatric patients. We have also been able to benchmark our performance with similar national and international institutions. © 2016 The Royal Australian and New Zealand College of Radiologists.

Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

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

Brady, Samuel L., E-mail: samuel.brady@stjude.org; Shulkin, Barry L.

2015-02-15

Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET imagesmore » were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.« less

Tomography Reconstruction of Ionospheric Electron Density with Empirical Orthonormal Functions Using Korea GNSS Network

NASA Astrophysics Data System (ADS)

Hong, Junseok; Kim, Yong Ha; Chung, Jong-Kyun; Ssessanga, Nicholas; Kwak, Young-Sil

2017-03-01

In South Korea, there are about 80 Global Positioning System (GPS) monitoring stations providing total electron content (TEC) every 10 min, which can be accessed through Korea Astronomy and Space Science Institute (KASI) for scientific use. We applied the computerized ionospheric tomography (CIT) algorithm to the TEC dataset from this GPS network for monitoring the regional ionosphere over South Korea. The algorithm utilizes multiplicative algebraic reconstruction technique (MART) with an initial condition of the latest International Reference Ionosphere-2016 model (IRI-2016). In order to reduce the number of unknown variables, the vertical profiles of electron density are expressed with a linear combination of empirical orthonormal functions (EOFs) that were derived from the IRI empirical profiles. Although the number of receiver sites is much smaller than that of Japan, the CIT algorithm yielded reasonable structure of the ionosphere over South Korea. We verified the CIT results with NmF2 from ionosondes in Icheon and Jeju and also with GPS TEC at the center of South Korea. In addition, the total time required for CIT calculation was only about 5 min, enabling the exploration of the vertical ionospheric structure in near real time.

[Exposure to CT scans in childhood and long-term cancer risk: A review of epidemiological studies].

PubMed

Baysson, Hélène; Journy, Neige; Roué, Tristan; Ducou-Lepointe, Hubert; Etard, Cécile; Bernier, Marie-Odile

2016-02-01

Amongst medical exams requiring ionizing radiation, computed tomography (CT) scans are used more frequently, including in children. These CT examinations are associated with absorbed doses that are much higher than those associated with conventional radiology. In comparison to adults, children have a greater sensitivity to radiation and a longer life span with more years at cancer risks. Five epidemiological studies on cancer risks after CT scan exposure during childhood were published between 2012 and 2015. The results of these studies are consistent and show an increase of cancer risks in children who have been exposed to several CT scans. However, methodological limits due to indication bias, retrospective assessment of radiation exposure from CT scans and lack of statistical power are to be taken into consideration. International projects such as EPI-CT (Epidemiological study to quantify risks for pediatric computerized tomography and to optimize dose), with a focus on dosimetric reconstruction and minimization of bias will provide more precise results. In the meantime, available results reinforce the necessity of justification and optimization of doses. Copyright © 2015 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Imaging findings of intestinal tuberculosis.

PubMed

Engin, Gulgun; Balk, Emre

2005-01-01

Intestinal tuberculosis (TB) has 3 main forms: ulcerative, hypertrophic or ulcerohypertrophic, and fibrous stricturing. In the ulcerative form, barium examination reveals thickened folds, spasticity, and shallow ulcers involving the cecum and terminal ileum. Computerized tomography shows preferential thickening of the ileocecal valve and medial wall of the cecum as well as a few small regional nodes. In the hypertrophic or ulcerohypertrophic form, a hyperplastic reaction is seen in the exophytic masses around the ulcerated lumen on computed tomography. An inflammatory mass that extends into adjacent muscle suggests TB. In the sclerotic form, the main reaction is fibrosis with single or multiple short strictures. The cecum classically becomes amputated, conical, shrunken, and retracted. In comparison, Crohn's disease (CD) has a rather uniform and lesser thickening of the bowel wall. Mural stratification, vascular jejunization or the comb sign, and mesenteric fibrofatty proliferation are seen only in CD. The hypertrophic form may also mimic malignant neoplasms, such as lymphoma or carcinoma. Cecal carcinoma rarely extends beyond the ileocecal valve, however. In lymphoma, it can be seen as a greater degree of wall thickness with aneurysmatic dilation of the intestinal lumen. Single or multiple strictures are also seen as a CD complication. Advanced skip lesions adjacent to the stricture are usually diagnostic for CD.

Choroidal metastasis from carcinoma of breast detected on F18-FDG PET CT scan: A case report and review of literature.

PubMed

Solav, Shrikant; Bhandari, Ritu; Sowani, Anuradha; Saxena, Sameer

2010-10-01

Intraocular choroidal metastasis is a very rare cause of blindness. Choroidal hemangioma and melanoma are other causes that may mimic the condition. Carcinoma of breast is the most common primary malignancy that accounts for choroidal metastasis in females and carcinoma of lung is the most common cause in males. Other primary neoplasms which can uncommonly metastasize to the choroid are testis, gastrointestinal tract, kidney, thyroid, pancreas, and prostate. Metastatic neoplasm to the eye outnumbers the primary tumors such as retinoblastomas and malignant melanoma. Sonography is usually the initial investigation after fundus examination to look for the architecture of the lesion. However, it lacks in specificity. We present a case of carcinoma of breast that had visual disturbances and wholebody F18-fluorodeoxyglucose, positron emission tomography-computerized tomography (FDG PET CT) revealed a choroidal lesion in addition to cerebral, pulmonary, and skeletal metastases. Choroidal metastasis from carcinoma of lung has been reported previously on FDG PET. To the best of our knowledge, this is the first case report of carcinoma of breast demonstrating choroid metastasis on F18-FDG PET CT scan.

Role of endoscopic ultrasonography in the loco-regional staging of patients with rectal cancer

PubMed Central

Marone, Pietro; de Bellis, Mario; D’Angelo, Valentina; Delrio, Paolo; Passananti, Valentina; Di Girolamo, Elena; Rossi, Giovanni Battista; Rega, Daniela; Tracey, Maura Claire; Tempesta, Alfonso Mario

2015-01-01

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery. PMID:26140096