Chronic cerebral herniation in shunted Dandy-Walker malformation.

PubMed

Naidich, T P; Radkowski, M A; McLone, D G; Leestma, J

1986-02-01

A review of serial computed tomography (CT) scans of 25 patients with the Dandy-Walker malformation revealed six patients with chronic downward transincisural herniation of the cerebrum after shunt decompression of the posterior fossa cyst or malfunction of a lateral ventricular drainage catheter, or both. Chronic cerebral herniation was detected postmortem in a seventh patient with the Dandy-Walker malformation. The CT findings and autopsy appearance of this previously undescribed feature of shunted Dandy-Walker malformation are illustrated.

Compact conscious animal positron emission tomography scanner

DOEpatents

Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

2006-10-24

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

Myocardial perfusion imaging: Lessons learned and work to be done-update.

PubMed

Iskandrian, Ami E; Dilsizian, Vasken; Garcia, Ernest V; Beanlands, Rob S; Cerqueira, Manuel; Soman, Prem; Berman, Daniel S; Cuocolo, Alberto; Einstein, Andrew J; Morgan, Charity J; Hage, Fadi G; Schelbert, Heinrich R; Bax, Jeroen J; Wu, Joseph C; Shaw, Leslee J; Sadeghi, Mehran M; Tamaki, Nagara; Kaufmann, Philipp A; Gropler, Robert; Dorbala, Sharmila; Van Decker, William

2018-02-01

As the second term of our commitment to Journal begins, we, the editors, would like to reflect on a few topics that have relevance today. These include prognostication and paradigm shifts; Serial testing: How to handle data? Is the change in perfusion predictive of outcome and which one? Ischemia-guided therapy: fractional flow reserve vs perfusion vs myocardial blood flow; positron emission tomography (PET) imaging using Rubidium-82 vs N-13 ammonia vs F-18 Flurpiridaz; How to differentiate microvascular disease from 3-vessel disease by PET? The imaging scene outside the United States, what are the differences and similarities? Radiation exposure; Special issues with the new cameras? Is attenuation correction needed? Are there normal databases and are these specific to each camera system? And finally, hybrid imaging with single-photon emission tomography or PET combined with computed tomography angiography or coronary calcium score. We hope these topics are of interest to our readers.

Acquisition of Real-Time Operation Analytics for an Automated Serial Sectioning System

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

Madison, Jonathan D.; Underwood, O. D.; Poulter, Gregory A.

Mechanical serial sectioning is a highly repetitive technique employed in metallography for the rendering of 3D reconstructions of microstructure. While alternate techniques such as ultrasonic detection, micro-computed tomography, and focused ion beam milling have progressed much in recent years, few alternatives provide equivalent opportunities for comparatively high resolutions over significantly sized cross-sectional areas and volumes. To that end, the introduction of automated serial sectioning systems has greatly heightened repeatability and increased data collection rates while diminishing opportunity for mishandling and other user-introduced errors. Unfortunately, even among current, state-of-the-art automated serial sectioning systems, challenges in data collection have not been fullymore » eradicated. Therefore, this paper highlights two specific advances to assist in this area; a non-contact laser triangulation method for assessment of material removal rates and a newly developed graphical user interface providing real-time monitoring of experimental progress. Furthermore, both are shown to be helpful in the rapid identification of anomalies and interruptions, while also providing comparable and less error-prone measures of removal rate over the course of these long-term, challenging, and innately destructive characterization experiments.« less

Acquisition of Real-Time Operation Analytics for an Automated Serial Sectioning System

DOE PAGES

Madison, Jonathan D.; Underwood, O. D.; Poulter, Gregory A.; ...

2017-03-22

Mechanical serial sectioning is a highly repetitive technique employed in metallography for the rendering of 3D reconstructions of microstructure. While alternate techniques such as ultrasonic detection, micro-computed tomography, and focused ion beam milling have progressed much in recent years, few alternatives provide equivalent opportunities for comparatively high resolutions over significantly sized cross-sectional areas and volumes. To that end, the introduction of automated serial sectioning systems has greatly heightened repeatability and increased data collection rates while diminishing opportunity for mishandling and other user-introduced errors. Unfortunately, even among current, state-of-the-art automated serial sectioning systems, challenges in data collection have not been fullymore » eradicated. Therefore, this paper highlights two specific advances to assist in this area; a non-contact laser triangulation method for assessment of material removal rates and a newly developed graphical user interface providing real-time monitoring of experimental progress. Furthermore, both are shown to be helpful in the rapid identification of anomalies and interruptions, while also providing comparable and less error-prone measures of removal rate over the course of these long-term, challenging, and innately destructive characterization experiments.« less

Positron emission tomography wrist detector

DOEpatents

Schlyer, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois

2006-08-15

A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

Dual-modality imaging of function and physiology

NASA Astrophysics Data System (ADS)

Hasegawa, Bruce H.; Iwata, Koji; Wong, Kenneth H.; Wu, Max C.; Da Silva, Angela; Tang, Hamilton R.; Barber, William C.; Hwang, Andrew B.; Sakdinawat, Anne E.

2002-04-01

Dual-modality imaging is a technique where computed tomography or magnetic resonance imaging is combined with positron emission tomography or single-photon computed tomography to acquire structural and functional images with an integrated system. The data are acquired during a single procedure with the patient on a table viewed by both detectors to facilitate correlation between the structural and function images. The resulting data can be useful for localization for more specific diagnosis of disease. In addition, the anatomical information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can be used to improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems also are being developed for biological research that involves small animals. The small-animal dual-modality systems offer advantages for measurements that currently are performed invasively using autoradiography and tissue sampling. By acquiring the required data noninvasively, dual-modality imaging has the potential to allow serial studies in a single animal, to perform measurements with fewer animals, and to improve the statistical quality of the data.

Image-guided transnasal cryoablation of a recurrent nasal adenocarcinoma in a dog.

PubMed

Murphy, S M; Lawrence, J A; Schmiedt, C W; Davis, K W; Lee, F T; Forrest, L J; Bjorling, D E

2011-06-01

An eight-year-old female spayed Airedale terrier with rapid recurrence of a nasal adenocarcinoma following image-guided intensity-modulated radiation therapy was treated with transnasal, image-guided cryotherapy. Ice ball size and location were monitored real-time with computed tomography-fluoroscopy to verify that the entire tumour was enveloped in ice. Serial computed tomography scans demonstrated reduction in and subsequent resolution of the primary tumour volume corresponding visually with the ice ball imaged during the ablation procedure. Re-imaging demonstrated focallysis of the cribriform plate following ablation that spontaneously resolved by 13 months. While mild chronic nasal discharge developed following cryoablation, no other clinical signs of local nasal neoplasia were present. Twenty-one months after nasal tumour cryoablation the dog was euthanased as a result of acute haemoabdomen. Image-guided cryotherapy may warrant further investigation for the management of focal residual or recurrent tumours in dogs, especially in regions where critical structures preclude surgical intervention. © 2011 British Small Animal Veterinary Association.

A long-term survivor of disseminated Aspergillus and mucorales infection: an instructive case.

PubMed

Davoudi, Setareh; Anderlini, Paolo; Fuller, Gregory N; Kontoyiannis, Dimitrios P

2014-12-01

Invasive fungal infections remain major causes of infection-related mortality in hematopoietic stem cell transplantation (HSCT) patients. Mixed infections and multiple organ involvement have been reported in these patients. Here, we report a case of mixed Aspergillus and Mucorales infection involving the lungs, brain, spleen and bone in a HSCT patient with relapsed acute myeloid leukemia, who finally improved with triple antifungal therapy and neurosurgical evacuation of brain abscesses. She was put on lifelong secondary prophylaxis with posaconazole with excellent compliance and no sign of toxicity despite over 10 years of drug administration. Serial galactomannan measurements and positron emission tomography/computed tomography were used and were helpful for disease activity monitoring. This is an instructive case of long-term survival after a severe combined mould infection.

Longitudinal follow-up of fibrosing interstitial pneumonia: relationship between physiologic testing, computed tomography changes, and survival rate.

PubMed

Hwang, Jeong-Hwa; Misumi, Shigeki; Curran-Everett, Douglas; Brown, Kevin K; Sahin, Hakan; Lynch, David A

2011-08-01

The aim of this study was to evaluate the prognostic implications of computed tomography (CT) and physiologic variables at baseline and on sequential evaluation in patients with fibrosing interstitial pneumonia. We identified 72 patients with fibrosing interstitial pneumonia (42 with idiopathic disease, 30 with collagen vascular disease). Pulmonary function tests and CT were performed at the time of diagnosis and at a median follow-up of 12 months, respectively. Two chest radiologists scored the extent of specific abnormalities and overall disease on baseline and follow-up CT. Rate of survival was estimated using the Kaplan-Meier method. Three Cox proportional hazards models were constructed to evaluate the relationship between CT and physiologic variables and rate of survival: model 1 included only baseline variables, model 2 included only serial change variables, and model 3 included both baseline and serial change variables. On follow-up CT, the extent of mixed ground-glass and reticular opacities (P<0.001), pure reticular opacity (P=0.04), honeycombing (P=0.02), and overall extent of disease (P<0.001) was increased in the idiopathic group, whereas these variables remained unchanged in the collagen vascular disease group. Patients with idiopathic disease had a shorter rate of survival than those with collagen vascular disease (P=0.03). In model 1, the extent of honeycombing on baseline CT was the only independent predictor of mortality (P=0.02). In model 2, progression in honeycombing was the only predictor of mortality (P=0.005). In model 3, baseline extent of honeycombing and progression of honeycombing were the only independent predictors of mortality (P=0.001 and 0.002, respectively). Neither baseline nor serial change physiologic variables, nor the presence of collagen vascular disease, was predictive of rate of survival. The extent of honeycombing at baseline and its progression on follow-up CT are important determinants of rate of survival in patients with fibrosing interstitial pneumonia.

Imaging of Traumatic Brain Injury.

PubMed

Bodanapally, Uttam K; Sours, Chandler; Zhuo, Jiachen; Shanmuganathan, Kathirkamanathan

2015-07-01

Imaging plays an important role in the management of patients with traumatic brain injury (TBI). Computed tomography (CT) is the first-line imaging technique allowing rapid detection of primary structural brain lesions that require surgical intervention. CT also detects various deleterious secondary insults allowing early medical and surgical management. Serial imaging is critical to identifying secondary injuries. MR imaging is indicated in patients with acute TBI when CT fails to explain neurologic findings. However, MR imaging is superior in patients with subacute and chronic TBI and also predicts neurocognitive outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

Delayed Development of Multiple Pancreaticoduodenal Arcade Pseudoaneurysms after Abdominal Trauma.

PubMed

Prosper, Ashley; Saremi, Farhood

2016-10-01

This case report demonstrates development and progressive enlargement of multiple pancreaticoduodenal arcade pseudoaneurysms using computed tomography angiographies over a period of 5 weeks after abdominal trauma. The mechanism of pseudoaneurysm formation, as shown by serial imaging, attributed to preexisting celiac axis stenosis by the median arcuate ligament, posttraumatic celiac artery dissection, and secondary occlusion of proper hepatic artery resulting in elevation of pressure and flow in the pancreaticoduodenal arcade and rupture of small arterial branches. Successful pseudoaneurysm occlusion was achieved through arterial embolization. Published by Elsevier Inc.

Large volume serial section tomography by Xe Plasma FIB dual beam microscopy.

PubMed

Burnett, T L; Kelley, R; Winiarski, B; Contreras, L; Daly, M; Gholinia, A; Burke, M G; Withers, P J

2016-02-01

Ga(+) Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga(+) FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe(+) Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC-Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (<24h) showing good grain orientation contrast and capturing microstructural features at the tens of nanometres to the tens of microns scale. Accompanying electron back scattered diffraction (EBSD) maps show high indexing rates suggesting low levels of surface damage. Further, under high current Ga(+) FIB milling WC-Co is prone to amorphisation of WC surface layers and phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60nA at 30kV. Xe(+) PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Imaging Cellular Proliferation During Chemo-Radiotherapy: A Pilot Study of Serial {sup 18}F-FLT Positron Emission Tomography/Computed Tomography Imaging for Non-Small-Cell Lung Cancer

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

Everitt, Sarah, E-mail: Sarah.Everitt@petermac.or; Department of Medical Imaging and Radiation Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria; Hicks, Rodney J.

2009-11-15

Purpose: To establish whether {sup 18}F-3'-deoxy-3'-fluoro-L-thymidine ({sup 18}F-FLT) can monitor changes in cellular proliferation of non-small-cell lung cancer (NSCLC) during radical chemo-radiotherapy (chemo-RT). Methods and Materials: As part of a prospective pilot study, 5 patients with locally advanced NSCLC underwent serial {sup 18}F-FLT positron emission tomography (PET)/computed tomography (CT) scans during treatment. Baseline {sup 18}F-FLT PET/CT scans were compared with routine staging {sup 18}F-FDG PET/CT scans. Two on-treatment {sup 18}F-FLT scans were performed for each patient on Days 2, 8, 15 or 29, providing a range of time points for response assessment. Results: In all 5 patients, baseline lesional uptakemore » of {sup 18}F-FLT on PET/CT corresponded to staging {sup 18}F-FDG PET/CT abnormalities. {sup 18}F-FLT uptake in tumor was observed on five of nine (55%) on-treatment scans, on Days 2, 8 and 29, but not Day 15. A 'flare' of {sup 18}F-FLT uptake in the primary tumor of one case was observed after 2 Gy of radiation (1.22 x baseline). The remaining eight on-treatment scans demonstrated a mean reduction in {sup 18}F-FLT tumor uptake of 0.58 x baseline. A marked reduction of {sup 18}F-FLT uptake in irradiated bone marrow was observed for all cases. This reduction was observed even after only 2 Gy, and all patients demonstrated a complete absence of proliferating marrow after 10 Gy. Conclusions: This proof of concept study indicates that {sup 18}F-FLT uptake can monitor the distinctive biologic responses of epithelial cancers and highly radiosensitive normal tissue changes during radical chemo-RT. Further studies of {sup 18}F-FLT PET/CT imaging during therapy may suggest that this tracer is useful in developing response-adapted RT for NSCLC.« less

Quantification of myocardial infarction: a comparison of single photon-emission computed tomography with pyrophosphate to serial plasma MB-creatine kinase measurements

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

Jansen, D.E.; Corbett, J.R.; Wolfe, C.L.

1985-08-01

Single photon-emission computed tomography (SPECT) with /sup 99m/Tc-pyrophosphate (PPi) has been shown to estimate size of myocardial infarction accurately in animals. The authors tested the hypothesis that SPECT with /sup /sup 99m//Tc-PPi and blood pool subtraction can provide prompt and accurate estimates of size of myocardial infarction in patients. SPECT estimates are potentially available early after the onset of infarction and should correlate with estimates of infarct size calculated from serial measurements of plasma MB-creatine kinase (CK) activity. Thirty-three patients with acute myocardial infarction and 16 control patients without acute myocardial infarction were studied. Eleven of the patients had transmuralmore » anterior myocardial infarction, 16 had transmural inferior myocardial infarction, and six had nontransmural myocardial infarction. SPECT was performed with a commercially available rotating gamma camera. Identical projection images of the distribution of 99mTc-PPi and the ungated cardiac blood pool were acquired sequentially over 180 degrees. Reconstructed sections were color coded and superimposed for purposes of localization of infarct. Areas of increased PPi uptake within myocardial infarcts were thresholded at 65% of peak activity. The blood pool was thresholded at 50% and subtracted to determine the endocardial border for the left ventricle. Myocardial infarcts ranged in size from 1 to 126 gram equivalents (geq) MB-CK. The correlation of MB-CK estimates of size of infarct with size determined by SPECT (both in geq) was good (r = .89 with a regression line of y = 13.1 + 1.5x).« less

Preliminary embryological study of the radiological concept of retroperitoneal interfascial planes: what are the interfascial planes?

PubMed

Ishikawa, Kazuo; Nakao, Shota; Murakami, Gen; Rodríguez-Vázquez, Jose Francisco; Matsuoka, Tetsuya; Nakamuro, Makoto; Shimazu, Takeshi

2014-12-01

Recently, the radiological concept of retroperitoneal interfascial planes has been widely accepted to explain the extension of retroperitoneal pathologies. This study aimed to explore embryologically based corroborative evidence, which remains to be elucidated, for this concept. Using serial or semi-serial transverse sections from 29 human fetuses at the 5th-25th week of fetal age, we microscopically observed the development of the retroperitoneal fasciae and other structures in the retroperitoneal connective tissue. A hypothesis for the formation of the interfascial planes was generated from the developmental study and analysis of retroperitoneal fasciae in computed tomography images from 224 patients. Whereas the loose connective tissue was uniformly distributed in the retroperitoneum by the 9th week, the primitive renal and transversalis fasciae appeared at the 10th-12th week, as previous research has noted. By the 23rd week, the renal fascia, transversalis fascia, and primitive adipose tissue of the flank pad emerged. In addition, the primitive lateroconal fascia, which runs parallel to and close to the posterior renal fascia, emerged between the renal fascia and the adipose tissue of the flank pad. Conversely, pre-existing loose connective tissue was sandwiched between the opposing fasciae and was compressed and narrowed by the developing organs and fatty tissues. Through this developmental study, we provided the hypothesis that the compressed loose connective tissue and both opposed fasciae compose the interfascial planes. Analysis of the thickened retroperitoneal fasciae in computed tomography images supported this hypothesis. Further developmental or histological studies are required to verify our hypothesis.

SPECT bone scintigraphy for the assessment of condylar growth activity in mandibular asymmetry: is it accurate?

PubMed

Chan, B H; Leung, Y Y

2018-04-01

The comparison of serial radiographs and clinical photographs is considered the current accepted standard for the diagnosis of active condylar hyperplasia in patients with facial asymmetry. Single photon emission computed tomography (SPECT) has recently been proposed as an alternative method. SPECT can be interpreted using three reported methods absolute difference in uptake, uptake ratio, and relative uptake. SPECT findings were compared to those from serial comparisons of radiographs and clinical photographs taken at the time of SPECT and a year later; the sensitivities and specificities were determined. Two hundred patient scans were evaluated. Thirty-four patients showed active growth on serial growth assessment. On comparison with serial growth assessment, the sensitivity and specificity of the three methods ranged between 32.4% and 67.6%, and 36.1% and 78.3%, respectively. Analysis using receiver operating characteristic (ROC) curves revealed area under the curve (AUC) values of <0.58. The average age (mean±standard deviation) of patients with active growth was 18.6±2.8 years, and average growth in the anteroposterior, vertical, and transverse directions was 0.94±0.91mm, 0.88±0.86mm, and 1.4±0.66 mm, respectively. With such low sensitivity and specificity values, it is not justifiable to use SPECT in place of serial growth assessment for the determination of condylar growth status. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning.

PubMed

Gee, Carole T

2013-11-01

As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. • MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D) visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. • If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. • This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction.

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).

Prosthetic liner wear in total hip replacement: a longitudinal 13-year study with computed tomography.

PubMed

Weidenhielm, Lars; Olivecrona, Henrik; Maguire, Gerald Q; Noz, Marilyn E

2018-06-01

This case report follows a woman who had a total hip replacement in 1992 when she was 45 years old. Six serial computed tomography (CT) examinations over a period of 13 years provided information that allowed her revision surgery to be limited to liner replacement as opposed to replacement of the entire prosthesis. Additionally, they provided data that ruled out the presence of osteolysis and indeed none was found at surgery. In 2004, when the first CT was performed, the 3D distance the femoral head had penetrated into the cup was determined to be 2.6 mm. By 2017, femoral head penetration had progressed to 5.0 mm. The extracted liner showed wear at the thinnest part to be 5.5 mm, as measured with a micrometer. The use of modern CT techniques can identify problems, while still correctable without major surgery. Furthermore, the ability of CT to assess the direction of wear revealed that the liner wear changed from the cranial to dorsal direction.

Three Dimensional Visualization of Human Cardiac Conduction Tissue in Whole Heart Specimens by High-Resolution Phase-Contrast CT Imaging Using Synchrotron Radiation.

PubMed

Shinohara, Gen; Morita, Kiyozo; Hoshino, Masato; Ko, Yoshihiro; Tsukube, Takuro; Kaneko, Yukihiro; Morishita, Hiroyuki; Oshima, Yoshihiro; Matsuhisa, Hironori; Iwaki, Ryuma; Takahashi, Masashi; Matsuyama, Takaaki; Hashimoto, Kazuhiro; Yagi, Naoto

2016-11-01

The feasibility of synchrotron radiation-based phase-contrast computed tomography (PCCT) for visualization of the atrioventricular (AV) conduction axis in human whole heart specimens was tested using four postmortem structurally normal newborn hearts obtained at autopsy. A PCCT imaging system at the beamline BL20B2 in a SPring-8 synchrotron radiation facility was used. The PCCT imaging of the conduction system was performed with "virtual" slicing of the three-dimensional reconstructed images. For histological verification, specimens were cut into planes similar to the PCCT images, then cut into 5-μm serial sections and stained with Masson's trichrome. In PCCT images of all four of the whole hearts of newborns, the AV conduction axis was distinguished as a low-density structure, which was serially traceable from the compact node to the penetrating bundle within the central fibrous body, and to the branching bundle into the left and right bundle branches. This was verified by histological serial sectioning. This is the first demonstration that visualization of the AV conduction axis within human whole heart specimens is feasible with PCCT. © The Author(s) 2016.

Evaluation of Esophageal Anastomotic Integrity With Serial Pleural Amylase Levels.

PubMed

Miller, Daniel L; Helms, Gerald A; Mayfield, William R

2018-01-01

An anastomotic leak is the most devastating and potentially fatal complication after esophagectomy. Current detection methods can be inaccurate and place patients at risk of other complications. Analysis of pleural fluid for amylase may be more accurate and place patients at less of a risk for evaluating the integrity of an esophageal anastomosis. We retrospectively reviewed prospective data of 45 consecutive patients who underwent an Ivor Lewis esophagectomy over an 18-month period and evaluated their anastomotic integrity with serial pleural amylase levels (PAL). There were 40 men (89%), and median age was 63 years (range, 35 to 79). Indication for esophagectomy was cancer in 38 patients (84%); 27 (71%) underwent neoadjuvant chemoradiation. A barium swallow was performed in the first 25 patients at median postoperative day (POD) 5 (range, 5 to 10); the swallow was negative in 23 patients (93%). Serial PALs were obtained starting on POD 3 and stopped 1 day after toleration of clear liquids. The PALs in the no-leak patients were highest on POD 3 (median 42 IU/L; range, 20 to 102 IU/L) and decreased (median 15 IU/L; range, 8 to 34 IU/L) to the lowest levels 1 day after clear liquid toleration (p = 0.04). Two patients had a leak and had peak PALs of 227 IU/L and 630 IU/L, respectively; both leaks occurred on POD 4, 1 day before their scheduled swallow test. The last 20 patients underwent serial PALs only, without a planned swallow test or computed tomography scan for anastomotic integrity evaluation. One of these patients had a leak on POD 5 with a low PAL of 55 IU/L the day before the spike of more than 4,000 IU/L. Two of the leaks were treated with esophageal stent placement and intravenous antibiotics, and the remaining patient's leak resolved with intravenous antibiotics, no oral intake, and observation only. None of the leak patients required transthoracic esophageal repair or drainage of an empyema. There was 1 postoperative death (2%) secondary to aspiration pneumonia on POD 10; no leak was ever identified, and the patient had been eating for 3 days before death. Complications occurred in 15 patients (33%), most commonly respiratory; no respiratory issues occurred in PAL-only evaluated patients. No late anastomotic leaks occurred in any patient while in the hospital or after discharge. Serial PALs for the detection of esophageal anastomotic leaks proved to be accurate, safe, and inexpensive. Elimination of barium swallows and computed tomography scans for evaluation of anastomotic integrity may decrease aspiration risks as well as associated pulmonary failure during the postoperative period. Serial PALs may be the preferred method of detecting an anastomotic leak after esophagectomy. A prospective randomized study is warranted. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Serial optical coherence scanning reveals an association between cardiac function and the heart architecture in the aging rodent heart

PubMed Central

Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Avti, Pramod; Moeini, Mohammad; Lesage, Frédéric

2017-01-01

Normal aging is accompanied by structural changes in the heart architecture. To explore this remodeling, we used a serial optical coherence tomography scanner to image entire mouse hearts at micron scale resolution. Ex vivo hearts of 7 young (4 months) and 5 old (24 months) C57BL/6 mice were acquired with the imaging platform. OCT of the myocardium revealed myofiber orientation changing linearly from the endocardium to the epicardium. In old mice, this rate of change was lower when compared to young mice while the average volume of old mice hearts was significantly larger (p<0.05). Myocardial wall thickening was also accompanied by extracellular spacing in the endocardium, resulting in a lower OCT attenuation coefficient in old mice endocardium (p<0.05). Prior to serial sectioning, cardiac function of the same hearts was imaged in vivo using MRI and revealed a reduced ejection fraction with aging. The use of a serial optical coherence tomography scanner allows new insight into fine age-related changes of the heart associated with changes in heart function. PMID:29188099

Serial 3-dimensional computed tomography and a novel method of volumetric analysis for the evaluation of the osteo-odonto-keratoprosthesis.

PubMed

Sipkova, Zuzana; Lam, Fook Chang; Francis, Ian; Herold, Jim; Liu, Christopher

2013-04-01

To assess the use of serial computed tomography (CT) in the detection of osteo-odonto-lamina resorption in osteo-odonto-keratoprosthesis (OOKP) and to investigate the use of new volumetric software, Advanced Lung Analysis software (3D-ALA; GE Healthcare), for detecting changes in OOKP laminar volume. A retrospective assessment of the radiological databases and hospital records was performed for 22 OOKP patients treated at the National OOKP referral center in Brighton, United Kingdom. Three-dimensional surface reconstructions of the OOKP laminae were performed using stored CT data. For the 2-dimensional linear analysis, the linear dimensions of the reconstructed laminae were measured, compared with original measurements taken at the time of surgery, and then assigned a CT grade based on a predetermined resorption grading scale. The volumetric analysis involved calculating the laminar volumes using 3D-ALA. The effectiveness of 2-dimensional linear analysis, volumetric analysis, and clinical examination in detecting laminar resorption was compared. The mean change in laminar volume between the first and second scans was -6.67% (range, +10.13% to -24.86%). CT grades assigned to patients based on laminar dimension measurements remained the same, despite significant changes in laminar volumes. Clinical examination failed to identify 60% of patients who were found to have resorption on volumetric analysis. Currently, the detection of laminar resorption relies on clinical examination and the measurement of laminar dimensions on the 2- and 3-dimensional radiological images. Laminar volume measurement is a useful new addition to the armamentarium. It provides an objective tool that allows for a precise and reproducible assessment of laminar resorption.

Radiotracer Imaging Allows for Noninvasive Detection and Quantification of Abnormalities in Angiosome Foot Perfusion in Diabetic Patients With Critical Limb Ischemia and Nonhealing Wounds

PubMed Central

Alvelo, Jessica L.; Papademetris, Xenophon; Mena-Hurtado, Carlos; Jeon, Sangchoon; Sumpio, Bauer E.; Sinusas, Albert J.

2018-01-01

Background: Single photon emission computed tomography (SPECT)/computed tomography (CT) imaging allows for assessment of skeletal muscle microvascular perfusion but has not been quantitatively assessed in angiosomes, or 3-dimensional vascular territories, of the foot. This study assessed and compared resting angiosome foot perfusion between healthy subjects and diabetic patients with critical limb ischemia (CLI). Additionally, the relationship between SPECT/CT imaging and the ankle–brachial index—a standard tool for evaluating peripheral artery disease—was assessed. Methods and Results: Healthy subjects (n=9) and diabetic patients with CLI and nonhealing ulcers (n=42) underwent SPECT/CT perfusion imaging of the feet. CT images were segmented into angiosomes for quantification of relative radiotracer uptake, expressed as standardized uptake values. Standardized uptake values were assessed in ulcerated angiosomes of patients with CLI and compared with whole-foot standardized uptake values in healthy subjects. Serial SPECT/CT imaging was performed to assess uptake kinetics of technetium-99m-tetrofosmin. The relationship between angiosome perfusion and ankle–brachial index was assessed via correlational analysis. Resting perfusion was significantly lower in CLI versus healthy subjects (P=0.0007). Intraclass correlation coefficients of 0.95 (healthy) and 0.93 (CLI) demonstrated excellent agreement between serial perfusion measurements. Correlational analysis, including healthy and CLI subjects, demonstrated a significant relationship between ankle–brachial index and SPECT/CT (P=0.01); however, this relationship was not significant for diabetic CLI patients only (P=0.2). Conclusions: SPECT/CT imaging assesses regional foot perfusion and detects abnormalities in microvascular perfusion that may be undetectable by conventional ankle–brachial index in patients with diabetes mellitus. SPECT/CT may provide a novel approach for evaluating responses to targeted therapies. PMID:29748311

An automatic alignment tool to improve repeatability of left ventricular function and dyssynchrony parameters in serial gated myocardial perfusion SPECT studies

PubMed Central

Zhou, Yanli; Faber, Tracy L.; Patel, Zenic; Folks, Russell D.; Cheung, Alice A.; Garcia, Ernest V.; Soman, Prem; Li, Dianfu; Cao, Kejiang; Chen, Ji

2013-01-01

Objective Left ventricular (LV) function and dyssynchrony parameters measured from serial gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) using blinded processing had a poorer repeatability than when manual side-by-side processing was used. The objective of this study was to validate whether an automatic alignment tool can reduce the variability of LV function and dyssynchrony parameters in serial gated SPECT MPI. Methods Thirty patients who had undergone serial gated SPECT MPI were prospectively enrolled in this study. Thirty minutes after the first acquisition, each patient was repositioned and a gated SPECT MPI image was reacquired. The two data sets were first processed blinded from each other by the same technologist in different weeks. These processed data were then realigned by the automatic tool, and manual side-by-side processing was carried out. All processing methods used standard iterative reconstruction and Butterworth filtering. The Emory Cardiac Toolbox was used to measure the LV function and dyssynchrony parameters. Results The automatic tool failed in one patient, who had a large, severe scar in the inferobasal wall. In the remaining 29 patients, the repeatability of the LV function and dyssynchrony parameters after automatic alignment was significantly improved from blinded processing and was comparable to manual side-by-side processing. Conclusion The automatic alignment tool can be an alternative method to manual side-by-side processing to improve the repeatability of LV function and dyssynchrony measurements by serial gated SPECT MPI. PMID:23211996

TU-A-12A-08: Computing Longitudinal Material Changes in Bone Metastases Using Dual Energy Computed Tomography

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

Schmidtlein, CR; Hwang, S; Veeraraghavan, H

Purpose: This study demonstrates a methodology for tracking changes in metastatic bone disease using trajectories in material basis space in serial dual energy computed tomography (DECT) studies. Methods: This study includes patients with bone metastases from breast cancer that had clinical surveillance CT scans using a General Electric CT750HD in dual energy mode. A radiologist defined regions-of-interested (ROI) for bone metastasis, normal bone, and marrow across the serial DECT scans. Our approach employs a Radon transform to forward-projection the basis images, namely, water and iodine, into sinogram space. This data is then repartitioned into fat/bone and effective density/Z image pairsmore » using assumed energy spectrums for the x-ray energies. This approach both helps remove negative material densities and avoids adding spectrum-hardening artifacts. These new basis data sets were then reconstructed via filtered back-projection to create new material basis pair images. The trajectories of these pairs were then plotted in the new basis space providing a means to both visualize and quantitatively measure changes in the material properties of the tumors. Results: ROI containing radiologist defined metastatic bone disease showed well-defined trajectories in both fat/bone and effective density/Z space. ROI that contained radiologist defined normal bone and marrow did not exhibit any discernible trajectories and were stable from scan to scan. Conclusions: The preliminary results show that changes in material composition and effective density/Z image pairs were seen primarily in metastasis and not in normal tissue. This study indicates that by using routine clinical DECT it may be possible to monitor therapy response of bone metastases because healing or worsening bone metastases change material composition of bone. Additional studies are needed to further validate these results and to test for their correlation with outcome.« less

Applying microCT and 3D visualization to Jurassic silicified conifer seed cones: A virtual advantage over thin-sectioning1

PubMed Central

Gee, Carole T.

2013-01-01

• Premise of the study: As an alternative to conventional thin-sectioning, which destroys fossil material, high-resolution X-ray computed tomography (also called microtomography or microCT) integrated with scientific visualization, three-dimensional (3D) image segmentation, size analysis, and computer animation is explored as a nondestructive method of imaging the internal anatomy of 150-million-year-old conifer seed cones from the Late Jurassic Morrison Formation, USA, and of recent and other fossil cones. • Methods: MicroCT was carried out on cones using a General Electric phoenix v|tome|x s 240D, and resulting projections were processed with visualization software to produce image stacks of serial single sections for two-dimensional (2D) visualization, 3D segmented reconstructions with targeted structures in color, and computer animations. • Results: If preserved in differing densities, microCT produced images of internal fossil tissues that showed important characters such as seed phyllotaxy or number of seeds per cone scale. Color segmentation of deeply embedded seeds highlighted the arrangement of seeds in spirals. MicroCT of recent cones was even more effective. • Conclusions: This is the first paper on microCT integrated with 3D segmentation and computer animation applied to silicified seed cones, which resulted in excellent 2D serial sections and segmented 3D reconstructions, revealing features requisite to cone identification and understanding of strobilus construction. PMID:25202495

Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study: rationale and design.

PubMed

Nakanishi, Rine; Post, Wendy S; Osawa, Kazuhiro; Jayawardena, Eranthi; Kim, Michael; Sheidaee, Nasim; Nezarat, Negin; Rahmani, Sina; Kim, Nicholas; Hathiramani, Nicolai; Susarla, Shriraj; Palella, Frank; Witt, Mallory; Blaha, Michael J; Brown, Todd T; Kingsley, Lawrence; Haberlen, Sabina A; Dailing, Christopher; Budoff, Matthew J

2018-01-01

The association of HIV with coronary atherosclerosis has been established; however, the progression of coronary atherosclerosis over time among participants with HIV is not well known. The Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study is a large prospective multicenter study quantifying progression of coronary plaque assessed by serial coronary computed tomography angiography (CTA). HIV-infected and uninfected men who were enrolled in the Multicenter AIDS Cohort Study Cardiovascular Substudy were eligible to complete a follow-up contrast coronary CTA 3-6 years after baseline. We measured coronary plaque volume and characteristics (calcified and noncalcified plaque including fibrous, fibrous-fatty, and low attenuation) and vulnerable plaque among HIV-infected and uninfected men using semiautomated plaque software to investigate the progression of coronary atherosclerosis over time. We describe a novel, large prospective multicenter study investigating incidence, transition of characteristics, and progression in coronary atherosclerosis quantitatively assessed by serial coronary CTAs among HIV-infected and uninfected men.

A Case of Pulmonary Mycobacterium kansasii Disease Complicated with Tension Pneumothorax.

PubMed

Boo, Ki Yung; Lee, Jong Hoo

2015-10-01

Pneumothorax is an extremely rare complication of non-tuberculous mycobacterial infection. A 52-year-old man presenting with difficulty breathing and chest pain was admitted to our hospital. A right-sided pneumothorax was observed on chest radiography and chest computed tomography showed multiple cavitating and non-cavitating nodules with consolidation in the upper to middle lung zones bilaterally. Serial sputum cultures were positive for Mycobacterium kansasii, and he was diagnosed with pulmonary M. kansasii disease complicated by tension pneumothorax. After initiation of treatment including decortications and pleurodesis, the patient made a full recovery. We herein describe this patient's course in detail and review the current relevant literature.

Spontaneous rectus sheath hematomas in dengue hemorrhagic fever: A case report.

PubMed

Nelwan, Erni Juwita; Angelina, Frida; Adiwinata, Randy; Matondang, Sahat; Andriono, Prasetyo

2017-01-01

Muscle hematomas are rare complications in dengue hemorrhagic fever (DHF). We report a case of 58-year-old-female admitted with dengue fever who developed spontaneous rectus sheath hematoma complicating DHF. She presented with progressive thrombocytopenia with platelet count reaching 13000/μL at its lowest point. There was evidence of plasma leakage and persistent cough during the course of illness. During the recovery phase, she reported severe abdominal pain and developed hematoma in the right rectus sheath, which was confirmed by abdominal computed-tomography scan and serial magnetic resonance imaging. This complication during convalescent period of DHF needs to be recognized so it can be managed appropriately.

3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy.

PubMed

Hashimoto, Teruo; Thompson, George E; Zhou, Xiaorong; Withers, Philip J

2016-04-01

Mechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Routine Clinical Quantitative Rest Stress Myocardial Perfusion for Managing Coronary Artery Disease: Clinical Relevance of Test-Retest Variability.

PubMed

Kitkungvan, Danai; Johnson, Nils P; Roby, Amanda E; Patel, Monika B; Kirkeeide, Richard; Gould, K Lance

2017-05-01

Positron emission tomography (PET) quantifies stress myocardial perfusion (in cc/min/g) and coronary flow reserve to guide noninvasively the management of coronary artery disease. This study determined their test-retest precision within minutes and daily biological variability essential for bounding clinical decision-making or risk stratification based on low flow ischemic thresholds or follow-up changes. Randomized trials of fractional flow reserve-guided percutaneous coronary interventions established an objective, quantitative, outcomes-driven standard of physiological stenosis severity. However, pressure-derived fractional flow reserve requires invasive coronary angiogram and was originally validated by comparison to noninvasive PET. The time course and test-retest precision of serial quantitative rest-rest and stress-stress global myocardial perfusion by PET within minutes and days apart in the same patient were compared in 120 volunteers undergoing serial 708 quantitative PET perfusion scans using rubidium 82 (Rb-82) and dipyridamole stress with a 2-dimensional PET-computed tomography scanner (GE DST 16) and University of Texas HeartSee software with our validated perfusion model. Test-retest methodological precision (coefficient of variance) for serial quantitative global myocardial perfusion minutes apart is ±10% (mean ΔSD at rest ±0.09, at stress ±0.23 cc/min/g) and for days apart is ±21% (mean ΔSD at rest ±0.2, at stress ±0.46 cc/min/g) reflecting added biological variability. Global myocardial perfusion at 8 min after 4-min dipyridamole infusion is 10% higher than at standard 4 min after dipyridamole. Test-retest methodological precision of global PET myocardial perfusion by serial rest or stress PET minutes apart is ±10%. Day-to-different-day biological plus methodological variability is ±21%, thereby establishing boundaries of variability on physiological severity to guide or follow coronary artery disease management. Maximum stress increases perfusion and coronary flow reserve, thereby reducing potentially falsely low values mimicking ischemia. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Multi-scale structural analysis of gas diffusion layers

NASA Astrophysics Data System (ADS)

Göbel, Martin; Godehardt, Michael; Schladitz, Katja

2017-07-01

The macroscopic properties of materials are strongly determined by their micro structure. Here, transport properties of gas diffusion layers (GDL) for fuel cells are considered. In order to simulate flow and thermal properties, detailed micro structural information is essential. 3D images obtained by high-resolution computed tomography using synchrotron radiation and scanning electron microscopy (SEM) combined with focused ion beam (FIB) serial slicing were used. A recent method for reconstruction of porous structures from FIB-SEM images and sophisticated morphological image transformations were applied to segment the solid structural components. The essential algorithmic steps for segmenting the different components in the tomographic data-sets are described and discussed. In this paper, two types of GDL, based on a non-woven substrate layer and a paper substrate layer were considered, respectively. More than three components are separated within the synchrotron radiation computed tomography data. That is, fiber system, polytetrafluoroethylene (PTFE) binder/impregnation, micro porous layer (MPL), inclusions within the latter, and pore space are segmented. The usage of the thus derived 3D structure data in different simulation applications can be demonstrated. Simulations of macroscopic properties such as thermal conductivity, depending on the flooding state of the GDL are possible.

Serial computed tomography scanning in acute pancreatitis: a prospective study.

PubMed Central

London, N J; Neoptolemos, J P; Lavelle, J; Bailey, I; James, D

1989-01-01

One hundred and two patients with acute pancreatitis had abdominal computed tomography (CT) scans within 72 hours of admission, at one week and at six weeks. Twenty eight attacks were clinically severe, 74 clinically mild. Ninety three (91%) admission scans, 85 (84%) one week scans, and 52 (51%) six week scans were abnormal. The aetiology of the pancreatitis could be inferred from 28 (27%) of admission scans, the CT sign of fatty liver having a sensitivity of 21% and specificity of 100% for alcoholic aetiology. The sensitivity of CT for gall stone aetiology was 34%, specificity 100%. The pancreatic size indices (max anteroposterior measurement of head x max anteroposterior measurement of body) of those patients with severe attacks were significantly greater than those with mild attacks on admission, at one week and at six weeks (p less than 0.004). Fourteen pseudocysts were detected by CT, five (36%) of which were clinically apparent. The pseudocyst size indices (max anteroposterior x max transverse measurement) of the pseudocysts which were clinically apparent were significantly greater than those which were not apparent (p less than 0.01) and only those pseudocysts with a size index greater than or equal to 15 cm2 required treatment. PMID:2651228

Serial block face scanning electron microscopy--the future of cell ultrastructure imaging.

PubMed

Hughes, Louise; Hawes, Chris; Monteith, Sandy; Vaughan, Sue

2014-03-01

One of the major drawbacks in transmission electron microscopy has been the production of three-dimensional views of cells and tissues. Currently, there is no one suitable 3D microscopy technique that answers all questions and serial block face scanning electron microscopy (SEM) fills the gap between 3D imaging using high-end fluorescence microscopy and the high resolution offered by electron tomography. In this review, we discuss the potential of the serial block face SEM technique for studying the three-dimensional organisation of animal, plant and microbial cells.

A prospective evaluation of the repeatability of left ventricular ejection fraction measurement by gated SPECT.

PubMed

Kliner, Dustin; Wang, Li; Winger, Daniel; Follansbee, William P; Soman, Prem

2015-12-01

Gated single-photon emission computed tomography (SPECT) is widely used for myocardial perfusion imaging and provides an automated assessment of left ventricular ejection fraction (LVEF). We prospectively tested the repeatability of serial SPECT-derived LVEF. This information is essential in order to inform the interpretation of a change in LV function on serial testing. Consenting patients (n = 50) from among those referred for clinically indicated gated myocardial perfusion SPECT (MPs) were recruited. Following the clinical rest-stress study, patients were repositioned on the camera table for a second acquisition using identical parameters. Patient positioning, image acquisition and processing for the second scan were independently performed by a technologist blinded to the clinical scan. Quantitative LVEF was generated by Quantitative Gated SPECT and recorded as EF1 and EF2, respectively. Repeatability of serial results was assessed using the Bland-Altman method. The limits of repeatability and repeatability coefficients were generated to determine the maximum variation in LVEF that can be expected to result from test variability. Repeatability was tested across a broad range of LV systolic function and myocardial perfusion. The mean difference between EF1 and EF2 was 1.6% (EF units), with 95% limits of repeatability of +9.1% to -6.0% (repeatability coefficient 7.5%). Correlation between serial EF measurements was excellent (r = 0.9809). Similar results were obtained in subgroups based on normal or abnormal EF and myocardial perfusion. The largest repeatability coefficient of 8.1% was seen in patients with abnormal LV systolic function. When test protocol and acquisition parameters are kept constant, a difference of >8% EF units on serial MPs is indicative of a true change 95% of the time.

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.

Diagnosis and management of solitary pulmonary nodules.

PubMed

Jeong, Yeon Joo; Lee, Kyung Soo; Kwon, O Jung

2008-12-01

The advent of computed tomography (CT) screening with or without the help of computer-aided detection systems has increased the detection rate of solitary pulmonary nodules (SPNs), including that of early peripheral lung cancer. Helical dynamic (HD)CT, providing the information on morphologic and hemodynamic characteristics with high specificity and reasonably high accuracy, can be used for the initial assessment of SPNs. (18)F-fluorodeoxyglucose PET/CT is more sensitive at detecting malignancy than HDCT. Therefore, PET/CT may be selectively performed to characterize SPNs when HDCT gives an inconclusive diagnosis. Serial volume measurements are currently the most reliable methods for the tissue characterization of subcentimeter nodules. When malignant nodule is highly suspected for subcentimeter nodules, video-assisted thoracoscopic surgery nodule removal after nodule localization using the pulmonary nodule-marker system may be performed for diagnosis and treatment.

Programed asynchronous serial data interrogation in a two-computer system

NASA Technical Reports Server (NTRS)

Schneberger, N. A.

1975-01-01

Technique permits redundant computers, with one unit in control mode and one in MONITOR mode, to interrogate the same serial data source. Its use for program-controlled serial data transfer results in extremely simple hardware and software mechanization.

Automated Stitching of Microtubule Centerlines across Serial Electron Tomograms

PubMed Central

Weber, Britta; Tranfield, Erin M.; Höög, Johanna L.; Baum, Daniel; Antony, Claude; Hyman, Tony; Verbavatz, Jean-Marc; Prohaska, Steffen

2014-01-01

Tracing microtubule centerlines in serial section electron tomography requires microtubules to be stitched across sections, that is lines from different sections need to be aligned, endpoints need to be matched at section boundaries to establish a correspondence between neighboring sections, and corresponding lines need to be connected across multiple sections. We present computational methods for these tasks: 1) An initial alignment is computed using a distance compatibility graph. 2) A fine alignment is then computed with a probabilistic variant of the iterative closest points algorithm, which we extended to handle the orientation of lines by introducing a periodic random variable to the probabilistic formulation. 3) Endpoint correspondence is established by formulating a matching problem in terms of a Markov random field and computing the best matching with belief propagation. Belief propagation is not generally guaranteed to converge to a minimum. We show how convergence can be achieved, nonetheless, with minimal manual input. In addition to stitching microtubule centerlines, the correspondence is also applied to transform and merge the electron tomograms. We applied the proposed methods to samples from the mitotic spindle in C. elegans, the meiotic spindle in X. laevis, and sub-pellicular microtubule arrays in T. brucei. The methods were able to stitch microtubules across section boundaries in good agreement with experts' opinions for the spindle samples. Results, however, were not satisfactory for the microtubule arrays. For certain experiments, such as an analysis of the spindle, the proposed methods can replace manual expert tracing and thus enable the analysis of microtubules over long distances with reasonable manual effort. PMID:25438148

Automated stitching of microtubule centerlines across serial electron tomograms.

PubMed

Weber, Britta; Tranfield, Erin M; Höög, Johanna L; Baum, Daniel; Antony, Claude; Hyman, Tony; Verbavatz, Jean-Marc; Prohaska, Steffen

2014-01-01

Tracing microtubule centerlines in serial section electron tomography requires microtubules to be stitched across sections, that is lines from different sections need to be aligned, endpoints need to be matched at section boundaries to establish a correspondence between neighboring sections, and corresponding lines need to be connected across multiple sections. We present computational methods for these tasks: 1) An initial alignment is computed using a distance compatibility graph. 2) A fine alignment is then computed with a probabilistic variant of the iterative closest points algorithm, which we extended to handle the orientation of lines by introducing a periodic random variable to the probabilistic formulation. 3) Endpoint correspondence is established by formulating a matching problem in terms of a Markov random field and computing the best matching with belief propagation. Belief propagation is not generally guaranteed to converge to a minimum. We show how convergence can be achieved, nonetheless, with minimal manual input. In addition to stitching microtubule centerlines, the correspondence is also applied to transform and merge the electron tomograms. We applied the proposed methods to samples from the mitotic spindle in C. elegans, the meiotic spindle in X. laevis, and sub-pellicular microtubule arrays in T. brucei. The methods were able to stitch microtubules across section boundaries in good agreement with experts' opinions for the spindle samples. Results, however, were not satisfactory for the microtubule arrays. For certain experiments, such as an analysis of the spindle, the proposed methods can replace manual expert tracing and thus enable the analysis of microtubules over long distances with reasonable manual effort.

Endoscopic ultrasound - fine needle aspiration of 2-deoxy-2-[18F] fluoro-D-glucose avid lymph nodes seen on positron emission tomography- computed tomography -what looks like cancer may not always be so.

PubMed

Malik, Anum Imran; Akhtar, Noreen; Loya, Asif; Yusuf, Muhammed Aasim

2014-07-31

Patients suffering from malignancies often undergo serial positron emission tomography - computed tomography (PET-CT) scans, using 2-deoxy-2-[18F] fluoro-D-glucose (FDG) for diagnosis and follow up. This principle may also be applied to benign conditions as inflammatory cells take up increased amounts of FDG as well. The aim of our study was to retrospectively review the cytological diagnoses made at EUS-FNA of FDG-avid PET-CT lesions in patients with a history of cancer and to determine whether the cause of FDG-avidity was neoplastic or benign. We used the endoscopy database to extract clinical information on all patients with malignancies who underwent EUS-FNA to obtain tissue from FDG-avid nodes seen on PET-CT at our institution from 2009 - 2012. All patients who were referred for EUS-FNA after their scans were included. Those who had contraindications to endoscopic procedures were excluded. The most common location of positive lymph nodes was the subcarinal region (46%). A definitive diagnosis was obtained in 87.8% cases, of which 51.2% had a diagnosis of malignancy confirmed on cytology, while 36.5% were benign. Out of these, 29% had granulomatous inflammation. In 12.2% of cases no definitive diagnosis was obtained. Our results show that great caution should be exercised when evaluating FDG-avid PET-CT nodes in patients with known malignant disease, as a significant proportion of these lesions may be benign, particularly in geographic locations with a high background prevalence of granulomatous inflammation.

Preclinical evaluation of isostructural Tc-99m- and Re-188-folate-Gly-Gly-Cys-Glu for folate receptor-positive tumor targeting.

PubMed

Kim, Woo Hyoung; Kim, Chang Guhn; Kim, Myoung Hyoun; Kim, Dae-Weung; Park, Cho Rong; Park, Ji Yong; Lee, Yun-Sang; Youn, Hyewon; Kang, Keon Wook; Jeong, Jae Min; Chung, June-Key

2016-06-01

The purpose of the present study was to prepare isostructural Tc-99m- and Re-188-folate-Gly-Gly-Cys-Glu (folate-GGCE), and to evaluate the feasibility of their use for folate receptor (FR)-targeted molecular imaging and as theranostic agents in a mouse tumor model. Folate-GGCE was synthesized using solid-phase peptide synthesis and radiolabeled with Tc-99m or Re-188. Radiochemical characterization was performed by radio-high-performance liquid chromatography. The biodistribution of Tc-99m-folate-GGCE was studied, with or without co-injection of excess free folate, in mice bearing both FR-positive (KB cell) and FR-negative (HT1080 cell) tumors. Biodistribution of Re-188-folate-GGCE was studied in mice bearing KB tumors. Serial planar scintigraphy was performed in the dual tumor mouse model after intravenous injection of Tc-99m-folate-GGCE. Serial micro-single photon emission computed tomography/computed tomography (SPECT/CT) studies were performed, with or without co-injection of excess free folate, in the mouse tumor model after injection of Tc-99m-folate-GGCE or Re-188-folate-GGCE. The radiolabeling efficiency and radiochemical stability of Tc-99m- and Re-188-folate-GGCE were more than 95 % for up to 4 h after radiolabeling. Uptake of Tc-99m-folate-GGCE at 1, 2, and 4 h after injection in KB tumor was 16.4, 23.2, and 17.6 % injected dose per gram (%ID/g), respectively. This uptake was suppressed by 97.4 % when excess free folate was co-administered. Tumor:normal organ ratios at 4 h for blood, liver, lung, muscle, and kidney were 54.3, 25.2, 38.3, 97.8, and 0.3, respectively. Tumor uptake of Re-188-folate-GGCE at 2, 4, 8, and 16 h after injection was 17.4, 21.7, 24.1, and 15.6 %ID/g, respectively. Tumor:normal organ ratios at 8 h for blood, liver, lung, muscle, and kidney were 126.8, 21.9, 54.8, 80.3, and 0.4, respectively. KB tumors were clearly visualized at a high intensity using serial scintigraphy and micro-SPECT/CT in mice injected with Tc-99m- or Re-188-folate-GGCE. The tumor uptake of these molecules was completely suppressed when excess free folate was co-administered. Isostructural Tc-99m- and Re-188-folate-GGCE showed high and FR-specific uptake by tumors and generally favorable tumor:normal organ ratios. The tumor targeting capabilities of Tc-99m- and Re-188-folate-GGCE were clearly evident on serial imaging studies. This isostructural pair may have potential diagnostic and theranostic applications for FR-positive tumors.

In vivo time-serial evaluation of laser-induced choroidal neovascularization in rats simultaneously using photoacoustic microscopy and optical coherence tomography

NASA Astrophysics Data System (ADS)

Dai, Cuixia; Li, Lin; Liu, Wenlu; Wang, Fenghua; Zhou, Chuanqing

2018-02-01

Determination of the precise location and degree of condition of the Choroidal neovascularization (CNV) lesion is essential for diagnosation Neovascular age-related macular degeneration (AMD) and evaluation the efficacy of treatment. Given the complimentary contrast mechanisms of Photoacoustic microscopy (PAM) and Optical coherence tomography (OCT), the combination of PAM and OCT imaging could potentially provide much sensitive and specific detection of CNV. In this paper, we validated the opportunity to evaluate the information of laser-induced CNV and presented the in vivo time-serial evaluation of the CNV by simultaneously using PAM and OCT techniques. In vivo PAM and OCT examination was performed after laser photocoagulation applied to the rat fundus at days 1, 3, 5, 7, 14. Time-serial results showed that CNV in rats increased to its maximum at day 7 and decreased at day 14. Evolution of CNV information was given in PAM images with a high contrast and details of high axial resolution OCT images were simultaneously given to show the hyperreflective reaction progress.

Current applications of molecular imaging and luminescence-based techniques in traditional Chinese medicine.

PubMed

Li, Jinhui; Wan, Haitong; Zhang, Hong; Tian, Mei

2011-09-01

Traditional Chinese medicine (TCM), which is fundamentally different from Western medicine, has been widely investigated using various approaches. Cellular- or molecular-based imaging has been used to investigate and illuminate the various challenges identified and progress made using therapeutic methods in TCM. Insight into the processes of TCM at the cellular and molecular changes and the ability to image these processes will enhance our understanding of various diseases of TCM and will provide new tools to diagnose and treat patients. Various TCM therapies including herbs and formulations, acupuncture and moxibustion, massage, Gua Sha, and diet therapy have been analyzed using positron emission tomography, single photon emission computed tomography, functional magnetic resonance imaging and ultrasound and optical imaging. These imaging tools have kept pace with developments in molecular biology, nuclear medicine, and computer technology. We provide an overview of recent developments in demystifying ancient knowledge - like the power of energy flow and blood flow meridians, and serial naturopathies - which are essential to visually and vividly recognize the body using modern technology. In TCM, treatment can be individualized in a holistic or systematic view that is consistent with molecular imaging technologies. Future studies might include using molecular imaging in conjunction with TCM to easily diagnose or monitor patients naturally and noninvasively. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Automated noninvasive classification of renal cancer on multiphase CT

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

Linguraru, Marius George; Wang, Shijun; Shah, Furhawn

2011-10-15

Purpose: To explore the added value of the shape of renal lesions for classifying renal neoplasms. To investigate the potential of computer-aided analysis of contrast-enhanced computed-tomography (CT) to quantify and classify renal lesions. Methods: A computer-aided clinical tool based on adaptive level sets was employed to analyze 125 renal lesions from contrast-enhanced abdominal CT studies of 43 patients. There were 47 cysts and 78 neoplasms: 22 Von Hippel-Lindau (VHL), 16 Birt-Hogg-Dube (BHD), 19 hereditary papillary renal carcinomas (HPRC), and 21 hereditary leiomyomatosis and renal cell cancers (HLRCC). The technique quantified the three-dimensional size and enhancement of lesions. Intrapatient and interphasemore » registration facilitated the study of lesion serial enhancement. The histograms of curvature-related features were used to classify the lesion types. The areas under the curve (AUC) were calculated for receiver operating characteristic curves. Results: Tumors were robustly segmented with 0.80 overlap (0.98 correlation) between manual and semi-automated quantifications. The method further identified morphological discrepancies between the types of lesions. The classification based on lesion appearance, enhancement and morphology between cysts and cancers showed AUC = 0.98; for BHD + VHL (solid cancers) vs. HPRC + HLRCC AUC = 0.99; for VHL vs. BHD AUC = 0.82; and for HPRC vs. HLRCC AUC = 0.84. All semi-automated classifications were statistically significant (p < 0.05) and superior to the analyses based solely on serial enhancement. Conclusions: The computer-aided clinical tool allowed the accurate quantification of cystic, solid, and mixed renal tumors. Cancer types were classified into four categories using their shape and enhancement. Comprehensive imaging biomarkers of renal neoplasms on abdominal CT may facilitate their noninvasive classification, guide clinical management, and monitor responses to drugs or interventions.« less

Disseminated cat-scratch disease: case report and review of the literature.

PubMed

Chang, Chih-Chen; Lee, Chia-Jie; Ou, Liang-Shiou; Wang, Chao-Jan; Huang, Yhu-Chering

2016-08-01

Cat scratch disease (CSD) can present as a systemic disease in 5-10% of cases and lead to various disease entities. A previously healthy 16-month-old boy presented with fever for 7 days without other obvious symptoms. Abdominal computed tomography scan demonstrated enlarged right inguinal lymph nodes and multiple small round hypodensities in the spleen. Despite antibiotic treatment for 1 week, the fever persisted and the intrasplenic lesions progressed. Inguinal lymph node biopsy confirmed CSD by immunohistochemistry staining. The diagnosis of CSD was also supported by a history of contact, imaging and serological findings. The patient recovered after treatment with azithromycin for a total of 5 weeks and, in serial follow-up, the hepatosplenic micro-abscesses resolved after 4th months.

Disseminated cat-scratch disease: case report and review of the literature.

PubMed

Chang, Chih-Chen; Lee, Chia-Jie; Ou, Liang-Shiou; Wang, Chao-Jan; Huang, Yhu-Chering

2016-01-12

Cat scratch disease (CSD) can present as a systemic disease in 5-10% of cases and lead to various disease entities. A previously healthy 16-month-old boy presented with fever for 7 days without other obvious symptoms. Abdominal computed tomography scan demonstrated enlarged right inguinal lymph nodes and multiple small round hypodensities in the spleen. Despite antibiotic treatment for 1 week, the fever persisted and the intrasplenic lesions progressed. Inguinal lymph node biopsy confirmed CSD by immunohistochemistry staining. The diagnosis of CSD was also supported by a history of contact, imaging and serological findings. The patient recovered after treatment with azithromycin for a total of 5 weeks and, in serial follow-up, the hepatosplenic micro-abscesses resolved after 4th months.

Novel application and serial evaluation of tissue-engineered portal vein grafts in a murine model.

PubMed

Maxfield, Mark W; Stacy, Mitchel R; Kurobe, Hirotsugu; Tara, Shuhei; Yi, Tai; Cleary, Muriel A; Zhuang, Zhen W; Rodriguez-Davalos, Manuel I; Emre, Sukru H; Iwakiri, Yasuko; Shinoka, Toshiharu; Breuer, Christopher K

2017-12-01

Surgical management of pediatric extrahepatic portal vein obstruction requires meso-Rex bypass using autologous or synthetic grafts. Tissue-engineered vascular grafts (TEVGs) provide an alternative, but no validated animal models using portal TEVGs exist. Herein, we preclinically assess TEVGs as portal vein bypass grafts. TEVGs were implanted as portal vein interposition conduits in SCID-beige mice, monitored by ultrasound and micro-computed tomography, and histologically assessed postmortem at 12 months. TEVGs remained patent for 12 months. Histologic analysis demonstrated formation of neovessels that resembled native portal veins, with similar content of smooth muscle cells, collagen type III and elastin. TEVGs are feasible portal vein conduits in a murine model. Further preclinical evaluation of TEVGs may facilitate pediatric clinical translation.

Optical coherence tomography findings of bilateral foveal leukemic infiltration.

PubMed

Le, John Q; Braich, Puneet S; Brar, Vikram S

2016-01-01

We report a case of a 59-year-old man with a history of atypical chronic myelogenous leukemia who presented with a several-week history of decreased vision in both eyes. His clinical examination revealed bilateral foveal infiltration, which was also demonstrated on optical coherence tomography. After a failed induction with imatinib (Gleevec(®)), he was treated with omacetaxine (Synribo(®)) with an appropriate hematologic response. As his leukemia improved with chemotherapy, his retinal lesions regressed as demonstrated by serial optical coherence tomography and fundus photographs, with near complete restoration of foveal architecture.

Design of a massively parallel computer using bit serial processing elements

NASA Technical Reports Server (NTRS)

Aburdene, Maurice F.; Khouri, Kamal S.; Piatt, Jason E.; Zheng, Jianqing

1995-01-01

A 1-bit serial processor designed for a parallel computer architecture is described. This processor is used to develop a massively parallel computational engine, with a single instruction-multiple data (SIMD) architecture. The computer is simulated and tested to verify its operation and to measure its performance for further development.

A serial digital data communications device. [for real time flight simulation

NASA Technical Reports Server (NTRS)

Fetter, J. L.

1977-01-01

A general purpose computer peripheral device which is used to provide a full-duplex, serial, digital data transmission link between a Xerox Sigma computer and a wide variety of external equipment, including computers, terminals, and special purpose devices is reported. The interface has an extensive set of user defined options to assist the user in establishing the necessary data links. This report describes those options and other features of the serial communications interface and its performance by discussing its application to a particular problem.

The Locus of Serial Processing in Reading Aloud: Orthography-to-Phonology Computation or Speech Planning?

ERIC Educational Resources Information Center

Mousikou, Petroula; Rastle, Kathleen; Besner, Derek; Coltheart, Max

2015-01-01

Dual-route theories of reading posit that a sublexical reading mechanism that operates serially and from left to right is involved in the orthography-to-phonology computation. These theories attribute the masked onset priming effect (MOPE) and the phonological Stroop effect (PSE) to the serial left-to-right operation of this mechanism. However,…

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY SHOWS INNER CHOROIDAL ISCHEMIA IN ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY.

PubMed

Dolz-Marco, Rosa; Sarraf, David; Giovinazzo, Vincent; Freund, K Bailey

2017-01-01

To describe multimodal imaging findings of an evolving case of acute posterior multifocal placoid pigment epitheliopathy occurring in a young healthy male. Case report of a patient with acute posterior multifocal placoid pigment epitheliopathy including comprehensive systemic and ocular examinations. Ultra-widefield autofluorescence, fluorescein angiography, indocyanine green angiography, and serial optical coherence tomography angiography were performed. A 34-year-old male presented with acute vision loss in his left eye for 2 weeks. His best-corrected visual acuity was 20/20 in his right eye and 20/200 in his left eye. Dilated funduscopic examination revealed multiple creamy white deep retinal lesions showing macular involvement of the left eye with a diffuse area of pigmentary changes. The presence of multiple areas of hypoperfusion of the inner choroid were demonstrated with fluorescein and indocyanine green angiography. Serial optical coherence tomography angiography showed multiple evolving areas of decreased flow at the level of the inner choroid. Although the pathogenesis of acute posterior multifocal placoid pigment epitheliopathy remains unknown, there is growing evidence of a primary choroidal involvement with secondary damage to the overlying retinal pigment epithelium and the outer retinal layers. Optical coherence tomography angiography may provide valuable information for the diagnosis and follow-up of this condition avoiding invasive angiographic procedures.

Single photon emission computed tomography/positron emission tomography imaging and targeted radionuclide therapy of melanoma: new multimodal fluorinated and iodinated radiotracers.

PubMed

Maisonial, Aurélie; Kuhnast, Bertrand; Papon, Janine; Boisgard, Raphaël; Bayle, Martine; Vidal, Aurélien; Auzeloux, Philippe; Rbah, Latifa; Bonnet-Duquennoy, Mathilde; Miot-Noirault, Elisabeth; Galmier, Marie-Josèphe; Borel, Michèle; Askienazy, Serge; Dollé, Frédéric; Tavitian, Bertrand; Madelmont, Jean-Claude; Moins, Nicole; Chezal, Jean-Michel

2011-04-28

This study reports a series of 14 new iodinated and fluorinated compounds offering both early imaging ((123)I, (124)I, (18)F) and systemic treatment ((131)I) of melanoma potentialities. The biodistribution of each (125)I-labeled tracer was evaluated in a model of melanoma B16F0-bearing mice, using in vivo serial γ scintigraphic imaging. Among this series, [(125)I]56 emerged as the most promising compound in terms of specific tumoral uptake and in vivo kinetic profile. To validate our multimodality concept, the radiosynthesis of [(18)F]56 was then optimized and this radiotracer has been successfully investigated for in vivo PET imaging of melanoma in B16F0- and B16F10-bearing mouse model. The therapeutic efficacy of [(131)I]56 was then evaluated in mice bearing subcutaneous B16F0 melanoma, and a significant slow down in tumoral growth was demonstrated. These data support further development of 56 for PET imaging ((18)F, (124)I) and targeted radionuclide therapy ((131)I) of melanoma using a single chemical structure.

Scientific and Technical Serials Holdings Optimization in an Inefficient Market: A LSU Serials Redesign Project Exercise.

ERIC Educational Resources Information Center

Bensman, Stephen J.; Wilder, Stanley J.

1998-01-01

Analyzes the structure of the library market for scientific and technical (ST) serials. Describes an exercise aimed at a theoretical reconstruction of the ST-serials holdings of Louisiana State University (LSU) Libraries. Discusses the set definitions, measures, and algorithms necessary in the design of a computer program to appraise ST serials.…

Positron Emission Tomography - Computed Tomography (PET/CT)

MedlinePlus

... A-Z Positron Emission Tomography - Computed Tomography (PET/CT) Positron emission tomography (PET) uses small amounts of ... What is Positron Emission Tomography – Computed Tomography (PET/CT) Scanning? Positron emission tomography, also called PET imaging ...

Early predictive value of supine and upright X-ray films of odontoid fractures treated with halo-vest immobilization.

PubMed

Kim, David H; Vaccaro, Alexander R; Affonso, Jesse; Jenis, Louis; Hilibrand, Alan S; Albert, Todd J

2008-01-01

Although halo-vest immobilization remains a common form of treatment for type II odontoid fractures, nonunion and C1-2 instability may be the result in up to 20% to 40% of patients. Supine and upright lateral X-ray films may allow early identification of patients likely to fail halo-vest treatment and earlier surgical treatment with decreased morbidity from prolonged unsuccessful halo-vest immobilization. A prospective cohort study was performed. Twenty patients with type II odontoid fractures. Posttreatment nonunion and C1-2 instability as determined by plain X-ray films and computed tomography scan. Both supine and upright lateral X-ray films were obtained immediately after halo-vest application and at the 2-week, 6-week, and 3-month follow-up. Flexion-extension lateral X-ray films were obtained after halo-vest removal. Patients with nonunion or instability underwent computed tomography scan. Upright X-ray films were compared serially to identify loss of reduction. Pairs of supine and upright X-ray films were compared to measure any change in displacement or angulation upon transition from supine to upright position. Nonunion patients were compared with healed patients to determine any difference in fracture behavior based on serial supine and upright X-ray films. Twenty patients with type II odontoid fractures were identified during the study period. Three patients with multiple trauma underwent immediate surgical stabilization. Three elderly patients with nondisplaced fractures were treated in a cervical orthosis. Fourteen patients initiated and completed 3 months of halo-vest immobilization. After halo-vest removal, 4 of 14 patients (29%) showed radiographic nonunion or instability. In all 4 nonunion patients, supine and upright radiographs at 2 weeks revealed change in fracture angulation > or =5 degrees between the supine and upright positions. In three of these patients standard serial upright lateral X-ray films failed to identify any loss of reduction. In the remaining patient, progressive angulation of 15 degrees was observed. No measurable change in angulation between supine and upright X-ray films was observed in any patient who healed successfully with halo-vest treatment. Obtaining both supine and upright lateral X-ray films during the follow-up period may identify patients at risk for failure of halo-vest treatment as early as 2 weeks after initiation of treatment. A change in fracture angulation > or =5 degrees suggests an increased risk of treatment failure and the potential benefit of early surgical stabilization.

Optical coherence tomography findings of bilateral foveal leukemic infiltration

PubMed Central

Le, John Q; Braich, Puneet S; Brar, Vikram S

2016-01-01

We report a case of a 59-year-old man with a history of atypical chronic myelogenous leukemia who presented with a several-week history of decreased vision in both eyes. His clinical examination revealed bilateral foveal infiltration, which was also demonstrated on optical coherence tomography. After a failed induction with imatinib (Gleevec®), he was treated with omacetaxine (Synribo®) with an appropriate hematologic response. As his leukemia improved with chemotherapy, his retinal lesions regressed as demonstrated by serial optical coherence tomography and fundus photographs, with near complete restoration of foveal architecture. PMID:27540313

Thin-Section Computed Tomography Manifestations During Convalescence and Long-Term Follow-Up of Patients with Severe Acute Respiratory Syndrome (SARS).

PubMed

Wu, Xiaohua; Dong, Dawei; Ma, Daqing

2016-08-08

BACKGROUND SARS is not only an acute disease, but also leads to long-term impaired lung diffusing capacity in some survivors. However, there is a paucity of data regarding long-term CT findings in survivors after SARS. The aim of this study was to assess the changes in lung function and lung thin-section computed tomography (CT) features in patients recovering from severe acute respiratory syndrome (SARS), especially the dynamic changes in ground-glass opacity (GGO). MATERIAL AND METHODS Clinical and radiological data from 11 patients with SARS were collected. The serial follow-up thin-section CTs were evaluated at 3, 6, and 84 months after SARS presentation. The distribution and predominant thin-section CT findings of lesions were evaluated. RESULTS The extent of the lesions on the CT scans of the 11 patients decreased at 6 and 84 months compared to 3 months. The number of segments involved on 84-month follow-up CTs was less than those at 6 months (P<0.05). The predominant thin-section CT manifestation at 84 months (intralobular and interlobular septal thickening) was different than that at 6 months, at which GGO was predominant. CONCLUSIONS During convalescence after SARS, GGO and intralobular and interlobular septal thickening were the main thin-section CT manifestation. Intralobular and interlobular septal thickening predominated over GGO at 84 months.

The long-term outcomes of partial arch repair using the frozen elephant trunk technique for distal arch aortic aneurysm.

PubMed

Sueda, Taijiro; Takahashi, Shinya; Katayama, Keijiro; Morita, Shohei; Watanabe, Masazumi; Kurosaki, Tatsuya

2018-06-22

The purpose of this study was to evaluate the long-term results of partial arch repair using the frozen elephant trunk (FET) technique for distal arch aortic aneurysm and to examine the late complications. Thirty-eight patients with true distal arch aortic aneurysms were repaired with FET introduced through an incision in the proximal arch aorta. Follow-up computed tomography was performed every 6 or 12 months in 36 surviving patients. The maximum dimension of the excluded aneurysmal space was measured to determine whether the aneurysmal space had decreased or disappeared. Late complications were also evaluated during the long-term follow-up. There was 1 hospital death (2.6%) and 1 (2.6%) case of paraplegia. There were 2 late sudden deaths (5.2%) thought to be due to aneurysm rupture and arrhythmia. Postoperative serial-computed tomography showed shrinkage of the excluded aneurysmal space in 33 of 36 patients. Late aneurysmal formation occurred in the anastomotic site in three patients. One patient underwent thoracic endovascular stent grafting 10 years after surgery, 1 patient had total arch replacement 9 years after surgery, and 1 died due to rupture. Frozen elephant trunk was found to be a useful alternative for treating true distal arch aortic aneurysm. However, we must be alert for late aneurysmal formation at the incision site.

Deformable anatomical templates for brachytherapy treatment planning in radiotherapy of cervical cancer

NASA Astrophysics Data System (ADS)

Christensen, Gary E.; Williamson, Jeffrey F.; Chao, K. S. C.; Miller, Michael I.; So, F. B.; Vannier, Michael W.

1997-10-01

This paper describes a new method to register serial, volumetric x-ray computed tomography (CT) data sets for tracking soft-tissue deformation caused by insertion of intracavity brachytherapy applicators to treat cervical cancer. 3D CT scans collected from the same patient with and without a brachytherapy applicator are registered to aid in computation of the radiation dose to tumor and normal tissue. The 3D CT image volume of pelvic anatomy with the applicator. Initial registration is accomplished by rigid alignment of the pelvic bones and non-rigid alignment of gray scale CT data and hand segmentations of the vagina, cervix, bladder, and rectum. A viscous fluid transformation model is used for non-rigid registration to allow for local, non-linear registration of the vagina, cervix, bladder, and rectum without disturbing the rigid registration of the bony pelvis and adjacent structures. Results are presented in which two 3D CT data sets of the same patient - imaged with and without a brachytherapy applicator - are registered.

A novel method to acquire 3D data from serial 2D images of a dental cast

NASA Astrophysics Data System (ADS)

Yi, Yaxing; Li, Zhongke; Chen, Qi; Shao, Jun; Li, Xinshe; Liu, Zhiqin

2007-05-01

This paper introduced a newly developed method to acquire three-dimensional data from serial two-dimensional images of a dental cast. The system consists of a computer and a set of data acquiring device. The data acquiring device is used to take serial pictures of the a dental cast; an artificial neural network works to translate two-dimensional pictures to three-dimensional data; then three-dimensional image can reconstruct by the computer. The three-dimensional data acquiring of dental casts is the foundation of computer-aided diagnosis and treatment planning in orthodontics.

Three-dimensional imaging of adherent cells using FIB/SEM and STEM.

PubMed

Villinger, Clarissa; Schauflinger, Martin; Gregorius, Heiko; Kranz, Christine; Höhn, Katharina; Nafeey, Soufi; Walther, Paul

2014-01-01

In this chapter we describe three different approaches for three-dimensional imaging of electron microscopic samples: serial sectioning transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) tomography, and focused ion beam/scanning electron microscopy (FIB/SEM) tomography. With these methods, relatively large volumes of resin-embedded biological structures can be analyzed at resolutions of a few nm within a reasonable expenditure of time. The traditional method is serial sectioning and imaging the same area in all sections. Another method is TEM tomography that involves tilting a section in the electron beam and then reconstruction of the volume by back projection of the images. When the scanning transmission (STEM) mode is used, thicker sections (up to 1 μm) can be analyzed. The third approach presented here is focused ion beam/scanning electron microscopy (FIB/SEM) tomography, in which a sample is repeatedly milled with a focused ion beam (FIB) and each newly produced block face is imaged with the scanning electron microscope (SEM). This process can be repeated ad libitum in arbitrary small increments allowing 3D analysis of relatively large volumes such as eukaryotic cells. We show that resolution of this approach is considerably improved when the secondary electron signal is used. However, the most important prerequisite for three-dimensional imaging is good specimen preparation. For all three imaging methods, cryo-fixed (high-pressure frozen) and freeze-substituted samples have been used.

A Lie-Theoretic Perspective on O(n) Mass Matrix Inversion for Serial Manipulators and Polypeptide Chains.

PubMed

Lee, Kiju; Wang, Yunfeng; Chirikjian, Gregory S

2007-11-01

Over the past several decades a number of O(n) methods for forward and inverse dynamics computations have been developed in the multi-body dynamics and robotics literature. A method was developed in 1974 by Fixman for O(n) computation of the mass-matrix determinant for a serial polymer chain consisting of point masses. In other recent papers, we extended this method in order to compute the inverse of the mass matrix for serial chains consisting of point masses. In the present paper, we extend these ideas further and address the case of serial chains composed of rigid-bodies. This requires the use of relatively deep mathematics associated with the rotation group, SO(3), and the special Euclidean group, SE(3), and specifically, it requires that one differentiates functions of Lie-group-valued argument.

Parallel and serial computing tools for testing single-locus and epistatic SNP effects of quantitative traits in genome-wide association studies

PubMed Central

Ma, Li; Runesha, H Birali; Dvorkin, Daniel; Garbe, John R; Da, Yang

2008-01-01

Background Genome-wide association studies (GWAS) using single nucleotide polymorphism (SNP) markers provide opportunities to detect epistatic SNPs associated with quantitative traits and to detect the exact mode of an epistasis effect. Computational difficulty is the main bottleneck for epistasis testing in large scale GWAS. Results The EPISNPmpi and EPISNP computer programs were developed for testing single-locus and epistatic SNP effects on quantitative traits in GWAS, including tests of three single-locus effects for each SNP (SNP genotypic effect, additive and dominance effects) and five epistasis effects for each pair of SNPs (two-locus interaction, additive × additive, additive × dominance, dominance × additive, and dominance × dominance) based on the extended Kempthorne model. EPISNPmpi is the parallel computing program for epistasis testing in large scale GWAS and achieved excellent scalability for large scale analysis and portability for various parallel computing platforms. EPISNP is the serial computing program based on the EPISNPmpi code for epistasis testing in small scale GWAS using commonly available operating systems and computer hardware. Three serial computing utility programs were developed for graphical viewing of test results and epistasis networks, and for estimating CPU time and disk space requirements. Conclusion The EPISNPmpi parallel computing program provides an effective computing tool for epistasis testing in large scale GWAS, and the epiSNP serial computing programs are convenient tools for epistasis analysis in small scale GWAS using commonly available computer hardware. PMID:18644146

Relationship between the Self-Rating Anxiety Scale score and the success rate of 64-slice computed tomography coronary angiography.

PubMed

Li, Hui; Jin, Dan; Qiao, Fang; Chen, Jianchang; Gong, Jianping

Computed tomography coronary angiography, a key method for obtaining coronary artery images, is widely used to screen for coronary artery diseases due to its noninvasive nature. In China, 64-slice computed tomography systems are now the most common models. As factors that directly affect computed tomography performance, heart rate and rhythm control are regulated by the autonomic nervous system and are highly related to the emotional state of the patient. The aim of this prospective study is to use a pre-computed tomography scan Self-Rating Anxiety Scale assessment to analyze the effects of tension and anxiety on computed tomography coronary angiography success. Subjects aged 18-85 years who were planned to undergo computed tomography coronary angiography were enrolled; 1 to 2 h before the computed tomography scan, basic patient data (gender, age, heart rate at rest, and family history) and Self-Rating Anxiety Scale score were obtained. The same group of imaging department doctors, technicians, and nurses performed computed tomography coronary angiography for all the enrolled subjects and observed whether those subjects could finish the computed tomography coronary angiography scan and provide clear, diagnostically valuable images. Participants were divided into successful (obtained diagnostically useful coronary images) and unsuccessful groups. Basic data and Self-Rating Anxiety Scale scores were compared between the groups. The Self-Rating Anxiety Scale standard score of the successful group was lower than that of the unsuccessful group (P = 0.001). As the Self-Rating Anxiety Scale standard score rose, the success rate of computed tomography coronary angiography decreased. The Self-Rating Anxiety Scale score has a negative relationship with computed tomography coronary angiography success. Anxiety can be a disadvantage in computed tomography coronary angiography examination. The pre-computed tomography coronary angiography scan Self-Rating Anxiety Scale score may be a useful tool for assessing whether a computed tomography coronary angiography scan will be successful or not. © The Author(s) 2015.

Computed Tomography (CT) - Spine

MedlinePlus

... Resources Professions Site Index A-Z Computed Tomography (CT) - Spine Computed tomography (CT) of the spine is ... of CT Scanning of the Spine? What is CT Scanning of the Spine? Computed tomography, more commonly ...

Imaging whole mouse brains with a dual resolution serial swept-source optical coherence tomography scanner

NASA Astrophysics Data System (ADS)

Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

2018-02-01

High resolution imaging of whole rodent brains using serial OCT scanners is a promising method to investigate microstructural changes in tissue related to the evolution of neuropathologies. Although micron to sub-micron sampling resolution can be obtained by using high numerical aperture objectives and dynamic focusing, such an imaging system is not adapted to whole brain imaging. This is due to the large amount of data it generates and the significant computational resources required for reconstructing such volumes. To address this limitation, a dual resolution serial OCT scanner was developed. The optical setup consists in a swept-source OCT made of two sample and reference arms, each arm being coupled with different microscope objectives (3X / 40X). Motorized flip mirrors were used to switch between each OCT arm, thus allowing low and high resolution acquisitions within the same sample. The low resolution OCT volumes acquired with the 3X arm were stitched together, providing a 3D map of the whole mouse brain. This brain can be registered to an OCT brain template to enable neurological structures localization. The high resolution volumes acquired with the 40X arm were also stitched together to create local high resolution 3D maps of the tissue microstructure. The 40X data can be acquired at any arbitrary location in the sample, thus limiting storage-heavy high resolution data to application restricted to specific regions of interest. By providing dual-resolution OCT data, this setup can be used to validate diffusion MRI with tissue microstructure derived metrics measured at any location in ex vivo brains.

A Lie-Theoretic Perspective on O(n) Mass Matrix Inversion for Serial Manipulators and Polypeptide Chains

PubMed Central

Lee, Kiju; Wang, Yunfeng; Chirikjian, Gregory S.

2010-01-01

Over the past several decades a number of O(n) methods for forward and inverse dynamics computations have been developed in the multi-body dynamics and robotics literature. A method was developed in 1974 by Fixman for O(n) computation of the mass-matrix determinant for a serial polymer chain consisting of point masses. In other recent papers, we extended this method in order to compute the inverse of the mass matrix for serial chains consisting of point masses. In the present paper, we extend these ideas further and address the case of serial chains composed of rigid-bodies. This requires the use of relatively deep mathematics associated with the rotation group, SO(3), and the special Euclidean group, SE(3), and specifically, it requires that one differentiates functions of Lie-group-valued argument. PMID:20165563

Clinical value of whole body fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of metastatic bladder cancer.

PubMed

Yang, Zhongyi; Pan, Lingling; Cheng, Jingyi; Hu, Silong; Xu, Junyan; Ye, Dingwei; Zhang, Yingjian

2012-07-01

To investigate the value of whole-body fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography for the detection of metastatic bladder cancer. From December 2006 to August 2010, 60 bladder cancer patients (median age 60.5 years old, range 32-96) underwent whole body positron emission tomography/computed tomography positron emission tomography/computed tomography. The diagnostic accuracy was assessed by performing both organ-based and patient-based analyses. Identified lesions were further studied by biopsy or clinically followed for at least 6 months. One hundred and thirty-four suspicious lesions were identified. Among them, 4 primary cancers (2 pancreatic cancers, 1 colonic and 1 nasopharyngeal cancer) were incidentally detected, and the patients could be treated on time. For the remaining 130 lesions, positron emission tomography/computed tomography detected 118 true positive lesions (sensitivity = 95.9%). On the patient-based analysis, the overall sensitivity and specificity resulted to be 87.1% and 89.7%, respectively. There was no difference of sensitivity and specificity in patients with or without adjuvant treatment in terms of detection of metastatic sites by positron emission tomography/computed tomography. Compared with conventional imaging modality, positron emission tomography/computed tomography correctly changed the management in 15 patients (25.0%). Positron emission tomography/computed tomography has excellent sensitivity and specificity in the detection of metastatic bladder cancer and it provides additional diagnostic information compared to standard imaging techniques. © 2012 The Japanese Urological Association.

Gestational Trophoblastic Disease: A Multimodality Imaging Approach with Impact on Diagnosis and Management

PubMed Central

Ramani, Subhash; Thakur, Meenkashi

2014-01-01

Gestational trophoblastic disease is a condition of uncertain etiology, comprised of hydatiform mole (complete and partial), invasive mole, choriocarcinoma, and placental site trophoblastic tumor. It arises from abnormal proliferation of trophoblastic tissue. Early diagnosis of gestational trophoblastic disease and its potential complications is important for timely and successful management of the condition with preservation of fertility. Initial diagnosis is based on a multimodality approach: encompassing clinical features, serial quantitative β-hCG titers, and pelvic ultrasonography. Pelvic magnetic resonance imaging (MRI) is sometimes used as a problem-solving tool to assess the depth of myometrial invasion and extrauterine disease spread in equivocal and complicated cases. Chest radiography, body computed tomography (CT), and brain MRI have been recommended as investigative tools for overall disease staging. Angiography has a role in management of disease complications and metastases. Efficacy of PET (positron emission tomography) and PET/CT in the evaluation of recurrent or metastatic disease has not been adequately investigated yet. This paper discusses the imaging features of gestational trophoblastic disease on various imaging modalities and the role of different imaging techniques in the diagnosis and management of this entity. PMID:25126425

State-of-the-art: Radiological investigation of pleural disease.

PubMed

Hallifax, R J; Talwar, A; Wrightson, J M; Edey, A; Gleeson, F V

2017-03-01

Pleural disease is common. Radiological investigation of pleural effusion, thickening, masses, and pneumothorax is key in diagnosing and determining management. Conventional chest radiograph (CXR) remains as the initial investigation of choice for patients with suspected pleural disease. When abnormalities are detected, thoracic ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) can each play important roles in further investigation, but appropriate modality selection is critical. US adds significant value in the identification of pleural fluid and pleural nodularity, guiding pleural procedures and, increasingly, as "point of care" assessment for pneumothorax, but is highly operator dependent. CT scan is the modality of choice for further assessment of pleural disease: Characterising pleural thickening, some pleural effusions and demonstration of homogeneity of pleural masses and areas of fatty attenuation or calcification. MRI has specific utility for soft tissue abnormalities and may have a role for younger patients requiring follow-up serial imaging. MRI and PET/CT may provide additional information in malignant pleural disease regarding prognosis and response to therapy. This article summarises existing techniques, highlighting the benefits and applications of these different imaging modalities and provides an up to date review of the evidence. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonoperative management of spontaneous splenic rupture in infectious mononucleosis: a case report and review of the literature.

PubMed

Stephenson, Jacob T; DuBois, Jeffrey J

2007-08-01

Spontaneous rupture of the spleen is a rare complication of infectious mononucleosis with no clear consensus on appropriate management. Although management of traumatic splenic rupture has largely moved to nonoperative treatment, splenectomy is still frequently used in dealing with rupture of the diseased spleen. Here we report the case of a 16-year-old boy with splenic rupture secondary to laboratory-confirmed infectious mononucleosis in the absence of trauma. Nonoperative management including ICU admission, serial computed tomography scans, and activity limitation was used successfully. Our experience, along with a review of the literature, leads us to conclude that splenic preservation can be a safe alternative to splenectomy in hemodynamically stable patients with spontaneous splenic rupture. This is of particular importance in the pediatric population, which is at higher risk for postsplenectomy sepsis.

Recurrent Bleeding After Perimesencephalic Hemorrhage.

PubMed

Kauw, Frans; Velthuis, Birgitta K; Kizilates, Ufuk; van der Schaaf, Irene C; Rinkel, Gabriel J E; Vergouwen, Mervyn D I

2017-12-01

Perimesencephalic hemorrhage (PMH) is a type of subarachnoid hemorrhage with excellent long-term outcomes. Only 1 well-documented case of in-hospital rebleeding after PMH is described in the literature, which occurred after initiating antithrombotic treatment because of myocardial ischemia. We describe a patient with PMH without antithrombotic treatment who had 2 episodes of recurrent bleeding on the day of ictus. To validate the radiologic findings, we conducted a case-control study. Six neuroradiologists and 2 neuroradiology fellows performed a blinded assessment of serial unenhanced head computed tomography (CT) scans of 8 patients with a perimesencephalic bleeding pattern (1 index patient, 6 patients with PMH, 1 patient with perimesencephalic bleeding pattern and basilar artery aneurysm) to investigate a potential increase in amount of subarachnoid blood. A 56-year-old woman with a perimesencephalic bleeding pattern and negative CT angiography had 2 episodes after the onset headache with a sudden increase of the headache. Blinded assessment of serial head CT scans of 8 patients with a perimesencephalic bleeding pattern identified the patient who was clinically suspected to have 2 episodes of recurrent bleeding to have an increased amount of subarachnoid blood on 2 subsequent CT scans. Recurrent bleeding after PMH may also occur in patients not treated with antithrombotics. Even after early rebleeding, the prognosis of PMH is excellent. Copyright © 2017 Elsevier Inc. All rights reserved.

The locus of serial processing in reading aloud: orthography-to-phonology computation or speech planning?

PubMed

Mousikou, Petroula; Rastle, Kathleen; Besner, Derek; Coltheart, Max

2015-07-01

Dual-route theories of reading posit that a sublexical reading mechanism that operates serially and from left to right is involved in the orthography-to-phonology computation. These theories attribute the masked onset priming effect (MOPE) and the phonological Stroop effect (PSE) to the serial left-to-right operation of this mechanism. However, both effects may arise during speech planning, in the phonological encoding process, which also occurs serially and from left to right. In the present paper, we sought to determine the locus of serial processing in reading aloud by testing the contrasting predictions that the dual-route and speech planning accounts make in relation to the MOPE and the PSE. The results from three experiments that used the MOPE and the PSE paradigms in English are inconsistent with the idea that these effects arise during speech planning, and consistent with the claim that a sublexical serially operating reading mechanism is involved in the print-to-sound translation. Simulations of the empirical data on the MOPE with the dual route cascaded (DRC) and connectionist dual process (CDP++) models, which are computational implementations of the dual-route theory of reading, provide further support for the dual-route account. (c) 2015 APA, all rights reserved.

Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy.

PubMed

Tardif, Pier-Luc; Bertrand, Marie-Jeanne; Abran, Maxime; Castonguay, Alexandre; Lefebvre, Joël; Stähli, Barbara E; Merlet, Nolwenn; Mihalache-Avram, Teodora; Geoffroy, Pascale; Mecteau, Mélanie; Busseuil, David; Ni, Feng; Abulrob, Abedelnasser; Rhéaume, Éric; L'Allier, Philippe; Tardif, Jean-Claude; Lesage, Frédéric

2016-12-15

Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology.

Modularized compact positron emission tomography detector for rapid system development

PubMed Central

Xi, Daoming; Liu, Xiang; Zeng, Chen; Liu, Wei; Li, Yanzhao; Hua, Yuexuan; Mei, Xiongze; Kim, Heejong; Xiao, Peng; Kao, Chien-Min; Xie, Qingguo

2016-01-01

Abstract. We report the development of a modularized compact positron emission tomography (PET) detector that outputs serial streams of digital samples of PET event pulses via an Ethernet interface using the UDP/IP protocol to enable rapid configuration of a PET system by connecting multiple such detectors via a network switch to a computer. Presently, the detector is 76  mm×50  mm×55  mm in extent (excluding I/O connectors) and contains an 18×12 array of 4.2×4.2×20  mm3 one-to-one coupled lutetium-yttrium oxyorthosilicate/silicon photomultiplier pixels. It employs cross-wire and stripline readouts to merge the outputs of the 216 detector pixels to 24 channels. Signals at these channels are sampled using a built-in 24-ch, 4-level field programmable gate arrays-only multivoltage threshold digitizer. In the computer, software programs are implemented to analyze the digital samples to extract event information and to perform energy qualification and coincidence filtering. We have developed two such detectors. We show that all their pixels can be accurately discriminated and measure a crystal-level energy resolution of 14.4% to 19.4% and a detector-level coincidence time resolution of 1.67 ns FWHM. Preliminary imaging results suggests that a PET system based on the detectors can achieve an image resolution of ∼1.6  mm. PMID:28018941

Micro-computed tomography in murine models of cerebral cavernous malformations as a paradigm for brain disease.

PubMed

Girard, Romuald; Zeineddine, Hussein A; Orsbon, Courtney; Tan, Huan; Moore, Thomas; Hobson, Nick; Shenkar, Robert; Lightle, Rhonda; Shi, Changbin; Fam, Maged D; Cao, Ying; Shen, Le; Neander, April I; Rorrer, Autumn; Gallione, Carol; Tang, Alan T; Kahn, Mark L; Marchuk, Douglas A; Luo, Zhe-Xi; Awad, Issam A

2016-09-15

Cerebral cavernous malformations (CCMs) are hemorrhagic brain lesions, where murine models allow major mechanistic discoveries, ushering genetic manipulations and preclinical assessment of therapies. Histology for lesion counting and morphometry is essential yet tedious and time consuming. We herein describe the application and validations of X-ray micro-computed tomography (micro-CT), a non-destructive technique allowing three-dimensional CCM lesion count and volumetric measurements, in transgenic murine brains. We hereby describe a new contrast soaking technique not previously applied to murine models of CCM disease. Volumetric segmentation and image processing paradigm allowed for histologic correlations and quantitative validations not previously reported with the micro-CT technique in brain vascular disease. Twenty-two hyper-dense areas on micro-CT images, identified as CCM lesions, were matched by histology. The inter-rater reliability analysis showed strong consistency in the CCM lesion identification and staging (K=0.89, p<0.0001) between the two techniques. Micro-CT revealed a 29% greater CCM lesion detection efficiency, and 80% improved time efficiency. Serial integrated lesional area by histology showed a strong positive correlation with micro-CT estimated volume (r(2)=0.84, p<0.0001). Micro-CT allows high throughput assessment of lesion count and volume in pre-clinical murine models of CCM. This approach complements histology with improved accuracy and efficiency, and can be applied for lesion burden assessment in other brain diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Note: optical receiver system for 152-channel magnetoencephalography.

PubMed

Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong

2014-11-01

An optical receiver system composing 13 serial data restore/synchronizer modules and a single module combiner converted optical 32-bit serial data into 32-bit synchronous parallel data for a computer to acquire 152-channel magnetoencephalography (MEG) signals. A serial data restore/synchronizer module identified 32-bit channel-voltage bits from 48-bit streaming serial data, and then consecutively reproduced 13 times of 32-bit serial data, acting in a synchronous clock. After selecting a single among 13 reproduced data in each module, a module combiner converted it into 32-bit parallel data, which were carried to 32-port digital input board in a computer. When the receiver system together with optical transmitters were applied to 152-channel superconducting quantum interference device sensors, this MEG system maintained a field noise level of 3 fT/√Hz @ 100 Hz at a sample rate of 1 kSample/s per channel.

Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography.

PubMed

McBride, E L; Rao, A; Zhang, G; Hoyne, J D; Calco, G N; Kuo, B C; He, Q; Prince, A A; Pokrovskaya, I D; Storrie, B; Sousa, A A; Aronova, M A; Leapman, R D

2018-06-01

Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach. Copyright © 2018. Published by Elsevier Inc.

[Diagnostic possibilities of digital volume tomography].

PubMed

Lemkamp, Michael; Filippi, Andreas; Berndt, Dorothea; Lambrecht, J Thomas

2006-01-01

Cone beam computed tomography allows high quality 3D images of cranio-facial structures. Although detail resolution is increased, x-ray exposition is reduced compared to classic computer tomography. The volume is analysed in three orthogonal plains, which can be rotated independently without quality loss. Cone beam computed tomography seems to be a less expensive and less x-ray exposing alternative to classic computer tomography.

The Integrated Library System Design Concepts for a Complete Serials Control Subsystem.

DTIC Science & Technology

1984-08-20

7AD-fl149 379 THE INTEGRTED LIBRARY SYSTEM DESIGN CONCEPTS FOR A 1/COMPLETE SERIALS CONTROL UBSYSTEM(U) ONLINE COMPUTER SYSTEMS INC GERMANTOWN MD 28...CONTROL SUBSYSTEM Presented to: The Pentagon Library The Pentagon Washington, DC 20310 Prepared by: Online Computer Systems, Inc. 20251 Century Blvd...MDA903-82-C-0535 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK AREA & WORK UNIT NUMBERS Online Computer Systems, Inc

Serial Back-Plane Technologies in Advanced Avionics Architectures

NASA Technical Reports Server (NTRS)

Varnavas, Kosta

2005-01-01

Current back plane technologies such as VME, and current personal computer back planes such as PCI, are shared bus systems that can exhibit nondeterministic latencies. This means a card can take control of the bus and use resources indefinitely affecting the ability of other cards in the back plane to acquire the bus. This provides a real hit on the reliability of the system. Additionally, these parallel busses only have bandwidths in the 100s of megahertz range and EMI and noise effects get worse the higher the bandwidth goes. To provide scalable, fault-tolerant, advanced computing systems, more applicable to today s connected computing environment and to better meet the needs of future requirements for advanced space instruments and vehicles, serial back-plane technologies should be implemented in advanced avionics architectures. Serial backplane technologies eliminate the problem of one card getting the bus and never relinquishing it, or one minor problem on the backplane bringing the whole system down. Being serial instead of parallel improves the reliability by reducing many of the signal integrity issues associated with parallel back planes and thus significantly improves reliability. The increased speeds associated with a serial backplane are an added bonus.

Detection and classification of interstitial lung diseases and emphysema using a joint morphological-fuzzy approach

NASA Astrophysics Data System (ADS)

Chang Chien, Kuang-Che; Fetita, Catalin; Brillet, Pierre-Yves; Prêteux, Françoise; Chang, Ruey-Feng

2009-02-01

Multi-detector computed tomography (MDCT) has high accuracy and specificity on volumetrically capturing serial images of the lung. It increases the capability of computerized classification for lung tissue in medical research. This paper proposes a three-dimensional (3D) automated approach based on mathematical morphology and fuzzy logic for quantifying and classifying interstitial lung diseases (ILDs) and emphysema. The proposed methodology is composed of several stages: (1) an image multi-resolution decomposition scheme based on a 3D morphological filter is used to detect and analyze the different density patterns of the lung texture. Then, (2) for each pattern in the multi-resolution decomposition, six features are computed, for which fuzzy membership functions define a probability of association with a pathology class. Finally, (3) for each pathology class, the probabilities are combined up according to the weight assigned to each membership function and two threshold values are used to decide the final class of the pattern. The proposed approach was tested on 10 MDCT cases and the classification accuracy was: emphysema: 95%, fibrosis/honeycombing: 84% and ground glass: 97%.

Computed Tomography

NASA Astrophysics Data System (ADS)

Castellano, Isabel; Geleijns, Jacob

After its clinical introduction in 1973, computed tomography developed from an x-ray modality for axial imaging in neuroradiology into a versatile three dimensional imaging modality for a wide range of applications in for example oncology, vascular radiology, cardiology, traumatology and even in interventional radiology. Computed tomography is applied for diagnosis, follow-up studies and screening of healthy subpopulations with specific risk factors. This chapter provides a general introduction in computed tomography, covering a short history of computed tomography, technology, image quality, dosimetry, room shielding, quality control and quality criteria.

Development and validation of automated 2D-3D bronchial airway matching to track changes in regional bronchial morphology using serial low-dose chest CT scans in children with chronic lung disease.

PubMed

Raman, Pavithra; Raman, Raghav; Newman, Beverley; Venkatraman, Raman; Raman, Bhargav; Robinson, Terry E

2010-12-01

To address potential concern for cumulative radiation exposure with serial spiral chest computed tomography (CT) scans in children with chronic lung disease, we developed an approach to match bronchial airways on low-dose spiral and low-dose high-resolution CT (HRCT) chest images to allow serial comparisons. An automated algorithm matches the position and orientation of bronchial airways obtained from HRCT slices with those in the spiral CT scan. To validate this algorithm, we compared manual matching vs automatic matching of bronchial airways in three pediatric patients. The mean absolute percentage difference between the manually matched spiral CT airway and the index HRCT airways were 9.4 ± 8.5% for the internal diameter measurements, 6.0 ± 4.1% for the outer diameter measurements, and 10.1 ± 9.3% for the wall thickness measurements. The mean absolute percentage difference between the automatically matched spiral CT airway measurements and index HRCT airway measurements were 9.2 ± 8.6% for the inner diameter, 5.8 ± 4.5% for the outer diameter, and 9.9 ± 9.5% for the wall thickness. The overall difference between manual and automated methods was 2.1 ± 1.2%, which was significantly less than the interuser variability of 5.1 ± 4.6% (p<0.05). Tests of equivalence had p<0.05, demonstrating no significant difference between the two methods. The time required for matching was significantly reduced in the automated method (p<0.01) and was as accurate as manual matching, allowing efficient comparison of airways obtained on low-dose spiral CT imaging with low-dose HRCT scans.

Liver cirrhosis in Fontan patients does not affect 1-year post-heart transplant mortality or markers of liver function.

PubMed

Simpson, Kathleen E; Esmaeeli, Amir; Khanna, Geetika; White, Francis; Turnmelle, Yumirle; Eghtesady, Pirooz; Boston, Umar; Canter, Charles E

2014-02-01

Liver cirrhosis is recognized with long-term follow-up of patients after the Fontan procedure. The effect of liver cirrhosis on the use of heart transplant (HT) and on post-HT outcomes is unknown. We reviewed Fontan patients evaluated for HT from 2004 to 2012 with hepatic computed tomography (CT) imaging, classified as normal, non-cirrhotic changes, or cirrhosis. The primary outcome was 1-year all-cause mortality, and the secondary outcome was differences in serial post-HT liver evaluation. CT imaging in 32 Fontan patients evaluated for HT revealed 20 (63%) with evidence of liver disease, including 13 (41%) with cirrhosis. Twenty underwent HT, including 5 non-cirrhotic and 7 cirrhosis patients. Characteristics at listing between normal or non-cirrhotic (n = 13) and cirrhosis (n = 7) groups were similar, except cirrhosis patients were older (median 17.6 vs 9.6 years, p = 0.002) and further from Fontan (median 180 vs 50 months, p < 0.05). Serial liver evaluation was similar, including aspartate aminotransferase, alanine aminotransferase, bilirubin, albumin, and tacrolimus dose at 1, 3, 6, 9, and 12 months. Overall patient survival was 80% at 1 year, with no difference between cirrhosis and non-cirrhosis patients (86% vs 77%, p = 0.681). Liver biopsies were performed in 7 patients before HT, and all specimens showed architectural changes with bridging fibrosis. Most patients evaluated for HT had abnormal liver findings by CT, with cirrhosis in 41%. One-year mortality and serial liver evaluation were similar between groups after HT. Liver cirrhosis identified by CT imaging may not be an absolute contraindication to HT alone in this population. © 2014 International Society for Heart and Lung Transplantation Published by International Society for the Heart and Lung Transplantation All rights reserved.

Do C-reactive protein level, white blood cell count, and pain location guide the selection of patients for computed tomography imaging in non-traumatic acute abdomen?

PubMed

Ozan, E; Atac, G K; Evrin, T; Alisar, K; Sonmez, L O; Alhan, A

2017-02-01

The value of abdominal computed tomography in non-traumatic abdominal pain has been well established. On the other hand, to manage computed tomography, appropriateness has become more of an issue as a result of the concomitant increase in patient radiation exposure with increased computed tomography use. The purpose of this study was to investigate whether C-reactive protein, white blood cell count, and pain location may guide the selection of patients for computed tomography in non-traumatic acute abdomen. Patients presenting with acute abdomen to the emergency department over a 12-month period and who subsequently underwent computed tomography were retrospectively reviewed. Those with serum C-reactive protein and white blood cell count measured on admission or within 24 h of the computed tomography were selected. Computed tomography examinations were retrospectively reviewed, and final diagnoses were designated either positive or negative for pathology relating to presentation with acute abdomen. White blood cell counts, C-reactive protein levels, and pain locations were analyzed to determine whether they increased or decreased the likelihood of producing a diagnostic computed tomography. The likelihood ratio for computed tomography positivity with a C-reactive protein level above 5 mg/L was 1.71, while this increased to 7.71 in patients with combined elevated C-reactive protein level and white blood cell count and right lower quadrant pain. Combined elevated C-reactive protein level and white blood cell count in patients with right lower quadrant pain may represent a potential factor that could guide the decision to perform computed tomography in non-traumatic acute abdomen.

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

Metastatic breast carcinoma presenting as unilateral pulsatile tinnitus: a case report.

PubMed

Moore, Andrew; Cunnane, Max; Fleming, Jason C

2015-02-01

Pulsatile tinnitus is a rare symptom, yet it may herald life-threatening pathology in the absence of other symptoms or signs. Pulsatile tinnitus tends to imply a vascular cause, but metastatic disease also can present in this way. Clinicians should therefore adopt a specific diagnostic algorithm for pulsatile tinnitus and always consider the possibility of metastatic disease. A history of malignant disease and new cranial nerve palsies should raise clinical suspicion for skull base metastases. We describe the case of a 63-year-old woman presenting with unilateral subjective pulsatile tinnitus and a middle ear mass visible on otoscopy. Her background included the diagnosis of idiopathic unilateral vagal and hypoglossal nerve palsies 4 years previously, with normal magnetic resonance imaging (MRI). Repeat MRI and computed tomography imaging were consistent with metastatic breast carcinoma. This case raises important questions about imaging protocols and the role of serial scanning in patients at high risk of metastatic disease.

Use of computed tomography renal angiography for screening feline renal transplant donors.

PubMed

Bouma, Jennifer L; Aronson, Lillian R; Keith, Dennis G; Saunders, H Mark

2003-01-01

Preoperative knowledge of the renal vascular anatomy is important for selection of the appropriate feline renal donor. Intravenous urograms (IVUs) have been performed routinely to screen potential donors at the Veterinary Hospital of the University of Pennsylvania (VHUP), but the vascular phase views lack sufficient detail of the renal vascular anatomy. Computed tomography angiography (CTA), which requires a helical computed tomography (CT) scanner, has been found to provide superior renal vascular anatomic information of prospective human renal donors. The specific aims of this study were as follows: 1) develop the CTA technique for the feline patient; and 2) obtain preliminary information on feline renal vessel anatomy in potential renal donors. Ten healthy, potential feline renal donors were anesthetized and imaged using a third-generation helical CT scanner. The time delay between i.v. contrast medium injection and image acquisition, and other parameters of slice collimation, slice interval, pitch, exposure settings, and reconstruction algorithms were varied to maximize contrast medium opacification of the renal vascular anatomy. Optimal CTA acquisition parameters were determined to be: 1) 10-sec delay post-i.v. bolus of iodinated contrast medium; 2) two serially acquired (corresponding to arterial and venous phases) helical scans through the renal vasculature; 3) pitch of 2 (4 mm/sec patient translation, 2 mm slice collimation); and 4) 120-kVp, 160-mA, and 1-sec exposure settings. Retrospective reconstructed CTA transverse images obtained at a 2-mm slice width and a 1-mm slice interval in combination with two-dimensional reformatted images and three-dimensional reconstructed images were qualitatively evaluated for vascular anatomy; vascular anatomy was confirmed at surgery. Four cats had single renal arteries and veins bilaterally; four cats had double renal veins. One cat had a small accessory artery supplying the caudal pole of the left kidney. One cat had a left renal artery originating from the aorta at a 90 degrees angle with the cranial mesenteric artery. CTA of the feline renal vascular anatomy is feasible, and reconstruction techniques provide excellent anatomic vascular detail. CTA is now used routinely at VHUP to screen all potential feline renal donors.

Effect of Intensive Statin Therapy on Coronary High-Intensity Plaques Detected by Noncontrast T1-Weighted Imaging: The AQUAMARINE Pilot Study.

PubMed

Noguchi, Teruo; Tanaka, Atsushi; Kawasaki, Tomohiro; Goto, Yoichi; Morita, Yoshiaki; Asaumi, Yasuhide; Nakao, Kazuhiro; Fujiwara, Reiko; Nishimura, Kunihiro; Miyamoto, Yoshihiro; Ishihara, Masaharu; Ogawa, Hisao; Koga, Nobuhiko; Narula, Jagat; Yasuda, Satoshi

2015-07-21

Coronary high-intensity plaques detected by noncontrast T1-weighted imaging may represent plaque instability. High-intensity plaques can be quantitatively assessed by a plaque-to-myocardium signal-intensity ratio (PMR). This pilot, hypothesis-generating study sought to investigate whether intensive statin therapy would lower PMR. Prospective serial noncontrast T1-weighted magnetic resonance imaging and computed tomography angiography were performed in 48 patients with coronary artery disease at baseline and after 12 months of intensive pitavastatin treatment with a target low-density lipoprotein cholesterol level <80 mg/dl. The control group consisted of coronary artery disease patients not treated with statins that were matched by propensity scoring (n = 48). The primary endpoint was the 12-month change in PMR. Changes in computed tomography angiography parameters and high-sensitivity C-reactive protein levels were analyzed. In the statin group, 12 months of statin therapy significantly improved low-density lipoprotein cholesterol levels (125 to 70 mg/dl; p < 0.001), PMR (1.38 to 1.11, an 18.9% reduction; p < 0.001), low-attenuation plaque volume, and the percentage of total atheroma volume on computed tomography. In the control group, the PMR increased significantly (from 1.22 to 1.49, a 19.2% increase; p < 0.001). Changes in PMR were correlated with changes in low-density lipoprotein cholesterol (r = 0.533; p < 0.001), high-sensitivity C-reactive protein (r = 0.347; p < 0.001), percentage of atheroma volume (r = 0.477; p < 0.001), and percentage of low-attenuation plaque volume (r = 0.416; p < 0.001). Statin treatment significantly reduced the PMR of high-intensity plaques. Noncontrast T1-weighted magnetic resonance imaging could become a useful technique for repeated quantitative assessment of plaque composition. (Attempts at Plaque Vulnerability Quantification with Magnetic Resonance Imaging Using Noncontrast T1-weighted Technique [AQUAMARINE]; UMIN000003567). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Automated Transmission-Mode Scanning Electron Microscopy (tSEM) for Large Volume Analysis at Nanoscale Resolution

PubMed Central

Kuwajima, Masaaki; Mendenhall, John M.; Lindsey, Laurence F.; Harris, Kristen M.

2013-01-01

Transmission-mode scanning electron microscopy (tSEM) on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm2 (65.54 µm per side) at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM) system, which were only 66.59 µm2 (8.160 µm per side) at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm). Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems. PMID:23555711

Localized cerebral energy failure in DNA polymerase gamma-associated encephalopathy syndromes.

PubMed

Tzoulis, Charalampos; Neckelmann, Gesche; Mørk, Sverre J; Engelsen, Bernt E; Viscomi, Carlo; Moen, Gunnar; Ersland, Lars; Zeviani, Massimo; Bindoff, Laurence A

2010-05-01

Mutations in the catalytic subunit of the mitochondrial DNA-polymerase gamma cause a wide spectrum of clinical disease ranging from infantile hepato-encephalopathy to juvenile/adult-onset spinocerebellar ataxia and late onset progressive external ophthalmoplegia. Several of these syndromes are associated with an encephalopathy that characteristically shows episodes of rapid neurological deterioration and the development of acute cerebral lesions. The purpose of this study was to investigate the nature, distribution and natural evolution of central nervous system lesions in polymerase gamma associated encephalopathy focusing particularly on lesions identified by magnetic resonance imaging. We compared radiological, electrophysiological and pathological findings where available to study potential mechanisms underlying the episodes of exacerbation and acute cerebral lesions. We studied a total of 112 magnetic resonance tomographies and 11 computed tomographies in 32 patients with polymerase gamma-encephalopathy, including multiple serial examinations performed during both the chronic and acute phases of the disease and, in several cases, magnetic resonance spectroscopy and serial diffusion weighted studies. Data from imaging, electroencephalography and post-mortem examination were compared in order to study the underlying disease process. Our findings show that magnetic resonance imaging in polymerase gamma-related encephalopathies has high sensitivity and can identify patterns that are specific for individual syndromes. One form of chronic polymerase gamma-encephalopathy, that is associated with the c.1399G > A and c.2243G > C mutations, is characterized by progressive cerebral and cerebellar atrophy and focal lesions of the thalamus, deep cerebellar structures and medulla oblongata. Acute encephalopathies, both infantile and later onset, show similar pictures with cortical stroke-like lesions occurring during episodes of exacerbation. These lesions can occur both with and without electroencephalographic evidence of concurrent epileptic activity, and have diffusion, spectroscopic and histological profiles strongly suggestive of neuronal energy failure. We suggest therefore that both infantile and later onset polymerase gamma related encephalopathies are part of a continuum.

Computed tomography vs. digital radiography assessment for detection of osteolysis in asymptomatic patients with uncemented cups: a proposal for a new classification system based on computer tomography.

PubMed

Sandgren, Buster; Crafoord, Joakim; Garellick, Göran; Carlsson, Lars; Weidenhielm, Lars; Olivecrona, Henrik

2013-10-01

Digital radiographic images in the anterior-posterior and lateral view have been gold standard for evaluation of peri-acetabular osteolysis for patients with an uncemented hip replacement. We compared digital radiographic images and computer tomography in detection of peri-acetabular osteolysis and devised a classification system based on computer tomography. Digital radiographs were compared with computer tomography on 206 hips, with a mean follow up 10 years after surgery. The patients had no clinical signs of osteolysis and none were planned for revision surgery. On digital radiographs, 192 cases had no osteolysis and only 14 cases had osteolysis. When using computer tomography there were 184 cases showing small or large osteolysis and only 22 patients had no osteolysis. A classification system for peri-acetabular osteolysis is proposed based on computer tomography that is easy to use on standard follow up evaluation. Copyright © 2013 Elsevier Inc. All rights reserved.

Verifying speculative multithreading in an application

DOEpatents

Felton, Mitchell D

2014-12-09

Verifying speculative multithreading in an application executing in a computing system, including: executing one or more test instructions serially thereby producing a serial result, including insuring that all data dependencies among the test instructions are satisfied; executing the test instructions speculatively in a plurality of threads thereby producing a speculative result; and determining whether a speculative multithreading error exists including: comparing the serial result to the speculative result and, if the serial result does not match the speculative result, determining that a speculative multithreading error exists.

Verifying speculative multithreading in an application

DOEpatents

Felton, Mitchell D

2014-11-18

Verifying speculative multithreading in an application executing in a computing system, including: executing one or more test instructions serially thereby producing a serial result, including insuring that all data dependencies among the test instructions are satisfied; executing the test instructions speculatively in a plurality of threads thereby producing a speculative result; and determining whether a speculative multithreading error exists including: comparing the serial result to the speculative result and, if the serial result does not match the speculative result, determining that a speculative multithreading error exists.

A parallel Jacobson-Oksman optimization algorithm. [parallel processing (computers)

NASA Technical Reports Server (NTRS)

Straeter, T. A.; Markos, A. T.

1975-01-01

A gradient-dependent optimization technique which exploits the vector-streaming or parallel-computing capabilities of some modern computers is presented. The algorithm, derived by assuming that the function to be minimized is homogeneous, is a modification of the Jacobson-Oksman serial minimization method. In addition to describing the algorithm, conditions insuring the convergence of the iterates of the algorithm and the results of numerical experiments on a group of sample test functions are presented. The results of these experiments indicate that this algorithm will solve optimization problems in less computing time than conventional serial methods on machines having vector-streaming or parallel-computing capabilities.

Comparing three-dimensional serial optical coherence tomography histology to MRI imaging in the entire mouse brain

NASA Astrophysics Data System (ADS)

Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Lesage, Frédéric

2018-01-01

An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5) μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging. The OCT brain template yielded a highly detailed map of the brain structure, with a high contrast in white matter fiber bundles and was highly resemblant to the in vivo MRI template. Brain labeling using the Allen brain framework showed little variation in regional brain volume among imaging modalities with no statistical differences. The high correspondence between the OCT template brain and its in vivo counterpart demonstrates the potential of whole brain histology to validate in vivo imaging.

Security Engineering Project - System Aware Cyber Security for an Autonomous Surveillance System On Board an Unmanned Aerial Vehicle

DTIC Science & Technology

2014-01-31

59 Figure 26. Raspberry Pi SBC... Raspberry Pi single compute board (SBC) (see section 3.3.1.2). These snoopers can intercept the serial data, decode the information, and retransmit the...data. The Raspberry Pi contains two serial ports that allow receiving, altering, and retransmitting of serial data. These monitor points will provide

On-Iine Management System for the Periodicals in JAERl

NASA Astrophysics Data System (ADS)

Itabashi, Keizo; Mineo, Yukinobu

The article describes the outlines of the on-line serials control system utilizing a mini-computer. The system is dealt with subscription, check-in, claiming, inquiry of serials information and binding of journals. In this system journal acquisition with serial arrival prediction in an on-line mode is carried on a priority principle to record the actual receipt of incoming issues.

Serial perfusion in native lungs in patients with idiopathic pulmonary fibrosis and other interstitial lung diseases after single lung transplantation.

PubMed

Sokai, Akihiko; Handa, Tomohiro; Chen, Fengshi; Tanizawa, Kiminobu; Aoyama, Akihiro; Kubo, Takeshi; Ikezoe, Kohei; Nakatsuka, Yoshinari; Oguma, Tsuyoshi; Hirai, Toyohiro; Nagai, Sonoko; Chin, Kazuo; Date, Hiroshi; Mishima, Michiaki

2016-04-01

Lung perfusions after single lung transplantation (SLT) have not been fully clarified in patients with interstitial lung disease (ILD). The present study aimed to investigate temporal changes in native lung perfusion and their associated clinical factors in patients with ILD who have undergone SLT. Eleven patients were enrolled. Perfusion scintigraphy was serially performed up to 12 months after SLT. Correlations between the post-operative perfusion ratio in the native lung and clinical parameters, including pre-operative perfusion ratio and computed tomography (CT) volumetric parameters, were evaluated. On average, the perfusion ratio of the native lung was maintained at approximately 30% until 12 months after SLT. However, the ratio declined more significantly in idiopathic pulmonary fibrosis (IPF) than in other ILDs (p = 0.014). The perfusion ratio before SLT was significantly correlated with that at three months after SLT (ρ = 0.64, p = 0.048). The temporal change of the perfusion ratio in the native lung did not correlate with those of the CT parameters. The pre-operative perfusion ratio may predict the post-operative perfusion ratio of the native lung shortly after SLT in ILD. Perfusion of the native lung may decline faster in IPF compared with other ILDs. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Real-time dosimeter employed to evaluate the half-value layer in CT

NASA Astrophysics Data System (ADS)

McKenney, Sarah E.; Seibert, J. Anthony; Burkett, George W.; Gelskey, Dale; Sunde, Paul B.; Newman, James D.; Boone, John M.

2014-01-01

Half-value layer (HVL) measurements on commercial whole body computer tomography (CT) scanners require serial measurements and, in many institutions, the presence of a service engineer. An assembly of aluminum filters (AAF), designed to be used in conjunction with a real-time dosimeter, was developed to provide estimates of the HVL using clinical protocols. Two real-time dose probes, a solid-state and air ionization chamber, were examined. The AAF consisted of eight rectangular filters of high-purity aluminum (Type 1100), symmetrically positioned to form a cylindrical ‘cage’ around the probe's detective volume. The incident x-ray beam was attenuated by varying thicknesses of aluminum filters as the gantry completed a minimum of one rotation. Measurements employing real-time chambers were conducted both in service mode and with a routine abdomen/pelvis protocol for several combinations of x-ray tube potentials and bow tie filters. These measurements were validated against conventional serial HVL measurements. The average relative difference between the HVL measurements using the two methods was less than 5% when using a 122 mm diameter AAF; relative differences were reduced to 1.1% when the diameter was increased to 505 mm, possibly due to reduced scatter contamination. Use of a real-time dose probe and the AAF allowed for time-efficient measurements of beam quality on a clinical CT scanner using clinical protocols.

Assessment of the Role of Different Imaging Modalities with Emphasis on Fdg Pet/Ct in the Management of Well Differentiated Thyroid Cancer (WDTC).

PubMed

Kendi A, Tuba Karagulle; Mudalegundi, Shwetha; Switchenko, Jeffrey; Lee, Daniel; Halkar, Raghuveer; Chen, Amy Y

2016-01-01

Positron emission tomography/computed tomography is suggested to have a role in detection of iodine negative recurrence in well differentiated thyroid cancer. The aim of this study is to identify role of different imaging modalities in the management of well differentiated thyroid cancer. We reviewed 900 well differentiated thyroid cancer patients after post-thyroidectomy who underwent recombinant human thyroid stimulating hormone stimulated Sodium Iodide I 131 imaging. Out of 900 patients, 74 had positron emission tomography/computed tomography. Multivariate analysis was performed by controlling positron emission tomography/computed tomography, Sodium Iodide I 131 scan, neck ultrasonography, age, sex, primary tumor size, stage, histology, thyroglobulin. Patients were grouped according to results of Sodium Iodide I 131 scan and positron emission tomography/computed tomography. Positron emission tomography/computed tomography was positive in 23 of 74 patients. The sensitivity for positron emission tomography was 11/11(100%), the specificity was 51/63 (81.0%), the positive predictive value was 11/23 (47.8%), and the negative predictive value was 51/51 (100%). The sensitivity for the neck ultrasonography was 4/8 (50%), the specificity was 53/60 (88.3%), positive predictive value was 4/11 (36.4%), and negative predictive value was 53/57 (93.0%). 50% of patients who had Sodium Iodide I 131 negative scan and positive positron emission tomography/computed tomography had a change in management. Thirty-six percent with positive neck ultrasonography had a change in management. Out of 11 recurrences, 6 had distant metastatic disease, and 5/11 had regional nodal disease. Neck ultrasonography showed nodal metastasis in 4/5 (80%). Positron emission tomography/computed tomography altered management in the presence of a high thyroglobulin level and a negative Sodium Iodide I 131 scan. Neck ultrasonography should be the first line of imaging with rising thyroglobulin levels. Positron emission tomography/computed tomography should be considered for cases with high thyroglobulin levels and normal neck ultrasonography to look for distant metastatic disease.

Metabolite profiling with HPLC-ICP-MS as a tool for in vivo characterization of imaging probes.

PubMed

Boros, Eszter; Pinkhasov, Omar R; Caravan, Peter

2018-01-01

Current analytical methods for characterizing pharmacokinetic and metabolic properties of positron emission tomography (PET) and single photon emission computed tomography (SPECT) probes are limited. Alternative methods to study tracer metabolism are needed. The study objective was to assess the potential of high performance liquid chromatography - inductively coupled plasma - mass spectrometry (HPLC-ICP-MS) for quantification of molecular probe metabolism and pharmacokinetics using stable isotopes. Two known peptide-DOTA conjugates were chelated with nat Ga and nat In. Limit of detection of HPLC-ICP-MS for 69 Ga and 115 In was determined. Rats were administered 50-150 nmol of Ga- and/or In-labeled probes, blood was serially sampled, and plasma analyzed by HPLC-ICP-MS using both reverse phase and size exclusion chromatography. The limits of detection were 0.16 pmol for 115 In and 0.53 pmol for 69 Ga. Metabolites as low as 0.001 %ID/g could be detected and transchelation products identified. Simultaneous administration of Ga- and In-labeled probes allowed the determination of pharmacokinetics and metabolism of both probes in a single animal. HPLC-ICP-MS is a robust, sensitive and radiation-free technique to characterize the pharmacokinetics and metabolism of imaging probes.

Body CT (CAT Scan)

MedlinePlus

... Resources Professions Site Index A-Z Computed Tomography (CT) - Body Computed tomography (CT) of the body uses ... of CT Scanning of the Body? What is CT Scanning of the Body? Computed tomography, more commonly ...

CT-guided automated detection of lung tumors on PET images

NASA Astrophysics Data System (ADS)

Cui, Yunfeng; Zhao, Binsheng; Akhurst, Timothy J.; Yan, Jiayong; Schwartz, Lawrence H.

2008-03-01

The calculation of standardized uptake values (SUVs) in tumors on serial [ 18F]2-fluoro-2-deoxy-D-glucose ( 18F-FDG) positron emission tomography (PET) images is often used for the assessment of therapy response. We present a computerized method that automatically detects lung tumors on 18F-FDG PET/Computed Tomography (CT) images using both anatomic and metabolic information. First, on CT images, relevant organs, including lung, bone, liver and spleen, are automatically identified and segmented based on their locations and intensity distributions. Hot spots (SUV >= 1.5) on 18F-FDG PET images are then labeled using the connected component analysis. The resultant "hot objects" (geometrically connected hot spots in three dimensions) that fall into, reside at the edges or are in the vicinity of the lungs are considered as tumor candidates. To determine true lesions, further analyses are conducted, including reduction of tumor candidates by the masking out of hot objects within CT-determined normal organs, and analysis of candidate tumors' locations, intensity distributions and shapes on both CT and PET. The method was applied to 18F-FDG-PET/CT scans from 9 patients, on which 31 target lesions had been identified by a nuclear medicine radiologist during a Phase II lung cancer clinical trial. Out of 31 target lesions, 30 (97%) were detected by the computer method. However, sensitivity and specificity were not estimated because not all lesions had been marked up in the clinical trial. The method effectively excluded the hot spots caused by mediastinum, liver, spleen, skeletal muscle and bone metastasis.

Noninvasive Assessment of Left Ventricular Assist Devices with Cardiovascular Computed Tomography and Impact on Management

PubMed Central

Raman, Subha V.; Sahu, Anurag; Merchant, Ali Z.; Louis, Louis B.; Firstenberg, Michael S.; Sun, Benjamin

2009-01-01

Background Left ventricular assist devices (LVADs) provide a bridge to recovery or heart transplantation, but require serial assessment. Echocardiographic approaches may be limited by device artifact and acoustic window. Cardiovascular computed tomography (CCT) provides noninvasive imaging of LVADs, yet no study has evaluated CCT’s impact on clinical care. We evaluated the diagnostic findings and clinical impact of CCT for noninvasive assessment of patients with LVADs. Methods CCT examinations performed between 2005 and 2008 in patients with LVADs were identified. Acquisitions were completed on the identical 64 detector-row scanner with intravenous contrast administration; electrocardiographic gating was used in patients with pulsatile devices, while peripheral pulse gating was used in patients with continuous-flow devices. Comparison was made between CCT results and 30-day outcomes, including echocardiographic and intraoperative findings. Results Thirty-two CCT examinations from 28 patients were reviewed. Indications included evaluation of low cardiac output symptoms, assessment of cannula position, low flow reading on the LVAD, and surgical planning. CCT identified critical findings in 6 patients including thrombosis and inlet cannula malposition, all confirmed intraoperatively; one case of intra-LVAD thrombus was missed by CCT. Using intraoperative findings as the gold standard, CCT’s sensitivity was 85% and specificity was 100%. Echocardiographic LVAD evaluation did not correlate with findings on CCT (kappa = −0.29, 95% CI −0.73−0.13). Conclusions This preliminary observational cohort study indicates that noninvasive imaging using CCT of LVADs is feasible and accurate. CCT warrants consideration in the initial evaluation of symptomatic patients with LVADs. PMID:19782594

Use of a balloon-expandable metallic stent for treatment of nasopharyngeal stenosis in dogs and cats: six cases (2005-2007).

PubMed

Berent, Allyson C; Weisse, Chick; Todd, Kimberly; Rondeau, Mark P; Reiter, Alexander M

2008-11-01

To determine outcome associated with use of a balloon-expandable metallic stent for treatment of nasopharyngeal stenosis in dogs and cats. Retrospective case series. 3 dogs and 3 cats. All 6 animals had severe inspiratory stertor at initial examination. Two animals had no orifice present at the stenosis. Nasopharyngeal stenosis was diagnosed and stent size determined by use of computed tomography. A percutaneous transluminal angioplasty balloon premounted with a balloon-expandable metallic stent was placed over a guidewire, advanced through the stenotic lesion under fluoroscopic and rhinoscopic guidance, and dilated to restore patency. All animals had immediate resolution of clinical signs after stent placement. The procedure took a median of 38 minutes (range, 22 to 70 minutes). One animal with a stenosis located far caudally needed the tip of the stent resected because of hairball entrapment and exaggerated swallowing. Both animals without an orifice in the stenosis had tissue in-growth requiring a covered stent. All animals were reexamined 6 to 12 weeks after treatment via rhinoscopy, radiography, computed tomography, or a combination of techniques. All animals lacked signs of discomfort; 5 of 6 were breathing normally 12 to 28 months after the procedure. Transnasal balloon-expandable metallic stent placement may represent a rapid, safe, noninvasive, and effective treatment in animals with nasopharyngeal stenosis. If the stenosis is extremely caudal in the nasopharynx, serial balloon dilatation might be considered prior to stent placement. A covered stent should be considered initially if the stenosis is completely closed.

68Ga/177Lu-labeled DOTA-TATE shows similar imaging and biodistribution in neuroendocrine tumor model.

PubMed

Liu, Fei; Zhu, Hua; Yu, Jiangyuan; Han, Xuedi; Xie, Qinghua; Liu, Teli; Xia, Chuanqin; Li, Nan; Yang, Zhi

2017-06-01

Somatostatin receptors are overexpressed in neuroendocrine tumors, whose endogenous ligands are somatostatin. DOTA-TATE is an analogue of somatostatin, which shows high binding affinity to somatostatin receptors. We aim to evaluate the 68 Ga/ 177 Lu-labeling DOTA-TATE kit in neuroendocrine tumor model for molecular imaging and to try human-positron emission tomography/computed tomography imaging of 68 Ga-DOTA-TATE in neuroendocrine tumor patients. DOTA-TATE kits were formulated and radiolabeled with 68 Ga/ 177 Lu for 68 Ga/ 177 Lu-DOTA-TATE (M-DOTA-TATE). In vitro and in vivo stability of 177 Lu-DOTA-TATE were performed. Nude mice bearing human tumors were injected with 68 Ga-DOTA-TATE or 177 Lu-DOTA-TATE for micro-positron emission tomography and micro-single-photon emission computed tomography/computed tomography imaging separately, and clinical positron emission tomography/computed tomography images of 68 Ga-DOTA-TATE were obtained at 1 h post-intravenous injection from patients with neuroendocrine tumors. Micro-positron emission tomography and micro-single-photon emission computed tomography/computed tomography imaging of 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE both showed clear tumor uptake which could be blocked by excess DOTA-TATE. In addition, 68 Ga-DOTA-TATE-positron emission tomography/computed tomography imaging in neuroendocrine tumor patients could show primary and metastatic lesions. 68 Ga-DOTA-TATE and 177 Lu-DOTA-TATE could accumulate in tumors in animal models, paving the way for better clinical peptide receptor radionuclide therapy for neuroendocrine tumor patients in Asian population.

A massively parallel computational approach to coupled thermoelastic/porous gas flow problems

NASA Technical Reports Server (NTRS)

Shia, David; Mcmanus, Hugh L.

1995-01-01

A new computational scheme for coupled thermoelastic/porous gas flow problems is presented. Heat transfer, gas flow, and dynamic thermoelastic governing equations are expressed in fully explicit form, and solved on a massively parallel computer. The transpiration cooling problem is used as an example problem. The numerical solutions have been verified by comparison to available analytical solutions. Transient temperature, pressure, and stress distributions have been obtained. Small spatial oscillations in pressure and stress have been observed, which would be impractical to predict with previously available schemes. Comparisons between serial and massively parallel versions of the scheme have also been made. The results indicate that for small scale problems the serial and parallel versions use practically the same amount of CPU time. However, as the problem size increases the parallel version becomes more efficient than the serial version.

Dual-Energy Computed Tomography in Cardiothoracic Vascular Imaging.

PubMed

De Santis, Domenico; Eid, Marwen; De Cecco, Carlo N; Jacobs, Brian E; Albrecht, Moritz H; Varga-Szemes, Akos; Tesche, Christian; Caruso, Damiano; Laghi, Andrea; Schoepf, Uwe Joseph

2018-07-01

Dual energy computed tomography is becoming increasingly widespread in clinical practice. It can expand on the traditional density-based data achievable with single energy computed tomography by adding novel applications to help reach a more accurate diagnosis. The implementation of this technology in cardiothoracic vascular imaging allows for improved image contrast, metal artifact reduction, generation of virtual unenhanced images, virtual calcium subtraction techniques, cardiac and pulmonary perfusion evaluation, and plaque characterization. The improved diagnostic performance afforded by dual energy computed tomography is not associated with an increased radiation dose. This review provides an overview of dual energy computed tomography cardiothoracic vascular applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Backtracking and Re-execution in the Automatic Debugging of Parallelized Programs

NASA Technical Reports Server (NTRS)

Matthews, Gregory; Hood, Robert; Johnson, Stephen; Leggett, Peter; Biegel, Bryan (Technical Monitor)

2002-01-01

In this work we describe a new approach using relative debugging to find differences in computation between a serial program and a parallel version of th it program. We use a combination of re-execution and backtracking in order to find the first difference in computation that may ultimately lead to an incorrect value that the user has indicated. In our prototype implementation we use static analysis information from a parallelization tool in order to perform the backtracking as well as the mapping required between serial and parallel computations.

A Freeware Path to Neutron Computed Tomography

NASA Astrophysics Data System (ADS)

Schillinger, Burkhard; Craft, Aaron E.

Neutron computed tomography has become a routine method at many neutron sources due to the availability of digital detection systems, powerful computers and advanced software. The commercial packages Octopus by Inside Matters and VGStudio by Volume Graphics have been established as a quasi-standard for high-end computed tomography. However, these packages require a stiff investment and are available to the users only on-site at the imaging facility to do their data processing. There is a demand from users to have image processing software at home to do further data processing; in addition, neutron computed tomography is now being introduced even at smaller and older reactors. Operators need to show a first working tomography setup before they can obtain a budget to build an advanced tomography system. Several packages are available on the web for free; however, these have been developed for X-rays or synchrotron radiation and are not immediately useable for neutron computed tomography. Three reconstruction packages and three 3D-viewers have been identified and used even for Gigabyte datasets. This paper is not a scientific publication in the classic sense, but is intended as a review to provide searchable help to make the described packages usable for the tomography community. It presents the necessary additional preprocessing in ImageJ, some workarounds for bugs in the software, and undocumented or badly documented parameters that need to be adapted for neutron computed tomography. The result is a slightly complicated, but surprisingly high-quality path to neutron computed tomography images in 3D, but not a replacement for the even more powerful commercial software mentioned above.

Terahertz Computed Tomography of NASA Thermal Protection System Materials

NASA Technical Reports Server (NTRS)

Roth, D. J.; Reyes-Rodriguez, S.; Zimdars, D. A.; Rauser, R. W.; Ussery, W. W.

2011-01-01

A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

Accelerating functional verification of an integrated circuit

DOEpatents

Deindl, Michael; Ruedinger, Jeffrey Joseph; Zoellin, Christian G.

2015-10-27

Illustrative embodiments include a method, system, and computer program product for accelerating functional verification in simulation testing of an integrated circuit (IC). Using a processor and a memory, a serial operation is replaced with a direct register access operation, wherein the serial operation is configured to perform bit shifting operation using a register in a simulation of the IC. The serial operation is blocked from manipulating the register in the simulation of the IC. Using the register in the simulation of the IC, the direct register access operation is performed in place of the serial operation.

High resolution macroscopy (HRMac) of the eye using nonlinear optical imaging

NASA Astrophysics Data System (ADS)

Winkler, Moritz; Jester, Bryan E.; Nien-Shy, Chyong; Chai, Dongyul; Brown, Donald J.; Jester, James V.

2010-02-01

Non-linear optical (NLO) imaging using femtosecond lasers provides a non-invasive means of imaging the structural organization of the eye through the generation of second harmonic signals (SHG). While NLO imaging is able to detect collagen, the small field of view (FoV) limits the ability to study how collagen is structurally organized throughout the larger tissue. To address this issue we have used computed tomography on optical and mechanical sectioned tissue to greatly expand the FoV and provide high resolution macroscopic (HRMac) images that cover the entire tissue (cornea and optic nerve head). Whole, fixed cornea (13 mm diameter) or optic nerve (3 mm diameter) were excised and either 1) embedded in agar and sectioned using a vibratome (200-300 um), or 2) embedded in LR White plastic resin and serially sectioned (2 um). Vibratome and plastic sections were then imaged using a Zeiss LSM 510 Meta and Chameleon femtosecond laser to generate NLO signals and assemble large macroscopic 3-dimensional tomographs with high resolution that varied in size from 9 to 90 Meg pixels per plane having a resolution of 0.88 um lateral and 2.0 um axial. 3-D reconstructions allowed for regional measurements within the cornea and optic nerve to quantify collagen content, orientation and organization over the entire tissue. We conclude that NLO based tomography to generate HRMac images provides a powerful new tool to assess collagen structural organization. Biomechanical testing combined with NLO tomography may provide new insights into the relationship between the extracellular matrix and tissue mechanics.

Comparison of magnetic resonance imaging and computed tomography in suspected lesions in the posterior cranial fossa.

PubMed Central

Teasdale, G. M.; Hadley, D. M.; Lawrence, A.; Bone, I.; Burton, H.; Grant, R.; Condon, B.; Macpherson, P.; Rowan, J.

1989-01-01

OBJECTIVE--To compare computed tomography and magnetic resonance imaging in investigating patients suspected of having a lesion in the posterior cranial fossa. DESIGN--Randomised allocation of newly referred patients to undergo either computed tomography or magnetic resonance imaging; the alternative investigation was performed subsequently only in response to a request from the referring doctor. SETTING--A regional neuroscience centre serving 2.7 million. PATIENTS--1020 Patients recruited between April 1986 and December 1987, all suspected by neurologists, neurosurgeons, or other specialists of having a lesion in the posterior fossa and referred for neuroradiology. The groups allocated to undergo computed tomography or magnetic resonance imaging were well matched in distributions of age, sex, specialty of referring doctor, investigation as an inpatient or an outpatient, suspected site of lesion, and presumed disease process; the referring doctor's confidence in the initial clinical diagnosis was also similar. INTERVENTIONS--After the patients had been imaged by either computed tomography or magnetic resonance (using a resistive magnet of 0.15 T) doctors were given the radiologist's report and a form asking if they considered that imaging with the alternative technique was necessary and, if so, why; it also asked for their current diagnoses and their confidence in them. MAIN OUTCOME MEASURES--Number of requests for the alternative method of investigation. Assessment of characteristics of patients for whom further imaging was requested and lesions that were suspected initially and how the results of the second imaging affected clinicians' and radiologists' opinions. RESULTS--Ninety three of the 501 patients who initially underwent computed tomography were referred subsequently for magnetic resonance imaging whereas only 28 of the 493 patients who initially underwent magnetic resonance imaging were referred subsequently for computed tomography. Over the study the number of patients referred for magnetic resonance imaging after computed tomography increased but requests for computed tomography after magnetic resonance imaging decreased. The reason that clinicians gave most commonly for requesting further imaging by magnetic resonance was that the results of the initial computed tomography failed to exclude their suspected diagnosis (64 patients). This was less common in patients investigated initially by magnetic resonance imaging (eight patients). Management of 28 patients (6%) imaged initially with computed tomography and 12 patients (2%) imaged initially with magnetic resonance was changed on the basis of the results of the alternative imaging. CONCLUSIONS--Magnetic resonance imaging provided doctors with the information required to manage patients suspected of having a lesion in the posterior fossa more commonly than computed tomography, but computed tomography alone was satisfactory in 80% of cases... PMID:2506965

Congruence Between Pulmonary Function and Computed Tomography Imaging Assessment of Cystic Fibrosis Severity.

PubMed

Rybacka, Anna; Goździk-Spychalska, Joanna; Rybacki, Adam; Piorunek, Tomasz; Batura-Gabryel, Halina; Karmelita-Katulska, Katarzyna

2018-05-04

In cystic fibrosis, pulmonary function tests (PFTs) and computed tomography are used to assess lung function and structure, respectively. Although both techniques of assessment are congruent there are lingering doubts about which PFTs variables show the best congruence with computed tomography scoring. In this study we addressed the issue by reinvestigating the association between PFTs variables and the score of changes seen in computed tomography scans in patients with cystic fibrosis with and without pulmonary exacerbation. This retrospective study comprised 40 patients in whom PFTs and computed tomography were performed no longer than 3 weeks apart. Images (inspiratory: 0.625 mm slice thickness, 0.625 mm interval; expiratory: 1.250 mm slice thickness, 10 mm interval) were evaluated with the Bhalla scoring system. The most frequent structural abnormality found in scans were bronchiectases and peribronchial thickening. The strongest relationship was found between the Bhalla sore and forced expiratory volume in 1 s (FEV1). The Bhalla sore also was related to forced vital capacity (FVC), FEV1/FVC ratio, residual volume (RV), and RV/total lung capacity (TLC) ratio. We conclude that lung structural data obtained from the computed tomography examination are highly congruent to lung function data. Thus, computed tomography imaging may supersede functional assessment in cases of poor compliance with spirometry procedures in the lederly or children. Computed tomography also seems more sensitive than PFTs in the assessment of cystic fibrosis progression. Moreover, in early phases of cystic fibrosis, computed tomography, due to its excellent resolution, may be irreplaceable in monitoring pulmonary damage.

SCCT guidelines for the performance and acquisition of coronary computed tomographic angiography: A report of the society of Cardiovascular Computed Tomography Guidelines Committee: Endorsed by the North American Society for Cardiovascular Imaging (NASCI).

PubMed

Abbara, Suhny; Blanke, Philipp; Maroules, Christopher D; Cheezum, Michael; Choi, Andrew D; Han, B Kelly; Marwan, Mohamed; Naoum, Chris; Norgaard, Bjarne L; Rubinshtein, Ronen; Schoenhagen, Paul; Villines, Todd; Leipsic, Jonathon

In response to recent technological advancements in acquisition techniques as well as a growing body of evidence regarding the optimal performance of coronary computed tomography angiography (coronary CTA), the Society of Cardiovascular Computed Tomography Guidelines Committee has produced this update to its previously established 2009 "Guidelines for the Performance of Coronary CTA" (1). The purpose of this document is to provide standards meant to ensure reliable practice methods and quality outcomes based on the best available data in order to improve the diagnostic care of patients. Society of Cardiovascular Computed Tomography Guidelines for the Interpretation is published separately (2). The Society of Cardiovascular Computed Tomography Guidelines Committee ensures compliance with all existing standards for the declaration of conflict of interest by all authors and reviewers for the purpose ofclarity and transparency. Copyright © 2016 Society of Cardiovascular Computed Tomography. All rights reserved.

Application of multidetector-row computed tomography in propeller flap planning.

PubMed

Ono, Shimpei; Chung, Kevin C; Hayashi, Hiromitsu; Ogawa, Rei; Takami, Yoshihiro; Hyakusoku, Hiko

2011-02-01

The propeller flap is defined as (1) being island-shaped, (2) having an axis that includes the perforators, and (3) having the ability to be rotated around an axis. The advantage of the propeller flap is that it is a pedicle flap that can be applied to cover defects located at the distal ends of the extremities. The specific aims of the authors' study were (1) to evaluate the usefulness of multidetector-row computed tomography in the planning of propeller flaps and (2) to present a clinical case series of propeller flap reconstructions that were planned preoperatively using multidetector-row computed tomography. The authors retrospectively analyzed all cases between April of 2007 and April of 2010 at Nippon Medical School Hospital in Tokyo, where multidetector-row computed tomography was used preoperatively to plan surgical reconstructions using propeller flaps. Thirteen patients underwent 16 flaps using the propeller flap technique. The perforators were identified accurately by multidetector-row computed tomography preoperatively in all cases. This is the first report describing the application of multidetector-row computed tomography in the planning of propeller flaps. Multidetector-row computed tomography is superior to other imaging methods because it demonstrates more precisely the perforator's position and subcutaneous course using high-resolution three-dimensional images. By using multidetector-row computed tomography to preoperatively identify a flap's perforators, the surgeon can better plan the flap design to efficiently conduct the flap surgery.

Comparison of computed tomography and magnetic resonance imaging for the evaluation of canine intranasal neoplasia.

PubMed

Drees, R; Forrest, L J; Chappell, R

2009-07-01

Canine intranasal neoplasia is commonly evaluated using computed tomography to indicate the diagnosis, to determine disease extent, to guide histological sampling location and to plan treatment. With the expanding use of magnetic resonance imaging in veterinary medicine, this modality has been recently applied for the same purpose. The aim of this study was to compare the features of canine intranasal neoplasia using computed tomography and magnetic resonance imaging. Twenty-one dogs with confirmed intranasal neoplasia underwent both computed tomography and magnetic resonance imaging. The images were reviewed retrospectively for the bony and soft tissue features of intranasal neoplasia. Overall computed tomography and magnetic resonance imaging performed very similarly. However, lysis of bones bordering the nasal cavity and mucosal thickening was found on computed tomography images more often than on magnetic resonance images. Small amounts of fluid in the nasal cavity were more often seen on magnetic resonance images. However, fluid in the frontal sinuses was seen equally well with both modalities. We conclude that computed tomography is satisfactory for evaluation of canine intranasal neoplasia, and no clinically relevant benefit is gained using magnetic resonance imaging for intranasal neoplasia without extent into the cranial cavity.

Pulmonary nodule characterization, including computer analysis and quantitative features.

PubMed

Bartholmai, Brian J; Koo, Chi Wan; Johnson, Geoffrey B; White, Darin B; Raghunath, Sushravya M; Rajagopalan, Srinivasan; Moynagh, Michael R; Lindell, Rebecca M; Hartman, Thomas E

2015-03-01

Pulmonary nodules are commonly detected in computed tomography (CT) chest screening of a high-risk population. The specific visual or quantitative features on CT or other modalities can be used to characterize the likelihood that a nodule is benign or malignant. Visual features on CT such as size, attenuation, location, morphology, edge characteristics, and other distinctive "signs" can be highly suggestive of a specific diagnosis and, in general, be used to determine the probability that a specific nodule is benign or malignant. Change in size, attenuation, and morphology on serial follow-up CT, or features on other modalities such as nuclear medicine studies or MRI, can also contribute to the characterization of lung nodules. Imaging analytics can objectively and reproducibly quantify nodule features on CT, nuclear medicine, and magnetic resonance imaging. Some quantitative techniques show great promise in helping to differentiate benign from malignant lesions or to stratify the risk of aggressive versus indolent neoplasm. In this article, we (1) summarize the visual characteristics, descriptors, and signs that may be helpful in management of nodules identified on screening CT, (2) discuss current quantitative and multimodality techniques that aid in the differentiation of nodules, and (3) highlight the power, pitfalls, and limitations of these various techniques.

F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Appearance of Extramedullary Hematopoesis in a Case of Primary Myelofibrosis

PubMed Central

Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

2017-01-01

A 44-year-old female with known primary myelofibrosis presented with shortness of breath. High Resolution Computed Tomography thorax revealed large heterogeneously enhancing extraparenchymal soft tissue density mass involving bilateral lung fields. F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed mildly FDG avid soft tissue density mass with specks of calcification involving bilateral lung fields, liver, and spleen. Subsequent histopathologic evaluation from the right lung mass was suggestive of extramedullary hematopoesis. PMID:28533647

Cone beam computed tomography in the diagnosis of dental disease.

PubMed

Tetradis, Sotirios; Anstey, Paul; Graff-Radford, Steven

2011-07-01

Conventional radiographs provide important information for dental disease diagnosis. However, they represent 2-D images of 3-D objects with significant structure superimposition and unpredictable magnification. Cone beam computed tomography, however, allows true 3-D visualization of the dentoalveolar structures, avoiding major limitations of conventional radiographs. Cone beam computed tomography images offer great advantages in disease detection for selected patients. The authors discuss cone beam computed tomography applications in dental disease diagnosis, reviewing the pertinent literature when available.

Multiscale tomographic analysis of heterogeneous cast Al-Si-X alloys.

PubMed

Asghar, Z; Requena, G; Sket, F

2015-07-01

The three-dimensional microstructure of cast AlSi12Ni and AlSi10Cu5Ni2 alloys is investigated by laboratory X-ray computed tomography, synchrotron X-ray computed microtomography, light optical tomography and synchrotron X-ray computed microtomography with submicrometre resolution. The results obtained with each technique are correlated with the size of the scanned volumes and resolved microstructural features. Laboratory X-ray computed tomography is sufficient to resolve highly absorbing aluminides but eutectic and primary Si remain unrevealed. Synchrotron X-ray computed microtomography at ID15/ESRF gives better spatial resolution and reveals primary Si in addition to aluminides. Synchrotron X-ray computed microtomography at ID19/ESRF reveals all the phases ≥ ∼1 μm in volumes about 80 times smaller than laboratory X-ray computed tomography. The volumes investigated by light optical tomography and submicrometre synchrotron X-ray computed microtomography are much smaller than laboratory X-ray computed tomography but both techniques provide local chemical information on the types of aluminides. The complementary techniques applied enable a full three-dimensional characterization of the microstructure of the alloys at length scales ranging over six orders of magnitude. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Electromagnetic Navigational Bronchoscopy Reduces the Time Required for Localization and Resection of Lung Nodules.

PubMed

Bolton, William David; Cochran, Thomas; Ben-Or, Sharon; Stephenson, James E; Ellis, William; Hale, Allyson L; Binks, Andrew P

The aims of the study were to evaluate electromagnetic navigational bronchoscopy (ENB) and computed tomography-guided placement as localization techniques for minimally invasive resection of small pulmonary nodules and determine whether electromagnetic navigational bronchoscopy is a safer and more effective method than computed tomography-guided localization. We performed a retrospective review of our thoracic surgery database to identify patients who underwent minimally invasive resection for a pulmonary mass and used either electromagnetic navigational bronchoscopy or computed tomography-guided localization techniques between July 2011 and May 2015. Three hundred eighty-three patients had a minimally invasive resection during our study period, 117 of whom underwent electromagnetic navigational bronchoscopy or computed tomography localization (electromagnetic navigational bronchoscopy = 81; computed tomography = 36). There was no significant difference between computed tomography and electromagnetic navigational bronchoscopy patient groups with regard to age, sex, race, pathology, nodule size, or location. Both computed tomography and electromagnetic navigational bronchoscopy were 100% successful at localizing the mass, and there was no difference in the type of definitive surgical resection (wedge, segmentectomy, or lobectomy) (P = 0.320). Postoperative complications occurred in 36% of all patients, but there were no complications related to the localization procedures. In terms of localization time and surgical time, there was no difference between groups. However, the down/wait time between localization and resection was significant (computed tomography = 189 minutes; electromagnetic navigational bronchoscopy = 27 minutes); this explains why the difference in total time (sum of localization, down, and surgery) was significant (P < 0.001). We found electromagnetic navigational bronchoscopy to be as safe and effective as computed tomography-guided wire placement and to provide a significantly decreased down time between localization and surgical resection.

Visualization of Monocytic Cells in Regressing Atherosclerotic Plaques by Intravital 2-Photon and Positron Emission Tomography-Based Imaging-Brief Report.

PubMed

Li, Wenjun; Luehmann, Hannah P; Hsiao, Hsi-Min; Tanaka, Satona; Higashikubo, Ryuji; Gauthier, Jason M; Sultan, Deborah; Lavine, Kory J; Brody, Steven L; Gelman, Andrew E; Gropler, Robert J; Liu, Yongjian; Kreisel, Daniel

2018-05-01

Aortic arch transplants have advanced our understanding of processes that contribute to progression and regression of atherosclerotic plaques. To characterize the dynamic behavior of monocytes and macrophages in atherosclerotic plaques over time, we developed a new model of cervical aortic arch transplantation in mice that is amenable to intravital imaging. Vascularized aortic arch grafts were transplanted heterotropically to the right carotid arteries of recipient mice using microsurgical suture techniques. To image immune cells in atherosclerotic lesions during regression, plaque-bearing aortic arch grafts from B6 ApoE-deficient donors were transplanted into syngeneic CX 3 CR1 GFP reporter mice. Grafts were evaluated histologically, and monocytic cells in atherosclerotic plaques in ApoE-deficient grafts were imaged intravitally by 2-photon microscopy in serial fashion. In complementary experiments, CCR2 + cells in plaques were serially imaged by positron emission tomography using specific molecular probes. Plaques in ApoE-deficient grafts underwent regression after transplantation into normolipidemic hosts. Intravital imaging revealed clusters of largely immotile CX 3 CR1 + monocytes/macrophages in regressing plaques that had been recruited from the periphery. We observed a progressive decrease in CX 3 CR1 + monocytic cells in regressing plaques and a decrease in CCR2 + positron emission tomography signal during 4 months. Cervical transplantation of atherosclerotic mouse aortic arches represents a novel experimental tool to investigate cellular mechanisms that contribute to the remodeling of atherosclerotic plaques. © 2018 American Heart Association, Inc.

Expanding Functionality of Commercial Optical Coherence Tomography Systems by Integrating a Custom Endoscope

PubMed Central

Welge, Weston A.; Barton, Jennifer K.

2015-01-01

Optical coherence tomography (OCT) is a useful imaging modality for detecting and monitoring diseases of the gastrointestinal tract and other tubular structures. The non-destructiveness of OCT enables time-serial studies in animal models. While turnkey commercial research OCT systems are plenty, researchers often require custom imaging probes. We describe the integration of a custom endoscope with a commercial swept-source OCT system and generalize this description to any imaging probe and OCT system. A numerical dispersion compensation method is also described. Example images demonstrate that OCT can visualize the mouse colon crypt structure and detect adenoma in vivo. PMID:26418811

Cardiac Sarcoidosis Concomitant with Large-vessel Aortitis Detected by 18F-fluorodeoxyglucose Positron Emission Tomography.

PubMed

Higuchi, Yoshihiro; Kimoto, Yasutaka; Tanoue, Rika; Tokunou, Tomotake; Tomonari, Kenichiro; Maeda, Toyoki; Horiuchi, Takahiko

2018-06-01

We herein report a case of concurrent cardiac sarcoidosis and large-vessel aortitis detected by 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) and followed up during immunosuppressive therapy. After high-dose prednisolone administration (1 mg/kg), serial FDG-PET showed that almost all of the abnormal FDG uptake in the heart and extracardiac region, including the abdominal to bilateral iliac arteries, had been disappeared. During the tapering of prednisolone, additive methotrexate therapy was needed to treat the recurrence of cardiac sarcoidosis. FDG-PET is a useful tool for detecting cardiac sarcoidosis concomitant with large-vessel aortitis and monitoring the effectiveness of immunosuppressive therapy.

Performance analysis of three dimensional integral equation computations on a massively parallel computer. M.S. Thesis

NASA Technical Reports Server (NTRS)

Logan, Terry G.

1994-01-01

The purpose of this study is to investigate the performance of the integral equation computations using numerical source field-panel method in a massively parallel processing (MPP) environment. A comparative study of computational performance of the MPP CM-5 computer and conventional Cray-YMP supercomputer for a three-dimensional flow problem is made. A serial FORTRAN code is converted into a parallel CM-FORTRAN code. Some performance results are obtained on CM-5 with 32, 62, 128 nodes along with those on Cray-YMP with a single processor. The comparison of the performance indicates that the parallel CM-FORTRAN code near or out-performs the equivalent serial FORTRAN code for some cases.

Use of CYBER 203 and CYBER 205 computers for three-dimensional transonic flow calculations

NASA Technical Reports Server (NTRS)

Melson, N. D.; Keller, J. D.

1983-01-01

Experiences are discussed for modifying two three-dimensional transonic flow computer programs (FLO 22 and FLO 27) for use on the CDC CYBER 203 computer system. Both programs were originally written for use on serial machines. Several methods were attempted to optimize the execution of the two programs on the vector machine: leaving the program in a scalar form (i.e., serial computation) with compiler software used to optimize and vectorize the program, vectorizing parts of the existing algorithm in the program, and incorporating a vectorizable algorithm (ZEBRA I or ZEBRA II) in the program. Comparison runs of the programs were made on CDC CYBER 175. CYBER 203, and two pipe CDC CYBER 205 computer systems.

An efficient parallel algorithm for the solution of a tridiagonal linear system of equations

NASA Technical Reports Server (NTRS)

Stone, H. S.

1971-01-01

Tridiagonal linear systems of equations are solved on conventional serial machines in a time proportional to N, where N is the number of equations. The conventional algorithms do not lend themselves directly to parallel computations on computers of the ILLIAC IV class, in the sense that they appear to be inherently serial. An efficient parallel algorithm is presented in which computation time grows as log sub 2 N. The algorithm is based on recursive doubling solutions of linear recurrence relations, and can be used to solve recurrence relations of all orders.

Serials Evaluation: An Innovative Approach.

ERIC Educational Resources Information Center

Berger, Marilyn; Devine, Jane

1990-01-01

Describes a method of analyzing serials collections in special libraries that combines evaluative criteria with database management technology. Choice of computer software is discussed, qualitative information used to evaluate subject coverage is examined, and quantitative and descriptive data that can be used for collection management are…

FireWire: Hot New Multimedia Interface or Flash in the Pan?

ERIC Educational Resources Information Center

Learn, Larry L., Ed.

1995-01-01

Examines potential solutions to the problem of personal computer cabling and configuration and serial port performance, namely "FireWire" (P1394) and "Universal Serial Bus" (USB). Discusses interface design, technical capabilities, user friendliness, compatibility, costs, and future perspectives. (AEF)

Sinonasal papilloma: what influences the decision to request a magnetic resonance imaging scan?

PubMed

Kasbekar, A V; Swords, C; Attlmayr, B; Kulkarni, T; Swift, A C

2018-06-18

Computed tomography is the standard pre-operative imaging modality for sinonasal papilloma. The complementary use of magnetic resonance imaging as an additional investigation is debated. This study aimed to establish whether magnetic resonance imaging can accurately detect tumour extent and is a useful adjunct to computed tomography. A retrospective review was conducted on 19 patients with sinonasal papilloma. The interpretation of computed tomography and magnetic resonance imaging scans, by three clinicians, was conducted by comparing prediction of tumour extent. The perceived necessity of magnetic resonance imaging was compared between clinicians. The addition of magnetic resonance imaging improved accuracy of pre-operative interpretation; specifically, this finding was significant in cases with frontal sinus involvement. Surgeons were more likely than a radiologist to request magnetic resonance imaging, particularly when computed tomography indicated frontal sinus disease. Pre-operative combined magnetic resonance imaging and computed tomography helped predict disease in the frontal sinus better than computed tomography alone. A close working relationship between the ENT and radiology departments is important for accurate tumour localisation.

Serial network simplifies the design of multiple microcomputer systems

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

Folkes, D.

1981-01-01

Recently there has been a lot of interest in developing network communication schemes for carrying digital data between locally distributed computing stations. Many of these schemes have focused on distributed networking techniques for data processing applications. These applications suggest the use of a serial, multipoint bus, where a number of remote intelligent units act as slaves to a central or host computer. Each slave would be serially addressable from the host and would perform required operations upon being addressed by the host. Based on an MK3873 single-chip microcomputer, the SCU 20 is designed to be such a remote slave device.more » The capabilities of the SCU 20 and its use in systems applications are examined.« less

Computer tomography of the neurocranium.

PubMed

Liliequist, B; Forssell, A

1976-07-01

The experience with computer tomography of the neurocranium in 300 patients submitted for computer tomography of the brain is reported. The more appropriate projections which may be obtained with the second generation of scanners in combination with an elaborated reconstruction technique seem to constitute a replacement of conventional skull films.

Study of Image Qualities From 6D Robot-Based CBCT Imaging System of Small Animal Irradiator.

PubMed

Sharma, Sunil; Narayanasamy, Ganesh; Clarkson, Richard; Chao, Ming; Moros, Eduardo G; Zhang, Xin; Yan, Yulong; Boerma, Marjan; Paudel, Nava; Morrill, Steven; Corry, Peter; Griffin, Robert J

2017-01-01

To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6 degrees of freedom robot for cone beam computed tomography imaging and conformal delivery of radiation doses. A series of 2-dimensional radiographic projection images were recorded in cone beam mode by placing and rotating microcomputed tomography phantoms on the "palm' of the robotic arm. Reconstructed images were studied for image quality (spatial resolution, image uniformity, computed tomography number linearity, voxel noise, and artifacts). Geometric accuracy was measured to be 2% corresponding to 0.7 mm accuracy on a Shelley microcomputed tomography QA phantom. Qualitative resolution of reconstructed axial computed tomography slices using the resolution coils was within 200 μm. Quantitative spatial resolution was found to be 3.16 lp/mm. Uniformity of the system was measured within 34 Hounsfield unit on a QRM microcomputed tomography water phantom. Computed tomography numbers measured using the linearity plate were linear with material density ( R 2 > 0.995). Cone beam computed tomography images of the QRM multidisk phantom had minimal artifacts. Results showed that the small animal conformal radiation therapy device is capable of producing high-quality cone beam computed tomography images for precise and conformal small animal dose delivery. With its high-caliber imaging capabilities, the small animal conformal radiation therapy device is a powerful tool for small animal research.

Morphometric analysis - Cone beam computed tomography to predict bone quality and quantity.

PubMed

Hohlweg-Majert, B; Metzger, M C; Kummer, T; Schulze, D

2011-07-01

Modified quantitative computed tomography is a method used to predict bone quality and quantify the bone mass of the jaw. The aim of this study was to determine whether bone quantity or quality was detected by cone beam computed tomography (CBCT) combined with image analysis. MATERIALS AND PROCEDURES: Different measurements recorded on two phantoms (Siemens phantom, Comac phantom) were evaluated on images taken with the Somatom VolumeZoom (Siemens Medical Solutions, Erlangen, Germany) and the NewTom 9000 (NIM s.r.l., Verona, Italy) in order to calculate a calibration curve. The spatial relationships of six sample cylinders and the repositioning from four pig skull halves relative to adjacent defined anatomical structures were assessed by means of three-dimensional visualization software. The calibration curves for computer tomography (CT) and cone beam computer tomography (CBCT) using the Siemens phantom showed linear correlation in both modalities between the Hounsfield Units (HU) and bone morphology. A correction factor for CBCT was calculated. Exact information about the micromorphology of the bone cylinders was only available using of micro computer tomography. Cone-beam computer tomography is a suitable choice for analysing bone mass, but, it does not give any information about bone quality. 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Italian Chapter of the International Society of Cardiovascular Ultrasound expert consensus document on coronary computed tomography angiography: overview and new insights.

PubMed

Sozzi, Fabiola B; Maiello, Maria; Pelliccia, Francesco; Parato, Vito Maurizio; Canetta, Ciro; Savino, Ketty; Lombardi, Federico; Palmiero, Pasquale

2016-09-01

Coronary computed tomography angiography is a noninvasive heart imaging test currently undergoing rapid development and advancement. The high resolution of the three-dimensional pictures of the moving heart and great vessels is performed during a coronary computed tomography to identify coronary artery disease and classify patient risk for atherosclerotic cardiovascular disease. The technique provides useful information about the coronary tree and atherosclerotic plaques beyond simple luminal narrowing and plaque type defined by calcium content. This application will improve image-guided prevention, medical therapy, and coronary interventions. The ability to interpret coronary computed tomography images is of utmost importance as we develop personalized medical care to enable therapeutic interventions stratified on the bases of plaque characteristics. This overview provides available data and expert's recommendations in the utilization of coronary computed tomography findings. We focus on the use of coronary computed tomography to detect coronary artery disease and stratify patients at risk, illustrating the implications of this test on patient management. We describe its diagnostic power in identifying patients at higher risk to develop acute coronary syndrome and its prognostic significance. Finally, we highlight the features of the vulnerable plaques imaged by coronary computed tomography angiography. © 2016, Wiley Periodicals, Inc.

Comparison of computed tomography and magnetic resonance imaging for the evaluation of canine intranasal neoplasia

PubMed Central

Drees, R.; Forrest, L. J.; Chappell, R.

2009-01-01

Objectives Canine intranasal neoplasia is commonly evaluated using computed tomography to indicate the diagnosis, to determine disease extent, to guide histological sampling location and to plan treatment. With the expanding use of magnetic resonance imaging in veterinary medicine, this modality has been recently applied for the same purpose. The aim of this study was to compare the features of canine intranasal neoplasia using computed tomography and magnetic resonance imaging. Methods Twenty-one dogs with confirmed intranasal neoplasia underwent both computed tomography and magnetic resonance imaging. The images were reviewed retrospectively for the bony and soft tissue features of intranasal neoplasia. Results Overall computed tomography and magnetic resonance imaging performed very similarly. However, lysis of bones bordering the nasal cavity and mucosal thickening was found on computed tomography images more often than on magnetic resonance images. Small amounts of fluid in the nasal cavity were more often seen on magnetic resonance images. However, fluid in the frontal sinuses was seen equally well with both modalities. Clinical Significance We conclude that computed tomography is satisfactory for evaluation of canine intranasal neoplasia, and no clinically relevant benefit is gained using magnetic resonance imaging for intranasal neoplasia without extent into the cranial cavity. PMID:19508490

Neurologic, neuropsychologic, and computed cranial tomography scan abnormalities in 2- to 10-year survivors of small-cell lung cancer.

PubMed

Johnson, B E; Becker, B; Goff, W B; Petronas, N; Krehbiel, M A; Makuch, R W; McKenna, G; Glatstein, E; Ihde, D C

1985-12-01

In order to evaluate the relationship between neurologic function and cranial irradiation, 20 patients treated on National Cancer Institute (NCI) small-cell lung cancer (SCLC) trials who were alive and free of cancer 2.4 to 10.6 years (median, 6.2) from the start of therapy were studied. All were tested with a neurologic history and examination, mental status examination, neuropsychologic testing, and review of serial computed cranial tomography (CCT) scans. Fifteen patients had been treated with prophylactic cranial irradiation (PCI), two patients with therapeutic cranial irradiation, and three received no cranial irradiation. All patients but one were ambulatory and none were institutionalized. Fifteen patients (75%) had neurologic complaints, 13 (65%) had abnormal neurologic examinations, 12 (60%) had abnormal mental status examinations, 13 (65%) had abnormal neuropsychologic testing, and 15 (75%) had abnormal CCT scans. Compared with those given low-dose maintenance chemotherapy during PCI using 200 to 300 rad per fraction, patients who were given high-dose induction chemotherapy during the time of cranial irradiation or large radiotherapy fractions (400 rad) were more likely to have abnormal mental status examinations (6/6 v 4/9) and abnormal neuropsychologic tests (6/6 v 4/9), but no major difference in CCT findings was present. CCT scans in the majority of cases (11/18) showed progressive ventricular dilatation or cerebral atrophy up to 8 years after stopping therapy. We conclude neurologic abnormalities are common in long-term survivors of SCLC, and may be more prominent in patients given high-dose chemotherapy during cranial irradiation or treated with large radiotherapy fractions. The CCT scan abnormalities are common and progressive years after prophylactic cranial irradiation and chemotherapy are stopped.

Risk Stratification for Avascular Necrosis of the Femoral Head After Internal Fixation of Femoral Neck Fractures by Post-Operative Bone SPECT/CT.

PubMed

Han, Sangwon; Oh, Minyoung; Yoon, Seokho; Kim, Jinsoo; Kim, Ji-Wan; Chang, Jae-Suk; Ryu, Jin-Sook

2017-03-01

Avascular necrosis (AVN) of the femoral head is a major complication after internal fixation of a femoral neck fracture and determines the functional prognosis. We investigated postoperative bone single-photon emission computed tomography/computed tomography (SPECT/CT) for assessing the risk of femoral head AVN. We retrospectively reviewed 53 consecutive patients who underwent bone SPECT/CT within 2 weeks of internal fixation of a femoral neck fracture and follow-up serial hip radiographs over at least 12 months. Nine patients developed femoral head AVN. In 15 patients who showed normal uptake on immediate postoperative SPECT/CT, no AVN occurred, whereas 9 of 38 patients who showed cold defects of the femoral head later developed AVN. The negative predictive value of immediate postoperative SPECT/CT for AVN was 100 %, whereas the positive predictive value was 24 %. Among 38 patients with cold defects, 1 developed AVN 3 months postoperatively. A follow-up bone SPECT/CT was performed in the other 37 patients at 2-10 months postoperatively. The follow-up bone SPECT/CT revealed completely normalized femoral head uptake in 27, partially normalized uptake in 8, and persistent cold defects in 2 patients. AVN developed in 3.7 % (1/27), 62.5 % (5/8), and 100 % (2/2) of each group, respectively. According to the time point of imaging, radiotracer uptake patterns of the femoral head on postoperative bone SPECT/CT indicate the risk of AVN after internal fixation of femoral neck fractures differently. Postoperative bone SPECT/CT may help orthopedic surgeons determine the appropriate follow-up of these patients.

Chest computed tomography for penetrating thoracic trauma after normal screening chest roentgenogram.

PubMed

Mollberg, Nathan M; Wise, Stephen R; De Hoyos, Alberto L; Lin, Fang-Ju; Merlotti, Gary; Massad, Malek G

2012-06-01

Chest computed tomography (CCT) is a method of screening for intrathoracic injuries in hemodynamically stable patients with penetrating thoracic trauma. The objective of this study was to examine the changes in utilization of CCT over time and evaluate its contribution to guiding therapeutic intervention. A level 1 trauma center registry was queried between 2006 and 2011. Patients undergoing CCT in the emergency department after penetrating thoracic trauma as well as patients undergoing thoracic operations for penetrating thoracic trauma were identified. Patient demographics, operative indications, use of CCT, injuries, and hospital admissions were analyzed. In all, 617 patients had CCTs performed, of whom 61.1% (371 of 617) had a normal screening plain chest radiograph (CXR). In 14.0% (51 of 371) of these cases, the CCT revealed findings not detected on screening CXR. The majority of these injuries were occult pneumothoraces or hemothoraces (84.3%; 43 of 51), of which 27 (62.8%) underwent tube thoracostomy. In only 0.5% (2 of 371), did the results of CCT alone lead to an operative indication: exploration for hemopericardium. The use of CCT in our patients significantly increased overall (28.8% to 71.4%) as well as after a normal screening CXR (23.3% to 74.6%) over the study period. The use of CCT for penetrating thoracic trauma increased 3.5-fold during the study period with a concurrent increase in findings of uncertain clinical significance. Patients with a normal screening CXR should be triaged with 3-hour delayed CXR, serial physical examinations, and focused assessment with sonography for trauma; and CCT should only be used selectively as a diagnostic modality. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Locoregional Control of Non-Small Cell Lung Cancer in Relation to Automated Early Assessment of Tumor Regression on Cone Beam Computed Tomography

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

Brink, Carsten, E-mail: carsten.brink@rsyd.dk; Laboratory of Radiation Physics, Odense University Hospital; Bernchou, Uffe

2014-07-15

Purpose: Large interindividual variations in volume regression of non-small cell lung cancer (NSCLC) are observable on standard cone beam computed tomography (CBCT) during fractionated radiation therapy. Here, a method for automated assessment of tumor volume regression is presented and its potential use in response adapted personalized radiation therapy is evaluated empirically. Methods and Materials: Automated deformable registration with calculation of the Jacobian determinant was applied to serial CBCT scans in a series of 99 patients with NSCLC. Tumor volume at the end of treatment was estimated on the basis of the first one third and two thirds of the scans.more » The concordance between estimated and actual relative volume at the end of radiation therapy was quantified by Pearson's correlation coefficient. On the basis of the estimated relative volume, the patients were stratified into 2 groups having volume regressions below or above the population median value. Kaplan-Meier plots of locoregional disease-free rate and overall survival in the 2 groups were used to evaluate the predictive value of tumor regression during treatment. Cox proportional hazards model was used to adjust for other clinical characteristics. Results: Automatic measurement of the tumor regression from standard CBCT images was feasible. Pearson's correlation coefficient between manual and automatic measurement was 0.86 in a sample of 9 patients. Most patients experienced tumor volume regression, and this could be quantified early into the treatment course. Interestingly, patients with pronounced volume regression had worse locoregional tumor control and overall survival. This was significant on patient with non-adenocarcinoma histology. Conclusions: Evaluation of routinely acquired CBCT images during radiation therapy provides biological information on the specific tumor. This could potentially form the basis for personalized response adaptive therapy.« less

Characteristics and outcomes of secondary nodules identified on initial computed tomography scan for patients undergoing resection for primary non-small cell lung cancer.

PubMed

Stiles, Brendon M; Schulster, Michael; Nasar, Abu; Paul, Subroto; Lee, Paul C; Port, Jeffrey L; Altorki, Nasser K

2015-01-01

We sought to define the prevalence, malignancy rate, and outcome of secondary nodules (SNs) detected on computed tomography (CT) scan for patients undergoing resection for primary non-small cell lung cancer (NSCLC). In consecutive patients with NSCLC, we reviewed all CT scan reports obtained at diagnosis of the dominant tumor for description of SNs. When resected, pathology was reviewed. Serial CT reports for 2 years postoperatively were evaluated to follow SNs not resected. Among 155 patients, 88 (57%) were found to have SNs. A total of 137 SNs were evaluated (median size, 0.5 cm). Thirty-two nodules were resected at primary resection. Nineteen (61%) resected nodules were benign, whereas 13 (39%) were malignant (8 synchronous primary tumors and 5 lobar metastases). A total of 105 unresected nodules were followed by CT. Of these, 32 (30%) resolved completely, 20 (19%) shrunk, and 28 (27%) were stable, whereas 11 (11%) were lost to follow-up. Fourteen SNs (13%) grew, of which 5 were found to be malignant, each a new primary. Overall 5-year survival was not different between patients with or without SNs (67% vs 64%; P = .88). The prevalence of SNs on CT scan in patients undergoing resection for primary NSCLC is high. Only a low proportion of SNs are ever found to be malignant, predominantly those on the ipsilateral side as the dominant tumor. The presence of SNs has no effect on survival. Patients with SNs, if otherwise appropriately staged, should not be denied surgical therapy. Copyright © 2015. Published by Elsevier Inc.

A polymorphism within the promoter of the TGFβ1 gene is associated with radiation sensitivity using an objective radiologic endpoint.

PubMed

Kelsey, Chris R; Jackson, Lauren; Langdon, Scott; Owzar, Kouros; Hubbs, Jessica; Vujaskovic, Zeljko; Das, Shiva; Marks, Lawrence B

2012-02-01

To evaluate whether single nucleotide polymorphisms (SNPs) in the transforming growth factor-β1 (TGFβ1) gene are associated with radiation sensitivity using an objective radiologic endpoint. Preradiation therapy and serial postradiation therapy single photon emission computed tomography (SPECT) lung perfusion scans were obtained in patients undergoing treatment for lung cancer. Serial blood samples were obtained to measure circulating levels of TGFβ1. Changes in regional perfusion were related to regional radiation dose yielding a patient-specific dose-response curve, reflecting the patient's inherent sensitivity to radiation therapy. Six TGFβ1 SNPs (-988, -800, -509, 869, 941, and 1655) were assessed using high-resolution melting assays and DNA sequencing. The association between genotype and slope of the dose-response curve, and genotype and TGFβ1 ratio (4-week/preradiation therapy), was analyzed using the Kruskal-Wallis test. 39 white patients with preradiation therapy and ≥ 6-month postradiation therapy SPECT scans and blood samples were identified. Increasing slope of the dose-response curve was associated with the C(-509)T SNP (p = 0.035), but not the other analyzed SNPs. This SNP was also associated with higher TGFβ1 ratios. This study suggests that a polymorphism within the promoter of the TGFβ1 gene is associated with increased radiation sensitivity (defined objectively by dose-dependent changes in SPECT lung perfusion). Copyright © 2012 Elsevier Inc. All rights reserved.

A Polymorphism Within the Promoter of the TGF{beta}1 Gene Is Associated With Radiation Sensitivity Using an Objective Radiologic Endpoint

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

Kelsey, Chris R., E-mail: kelse003@mc.duke.edu; Jackson, Lauren; Langdon, Scott

2012-02-01

Purpose: To evaluate whether single nucleotide polymorphisms (SNPs) in the transforming growth factor-{beta}1 (TGF{beta}1) gene are associated with radiation sensitivity using an objective radiologic endpoint. Methods and Materials: Preradiation therapy and serial postradiation therapy single photon emission computed tomography (SPECT) lung perfusion scans were obtained in patients undergoing treatment for lung cancer. Serial blood samples were obtained to measure circulating levels of TGF{beta}1. Changes in regional perfusion were related to regional radiation dose yielding a patient-specific dose-response curve, reflecting the patient's inherent sensitivity to radiation therapy. Six TGF{beta}1 SNPs (-988, -800, -509, 869, 941, and 1655) were assessed using high-resolutionmore » melting assays and DNA sequencing. The association between genotype and slope of the dose-response curve, and genotype and TGF{beta}1 ratio (4-week/preradiation therapy), was analyzed using the Kruskal-Wallis test. Results: 39 white patients with preradiation therapy and {>=}6-month postradiation therapy SPECT scans and blood samples were identified. Increasing slope of the dose-response curve was associated with the C(-509)T SNP (p = 0.035), but not the other analyzed SNPs. This SNP was also associated with higher TGF{beta}1 ratios. Conclusions: This study suggests that a polymorphism within the promoter of the TGF{beta}1 gene is associated with increased radiation sensitivity (defined objectively by dose-dependent changes in SPECT lung perfusion).« less

Direct kinematics solution architectures for industrial robot manipulators: Bit-serial versus parallel

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, K.

A Very Large Scale Integration (VLSI) architecture for robot direct kinematic computation suitable for industrial robot manipulators was investigated. The Denavit-Hartenberg transformations are reviewed to exploit a proper processing element, namely an augmented CORDIC. Specifically, two distinct implementations are elaborated on, such as the bit-serial and parallel. Performance of each scheme is analyzed with respect to the time to compute one location of the end-effector of a 6-links manipulator, and the number of transistors required.

Direct kinematics solution architectures for industrial robot manipulators: Bit-serial versus parallel

NASA Technical Reports Server (NTRS)

Lee, J.; Kim, K.

1991-01-01

A Very Large Scale Integration (VLSI) architecture for robot direct kinematic computation suitable for industrial robot manipulators was investigated. The Denavit-Hartenberg transformations are reviewed to exploit a proper processing element, namely an augmented CORDIC. Specifically, two distinct implementations are elaborated on, such as the bit-serial and parallel. Performance of each scheme is analyzed with respect to the time to compute one location of the end-effector of a 6-links manipulator, and the number of transistors required.

Measurement of Three-dimensional Density Distributions by Holographic Interferometry and Computer Tomography

NASA Technical Reports Server (NTRS)

Vest, C. M.

1982-01-01

The use of holographic interferometry to measure two and threedimensional flows and the interpretation of multiple-view interferograms with computer tomography are discussed. Computational techniques developed for tomography are reviewed. Current research topics are outlined including the development of an automated fringe readout system, optimum reconstruction procedures for when an opaque test model is present in the field, and interferometry and tomography with strongly refracting fields and shocks.

rCBF-SPECT in brain infarction: When does it predict outcome

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

Limburg, M.; van Royen, E.A.; Hijdra, A.

1991-03-01

We prospectively studied 26 patients with ischemic stroke within 24 hr, after 2 wk, and after 6 mo with thallium-201-diethyldithiocarbamate single-photon emission computed tomography (SPECT) and neurologic and functional assessments. The admission flow deficits correlated with outcome. The admission and 6-mo scores correlated with clinical conditions at each time. At 2 wk, the flow deficits were smaller and did not correlate with clinical parameters. Nor did the presence or absence of hyperfixation of the radiopharmaceutical. Six months after the infarct, the flow defect had decreased in 9 of 15 patients in whom three serial scans were available, with better clinicalmore » improvement than in the remaining six whose flow deficits increased. More patients in the first group had been treated randomly with the calcium-entry blocker flunarizine. SPECT imaging of rCBF within 24 hr after stroke correlates with clinical outcome and condition, whereas rCBF imaging at 2 wk after the stroke shows no clinical correlation.« less

Quantitative 3D reconstruction of airway and pulmonary vascular trees using HRCT

NASA Astrophysics Data System (ADS)

Wood, Susan A.; Hoford, John D.; Hoffman, Eric A.; Zerhouni, Elias A.; Mitzner, Wayne A.

1993-07-01

Accurate quantitative measurements of airway and vascular dimensions are essential to evaluate function in the normal and diseased lung. In this report, a novel method is described for three-dimensional extraction and analysis of pulmonary tree structures using data from High Resolution Computed Tomography (HRCT). Serially scanned two-dimensional slices of the lower left lobe of isolated dog lungs were stacked to create a volume of data. Airway and vascular trees were three-dimensionally extracted using a three dimensional seeded region growing algorithm based on difference in CT number between wall and lumen. To obtain quantitative data, we reduced each tree to its central axis. From the central axis, branch length is measured as the distance between two successive branch points, branch angle is measured as the angle produced by two daughter branches, and cross sectional area is measured from a plane perpendicular to the central axis point. Data derived from these methods can be used to localize and quantify structural differences both during changing physiologic conditions and in pathologic lungs.

Three-Dimensional Structure Analysis and Percolation Properties of a Barrier Marine Coating

PubMed Central

Chen, Bo; Guizar-Sicairos, Manuel; Xiong, Gang; Shemilt, Laura; Diaz, Ana; Nutter, John; Burdet, Nicolas; Huo, Suguo; Mancuso, Joel; Monteith, Alexander; Vergeer, Frank; Burgess, Andrew; Robinson, Ian

2013-01-01

Artificially structured coatings are widely employed to minimize materials deterioration and corrosion, the annual direct cost of which is over 3% of the gross domestic product (GDP) for industrial countries. Manufacturing higher performance anticorrosive coatings is one of the most efficient approaches to reduce this loss. However, three-dimensional (3D) structure of coatings, which determines their performance, has not been investigated in detail. Here we present a quantitative nano-scale analysis of the 3D spatial structure of an anticorrosive aluminium epoxy barrier marine coating obtained by serial block-face scanning electron microscopy (SBFSEM) and ptychographic X-ray computed tomography (PXCT). We then use finite element simulations to demonstrate how percolation through this actual 3D structure impedes ion diffusion in the composite materials. We found the aluminium flakes align within 15° of the coating surface in the material, causing the perpendicular diffusion resistance of the coating to be substantially higher than the pure epoxy. PMID:23378910

Mapping social behavior-induced brain activation at cellular resolution in the mouse

PubMed Central

Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C.; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J.; Rockland, Kathleen; Seung, H. Sebastian; Osten, Pavel

2014-01-01

Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate early gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP-positive neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

Three-dimensional power doppler ultrasound is useful to monitor the response to treatment in a patient with primary papillary serous carcinoma of the peritoneum.

PubMed

Su, Jen-Min; Huang, Yu-Fang; Chen, Helen H W; Cheng, Ya-Min; Chou, Cheng-Yang

2006-05-01

To date, this is the first report to monitor changes of intratumor vascularization and the response to radiation and Cyberknife therapy in a patient with recurrent primary papillary serous carcinoma of the peritoneum by three dimensional (3D) power Doppler ultrasonography (PDUS). Transvaginal 3D PDUS detected a recurrent presacral tumor with abundant intratumor vascularity. Serial examinations of the tumor volume and serum CA-125 level were studied before, during, and 6 mo after therapy. Meanwhile, the intratumor blood flow was measured and expressed as vascularity indices. All of the tumor volume, intratumor vascularity indices and serum CA-125 level decreased progressively following therapy. A remaining lesion with nearly absent intratumor power Doppler signals suggested a scarring lesion posttreatment. Indeed, CT-guided tissue biopsy confirmed fibrotic change. 3D PDUS is useful to monitor the response to treatments and to differentiate residual tumors from lesions of scarring change posttreatment. It provides more accurate posttreatment information than pelvic computed tomography.

Changes over Time in Intracranial Air in Patients with Cerebral Air Embolism: Radiological Study in Two Cases

PubMed Central

Kaichi, Yoko; Kakeda, Shingo; Korogi, Yukunori; Nezu, Tomohisa; Aoki, Shiro; Matsumoto, Masayasu; Iida, Makoto; Awai, Kazuo

2015-01-01

Cerebral air embolism can be easily identified on computed tomography (CT) scans. However, changes in the distribution and amount of intracranial air are not well known. We report two patients with cerebral air embolism and present imaging findings on the serial changes in the intracranial air. We thought that the embolic source was venous in one patient because CT showed air inflow in cortical veins in the bilateral frontal areas, reflecting air buoyancy. In the other patient, CT showed air inflow into not only the cortical veins but also the bilateral cerebral hemispheres and we thought this to be a paradoxical cerebral air embolism. We found that intracranial air can be promptly absorbed and while cerebral infarcts due to air are clearly visualized on diffusion-weighted images (DWI), the air may rapidly disappear from images. In patients with suspected cerebral air embolism whose CT findings show no intracranial air, DWI should be performed because it may reveal cerebral infarction due to cerebral air embolism. PMID:26640730

Simultaneously diagnosed pulmonary thromboembolism and hemopericardium in a man with thoracic spinal cord injury.

PubMed

Han, Jae-Young; Seon, Hyo-Jeong; Choi, In-Sung; Ahn, Youngkeun; Jeong, Myung-Ho; Lee, Sam-Gyu

2012-05-01

Simultaneous pulmonary thromboembolism (PTE) and hemopericardium is a rare but life-threatening condition. As hemopericardium is a contraindication to anticoagulation treatment, it is challenging to handle both conditions together. The objective of the study was to report a rare case of a man with thoracic spinal cord injury presenting with simultaneous PTE and hemopericardium. Case report. A 43-year-old man with incomplete T9 paraplegia (American Spinal Injury Association Impairment Scale D) complained of fever one and a half months after spinal cord injury sustained in a fall. During evaluation of fever origin, chest computed tomography and transthoracic echocardiogram revealed simultaneous PTE and hemopericardium. After serial echocardiograms over 2 days demonstrated stability, intravenous heparin, and oral warfarin were administered and his medical status was observed closely. Ultimately, both conditions improved without significant complications. We report successful treatment of man with acute spinal cord injury who presented with simultaneously diagnosed PTE and hemopericardium, a rare complication involving two distinct and opposing pathological mechanisms and conflicting treatments.

Molecular imaging in stem cell-based therapies of cardiac diseases.

PubMed

Li, Xiang; Hacker, Marcus

2017-10-01

In the past 15years, despite that regenerative medicine has shown great potential for cardiovascular diseases, the outcome and safety of stem cell transplantation has shown controversial results in the published literature. Medical imaging might be useful for monitoring and quantifying transplanted cells within the heart and to serially characterize the effects of stem cell therapy of the myocardium. From the multiple available noninvasive imaging techniques, magnetic resonance imaging and nuclear imaging by positron (PET) or single photon emission computer tomography (SPECT) are the most used clinical approaches to follow the fate of transplanted stem cells in vivo. In this article, we provide a review on the role of different noninvasive imaging modalities and discuss their advantages and disadvantages. We focus on the different in-vivo labeling and reporter gene imaging strategies for stem cell tracking as well as the concept and reliability to use imaging parameters as noninvasive surrogate endpoints for the evaluation of the post-therapeutic outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

Preclinical Multimodal Molecular Imaging Using 18F-FDG PET/CT and MRI in a Phase I Study of a Knee Osteoarthritis in In Vivo Canine Model.

PubMed

Menendez, Maria I; Hettlich, Bianca; Wei, Lai; Knopp, Michael V

2017-01-01

The aim of this study was to use a multimodal molecular imaging approach to serially assess regional metabolic changes in the knee in an in vivo anterior cruciate ligament transection (ACLT) canine model of osteoarthritis (OA). Five canine underwent ACLT in one knee and the contralateral knee served as uninjured control. Prior, 3, 6, and 12 weeks post-ACLT, the dogs underwent 18 F-fluoro-d-glucose ( 18 F-FDG) positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI). The MRI was coregistered with the PET/CT, and 3-dimensional regions of interest (ROIs) were traced manually and maximum standardized uptake values (SUV max ) were evaluated. 18 F-fluoro-d-glucose SUV max in the ACLT knee ROIs was significantly higher compared to the uninjured contralateral knees at 3, 6, and 12 weeks. Higher 18 F-FDG uptake observed in ACLT knees compared to the uninjured knees reflects greater metabolic changes in the injured knees over time. Knee 18 F-FDG uptake in an in vivo ACLT canine model using combined PET/CT and MRI demonstrated to be highly sensitive in the detection of metabolic alterations in osseous and nonosteochondral structures comprising the knee joint. 18 F-fluoro-d-glucose appeared to be a capable potential imaging biomarker for early human knee OA diagnosis, prognosis, and management.

Inflammation Modulates Murine Venous Thrombosis Resolution In Vivo: Assessment by Multimodal Fluorescence Molecular Imaging

PubMed Central

Ripplinger, Crystal M.; Kessinger, Chase W.; Li, Chunqiang; Kim, Jin Won; McCarthy, Jason R.; Weissleder, Ralph; Henke, Peter K.; Lin, Charles P.; Jaffer, Farouc A.

2012-01-01

Objective Assessment of thrombus inflammation in vivo could provide new insights into deep vein thrombosis (DVT) resolution. Here we develop and evaluate two integrated fluorescence molecular-structural imaging strategies to quantify DVT-related inflammation and architecture, and to assess the effect of thrombus inflammation on subsequent DVT resolution in vivo. Methods and Results Murine DVT were created with topical 5% FeCl3 application to thigh or jugular veins (n=35). On day 3, mice received macrophage and matrix metalloproteinase (MMP) activity fluorescence imaging agents. On day 4, integrated assessment of DVT inflammation and architecture was performed using confocal fluorescence intravital microscopy (IVM). Day 4 analyses showed robust relationships among in vivo thrombus macrophages, MMP activity, and FITC-dextran deposition (r>0.70, p<0.01). In a serial two-timepoint study, mice with DVT underwent IVM at day 4 and at day 6. Analyses revealed that the intensity of thrombus inflammation at day 4 predicted the magnitude of DVT resolution at day 6 (p<0.05). In a second approach, noninvasive fluorescence molecular tomography-computed tomography (FMT-CT) was employed, and detected macrophages within jugular DVT (p<0.05 vs. sham-controls). Conclusions Integrated fluorescence molecular-structural imaging demonstrates that the DVT-induced inflammatory response can be readily assessed in vivo, and can inform the magnitude of thrombus resolution. PMID:22995524

Improving early diagnosis of pulmonary infections in patients with febrile neutropenia using low-dose chest computed tomography.

PubMed

Gerritsen, M G; Willemink, M J; Pompe, E; van der Bruggen, T; van Rhenen, A; Lammers, J W J; Wessels, F; Sprengers, R W; de Jong, P A; Minnema, M C

2017-01-01

We performed a prospective study in patients with chemotherapy induced febrile neutropenia to investigate the diagnostic value of low-dose computed tomography compared to standard chest radiography. The aim was to compare both modalities for detection of pulmonary infections and to explore performance of low-dose computed tomography for early detection of invasive fungal disease. The low-dose computed tomography remained blinded during the study. A consensus diagnosis of the fever episode made by an expert panel was used as reference standard. We included 67 consecutive patients on the first day of febrile neutropenia. According to the consensus diagnosis 11 patients (16.4%) had pulmonary infections. Sensitivity, specificity, positive predictive value and negative predictive value were 36%, 93%, 50% and 88% for radiography, and 73%, 91%, 62% and 94% for low-dose computed tomography, respectively. An uncorrected McNemar showed no statistical difference (p = 0.197). Mean radiation dose for low-dose computed tomography was 0.24 mSv. Four out of 5 included patients diagnosed with invasive fungal disease had radiographic abnormalities suspect for invasive fungal disease on the low-dose computed tomography scan made on day 1 of fever, compared to none of the chest radiographs. We conclude that chest radiography has little value in the initial assessment of febrile neutropenia on day 1 for detection of pulmonary abnormalities. Low-dose computed tomography improves detection of pulmonary infiltrates and seems capable of detecting invasive fungal disease at a very early stage with a low radiation dose.

Improving early diagnosis of pulmonary infections in patients with febrile neutropenia using low-dose chest computed tomography

PubMed Central

Pompe, E.; van der Bruggen, T.; van Rhenen, A.; Lammers, J. W. J.; Wessels, F.; Sprengers, R. W.; de Jong, P. A.; Minnema, M. C.

2017-01-01

We performed a prospective study in patients with chemotherapy induced febrile neutropenia to investigate the diagnostic value of low-dose computed tomography compared to standard chest radiography. The aim was to compare both modalities for detection of pulmonary infections and to explore performance of low-dose computed tomography for early detection of invasive fungal disease. The low-dose computed tomography remained blinded during the study. A consensus diagnosis of the fever episode made by an expert panel was used as reference standard. We included 67 consecutive patients on the first day of febrile neutropenia. According to the consensus diagnosis 11 patients (16.4%) had pulmonary infections. Sensitivity, specificity, positive predictive value and negative predictive value were 36%, 93%, 50% and 88% for radiography, and 73%, 91%, 62% and 94% for low-dose computed tomography, respectively. An uncorrected McNemar showed no statistical difference (p = 0.197). Mean radiation dose for low-dose computed tomography was 0.24 mSv. Four out of 5 included patients diagnosed with invasive fungal disease had radiographic abnormalities suspect for invasive fungal disease on the low-dose computed tomography scan made on day 1 of fever, compared to none of the chest radiographs. We conclude that chest radiography has little value in the initial assessment of febrile neutropenia on day 1 for detection of pulmonary abnormalities. Low-dose computed tomography improves detection of pulmonary infiltrates and seems capable of detecting invasive fungal disease at a very early stage with a low radiation dose. PMID:28235014

Micro-CT images reconstruction and 3D visualization for small animal studying

NASA Astrophysics Data System (ADS)

Gong, Hui; Liu, Qian; Zhong, Aijun; Ju, Shan; Fang, Quan; Fang, Zheng

2005-01-01

A small-animal x-ray micro computed tomography (micro-CT) system has been constructed to screen laboratory small animals and organs. The micro-CT system consists of dual fiber-optic taper-coupled CCD detectors with a field-of-view of 25x50 mm2, a microfocus x-ray source, a rotational subject holder. For accurate localization of rotation center, coincidence between the axis of rotation and centre of image was studied by calibration with a polymethylmethacrylate cylinder. Feldkamp"s filtered back-projection cone-beam algorithm is adopted for three-dimensional reconstruction on account of the effective corn-beam angle is 5.67° of the micro-CT system. 200x1024x1024 matrix data of micro-CT is obtained with the magnification of 1.77 and pixel size of 31x31μm2. In our reconstruction software, output image size of micro-CT slices data, magnification factor and rotation sample degree can be modified in the condition of different computational efficiency and reconstruction region. The reconstructed image matrix data is processed and visualization by Visualization Toolkit (VTK). Data parallelism of VTK is performed in surface rendering of reconstructed data in order to improve computing speed. Computing time of processing a 512x512x512 matrix datasets is about 1/20 compared with serial program when 30 CPU is used. The voxel size is 54x54x108 μm3. The reconstruction and 3-D visualization images of laboratory rat ear are presented.

Nasal computed tomography.

PubMed

Kuehn, Ned F

2006-05-01

Chronic nasal disease is often a challenge to diagnose. Computed tomography greatly enhances the ability to diagnose chronic nasal disease in dogs and cats. Nasal computed tomography provides detailed information regarding the extent of disease, accurate discrimination of neoplastic versus nonneoplastic diseases, and identification of areas of the nose to examine rhinoscopically and suspicious regions to target for biopsy.

Multislice Computed Tomography Accurately Detects Stenosis in Coronary Artery Bypass Conduits

PubMed Central

Duran, Cihan; Sagbas, Ertan; Caynak, Baris; Sanisoglu, Ilhan; Akpinar, Belhhan; Gulbaran, Murat

2007-01-01

The aim of this study was to evaluate the accuracy of multislice computed tomography in detecting graft stenosis or occlusion after coronary artery bypass grafting, using coronary angiography as the standard. From January 2005 through May 2006, 25 patients (19 men and 6 women; mean age, 54 ± 11.3 years) underwent diagnostic investigation of their bypass grafts by multislice computed tomography within 1 month of coronary angiography. The mean time elapsed after coronary artery bypass grafting was 6.2 years. In these 25 patients, we examined 65 bypass conduits (24 arterial and 41 venous) and 171 graft segments (the shaft, proximal anastomosis, and distal anastomosis). Compared with coronary angiography, the segment-based sensitivity, specificity, and positive and negative predictive values of multislice computed tomography in the evaluation of stenosis were 89%, 100%, 100%, and 99%, respectively. The patency rate for multislice compu-ted tomography was 85% (55/65: 3 arterial and 7 venous grafts were occluded), with 100% sensitivity and specificity. From these data, we conclude that multislice computed tomography can accurately evaluate the patency and stenosis of bypass grafts during outpatient follow-up. PMID:17948078

Differences between postmortem computed tomography and conventional autopsy in a stabbing murder case

PubMed Central

Zerbini, Talita; da Silva, Luiz Fernando Ferraz; Ferro, Antonio Carlos Gonçalves; Kay, Fernando Uliana; Junior, Edson Amaro; Pasqualucci, Carlos Augusto Gonçalves; do Nascimento Saldiva, Paulo Hilario

2014-01-01

OBJECTIVE: The aim of the present work is to analyze the differences and similarities between the elements of a conventional autopsy and images obtained from postmortem computed tomography in a case of a homicide stab wound. METHOD: Comparison between the findings of different methods: autopsy and postmortem computed tomography. RESULTS: In some aspects, autopsy is still superior to imaging, especially in relation to external examination and the description of lesion vitality. However, the findings of gas embolism, pneumothorax and pulmonary emphysema and the relationship between the internal path of the instrument of aggression and the entry wound are better demonstrated by postmortem computed tomography. CONCLUSIONS: Although multislice computed tomography has greater accuracy than autopsy, we believe that the conventional autopsy method is fundamental for providing evidence in criminal investigations. PMID:25518020

Interlaced X-ray diffraction computed tomography

PubMed Central

Vamvakeros, Antonios; Jacques, Simon D. M.; Di Michiel, Marco; Senecal, Pierre; Middelkoop, Vesna; Cernik, Robert J.; Beale, Andrew M.

2016-01-01

An X-ray diffraction computed tomography data-collection strategy that allows, post experiment, a choice between temporal and spatial resolution is reported. This strategy enables time-resolved studies on comparatively short timescales, or alternatively allows for improved spatial resolution if the system under study, or components within it, appear to be unchanging. The application of the method for studying an Mn–Na–W/SiO2 fixed-bed reactor in situ is demonstrated. Additionally, the opportunities to improve the data-collection strategy further, enabling post-collection tuning between statistical, temporal and spatial resolutions, are discussed. In principle, the interlaced scanning approach can also be applied to other pencil-beam tomographic techniques, like X-ray fluorescence computed tomography, X-ray absorption fine structure computed tomography, pair distribution function computed tomography and tomographic scanning transmission X-ray microscopy. PMID:27047305

Colovesical fistula causing an uncommon reason for failure of computed tomography colonography: a case report.

PubMed

Neroladaki, Angeliki; Breguet, Romain; Botsikas, Diomidis; Terraz, Sylvain; Becker, Christoph D; Montet, Xavier

2012-07-23

Computed tomography colonography, or virtual colonoscopy, is a good alternative to optical colonoscopy. However, suboptimal patient preparation or colon distension may reduce the diagnostic accuracy of this imaging technique. We report the case of an 83-year-old Caucasian woman who presented with a five-month history of pneumaturia and fecaluria and an acute episode of macrohematuria, leading to a high clinical suspicion of a colovesical fistula. The fistula was confirmed by standard contrast-enhanced computed tomography. Optical colonoscopy was performed to exclude the presence of an underlying colonic neoplasm. Since optical colonoscopy was incomplete, computed tomography colonography was performed, but also failed due to inadequate colon distension. The insufflated air directly accumulated within the bladder via the large fistula. Clinicians should consider colovesical fistula as a potential reason for computed tomography colonography failure.

Tumor volume changes on serial imaging with megavoltage CT for non-small-cell lung cancer during intensity-modulated radiotherapy: how reliable, consistent, and meaningful is the effect?

PubMed

Siker, Malika L; Tomé, Wolfgang A; Mehta, Minesh P

2006-09-01

Adaptive radiotherapy allows treatment plan modification based on data obtained during treatment. Assessing volume changes during treatment is now possible with intratreatment imaging capabilities on radiotherapy devices. This study assesses non-small-cell lung cancer (NSCLC) volume changes during treatment with conformal intensity-modulated radiotherapy by evaluating serial megavoltage computed tomography (MVCT) scans, with a specific emphasis on the frequency, reliability, and meaningfulness of these changes. Megavoltage CTs were retrospectively reviewed for 25 patients treated with the TomoTherapy Hi-Art system at the University of Wisconsin. Twenty-one patients received definitive radiotherapy, 4 with extracranial stereotactic radioablation (60 Gy in five fractions) and 17 on a dose-per-fraction escalation protocol (57-80.5 Gy in 25 fractions). Four patients were treated palliatively (22-30 Gy in 8 to 10 fractions). Gross tumor volumes were contoured on serial MVCTs at weekly intervals. Each patient had 4 to 25 scans, including at least one at the beginning, midway, and one at the end of treatment. At completion of treatment, no patient demonstrated a complete response. Partial response occurred in 3 (12%) and marginal response was noted in 5 (20%). The remaining 17 patients (68%) showed stable disease. The minimum "scorable threshold" for volume discrepancy between scans to account for interscan assessment variability was set at >25% volume change; 10 patients (40%) had >25% tumor regression. None of the patients treated ablatively or palliatively showed tumor regression during treatment. Although gross tumor regression during treatment may be objectively measured using MVCTs, substantial volumetric decrease occurs only in a minority. The clinical significance of this regression is questionable, because there is no way to document histologic tumor clearance, and therefore field reductions during radiotherapy cannot be recommended.

Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

PubMed

Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

2015-01-01

We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly. Published by Elsevier Inc.

Incidental renal tumours on low-dose CT lung cancer screening exams.

PubMed

Pinsky, Paul F; Dunn, Barbara; Gierada, David; Nath, P Hrudaya; Munden, Reginald; Berland, Lincoln; Kramer, Barnett S

2017-06-01

Introduction Renal cancer incidence has increased markedly in the United States in recent decades, largely due to incidentally detected tumours from computed tomography imaging. Here, we analyze the potential for low-dose computed tomography lung cancer screening to detect renal cancer. Methods The National Lung Screening Trial randomized subjects to three annual screens with either low-dose computed tomography or chest X-ray. Eligibility criteria included 30 + pack-years, current smoking or quit within 15 years, and age 55-74. Subjects were followed for seven years. Low-dose computed tomography screening forms collected information on lung cancer and non-lung cancer abnormalities, including abnormalities below the diaphragm. A reader study was performed on a sample of National Lung Screening Trial low-dose computed tomography images assessing presence of abnormalities below the diaphragms and abnormalities suspicious for renal cancer. Results There were 26,722 and 26,732 subjects enrolled in the low-dose computed tomography and chest X-ray arms, respectively, and there were 104 and 85 renal cancer cases diagnosed, respectively (relative risk = 1.22, 95% CI: 0.9-1.5). From 75,126 low-dose computed tomography screens, there were 46 renal cancer diagnoses within one year. Abnormalities below the diaphragm rates were 39.1% in screens with renal cancer versus 4.1% in screens without (P < 0.001). Cases with abnormalities below the diaphragms had shorter median time to diagnosis than those without (71 vs. 160 days, P = 0.004). In the reader study, 64% of renal cancer cases versus 13% of non-cases had abnormalities below the diaphragms; 55% of cases and 0.8% of non-cases had a finding suspicious for renal cancer (P < 0.001). Conclusion Low-dose computed tomography screens can potentially detect renal cancers. The benefits to harms tradeoff of incidental detection of renal tumours on low-dose computed tomography is unknown.

Meta-Analysis of Stress Myocardial Perfusion Imaging

ClinicalTrials.gov

2017-06-06

Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

Positron Computed Tomography: Current State, Clinical Results and Future Trends

DOE R&D Accomplishments Database

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1980-09-01

An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

Diagnostic dilemma of degenerative joint disease, chronic avascular necrosis or metastasis in planar Tc-99m-methylene diphosphonate planar skeletal scintigraphy excluded by single positron emission computed tomography/computed tomography.

PubMed

Jain, Tarun Kumar; Phulsunga, Rohit Kumar; Basher, Rajender Kumar; Kumar, Narendra; Bhattacharya, Anish; Mittal, Bhagwant Rai

2015-01-01

We present a 71-year-old male patient subjected to skeletal scintigraphy for metastasis work up of prostate cancer. Whole body planar images revealed a solitary focal tracer uptake in left femoral head mimicking as solitary metastatic focus. Single positron emission computed tomography/computed tomography images localized this increased tracer uptake to the subchondral cysts with minimal sclerosis in left femur head with no decrease in size of femur head and was reported as (degenerative joint disease).

Diagnostic dilemma of degenerative joint disease, chronic avascular necrosis or metastasis in planar Tc-99m-methylene diphosphonate planar skeletal scintigraphy excluded by single positron emission computed tomography/computed tomography

PubMed Central

Jain, Tarun Kumar; Phulsunga, Rohit Kumar; Basher, Rajender Kumar; Kumar, Narendra; Bhattacharya, Anish; Mittal, Bhagwant Rai

2015-01-01

We present a 71-year-old male patient subjected to skeletal scintigraphy for metastasis work up of prostate cancer. Whole body planar images revealed a solitary focal tracer uptake in left femoral head mimicking as solitary metastatic focus. Single positron emission computed tomography/computed tomography images localized this increased tracer uptake to the subchondral cysts with minimal sclerosis in left femur head with no decrease in size of femur head and was reported as (degenerative joint disease). PMID:26170582

The early development of medial coronoid disease in growing Labrador retrievers: radiographic, computed tomographic, necropsy and micro-computed tomographic findings.

PubMed

Lau, S F; Wolschrijn, C F; Hazewinkel, H A W; Siebelt, M; Voorhout, G

2013-09-01

Medial coronoid disease (MCD) encompasses lesions of the entire medial coronoid process (MCP), both of the articular cartilage and the subchondral bone. To detect the earliest signs of MCD, radiography and computed tomography were used to monitor the development of MCD in 14 Labrador retrievers, from 6 to 7 weeks of age until euthanasia. The definitive diagnosis of MCD was based on necropsy and micro-computed tomography findings. The frequency of MCD in the dogs studied was 50%. Radiographic findings did not provide evidence of MCD, ulnar subtrochlear sclerosis or blunting of the cranial edge of the MCP. Computed tomography was more sensitive (30.8%) than radiography (0%) in detecting early MCD, with the earliest signs detectable at 14 weeks of age. A combination of the necropsy and micro-computed tomography findings of the MCP showed that MCD was manifested as a lesion of only the subchondral bone in dogs <18 weeks of age. In all dogs (affected and unaffected), there was close contact between the base of the MCP and the proximal radial head in the congruent joints. Computed tomography and micro-computed tomography findings indicated that the lesions of MCD probably originated at the base of the MCP. Copyright © 2013 Elsevier Ltd. All rights reserved.

Star adaptation for two-algorithms used on serial computers

NASA Technical Reports Server (NTRS)

Howser, L. M.; Lambiotte, J. J., Jr.

1974-01-01

Two representative algorithms used on a serial computer and presently executed on the Control Data Corporation 6000 computer were adapted to execute efficiently on the Control Data STAR-100 computer. Gaussian elimination for the solution of simultaneous linear equations and the Gauss-Legendre quadrature formula for the approximation of an integral are the two algorithms discussed. A description is given of how the programs were adapted for STAR and why these adaptations were necessary to obtain an efficient STAR program. Some points to consider when adapting an algorithm for STAR are discussed. Program listings of the 6000 version coded in 6000 FORTRAN, the adapted STAR version coded in 6000 FORTRAN, and the STAR version coded in STAR FORTRAN are presented in the appendices.

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.

Three-dimensional fine structure of the organization of microtubules in neurite varicosities by ultra-high voltage electron microscope tomography.

PubMed

Nishida, Tomoki; Yoshimura, Ryoichi; Endo, Yasuhisa

2017-09-01

Neurite varicosities are highly specialized compartments that are involved in neurotransmitter/ neuromodulator release and provide a physiological platform for neural functions. However, it remains unclear how microtubule organization contributes to the form of varicosity. Here, we examine the three-dimensional structure of microtubules in varicosities of a differentiated PC12 neural cell line using ultra-high voltage electron microscope tomography. Three-dimensional imaging showed that a part of the varicosities contained an accumulation of organelles that were separated from parallel microtubule arrays. Further detailed analysis using serial sections and whole-mount tomography revealed microtubules running in a spindle shape of swelling in some other types of varicosities. These electron tomographic results showed that the structural diversity and heterogeneity of microtubule organization supported the form of varicosities, suggesting that a different distribution pattern of microtubules in varicosities is crucial to the regulation of varicosities development.

Array tomography: characterizing FAC-sorted populations of zebrafish immune cells by their 3D ultrastructure.

PubMed

Wacker, Irene; Chockley, Peter; Bartels, Carolin; Spomer, Waldemar; Hofmann, Andreas; Gengenbach, Ulrich; Singh, Sachin; Thaler, Marlene; Grabher, Clemens; Schröder, Rasmus R

2015-08-01

For 3D reconstructions of whole immune cells from zebrafish, isolated from adult animals by FAC-sorting we employed array tomography on hundreds of serial sections deposited on silicon wafers. Image stacks were either recorded manually or automatically with the newly released ZEISS Atlas 5 Array Tomography platform on a Zeiss FEGSEM. To characterize different populations of immune cells, organelle inventories were created by segmenting individual cells. In addition, arrays were used for quantification of cell populations with respect to the various cell types they contained. The detection of immunological synapses in cocultures of cell populations from thymus or WKM with cancer cells helped to identify the cytotoxic nature of these cells. Our results demonstrate the practicality and benefit of AT for high-throughput ultrastructural imaging of substantial volumes. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Tomography in Geology: 3D Modeling and Analysis of Structural Features of Rocks Using Computed MicroTomography

NASA Astrophysics Data System (ADS)

Ponomarev, A. A.; Mamadaliev, R. A.; Semenova, T. V.

2016-10-01

The article presents a brief overview of the current state of computed tomography in the sphere of oil and gas production in Russia and in the world. Operation of computed microtomograph Skyscan 1172 is also provided, as well as personal examples of its application in solving geological problems.

Aerosolized intranasal midazolam for safe and effective sedation for quality computed tomography imaging in infants and children.

PubMed

Mekitarian Filho, Eduardo; de Carvalho, Werther Brunow; Gilio, Alfredo Elias; Robinson, Fay; Mason, Keira P

2013-10-01

This pilot study introduces the aerosolized route for midazolam as an option for infant and pediatric sedation for computed tomography imaging. This technique produced predictable and effective sedation for quality computed tomography imaging studies with minimal artifact and no significant adverse events. Copyright © 2013 Mosby, Inc. All rights reserved.

Computed Tomography Measuring Inside Machines

NASA Technical Reports Server (NTRS)

Wozniak, James F.; Scudder, Henry J.; Anders, Jeffrey E.

1995-01-01

Computed tomography applied to obtain approximate measurements of radial distances from centerline of turbopump to leading edges of diffuser vanes in turbopump. Use of computed tomography has significance beyond turbopump application: example of general concept of measuring internal dimensions of assembly of parts without having to perform time-consuming task of taking assembly apart and measuring internal parts on coordinate-measuring machine.

A Heat Pipe Coupled Planar Thermionic Converter: Performance Characterization, Nondestructive Testing, and Evaluation.

DTIC Science & Technology

1992-03-15

Pipes, Computer Modelling, Nondestructive Testing. Tomography , Planar Converter, Cesium Reservoir 19. ABSTRACT (Continue on reverse if necessary and...Investigation ........................ 32 4.3 Computed Tomography ................................ 33 4.4 X-Ray Radiography...25 3.4 LEOS generated output data for Mo-Re converter ................ 26 4.1 Distance along converter imaged by the computed tomography

Dynamic Edematous Response of the Human Heart to Myocardial Infarction

PubMed Central

Fernández-Jiménez, Rodrigo; Barreiro-Pérez, Manuel; Martin-García, Ana; Sánchez-González, Javier; Agüero, Jaume; Galán-Arriola, Carlos; García-Prieto, Jaime; Díaz-Pelaez, Elena; Vara, Pedro; Martinez, Irene; Zamarro, Ivan; Garde, Beatriz; Sanz, Javier; Fuster, Valentin

2017-01-01

Background: Clinical protocols aimed to characterize the post–myocardial infarction (MI) heart by cardiac magnetic resonance (CMR) need to be standardized to take account of dynamic biological phenomena evolving early after the index ischemic event. Here, we evaluated the time course of edema reaction in patients with ST-segment–elevation MI by CMR and assessed its implications for myocardium-at-risk (MaR) quantification both in patients and in a large-animal model. Methods: A total of 16 patients with anterior ST-segment–elevation MI successfully treated by primary angioplasty and 16 matched controls were prospectively recruited. In total, 94 clinical CMR examinations were performed: patients with ST-segment–elevation MI were serially scanned (within the first 3 hours after reperfusion and at 1, 4, 7, and 40 days), and controls were scanned only once. T2 relaxation time in the myocardium (T2 mapping) and the extent of edema on T2-weighted short-tau triple inversion-recovery (ie, CMR-MaR) were evaluated at all time points. In the experimental study, 20 pigs underwent 40-minute ischemia/reperfusion followed by serial CMR examinations at 120 minutes and 1, 4, and 7 days after reperfusion. Reference MaR was assessed by contrast-multidetector computed tomography during the index coronary occlusion. Generalized linear mixed models were used to take account of repeated measurements. Results: In humans, T2 relaxation time in the ischemic myocardium declines significantly from early after reperfusion to 24 hours, and then increases up to day 4, reaching a plateau from which it decreases from day 7. Consequently, edema extent measured by T2-weighted short-tau triple inversion-recovery (CMR-MaR) varied with the timing of the CMR examination. These findings were confirmed in the experimental model by showing that only CMR-MaR values for day 4 and day 7 postreperfusion, coinciding with the deferred edema wave, were similar to values measured by reference contrast-multidetector computed tomography. Conclusions: Post-MI edema in patients follows a bimodal pattern that affects CMR estimates of MaR. Dynamic changes in post–ST-segment–elevation MI edema highlight the need for standardization of CMR timing to retrospectively delineate MaR and quantify myocardial salvage. According to the present clinical and experimental data, a time window between days 4 and 7 post-MI seems a good compromise solution for standardization. Further studies are needed to study the effect of other factors on these variables. PMID:28687712

Nondestructive microimaging during preclinical pin-on-plate testing of novel materials for arthroplasty.

PubMed

Teeter, Matthew G; Langohr, G Daniel G; Medley, John B; Holdsworth, David W

2014-02-01

The purpose of this study was to determine the ability of micro-computed tomography to quantify wear in preclinical pin-on-plate testing of materials for use in joint arthroplasty. Wear testing of CoCr pins articulating against six polyetheretherketone plates was performed using a pin-on-plate apparatus over 2 million cycles. Change in volume due to wear was quantified with gravimetric analysis and with micro-computed tomography, and the volumes were compared. Separately, the volume of polyetheretherketone pin-on-plate specimens that had been soaking in fluid for 52 weeks was quantified with both gravimetric analysis and micro-computed tomography, and repeated after drying. The volume change with micro-computed tomography was compared to the mass change with gravimetric analysis. The mean wear volume measured was 8.02 ± 6.38 mm(3) with gravimetric analysis and 6.76 ± 5.38 mm(3) with micro-computed tomography (p = 0.06). Micro-computed tomography volume measurements did not show a statistically significant change with drying for either the plates (p = 0.60) or the pins (p = 0.09), yet drying had a significant effect on the gravimetric mass measurements for both the plates (p = 0.03) and the pins (p = 0.04). Micro-computed tomography provided accurate measurements of wear in polyetheretherketone pin-on-plate test specimens, and no statistically significant change was caused by fluid uptake. Micro-computed tomography quantifies wear depth and wear volume, mapped to the specific location of damage on the specimen, and is also capable of examining subsurface density as well as cracking. Its noncontact, nondestructive nature makes it ideal for preclinical testing of materials, in which further additional analysis techniques may be utilized.

Preoperative (3-dimensional) computed tomography lung reconstruction before anatomic segmentectomy or lobectomy for stage I non-small cell lung cancer.

PubMed

Chan, Ernest G; Landreneau, James R; Schuchert, Matthew J; Odell, David D; Gu, Suicheng; Pu, Jiantao; Luketich, James D; Landreneau, Rodney J

2015-09-01

Accurate cancer localization and negative resection margins are necessary for successful segmentectomy. In this study, we evaluate a newly developed software package that permits automated segmentation of the pulmonary parenchyma, allowing 3-dimensional assessment of tumor size, location, and estimates of surgical margins. A pilot study using a newly developed 3-dimensional computed tomography analytic software package was performed to retrospectively evaluate preoperative computed tomography images of patients who underwent segmentectomy (n = 36) or lobectomy (n = 15) for stage 1 non-small cell lung cancer. The software accomplishes an automated reconstruction of anatomic pulmonary segments of the lung based on bronchial arborization. Estimates of anticipated surgical margins and pulmonary segmental volume were made on the basis of 3-dimensional reconstruction. Autosegmentation was achieved in 72.7% (32/44) of preoperative computed tomography images with slice thicknesses of 3 mm or less. Reasons for segmentation failure included local severe emphysema or pneumonitis, and lower computed tomography resolution. Tumor segmental localization was achieved in all autosegmented studies. The 3-dimensional computed tomography analysis provided a positive predictive value of 87% in predicting a marginal clearance greater than 1 cm and a 75% positive predictive value in predicting a margin to tumor diameter ratio greater than 1 in relation to the surgical pathology assessment. This preoperative 3-dimensional computed tomography analysis of segmental anatomy can confirm the tumor location within an anatomic segment and aid in predicting surgical margins. This 3-dimensional computed tomography information may assist in the preoperative assessment regarding the suitability of segmentectomy for peripheral lung cancers. Published by Elsevier Inc.

Role of post-mapping computed tomography in virtual-assisted lung mapping.

PubMed

Sato, Masaaki; Nagayama, Kazuhiro; Kuwano, Hideki; Nitadori, Jun-Ichi; Anraku, Masaki; Nakajima, Jun

2017-02-01

Background Virtual-assisted lung mapping is a novel bronchoscopic preoperative lung marking technique in which virtual bronchoscopy is used to predict the locations of multiple dye markings. Post-mapping computed tomography is performed to confirm the locations of the actual markings. This study aimed to examine the accuracy of marking locations predicted by virtual bronchoscopy and elucidate the role of post-mapping computed tomography. Methods Automated and manual virtual bronchoscopy was used to predict marking locations. After bronchoscopic dye marking under local anesthesia, computed tomography was performed to confirm the actual marking locations before surgery. Discrepancies between marking locations predicted by the different methods and the actual markings were examined on computed tomography images. Forty-three markings in 11 patients were analyzed. Results The average difference between the predicted and actual marking locations was 30 mm. There was no significant difference between the latest version of the automated virtual bronchoscopy system (30.7 ± 17.2 mm) and manual virtual bronchoscopy (29.8 ± 19.1 mm). The difference was significantly greater in the upper vs. lower lobes (37.1 ± 20.1 vs. 23.0 ± 6.8 mm, for automated virtual bronchoscopy; p < 0.01). Despite this discrepancy, all targeted lesions were successfully resected using 3-dimensional image guidance based on post-mapping computed tomography reflecting the actual marking locations. Conclusions Markings predicted by virtual bronchoscopy were dislocated from the actual markings by an average of 3 cm. However, surgery was accurately performed using post-mapping computed tomography guidance, demonstrating the indispensable role of post-mapping computed tomography in virtual-assisted lung mapping.

Utility of screening computed tomography of chest, abdomen and pelvis in patients after heart transplantation.

PubMed

Dasari, Tarun W; Pavlovic-Surjancev, Biljana; Dusek, Linda; Patel, Nilamkumar; Heroux, Alain L

2011-12-01

Malignancy is a late cause of mortality in heart transplant recipients. It is unknown if screening computed tomography scan would lead to early detection of such malignancies or serious vascular anomalies post heart transplantation. This is a single center observational study of patients undergoing surveillance computed tomography of chest, abdomen and pelvis at least 5 years after transplantation. Abnormal findings, included pulmonary nodules, lymphadenopathy and intra-thoracic and intra-abdominal masses and vascular anomalies such as abdominal aortic aneurysm. The clinical follow up of each of these major abnormal findings is summarized. A total of 63 patients underwent computed tomography scan of chest, abdomen and pelvis at least 5 years after transplantation. Of these, 54 (86%) were male and 9 (14%) were female. Mean age was 52±9.2 years. Computed tomography revealed 1 lung cancer (squamous cell) only. Non specific pulmonary nodules were seen in 6 patients (9.5%). The most common incidental finding was abdominal aortic aneurysms (N=6 (9.5%)), which necessitated follow up computed tomography (N=5) or surgery (N=1). Mean time to detection of abdominal aortic aneurysms from transplantation was 14.6±4.2 years. Mean age at the time of detection of abdominal aortic aneurysms was 74.5±3.2 years. Screening computed tomography scan in patients 5 years from transplantation revealed only one malignancy but lead to increased detection of abdominal aortic aneurysms. Thus the utility is low in terms of detection of malignancy. Based on this study we do not recommend routine computed tomography post heart transplantation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A unifying framework for rigid multibody dynamics and serial and parallel computational issues

NASA Technical Reports Server (NTRS)

Fijany, Amir; Jain, Abhinandan

1989-01-01

A unifying framework for various formulations of the dynamics of open-chain rigid multibody systems is discussed. Their suitability for serial and parallel processing is assessed. The framework is based on the derivation of intrinsic, i.e., coordinate-free, equations of the algorithms which provides a suitable abstraction and permits a distinction to be made between the computational redundancy in the intrinsic and extrinsic equations. A set of spatial notation is used which allows the derivation of the various algorithms in a common setting and thus clarifies the relationships among them. The three classes of algorithms viz., O(n), O(n exp 2) and O(n exp 3) or the solution of the dynamics problem are investigated. Researchers begin with the derivation of O(n exp 3) algorithms based on the explicit computation of the mass matrix and it provides insight into the underlying basis of the O(n) algorithms. From a computational perspective, the optimal choice of a coordinate frame for the projection of the intrinsic equations is discussed and the serial computational complexity of the different algorithms is evaluated. The three classes of algorithms are also analyzed for suitability for parallel processing. It is shown that the problem belongs to the class of N C and the time and processor bounds are of O(log2/2(n)) and O(n exp 4), respectively. However, the algorithm that achieves the above bounds is not stable. Researchers show that the fastest stable parallel algorithm achieves a computational complexity of O(n) with O(n exp 4), respectively. However, the algorithm that achieves the above bounds is not stable. Researchers show that the fastest stable parallel algorithm achieves a computational complexity of O(n) with O(n exp 2) processors, and results from the parallelization of the O(n exp 3) serial algorithm.

Petamenophis (Padiamenemipet), an Egyptian Child Mummy Protected for Eternity: Revelation by Multidetector Computed Tomography.

PubMed

Martina, Maria Cristina; Cesarani, Federico; Boano, Rosa; Fiore Marochetti, Elisa; Gandini, Giovanni

The objective of our work was to report the most recent findings obtained with multidetector computed tomography of a child mummy from the Roman period (119-123 CE) housed at the Egyptian Museum in Turin, Italy. Multidetector computed tomography and postprocessing were applied to understand the embalming techniques, the nature of a foreign object, and anthropometrical values. The information was compared with that from other mummies that were buried in the same tomb, but today housed in different museums. New information regarding the embalming technique was revealed. Multidetector computed tomography allowed the identification of a knife-like metallic object, probably an amulet for the child's protection in the afterlife. Multidetector computed tomography and image postprocessing confirm their valuable role in noninvasive studies in ancient mummies and provided evidence of a unique cultural practice in the late history of Ancient Egypt such as placing a knife possibly as an amulet.

Diagnosis of sinusoidal obstruction syndrome by positron emission tomography/computed tomography: report of two cases treated by defibrotide.

PubMed

Gauthé, Mathieu; Bozec, Laurence; Bedossa, Pierre

2014-11-01

Sinusoidal obstruction syndrome (SOS) is a potentially fatal liver injury that mainly occurs after myeloablative chemotherapy. We report two cases of SOS investigated by 18F-fluorodeoxyglucose positron emission tomography/computed tomography and treated with defibrotide. © 2014 by the American Association for the Study of Liver Diseases.

Measuring Weld Profiles By Computer Tomography

NASA Technical Reports Server (NTRS)

Pascua, Antonio G.; Roy, Jagatjit

1990-01-01

Noncontacting, nondestructive computer tomography system determines internal and external contours of welded objects. System makes it unnecessary to take metallurgical sections (destructive technique) or to take silicone impressions of hidden surfaces (technique that contaminates) to inspect them. Measurements of contours via tomography performed 10 times as fast as measurements via impression molds, and tomography does not contaminate inspected parts.

Parallelizing serial code for a distributed processing environment with an application to high frequency electromagnetic scattering

NASA Astrophysics Data System (ADS)

Work, Paul R.

1991-12-01

This thesis investigates the parallelization of existing serial programs in computational electromagnetics for use in a parallel environment. Existing algorithms for calculating the radar cross section of an object are covered, and a ray-tracing code is chosen for implementation on a parallel machine. Current parallel architectures are introduced and a suitable parallel machine is selected for the implementation of the chosen ray-tracing algorithm. The standard techniques for the parallelization of serial codes are discussed, including load balancing and decomposition considerations, and appropriate methods for the parallelization effort are selected. A load balancing algorithm is modified to increase the efficiency of the application, and a high level design of the structure of the serial program is presented. A detailed design of the modifications for the parallel implementation is also included, with both the high level and the detailed design specified in a high level design language called UNITY. The correctness of the design is proven using UNITY and standard logic operations. The theoretical and empirical results show that it is possible to achieve an efficient parallel application for a serial computational electromagnetic program where the characteristics of the algorithm and the target architecture critically influence the development of such an implementation.

Parallel Computing for the Computed-Tomography Imaging Spectrometer

NASA Technical Reports Server (NTRS)

Lee, Seungwon

2008-01-01

This software computes the tomographic reconstruction of spatial-spectral data from raw detector images of the Computed-Tomography Imaging Spectrometer (CTIS), which enables transient-level, multi-spectral imaging by capturing spatial and spectral information in a single snapshot.

The Influence of Changes in Tumor Hypoxia on Dose-Painting Treatment Plans Based on {sup 18}F-FMISO Positron Emission Tomography

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

Lin Zhixiong; Mechalakos, James; Nehmeh, Sadek

2008-03-15

Purpose: To evaluate how changes in tumor hypoxia, according to serial fluorine-18-labeled fluoro-misonidazole ({sup 18}F-FMISO) positron emission tomography (PET) imaging, affect the efficacy of intensity-modulated radiotherapy (IMRT) dose painting. Methods and Materials: Seven patients with head and neck cancers were imaged twice with FMISO PET, separated by 3 days, before radiotherapy. Intensity-modulated radiotherapy plans were designed, on the basis of the first FMISO scan, to deliver a boost dose of 14 Gy to the hypoxic volume, in addition to the 70-Gy prescription dose. The same plans were then applied to hypoxic volumes from the second FMISO scan, and the efficacymore » of dose painting evaluated by assessing coverage of the hypoxic volumes using D{sub max}, D{sub min}, D{sub mean}, D{sub 95}, and equivalent uniform dose (EUD). Results: Similar hypoxic volumes were observed in the serial scans for 3 patients but dissimilar ones for the other 4. There was reduced coverage of hypoxic volumes of the second FMISO scan relative to that of the first scan (e.g., the average EUD decreased from 87 Gy to 80 Gy). The decrease was dependent on the similarity of the hypoxic volumes of the two scans (e.g., the average EUD decrease was approximately 4 Gy for patients with similar hypoxic volumes and approximately 12 Gy for patients with dissimilar ones). Conclusions: The changes in spatial distribution of tumor hypoxia, as detected in serial FMISO PET imaging, compromised the coverage of hypoxic tumor volumes achievable by dose-painting IMRT. However, dose painting always increased the EUD of the hypoxic volumes.« less

[The comparison of the expansion of polyps according to the Ki-67 and computed tomography scores].

PubMed

Aydin, Sedat; Sanli, Arif; Tezer, Ilter; Hardal, Umit; Barişik, Nagehan Ozdemir

2009-01-01

The disease extention in nasal polyps was compared by using the mitotic activity rates and the computed tomography scores. This study was conducted on 19 nasal polyposis patients (8 males, 11 females; mean age 40.0+/-13.7 years; range 20 to 63 years). The preoperative computed tomography records of the patients were evaluated according to the Lund-Mackay grading system. The polyp tissues of the same patients were stained with the Ki-67 antigen for immunohistochemical evaluation. The correlation between the radiologic results and the Ki-67 values was compared by means of the Spearman's correlation test. The mean computed tomography score was observed as 14.3+/-4.7 (range 7-24). The mean Ki-67 score resulting from the immunohistochemical staining was calculated as 24.3+/-18.5 (range 3.3-73.5%). A significant correlation was determined between the Ki-67 values and the computed tomography scores. ("Spearman's" correlation factor: 0.677; p<0.001). As the mitotic activity rate of nasal polyps increases, both the volume of the polyps and the computed tomography scores increase as a result of the blockage of the sinus ostiums by the increased polyp volume.

A Projection Quality-Driven Tube Current Modulation Method in Cone-Beam CT for IGRT: Proof of Concept.

PubMed

Men, Kuo; Dai, Jianrong

2017-12-01

To develop a projection quality-driven tube current modulation method in cone-beam computed tomography for image-guided radiotherapy based on the prior attenuation information obtained by the planning computed tomography and then evaluate its effect on a reduction in the imaging dose. The QCKV-1 phantom with different thicknesses (0-400 mm) of solid water upon it was used to simulate different attenuation (μ). Projections were acquired with a series of tube current-exposure time product (mAs) settings, and a 2-dimensional contrast to noise ratio was analyzed for each projection to create a lookup table of mAs versus 2-dimensional contrast to noise ratio, μ. Before a patient underwent computed tomography, the maximum attenuation [Formula: see text] within the 95% range of each projection angle (θ) was estimated according to the planning computed tomography images. Then, a desired 2-dimensional contrast to noise ratio value was selected, and the mAs setting at θ was calculated with the lookup table of mAs versus 2-dimensional contrast to noise ratio,[Formula: see text]. Three-dimensional cone-beam computed tomography images were reconstructed using the projections acquired with the selected mAs. The imaging dose was evaluated with a polymethyl methacrylate dosimetry phantom in terms of volume computed tomography dose index. Image quality was analyzed using a Catphan 503 phantom with an oval body annulus and a pelvis phantom. For the Catphan 503 phantom, the cone-beam computed tomography image obtained by the projection quality-driven tube current modulation method had a similar quality to that of conventional cone-beam computed tomography . However, the proposed method could reduce the imaging dose by 16% to 33% to achieve an equivalent contrast to noise ratio value. For the pelvis phantom, the structural similarity index was 0.992 with a dose reduction of 39.7% for the projection quality-driven tube current modulation method. The proposed method could reduce the additional dose to the patient while not degrading the image quality for cone-beam computed tomography. The projection quality-driven tube current modulation method could be especially beneficial to patients who undergo cone-beam computed tomography frequently during a treatment course.

Adapting the serial Alpgen parton-interaction generator to simulate LHC collisions on millions of parallel threads

NASA Astrophysics Data System (ADS)

Childers, J. T.; Uram, T. D.; LeCompte, T. J.; Papka, M. E.; Benjamin, D. P.

2017-01-01

As the LHC moves to higher energies and luminosity, the demand for computing resources increases accordingly and will soon outpace the growth of the Worldwide LHC Computing Grid. To meet this greater demand, event generation Monte Carlo was targeted for adaptation to run on Mira, the supercomputer at the Argonne Leadership Computing Facility. Alpgen is a Monte Carlo event generation application that is used by LHC experiments in the simulation of collisions that take place in the Large Hadron Collider. This paper details the process by which Alpgen was adapted from a single-processor serial-application to a large-scale parallel-application and the performance that was achieved.

Charles Darwin and the evolution of human grammatical systems.

PubMed

Buckingham, Hugh W; Christman, Sarah S

2010-04-08

Charles Darwin's evolutionary theories of animal communication were deeply embedded in a centuries-old model of association psychology, whose prodromes have most often been traced to the writings of Aristotle. His notions of frequency of occurrence of pairings have been passed down through the centuries and were a major ontological feature in the formation of associative connectivity. He focused on the associations of cause and effect, contiguity of sequential occurrence, and similarity among items. Cause and effect were often reduced to another type of contiguity relation, so that Aristotle is most often evoked as the originator of the associative bondings through similarity and contiguity, contiguity being the most powerful and frequent means of association. Contiguity eventually became the overriding mechanism for serial ordering of mental events in both perception and action. The notions of concatenation throughout the association psychology took the form of "trains" of events, both sensory and motor, in such a way that serial ordering came to be viewed as an item-by-item string of locally contiguous events. Modern developments in the mathematics of serial ordering have advanced in sophistication since the early and middle twentieth century, and new computational methods have allowed us to reevaluate the serial concatenative theories of Darwin and the associationists. These new models of serial order permit a closer comparative scrutiny between human and nonhuman. The present study considers Darwin's insistence on a "degree" continuity between human and nonhuman animal serial ordering. We will consider a study of starling birdsongs and whether the serial ordering of those songs provides evidence that they have a syntax that at best differs only in degree and not in kind with the computations of human grammatical structures. We will argue that they, in fact, show no such thing.

MPI_XSTAR: MPI-based Parallelization of the XSTAR Photoionization Program

NASA Astrophysics Data System (ADS)

Danehkar, Ashkbiz; Nowak, Michael A.; Lee, Julia C.; Smith, Randall K.

2018-02-01

We describe a program for the parallel implementation of multiple runs of XSTAR, a photoionization code that is used to predict the physical properties of an ionized gas from its emission and/or absorption lines. The parallelization program, called MPI_XSTAR, has been developed and implemented in the C++ language by using the Message Passing Interface (MPI) protocol, a conventional standard of parallel computing. We have benchmarked parallel multiprocessing executions of XSTAR, using MPI_XSTAR, against a serial execution of XSTAR, in terms of the parallelization speedup and the computing resource efficiency. Our experience indicates that the parallel execution runs significantly faster than the serial execution, however, the efficiency in terms of the computing resource usage decreases with increasing the number of processors used in the parallel computing.

Just Scan It!-Weapon Reconstruction in Computed Tomography on Historical and Current Swiss Military Guns.

PubMed

Franckenberg, Sabine; Binder, Thomas; Bolliger, Stephan; Thali, Michael J; Ross, Steffen G

2016-09-01

Cross-sectional imaging, such as computed tomography, has been increasingly implemented in both historic and recent postmortem forensic investigations. It aids in determining cause and manner of death as well as in correlating injuries to possible weapons. This study illuminates the feasibility of reconstructing guns in computed tomography and gives a distinct overview of historic and recent Swiss Army guns.

The use of computed tomography to diagnose chronic shoulder arthritis in an American white pelican (Pelecanus erythrorhynchos).

PubMed

Whitehead, Michelle C; Parker, Dennilyn L

2015-03-01

An American white pelican was presented with a complete left wing droop and no abnormal findings on conventional radiography. Computed tomography was used to diagnose chronic shoulder arthritis as a sequela to a suspected traumatic compressive fracture. This is the first case report to describe use of computed tomography to evaluate the avian shoulder joint.

Embracing Statistical Challenges in the Information Technology Age

DTIC Science & Technology

2006-01-01

computation and feature selection. Moreover, two research projects on network tomography and arctic cloud detection are used throughout the paper to bring...prominent Network Tomography problem, origin- destination (OD) traffic estimation. It demonstrates well how the two modes of data collection interact...software debugging (Biblit et al, 2005 [2]), and network tomography for computer network management. Computer sys- tem problems exist long before the IT

Computed Tomography For Internal Inspection Of Castings

NASA Technical Reports Server (NTRS)

Hanna, Timothy L.

1995-01-01

Computed tomography used to detect internal flaws in metal castings before machining and otherwise processing them into finished parts. Saves time and money otherwise wasted on machining and other processing of castings eventually rejected because of internal defects. Knowledge of internal defects gained by use of computed tomography also provides guidance for changes in foundry techniques, procedures, and equipment to minimize defects and reduce costs.

The Impact of Computed Tomography on Decision Making in Tibial Plateau Fractures.

PubMed

Castiglia, Marcello Teixeira; Nogueira-Barbosa, Marcello Henrique; Messias, Andre Marcio Vieira; Salim, Rodrigo; Fogagnolo, Fabricio; Schatzker, Joseph; Kfuri, Mauricio

2018-02-14

Schatzker introduced one of the most used classification systems for tibial plateau fractures, based on plain radiographs. Computed tomography brought to attention the importance of coronal plane-oriented fractures. The goal of our study was to determine if the addition of computed tomography would affect the decision making of surgeons who usually use the Schatzker classification to assess tibial plateau fractures. Image studies of 70 patients who sustained tibial plateau fractures were uploaded to a dedicated homepage. Every patient was linked to a folder which contained two radiographic projections (anteroposterior and lateral), three interactive videos of computed tomography (axial, sagittal, and coronal), and eight pictures depicting tridimensional reconstructions of the tibial plateau. Ten attending orthopaedic surgeons, who were blinded to the cases, were granted access to the homepage and assessed each set of images in two different rounds, separated to each other by an interval of 2 weeks. Each case was evaluated in three steps, where surgeons had access, respectively to radiographs, two-dimensional videos of computed tomography, and three-dimensional reconstruction images. After every step, surgeons were asked to present how would they classify the case using the Schatzker system and which surgical approaches would be appropriate. We evaluated the inter- and intraobserver reliability of the Schatzker classification using the Kappa concordance coefficient, as well as the impact of computed tomography in the decision making regarding the surgical approach for each case, by using the chi-square test and likelihood ratio. The interobserver concordance kappa coefficients after each assessment step were, respectively, 0.58, 0.62, and 0.64. For the intraobserver analysis, the coefficients were, respectively, 0.76, 0.75, and 0.78. Computed tomography changed the surgical approach selection for the types II, V, and VI of Schatzker ( p  < 0.01). The addition of computed tomography scans to plain radiographs improved the interobserver reliability of Schatzker classification. Computed tomography had a statistically significant impact in the selection of surgical approaches for the lateral tibial plateau. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Automated quantification of cerebral edema following hemispheric infarction: Application of a machine-learning algorithm to evaluate CSF shifts on serial head CTs.

PubMed

Chen, Yasheng; Dhar, Rajat; Heitsch, Laura; Ford, Andria; Fernandez-Cadenas, Israel; Carrera, Caty; Montaner, Joan; Lin, Weili; Shen, Dinggang; An, Hongyu; Lee, Jin-Moo

2016-01-01

Although cerebral edema is a major cause of death and deterioration following hemispheric stroke, there remains no validated biomarker that captures the full spectrum of this critical complication. We recently demonstrated that reduction in intracranial cerebrospinal fluid (CSF) volume (∆ CSF) on serial computed tomography (CT) scans provides an accurate measure of cerebral edema severity, which may aid in early triaging of stroke patients for craniectomy. However, application of such a volumetric approach would be too cumbersome to perform manually on serial scans in a real-world setting. We developed and validated an automated technique for CSF segmentation via integration of random forest (RF) based machine learning with geodesic active contour (GAC) segmentation. The proposed RF + GAC approach was compared to conventional Hounsfield Unit (HU) thresholding and RF segmentation methods using Dice similarity coefficient (DSC) and the correlation of volumetric measurements, with manual delineation serving as the ground truth. CSF spaces were outlined on scans performed at baseline (< 6 h after stroke onset) and early follow-up (FU) (closest to 24 h) in 38 acute ischemic stroke patients. RF performed significantly better than optimized HU thresholding (p < 10 - 4 in baseline and p < 10 - 5 in FU) and RF + GAC performed significantly better than RF (p < 10 - 3 in baseline and p < 10 - 5 in FU). Pearson correlation coefficients between the automatically detected ∆ CSF and the ground truth were r  = 0.178 (p = 0.285), r  = 0.876 (p < 10 - 6 ) and r  = 0.879 (p < 10 - 6 ) for thresholding, RF and RF + GAC, respectively, with a slope closer to the line of identity in RF + GAC. When we applied the algorithm trained from images of one stroke center to segment CTs from another center, similar findings held. In conclusion, we have developed and validated an accurate automated approach to segment CSF and calculate its shifts on serial CT scans. This algorithm will allow us to efficiently and accurately measure the evolution of cerebral edema in future studies including large multi-site patient populations.

Limitations of PET/CT in the Detection of Occult N1 Metastasis in Clinical Stage I(T1-2aN0) Non-Small Cell Lung Cancer for Staging Prior to Stereotactic Body Radiotherapy.

PubMed

Akthar, Adil S; Ferguson, Mark K; Koshy, Matthew; Vigneswaran, Wickii T; Malik, Renuka

2017-02-01

Patients receiving stereotactic body radiotherapy for stage I non-small cell lung cancer are typically staged clinically with positron emission tomography-computed tomography. Currently, limited data exist for the detection of occult hilar/peribronchial (N1) disease. We hypothesize that positron emission tomography-computed tomography underestimates spread of cancer to N1 lymph nodes and that future stereotactic body radiotherapy patients may benefit from increased pathologic evaluation of N1 nodal stations in addition to N2 nodes. A retrospective study was performed of all patients with clinical stage I (T1-2aN0) non-small cell lung cancer (American Joint Committee on Cancer, 7th edition) by positron emission tomography-computed tomography at our institution from 2003 to 2011, with subsequent surgical resection and lymph node staging. Findings on positron emission tomography-computed tomography were compared to pathologic nodal involvement to determine the negative predictive value of positron emission tomography-computed tomography for the detection of N1 nodal disease. An analysis was conducted to identify predictors of occult spread. A total of 105 patients with clinical stage I non-small cell lung cancer were included in this study, of which 8 (7.6%) patients were found to have occult N1 metastasis on pathologic review yielding a negative predictive value for N1 disease of 92.4%. No patients had occult mediastinal nodes. The negative predictive value for positron emission tomography-computed tomography in patients with clinical stage T1 versus T2 tumors was 72 (96%) of 75 versus 25 (83%) of 30, respectively ( P = .03), and for peripheral versus central tumor location was 77 (98%) of 78 versus 20 (74%) of 27, respectively ( P = .0001). The negative predictive values for peripheral T1 and T2 tumors were 98% and 100%, respectively; while for central T1 and T2 tumors, the rates were 85% and 64%, respectively. Occult lymph node involvement was not associated with primary tumor maximum standard uptake value, histology, grade, or interval between positron emission tomography-computed tomography and surgery. Our results support pathologic assessment of N1 lymph nodes in patients with stage Inon-small cell lung cancer considered for stereotactic body radiotherapy, with the greatest benefit in patients with central and T2 tumors. Diagnostic evaluation with endoscopic bronchial ultrasound should be considered in the evaluation of stereotactic body radiotherapy candidates.

Postmortem whole-body computed tomography angiography visualizing vascular rupture in a case of fatal car crash.

PubMed

Flach, Patricia M; Ross, Steffen G; Bolliger, Stephan A; Preiss, Ulrich S; Thali, Michael J; Spendlove, Danny

2010-01-01

In addition to the increasingly significant role of multislice computed tomography in forensic pathology, the performance of whole-body computed tomography angiography provides outstanding results. In this case, we were able to detect multiple injuries of the parenchymal organs in the upper abdomen as well as lesions of the brain parenchyma and vasculature of the neck. The radiologic findings showed complete concordance with the autopsy and even supplemented the autopsy findings in areas that are difficult to access via a manual dissection (such as the vasculature of the neck). This case shows how minimally invasive computed tomography angiography can serve as an invaluable adjunct to the classic autopsy procedure.

Computed tomography in the evaluation of Crohn disease

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

Goldberg, H.I.; Gore, R.M.; Margulis, A.R.

1983-02-01

The abdominal and pelvic computed tomographic examinations in 28 patients with Crohn disease were analyzed and correlated with conventional barium studies, sinograms, and surgical findings. Mucosal abnormalities such as aphthous lesions, pseudopolyps, and ulcerations were only imaged by conventional techniques. Computed tomography proved superior in demonstrating the mural, serosal, and mesenteric abnormalities such as bowel wall thickening (82%), fibrofatty proliferation of mesenteric fat (39%), mesenteric abscess (25%), inflammatory reaction of the mesentery (14%), and mesenteric lymphadenopathy (18%). Computed tomography was most useful clinically in defining the nature of mass effects, separation, or displacement of small bowel segments seen on smallmore » bowel series. Although conventional barium studies remain the initial diagnostic procedure in evaluating Crohn disease, computed tomography can be a useful adjunct in resolving difficult clinical and radiologic diagnostic problems.« less

The efficacy of preoperative positron emission tomography-computed tomography (PET-CT) for detection of lymph node metastasis in cervical and endometrial cancer: clinical and pathological factors influencing it.

PubMed

Nogami, Yuya; Banno, Kouji; Irie, Haruko; Iida, Miho; Kisu, Iori; Masugi, Yohei; Tanaka, Kyoko; Tominaga, Eiichiro; Okuda, Shigeo; Murakami, Koji; Aoki, Daisuke

2015-01-01

We studied the diagnostic performance of (18)F-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography in cervical and endometrial cancers with particular focus on lymph node metastases. Seventy patients with cervical cancer and 53 with endometrial cancer were imaged with (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography before lymphadenectomy. We evaluated the diagnostic performance of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography using the final pathological diagnoses as the golden standard. We calculated the sensitivity, specificity, positive predictive value and negative predictive value of (18)F-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography. In cervical cancer, the results evaluated by cases were 33.3, 92.7, 55.6 and 83.6%, respectively. When evaluated by the area of lymph nodes, the results were 30.6, 98.9, 55.0 and 97.0%, respectively. As for endometrial cancer, the results evaluated by cases were 50.0, 93.9, 40.0 and 95.8%, and by area of lymph nodes, 45.0, 99.4, 64.3 and 98.5%, respectively. The limitation of the efficacy was found out by analyzing it by the region of the lymph node, the size of metastatic node, the historical type of tumor in cervical cancer and the prevalence of lymph node metastasis. The efficacy of positron emission tomography/computed tomography regarding the detection of lymph node metastasis in cervical and endometrial cancer is not established and has limitations associated with the region of the lymph node, the size of metastasis lesion in lymph node and the pathological type of primary tumor. The indication for the imaging and the interpretation of the results requires consideration for each case by the pretest probability based on the information obtained preoperatively. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diagnostic ability of computed tomography using DentaScan software in endodontics: case reports.

PubMed

Siotia, Jaya; Gupta, Sunil K; Acharya, Shashi R; Saraswathi, Vidya

2011-01-01

Radiographic examination is essential in diagnosis and treatment planning in endodontics. Conventional radiographs depict structures in two dimensions only. The ability to assess the area of interest in three dimensions is advantageous. Computed tomography is an imaging technique which produces three-dimensional images of an object by taking a series of two-dimensional sectional X-ray images. DentaScan is a computed tomography software program that allows the mandible and maxilla to be imaged in three planes: axial, panoramic, and cross-sectional. As computed tomography is used in endodontics, DentaScan can play a wider role in endodontic diagnosis. It provides valuable information in the assessment of the morphology of the root canal, diagnosis of root fractures, internal and external resorptions, pre-operative assessment of anatomic structures etc. The aim of this article is to explore the clinical usefulness of computed tomography and DentaScan in endodontic diagnosis, through a series of four cases of different endodontic problems.

Recent Scientific Evidence and Technical Developments in Cardiovascular Computed Tomography.

PubMed

Marcus, Roy; Ruff, Christer; Burgstahler, Christof; Notohamiprodjo, Mike; Nikolaou, Konstantin; Geisler, Tobias; Schroeder, Stephen; Bamberg, Fabian

2016-05-01

In recent years, coronary computed tomography angiography has become an increasingly safe and noninvasive modality for the evaluation of the anatomical structure of the coronary artery tree with diagnostic benefits especially in patients with a low-to-intermediate pretest probability of disease. Currently, increasing evidence from large randomized diagnostic trials is accumulating on the diagnostic impact of computed tomography angiography for the management of patients with acute and stable chest pain syndrome. At the same time, technical advances have substantially reduced adverse effects and limiting factors, such as radiation exposure, the amount of iodinated contrast agent, and scanning time, rendering the technique appropriate for broader clinical applications. In this work, we review the latest developments in computed tomography technology and describe the scientific evidence on the use of cardiac computed tomography angiography to evaluate patients with acute and stable chest pain syndrome. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

[Computer Assisted Instruction.

ERIC Educational Resources Information Center

Broderick, Bill; And Others

1987-01-01

These two serial issues are devoted to the impact of computers on education, and specifically their effects on developmental education programs. First "The Effects of Computer-Based Instruction" summarizes the literature on the impact of computer-based instruction, including a study by James and Chen-Lin Kulik and Peter Cohen, which found that:…

Dental application of novel finite element analysis software for three-dimensional finite element modeling of a dentulous mandible from its computed tomography images.

PubMed

Nakamura, Keiko; Tajima, Kiyoshi; Chen, Ker-Kong; Nagamatsu, Yuki; Kakigawa, Hiroshi; Masumi, Shin-ich

2013-12-01

This study focused on the application of novel finite-element analysis software for constructing a finite-element model from the computed tomography data of a human dentulous mandible. The finite-element model is necessary for evaluating the mechanical response of the alveolar part of the mandible, resulting from occlusal force applied to the teeth during biting. Commercially available patient-specific general computed tomography-based finite-element analysis software was solely applied to the finite-element analysis for the extraction of computed tomography data. The mandibular bone with teeth was extracted from the original images. Both the enamel and the dentin were extracted after image processing, and the periodontal ligament was created from the segmented dentin. The constructed finite-element model was reasonably accurate using a total of 234,644 nodes and 1,268,784 tetrahedral and 40,665 shell elements. The elastic moduli of the heterogeneous mandibular bone were determined from the bone density data of the computed tomography images. The results suggested that the software applied in this study is both useful and powerful for creating a more accurate three-dimensional finite-element model of a dentulous mandible from the computed tomography data without the need for any other software.

Evaluation of the diagnostic yield of dental radiography and cone-beam computed tomography for the identification of anatomic landmarks in small to medium-sized brachycephalic dogs.

PubMed

Döring, Sophie; Arzi, Boaz; Barich, Catherine R; Hatcher, David C; Kass, Philip H; Verstraete, Frank J M

2018-01-01

OBJECTIVE To evaluate the diagnostic yield of dental radiography (Rad method) and 3 cone-beam CT (CBCT) methods for the identification of predefined anatomic landmarks in brachycephalic dogs. ANIMALS 19 client-owned brachycephalic dogs admitted for evaluation and treatment of dental disease. PROCEDURES 26 predefined anatomic landmarks were evaluated separately by use of the RAD method and 3 CBCT software modules (serial CBCT slices and custom cross sections, tridimensional rendering, and reconstructed panoramic views). A semiquantitative scoring system was used, and mean scores were calculated for each anatomic landmark and imaging method. The Friedman test was used to evaluate values for significant differences in diagnostic yield. For values that were significant, the Wilcoxon signed rank test was used with the Bonferroni-Holm multiple comparison adjustment to determine significant differences among each of the 6 possible pairs of diagnostic methods. RESULTS Differences of diagnostic yield among the Rad and 3 CBCT methods were significant for 19 of 26 anatomic landmarks. For these landmarks, Rad scores were significantly higher than scores for reconstructed panoramic views for 4 of 19 anatomic landmarks, but Rad scores were significantly lower than scores for reconstructed panoramic views for 8 anatomic landmarks, tridimensional rendering for 18 anatomic landmarks, and serial CBCT slices and custom cross sections for all 19 anatomic landmarks. CONCLUSIONS AND CLINICAL RELEVANCE CBCT methods were better suited than dental radiography for the identification of anatomic landmarks in brachycephalic dogs. Results of this study can serve as a basis for CBCT evaluation of dental disorders in brachycephalic dogs.

Rib Radiography versus Chest Computed Tomography in the Diagnosis of Rib Fractures.

PubMed

Sano, Atsushi

2018-05-01

 The accurate diagnosis of rib fractures is important in chest trauma. Diagnostic images following chest trauma are usually obtained via chest X-ray, chest computed tomography, or rib radiography. This study evaluated the diagnostic characteristics of rib radiography and chest computed tomography.  Seventy-five rib fracture patients who underwent both chest computed tomography and rib radiography between April 2008 and December 2013 were included. Rib radiographs, centered on the site of pain, were taken from two directions. Chest computed tomography was performed using a 16-row multidetector scanner with 5-mm slice-pitch without overlap, and axial images were visualized in a bone window.  In total, 217 rib fractures were diagnosed in 75 patients. Rib radiography missed 43 rib fractures in 24 patients. The causes were overlap with organs in 15 cases, trivial fractures in 21 cases, and injury outside the imaging range in 7 cases. Left lower rib fractures were often missed due to overlap with the heart, while middle and lower rib fractures were frequently not diagnosed due to overlap with abdominal organs. Computed tomography missed 21 rib fractures in 17 patients. The causes were horizontal fractures in 10 cases, trivial fractures in 9 cases, and insufficient breath holding in 1 case.  In rib radiography, overlap with organs and fractures outside the imaging range were characteristic reasons for missed diagnoses. In chest computed tomography, horizontal rib fractures and insufficient breath holding were often responsible. We should take these challenges into account when diagnosing rib fractures. Georg Thieme Verlag KG Stuttgart · New York.

64 slice-coronary computed tomography sensitivity and specificity in the evaluation of coronary artery bypass graft stenosis: A meta-analysis.

PubMed

Barbero, Umberto; Iannaccone, Mario; d'Ascenzo, Fabrizio; Barbero, Cristina; Mohamed, Abdirashid; Annone, Umberto; Benedetto, Sara; Celentani, Dario; Gagliardi, Marco; Moretti, Claudio; Gaita, Fiorenzo

2016-08-01

A non-invasive approach to define grafts patency and stenosis in the follow-up of coronary artery bypass graft (CABG) patients may be an interesting alternative to coronary angiography. 64-slice-coronary computed tomography is nowadays a diffused non-invasive method that permits an accurate evaluation of coronary stenosis, due to a high temporal and spatial resolution. However, its sensitivity and specificity in CABG evaluation has to be clearly defined, since published studies used different protocols and scanners. We collected all studies investigating patients with stable symptoms and previous CABG and reporting the comparison between diagnostic performances of invasive coronary angiography and 64-slice-coronary computed tomography. As a result, sensitivity and specificity of 64-slice-coronary computed tomography for CABG occlusion were 0.99 (95% CI 0.97-1.00) and 0.99 (95% CI: 0.99-1.00) with an area under the curve (AUC) of 0.99. 64-slice-coronary computed tomography sensitivity and specificity for the presence of any CABG stenosis >50% were 0.98 (95% CI: 0.97-0.99) and 0.98 (95% CI: 0.96-0.98), while AUC was 0.99. At meta-regression, neither the age nor the time from graft implantation had effect on sensitivity and specificity of 64-slice-coronary computed tomography detection of significant CABG stenosis or occlusion. In conclusion 64-slice-coronary computed tomography confirmed its high sensitivity and specificity in CABG stenosis or occlusion evaluation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Quadruple Axis Neutron Computed Tomography

NASA Astrophysics Data System (ADS)

Schillinger, Burkhard; Bausenwein, Dominik

Neutron computed tomography takes more time for a full tomography than X-rays or Synchrotron radiation, because the source intensity is limited. Most neutron imaging detectors have a square field of view, so if tomography of elongated, narrow samples, e.g. fuel rods, sword blades is recorded, much of the detector area is wasted. Using multiple rotation axes, several samples can be placed inside the field of view, and multiple tomographies can be recorded at the same time by later splitting the recorded images into separate tomography data sets. We describe a new multiple-axis setup using four independent miniaturized rotation tables.

REMOTE: Modem Communicator Program for the IBM personal computer

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

McGirt, F.

1984-06-01

REMOTE, a Modem Communicator Program, was developed to provide full duplex serial communication with arbitrary remote computers via either dial-up telephone modems or direct lines. The latest version of REMOTE (documented in this report) was developed for the IBM Personal Computer.

Fast Grasp Contact Computation for a Serial Robot

NASA Technical Reports Server (NTRS)

Hargrave, Brian (Inventor); Shi, Jianying (Inventor); Diftler, Myron A. (Inventor)

2015-01-01

A system includes a controller and a serial robot having links that are interconnected by a joint, wherein the robot can grasp a three-dimensional (3D) object in response to a commanded grasp pose. The controller receives input information, including the commanded grasp pose, a first set of information describing the kinematics of the robot, and a second set of information describing the position of the object to be grasped. The controller also calculates, in a two-dimensional (2D) plane, a set of contact points between the serial robot and a surface of the 3D object needed for the serial robot to achieve the commanded grasp pose. A required joint angle is then calculated in the 2D plane between the pair of links using the set of contact points. A control action is then executed with respect to the motion of the serial robot using the required joint angle.

SSCC TD: A Serial and Simultaneous Configural-Cue Compound Stimuli Representation for Temporal Difference Learning

PubMed Central

Mondragón, Esther; Gray, Jonathan; Alonso, Eduardo; Bonardi, Charlotte; Jennings, Dómhnall J.

2014-01-01

This paper presents a novel representational framework for the Temporal Difference (TD) model of learning, which allows the computation of configural stimuli – cumulative compounds of stimuli that generate perceptual emergents known as configural cues. This Simultaneous and Serial Configural-cue Compound Stimuli Temporal Difference model (SSCC TD) can model both simultaneous and serial stimulus compounds, as well as compounds including the experimental context. This modification significantly broadens the range of phenomena which the TD paradigm can explain, and allows it to predict phenomena which traditional TD solutions cannot, particularly effects that depend on compound stimuli functioning as a whole, such as pattern learning and serial structural discriminations, and context-related effects. PMID:25054799

Impact of Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and Positron Emission Tomography/Computed Tomography (PET/CT) in the Diagnosis of Traumatic Brain Injury (TBI): Case Report.

PubMed

Molina-Vicenty, Irma L; Santiago-Sánchez, Michelaldemar; Vélez-Miró, Iván; Motta-Valencia, Keryl

2016-09-01

Traumatic brain injury (TBI) is defined as damage to the brain resulting from an external force. TBI, a global leading cause of death and disability, is associated with serious social, economic, and health problems. In cases of mild-to-moderate brain damage, conventional anatomical imaging modalities may or may not detect the cascade of metabolic changes that have occurred or are occurring at the intracellular level. Functional nuclear medicine imaging and neurophysiological parameters can be used to characterize brain damage, as the former provides direct visualization of brain function, even in the absence of overt behavioral manifestations or anatomical findings. We report the case of a 30-year-old Hispanic male veteran who, after 2 traumatic brain injury events, developed cognitive and neuropsychological problems with no clear etiology in the presence of negative computed tomography (CT) findings.

Using Histories to Implement Atomic Objects

NASA Technical Reports Server (NTRS)

Ng, Pui

1987-01-01

In this paper we describe an approach of implementing atomicity. Atomicity requires that computations appear to be all-or-nothing and executed in a serialization order. The approach we describe has three characteristics. First, it utilizes the semantics of an application to improve concurrency. Second, it reduces the complexity of application-dependent synchronization code by analyzing the process of writing it. In fact, the process can be automated with logic programming. Third, our approach hides the protocol used to arrive at a serialization order from the applications. As a result, different protocols can be used without affecting the applications. Our approach uses a history tree abstraction. The history tree captures the ordering relationship among concurrent computations. By determining what types of computations exist in the history tree and their parameters, a computation can determine whether it can proceed.

Predicting severe hematologic toxicity from extended-field chemoradiation of para-aortic nodal metastases from cervical cancer.

PubMed

Yan, Kevin; Ramirez, Ezequiel; Xie, Xian-Jin; Gu, Xuejun; Xi, Yin; Albuquerque, Kevin

The purpose of this study was to determine factors predictive for severe hematologic toxicity (HT) in cervical cancer patients with para-aortic lymph node metastasis treated with concurrent cisplatin chemoradiation to an extended field (EFCRT). Thirty-eight patients with cervical cancer and para-aortic lymph node metastasis who underwent EFCRT were analyzed. Active bone marrow was defined as the region within irradiated total bone marrow (BM TOT ) with a standard uptake value on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography greater than the mean standard uptake value for BM TOT . Serial weekly blood counts from the beginning to the end of radiation treatment were evaluated for HT using Common Terminology Criteria for Adverse Events, version 4.0. Nineteen patients had grade 3 or higher hematologic toxicity (HT3+), not including lymphocyte toxicity. Obese patients (n = 12) were less likely to get HT3+ (P = .03) despite getting equivalent doses of chemotherapy. Volumes of BM TOT and active bone marrow receiving doses of 20, 30, and 45 Gy and body mass index significantly predicted HT3+. Patients who had HT3+ had prolonged treatment time (62 vs 53 days, P < .001). For patients receiving EFCRT, bone marrow irradiation parameters and patient body mass index were associated with HT3+. A simplified nomogram has been created to predict HT3+ in these patients, allowing the potential to explore bone marrow-sparing delivery techniques. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Adapting the serial Alpgen parton-interaction generator to simulate LHC collisions on millions of parallel threads

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

Childers, J. T.; Uram, T. D.; LeCompte, T. J.

As the LHC moves to higher energies and luminosity, the demand for computing resources increases accordingly and will soon outpace the growth of the World- wide LHC Computing Grid. To meet this greater demand, event generation Monte Carlo was targeted for adaptation to run on Mira, the supercomputer at the Argonne Leadership Computing Facility. Alpgen is a Monte Carlo event generation application that is used by LHC experiments in the simulation of collisions that take place in the Large Hadron Collider. This paper details the process by which Alpgen was adapted from a single-processor serial-application to a large-scale parallel-application andmore » the performance that was achieved.« less

Adapting the serial Alpgen parton-interaction generator to simulate LHC collisions on millions of parallel threads

DOE PAGES

Childers, J. T.; Uram, T. D.; LeCompte, T. J.; ...

2016-09-29

As the LHC moves to higher energies and luminosity, the demand for computing resources increases accordingly and will soon outpace the growth of the Worldwide LHC Computing Grid. To meet this greater demand, event generation Monte Carlo was targeted for adaptation to run on Mira, the supercomputer at the Argonne Leadership Computing Facility. Alpgen is a Monte Carlo event generation application that is used by LHC experiments in the simulation of collisions that take place in the Large Hadron Collider. Finally, this paper details the process by which Alpgen was adapted from a single-processor serial-application to a large-scale parallel-application andmore » the performance that was achieved.« less

Adapting the serial Alpgen parton-interaction generator to simulate LHC collisions on millions of parallel threads

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

Childers, J. T.; Uram, T. D.; LeCompte, T. J.

As the LHC moves to higher energies and luminosity, the demand for computing resources increases accordingly and will soon outpace the growth of the Worldwide LHC Computing Grid. To meet this greater demand, event generation Monte Carlo was targeted for adaptation to run on Mira, the supercomputer at the Argonne Leadership Computing Facility. Alpgen is a Monte Carlo event generation application that is used by LHC experiments in the simulation of collisions that take place in the Large Hadron Collider. Finally, this paper details the process by which Alpgen was adapted from a single-processor serial-application to a large-scale parallel-application andmore » the performance that was achieved.« less

Imaging mouse cerebellum with serial optical coherence scanner (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Chao J.; Williams, Kristen; Orr, Harry; Taner, Akkin

2017-02-01

We present the serial optical coherence scanner (SOCS), which consists of a polarization sensitive optical coherence tomography and a vibratome with associated controls for serial imaging, to visualize the cerebellum and adjacent brainstem of mouse. The cerebellar cortical layers and white matter are distinguished by using intrinsic optical contrasts. Images from serial scans reveal the large-scale anatomy in detail and map the nerve fiber pathways in the cerebellum and adjacent brainstem. The optical system, which has 5.5 μm axial resolution, utilizes a scan lens or a water-immersion microscope objective resulting in 10 μm or 4 μm lateral resolution, respectively. The large-scale brain imaging at high resolution requires an efficient way to collect large datasets. It is important to improve the SOCS system to deal with large-scale and large number of samples in a reasonable time. The imaging and slicing procedure for a section took about 4 minutes due to a low speed of the vibratome blade to maintain slicing quality. SOCS has potential to investigate pathological changes and monitor the effects of therapeutic drugs in cerebellar diseases such as spinocerebellar ataxia 1 (SCA1). The SCA1 is a neurodegenerative disease characterized by atrophy and eventual loss of Purkinje cells from the cerebellar cortex, and the optical contrasts provided by SOCS is being evaluated for biomarkers of the disease.

Segmented swept source optical coherence tomography angiography assessment of the perifoveal vasculature in patients with X-linked juvenile retinoschisis: a serial case report.

PubMed

Stringa, Francesco; Tsamis, Emmanouli; Papayannis, Alessandro; Chwiejczak, Katarzyna; Jalil, Assad; Biswas, Susmito; Ahmad, Hassan; Stanga, Paulo Eduardo

2017-01-01

To describe perifoveal microvascular changes occurring in X-linked juvenile retinoschisis (XLRS) using swept source optical coherence tomography angiography (SS OCTA). This is a serial case report of three patients. Retrospective data of patients affected by XLRS were collected. Structural optical coherence tomography (OCT) and color fundus photography (CFPh) were carried out with Topcon ® OCT 2000 3D OCT as part of the standard care. Two patients were imaged on Topcon Atlantis ® SS OCTA and one on Topcon Triton ® SS OCTA. SS OCTA images were acquired using the 3 × 3 mm fovea-centered cubes scanning protocol. Analysis of both perifoveal superficial vascular plexus (pSVP) and perifoveal deep vascular plexus (pDVP) was performed by two observers after automated segmentation. Four eyes of three males (mean age 14 ± 3.8 years) were analyzed. All eyes showed foveoschisis on CFPh images. OCT B-scans of three eyes showed schistic cysts in the ganglion cell layer, inner nuclear layer (INL) and outer nuclear layer (ONL); in one eye, cysts were depicted in INL and ONL only. In two eyes, SS OCTA showed abnormal foveal avascular zone (FAZ) shape in the pSVP, and in the other two, FAZ shape was abnormal in both plexuses. In all eyes, retinal vascular abnormalities (ie, microvascular protrusions) were present in pDVP. SS OCTA can depict perifoveal microvascular changes in young patients affected by XLRS. In this study, the structural and vascular changes seem to be more evident in the pDVP and may represent a useful biomarker of prognosis.

Advanced Computed-Tomography Inspection System

NASA Technical Reports Server (NTRS)

Harris, Lowell D.; Gupta, Nand K.; Smith, Charles R.; Bernardi, Richard T.; Moore, John F.; Hediger, Lisa

1993-01-01

Advanced Computed Tomography Inspection System (ACTIS) is computed-tomography x-ray apparatus revealing internal structures of objects in wide range of sizes and materials. Three x-ray sources and adjustable scan geometry gives system unprecedented versatility. Gantry contains translation and rotation mechanisms scanning x-ray beam through object inspected. Distance between source and detector towers varied to suit object. System used in such diverse applications as development of new materials, refinement of manufacturing processes, and inspection of components.

Usefulness of Tc99m-mebrofenin Hepatobiliary Scintigraphy and Single Photon Emission Computed Tomography/Computed Tomography in the Diagnosis of Bronchobiliary Fistula.

PubMed

Parghane, Rahul Vithalrao; Phulsunga, Rohit Kumar; Gupta, Rajesh; Basher, Rajender Kumar; Bhattacharya, Anish; Mittal, Bhagwant Rai

2017-01-01

Bronchobiliary fistula (BBF), a rare complication of liver disease, is an abnormal communication between the biliary tract and bronchial tree. BBF may occur as a consequence of local liver infections such as hydatid or amebic disease, pyogenic liver abscess or trauma to the liver, obstruction of biliary tract, and tumor. As such management of liver disease with BBF is very difficult and often associated with a high rate of morbidity and mortality. Therefore, timely diagnosis of BBF is imperative. Hepatobiliary scintigraphy along with hybrid single photon emission computed tomography/computed tomography using Tc99m-mebrofenin is a very useful noninvasive imaging modality, in the diagnosis of BBF.

Usefulness of Tc99m-mebrofenin Hepatobiliary Scintigraphy and Single Photon Emission Computed Tomography/Computed Tomography in the Diagnosis of Bronchobiliary Fistula

PubMed Central

Parghane, Rahul Vithalrao; Phulsunga, Rohit Kumar; Gupta, Rajesh; Basher, Rajender Kumar; Bhattacharya, Anish; Mittal, Bhagwant Rai

2017-01-01

Bronchobiliary fistula (BBF), a rare complication of liver disease, is an abnormal communication between the biliary tract and bronchial tree. BBF may occur as a consequence of local liver infections such as hydatid or amebic disease, pyogenic liver abscess or trauma to the liver, obstruction of biliary tract, and tumor. As such management of liver disease with BBF is very difficult and often associated with a high rate of morbidity and mortality. Therefore, timely diagnosis of BBF is imperative. Hepatobiliary scintigraphy along with hybrid single photon emission computed tomography/computed tomography using Tc99m-mebrofenin is a very useful noninvasive imaging modality, in the diagnosis of BBF. PMID:29033682

Weightbearing Computed Tomography of the Foot and Ankle: Emerging Technology Topical Review.

PubMed

Barg, Alexej; Bailey, Travis; Richter, Martinus; de Cesar Netto, Cesar; Lintz, François; Burssens, Arne; Phisitkul, Phinit; Hanrahan, Christopher J; Saltzman, Charles L

2018-03-01

In the last decade, cone-beam computed tomography technology with improved designs allowing flexible gantry movements has allowed both supine and standing weight-bearing imaging of the lower extremity. There is an increasing amount of literature describing the use of weightbearing computed tomography in patients with foot and ankle disorders. To date, there is no review article summarizing this imaging modality in the foot and ankle. Therefore, we performed a systematic literature review of relevant clinical studies targeting the use of weightbearing computed tomography in diagnosis of patients with foot and ankle disorders. Furthermore, this review aims to offer insight to those with interest in considering possible future research opportunities with use of this technology. Level V, expert opinion.

Universal Linear Motor Driven Leg Press Dynamometer and Concept of Serial Stretch Loading.

PubMed

Hamar, Dušan

2015-08-24

Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase) or acceleration (in eccentric phase). Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients.

Evaluating the risk of appendiceal perforation when using ultrasound as the initial diagnostic imaging modality in children with suspected appendicitis.

PubMed

Alerhand, Stephen; Meltzer, James; Tay, Ee Tein

2017-08-01

Ultrasound scan has gained attention for diagnosing appendicitis due to its avoidance of ionizing radiation. However, studies show that ultrasound scan carries inferior sensitivity to computed tomography scan. A non-diagnostic ultrasound scan could increase the time to diagnosis and appendicectomy, particularly if follow-up computed tomography scan is needed. Some studies suggest that delaying appendicectomy increases the risk of perforation. To investigate the risk of appendiceal perforation when using ultrasound scan as the initial diagnostic imaging modality in children with suspected appendicitis. We retrospectively reviewed 1411 charts of children ≤17 years old diagnosed with appendicitis at two urban academic medical centers. Patients who underwent ultrasound scan first were compared to those who underwent computed tomography scan first. In the sub-group analysis, patients who only received ultrasound scan were compared to those who received initial ultrasound scan followed by computed tomography scan. Main outcome measures were appendiceal perforation rate and time from triage to appendicectomy. In 720 children eligible for analysis, there was no significant difference in perforation rate between those who had initial ultrasound scan and those who had initial computed tomography scan (7.3% vs. 8.9%, p = 0.44), nor in those who had ultrasound scan only and those who had initial ultrasound scan followed by computed tomography scan (8.0% vs. 5.6%, p = 0.42). Those patients who had ultrasound scan first had a shorter triage-to-incision time than those who had computed tomography scan first (9.2 (IQR: 5.9, 14.0) vs. 10.2 (IQR: 7.3, 14.3) hours, p = 0.03), whereas those who had ultrasound scan followed by computed tomography scan took longer than those who had ultrasound scan only (7.8 (IQR: 5.3, 11.6) vs. 15.1 (IQR: 10.6, 20.6), p < 0.001). Children < 12 years old receiving ultrasound scan first had lower perforation rate (p = 0.01) and shorter triage-to-incision time (p = 0.003). Children with suspected appendicitis receiving ultrasound scan as the initial diagnostic imaging modality do not have increased risk of perforation compared to those receiving computed tomography scan first. We recommend that children <12 years of age receive ultrasound scan first.

Formalization, equivalence and generalization of basic resonance electrical circuits

NASA Astrophysics Data System (ADS)

Penev, Dimitar; Arnaudov, Dimitar; Hinov, Nikolay

2017-12-01

In the work are presented basic resonance circuits, which are used in resonance energy converters. The following resonant circuits are considered: serial, serial with parallel load parallel capacitor, parallel and parallel with serial loaded inductance. For the circuits under consideration, expressions are generated for the frequencies of own oscillations and for the equivalence of the active power emitted in the load. Mathematical expressions are graphically constructed and verified using computer simulations. The results obtained are used in the model based design of resonant energy converters with DC or AC output. This guaranteed the output indicators of power electronic devices.

Neural networks for calibration tomography

NASA Technical Reports Server (NTRS)

Decker, Arthur

1993-01-01

Artificial neural networks are suitable for performing pattern-to-pattern calibrations. These calibrations are potentially useful for facilities operations in aeronautics, the control of optical alignment, and the like. Computed tomography is compared with neural net calibration tomography for estimating density from its x-ray transform. X-ray transforms are measured, for example, in diffuse-illumination, holographic interferometry of fluids. Computed tomography and neural net calibration tomography are shown to have comparable performance for a 10 degree viewing cone and 29 interferograms within that cone. The system of tomography discussed is proposed as a relevant test of neural networks and other parallel processors intended for using flow visualization data.

Use of cone beam computed tomography in implant dentistry: current concepts, indications and limitations for clinical practice and research.

PubMed

Bornstein, Michael M; Horner, Keith; Jacobs, Reinhilde

2017-02-01

Diagnostic radiology is an essential component of treatment planning in the field of implant dentistry. This narrative review will present current concepts for the use of cone beam computed tomography imaging, before and after implant placement, in daily clinical practice and research. Guidelines for the selection of three-dimensional imaging will be discussed, and limitations will be highlighted. Current concepts of radiation dose optimization, including novel imaging modalities using low-dose protocols, will be presented. For preoperative cross-sectional imaging, data are still not available which demonstrate that cone beam computed tomography results in fewer intraoperative complications such as nerve damage or bleeding incidents, or that implants inserted using preoperative cone beam computed tomography data sets for planning purposes will exhibit higher survival or success rates. The use of cone beam computed tomography following the insertion of dental implants should be restricted to specific postoperative complications, such as damage of neurovascular structures or postoperative infections in relation to the maxillary sinus. Regarding peri-implantitis, the diagnosis and severity of the disease should be evaluated primarily based on clinical parameters and on radiological findings based on periapical radiographs (two dimensional). The use of cone beam computed tomography scans in clinical research might not yield any evident beneficial effect for the patient included. As many of the cone beam computed tomography scans performed for research have no direct therapeutic consequence, dose optimization measures should be implemented by using appropriate exposure parameters and by reducing the field of view to the actual region of interest. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

How reliably can computed tomography predict thyroid invasion prior to laryngectomy?

PubMed

Harris, Andrew S; Passant, Carl D; Ingrams, Duncan R

2018-05-01

There is little evidence to support the removal of thyroid tissue during total laryngectomy. Although oncological control of the tumor is the priority, thyroidectomy can lead to hypothyroidism and hypoparathyroidism. This study aimed to test the usefulness of preoperative computed tomography in predicting histological invasion of the thyroid. Ambispective cohort study. All patients undergoing total laryngectomy for squamous cell carcinoma at one center from 2006 to 2016 were included. Data were recorded prospectively as part of the patients' standard care, but were collated retrospectively, giving this study an ambispective design. The histology report for thyroid invasion was taken as the gold standard. The computed tomography report was categorized by invasion of tumor into intralaryngeal, laryngeal cartilage involvement, and extralaryngeal tissues. Seventy-nine patients were included. Nine patients had thyroid involvement on histology, translating to an incidence of 11.29% in this population. The positive predictive value for cartilage involvement on computed tomography for thyroid invasion was 52.9% (95% confidence interval [CI]: 28.5%-76.1%) and the negative predictive value was 100% (95% CI: 92.7%-100%).The positive predictive value for extralaryngeal spread on computed tomography for thyroid involvement was 100% (95% CI: 62.9%-100%), and the negative predictive value was also 100% (95% CI: 93.5%-100%). This study has shown that preoperative computed tomography is an effective method of ruling out thyroid gland invasion. The absence of extralaryngeal spread on computed tomography has been shown to be the most useful finding, with a high negative predictive value and a narrow 95% CI. 4. Laryngoscope, 128:1099-1102, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Diverticular Disease of the Colon: News From Imaging.

PubMed

Flor, Nicola; Soldi, Simone; Zanchetta, Edoardo; Sbaraini, Sara; Pesapane, Filippo

2016-10-01

Different scenarios embrace computed tomography imaging and diverticula, including asymptomatic (diverticulosis) and symptomatic patients (acute diverticulitis, follow-up of acute diverticulitis, chronic diverticulitis). If the role of computed tomography is validated and widely supported by evidence in case of acute diverticulitis, this is not the case of patients in their follow-up for acute diverticulitis or with symptoms related to diverticula, but without acute inflammation. In these settings, computed tomography colonography is gaining consensus as the preferred radiologic test.

Plain X-ray, computed tomography and magnetic resonance imaging findings of telangiectatic osteosarcoma: a case report.

PubMed

Skiadas, Vasilios; Koutoulidis, Vasilios; Koureas, Andreas; Moulopoulos, Lia; Gouliamos, Athanasios

2009-09-16

An 18-year-old male patient presented with chronic nonspecific pain of three months located at his left proximal tibia. The patient was admitted to our department for plain X-ray, computed tomography and magnetic resonance imaging examination. Plain X-ray and computed tomography revealed a geographic lytic lesion at the medial aspect of the proximal tibia. Biopsy of the lesion showed telangiectatic osteosarcoma. Image findings of all modalities are presented.

Advances in equine computed tomography and use of contrast media.

PubMed

Puchalski, Sarah M

2012-12-01

Advances in equine computed tomography have been made as a result of improvements in software and hardware and an increasing body of knowledge. Contrast media can be administered intravascularly or intrathecally. Contrast media is useful to differentiate between tissues of similar density. Equine computed tomography can be used for many different clinical conditions, including lameness diagnosis, fracture identification and characterization, preoperative planning, and characterization of skull diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

[The radiologist physician in major trauma evaluation].

PubMed

Motta-Ramírez, Gaspar Alberto

2016-01-01

Trauma is the most common cause of death in young adults. A multidisciplinary trauma team consists of at least a surgical team, an anesthesiology team, radiologic team, and an emergency department team. Recognize the integration of multidisciplinary medical team in managing the trauma patient and which must include the radiologist physician responsible for the institutional approach to the systematization of the trauma patient regarding any radiological and imaging study with emphasis on the FAST (del inglés, Focused Assessment with Sonography in Trauma)/USTA, Whole body computed tomography. Ultrasound is a cross-sectional method available for use in patients with major trauma. Whole-body multidetector computed tomography became the imaging modality of choice in the late 1990s. In patients with major trauma, examination FAST often is the initial imaging examination, extended to extraabdominal regions. Patients who have multitrauma from blunt mechanisms often require multiple diagnostic examinations, including Computed Tomography imaging of the torso as well as abdominopelvic Computed Tomography angiography. Multiphasic Whole-body trauma imaging is feasible, helps detect clinically relevant vascular injuries, and results in diagnostic image quality in the majority of patients. Computed Tomography has gained importance in the early diagnostic phase of trauma care in the emergency room. With a single continuous acquisition, whole-body computed tomography angiography is able to demonstrate all potentially injured organs, as well as vascular and bone structures, from the circle of Willis to the symphysis pubis.

Development of computational small animal models and their applications in preclinical imaging and therapy research.

PubMed

Xie, Tianwu; Zaidi, Habib

2016-01-01

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and the development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.

High-resolution PET [Positron Emission Tomography] for Medical Science Studies

DOE R&D Accomplishments Database

Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

1989-09-01

One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

Tomography experiment of an integrated circuit specimen using 3 MeV electrons in the transmission electron microscope.

PubMed

Zhang, Hai-Bo; Zhang, Xiang-Liang; Wang, Yong; Takaoka, Akio

2007-01-01

The possibility of utilizing high-energy electron tomography to characterize the micron-scale three dimensional (3D) structures of integrated circuits has been demonstrated experimentally. First, electron transmission through a tilted SiO(2) film was measured with an ultrahigh-voltage electron microscope (ultra-HVEM) and analyzed from the point of view of elastic scattering of electrons, showing that linear attenuation of the logarithmic electron transmission still holds valid for effective specimen thicknesses up to 5 microm under 2 MV accelerating voltages. Electron tomography of a micron-order thick integrated circuit specimen including the Cu/via interconnect was then tried with 3 MeV electrons in the ultra-HVEM. Serial projection images of the specimen tilted at different angles over the range of +/-90 degrees were acquired, and 3D reconstruction was performed with the images by means of the IMOD software package. Consequently, the 3D structures of the Cu lines, via and void, were revealed by cross sections and surface rendering.

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.

Use of radiography, computed tomography and magnetic resonance imaging for evaluation of navicular syndrome in the horse.

PubMed

Widmer, W R; Buckwalter, K A; Fessler, J F; Hill, M A; VanSickle, D C; Ivancevich, S

2000-01-01

Radiographic evaluation of navicular syndrome is problematic because of its inconsistent correlation with clinical signs. Scintigraphy often yields false positive and false negative results and diagnostic ultrasound is of limited value. Therefore, we assessed the use of computed tomography and magnetic resonance imaging in a horse with clinical and radiographic signs of navicular syndrome. Cadaver specimens were examined with spiral computed tomographic and high-field magnetic resonance scanners and images were correlated with pathologic findings. Radiographic changes consisted of bony remodeling, which included altered synovial fossae, increased medullary opacity, cyst formation and shape change. These osseous changes were more striking and more numerous on computed tomographic and magnetic resonance images. They were most clearly defined with computed tomography. Many osseous changes seen with computed tomography and magnetic resonance imaging were not radiographically evident. Histologically confirmed soft tissue alterations of the deep digital flexor tendon, impar ligament and marrow were identified with magnetic resonance imaging, but not with conventional radiography. Because of their multiplanar capability and tomographic nature, computed tomography and magnetic resonance imaging surpass conventional radiography for navicular imaging, facilitating earlier, more accurate diagnosis. Current advances in imaging technology should make these imaging modalities available to equine practitioners in the future.

Quantitative Comparison of Virtual Monochromatic Images of Dual Energy Computed Tomography Systems: Beam Hardening Artifact Correction and Variance in Computed Tomography Numbers: A Phantom Study.

PubMed

Wu, Rongli; Watanabe, Yoshiyuki; Satoh, Kazuhiko; Liao, Yen-Peng; Takahashi, Hiroto; Tanaka, Hisashi; Tomiyama, Noriyuki

2018-05-21

The aim of this study was to quantitatively compare the reduction in beam hardening artifact (BHA) and variance in computed tomography (CT) numbers of virtual monochromatic energy (VME) images obtained with 3 dual-energy computed tomography (DECT) systems at a given radiation dose. Five different iodine concentrations were scanned using dual-energy and single-energy (120 kVp) modes. The BHA and CT number variance were evaluated. For higher iodine concentrations, 40 and 80 mgI/mL, BHA on VME imaging was significantly decreased when the energy was higher than 50 keV (P = 0.003) and 60 keV (P < 0.001) for GE, higher than 80 keV (P < 0.001) and 70 keV (P = 0.002) for Siemens, and higher than 40 keV (P < 0.001) and 60 keV (P < 0.001) for Toshiba, compared with single-energy CT imaging. Virtual monochromatic energy imaging can decrease BHA and improve CT number accuracy in different dual-energy computed tomography systems, depending on energy levels and iodine concentrations.

Virtopsy: postmortem imaging of laryngeal foreign bodies.

PubMed

Oesterhelweg, Lars; Bolliger, Stephan A; Thali, Michael J; Ross, Steffen

2009-05-01

Death from corpora aliena in the larynx is a well-known entity in forensic pathology. The correct diagnosis of this cause of death is difficult without an autopsy, and misdiagnoses by external examination alone are common. To determine the postmortem usefulness of modern imaging techniques in the diagnosis of foreign bodies in the larynx, multislice computed tomography, magnetic resonance imaging, and postmortem full-body computed tomography-angiography were performed. Three decedents with a suspected foreign body in the larynx underwent the 3 different imaging techniques before medicolegal autopsy. Multislice computed tomography has a high diagnostic value in the noninvasive localization of a foreign body and abnormalities in the larynx. The differentiation between neoplasm or soft foreign bodies (eg, food) is possible, but difficult, by unenhanced multislice computed tomography. By magnetic resonance imaging, the discrimination of the soft tissue structures and soft foreign bodies is much easier. In addition to the postmortem multislice computed tomography, the combination with postmortem angiography will increase the diagnostic value. Postmortem, cross-sectional imaging methods are highly valuable procedures for the noninvasive detection of corpora aliena in the larynx.

Cannabis-induced bullous lung disease leading to pneumothorax: Case report and literature review.

PubMed

Mishra, Rashmi; Patel, Ravi; Khaja, Misbahuddin

2017-05-01

Marijuana use has been increasing in the United States among college students and young adults. Marijuana use has been associated with bullous lung disease which can lead to pneumothorax. There are other recreational drugs like methylphenidate, cocaine and heroin which have been associated with pneumothorax. We present a case of a 30-year-old man with spontaneous pneumothorax associated with marijuana use. The patient had no medical conditions and presented to the emergency room with chest pain. The physical examination revealed decreased breath sound on the right side of the chest. Bed side ultrasound of chest showed stratosphere sign, absent lung sliding; consistent with right-sided pneumothorax. The patient underwent placement of a chest tube. Computed tomography chest scans performed on day two also showed bullous lung disease in the right lung. Serial x-rays of the chest showed re-expansion of the lung. Despite the beneficial effects of Marijuana there are deleterious effects which are emphasized here. This case highlights the need for further studies to establish the relationship between marijuana use and lung diseases in the absence of nicotine use.

The C-reactive protein.

PubMed

Clyne, B; Olshaker, J S

1999-01-01

C-reactive protein (CRP) was identified in 1930 and was subsequently considered to be an "acute phase protein," an early indicator of infectious or inflammatory conditions. Since its discovery, CRP has been studied as a screening device for inflammation, a marker for disease activity, and as a diagnostic adjunct. Improved methods of quantifying CRP have led to increased application to clinical medicine. In the emergency department (ED), CRP must be interpreted in the clinical context; no single value can be used to rule in or rule out a specific diagnosis. We conclude that CRP has limited utility in the ED. It may be a useful adjunct to serial examinations in equivocal presentations of appendicitis in those centers without ready access to computed tomography (CT) scan. It may be elevated with complications or treatment failures in patients with pneumonia, pancreatitis, pelvic inflammatory disease (PID), and urinary tract infections. In patients with meningitis, neonatal sepsis, and occult bacteremia, CRP is usually elevated. However, CRP has no role in diagnosing these clinical entities, and a normal CRP level should never delay antibiotic coverage.

Traumatic occlusion of the anterior cerebral artery--case report.

PubMed

Ishibashi, A; Kubota, Y; Yokokura, Y; Soejima, Y; Hiratsuka, T

1995-12-01

A 71-year-old female presented with posttraumatic occlusion of the anterior cerebral artery (ACA) after a road accident in which she was hit in the mid-frontal region. Initial computed tomography (CT) demonstrated frontal skull fractures and pneumocephalus. High density areas were also identified in the right basal cisterns, suggesting traumatic subarachnoid hemorrhage. She was alert on admission, but with attendant shock due to crush wounds. Her condition rapidly deteriorated and an emergency amputation of her left leg was performed. After aggressive treatment with transfusion and infusion, her systolic pressure increased to 120 mmHg. Her consciousness remained disturbed. Serial CT disclosed hemorrhagic infarction in the entire medial side of the right frontal lobe. Magnetic resonance angiography demonstrated decreased flow voids in the bilateral A1 segments and right ACA, and a basilar artery aneurysm, which was unruptured clinically. Three weeks after the injury, she regained consciousness. Six months later, she had motor aphasia and left upper extremity weakness. The clinicopathological mechanism causing the traumatic occlusion of the ACA in the present case was probably dissecting aneurysm.

Subsolid pulmonary nodules: imaging evaluation and strategic management.

PubMed

Godoy, Myrna C B; Sabloff, Bradley; Naidich, David P

2012-07-01

Given the higher rate of malignancy of subsolid pulmonary nodules and the considerably lower growth rate of ground-glass nodules (GGNs), dedicated standardized guidelines for management of these nodules have been proposed, including long-term low-dose computed tomography (CT) follow-up (≥3 years). Physicians must be familiar with the strategic management of subsolid pulmonary nodules, and should be able to identify imaging features that suggest invasive adenocarcinoma requiring a more aggressive management. Low-dose CT screening studies for early detection of lung cancer have increased our knowledge of pulmonary nodules, and in particular our understanding of the strong although imperfect correlation of the subsolid pulmonary nodules, including pure GGNs and part-solid nodules, with the spectrum of preinvasive to invasive lung adenocarcinoma. Serial CT imaging has shown stepwise progression in a subset of these nodules, characterized by increase in size and density of pure GGNs and development of a solid component, the latter usually indicating invasive adenocarcinoma. There is close correlation between the CT features of subsolid nodules (SSNs) and the spectrum of lung adenocarcinoma. Standardized guidelines are suggested for management of SSNs.

Leg CT scan

MedlinePlus

CAT scan - leg; Computed axial tomography scan - leg; Computed tomography scan - leg; CT scan - leg ... CT scan makes detailed pictures of the body very quickly. The test may help look for: An abscess ...

Arm CT scan

MedlinePlus

CAT scan - arm; Computed axial tomography scan - arm; Computed tomography scan - arm; CT scan - arm ... Healing problems or scar tissue following surgery A CT scan may also be used to guide a surgeon ...

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.

Multidetector Computed Tomography for Congenital Anomalies of the Aortic Arch: Vascular Rings.

PubMed

García-Guereta, Luis; García-Cerro, Estefanía; Bret-Zurita, Montserrat

2016-07-01

The development of multidetector computed tomography has triggered a revolution in the study of the aorta and other large vessels and has replaced angiography in the diagnosis of congenital anomalies of the aortic arch, particularly vascular rings. The major advantage of multidetector computed tomography is that it permits clear 3-dimensional assessment of not only vascular structures, but also airway and esophageal compression. The current update aims to summarize the embryonic development of the aortic arch and the developmental anomalies leading to vascular ring formation and to discuss the current diagnostic and therapeutic role of multidetector computed tomography in this field. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Comprehensive Digital Imaging Network Project At Georgetown University Hospital

NASA Astrophysics Data System (ADS)

Mun, Seong K.; Stauffer, Douglas; Zeman, Robert; Benson, Harold; Wang, Paul; Allman, Robert

1987-10-01

The radiology practice is going through rapid changes due to the introduction of state-of-the-art computed based technologies. For the last twenty years we have witnessed the introduction of many new medical diagnostic imaging systems such as x-ray computed tomo-graphy, digital subtraction angiography (DSA), computerized nuclear medicine, single pho-ton emission computed tomography (SPECT), positron emission tomography (PET) and more re-cently, computerized digital radiography and nuclear magnetic resonance imaging (MRI). Other than the imaging systems, there has been a steady introduction of computed based information systems for radiology departments and hospitals.

Utility of three-dimensional and multiplanar reformatted computed tomography for evaluation of pediatric congenital spine abnormalities.

PubMed

Newton, Peter O; Hahn, Gregory W; Fricka, Kevin B; Wenger, Dennis R

2002-04-15

A retrospective radiographic review of 31 patients with congenital spine abnormalities who underwent conventional radiography and advanced imaging studies was conducted. To analyze the utility of three-dimensional computed tomography with multiplanar reformatted images for congenital spine anomalies, as compared with plain radiographs and axial two-dimensional computed tomography imaging. Conventional radiographic imaging for congenital spine disorders often are difficult to interpret because of the patient's small size, the complexity of the disorder, a deformity not in the plane of the radiographs, superimposed structures, and difficulty in forming a mental three-dimensional image. Multiplanar reformatted and three-dimensional computed tomographic imaging offers many potential advantages for defining congenital spine anomalies including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. The imaging studies of patients who had undergone a three-dimensional computed tomography for congenital deformities of the spine between 1992 and 1998 were reviewed (31 cases). All plain radiographs and axial two-dimensional computed tomography images performed before the three-dimensional computed tomography were reviewed and the findings documented. This was repeated for the three-dimensional reconstructions and, when available, the multiplanar reformatted images (15 cases). In each case, the utility of the advanced imaging was graded as one of the following: Grade A (substantial new information obtained), Grade B (confirmatory with improved visualization and understanding of the deformity), and Grade C (no added useful information obtained). In 17 of 31 cases, the multiplanar reformatted and three-dimensional images allowed identification of unrecognized malformations. In nine additional cases, the advanced imaging was helpful in better visualizing and understanding previously identified deformities. In five cases, no new information was gained. The standard and curved multiplanar reformatted images were best for defining the occiput-C1-C2 anatomy and the extent of segmentation defects. The curved multiplanar reformatted images were especially helpful in keeping the spine from "coming in" and "going out" of the plane of the image when there was significant spine deformity in the sagittal or coronal plane. The three-dimensional reconstructions proved valuable in defining failures of formation. Advanced computed tomography imaging (three-dimensional computed tomography and curved/standard multiplanar reformatted images) allows better definition of congenital spine anomalies. More than 50% of the cases showed additional abnormalities not appreciated on plain radiographs or axial two-dimensional computed tomography images. Curved multiplanar reformatted images allowed imaging in the coronal and sagittal planes of the entire deformity.

Heart CT scan

MedlinePlus

... Computed tomography scan - heart; Calcium scoring; Multi-detector CT scan - heart; Electron beam computed tomography - heart; Agatston ... table that slides into the center of the CT scanner. You will lie on your back with ...

Evaluation of 3D airway imaging of obstructive sleep apnea with cone-beam computed tomography.

PubMed

Ogawa, Takumi; Enciso, Reyes; Memon, Ahmed; Mah, James K; Clark, Glenn T

2005-01-01

This study evaluates the use of cone-beam Computer Tomography (CT) for imaging the upper airway structure of Obstructive Sleep Apnea (OSA) patients. The total airway volume and the anteroposterior dimension of oropharyngeal airway showed significant group differences between OSA and gender-matched controls, so if we increase sample size these measurements may distinguish the two groups. We demonstrate the utility of diagnosis of anatomy with the 3D airway imaging with cone-beam Computed Tomography.

Cone beam computed tomography in Endodontics - a review.

PubMed

Patel, S; Durack, C; Abella, F; Shemesh, H; Roig, M; Lemberg, K

2015-01-01

Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on the applications and limitations of CBCT; (ii) make recommendations for the use of CBCT in Endodontics; (iii) highlight areas of further research of CBCT in Endodontics. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 1: Technology and Terminology.

PubMed

Siegel, Marilyn J; Kaza, Ravi K; Bolus, David N; Boll, Daniel T; Rofsky, Neil M; De Cecco, Carlo N; Foley, W Dennis; Morgan, Desiree E; Schoepf, U Joseph; Sahani, Dushyant V; Shuman, William P; Vrtiska, Terri J; Yeh, Benjamin M; Berland, Lincoln L

This is the first of a series of 4 white papers that represent Expert Consensus Documents developed by the Society of Computed Body Tomography and Magnetic Resonance through its task force on dual-energy computed tomography (DECT). This article, part 1, describes the fundamentals of the physical basis for DECT and the technology of DECT and proposes uniform nomenclature to account for differences in proprietary terms among manufacturers.

[Cardiac computed tomography: new applications of an evolving technique].

PubMed

Martín, María; Corros, Cecilia; Calvo, Juan; Mesa, Alicia; García-Campos, Ana; Rodríguez, María Luisa; Barreiro, Manuel; Rozado, José; Colunga, Santiago; de la Hera, Jesús M; Morís, César; Luyando, Luis H

2015-01-01

During the last years we have witnessed an increasing development of imaging techniques applied in Cardiology. Among them, cardiac computed tomography is an emerging and evolving technique. With the current possibility of very low radiation studies, the applications have expanded and go further coronariography In the present article we review the technical developments of cardiac computed tomography and its new applications. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

Plain X-ray, computed tomography and magnetic resonance imaging findings of telangiectatic osteosarcoma: a case report

PubMed Central

Koutoulidis, Vasilios; Koureas, Andreas; Moulopoulos, Lia; Gouliamos, Athanasios

2009-01-01

An 18-year-old male patient presented with chronic nonspecific pain of three months located at his left proximal tibia. The patient was admitted to our department for plain X-ray, computed tomography and magnetic resonance imaging examination. Plain X-ray and computed tomography revealed a geographic lytic lesion at the medial aspect of the proximal tibia. Biopsy of the lesion showed telangiectatic osteosarcoma. Image findings of all modalities are presented. PMID:19918488

Massively parallel simulator of optical coherence tomography of inhomogeneous turbid media.

PubMed

Malektaji, Siavash; Lima, Ivan T; Escobar I, Mauricio R; Sherif, Sherif S

2017-10-01

An accurate and practical simulator for Optical Coherence Tomography (OCT) could be an important tool to study the underlying physical phenomena in OCT such as multiple light scattering. Recently, many researchers have investigated simulation of OCT of turbid media, e.g., tissue, using Monte Carlo methods. The main drawback of these earlier simulators is the long computational time required to produce accurate results. We developed a massively parallel simulator of OCT of inhomogeneous turbid media that obtains both Class I diffusive reflectivity, due to ballistic and quasi-ballistic scattered photons, and Class II diffusive reflectivity due to multiply scattered photons. This Monte Carlo-based simulator is implemented on graphic processing units (GPUs), using the Compute Unified Device Architecture (CUDA) platform and programming model, to exploit the parallel nature of propagation of photons in tissue. It models an arbitrary shaped sample medium as a tetrahedron-based mesh and uses an advanced importance sampling scheme. This new simulator speeds up simulations of OCT of inhomogeneous turbid media by about two orders of magnitude. To demonstrate this result, we have compared the computation times of our new parallel simulator and its serial counterpart using two samples of inhomogeneous turbid media. We have shown that our parallel implementation reduced simulation time of OCT of the first sample medium from 407 min to 92 min by using a single GPU card, to 12 min by using 8 GPU cards and to 7 min by using 16 GPU cards. For the second sample medium, the OCT simulation time was reduced from 209 h to 35.6 h by using a single GPU card, and to 4.65 h by using 8 GPU cards, and to only 2 h by using 16 GPU cards. Therefore our new parallel simulator is considerably more practical to use than its central processing unit (CPU)-based counterpart. Our new parallel OCT simulator could be a practical tool to study the different physical phenomena underlying OCT, or to design OCT systems with improved performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Accuracy and Precision of Radioactivity Quantification in Nuclear Medicine Images

PubMed Central

Frey, Eric C.; Humm, John L.; Ljungberg, Michael

2012-01-01

The ability to reliably quantify activity in nuclear medicine has a number of increasingly important applications. Dosimetry for targeted therapy treatment planning or for approval of new imaging agents requires accurate estimation of the activity in organs, tumors, or voxels at several imaging time points. Another important application is the use of quantitative metrics derived from images, such as the standard uptake value commonly used in positron emission tomography (PET), to diagnose and follow treatment of tumors. These measures require quantification of organ or tumor activities in nuclear medicine images. However, there are a number of physical, patient, and technical factors that limit the quantitative reliability of nuclear medicine images. There have been a large number of improvements in instrumentation, including the development of hybrid single-photon emission computed tomography/computed tomography and PET/computed tomography systems, and reconstruction methods, including the use of statistical iterative reconstruction methods, which have substantially improved the ability to obtain reliable quantitative information from planar, single-photon emission computed tomography, and PET images. PMID:22475429

Report on the Total System Computer Program for Medical Libraries.

ERIC Educational Resources Information Center

Divett, Robert T.; Jones, W. Wayne

The objective of this project was to develop an integrated computer program for the total operations of a medical library including acquisitions, cataloging, circulation, reference, a computer catalog, serials controls, and current awareness services. The report describes two systems approaches: the batch system and the terminal system. The batch…

FFT Computation with Systolic Arrays, A New Architecture

NASA Technical Reports Server (NTRS)

Boriakoff, Valentin

1994-01-01

The use of the Cooley-Tukey algorithm for computing the l-d FFT lends itself to a particular matrix factorization which suggests direct implementation by linearly-connected systolic arrays. Here we present a new systolic architecture that embodies this algorithm. This implementation requires a smaller number of processors and a smaller number of memory cells than other recent implementations, as well as having all the advantages of systolic arrays. For the implementation of the decimation-in-frequency case, word-serial data input allows continuous real-time operation without the need of a serial-to-parallel conversion device. No control or data stream switching is necessary. Computer simulation of this architecture was done in the context of a 1024 point DFT with a fixed point processor, and CMOS processor implementation has started.

Meaning of Interior Tomography

PubMed Central

Wang, Ge; Yu, Hengyong

2013-01-01

The classic imaging geometry for computed tomography is for collection of un-truncated projections and reconstruction of a global image, with the Fourier transform as the theoretical foundation that is intrinsically non-local. Recently, interior tomography research has led to theoretically exact relationships between localities in the projection and image spaces and practically promising reconstruction algorithms. Initially, interior tomography was developed for x-ray computed tomography. Then, it has been elevated as a general imaging principle. Finally, a novel framework known as “omni-tomography” is being developed for grand fusion of multiple imaging modalities, allowing tomographic synchrony of diversified features. PMID:23912256

Correlation between Preoperative High Resolution Computed Tomography (CT) Findings with Surgical Findings in Chronic Otitis Media (COM) Squamosal Type.

PubMed

Karki, S; Pokharel, M; Suwal, S; Poudel, R

Background The exact role of High resolution computed tomography (HRCT) temporal bone in preoperative assessment of Chronic suppurative otitis media atticoantral disease still remains controversial. Objective To evaluate the role of high resolution computed tomography temporal bone in Chronic suppurative otitis media atticoantral disease and to compare preoperative computed tomographic findings with intra-operative findings. Method Prospective, analytical study conducted among 65 patients with chronic suppurative otitis media atticoantral disease in Department of Radiodiagnosis, Kathmandu University Dhulikhel Hospital between January 2015 to July 2016. The operative findings were compared with results of imaging. The parameters of comparison were erosion of ossicles, scutum, facial canal, lateral semicircular canal, sigmoid and tegmen plate along with extension of disease to sinus tympani and facial recess. Sensitivity, specificity, negative predictive value, positive predictive values were calculated. Result High resolution computed tomography temporal bone offered sensitivity (Se) and specificity (Sp) of 100% for visualization of sigmoid and tegmen plate erosion. The performance of HRCT in detecting malleus (Se=100%, Sp=95.23%), incus (Se=100%,Sp=80.48%) and stapes (Se=96.55%, Sp=71.42%) erosion was excellent. It offered precise information about facial canal erosion (Se=100%, Sp=75%), scutum erosion (Se=100%, Sp=96.87%) and extension of disease to facial recess and sinus tympani (Se=83.33%,Sp=100%). high resolution computed tomography showed specificity of 100% for lateral semicircular canal erosion (Sp=100%) but with low sensitivity (Se=53.84%). Conclusion The findings of high resolution computed tomography and intra-operative findings were well comparable except for lateral semicircular canal erosion. high resolution computed tomography temporal bone acts as a road map for surgeon to identify the extent of disease, plan for appropriate procedure that is required and prepare for potential complications that can be encountered during surgery.

Trails on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Leading to Diagnosis of Testicular Adrenal Rest Tumor.

PubMed

Kashyap, Raghava

2018-01-01

Testicular adrenal rest tumors (TARTs) are secondary to hypertrophy of adrenal rest cells in the rete testis in settings of hypersecretion of androgens. We present a case of congenital adrenal hyperplasia with TART with clues to the diagnosis on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT). To the best of our knowledge, this is the first reported case on the role of 18 F-FDG PET/CT in TART.

Pleuroperitoneal Mesothelioma: A Rare Entity on 18F-FDG PET/CT

PubMed Central

Sahoo, Manas Kumar; Mukherjee, Anirban; Girish; Parida, Kumar; Agarwal, Krishan Kant; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

2017-01-01

Pleuroperitoneal mesothelioma is an extremely rare entity. Only few cases are reported worldwide. We hereby represent a case of pleural mesothelioma referred for F-18-Fluorodeoxyglucose positron emission tomography/computed tomography for response evaluation. Diffuse F-18-Fluorodeoxyglucose avid peritoneal and omental thickening noted which subsequently turned out to be mesothelial involvement on peritoneal biopsy. This case demonstrates the role of F-18-Fluorodeoxyglucose positron emission tomography/computed tomography in detecting other sites of involvement in case of malignant mesothelioma. PMID:28242997

Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

PubMed

Tripathy, Sarthak; Parida, Girish Kumar; Roy, Shambo Guha; Singhal, Abhinav; Mallick, Saumya Ranjan; Tripathi, Madhavi; Shamim, Shamim Ahmed

2017-01-01

Disseminated cryptococcosis without pulmonary involvement is a very rare phenomenon. Patterns of organ involvement in cryptococcosis resemble various other infective conditions as well as malignant conditions on fluorodeoxyglucose positron emission tomography-computed tomography. We present a case of a 43-year-old male patient who had disseminated cryptococcosis. The rarity of the case being noninvolvement of lungs and meninges and resembling more like lymphoma due to the diffuse involvement of the lymph nodes on both sides of the diaphragm.

CT Perfusion of the Head

MedlinePlus

... News Physician Resources Professions Site Index A-Z CT Perfusion of the Head Computed tomography (CT) perfusion ... of CT Perfusion of the Head? What is CT Perfusion of the Head? Computed tomography (CT) perfusion ...

Visualization of Pulsar Search Data

NASA Astrophysics Data System (ADS)

Foster, R. S.; Wolszczan, A.

1993-05-01

The search for periodic signals from rotating neutron stars or pulsars has been a computationally taxing problem to astronomers for more than twenty-five years. Over this time interval, increases in computational capability have allowed ever more sensitive searches, covering a larger parameter space. The volume of input data and the general presence of radio frequency interference typically produce numerous spurious signals. Visualization of the search output and enhanced real-time processing of significant candidate events allow the pulsar searcher to optimally processes and search for new radio pulsars. The pulsar search algorithm and visualization system presented in this paper currently runs on serial RISC based workstations, a traditional vector based super computer, and a massively parallel computer. A description of the serial software algorithm and its modifications for massively parallel computing are describe. The results of four successive searches for millisecond period radio pulsars using the Arecibo telescope at 430 MHz have resulted in the successful detection of new long-period and millisecond period radio pulsars.

Quantification of pericardial effusions by echocardiography and computed tomography.

PubMed

Leibowitz, David; Perlman, Gidon; Planer, David; Gilon, Dan; Berman, Philip; Bogot, Naama

2011-01-15

Echocardiography is a well-accepted tool for the diagnosis and quantification of pericardial effusion (PEff). Given the increasing use of computed tomographic (CT) scanning, more PEffs are being initially diagnosed by computed tomography. No study has compared quantification of PEff by computed tomography and echocardiography. The objective of this study was to assess the accuracy of quantification of PEff by 2-dimensional echocardiography and computed tomography compared to the amount of pericardial fluid drained at pericardiocentesis. We retrospectively reviewed an institutional database to identify patients who underwent chest computed tomography and echocardiography before percutaneous pericardiocentesis with documentation of the amount of fluid withdrawn. Digital 2-dimensional echocardiographic and CT images were retrieved and quantification of PEff volume was performed by applying the formula for the volume of a prolate ellipse, π × 4/3 × maximal long-axis dimension/2 × maximal transverse dimension/2 × maximal anteroposterior dimension/2, to the pericardial sac and to the heart. Nineteen patients meeting study qualifications were entered into the study. The amount of PEff drained was 200 to 1,700 ml (mean 674 ± 340). Echocardiographically calculated pericardial effusion volume correlated relatively well with PEff volume (r = 0.73, p <0.001, mean difference -41 ± 225 ml). There was only moderate correlation between CT volume quantification and actual volume drained (r = 0.4, p = 0.004, mean difference 158 ± 379 ml). In conclusion, echocardiography appears a more accurate imaging technique than computed tomography in quantitative assessment of nonloculated PEffs and should continue to be the primary imaging in these patients. Copyright © 2011 Elsevier Inc. All rights reserved.

Development of computational small animal models and their applications in preclinical imaging and therapy research

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

Xie, Tianwu; Zaidi, Habib, E-mail: habib.zaidi@hcuge.ch; Geneva Neuroscience Center, Geneva University, Geneva CH-1205

The development of multimodality preclinical imaging techniques and the rapid growth of realistic computer simulation tools have promoted the construction and application of computational laboratory animal models in preclinical research. Since the early 1990s, over 120 realistic computational animal models have been reported in the literature and used as surrogates to characterize the anatomy of actual animals for the simulation of preclinical studies involving the use of bioluminescence tomography, fluorescence molecular tomography, positron emission tomography, single-photon emission computed tomography, microcomputed tomography, magnetic resonance imaging, and optical imaging. Other applications include electromagnetic field simulation, ionizing and nonionizing radiation dosimetry, and themore » development and evaluation of new methodologies for multimodality image coregistration, segmentation, and reconstruction of small animal images. This paper provides a comprehensive review of the history and fundamental technologies used for the development of computational small animal models with a particular focus on their application in preclinical imaging as well as nonionizing and ionizing radiation dosimetry calculations. An overview of the overall process involved in the design of these models, including the fundamental elements used for the construction of different types of computational models, the identification of original anatomical data, the simulation tools used for solving various computational problems, and the applications of computational animal models in preclinical research. The authors also analyze the characteristics of categories of computational models (stylized, voxel-based, and boundary representation) and discuss the technical challenges faced at the present time as well as research needs in the future.« less

[Computed tomography semiotics of osteonecrosis and sequestration in chronic hematogenic osteomyelitis].

PubMed

D'iachkova, G V; Mitina, Iu L

2007-01-01

Based on the data of computed tomography, radiography and densitometry in 39 patients the authors describe in detail the signs of osteonecrosis and sequestration of different localization and extension.

Pelvic CT scan

MedlinePlus

CAT scan - pelvis; Computed axial tomography scan - pelvis; Computed tomography scan - pelvis; CT scan - pelvis ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye CT scans do expose you to more radiation ...

Lumbar spine CT scan

MedlinePlus

CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... CT scans rapidly makes detailed pictures of the lower back. The test may be used to look for: ...

Shoulder CT scan

MedlinePlus

CAT scan - shoulder; Computed axial tomography scan - shoulder; Computed tomography scan - shoulder; CT scan - shoulder ... Risks of CT scans include: Being exposed to radiation Allergic reaction to contrast dye Birth defect if done during pregnancy CT scans ...

Cone-beam computed tomography for lung cancer - validation with CT and monitoring tumour response during chemo-radiation therapy.

PubMed

Michienzi, Alissa; Kron, Tomas; Callahan, Jason; Plumridge, Nikki; Ball, David; Everitt, Sarah

2017-04-01

Cone-beam computed tomography (CBCT) is a valuable image-guidance tool in radiation therapy (RT). This study was initiated to assess the accuracy of CBCT for quantifying non-small cell lung cancer (NSCLC) tumour volumes compared to the anatomical 'gold standard', CT. Tumour regression or progression on CBCT was also analysed. Patients with Stage I-III NSCLC, prescribed 60 Gy in 30 fractions RT with concurrent platinum-based chemotherapy, routine CBCT and enrolled in a prospective study of serial PET/CT (baseline, weeks two and four) were eligible. Time-matched CBCT and CT gross tumour volumes (GTVs) were manually delineated by a single observer on MIM software, and were analysed descriptively and using Pearson's correlation coefficient (r) and linear regression (R 2 ). Of 94 CT/CBCT pairs, 30 patients were eligible for inclusion. The mean (± SD) CT GTV vs CBCT GTV on the four time-matched pairs were 95 (±182) vs 98.8 (±160.3), 73.6 (±132.4) vs 70.7 (±96.6), 54.7 (±92.9) vs 61.0 (±98.8) and 61.3 (±53.3) vs 62.1 (±47.9) respectively. Pearson's correlation coefficient (r) was 0.98 (95% CI 0.97-0.99, ρ < 0.001). The mean (±SD) CT/CBCT Dice's similarity coefficient was 0.66 (±0.16). Of 289 CBCT scans, tumours in 27 (90%) patients regressed by a mean (±SD) rate of 1.5% (±0.75) per fraction. The mean (±SD) GTV regression was 43.1% (±23.1) from the first to final CBCT. Primary lung tumour volumes observed on CBCT and time-matched CT are highly correlated (although not identical), thereby validating observations of GTV regression on CBCT in NSCLC. © 2016 The Royal Australian and New Zealand College of Radiologists.

The early and midterm function of decellularized aortic valve allografts.

PubMed

da Costa, Francisco D A; Costa, Ana Claudia B A; Prestes, Roberta; Domanski, Ana Carolina; Balbi, Eduardo Mendel; Ferreira, Andreia D A; Lopes, Sergio Veiga

2010-12-01

This study evaluates the early and midterm results of decellularized aortic valve allografts (DAVA) as an aortic valve replacement. Between October 2005 and February 2010, 41 patients, 28 of whom were male, with a median age of 34 years (range, 0.1 to 71), had aortic valve replacement with DAVA. Decellularization was obtained with a 0.1% sodium dodecyl sulfate solution. Postoperative evaluation was performed with serial echocardiograms, magnetic resonance imaging, and multislice computed tomography studies to evaluate valve hemodynamics, allograft conduit dimensions, and calcification scores. There were 3 early deaths and 1 late death, with a mean follow-up of 19 months (range, 1 to 53). There was 1 reoperation due to a failed mitral valve repair. By echocardiography in all patients, the median immediate postoperative peak gradient was 7 mm Hg (range, 1 to 26 mm Hg), and at last follow-up it was 4 mm Hg (range, 1 to 16 mm Hg); valvular regurgitation was graded as none or trivial in all but 1 patient, who had a regurgitation graded as mild to moderate. By magnetic resonance imaging (n = 4), mean root dimensions were stable at the annulus (24 mm), sinus of Valsalva (33 mm), and sinotubular junction (28 mm). By computed tomography (n = 22), there was only discrete conduit calcification (median calcium score 63 Hounsfield units [HU]; range, 0 to 894 HU) to 3 years of follow-up. Conduit biopsy in the patient who underwent reoperation demonstrated well-preserved wall structure, absence of calcification, and limited in vivo host repopulation. The early and midterm results with DAVA demonstrated stable structural integrity, low rate of calcification, and adequate hemodynamics. Although longer periods of observation are necessary, DAVA appears to be a promising alternative for aortic valve replacement in selected patients. Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Highly sensitive troponin and coronary computed tomography angiography in the evaluation of suspected acute coronary syndrome in the emergency department.

PubMed

Ferencik, Maros; Hoffmann, Udo; Bamberg, Fabian; Januzzi, James L

2016-08-07

The evaluation of patients presenting to the emergency department with suspected acute coronary syndrome (ACS) remains a clinical challenge. The traditional assessment includes clinical risk assessment based on cardiovascular risk factors with serial electrocardiograms and cardiac troponin measurements, often followed by advanced cardiac testing as inpatient or outpatient (i.e. stress testing, imaging). Despite this costly and lengthy work-up, there is a non-negligible rate of missed ACS with an increased risk of death. There is a clinical need for diagnostic strategies that will lead to rapid and reliable triage of patients with suspected ACS. We provide an overview of the evidence for the role of highly sensitive troponin (hsTn) in the rapid and efficient evaluation of suspected ACS. Results of recent research studies have led to the introduction of hsTn with rapid rule-in and rule-out protocols into the guidelines. Highly sensitive troponin increases the sensitivity for the detection of myocardial infarction and decreases time to diagnosis; however, it may decrease the specificity, especially when used as a dichotomous variable, rather than continuous variable as recommended by guidelines; this may increase clinician uncertainty. We summarize the evidence for the use of coronary computed tomography angiography (CTA) as the rapid diagnostic tool in this population when used with conventional troponin assays. Coronary CTA significantly decreases time to diagnosis and discharge in patients with suspected ACS, while being safe. However, it may lead to increase in invasive procedures and includes radiation exposure. Finally, we outline the opportunities for the combined use of hsTn and coronary CTA that may result in increased efficiency, decreased need for imaging, lower cost, and decreased radiation dose. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

SPECT/CT in imaging foot and ankle pathology-the demise of other coregistration techniques.

PubMed

Mohan, Hosahalli K; Gnanasegaran, Gopinath; Vijayanathan, Sanjay; Fogelman, Ignac

2010-01-01

Disorders of the ankle and foot are common and given the complex anatomy and function of the foot, they present a significant clinical challenge. Imaging plays a crucial role in the management of these patients, with multiple imaging options available to the clinician. The American College of radiology has set the appropriateness criteria for the use of the available investigating modalities in the management of foot and ankle pathologies. These are broadly classified into anatomical and functional imaging modalities. Recently, single-photon emission computed tomography and/or computed tomography scanners, which can elegantly combine functional and anatomical images have been introduced, promising an exciting and important development. This review describes our clinical experience with single-photon emission computed tomography and/or computed tomography and discusses potential applications of these techniques.

Comparison of radiological and morphologic assessments of myocardial bridges.

PubMed

Ercakmak, Burcu; Bulut, Elif; Hayran, Mutlu; Kaymaz, Figen; Bilgin, Selma; Hazirolan, Tuncay; Bayramoglu, Alp; Erbil, Mine

2015-09-01

In this study we aimed to compare the findings of coronary dual-source computed tomography angiography of myocardial bridges with cadaveric dissections. Forty-one isolated, non-damaged fresh sheep hearts were used in this study. Myocardial bridges of the anterior interventricular branch of the left coronary artery were demonstrated and analyzed by a coronary dual-source computed tomography angiography. Dissections along the left anterior interventricular branch of the left coronary artery were performed by using Zeiss OPMI pico microscope and the length of the bridges were measured. The depths of the myocardial bridges were measured from the stained sections by using the light microscope (Leica DM 6000B). MBs were found in all 41 hearts (100%) during dissections. Dual-source computed tomography angiography successfully detected 87.8% (36 of the 41 hearts) of the myocardial bridges measured on left anterior interventricular branch of left coronary artery. The lengths of the myocardial bridges were found 5-40 and 8-50 mm with dissection and dual-source computed tomography angiography, respectively. And the depths were found 0.7-4.5 mm by dual-source computed tomography angiography and 0.745-4.632 mm morphologically. Comparison of the mean values of the lengths showed statistically significantly higher values (22.0 ± 8.5, 17.7 ± 7.7 mm, p = 0.003) for the dissections. Radiological assessment also effectively discriminated complete bridges from incomplete ones. Our study showed that coronary computed tomography angiography is reliable in evaluating the presence and depth of myocardial bridges.

High-Throughput Bit-Serial LDPC Decoder LSI Based on Multiple-Valued Asynchronous Interleaving

NASA Astrophysics Data System (ADS)

Onizawa, Naoya; Hanyu, Takahiro; Gaudet, Vincent C.

This paper presents a high-throughput bit-serial low-density parity-check (LDPC) decoder that uses an asynchronous interleaver. Since consecutive log-likelihood message values on the interleaver are similar, node computations are continuously performed by using the most recently arrived messages without significantly affecting bit-error rate (BER) performance. In the asynchronous interleaver, each message's arrival rate is based on the delay due to the wire length, so that the decoding throughput is not restricted by the worst-case latency, which results in a higher average rate of computation. Moreover, the use of a multiple-valued data representation makes it possible to multiplex control signals and data from mutual nodes, thus minimizing the number of handshaking steps in the asynchronous interleaver and eliminating the clock signal entirely. As a result, the decoding throughput becomes 1.3 times faster than that of a bit-serial synchronous decoder under a 90nm CMOS technology, at a comparable BER.

Temporal Subtraction of Serial CT Images with Large Deformation Diffeomorphic Metric Mapping in the Identification of Bone Metastases.

PubMed

Sakamoto, Ryo; Yakami, Masahiro; Fujimoto, Koji; Nakagomi, Keita; Kubo, Takeshi; Emoto, Yutaka; Akasaka, Thai; Aoyama, Gakuto; Yamamoto, Hiroyuki; Miller, Michael I; Mori, Susumu; Togashi, Kaori

2017-11-01

Purpose To determine the improvement of radiologist efficiency and performance in the detection of bone metastases at serial follow-up computed tomography (CT) by using a temporal subtraction (TS) technique based on an advanced nonrigid image registration algorithm. Materials and Methods This retrospective study was approved by the institutional review board, and informed consent was waived. CT image pairs (previous and current scans of the torso) in 60 patients with cancer (primary lesion location: prostate, n = 14; breast, n = 16; lung, n = 20; liver, n = 10) were included. These consisted of 30 positive cases with a total of 65 bone metastases depicted only on current images and confirmed by two radiologists who had access to additional imaging examinations and clinical courses and 30 matched negative control cases (no bone metastases). Previous CT images were semiautomatically registered to current CT images by the algorithm, and TS images were created. Seven radiologists independently interpreted CT image pairs to identify newly developed bone metastases without and with TS images with an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Reading time was recorded, and usefulness was evaluated with subjective scores of 1-5, with 5 being extremely useful and 1 being useless. Significance of these values was tested with the Wilcoxon signed-rank test. Results The subtraction images depicted various types of bone metastases (osteolytic, n = 28; osteoblastic, n = 26; mixed osteolytic and blastic, n = 11) as temporal changes. The average reading time was significantly reduced (384.3 vs 286.8 seconds; Wilcoxon signed rank test, P = .028). The average figure-of-merit value increased from 0.758 to 0.835; however, this difference was not significant (JAFROC analysis, P = .092). The subjective usefulness survey response showed a median score of 5 for use of the technique (range, 3-5). Conclusion TS images obtained from serial CT scans using nonrigid registration successfully depicted newly developed bone metastases and showed promise for their efficient detection. © RSNA, 2017 Online supplemental material is available for this article.

Serial multiplier arrays for parallel computation

NASA Technical Reports Server (NTRS)

Winters, Kel

1990-01-01

Arrays of systolic serial-parallel multiplier elements are proposed as an alternative to conventional SIMD mesh serial adder arrays for applications that are multiplication intensive and require few stored operands. The design and operation of a number of multiplier and array configurations featuring locality of connection, modularity, and regularity of structure are discussed. A design methodology combining top-down and bottom-up techniques is described to facilitate development of custom high-performance CMOS multiplier element arrays as well as rapid synthesis of simulation models and semicustom prototype CMOS components. Finally, a differential version of NORA dynamic circuits requiring a single-phase uncomplemented clock signal introduced for this application.

Sinus CT scan

MedlinePlus

CAT scan - sinus; Computed axial tomography scan - sinus; Computed tomography scan - sinus; CT scan - sinus ... Risks for a CT scan includes: Being exposed to radiation Allergic reaction to contrast dye CT scans expose you to more radiation than regular ...

Brain PET scan

MedlinePlus

... tissues are working. Other imaging tests, such as magnetic resonance imaging ( MRI ) and computed tomography ( CT ) scans only reveal ... M, Hellwig S, Kloppel S, Weiller C. Functional neuroimaging: functional magnetic resonance imaging, positron emission tomography, and single-photon emission computed ...

Three-dimensional characterization of ODS ferritic steel using by FIB-SEM serial sectioning method.

PubMed

Endo, T; Sugino, Y; Ohono, N; Ukai, S; Miyazaki, N; Wang, Y; Ohnuki, S

2014-11-01

Considerable attention has been paid to the research of the electron tomography due to determine the three-dimensional (3D) structure of materials [1]. One of the electron tomography techniques, focused ion beam/scanning electron microscopy (FIB-SEM) imaging has advantages of high resolutions (10 nm), large area observation (μm order) and simultaneous energy dispersive x- ray microanalysis (EDS)/ electron backscatter diffraction (EBSD) analysis. The purpose of this study, three-dimensional EBSD analysis of ODS ferritic steel which carried out cold work using FIB-SEM equipment was conducted, and it aimed at analyzing the microstructure obtained there. The zone annealing tests were conducted for ferritic steel [2,3], which were produced through mechanical alloying and hot-extrusion. After zone annealing, specimens were mechanically polished with #400∼4000 emery paper, 1 µm diamond paste and alumina colloidal silica. The serial sectioning and the 3D-electron backscattering diffraction (3D-EBSD) analysis were carried out. We made the micro pillar (30 x 30 x 15 µm). The EBSD measurements were carried out in each layer after serial sectioning at a step size and milling depth was 80 nm with 30 slices. After EBSD analysis, the series of cross-sectional images were aligned according to arbitrarily specified areas and then stacked up to form a volume. Consequently, we obtained the 3D-IPF maps for ODS ferritic steel. In this specimen, the {111} and {001} grains are layered by turns. In addition, the volume fraction value of both plane are similar. The aspect ratio increases with specimen depth. The 3D-EBSD mapping is useful to analysis of the bulk material since this method obtain many microstructure information, such a shape, volume and orientation of the crystal, grain boundary. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Development of the OMPAT Neuropsychological/Psychomotor Performance Evaluation and OMPAT Data and Timing Support Programs

DTIC Science & Technology

1993-12-31

effect of Ritalin on attention and traumatically brain injured adults and the issues concerning repeated measures using computer based testing with...heat, cold and fatigue on neurological functions, as well as, the interactive and independent effects of chemical agents and pharmaceuticals. 5) A...serial manner was becoming an increasingly important task in neuropsychology. Serial assessment was important for monitoring medication effects

Describing, using 'recognition cones'. [parallel-series model with English-like computer program

NASA Technical Reports Server (NTRS)

Uhr, L.

1973-01-01

A parallel-serial 'recognition cone' model is examined, taking into account the model's ability to describe scenes of objects. An actual program is presented in an English-like language. The concept of a 'description' is discussed together with possible types of descriptive information. Questions regarding the level and the variety of detail are considered along with approaches for improving the serial representations of parallel systems.

77 FR 8223 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

..., or Partially-Exclusive Licensing of an Invention Concerning a Computer Controlled System for Laser... provides a computer controlled system for laser energy delivery to the retina. Information is received from... Application Serial No. 13/130,380, entitled ``Computer Controlled System for Laser Energy Delivery to the...

Jargon that Computes: Today's PC Terminology.

ERIC Educational Resources Information Center

Crawford, Walt

1997-01-01

Discusses PC (personal computer) and telecommunications terminology in context: Integrated Services Digital Network (ISDN); Asymmetric Digital Subscriber Line (ADSL); cable modems; satellite downloads; T1 and T3 lines; magnitudes ("giga-,""nano-"); Central Processing Unit (CPU); Random Access Memory (RAM); Universal Serial Bus…

Cone beam computed tomography: basics and applications in dentistry.

PubMed

Venkatesh, Elluru; Elluru, Snehal Venkatesh

2017-01-01

The introduction of cone beam computed tomography (CBCT) devices, changed the way oral and maxillofacial radiology is practiced. CBCT was embraced into the dental settings very rapidly due to its compact size, low cost, low ionizing radiation exposure when compared to medical computed tomography. Alike medical CT, 3 dimensional evaluation of the maxillofacial region with minimal distortion is offered by the CBCT. This article provides an overview of basics of CBCT technology and reviews the specific application of CBCT technology to oral and maxillofacial region with few illustrations.

Microstructure of cotton fibrous assemblies based on computed tomography

NASA Astrophysics Data System (ADS)

Jing, Hui; Yu, Weidong

2017-12-01

This paper describes for the first time the analysis of inner microstructure of cotton fibrous assemblies using computed tomography. Microstructure parameters such as packing density, fractal dimension as well as porosity including open porosity, closed porosity and total porosity are calculated based on 2D data from computed tomography. Values of packing density and fractal dimension are stable in random oriented fibrous assemblies, and there exists a satisfactory approximate linear relationship between them. Moreover, poles analysis indicates that porosity represents the tightness of fibrous assemblies and open poles are main existence.

Progress of projection computed tomography by upgrading of the beamline 37XU of SPring-8

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

Terada, Yasuko, E-mail: yterada@spring8.or.jp; Suzuki, Yoshio; Uesugi, Kentaro

2016-01-28

Beamline 37XU at SPring-8 has been upgraded for nano-focusing applications. The length of the beamline has been extended to 80 m. By utilizing this length, the beamline has advantages for experiments such as X-ray focusing, X-ray microscopic imaging and X-ray computed tomography. Projection computed tomography measurements were carried out at experimental hutch 3 located 80 m from the light source. CT images of a microcapsule have been successfully obtained with a wide X-ray energy range.

The use of iohexol as oral contrast for computed tomography of the abdomen and pelvis.

PubMed

Horton, Karen M; Fishman, Elliot K; Gayler, Bob

2008-01-01

Positive oral contrast agents (high-osmolar iodinated solutions [high-osmolar contrast medium] or barium sulfate suspensions) are used routinely for abdominal computed tomography. However, these agents are not ideal. Patients complain about the taste and, sometimes, refuse to drink the required quantity. Nausea, vomiting, and diarrhea are frequent. In certain clinical indications, either barium suspensions or high-osmolar contrast mediums may be contraindicated. This technical note describes the potential advantages of using low-osmolar iodinated solutions as an oral contrast agent for computed tomography.

Phase-contrast x-ray computed tomography for observing biological specimens and organic materials

NASA Astrophysics Data System (ADS)

Momose, Atsushi; Takeda, Tohoru; Itai, Yuji

1995-02-01

A novel three-dimensional x-ray imaging method has been developed by combining a phase-contrast x-ray imaging technique with x-ray computed tomography. This phase-contrast x-ray computed tomography (PCX-CT) provides sectional images of organic specimens that would produce absorption-contrast x-ray CT images with little contrast. Comparing PCX-CT images of rat cerebellum and cancerous rabbit liver specimens with corresponding absorption-contrast CT images shows that PCX-CT is much more sensitive to the internal structure of organic specimens.

Progression of fibrosis in usual interstitial pneumonia: serial evaluation of the native lung after single lung transplantation.

PubMed

Grgic, Aleksandar; Lausberg, Henning; Heinrich, Marc; Koenig, Jochem; Uder, Michael; Sybrecht, Gerhard W; Wilkens, Heinrike

2008-01-01

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a poor prognosis. Usual interstitial pneumonia (UIP) is the histopathological pattern identifying patients with the clinical entity of IPF. Despite aggressive immunosuppressive therapy the clinical course is usually dismal. For selected patients only lung transplantation improves prognosis and quality of life. After lung transplantation patients often receive a potent cyclosporine-based immunosuppressive therapy. Some reports suggest that cyclosporine has the potential to prevent progression of fibrosis. In patients with single lung transplantation (sLTx) for UIP we evaluated the effect of cyclosporine-based immunosuppressive therapy on progression of fibrosis using a high-resolution computed tomography (HRCT) scoring system. This retrospective observational study included 13 patients (24-64 years old) with histologically confirmed UIP who had HRCT scans preceding and following sLTx and who survived at least 6 months after sLTx. All patients were initially treated with cyclosporin A, prednisone and azathioprine. Three radiologists analyzed HRCT scans by setting a score regarding fibrosis [fibrosis score (FS); range 0-5 for each lobe] and ground-glass opacity [ground-glass score (GGS); range 0-5 for each lobe]. A comparison of serial changes (interval: 12-96 months posttransplant, 2-4 HRCT examinations/patient) was performed with the sign test. Mean pretransplant FS and GGS of the nontransplanted lung were 1.80 and 1.61, respectively. Comparing pre- and posttransplant HRCT scans, mean lung FS significantly increased (0.35 +/- 0.15/year; p = 0.00024), while GGS tended to decrease (0.06 +/- 0.26/year; p = 0.5). A cyclosporin A based triple immunosuppressive regimen following sLTx does not seem to prevent progression of the fibrotic changes of the native lung in patients with IPF. Copyright 2007 S. Karger AG, Basel.

Acute invasive fungal rhinosinusitis: our experience with 18 cases.

PubMed

Bakhshaee, Mehdi; Bojdi, Amin; Allahyari, Abolghasem; Majidi, Mohammad Reza; Tavakol, Sherwin; Najafzadeh, Mohammad Javad; Asghari, Masoud

2016-12-01

Acute invasive fungal rhinosinusitis (AIFRS) is a rapidly progressive life threatening infection that is seen most commonly among immunocompromised patients. We present a case series of 18 patients clinically and histopathologically diagnosed with AIFRS with a mean follow-up of 9.11 ± 2.51 months (range 6-17). Demographic data, apparent symptoms and signs, underlying disorders, and outcomes are discussed. The mean age was 39.56 ± 20.66 years (range 2-75). The most common underlying diseases were diabetes mellitus (50 %) and leukemia (44.44 %). Mucosal biopsy confirmed fungal invasion of the nasal mucosa in all cases. The main fungi were Rhizopus oryzae (55.56 %), Absidia mucor (16.67 %), and Aspergillus fumigatus (27.78 %). Headache and facial pain (77.8 %), facial paresthesia (55.6 %), and ophthalmoplegia (33.3 %) were the most common symptoms and signs. Computed tomography and endoscopic findings showed various stages of sinonasal (100 %), pterygopalatine fossa (55.56 %), orbital (44.45 %), and cerebral (5.56 %) involvement. All patients underwent serial surgical debridement (3.78 ± 1.80 times; range 2-8) simultaneously with systemic antifungal therapy and proper management of the underlying disease. The most extreme case with brain involvement survived and recovered with no evidence of recurrent disease following treatment. All patients were considered cured after two endoscopic negative histopathologic evaluations. Three patients (16.67 %) died, one from uncontrolled leukemia and two due to renal failure. AIFRS is a potentially fatal condition, however, early diagnosis and management of the underlying disease accompanied with systemic antifungal and aggressive serial surgical intervention appears to be effective in reducing mortality in most patients.

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

PubMed

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

2017-05-01

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

Development of the ethmoid in Caluromys philander (Didelphidae, Marsupialia) with a discussion on the homology of the turbinal elements in marsupials.

PubMed

Macrini, Thomas E

2014-11-01

Homology of turbinals, or scroll bones, of the mammalian ethmoid bone is poorly known and complicated by a varied terminology. Positionally, there are two main types of ossified adult turbinals known as endoturbinals and ectoturbinals, and their cartilaginous precursors are called ethmoturbinals and frontoturbinals, respectively. Endoturbinals are considered to be serially homologous due to similarity in their developmental patterns. Consequently, endoturbinals from mammals with differing numbers of elements cannot be individually homogenized. In this study, the development of the ethmoid of Caluromys philander, the bare-tailed woolly opossum, is described based on serial sections of six pouchlings ranging in age from 20 to 84 days postnatal (PND-84), and computed tomography images of an adult skull. I found that four ethmoturbinals initially develop as seen in PND-20 and PND-30 individuals but by PND-64 an interturbinal (corresponding to endoturbinal III in adults) is present between ethmoturbinals II and III. This developmental pattern is identical to that of Monodelphis domestica, the gray short-tailed opossum, and is probably also present in the marsupials Didelphis marsupialis, and Thylacinus cynocephalus based on work of previous authors. These data suggest that endoturbinal III has a developmental pattern that differs from other endoturbinals, and the name interturbinal should be retained for the adult structure in recognition of this difference. These results may prove useful for homologizing this individual turbinal element across marsupials, the majority of which have five endoturbinals as adults. This might also explain the presumed placental ancestral condition of four endoturbinals if the marsupial interturbinal is lost. © 2014 Wiley Periodicals, Inc.

Contours identification of elements in a cone beam computed tomography for investigating maxillary cysts

NASA Astrophysics Data System (ADS)

Chioran, Doina; Nicoarǎ, Adrian; Roşu, Şerban; Cǎrligeriu, Virgil; Ianeş, Emilia

2013-10-01

Digital processing of two-dimensional cone beam computer tomography slicesstarts by identification of the contour of elements within. This paper deals with the collective work of specialists in medicine and applied mathematics in computer science on elaborating and implementation of algorithms in dental 2D imagery.

Neuroanatomy of cranial computed tomography

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

Kretschmann, H.J.; Weinrich, W.

1985-01-01

Based on the fundamental structures visualized by means of computed tomography, the authors present the functional systems which are relevant in neurology by means of axial cross-sections. All drawings were prepared from original preparations by means of a new technique which is similar to the grey values of X-ray CT and nuclear magnetic resonance tomography. A detailed description is given of the topics of neurofunctional lesions.

Predicting Radiation Esophagitis Using 18F-FDG PET During Chemoradiotherapy for Locally Advanced Non-Small Cell Lung Cancer.

PubMed

Mehmood, Qurrat; Sun, Alexander; Becker, Nathan; Higgins, Jane; Marshall, Andrea; Le, Lisa W; Vines, Douglass C; McCloskey, Paula; Ford, Victoria; Clarke, Katy; Yap, Mei; Bezjak, Andrea; Bissonnette, Jean-Pierre

2016-02-01

Treatment of locally advanced non-small cell lung cancer with chemoradiotherapy (CRT) is limited by development of toxicity in normal tissue, including radiation esophagitis (RE). Increasingly, (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is being used for adaptive planning. Our aim was to assess changes in esophageal FDG uptake during CRT and relate the changes to the onset and severity of RE. This prospective study in patients with stage II-III non-small cell lung cancer involved serial four-dimensional computed tomography and PET scans during CRT (60-74Gy). RE was recorded weekly using the Common Terminology Criteria for Adverse Events (v4.0), and imaging was performed at weeks 0, 2, 4, and 7. Changes in the esophagus's peak standard uptake value (SUVpeak) were analyzed for each time point and correlated with grade of RE using the Wilcoxon rank-sum test. The volume of esophagus receiving 50 Gy (V50) and volume of esophagus receiving 60 Gy (V60) were correlated with the development of RE, and the C-statistic (area under the curve [AUC]) was calculated to measure predictivity of grade 3 RE. RE developed in 20 of 27 patients (74%), with grade 3 reached in 6 (22%). A significant percentage increase in SUVpeak in the patients with RE was noted at week 4 (p = 0.01) and week 7 (p = 0.03). For grade 3 RE, a significant percentage increase in SUVpeak was noted at week 2 (p = 0.01) and week 7 (p = 0.03) compared with that for less than grade 3 RE. Median V50 (46.3%) and V60 (33.4%) were significantly higher in patients with RE (p = 0.04). The AUC measurements suggested that the percentage change in SUVpeak at week 2 (AUC = 0.69) and V50 (AUC = 0.67) and V60 (AUC = 0.66) were similarly predictive of grade 3 RE. Serial FDG-PET images during CRT show significant increases in SUVpeak for patients in whom RE develops. The changes at week 2 may predict those at risk for the development of grade 3 RE and may be informative for adaptive planning and early intervention. Copyright © 2015 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

HDL mimetic CER-001 targets atherosclerotic plaques in patients.

PubMed

Zheng, Kang He; van der Valk, Fleur M; Smits, Loek P; Sandberg, Mara; Dasseux, Jean-Louis; Baron, Rudi; Barbaras, Ronald; Keyserling, Constance; Coolen, Bram F; Nederveen, Aart J; Verberne, Hein J; Nell, Thijs E; Vugts, Danielle J; Duivenvoorden, Raphaël; Fayad, Zahi A; Mulder, Willem J M; van Dongen, Guus A M S; Stroes, Erik S G

2016-08-01

Infusion of high-density lipoprotein (HDL) mimetics aimed at reducing atherosclerotic burden has led to equivocal results, which may relate in part to the inability of HDL mimetics to adequately reach atherosclerotic lesions in humans. This study evaluated delivery of recombinant human apolipoprotein A-I (apoA-I) containing HDL mimetic CER-001 in carotid plaques in patients. CER-001 was radiolabeled with the long-lived positron emitter zirconium-89 ((89)Zr) to enable positron emission tomography with computed tomography (PET/CT) imaging. Eight patients with atherosclerotic carotid artery disease (>50% stenosis) received a single infusion of unlabeled CER-001 (3 mg/kg), co-administered with 10 mg of (89)Zr-labeled CER-001 (18 MBq). Serial PET/CT imaging and contrast enhanced-magnetic resonance imaging (CE-MRI) were performed to evaluate targeted delivery of CER-001. One hour after infusion, mean plasma apoA-I levels increased by 9.9 mg/dL (p = 0.026), with a concomitant relative increase in the plasma cholesterol efflux capacity of 13.8% (p < 0.001). Using serial PET/CT imaging, we showed that arterial uptake of CER-001 expressed as target-to-background ratio (TBRmax) increased significantly 24 h after infusion, and remained increased up to 48 h (TBRmax t = 10 min: 0.98; t = 24 h: 1.14 (p = 0.001); t = 48 h: 1.12 (p = 0.007)). TBRmax was higher in plaque compared with non-plaque segments (1.18 vs. 1.05; p < 0.001). Plaque TBRmax correlated with local plaque contrast enhancement (r = 0.56; p = 0.019) as assessed by CE-MRI. Infusion of HDL mimetic CER-001 increases plasma apoA-I concentration and plasma cholesterol efflux capacity. Our data support the concept that CER-001 targets plaque regions in patients, which correlates with plaque contrast enhancement. These clinical findings may also guide future nanomedicine development using HDL particles for drug delivery in atherosclerosis. Netherlands Trial Registry - NTR5178. http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5178. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Frozen Gaussian approximation for 3D seismic tomography

NASA Astrophysics Data System (ADS)

Chai, Lihui; Tong, Ping; Yang, Xu

2018-05-01

Three-dimensional (3D) wave-equation-based seismic tomography is computationally challenging in large scales and high-frequency regime. In this paper, we apply the frozen Gaussian approximation (FGA) method to compute 3D sensitivity kernels and seismic tomography of high-frequency. Rather than standard ray theory used in seismic inversion (e.g. Kirchhoff migration and Gaussian beam migration), FGA is used to compute the 3D high-frequency sensitivity kernels for travel-time or full waveform inversions. Specifically, we reformulate the equations of the forward and adjoint wavefields for the purpose of convenience to apply FGA, and with this reformulation, one can efficiently compute the Green’s functions whose convolutions with source time function produce wavefields needed for the construction of 3D kernels. Moreover, a fast summation method is proposed based on local fast Fourier transform which greatly improves the speed of reconstruction as the last step of FGA algorithm. We apply FGA to both the travel-time adjoint tomography and full waveform inversion (FWI) on synthetic crosswell seismic data with dominant frequencies as high as those of real crosswell data, and confirm again that FWI requires a more sophisticated initial velocity model for the convergence than travel-time adjoint tomography. We also numerically test the accuracy of applying FGA to local earthquake tomography. This study paves the way to directly apply wave-equation-based seismic tomography methods into real data around their dominant frequencies.

Pediatric minor head trauma: do cranial CT scans change the therapeutic approach?

PubMed

Andrade, Felipe P; Montoro, Roberto; Oliveira, Renan; Loures, Gabriela; Flessak, Luana; Gross, Roberta; Donnabella, Camille; Puchnick, Andrea; Suzuki, Lisa; Regacini, Rodrigo

2016-10-01

1) To verify clinical signs correlated with appropriate cranial computed tomography scan indications and changes in the therapeutic approach in pediatric minor head trauma scenarios. 2) To estimate the radiation exposure of computed tomography scans with low dose protocols in the context of trauma and the additional associated risk. Investigators reviewed the medical records of all children with minor head trauma, which was defined as a Glasgow coma scale ≥13 at the time of admission to the emergency room, who underwent computed tomography scans during the years of 2013 and 2014. A change in the therapeutic approach was defined as a neurosurgical intervention performed within 30 days, hospitalization, >12 hours of observation, or neuro-specialist evaluation. Of the 1006 children evaluated, 101 showed some abnormality on head computed tomography scans, including 49 who were hospitalized, 16 who remained under observation and 36 who were dismissed. No patient underwent neurosurgery. No statistically significant relationship was observed between patient age, time between trauma and admission, or signs/symptoms related to trauma and abnormal imaging results. A statistically significant relationship between abnormal image results and a fall higher than 1.0 meter was observed (p=0.044). The mean effective dose was 2.0 mSv (0.1 to 6.8 mSv), corresponding to an estimated additional cancer risk of 0.05%. A computed tomography scan after minor head injury in pediatric patients did not show clinically relevant abnormalities that could lead to neurosurgical indications. Patients who fell more than 1.0 m were more likely to have changes in imaging tests, although these changes did not require neurosurgical intervention; therefore, the use of computed tomography scans may be questioned in this group. The results support the trend of more careful indications for cranial computed tomography scans for children with minor head trauma.

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model.

PubMed

Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Graumann, Ole; Pedersen, Bodil Ginnerup; Andersen, Gratien; Høyer, Søren; Borre, Michael

2017-08-01

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.

Validation of a computational knee joint model using an alignment method for the knee laxity test and computed tomography.

PubMed

Kang, Kyoung-Tak; Kim, Sung-Hwan; Son, Juhyun; Lee, Young Han; Koh, Yong-Gon

2017-01-01

Computational models have been identified as efficient techniques in the clinical decision-making process. However, computational model was validated using published data in most previous studies, and the kinematic validation of such models still remains a challenge. Recently, studies using medical imaging have provided a more accurate visualization of knee joint kinematics. The purpose of the present study was to perform kinematic validation for the subject-specific computational knee joint model by comparison with subject's medical imaging under identical laxity condition. The laxity test was applied to the anterior-posterior drawer under 90° flexion and the varus-valgus under 20° flexion with a series of stress radiographs, a Telos device, and computed tomography. The loading condition in the computational subject-specific knee joint model was identical to the laxity test condition in the medical image. Our computational model showed knee laxity kinematic trends that were consistent with the computed tomography images, except for negligible differences because of the indirect application of the subject's in vivo material properties. Medical imaging based on computed tomography with the laxity test allowed us to measure not only the precise translation but also the rotation of the knee joint. This methodology will be beneficial in the validation of laxity tests for subject- or patient-specific computational models.

Computed tomography or rhinoscopy as the first-line procedure for suspected nasal tumor: a pilot study.

PubMed

Finck, Marlène; Ponce, Frédérique; Guilbaud, Laurent; Chervier, Cindy; Floch, Franck; Cadoré, Jean-Luc; Chuzel, Thomas; Hugonnard, Marine

2015-02-01

There are no evidence-based guidelines as to whether computed tomography (CT) or endoscopy should be selected as the first-line procedure when a nasal tumor is suspected in a dog or a cat and only one examination can be performed. Computed tomography and rhinoscopic features of 17 dogs and 5 cats with a histopathologically or cytologically confirmed nasal tumor were retrospectively reviewed. The level of suspicion for nasal neoplasia after CT and/or rhinoscopy was compared to the definitive diagnosis. Twelve animals underwent CT, 14 underwent rhinoscopy, and 4 both examinations. Of the 12 CT examinations performed, 11 (92%) resulted in the conclusion that a nasal tumor was the most likely diagnosis compared with 9/14 (64%) for rhinoscopies. Computed tomography appeared to be more reliable than rhinoscopy for detecting nasal tumors and should therefore be considered as the first-line procedure.

Computed tomography or rhinoscopy as the first-line procedure for suspected nasal tumor: A pilot study

PubMed Central

Finck, Marlène; Ponce, Frédérique; Guilbaud, Laurent; Chervier, Cindy; Floch, Franck; Cadoré, Jean-Luc; Chuzel, Thomas; Hugonnard, Marine

2015-01-01

There are no evidence-based guidelines as to whether computed tomography (CT) or endoscopy should be selected as the first-line procedure when a nasal tumor is suspected in a dog or a cat and only one examination can be performed. Computed tomography and rhinoscopic features of 17 dogs and 5 cats with a histopathologically or cytologically confirmed nasal tumor were retrospectively reviewed. The level of suspicion for nasal neoplasia after CT and/or rhinoscopy was compared to the definitive diagnosis. Twelve animals underwent CT, 14 underwent rhinoscopy, and 4 both examinations. Of the 12 CT examinations performed, 11 (92%) resulted in the conclusion that a nasal tumor was the most likely diagnosis compared with 9/14 (64%) for rhinoscopies. Computed tomography appeared to be more reliable than rhinoscopy for detecting nasal tumors and should therefore be considered as the first-line procedure. PMID:25694669

Review of cardiovascular imaging in The Journal of Nuclear Cardiology in 2014: Part 1 of 2: Positron emission tomography, computed tomography, and neuronal imaging.

PubMed

AlJaroudi, Wael A; Hage, Fadi G

2015-06-01

The year 2014 has been an exciting year for the cardiovascular imaging community with significant advances in the realm of nuclear and multimodality cardiac imaging. In this new feature of the Journal of Nuclear Cardiology, we will summarize some of the breakthroughs that were published in the Journal in 2014 in 2 sister articles. This first article will concentrate on publications dealing with cardiac positron emission tomography (PET), computed tomography (CT), and neuronal imaging.

Trends in micro- and nanoComputed Tomography 2008-2010

NASA Astrophysics Data System (ADS)

Stock, S. R.

2010-09-01

Trends in micro- and nanoComputed Tomography (CT) from January 2008 through July 2010 are the subject of this brief report which takes up where a previous report in Developments in X-ray Tomography VI (2008) concluded. First, the number of systems operating world-wide is estimated. The main focus is on what searches of three citation indices (Web of Science, Compendex and PubMed) reveal about the field of micro- and nanoCT. Given research-fielddependent and disparate terminology used by investigators, searches were on "microtomography", "microCT" and "synchrotron tomography".

Radiologic Responses in Cynomolgus Macaques for Assessing Tuberculosis Chemotherapy Regimens

PubMed Central

Lin, Philana Ling; Coleman, Teresa; Carney, Jonathan P. J.; Lopresti, Brian J.; Tomko, Jaime; Fillmore, Dan; Dartois, Veronique; Scanga, Charles; Frye, L. James; Janssen, Christopher; Klein, Edwin; Barry, Clifton E.

2013-01-01

Trials to test new drugs currently in development against tuberculosis in humans are impractical. All animal models to prioritize new regimens are imperfect, but nonhuman primates (NHPs) infected with Mycobacterium tuberculosis develop active tuberculosis (TB) disease with a full spectrum of lesion types seen in humans. Serial 2-deoxy-2-[18F]-fluoro-d-glucose (FDG) positron emission tomography (PET) with computed tomography (CT) imaging was performed on cynomolgus macaques during infection and chemotherapy with individual agents or the four-drug combination therapy most widely used globally. The size and metabolic activity of lung granulomas varied among animals and even within a single animal during development of disease. Individual granulomas within untreated animals had highly local and independent outcomes, some progressing in size and FDG uptake, while others waned, illustrating the highly dynamic nature of active TB. At necropsy, even untreated animals were found to have a proportion of sterile lesions consistent with the dynamics of this infection. A more marked reduction in overall metabolic activity in the lungs (decreased FDG uptake) was associated with effective treatment. A reduction in the size of individual lesions correlated with a lower bacterial burden at necropsy. Isoniazid treatment was associated with a transient increase in metabolic activity in individual lesions, whereas a net reduction occurred in most lesions from rifampin-treated animals. Quadruple-drug therapy resulted in the highest decrease in FDG uptake. The findings of PET-CT imaging may provide an important early correlate of the efficacy of novel combinations of new drugs that can be directly translated to human clinical trials. PMID:23796926

[Measurement of intracranial hematoma volume by personal computer].

PubMed

DU, Wanping; Tan, Lihua; Zhai, Ning; Zhou, Shunke; Wang, Rui; Xue, Gongshi; Xiao, An

2011-01-01

To explore the method for intracranial hematoma volume measurement by the personal computer. Forty cases of various intracranial hematomas were measured by the computer tomography with quantitative software and personal computer with Photoshop CS3 software, respectively. the data from the 2 methods were analyzed and compared. There was no difference between the data from the computer tomography and the personal computer (P>0.05). The personal computer with Photoshop CS3 software can measure the volume of various intracranial hematomas precisely, rapidly and simply. It should be recommended in the clinical medicolegal identification.

Computed Tomography of the Musculoskeletal System.

PubMed

Ballegeer, Elizabeth A

2016-05-01

Computed tomography (CT) has specific uses in veterinary species' appendicular musculoskeletal system. Parameters for acquisition of images, interpretation limitations, as well as published information regarding its use in small animals is reviewed. Copyright © 2016 Elsevier Inc. All rights reserved.

Cholangiocarcinoma associated with limbic encephalitis and early cerebral abnormalities detected by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography: a case report.

PubMed

Schmidt, Sergio L; Schmidt, Juliana J; Tolentino, Julio C; Ferreira, Carlos G; de Almeida, Sergio A; Alvarenga, Regina P; Simoes, Eunice N; Schmidt, Guilherme J; Canedo, Nathalie H S; Chimelli, Leila

2016-07-20

Limbic encephalitis was originally described as a rare clinical neuropathological entity involving seizures and neuropsychological disturbances. In this report, we describe cerebral patterns visualized by positron emission tomography in a patient with limbic encephalitis and cholangiocarcinoma. To our knowledge, there is no other description in the literature of cerebral positron emission tomography findings in the setting of limbic encephalitis and subsequent diagnosis of cholangiocarcinoma. We describe a case of a 77-year-old Caucasian man who exhibited persistent cognitive changes 2 years before his death. A cerebral scan obtained at that time by 2-deoxy-2-[fluorine-18]fluoro- D -glucose integrated with computed tomography-positron emission tomography showed low radiotracer uptake in the frontal and temporal lobes. Cerebrospinal fluid analysis indicated the presence of voltage-gated potassium channel antibodies. Three months before the patient's death, a lymph node biopsy indicated a cholangiocarcinoma, and a new cerebral scan obtained by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography showed an increment in the severity of metabolic deficit in the frontal and parietal lobes, as well as hypometabolism involving the temporal lobes. Two months before the patient's death, cerebral metastases were detected on a contrast-enhanced computed tomographic scan. Postmortem examination revealed a cholangiocarcinoma with multiple metastases including the lungs and lymph nodes. The patient's brain weighed 1300 g, and mild cortical atrophy, ex vacuo dilation of the ventricles, and mild focal thickening of the cerebellar leptomeninges, which were infiltrated by neoplastic epithelial cells, were observed. These findings support the need for continued vigilance in malignancy surveillance in patients with limbic encephalitis and early cerebral positron emission tomographic scan abnormalities. The difficulty in early diagnosis of small tumors, such as a cholangiocarcinoma, is discussed in the context of the clinical utility of early cerebral hypometabolism detected by 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography-positron emission tomography in patients with rapidly progressive dementia.

A Computer Engineering Curriculum for the Air Force Academy: An Implementation Plan

DTIC Science & Technology

1985-04-01

engineerinq is needed as a r ul of the findings? 5. What is the impact of this study’s rocommendat ion to pursue the Electrico I Engineering deqree with onpt...stepper motor 9 S35 LAB 36 Serial 10 S37 GR #3 - 38 8251 10 chip ) 39 LAB serial 10 10 * 40 LAB " 1)41 LAB S 42 Course review - S FINAL EXAM 00 % 80 0

Domain identification in impedance computed tomography by spline collocation method

NASA Technical Reports Server (NTRS)

Kojima, Fumio

1990-01-01

A method for estimating an unknown domain in elliptic boundary value problems is considered. The problem is formulated as an inverse problem of integral equations of the second kind. A computational method is developed using a splice collocation scheme. The results can be applied to the inverse problem of impedance computed tomography (ICT) for image reconstruction.

INDIRECT COMPUTED TOMOGRAPHIC LYMPHOGRAPHY FOR ILIOSACRAL LYMPHATIC MAPPING IN A COHORT OF DOGS WITH ANAL SAC GLAND ADENOCARCINOMA: TECHNIQUE DESCRIPTION.

PubMed

Majeski, Stephanie A; Steffey, Michele A; Fuller, Mark; Hunt, Geraldine B; Mayhew, Philipp D; Pollard, Rachel E

2017-05-01

Sentinel lymph node mapping can help to direct surgical oncologic staging and metastatic disease detection in patients with complex lymphatic pathways. We hypothesized that indirect computed tomographic lymphography (ICTL) with a water-soluble iodinated contrast agent would successfully map lymphatic pathways of the iliosacral lymphatic center in dogs with anal sac gland carcinoma, providing a potential preoperative method for iliosacral sentinel lymph node identification in dogs. Thirteen adult dogs diagnosed with anal sac gland carcinoma were enrolled in this prospective, pilot study, and ICTL was performed via peritumoral contrast injection with serial caudal abdominal computed tomography scans for iliosacral sentinel lymph node identification. Technical and descriptive details for ICTL were recorded, including patient positioning, total contrast injection volume, timing of contrast visualization, and sentinel lymph nodes and lymphatic pathways identified. Indirect CT lymphography identified lymphatic pathways and sentinel lymph nodes in 12/13 cases (92%). Identified sentinel lymph nodes were ipsilateral to the anal sac gland carcinoma in 8/12 and contralateral to the anal sac gland carcinoma in 4/12 cases. Sacral, internal iliac, and medial iliac lymph nodes were identified as sentinel lymph nodes, and patterns were widely variable. Patient positioning and timing of imaging may impact successful sentinel lymph node identification. Positioning in supported sternal recumbency is recommended. Results indicate that ICTL may be a feasible technique for sentinel lymph node identification in dogs with anal sac gland carcinoma and offer preliminary data to drive further investigation of iliosacral lymphatic metastatic patterns using ICTL and sentinel lymph node biopsy. © 2017 American College of Veterinary Radiology.

Optical transmission modules for multi-channel superconducting quantum interference device readouts.

PubMed

Kim, Jin-Mok; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong

2013-12-01

We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.

Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction.

PubMed

Freyer, Marcus; Ale, Angelique; Schulz, Ralf B; Zientkowska, Marta; Ntziachristos, Vasilis; Englmeier, Karl-Hans

2010-01-01

The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.

Clinical applications of cone beam computed tomography in endodontics: A comprehensive review.

PubMed

Cohenca, Nestor; Shemesh, Hagay

2015-09-01

The use of cone beam computed tomography (CBCT) in endodontics has been extensively reported in the literature. Compared with the traditional spiral computed tomography, limited field of view (FOV) CBCT results in a fraction of the effective absorbed dose of radiation. The purpose of this manuscript is to review the application and advantages associated with advanced endodontic problems and complications, while reducing radiation exposure during complex endodontic procedures. The benefits of the added diagnostic information provided by intraoperative CBCT images in select cases justify the risk associated with the limited level of radiation exposure.

Dry coupling for whole-body small-animal photoacoustic computed tomography

NASA Astrophysics Data System (ADS)

Yeh, Chenghung; Li, Lei; Zhu, Liren; Xia, Jun; Li, Chiye; Chen, Wanyi; Garcia-Uribe, Alejandro; Maslov, Konstantin I.; Wang, Lihong V.

2017-04-01

We have enhanced photoacoustic computed tomography with dry acoustic coupling that eliminates water immersion anxiety and wrinkling of the animal and facilitates incorporating complementary modalities and procedures. The dry acoustic coupler is made of a tubular elastic membrane enclosed by a closed transparent water tank. The tubular membrane ensures water-free contact with the animal, and the closed water tank allows pressurization for animal stabilization. The dry coupler was tested using a whole-body small-animal ring-shaped photoacoustic computed tomography system. Dry coupling was found to provide image quality comparable to that of conventional water coupling.

Linear-array based full-view high-resolution photoacoustic computed tomography of whole mouse brain functions in vivo

NASA Astrophysics Data System (ADS)

Li, Lei; Zhang, Pengfei; Wang, Lihong V.

2018-02-01

Photoacoustic computed tomography (PACT) is a non-invasive imaging technique offering high contrast, high resolution, and deep penetration in biological tissues. We report a photoacoustic computed tomography (PACT) system equipped with a high frequency linear array for anatomical and functional imaging of the mouse whole brain. The linear array was rotationally scanned in the coronal plane to achieve the full-view coverage. We investigated spontaneous neural activities in the deep brain by monitoring the hemodynamics and observed strong interhemispherical correlations between contralateral regions, both in the cortical layer and in the deep regions.

Broadband Terahertz Computed Tomography Using a 5k-pixel Real-time THz Camera

NASA Astrophysics Data System (ADS)

Trichopoulos, Georgios C.; Sertel, Kubilay

2015-07-01

We present a novel THz computed tomography system that enables fast 3-dimensional imaging and spectroscopy in the 0.6-1.2 THz band. The system is based on a new real-time broadband THz camera that enables rapid acquisition of multiple cross-sectional images required in computed tomography. Tomographic reconstruction is achieved using digital images from the densely-packed large-format (80×64) focal plane array sensor located behind a hyper-hemispherical silicon lens. Each pixel of the sensor array consists of an 85 μm × 92 μm lithographically fabricated wideband dual-slot antenna, monolithically integrated with an ultra-fast diode tuned to operate in the 0.6-1.2 THz regime. Concurrently, optimum impedance matching was implemented for maximum pixel sensitivity, enabling 5 frames-per-second image acquisition speed. As such, the THz computed tomography system generates diffraction-limited resolution cross-section images as well as the three-dimensional models of various opaque and partially transparent objects. As an example, an over-the-counter vitamin supplement pill is imaged and its material composition is reconstructed. The new THz camera enables, for the first time, a practical application of THz computed tomography for non-destructive evaluation and biomedical imaging.

[Contribution of X-ray computed tomography in the evaluation of kidney performance].

PubMed

Lemoine, Sandrine; Rognant, Nicolas; Collet-Benzaquen, Diane; Juillard, Laurent

2012-07-01

X-ray computer assisted tomography scanner is an imaging method based on the use of X-ray attenuation in tissue. This attenuation is proportional to the density of the tissue (without or after contrast media injection) in each pixel image of the image. Spiral scanner, the electron beam computed tomography (EBCT) scanner and multidetector computed tomography scanner allow renal anatomical measurements, such as cortical and medullary volume, but also the measurement of renal functional parameters, such as regional renal perfusion, renal blood flow and glomerular filtration rate. These functional parameters are extracted from the modeling of the kinetics of the contrast media concentration in the vascular space and the renal tissue, using two main mathematical models (the gamma variate model and the Patlak model). Renal functional imaging allows measuring quantitative parameters on each kidney separately, in a non-invasive manner, providing significant opportunities in nephrology, both for experimental and clinical studies. However, this method uses contrast media that may alter renal function, thus limiting its use in patients with chronic renal failure. Moreover, the increase irradiation delivered to the patient with multi detector computed tomography (MDCT) should be considered. Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

CAMAC throughput of a new RISC-based data acquisition computer at the DIII-D tokamak

NASA Astrophysics Data System (ADS)

Vanderlaan, J. F.; Cummings, J. W.

1993-10-01

The amount of experimental data acquired per plasma discharge at DIII-D has continued to grow. The largest shot size in May 1991 was 49 Mbyte; in May 1992, 66 Mbyte; and in April 1993, 80 Mbyte. The increasing load has prompted the installation of a new Motorola 88100-based MODCOMP computer to supplement the existing core of three older MODCOMP data acquisition CPU's. New Kinetic Systems CAMAC serial highway driver hardware runs on the 88100 VME bus. The new operating system is MODCOMP REAL/IX version of AT&T System V UNIX with real-time extensions and networking capabilities; future plans call for installation of additional computers of this type for tokamak and neutral beam control functions. Experiences with the CAMAC hardware and software will be chronicled, including observation of data throughput. The Enhanced Serial Highway crate controller is advertised as twice as fast as the previous crate controller, and computer I/O speeds are expected to also increase data rates.

Advances in Integrating Autonomy with Acoustic Communications for Intelligent Networks of Marine Robots

DTIC Science & Technology

2013-02-01

Sonar AUV #Environmental Sampling Environmental AUV +name : string = OEX Ocean Explorer +name : string = Hammerhead Iver2 +name : string = Unicorn ...executable» Google Earth Bluefin 21 AUV ( Unicorn ) MOOS Computer GPS «serial» Bluefin 21 AUV (Macrura) MOOS Computer «acoustic» Micro-Modem «wired...Computer Bluefin 21 AUV ( Unicorn ) MOOS Computer NURC AUV (OEX) MOOS Computer Topside MOOS Computer «wifi» 5.0GHz WiLan «acoustic» Edgetech GPS

Phase-contrast tomography of neuronal tissues: from laboratory- to high resolution synchrotron CT

NASA Astrophysics Data System (ADS)

Töpperwien, Mareike; Krenkel, Martin; Müller, Kristin; Salditt, Tim

2016-10-01

Assessing the three-dimensional architecture of neuronal tissues with sub-cellular resolution presents a significant analytical challenge. Overcoming the limitations associated with serial slicing, phase-contrast x-ray tomography has the potential to contribute to this goal. Even compact laboratory CT at an optimized liquid-metal jet micro- focus source combined with suitable phase-retrieval algorithms and preparation protocols can yield renderings with single cell sensitivity in millimeter sized brain areas of mouse. Here, we show the capabilities of the setup by imaging a Golgi-Cox impregnated mouse brain. Towards higher resolution we extend these studies at our recently upgraded waveguide-based cone-beam holo-tomography instrument GINIX at DESY. This setup allows high resolution recordings with adjustable field of view and resolution, down to the voxel sizes in the range of a few ten nanometers. The recent results make us confident that important issues of neuronal connectivity can be addressed by these methods, and that 3D (virtual) histology with nanoscale resolution will become an attractive modality for neuroscience research.

Reconstructing the Auditory Apparatus of Therapsids by Means of Neutron Tomography

NASA Astrophysics Data System (ADS)

Laaß, Michael; Schillinger, Burkhard

The internal cranial structure of mammalian ancestors, i.e. the therapsids or ;mammal-like reptiles;, is crucial for understanding the early mammalian evolution. In the past therapsid skulls were investigated by mechanical sectioning or serial grinding, which was a very time-consuming and destructive process and could only be applied to non-valuable or poorly preserved specimens. As most therapsid skulls are embedded in terrestrial iron-rich sediments of Late Permian or Triassic age, i.e. so called ;Red beds;, a successful investigation with X-Rays is often not possible. We successfully investigated therapsid skulls by means of neutron tomography at the facility ANTARES at FRM II in Munich using cold neutron radiation. This kind of radiation is able to penetrate iron-rich substances in the range between 5 and 15 cm and produces a good contrast between matrix and bones, which enables segmentation of internal cranial structures such as bones, cavities and canals of nerves and blood vessels. In particular, neutron tomography combined with methods of 3D modeling was used here for the investigation and reconstruction of the auditory apparatus of therapsids.

Inter- and intraobserver reliability of the vertebral, local and segmental kyphosis in 120 traumatic lumbar and thoracic burst fractures: evaluation in lateral X-rays and sagittal computed tomographies

PubMed Central

Brunner, Alexander; Gühring, Markus; Schmälzle, Traude; Weise, Kuno; Badke, Andreas

2009-01-01

Evaluation of the kyphosis angle in thoracic and lumbar burst fractures is often used to indicate surgical procedures. The kyphosis angle could be measured as vertebral, segmental and local kyphosis according to the method of Cobb. The vertebral, segmental and local kyphosis according to the method of Cobb were measured at 120 lateral X-rays and sagittal computed tomographies of 60 thoracic and 60 lumbar burst fractures by 3 independent observers on 2 separate occasions. Osteoporotic fractures were excluded. The intra- and interobserver reliability of these angles in X-ray and computed tomogram, using the intra class correlation coefficient (ICC) were evaluated. Highest reproducibility showed the segmental kyphosis followed by the vertebral kyphosis. For thoracic fractures segmental kyphosis shows in X-ray “excellent” inter- and intraobserver reliabilities (ICC 0.826, 0.802) and for lumbar fractures “good” to “excellent” inter- and intraobserver reliabilities (ICC = 0.790, 0.803). In computed tomography, the segmental kyphosis showed “excellent” inter- and intraobserver reliabilities (ICC = 0.824, 0.801) for thoracic and “excellent” inter- and intraobserver reliabilities (ICC = 0.874, 0.835) for the lumbar fractures. Regarding both diagnostic work ups (X-ray and computed tomography), significant differences were evaluated in interobserver reliabilities for vertebral kyphosis measured in lumbar fracture X-rays (p = 0.035) and interobserver reliabilities for local kyphosis, measured in thoracic fracture X-rays (p = 0.010). Regarding both fracture localizations (thoracic and lumbar fractures), significant differences could only be evaluated in interobserver reliabilities for the local kyphosis measured in computed tomographies (p = 0.045) and in intraobserver reliabilities for the vertebral kyphosis measured in X-rays (p = 0.024). “Good” to “excellent” inter- and intraobserver reliabilities for vertebral, segmental and local kyphosis in X-ray make these angles to a helpful tool, indicating surgical procedures. For the practical use in lateral X-ray, we emphasize the determination of the segmental kyphosis, because of the highest reproducibility of this angle. “Good” to “excellent” inter- and intraobserver reliabilities for these three angles could also be evaluated in computed tomographies. Therefore, also in computed tomography, the use of these three angles seems to be generally possible. For a direct correlation of the results in lateral X-ray and in computed tomography, further studies should be needed. PMID:19953277

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.

Role of positron emission tomography/computed tomography in breast cancer.

PubMed

Bourgeois, Austin C; Warren, Lance A; Chang, Ted T; Embry, Scott; Hudson, Kathleen; Bradley, Yong C

2013-09-01

Although positron emission tomography (PET) imaging may not be used in the diagnosis of breast cancer, the use of PET/computed tomography is imperative in all aspects of breast cancer staging, treatment, and follow-up. PET will continue to be relevant in personalized medicine because accurate tumor status will be even more critical during and after the transition from a generic metabolic agent to receptor imaging. Positron emission mammography is an imaging proposition that may have benefits in lower doses, but its use is limited without new radiopharmaceuticals. Copyright © 2013 Elsevier Inc. All rights reserved.

Transurethral Ultrasound Diffraction Tomography

DTIC Science & Technology

2007-03-01

the covariance matrix was derived. The covariance reduced to that of the X- ray CT under the assumptions of linear operator and real data.[5] The...the covariance matrix in the linear x- ray computed tomography is a special case of the inverse scattering matrix derived in this paper. The matrix was...is derived in Sec. IV, and its relation to that of the linear x- ray computed tomography appears in Sec. V. In Sec. VI, the inverse scattering

APPLICATION OF COMPUTER AIDED TOMOGRAPHY (CAT) TO THE STUDY OF MARINE BENTIC COMMUNITIES

EPA Science Inventory

Sediment cores were imaged using a Computer-Aided Tomography (CT) scanner at Massachusetts General Hospital, Boston, Massachusetts, United States. Procedures were developed, using the attenuation of X-rays, to differentiate between sediment and the water contained in macrobenthic...

How to interpret computed tomography of the lumbar spine

PubMed Central

Mobasheri, R; Das, T; Vaidya, S; Mallik, S; El-Hussainy, M; Casey, A

2014-01-01

Computed tomography (CT) of the spine has remained an important tool in the investigation of spinal pathology. This article helps to explain the basics of CT of the lumbar spine to allow the clinician better use of this diagnostic tool. PMID:25245727

Clinical and computed tomography features of secondary renal hyperparathyroidism

PubMed Central

Vanbrugghe, Benoît; Blond, Laurent; Carioto, Lisa; Carmel, Eric Norman; Nadeau, Marie-Eve

2011-01-01

An atypical case of secondary renal hyperparathyroidism was diagnosed in a 9-year-old miniature schnauzer after a skull computed tomography (CT) showed the presence of 2 bilateral and symmetrical soft tissue maxillary masses, and osteopenia of the skull. PMID:21532826

High-Performance Computation of Distributed-Memory Parallel 3D Voronoi and Delaunay Tessellation

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

Peterka, Tom; Morozov, Dmitriy; Phillips, Carolyn

2014-11-14

Computing a Voronoi or Delaunay tessellation from a set of points is a core part of the analysis of many simulated and measured datasets: N-body simulations, molecular dynamics codes, and LIDAR point clouds are just a few examples. Such computational geometry methods are common in data analysis and visualization; but as the scale of simulations and observations surpasses billions of particles, the existing serial and shared-memory algorithms no longer suffice. A distributed-memory scalable parallel algorithm is the only feasible approach. The primary contribution of this paper is a new parallel Delaunay and Voronoi tessellation algorithm that automatically determines which neighbormore » points need to be exchanged among the subdomains of a spatial decomposition. Other contributions include periodic and wall boundary conditions, comparison of our method using two popular serial libraries, and application to numerous science datasets.« less

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.

Single-Photon Emission Computed Tomography/Computed Tomography Imaging in a Rabbit Model of Emphysema Reveals Ongoing Apoptosis In Vivo

PubMed Central

Goldklang, Monica P.; Tekabe, Yared; Zelonina, Tina; Trischler, Jordis; Xiao, Rui; Stearns, Kyle; Romanov, Alexander; Muzio, Valeria; Shiomi, Takayuki; Johnson, Lynne L.

2016-01-01

Evaluation of lung disease is limited by the inability to visualize ongoing pathological processes. Molecular imaging that targets cellular processes related to disease pathogenesis has the potential to assess disease activity over time to allow intervention before lung destruction. Because apoptosis is a critical component of lung damage in emphysema, a functional imaging approach was taken to determine if targeting apoptosis in a smoke exposure model would allow the quantification of early lung damage in vivo. Rabbits were exposed to cigarette smoke for 4 or 16 weeks and underwent single-photon emission computed tomography/computed tomography scanning using technetium-99m–rhAnnexin V-128. Imaging results were correlated with ex vivo tissue analysis to validate the presence of lung destruction and apoptosis. Lung computed tomography scans of long-term smoke–exposed rabbits exhibit anatomical similarities to human emphysema, with increased lung volumes compared with controls. Morphometry on lung tissue confirmed increased mean linear intercept and destructive index at 16 weeks of smoke exposure and compliance measurements documented physiological changes of emphysema. Tissue and lavage analysis displayed the hallmarks of smoke exposure, including increased tissue cellularity and protease activity. Technetium-99m–rhAnnexin V-128 single-photon emission computed tomography signal was increased after smoke exposure at 4 and 16 weeks, with confirmation of increased apoptosis through terminal deoxynucleotidyl transferase dUTP nick end labeling staining and increased tissue neutral sphingomyelinase activity in the tissue. These studies not only describe a novel emphysema model for use with future therapeutic applications, but, most importantly, also characterize a promising imaging modality that identifies ongoing destructive cellular processes within the lung. PMID:27483341

Design Principles for a Comprehensive Library System.

ERIC Educational Resources Information Center

Uluakar, Tamer; And Others

1981-01-01

Describes an online design featuring circulation control, catalog access, and serial holdings that uses an incremental approach to system development. Utilizing a dedicated computer, this second of three releases pays particular attention to present and predicted computing capabilities as well as trends in library automation. (Author/RAA)

Medical serials control systems by computer--a state of the art review.

PubMed

Brodman, E; Johnson, M F

1976-01-01

A review of the problems encountered in serials control systems is followed by a description of some of the present-day attempts to solve these problems. Specific networks are described, notably PHILSOM (developed at Washington University School of Medicine Library), the UCLA Biomedical Library's system, and OCLC in Columbus, Ohio. Finally, the role of minicomputers in present and future developments is discussed, and some cautious guesses are made on future directions in the field.

Climate change and the detection of trends in annual runoff

USGS Publications Warehouse

McCabe, G.J.; Wolock, D.M.

1997-01-01

This study examines the statistical likelihood of detecting a trend in annual runoff given an assumed change in mean annual runoff, the underlying year-to-year variability in runoff, and serial correlation of annual runoff. Means, standard deviations, and lag-1 serial correlations of annual runoff were computed for 585 stream gages in the conterminous United States, and these statistics were used to compute the probability of detecting a prescribed trend in annual runoff. Assuming a linear 20% change in mean annual runoff over a 100 yr period and a significance level of 95%, the average probability of detecting a significant trend was 28% among the 585 stream gages. The largest probability of detecting a trend was in the northwestern U.S., the Great Lakes region, the northeastern U.S., the Appalachian Mountains, and parts of the northern Rocky Mountains. The smallest probability of trend detection was in the central and southwestern U.S., and in Florida. Low probabilities of trend detection were associated with low ratios of mean annual runoff to the standard deviation of annual runoff and with high lag-1 serial correlation in the data.

The universal serial bus endoscope: design and initial clinical experience.

PubMed

Hernandez-Zendejas, Gregorio; Dobke, Marek K; Guerrerosantos, Jose

2004-01-01

Endoscopic forehead lift is a well-established procedure in aesthetic plastic surgery. Many agree that currently available video-endoscopic equipment is bulky, multipieced and sometimes cumbersome in the operating theater. A novel system, the Universal Serial Bus Endoscope (USBE) was designed to simplify and reduce the number of necessary equipment pieces in the endoscopic setup. The USBE is attached by a single cable to a Universal Serial Bus (USB) port of a laptop computer. A built-in miniaturized cold light source provides illumination. A built-in digital camera chip enables procedure recording. The real-time images and movies obtained with USBE are displayed on the computer's screen and recorded on the laptop's hard disk drive. In this study, 25 patients underwent endoscopic browlift using the USBE system to test its clinical usefulness, all with good results and without complications or need for revision. The USBE was found to be reliable and easier to use than current video-endoscope equipment. The operative time needed to complete the procedure by the authors was reduced approximately 50%. The design and main technical characteristics of the USBE are presented.

Quantitative X-ray fluorescence computed tomography for low-Z samples using an iterative absorption correction algorithm

NASA Astrophysics Data System (ADS)

Huang, Rong; Limburg, Karin; Rohtla, Mehis

2017-05-01

X-ray fluorescence computed tomography is often used to measure trace element distributions within low-Z samples, using algorithms capable of X-ray absorption correction when sample self-absorption is not negligible. Its reconstruction is more complicated compared to transmission tomography, and therefore not widely used. We describe in this paper a very practical iterative method that uses widely available transmission tomography reconstruction software for fluorescence tomography. With this method, sample self-absorption can be corrected not only for the absorption within the measured layer but also for the absorption by material beyond that layer. By combining tomography with analysis for scanning X-ray fluorescence microscopy, absolute concentrations of trace elements can be obtained. By using widely shared software, we not only minimized the coding, took advantage of computing efficiency of fast Fourier transform in transmission tomography software, but also thereby accessed well-developed data processing tools coming with well-known and reliable software packages. The convergence of the iterations was also carefully studied for fluorescence of different attenuation lengths. As an example, fish eye lenses could provide valuable information about fish life-history and endured environmental conditions. Given the lens's spherical shape and sometimes the short distance from sample to detector for detecting low concentration trace elements, its tomography data are affected by absorption related to material beyond the measured layer but can be reconstructed well with our method. Fish eye lens tomography results are compared with sliced lens 2D fluorescence mapping with good agreement, and with tomography providing better spatial resolution.

Spectral domain optical coherence tomography in the evaluation and management of infectious retinitis.

PubMed

Kurup, Sudhi P; Khan, Samira; Gill, Manjot K

2014-11-01

To describe spectral domain optical coherence tomography (SD-OCT) findings of infectious retinitis, including affected layer of retinal involvement, changes at the vitreoretinal interface, and response to therapy. Observational case series. A retrospective review of five patients with infectious retinitis: one with toxoplasmosis, three with herpetic retinitis secondary to cytomegalovirus, and one with herpetic retinitis secondary to varicella zoster virus. Each patient underwent a complete ophthalmologic examination, fundus photography, and SD-OCT imaging (Heidelberg Spectralis; Heidelberg Engineering, Heidelberg, Germany) of the affected retina at the initial visit with serial fundus photography and SD-OCT imaging at follow-up visits. Approval was obtained from the Institutional Review Board of Northwestern University. Spectral domain ocular coherence tomography of retinitis associated with Toxoplasma, cytomegalovirus, or varicella zoster virus demonstrates full-thickness disruption of the retinal architecture and overall thickening. This was in contrast to clinically imitating lesions such as cotton-wool spots, which only showed focal swelling of the inner retina. There was a clear demarcation between the area of active retinitis and unaffected retina. Inactivity was apparent when the previously affected thickened area became atrophic. The SD-OCT also demonstrated changes at the vitreoretinal interface where there was frequently a detachment of the posterior hyaloid (four of five cases) associated with overlying vitreous debris and formation of tractional changes. In the case of varicella zoster virus retinitis, this traction subsequently led to a total retinal detachment. In the assessment of infectious retinitides, SD-OCT is a helpful adjunct to clinical examination and fundus photography. It provides high-resolution detail regarding the border of infectious activity, the vitreoretinal interface, and the differentiation of lesions that can clinically mimic active retinitis. Serial SD-OCT also provides further insight into response to therapy and postinfectious retinal changes by highlighting areas that are at greater risk for complications such as retinal detachment.

Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning.

PubMed

Ozcan, Namik; Ozcam, Giray; Kosar, Pinar; Ozcan, Ayse; Basar, Hulya; Kaymak, Cetin

2016-01-01

Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

A USB 2.0 computer interface for the UCO/Lick CCD cameras

NASA Astrophysics Data System (ADS)

Wei, Mingzhi; Stover, Richard J.

2004-09-01

The new UCO/Lick Observatory CCD camera uses a 200 MHz fiber optic cable to transmit image data and an RS232 serial line for low speed bidirectional command and control. Increasingly RS232 is a legacy interface supported on fewer computers. The fiber optic cable requires either a custom interface board that is plugged into the mainboard of the image acquisition computer to accept the fiber directly or an interface converter that translates the fiber data onto a widely used standard interface. We present here a simple USB 2.0 interface for the UCO/Lick camera. A single USB cable connects to the image acquisition computer and the camera's RS232 serial and fiber optic cables plug into the USB interface. Since most computers now support USB 2.0 the Lick interface makes it possible to use the camera on essentially any modern computer that has the supporting software. No hardware modifications or additions to the computer are needed. The necessary device driver software has been written for the Linux operating system which is now widely used at Lick Observatory. The complete data acquisition software for the Lick CCD camera is running on a variety of PC style computers as well as an HP laptop.

Radiation-Induced Liver Injury Mimicking Metastatic Disease in a Patient With Esophageal Cancer: Correlation of Positron Emission Tomography/Computed Tomography With Magnetic Resonance Imaging and Literature Review.

PubMed

Rabe, Tiffany M; Yokoo, Takeshi; Meyer, Jeffrey; Kernstine, Kemp H; Wang, David; Khatri, Gaurav

2016-01-01

Post-radiation therapy evaluation of distal esophageal cancers with positron emission tomography/computed tomography can be problematic. Differentiation of recurrent neoplasm from postradiation changes is difficult in areas of fluorodeoxyglucose avidity in adjacent, incidentally irradiated organs. Few studies have described the magnetic resonance imaging appearance of radiation-induced hepatic injury. We report a case of focal radiation-induced liver injury with a new focus of fluorodeoxyglucose uptake on posttreatment positron emission tomography as well as masslike enhancement and signal abnormality on magnetic resonance imaging, thus mimicking new liver metastasis. Correlation with radiation planning images suggested the correct diagnosis, which was confirmed on follow-up imaging.

A multiresolution approach to iterative reconstruction algorithms in X-ray computed tomography.

PubMed

De Witte, Yoni; Vlassenbroeck, Jelle; Van Hoorebeke, Luc

2010-09-01

In computed tomography, the application of iterative reconstruction methods in practical situations is impeded by their high computational demands. Especially in high resolution X-ray computed tomography, where reconstruction volumes contain a high number of volume elements (several giga voxels), this computational burden prevents their actual breakthrough. Besides the large amount of calculations, iterative algorithms require the entire volume to be kept in memory during reconstruction, which quickly becomes cumbersome for large data sets. To overcome this obstacle, we present a novel multiresolution reconstruction, which greatly reduces the required amount of memory without significantly affecting the reconstructed image quality. It is shown that, combined with an efficient implementation on a graphical processing unit, the multiresolution approach enables the application of iterative algorithms in the reconstruction of large volumes at an acceptable speed using only limited resources.

X-ray Computed Tomography.

ERIC Educational Resources Information Center

Michael, Greg

2001-01-01

Describes computed tomography (CT), a medical imaging technique that produces images of transaxial planes through the human body. A CT image is reconstructed mathematically from a large number of one-dimensional projections of a plane. The technique is used in radiological examinations and radiotherapy treatment planning. (Author/MM)

The Power of Computer-aided Tomography to Investigate Marine Benthic Communities

EPA Science Inventory

Utilization of Computer-aided-Tomography (CT) technology is a powerful tool to investigate benthic communities in aquatic systems. In this presentation, we will attempt to summarize our 15 years of experience in developing specific CT methods and applications to marine benthic co...

Three-dimensional evaluation of human jaw bone microarchitecture: correlation between the microarchitectural parameters of cone beam computed tomography and micro-computer tomography.

PubMed

Kim, Jo-Eun; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Huh, Kyung-Hoe

2015-12-01

To evaluate the potential feasibility of cone beam computed tomography (CBCT) in the assessment of trabecular bone microarchitecture. Sixty-eight specimens from four pairs of human jaw were scanned using both micro-computed tomography (micro-CT) of 19.37-μm voxel size and CBCT of 100-μm voxel size. The correlation of 3-dimensional parameters between CBCT and micro-CT was evaluated. All parameters, except bone-specific surface and trabecular thickness, showed linear correlations between the 2 imaging modalities (P < .05). Among the parameters, bone volume, percent bone volume, trabecular separation, and degree of anisotropy (DA) of CBCT images showed strong correlations with those of micro-CT images. DA showed the strongest correlation (r = 0.693). Most microarchitectural parameters from CBCT were correlated with those from micro-CT. Some microarchitectural parameters, especially DA, could be used as strong predictors of bone quality in the human jaw. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

PubMed

Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

2016-02-01

The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p < 0.05 to all). Significant decrease in hepatic artery perfusion was also observed in pericancerous liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy. © The Author(s) 2014.

Characterization of normal feline renal vascular anatomy with dual-phase CT angiography.

PubMed

Cáceres, Ana V; Zwingenberger, Allison L; Aronson, Lillian R; Mai, Wilfried

2008-01-01

Helical computed tomography angiography was used to evaluate the renal vascular anatomy of potential feline renal donors. One hundred and fourteen computed tomography angiograms were reviewed. The vessels were characterized as single without bifurcation, single with bifurcation, double, or triple. Multiplicity was most commonly seen for the right renal vein (45/114 vs. 3/114 multiple left renal veins, 0/114 multiple right renal arteries, and 8/114 multiple left renal arteries). The right kidney was 13.3 times more likely than the left to have multiple renal veins. Additional vascular variants included double caudal vena cava and an accessory renal artery. For the left kidney, surgery and computed tomography angiography findings were in agreement in 92% of 74 cats. For the right kidney, surgery and computed tomography angiography findings were in agreement in 6/6 cats. Our findings of renal vascular anatomy variations in cats were similar to previous reports in humans. Identifying and recognizing the pattern of distribution of these vessels is important when performing renal transplantation.

Stress Computed Tomography Myocardial Perfusion Imaging: A New Topic in Cardiology.

PubMed

Seitun, Sara; Castiglione Morelli, Margherita; Budaj, Irilda; Boccalini, Sara; Galletto Pregliasco, Athena; Valbusa, Alberto; Cademartiri, Filippo; Ferro, Carlo

2016-02-01

Since its introduction about 15 years ago, coronary computed tomography angiography has become today the most accurate clinical instrument for noninvasive assessment of coronary atherosclerosis. Important technical developments have led to a continuous stream of new clinical applications together with a significant reduction in radiation dose exposure. Latest generation computed tomography scanners (≥ 64 slices) allow the possibility of performing static or dynamic perfusion imaging during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson), combining both functional and anatomical information in the same examination. In this article, the emerging role and state-of-the-art of myocardial computed tomography perfusion imaging are reviewed and are illustrated by clinical cases from our experience with a second-generation dual-source 128-slice scanner (Somatom Definition Flash, Siemens; Erlangen, Germany). Technical aspects, data analysis, diagnostic accuracy, radiation dose and future prospects are reviewed. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Parallel peak pruning for scalable SMP contour tree computation

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

Carr, Hamish A.; Weber, Gunther H.; Sewell, Christopher M.

As data sets grow to exascale, automated data analysis and visualisation are increasingly important, to intermediate human understanding and to reduce demands on disk storage via in situ analysis. Trends in architecture of high performance computing systems necessitate analysis algorithms to make effective use of combinations of massively multicore and distributed systems. One of the principal analytic tools is the contour tree, which analyses relationships between contours to identify features of more than local importance. Unfortunately, the predominant algorithms for computing the contour tree are explicitly serial, and founded on serial metaphors, which has limited the scalability of this formmore » of analysis. While there is some work on distributed contour tree computation, and separately on hybrid GPU-CPU computation, there is no efficient algorithm with strong formal guarantees on performance allied with fast practical performance. Here in this paper, we report the first shared SMP algorithm for fully parallel contour tree computation, withfor-mal guarantees of O(lgnlgt) parallel steps and O(n lgn) work, and implementations with up to 10x parallel speed up in OpenMP and up to 50x speed up in NVIDIA Thrust.« less

Missile Manufacturing Technology Conference Held at Hilton Head Island, South Carolina on 22-26 September 1975. Panel Presentations. Test Equipment

DTIC Science & Technology

1975-01-01

in the computer in 16 bit parallel computer DIO transfers at the max- imum computer I/O speed. it then transmits this data in a bit- serial echo...maximum DIO rate under computer interrupt control. The LCI also provides station interrupt information for transfer to the computer under computer...been in daily operation since 1973. The SAM-D Missile system is currently in the Engineering De - velopment phase which precedes the Production and

Fatal Road Traffic Vehicle Collisions With Pedestrian Victims: Forensic Postmortem Computed Tomography and Autopsy Correlation.

PubMed

Chatzaraki, Vasiliki; Thali, Michael J; Ampanozi, Garyfalia; Schweitzer, Wolf

2018-06-01

Fatal car-to-pedestrian collisions regularly appear in the forensic pathologist's routine, particularly in places of extended urbanization. Postmortem computed tomography has gained an exceptional role to supplement autopsy worldwide, giving information that is supplementary or complimentary to conventional autopsy. In this retrospective study, a total number of 320 findings in a series of 21 pedestrians fatally hit by cars and trucks of both postmortem computed tomography and autopsy were correlated. According to our results, it is best to combine both methods to give well-founded answers to questions pertaining to both collision reconstruction and cause of death.

[Axial computer tomography of the neurocranium (author's transl)].

PubMed

Stöppler, L

1977-05-27

Computer tomography (CT), a new radiographic examination technique, is very highly efficient, for it has high informative content with little stress for the patient. In contrast to the conventional X-ray technology, CT succeeds, by direct presentation of the structure of the soft parts, in obtaining information which comes close to that of macroscopic neuropathology. The capacity and limitations of the method at the present stage of development are reported. Computer tomography cannot displace conventional neuroradiological methods of investigation, although it is rightly presented as a screening method and helps towards selective use. Indications, technical integration and handling of CT are prerequisites for the exhaustive benefit of the excellent new technique.

Ambient noise adjoint tomography for a linear array in North China

NASA Astrophysics Data System (ADS)

Zhang, C.; Yao, H.; Liu, Q.; Yuan, Y. O.; Zhang, P.; Feng, J.; Fang, L.

2017-12-01

Ambient noise tomography based on dispersion data and ray theory has been widely utilized for imaging crustal structures. In order to improve the inversion accuracy, ambient noise tomography based on the 3D adjoint approach or full waveform inversion has been developed recently, however, the computational cost is tremendous. In this study we present 2D ambient noise adjoint tomography for a linear array in north China with significant computational efficiency compared to 3D ambient noise adjoint tomography. During the preprocessing, we first convert the observed data in 3D media, i.e., surface-wave empirical Green's functions (EGFs) from ambient noise cross-correlation, to the reconstructed EGFs in 2D media using a 3D/2D transformation scheme. Different from the conventional steps of measuring phase dispersion, the 2D adjoint tomography refines 2D shear wave speeds along the profile directly from the reconstructed Rayleigh wave EGFs in the period band 6-35s. With the 2D initial model extracted from the 3D model from traditional ambient noise tomography, adjoint tomography updates the model by minimizing the frequency-dependent Rayleigh wave traveltime misfits between the reconstructed EGFs and synthetic Green function (SGFs) in 2D media generated by the spectral-element method (SEM), with a preconditioned conjugate gradient method. The multitaper traveltime difference measurement is applied in four period bands during the inversion: 20-35s, 15-30s, 10-20s and 6-15s. The recovered model shows more detailed crustal structures with pronounced low velocity anomaly in the mid-lower crust beneath the junction of Taihang Mountains and Yin-Yan Mountains compared with the initial model. This low velocity structure may imply the possible intense crust-mantle interactions, probably associated with the magmatic underplating during the Mesozoic to Cenozoic evolution of the region. To our knowledge, it's first time that ambient noise adjoint tomography is implemented in 2D media. Considering the intensive computational cost and storage of 3D adjoint tomography, this 2D ambient noise adjoint tomography has potential advantages to get high-resolution 2D crustal structures with limited computational resource.

X-Ray Radiography of Gas Turbine Ceramics.

DTIC Science & Technology

1979-10-20

Microfocus X-ray equipment. 1a4ihe definition of equipment concepts for a computer assisted tomography ( CAT ) system; and 4ffthe development of a CAT ...were obtained from these test coupons using Microfocus X-ray and image en- hancement techniques. A Computer Assisted Tomography ( CAT ) design concept...monitor. Computer reconstruction algorithms were investigated with respect to CAT and a preferred approach was determined. An appropriate CAT algorithm

Case Studies in Library Computer Systems.

ERIC Educational Resources Information Center

Palmer, Richard Phillips

Twenty descriptive case studies of computer applications in a variety of libraries are presented in this book. Computerized circulation, serial and acquisition systems in public, high school, college, university and business libraries are included. Each of the studies discusses: 1) the environment in which the system operates, 2) the objectives of…

Efficient Application of Continuous Fractional Component Monte Carlo in the Reaction Ensemble

PubMed Central

2017-01-01

A new formulation of the Reaction Ensemble Monte Carlo technique (RxMC) combined with the Continuous Fractional Component Monte Carlo method is presented. This method is denoted by serial Rx/CFC. The key ingredient is that fractional molecules of either reactants or reaction products are present and that chemical reactions always involve fractional molecules. Serial Rx/CFC has the following advantages compared to other approaches: (1) One directly obtains chemical potentials of all reactants and reaction products. Obtained chemical potentials can be used directly as an independent check to ensure that chemical equilibrium is achieved. (2) Independent biasing is applied to the fractional molecules of reactants and reaction products. Therefore, the efficiency of the algorithm is significantly increased, compared to the other approaches. (3) Changes in the maximum scaling parameter of intermolecular interactions can be chosen differently for reactants and reaction products. (4) The number of fractional molecules is reduced. As a proof of principle, our method is tested for Lennard-Jones systems at various pressures and for various chemical reactions. Excellent agreement was found both for average densities and equilibrium mixture compositions computed using serial Rx/CFC, RxMC/CFCMC previously introduced by Rosch and Maginn (Journal of Chemical Theory and Computation, 2011, 7, 269–279), and the conventional RxMC approach. The serial Rx/CFC approach is also tested for the reaction of ammonia synthesis at various temperatures and pressures. Excellent agreement was found between results obtained from serial Rx/CFC, experimental results from literature, and thermodynamic modeling using the Peng–Robinson equation of state. The efficiency of reaction trial moves is improved by a factor of 2 to 3 (depending on the system) compared to the RxMC/CFCMC formulation by Rosch and Maginn. PMID:28737933

Return to play after liver and spleen trauma.

PubMed

Juyia, Rushad F; Kerr, Hamish A

2014-05-01

Sport-related spleen and liver injuries pose a challenge for the physician. Although rare, these injuries can have serious and even life-threatening outcomes if not accurately diagnosed and managed in a timely fashion. Currently, there are no evidence-based guidelines on duration and intensity of restricted activity and return to play after spleen and liver injury. In addition, there is controversy on follow-up imaging after injury. PubMed was searched using the terms splenic or spleen and trauma and hepatic or liver and trauma from 1980 to 2013. The citations from sentinel papers were also reviewed. Clinical review. Level 3. Ultrasound is ideal in the unstable athlete. Nonoperative management of blunt splenic and hepatic injuries is recommended for hemodynamically stable patients regardless of injury grade, patient age, or presence of associated injuries. Follow-up imaging is not routinely recommended unless clinically indicated. Athletes may engage in light activity for the first 3 months after injury and then gradual return to unrestricted activity as tolerated. High-level athletes may choose splenectomy or serial imaging for faster return to play. Intravenous contrast-enhanced computed tomography is the diagnostic imaging modality of choice in stable athletes with blunt abdominal trauma. C.

A mesoscale connectome of the mouse brain

PubMed Central

Oh, Seung Wook; Harris, Julie A.; Ng, Lydia; Winslow, Brent; Cain, Nicholas; Mihalas, Stefan; Wang, Quanxin; Lau, Chris; Kuan, Leonard; Henry, Alex M.; Mortrud, Marty T.; Ouellette, Benjamin; Nguyen, Thuc Nghi; Sorensen, Staci A.; Slaughterbeck, Clifford R.; Wakeman, Wayne; Li, Yang; Feng, David; Ho, Anh; Nicholas, Eric; Hirokawa, Karla E.; Bohn, Phillip; Joines, Kevin M.; Peng, Hanchuan; Hawrylycz, Michael J.; Phillips, John W.; Hohmann, John G.; Wohnoutka, Paul; Gerfen, Charles R.; Koch, Christof; Bernard, Amy; Dang, Chinh; Jones, Allan R.; Zeng, Hongkui

2016-01-01

Comprehensive knowledge of the brain’s wiring diagram is fundamental for understanding how the nervous system processes information at both local and global scales. However, with the singular exception of the C. elegans microscale connectome, there are no complete connectivity data sets in other species. Here we report a brain-wide, cellular-level, mesoscale connectome for the mouse. The Allen Mouse Brain Connectivity Atlas uses enhanced green fluorescent protein (EGFP)-expressing adeno-associated viral vectors to trace axonal projections from defined regions and cell types, and high-throughput serial two-photon tomography to image the EGFP-labelled axons throughout the brain. This systematic and standardized approach allows spatial registration of individual experiments into a common three dimensional (3D) reference space, resulting in a whole-brain connectivity matrix. A computational model yields insights into connectional strength distribution, symmetry and other network properties. Virtual tractography illustrates 3D topography among interconnected regions. Cortico-thalamic pathway analysis demonstrates segregation and integration of parallel pathways. The Allen Mouse Brain Connectivity Atlas is a freely available, foundational resource for structural and functional investigations into the neural circuits that support behavioural and cognitive processes in health and disease. PMID:24695228

Evaluation of patients with hepatic portal venous gas who can be treated with conservative therapy.

PubMed

Higashi, Takaaki; Hayashi, Hiromitsu; Takeyama, Hideaki; Arima, Kota; Taki, Katsunobu; Takamori, Hiroshi; Baba, Hideo

2016-01-01

Hepatic portal venous gas is an indication for emergency surgery and reportedly has a high mortality rate. However, these days, cases of hepatic portal venous gas associated with milder disease are increasing. In this report, we compared two groups to investigate whether there were any objective indicators for selecting conservative therapy. From July 2007 to August 2011, 19 patients with hepatic portal venous gas were evaluated at our hospital. The condition was diagnosed by computed tomography imaging. Vital signs, laboratory test results, and physical examination findings were compared. The A group included 12 patients who could be treated with conservative therapy. The B group included 7 patients who could not be treated with conservative therapy. The combined mortality rate was 31.5% (6/19 patients). There was a significant difference in the pulse rate and shock index. In the A group, none of the patients had signs of peritoneal irritation. However, in the B group, physical examination revealed signs of peritoneal irritation in all patients. Conservative therapy may be possible in patients with hepatic portal venous gas, depending on the cause. Evaluation of vital signs and serial changes on physical examination are important.

Femoral head shape differences during development may identify hips at risk of degeneration.

PubMed

Vanden Berg-Foels, Wendy S; Schwager, Steven J; Todhunter, Rory J; Reeves, Anthony P

2011-12-01

Developmental dysplasia of the hip (DDH) is a common cause of elevated contact stress and early onset osteoarthritis (OA). We hypothesized that adaptation to focal loading during postnatal development would result in signature changes to the shape of the femoral head secondary center of ossification (SCO). SCO shape was evaluated in a canine model of DDH at ages 14 and 32 weeks. The evolving 3D morphology of the SCO was captured using serial quantitative computed tomography. A discrete medial representation shape model was fit to each SCO and served as the basis for quantitative thickness and bending measurements. Shape measurements were tested for associations with hip subluxation and degeneration. At 32 weeks, the SCO was thinner (flatter) in the perifoveal region, the site of focal loading; a greater bend to the SCO was present lateral to the site of thinning; SCO thinning and bending were associated with less femoral head coverage and with a higher probability of degeneration. Shape changes were not detected at 14 weeks. Measurement and visualization of SCO shape changes due to altered loading may provide a basis for identifying hips at risk of early onset OA and a tool for surgical planning of hip restructuring.

A Tourette-like syndrome following cardiopulmonary bypass and hypothermia: MRI volumetric measurements.

PubMed

Singer, H S; Dela Cruz, P S; Abrams, M T; Bean, S C; Reiss, A L

1997-07-01

We present the case of an adolescent boy who developed a variety of simple and complex motor and vocal tics (Tourette-like syndrome), along with inattentiveness and obsessive-compulsive behaviors after cardiac surgery with cardiopulmonary bypass and profound hypothermia. A single photon emission computed tomography study 2 months after surgery showed reduced uptake in the left hemisphere and 2 years later a perfusion defect in the basal ganglia. Serial magnetic resonance imaging (MRI) studies were normal. Volumetric MRI studies were obtained 4 years after surgery and compared with published values for normal individuals and children with Tourette syndrome (TS), including subsets matched for age, sex, and handedness. Measurement of basal ganglia structures showed a right-dominant asymmetry of the caudate and putamen, in part similar to findings previously reported in patients with TS. Other volumetric abnormalities included a > 2-SD reduction of cortical gray matter, a small decrease of total cerebral volume, and increase in cerebral white matter. Although a variety of neurological problems may occur after cardiopulmonary bypass, to our knowledge this case represents the first report of a chronic tic disorder following cardiac surgery with cardiopulmonary bypass and hypothermia.

Remora fish suction pad attachment is enhanced by spinule friction.

PubMed

Beckert, Michael; Flammang, Brooke E; Nadler, Jason H

2015-11-01

The remora fishes are capable of adhering to a wide variety of natural and artificial marine substrates using a dorsal suction pad. The pad is made of serial parallel pectinated lamellae, which are homologous to the dorsal fin elements of other fishes. Small tooth-like projections of mineralized tissue from the dorsal pad lamella, known as spinules, are thought to increase the remora's resistance to slippage and thereby enhance friction to maintain attachment to a moving host. In this work, the geometry of the spinules and host topology as determined by micro-computed tomography and confocal microscope data, respectively, are combined in a friction model to estimate the spinule contribution to shear resistance. Model results are validated with natural and artificially created spinules and compared with previous remora pull-off experiments. It was found that spinule geometry plays an essential role in friction enhancement, especially at short spatial wavelengths in the host surface, and that spinule tip geometry is not correlated with lamellar position. Furthermore, comparisons with pull-off experiments suggest that spinules are primarily responsible for friction enhancement on rough host topologies such as shark skin. © 2015. Published by The Company of Biologists Ltd.

Three-dimensional and topographic relationships between the orbital margins with reference to assessment of eyeball protrusion.

PubMed

Shin, Kang-Jae; Lee, Shin-Hyo; Koh, Ki-Seok; Song, Wu-Chul

2017-03-01

This study investigated the topographic relationships among the eyeball and four orbital margins with the aim of identifying the correlation between orbital geometry and eyeball protrusion in Koreans. Three-dimensional (3D) volume rendering of the face was performed using serial computed-tomography images of 141 Koreans, and several landmarks on the bony orbit and the cornea were directly marked on the 3D volumes. The anterior-posterior distances from the apex of the cornea to each orbital margin and between the orbital margins were measured in both eyes. The distances from the apex of the cornea to the superior, medial, inferior, and lateral orbital margins were 5.8, 5.8, 12.0, and 17.9 mm, respectively. Differences between sides were observed in all of the orbital margins, and the distances from the apex of the cornea to the superior and inferior orbital margins were significantly greater in females than in males. The anterior-posterior distance between the superior and inferior orbital margins did not differ significantly between males (6.3 mm) and females (6.2 mm). The data obtained in this study will be useful when developing practical guidelines applicable to forensic facial reconstruction and orbitofacial surgeries.

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents

PubMed Central

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-01-01

Aim To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Methods Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Results Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. Conclusion MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema. PMID:23444240

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents.

PubMed

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-02-01

To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema.

Role of Animal Models in Coronary Stenting.

PubMed

Iqbal, Javaid; Chamberlain, Janet; Francis, Sheila E; Gunn, Julian

2016-02-01

Coronary angioplasty initially employed balloon dilatation only. This technique revolutionized the treatment of coronary artery disease, although outcomes were compromised by acute vessel closure, late constrictive remodeling, and restenosis due to neointimal proliferation. These processes were studied in animal models, which contributed to understanding the biology of endovascular arterial injury. Coronary stents overcome acute recoil, with improvements in the design and metallurgy since then, leading to the development of drug-eluting stents and bioresorbable scaffolds. These devices now undergo computer modeling and benchtop and animal testing before evaluation in clinical trials. Animal models, including rabbit, sheep, dog and pig are available, all with individual benefits and limitations. In smaller mammals, such as mouse and rabbit, the target for stenting is generally the aorta; whereas in larger animals, such as the pig, it is generally the coronary artery. The pig coronary stenting model is a gold-standard for evaluating safety; but insights into biomechanical properties, the biology of stenting, and efficacy in controlling neointimal proliferation can also be gained. Intra-coronary imaging modalities such as intravascular ultrasound and optical coherence tomography allow precise serial evaluation in vivo, and recent developments in genetically modified animal models of atherosclerosis provide realistic test beds for future stents and scaffolds.

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

Kirsch, David G., E-mail: david.kirsch@duke.ed; Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA; Departments of Radiation Oncology and Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC

Purpose: To image a genetically engineered mouse model of non-small-cell lung cancer with micro-computed tomography (micro-CT) to measure tumor response to radiation therapy. Methods and Materials: The Cre-loxP system was used to generate primary lung cancers in mice with mutation in K-ras alone or in combination with p53 mutation. Mice were serially imaged by micro-CT, and tumor volumes were determined. A comparison of tumor volume by micro-CT and tumor histology was performed. Tumor response to radiation therapy (15.5 Gy) was assessed with micro-CT. Results: The tumor volume measured with free-breathing micro-CT scans was greater than the volume calculated by histology.more » Nevertheless, this imaging approach demonstrated that lung cancers with mutant p53 grew more rapidly than lung tumors with wild-type p53 and also showed that radiation therapy increased the doubling time of p53 mutant lung cancers fivefold. Conclusions: Micro-CT is an effective tool to noninvasively measure the growth of primary lung cancers in genetically engineered mice and assess tumor response to radiation therapy. This imaging approach will be useful to study the radiation biology of lung cancer.« less

RADIAL COMPUTED TOMOGRAPHY OF AIR CONTAMINANTS USING OPTICAL REMOTE SENSING

EPA Science Inventory

The paper describes the application of an optical remote-sensing (ORS) system to map air contaminants and locate fugitive emissions. Many ORD systems may utilize radial non-overlapping beam geometry and a computed tomography (CT) algorithm to map the concentrations in a plane. In...

Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

USDA-ARS?s Scientific Manuscript database

An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

21 CFR 892.1200 - Emission computed tomography system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

21 CFR 892.1200 - Emission computed tomography system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

21 CFR 892.1200 - Emission computed tomography system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

21 CFR 892.1200 - Emission computed tomography system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

21 CFR 892.1200 - Emission computed tomography system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Emission computed tomography system. 892.1200 Section 892.1200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component...

A computer-aided system for automatic extraction of femur neck trabecular bone architecture using isotropic volume construction from clinical hip computed tomography images.

PubMed

Vivekanandhan, Sapthagirivasan; Subramaniam, Janarthanam; Mariamichael, Anburajan

2016-10-01

Hip fractures due to osteoporosis are increasing progressively across the globe. It is also difficult for those fractured patients to undergo dual-energy X-ray absorptiometry scans due to its complicated protocol and its associated cost. The utilisation of computed tomography for the fracture treatment has become common in the clinical practice. It would be helpful for orthopaedic clinicians, if they could get some additional information related to bone strength for better treatment planning. The aim of our study was to develop an automated system to segment the femoral neck region, extract the cortical and trabecular bone parameters, and assess the bone strength using an isotropic volume construction from clinical computed tomography images. The right hip computed tomography and right femur dual-energy X-ray absorptiometry measurements were taken from 50 south-Indian females aged 30-80 years. Each computed tomography image volume was re-constructed to form isotropic volumes. An automated system by incorporating active contour models was used to segment the neck region. A minimum distance boundary method was applied to isolate the cortical and trabecular bone components. The trabecular bone was enhanced and segmented using trabecular enrichment approach. The cortical and trabecular bone features were extracted and statistically compared with dual-energy X-ray absorptiometry measured femur neck bone mineral density. The extracted bone measures demonstrated a significant correlation with neck bone mineral density (r > 0.7, p < 0.001). The inclusion of cortical measures, along with the trabecular measures extracted after isotropic volume construction and trabecular enrichment approach procedures, resulted in better estimation of bone strength. The findings suggest that the proposed system using the clinical computed tomography images scanned with low dose could eventually be helpful in osteoporosis diagnosis and its treatment planning. © IMechE 2016.

Direct estimation of human trabecular bone stiffness using cone beam computed tomography.

PubMed

Klintström, Eva; Klintström, Benjamin; Pahr, Dieter; Brismar, Torkel B; Smedby, Örjan; Moreno, Rodrigo

2018-04-10

The aim of this study was to evaluate the possibility of estimating the biomechanical properties of trabecular bone through finite element simulations by using dental cone beam computed tomography data. Fourteen human radius specimens were scanned in 3 cone beam computed tomography devices: 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan), NewTom 5 G (QR Verona, Verona, Italy), and Verity (Planmed, Helsinki, Finland). The imaging data were segmented by using 2 different methods. Stiffness (Young modulus), shear moduli, and the size and shape of the stiffness tensor were studied. Corresponding evaluations by using micro-CT were regarded as the reference standard. The 3-D Accuitomo 80 (J. Morita MFG., Kyoto, Japan) showed good performance in estimating stiffness and shear moduli but was sensitive to the choice of segmentation method. NewTom 5 G (QR Verona, Verona, Italy) and Verity (Planmed, Helsinki, Finland) yielded good correlations, but they were not as strong as Accuitomo 80 (J. Morita MFG., Kyoto, Japan). The cone beam computed tomography devices overestimated both stiffness and shear compared with the micro-CT estimations. Finite element-based calculations of biomechanics from cone beam computed tomography data are feasible, with strong correlations for the Accuitomo 80 scanner (J. Morita MFG., Kyoto, Japan) combined with an appropriate segmentation method. Such measurements might be useful for predicting implant survival by in vivo estimations of bone properties. Copyright © 2018 Elsevier Inc. All rights reserved.

High-Speed and Scalable Whole-Brain Imaging in Rodents and Primates.

PubMed

Seiriki, Kaoru; Kasai, Atsushi; Hashimoto, Takeshi; Schulze, Wiebke; Niu, Misaki; Yamaguchi, Shun; Nakazawa, Takanobu; Inoue, Ken-Ichi; Uezono, Shiori; Takada, Masahiko; Naka, Yuichiro; Igarashi, Hisato; Tanuma, Masato; Waschek, James A; Ago, Yukio; Tanaka, Kenji F; Hayata-Takano, Atsuko; Nagayasu, Kazuki; Shintani, Norihito; Hashimoto, Ryota; Kunii, Yasuto; Hino, Mizuki; Matsumoto, Junya; Yabe, Hirooki; Nagai, Takeharu; Fujita, Katsumasa; Matsuda, Toshio; Takuma, Kazuhiro; Baba, Akemichi; Hashimoto, Hitoshi

2017-06-21

Subcellular resolution imaging of the whole brain and subsequent image analysis are prerequisites for understanding anatomical and functional brain networks. Here, we have developed a very high-speed serial-sectioning imaging system named FAST (block-face serial microscopy tomography), which acquires high-resolution images of a whole mouse brain in a speed range comparable to that of light-sheet fluorescence microscopy. FAST enables complete visualization of the brain at a resolution sufficient to resolve all cells and their subcellular structures. FAST renders unbiased quantitative group comparisons of normal and disease model brain cells for the whole brain at a high spatial resolution. Furthermore, FAST is highly scalable to non-human primate brains and human postmortem brain tissues, and can visualize neuronal projections in a whole adult marmoset brain. Thus, FAST provides new opportunities for global approaches that will allow for a better understanding of brain systems in multiple animal models and in human diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

ultraLM and miniLM: Locator tools for smart tracking of fluorescent cells in correlative light and electron microscopy.

PubMed

Brama, Elisabeth; Peddie, Christopher J; Wilkes, Gary; Gu, Yan; Collinson, Lucy M; Jones, Martin L

2016-12-13

In-resin fluorescence (IRF) protocols preserve fluorescent proteins in resin-embedded cells and tissues for correlative light and electron microscopy, aiding interpretation of macromolecular function within the complex cellular landscape. Dual-contrast IRF samples can be imaged in separate fluorescence and electron microscopes, or in dual-modality integrated microscopes for high resolution correlation of fluorophore to organelle. IRF samples also offer a unique opportunity to automate correlative imaging workflows. Here we present two new locator tools for finding and following fluorescent cells in IRF blocks, enabling future automation of correlative imaging. The ultraLM is a fluorescence microscope that integrates with an ultramicrotome, which enables 'smart collection' of ultrathin sections containing fluorescent cells or tissues for subsequent transmission electron microscopy or array tomography. The miniLM is a fluorescence microscope that integrates with serial block face scanning electron microscopes, which enables 'smart tracking' of fluorescent structures during automated serial electron image acquisition from large cell and tissue volumes.

Positron emission tomography/computed tomography in melanoma.

PubMed

Bourgeois, Austin C; Chang, Ted T; Fish, Lindsay M; Bradley, Yong C

2013-09-01

Fludeoxyglucose F 18 positron emission tomography/computed tomography (PET/CT) has been invaluable in the assessment of melanoma throughout the course of the disease. As with any modality, the studies are incomplete and more information will be gleaned as our experience progresses. Additionally, it is hoped that a newer PET agent in the pipeline will give us even greater success in the identification and subsequent treatment of melanoma. This article aims to examine the utilization of PET/CT in the staging, prognostication, and follow-up of melanoma while providing the physicians who order and interpret these studies practical guidelines and interpretive pitfalls. Copyright © 2013 Elsevier Inc. All rights reserved.

Miscellaneous indications in bone scintigraphy: metabolic bone diseases and malignant bone tumors.

PubMed

Cook, Gary J R; Gnanasegaran, Gopinath; Chua, Sue

2010-01-01

The diphosphonate bone scan is ideally suited to assess many global, focal or multifocal metabolic bone disorders and there remains a role for conventional bone scintigraphy in metabolic bone disorders at diagnosis, investigation of complications, and treatment response assessment. In contrast, the role of bone scintigraphy in the evaluation of primary malignant bone tumors has reduced with the improvement of morphologic imaging, such as computed tomography and magnetic resonance imaging. However, an increasing role for (18)F-fluorodeoxyglucose positron emission tomography and positron emission tomography/computed tomography is emerging as a functional assessment at diagnosis, staging, and neoadjuvant treatment response assessment.

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.

A transient FETI methodology for large-scale parallel implicit computations in structural mechanics

NASA Technical Reports Server (NTRS)

Farhat, Charbel; Crivelli, Luis; Roux, Francois-Xavier

1992-01-01

Explicit codes are often used to simulate the nonlinear dynamics of large-scale structural systems, even for low frequency response, because the storage and CPU requirements entailed by the repeated factorizations traditionally found in implicit codes rapidly overwhelm the available computing resources. With the advent of parallel processing, this trend is accelerating because explicit schemes are also easier to parallelize than implicit ones. However, the time step restriction imposed by the Courant stability condition on all explicit schemes cannot yet -- and perhaps will never -- be offset by the speed of parallel hardware. Therefore, it is essential to develop efficient and robust alternatives to direct methods that are also amenable to massively parallel processing because implicit codes using unconditionally stable time-integration algorithms are computationally more efficient when simulating low-frequency dynamics. Here we present a domain decomposition method for implicit schemes that requires significantly less storage than factorization algorithms, that is several times faster than other popular direct and iterative methods, that can be easily implemented on both shared and local memory parallel processors, and that is both computationally and communication-wise efficient. The proposed transient domain decomposition method is an extension of the method of Finite Element Tearing and Interconnecting (FETI) developed by Farhat and Roux for the solution of static problems. Serial and parallel performance results on the CRAY Y-MP/8 and the iPSC-860/128 systems are reported and analyzed for realistic structural dynamics problems. These results establish the superiority of the FETI method over both the serial/parallel conjugate gradient algorithm with diagonal scaling and the serial/parallel direct method, and contrast the computational power of the iPSC-860/128 parallel processor with that of the CRAY Y-MP/8 system.

FDG-PET/CT in the evaluation of anal carcinoma

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

Cotter, Shane E.; Medical Scientist Training Program, Washington University School of Medicine, St. Louis, MO; Grigsby, Perry W.

2006-07-01

Purpose: Surgical staging and treatment of anal carcinoma has been replaced by noninvasive staging studies and combined modality therapy. In this study, we compare computed tomography (CT) and physical examination to [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in the staging of carcinoma of the anal canal, with special emphasis on determination of spread to inguinal lymph nodes. Methods and Materials: Between July 2003 and July 2005, 41 consecutive patients with biopsy-proved anal carcinoma underwent a complete staging evaluation including physical examination, CT, and 2-FDG-PET/CT. Patients ranged in age from 30 to 89 years. Nine men were HIV-positive. Treatment was withmore » standard Nigro regimen. Results: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) detected 91% of nonexcised primary tumors, whereas CT visualized 59%. FDG-PET/CT detected abnormal uptake in pelvic nodes of 5 patients with normal pelvic CT scans. FDG-PET/CT detected abnormal nodes in 20% of groins that were normal by CT, and in 23% without abnormality on physical examination. Furthermore, 17% of groins negative by both CT and physical examination showed abnormal uptake on FDG-PET/CT. HIV-positive patients had an increased frequency of PET-positive lymph nodes. Conclusion: [{sup 18}F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography detects the primary tumor more often than CT. FDG-PET/CT detects substantially more abnormal inguinal lymph nodes than are identified by standard clinical staging with CT and physical examination.« less

Medical serials control systems by computer--a state of the art review.

PubMed Central

Brodman, E; Johnson, M F

1976-01-01

A review of the problems encountered in serials control systems is followed by a description of some of the present-day attempts to solve these problems. Specific networks are described, notably PHILSOM (developed at Washington University School of Medicine Library), the UCLA Biomedical Library's system, and OCLC in Columbus, Ohio. Finally, the role of minicomputers in present and future developments is discussed, and some cautious guesses are made on future directions in the field. PMID:1247704

Segmenting root systems in xray computed tomography images using level sets

USDA-ARS?s Scientific Manuscript database

The segmentation of plant roots from soil and other growing mediums in xray computed tomography images is needed to effectively study the shapes of roots without excavation. However, segmentation is a challenging problem in this context because the root and non-root regions share similar features. ...

Retroperitoneal tumour radiotherapy: clinical improvements using kilovoltage cone beam computed tomography.

PubMed

Juan-Senabre, Xavier J; Ferrer-Albiach, Carlos; Rodríguez-Cordón, Marta; Santos-Serra, Agustín; López-Tarjuelo, Juan; Calzada-Feliu, Salvador

2009-04-01

We present a clinical case of a patient diagnosed with a retroperitoneal sarcoma, which received preoperative treatment with daily verification via computed tomography obtained with kilovoltage cone beam. We compare the benefit of this treatment compared to other conventional treatment without image guiding, reporting quantitative results.

Imaging Techniques in Endodontics: An Overview

PubMed Central

Deepak, B. S.; Subash, T. S.; Narmatha, V. J.; Anamika, T.; Snehil, T. K.; Nandini, D. B.

2012-01-01

This review provides an overview of the relevance of imaging techniques such as, computed tomography, cone beam computed tomography, and ultrasound, to endodontic practice. Many limitations of the conventional radiographic techniques have been overcome by the newer methods. Advantages and disadvantages of various imaging techniques in endodontic practice are also discussed. PMID:22530184

SIMULATION STUDY FOR GASEOUS FLUXES FROM AN AREA SOURCE USING COMPUTED TOMOGRAPHY AND OPTICAL REMOTE SENSING

EPA Science Inventory

The paper presents a new approach to quantifying emissions from fugitive gaseous air pollution sources. Computed tomography (CT) and path-integrated optical remote sensing (PI-ORS) concentration data are combined in a new field beam geometry. Path-integrated concentrations are ...

Computed tomography as a diagnostic aid for extracanal invasive resorption.

PubMed

Kim, Euiseong; Kim, Kee-Deog; Roh, Byoung-Duck; Cho, Yong-Sik; Lee, Seung-Jong

2003-07-01

A case of multiple extracanal invasive resorption is reported. The patient had a history of hypothyroidism for approximately 1 yr before the dental visit. Utilization of computed tomography and a rapid prototyping tooth model in diagnosing the exact location and the size of the resorption area are discussed.

Single photon emission computed tomography in motor neuron disease with dementia.

PubMed

Sawada, H; Udaka, F; Kishi, Y; Seriu, N; Mezaki, T; Kameyama, M; Honda, M; Tomonobu, M

1988-01-01

Single photon emission computed tomography with [123 I] isopropylamphetamine was carried out on a patient with motor neuron disease with dementia. [123 I] uptake was decreased in the frontal lobes. This would reflect the histopathological findings such as neuronal loss and gliosis in the frontal lobes.

APPLICATION OF 3D COMPUTER-AIDED TOMOGRAPHY TO THE QUANTIFICATION OF MARINE SEDIMENT COMMUNITIES IN POLLUTION GRADIENTS

EPA Science Inventory

Computer-Aided Tomography (CT) has been demonstrated to be a cost efficient tool for the qualitative and quantitative study of estuarine benthic communities along pollution gradients.
Now we have advanced this technology to successfully visualize and discriminate three dimen...

Spatial image modulation to improve performance of computed tomography imaging spectrometer

NASA Technical Reports Server (NTRS)

Bearman, Gregory H. (Inventor); Wilson, Daniel W. (Inventor); Johnson, William R. (Inventor)

2010-01-01

Computed tomography imaging spectrometers ("CTIS"s) having patterns for imposing spatial structure are provided. The pattern may be imposed either directly on the object scene being imaged or at the field stop aperture. The use of the pattern improves the accuracy of the captured spatial and spectral information.

Advanced imaging in COPD: insights into pulmonary pathophysiology

PubMed Central

Milne, Stephen

2014-01-01

Chronic obstructive pulmonary disease (COPD) involves a complex interaction of structural and functional abnormalities. The two have long been studied in isolation. However, advanced imaging techniques allow us to simultaneously assess pathological processes and their physiological consequences. This review gives a comprehensive account of the various advanced imaging modalities used to study COPD, including computed tomography (CT), magnetic resonance imaging (MRI), and the nuclear medicine techniques positron emission tomography (PET) and single-photon emission computed tomography (SPECT). Some more recent developments in imaging technology, including micro-CT, synchrotron imaging, optical coherence tomography (OCT) and electrical impedance tomography (EIT), are also described. The authors identify the pathophysiological insights gained from these techniques, and speculate on the future role of advanced imaging in both clinical and research settings. PMID:25478198

Viewing Welds By Computer Tomography

NASA Technical Reports Server (NTRS)

Pascua, Antonio G.; Roy, Jagatjit

1990-01-01

Computer tomography system used to inspect welds for root penetration. Source illuminates rotating welded part with fan-shaped beam of x rays or gamma rays. Detectors in circular array on opposite side of part intercept beam and convert it into electrical signals. Computer processes signals into image of cross section of weld. Image displayed on video monitor. System offers only nondestructive way to check penetration from outside when inner surfaces inaccessible.

Comparison of computed tomography with radiography as a noninvasive diagnostic technique for chronic nasal disease in dogs.

PubMed

Codner, E C; Lurus, A G; Miller, J B; Gavin, P R; Gallina, A; Barbee, D D

1993-04-01

Computed tomography was evaluated as a noninvasive technique for the diagnosis of chronic nasal disease in dogs. Computed tomographic images, radiographs, and histopathologic findings were compared in 11 dogs with chronic nasal disease. Definitive diagnosis was made following traumatic nasal flush, exploratory surgery, or necropsy. The study included 8 dogs with intranasal tumors, 2 dogs with bacterial rhinitis (Pasteurella sp), and 1 dog with mycotic rhinitis (Aspergillus sp). Computed tomography was superior to radiography in defining the extent of the disease process and in differentiating infectious rhinitis from nasal neoplasms. It defined lesions in the palate, nasopharyngeal meatus, maxillary sinus, caudal ethmoturbinates, and periorbital tissues that were difficult to demonstrate by use of conventional radiography. Tumors appeared as space-occupying lesions that obliterated the turbinates, caused deviation of the nasal septum, and eroded bone. Rhinitis appeared as a cavitating lesion that spared the paranasal sinuses, thickened and distorted the turbinates, and widened the meatus. Although morphologically distinct on computed tomographic images, infectious rhinitis and nasal neoplasms could not be differentiated by attenuation measurements or degree of contrast enhancement. Computed tomography appeared to be a reliable, noninvasive technique for the diagnosis of chronic nasal disease in dogs, and a promising alternative to diagnostic techniques currently in use.

PETSc Users Manual Revision 3.7

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

Balay, Satish; Abhyankar, S.; Adams, M.

This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.

PETSc Users Manual Revision 3.8

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

Balay, S.; Abhyankar, S.; Adams, M.

This manual describes the use of PETSc for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc uses the MPI standard for all message-passing communication.

[CONE BEAM COMPUTED TOMOGRAPHY IN DIAGNOSTICS OF ODONTOGENIC MAXILLARY SINUSITIS (CASE REPORTS)].

PubMed

Demidova, E; Khurdzidze, G

2017-06-01

Diagnostic studies performed by cone beam computed tomography Morita 3D made possible to obtain high resolution images of hard tissues of upper jawbone and maxillary sinus, to detect bony tissue defects, such as odontogenic cysts, cystogranulomas and granulomas. High-resolution and three dimensional tomographic image reconstructions allowed for optimal and prompt determination of the scope of surgical treatment and planning of effective conservative treatment regimen. Interactive diagnostics helped to estimate cosmetic and functional results of surgical treatment, to prevent the occurrence of surgical complications, and to evaluate the efficacy of conservative treatment. The obtained data contributed to determination of particular applications of cone beam computed tomography in the diagnosis of odontogenic maxillary sinusitis, detection of specific defects with cone beam tomography as the most informative method of diagnosis; as well as to determination of weak and strong sides, and helped to offer mechanisms of x-ray diagnostics to dental surgeons and ENT specialists.

Dynamic contrast enhanced CT in nodule characterization: How we review and report.

PubMed

Qureshi, Nagmi R; Shah, Andrew; Eaton, Rosemary J; Miles, Ken; Gilbert, Fiona J

2016-07-18

Incidental indeterminate solitary pulmonary nodules (SPN) that measure less than 3 cm in size are an increasingly common finding on computed tomography (CT) worldwide. Once identified there are a number of imaging strategies that can be performed to help with nodule characterization. These include interval CT, dynamic contrast enhanced computed tomography (DCE-CT), (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET-CT). To date the most cost effective and efficient non-invasive test or combination of tests for optimal nodule characterization has yet to be determined.DCE-CT is a functional test that involves the acquisition of a dynamic series of images of a nodule before and following the administration of intravenous iodinated contrast medium. This article provides an overview of the current indications and limitations of DCE- CT in nodule characterization and a systematic approach to how to perform, analyse and interpret a DCE-CT scan.

[Quantification of acetabular coverage in normal adult].

PubMed

Lin, R M; Yang, C Y; Yu, C Y; Yang, C R; Chang, G L; Chou, Y L

1991-03-01

Quantification of acetabular coverage is important and can be expressed by superimposition of cartilage tracings on the maximum cross-sectional area of the femoral head. A practical Autolisp program on PC AutoCAD has been developed by us to quantify the acetabular coverage through numerical expression of the images of computed tomography. Thirty adults (60 hips) with normal center-edge angle and acetabular index in plain X ray were randomly selected for serial drops. These slices were prepared with a fixed coordination and in continuous sections of 5 mm in thickness. The contours of the cartilage of each section were digitized into a PC computer and processed by AutoCAD programs to quantify and characterize the acetabular coverage of normal and dysplastic adult hips. We found that a total coverage ratio of greater than 80%, an anterior coverage ratio of greater than 75% and a posterior coverage ratio of greater than 80% can be categorized in a normal group. Polar edge distance is a good indicator for the evaluation of preoperative and postoperative coverage conditions. For standardization and evaluation of acetabular coverage, the most suitable parameters are the total coverage ratio, anterior coverage ratio, posterior coverage ratio and polar edge distance. However, medial coverage and lateral coverage ratios are indispensable in cases of dysplastic hip because variations between them are so great that acetabuloplasty may be impossible. This program can also be used to classify precisely the type of dysplastic hip.

Comparative study of cranial anthropometric measurement by traditional calipers to computed tomography and three-dimensional photogrammetry.

PubMed

Mendonca, Derick A; Naidoo, Sybill D; Skolnick, Gary; Skladman, Rachel; Woo, Albert S

2013-07-01

Craniofacial anthropometry by direct caliper measurements is a common method of quantifying the morphology of the cranial vault. New digital imaging modalities including computed tomography and three-dimensional photogrammetry are similarly being used to obtain craniofacial surface measurements. This study sought to compare the accuracy of anthropometric measurements obtained by calipers versus 2 methods of digital imaging.Standard anterior-posterior, biparietal, and cranial index measurements were directly obtained on 19 participants with an age range of 1 to 20 months. Computed tomographic scans and three-dimensional photographs were both obtained on each child within 2 weeks of the clinical examination. Two analysts measured the anterior-posterior and biparietal distances on the digital images. Measures of reliability and bias between the modalities were calculated and compared.Caliper measurements were found to underestimate the anterior-posterior and biparietal distances as compared with those of the computed tomography and the three-dimensional photogrammetry (P < 0.001). Cranial index measurements between the computed tomography and the calipers differed by up to 6%. The difference between the 2 modalities was statistically significant (P = 0.021). The biparietal and cranial index results were similar between the digital modalities, but the anterior-posterior measurement was greater with the three-dimensional photogrammetry (P = 0.002). The coefficients of variation for repeated measures based on the computed tomography and the three-dimensional photogrammetry were 0.008 and 0.007, respectively.In conclusion, measurements based on digital modalities are generally reliable and interchangeable. Caliper measurements lead to underestimation of anterior-posterior and biparietal values compared with digital imaging.

Imaging of a parapharyngeal hemangiopericytoma. Radioimmunoscintigraphy (SPECT) with indium-111-labeled anti-CEA antibody, and comparison to digital subtraction angiography, computed tomography, and immunohistochemistry

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

Kairemo, K.J.; Hopsu, E.V.; Melartin, E.J.

1991-01-01

A 27-year-old male patient with a parapharyngeal hemangiopericytoma was investigated radiologically with orthopantomography, computed tomography, and digital subtraction angiography before the operation. Because a malignancy was suspected, the patient was imaged with gamma camera using radiolabeled monoclonal anticarcinoembryonal antigen antibody including single photon emission computed tomography. The radioantibody accumulated strongly into the neoplasm. Tumor to background ratio was 2.2. Samples of the excised tumor were stained immunohistochemically for desmin, vimentin, muscle actin, cytokeratin, CEA (carcinoembryonic antigen), and factor VIII. They showed that the antibody uptake was of unspecific nature and not due to CEA expression in the tumor.

Normal Variants and Pitfalls Encountered in PET Assessment of Gynecologic Malignancies.

PubMed

Yu, Jian Q; Doss, Mohan; Alpaugh, R Katherine

2018-04-01

Combined PET/computed tomography is used for oncological indications. PET/computed tomography benefits from the metabolic information of PET and the anatomic localization of computed tomography. The integrated scanner provides data with accurate registration of anatomy and molecular information. Many physiologic conditions, normal variants, and benign lesions within the pelvis and the body can cause confusion and uncertainty. False-negative results owing to low 18 F-fluorodeoxyglucose uptake from the tumor can produce diagnostic challenges and inaccurate conclusions. This article reviews normal variants and potential pitfalls encountered in PET assessment of gynecologic malignancies to provide useful information for the referring and reporting physicians. Copyright © 2017 Elsevier Inc. All rights reserved.

Computed Tomography and Thermography Increases CMC Material and Process Development Efficiency and Testing Effectiveness

NASA Technical Reports Server (NTRS)

Effinger, Michael; Beshears, Ron; Hufnagle, David; Walker, James; Russell, Sam; Stowell, Bob; Myers, David

2002-01-01

Nondestructive characterization techniques have been used to steer development and testing of CMCs. Computed tomography is used to determine the volumetric integrity of the CMC plates and components. Thermography is used to determine the near surface integrity of the CMC plates and components. For process and material development, information such as density uniformity, part delamination, and dimensional tolerance conformity is generated. The information from the thermography and computed tomography is correlated and then specimen cutting maps are superimposed on the thermography images. This enables for tighter data and potential explanation of off nominal test data. Examples of nondestructive characterization utilization to make decisions in process and material development and testing are presented.

UNSEDATED COMPUTED TOMOGRAPHY FOR DIAGNOSIS OF PELVIC CANAL OBSTRUCTION IN A LEOPARD GECKO (EUBLEPHARIS MACULARIUS).

PubMed

DeCourcy, Kelly; Hostnik, Eric T; Lorbach, Josh; Knoblaugh, Sue

2016-12-01

An adult leopard gecko ( Eublepharis macularius ) presented for lethargy, hyporexia, weight loss, decreased passage of waste, and a palpable caudal coelomic mass. Computed tomography showed a heterogeneous hyperattenuating (∼143 Hounsfield units) structure within the right caudal coelom. The distal colon-coprodeum lumen or urinary bladder was hypothesized as the most likely location for the heterogeneous structure. Medical support consisted of warm water and lubricant enema, as well as a heated environment. Medical intervention aided the passage of a plug comprised centrally of cholesterol and urates with peripheral stratified layers of fibrin, macrophages, heterophils, and bacteria. Within 24 hr, a follow-up computed tomography scan showed resolution of the pelvic canal plug.

Diffraction scattering computed tomography: a window into the structures of complex nanomaterials

PubMed Central

Birkbak, M. E.; Leemreize, H.; Frølich, S.; Stock, S. R.

2015-01-01

Modern functional nanomaterials and devices are increasingly composed of multiple phases arranged in three dimensions over several length scales. Therefore there is a pressing demand for improved methods for structural characterization of such complex materials. An excellent emerging technique that addresses this problem is diffraction/scattering computed tomography (DSCT). DSCT combines the merits of diffraction and/or small angle scattering with computed tomography to allow imaging the interior of materials based on the diffraction or small angle scattering signals. This allows, e.g., one to distinguish the distributions of polymorphs in complex mixtures. Here we review this technique and give examples of how it can shed light on modern nanoscale materials. PMID:26505175

Evaluation of dosimetry and image of very low-dose computed tomography attenuation correction for pediatric positron emission tomography/computed tomography: phantom study

NASA Astrophysics Data System (ADS)

Bahn, Y. K.; Park, H. H.; Lee, C. H.; Kim, H. S.; Lyu, K. Y.; Dong, K. R.; Chung, W. K.; Cho, J. H.

2014-04-01

In this study, phantom was used to evaluate attenuation correction computed tomography (CT) dose and image in case of pediatric positron emission tomography (PET)/CT scan. Three PET/CT scanners were used along with acryl phantom in the size for infant and ion-chamber dosimeter. The CT image acquisition conditions were changed from 10 to 20, 40, 80, 100 and 160 mA and from 80 to 100, 120 and 140 kVp, which aimed at evaluating penetrate dose and computed tomography dose indexvolume (CTDIvol) value. And NEMA PET Phantom™ was used to obtain PET image under the same CT conditions in order to evaluate each attenuation-corrected PET image based on standard uptake value (SUV) value and signal-to-noise ratio (SNR). In general, the penetrate dose was reduced by around 92% under the minimum CT conditions (80 kVp and 10 mA) with the decrease in CTDIvol value by around 88%, compared with the pediatric abdomen CT conditions (100 kVp and 100 mA). The PET image with its attenuation corrected according to each CT condition showed no change in SUV value and no influence on the SNR. In conclusion, if the minimum dose CT that is properly applied to body of pediatric patient is corrected for attenuation to ensure that the effective dose is reduced by around 90% or more compared with that for adult patient, this will be useful to reduce radiation exposure level.

Fusion Imaging: A Novel Staging Modality in Testis Cancer

PubMed Central

Sterbis, Joseph R.; Rice, Kevin R.; Javitt, Marcia C.; Schenkman, Noah S.; Brassell, Stephen A.

2010-01-01

Objective: Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. Methods: A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. Results: There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. Conclusions: In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making. PMID:21103077

Fusion imaging: a novel staging modality in testis cancer.

PubMed

Sterbis, Joseph R; Rice, Kevin R; Javitt, Marcia C; Schenkman, Noah S; Brassell, Stephen A

2010-11-05

Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making.

CAVIAR: a serial ECG processing system for the comparative analysis of VCGs and their interpretation with auto-reference to the patient.

PubMed

Fayn, J; Rubel, P

1988-01-01

The authors present a new computer program for serial ECG analysis that allows a direct comparison of any couple of three-dimensional ECGs and quantitatively assesses the degree of evolution of the spatial loops as well as of their initial, central, or terminal sectors. Loops and sectors are superposed as best as possible, with the aim of overcoming tracing variability of nonpathological origin. As a result, optimal measures of evolution are computed and a tabular summary of measurements is dynamically configured with respect to the patient's history and is then printed. A multivariate classifier assigns each couple of tracings to one of four classes of evolution. Color graphic displays corresponding to several modes of representation may also be plotted.

Xyce

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

Thomquist, Heidi K.; Fixel, Deborah A.; Fett, David Brian

The Xyce Parallel Electronic Simulator simulates electronic circuit behavior in DC, AC, HB, MPDE and transient mode using standard analog (DAE) and/or device (PDE) device models including several age and radiation aware devices. It supports a variety of computing platforms (both serial and parallel) computers. Lastly, it uses a variety of modern solution algorithms dynamic parallel load-balancing and iterative solvers.

Computational adaptive optics for broadband interferometric tomography of tissues and cells

NASA Astrophysics Data System (ADS)

Adie, Steven G.; Mulligan, Jeffrey A.

2016-03-01

Adaptive optics (AO) can shape aberrated optical wavefronts to physically restore the constructive interference needed for high-resolution imaging. With access to the complex optical field, however, many functions of optical hardware can be achieved computationally, including focusing and the compensation of optical aberrations to restore the constructive interference required for diffraction-limited imaging performance. Holography, which employs interferometric detection of the complex optical field, was developed based on this connection between hardware and computational image formation, although this link has only recently been exploited for 3D tomographic imaging in scattering biological tissues. This talk will present the underlying imaging science behind computational image formation with optical coherence tomography (OCT) -- a beam-scanned version of broadband digital holography. Analogous to hardware AO (HAO), we demonstrate computational adaptive optics (CAO) and optimization of the computed pupil correction in 'sensorless mode' (Zernike polynomial corrections with feedback from image metrics) or with the use of 'guide-stars' in the sample. We discuss the concept of an 'isotomic volume' as the volumetric extension of the 'isoplanatic patch' introduced in astronomical AO. Recent CAO results and ongoing work is highlighted to point to the potential biomedical impact of computed broadband interferometric tomography. We also discuss the advantages and disadvantages of HAO vs. CAO for the effective shaping of optical wavefronts, and highlight opportunities for hybrid approaches that synergistically combine the unique advantages of hardware and computational methods for rapid volumetric tomography with cellular resolution.

A heterogeneous computing accelerated SCE-UA global optimization method using OpenMP, OpenCL, CUDA, and OpenACC.

PubMed

Kan, Guangyuan; He, Xiaoyan; Ding, Liuqian; Li, Jiren; Liang, Ke; Hong, Yang

2017-10-01

The shuffled complex evolution optimization developed at the University of Arizona (SCE-UA) has been successfully applied in various kinds of scientific and engineering optimization applications, such as hydrological model parameter calibration, for many years. The algorithm possesses good global optimality, convergence stability and robustness. However, benchmark and real-world applications reveal the poor computational efficiency of the SCE-UA. This research aims at the parallelization and acceleration of the SCE-UA method based on powerful heterogeneous computing technology. The parallel SCE-UA is implemented on Intel Xeon multi-core CPU (by using OpenMP and OpenCL) and NVIDIA Tesla many-core GPU (by using OpenCL, CUDA, and OpenACC). The serial and parallel SCE-UA were tested based on the Griewank benchmark function. Comparison results indicate the parallel SCE-UA significantly improves computational efficiency compared to the original serial version. The OpenCL implementation obtains the best overall acceleration results however, with the most complex source code. The parallel SCE-UA has bright prospects to be applied in real-world applications.

Imaging skeletal muscle volume, density, and FDG uptake before and after induction therapy for non-small cell lung cancer.

PubMed

Goncalves, M D; Taylor, S; Halpenny, D F; Schwitzer, E; Gandelman, S; Jackson, J; Lukose, A; Plodkowski, A J; Tan, K S; Dunphy, M; Jones, L W; Downey, R J

2018-05-01

To assess whether changes in body composition could be assessed serially using conventional thoracic computed tomography (CT) and positron-emission tomography (PET)/CT imaging in patients receiving induction chemotherapy for non-small cell lung cancer (NSCLC). CT-based skeletal muscle volume and density were measured retrospectively from thoracic and lumbar segment CT images from 88 patients with newly diagnosed and untreated NSCLC before and after induction chemotherapy. Skeletal muscle 2-[ 18 F]-fluoro-2-deoxy-d-glucose (FDG) uptake was measured from PET/CT images from a subset of patients (n=42). Comparisons of each metric before and after induction chemotherapy were conducted using the non-parametric Wilcoxon signed-rank test for paired data. The association between clinical factors and percentage change in muscle volume was examined using univariate linear regression models, with adjustment for baseline muscle volume. Following induction chemotherapy, thoracic (-3.3%, p=0.0005) and lumbar (-2.6%, p=0.0101) skeletal muscle volume were reduced (adiposity remained unchanged). The proportion of skeletal muscle with a density <0 HU increased (7.9%, p<0.0001), reflecting a decrease in skeletal muscle density and skeletal muscle FDG uptake increased (10.4-31%, p<0.05). No imaging biomarkers were correlated with overall survival. Changes in body composition can be measured from routine thoracic imaging. During chemotherapy skeletal muscle volume and metabolism are altered; however, there was no impact on survival in this retrospective series, and further validation in prospective, well-controlled studies are required. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Incidence of Thyroid-Related Adverse Events in Melanoma Patients Treated With Pembrolizumab

PubMed Central

Jansen, Yanina; Schreuer, Max; Everaert, Hendrik; Velkeniers, Brigitte; Neyns, Bart; Bravenboer, Bert

2016-01-01

Context: Immune checkpoint blockade is associated with endocrine-related adverse events. Thyroid dysfunction during pembrolizumab therapy, an anti-programmed cell death 1 (PD-1) receptor monoclonal antibody, remains to be fully characterized. Objective: To assess the incidence and characteristics of pembrolizumab-associated thyroid dysfunction. Design and Setting: Thyroid function was monitored prospectively in melanoma patients who initiated pembrolizumab within an expanded access program at a referral oncology center. 18Fluorodeoxyglucose uptake on positron emission tomography/computed tomography (18FDG-PET/CT) was reviewed in cases compatible with inflammatory thyroiditis. Patients: Ninety-nine patients with advanced melanoma (age, 26.3–93.6 years; 63.6% females) who received at least one administration of pembrolizumab. Main Outcome Measures: Patient characteristics, thyroid function (TSH, free T4), thyroid autoantibodies, and 18FDG-PET/CT. Results: Eighteen adverse events of thyroid dysfunction were observed in 17 patients. Thyrotoxicosis occurred in 12 patients, of which nine evolved to hypothyroidism. Isolated hypothyroidism was present in six patients. Levothyroxine therapy was required in 10 of 15 hypothyroid patients. Thyroid autoantibodies were elevated during thyroid dysfunction in four of 10 cases. Diffuse increased 18FDG uptake by the thyroid gland was observed in all seven thyrotoxic patients who progressed to hypothyroidism. Conclusions: Thyroid dysfunction is common in melanoma patients treated with pembrolizumab. Hypothyroidism and thyrotoxicosis related to inflammatory thyroiditis are the most frequent presentations. Serial measurements of thyroid function tests are indicated during anti-PD-1 monoclonal antibody therapy. Thyrotoxicosis compatible with inflammatory thyroiditis was associated with diffuse increased 18FDG uptake by the thyroid gland. The prospective role of thyroid autoantibodies should be further investigated, together with the histopathological correlates. PMID:27571185

Metabolic Tumor Volume as a Prognostic Imaging-Based Biomarker for Head-and-Neck Cancer: Pilot Results From Radiation Therapy Oncology Group Protocol 0522

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

Schwartz, David L., E-mail: david.schwartz@utsw.edu; Harris, Jonathan; Yao, Min

2015-03-15

Purpose: To evaluate candidate fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging biomarkers for head-and-neck chemoradiotherapy outcomes in the cooperative group trial setting. Methods and Materials: Radiation Therapy Oncology Group (RTOG) protocol 0522 patients consenting to a secondary FDG-PET/CT substudy were serially imaged at baseline and 8 weeks after radiation. Maximum standardized uptake value (SUVmax), SUV peak (mean SUV within a 1-cm sphere centered on SUVmax), and metabolic tumor volume (MTV) using 40% of SUVmax as threshold were obtained from primary tumor and involved nodes. Results: Of 940 patients entered onto RTOG 0522, 74 were analyzable for this substudy. Neither high baselinemore » SUVmax nor SUVpeak from primary or nodal disease were associated with poor treatment outcomes. However, primary tumor MTV above the cohort median was associated with worse local-regional control (hazard ratio 4.01, 95% confidence interval 1.28-12.52, P=.02) and progression-free survival (hazard ratio 2.34, 95% confidence interval 1.02-5.37, P=.05). Although MTV and T stage seemed to correlate (mean MTV 6.4, 13.2, and 26.8 for T2, T3, and T4 tumors, respectively), MTV remained a strong independent prognostic factor for progression-free survival in bivariate analysis that included T stage. Primary MTV remained prognostic in p16-associated oropharyngeal cancer cases, although sample size was limited. Conclusion: High baseline primary tumor MTV was associated with worse treatment outcomes in this limited patient subset of RTOG 0522. Additional confirmatory work will be required to validate primary tumor MTV as a prognostic imaging biomarker for patient stratification in future trials.« less

Optics Program Modified for Multithreaded Parallel Computing

NASA Technical Reports Server (NTRS)

Lou, John; Bedding, Dave; Basinger, Scott

2006-01-01

A powerful high-performance computer program for simulating and analyzing adaptive and controlled optical systems has been developed by modifying the serial version of the Modeling and Analysis for Controlled Optical Systems (MACOS) program to impart capabilities for multithreaded parallel processing on computing systems ranging from supercomputers down to Symmetric Multiprocessing (SMP) personal computers. The modifications included the incorporation of OpenMP, a portable and widely supported application interface software, that can be used to explicitly add multithreaded parallelism to an application program under a shared-memory programming model. OpenMP was applied to parallelize ray-tracing calculations, one of the major computing components in MACOS. Multithreading is also used in the diffraction propagation of light in MACOS based on pthreads [POSIX Thread, (where "POSIX" signifies a portable operating system for UNIX)]. In tests of the parallelized version of MACOS, the speedup in ray-tracing calculations was found to be linear, or proportional to the number of processors, while the speedup in diffraction calculations ranged from 50 to 60 percent, depending on the type and number of processors. The parallelized version of MACOS is portable, and, to the user, its interface is basically the same as that of the original serial version of MACOS.

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

[Multispiral computed tomographic semiotics of laryngeal cancer].

PubMed

Vasil'ev, P V; Iudin, A L; Sdvizhkov, A M; Kozhanov, L G

2007-01-01

Multispiral computed tomography (MSCT) with intravenous bolus contrasting is a currently available method for radiodiagnosis of laryngeal cancer. MSCT is of much higher informative value in estimating the extent of a tumorous lesion than the traditional radiodiagnostic techniques: linear tomography, lateral X-ray study, roentgenoscopy and roentgenography of the laryngopharynx and esophagus with barium meal.

Diffuse cylindrical bronchiectasis due to eosinophilic bronchopneumopathy in a dog

PubMed Central

Meler, Erika; Pressler, Barrak M.; Heng, Hock Gan; Baird, Debra K.

2010-01-01

A miniature pinscher-cross was evaluated for chronic coughing. Computed tomography and bronchoscopy revealed severe, diffuse, cylindrical bronchiectasis secondary to eosinophilic bronchopneumopathy. Computed tomography is the gold standard for diagnosis of bronchiectasis in humans, and should be further investigated in dogs as a means of characterizing severity and pattern of disease. PMID:20885829

Abernethy malformation with portal vein aneurysm in a child.

PubMed

Chandrashekhara, Sheragaru H; Bhalla, Ashu Seith; Gupta, Arun Kumar; Vikash, C S; Kabra, Susheel Kumar

2011-01-01

Abernethy malformation is an extremely rare anomaly of the splanchnic venous system. We describe multidetector computed tomography findings of an incidentally detected Abernethy malformation with portal vein aneurysm in a two-and-half-year old child. The computed tomography scan was performed for the evaluation of respiratory distress, poor growth, and loss of appetite.

Computed tomography guided localization of clinically occult breast carcinoma-the ''N'' skin guide

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

Kopans, D.B.; Meyer, J.E.

1982-10-01

Standard computed tomography (CT) can be used for the three-dimensional localization of clinically occult suspicious breast lesions whose exact position cannot be determined by standard mammographic views. A method is described that facilitates accurate preoperative needle localization using CT guidance, once the position of these lesions is defined.

Presence of gas in left ventricle due to infective endocarditis.

PubMed

Laiq, Zenab; Yarmohammadi, Hirad; Nabeel, Yassar; Adatya, Sirtaz

2016-01-01

Gas in myocardium is a rare manifestation of infective endocarditis caused by gas producing bacteria. We present a case of infective endocarditis caused by Citrobacter Koseri initially diagnosed by computed tomography and confirmed with transesophageal echocardiogram. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

21 CFR 892.1750 - Computed tomography x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Computed tomography x-ray system. 892.1750 Section 892.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... same axial plane taken at different angles. This generic type of device may include signal analysis and...

21 CFR 892.1750 - Computed tomography x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Computed tomography x-ray system. 892.1750 Section 892.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... same axial plane taken at different angles. This generic type of device may include signal analysis and...

21 CFR 892.1750 - Computed tomography x-ray system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Computed tomography x-ray system. 892.1750 Section 892.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... same axial plane taken at different angles. This generic type of device may include signal analysis and...

21 CFR 892.1750 - Computed tomography x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Computed tomography x-ray system. 892.1750 Section 892.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... same axial plane taken at different angles. This generic type of device may include signal analysis and...

21 CFR 892.1750 - Computed tomography x-ray system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Computed tomography x-ray system. 892.1750 Section 892.1750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... same axial plane taken at different angles. This generic type of device may include signal analysis and...

Use of Computed Tomography Imaging for Qualifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils

EPA Science Inventory

Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals such as polychaetes, amphipods, and shrimp. Here, for the first time, CT imaging is used to successfully quantify wet mass of coarse roots, rhizomes, and peat in cores collected from...

Use of Computer-Aided Tomography (CT) Imaging for Quantifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils

EPA Science Inventory

Computer-aided Tomography (CT) imaging was utilized to quantify wet mass of coarse roots, rhizomes, and peat in cores collected from organic-rich (Jamaica Bay, NY) and mineral (North Inlet, SC) Spartina alterniflora soils. Calibration rods composed of materials with standard dens...

APPLICATION OF COMPUTER-AIDED TOMOGRAPHY TO VISUALIZE AND QUANTIFY BIOGENIC STRUCTURES IN MARINE SEDIMENTS

EPA Science Inventory

We used computer-aided tomography (CT) for 3D visualization and 2D analysis of

marine sediment cores from 3 stations (at 10, 75 and 118 m depths) with different environmental

impact. Biogenic structures such as tubes and burrows were quantified and compared among st...

Micro-computed tomography of pupal metamorphosis in the solitary bee Megachile rotundata

USDA-ARS?s Scientific Manuscript database

Insect metamorphosis involves a complex change in form and function, but most of these changes are internal and treated as a black box. In this study, we examined development of the solitary bee, Megachile rotundata, using micro-computed tomography (µCT) and digital volume analysis. We describe deve...

Reliability of voxel gray values in cone beam computed tomography for preoperative implant planning assessment.

PubMed

Parsa, Azin; Ibrahim, Norliza; Hassan, Bassam; Motroni, Alessandro; van der Stelt, Paul; Wismeijer, Daniel

2012-01-01

To assess the reliability of cone beam computed tomography (CBCT) voxel gray value measurements using Hounsfield units (HU) derived from multislice computed tomography (MSCT) as a clinical reference (gold standard). Ten partially edentulous human mandibular cadavers were scanned by two types of computed tomography (CT) modalities: multislice CT and cone beam CT. On MSCT scans, eight regions of interest (ROI) designating the site for preoperative implant placement were selected in each mandible. The datasets from both CT systems were matched using a three-dimensional (3D) registration algorithm. The mean voxel gray values of the region around the implant sites were compared between MSCT and CBCT. Significant differences between the mean gray values obtained by CBCT and HU by MSCT were found. In all the selected ROIs, CBCT showed higher mean values than MSCT. A strong correlation (R=0.968) between mean voxel gray values of CBCT and mean HU of MSCT was determined. Voxel gray values from CBCT deviate from actual HU units. However, a strong linear correlation exists, which may permit deriving actual HU units from CBCT using linear regression models.

Renal vein thrombosis mimicking urinary calculus: a dilemma of diagnosis.

PubMed

Wang, Yimin; Chen, Shanwen; Wang, Wei; Liu, Jianyong; Jin, Baiye

2015-07-02

Renal vein thrombosis (RVT) with flank pain, and hematuria, is often mistaken with renal colic originating from ureteric or renal calculus. Especially in young and otherwise healthy patients, clinicians are easily misled by clinical presentation and calcified RVT. A 38-year-old woman presented with flank pain and hematuria suggestive of renal calculus on ultrasound. She underwent extracorporeal shock wave lithotripsy that failed, leading to the recommendation that percutaneous lithotomy was necessary to remove the renal calculus. In preoperative view of the unusual shape of the calculus without hydronephrosis, noncontrast computed tomography was taken and demonstrated left ureteric calculus. However computed tomography angiography revealed, to our surprise, a calcified RVT that was initially thought to be a urinary calculus. This case shows that a calcified RVT might mimic a urinary calculus on conventional ultrasonography and ureteric calculus on noncontrast computed tomography. Subsequent computed tomography angiography disclosed that a calcified RVT caused the imaging findings, thus creating a potentially dangerous clinical pitfall. Hence, it is suggested that the possibility of a RVT needs to be considered in the differential diagnosis whenever one detects an uncommon shape for a urinary calculus.

Inflammatory Pseudotumor-Like Follicular Dendritic Cell Sarcoma of the Spleen: Computed Tomography Imaging Characteristics in 5 Patients.

PubMed

Li, Xiumei; Shi, Zhenshan; You, Ruixiong; Li, Yueming; Cao, Dairong; Lin, Renjie; Huang, Xinming

The purpose of this study was to retrospectively review the computed tomography (CT) and clinicopathological characteristics of inflammatory pseudotumor (IPT)-like follicular dendritic cell sarcoma (FDCS) of the spleen in 5 patients. Clinical, pathologic, and CT imaging findings of 5 patients with IPT-like FDCS of the spleen were reviewed and analyzed. Computed tomography imaging and pathologic features were compared. Abdominal unenhanced CT revealed a well-defined hypodense mass in the spleen with complex internal architecture with focal necrosis and/or speckle-strip calcification. On postcontrast CT, slightly delayed enhancement was observed in 5 cases. Four patients had a normalized spleen. The fourth patient had lung metastasis. The fifth patient had 2 relatively small lesions as well as metastases to the spine. Computed tomography imaging features of IPT-like FDCS of the spleen are distinctly different from other hypovascular splenic neoplasm; however, the definitive diagnosis requires further confirmation with needle biopsy or surgery. Inflammatory pseudotumor-like FDCS of the spleen should be suggested by using the CT imaging features of the splenic mass with evidence of metastatic disease.

Malignant head and neck tumours in Radiology Department JPMC Karachi -- a tertiary care experience.

PubMed

Kadri, Shazia; Uddin, Sami; Ahmed, Naveed; Mahmood, Tariq

2015-08-01

To study age, gender and sites of malignant head and neck tumours on contrast-enhanced computed tomography and to elucidate its role. The retrospective study was conducted at the Jinnah Postgraduate Medical Centre, Karachi, and comprised data of patients with histologically proven malignant head and neck tumours reporting from February 2013 to February 2014. Contrast enhanced computed tomography with puffed cheek technique was done in cases of oral cancer, while routine contrast computed tomography was done in cases of other head and neck tumours. SPSS 19 was used for statistical analysis. A total of 100 biopsy-proven cases of malignant tumours comprised the study sample. The male: female ratio was 1.5:1 with an overall mean age of 46.4±16-76 years. . The most common histopathologically proven tumour was squamous cell carcinoma affecting oral mucosa 43(43%), followed by larynx 27(27%) and pharynx 10(10%) . Oral squamous cell carcinoma was the commonest tumour. Compute tomography scan with puffed cheek technique played a beneficial role in locating the site of primary tumour.

Imaging of the midpalatal suture in a porcine model: flat-panel volume computed tomography compared with multislice computed tomography.

PubMed

Hahn, Wolfram; Fricke-Zech, Susanne; Fialka-Fricke, Julia; Dullin, Christian; Zapf, Antonia; Gruber, Rudolf; Sennhenn-kirchner, Sabine; Kubein-Meesenburg, Dietmar; Sadat-Khonsari, Reza

2009-09-01

An investigation was conducted to compare the image quality of prototype flat-panel volume computed tomography (fpVCT) and multislice computed tomography (MSCT) of suture structures. Bone samples were taken from the midpalatal suture of 5 young (16 weeks) and 5 old (200 weeks) Sus scrofa domestica and fixed in formalin solution. An fpVCT prototype and an MSCT were used to obtain images of the specimens. The facial reformations were assessed by 4 observers using a 1 (excellent) to 5 (poor) rating scale for the weighted criteria visualization of the suture structure. A linear mixed model was used for statistical analysis. Results with P < .05 were considered to be statistically significant. The visualization of the suture of young specimens was significantly better than that of older animals (P < .001). The visualization of the suture with fpVCT was significantly better than that with MSCT (P < .001). Compared with MSCT, fpVCT produces superior results in the visualization of the midpalatal suture in a Sus scrofa domestica model.

Spectrally resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography

PubMed Central

Cong, Wenxiang; Shen, Haiou; Wang, Ge

2011-01-01

The nanophosphors, or other similar materials, emit near-infrared (NIR) light upon x-ray excitation. They were designed as optical probes for in vivo visualization and analysis of molecular and cellular targets, pathways, and responses. Based on the previous work on x-ray fluorescence computed tomography (XFCT) and x-ray luminescence computed tomography (XLCT), here we propose a spectrally-resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography (SXLCT or SXFCT) approach to quantify a spatial distribution of nanophosphors (other similar materials or chemical elements) within a biological object. In this paper, the x-ray scattering is taken into account in the reconstruction algorithm. The NIR scattering is described in the diffusion approximation model. Then, x-ray excitations are applied with different spectra, and NIR signals are measured in a spectrally resolving fashion. Finally, a linear relationship is established between the nanophosphor distribution and measured NIR data using the finite element method and inverted using the compressive sensing technique. The numerical simulation results demonstrate the feasibility and merits of the proposed approach. PMID:21721815

Radiolabeling, whole-body single photon emission computed tomography/computed tomography imaging, and pharmacokinetics of carbon nanohorns in mice

PubMed Central

Zhang, Minfang; Jasim, Dhifaf A; Ménard-Moyon, Cécilia; Nunes, Antonio; Iijima, Sumio; Bianco, Alberto; Yudasaka, Masako; Kostarelos, Kostas

2016-01-01

In this work, we report that the biodistribution and excretion of carbon nanohorns (CNHs) in mice are dependent on their size and functionalization. Small-sized CNHs (30–50 nm; S-CNHs) and large-sized CNHs (80–100 nm; L-CNHs) were chemically functionalized and radiolabeled with [111In]-diethylenetriaminepentaacetic acid and intravenously injected into mice. Their tissue distribution profiles at different time points were determined by single photon emission computed tomography/computed tomography. The results showed that the S-CNHs circulated longer in blood, while the L-CNHs accumulated faster in major organs like the liver and spleen. Small amounts of S-CNHs- and L-CNHs were excreted in urine within the first few hours postinjection, followed by excretion of smaller quantities within the next 48 hours in both urine and feces. The kinetics of excretion for S-CNHs were more rapid than for L-CNHs. Both S-CNH and L-CNH material accumulated mainly in the liver and spleen; however, S-CNH accumulation in the spleen was more prominent than in the liver. PMID:27524892

Clinical and Radiographic Response of Extramedullary Leukemia in Patients Treated With Gemtuzumab Ozogamicin.

PubMed

McNeil, Michael J; Parisi, Marguerite T; Hijiya, Nobuko; Meshinchi, Soheil; Cooper, Todd; Tarlock, Katherine

2018-05-04

Extramedullary leukemia (EML) is common in pediatric acute leukemia and can present at diagnosis or relapse. CD33 is detected on the surface of myeloid blasts in many patients with acute myelogenous leukemia and is the target of the antibody drug conjugate gemtuzumab ozogamicin (GO). Here we present 2 patients with CD33 EML treated with GO. They achieved significant response, with reduction of EML on both clinical and radiographic exams, specifically fluorine fluorodeoxyglucose positron emission tomography/computed tomography, demonstrating potential for targeted therapy with GO as a means of treating EML in patients with CD33 leukemia and the utility of fluorine fluorodeoxyglucose positron emission tomography/computed tomography monitoring in EML.

68Gallium-Arginine-Glycine-Aspartic Acid and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Chondroblastic Osteosarcoma of the Skull.

PubMed

Orunmuyi, Akintunde; Modiselle, Moshe; Lengana, Thabo; Ebenhan, Thomas; Vorster, Mariza; Sathekge, Mike

2017-09-01

We report the case of a 32 year-old male with Chondroblastic Osteosarcoma of the skull, which was imaged with both 18 [F]fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) and 68 Gallium-arginine-glycine-aspartic acid ( 68 Ga-RGD) PET/CT. The 18 F-FDG PET/CT did not demonstrate the tumour, whereas the 68 Ga-RGD PET/CT clearly depicted a left-sided frontal tumour. 68 Ga-RGD PET/CT may be a clinically useful imaging modality for early detection of recurrent osteosarcoma, considering the limitations of 18 F-FDG PET in a setting of low glycolytic activity.

Nonmetastatic Castration-resistant Prostate Cancer: A Modern Perspective.

PubMed

Cancian, Madeline; Renzulli, Joseph F

2018-06-01

Nonmetastatic castration-resistant prostate cancer (nmCRPC) presents a challenge to urologists as currently there are no Food and Drug Administration-approved therapies. However, there are new imaging modalities, including fluciclovine positron emission tomography-computed tomography and Ga-PSMA (prostate specific membrane antigent) positron emission tomography-computed tomography, which are improving accuracy of diagnosis. With improved imaging, we are better able to target therapy. Today there are 3 ongoing clinical trials studying second-generation antiandrogens in nmCRPC, which hold the promise of a new treatment paradigm. In this article, we will review the new imaging techniques and the rationale behind novel treatment modalities in nmCRPC. Copyright © 2018 Elsevier Inc. All rights reserved.

Image-Based Macro-Micro Finite Element Models of a Canine Femur with Implant Design Implications

NASA Astrophysics Data System (ADS)

Ghosh, Somnath; Krishnan, Ganapathi; Dyce, Jonathan

2006-06-01

In this paper, a comprehensive model of a bone-cement-implant assembly is developed for a canine cemented femoral prosthesis system. Various steps in this development entail profiling the canine femur contours by computed tomography (CT) scanning, computer aided design (CAD) reconstruction of the canine femur from CT images, CAD modeling of the implant from implant blue prints and CAD modeling of the interface cement. Finite element analysis of the macroscopic assembly is conducted for stress analysis in individual components of the system, accounting for variation in density and material properties in the porous bone material. A sensitivity analysis is conducted with the macroscopic model to investigate the effect of implant design variables on the stress distribution in the assembly. Subsequently, rigorous microstructural analysis of the bone incorporating the morphological intricacies is conducted. Various steps in this development include acquisition of the bone microstructural data from histological serial sectioning, stacking of sections to obtain 3D renderings of void distributions, microstructural characterization and determination of properties and, finally, microstructural stress analysis using a 3D Voronoi cell finite element method. Generation of the simulated microstructure and analysis by the 3D Voronoi cell finite element model provides a new way of modeling complex microstructures and correlating to morphological characteristics. An inverse calculation of the material parameters of bone by combining macroscopic experiments with microstructural characterization and analysis provides a new approach to evaluating properties without having to do experiments at this scale. Finally, the microstructural stresses in the femur are computed using the 3D VCFEM to study the stress distribution at the scale of the bone porosity. Significant difference is observed between the macroscopic stresses and the peak microscopic stresses at different locations.

Surveillance of industrial processes with correlated parameters

DOEpatents

White, Andrew M.; Gross, Kenny C.; Kubic, William L.; Wigeland, Roald A.

1996-01-01

A system and method for surveillance of an industrial process. The system and method includes a plurality of sensors monitoring industrial process parameters, devices to convert the sensed data to computer compatible information and a computer which executes computer software directed to analyzing the sensor data to discern statistically reliable alarm conditions. The computer software is executed to remove serial correlation information and then calculate Mahalanobis distribution data to carry out a probability ratio test to determine alarm conditions.

Optimization of a Solid-State Electron Spin Qubit Using Gate Set Tomography (Open Access, Publisher’s Version)

DTIC Science & Technology

2016-10-13

enielse@sandia.gov and a.morello@unsw.edu.au Keywords: quantum computing , silicon, tomography Supplementarymaterial for this article is available online...Abstract State of the art qubit systems are reaching the gatefidelities required for scalable quantum computation architectures. Further improvements in...and addressedwhen the qubit is usedwithin a fault-tolerant quantum computation scheme. 1. Introduction One of themain challenges in the physical

Adaptive-optics optical coherence tomography processing using a graphics processing unit.

PubMed

Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

2014-01-01

Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability.

Change in lumen eccentricity and asymmetry after treatment with Absorb bioresorbable vascular scaffolds in the ABSORB cohort B trial: a five-year serial optical coherence tomography imaging study.

PubMed

Suwannasom, Pannipa; Sotomi, Yohei; Asano, Taku; Koon, Jaryl Ng Chen; Tateishi, Hiroki; Zeng, Yaping; Tenekecioglu, Erhan; Wykrzykowska, Joanna J; Foin, Nicolas; de Winter, Robbert J; Ormiston, John A; Serruys, Patrick W; Onuma, Yoshinobu

2017-04-07

The aim of the study was to investigate long-term changes in lumen eccentricity and asymmetry at five years after implantation of the Absorb bioresorbable vascular scaffold (BVS). Out of 101 patients from the ABSORB cohort B trial, 28 patients (29 lesions) with serial optical coherence tomography (OCT) examination at four different time points (cohort B1: post-procedure, six months, two, and five years [n=13]; cohort B2: post-procedure, one, three, and five years [n=16]) were evaluated. The longitudinal variance in lumen diameter was assessed by asymmetry index (AI). An asymmetric lesion was defined as AI >0.3. The circularity of the lumen or scaffold was evaluated by the eccentricity index calculated as minimal divided by maximal luminal or scaffold diameter per cross-section. The lowest lumen eccentricity index within a scaffold segment (EIL) <0.7 was defined as an eccentric lesion. Post procedure, an eccentric lesion was observed in 72.4% and became concentric in 93.1% at five years (post EIL 0.67±0.05 vs. five-year EIL 0.80±0.10, p=0.03) with a modest reduction of the lumen area from baseline to five years by 0.75±0.32 mm2. Asymmetric lumen morphology was observed in 93.1% (n=27) post implantation and persisted until five-year follow-up. On serial OCT analyses, there was a substantial increase in the scaffold EI during the first two years (post 0.70±0.06, six months 0.76±0.08, two years 0.85±0.07); then, it remained stable whereas the lumen circularity improved further. There were no significant differences in major adverse cardiac events regarding the lumen morphology over the five-year follow-up. In patients treated with the Absorb BVS, the cross-sectional circularity improved over five years while the variance in longitudinal diameters remained. Regaining of lumen circularity is mainly caused by reshaping of the scaffold during the first two years.

Parallel Monotonic Basin Hopping for Low Thrust Trajectory Optimization

NASA Technical Reports Server (NTRS)

McCarty, Steven L.; McGuire, Melissa L.

2018-01-01

Monotonic Basin Hopping has been shown to be an effective method of solving low thrust trajectory optimization problems. This paper outlines an extension to the common serial implementation by parallelizing it over any number of available compute cores. The Parallel Monotonic Basin Hopping algorithm described herein is shown to be an effective way to more quickly locate feasible solutions, and improve locally optimal solutions in an automated way without requiring a feasible initial guess. The increased speed achieved through parallelization enables the algorithm to be applied to more complex problems that would otherwise be impractical for a serial implementation. Low thrust cislunar transfers and a hybrid Mars example case demonstrate the effectiveness of the algorithm. Finally, a preliminary scaling study quantifies the expected decrease in solve time compared to a serial implementation.,

High-Resolution Computed Tomography and Pulmonary Function Findings of Occupational Arsenic Exposure in Workers.

PubMed

Ergün, Recai; Evcik, Ender; Ergün, Dilek; Ergan, Begüm; Özkan, Esin; Gündüz, Özge

2017-05-05

The number of studies where non-malignant pulmonary diseases are evaluated after occupational arsenic exposure is very few. To investigate the effects of occupational arsenic exposure on the lung by high-resolution computed tomography and pulmonary function tests. Retrospective cross-sectional study. In this study, 256 workers with suspected respiratory occupational arsenic exposure were included, with an average age of 32.9±7.8 years and an average of 3.5±2.7 working years. Hair and urinary arsenic levels were analysed. High-resolution computed tomography and pulmonary function tests were done. In workers with occupational arsenic exposure, high-resolution computed tomography showed 18.8% pulmonary involvement. In pulmonary involvement, pulmonary nodule was the most frequently seen lesion (64.5%). The other findings of pulmonary involvement were 18.8% diffuse interstitial lung disease, 12.5% bronchiectasis, and 27.1% bullae-emphysema. The mean age of patients with pulmonary involvement was higher and as they smoked more. The pulmonary involvement was 5.2 times higher in patients with skin lesions because of arsenic. Diffusing capacity of lung for carbon monoxide was significantly lower in patients with pulmonary involvement. Besides lung cancer, chronic occupational inhalation of arsenic exposure may cause non-malignant pulmonary findings such as bronchiectasis, pulmonary nodules and diffuse interstitial lung disease. So, in order to detect pulmonary involvement in the early stages, workers who experience occupational arsenic exposure should be followed by diffusion test and high-resolution computed tomography.

The Influence of Reconstruction Kernel on Bone Mineral and Strength Estimates Using Quantitative Computed Tomography and Finite Element Analysis.

PubMed

Michalski, Andrew S; Edwards, W Brent; Boyd, Steven K

2017-10-17

Quantitative computed tomography has been posed as an alternative imaging modality to investigate osteoporosis. We examined the influence of computed tomography convolution back-projection reconstruction kernels on the analysis of bone quantity and estimated mechanical properties in the proximal femur. Eighteen computed tomography scans of the proximal femur were reconstructed using both a standard smoothing reconstruction kernel and a bone-sharpening reconstruction kernel. Following phantom-based density calibration, we calculated typical bone quantity outcomes of integral volumetric bone mineral density, bone volume, and bone mineral content. Additionally, we performed finite element analysis in a standard sideways fall on the hip loading configuration. Significant differences for all outcome measures, except integral bone volume, were observed between the 2 reconstruction kernels. Volumetric bone mineral density measured using images reconstructed by the standard kernel was significantly lower (6.7%, p < 0.001) when compared with images reconstructed using the bone-sharpening kernel. Furthermore, the whole-bone stiffness and the failure load measured in images reconstructed by the standard kernel were significantly lower (16.5%, p < 0.001, and 18.2%, p < 0.001, respectively) when compared with the image reconstructed by the bone-sharpening kernel. These data suggest that for future quantitative computed tomography studies, a standardized reconstruction kernel will maximize reproducibility, independent of the use of a quantitative calibration phantom. Copyright © 2017 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Assessment of cardiovascular risk profile based on measurement of tophus volume in patients with gout.

PubMed

Lee, Kyung-Ann; Ryu, Se-Ri; Park, Seong-Jun; Kim, Hae-Rim; Lee, Sang-Heon

2018-05-01

Hyperuricemia and gout are associated with increased risk of cardiovascular disease and metabolic syndrome. The aim of this study was to evaluate the correlation of total tophus volumes, measured using dual-energy computed tomography, with cardiovascular risk and the presence of metabolic syndrome. Dual-energy computed tomography datasets from 91 patients with a diagnosis of gout were analyzed retrospectively. Patients who received urate lowering therapy were excluded to avoid the effect on tophus volume. The total volumes of tophaceous deposition were quantified using automated volume assessment software. The 10-year cardiovascular risk using the Framingham Risk Score and metabolic syndrome based on the Third Adult Treatment Panel criteria were estimated. Fifty-five and 36 patients with positive and negative dual-energy computed tomography results, respectively, were assessed. Patients with positive dual-energy computed tomography results showed significantly higher systolic blood pressure, diastolic blood pressure, fasting glucose, and higher prevalence of chronic kidney disease, compared with those with negative dual-energy computed tomography results. The total tophus volumes were significantly correlated with the Framingham Risk Score, and the number of metabolic syndrome components (r = 0.22 and p = 0.036 and r = 0.373 and p < 0.001, respectively). The total tophus volume was one of the independent prognostic factors for the Framingham Risk Score in a multivariate analysis. This study showed the correlation of total tophus volumes with cardiovascular risk and metabolic syndrome-related comorbidities. A high urate burden could affect unfavorable cardiovascular profiles.

Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists

PubMed Central

Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M.

2016-01-01

Purpose To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. Methods As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Results Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = < .004). No significant differences were detected concerning the modalities’ specificities (with values between P = .98). Raters' confidence was higher in RED-MDCT and RED-CBCT compared to radiography (P < .001). Conclusion The diagnostic accuracy of RED-MDCT and RED-CBCT for wrist fractures proved to be similar and in some parts even higher compared to radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run. PMID:27788215

Single photon emission computed tomography and oth selected computer topics

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

Frey, G.D.

1981-07-01

This book, the proceedings of a meeting in January 1980, contains 21 papers. Thirteen are devoted to aspects of emission tomography, four to nuclear cardiology, and five to other topics. The initial set of papers consists of reviews of the single photon emission tomography process. These include transverse axial tomography using scintillation cameras and other devices, longitudinal section tomography, and pin-hole and slant-hole systems. These reviews are generally well done, but as might be expected, lack any coherence from paper to paper. The papers on nuclear cardiology include several of Fourier analysis in nuclear cardiology and one on shunt quantification.more » Other clinical papers are on quantifying Tc-99m glucoheptonate uptake in the brain and on iron-59 retention studies. A general criticism of the book is the poor quality of photographic reproductions.« less

Serial imaging and structure-function correlates of high-density rings of fundus autofluorescence in retinitis pigmentosa.

PubMed

Robson, Anthony G; Tufail, Adnan; Fitzke, Fred; Bird, Alan C; Moore, Anthony T; Holder, Graham E; Webster, Andrew R

2011-09-01

To document the evolution and functional and structural significance of parafoveal rings of high-density fundus autofluorescence (AF) in patients with retinitis pigmentosa and preserved visual acuity. Fifty-two patients with nonsyndromic retinitis pigmentosa or Usher syndrome, who had a parafoveal ring of high-density AF and a visual acuity of 20/30 or better, were ascertained. All had international standard full-field electroretinography and pattern electroretinography. Autofluorescence imaging was repeated in 30 patients after periods of up to 9.3 years. Of the 52 patients, 35 underwent optical coherence tomography. Progressive constriction of the ring was detected in 17 patients. Ring radius reduced by up to 40% at a mean rate of between 0.8% and 15.8% per year. In 1 patient, a small ring was replaced by irregular AF; visual acuity deteriorated over the same period. There was a high correspondence between the lateral extent of the preserved optical coherence tomography inner segment/outer segment band and the diameter of the ring along the same optical coherence tomographic scan plane (slope, 0.9; r = 0.97; P < 0.005; n = 35) and between preserved inner segment/outer segment lamina and the pattern electroretinography P50 measure of macular function (R = 0.72; P < 0.005; n = 34). Rings of increased AF surround areas of preserved outer retina and preserved photopic function. Serial fundus AF may provide prognostic indicators for preservation of central acuity and potentially assist in the identification and evaluation of patients suitable for treatment aimed at preservation of remaining function.

Serial intracameral visualization of the Ahmed glaucoma valve tube by anterior segment optical coherence tomography.

PubMed

Lopilly Park, H-Y; Jung, K I; Park, C K

2012-09-01

To investigate serial changes of the Ahmed glaucoma valve (AGV) implant tube in the anterior chamber by anterior segment optical coherence tomography (AS-OCT). Patients who had received AGV implantation without complications (n=48) were included in this study. Each patient received follow-up examinations including AS-OCT at days 1 and 2, week 1, and months 1, 3, 6, and 12. Tube parameters were defined to measure its length and position. The intracameral length of the tube was from the tip of the bevel-edged tube to the sclerolimbal junction. The distance between the extremity of the tube and the anterior iris surface (T-I distance), and the angle between the tube and the posterior endothelial surface of the cornea (T-C angle) were defined. Factors that were related to tube parameters were analysed by multiple regression analysis. The mean change in tube length was -0.20 ± 0.17 mm, indicating that the tube length shortened from the initial inserted length. The mean T-I distance change was 0.11 ± 0.07 mm and the mean T-C angle change was -6.7 ± 5.6°. Uveitic glaucoma and glaucoma following penetrating keratoplasty showed the most changes in tube parameters. By multiple regression analysis, diagnosis of glaucoma including uveitic glaucoma (P=0.049) and glaucoma following penetrating keratoplasty (P=0.008) were related to the change of intracameral tube length. These results suggest that the length and position of the AGV tube changes after surgery. The change was prominent in uveitic glaucoma and glaucoma following penetrating keratoplasty.

Optical Coherence Tomography Study of Experimental Anterior Ischemic Optic Neuropathy and Histologic Confirmation

PubMed Central

Ho, Joyce K.; Stanford, Madison P.; Shariati, Mohammad A.; Dalal, Roopa; Liao, Yaping Joyce

2013-01-01

Purpose. The optic nerve is part of the central nervous system, and interruption of this pathway due to ischemia typically results in optic atrophy and loss of retinal ganglion cells. In this study, we assessed in vivo retinal changes following murine anterior ischemic optic neuropathy (AION) by using spectral-domain optical coherence tomography (SD-OCT) and compared these anatomic measurements to that of histology. Methods. We induced ischemia at the optic disc via laser-activated photochemical thrombosis, performed serial SD-OCT and manual segmentation of the retinal layers to measure the ganglion cell complex (GCC) and total retinal thickness, and correlated these measurements with that of histology. Results. There was impaired perfusion and leakage at the optic disc on fluorescein angiography immediately after AION and severe swelling and distortion of the peripapillary retina on day-1. We used SD-OCT to quantify the changes in retinal thickness following experimental AION, which revealed significant thickening of the GCC on day-1 after ischemia followed by gradual thinning that plateaued by week-3. Thickness of the peripapillary sensory retina was also increased on day-1 and thinned chronically. This pattern of acute retinal swelling and chronic thinning on SD-OCT correlated well with changes seen in histology and corresponded to loss of retinal ganglion layer cells after ischemia. Conclusions. This was a serial SD-OCT quantification of acute and chronic changes following experimental AION, which revealed changes in the GCC similar to that of human AION, but over a time frame of weeks rather than months. PMID:23887804

Developing 3D SEM in a broad biological context

PubMed Central

Kremer, A; Lippens, S; Bartunkova, S; Asselbergh, B; Blanpain, C; Fendrych, M; Goossens, A; Holt, M; Janssens, S; Krols, M; Larsimont, J-C; Mc Guire, C; Nowack, MK; Saelens, X; Schertel, A; Schepens, B; Slezak, M; Timmerman, V; Theunis, C; Van Brempt, R; Visser, Y; GuÉRin, CJ

2015-01-01

When electron microscopy (EM) was introduced in the 1930s it gave scientists their first look into the nanoworld of cells. Over the last 80 years EM has vastly increased our understanding of the complex cellular structures that underlie the diverse functions that cells need to maintain life. One drawback that has been difficult to overcome was the inherent lack of volume information, mainly due to the limit on the thickness of sections that could be viewed in a transmission electron microscope (TEM). For many years scientists struggled to achieve three-dimensional (3D) EM using serial section reconstructions, TEM tomography, and scanning EM (SEM) techniques such as freeze-fracture. Although each technique yielded some special information, they required a significant amount of time and specialist expertise to obtain even a very small 3D EM dataset. Almost 20 years ago scientists began to exploit SEMs to image blocks of embedded tissues and perform serial sectioning of these tissues inside the SEM chamber. Using first focused ion beams (FIB) and subsequently robotic ultramicrotomes (serial block-face, SBF-SEM) microscopists were able to collect large volumes of 3D EM information at resolutions that could address many important biological questions, and do so in an efficient manner. We present here some examples of 3D EM taken from the many diverse specimens that have been imaged in our core facility. We propose that the next major step forward will be to efficiently correlate functional information obtained using light microscopy (LM) with 3D EM datasets to more completely investigate the important links between cell structures and their functions. Lay Description Life happens in three dimensions. For many years, first light, and then EM struggled to image the smallest parts of cells in 3D. With recent advances in technology and corresponding improvements in computing, scientists can now see the 3D world of the cell at the nanoscale. In this paper we present the results of high resolution 3D imaging in a number of diverse cells and tissues from multiple species. 3D reconstructions of cell structures often revealed them to be significantly more complex when compared to extrapolations made from 2D studies. Correlating functional 3D LM studies with 3D EM results opens up the possibility of making new strides in our understanding of how cell structure is connected to cell function. PMID:25623622

Potential risk of alpha-glucosidase inhibitor administration in prostate cancer external radiotherapy by exceptional rectal gas production: a case report.

PubMed

Nishimura, Takuya; Yamazaki, Hideya; Iwama, Kazuki; Oota, Yoshitaka; Aibe, Norihiro; Nakamura, Satoaki; Yoshida, Ken; Okabe, Haruumi; Yamada, Kei

2014-05-05

Radiotherapy is a standard treatment for prostate cancer, and image-guided radiotherapy is increasingly being used to aid precision of dose delivery to targeted tissues. However, precision during radiotherapy cannot be maintained when unexpected intrafraction organ motion occurs. We report our experience of internal organ motion caused by persistent gas production in a patient taking an alpha-glucosidase inhibitor. A 68-year-old Japanese man with prostate cancer visited our institution for treatment with helical tomotherapy. He suffered from diabetes mellitus and took an alpha-glucosidase inhibitor. Routine treatment planning computed tomography showed a large volume of rectal gas; an enema was given to void the rectum. Subsequent treatment planning computed tomography again showed a large volume of gas. After exercise (walking) to remove the intestinal gas, a third scan was performed as a test scan without tight fixation, which showed a sufficiently empty rectum for planning. However, after only a few minutes, treatment planning computed tomography again showed extreme accumulation of gas. Therefore, we postponed treatment planning computed tomography and consulted his doctor to suspend the alpha-glucosidase inhibitor, which was the expected cause of his persistent gas. Four days after the alpha-glucosidase inhibitor regimen was suspended, we took a fourth treatment planning computed tomography and made a treatment plan without gas accumulation. Thereafter, the absence of rectal gas accumulation was confirmed using daily megavolt computed tomography before treatment, and the patient received 37 fractions of intensity-modified radiotherapy at 74 Gy without rectal gas complications. In this case study, the alpha-glucosidase inhibitor induced the accumulation of intestinal gas, which may have caused unexpected organ motion, untoward reactions, and insufficient doses to clinical targets. We suggest that patients who are taking an alpha-glucosidase inhibitor for diabetes should discontinue use of that particular medicine prior to beginning radiotherapy.

Comparison of Online 6 Degree-of-Freedom Image Registration of Varian TrueBeam Cone-Beam CT and BrainLab ExacTrac X-Ray for Intracranial Radiosurgery.

PubMed

Li, Jun; Shi, Wenyin; Andrews, David; Werner-Wasik, Maria; Lu, Bo; Yu, Yan; Dicker, Adam; Liu, Haisong

2017-06-01

The study was aimed to compare online 6 degree-of-freedom image registrations of TrueBeam cone-beam computed tomography and BrainLab ExacTrac X-ray imaging systems for intracranial radiosurgery. Phantom and patient studies were performed on a Varian TrueBeam STx linear accelerator (version 2.5), which is integrated with a BrainLab ExacTrac imaging system (version 6.1.1). The phantom study was based on a Rando head phantom and was designed to evaluate isocenter location dependence of the image registrations. Ten isocenters at various locations representing clinical treatment sites were selected in the phantom. Cone-beam computed tomography and ExacTrac X-ray images were taken when the phantom was located at each isocenter. The patient study included 34 patients. Cone-beam computed tomography and ExacTrac X-ray images were taken at each patient's treatment position. The 6 degree-of-freedom image registrations were performed on cone-beam computed tomography and ExacTrac, and residual errors calculated from cone-beam computed tomography and ExacTrac were compared. In the phantom study, the average residual error differences (absolute values) between cone-beam computed tomography and ExacTrac image registrations were 0.17 ± 0.11 mm, 0.36 ± 0.20 mm, and 0.25 ± 0.11 mm in the vertical, longitudinal, and lateral directions, respectively. The average residual error differences in the rotation, roll, and pitch were 0.34° ± 0.08°, 0.13° ± 0.09°, and 0.12° ± 0.10°, respectively. In the patient study, the average residual error differences in the vertical, longitudinal, and lateral directions were 0.20 ± 0.16 mm, 0.30 ± 0.18 mm, 0.21 ± 0.18 mm, respectively. The average residual error differences in the rotation, roll, and pitch were 0.40°± 0.16°, 0.17° ± 0.13°, and 0.20° ± 0.14°, respectively. Overall, the average residual error differences were <0.4 mm in the translational directions and <0.5° in the rotational directions. ExacTrac X-ray image registration is comparable to TrueBeam cone-beam computed tomography image registration in intracranial treatments.