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Sample records for multidetector computed tomographic

  1. Multidetector computed tomographic angiography of the cardiovascular system

    PubMed Central

    Burrill, Joshua; Dabbagh, Zaid; Gollub, Frank; Hamady, Mohamed

    2007-01-01

    The introduction of multidetector computed tomography (MDCT) is considered a dramatic development in CT imaging that has direct implication in the imaging of various systems, in particular the cardiovascular system. The advantages of MDCT are an enormous increase in imaging acquisition speed, more coverage of the patient, and high spatial resolution. This article reviews the recent developments in CT angiography and discusses the clinical application relevant to diagnosis and endovascular treatment of cardiovascular diseases. PMID:17989269

  2. Comparison between clinical indicators of transmembrane oxygenator thrombosis and multidetector computed tomographic analysis.

    PubMed

    Panigada, Mauro; L'Acqua, Camilla; Passamonti, Serena Maria; Mietto, Cristina; Protti, Alessandro; Riva, Roberto; Gattinoni, Luciano

    2015-04-01

    This study aims to assess whether multidetector computed tomography (MDCT) could accurately confirm the clinical suspicion of transmembrane oxygenator thrombosis (MOT) during extracorporeal membrane oxygenation (ECMO). Twenty-seven oxygenators were examined using MDCT at the end of patient treatment. Transmembrane oxygenator thrombosis was suspected in 15 of them according to the presence of at least 2 of the following clinical indicators: (1) increase in d-dimer, (2) decrease in platelet count, (3) decrease in oxygenator performance, and (4) presence of clots on the surface of the oxygenator. Transmembrane oxygenator thrombosis was confirmed by MDCT in 5 (33%) of them. Transmembrane oxygenator thrombosis was unexpectedly found in 5 (41%) of the remaining 12 oxygenators not suspected for MOT. Eight (80%) of these oxygenators had clots accounting for less than 1% of total volume. Clots were mainly detectable at the apical corner of the oxygenator, most likely due to greater blood stasis. We found a significant increase in d-dimer and in membrane oxygenator shunt and a decrease in platelet count from the start to the discontinuation of ECMO. Hemostatic abnormalities significantly reverted 48 hours after oxygenator removal, suggesting the role of ECMO in activation of the coagulation cascade. Multidetector computed tomographic scan could not accurately confirm the clinical suspicion of MOT. PMID:25547046

  3. Staging of colorectal cancer using contrast-enhanced multidetector computed tomographic colonography

    PubMed Central

    Narayanan, Srikala; Kalra, Naveen; Bhatia, Anmol; Wig, Jaidev; Rana, Surinder; Bhasin, Deepak; Vaiphei, Kim; Khandelwal, Niranjan

    2014-01-01

    INTRODUCTION Preoperative staging is essential for the optimal treatment and surgical planning of colorectal cancers. This study was aimed to evaluate the accuracy of colorectal cancer staging done using contrast-enhanced multidetector computed tomographic colonography (CEMDCTC). METHODS We recruited 25 patients with 28 proven colorectal cancers. A 16-slice multidetector computed tomography scanner was used to generate two-dimensional multiplanar reformatted sagittal, coronal and oblique coronal images, and three-dimensional virtual colonography (endoluminal) images. Axial and reformatted views were analysed, and TNM staging was done. Patients underwent surgery and conventional colonoscopy, and surgical histopathological correlation was obtained. RESULTS The diagnostic accuracies for TNM colorectal cancer staging were 92.3% for T staging, 42.3% for N staging and 96.1% for M staging using CEMDCTC. There was excellent positive correlation for T staging between CEMDCTC and both surgery (κ-value = 0.686) and histopathology (κ-value = 0.838) (p < 0.0001), and moderate positive correlation for N staging between CEMDCTC and surgery (κ-value = 0.424; p < 0.0001). The correlation between CEMDCTC and histopathology for N staging was poor (κ-value = 0.186; p < 0.05); the negative predictive value was 100% for lymph node detection. Moderate positive correlation was seen for M staging between CEMDCTC and both surgery (κ-value = 0.462) and histopathology (κ-value = 0.649). No false negatives were identified in any of the M0 cases. CONCLUSION CEMDCTC correlated well with pathologic T and M stages, but poorly with pathologic N stage. It is an extremely accurate tool for T staging, but cannot reliably distinguish between malignant lymph nodes and enlarged reactive lymph nodes. PMID:25630322

  4. Evaluation of hepatic arterial anatomy by multidetector computed tomographic angiography in living donor liver transplantation.

    PubMed

    Keles, Papatya; Yuce, Ihsan; Keles, Sait; Kantarci, Mecit

    2016-06-01

    The aim of this study was to define the different courses and percentages of hepatic artery that were detected during preoperative evaluation of living liver donors by multidetector computed tomographic angiography (MDCTA). We evaluated 150 donors before hepatic transplantation. All of the donors were evaluated by multislice CT scan with 256 detectors. For each patient, arterial, portal and venous phase images were obtained. The hepatic arterial variations were evaluated by the same radiologist according to Michels' classification. Common hepatic arterial anatomy (type I) was observed in 95 donors (63.3%). Other arterial variations were determined in the remaining 55 donors (36.6%). The second common variation was type XI which did not match with the description of Michels' classification variation in 15 donors (10%). The remaining variations described in Michels' classification were seen at lower rates. Type VII or X variation was not seen. MDCTA is a useful method to identify the blood supply of the liver before the liver transplantations, and surgeons can make their plan on the basis of CT data. PMID:26910605

  5. MULTIDETECTOR-ROW COMPUTED TOMOGRAPHIC CHARACTERISTICS OF PRESUMED PREURETERAL VENA CAVA IN CATS.

    PubMed

    Pey, Pascaline; Marcon, Oriana; Drigo, Michele; Specchi, Swan; Bertolini, Giovanna

    2015-01-01

    Preureteral vena cava (circumcaval ureter, retrocaval ureter) occurs in a third of the feline population and has been associated with ureteral strictures in humans. The aim of this retrospective cross-sectional study was to describe the contrast-enhanced multidetector row computed tomographic (MDCT) characteristics of presumed preureteral vena cava in a group of cats. Medical records from two institutions located in different continents were searched from 2010-2013 for cases with complete contrast-enhanced MDCT examinations of the abdomen (i.e. included the entire course of the ureters and prerenal and renal segments of the caudal vena cava) and a diagnosis of preureteral caudal vena cava. For cases meeting inclusion criteria, CT scan data were retrieved and characteristics of the preureteral caudal vena cava were recorded. Presence of concomitant renal or ureteral diseases was also recorded. A total of 272 cats had contrast-enhanced abdominal CT scans during the study period and of these, 68 cats (22.43 ± 4.96%) had a diagnosis of presumed preureteral vena cava. In all affected cats, a "reverse-J ureter" was observed, i.e. a ureter running medially at the level of L4-5, passing dorsally to the caudal vena cava and then exiting ventrally between the caudal vena cava and aorta returning to its normal position. Having a preureteral vena cava resulted in an increased risk for concurrent urinary signs (OR = 3.00; CI: 95%; 1.28-6.99; P = 0.01). Findings supported the use of contrast-enhanced MDCT for characterizing morphology of preureteral vena cava and its relation with ureters in cats. PMID:25786990

  6. Prediction of Small Bowel Obstruction Caused by Bezoars Using Risk Factor Categories on Multidetector Computed Tomographic Findings

    PubMed Central

    Kuang, Lian-qin; Cheng, Cheng

    2016-01-01

    Objectives. The aim of this study was to detect factors associated with small bowel obstruction (SBO) caused by bezoars on multidetector computed tomographic findings. Methods. We retrospectively reviewed 61 patients who had bezoars in the small bowels on MDCT. The patients were divided into SBO patients group and non-SBO patients group. The mean values of the diameter, volume, and CT attenuation as well as location and characteristics of the bezoars were compared between the two groups. Multivariate analysis was performed to determine factors associated with SBO. Results. There were 32 patients (52.5%) in the SBO group and 29 patients (47.5%) in the non-SBO group. The bezoars in the SBO group had greater values of each mean diameter and mean volume than those in the non-SBO group (3.2 ± 0.5 cm versus 1.6 ± 0.7 cm, P < 0.0001, 14.9 ± 6.4 cm3 versus 2.5 ± 2.7 cm3, P < 0.0001, resp.) and had a lower CT attenuation than the non-SBO group (55.5 ± 23.4 versus 173.0 ± 68.0, P < 0.0001). The SBO group had higher prevalence of phytobezoar appearance (75.0% versus 10.3%, P < 0.0001). Major diameters of bezoar and phytobezoar were significant independent risk factors associated with SBO (odds ratio = 36.09, 8.26, resp., and P = 0.0004, 0.044, resp.). Conclusions. Major diameter of bezoar or phytobezoar is a potential risk factor associated with SBO. PMID:27403434

  7. Spinopelvic dissociation: multidetector computed tomographic evaluation of fracture patterns and associated injuries at a single level 1 trauma center.

    PubMed

    Gupta, Pushpender; Barnwell, Jonathan C; Lenchik, Leon; Wuertzer, Scott D; Miller, Anna N

    2016-06-01

    The objective of the present study is to evaluate multidetector computed tomographic (MDCT) fracture patterns and associated injuries in patients with spinopelvic dissociation (SPD). Our institutional trauma registry database was reviewed from Jan. 1, 2006, to Sept. 30, 2012, specifically evaluating patients with sacral fractures. MDCT scans of patients with sacral fractures were reviewed to determine the presence of SPD. SPD cases were characterized into the following fracture patterns: U-shaped, Y-shaped, T-shaped, H-shaped, and burst. The following MDCT features were recorded: level of the horizontal fracture, location of vertical fracture, kyphosis between major fracture fragments, displacement of fracture fragment, narrowing of central spinal canal, narrowing of neural foramina, and extension into sacroiliac joints. Quantitative evaluation of the sacral fractures was performed in accordance with the consensus statement by the Spine Trauma Study Group. Medical records were reviewed to determine associated pelvic and non-pelvic fractures, bladder and bowel injuries, nerve injuries, and type of surgical intervention. Twenty-one patients had SPD, of whom 13 were men and eight were women. Mean age was 41.8 years (range 18.8 to 87.7). Five fractures (24 %) were U-shaped, six (29 %) H-shaped, four (19 %) Y-shaped, and six (29 %) burst. Nine patients (43 %) had central canal narrowing, and 19 (90 %) had neural foramina narrowing. Eleven patients (52 %) had kyphotic angulation between major fracture fragments, and seven patients (33 %) had either anterior (24 %) or posterior (10 %) displacement of the proximal fracture fragment. Fourteen patients (67 %) had associated pelvic fractures, and 20 (95 %) had associated non-pelvic fractures. Two patients (10 %) had associated urethral injuries, and one (5 %) had an associated colon injury. Seven patients (33 %) had associated nerve injuries. Six patients (29 %) had surgical fixation while 15 (71 %) were

  8. Multidetector-row Computed Tomographic Angiography in the Planning of the Local Perforator Flaps

    PubMed Central

    Sliesarenko, Sergii V.

    2015-01-01

    Background: The perforator vessels are highly variable in number, localization types, hemodynamic specifications, and the anatomical interactions with other structures. For these reasons, the identification of the best perforator before the operation is very important for the choice of the main feed vessel and the design of the perforator flap. Methods: The authors retrospectively analyzed all cases in which multiple detector computed tomography (MDCT) with 3-dimensional (3D) image reconstruction was used in the preoperative planning in preparation for the reconstruction with local perforator flaps, which took place between July 2012 and December 2014 in the hospital. Results: A total of 24 people were examined and underwent operations with 26 reconstructions using local perforator flaps. All perforators, which were identified during the MDCT with 3D reconstruction examination, were located intraoperationally without any errors. Conclusions: The preoperative MDCT with 3D reconstruction investigations of the topographic anatomical specifics of the perforator vessel on which the formation of the flap feed pedicle is planned allow for the fast and precise identification of the perforation at the preoperative stage while minimizing the amount of injury caused to the perforator during the operation and decrease the operation time. PMID:26495229

  9. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 3,2015 ... facts MDCT is a very fast type of computed tomography (CT) scan. MDCT creates pictures of the healthy ...

  10. [Multislice computed tomographic myelography].

    PubMed

    Klingebiel, R; Masuhr, F; Rogalla, P; Hein, E; Juran, R; Bauknecht, H C; Bohner, G

    2006-02-01

    While magnetic resonance imaging (MRI) is the first line modality in depicting intramedullary spinal lesions, computed tomographic (CT) myelography has gained renewed attention due to the introduction of multislice scanning (MS-CT). Compared with conventional CT, MS-CT permits rapid, high-resolution imaging of various spinal pathologies with extended scan length. Although soft tissue contrast is inferior to that with MRI, MS-CT myelography performs best in detailed assessment of osseous pathologies, 3D imaging of orthopedic and anesthesiologic implants, and showing dural leakage and causes of CSF circulation impairment. Whenever MRI is not available or contraindicated, MS-CT myelography is the method of choice for evaluating spinal lesions. PMID:16283150

  11. [Valvular heart disease: multidetector computed tomography evaluation].

    PubMed

    Franco, A; Fernández-Pérez, G C; Tomás-Mallebrera, M; Badillo-Portugal, S; Orejas, M

    2014-01-01

    Heart valve disease is a clinical problem that has been studied with classical imaging techniques like echocardiography and MRI. Technological advances in CT make it possible to obtain static and dynamic images that enable not only a morphological but also a functional analysis in many cases. Although it is currently indicated only in patients with inconclusive findings at echocardiography and MRI or those in whom these techniques are contraindicated, multidetector CT makes it possible to diagnose stenosis or regurgitation through planimetry, to evaluate and quantify valvular calcium, and to show the functional repercussions of these phenomena on the rest of the structures of the heart. Given that multidetector CT is being increasingly used in the diagnosis of ischemic heart disease, we think it is interesting for radiologists to know its potential for the study of valvular disease. PMID:23246401

  12. Computed tomographic findings in bilateral adrenal tuberculosis

    SciTech Connect

    Wilms, G.E.; Baert, A.L.; Kint, E.J.; Pringot, J.H.; Goddeeris, P.G.

    1983-03-01

    The computed tomographic (CT) features of bilateral adrenal tuberculosis are reported in two cases that demonstrate two typical different clinical and morphological manifestations of the disease. The incidence and CT appearance of adrenal tuberculosis are discussed, with emphasis on differential diagnosis.

  13. Computed tomographic staging of traumatic epidural bleeding

    SciTech Connect

    Zimmerman, R.A.; Bilaniuk, L.T.

    1982-09-01

    The computed tomographic findings in 45 patients with post-traumatic epidural hemotomas are subdivided into three categories (acute, subacute, and chronic) and correlated with the severity of bleeding, clot formation, and clot resorption. Active epidural bleeding may be identified in acute cases.

  14. Computed tomographic evaluation of laryngoceles

    SciTech Connect

    Silverman, P.M.; Korobkin, M.

    1982-10-01

    Computed tomography (CT) of the larynx was used in three patients with laryngoceles. One of the cases is described. CT was able to define the extent of the laryngocele more precisely than either clinical examination or conventional radiographic techniques.

  15. Computed tomographic arthrography of the normal canine elbow.

    PubMed

    Gendler, Andrew; Keuler, Nicholas S; Schaefer, Susan L

    2015-01-01

    Comprehensive evaluation of canine elbow joint dysfunction includes assessment of articular cartilage, which can noninvasively be performed with contrast arthrography. Aims of this prospective study were to compare positive contrast computed tomographic (CT) arthrography and histomorphometry measures of cartilage thickness in normal canine elbows, and to determine the optimal contrast medium concentration. Thirty-two canine cadaver elbows were examined using multidetector CT, before and after intra-articular administration of iohexol at one of three different concentrations. Articular cartilage thickness was measured on both the CT arthrography images and corresponding histologic specimens. Mean difference (bias) between the CT arthrography and histomorphologic measurements was 0.18 and 0.19 mm in the sagittal and dorsal planes, respectively. Mean bias and precision of CT arthrography measurements made in the sagittal or dorsal reformations were not significantly different from one another. Computed tomographic arthrography measurements from elbows with 75 mg I/ml were significantly larger and had greater bias compared to other contrast medium groups (150 and 37.5 mg I/ml). There was no significant difference in CT arthrography measurement precision between different contrast medium concentrations. Histomorphologic thickness of the articular cartilage overlying the cranial aspect of the ulna (mean 0.32 mm) was significantly thinner than cartilage of the radius (0.36 mm) or humerus (0.36 mm). Findings from this cadaver study indicated that CT arthrography delineates articular cartilage of the normal canine elbow; yields cartilage thickness measures slightly greater than histomorphometry measures; and provides high measurement precision regardless of image plane, contrast medium concentration, or anatomic zone. PMID:25154869

  16. Pediatric computed tomographic angiography: imaging the cardiovascular system gently.

    PubMed

    Hellinger, Jeffrey C; Pena, Andres; Poon, Michael; Chan, Frandics P; Epelman, Monica

    2010-03-01

    Whether congenital or acquired, timely recognition and management of disease is imperative, as hemodynamic alterations in blood flow, tissue perfusion, and cellular oxygenation can have profound effects on organ function, growth and development, and quality of life for the pediatric patient. Ensuring safe computed tomographic angiography (CTA) practice and "gentle" pediatric imaging requires the cardiovascular imager to have sound understanding of CTA advantages, limitations, and appropriate indications as well as strong working knowledge of acquisition principles and image post processing. From this vantage point, CTA can be used as a useful adjunct along with the other modalities. This article presents a summary of dose reduction CTA methodologies along with techniques the authors have employed in clinical practice to achieve low-dose and ultralow-dose exposure in pediatric CTA. CTA technical principles are discussed with an emphasis on the low-dose methodologies and safe contrast medium delivery strategies. Recommended parameters for currently available multidetector-row computed tomography scanners are summarized alongside recommended radiation and contrast medium parameters. In the second part of the article an overview of pediatric CTA clinical applications is presented, illustrating low-dose and ultra-low dose techniques, with an emphasis on the specific protocols. PMID:20609882

  17. Multidetector Computer Tomography: Evaluation of Blunt Chest Trauma in Adults

    PubMed Central

    Matos, António P.; Mascarenhas, Vasco; Herédia, Vasco

    2014-01-01

    Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. PMID:25295188

  18. Multidetector computer tomography: evaluation of blunt chest trauma in adults.

    PubMed

    Palas, João; Matos, António P; Mascarenhas, Vasco; Herédia, Vasco; Ramalho, Miguel

    2014-01-01

    Imaging plays an essential part of chest trauma care. By definition, the employed imaging technique in the emergency setting should reach the correct diagnosis as fast as possible. In severe chest blunt trauma, multidetector computer tomography (MDCT) has become part of the initial workup, mainly due to its high sensitivity and diagnostic accuracy of the technique for the detection and characterization of thoracic injuries and also due to its wide availability in tertiary care centers. The aim of this paper is to review and illustrate a spectrum of characteristic MDCT findings of blunt traumatic injuries of the chest including the lungs, mediastinum, pleural space, and chest wall. PMID:25295188

  19. Chronic beryllium disease: computed tomographic findings.

    PubMed

    Sharma, Nidhi; Patel, Jeet; Mohammed, Tan-Lucien H

    2010-01-01

    Chronic beryllium disease is a rare multisystem granulomatous disease predominantly involving the lungs and resulting from an immunologic response to long-term occupational exposure. Computed tomography of the chest reveals important lung parenchymal and mediastinal findings and plays an important role in the diagnosis and follow-up assessment of patients with chronic beryllium disease. Its significance lies in the exact localization and evaluation of the extent of lesions. We present an overview of the subject and a pictorial review of the spectrum of computed tomographic features of beryllium disease. PMID:21084914

  20. Jugular foramen: anatomic and computed tomographic study

    SciTech Connect

    Daniels, D.L.; Williams, A.L.; Haughton, V.M.

    1984-01-01

    The computed tomographic (CT) appearance of the jugular foramen was examined in detail, and anatomic and CT sections were correlated. The pars nervosa and pars vascularis were identified, and, with intravenous contrast enhancement, a rapid sequence of scans at a gantry angle of +30/sup 0/ to the canthomeatal line demonstrated cranial nerves IX, X, and XI. The osseous margins of the jugular foramen were best shown by CT at planes of sections parallel and positive (0/sup 0/-30/sup 0/) to the canthomeatal line. CT can be used to evaluate osseous anatomy and the jugular foramen with precision sufficient to confidently exclude an intracanalicular mass.

  1. Health risks from computed tomographic screening.

    PubMed

    Krantz, Seth B; Meyers, Bryan F

    2015-05-01

    Results of the recent National Lung Cancer Screening Trial show a significant survival benefit for annual screening with a low-dose computed tomographic (CT) scan in high-risk individuals. This result has led the US Preventive Services Task Force to recommend annual low-dose CT scans for this at-risk population. Less well characterized are the risks from screening. The primary risks from screening are radiation exposure, false-positive results and unnecessary diagnostic and therapeutic procedures, overdiagnosis and overtreatment, and increased psychological distress. This article reviews these risks, which must be considered and weighed against the benefits when discussing enrollment with patients. PMID:25901559

  2. Computed tomographic features of canine nonparenchymal hemangiosarcoma.

    PubMed

    Fukuda, Shoko; Kobayashi, Tetsuya; Robertson, Ian D; Oshima, Fukiko; Fukazawa, Eri; Nakano, Yuko; Ono, Shin; Thrall, Donald E

    2014-01-01

    The purpose of this retrospective study was to describe pre- and postcontrast computed tomographic (CT) characteristics of confirmed nonparenchymal hemangiosarcoma in a group of dogs. Medical records were searched during the period of July 2003 and October 2011 and dogs with histologically confirmed nonparenchymal hemangiosarcoma and pre- and postcontrast CT images were recruited. Two observers recorded a consensus opinion for the following CT characteristics for each dog: largest transverse tumor diameter, number of masses, general tumor shape, character of the tumor margin, precontrast appearance, presence of dystrophic calcification, presence of postcontrast enhancement, pattern of postcontrast enhancement, presence of regional lymphadenopathy, and presence of associated cavitary fluid. A total of 17 dogs met inclusion criteria. Tumors were located in the nasal cavity, muscle, mandible, mesentery, subcutaneous tissue, and retroperitoneal space. Computed tomographic features of nonparenchymal hemangiosarcoma were similar to those of other soft tissue sarcomas, with most tumors being heterogeneous in precontrast images, invasive into adjacent tissue, and heterogeneously contrast enhancing. One unexpected finding was the presence of intense foci of contrast enhancement in 13 of the 17 tumors (76%). This appearance, which is not typical of other soft tissue sarcomas, was consistent with contrast medium residing in vascular channels. Findings indicated that there were no unique distinguishing CT characteristics for nonparenchymal hemangiosarcoma in dogs; however, the presence of highly attenuating foci of contrast enhancement may warrant further investigation in prospective diagnostic sensitivity and treatment outcome studies. PMID:24382330

  3. Multidetector computed tomography of temporomandibular joint: A road less travelled

    PubMed Central

    Pahwa, Shivani; Bhalla, Ashu Seith; Roychaudhary, Ajoy; Bhutia, Ongkila

    2015-01-01

    This article reviews the imaging anatomy of temporomandibular joint (TMJ), describes the technique of multi-detector computed tomography (MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures. PMID:25984518

  4. Multidetector computed tomography findings in deaths with severe burns.

    PubMed

    Levy, Angela D; Harcke, Howard T; Getz, John M; Mallak, Craig T

    2009-06-01

    This study compared autopsy with postmortem multidetector computed tomography (MDCT) findings in charred remains. Seventeen consecutive male subjects (mean age, 29.4 years) who perished in a fire-related event resulting in charred remains underwent total body MDCT immediately prior to routine autopsy that included serum carboxyhemoglobin measurement. MDCT showed all thermal tissue changes (skin and subcutaneous fat loss, skeletal muscle retraction, pugilistic attitude, cortical fractures, bone and organ destruction, thermal epidural hematoma, and thermal amputation) and established all fracture patterns that were lethal, but autopsy added the fire as a contributory cause of death when there was carboxyhemoglobin elevation. MDCT had limited value in determination of lethal vascular and visceral injuries. MDCT is an effective complement to autopsy in the setting of charred remains and may serve to augment a limited autopsy. This may be particularly useful in mass casualty scenarios. PMID:19465802

  5. Cardiac Injuries: A Review of Multidetector Computed Tomography Findings

    PubMed Central

    Baxi, Ameya Jagdish; Restrepo, Carlos; Mumbower, Amy; McCarthy, Michael; Rashmi, Katre

    2015-01-01

    Trauma is the leading cause of death in United States in the younger population. Cardiac trauma is common following blunt chest injuries and is associated with high morbidity and mortality. This study discusses various multidetector computed tomography (MDCT) findings of cardiac trauma. Cardiac injuries are broadly categorized into the most commonly occurring blunt cardiac injury and the less commonly occurring penetrating injury. Signs and symptoms of cardiac injury can be masked by the associated injuries. Each imaging modality including chest radiographs, echocardiography, magnetic resonance imaging and MDCT has role in evaluating these patients. However, MDCT is noninvasive; universally available and has a high spatial, contrast, and temporal resolution. It is a one stop shop to diagnose and evaluate complications of cardiac injury. MDCT is an imaging modality of choice to evaluate patients with cardiac injuries especially the injuries capable of causing hemodynamic instability. PMID:26839855

  6. Computed tomographic analysis of meteorite inclusions

    NASA Technical Reports Server (NTRS)

    Arnold, J. R.; Testa, J. P., Jr.; Friedman, P. J.; Kambic, G. X.

    1983-01-01

    The feasibility of obtaining nondestructively a cross-sectional display of very dense heterogeneous rocky specimens, whether lunar, terrestrial or meteoritic, by using a fourth generation computed tomographic (CT) scanner, with modifications to the software only, is discussed. A description of the scanner, and of the experimental and analytical procedures is given. Using this technique, the interior of heterogeneous materials such as Allende can be probed nondestructively. The regions of material with high and low atomic numbers are displayed quickly; the object can then be cut to obtain for analysis just the areas of interest. A comparison of this technique with conventional industrial and medical techniques is made in terms of image resolution and density distribution display precision.

  7. Computed tomographic features of primary brain lymphoma.

    PubMed

    Barsky, M F; Coates, R K; Macdonald, D R

    1989-04-01

    Head computed tomographic (CT) examinations of 14 patients with primary brain lymphoma were reviewed to assess the CT features of the presenting and subsequent lesions. Presenting lesions were single in 62% and multiple in 38%. Lesions tended to be iso- or hyperdense and homogeneously enhancing. They were commonly located in the deep hemispheric regions, corpus callosum, and posterior fossa. Despite these characteristic patterns, the diagnosis of lymphoma was initially considered in just three patients. Follow-up CT showed good initial response to radiotherapy in 10 patients although mortality was high and posttherapy changes were frequent. Consideration of primary brain lymphoma by radiologists is important, as needle biopsy and radiotherapy may be preferred to a surgical resection. PMID:2702505

  8. Neck after vertical hemilaryngectomy: computed tomographic study

    SciTech Connect

    DiSantis, D.J.; Balfe, D.M.; Hayden, R.; Sessions, D.; Sagel, S.S.

    1984-06-01

    Computed tomographic scans in 22 postoperative vertical hemilaryngectomy patients were analyzed retrospectively to determine the normal postoperative appearance and to evaluate the role of CT in assessing recurrent neoplasm. Twelve patients without clinical evidence of recurrence illustrated the normal postoperative changes. In the six patients with recurrent neoplasm, the CT manifestations included increased width of the remaining true vocal cord, convexity of the surgically formed pseudocord at glottic level, subglottic tumor, and extralaryngeal neck masses. Recurrence was mimicked in four patients by bulky soft tissue at the endolaryngeal operative site at both CT and laryngoscopy. CT supplemented the physical examination and indirect laryngoscopy, providing information regarding the presence and extent of tumor that was useful in planning the mode or scope of subsequent therapy.

  9. Computed tomographic recognition of gastric varices

    SciTech Connect

    Balthazar, E.J.; Megibow, A.; Naidich, D.; LeFleur, R.S.

    1984-06-01

    The computed tomographic (CT) findings in 13 consecutive patients with proven gastric varices were analyzed and correlated with the radiographic, angiographic, and gastroscopic evaluations. In 11 patients, CT clearly identified large (five) or smaller (six) varices located mainly along the posteromedial wall of the gastric fundus and proximal body of the stomach. Well defined rounded or tubular densities that enhanced during intravenous administration of contrast material and could not be distinguished from the gastric wall were identified. Dense, enhancing, round or tubular, intraluminal filling defects were seen in the cases where the stomach was distended with water. In seven patients, the CT examination correctly diagnosed the pathogenesis of gastric varices by identifying hepatic cirrhosis, calcific pancreatis, and carcinoma of the pancreas.

  10. Computed tomographic anatomy of the equine foot.

    PubMed

    Claerhoudt, S; Bergman, E H J; Saunders, J H

    2014-10-01

    This study describes a detailed computed tomographic reference of the normal equine foot. Ten forefeet of five adult cadavers, without evidence of orthopaedic disease, were used. Computed tomography (CT) was performed on all feet. Two-millimetre thick transverse slices were obtained, and sagittal and dorsal planes were reformatted. The CT images were matched with the corresponding anatomic slices. The phalanges and the distal sesamoid bone showed excellent detail. The extensor and flexor tendons (including their attachments) could be clearly evaluated. The collateral (sesamoidean) ligaments could be readily located, but were difficult to delineate at their proximal attachment. The distal digital annular ligament could only be distinguished from the deep digital flexor tendon proximal to the distal sesamoid bone, and its proximal attachment could be identified, but not its distal insertion. Small ligaments (impar ligament, chondrosesamoidean, chondrocoronal and chondrocompedal ligaments, axial and abaxial palmar ligaments of the proximal inter-phalangeal joint) were seen with difficulty and not at all slices. The joint capsules could not be delineated from the surrounding soft tissue structures. The lateral and medial proprius palmar digital artery and vein could be visualized occasionally on some slices. The ungular cartilages, corium and hoof wall layering were seen. The nerves, the articular and fibrocartilage of the distal sesamoid bone and the chondroungular ligament could not be assessed. Computed tomography of the equine foot can be of great value when results of radiography and ultrasonography are inconclusive. Images obtained in this study may serve as reference for CT of the equine foot. PMID:24611958

  11. Computed tomographic findings in orbital Mucor

    SciTech Connect

    Greenberg, M.R.; Lippman, S.M.; Grinnell, V.S.; Colman, M.F.; Edwards, J.E. Jr.

    1985-07-01

    Mucormycosis is an increasingly important infection in immunocompromised patients; knowledge regarding the variability of its clinical manifestations is expanding steadily. The infection is of paranasal sinus origin and may involve the orbit secondarily via freely communicating foramina and venous channels. Death often ensues when the infection spreads either into the cavernous sinus or the central nervous system. Early diagnosis of rhinocerebral mucormycosis is crucial for a successful outcome. Computed tomographic (CT) scanning is used to visualize many intraorbital pathologic abnormalities. The patient discussed in this paper had extensive orbital Mucor that appeared minimal on a CT scan. This inability of the scan to reflect the severity of infection prompted a review of the literature describing the use of CT scans for detecting this potentially fatal, opportunistic infection. The search showed that a disparity between scan findings and the severity of the disease is the rule rather than the exception. Recognition of this disparity has significant implications for appropriate diagnosis and management of orbital Mucor.

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

    PubMed

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

    2014-10-01

    With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%. PMID:25675779

  13. Detection of plaque rupture using 64-slice multidetector row computed tomography

    PubMed Central

    Reimann, Anja J; Beck, Torsten; Heuschmid, Martin; Brodoefel, Harald; Burgstahler, Christof; Schröder, Stephen; Kopp, Andreas F

    2008-01-01

    The present case report describes a 37-year-old man who presented to the emergency room with symptoms of a myocardial infarction but no high-grade stenosis on conventional catheter angiography. Consecutive multi-detector row computed tomography of the coronary arteries showed an intimal flap along a fibrous plaque formation in the left anterior descending artery. This finding was found to represent a plaque rupture, and the lesion was treated with an 18 mm stent. Multidetector row computed tomography helped to correctly position the stent by identifying the exact location of the rupture along the long plaque formation. PMID:18340394

  14. A computed tomographic study of schizophrenia.

    PubMed

    Siddharatha; Lal, N; Tewari, S C; Dalal, P K; Kohli, N; Srivastava, S

    1997-04-01

    Fifty schizophrenic patients fulfilling DSM-III-R criteria, and group matched normal healthy controls were selected for the study The case and control groups have been compared in terms of VBR, WSF and WTF. In the study schizophrenics have been divided into positive, negative and mixed subgroups on basis of SAPS and SANS, and these subgroups are compared with each other for VBR, WSF & WTF. Tomographic abnormalities were noted in schizophrenics, particularly with negative and mixed subtypes, when compared to controls. PMID:21584057

  15. A Study of Internal Thoracic Arteriovenous Principal Perforators by Using Multi-detector Row Computed Tomography Angiography

    PubMed Central

    Hashikawa, Kazunobu; Sakakibara, Shunsuke; Onishi, Hiroyuki; Terashi, Hiroto

    2016-01-01

    Objective: There are numerous reports of perforating branches from the intercostal spaces of the internal thoracic vessels. These branches have varying diameters, and a main perforating branch, the principal perforator, most often found in the second or third intercostal space. We report different results based on multi-detector row computed tomography. Methods: We evaluated 121 sides from 70 women scheduled for breast reconstruction with free lower abdominal skin flaps who underwent preoperative multi-detector row computed tomographic scan between June 2008 and June 2015. For primary reconstruction, we analyzed both sides, and for 1-sided secondary reconstruction, we analyzed only the unaffected side. We evaluated both early arterial phase and late venous phase 5-mm horizontal, cross-sectional, and volume-rendering images for perforation sites and internal thoracic arteriovenous perforating branches’ intercostal space thickness. We analyzed differences in thickness between the internal thoracic arteries and veins and symmetry in cases involving both sides. Results: Venous principal perforators nearly always perforated the same intercostal spaces as accompanying veins of arterial principal perforators (99.2%), forming arteriovenous principal perforators. We found 49 principal perforators in the first intercostal space (37.4%), 52 in the second intercostal space (39.7%), 23 in the third intercostal space (17.6%), 6 in the fourth intercostal space (4.6%), and 1 in the fifth intercostal space (0.7%). Of the 51 cases in which we studied both sides, 25 cases (49%) had principal perforators with bilateral symmetry. Conclusions: In contrast to findings from past reports, we found that internal thoracic arteriovenous principal perforators were often present in almost the same numbers in the first and second intercostal spaces. PMID:26958104

  16. The computed tomographic findings of peritentorial subdural hemorrhage

    SciTech Connect

    Lau, L.S.; Pike, J.W.

    1983-03-01

    The computed tomographic (CT) findings in six cases of subdural hemorrhage in the peritentorial region are listed and discussed. The CT appearance of peritentorial subdural hemorrhage sometimes mimicks that of intra-axial lesions, but coronal scanning or reconstruction can be used to resolve this problem. Awareness of this unusual location for subdural hemorrhage is helpful in providing an accurate preoperative diagnosis.

  17. Feasibility of 320-row multi-detector computed tomography angiography to assess bioabsorbable everolimus-eluting vascular scaffolds.

    PubMed

    Asami, Masahiko; Aoki, Jiro; Serruys, Patrick W; Abizaid, Alexandre; Saito, Shigeru; Onuma, Yoshinobu; Kimura, Takeshi; Simonton, Charles A; Tanabe, Kengo

    2016-04-01

    Coronary computer tomographic angiography (CCTA) for screening intra-arterial vessel disease is gaining rapid clinical acceptance in recent years, but its use for such assessments in metal-stented vessel segments is very limited due to blooming artifacts introduced by the metal. However, vessel segments treated by the polymeric everolimus-eluting bioresorbable vascular scaffolds (Absorb) are readily monitored for intravascular disease over time with CCTA. The data on the accuracy of multi-detector computed tomography (MDCT) in patients treated with Absorb is still sparse. Results on 5 Japanese case studies from ABSORB EXTEND are presented here. Five patients were treated with Absorb, and follow-up angiography was conducted at 8 to 14 months as per routine site standard of practice. 320-row MDCT scan was performed within 1 month before the angiography. By MDCT, all Absorb-treated lesions were clearly evaluated and restenosis were not observed. Minimal diameter and % diameter stenosis were similar between MDCT and quantitative angiography (2.07 ± 0.13 vs. 2.03 ± 0.06 mm, P = 0.86, and 22.5 ± 5.0 vs. 21.5 ± 4.5 %, P = 0.88, respectively). MDCT appears to be feasible and useful for evaluating lumen patency and vessel disease in segments implanted with Absorb at follow-up. PMID:26445951

  18. Multi-Detector Computed Tomography Angiography for Coronary Artery Disease

    PubMed Central

    2005-01-01

    Executive Summary Purpose Computed tomography (CT) scanning continues to be an important modality for the diagnosis of injury and disease, most notably for indications of the head and abdomen. (1) According to a recent report published by the Canadian Institutes of Health Information, (1) there were about 10.3 scanners per million people in Canada as of January 2004. Ontario had the fewest number of CT scanners per million compared to the other provinces (8 CT scanners per million). The wait time for CT in Ontario of 5 weeks approaches the Canadian median of 6 weeks. This health technology and policy appraisal systematically reviews the published literature on multidetector CT (MDCT) angiography as a diagnostic tool for the newest indication for CT, coronary artery disease (CAD), and will apply the results of the review to current health care practices in Ontario. This review does not evaluate MDCT to detect coronary calcification without contrast medium for CAD screening purposes. The Technology Compared with conventional CT scanning, MDCT can provide smaller pieces of information and can cover a larger area faster. (2) Advancing MDCT technology (8, 16, 32, 64 slice systems) is capable of producing more images in less time. For general CT scanning, this faster capability can reduce the time that patients must stay still during the procedure, thereby reducing potential movement artefact. However, the additional clinical utility of images obtained from faster scanners compared to the images obtained from conventional CT scanners for current CT indications (i.e., non-moving body parts) is not known. There are suggestions that the new fast scanners can reduce wait times for general CT. MDCT angiography that utilizes a contrast medium, has been proposed as a minimally invasive replacement to coronary angiography to detect coronary artery disease. MDCT may take between 15 to 45 minutes; coronary angiography may take up to 1 hour. Although 16-slice and 32-slice CT

  19. Verifying X-Radiographs With Computed Tomographs

    NASA Technical Reports Server (NTRS)

    Roy, Jagatjit; Pascua, Antonio G.

    1991-01-01

    Nondestructive technique gives added confidence in inspection. Ambiguous indications in radiographic inspections of metal castings checked by computed tomography. Fast and inexpensive conventional x-ray inspection used to make film image of overall casting, and slower, more costly computed tomography used to reinspect relatively few parts of casting presenting possible diffraction patterns or other difficult-to-interpret features. Method effective in resolving ambiguities in radiographs of turbine blades. Provides same information as metallurgical sectioning.

  20. Multidetector computed tomography evaluation of cavernous haemangioma of the azygous vein

    PubMed Central

    Das, Karuna Moy; Ahmed, Ali M.; Aljubab, Abdulwahab; Alzoum, Mohammed A.

    2013-01-01

    Giant cavernous haemangioma of azygous arch is extremely rare. We present the multidetector computed tomography (MDCT) features of a mediastinal cavernous haemangioma in an asymptomatic child detected in a follow-up examination. MDCT features with multiple venous lakes filling from the periphery, focal specks of calcification, low-density soft tissue mass along with tortuous varicose veins and large feeding veins from the abdomen are suggestive of cavernous haemangioma. PMID:23660735

  1. Computed tomographic findings in penetrating peptic ulcer

    SciTech Connect

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-12-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease.

  2. Bilateral pulmonary sequestration: computed tomographic appearance

    SciTech Connect

    Wimbish, K.J.; Agha, F.P.; Brady, T.M.

    1983-04-01

    Intralobar pulmonary sequestration is one manifestation of the wide spectrum of congenital bronchopulmonary foregut malformations. Bilateral intralobar pulmonary sequestration is an exceedingly rare anomaly. Only two pathologically proven cases and one possible case have been reported. We report a case presenting as bilateral paraspinal masses, studied by computed tomograpy (CT) and angiography.

  3. Computed tomographic inspection of sample ampoule cartridge assemblies (SACA)

    SciTech Connect

    Krauss, D.G.

    1996-12-31

    This paper will describe and analyze the steps taken to provide Computed Tomographic (CT) inspection of Crystal Growth Furnace (CGF) Sample Ampoule Cartridge Assemblies (SACA). These cartridges were aboard STS-73 during its micro gravity laboratory (USML-2) flight in September 1995. Available radiation sources included a Seifert 420 kilovoltage constant potential dual focal spot X-Ray system and a Gamma Industries Cobalt{sup 60} radioactive isotope camera currently containing 35 curies of source strength.

  4. Dynamic computed tomographic scans in experimental brain abscess.

    PubMed

    Enzmann, D R; Placone, R C; Britt, R H

    1984-01-01

    Dynamic computed tomographic scans were performed in an experimental brain abscess model to establish criteria that could be utilized in abscess staging. The vascular phase of the time-density curves did not differentiate cerebritis and capsule stages. The amount of residual enhancement after the first pass of an intra-arterial contrast bolus differed between major abscess stages, the greater residual enhancement being noted in the capsule stage. PMID:6462439

  5. Computed tomographic findings in 15 dogs with eosinophilic bronchopneumopathy.

    PubMed

    Mesquita, Luis; Lam, Richard; Lamb, Christopher R; McConnell, J Fraser

    2015-01-01

    Eosinophilic bronchopneumopathy is a disease characterized by the infiltration of the lung and bronchial mucosa by eosinophils. The aim of the present study was to describe the CT findings in a large series of dogs with confirmed diagnosis of eosinophilic bronchopneumopathy. Computed tomographic scans of 15 dogs with confirmed diagnosis of eosinophilic bronchopneumopathy were evaluated retrospectively by two boarded radiologists who reached a consensus. Abnormalities were identified in 14/15 (93%) dogs, including pulmonary parenchymal abnormalities in 14/15 (93%) dogs, bronchial wall thickening in 13 (87%) dogs, which was considered marked in eight (53%), plugging of the bronchial lumen by mucus/debris in 11 (73%) dogs, and bronchiectasis in nine (60%) dogs. Pulmonary nodules were identified in 5/15 (33%) dogs including one dog with a mass. All dogs with a nodular lung pattern had additional abnormalities. Lymphadenopathy was present in 10 dogs (67%). Lesions associated with eosinophilic bronchopneumopathy are variable and heterogeneous and encompass a wider variety of computed tomographic features than reported previously. Computed tomographic images were abnormal in the majority of affected dogs, hence CT is a useful modality to characterize the nature and distribution of thoracic lesions in dogs with eosinophilic bronchopneumopathy. PMID:25124052

  6. Multi-detector row computed tomography angiography of peripheral arterial disease

    PubMed Central

    Dijkshoorn, Marcel L.; Pattynama, Peter M. T.; Myriam Hunink, M. G.

    2007-01-01

    With the introduction of multi-detector row computed tomography (MDCT), scan speed and image quality has improved considerably. Since the longitudinal coverage is no longer a limitation, multi-detector row computed tomography angiography (MDCTA) is increasingly used to depict the peripheral arterial runoff. Hence, it is important to know the advantages and limitations of this new non-invasive alternative for the reference test, digital subtraction angiography. Optimization of the acquisition parameters and the contrast delivery is important to achieve a reliable enhancement of the entire arterial runoff in patients with peripheral arterial disease (PAD) using fast CT scanners. The purpose of this review is to discuss the different scanning and injection protocols using 4-, 16-, and 64-detector row CT scanners, to propose effective methods to evaluate and to present large data sets, to discuss its clinical value and major limitations, and to review the literature on the validity, reliability, and cost-effectiveness of multi-detector row CT in the evaluation of PAD. PMID:17882427

  7. Computed tomographic evaluation of pineal calcification.

    PubMed

    Kohli, N; Rastogi, H; Bhadury, S; Tandon, V K

    1992-04-01

    A prospective study to ascertain the incidence of normally calcified pineal gland, was carried out in 1000 consecutive patients from different parts of Uttar Pradesh (India), undergoing cranial computed tomography for reasons other than a pineal or parapineal pathology. A total of 167 (16.70%) patients were found to have calcified pineals. Of these 128 were males and 39 females. The incidence rose from 1.16 per cent in the first decade to 31.88 per cent above the age of 50 yr. The percentage incidence of normal pineal calcification was lower than that seen in the Western population. No significant difference was found between men and women in any age group. Although calcification appeared as early as the first decade, this percentage was significantly lower than in the higher age groups. Significantly higher incidence rates were seen in the second decade, third decade and sixth decade onwards. PMID:1428055

  8. Lymphadenopathy in celiac disease: computed tomographic observations

    SciTech Connect

    Jones, B.; Bayless, T.M.; Fishman, E.K.; Siegelman, S.S.

    1984-06-01

    Lymphadenopathy in patients with celiac disease is generally viewed with alarm due to the association between celiac disease and intestinal lymphoma. Four patients with celiac disease are described in whom significant mesenteric and paraaortic adenopathy was demonstrated by computed tomogrophy (CT). The subsequent clinical course of these patients revealed no evidence of lymphoma. In two patients with longstanding celiac disease and recent relapse, exploratory laparotomy revealed reactive hyperplasia in the enlarged glands; in one patient this was associated with intestinal ulceration, and in the other no underlying pathology was found. Follow-up CT scans in both these patients demonstrated regression of the findings with clinical improvement. In the other two patients, CT was performed as part of the initial evaluation.

  9. A computed tomographic imaging system for experimentation

    NASA Astrophysics Data System (ADS)

    Lu, Yanping; Wang, Jue; Liu, Fenglin; Yu, Honglin

    2008-03-01

    Computed tomography (CT) is a non-invasive imaging technique, which is widely applied in medicine for diagnosis and surgical planning, and in industry for non-destructive testing (NDT) and non-destructive evaluation (NDE). So, it is significant for college students to understand the fundamental of CT. In this work, A CT imaging system named CD-50BG with 50mm field-of-view has been developed for experimental teaching at colleges. With the translate-rotate scanning mode, the system makes use of a 7.4×10 8Bq (20mCi) activity 137Cs radioactive source which is held in a tungsten alloy to shield the radiation and guarantee no harm to human body, and a single plastic scintillator + photomultitude detector which is convenient for counting because of its short-time brightness and good single pulse. At same time, an image processing software with the functions of reconstruction, image processing and 3D visualization has also been developed to process the 16 bits acquired data. The reconstruction time for a 128×128 image is less than 0.1 second. High quality images with 0.8mm spatial resolution and 2% contrast sensitivity can be obtained. So far in China, more than ten institutions of higher education, including Tsinghua University and Peking University, have already applied the system for elementary teaching.

  10. Bosniak classification of renal cystic lesions according to multidetector computed tomography findings*

    PubMed Central

    de Miranda, Christiana Maia Nobre Rocha; Maranhão, Carol Pontes de Miranda; dos Santos, Carla Jotta Justo; Padilha, Igor Gomes; de Farias, Lucas de Pádua Gomes; da Rocha, Milzi Sarmento

    2014-01-01

    Renal cystic lesions are usually diagnosed in the radiologists’ practice and therefore their characterization is crucial to determine the clinical approach to be adopted and prognosis. The Bosniak classification based on computed tomography findings has allowed for standardization and categorization of lesions in increasing order of malignancy (I, II, IIF, III and IV) in a simple and accurate way. The present iconographic essay developed with multidetector computed tomography images of selected cases from the archives of the authors’ institution, is aimed at describing imaging findings that can help in the diagnosis of renal cysts. PMID:25741060

  11. Pineal region tumors: computed tomographic-pathologic spectrum

    SciTech Connect

    Futrell, N.N.; Osborn, A.G.; Cheson. B.D.

    1981-11-01

    While several computed tomographic (CT) studies of posterior third ventricular neoplasms have included descriptions of pineal tumors, few reports have concentrated on these uncommon lesions. Some authors have asserted that the CT appearance of many pineal tumors is virtually pathognomonic. A series of nine biopsy-proved pineal gland and eight other presumed tumors is presented that illustrates their remarkable heterogeneity in both histopathologic and CT appearance. These tumors included germinomas, teratocarcinomas, hamartomas, and other varieties. They had variable margination, attentuation, calcification, and suprasellar extension. Germinomas have the best response to radiation therapy. Biopsy of pineal region tumors is now feasible and is recommended for treatment planning.

  12. Computed tomographic spectrum of intracranial mycosis: correlation with histopathology

    SciTech Connect

    Whelan, M.A.; Stern, J.; deNapoli, R.A.

    1981-12-01

    Four cases of intracerebral fungal infection are reviewed. The clinical course is outlined, and the computed tomographic (CT) characteristics are analyzed in light of known pathological data. The CT appearance of intracranial mycosis is dependent on the type of fungus as well as the dominant infecting form, i.e., yeast or hyphae. The hyphal form leads predominantly to a CT pattern consistent with vascular occlusion and secondary abscess formation; the yeast form generally results in noncaseating granulomas, which appear on CT scan as nodular enhancing lesions. If the patient survives the acute infective process, these fungal lesions undergo a prolonged subacute phase, and may eventually calcify.

  13. The UF series of tomographic computational phantoms of pediatric patients

    SciTech Connect

    Lee, Choonik; Williams, Jonathan L.; Lee, Choonsik; Bolch, Wesley E.

    2005-12-15

    Two classes of anthropomorphic computational phantoms exist for use in Monte Carlo radiation transport simulations: tomographic voxel phantoms based upon three-dimensional (3D) medical images, and stylized mathematical phantoms based upon 3D surface equations for internal organ definition. Tomographic phantoms have shown distinct advantages over the stylized phantoms regarding their similarity to real human anatomy. However, while a number of adult tomographic phantoms have been developed since the early 1990s, very few pediatric tomographic phantoms are presently available to support dosimetry in pediatric diagnostic and therapy examinations. As part of a larger effort to construct a series of tomographic phantoms of pediatric patients, five phantoms of different ages (9-month male, 4-year female, 8-year female, 11-year male, and 14-year male) have been constructed from computed tomography (CT) image data of live patients using an IDL-based image segmentation tool. Lungs, bones, and adipose tissue were automatically segmented through use of window leveling of the original CT numbers. Additional organs were segmented either semiautomatically or manually with the aid of both anatomical knowledge and available image-processing techniques. Layers of skin were created by adding voxels along the exterior contour of the bodies. The phantoms were created from fused images taken from head and chest-abdomen-pelvis CT exams of the same individuals (9-month and 4-year phantoms) or of two different individuals of the same sex and similar age (8-year, 11-year, and 14-year phantoms). For each model, the resolution and slice positions of the image sets were adjusted based upon their anatomical coverage and then fused to a single head-torso image set. The resolutions of the phantoms for the 9-month, 4-year, 8-year, 11-year, and 14-year are 0.43x0.43x3.0 mm, 0.45x0.45x5.0 mm, 0.58x0.58x6.0 mm, 0.47x0.47x6.00 mm, and 0.625x0.625x6.0 mm, respectively. While organ masses can be

  14. Evaluation of pulmonary sequestration with multidetector computed tomography angiography in a select cohort of patients: A retrospective study

    PubMed Central

    Long, Qihua; Zha, Yunfei; Yang, Zhigang

    2016-01-01

    OBJECTIVES: This study aimed to evaluate the role of multidetector computed tomography angiography in diagnosing patients with pulmonary sequestration. METHODS: We retrospectively analyzed the computed tomography studies and clinical materials of 43 patients who had undergone preoperative multidetector computed tomography angiography in our hospital and had pathologically proven pulmonary sequestration. Each examination of pulmonary sequestration was reviewed for type, location, parenchymal changes, arterial supply and venous drainage on two-dimensional and three-dimensional computed tomography images. RESULTS: Multidetector computed tomography successfully detected all pulmonary sequestrations in the 43 patients (100%). This included 40 patients (93.0%) with intralobar sequestration and 3 patients (7.0%) with extralobar sequestration. The locations of pulmonary sequestration were left lower lobe (28 cases, 70% of intralobar sequestrations), right lower lobe (12 cases, 30% of intralobar sequestrations) and costodiaphragmatic sulcus (3 cases). Cases of sequestered lung presented as mass lesions (37.2%), cystic lesions (32.6%), pneumonic lesions (16.3%), cavitary lesions (9.3%) and bronchiectasis (4.6%). The angioarchitecture of pulmonary sequestration, including feeding arteries from the thoracic aorta (86.1%), celiac truck (9.3%), abdominal aorta (2.3%) and left gastric artery (2.3%) and venous drainage into inferior pulmonary veins (86.0%) and the azygos vein system (14.0%), was visualized on multidetector computed tomography. Finally, the multidetector computed tomography angiography results of the sequestered lungs and angioarchitectures were surgically confirmed in all the patients. CONCLUSIONS: As a noninvasive modality, multidetector computed tomography angiography is helpful for making diagnostic decisions regarding pulmonary sequestration with high confidence and for visualizing the related parenchymal characteristics, arterial supply, and venous drainage

  15. Computed tomographic features of fibrous dysplasia of maxillofacial region

    PubMed Central

    Karjodkar, Freny R; Umarji, Hemant R

    2011-01-01

    Purpose This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. Materials and Methods All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. Results All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. Conclusion The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images. PMID:21977470

  16. Role of Multidetector Computed Tomography in the Diagnosis of Colorectal Perforations.

    PubMed

    Saturnino, Pietro Paolo; Pinto, Antonio; Liguori, Carlo; Ponticiello, Gianluca; Romano, Luigia

    2016-02-01

    Colonic perforations can be classified into perforations that occur at the site of a localized pathologic process and cecal perforations that occur secondary to distal colonic obstructions. Rectal perforations may result from foreign bodies inserted into the rectum; moreover, deep rectal biopsies, polypectomy, improper cleansing enema, or thermometer placement may also lead to rectal perforation. Correct identification of the cause and site of the perforation is crucial for appropriate management and surgical planning. Multidetector row computed tomography has a pivot role in planning the type of operative treatment, the prognosis, and in assessing those patients who have clinical symptoms of peritonitis but no radiographic signs of perforation. PMID:26827738

  17. Tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography: association with N categories

    PubMed Central

    Li, Hang; Chen, Xiao-li; Li, Jun-ru; Li, Zhen-lin; Chen, Tian-wu; Pu, Hong; Yin, Long-lin; Xu, Guo-hui; Li, Zhen-wen; Reng, Jing; Zhou, Peng; Cheng, Zhu-zhong; Cao, Ying

    2016-01-01

    OBJECTIVE: To determine whether the gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict the presence of regional lymph node metastasis and could determine N categories. MATERIALS AND METHODS: A total of 202 consecutive patients with gastric adenocarcinoma who had undergone gastrectomy 1 week after contrast-enhanced multidetector computed tomography were retrospectively identified. The gross tumor volume was evaluated on multidetector computed tomography images. Univariate and multivariate analyses were performed to determine whether the gross tumor volume could predict regional lymph node metastasis, and the Mann-Whitney U test was performed to compare the gross tumor volume among N categories. Additionally, a receiver operating characteristic analysis was performed to identify the accuracy of the gross tumor volume in differentiating N categories. RESULTS: The gross tumor volume could predict regional lymph node metastasis (p<0.0001) in the univariate analysis, and the multivariate analyses indicated that the gross tumor volume was an independent risk factor for regional lymph node metastasis (p=0.005, odds ratio=1.364). The Mann-Whitney U test showed that the gross tumor volume could distinguish N0 from the N1-N3 categories, N0-N1 from N2-N3, and N0-N2 from N3 (all p<0.0001). In the T1-T4a categories, the gross tumor volume could differentiate N0 from the N1-N3 categories (cutoff, 12.3 cm3), N0-N1 from N2-N3 (cutoff, 16.6 cm3), and N0-N2 from N3 (cutoff, 24.6 cm3). In the T4a category, the gross tumor volume could differentiate N0 from the N1-N3 categories (cutoff, 15.8 cm3), N0-N1 from N2-N3 (cutoff, 17.8 cm3), and N0-N2 from N3 (cutoff, 24 cm3). CONCLUSION: The gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict regional lymph node metastasis and N categories. PMID:27166769

  18. Congenital pulmonary venolobar syndrome: Value of multidetector computed tomography in preoperative assessment

    PubMed Central

    Hamad, Abdel-Mohsen Mahmoud

    2012-01-01

    A 6-month old baby referred to our department because of recurrent attacks of respiratory distress with chest infection. Chest radiology revealed reduction of the right hemithorax with mediastinal shift to the right. Multidetector computed tomography showed hypoplasia of the right lung and right pulmonary artery, systemic arterial supply to the lung from the abdominal aorta, and and absence of right venous drainage to the left atrium. This picture is consistent with congenital pulmonary venolobar syndrome. The patient underwent right pneumonectomy; the postoperative course was uneventful. PMID:22924077

  19. Multidetector computed tomography imaging of congenital anomalies of major airways: A pictorial essay.

    PubMed

    Sundarakumar, Dinesh Kumar; Bhalla, Ashu Seith; Sharma, Raju; Gupta, Arun Kumar; Kabra, Susheel Kumar; Jagia, Priya

    2011-12-28

    Congenital airway anomalies can be asymptomatic or may cause severe respiratory distress requiring immediate treatment. These anomalies can present early in life, or may be just incidental findings. It is important to recognize these entities to realize their clinical significance and to avoid false diagnosis. In this article, the various congenital airway anomalies and their imaging features by multidetector computed tomography (MDCT) are reviewed in order of occurrence during the embryological timeline. This pictorial essay reviews the various distinct congenital airway lesions and their MDCT manifestations. It also provides insight into the embryological basis of the congenital airway lesions encountered. PMID:22224177

  20. Multi-detector computed tomography imaging of large airway pathology: A pictorial review

    PubMed Central

    Jugpal, Tejeshwar Singh; Garg, Anju; Sethi, Gulshan Rai; Daga, Mradul Kumar; Kumar, Jyoti

    2015-01-01

    The tracheobronchial tree is a musculo-cartilagenous framework which acts as a conduit to aerate the lungs and consequently the entire body. A large spectrum of pathological conditions can involve the trachea and bronchial airways. These may be congenital anomalies, infections, post-intubation airway injuries, foreign body aspiration or neoplasms involving the airway. Appropriate management of airway disease requires an early and accurate diagnosis. In this pictorial essay review, we will comprehensively describe the various airway pathologies and their imaging findings by multi-detector computed tomography. PMID:26753061

  1. Sex estimation from sternal measurements using multidetector computed tomography.

    PubMed

    Ekizoglu, Oguzhan; Hocaoglu, Elif; Inci, Ercan; Bilgili, Mustafa Gokhan; Solmaz, Dilek; Erdil, Irem; Can, Ismail Ozgur

    2014-12-01

    We aimed to show the utility and reliability of sternal morphometric analysis for sex estimation.Sex estimation is a very important step in forensic identification. Skeletal surveys are main methods for sex estimation studies. Morphometric analysis of sternum may provide high accuracy rated data in sex discrimination. In this study, morphometric analysis of sternum was evaluated in 1 mm chest computed tomography scans for sex estimation. Four hundred forty 3 subjects (202 female, 241 male, mean age: 44 ± 8.1 [distribution: 30-60 year old]) were included the study. Manubrium length (ML), mesosternum length (2L), Sternebra 1 (S1W), and Sternebra 3 (S3W) width were measured and also sternal index (SI) was calculated. Differences between genders were evaluated by student t-test. Predictive factors of sex were determined by discrimination analysis and receiver operating characteristic (ROC) analysis. Male sternal measurement values are significantly higher than females (P < 0.001) while SI is significantly low in males (P < 0.001). In discrimination analysis, MSL has high accuracy rate with 80.2% in females and 80.9% in males. MSL also has the best sensitivity (75.9%) and specificity (87.6%) values. Accuracy rates were above 80% in 3 stepwise discrimination analysis for both sexes. Stepwise 1 (ML, MSL, S1W, S3W) has the highest accuracy rate in stepwise discrimination analysis with 86.1% in females and 83.8% in males. Our study showed that morphometric computed tomography analysis of sternum might provide important information for sex estimation. PMID:25501090

  2. Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations*

    PubMed Central

    de Mello Júnior, Carlos Fernando; Araujo Neto, Severino Aires; de Carvalho Junior, Arlindo Monteiro; Rebouças, Rafael Batista; Negromonte, Gustavo Ramalho Pessoa; de Oliveira, Carollyne Dantas

    2016-01-01

    Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations.

  3. Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations.

    PubMed

    de Mello Júnior, Carlos Fernando; Araujo Neto, Severino Aires; de Carvalho Junior, Arlindo Monteiro; Rebouças, Rafael Batista; Negromonte, Gustavo Ramalho Pessoa; de Oliveira, Carollyne Dantas

    2016-01-01

    Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations. PMID:27403020

  4. Cystic tumors of the fetal and neonatal cerebrum: ultrasound and computed tomographic evaluation

    SciTech Connect

    Sauerbrei, E.E.; Cooperberg, P.L.

    1983-06-01

    Three patients (two infants and one fetus) had complex (partially cystic and partially solid) supratentorial tumors involving the brain. The sonographic and computed tomographic appearance in each of these lesions is described and discussed. The cystic component of each lesion was equally well delineated by the two modalities, whereas the peripheral solid component was better defined by contrast-enhanced computed tomographic scans.

  5. Computed tomographic evaluation of gallstone calcification for biliary lithotripsy.

    PubMed

    Caslowitz, P L; Fishman, E K; Kafonek, D R; Lillemoe, K D; Mitchell, S; Widlus, D M; Saba, G P

    1991-04-01

    As the Food and Drug Administration trials for biliary lithotripsy in the United States near completion, future criteria for patient eligibility remain to be defined. Gallstone calcification greater than 3-mm partial rim on plain film (KUB) or oral cholecystogram (OCG) has excluded patients thus far, since early results of gallstone clearance (lithotripsy plus chemodissolution) were suboptimal with calcified stones. To evaluate the usefulness of these criteria for gallstone fragmentation, computed tomographic (CT) scans were performed on 20 patients immediately prior to lithotripsy to evaluate gallstone density and 24 hours after lithotripsy to observe the CT appearance of fragmentation. The adequacy of fragmentation was determined by pre- and post-lithotripsy sonography. This report constitutes the results of these investigations. PMID:10149158

  6. Is computed tomographic colonography being held to a higher standard?

    PubMed

    Garg, Samita; Ahnen, Dennis J

    2010-02-01

    Recent guidelines for colorectal cancer screening have reached different conclusions on whether computed tomographic colonography (CTC) is an acceptable screening option, and the Centers for Medicare & Medicaid Services recently decided not to cover CTC screening. The rationale against recommending or covering CTC screening includes concerns about radiation exposure, false-negative rates for small polyps, the discovery of extracolonic findings, variability in performance, a lack of targeted studies, a higher adenoma rate in the Medicare-eligible age group, and an absence of evidence that covering CTC would increase overall screening rates. Similar concerns can be raised for other recommended and covered colon cancer screening tests, but it seems that CTC is being held to a new and higher standard. PMID:20124234

  7. Epinephrine-enhanced computed tomographic arthrography of the canine shoulder.

    PubMed

    De Rycke, Lieve; van Bree, Henri; Van Caelenberg, Annemie; Polis, Ingeborgh; Duchateau, Luc; Gielen, Ingrid

    2015-10-01

    The aim of this study was to investigate the effect of epinephrine-enhanced computed tomographic arthrography (CTA) on the image sharpness of the lateral and medial glenohumeral ligaments (LGHL and MGHL, respectively), biceps tendon (BT) and joint cartilage (JC) in the canine shoulder. The shoulders of eight normal dogs were examined using a 4-slice helical CT scanner. The right shoulders were injected with Iohexol and the left shoulders with a mixture of Iohexol and epinephrine. CTA images were obtained after 1, 3, 5, 9, 13, 20 and 30 min and the image sharpness of the intra-articular structures in both shoulders was graded for visibility. The attenuation values were measured to examine the persistence of contrast appearance. Admixture of epinephrine and Iohexol significantly improved the image sharpness of the LGHL and the BT, especially on delayed CTA images. The use of epinephrine did not negatively affect post-CTA recovery. PMID:26412512

  8. Central nervous system leukemia and lymphoma: computed tomographic manifestations

    SciTech Connect

    Pagani, J.J.; Libshitz, H.I.; Wallace, S.; Hayman, L.A.

    1981-12-01

    Computed tomographic (CT) abnormalities in the brain were identified in 31 of 405 patients with leukemia or lymphoma. Abnormalities included neoplastic masses (15), hemorrhage (nine), abscess (two), other brain tumors (four), and methotrexate leukoencephalopathy (one). CT was normal in 374 patients including 148 with meningeal disease diagnosed by cerebrospinal fluid cytologic examination. Prior to treatment, malignant masses were isodense or of greater density with varying amounts of edema. Increase in size or number of the masses indicated worsening. Response to radiation and chemotherapy was manifested by development of a central low density region with an enhancing rim. CT findings correlated with clinical and cerebrospinal fluid findings. The differential diagnosis of the various abnormalities is considered.

  9. An Unusual Left Ventricular Outflow Pseudoaneurysm: Usefulness of Echocardiography and Multidetector Computed Tomography for Surgical Repair

    SciTech Connect

    Da Col, Uberto; Ramoni, Enrico Di Bella, Isidoro; Ragni, Temistocle

    2009-01-15

    Left ventricular outflow tract (LVOT) pseudoaneurysm is a rare but potentially lethal complication, mainly after aortic root endocarditis or surgery. Usually it originates from a dehiscence in the mitral-aortic intervalvular fibrosa and it arises posteriorly to the aortic root. Due to these anatomical features, its imaging assessment is challenging and surgical repair requires complex procedures. An unusual case of LVOT pseudoaneurysm is described. It was detected by transthoracic ecocardiography 7 months after aortic root replacement for acute endocarditis. Multidetector computed tomography (MDCT) confirmed the presence of a pouch located between the aortic root and the right atrium. Computed tomography also detected the origin of the pseudoaneurysm from the muscular interventricular septum of the LVOT, rather below the aortic valve plane. It was repaired with an extracardiac surgical approach, sparing the aortic root bioprosthesis previously implanted. The high-resolution three-dimensional details provided by the preoperative MDCT allowed us to plan a simple and effective surgical strategy.

  10. Multi-detector computed tomography demonstrates smoke inhalation injury at early stage.

    PubMed

    Koljonen, Virve; Maisniemi, Kreu; Virtanen, Kaisa; Koivikko, Mika

    2007-06-01

    A multitrauma victim was transported to our trauma centre. Smoke inhalation injury was suspected based on trauma history and clinical examination. The first trauma computer tomography (CT) obtained 2.8 h after the injury revealed subtle ground-glass opacifications with mainly peribronchial distribution and patchy peribronchial consolidations centrally in the left lung. A repeated scan showed a more distinctive demarcation of the peribronchial opacities, further substantiating the clinically verified smoke inhalation injury. The golden standard for diagnosing smoke inhalation injury still is fibroptic bronchoscopy examination. This paper shows that lesions typical to smoke inhalation injury appear much earlier than previously reported. Whether assessment of smoke inhalation injury severity using CT could clinically benefit patients is controversial and still requires further research. Multi-detector computed tomography is readily available in trauma centres and to simply neglect its potential as a diagnostic tool in some inhalation injury would be unwise. PMID:17285330

  11. Ultrasound and multidetector computed tomography of mandibular salivary gland adenocarcinoma in two dogs

    PubMed Central

    Lenoci, D.; Ricciardi, M.

    2015-01-01

    Malignant tumors of the salivary glands are rare in dogs, with adenocarcinoma being the most represented. Parotid and mandibular glands are most commonly affected in dogs. Because of local invasivity and high metastatic potential, preoperative imaging evaluation of mandibular region and tumoral staging is essential along with biopsy sampling. The present manuscript describes the ultrasound and computed tomographic imaging findings of mandibular gland adenocarcinoma in two dogs and discusses their clinical utility. PMID:26753133

  12. Computed tomographic quantification of canine adrenal gland volume and attenuation.

    PubMed

    Bertolini, Giovanna; Furlanello, Tommaso; De Lorenzi, Davide; Caldin, Marco

    2006-01-01

    We conducted a retrospective study in presumed normal dogs to determine the adrenal gland attenuation and volume values. Multidetector computer tomography (MDCT 16) analysis of the gland was carried out in 48 adult dogs without evidence of adrenal gland disease that underwent CT examination for acute spinal injuries. The mean nonenhanced attenuation value +/- SD of the left adrenal gland was 36.0 +/- 5.3 HU (range: 22.0-42.0 HU). The mean nonenhanced attenuation value +/- SD of the right gland was 34.3 +/- 7.0 HU (range: 20.4-48.6HU). The mean enhanced attenuation value +/- SD were: left gland 101.5 +/- 10.6HU (range: 86.8-128.0 HU), and right gland 97.4 +/- 12.4 HU (range: 58.9-123.6 HU). The mean CT volume +/- SD were: left gland was 0.60 cm3 (range: 0.20-0.95; SD 0.17), and right gland (0.55cm3, range: 0.22-1.01; SD 0.19). Attenuation values and volume data were related to age, weight, and gender, using ANOVA. There was no statistically significant difference between the left and right side or in adrenal measurements, because of body weight class effects. The animal effect was the most important source of variation for all adrenal measurements. Based on our study, CT is an effective method for assessing adrenal characteristics in the dog. Normative CT data are provided to allow estimation of normal adrenal gland size and volume. PMID:17009504

  13. Three-dimensional reconstruction of New Zealand rabbit antebrachium by multidetector computed tomography

    PubMed Central

    Özkadif, S; Eken, E; Beşoluk, K; Dayan, M. O.

    2015-01-01

    The aim of this study was to reveal biometric peculiarities of New Zealand white rabbit antebrachium (radius and ulna) by means of three-dimensional (3D) reconstruction of multidetector computed tomography (MDCT) images. Under general anesthesia, the antebrachiums of a total of sixteen rabbits of both sexes were scanned with a general diagnostic MDCT. Biometric measurements of the reconstructed models from high resolution MDCT images were analyzed statistically. Consequently, when biometric measurement values of corresponding bones of antebrachium were compared, it was revealed that there was no statistical significance within both sexes but there were statistically important differences between both sexes in some biometric measurements. It has been suggested that the results from the study can shed light on future studies on the skeletal system and can form a modern point of view to anatomical education. PMID:27175177

  14. [Multidetector computed tomography of coronary arteries: state of the art. Second part: clinical applications].

    PubMed

    González, Aloha Meave; Rosas, Erick Alexánderson; Valero, Mónica Rodríguez; Ramírez, Gabriela Meléndez; García, Alfonso Martínez; Fernández, Carlos Sierra; Torres, Rodrigo Calleja; Castillo, Leonardo García-Rojas; Molina, Pedro Alberto Lamothe; Zarza, Mary Carmen Herrera; de Avila, Martha Armas; López, Juan Manuel Ochoa; Vázquez-Lamadrid, Jorge; Hayama, Eric Kimura

    2008-01-01

    At the beginning of the evaluation of Coronary Artery Disease (CAD), Coronary Multidetector Computed Tomography (MDCT) was exclusively used to detect calcified plaques in coronary arteries through the Calcium Score, whose value by itself is limited. Nowadays, thanks to the technological advancements, potential clinical applications, with this method, include detection of coronary arterial stenosis, assessment of coronary bridges, and evaluation of anomalous coronaries. The intraluminal coronary stent evaluation is not possible yet, but this might become possible with the new-generation scanners. At the moment, the published results seem to be promising, nonetheless, the enthusiasm generated by this method should be accompanied by adequate training, as well as by its validation and certification. PMID:18754411

  15. Congenital coronary arteries anomalies: review of the literature and multidetector computed tomography (MDCT)-appearance.

    PubMed

    Montaudon, M; Latrabe, V; Iriart, X; Caix, P; Laurent, F

    2007-07-01

    The prevalence of coronary arteries congenital anomalies is 1 to 2% in the general population. Although the spectrum of their clinical manifestations is very broad from total inocuity to lethal, anomalies of coronary arteries need to be recognized by clinicians in certain circumstances: they are the first cause of death in young adults under physical exercise and an abnormal course of a coronary artery can complicate a cardiac surgery. Therefore, a non-invasive test is highly suitable for detecting anomalies of coronary arteries and multidetector computed tomography (MDCT) is likely to be the best one. To understand how anomalies of coronary arteries may occur, we have reviewed the recent literature about their development. Then, the main types of anomalies are presented with their clinical context, and representative MDCT images from our personal database are used for illustration. PMID:17563833

  16. Demonstration of normal and dilated testicular veins by multidetector computed tomography.

    PubMed

    Karcaaltincaba, Musturay

    2011-04-01

    Recent advances in multidetector computed tomography (MDCT) technology enabled better visualization of testicular (gonadal) vein using submillimeter slice thickness and three-dimensional images. Normally, the testicular vein measures 1-3 mm and drains into the inferior vena cava and left renal vein on the right and left sides, respectively. They can be seen in most patients during MDCT studies. Curved planar and volume-rendered images can be used to display testicular veins. We aim to demonstrate MDCT findings of normal testicular vein and its pathologies including varicocele, varices, the testicular vascular pedicle sign, and phlebolith. The testicular vein can be dilated owing to varicocele or portal hypertension and in patients with intraabdominal seminomas arising from undescended testis. The testicular vein can also cause ureteral compression at the crossing point. Understanding MDCT findings of the normal testicular vein and its various pathologies can allow a correct diagnosis, thereby avoiding further diagnostic tests. PMID:21519988

  17. [Review of pre- and post-treatment multidetector computed tomography findings in abdominal aortic aneurysms].

    PubMed

    Casula, E; Lonjedo, E; Cerverón, M J; Ruiz, A; Gómez, J

    2014-01-01

    The increase in the frequency of abdominal aortic aneurysms (AAA) and the widely accepted use of endovascular aneurysm repair (EVAR) as a first-line treatment or as an alternative to conventional surgery make it necessary for radiologists to have thorough knowledge of the pre- and post-treatment findings. The high image quality provided by multidetector computed tomography (MDCT) enables CT angiography to play a fundamental role in the study of AAA and in planning treatment. The objective of this article is to review the cases of AAA in which CT angiography was the main imaging technique, so that radiologists will be able to detect the signs related to this disease, to diagnose it, to plan treatment, and to detect complications in the postoperative period. PMID:23489768

  18. Computed tomographic appearances of the pelvis following hindquarter amputation.

    PubMed

    Fowler, J; Davies, A M; Carter, S R; Grimer, R J; Sneath, R S

    1992-12-01

    Bilateral and midline symmetry of the normal pelvic anatomy is an aid to the interpretation of computed tomographic (CT) examinations. Following hindquarter amputation (HQA) or partial hemipelvectomy (PHP) the normal anatomical relationships are disturbed. The CT examinations of 15 patients who had undergone either an HQA or a PHP for an advanced musculoskeletal malignancy are reviewed. The new "normal" anatomy revealed displacement of the bladder and small bowel to the side of surgery in one third of patients, more commonly in the PHP cases. There were varying degrees of wasting of the ipsilateral musculature, gluteus maximus muscle flap, erector spinae and psoas muscles, etc., because of partial denervation and disruption of their origin or insertion. Recurrent tumour was identified in eight of 10 cases in which it was clinically suspected prior to the CT examination. Invariably the recurrence arose within the muscle flap at the resection margin. Bone involvement by direct tumour spread was present in three cases. Pitfalls in differentiating recurrent tumour from scar tissue are discussed. PMID:1286416

  19. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography.

    PubMed

    Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias

    2015-01-01

    The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT. PMID:26415384

  20. Dose reduction by automatic exposure control in multidetector computed tomography: comparison between measurement and calculation.

    PubMed

    Lechel, U; Becker, C; Langenfeld-Jäger, G; Brix, G

    2009-04-01

    The aim of this study was to investigate the potential of dose reduction in multidetector computed tomography (MDCT) by current-modulated automatic exposure control (AEC) and to test the reliability of the dose estimation by the conventional CT dosimetry program CT-EXPO, when an average tube current is used. Phantom measurements were performed at a CT system with 64 detector rows for four representative examination protocols, each without and with current-modulated AEC. Organ and effective doses were measured by thermoluminescence dosimeters (TLD) at an anthropomorphic Alderson phantom and compared with those given by the calculation with CT-EXPO. The application of AEC yielded dose reductions between 27 and 40% (TLD measurements). While good linearity was observed between measured and computed effective dose values both without and with AEC, the organ doses showed large deviations between measurement and calculation. The dose to patients undergoing a MDCT examination can be reduced considerably by applying a current-modulated AEC. Dosimetric algorithms using a constant current-time product provide reliable estimates of the effective dose. PMID:18987864

  1. Multidetector computed tomography findings and correlations with proteinuria in nutcracker syndrome.

    PubMed

    Cho, Byoung Soo; Suh, Jin Soon; Hahn, Won Ho; Kim, Sung Do; Lim, Joo Won

    2010-03-01

    We evaluated the effectiveness of multidetector computed tomography (MDCT) as a diagnostic tool for nutcracker syndrome (NS) and its association with proteinuria. The angle and distance between the aorta and the superior mesenteric artery (SMA), the degree of difference in corticomedullary enhancement (DCE) between kidneys in the nephrographic phase of computed tomography, peak velocity ratio (PVR), and anteroposterior diameter ratio (APDR) in the sonogram were measured. The MDCT results, sonogram results, and the ratio of protein:creatinine were significantly different between NS patients and the controls. The area under the curve for angle, distance, and DCE were 0.895 +/- 0.058, 0.876 +/- 0.063, and 0.942 +/- 0.036, respectively. The cutoff values for angle and distance had sensitivity and specificity values of 96.2 and 80% for <22.4 degrees and 84.6 and 80% for <4.9 mm, respectively. The DCE had a sensitivity of 88.5% and a specificity of 100% for the positive scores. There were significant correlations between the degree of DCE and the ratio of protein:creatinine (r = 0.337, p = 0.031), and between distance and the ratio of protein:creatinine (r = -0.419, p = 0.006). We conclude that MDCT has diagnostic value for NS in children and that MDCT findings are correlated with proteinuria. PMID:20020159

  2. Predictors of Incomplete Optical Colonoscopy Using Computed Tomographic Colonography

    PubMed Central

    Sachdeva, Reetika; Tsai, Salina D.; El Zein, Mohamad H.; Tieu, Alan A.; Abdelgelil, Ahmed; Besharati, Sepideh; Khashab, Mouen A.; Kalloo, Anthony N.; Kumbhari, Vivek

    2016-01-01

    Background/Aims: Optical colonoscopy (OC) is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC). We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. Patients and Methods: In this case–control study, 70 cases (with incomplete OC) and 70 controls (with complete OC) were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model. Results: On analysis, female gender (80% vs 58.6% P = 0.007), prior abdominal/pelvic surgeries (51.4% vs 14.3% P < 0.001), colonic length (187.6 ± 30.0 cm vs 163.8 ± 27.2 cm P < 0.001), and number of flexures (11.4 ± 3.1 vs 8.4 ± 2.9 P < 0.001) increased the risk for incomplete OC. No significant association was observed for increasing age (P = 0.881) and history of severe diverticulosis (P = 0.867) with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. Conclusion: Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC. PMID:26831606

  3. Multidetector computed tomography analysis of benign and malignant nodules in patients with chronic lymphocytic thyroiditis

    PubMed Central

    ZHU, CAISONG; LIU, WEI; YANG, JUN; YANG, JING; SHAO, KANGWEI; YUAN, LIXIN; CHEN, HAIRONG; LU, WEI; ZHU, YING

    2016-01-01

    The aim of the present study was to compare the multidetector computed tomography (MDCT) features of benign and malignant nodules in patients with chronic lymphocytic thyroiditis (CLT). MDCT findings, including the size, solid percentage, calcification, margin, capsule, anteroposterior-transverse diameter ratio as well as the mode and the degree of enhancement of 137 thyroid nodules in 127 CLT cases were retrospectively analyzed. Furthermore, the correlation between MDCT findings and pathological results combined with the CT perfusion imaging was analyzed for the differences between benign and malignant nodules. A total of 77.5% (31/40) of malignant nodules were completely solid, and 33% (32/97) of benign nodules were predominantly cystic. Compared with the benign nodules, micro-calcification and internal calcification were more frequently observed in the malignant nodules (P<0.05). MDCT features such as ill-defined margin, absence of capsule or incomplete capsule or homogeneous enhancement were more likely to be present in the malignant nodules (P<0.05). Nevertheless, no significant difference was observed in the enhancement degree at arterial or venous phase between benign and malignant nodules (P>0.05). MDCT features are useful in differentiating the benign and malignant nodules in CLT patients, and it may be essential for a radiologist to review the MDCT characteristics of nodules in the clinical practice. PMID:27347131

  4. Complete Preoperative Evaluation of Pulmonary Atresia with Ventricular Septal Defect with Multi-Detector Computed Tomography

    PubMed Central

    Liu, Jingzhe; Li, Hongyin; Liu, Zhibo; Wu, Qingyu; Xu, Yufeng

    2016-01-01

    Objective To compare multi-detector computed tomography (MDCT) with cardiac catheterization and transthoracic echocardiography (TTE) in comprehensive evaluation of the global cardiovascular anatomy in patients with pulmonary atresia with ventricular septal defect (PA-VSD). Methods The clinical and imaging data of 116 patients with PA-VSD confirmed by surgery were reviewed. Using findings at surgery as the reference standard, data from MDCT, TTE and catheterization were reviewed for assessment of native pulmonary vasculature and intracardiac defects. Results MDCT was more accurate than catheterization and TTE in identification of native pulmonary arteries. MDCT is also the most accurate test for delineation of the major aortopulmonary collateral arteries. The inter-modality agreement for evaluation of overriding aorta and VSD were both excellent. In the subgroup with surgical correlation, excellent agreement was found between TTE and surgery, and substantial agreement was also found at MDCT. Conclusion MDCT can correctly delineate the native pulmonary vasculatures and intracardiac defects and may be a reliable method for noninvasive assessment of global cardiovascular abnormalities in patients with PA-VSD. PMID:26741649

  5. Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

    PubMed Central

    Tsili, Athina C; Argyropoulou, Maria I

    2015-01-01

    Renal cell carcinoma (RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography (CT) is considered the examination of choice for the detection and staging of RCC. Multidetector CT (MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and three-dimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment. PMID:26120380

  6. Multidetector Computed Tomography Features in Differentiating Exophytic Renal Angiomyolipoma from Retroperitoneal Liposarcoma

    PubMed Central

    Wang, Qiushi; Juan, Yu-Hsiang; Li, Yong; Xie, Jia-Jun; Liu, Hui; Huang, Hongfei; Liu, Zaiyi; Zheng, Junhui; Saboo, Ujwala S.; Saboo, Sachin S.; Liang, Changhong

    2015-01-01

    Abstract This study aims to evaluate the multidetector computed tomography (CT) imaging features in differentiating exophytic renal angiomyolipoma (AML) from retroperitoneal liposarcoma. We retrospectively enrolled 42 patients with confirmed exophytic renal AML (31 patients) or retroperitoneal liposarcoma (11 patients) during 8 years period to assess: renal parenchymal defect at site of tumor contact, supply from branches of renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, hemorrhage, non–fat-containing intratumoral nodules with postcontrast enhancement, calcification, renal sinus enlargement, anterior displacement of kidneys, and other associated AML. Renal parenchymal defect, renal arterial blood supply, tumoral vessel through the renal parenchyma, dilated intratumoral vessels, intratumoral/perirenal hemorrhage, renal sinus enlargement, and associated AML were seen only or mainly in exophytic renal AML (all P value < 0.05); however, non–fat-attenuating enhancing intratumoral nodules, intratumoral calcification, and anterior displacement of the kidney were more common in liposarcoma (all P value < 0.05). AMLs reveal renal parenchymal defect at the site of tumor contact, supply from renal artery, tumoral vessel extending through the renal parenchyma, dilated intratumoral vessels, intratumoral and/or perirenal hemorrhage, renal sinus enlargement, and associated AML. Non–fat-attenuating enhancing intratumoral nodules, intratumoral calcifications, and anterior displacement of kidney were more commonly seen in liposarcoma. PMID:26376398

  7. To assess vascular calcification in the patients of hypoparathyroidism using multidetector computed tomography scan

    PubMed Central

    Agarwal, Pooja; Prakash, Mahesh; Singhal, Manphool; Bhadada, Sanjay Kumar; Gupta, Yashdeep; Khandelwal, Niranjan

    2015-01-01

    Background: Our pilot data showed an increased intima media thickness in the patients with sporadic idiopathic hypoparathyroidism (SIH). Alteration in homeostasis of calcium, phosphate, and parathyroid hormone (PTH) may predispose to increase the risk of cardiovascular morbidity and mortality. The data on objective assessment of this increased risk is however lacking. Objective: To assess the effect of altered calcium, phosphate, and PTH homeostasis in the patients with SIH on coronary calcium score (a marker of increase vascular risk) by multidetector computed tomography scan (MDCT). Methods: In this case-control study, we measured coronary CT calcium score in 30 patients of SIH and compared with 40 age and sex matched healthy subjects. Correlation of coronary calcium score with biochemical parameters was evaluated. Results: Three of the 30 cases (10%) with SIH were found to have coronary artery calcification (CAC) of varying degree, whereas none of the control showed CAC (P = 0.07). The patients with CAC had significantly lower serum calcium levels (albumin corrected), as compared to the patients without CAC. Inverse correlation of CAC was found with serum calcium levels. No correlation was found with other biochemical parameters. Conclusion: The vascular risk is increased in the patients with SIH as assessed by coronary calcium score measured by MDCT. Low serum calcium levels might be a predisposing factor for this increased risk. PMID:26693429

  8. A Structural and Functional Assessment of the Lung via Multidetector-Row Computed Tomography

    PubMed Central

    Hoffman, Eric A.; Simon, Brett A.; McLennan, Geoffrey

    2006-01-01

    With advances in multidetector-row computed tomography (MDCT), it is now possible to image the lung in 10 s or less and accurately extract the lungs, lobes, and airway tree to the fifth- through seventh-generation bronchi and to regionally characterize lung density, texture, ventilation, and perfusion. These methods are now being used to phenotype the lung in health and disease and to gain insights into the etiology of pathologic processes. This article outlines the application of these methodologies with specific emphasis on chronic obstructive pulmonary disease. We demonstrate the use of our methods for assessing regional ventilation and perfusion and demonstrate early data that show, in a sheep model, a regionally intact hypoxic pulmonary vasoconstrictor (HPV) response with an apparent inhibition of HPV regionally in the presence of inflammation. We present the hypothesis that, in subjects with pulmonary emphysema, one major contributing factor leading to parenchymal destruction is the lack of a regional blunting of HPV when the regional hypoxia is related to regional inflammatory events (bronchiolitis or alveolar flooding). If maintaining adequate blood flow to inflamed lung regions is critical to the nondestructive resolution of inflammatory events, the pathologic condition whereby HPV is sustained in regions of inflammation would likely have its greatest effect in the lung apices where blood flow is already reduced in the upright body posture. PMID:16921136

  9. Computed Tomographic Findings of Syphilitic Aortitis: A Case Report

    SciTech Connect

    Kimura, Fumiko; Satoh, Hideyuki; Sakai, Fumikazu; Nishii, Noriko; Tohda, Joe; Fujimura, Mikihiko; Haruta, Shoji; Yamazaki, Kenji; Endo, Masahiro; Sakomura, Yasunari; Kurosama, Hiromi; Kasanuki, Hiroshi

    2004-03-15

    We describe the computerized tomographic (CT) findings of the aortic wall in a case of acute-phase syphilitic arteritis. The delayed phase of the contrast-enhanced CT shows a double-ring configuration of the thick thoracic aortic wall, which is similar to CT findings previously reported for Takayasu arteritis. We speculate that the resemblance of the CT findings for these two diseases accounts for their similar histopathological features.

  10. Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants *

    PubMed Central

    Araujo Neto, Severino Aires; de Mello Júnior, Carlos Fernando; Franca, Henrique Almeida; Duarte, Cláudia Martina Araújo; Borges, Rafael Farias; de Magalhães, Ana Guardiana Ximenes

    2016-01-01

    Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications. PMID:26929461

  11. Multidetector computed tomography in the evaluation of pediatric acute abdominal pain in the emergency department.

    PubMed

    Lin, Wei-Ching; Lin, Chien-Heng

    2016-06-01

    The accurate diagnosis of pediatric acute abdominal pain is one of the most challenging tasks in the emergency department (ED) due to its unclear clinical presentation and non-specific findings in physical examinations, laboratory data, and plain radiographs. The objective of this study was to evaluate the impact of abdominal multidetector computed tomography (MDCT) performed in the ED on pediatric patients presenting with acute abdominal pain. A retrospective chart review of children aged <18 years with acute abdominal pain who visited the emergency department and underwent MDCT between September 2004 and June 2007 was conducted. Patients with a history of trauma were excluded. A total of 156 patients with acute abdominal pain (85 males and 71 females, age 1-17 years; mean age 10.9 ± 4.6 years) who underwent abdominal MDCT in the pediatric ED during this 3-year period were enrolled in the study. One hundred and eighteen patients with suspected appendicitis underwent abdominal MDCT. Sixty four (54.2%) of them had appendicitis, which was proven by histopathology. The sensitivity of abdominal MDCT for appendicitis was found to be 98.5% and the specificity was 84.9%. In this study, the other two common causes of nontraumatic abdominal emergencies were gastrointestinal tract (GI) infections and ovarian cysts. The most common etiology of abdominal pain in children that requires imaging with abdominal MDCT is appendicitis. MDCT has become a preferred and invaluable imaging modality in evaluating uncertain cases of pediatric acute abdominal pain in ED, in particular for suspected appendicitis, neoplasms, and gastrointestinal abnormalities. PMID:27154197

  12. Tendon entrapments and dislocations in ankle and hindfoot fractures: evaluation with multidetector computed tomography.

    PubMed

    Ballard, David H; Campbell, Kevin J; Blanton, Lee E; Williams, Jason T; Sangster, Guillermo; Hollister, Anne M; Simoncini, Alberto A

    2016-08-01

    The purpose of this study was to assess the incidence of tendon entrapments and tendon dislocations associated with ankle and hindfoot fractures in patients studied by multidetector computed tomography (MDCT). Additionally, we describe particular tendon injuries associated with specific fractures. This was a retrospective review of all individuals with a trauma-protocol CT for suspected ankle and/or hindfoot fractures during a consecutive 41-month time period at a single Level I Trauma Center. Each patient's images were evaluated by two radiologists and an orthopedic surgeon for tendon entrapment, tendon dislocation, and bone(s) fractured or dislocated. There were 398 patients with ankle and/or hindfoot fractures that showed tendon entrapment or dislocation in 64 (16.1 %) patients. There were 30 (46.9 %) patients with 40 tendon entrapments, 31 (48.4 %) patients with 59 tendon dislocations, and three (4.7 %) patients with both tendon entrapment and dislocation. All patients with tendon entrapments were seen with either pilon fractures and/or a combination of posterior, medial, or lateral malleolar fractures. The most frequently entrapped tendon was the posterior tibialis tendon (PTT) in 27 patients (27/30, 90.0 %). The peroneal tendons were the most frequently dislocated, representing 27 (87.1 %) of patients with tendon dislocation; all resulted from a talar or calcaneal fracture or subluxation. This study demonstrates that tendon entrapments and tendon dislocations are commonly seen in complex fractures of the ankle and hindfoot. Pilon fractures were associated with the majority of tendon entrapments, whereas calcaneus fractures were associated with the majority of tendon dislocations. PMID:27234977

  13. Anthropometric Assessment of Neck Adipose Tissue and Airway Volume Using Multidetector Computed Tomography

    PubMed Central

    Maresky, Hillel S.; Sharfman, Zachary; Ziv-Baran, Tomer; Gomori, J.M.; Copel, Laurian; Tal, Sigal

    2015-01-01

    Abstract Neck adiposity tissue volume (NATV) accumulation is an indicator for metabolic syndrome and cardiovascular disease (CVD). Neck circumference is a poor measure of NATV, and a quantifier for this entity has not yet been established. To evaluate volumetric quantification by multidetector computed tomography (MDCT) as a reproducible anthropometric tool to measure NATV and airway volume (AWV). A total of 519 patients, including a subset of 70 random patients who underwent head and neck CT scanning in our hospital within 1 year (2013), were studied. Included patients were all those undergoing nonenhanced CT (NECT) or CT angiography (CTA). Neck cross-sectional areas (NCSA) were measured at 2 separate levels of the neck, and 3D postprocessing tissue reconstruction was performed, and NATV and AWVs were quantified volumetrically for all patients within the year. The average NCSA at the level of the soft palate and thyroid cartilage was 22,579 and 14,500 mm2, respectively. NATV when compared to the upper and lower levels of NCSA showed correlations of 0.64 and 0.79, respectively (P < 0.001). Interobserver analysis showed mean deviations of 0.46% and 0.32% for NATV and AWV, respectively. A strong correlation between NATV and body mass index (BMI) was found (r = 0.658, P < 0.001), and the top quartile of NATV:AWV patients (out of 519 patients) displayed a statistically significant mortality rate during 670 days of follow-up (d = 7.5%, P = 0.032). After adjustment for age and gender, the association between NATV:AWV and mortality was close to significant (P = 0.072). Volumetric quantification of NATV and AWV is a reproducible and prognostic anthropometric tool, as a high NATV:AWV demonstrated a significant risk factor for mortality; future research may further advance our understanding of this phenomenon. PMID:26559286

  14. Multidetector Computed Tomography and Magnetic Resonance Imaging Evaluation of Craniovertebral junction Abnormalities

    PubMed Central

    Dhadve, Rajshree U.; Garge, Shaileshkumar S.; Vyas, Pooja D.; Thakker, Nirav R.; Shah, Sonali H.; Jaggi, Sunila T.; Talwar, Inder A.

    2015-01-01

    Background: Craniovertebral junction (CVJ) abnormalities constitute an important group of treatable neurological disorders with diagnostic dilemma. Their precise diagnosis, identification of probable etiology, and pretreatment evaluation significantly affects prognosis and quality of life of patients. Aims: The study was to classify various craniovertebral junction disorders according to their etiology and to define the importance of precise diagnosis for pretreatment evaluation with multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods: This is a prospective observational study of 62 patients referred to our department between October 2012 and September 2014. All patients suspected to have a craniovertebral junction disorder were included in the study, from all age groups and both genders. Detailed clinical history was taken. Radiographs of cervical spine were collected if available. All patients were subjected to MDCT and/or MRI. Results: In our study of 62 patients; 39 were males and 23 were females, with male to female ratio of 1.6:1. Most common age group was 2nd -3rd decade (19 patients, 30.64%). Developmental anomalies (33 patients, 53.22%) were the most common etiology group followed by traumatic (10 patients, 16.12%), degenerative (eight patients, 12.90%), infective (four patients, 6.45%), inflammatory and neoplastic (three patients each, 4.8%), and no cause found in one patient. Conclusions: CVJ abnormalities constitute an important group of treatable neurological disorders, especially in certain ethnic groups and are approached with much caution by clinicians. Thus, it is essential that radiologists should be able to make a precise diagnosis of craniovertebral junction abnormalities, classify them into etiological group, and rule out important mimickers on MDCT and/or MRI, as this information ultimately helps determine the management of such abnormalities, prognosis, and quality of life of patients. PMID

  15. Multidetector computed tomography features of pancreatic metastases from leiomyosarcoma: Experience at a tertiary cancer center

    PubMed Central

    Suh, Chong Hyun; Keraliya, Abhishek; Shinagare, Atul B; Kim, Kyung Won; Ramaiya, Nikhil H; Tirumani, Sree Harsha

    2016-01-01

    AIM: To describe the multidetector computed tomography features of pancreatic metastasis from leiomyosarcoma (LMS). METHODS: Between January 1995 and December 2012, 13 consecutive patients (11 women, 2 men; mean age of 57 years; range, 38-78 years) with pancreatic metastases from LMS were included in our study. Imaging features including location, number, largest dimension, tumor attenuation and enhancement characteristics, presence of necrosis, pancreatic ductal dilatation, common bile duct (CBD) dilatation, presence of pancreatitis, and atrophy were documented. RESULTS: The most common site of origin of the pancreatic metastases from LMS was uterus (38.5%), followed by retroperitoneum (30.8%) and extremity (23.1%). None of the patients in our study had pancreas as the first site of metastasis. All patients developed pancreatic metastases at a median interval of 24 mo. Pancreatic metastases from LMS were solitary in 8/13 patients and multiple in 5/13 patients, had no predilection for any part of the pancreas, were hypovascular on arterial phase in 10/13 patients and associated with pancreatic duct dilatation in 3/13 patients. None had CBD dilatation. None of the pancreatic metastases in LMS cohort caused pancreatitis, and atrophy. Median duration of follow-up was 19 mo for LMS cohort during which two patients underwent resection of metastasis (median survival 45 mo) while the remaining underwent systemic therapy (median survival 13 mo). CONCLUSION: Pancreatic metastases from LMS are often solitary and hypovascular masses and less commonly associated with pancreatic ductal dilatation, CBD dilatation, pancreatitis or pancreatic atrophy. Surgical resection of solitary LMS pancreatic metastasis can be considered due to the long survival of these patients. PMID:27027985

  16. Material characterization of dual-energy computed tomographic data using polar coordinates.

    PubMed

    Havla, Lukas; Peller, Michael; Cyran, Clemens; Nikolaou, Konstantin; Reiser, Maximilian; Dietrich, Olaf

    2015-01-01

    The purpose of this study was to evaluate a new dual-energy computed tomographic postprocessing approach on the basis of the transformation of dual-energy radiodensity data into polar coordinates. Given 2 corresponding dual-energy computed tomographic images, the attenuation data D(U1), D(U2) in Hounsfield units of both tube voltages (U1,U2) were transformed for each voxel to polar coordinates: r (distance to the radiodensity coordinate origin) is an approximate measure of electron density and φ (angle to the abscissa) differentiates between materials. PMID:25279847

  17. Analysis of computed tomographic imaging spectrometers. I. Spatial and spectral resolution.

    PubMed

    Hagen, Nathan; Dereniak, Eustace L

    2008-10-01

    Computed tomographic imaging spectrometers measure the spectrally resolved image of an object scene in an entirely different manner from traditional whisk-broom or push-broom systems, and thus their noise behavior and data artifacts are unfamiliar. We review computed tomographic imaging spectrometry (CTIS) measurement systems and analyze their performance, with the aim of providing a vocabulary for discussing resolution in CTIS instruments, by illustrating the artifacts present in their reconstructed data and contributing a rule-of-thumb measure of their spectral resolution. We also show how the data reconstruction speed can be improved, at no cost in reconstruction quality, by ignoring redundant projections within the measured raw images. PMID:18830288

  18. A case of fatal sigmoid volvulus visualized on postmortem radiography: The importance of image optimization with multidetector computed tomography.

    PubMed

    Usui, Akihito; Kawasumi, Yusuke; Hosokai, Yoshiyuki; Ishizuka, Yuya; Ikeda, Tomoya; Saito, Haruo; Funayama, Masato

    2016-03-01

    This report describes the case of a man who developed fatal sigmoid volvulus that was identified on postmortem radiography before forensic autopsy. Postmortem radiography is useful for visualizing the body prior to autopsy. We discuss postmortem multidetector computed tomography that was tailored for optimum image quality to allow reconstruction of the fatal findings in multiple axes and in three dimensions, helping to pinpoint the anatomical sites of interest. This involves techniques such as manipulation of the scanning beam pitch and overlapping CT section acquisition. These techniques are best performed by personnel with CT technology training. PMID:26980251

  19. Incidental finding of a papillary fibroelastoma on the aortic valve in 16 slice multi-detector row computed tomography.

    PubMed

    Bootsveld, A; Puetz, J; Grube, E

    2004-06-01

    Papillary fibroelastoma (PFE) is a benign, rare, gelatinous tumour derived from the endocardium, primarily the cardiac valves, which is usually diagnosed by high resolution echocardiography. Although rarely clinically symptomatic, PFEs have a potential for coronary ischaemia, systemic embolisation with neurologic symptoms, and sometimes valvar dysfunction. There are reports of coronary occlusion and even sudden cardiac death due to a ball valve phenomenon on the coronary ostia. This report describes the characteristics of a PFE with multidetector 16 slice computed tomography and 1.5 Tesla cardiac magnetic resonance imaging. PMID:15145899

  20. Sex estimation based on scapula analysis in a Japanese population using multidetector computed tomography.

    PubMed

    Torimitsu, Suguru; Makino, Yohsuke; Saitoh, Hisako; Sakuma, Ayaka; Ishii, Namiko; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Yamaguchi, Rutsuko; Hashimoto, Mari; Hoshioka, Yumi; Iwase, Hirotaro

    2016-05-01

    Accurate sex estimation based on measurements of dimorphic dimensions in human unknown remains is important as the first step toward making individual identification. The purpose of this study was to assess the sexual dimorphism of the scapula and to quantify the accuracy of sex estimation in a contemporary Japanese forensic sample using scapular measurements based on three-dimensional (3D) computed tomographic (CT) images. A total of 218 cadavers (109 males, 109 females) that underwent postmortem CT and subsequent forensic autopsy were used. Ten scapular measurements were performed on 3D CT reconstructed images that extracted only bone data, and were analyzed using descriptive statistics and discriminant function analyses (DFA). All measurements were dimorphic in terms of sex differences. Univariate DFA provided sex classification accuracy rates of 75.7-91.3%. Stepwise DFA yielded sex prediction accuracy rates of 93.1-94.5%. In conclusion, the scapular measurements using 3D CT images of a contemporary Japanese population may be useful for the estimation of skeletal sex in the field of forensic anthropology. PMID:26965402

  1. Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

    PubMed Central

    Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro

    2016-01-01

    AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images

  2. Precision of dosimetry-related measurements obtained on current multidetector computed tomography scanners

    SciTech Connect

    Mathieu, Kelsey B.; McNitt-Gray, Michael F.; Zhang, Di; Kim, Hyun J.; Cody, Dianna D.

    2010-08-15

    Purpose: Computed tomography (CT) intrascanner and interscanner variability has not been well characterized. Thus, the purpose of this study was to examine the within-run, between-run, and between-scanner precision of physical dosimetry-related measurements collected over the course of 1 yr on three different makes and models of multidetector row CT (MDCT) scanners. Methods: Physical measurements were collected using nine CT scanners (three scanners each of GE VCT, GE LightSpeed 16, and Siemens Sensation 64 CT). Measurements were made using various combinations of technical factors, including kVp, type of bowtie filter, and x-ray beam collimation, for several dosimetry-related quantities, including (a) free-in-air CT dose index (CTDI{sub 100,air}); (b) calculated half-value layers and quarter-value layers; and (c) weighted CT dose index (CTDI{sub w}) calculated from exposure measurements collected in both a 16 and 32 cm diameter CTDI phantom. Data collection was repeated at several different time intervals, ranging from seconds (for CTDI{sub 100,air} values) to weekly for 3 weeks and then quarterly or triannually for 1 yr. Precision of the data was quantified by the percent coefficient of variation (%CV). Results: The maximum relative precision error (maximum %CV value) across all dosimetry metrics, time periods, and scanners included in this study was 4.33%. The median observed %CV values for CTDI{sub 100,air} ranged from 0.05% to 0.19% over several seconds, 0.12%-0.52% over 1 week, and 0.58%-2.31% over 3-4 months. For CTDI{sub w} for a 16 and 32 cm CTDI phantom, respectively, the range of median %CVs was 0.38%-1.14% and 0.62%-1.23% in data gathered weekly for 3 weeks and 1.32%-2.79% and 0.84%-2.47% in data gathered quarterly or triannually for 1 yr. Conclusions: From a dosimetry perspective, the MDCT scanners tested in this study demonstrated a high degree of within-run, between-run, and between-scanner precision (with relative precision errors typically well

  3. Quantitative Analysis of Intraventricular Dyssynchrony Using Wall Thickness by Multidetector Computed Tomography

    PubMed Central

    Truong, Quynh A.; Singh, Jagmeet P.; Cannon, Christopher P.; Sarwar, Ammar; Nasir, Khurram; Auricchio, Angelo; Faletra, Francesco F.; Sorgente, Antonio; Conca, Cristina; Moccetti, Tiziano; Handschumacher, Mark; Brady, Thomas J.; Hoffmann, Udo

    2009-01-01

    OBJECTIVES We sought to determine the feasibility of cardiac computed tomography (CT) to detect significant differences in the extent of left ventricular dyssynchrony in heart failure (HF) patients with wide QRS, HF patients with narrow QRS, and age-matched controls. BACKGROUND The degree of mechanical dyssynchrony has been suggested as a predictor of response to cardiac resynchronization therapy. There have been no published reports of dyssynchrony assessment with the use of CT. METHODS Thirty-eight subjects underwent electrocardiogram-gated contrast-enhanced 64-slice multidetector CT. The left ventricular endocardial and epicardial boundaries were delineated from short-axis images reconstructed at 10% phase increments of the cardiac cycle. Global and segmental CT dyssynchrony metrics that used changes in wall thickness, wall motion, and volume over time were assessed for reproducibility. We defined a global metric using changes in wall thickness as the dyssynchrony index (DI). RESULTS The DI was the most reproducible metric (interobserver and intraobserver intraclass correlation coefficients ≥0.94, p < 0.0001) and was used to determine differences between the 3 groups: HF-wide QRS group (ejection fraction [EF] 22 ± 8%, QRS 163 ± 28 ms), HF-narrow QRS (EF 26 ± 7%, QRS 96 ± 11 ms), and age-matched control subjects (EF 64 ± 5%, QRS 87 ± 9 ms). Mean DI was significantly different between the 3 groups (HF-wide QRS: 152 ± 44 ms, HF-narrow QRS: 121 ± 58 ms, and control subjects: 65 ± 12 ms; p < 0.0001) and greater in the HF-wide QRS (p < 0.0001) and HF-narrow QRS (p = 0.005) groups compared with control subjects. We found that DI had a good correlation with 2-dimensional (r = 0.65, p = 0.012) and 3-dimensional (r = 0.68, p = 0.008) echocardiographic dyssynchrony. CONCLUSIONS Quantitative assessment of global CT-derived DI, based on changes in wall thickness over time, is highly reproducible and renders significant differences between subjects most likely to

  4. The effect of z overscanning on patient effective dose from multidetector helical computed tomography examinations

    SciTech Connect

    Tzedakis, A.; Damilakis, J.; Perisinakis, K.; Stratakis, J.; Gourtsoyiannis, N.

    2005-06-15

    z overscanning in multidetector (MD) helical CT scanning is prerequisite for the interpolation of acquired data required during image reconstruction and refers to the exposure of tissues beyond the boundaries of the volume to be imaged. The aim of the present study was to evaluate the effect of z overscanning on the patient effective dose from helical MD CT examinations. The Monte Carlo N-particle radiation transport code was employed in the current study to simulate CT exposure. The validity of the Monte Carlo simulation was verified by (a) a comparison of calculated and measured standard computed tomography dose index (CTDI) dosimetric data, and (b) a comparison of calculated and measured dose profiles along the z axis. CTDI was measured using a pencil ionization chamber and head and body CT phantoms. Dose profiles along the z axis were obtained using thermoluminescence dosimeters. A commercially available mathematical anthropomorphic phantom was used for the estimation of effective doses from four standard CT examinations, i.e., head and neck, chest, abdomen and pelvis, and trunk studies. Data for both axial and helical modes of operation were obtained. In the helical mode, z overscanning was taken into account. The calculated effective dose from a CT exposure was normalized to CTDI{sub freeinair}. The percentage differences in the normalized effective dose between contiguous axial and helical scans with pitch=1, may reach 13.1%, 35.8%, 29.0%, and 21.5%, for head and neck, chest, abdomen and pelvis, and trunk studies, respectively. Given that the same kilovoltage and tube load per rotation were used in both axial and helical scans, the above differences may be attributed to z overscanning. For helical scans with pitch=1, broader beam collimation is associated with increased z overscanning and consequently higher normalized effective dose value, when other scanning parameters are held constant. For a given beam collimation, the selection of a higher value of

  5. Clinical Structural Anatomy of the Inferior Pyramidal Space Reconstructed Within the Cardiac Contour Using Multidetector-Row Computed Tomography.

    PubMed

    Mori, Shumpei; Fukuzawa, Koji; Takaya, Tomofumi; Takamine, Sachiko; Ito, Tatsuro; Fujiwara, Sei; Nishii, Tatsuya; Kono, Atsushi K; Yoshida, Akihiro; Hirata, Ken-Ichi

    2015-07-01

    Although many studies have described the detailed anatomy of the inferior pyramidal space, it may not be easy for cardiologists who have few chances to study cadaveric hearts to understand the correct morphology of the structure. The inferior pyramidal space is the part of extracardiac fibro-adipose tissue wedging between the 4 cardiac chambers from the diaphragmatic surface of the heart. Many cardiologists have interests in pericardial adipose tissue, but the inferior pyramidal space seems to have been neglected. A number of important structures, including the coronary sinus, atrioventricular node, atrioventricular nodal artery, membranous septum, muscular atrioventricular sandwich (previously called the "muscular atrioventricular septum"), atrial septum, ventricular septum, aortic valvar complex, mitral valvar attachment, and tricuspid valvar attachment are associated with the inferior pyramidal space. We previously revealed its 3-dimensional live anatomy using multidetector-row computed tomography. Moreover, the 3-dimensional understanding of the anatomy in association with the cardiac contour is important from the viewpoints of clinical cardiac electrophysiology. The purpose of this article is to demonstrate extended findings regarding the clinical structural anatomy of the inferior pyramidal space, which was reconstructed in combination with the cardiac contour using multidetector-row computed tomography, and discuss the clinical implications of the findings. PMID:25884276

  6. Detection of root perforations using conventional and digital intraoral radiography, multidetector computed tomography and cone beam computed tomography

    PubMed Central

    Eskandarloo, Amir; Noruzi-Gangachin, Maruf; Khajeh, Samira

    2015-01-01

    Objectives This study aimed to compare the accuracy of conventional intraoral (CI) radiography, photostimulable phosphor (PSP) radiography, cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) for detection of strip and root perforations in endodontically treated teeth. Materials and Methods Mesial and distal roots of 72 recently extracted molar were endodontically prepared. Perforations were created in 0.2, 0.3, or 0.4 mm diameter around the furcation of 48 roots (strip perforation) and at the external surface of 48 roots (root perforation); 48 roots were not perforated (control group). After root obturation, intraoral radiography, CBCT and MDCT were taken. Discontinuity in the root structure was interpreted as perforation. Two observers examined the images. Data were analyzed using Stata software and Chi-square test. Results The sensitivity and specificity of CI, PSP, CBCT and MDCT in detection of strip perforations were 81.25% and 93.75%, 85.42% and 91.67%, 97.92% and 85.42%, and 72.92% and 87.50%, respectively. For diagnosis of root perforation, the sensitivity and specificity were 87.50% and 93.75%, 89.58% and 91.67%, 97.92% and 85.42%, and 81.25% and 87.50%, respectively. For detection of strip perforation, the difference between CBCT and all other methods including CI, PSP and MDCT was significant (p < 0.05). For detection of root perforation, only the difference between CBCT and MDCT was significant, and for all the other methods no statistically significant difference was observed. Conclusions If it is not possible to diagnose the root perforations by periapical radiographs, CBCT is the best radiographic technique while MDCT is not recommended. PMID:25671214

  7. Efficient control schemes with limited computation complexity for Tomographic AO systems on VLTs and ELTs

    NASA Astrophysics Data System (ADS)

    Petit, C.; Le Louarn, M.; Fusco, T.; Madec, P.-Y.

    2011-09-01

    Various tomographic control solutions have been proposed during the last decades to ensure efficient or even optimal closed-loop correction to tomographic Adaptive Optics (AO) concepts such as Laser Tomographic AO (LTAO), Multi-Conjugate AO (MCAO). The optimal solution, based on Linear Quadratic Gaussian (LQG) approach, as well as suboptimal but efficient solutions such as Pseudo-Open Loop Control (POLC) require multiple Matrix Vector Multiplications (MVM). Disregarding their respective performance, these efficient control solutions thus exhibit strong increase of on-line complexity and their implementation may become difficult in demanding cases. Among them, two cases are of particular interest. First, the system Real-Time Computer architecture and implementation is derived from past or present solutions and does not support multiple MVM. This is the case of the AO Facility which RTC architecture is derived from the SPARTA platform and inherits its simple MVM architecture, which does not fit with LTAO control solutions for instance. Second, considering future systems such as Extremely Large Telescopes, the number of degrees of freedom is twenty to one hundred times bigger than present systems. In these conditions, tomographic control solutions can hardly be used in their standard form and optimized implementation shall be considered. Single MVM tomographic control solutions represent a potential solution, and straightforward solutions such as Virtual Deformable Mirrors have been already proposed for LTAO but with tuning issues. We investigate in this paper the possibility to derive from tomographic control solutions, such as POLC or LQG, simplified control solutions ensuring simple MVM architecture and that could be thus implemented on nowadays systems or future complex systems. We theoretically derive various solutions and analyze their respective performance on various systems thanks to numerical simulation. We discuss the optimization of their performance and

  8. Computed tomographic coronary angiography: how many slices do you need?

    PubMed Central

    Peebles, C

    2006-01-01

    While increasing the number of slices in multislice computed tomography clearly brings benefits in terms of detecting significant coronary disease, heavy calcification remains a problem, as does the high radiation burden PMID:16614268

  9. Validation of a paediatric thyroid phantom using different multidetector computed tomography models

    NASA Astrophysics Data System (ADS)

    Alsabbagh, M.; Ng, L. Y.; Tajuddin, A. A.; Manap, M. A.; Zainon, R.

    2016-03-01

    The aim of this study was to compare the attenuation values of a fabricated paediatric thyroid phantom material using different MDCT models. A paediatric thyroid phantom was designed to mimic the shape and size of a paediatric patient with an age of 9 years using high- density Polyethylene as the phantom material. The fabricated phantom was scanned using two different multidetector CT scanners (16- and 128-row detectors). The CT numbers were evaluated and the mass attenuation coefficients (μ/ρ) of the phantom material were obtained at each applied energy from each scanner. The results were compared with the tables of the National Institute of Standards and Technology (NIST). The CTs of 16- and 128-row detectors showed that the obtained attenuation values are very similar to the NIST's values. However, the CT of the 128-row detectors showed a slightly much closer match to the NIST's values. This refers to the type and quality of the electronic connections between the detectors. Furthermore, the type and number of detectors (16- and 128-detectors) could affect the details and quality of the output images. The results show that different multidetector CTs can be used to validate the phantom and determine the mass attenuation coefficients of its material.

  10. Multidetector CT of blunt abdominal trauma.

    PubMed

    Soto, Jorge A; Anderson, Stephan W

    2012-12-01

    The morbidity, mortality, and economic costs resulting from trauma in general, and blunt abdominal trauma in particular, are substantial. The "panscan" (computed tomographic [CT] examination of the head, neck, chest, abdomen, and pelvis) has become an essential element in the early evaluation and decision-making algorithm for hemodynamically stable patients who sustained abdominal trauma. CT has virtually replaced diagnostic peritoneal lavage for the detection of important injuries. Over the past decade, substantial hardware and software developments in CT technology, especially the introduction and refinement of multidetector scanners, have expanded the versatility of CT for examination of the polytrauma patient in multiple facets: higher spatial resolution, faster image acquisition and reconstruction, and improved patient safety (optimization of radiation delivery methods). In this article, the authors review the elements of multidetector CT technique that are currently relevant for evaluating blunt abdominal trauma and describe the most important CT signs of trauma in the various organs. Because conservative nonsurgical therapy is preferred for all but the most severe injuries affecting the solid viscera, the authors emphasize the CT findings that are indications for direct therapeutic intervention. PMID:23175542

  11. Epidemiology and association of vascular and valvular calcium quantified by multidetector computed tomography in elderly asymptomatic subjects.

    PubMed

    Cury, Ricardo C; Ferencik, Maros; Hoffmann, Udo; Ferullo, Ashley; Moselewski, Fabian; Abbara, Suhny; Booth, Sarah L; O'Donnell, Christopher J; Brady, Thomas J; Achenbach, Stephan

    2004-08-01

    The epidemiology of and association between vascular and valvular calcium as quantified by multidetector computed tomography (MDCT) were studied in 416 elderly subjects with no history of coronary artery disease. Coronary calcium (CC), descending thoracic aortic calcium (DTAC), aortic valve calcium (AVC), and mitral valve calcium (MVC) were present in 282 (68%), 214 (51%), 152 (37%), and 68 (16%) subjects, respectively. Multiple logistic regression analysis showed that after adjusting for age and gender, subjects with AVC (odds ratio [OR] 2.3), MVC (OR 2.81), and DTAC (OR 2.79) were independently and significantly more likely to have CC. Further evidence is provided for the notion that calcifications in those regions are associated and that MDCT can be used as a tool for the global assessment of vascular and valvular calcium. PMID:15276102

  12. Autopsy radiography: digital radiographs (DR) vs multidetector computed tomography (MDCT) in high-velocity gunshot-wound victims.

    PubMed

    Harcke, H Theodore; Levy, Angela D; Abbott, Robert M; Mallak, Craig T; Getz, John M; Champion, Howard R; Pearse, Lisa

    2007-03-01

    This study compared full-body digital radiography (DR) with multidetector computed tomography (MDCT) in the postmortem evaluation of gunshot wound (GSW) victims. Thirteen consecutive male GSW victims (mean age, 27 years) had full-body DR and MDCT prior to routine autopsy. DR successfully identified all metallic fragments, but MDCT was superior in its ability to precisely determine location because it provided 3-dimensional anatomic localization. In all cases, MDCT more accurately assessed organ injuries and wound tracks. Both DR and MDCT are limited in classifying multiple wounds and major vessel injury, but MDCT is generally superior to DR. MDCT shows significant advantages over DR in the forensic evaluation of GSW victims. This is particularly advantageous for the pathologist retrieving metallic fragments and for describing fracture detail accurately. Use of MDCT instead of radiographs will require medical examiners to become familiar with reading cross-sectional images. PMID:17325457

  13. Observational case series: an algorithm incorporating multidetector computed tomography in the medicolegal investigation of human remains after a natural disaster.

    PubMed

    Berran, Philip J; Mazuchowski, Edward L; Marzouk, Abubakr; Harcke, H Theodore

    2014-07-01

    An algorithm incorporating multidetector computed tomography (MDCT), digital radiographs, and external examination was used to triage cases for noninvasive or complete autopsy after a natural disaster. The algorithm was applied to 27 individuals who died during or soon after the earthquake that struck the Republic of Haiti on January 12, 2010. Of the 27 cases reviewed, 7 (26%) required a complete autopsy to determine cause and manner of death. In the remaining 20 (74%), cause and manner of death were determined with a reasonable degree of medical certainty after review of circumstances, an external examination, and postmortem imaging by MDCT and digital radiography (noninvasive autopsy). MDCT was particularly useful in detecting skeletal fractures caused by blunt force injury which were not evident on digital radiographs. The algorithm incorporating postmortem MDCT can be useful in the triage of human remains for autopsy after a natural disaster. PMID:24684535

  14. Computed tomographic anatomy of the canine inner and middle ear.

    PubMed

    Russo, Marco; Covelli, Eugenio M; Meomartino, Leonardo; Lamb, Christopher R; Brunetti, Arturo

    2002-01-01

    A series of high-resolution computed x-ray tomography (CT) images of the normal canine middle and inner ear are presented to serve as a reference for optimal interpretation of clinical CT images of animals with diseases affecting this region. PMID:11866039

  15. [Image characteristics of the computer tomograph (author's transl)].

    PubMed

    Schultz, E; Felix, R; Lackner, K; Bergeder, H D; Thurn, P

    1979-04-01

    In the present paper the images produced by spheres of varying diameter (d = 4,6,8,10 mm) embedded in a homogeneous substance of varying densities (H' = 3,48,93,137 Hounsfield units) as produced by computer tomography were studied. Measurements show that for each sphere diameter there is a minimum contrast between the substance of the sphere and its surroundings which must exist in order to show this sphere by computer tomography. It was also shown that the partial volume effect is of significance for the attenuation of the spheres. The effect of the position of the spheres within the slices to be imaged was studied. The results clearly indicate that in the investigation of small tissue changes in the body, the thickness of the slice and patient displacement should be kept as small as possible. PMID:155606

  16. Computed tomographic beam-hardening artefacts: mathematical characterization and analysis

    PubMed Central

    Park, Hyoung Suk; Chung, Yong Eun; Seo, Jin Keun

    2015-01-01

    This paper presents a mathematical characterization and analysis of beam-hardening artefacts in X-ray computed tomography (CT). In the field of dental and medical radiography, metal artefact reduction in CT is becoming increasingly important as artificial prostheses and metallic implants become more widespread in ageing populations. Metal artefacts are mainly caused by the beam-hardening of polychromatic X-ray photon beams, which causes mismatch between the actual sinogram data and the data model being the Radon transform of the unknown attenuation distribution in the CT reconstruction algorithm. We investigate the beam-hardening factor through a mathematical analysis of the discrepancy between the data and the Radon transform of the attenuation distribution at a fixed energy level. Separation of cupping artefacts from beam-hardening artefacts allows causes and effects of streaking artefacts to be analysed. Various computer simulations and experiments are performed to support our mathematical analysis. PMID:25939628

  17. Computed tomographic beam-hardening artefacts: mathematical characterization and analysis.

    PubMed

    Park, Hyoung Suk; Chung, Yong Eun; Seo, Jin Keun

    2015-06-13

    This paper presents a mathematical characterization and analysis of beam-hardening artefacts in X-ray computed tomography (CT). In the field of dental and medical radiography, metal artefact reduction in CT is becoming increasingly important as artificial prostheses and metallic implants become more widespread in ageing populations. Metal artefacts are mainly caused by the beam-hardening of polychromatic X-ray photon beams, which causes mismatch between the actual sinogram data and the data model being the Radon transform of the unknown attenuation distribution in the CT reconstruction algorithm. We investigate the beam-hardening factor through a mathematical analysis of the discrepancy between the data and the Radon transform of the attenuation distribution at a fixed energy level. Separation of cupping artefacts from beam-hardening artefacts allows causes and effects of streaking artefacts to be analysed. Various computer simulations and experiments are performed to support our mathematical analysis. PMID:25939628

  18. Computed tomographic identification of calcified optic nerve drusen

    SciTech Connect

    Ramirez, H.; Blatt, E.S.; Hibri, N.S.

    1983-07-01

    Four cases of optic disk drusen were accurately diagnosed with orbital computed tomography (CT). The radiologist should be aware of the characteristic CT finding of discrete calcification within an otherwise normal optic disk. This benign process is easily differentiated from lesions such as calcific neoplastic processes of the posterior globe. CT identification of optic disk drusen is essential in the evaluation of visual field defects, migraine-like headaches, and pseudopapilledema.

  19. Budd-Chiari syndrome: computed tomographic and ultrasonographic findings

    SciTech Connect

    Yang, P.J.; Glazer, G.M.; Bowerman, R.A.

    1983-02-01

    A case of Budd-Chiari syndrome is presented in which computed tomography (CT) and ultrasonography suggested the correct diagnosis and excluded adjacent tumor as the cause of hepatic vein occlusion. The CT appearance in this case (homogeneously increased attenuation of an enlarged caudate lobe) differed from the appearance previously reported (patchy liver enhancement) in Budd-Chiari syndrome. Underlying mechanisms responsible for the different CT appearance are discussed.

  20. Computed Tomographic Tenography of Normal Equine Digital Flexor Tendon Sheath: An Ex Vivo Study

    PubMed Central

    Lacitignola, Luca; De Luca, Pasquale; Guarracino, Alessandro; Crovace, Antonio

    2015-01-01

    Aim of this study was to document the normal computed tomographic tenography findings of digital flexor tendon sheath. Six ex vivo normal equine forelimbs were used. An axial approach was used to inject 185 mg/mL of iopamidol in a total volume of 60 mL into the digital flexor tendon sheaths. Single-slice helical scans, with 5 mm thickness, spaced every 3 mm, for a pitch of 0.6, and with bone algorithm reconstruction, were performed before and after injections of contrast medium. To obtain better image quality for multiplanar reconstruction and 3D reformatting, postprocessing retroreconstruction was performed to reduce the images to submillimetre thickness. Computed tomographic tenography of digital flexor tendon sheaths could visualize the following main tendon structures for every forelimb in contrast-enhanced images as low densities surrounded by high densities: superficial digital flexor tendon, deep digital flexor tendon, manica flexoria, mesotendons, and synovial recess. Results of this study suggest that computed tomographic tenography can be used with accuracy and sensitivity to evaluate the common disorders of the equine digital flexor tendon sheath and the intrathecal structures. PMID:26185709

  1. Development of an electrical impedance computed tomographic two-phase flows analyzer. Annual technical report for program renewal

    SciTech Connect

    Jones, O.C.

    1993-05-01

    This progress report details the theoretical development, numerical results, experimental design (mechanical), experimental design (electronic), and experimental results for the research program for the development of an electrical impedance computed tomographic two-phase flow analyzer.

  2. Multi-Detector Row Computed Tomography Findings of Pelvic Congestion Syndrome Caused by Dilated Ovarian Veins

    PubMed Central

    Eren, Suat

    2010-01-01

    Objective: To evaluate the efficacy of multi-detector row CT (MDCT) on pelvic congestion syndrome (PCS), which is often overlooked or poorly visualized with routine imaging examination. Materials and Methods: We evaluated the MDCT features of 40 patients with PCS (mean age, 45 years; range, 29–60 years) using axial, coronal, sagittal, 3D volume-rendered, and Maximum Intensity Projection MIP images. Results: MDCT revealed pelvic varices and ovarian vein dilatations in all patients. Bilateral ovarian vein dilatation was present in 25 patients, and 15 patients had unilateral dilatation. While 12 cases of secondary pelvic varices occurred simultaneously with a retroaortic left renal vein, 10 cases were due solely to a mass obstruction or stenosis of venous structures. Conclusion: MDCT is an effective tool in the evaluation of PCS, and it has more advantages than other imaging modalities. PMID:25610142

  3. [Computed tomographic atlas of benign asbestos related pathology].

    PubMed

    Beigelman-Aubry, C; Ferretti, G; Mompoint, D; Ameille, J; Letourneux, M; Frija, J; Laurent, F

    2007-06-01

    The demonstration by computed tomography of abnormalities related to asbestos is essential for the recognition of industrial disease, the compensation of which has considerable economic consequences. The use of compute tomography, the most reliable technique for the detection of pleuro-parenchymatous abnormalities related to asbestos exposure, has increased considerably in France since the publication of the results of a consensus conference in Paris in 1999. Since that time, developments in technology have noticeably modified the protocols of investigation and increased the sensitivity of the detection of pleural and interstitial parenchymatous abnormalities and of nodules. The technical recommendations and those for the interpretation of pleural and parenchymatous abnormalities need to be well known. They are presented in the form of an atlas that gives detailed criteria for asbestosis, pleural plaques and pleural fibrosis. The diagnosis of pleural plaques depends on the combination of clear limits at the pleural and pulmonary interface, typical topography and multiple, bilateral localization. In the context of asbestos exposure the plaques are characteristic of this exposure, unlike diffuse pleural thickening, crow's feet images, parenchymatous bands and entrapped atalectasis. The writing of the radiological report would be most appropriate on this basis. PMID:17652978

  4. [Computed tomographic atlas of benign asbestos related pathology].

    PubMed

    Beigelman-Aubry, C; Ferretti, G; Mompoint, D; Ameille, J; Letourneux, M; Laurent, F

    2007-06-01

    The demonstration by computed tomography of abnormalities related to asbestos is essential for the recognition of industrial disease, the compensation of which has considerable economic consequences. The use of computed tomography, the most reliable technique for the detection of pleuro-parenchymatous abnormalities related to asbestos exposure, has increased considerably in France since the publication of the results of a consensus conference in Paris in 1999. Since that time, developments in CT technology have noticeably modified the protocols of investigation and increased the sensitivity of the detection of pleural and interstitial parenchymatous abnormalities and of nodules. The technical recommendations and those for the interpretation of pleural and parenchymatous abnormalities need to be well known. They are presented in the form of an atlas that gives detailed criteria for asbestosis, pleural plaques and pleural fibrosis. The diagnosis of pleural plaques depends on the combination of clear limits at the pleural and pulmonary interface, typical topography and multiple, bilateral localization. In the context of asbestos exposure the plaques are characteristic of this exposure, unlike diffuse pleural thickening, crow's feet images, parenchymatous bands and entrapped atalectasis. The writing of the radiological report would be most appropriate on this basis. PMID:17632435

  5. Computed tomographic patterns of intracranial infarcts in Ghanaians.

    PubMed

    Obajimi, M O; Nyame, P K; Jumah, K B; Wiredu, E K

    2002-01-01

    Computed tomography has given a boost to intracranial imaging in general, and the diagnosis of the subtypes of Cerebrovascular Accident (CVA) in particular. In this study of 1,172 cases of CVA examined by Computed Tomography (CT), 552 (47.10%) showed features of cerebral infarction. There was a male prevalence in the study and the mean age was 59.8 years. As in all infarcts the diagnostic appearance was a wedge shaped hypodensity within the brain parenchyma. This was most often found in the parietal lobe (73.6%) and was always without a mass effect. Even though solitary infarcts were frequent, multiple lesions were reported in 9.3% of cases and these group of respondents presented mostly with seizures. Diabetes mellitus was an important predisposing factor and was found in 163% of cases, while hypertension was found in only 9.1% of cases studied. Other CT findings were cerebral and cerebrellar atrophy. Calcification of the falx and the basal ganglia were also noted. PMID:12403033

  6. Maturation of normal primate white matter: computed tomographic correlation

    SciTech Connect

    Quencer, R.M.

    1982-09-01

    Five infant baboons were examined with computed tomography (CT) during the first year of their lives to determine the rate and degree of normal white matter maturation in frontal, occipital, and parietal areas. The increase in CT numbers with age was correlated with gross and histologic specimens. Two phases of maturation were identified: a rapid phase (first 8-12 weeks) and a gradual phase (after 12 weeks). Frontal white matter was the most immature in the immediate postnatal period but it became equal in attenuation to the other regions by 4 weeks of age. Knowledge of white matter maturation rates may be particularly useful in cases of neonatal hypoxia/ischemia where zones of periventricular hypodensity are identified. The failure of such regions to follow a normal rate of maturation may indicate damage to the white matter and have significant prognostic implications.

  7. Recurrent largngeal nerve paralysis: a laryngographic and computed tomographic study

    SciTech Connect

    Agha, F.P.

    1983-07-01

    Vocal cord paralysis is a relatively common entity, usually resulting from a pathologic process of the vagus nerve or its recurrent larynegeal branch. It is rarely caused by intralargngeal lesions. Four teen patients with recurrent laryngeal nerve paralysis (RLNP) were evaluated by laryngography, computed tomography (CT), or both. In the evaluation of the paramedian cord, CT was limited in its ability to differentiate between tumor or RLNP as the cause of the fixed cord, but it yielded more information than laryngography on the structural abnormalities of the larynx and pre-epiglottic and paralaryngeal spaces. Laryngography revealed distinct features of RLNP and is the procedure of choice for evaluation of functional abnormalities of the larynx until further experience with faster CT scanners and dynamic scanning of the larynx is gained.

  8. Computed tomographic diagnosis of intraventricular hemorrhage: etiology and prognosis

    SciTech Connect

    Graeb, D.A.; Robertson, W.D.; Lapointe, J.S.; Nugent, R.A.; Harrison, P.B.

    1982-04-01

    Sixty-eight patients with intraventricular hemorrhage (IVH) diagnosed by computed tomography (CT) were reviewed retrospectively to determine the etiology and prognosis, relationship to delayed hydrocephalus, and effect on neurological outcome. The most common causes were a ruptured aneurysm, trauma, and hypertensive hemorrhage. Ruptured aneurysms of the anterior communicating artery can often be predicted from the nonenhanced CT scan. The total mortality rate was 50%; however, 21% of patients returned to normal or had only mild disability. Patients in whom no cause was identified had a better prognosis. Delayed hydrocephalus was related to the effects of subarachnoid hemorrahage rather than obstruction of the ventricular system by blood. IVH per se is seldon a major factor in the neurological outcome.

  9. Temporomandibular joints: high-resolution computed tomographic evaluation

    SciTech Connect

    Thompson, J.R.; Christiansen, E.; Hasso, A.N.; Hinshaw, D.B. Jr.

    1984-01-01

    High-resolution computed tomography of the temporomandibular joint (TMJ) was performed in 43 patients. Exquisite detail of the face, skull base, and TMJs was obtained with CT using soft tissue and bone algorithms, narrow collimation, and multiplanar images. In 10 patients clinically suspected of joint derangement, CT results were in close agreement with surgical findings and arthrography in 13/15 joints. CT showed indirect signs of disc dislocation, and the dislocated disc itself in 81% of affected joints. In two patients, arthrography with CT proved to be more helpful than conventional arthrography alone. CT without intra-articular contrast material provided information not appreciated on conventional radiogaphs in 28 patients (65%) and was particularly helpful in evaluating patients with disc pathosis and trauma. Early experience with CT of the TMJ shows that it is an excellent method of evaluation at acceptable radiation exposure levels that adds essential information not seen on standard radiographs.

  10. Cone Beam Computed Tomographic Assessment of Bifid Mandibular Condyle

    PubMed Central

    Khojastepour, Leila; Kolahi, Shirin; Panahi, Nazi

    2015-01-01

    Objectives: Differential diagnosis of bifid mandibular condyle (BMC) is important, since it may play a role in temporomandibular joint (TMJ) dysfunctions and joint symptoms. In addition, radiographic appearance of BMC may mimic tumors and/or fractures. The aim of this study was to evaluate the prevalence and orientation of BMC based on cone beam computed tomography (CBCT) scans. Materials and Methods: This cross-sectional study was performed on CBCT scans of paranasal sinuses of 425 patients. In a designated NNT station, all CBCT scans were evaluated in the axial, coronal and sagittal planes to find the frequency of BMC. The condylar head horizontal angulations were also determined in the transverse plane. T-test was used to compare the frequency of BMC between the left and right sides and between males and females. Results: Totally, 309 patients with acceptable visibility of condyles on CBCT scans were entered in the study consisting of 170 (55%) females and 139 (45%) males with a mean age of 39.43±9.7 years. The BMC was detected in 14 cases (4.53%). Differences between males and females, sides and horizontal angulations of condyle of normal and BMC cases were not significant. Conclusion: The prevalence of BMC in the studied population was 4.53%. No significant difference was observed between males and females, sides or horizontal angulations of the involved and uninvolved condyles.

  11. Computed tomographic bronchioarterial ratio for brachycephalic dogs without pulmonary disease.

    PubMed

    Won, Sungjun; Lee, Ahra; Choi, Jihye; Choi, Mincheol; Yoon, Junghee

    2015-01-01

    The bronchoarterial (BA) ratio measured with computed tomography is widely used in human medicine to diagnose bronchial dilation or collapse. Although use of the BA ratio in veterinary medicine has been recently studied, this has not been evaluated in brachycephalic dogs predisposed to bronchial diseases including bronchial collapse. The purpose of this study was to establish BA ratios for brachycephalic dogs and compare the values with those of non-brachycephalic dogs. Twenty-three brachycephalic dogs and 15 non-brachycephalic dogs without clinical pulmonary disease were evaluated. The BA ratio of the lobar bronchi in the left and right cranial as well as the right middle, left, and right caudal lung lobes was measured. No significant difference in mean BA ratio was observed between lung lobes or the individual animals (p = 0.148). The mean BA ratio was 1.08 ± 0.10 (99%CI = 0.98~1.18) for brachycephalic dogs and 1.51 ± 0.05 (99% CI = 1.46~1.56) for the non-brachycephalic group. There was a significant difference between the mean BA ratios of the brachycephalic and non-brachycephalic groups (p = 0.00). Defining the normal limit of the BA ratio for brachycephalic breeds may be helpful for diagnosing bronchial disease in brachycephalic dogs. PMID:25643795

  12. Computed tomographic bronchioarterial ratio for brachycephalic dogs without pulmonary disease

    PubMed Central

    Won, Sungjun; Lee, Ahra; Choi, Jihye; Choi, Mincheol

    2015-01-01

    The bronchoarterial (BA) ratio measured with computed tomography is widely used in human medicine to diagnose bronchial dilation or collapse. Although use of the BA ratio in veterinary medicine has been recently studied, this has not been evaluated in brachycephalic dogs predisposed to bronchial diseases including bronchial collapse. The purpose of this study was to establish BA ratios for brachycephalic dogs and compare the values with those of non-brachycephalic dogs. Twenty-three brachycephalic dogs and 15 non-brachycephalic dogs without clinical pulmonary disease were evaluated. The BA ratio of the lobar bronchi in the left and right cranial as well as the right middle, left, and right caudal lung lobes was measured. No significant difference in mean BA ratio was observed between lung lobes or the individual animals (p = 0.148). The mean BA ratio was 1.08 ± 0.10 (99% CI = 0.98~1.18) for brachycephalic dogs and 1.51 ± 0.05 (99% CI = 1.46~1.56) for the non-brachycephalic group. There was a significant difference between the mean BA ratios of the brachycephalic and non-brachycephalic groups (p = 0.00). Defining the normal limit of the BA ratio for brachycephalic breeds may be helpful for diagnosing bronchial disease in brachycephalic dogs. PMID:25643795

  13. Computed tomographic imaging characteristics of the normal canine lacrimal glands

    PubMed Central

    2014-01-01

    Background The canine lacrimal gland (LG) and accessory lacrimal gland of the third eyelid (TEG) are responsible for production of the aqueous portion of the precorneal tear film. Immune-mediated, toxic, neoplastic, or infectious processes can affect the glands directly or can involve adjacent tissues, with secondary gland involvement. Disease affecting these glands can cause keratoconjunctivitis sicca, corneal ulcers, and loss of vision. Due to their location in the orbit, these small structures are difficult to evaluate and measure, making cross-sectional imaging an important diagnostic tool. The detailed cross-sectional imaging appearance of the LG and TEG in dogs using computed tomography (CT) has not been reported to date. Results Forty-two dogs were imaged, and the length, width, and height were measured and the volume calculated for the LGs & TEGs. The glands were best visualized in contrast-enhanced CT images. The mean volume of the LG was 0.14 cm3 and the TEG was 0.1 cm3. The mean height, width, and length of the LG were, 9.36 mm, 4.29 mm, and 9.35 mm, respectively; the corresponding values for the TEG was 2.02 mm, 9.34 mm, and 7.90 mm. LG and TEG volume were positively correlated with body weight (p < 0.05). Conclusions Contrast-enhanced CT is a valuable tool for noninvasive assessment of canine lacrimal glands. PMID:24886364

  14. COMPUTED TOMOGRAPHIC FEATURES OF PHARYNGEAL NEOPLASIA IN 25 DOGS.

    PubMed

    Carozzi, Gregorio; Zotti, Alessandro; Alberti, Monica; Rossi, Federica

    2015-01-01

    Computed tomography (CT) is commonly used to investigate head tumors in dogs, however little information is available for lesions of the pharyngeal area. The purpose of this multicentric, retrospective, cross-sectional study was to describe the CT findings in a sample of dogs with pathologically confirmed pharyngeal neoplasia and determine whether any CT features allowed differentiation of tumor type. Location of lesions, size and shape, margins, relationship with surrounding structures and vessels, attenuation characteristics and enhancement pattern, regional lymph node changes, and presence of metastasis were recorded by three observers (1 DECVDI). The effect of final diagnosis on each CT feature was tested. A total of 25 dogs were included: 15 with carcinomas, five sarcomas, four melanomas, and one lymphoma. The oropharynx and laryngopharynx were more frequently involved. Among tumor groups, lesions were of similar size, irregularly shaped, had ill-defined margins, and had moderate-to-marked heterogeneous contrast enhancement. Lysis of hyoid bones was recorded in two carcinomas and infiltration of the lingual artery occurred in one case. Marked medial retropharyngeal lymphoadenomegaly was recorded in 11 of 14 carcinomas, in all sarcomas and in two of four melanomas. The single lymphoma case showed ill-defined thickening of the oropharyngeal and laryngeal wall with retropharyngeal and mandibular lymphadenomegaly. Lung metastases were found in two of five sarcomas and two of four melanomas. Findings from the current study did not support the hypothesis that CT features could be used to predict pharyngeal tumor type in dogs. However, CT was helpful for determining mass extension, lymph node involvement, and distant metastatic spread. PMID:26173553

  15. Computed Tomographic measurement of distal femor rotation in Iranian population

    PubMed Central

    Moghtadaei, Mehdi; Moghimi, Javad; Shahhoseini, Gholamreza

    2015-01-01

    Background: Proper rotation of components in total knee arthroplasty (TKA) will largely affect the postoperative outcome. Ethnical variation may affect rotational profile. We aimed to evaluate distal femur rotation in Iranian population using transepicondylar axes. Methods: From a total of 450 knee CT scans and via consecutive sampling, 150 qualified subjects with normal lower extremities alignment were selected comprising 96 (64%) males and 54 (36%) females aging 17-80 years. The posterior condylar angle and condylar twist angles were defined as angles between either surgical epicondylar axis (line connecting lateral epicondylar prominence and the medial sulcus) or clinical epicondylar axis (line connecting most prominent points of both epicondyle) and posterior conylar line. Data were compared among genders. Results: Average age of our samples was 43 years (ranging 11-80). Mean (±sd) values for posterior condylar angle and condylar twist angles were 2.35º (±1.34) and 5.77º (±1.70), respectively. The former variable was not discernible in twenty of our subjects because of obscure medial sulcus. Our findings were totally appeared similar to studies from other ethnicities and the observed minor differences may have originated from amount of osteoarthritis and malalignment. Conclusion: Overall, Iranian distal femur rotational profile was similar to other reports. Some minor observed differences may be partially due to samples’ age and different amount of knee osteoarthritis. It is proposed to rely on several methods for determining rotational profile while performing TKA. Moreover, preoperative computed tomography should be fully scrutinized especially in severely osteoarthitic knees. PMID:26034722

  16. Coronary Atherosclerotic Plaque Detected by Computed Tomographic Angiography in Subjects with Diabetes Compared to Those without Diabetes

    PubMed Central

    Khazai, Bahram; Luo, Yanting; Rosenberg, Steven; Wingrove, James; Budoff, Matthew J

    2015-01-01

    Objectives Little data are available regarding coronary plaque composition and semi-quantitative scores in individuals with diabetes; the extent to which diabetes may affect the presence and extent of Coronary Artery Calcium (CAC) needs more evaluation. Considering that this information may be of great value in formulating preventive interventions in this population, we compared these findings in individuals with diabetes to those without. Methods Multi-Detector Computed Tomographic (MDCT) images of 861 consecutive patients with diabetes who were referred to Los Angeles Biomedical Research Institute from January 2000 to September 2012, were evaluated using a 15–coronary segment model. All 861 patients underwent calcium scoring and from these; 389 had coronary CT angiography (CTA). CAC score was compared to 861 age, sex and ethnicity matched controls without diabetes after adjustment for Body Mass Index (BMI), family history of coronary artery disease, hyperlipidemia, hypertension and smoking. Segment Involvement Score (SIS; the total number of segments with any plaque), Segment Stenosis Score (SSS; the sum of maximal stenosis score per segment), Total Plaque Score (TPS; the sum of the plaque amount per segment) and plaque compositionwere compared to 389 age, sex and ethnicity matched controls without diabetes after adjustment for BMI, family history of coronary artery disease, hyperlipidemia, hypertension and smoking. Results Diabetes was positively correlated to the presence and extent of CAC (P<0.0001 for both). SIS, SSS and TPS were significantly higher in those with diabetes (P<0.0001). Number of mixed and calcified plaques were significantly higher in those with diabetes (P = 0.018 and P<0.001 respectively) but there was no significant difference in the number of non-calcified plaques between the two groups (P = 0.398). Conclusions Patients with diabetes have higher CAC and semi-quantitative coronary plaque scores compared to the age, gender and ethnicity

  17. Quantification of Vasa Vasorum Density in Multi-Slice Computed Tomographic Coronary Angiograms: Role of Computed Tomographic Image Voxel Size

    SciTech Connect

    Moritz, R.; Eaker, D; Langheinrich, A; Jorgensen, S; Bohle, R; Ritman, E

    2010-01-01

    This study is motivated by the possibility of using computed tomography (CT) to detect early coronary atherosclerosis by the increased CT values within the arterial wall resulting from vasa vasorum proliferation. Coronary arteries (n = 5) with early atherosclerotic changes were injected with Microfil and scanned (micro-CT). Noise was added to the CT projection data sets (to represent the radiation exposure of current clinical CT scanners) and then reconstructed to generate 3-dimensional images at different voxel sizes. Higher CT values were detected because of contrast agent in vasa vasorum if voxel size was less than (150 {micro}m){sup 3}. Contrast in the main lumen increased the CT values dramatically at voxels greater than (100 {micro}m){sup 3}, whereas CT values of the same specimen without contrast in the main lumen remained constant. Voxel sizes less than (200 {micro}m){sup 3} are needed to quantitate arterial wall opacification due to vasa vasorum proliferation.

  18. Magnetic resonance imaging and multi-detector computed tomography assessment of extracellular compartment in ischemic and non-ischemic myocardial pathologies

    PubMed Central

    Saeed, Maythem; Hetts, Steven W; Jablonowski, Robert; Wilson, Mark W

    2014-01-01

    Myocardial pathologies are major causes of morbidity and mortality worldwide. Early detection of loss of cellular integrity and expansion in extracellular volume (ECV) in myocardium is critical to initiate effective treatment. The three compartments in healthy myocardium are: intravascular (approximately 10% of tissue volume), interstitium (approximately 15%) and intracellular (approximately 75%). Myocardial cells, fibroblasts and vascular endothelial/smooth muscle cells represent intracellular compartment and the main proteins in the interstitium are types I/III collagens. Microscopic studies have shown that expansion of ECV is an important feature of diffuse physiologic fibrosis (e.g., aging and obesity) and pathologic fibrosis [heart failure, aortic valve disease, hypertrophic cardiomyopathy, myocarditis, dilated cardiomyopathy, amyloidosis, congenital heart disease, aortic stenosis, restrictive cardiomyopathy (hypereosinophilic and idiopathic types), arrythmogenic right ventricular dysplasia and hypertension]. This review addresses recent advances in measuring of ECV in ischemic and non-ischemic myocardial pathologies. Magnetic resonance imaging (MRI) has the ability to characterize tissue proton relaxation times (T1, T2, and T2*). Proton relaxation times reflect the physical and chemical environments of water protons in myocardium. Delayed contrast enhanced-MRI (DE-MRI) and multi-detector computed tomography (DE-MDCT) demonstrated hyper-enhanced infarct, hypo-enhanced microvascular obstruction zone and moderately enhanced peri-infarct zone, but are limited for visualizing diffuse fibrosis and patchy microinfarct despite the increase in ECV. ECV can be measured on equilibrium contrast enhanced MRI/MDCT and MRI longitudinal relaxation time mapping. Equilibrium contrast enhanced MRI/MDCT and MRI T1 mapping is currently used, but at a lower scale, as an alternative to invasive sub-endomyocardial biopsies to eliminate the need for anesthesia, coronary

  19. Multi-detector computed tomography in the diagnosis and management of acute aortic syndromes

    PubMed Central

    Hallinan, James Thomas Patrick Decourcy; Anil, Gopinathan

    2014-01-01

    Acute aortic syndrome (AAS) is a spectrum of conditions, which may ultimately progress to potentially life-threatening aortic rupture. This syndrome encompasses aortic dissection (AD), intramural haematoma, penetrating atherosclerotic ulcer and unstable thoracic aortic aneurysms. Multi-detector CT (MDCT) is crucial for the diagnosis of AAS, especially in the emergency setting due to its speed, accuracy and ready availability. This review attends to the value of appropriate imaging protocols in obtaining good quality images that can permit a confident diagnosis of AAS. AD is the most commonly encountered AAS and also the one with maximum potential to cause catastrophic outcome if not diagnosed and managed promptly. Hence, this review briefly addresses certain relevant clinical perspectives on this condition. Differentiating the false from the true lumen in AD is often essential; a spectrum of CT findings, e.g., “beak sign”, aortic “cobwebs” that allows such differentiation have been described with explicit illustrations. The value of non enhanced CT scans, especially useful in the diagnosis of an intramural hematoma has also been illustrated. Overlap in the clinical and imaging features of the various conditions presenting as AAS is not unusual. However, on most instances MDCT enables the right diagnosis. On select occasions MRI or trans-esophageal echocardiography may be required as a problem solving tool. PMID:24976936

  20. [PROGNOSTIC VALUE OF SOME HEMOSTASIS-RELATED, HOMOCYSTEINE, HIGH SENSITIVE C R P AND MULTIDETECTOR COMPUTED TOMOGRAPHY PARAMETERS IN PULMONARY EMBOLISM].

    PubMed

    Todua, F; Akhvlediani, M; Vorobiova, E; Baramidze, A; Tsivtsivadze, G; Gachechiladze, D

    2016-05-01

    Nowadays, an arsenal of diagnostic methods is used in diagnosis of pulmonary embolism, which includes x-ray, angiography, perfusion-ventilation scintigraphy, CT and magnetic resonance imaging, Doppler and laboratory studies. Purpose of our study was to evaluate the diagnostic significance of determination of some parameters of hemostasis (D-dimer, Soluble fibrinmonomer complexes, fibrinogen), homocysteine, hs-CRP and multidetector computed tomography in suspected pulmonary embolism. We have examined 54 patients -31 men and 23 women, aged 18 to 76 years, with characteristics of pulmonary embolism. According to our data, Multidetector computed tomography angiopulmonography , measuring D-dimer, fibrinogen and related hyperhomocysteinemia with increased level of hs-CRP may serve as binding, diagnostically significant laboratory markers in the diagnosis and treatment efficacy of pulmonary thromboembolism. PMID:27348165

  1. Stature estimation based on measurements of the sternal medullary cavity using multidetector computed tomography images of Japanese cadavers.

    PubMed

    Torimitsu, Suguru; Makino, Yohsuke; Saitoh, Hisako; Sakuma, Ayaka; Ishii, Namiko; Hayakawa, Mutsumi; Yajima, Daisuke; Inokuchi, Go; Motomura, Ayumi; Chiba, Fumiko; Iwase, Hirotaro

    2014-09-01

    Stature estimation using a skeleton is important for the medicolegal investigation of unidentified human remains. The aims of this study were to identify a correlation between stature and measurements of the sternal medullary cavity using multidetector computed tomography (MDCT) and derive regression equations for stature estimation in the Japanese population. Measurements were conducted on 215 Japanese subjects (107 males, 108 females) who underwent postmortem computed tomography with subsequent forensic autopsy between May 2012 and January 2014. For assessment, MDCT cross-sections through the mid-point of the first costal facets were chosen. The length of a rising diagonal stroke from the bottom left to the top right of the sternal medullary cavity (RS) and the length of a falling diagonal stroke from top left to bottom right of the sternal medullary cavity (FS) were measured. Statistical analyses indicated that both RS and FS were positively correlated with stature regardless of sex. The correlations were stronger for males than for females. The correlation coefficients for RS were higher than those for FS, and standard errors of estimation calculated by regression analysis using RS were lower than those using FS regardless of sex. Measurement of the sternal medullary cavity using MDCT images may be a potentially useful tool for stature estimation, particularly in cases where better predictors such as long bones are not available. PMID:25082372

  2. Experimental Actinobacillus pleuropneumoniae challenge in swine: Comparison of computed tomographic and radiographic findings during disease

    PubMed Central

    2012-01-01

    Background In pigs, diseases of the respiratory tract like pleuropneumonia due to Actinobacillus pleuropneumoniae (App) infection have led to high economic losses for decades. Further research on disease pathogenesis, pathogen-host-interactions and new prophylactic and therapeutic approaches are needed. In most studies, a large number of experimental animals are required to assess lung alterations at different stages of the disease. In order to reduce the required number of animals but nevertheless gather information on the nature and extent of lung alterations in living pigs, a computed tomographic scoring system for quantifying gross pathological findings was developed. In this study, five healthy pigs served as control animals while 24 pigs were infected with App, the causative agent of pleuropneumonia in pigs, in an established model for respiratory tract disease. Results Computed tomographic (CT) findings during the course of App challenge were verified by radiological imaging, clinical, serological, gross pathology and histological examinations. Findings from clinical examinations and both CT and radiological imaging, were recorded on day 7 and day 21 after challenge. Clinical signs after experimental App challenge were indicative of acute to chronic disease. Lung CT findings of infected pigs comprised ground-glass opacities and consolidation. On day 7 and 21 the clinical scores significantly correlated with the scores of both imaging techniques. At day 21, significant correlations were found between clinical scores, CT scores and lung lesion scores. In 19 out of 22 challenged pigs the determined disease grades (not affected, slightly affected, moderately affected, severely affected) from CT and gross pathological examination were in accordance. Disease classification by radiography and gross pathology agreed in 11 out of 24 pigs. Conclusions High-resolution, high-contrast CT examination with no overlapping of organs is superior to radiography in the

  3. Computed tomographic epidurography: an aid to understanding deformation of the lumbar dural sac by epidural injections.

    PubMed

    Fukushige, T; Kano, T; Sano, T; Irie, M

    1999-09-01

    Local anaesthetics injected into the epidural space may deform the dural sac to a variable degree, thereby contributing to variability in the extent of the block. We investigated deformation of the lumbar dural sac after injection into the lumbar epidural space. The subjects were 26 patients with low-back pain who underwent lumbar epidurography and computed tomographic (CT) epidurography, of whom seven also underwent myelography and computed tomographic myelography. The epidural space was entered via the sacral hiatus in 24 patients and through the L5/S1 interspace in two patients. Ten millilitres of local anaesthetic was then injected into the epidural space followed by 20 mL of contrast medium. Computed tomographic epidurography was undertaken approximately 30-min after the epidural injection at the mid-vertebral and mid-discal levels from the first lumbar through to the first sacral vertebrae. The dural sac usually showed an oval or hexagonal shape on the transverse views at the first and second lumbar vertebral levels, and the shape of an inverted triangle below the level of the third lumbar vertebra. A median line of translucency was also observed on the posteroanterior epidurographic view in 25 of the 26 patients. This line was though to be a manifestation of the dural deformation to the inverted triangle. Dural sac deformation usually shows a specific pattern, although there are individual variations. Dural deformability is an important consideration in any analysis of the spread of epidural block or of the changes of epidural pressure after epidural injection of local anaesthetics. PMID:10549463

  4. Sonography of Gastrointestinal Tract Diseases: Correlation With Computed Tomographic Findings and Endoscopy.

    PubMed

    Ahn, Sung Eun; Moon, Sung Kyoung; Lee, Dong Ho; Park, Seong Jin; Lim, Joo Won; Kim, Hyun Cheol; Lee, Han Na

    2016-07-01

    Sonographic evaluation of the gastrointestinal (GI) tract may be difficult because of overlying intraluminal bowel gas and gas-related artifacts. However, in the absence of these factors and with the development of high-resolution scanners and the technical experience of radiologists, sonography can become a powerful tool for GI tract assessment. This pictorial essay focuses on sonographic findings of GI tract lesions compared with endoscopic, computed tomographic, and magnetic resonance imaging findings. Neoplastic and non-neoplastic diseases and postoperative complications are illustrated, and the distinctive sonographic characteristics of these entities are highlighted. PMID:27268998

  5. The computed tomographic appearance of cerebral cysticercosis in adults and children

    SciTech Connect

    Byrd, S.E.; Locke, G.E.; Biggers, S.; Percy, A.K.

    1982-09-01

    The computed tomographic (CT) scans of 45 patients (30 adults, 15 children) with cerebral cysticercosis were reviewed. These patients had undergone complete diagnostic evaluations including skin tests, laboratory tests, plain skull radiography, radionuclide brain scanning, CT, and cerebral angiography. All of these tests were unrewarding except CT and the indirect hemagglutination tests on the serum. A classification of cerebral cysticercosis based on the location of the lesions in the brain and the CT appearance was developed. Cerebral cysticercosis can be diagnosed by CT findings when there is also a history of seizures and of the patient having lived in an area where the disease is endemic.

  6. Use of spiral computed tomographic angiography in monitoring abdominal aortic aneurysms after transfemoral endovascular repair.

    PubMed Central

    Balm, R; Jacobs, M J

    1997-01-01

    Transfemoral endovascular repair of abdominal aortic aneurysms has proved to be technically feasible in a selected group of patients. However, long-term efficacy has not been proved. Graft performance after implantation can be monitored by a single imaging technique: spiral computed tomographic angiography. With this technique, the parameters for continuing clinical success of the procedure-graft patency, endoleaks, graft migration, attachment site diameter, attachment system failure, and aneurysm diameter-can be monitored. Only in selected cases will an additional imaging technique be necessary. PMID:9339508

  7. Conventional metrizamide myelography (MM) and computed tomographic metrizamide myelography (CTMM) in scoliosis: a comparative study

    SciTech Connect

    Pettersson, H.; Harwood-Nash, D.C.; Fitz, C.R.; Chuang, H.S.; Armstrong, E.

    1982-01-01

    A retrospective examination was performed to assess the accuracy of metrizamide myelography (MM) and computed tomographic metrizamide myelography (CTMM) in scoliosis. Of 81 consecutive scoliotic children studied by myelography, 30 had only MM while the remaining 51 had CTMM immediately afterward. CTMM added esential diagnostic information in 13 cases of dysraphism and 4 cases, both methods gave the same imformation. The outhors conclude that in patients with severe scoliosis, dysraphism, and scoliosis with localized neurological disturbances, CTMM should always be added to MM or be the only examination; while in idiopathic scoliosis with vague neurological disturbances a survey of the entire spine is essential, preferably with MM.

  8. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

    PubMed Central

    Dong, Zhi-hui; Yang, Zhi-gang; Chen, Tian-wu; Chu, Zhi-gang; Deng, Wen; Shao, Heng

    2011-01-01

    PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR = 1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR = 1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR = 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR = 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR = 1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries. PMID:21789386

  9. MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY PATTERNS OF BRONCHOESPHAGEAL ARTERY HYPERTROPHY AND SYSTEMIC-TO-PULMONARY FISTULA IN DOGS.

    PubMed

    Ledda, Gianluca; Caldin, Marco; Mezzalira, Giorgia; Bertolini, Giovanna

    2015-01-01

    Anomalies involving arterial branches in the lungs are one of the causes of hemoptysis in humans and dogs. Congenital and acquired patterns of bronchoesophageal artery hypertrophy have been reported in humans based on CT characteristics. The purpose of this retrospective study was to describe clinical, echocardiographic, and multidetector computed tomography features of bronchoesophageal artery hypertrophy and systemic-to-pulmonary arterial communications in a sample of 14 dogs. Two main vascular patterns were identified in dogs that resembled congenital and acquired conditions reported in humans. Pattern 1 appeared as an aberrant origin of the right bronchoesophageal artery, normal origin of the left one, and enlargement of both the bronchial and esophageal branches that formed a dense network terminating in a pulmonary artery through an orifice. Pattern 2 appeared as a normal origin of both right and left bronchoesophageal arteries, with an enlarged and tortuous course along the bronchi to the periphery of the lung, where they communicated with subsegmental pulmonary arteries. Dogs having Pattern 1 also had paraesophageal and esophageal varices, with the latter being confirmed by videoendoscopy examination. Authors conclude that dogs with Pattern 1 should be differentiated from dogs with other congenital vascular systemic-to-pulmonary connections. Dogs having Pattern 2 should be evaluated for underlying pleural or pulmonary diseases. Bronchoesophageal artery hypertrophy can be accompanied by esophageal venous engorgement and should be included in the differential diagnosis for esophageal and paraesophageal varices in dogs. PMID:25961802

  10. The value of computed tomographic metrizamide myelography in the neuroradiological evaluation of the spine

    SciTech Connect

    Dublin, A.B.; McGahan, J.P.; Reid, M.H.

    1983-01-01

    The diagnostic value of plain film metrizamide myelopgraphy (PFMM) was compared with computed tomographic metrizamide myelography (CTMM) in a study of 106 individuals who had undergone high-resolution computed tomographic scanning of the spine. CTMM provided more significant information than PFMM in 42 of 106 cases (40%), but showed no advantage over PFMM in 63 of 106 cases (59%). In 19 of the 42 cases (45%), PFMM was useful in directing the CT analysis to the appropriate region of pathology. In one patient, PFMM revealed a mobile herniated disc that had not been visualized with CTMM. In 30 of 106 cases in which plain CT scans of the spine were also obtained, the addition of intrathecal metrizamide demonstrated additional pathology in ten individuals. In general, CTMM was useful in the delineation of a variety of pathologic entities, especially neoplasms and congenital abnormalities. Low-dose CTMM (3 ml of a 150 ml/mg concentration) was performed as an outpatient procedure and found to be a useful adjunct to plain CT in two patients. A schema for the radiological evaluation of pathology of the spine is presented.

  11. PATHOLOGIC BASIS FOR RIM ENHANCEMENT OBSERVED IN COMPUTED TOMOGRAPHIC IMAGES OF FELINE NASOPHARYNGEAL POLYPS.

    PubMed

    Lamb, Christopher R; Sibbing, Kendall; Priestnall, Simon L

    2016-03-01

    In postcontrast computed tomographic (CT) images, feline nasopharyngeal polyps typically demonstrate enhancement of the peripheral rim. Computed tomographic images and histologic specimens of a case series of 22 cats with surgically removed nasopharyngeal polyps were reviewed retrospectively in an attempt to elucidate the origin of rim enhancement. Polyps were present in the tympanic cavity in 15 (68%) cats (three with extension into the nasopharynx), only in the nasopharynx in four (18%) cats, and only in the external ear canal in the remaining three (14%) cats. All polyps had variable degrees of epithelial injury. Hemorrhage and inflammatory infiltration were significantly more marked in the superficial stroma whereas edema was significantly more marked in the core stroma. In noncontrast CT images (n = 22), the tympanic bulla was thickened in all 15 cats with a polyp in the tympanic cavity and enlarged in eight (53%) of these cats. In postcontrast CT images (n = 15), an outer zone of relatively increased attenuation compatible with a rim was observed in 11 (73%) polyps. The magnitude and extent of rim enhancement in CT images was positively correlated with the histologic grade of inflammation in the superficial stroma and negatively correlated with the grade of edema in the superficial stroma. It appears that inflammation is the major determinant of contrast medium accumulation in feline nasopharyngeal polyps, and the tendency for inflammation to affect predominantly the superficial layers explains the frequent observation of a rim in postcontrast CT images. PMID:26763944

  12. Myocardial bridging of the right coronary artery inside the right atrial myocardium identified by ECG-gated 64-slice multidetector computed tomography angiography.

    PubMed

    Chen, Chien-Cheng; Chen, Huan-Wu; Fu, Chen-Ju; Lin, Fen-Chiung; Wen, Ming-Shien; Liu, Yuan-Chang

    2010-01-01

    A myocardial bridge (MB) is defined as an intramyocardial course of a major epicardial coronary artery, and it is mainly confined to the left ventricle and the left anterior descending coronary artery. There are rare reports of right coronary MB seen during angiographic examination. Herein, we present a 49 year-old man with right coronary artery MB without luminal narrowing in the diastolic and systolic phases of electrocardiography-gated computed tomography images. The value of multi-detector computed tomography for the detection of anatomical variants in the cardiovascular system is further discussed. PMID:20438676

  13. COMPUTED TOMOGRAPHIC AND ULTRASONOGRAPHIC CHARACTERISTICS OF CAVERNOUS TRANSFORMATION OF THE OBSTRUCTED PORTAL VEIN IN SMALL ANIMALS.

    PubMed

    Specchi, Swan; Pey, Pascaline; Ledda, Gianluca; Lustgarten, Meghann; Thrall, Donald; Bertolini, Giovanna

    2015-01-01

    In humans, the process of development of collateral vessels with hepatopetal flow around the portal vein in order to bypass an obstruction is called "cavernous transformation of the portal vein." The purpose of this retrospective, cross-sectional, multicentric study was to describe presumed cavernous transformation of the portal vein in small animals with portal vein obstruction using ultrasound and multidetector-row computed tomography (MDCT). Databases from three different institutions were searched for patients with an imaging diagnosis of cavernous transformation of the portal vein secondary to portal vein obstruction of any cause. Images were retrieved and reanalyzed. With MDCT-angiography, two main portoportal collateral pathways were identified: short tortuous portoportal veins around/inside the thrombus and long portoportal collaterals bypassing the site of portal obstruction. Three subtypes of the long collaterals, often coexisting, were identified. Branches of the hepatic artery where involved in collateral circulation in nine cases. Concomitant acquired portosystemic shunts were identified in six patients. With ultrasound, cavernous transformation of the portal vein was suspected in three dogs and one cat based on visualization of multiple and tortuous vascular structures corresponding to periportal collaterals. In conclusion, the current study provided descriptive MDCT and ultrasonographic characteristics of presumed cavernous transformation of the portal vein in a sample of small animals. Cavernous transformation of the portal vein could occur as a single condition or could be concurrent with acquired portosystemic shunts. PMID:25877678

  14. Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars

    PubMed Central

    Sharma, Pranjal; Swamy, Dinesh Francis; Shashidara, R; Swamy, Elaine Barretto

    2015-01-01

    ABSTRACT Need for the study: The most important procedure for a successful endodontic treatment is the cleaning and shaping of the canal system. Understanding the internal anatomy of teeth provides valuable information to the clinician that would help him achieve higher clinical success during endodontic therapy. Aims: To evaluate by computed tomography—the internal anatomy of mandibular second primary molars with respect to the number of canals, cross-sectional shape of canals, cross-sectional area of canals and the root dentin thickness. Materials and methods: A total of 31 mandibular second primary molars were subjected to computed-tomographic evaluation in the transverse plane, after mounting them in a prefabricated template. The images, thus, obtained were analyzed using De-winter Bio-wizard® software. Results: All the samples demonstrated two canals in the mesial root, while majority of the samples (65.48%) demonstrated two canals in the distal root. The cross-sectional images of the mesial canals demonstrated a round shape, while the distal canals demonstrated an irregular shape. The root dentin thickness was highly reduced on the distal aspect of mesial and mesial aspect of distal canals. Conclusion: The mandibular second primary molars demonstrated wide variation and complexities in their internal anatomy. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, determining the apical limits and dimensions of canal preparations, and for performing successful endodontic procedures. How to cite this article: Kurthukoti AJ, Sharma P, Swamy DF, Shashidara R, Swamy EB. Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars. Int J Clin Pediatr Dent 2015;8(3):202-207. PMID:26628855

  15. Multidetector computed tomography angiography for assessment of in-stent restenosis: meta-analysis of diagnostic performance

    PubMed Central

    Vanhoenacker, Piet K; Decramer, Isabel; Bladt, Olivier; Sarno, Giovanna; Van Hul, Erik; Wijns, William; Dwamena, Ben A

    2008-01-01

    Background Multi-detector computed tomography angiography (MDCTA)of the coronary arteries after stenting has been evaluated in multiple studies. The purpose of this study was to perform a structured review and meta-analysis of the diagnostic performance of MDCTA for the detection of in-stent restenosis in the coronary arteries. Methods A Pubmed and manual search of the literature on in-stent restenosis (ISR) detected on MDCTA compared with conventional coronary angiography (CA) was performed. Bivariate summary receiver operating curve (SROC) analysis, with calculation of summary estimates was done on a stent and patient basis. In addition, the influence of study characteristics on diagnostic performance and number of non-assessable segments (NAP) was investigated with logistic meta-regression. Results Fourteen studies were included. On a stent basis, Pooled sensitivity and specificity were 0.82(0.72–0.89) and 0.91 (0.83–0.96). Pooled negative likelihood ratio and positive likelihood ratio were 0.20 (0.13–0.32) and 9.34 (4.68–18.62) respectively. The exclusion of non-assessable stents and the strut thickness of the stents had an influence on the diagnostic performance. The proportion of non-assessable stents was influenced by the number of detectors, stent diameter, strut thickness and the use of an edge-enhancing kernel. Conclusion The sensitivity of MDTCA for the detection of in-stent stenosis is insufficient to use this test to select patients for further invasive testing as with this strategy around 20% of the patients with in-stent stenosis would be missed. Further improvement of scanner technology is needed before it can be recommended as a triage instrument in practice. In addition, the number of non-assessable stents is also high. PMID:18671850

  16. Relationship between Coronary Artery Calcium Score by Multidetector Computed Tomography and Plaque Components by Virtual Histology Intravascular Ultrasound

    PubMed Central

    Choi, Yun Ha; Park, In Hyae; Jeong, Myung Ho; Ahmed, Khurshid; Hwang, Seung Hwan; Lee, Min Goo; Park, Keun-Ho; Sim, Doo Sun; Kim, Ju Han; Ahn, Youngkeun; Cho, Jeong Gwan; Park, Jong Chun; Kang, Jung Chaee

    2011-01-01

    The aim of this study was to evaluate the relationship between coronary artery calcium score (CACS) assessed by multidetector computed tomography (MDCT) and plaque components assessed by virtual histology-intravascular ultrasound (VH-IVUS) in 172 coronary artery disease (CAD) patients with 250 coronary lesions. CACS was assessed according to Agatston scoring method by MDCT and patients were divided into four groups: Group I (CACS = 0 [n = 52]); Group II (CACS = 1-100 [n = 99]); Group III (CACS = 101-400 [n = 84]); and Group IV (CACS > 400 [n = 15]). Total atheroma volume was greatest in Group IV (152 ± 132 µL vs 171 ± 114 µL vs 195 ± 149 µL vs 321±182 µL, P < 0.001). The absolute dense calcium (DC) and necrotic core (NC) volumes were greatest, and relative DC volume was greatest in Group IV (5.5 ± 6.6 µL vs 11.0 ± 10.3 µL vs 15.6 ± 13.6 µL vs 36.6 ± 18.2 µL, P < 0.001, and 14.8 ± 18.2 µL vs 19.5 ± 18.9 µL vs 22.5 ± 19.1 µL vs 41.7 ± 27.9 µL, P < 0.001, and 6.4 ± 5.3% vs 11.0 ± 6.2% vs 14.0 ± 6.5% vs 20.0 ± 7.8%, P < 0.001, respectively). The absolute plaque and DC and NC volumes and the relative DC volume correlated positively with calcium score. CAD patients with high calcium score have more vulnerable plaque components (greater DC and NC-containing plaques) than those with low calcium score. PMID:21860556

  17. Multidetector computed tomography versus platelet/spleen diameter ratio as methods for the detection of gastroesophageal varices

    PubMed Central

    Karatzas, Andreas; Triantos, Christos; Kalafateli, Maria; Marzigie, Misiel; Labropoulou-Karatza, Chryssoula; Thomopoulos, Konstantinos; Petsas, Theodoros; Kalogeropoulou, Christina

    2016-01-01

    Background All patients with liver cirrhosis should undergo screening endoscopy, but there are limitations and this approach places a heavy burden upon endoscopy units. The aim of this study was to compare multidetector computed tomography (MDCT) and the platelet/spleen diameter ratio as non-invasive methods for the detection of gastroesophageal varices. Methods The study included 38 cirrhotics who underwent upper gastrointestinal (GI) endoscopy and MDCT within one month. Two radiologists reviewed the scans, in order to determine the presence and the size of varices. Blood tests and measurement of the spleen maximum diameter were also carried out and the platelet/spleen diameter ratio was calculated. Endoscopy was considered the gold standard and the results of the two methods were compared to it. Results Varices were detected by upper GI endoscopy in 24 of 38 patients. The mean sensitivity and specificity of MDCT for the two observers was 86.1% and 57.1% respectively. In patients with large varices (>5 mm), the sensitivity was 100% (4/4). Using 909 as a cut-off value of the platelet/spleen diameter ratio this method yielded a sensitivity of 56.5% and a specificity of 35.7%. The difference in sensitivity and specificity between the two methods was statistically significant P<0.05. Conclusion MDCT was accurate for the detection of gastroesophageal varices, especially those with clinically significant size (>5 mm), and superior to platelet/spleen diameter ratio. MDCT could replace, in selected patients, upper GI endoscopy as a method for detecting gastroesophageal varices in cirrhotic patients. PMID:26751694

  18. Optical tomographic detection of rheumatoid arthritis with computer-aided classification schemes

    NASA Astrophysics Data System (ADS)

    Klose, Christian D.; Klose, Alexander D.; Netz, Uwe; Beuthan, Jürgen; Hielscher, Andreas H.

    2009-02-01

    A recent research study has shown that combining multiple parameters, drawn from optical tomographic images, leads to better classification results to identifying human finger joints that are affected or not affected by rheumatic arthritis RA. Building up on the research findings of the previous study, this article presents an advanced computer-aided classification approach for interpreting optical image data to detect RA in finger joints. Additional data are used including, for example, maximum and minimum values of the absorption coefficient as well as their ratios and image variances. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index and area under the curve AUC. Results were compared to different benchmarks ("gold standard"): magnet resonance, ultrasound and clinical evaluation. Maximum accuracies (AUC=0.88) were reached when combining minimum/maximum-ratios and image variances and using ultrasound as gold standard.

  19. Rare Root Canal Configuration of Bilateral Maxillary Second Molar Using Cone-beam Computed Tomographic Scanning.

    PubMed

    Zeng, Chang; Shen, Ya; Guan, Xiaoyue; Wang, Xin; Fan, Mingwen; Li, Yuhong

    2016-04-01

    The aim of this article was to present a right maxillary second molar with an unusual root canal morphology of 4 roots and 5 canals as confirmed by cone-beam computed tomographic (CBCT) imaging. The tooth had a C-shaped mesiobuccal root (CBCT imaging revealed that the root was closer to the palate than the buccal side) with 2 canals, 2 fused distobuccal roots with 2 separate canals, and 1 normal bulky palatal root with 1 canal. After thoroughly examining the rare anatomy, root canal treatment was applied on the tooth. This article shows the complexity of maxillary second molar variation and shows the significance of CBCT imaging in the confirmation of the 3-dimensional anatomy of teeth and endodontic treatment. PMID:26920931

  20. Computed tomographic findings in children with spastic diplegia: correlation with the severity of their motor abnormality.

    PubMed

    Yokochi, K; Horie, M; Inukai, K; Kito, H; Shimabukuro, S; Kodama, K

    1989-01-01

    Computed tomographic findings of 46 children with spastic diplegia examined at nine months to three years of age corrected for preterm births were analyzed. Both the size of the lateral ventricles measured by the width of the anterior horns, and the volume of the extracerebral low-density areas were enlarged in some patients. Both enlargements did not, however, correlate to the severity of the motor abnormality in the patients. The low-density areas of the periventricular white matter, especially adjacent to the trigone, were reduced in many children, probably due to the atrophy of the cerebral white matter having periventricular leukomalacia. The anterior expansion of the white matter reduction from the trigone corresponded to the severe motor abnormality in the children with spastic diplegia. PMID:2774092

  1. Myocardial stunning in hypertrophic cardiomyopathy: recovery predicted by single photon emission computed tomographic thallium-201 scintigraphy

    SciTech Connect

    Fine, D.G.; Clements, I.P.; Callahan, M.J.

    1989-05-01

    A young woman with hypertrophic cardiomyopathy confirmed by echocardiography and cardiac catheterization presented with chest pain and features of a large left ventricular aneurysm. The initial diagnosis was myocardial ischemia with either an evolving or an ancient myocardial infarction. Subsequently, verapamil therapy was associated with complete resolution of the extensive left ventricular wall motion abnormalities, normalization of left ventricular ejection fraction and a minimal myocardial infarction. Normal thallium uptake on single photon emission computed tomographic scintigraphy early in the hospital course predicted myocardial viability in the region of the aneurysm. Thus, orally administered verapamil may reverse spontaneous extensive myocardial ischemia in hypertrophic cardiomyopathy and possibly limit the extent of myocardial infarction in such circumstances.

  2. The spine in 3D. Computed tomographic reformation from 2D axial sections.

    PubMed

    Virapongse, C; Gmitro, A; Sarwar, M

    1986-01-01

    A new program (3D83, General Electric) was used to reformat three-dimensional (3D) images from two-dimensional (2D) computed tomographic axial scans in 18 patients who had routine scans of the spine. The 3D spine images were extremely true to life and could be rotated around all three principle axes (constituting a movie), so that an illusion of head-motion parallax was created. The benefit of 3D reformation with this program is primarily for preoperative planning. It appears that 3D can also effectively determine the patency of foraminal stenosis by reformatting in hemisections. Currently this program is subject to several drawbacks that require user interaction and long reconstruction time. With further improvement, 3D reformation will find increasing clinical applicability. PMID:3787319

  3. Computed tomographic evidence of atherosclerosis in the mummified remains of humans from around the world.

    PubMed

    Thompson, Randall C; Allam, Adel H; Zink, Albert; Wann, L Samuel; Lombardi, Guido P; Cox, Samantha L; Frohlich, Bruno; Sutherland, M Linda; Sutherland, James D; Frohlich, Thomas C; King, Samantha I; Miyamoto, Michael I; Monge, Janet M; Valladolid, Clide M; El-Halim Nur El-Din, Abd; Narula, Jagat; Thompson, Adam M; Finch, Caleb E; Thomas, Gregory S

    2014-06-01

    Although atherosclerosis is widely thought to be a disease of modernity, computed tomographic evidence of atherosclerosis has been found in the bodies of a large number of mummies. This article reviews the findings of atherosclerotic calcifications in the remains of ancient people-humans who lived across a very wide span of human history and over most of the inhabited globe. These people had a wide range of diets and lifestyles and traditional modern risk factors do not thoroughly explain the presence and easy detectability of this disease. Nontraditional risk factors such as the inhalation of cooking fire smoke and chronic infection or inflammation might have been important atherogenic factors in ancient times. Study of the genetic and environmental risk factors for atherosclerosis in ancient people may offer insights into this common modern disease. PMID:25667088

  4. Beyond Coronary Stenosis: Coronary Computed Tomographic Angiography for the Assessment of Atherosclerotic Plaque Burden

    PubMed Central

    Kwan, Alan C; Cater, George; Vargas, Jose

    2013-01-01

    Coronary computed tomographic angiography (CCTA) is emerging as a key non-invasive method for assessing cardiovascular risk by measurement of coronary stenosis and coronary artery calcium (CAC). New advancements in CCTA technology have led to the ability to directly identify and quantify the so-called “vulnerable” plaques that have features of positive remodeling and low density components. In addition, CCTA presents a new opportunity for noninvasive measurement of total coronary plaque burden that has not previously been available. The use of CCTA needs also to be balanced by its risks and, in particular, the associated radiation exposure. We review current uses of CCTA, CCTA’s ability to measure plaque quantity and characteristics, and new developments in risk stratification and CCTA technology. CCTA represents a quickly developing field that will play a growing role in the non-invasive management of cardiovascular disease. PMID:23524381

  5. Fluoroscopic and computed tomographic features of the pharyngeal airway in obstructive sleep apnea.

    PubMed

    Suratt, P M; Dee, P; Atkinson, R L; Armstrong, P; Wilhoit, S C

    1983-04-01

    Because it has been suggested that patients with obstructive sleep apnea have a narrower pharyngeal airway than normal persons, we performed lateral fluoroscopy and computed tomographic (CT) scans of the pharynx in patients with this syndrome. Fluoroscopy in 6 sleeping patients showed that the obstruction always began during inspiration when the soft palate touched the tongue and posterior pharyngeal wall. The CT scans in 9 awake subjects demonstrated that the narrowest section of the airway in patients and in control subjects was the region posterior to the soft palate. The cross-sectional area of this region was significantly narrower in patients than it was in control subjects (p less than 0.001). Because a narrow airway would be more likely to collapse during inspiration than a normal one would (Bernoulli's Principle), we conclude that the narrow airways we observed in awake patients may be an important contributing factor in the pathogenesis of obstructive sleep apnea. PMID:6838055

  6. Development of the two Korean adult tomographic computational phantoms for organ dosimetry

    SciTech Connect

    Lee, Choonsik; Lee, Choonik; Park, Sang-Hyun; Lee, Jai-Ki

    2006-02-15

    Following the previously developed Korean tomographic phantom, KORMAN, two additional whole-body tomographic phantoms of Korean adult males were developed from magnetic resonance (MR) and computed tomography (CT) images, respectively. Two healthy male volunteers, whose body dimensions were fairly representative of the average Korean adult male, were recruited and scanned for phantom development. Contiguous whole body MR images were obtained from one subject exclusive of the arms, while whole-body CT images were acquired from the second individual. A total of 29 organs and tissues and 19 skeletal sites were segmented via image manipulation techniques such as gray-level thresholding, region growing, and manual drawing, in which each of segmented image slice was subsequently reviewed by an experienced radiologist for anatomical accuracy. The resulting phantoms, the MR-based KTMAN-1 (Korean Typical MAN-1) and the CT-based KTMAN-2 (Korean Typical MAN-2), consist of 300x150x344 voxels with a voxel resolution of 2x2x5 mm{sup 3} for both phantoms. Masses of segmented organs and tissues were calculated as the product of a nominal reference density, the prevoxel volume, and the cumulative number of voxels defining each organs or tissue. These organs masses were then compared with those of both the Asian and the ICRP reference adult male. Organ masses within both KTMAN-1 and KTMAN-2 showed differences within 40% of Asian and ICRP reference values, with the exception of the skin, gall bladder, and pancreas which displayed larger differences. The resulting three-dimensional binary file was ported to the Monte Carlo code MCNPX2.4 to calculate organ doses following external irradiation for illustrative purposes. Colon, lung, liver, and stomach absorbed doses, as well as the effective dose, for idealized photon irradiation geometries (anterior-posterior and right lateral) were determined, and then compared with data from two other tomographic phantoms (Asian and Caucasian), and

  7. Fractional Flow Reserve and Coronary Computed Tomographic Angiography: A Review and Critical Analysis.

    PubMed

    Hecht, Harvey S; Narula, Jagat; Fearon, William F

    2016-07-01

    Invasive fractional flow reserve (FFR) is now the gold standard for intervention. Noninvasive functional imaging analyses derived from coronary computed tomographic angiography (CTA) offer alternatives for evaluating lesion-specific ischemia. CT-FFR, CT myocardial perfusion imaging, and transluminal attenuation gradient/corrected contrast opacification have been studied using invasive FFR as the gold standard. CT-FFR has demonstrated significant improvement in specificity and positive predictive value compared with CTA alone for predicting FFR of ≤0.80, as well as decreasing the frequency of nonobstructive invasive coronary angiography. High-risk plaque characteristics have also been strongly implicated in abnormal FFR. Myocardial computed tomographic perfusion is an alternative method with promising results; it involves more radiation and contrast. Transluminal attenuation gradient/corrected contrast opacification is more controversial and may be more related to vessel diameter than stenosis. Important considerations remain: (1) improvement of CTA quality to decrease unevaluable studies, (2) is the diagnostic accuracy of CT-FFR sufficient? (3) can CT-FFR guide intervention without invasive FFR confirmation? (4) what are the long-term outcomes of CT-FFR-guided treatment and how do they compare with other functional imaging-guided paradigms? (5) what degree of stenosis on CTA warrants CT-FFR? (6) how should high-risk plaque be incorporated into treatment decisions? (7) how will CT-FFR influence other functional imaging test utilization, and what will be the effect on the practice of cardiology? (8) will a workstation-based CT-FFR be mandatory? Rapid progress to date suggests that CTA-based lesion-specific ischemia will be the gatekeeper to the cardiac catheterization laboratory and will transform the world of intervention. PMID:27390333

  8. A Case of Coronary Cameral Fistula with Associated Aneurysm: Role of ECG Gated 256- Slice Dual Source Multidetector Computed Tomography in Diagnosis

    PubMed Central

    Garg, Lalit; Rissam, Harmeet Kaur; Puri, Sunil Kumar

    2016-01-01

    We report an interesting case of coronary cameral fistula with associated aneurysmal dilatation of coronary artery. The complete evaluation including anatomical relationships with surrounding vascular and non-vascular structures can be achieved with ECG gated multi-detector computed tomography (MDCT). MDCT has many advantages over echocardiography and digital subtraction catheter angiography, because of its ability to demonstrate the fistula separate from surrounding cardiovascular structures along with any aneurysm or obstruction in its course. Thus, MDCT is emerging as the initial non-invasive imaging technique for comprehensive preoperative evaluation of these rare congenital anomalies for cardiovascular surgeons to achieve better operative assessibity and outcome. PMID:27437325

  9. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws: A Phantom Study.

    PubMed

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M

    2015-08-01

    To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner.We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy.The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences.Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  10. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws

    PubMed Central

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M.

    2015-01-01

    Abstract To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner. We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy. The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences. Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  11. Advances in imaging protocols for cardiac MDCT: from 16- to 64-row multidetector computed tomography.

    PubMed

    Kopp, Andreas F; Heuschmid, Martin; Reimann, Anja; Kuettner, Axel; Beck, Thorsten; Burgstahler, Christoph; Brodoefel, Harald; Claussen, Claus D; Schroeder, Stephen

    2005-12-01

    Coronary artery disease (CAD) is the leading cause of morbidity and mortality in the Western world. Since the majority of all invasive diagnostic coronary angiography procedures are not followed by therapeutic interventions, interest is growing in noninvasive technologies to diagnose and visualize CAD. The most promising of these is multislice spiral computed tomography (MSCT), which can visualize human coronary arteries in vivo noninvasively. Since 1999, this technique has improved rapidly, offering faster gantry rotation times and smaller voxel sizes. The image quality has become significantly more stable and MSCT has become a robust imaging modality. Beginning with 4-slice scanners in 1999, the latest scanner generation employs 64 slices. The present article summarizes the technical principles, image protocols and possible clinical applications of the current 64-row scanners. PMID:18637233

  12. Criteria for establishing shielding of multi-detector computed tomography (MDCT) rooms.

    PubMed

    Verdun, F R; Aroua, A; Baechler, S; Schmidt, S; Trueb, P R; Bochud, F O

    2010-01-01

    The aim of this work is to compare two methods used for determining the proper shielding of computed tomography (CT) rooms while considering recent technological advances in CT scanners. The approaches of the German Institute for Standardisation and the US National Council on Radiation Protection and Measurements were compared and a series of radiation measurements were performed in several CT rooms at the Lausanne University Hospital. The following three-step procedure is proposed for assuring sufficient shielding of rooms hosting new CT units with spiral mode acquisition and various X-ray beam collimation widths: (1) calculate the ambient equivalent dose for a representative average weekly dose length product at the position where shielding is required; (2) from the maximum permissible weekly dose at the location of interest, calculate the transmission factor F that must be taken to ensure proper shielding and (3) convert the transmission factor into a thickness of lead shielding. A similar approach could be adopted to use when designing shielding for fluoroscopy rooms, where the basic quantity would be the dose area product instead of the load of current (milliampere-minute). PMID:20215444

  13. Distribution of Mitral Annular and Aortic Valve Calcium as Assessed by Unenhanced Multidetector Computed Tomography.

    PubMed

    Koshkelashvili, Nikoloz; Codolosa, Jose N; Goykhman, Igor; Romero-Corral, Abel; Pressman, Gregg S

    2015-12-15

    Aging is associated with calcium deposits in various cardiovascular structures, but patterns of calcium deposition, if any, are unknown. In search of such patterns, we performed quantitative assessment of mitral annular calcium (MAC) and aortic valve calcium (AVC) in a broad clinical sample. Templates were created from gated computed tomography (CT) scans depicting the aortic valve cusps and mitral annular segments in relation to surrounding structures. These were then applied to CT reconstructions from ungated, clinically indicated CT scans of 318 subjects, aged ≥65 years. Calcium location was assigned using the templates and quantified by the Agatston method. Mean age was 76 ± 7.3 years; 48% were men and 58% were white. Whites had higher prevalence (p = 0.03) and density of AVC than blacks (p = 0.02), and a trend toward increased MAC (p = 0.06). Prevalence of AVC was similar between men and women, but AVC scores were higher in men (p = 0.008); this difference was entirely accounted for by whites. Within the aortic valve, the left cusp was more frequently calcified than the others. MAC was most common in the posterior mitral annulus, especially its middle (P2) segment. For the anterior mitral annulus, the medial (A3) segment calcified most often. In conclusion, AVC is more common in whites than blacks, and more intense in men, but only in whites. Furthermore, calcium deposits in the mitral annulus and aortic valve favor certain locations. PMID:26517948

  14. Visual vs Fully Automatic Histogram-Based Assessment of Idiopathic Pulmonary Fibrosis (IPF) Progression Using Sequential Multidetector Computed Tomography (MDCT)

    PubMed Central

    Colombi, Davide; Dinkel, Julien; Weinheimer, Oliver; Obermayer, Berenike; Buzan, Teodora; Nabers, Diana; Bauer, Claudia; Oltmanns, Ute; Palmowski, Karin; Herth, Felix; Kauczor, Hans Ulrich; Sverzellati, Nicola

    2015-01-01

    Objectives To describe changes over time in extent of idiopathic pulmonary fibrosis (IPF) at multidetector computed tomography (MDCT) assessed by semi-quantitative visual scores (VSs) and fully automatic histogram-based quantitative evaluation and to test the relationship between these two methods of quantification. Methods Forty IPF patients (median age: 70 y, interquartile: 62-75 years; M:F, 33:7) that underwent 2 MDCT at different time points with a median interval of 13 months (interquartile: 10-17 months) were retrospectively evaluated. In-house software YACTA quantified automatically lung density histogram (10th-90th percentile in 5th percentile steps). Longitudinal changes in VSs and in the percentiles of attenuation histogram were obtained in 20 untreated patients and 20 patients treated with pirfenidone. Pearson correlation analysis was used to test the relationship between VSs and selected percentiles. Results In follow-up MDCT, visual overall extent of parenchymal abnormalities (OE) increased in median by 5 %/year (interquartile: 0 %/y; +11 %/y). Substantial difference was found between treated and untreated patients in HU changes of the 40th and of the 80th percentiles of density histogram. Correlation analysis between VSs and selected percentiles showed higher correlation between the changes (Δ) in OE and Δ 40th percentile (r=0.69; p<0.001) as compared to Δ 80th percentile (r=0.58; p<0.001); closer correlation was found between Δ ground-glass extent and Δ 40th percentile (r=0.66, p<0.001) as compared to Δ 80th percentile (r=0.47, p=0.002), while the Δ reticulations correlated better with the Δ 80th percentile (r=0.56, p<0.001) in comparison to Δ 40th percentile (r=0.43, p=0.003). Conclusions There is a relevant and fully automatically measurable difference at MDCT in VSs and in histogram analysis at one year follow-up of IPF patients, whether treated or untreated: Δ 40th percentile might reflect the change in overall extent of lung

  15. The role of 64-slice multi-detector computed tomography in the detection of subclinical atherosclerosis of the coronary artery.

    PubMed

    Jeong, Hae Chang; Ahn, Youngkeun; Ko, Jum Suk; Lee, Min Goo; Sim, Doo Sun; Park, Keun Ho; Yoon, Nam Sik; Youn, Hyun Ju; Hong, Young Joon; Kim, Kye Hun; Park, Hyung Wook; Kim, Ju Han; Kim, Yun-Hyeon; Jeong, Myung Ho; Cho, Jeong Gwan; Park, Jong Chun; Kang, Jung Chaee

    2010-12-01

    Multi-detector computed tomography (MDCT) has been used for detecting or excluding coronary atherosclerotic stenosis in symptomatic patients. However, the role of MDCT for routine medical examination in asymptomatic, high-risk patients has not been established. We therefore conducted the present study to test the hypothesis that MDCT could be a valuable method for detecting subclinical coronary artery stenosis in asymptomatic patients. An observational, retrospective, single-centre study was conducted with a cohort of 1,529 patients (mean age, 56.4 ± 8.3 years; 1,353 males) who had undergone MDCT as part of their general medical checkups from November 2005 to April 2008. The patients who had a past history of coronary artery disease, typical chest pain, or evidence of myocardial ischemia were excluded. During clinical follow up of these patients, the incidence of subclinical coronary stenosis and the usefulness of MDCT for routine medical examination in asymptomatic patients were investigated. Of the 1,529 enrolled patients, 42.3% had hypertension, 13.5% had diabetes mellitus, 7.7% had hyperlipidemia, and 40.4% were current smokers. Abnormal MDCT findings were noted in 560 (36.6%) patients, who were classified into two groups. One group had the presence coronary calcium with a luminal diameter stenosis of the coronary artery of <50% (n = 508, 33.2%). These patients were treated with medication or clinical follow-up. The other group had a luminal diameter stenosis of the coronary artery of ≥50% with the presence or absence of coronary calcium (n = 52, 3.4%). These patients underwent a conventional coronary angiogram and intravascular ultrasound. A total of 29 of the 1,529 patients (1.9%) presented with insignificant stenosis or myocardial bridge, and 23 patients (1.5%) presented with significant stenosis. The patients with significant stenosis underwent percutaneous coronary intervention (PCI) with stent implantation. Major adverse cardiac events occurred

  16. Role of 16-multidetector computed tomography in the assessment of coronary artery stenoses: A prospective study of consecutive patients

    PubMed Central

    Postel, Thomas; Frick, Matthias; Feuchtner, Gudrun; Alber, Hannes; Zwick, Ralf; Suessenbacher, Alois; Mallouhi, Ammar; Friedrich, Guy; Pachinger, Otmar; Nedden, Dieter Zur; Weidinger, Franz

    2007-01-01

    BACKGROUND Recent studies have demonstrated a high sensitivity (S) of 16-multidetector computed tomography (16-MDCT) for the detection of significant coronary artery stenoses. Whether these results are applicable to clinical practice is unclear. Therefore, the aim of the present study was to compare 16-MDCT angiography with conventional coronary angiography (CCA) for the detection of significant coronary artery stenoses in a consecutive series of patients. METHOD A total of 93 consecutive patients (mean [± SD] age 59±9 years), in whom CCA was performed for stable angina pectoris, underwent 16-MDCT angiography (16×0.75 mm, table feed 6.5 mm/s, rotation time 0.42 s; Sensation 16, Siemens Medical Solutions, Germany) the day before performing CCA. Patients with diabetes mellitus, serum creatinine level higher than 132.6 μmol/L and/or acute coronary syndromes were excluded. Two observers blinded to CCA results evaluated MDCT angiograms according to standard criteria. Segment-based (13 segments per patient) and patient-based (at least one stenosis greater than 50% lumen diameter reduction) analyses were performed. RESULTS A total of 1209 segments were analyzed. Of these segments, 173 (14%) were excluded due to poor image quality or massive calcification. In 86 segments, CCA revealed significant coronary artery stenosis (greater than 50% diameter reduction). However, 16-MDCT detected only 47 of these, resulting in a S of 55% and a specificity (SP) of 97% (positive predictive value 64%; negative predictive value 96%). On a patient-based analysis, the S increased to 89%, whereas the SP still remained high (87%). CONCLUSION In this relatively large consecutive cohort, S for the detection of significant coronary artery stenoses was moderate on a segment-based analysis but increased on a patient-based analysis using 16-MDCT. In contrast, SP was high in both analyses, supporting the use of 16-MDCT for the exclusion of significant coronary artery stenoses. Further

  17. Relevant incidental findings at abdominal multi-detector contrast-enhanced computed tomography: A collateral screening?

    PubMed Central

    Sconfienza, Luca Maria; Mauri, Giovanni; Muzzupappa, Claudia; Poloni, Alessandro; Bandirali, Michele; Esseridou, Anastassia; Tritella, Stefania; Secchi, Francesco; Di Leo, Giovanni; Sardanelli, Francesco

    2015-01-01

    AIM: To investigate the prevalence of relevant incidental findings (RIFs) detected during routine abdominal contrast-enhanced computed tomography (CeCT). METHODS: We retrospectively evaluated the reports of a consecutive series of abdominal CeCT studies performed between January and May 2013. For each report, patients’ age and sex, admission as inpatient or outpatient, clinical suspicion as indicated by the requesting physician, availability of a previous abdominal examination, and name of the reporting radiologist were recorded. Based on the clinical suspicion, the presence and features of any RIFs (if needing additional workup) was noted. RESULTS: One thousand forty abdominal CeCT were performed in 949 patients (528 males, mean age 66 ± 14 years). No significant difference was found between inpatients and outpatients age and sex distribution (P > 0.472). RIFs were found in 195/1040 (18.8%) CeCT [inpatients = 108/470 (23.0%); outpatients = 87/570 (15.2%); P = 0.002]. RIFs were found in 30/440 (6.8%) CeCT with a previous exam and in 165/600 (27.5%) without a previous exam (P < 0.001). Radiologists’ distribution between inpatients or outpatients was significantly different (P < 0.001). RIFs prevalence increased with aging, except for a peak in 40-49 year group. Most involved organs were kidneys, gallbladder, and lungs. CONCLUSION: A RIF is detected in 1/5 patients undergoing abdominal CeCT. Risk of overdiagnosis should be taken into account. PMID:26516432

  18. Pedicle Morphometry for Thoracic Screw Fixation in Ethnic Koreans : Radiological Assessment Using Computed Tomographic Myelography

    PubMed Central

    Choi, Yong Soo; Yi, Hyeong-Joong; Kim, Young-Joon

    2009-01-01

    Objective In the thoracic spine, insertion of a pedicle screw is annoying due to small pedicle size and wide morphological variation between different levels of the spine and between individuals. The aim of our study was to analyze radiologic parameters of the pedicle morphometry from T1 to T8 using computed tomographic myelography (CTM) in Korean population. Methods For evaluation of the thoracic pedicle morphometry, the authors prospectively analyzed a consecutive series of 26 patients with stable thoracic spines. With the consent of patients, thoracic CTM were performed, from T1 to T8. We calculated the transverse outer diameters and the transverse angles of the pedicle, distance from the cord to the inner cortical wall of the pedicle, and distance from the cord to the dura. Results Transverse outer pedicle diameter was widest at T1 (7.66 ± 2.14 mm) and narrowest at T4 (4.38 ± 1.55 mm). Transverse pedicle angle was widest at T1 (30.2 ± 12.0°) and it became less than 9.0° below T6 level. Theoretical safety zone of the medial perforation of the pedicle screw, namely, distance from the cord to inner cortical wall of the pedicle was more than 4.5 mm. Conclusion Based on this study, we suggest that the current pedicle screw system is not always suitable for Korean patients. Computed tomography is required before performing a transpedicular screw fixation at the thoracic levels. PMID:19893719

  19. Two methods of Haustral fold detection from computed tomographic virtual colonoscopy images

    NASA Astrophysics Data System (ADS)

    Chowdhury, Ananda S.; Tan, Sovira; Yao, Jianhua; Linguraru, Marius G.; Summers, Ronald M.

    2009-02-01

    Virtual colonoscopy (VC) has gained popularity as a new colon diagnostic method over the last decade. VC is a new, less invasive alternative to the usually practiced optical colonoscopy for colorectal polyp and cancer screening, the second major cause of cancer related deaths in industrial nations. Haustral (colonic) folds serve as important landmarks for virtual endoscopic navigation in the existing computer-aided-diagnosis (CAD) system. In this paper, we propose and compare two different methods of haustral fold detection from volumetric computed tomographic virtual colonoscopy images. The colon lumen is segmented from the input using modified region growing and fuzzy connectedness. The first method for fold detection uses a level set that evolves on a mesh representation of the colon surface. The colon surface is obtained from the segmented colon lumen using the Marching Cubes algorithm. The second method for fold detection, based on a combination of heat diffusion and fuzzy c-means algorithm, is employed on the segmented colon volume. Folds obtained on the colon volume using this method are then transferred to the corresponding colon surface. After experimentation with different datasets, results are found to be promising. The results also demonstrate that the first method has a tendency of slight under-segmentation while the second method tends to slightly over-segment the folds.

  20. Assessment of the Radiation Effects of Cardiac Computed Tomographic Angiography Using Protein and Genetic Biomarkers

    PubMed Central

    Nguyen, Patricia K.; Lee, Won Hee; Li, Yong Fuga; Hong, Wan Xing; Hu, Shijun; Chan, Charles; Liang, Grace; Nguyen, Ivy; Ong, Sang-Ging; Churko, Jared; Wang, Jia; Altman, Russ B.; Fleischmann, Dominik; Wu, Joseph C.

    2016-01-01

    Objectives To evaluate whether radiation exposure from cardiac computed tomographic angiography is associated with DNA damage and whether damage leads to programmed cell death and activation of genes involved in apoptosis and DNA repair. Background Exposure to radiation from medical imaging has become a public health concern, but whether it causes significant cell damage remains unclear. Methods We conducted a prospective cohort study in 67 patients undergoing cardiac computed tomographic angiography (CTA) between January 2012 and December 2013 in two US medical centers. Median blood radiation exposure was estimated using phantom dosimetry. Biomarkers of DNA damage and apoptosis were measured by flow cytometry, whole genome sequencing, and single cell polymerase chain reaction. Results The median DLP was 1535.3 mGy·cm (969.7 – 2674.0 mGy·cm). The median radiation dose to the blood was 29.8 milliSieverts (18.8 – 48.8 mSv). Median DNA damage increased 3.39% (1.29 – 8.04%, P<0.0001) post-radiation. Median apoptosis increased 3.1-fold (1.4 – 5.1-fold, P<0.0001) post-radiation. Whole genome sequencing revealed changes in the expression of 39 transcription factors involved in the regulation of apoptosis, cell cycle, and DNA repair. Genes involved in mediating apoptosis and DNA repair were significantly changed post-radiation, including DDB2 [1.9-fold (1.5 – 3.0-fold), P<0.001], XRCC4 [3.0-fold (1.1 – 5.4-fold), P=0.005], and BAX [1.6-fold (0.9 – 2.6-fold), P<0.001]. Exposure to radiation was associated with DNA damage [OR: 1.8 (1.2 – 2.6), P=0.003]. DNA damage was associated with apoptosis [OR: 1.9 (1.2 – 5.1), P<0.0001] and gene activation [OR: 2.8 (1.2 – 6.2), P=0.002]. Conclusions Patients exposed to radiation from cardiac CTA had evidence of DNA damage, which was associated with programmed cell death and activation of genes involved in apoptosis and DNA repair. PMID:26210695

  1. Role of 64 slice multidetector computed tomography and angiography to establish relationship between tumor size, aneurysm formation and spontaneous rupture of renal angiomyolipomas: Single center experience

    PubMed Central

    Gandhi, Shruti P.; Pal, Bipin Chandra; Patel, Kajal N.; Sutariya, Harsh; Trivedi, Hargovind L.

    2016-01-01

    Objective: To evaluate the role of computed tomography (CT) angiography using 64 slice multidetector CT scan to establish relationships among tumor size, aneurysm formation, and spontaneous rupture of renal angiomyolipomas (AML). Materials and Methods: Total 27 patients were diagnosed as having renal angiomyolipoma (AML) at institute of kidney disease and research center from June 2008 to June 2015. All patients with renal AML underwent contrast-enhanced CT (CECT) with CT angiography with 64 slice multidetector CT scan. Results: Total 34 kidneys were found to be affected by AML. Out of which 6 AML were ruptured and remaining 28 were unruptured. If tumor size of 4 cm or larger is used as predictor of rupture; sensitivity 20%, specificity 89%, positive predictive value 83.3%, and negative predictive value 28.5%; and If aneurysm size >5 mm is used as predictor of rupture; sensitivity 75%, specificity 90%, positive predictive value 50%, and negative predictive value 96.4% was found. Conclusion: Tumor size, aneurysm size and tumor multiplicity cannot use as a predictor of spontaneous rupture of the tumor. PMID:27141187

  2. Coronary Computed Tomographic Angiography in the Evaluation of Liver Transplant Candidates.

    PubMed

    Poulin, Marie-France; Chan, Edie Y; Doukky, Rami

    2015-10-01

    The feasibility, safety, and value of coronary computed tomographic angiography (CCTA) in evaluating orthotopic liver transplant (OLT) candidates are unknown. We studied a cohort of consecutive OLT candidates with intermediate-to-high risk of coronary artery disease (CAD). Intermediate risk candidates received CCTA, and those at high risk or with abnormal noninvasive testing underwent invasive coronary angiography (ICA). One hundred consecutive patients were evaluated. Fifty patients underwent a CCTA, 71.4% were β-blocked, the image quality was "good" or "excellent" in 71.4% of cases, and there was no event of significant contrast-induced nephropathy. Twenty (20%) patients were found to have severe CAD (≥70% stenosis) by CCTA and/or ICA. Independent predictors of severe CAD were age (odds ratio [OR] = 5.4 per 10-year increment, 95% confidence interval [CI] = 1.7-17.0; P = .004), dyslipidemia (OR = 12.3, 95% CI = 2.6-57.6; P = .001), and chest pain (OR = 6.0, 95% CI = 1.2-29.1; P = .03). Implementing CCTA in the evaluation of intermediate/high CAD risk OLT candidates is challenging but feasible and seems safe. PMID:25520410

  3. Stereotactic interstitial brachytherapy of malignant astrocytomas with remarks on postimplantation computed tomographic appearance

    SciTech Connect

    Willis, B.K.; Heilbrun, M.P.; Sapozink, M.D.; McDonald, P.R.

    1988-09-01

    Seventeen patients were treated with stereotactically implanted high activity iodine-125 seeds, 12 patients for recurrent malignant astrocytomas (Protocol I) and 5 patients for newly diagnosed glioblastomas (Protocol II). Total radiation dosage to the recurrent tumors in Protocol I, including prior external beam irradiation, averaged 13,500 cGy. In the follow-up period of 6 to 50 months, the survival rate was 93% at 6 months, 60% at 12 months, 50% at 18 months, and 38% at 24 months after implantation. In Protocol II, brachytherapy was used as an interstitial radiation boost to the conventional treatment of newly diagnosed glioblastomas. External beam therapy and interstitial brachytherapy provided 11,000 cGy to these tumors. In the follow-up period of 15 to 27 months, there was a 100% survival at 12 months, 75% at 18 months, and 25% at 24 months after implantation. Eight of our 17 patients required reoperation for persistent or recurrent mass lesions at 6 to 15 months postimplantation; 7 were found to harbor masses of radionecrosis containing nests of anaplastic astrocytes; 1 had frank tumor recurrence. Median survival in this group of patients requiring reoperation was 18.7 months postimplantation. In a review of postimplantation computed tomographic scans, significant mass effect and crossover of hypodensity or enhancement into the corpus callosum or opposite hemisphere were found to have prognostic significance; persistent areas of contrast enhancement and excessive peritumoral hypodensity did not.

  4. A negative cranial computed tomographic scan is not adequate to support a diagnosis of pseudotumor cerebri.

    PubMed

    Said, Rana R; Rosman, N Paul

    2004-08-01

    A 10-year-old boy with daily headache for 1 month and intermittent diplopia for 1 week was found to have a unilateral partial abducens palsy and bilateral papilledema; otherwise, his neurologic examination showed no abnormalities. A cranial computed tomographic (CT) scan was normal. Lumbar puncture disclosed a markedly elevated opening pressure of > 550 mm of cerebrospinal fluid with normal cerebrospinal fluid. Medical therapy with acetazolamide for presumed pseudotumor cerebri was begun. Magnetic resonance imaging (MRI) of the brain, done several days later because of continuing symptoms, unexpectedly showed multiple hyperintensities of cerebral white matter on T2-weighted and fluid-attenuated inversion recovery images. Despite high-dose intravenous methylprednisolone for possible demyelinating disease, he failed to improve. A left temporal brain biopsy followed and disclosed an anaplastic oligodendroglioma. In a patient with features indicating pseudotumor cerebri, a negative cranial CT scan is not adequate to rule out underlying pathology; thus, MRI of the brain should probably always be performed. A revised definition of pseudotumor cerebri could better include "normal MRI of the brain" rather than "normal neuroimaging." PMID:15605471

  5. A novel colonic polyp volume segmentation method for computer tomographic colonography

    NASA Astrophysics Data System (ADS)

    Wang, Huafeng; Li, Lihong C.; Han, Hao; Song, Bowen; Peng, Hao; Wang, Yunhong; Wang, Lihua; Liang, Zhengrong

    2014-03-01

    Colorectal cancer is the third most common type of cancer. However, this disease can be prevented by detection and removal of precursor adenomatous polyps after the diagnosis given by experts on computer tomographic colonography (CTC). During CTC diagnosis, the radiologist looks for colon polyps and measures not only the size but also the malignancy. It is a common sense that to segment polyp volumes from their complicated growing environment is of much significance for accomplishing the CTC based early diagnosis task. Previously, the polyp volumes are mainly given from the manually or semi-automatically drawing by the radiologists. As a result, some deviations cannot be avoided since the polyps are usually small (6~9mm) and the radiologists' experience and knowledge are varying from one to another. In order to achieve automatic polyp segmentation carried out by the machine, we proposed a new method based on the colon decomposition strategy. We evaluated our algorithm on both phantom and patient data. Experimental results demonstrate our approach is capable of segment the small polyps from their complicated growing background.

  6. Assessment of Potential Live Kidney Donors and Computed Tomographic Renal Angiograms at Christchurch Hospital

    PubMed Central

    Mark, Stephen; Armstrong, Sarah; McGregor, David

    2016-01-01

    Aims. To examine the outcome of potential live kidney donors (PLKD) assessment program at Christchurch Hospital and, also, to review findings of Computed Tomographic (CT) renal angiograms that led to exclusion in the surgical assessment. Methods. Clinical data was obtained from the database of kidney transplants, Proton. Radiological investigations were reviewed using the hospital database, Éclair. The transplant coordinator was interviewed to clarify information about PLKD who did not proceed to surgery, and a consultant radiologist was interviewed to explain unfavorable findings on CT renal angiograms. Results. 162 PLKD were identified during the period January 04–June 08. Of those, 65 (40%) proceeded to have nephrectomy, 15 were accepted and planned to proceed to surgery, 13 were awaiting further assessment, and 69 (42.5%) did not proceed to nephrectomy. Of the 162 PLKD, 142 (88%) were directed donors. The proportion of altruistic PLKD who opted out was significantly higher than that of directed PLKD (45% versus 7%, P = 0.00004). Conclusions. This audit demonstrated a positive experience of live kidney donation at Christchurch Hospital. CT renal angiogram can potentially detect incidental or controversial pathologies in the kidney and the surrounding structures. Altruistic donation remains controversial with higher rates of opting out. PMID:27034659

  7. Coronary computer tomographic angiography for preoperative risk stratification in patients undergoing liver transplantation.

    PubMed

    Jodocy, Daniel; Abbrederis, Susanne; Graziadei, Ivo W; Vogel, Wolfgang; Pachinger, Otmar; Feuchtner, Gudrun M; Jaschke, Werner; Friedrich, Guy

    2012-09-01

    The assessment of the cardiovascular risk profile in patients with end-stage liver disease is essential prior to liver transplantation (LT) as cardiovascular diseases are major causes of morbidity and mortality in the posttransplant course. The aim of this study was to evaluate the accuracy of a 64-slice coronary computed tomographic angiography (CTA) and coronary calcium scoring (CCS) to predict the postoperative cardiovascular risk of patients assessed for LT. In this single center, observational study we included 54 consecutive patients who were assessed for LT and consequently transplanted. Twenty-four patients (44%) presented with a high CCS above 300 and/or a significant stenosis (>50% percent narrowing due to stenotic plaques) and were further referred to coronary angiography. Three of these patients had a more than 70% LAD stenosis with subsequent angioplasty (n=1) or conservative therapy (n=2). The other patients showed only diffuse CAD without significant stenosis. The remaining 30 patients with normal CTA findings were listed for LT without further tests. None of the 54 patients developed cardiovascular events peri- and postoperatively. This study indicated that CTA combined with CCS is a useful non-invasive imaging technique for pre-LT assessment of coronary artery disease and safe tool in the risk assessment of peri- and postoperative cardiovascular events in patients undergoing LT. PMID:21665396

  8. Whole-Brain Computed Tomographic Perfusion Imaging in Acute Cerebral Venous Sinus Thrombosis

    PubMed Central

    Mokin, Maxim; Ciambella, Chelsey C.; Masud, Muhammad W.; Levy, Elad I.; Snyder, Kenneth V.; Siddiqui, Adnan H.

    2016-01-01

    Background Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood. Summary We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced. Key Messages Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction. PMID:27051406

  9. The Diminishing Role of Pelvic Stability Evaluation in the Era of Computed Tomographic Scanning

    PubMed Central

    Fu, Chih-Yuan; Teng, Lan-Hsuan; Liao, Chien-Hung; Hsu, Yu-Pao; Wang, Shang-Yu; Kuo, Ling-Wei; Yuan, Kuo-Ching

    2016-01-01

    Abstract Pelvic fractures can result in life-threatening hemorrhages or other associated injuries. Therefore, computed tomography (CT) scanning plays a key role in the management of pelvic fracture patients. However, CT scanning is utilized as an adjunct in secondary survey according to traditional Advanced Trauma Life Support (ATLS) guidelines, whereas pelvic x-ray is used as a primary tool to evaluate pelvic stability and the necessity of further CT scanning. In the current study, we attempted to evaluate the role of CT scanning in the era of advanced technology. The significance of pelvic stability was also analyzed. From January 2012 to December 2014, the trauma registry and medical records of pelvic fracture patients were retrospectively reviewed. A 64-slice multidetector CT scanner was used in our emergency department as a standard diagnostic tool for evaluating trauma patients. Pelvic x-ray was used as a primary tool for screening pelvic fractures, and pelvic stability was evaluated accordingly. CT scans were performed in patients with unstable pelvic fractures, suspected associated intra-abdominal injuries (IAIs), or other conditions based on the physicians’ clinical judgment. The clinical features of patients with stable and unstable pelvic fractures were compared. The patients with stable pelvic fractures were analyzed to determine the characteristics associated with retroperitoneal hemorrhage (RH) or IAIs. Patients with stable pelvic fractures were also compared based on whether they underwent a CT scan. A total of 716 patients were enrolled in this study. There were 533 (74.4%) patients with stable pelvic fractures. Of these patients, there were 66 (12.4%) and 50 (9.4%) patients with associated RH and IAI, respectively. There were no significant differences between the patients with associated RH based on their primary evaluation (vital signs, volume of blood transfusion, and hemoglobin level). Similarly, the demographics and the primary evaluation

  10. Computed tomographic coronary angiography: experience at Baylor University Medical Center/Baylor Jack and Jane Hamilton Heart and Vascular Hospital

    PubMed Central

    2005-01-01

    Noninvasive cardiac computed tomographic imaging using multislice or electron beam technology has been shown to be highly specific and sensitive in diagnosing coronary heart disease. It is about a fifth of the cost of coronary angiography and is particularly well suited for evaluating patients with a low or low to moderate probability of having obstructive coronary atherosclerosis. In addition, it offers more information than calcium scoring: because of the intravenous contrast used, it temporarily increases the density of the lumen and allows differentiation of soft plaque from calcified plaque. The Baylor Hamilton Heart and Vascular Hospital now uses this modality to define coronary atherosclerosis in patients who would otherwise have needed invasive coronary angiography; several research protocols with the technique are also under way. Baylor has recently upgraded to the 64-slice scanner. It is expected that computed tomographic coronary angiography will replace a significant percentage of invasive cardiac catheterizations. PMID:16200178

  11. Producing a full-scale model from computed tomographic data with the rapid prototyping technique using the binder jet method: a comparison with the laser lithography method using a dry skull.

    PubMed

    Ono, I; Abe, K; Shiotani, S; Hirayama, Y

    2000-11-01

    Rapid prototyping using the binder jet method has recently been established and has already produced excellent results in industrial applications. The authors recently developed a technique for producing a full-scale model from computed tomographic (CT) data with the binder jet method as an approach to overcome the shortcomings of the laser lithography method, which is already widely used in medicine. They conducted a comparative investigation of full-scale models made with both techniques using a dry skull to determine the accuracy of the models. It was clearly demonstrated that the accuracy of the binder jet method was high enough to be used in craniomaxillofacial surgery because it was the same as the laser lithography method. This study employed data from the latest helical volume scan computed tomography device using a multidetector. The study showed that the new rapid prototyping technique was satisfactory in terms of speed, cost, installation environment, and accuracy of models, and that detailed shapes and structures can be reproduced well. Because this technique has many advantages over the laser lithography method, it should play a major role in craniomaxillofacial surgery and in other medical fields in combination with advances in CT devices. Although plaster is a more suitable fixation material when the emphasis is on the reproducibility of detailed structures, the binder jet method using starch is extremely useful for simulating operations and determining implant shapes because it allows for the prompt production of models. PMID:11314492

  12. Radiographic and computed tomographic demonstration of pseudotumor cerebri due to rapid weight gain in a child with pelvic rhabdomyosarcoma

    SciTech Connect

    Berdon, W.E.; Barker, D.H.; Barash, F.S.

    1982-06-01

    Rapid weight gain in a malnourished child can be associated with suture diastasis in the pattern of pseudotumor cerebri; this has been previously reported in deprivational dwarfism and cystic fibrosis. In a child with pelvic rhabdomyosarcoma, skull radiographs and cranial computed tomographic (CT) scans were available prior to a period of rapid weight gain induced by hyperalimentation. Suture diastasis developed and repeat CT scans showed this to be accompanied by smaller ventricles.

  13. Automatic pulmonary vessel segmentation in 3D computed tomographic pulmonary angiographic (CTPA) images

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Patel, Smita; Cascade, Philip N.; Sahiner, Berkman; Wei, Jun; Ge, Jun; Kazerooni, Ella A.

    2006-03-01

    Automatic and accurate segmentation of the pulmonary vessels in 3D computed tomographic angiographic images (CTPA) is an essential step for computerized detection of pulmonary embolism (PE) because PEs only occur inside the pulmonary arteries. We are developing an automated method to segment the pulmonary vessels in 3D CTPA images. The lung region is first extracted using thresholding and morphological operations. 3D multiscale filters in combination with a newly developed response function derived from the eigenvalues of Hessian matrices are used to enhance all vascular structures including the vessel bifurcations and suppress non-vessel structures such as the lymphoid tissues surrounding the vessels. At each scale, a volume of interest (VOI) containing the response function value at each voxel is defined. The voxels with a high response indicate that there is an enhanced vessel whose size matches the given filter scale. A hierarchical expectation-maximization (EM) estimation is then applied to the VOI to segment the vessel by extracting the high response voxels at this single scale. The vessel tree is finally reconstructed by combining the segmented vessels at all scales based on a "connected component" analysis. Two experienced thoracic radiologists provided the gold standard of pulmonary arteries by manually tracking the arterial tree and marking the center of the vessels using a computer graphical user interface. Two CTPA cases containing PEs were used to evaluate the performance. One of these two cases also contained other lung diseases. The accuracy of vessel tree segmentation was evaluated by the percentage of the "gold standard" vessel center points overlapping with the segmented vessels. The result shows that 97.3% (1868/1920) and 92.0% (2277/2476) of the manually marked center points overlapped with the segmented vessels for the cases without and with other lung disease, respectively. The results demonstrate that vessel segmentation using our method is

  14. Automatic centerline extraction of coronary arteries in coronary computed tomographic angiography.

    PubMed

    Yang, Guanyu; Kitslaar, Pieter; Frenay, Michel; Broersen, Alexander; Boogers, Mark J; Bax, Jeroen J; Reiber, Johan H C; Dijkstra, Jouke

    2012-04-01

    Coronary computed tomographic angiography (CCTA) is a non-invasive imaging modality for the visualization of the heart and coronary arteries. To fully exploit the potential of the CCTA datasets and apply it in clinical practice, an automated coronary artery extraction approach is needed. The purpose of this paper is to present and validate a fully automatic centerline extraction algorithm for coronary arteries in CCTA images. The algorithm is based on an improved version of Frangi's vesselness filter which removes unwanted step-edge responses at the boundaries of the cardiac chambers. Building upon this new vesselness filter, the coronary artery extraction pipeline extracts the centerlines of main branches as well as side-branches automatically. This algorithm was first evaluated with a standardized evaluation framework named Rotterdam Coronary Artery Algorithm Evaluation Framework used in the MICCAI Coronary Artery Tracking challenge 2008 (CAT08). It includes 128 reference centerlines which were manually delineated. The average overlap and accuracy measures of our method were 93.7% and 0.30 mm, respectively, which ranked at the 1st and 3rd place compared to five other automatic methods presented in the CAT08. Secondly, in 50 clinical datasets, a total of 100 reference centerlines were generated from lumen contours in the transversal planes which were manually corrected by an expert from the cardiology department. In this evaluation, the average overlap and accuracy were 96.1% and 0.33 mm, respectively. The entire processing time for one dataset is less than 2 min on a standard desktop computer. In conclusion, our newly developed automatic approach can extract coronary arteries in CCTA images with excellent performances in extraction ability and accuracy. PMID:21637981

  15. Computed 3D visualisation of an extinct cephalopod using computer tomographs

    NASA Astrophysics Data System (ADS)

    Lukeneder, Alexander

    2012-08-01

    The first 3D visualisation of a heteromorph cephalopod species from the Southern Alps (Dolomites, northern Italy) is presented. Computed tomography, palaeontological data and 3D reconstructions were included in the production of a movie, which shows a life reconstruction of the extinct organism. This detailed reconstruction is according to the current knowledge of the shape and mode of life as well as habitat of this animal. The results are based on the most complete shell known thus far of the genus Dissimilites. Object-based combined analyses from computed tomography and various computed 3D facility programmes help to understand morphological details as well as their ontogentical changes in fossil material. In this study, an additional goal was to show changes in locomotion during different ontogenetic phases of such fossil, marine shell-bearing animals (ammonoids). Hence, the presented models and tools can serve as starting points for discussions on morphology and locomotion of extinct cephalopods in general, and of the genus Dissimilites in particular. The heteromorph ammonoid genus Dissimilites is interpreted here as an active swimmer of the Tethyan Ocean. This study portrays non-destructive methods of 3D visualisation applied on palaeontological material, starting with computed tomography resulting in animated, high-quality video clips. The here presented 3D geometrical models and animation, which are based on palaeontological material, demonstrate the wide range of applications, analytical techniques and also outline possible limitations of 3D models in earth sciences and palaeontology. The realistic 3D models and motion pictures can easily be shared amongst palaeontologists. Data, images and short clips can be discussed online and, if necessary, adapted in morphological details and motion-style to better represent the cephalopod animal.

  16. Computed 3D visualisation of an extinct cephalopod using computer tomographs

    PubMed Central

    Lukeneder, Alexander

    2012-01-01

    The first 3D visualisation of a heteromorph cephalopod species from the Southern Alps (Dolomites, northern Italy) is presented. Computed tomography, palaeontological data and 3D reconstructions were included in the production of a movie, which shows a life reconstruction of the extinct organism. This detailed reconstruction is according to the current knowledge of the shape and mode of life as well as habitat of this animal. The results are based on the most complete shell known thus far of the genus Dissimilites. Object-based combined analyses from computed tomography and various computed 3D facility programmes help to understand morphological details as well as their ontogentical changes in fossil material. In this study, an additional goal was to show changes in locomotion during different ontogenetic phases of such fossil, marine shell-bearing animals (ammonoids). Hence, the presented models and tools can serve as starting points for discussions on morphology and locomotion of extinct cephalopods in general, and of the genus Dissimilites in particular. The heteromorph ammonoid genus Dissimilites is interpreted here as an active swimmer of the Tethyan Ocean. This study portrays non-destructive methods of 3D visualisation applied on palaeontological material, starting with computed tomography resulting in animated, high-quality video clips. The here presented 3D geometrical models and animation, which are based on palaeontological material, demonstrate the wide range of applications, analytical techniques and also outline possible limitations of 3D models in earth sciences and palaeontology. The realistic 3D models and motion pictures can easily be shared amongst palaeontologists. Data, images and short clips can be discussed online and, if necessary, adapted in morphological details and motion-style to better represent the cephalopod animal. PMID:24850976

  17. Computed 3D visualisation of an extinct cephalopod using computer tomographs.

    PubMed

    Lukeneder, Alexander

    2012-08-01

    The first 3D visualisation of a heteromorph cephalopod species from the Southern Alps (Dolomites, northern Italy) is presented. Computed tomography, palaeontological data and 3D reconstructions were included in the production of a movie, which shows a life reconstruction of the extinct organism. This detailed reconstruction is according to the current knowledge of the shape and mode of life as well as habitat of this animal. The results are based on the most complete shell known thus far of the genus Dissimilites. Object-based combined analyses from computed tomography and various computed 3D facility programmes help to understand morphological details as well as their ontogentical changes in fossil material. In this study, an additional goal was to show changes in locomotion during different ontogenetic phases of such fossil, marine shell-bearing animals (ammonoids). Hence, the presented models and tools can serve as starting points for discussions on morphology and locomotion of extinct cephalopods in general, and of the genus Dissimilites in particular. The heteromorph ammonoid genus Dissimilites is interpreted here as an active swimmer of the Tethyan Ocean. This study portrays non-destructive methods of 3D visualisation applied on palaeontological material, starting with computed tomography resulting in animated, high-quality video clips. The here presented 3D geometrical models and animation, which are based on palaeontological material, demonstrate the wide range of applications, analytical techniques and also outline possible limitations of 3D models in earth sciences and palaeontology. The realistic 3D models and motion pictures can easily be shared amongst palaeontologists. Data, images and short clips can be discussed online and, if necessary, adapted in morphological details and motion-style to better represent the cephalopod animal. PMID:24850976

  18. A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation

    PubMed Central

    Ma, Yue; Han, Ting; Chen, Xinyu; Wan, Fang; Lu, Yating; Yan, Songhe; Wang, Yan

    2015-01-01

    The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice–disto-lingual canal orifice–mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation. PMID:26241480

  19. Computed tomographic morphology and clinical features of extrahepatic portosystemic shunts in 172 dogs in Japan.

    PubMed

    Fukushima, K; Kanemoto, H; Ohno, K; Takahashi, M; Fujiwara, R; Nishimura, R; Tsujimoto, H

    2014-03-01

    Canine extrahepatic congenital portosystemic shunts (EH-cPSS) are classified into several anatomical types, depending on the origin and termination of the shunt vessel. The aim of this retrospective study was to determine the proportion and clinical features of each anatomical shunt type in a population of dogs presented to a veterinary teaching hospital in Japan. Dogs diagnosed with EH-cPSS using computed tomographic (CT) portography were included (n=172) and shunts were classified based on previous reports. Clinical data were collected from case records and analysed statistically. The most common anatomical type was the spleno-phrenic shunt (n=64), followed by the spleno-azygos (n=38), right gastric-caval (n=29), spleno-caval (n=21), right gastric-caval with caudal loop (n=9), right gastric-phrenic (n=6), colono-caval (n=3), spleno-phrenic and azygos (n=1), and porto-caval (n=1) shunts. Spleno-phrenic and spleno-azygos shunts were diagnosed more frequently in older dogs than right gastric-caval and spleno-caval shunts (P<0.05). The portal vein/aortic (PV/Ao) ratio was significantly larger in dogs with spleno-phrenic shunts than in dogs with spleno-azygos, right gastric-caval or spleno-caval shunts (P<0.05). The PV/Ao ratio was significantly larger in dogs with spleno-azygos shunts than in dogs with right gastric-caval shunts. Dogs with spleno-phrenic shunts had significantly lower serum alkaline phosphatase activities than those with right gastric-caval or spleno-caval shunts. Dogs with spleno-phrenic shunts had significantly lower fasting ammonia concentrations than those with spleno-caval shunts. PMID:24512983

  20. Computed tomographic study of the patterns of oesteoarthritic change which occur on the mandibular condyle.

    PubMed

    Lim, Mi-Ji; Lee, Jeong-Yun

    2014-12-01

    The aim of this study was to investigate which parts of the articular surface of the mandibular condyle are involved in osteoarthritic (OA) change (the occurring pattern) and the relationship of these patterns to clinical signs and symptoms. The computed tomographic (CT) images and clinical records of patients with OA involvement of one or both of their temporomandibular joints (TMJs) were reviewed (OA changes confirmed by CT; 684 TMJs included). The condylar articular surface was divided into nine imaginary sections on the CT images: antero-medial (AM), antero-central (AC), antero-lateral (AL), centri-medial (CM), centri-central (CC), centri-lateral (CL), postero-medial (PM), postero-central (PC), and postero-lateral (PL) section. The occurring patterns were classified with hierarchical cluster analysis based on the distribution of the sections involved by OA changes. OA changes were observed the most frequently on the AC (62.4%) followed by the AM (55.0%), CC (48.2%), AL (43.0%), CL (43.3%), CM (33.3%), PC (28.9%), PL (25.3%), and PM (23.1%). The occurring patterns were classified into three types among which subjective joint pain (P < 0.001) and noise (P < 0.05) were more frequently reported in the entire-involved type followed by lateral- and antero-medial types in descending order, while no significant differences for age, gender, side, pain on palpation, clicking, crepitus, mouth opening range and craniomandibular index were observed. OA changes are more likely to occur on the anterior than the posterior and on the medial than the lateral surface of the mandibular condyle, while subjective joint pain and noise are more frequently reported with OA changes involving the lateral or entire part. Pain on palpation, noise, and mouth opening range were not related to the occurring pattern of OA changes. PMID:25240743

  1. Usefulness of Intraprocedural Coronary Computed Tomographic Angiography During Intervention for Chronic Total Coronary Occlusion.

    PubMed

    Kim, Byeong-Keuk; Cho, Iksung; Hong, Myeong-Ki; Chang, Hyuk-Jae; Shin, Dong-Ho; Kim, Jung-Sun; Shin, Sanghoon; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo

    2016-06-15

    Although intraprocedural coronary computed tomographic angiography (CCTA) allows for scanning during intervention without relocation of the patient, studies have yet to report on its use during chronic total occlusion (CTO) intervention. Therefore, we investigated the role of CCTA during CTO intervention, particularly whether CCTA could be used to evaluate the location of guidewires. A total of 61 patients scheduled for elective CTO intervention were consecutively enrolled and underwent CCTA and on-site analyses during intervention. Transverse axial and the curved multiplanar images in a 360-degree view were interactively used together to identify the location of guidewires, along with the adjustment of window condition. Intracoronary contrast injection was used for specific cases requiring enhancement of the distal part of the CTO. Most CCTAs were performed to confirm the location of a single guidewire; CCTA was also performed to evaluate parallel (3 patients) or retrograde wires (5 patients). The initial identification rate for guidewire location was 56% with immediate transaxial images, but it significantly increased to 87% after interactive on-site uses of the curved multiplanar images (p <0.001). Cases in which guidewire location could be predicted with CCTA evaluation show a numerically higher success rate than those that could not (83% vs 63%) but not statistical significance (p = 0.174). The mean time for CCTA evaluation and mean radiation dose were 8.6 minutes and 2.9 mSv, respectively. No specific complications occurred after CCTA and CTO procedures. Intraprocedural CCTA for identifying the location of the guidewires is feasible and safe when used for various CTO procedural steps. PMID:27134060

  2. Computed tomographic and radiographic examination of dental structures in South American camelid specimen of different ages

    PubMed Central

    2014-01-01

    Background Tooth root problems and periodontal diseases are common in South American camelids (SAC). The objective was to evaluate and optimize the imaging technique for dental radiography in SAC and to describe the radiographic and computed tomographic (CT) anatomy of normal teeth at different ages. In this study, the heads of 20 healthy SAC slaughtered for meat production or euthanized for reasons not related to dental problems included 7 female and 10 male llamas and 3 male alpacas. Using a standardized protocol, radiographs and CT scans of the 20 specimen were performed. Results The most useful radiographic projections for mandibular and maxillary cheek teeth evaluation turned out to be lateral30°ventral - laterodorsal and lateral30°dorsal - lateroventral with slight separation of the dental arcades respectively. Digital radiographic and CT appearance of the mandibular and maxillary teeth were described from the beginning of mineralization till maturity. In addition the normal range of the CT radio density of different cheek teeth and different dental tissues were measured. Hounsfield units of different dental tissues of SAC turned out to be similar to equids. Deviation, shortening and partial destruction of the distal tooth root of mandibular 09′s and 10′s and of maxillary 09′s was observed and the existence of a common pulp chamber in younger teeth was revealed. Conclusions The present study provides information about the dental imaging morphology in clinically healthy SAC. This basic information provides fundamental knowledge for evaluating images and planning treatments in clinically affected animals. PMID:24393365

  3. Blood and Sputum Eosinophil Levels in Asthma and Their Relationship to Sinus Computed Tomographic Findings

    PubMed Central

    Mehta, Vinay; Campeau, Norbert G.; Kita, Hirohito; Hagan, John B.

    2010-01-01

    OBJECTIVE To investigate the relationship among blood and sputum eosinophil levels, sinus mucosal thickening, and osteitis in patients with asthma. PATIENTS AND METHODS We conducted an observational study of 201 patients with asthma who underwent sinus computed tomographic (CT) imaging and induced sputum analysis at Mayo Clinic's site in Rochester, MN, from November 1, 2000, through December 31, 2005. Sinus CT scans were reviewed by an investigator blinded to patients' identity and chart information (J.B.H.) to assess for mucosal thickening. Each scan was assigned a CT score based on the Lund-Mackay staging scale. Approximately 20% of the scans were reviewed at random by a radiologist (N.G.C.) to ensure quality control. Bone changes consistent with osteitis were ascertained from radiology reports. Lung function was measured, and sputum was analyzed by conventional methods. RESULTS Sinus CT scans revealed abnormalities in 136 (68%) of the 201 study patients. Severe mucosal thickening (CT score, ≥12) was found in 60 patients (30%) and osteitis in 18 patients (9%). There was a positive correlation between CT scores and eosinophil levels in both peripheral blood (ρ=0.45; 95% confidence interval, 0.33–0.56; P<.001) and induced sputum (ρ=0.46; 95% confidence interval, 0.34–0.57; P<.001). Further, elevated blood and sputum eosinophil levels were associated with the presence of osteitis on CT scan and previous sinus surgery. CONCLUSION Blood and sputum eosinophil levels in patients with asthma are directly correlated with sinus mucosal thickening and are associated with osteitis, lending further support to the hypothesis that asthma and chronic rhinosinusitis are mediated by similar inflammatory processes. PMID:18533084

  4. Dataset of calcified plaque condition in the stenotic coronary artery lesion obtained using multidetector computed tomography to indicate the addition of rotational atherectomy during percutaneous coronary intervention.

    PubMed

    Akutsu, Yasushi; Hamazaki, Yuji; Sekimoto, Teruo; Kaneko, Kyouichi; Kodama, Yusuke; Li, Hui-Ling; Suyama, Jumpei; Gokan, Takehiko; Sakai, Koshiro; Kosaki, Ryota; Yokota, Hiroyuki; Tsujita, Hiroaki; Tsukamoto, Shigeto; Sakurai, Masayuki; Sambe, Takehiko; Oguchi, Katsuji; Uchida, Naoki; Kobayashi, Shinichi; Aoki, Atsushi; Kobayashi, Youichi

    2016-06-01

    Our data shows the regional coronary artery calcium scores (lesion CAC) on multidetector computed tomography (MDCT) and the cross-section imaging on MDCT angiography (CTA) in the target lesion of the patients with stable angina pectoris who were scheduled for percutaneous coronary intervention (PCI). CAC and CTA data were measured using a 128-slice scanner (Somatom Definition AS+; Siemens Medical Solutions, Forchheim, Germany) before PCI. CAC was measured in a non-contrast-enhanced scan and was quantified using the Calcium Score module of SYNAPSE VINCENT software (Fujifilm Co. Tokyo, Japan) and expressed in Agatston units. CTA were then continued with a contrast-enhanced ECG gating to measure the severity of the calcified plaque condition. We present that both CAC and CTA data are used as a benchmark to consider the addition of rotational atherectomy during PCI to severely calcified plaque lesions. PMID:26977441

  5. A multislice positron emission computed tomograph (PETT IV) yielding transverse and longitudinal images.

    PubMed

    Ter-Pogossian, M M; Mullani, N A; Hood, J; Higgins, C S; Currie, C M

    1978-08-01

    We designed, built, and tested a positron emission tomograph (PETT IV) capable of providing seven slices of the human body simultaneously. PETT IV utilizes a moving hexagonal array of 48 scintillation detectors placed around the subject. Each detector consists of a cylindrical activated sodium iodide crystal optically coupled to two photomultiplier tubes. The multislice capability is achieved by comparing the light outputs of the two photomultiplier tubes in each detector. The images are displayed either as transverse or as longitudinal tomographic sections. This system provides high sensitivity and resolution, and permits rapid and accurate three-dimensional imaging of the head and body. PMID:663264

  6. Cost-Effectiveness of Computed Tomographic Colonography Screening for Colorectal Cancer in the Medicare Population

    PubMed Central

    Lansdorp-Vogelaar, Iris; Rutter, Carolyn M.; Savarino, James E.; van Ballegooijen, Marjolein; Kuntz, Karen M.; Zauber, Ann G.

    2010-01-01

    Background The Centers for Medicare and Medicaid Services (CMS) considered whether to reimburse computed tomographic colonography (CTC) for colorectal cancer screening of Medicare enrollees. To help inform its decision, we evaluated the reimbursement rate at which CTC screening could be cost-effective compared with the colorectal cancer screening tests that are currently reimbursed by CMS and are included in most colorectal cancer screening guidelines, namely annual fecal occult blood test (FOBT), flexible sigmoidoscopy every 5 years, flexible sigmoidoscopy every 5 years in conjunction with annual FOBT, and colonoscopy every 10 years. Methods We used three independently developed microsimulation models to assess the health outcomes and costs associated with CTC screening and with currently reimbursed colorectal cancer screening tests among the average-risk Medicare population. We assumed that CTC was performed every 5 years (using test characteristics from either a Department of Defense CTC study or the National CTC Trial) and that individuals with findings of 6 mm or larger were referred to colonoscopy. We computed incremental cost-effectiveness ratios for the currently reimbursed screening tests and calculated the maximum cost per scan (ie, the threshold cost) for the CTC strategy to lie on the efficient frontier. Sensitivity analyses were performed on key parameters and assumptions. Results Assuming perfect adherence with all tests, the undiscounted number life-years gained from CTC screening ranged from 143 to 178 per 1000 65-year-olds, which was slightly less than the number of life-years gained from 10-yearly colonoscopy (152–185 per 1000 65-year-olds) and comparable to that from 5-yearly sigmoidoscopy with annual FOBT (149–177 per 1000 65-year-olds). If CTC screening was reimbursed at $488 per scan (slightly less than the reimbursement for a colonoscopy without polypectomy), it would be the most costly strategy. CTC screening could be cost-effective at

  7. Virtual pathology: a new paradigm for interpretation of computed tomographic colonography

    NASA Astrophysics Data System (ADS)

    Reed, Judd E.; Johnson, C. Daniel

    1998-06-01

    Computed tomographic colonography (CTC or virtual colonoscopy) is a new technique for imaging the colon for the detection of colorectal neoplasm. Early clinical assessment of this procedure has shown that the performance of this test is acceptable for colorectal screening examinations. The current version of CTC utilizes an interactive combination of axial, reformatted 2D and 3D images (from an endoluminal perspective) that are generated in real time. Navigating the colorectum within the virtual endoscopy (VE) metaphor is tedious. To alleviate this problem and free the radiologist to concentrate on diagnosis, a two pass approach has been adopted. In the first pass, the colon is semiautomatically navigated and its midline is recorded. Then in a second pass, the radiologist moves the view point (virtual endoscope tip) along this midline. This second pass alone takes from 15 to 40 minutes per scan. Additional volume rendered displays have been developed which show longer segments of the colon in formats analogous to views which may be seen at autopsy. These include a technique called planar virtual pathology' (PVP) which uses image planes of the two longitudinal transcolonic sections as cut planes within isometric volume rendered images. Scenes are rendered with rays passing orthogonally through these planes from both sides. Each of the four resulting images depicts approximately one half of the inner surface of a 12 cm bowel segment. Interpretation is performed by viewing these colon segments at approximately 8 cm intervals. In this way, the entire colon can be rapidly examined with a minimum of navigational input from the radiologist. Other virtual pathology views have also been developed. These include cylindrical virtual pathology (CVP) and mercator virtual pathology (MVP). CVP views are formed by casting rays perpendicular to a straight line which approximates a segment of the colon midline. These views are analogous to the result of splitting a segment of

  8. Physiological and Computed Tomographic Predictors of Outcome from Lung Volume Reduction Surgery

    PubMed Central

    Washko, George R.; Martinez, Fernando J.; Hoffman, Eric A.; Loring, Stephen H.; Estépar, Raúl San José; Diaz, Alejandro A.; Sciurba, Frank C.; Silverman, Edwin K.; Han, MeiLan K.; DeCamp, Malcolm; Reilly, John J.

    2010-01-01

    Rationale: Previous investigations have identified several potential predictors of outcomes from lung volume reduction surgery (LVRS). A concern regarding these studies has been their small sample size, which may limit generalizability. We therefore sought to examine radiographic and physiologic predictors of surgical outcomes in a large, multicenter clinical investigation, the National Emphysema Treatment Trial. Objectives: To identify objective radiographic and physiological indices of lung disease that have prognostic value in subjects with chronic obstructive pulmonary disease being evaluated for LVRS. Methods: A subset of the subjects undergoing LVRS in the National Emphysema Treatment Trial underwent preoperative high-resolution computed tomographic (CT) scanning of the chest and measures of static lung recoil at total lung capacity (SRtlc) and inspiratory resistance (Ri). The relationship between CT measures of emphysema, the ratio of upper to lower zone emphysema, CT measures of airway disease, SRtlc, Ri, the ratio of residual volume to total lung capacity (RV/TLC), and both 6-month postoperative changes in FEV1 and maximal exercise capacity were assessed. Measurements and Main Results: Physiological measures of lung elastic recoil and inspiratory resistance were not correlated with improvement in either the FEV1 (R = −0.03, P = 0.78 and R = –0.17, P = 0.16, respectively) or maximal exercise capacity (R = –0.02, P = 0.83 and R = 0.08, P = 0.53, respectively). The RV/TLC ratio and CT measures of emphysema and its upper to lower zone ratio were only weakly predictive of postoperative changes in both the FEV1 (R = 0.11, P = 0.01; R = 0.2, P < 0.0001; and R = 0.23, P < 0.0001, respectively) and maximal exercise capacity (R = 0.17, P = 0.0001; R = 0.15, P = 0.002; and R = 0.15, P = 0.002, respectively). CT assessments of airway disease were not predictive of change in FEV1 or exercise capacity in this cohort. Conclusions: The RV/TLC ratio and CT measures

  9. Dual-source computed tomographic coronary angiography: image quality and stenosis diagnosis in patients with high heart rates.

    PubMed

    Zheng, Minwen; Li, Jiayi; Xu, Jian; Chen, Kang; Zhao, Hongliang; Huan, Yi

    2009-01-01

    We sought to evaluate prospectively the effects of heart rate and heart-rate variability on dual-source computed tomographic coronary image quality in patients whose heart rates were high, and to determine retrospectively the accuracy of dual-source computed tomographic diagnosis of coronary artery stenosis in the same patients.We compared image quality and diagnostic accuracy in 40 patients whose heart rates exceeded 70 beats/min with the same data in 40 patients whose heart rates were 70 beats/min or slower. In both groups, we analyzed 1,133 coronary arterial segments. Five hundred forty-five segments (97.7%) in low-heart-rate patients and 539 segments (93.7%) in high-heart-rate patients were of diagnostic image quality. We considered P < 0.05 to be statistically significant. No statistically significant differences between the groups were found in diagnostic-image quality scores of total segments or of any coronary artery, nor were any significant differences found between the groups in the accurate diagnosis of angiographically significant stenosis.Calcification was the chief factor that affected diagnostic accuracy. In high-heart-rate patients, heart-rate variability was significantly related to the diagnostic image quality of all segments (P = 0.001) and of the left circumflex coronary artery (P = 0.016). Heart-rate variability of more than 5 beats/min most strongly contributed to an inability to evaluate segments in both groups. When heart rates rose, the optimal reconstruction window shifted from diastole to systole.The image quality of dual-source computed tomographic coronary angiography at high heart rates enables sufficient diagnosis of stenosis, although variability of heart rates significantly deteriorates image quality. PMID:19436804

  10. Organ dose assessment in pediatric fluoroscopy and CT via a tomographic computational phantom of the newborn patient

    NASA Astrophysics Data System (ADS)

    Staton, Robert J.

    Of the various types of imaging modalities used in pediatric radiology, fluoroscopy and computed tomography (CT) have the highest associated radiation dose. While these examinations are commonly used for pediatric patients, little data exists on the magnitude of the organ and effective dose values for these procedures. Calculation of these dose values is necessary because of children's increased sensitivity to radiation and their long life expectancy for which to express radiation's latent effects. In this study, a newborn tomographic phantom has been implemented in a radiation transport code to evaluate organ and effective doses for newborn patients in commonly performed fluoroscopy and CT examinations. Organ doses were evaluated for voiding cystourethrogram (VCUG) fluoroscopy studies of infant patients. Time-sequence analysis was performed for videotaped VCUG studies of five different patients. Organ dose values were then estimated for each patient through Monte Carlo (MC) simulations. The effective dose values of the VCUG examination for five patients ranged from 0.6 mSv to 3.2 mSv, with a mean of 1.8 +/- 0.9 mSv. Organ doses were also assessed for infant upper gastrointestinal (UGI) fluoroscopy exams. The effective dose values of the UGI examinations for five patients ranged from 1.05 mSv to 5.92 mSv, with a mean of 2.90 +/- 1.97 mSv. MC simulations of helical multislice CT (MSCT) exams were also completed using, the newborn tomographic phantom and a stylized newborn phantom. The helical path of the source, beam shaping filter, beam profile, patient table, were all included in the MC simulations of the helical MSCT scanner. Organ doses and effective doses and their dependence on scan parameters were evaluated for newborn patients. For all CT scans, the effective dose was found to range approximately 1-13 mSv, with the largest values occurring for CAP scans. Tube current modulation strategies to reduce patient dose were also evaluated for newborn patients

  11. Thoracolumbar intradural disc herniation in eight dogs: clinical, low-field magnetic resonance imaging, and computed tomographic myelography findings.

    PubMed

    Tamura, Shinji; Doi, Shoko; Tamura, Yumiko; Takahashi, Kuniaki; Enomoto, Hirokazu; Ozawa, Tsuyoshi; Uchida, Kazuyuki

    2015-01-01

    Intradural disc herniation is a rarely reported cause of neurologic deficits in dogs and few published studies have described comparative imaging characteristics. The purpose of this retrospective cross sectional study was to describe clinical and imaging findings in a group of dogs with confirmed thoracolumbar intradural disc herniation. Included dogs were referred to one of four clinics, had acute mono/paraparesis or paraplegia, had low field magnetic resonance imaging (MRI) and/or computed tomographic myelography, and were diagnosed with thoracolumbar intradural disc herniation during surgery. Eight dogs met inclusion criteria. The prevalence of thoracolumbar intradural disc herniation amongst the total population of dogs that developed a thoracolumbar intervertebral disc herniation and that were treated with a surgical procedure was 0.5%. Five dogs were examined using low-field MRI. Lesions that were suspected to be intervertebral disc herniations were observed; however, there were no specific findings indicating that the nucleus pulposus had penetrated into the subarachnoid space or into the spinal cord parenchyma. Thus, the dogs were misdiagnosed as having a conventional intervertebral disc herniation. An intradural extramedullary disc herniation (three cases) or intramedullary disc herniation (two cases) was confirmed during surgery. By using computed tomographic myelography (CTM) for the remaining three dogs, an intradural extramedullary mass surrounded by an accumulation of contrast medium was observed and confirmed during surgery. Findings from this small sample of eight dogs indicated that CTM may be more sensitive for diagnosing canine thoracolumbar intradural disc herniation than low-field MRI. PMID:25263808

  12. Imaging of extralobar pulmonary sequestration in a patient with tetralogy of Fallot with pulmonary atresia, ventricular septal defect and multiple aorto-pulmonary collateral arteries with multidetector computed tomography.

    PubMed

    Greil, Gerald F; Schoebinger, Max; Kuettner, Axel; Schaefer, Jürgen F; Hofbeck, Michael; Claussen, Claus D; Meinzer, Hans-Peter; Sieverding, Ludger

    2008-01-01

    Complex pulmonary vascular blood supply is common in patients with tetralogy of Fallot with pulmonary atresia, major systemic to pulmonary collateral arteries and hypoplastic or deficient central pulmonary arteries. An extralobar lung sequestration, which has not been described previously in these patients, was imaged in a 6-week-old infant with multidetector computed tomography with sub-millimeter resolution. Arterial and venous vessels were analyzed using three-dimensional vascular exploration tools and results were confirmed with cardiac catheterization. PMID:18715464

  13. 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. PMID:23702281

  14. Mapping Faults from 3-D Tomographic Velocity Model using Image Processing / Computer Vision Algorithms: Application to Northern Cascadia

    NASA Astrophysics Data System (ADS)

    Ramachandran, K.

    2011-12-01

    Three dimensional velocity models constructed through seismic tomography are seldom digitally processed further for imaging structural features. A study conducted to evaluate the potential for imaging subsurface discontinuities in horizontal and vertical direction from three dimensional velocity models using image processing/computer vision techniques has provided significant results. Three-dimensional velocity models constructed through tomographic inversion of active source and/or earthquake traveltime data are generally built from an initial 1-D velocity model that varies only with depth. Regularized tomographic inversion algorithms impose constraints on the roughness of the model that help to stabilize the inversion process. Final velocity models obtained from regularized tomographic inversions have smooth three-dimensional structures that are required by the data. Final velocity models are usually analyzed and interpreted either as a perturbation velocity model or as an absolute velocity model. Compared to perturbation velocity model, absolute velocity model has an advantage of providing constraints on lithology. Both velocity models lack the ability to provide sharp constraints on subsurface faults. However, results from the analysis of the 3-D velocity model from northern Cascadia using Roberts, Prewitt, Sobel, and Canny operators show that subsurface faults that are not clearly interpretable from velocity model plots can be identified through this approach. This analysis resulted in inferring the locations of Tacoma Fault, Seattle Fault, Southern Whidbey Island Fault, and Darrington Devils Mountain fault much clearly. The Coast Range Boundary Fault, previously hypothesized on the basis of sedimentological and tectonic observations is inferred clearly from processed images. Many of the fault locations so imaged correlate with earthquake hypocenters indicating their seismogenic nature.

  15. The Role of Multidetector Computed Tomography in the Early Diagnosis of Invasive Pulmonary Aspergillosis in Patients with Febrile Neutropenia Undergoing Hematopoietic Stem Cell Transplantation

    PubMed Central

    Çiledağ, Nazan; Arda, Kemal; Arıbaş, Bilgin Kadri; Tekgündüz, Ali Irfan Emre; Altuntaş, Fevzi

    2012-01-01

    Objective: To evaluate vessel involvement and the role of multidetector computed tomography (MDCT) in the earlydiagnosis of invasive pulmonary aspergillosis (IPA) in patients with febrile neutropenia and antibiotic-resistant feverundergoing autologous bone morrow transplantation. Material and Methods: In all, 74 pulmonary MDCT examinations in 37 consecutive hematopoietic stem celltransplantation patients with febrile neutropenia and clinically suspected IPA were retrospectively evaluated. Results: Diagnosis of IPA was based on Fungal Infections Cooperative Group, and National Institute of Allergy andInfectious Diseases Mycoses Study Consensus Group criteria. In all, 0, 14, and 11 patients were diagnosed as proven,probable, and possible IPA, respectively. Among the 25 patients accepted as probable and possible IPA, all had pulmonaryMDCT findings consistent with IPA. The remaining 12 patients were accepted as having fever of unknown origin (FUO)and had patent vessels based on MDCT findings.In the patients with probable and possible IPA, 72 focal pulmonary lesions were observed; in 41 of the 72 (57%) lesionsvascular occlusion was noted and the CT halo sign was observed in 25 of these 41 (61%) lesions. Resolution of feveroccurred following antifungal therapy in 19 (76%) of the 25 patients with probable and possible IPA. In all, 6 (25%)of the patients diagnosed as IPA died during follow-up. Transplant-related mortality 100 d post transplant in patientswith IPA and FUO was 24% and 0%, respectively. Conclusion: In conclusion, MDCT has a potential role in the early diagnosis of IPA via detection of vessel occlusion. PMID:24744620

  16. State of the Art. A structural and functional assessment of the lung via multidetector-row computed tomography: phenotyping chronic obstructive pulmonary disease.

    PubMed

    Hoffman, Eric A; Simon, Brett A; McLennan, Geoffrey

    2006-08-01

    With advances in multidetector-row computed tomography (MDCT), it is now possible to image the lung in 10 s or less and accurately extract the lungs, lobes, and airway tree to the fifth- through seventh-generation bronchi and to regionally characterize lung density, texture, ventilation, and perfusion. These methods are now being used to phenotype the lung in health and disease and to gain insights into the etiology of pathologic processes. This article outlines the application of these methodologies with specific emphasis on chronic obstructive pulmonary disease. We demonstrate the use of our methods for assessing regional ventilation and perfusion and demonstrate early data that show, in a sheep model, a regionally intact hypoxic pulmonary vasoconstrictor (HPV) response with an apparent inhibition of HPV regionally in the presence of inflammation. We present the hypothesis that, in subjects with pulmonary emphysema, one major contributing factor leading to parenchymal destruction is the lack of a regional blunting of HPV when the regional hypoxia is related to regional inflammatory events (bronchiolitis or alveolar flooding). If maintaining adequate blood flow to inflamed lung regions is critical to the nondestructive resolution of inflammatory events, the pathologic condition whereby HPV is sustained in regions of inflammation would likely have its greatest effect in the lung apices where blood flow is already reduced in the upright body posture. PMID:16921136

  17. The Emerging Roles of Coronary Computed Tomographic Angiography: Acute Chest Pain Evaluation and Screening for Asymptomatic Individuals

    PubMed Central

    Chien, Ning; Wang, Tzung-Dau; Chang, Yeun-Chung; Lin, Po-Chih; Tseng, Yao-Hui; Lee, Yee-Fan; Ko, Wei-Chun; Lee, Bai-Chin; Lee, Wen-Jeng

    2016-01-01

    Coronary computed tomographic angiography (CCTA) has been widely available since 2004. After that, the diagnostic accuracy of CCTA has been extensively validated with invasive coronary angiography for detection of coronary arterial stenosis. In this paper, we reviewed the updated evidence of the role of CCTA in both scenarios including acute chest pain and screening in asymptomatic adults. Several large-scale studies have been conducted to evaluate the diagnostic value of CCTA in the context of acute chest pain patients. CCTA could play a role in delivering more efficient care. For risk stratification of asymptomatic patients using CCTA, latest studies have revealed incremental benefits. Future studies evaluating the totality of plaque characteristics may be useful for determining the role of noncalcified plaque for risk stratification in asymptomatic individuals. PMID:27122947

  18. Three-dimensional reconstructions from computed tomographic scans on smartphones and tablets: a simple tutorial for the ward and operating room using public domain software.

    PubMed

    Ketoff, Serge; Khonsari, Roman Hossein; Schouman, Thomas; Bertolus, Chloé

    2014-11-01

    Handling 3-dimensional reconstructions of computed tomographic scans on portable devices is problematic because of the size of the Digital Imaging and Communications in Medicine (DICOM) stacks. The authors provide a user-friendly method allowing the production, transfer, and sharing of good-quality 3-dimensional reconstructions on smartphones and tablets. PMID:25438270

  19. Detection of Cement Leakage After Vertebroplasty with a Non-Flat-Panel Angio Unit Compared to Multidetector Computed Tomography - An Ex Vivo Study

    SciTech Connect

    Baumann, Clemens Fuchs, Heiko; Westphalen, Kerstin; Hierholzer, Johannes

    2008-11-15

    The purpose of this study was to investigate the detection of cement leakages after vertebroplasty using angiographic computed tomography (ACT) in a non-flat-panel angio unit compared to multidetector computed tomography (MDCT). Vertebroplasty was performed in 19 of 33 cadaver vertebrae (23 thoracic and 10 lumbar segments). In the angio suite, ACT (190{sup o}; 1.5{sup o} per image) was performed to obtain volumetric data. Another volumetric data set of the specimen was obtained by MDCT using a standard algorithm. Nine multiplanar reconstructions in standardized axial, coronal, and sagittal planes of every vertebra were generated from both data sets. Images were evaluated on the basis of a nominal scale with 18 criteria, comprising osseous properties (e.g., integrity of the end plate) and cement distribution (e.g., presence of intraspinal cement). MDCT images were regarded as gold standard and analyzed by two readers in a consensus mode. Rotational acquisitions were analyzed by six blinded readers. Results were correlated with the gold standard using Cohen's {kappa}-coefficient analysis. Furthermore, interobserver variability was calculated. Correlation with the gold standard ranged from no correlation (osseous margins of the neuroforamen, {kappa} = 0.008) to intermediate (trace of vertebroplasty canula; {kappa} = 0.615) for criteria referring to osseous morphology. However, there was an excellent correlation for those criteria referring to cement distribution, with {kappa} values ranging from 0.948 (paravertebral cement distribution) to 0.972 (intraspinal cement distribution). With a minimum of {kappa} = 0.768 ('good correlation') and a maximum of {kappa} = 0.91 ('excellent'), interobserver variability was low. In conclusion, ACT in an angio suite without a flat-panel detector depicts a cement leakage after vertebroplasty as well as MDCT. However, the method does not provide sufficient depiction of osseous morphology.

  20. Comparison of enhancement and image quality: different iodine concentrations for liver on 128-slice multidetector computed tomography in the same chronic liver disease patients

    PubMed Central

    Jo, Byoung Goo; Song, Yun Gyu; Shim, Sang Goon; Kim, Young Wook

    2016-01-01

    Background/Aims: The objective of this study was to compare the degree of hepatic enhancement and image quality using contrast media of different iodine concentrations with the same iodine dose. Methods: From July 2011 to June 2013, 50 patients with chronic liver disease who underwent baseline and follow-up 128-slice multidetector computed tomography(MDCT) using contrast media with 350 mg I/mL (group A) and 400 mg I/mL (group B) iodine concentrations were included in this prospective study. The patients were randomly allocated to one of two protocols: 350 mg I/mL initially and then 400 mg I/mL; and 400 mg I/mL initially and then 350 mg I/mL. The bolus tracking technique was used to initiate the arterial phase scan. The computed tomography values of hepatic parenchyma, abdominal aorta and portal vein were measured. The degrees of hepatic and vascular enhancement were rated on a 4-point scale for qualitative assessment. The paired Student t test was used to compare outcome variables. Results: The mean hepatic enhancement was significantly higher in group B than in group A during the portal (p = 0.025) and equilibrium phases (p = 0.021). In all phases, group B had significantly higher mean liver-to-aorta contrast (p < 0.05) and mean visual scores for hepatic and vascular enhancement (p < 0.001). Conclusions: This study showed that a higher iodine concentration (400 mg I/mL) in contrast media was more effective at improving hepatic enhancement in portal and equilibrium phase images and overall image quality using 128-slice MDCT in chronic liver disease patients. PMID:26701234

  1. Anthropometric Assessment of Neck Adipose Tissue and Airway Volume Using Multidetector Computed Tomography: An Imaging Approach and Association With Overall Mortality.

    PubMed

    Maresky, Hillel S; Sharfman, Zachary; Ziv-Baran, Tomer; Gomori, J M; Copel, Laurian; Tal, Sigal

    2015-11-01

    Neck adiposity tissue volume (NATV) accumulation is an indicator for metabolic syndrome and cardiovascular disease (CVD). Neck circumference is a poor measure of NATV, and a quantifier for this entity has not yet been established. To evaluate volumetric quantification by multidetector computed tomography (MDCT) as a reproducible anthropometric tool to measure NATV and airway volume (AWV). A total of 519 patients, including a subset of 70 random patients who underwent head and neck CT scanning in our hospital within 1 year (2013), were studied. Included patients were all those undergoing nonenhanced CT (NECT) or CT angiography (CTA). Neck cross-sectional areas (NCSA) were measured at 2 separate levels of the neck, and 3D postprocessing tissue reconstruction was performed, and NATV and AWVs were quantified volumetrically for all patients within the year. The average NCSA at the level of the soft palate and thyroid cartilage was 22,579 and 14,500 mm, respectively. NATV when compared to the upper and lower levels of NCSA showed correlations of 0.64 and 0.79, respectively (P < 0.001). Interobserver analysis showed mean deviations of 0.46% and 0.32% for NATV and AWV, respectively. A strong correlation between NATV and body mass index (BMI) was found (r = 0.658, P < 0.001), and the top quartile of NATV:AWV patients (out of 519 patients) displayed a statistically significant mortality rate during 670 days of follow-up (d = 7.5%, P = 0.032). After adjustment for age and gender, the association between NATV:AWV and mortality was close to significant (P = 0.072). Volumetric quantification of NATV and AWV is a reproducible and prognostic anthropometric tool, as a high NATV:AWV demonstrated a significant risk factor for mortality; future research may further advance our understanding of this phenomenon. PMID:26559286

  2. Perforated duodenal ulcer presenting with a subphrenic abscess revealed by plain abdominal X-ray films and confirmed by multi-detector computed tomography: a case report

    PubMed Central

    2013-01-01

    Introduction Peptic ulcer disease is still the major cause of gastrointestinal perforation despite major improvements in both diagnostic and therapeutic strategies. While the diagnosis of a perforated ulcer is straightforward in typical cases, its clinical onset may be subtle because of comorbidities and/or concurrent therapies. Case presentation We report the case of a 53-year-old Caucasian man with a history of chronic myeloid leukemia on maintenance therapy (100mg/day) with imatinib who was found to have a subphrenic abscess resulting from a perforated duodenal ulcer that had been clinically overlooked. Our patient was febrile (38.5°C) with abdominal tenderness and hypoactive bowel sounds. On the abdominal plain X-ray films, a right subphrenic abscess could be seen. On contrast-enhanced multi-detector computed tomography, a huge air-fluid collection extending from the subphrenic to the subhepatic anterior space was observed. After oral administration of 500cm3 of 3 percent diluted diatrizoate meglumine, an extraluminal leakage of the water-soluble iodinated contrast media could then be appreciated as a result of a perforated duodenal ulcer. During surgery, the abscess was drained and extensive adhesiolysis had to be performed to expose the duodenal bulb where the ulcer was first identified by methylene blue administration and then sutured. Conclusions While subphrenic abscesses are well known complications of perforated gastric or duodenal ulcers, they have nowadays become rare thanks to advances in both diagnostic and therapeutic strategies for peptic ulcer disease. However, when peptic ulcer disease is not clinically suspected, the contribution of imaging may be substantial. PMID:24215711

  3. Morphometric Evaluation of Bony Nasolacrimal Canal in a Caucasian Population with Primary Acquired Nasolacrimal Duct Obstruction: A Multidetector Computed Tomography Study

    PubMed Central

    Yazici, Alper; Yanik, Bahar; Yazici, Hasmet; Demirpolat, Gulen

    2016-01-01

    Objective The bony nasolacrimal duct (BNLD) morphology as a contributory factor in primary acquired nasolacrimal duct obstruction (PANDO) is still controversial. The objectives of this study were to evaluate the morphometric differences of BNLDs in unilateral PANDO patients between PANDO and non-PANDO sides, as compared with the control group using multidetector computed tomography (CT). Materials and Methods Bilateral BNLDs in 39 unilateral PANDO patients and 36 control subjects were retrospectively reviewed. CT images with 0.5-mm thickness were obtained with a 64-slice scanner. The length, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were assessed. The entrance, minimum and distal end transverse diameters (TD) of BNLD was investigated. Results The mean minimum and distal end BNLD TDs measurements were significantly narrower in PANDO patients, both in PANDO and non-PANDO sides, as compared with the control group (p < 0.001 and p = 0.040, respectively); however, there were no significant differences between PANDO and non-PANDO sides within PANDO patients. The length, entrance TD, volume, coronal orientation type, sagittal orientation angle of BNLD, and relative lacrimal sac-BNLD angle were not significantly different between PANDO patients and control subjects, as well as between PANDO and non-PANDO sides within PANDO patients. Conclusion The narrow mean minimum and distal end BNLD TD in PANDO patients, in both PANDO and non-PANDO sides, may be associated with PANDO development. The lack of difference between PANDO and non-PANDO sides within PANDO patients and some overlap between PANDO patients and control subjects suggest that narrow BNLD is not the sole factor. PMID:26957913

  4. Multidetector-Row Computed Tomography in the Evaluation of Transjugular Intrahepatic Portosystemic Shunt Performed with Expanded-Polytetrafluoroethylene-Covered Stent-Graft

    SciTech Connect

    Fanelli, Fabrizio Bezzi, Mario; Bruni, Antonio; Corona, Mario; Boatta, Emanuele; Lucatelli, Pierleone; Passariello, Roberto

    2011-02-15

    We assessed, in a prospective study, the efficacy of multidetector spiral computed tomography (MDCT) in the evaluation of transjugular intrahepatic portosystemic shunt (TIPS) patency in patients treated with the Viatorr (Gore, Flagstaff, AZ) expanded-polytetrafluoroethylene (e-PTFE)-covered stent-graft. Eighty patients who underwent TIPS procedure using the Viatorr self-expanding e-PTFE stent-graft were evaluated at follow-up of 1, 3, 6, and 12 months with clinical and laboratory tests as well as ultrasound-color Doppler (USCD) imaging. In case of varices, upper gastrointestinal endoscopy was also performed. In addition, the shunt was evaluated using MDCT at 6 and 12 months. In all cases of abnormal findings and discrepancy between MDCT and USCD, invasive control venography was performed. MDCT images were acquired before and after injection of intravenous contrast media on the axial plane and after three-dimensional reconstruction using different algorithms. MDCT was successfully performed in all patients. No artefacts correlated to the Viatorr stent-graft were observed. A missing correlation between UCSD and MDCT was noticed in 20 of 80 (25%) patients. Invasive control venography confirmed shunt patency in 16 (80%) cases and shunt malfunction in 4 (20%) cases. According to these data, MDCT sensitivity was 95.2%; specificity was 96.6%; and positive (PPV) and negative predictive values (NPV) were 90.9 and 98.2%, respectively. USCD sensitivity was 90%; specificity was 75%; and PPV and NPV were 54.5 and 95.7%, respectively. A high correlation (K value = 0.85) between MDCT and invasive control venography was observed. On the basis of these results, MDCT shows superior sensitivity and specificity compared with USCD in those patients in whom TIPS was performed with the Viatorr stent-graft. MDCT can be considered a valid tool in the follow-up of these patients.

  5. Effect of beta blockade on single photon emission computed tomographic (SPECT) thallium-201 images in patients with coronary disease

    SciTech Connect

    Narahara, K.A.; Thompson, C.J.; Hazen, J.F.; Brizendine, M.; Mena, I.

    1989-05-01

    We evaluated the effect of beta blockers on thallium-201 (Tl-201) single photon emission computed tomographic (SPECT) imaging in 12 patients with coronary disease using an automated computer algorithm. Maximal exercise heart rate and blood pressure were reduced and exercise time was increased with beta blockers. Estimated stress defect size decreased from 47 +/- 36.3 gm during placebo treatment to 32 +/- 27.1 gm during beta blocker therapy (-32%; p less than 0.01). The placebo treatment redistribution defect was estimated to be 28 +/- 29.8 gm. It fell to 15 +/- 23.3 gm with beta blockade (-46%; p less than 0.005). All patients had a stress Tl-201 defect during placebo treatment and eight had redistribution defects consistent with residual scar. During beta blocker therapy, 2 of 12 patients had normal stress-redistribution studies and only five patients had redistribution defects. Beta blockade can reduce exercise and redistribution Tl-201 SPECT defect size significantly while simultaneously increasing exercise time and reducing angina. Beta blockers may unmask or may eliminate evidence of redistribution. Tl-201 SPECT imaging may be useful in defining the reduction in ischemia produced by cardiac drugs.

  6. Imaging pitfalls, normal anatomy, and anatomical variants that can simulate disease on cardiac imaging as demonstrated on multidetector computed tomography

    PubMed Central

    White, Charles S

    2015-01-01

    Advances in computed tomography have led to continuous improvement in cardiac imaging. Dedicated postprocessing capabilities, faster scan times, and cardiac gating methods reveal details of normal cardiac anatomy and anatomic variants that can mimic pathologic conditions. This article will review normal cardiac anatomy and variants that can mimic disease. Radiologists should be familiar with normal cardiac anatomy and anatomic variants to avoid misinterpretation of normal findings for pathologic processes. PMID:25610617

  7. Diagnosis of sclerosing cholangitis with technetium 99m-labeled iminodiacetic acid planar and single photon emission computed tomographic scintigraphy

    SciTech Connect

    Rodman, C.A.; Keeffe, E.B.; Lieberman, D.A.; Krishnamurthy, S.; Krishnamurthy, G.T.; Gilbert, S.; Eklem, M.J.

    1987-03-01

    The purpose of this study was to determine whether /sup 99m/Tc-iminodiacetic acid planar biliary scintigraphy combined with single photon emission computed tomography could detect sclerosing cholangitis and provide additional information regarding the extent and severity of disease. Thirteen patients with sclerosing cholangitis and 13 normal control subjects were studied. Scintigraphic results were also compared with previously reported studies of patients with isolated common bile duct obstruction and with primary biliary cirrhosis. The planar scintigraphy in patients with sclerosing cholangitis showed beading or bandlike constrictions of the biliary tract corresponding to lesions seen on cholangiography, and the image pattern was distinctly different from images obtained from patients with isolated common bile duct obstruction or primary biliary cirrhosis. The single photon emission computed tomography images of the liver in patients with sclerosing cholangitis demonstrated multiple focal areas of /sup 99m/Tc-iminodiacetic acid retention, representing bile stasis in intrahepatic bile ducts. Compared to controls, the mean hepatic clearance half-time of /sup 99m/Tc-iminodiacetic acid was markedly delayed in patients with sclerosing cholangitis (6-10 times normal). Individual patients with sclerosing cholangitis had wider variation in isotope clearance half-time from three regions of the liver than patients with isolated common bile duct obstruction, consistent with regional difference in disease severity and variable impairment of bile flow. In 4 patients with sclerosing cholangitis with incomplete filling of the right and left hepatic ducts at cholangiography, planar and single photon emission computed tomographic scintigraphy provided evidence of significant intrahepatic sclerosing cholangitis.

  8. COMPUTED TOMOGRAPHIC, RADIOGRAPHIC, AND ENDOSCOPIC TRACHEAL DIMENSIONS IN ENGLISH BULLDOGS WITH GRADE 1 CLINICAL SIGNS OF BRACHYCEPHALIC AIRWAY SYNDROME.

    PubMed

    Kaye, Benjamin M; Boroffka, Susanne A E B; Haagsman, Annika N; Ter Haar, Gert

    2015-01-01

    Tracheal hypoplasia is commonly seen in English Bulldogs affected with brachycephalic airway syndrome. Previously published diagnostic criteria for tracheal hypoplasia in this breed have been a radiographic tracheal diameter:tracheal inlet ratio (TD:TI) < 0.12 or a tracheal diameter:third rib diameter ratio (TD:3R) < 2.0. Computed tomography has become increasingly used for airway evaluation, however published information is lacking regarding CT tracheal dimensions in English Bulldogs. Objectives of this prospective cross-sectional study were to describe radiographic and CT tracheal dimensions in a sample of clinically normal English Bulldogs and compare these values with tracheoscopy scores. Computed tomography (n = 40), radiography (n = 38), and tracheoscopy (n = 40) studies were performed during a single general anesthesia session for each included dog. Tracheal measurements were recorded at three locations: cervical, thoracic inlet, and thorax. Tracheal diameters were narrowest at the thoracic inlet with all techniques. Computed tomographic measurements averaged 19% greater than radiographic measurements. All included dogs had radiographic tracheal measurements greater than the previously published criteria for tracheal hypoplasia. Mean CT TD:TI was 0.26 (± 0.03, 0.20-0.33), and mean CT TT:3R was 2.27 (± 0.24, 1.71-2.74). Radiographic TD:TI and CT TD:TI were significantly correlated (P = 0.00); however radiographic TT:3R and CT TT:3R were not significantly correlated (P = 0.25). Tracheoscopy identified hypoplastic changes in all dogs and tracheoscopy scores were not correlated with CT or radiography diameter measurements. In conclusion, findings indicated that some CT and radiographic tracheal diameter measurements were comparable in English Bulldogs however diameters for both imaging techniques were not comparable with tracheoscopy scores. PMID:26202379

  9. The use of a computed tomographic application for mobile devices in the diagnosis of oral and maxillofacial surgery.

    PubMed

    Aoki, Eduardo Massaharu; Cortes, Arthur Rodriguez Gonzalez; Arita, Emiko Saito

    2015-01-01

    The aim of the current technical report was to introduce a computed tomographic (CT) application for mobile devices as a diagnostic tool for analyzing CT images. An iPad and an iPhone (Apple, Cuppertino, CA) were used to navigate through multiplanar reconstructions of cone beam CT scans, using an application derived from the OsiriX CT software. Tools and advantages of this method were recorded. In addition, images rendered in the iPad were manipulated during dental implant placement and grafting procedures to follow up and confirm the implant digital planning in real time. The study population consisted of 10 patients. In all cases, it was possible to use image manipulation tools, such as changing contrast and brightness, zooming, rotating, panning, performing both linear and area measurements, and analyzing gray-scale values of a region of interest. Furthermore, it was possible to use the OsiriX application in the dental clinic where the study was conducted, to follow-up the analyzed implant placement and grafting procedures at the chairside. The current findings suggest that technological and practical methods to visualize radiographic images are invaluable resources to improve training, teaching, networking, and the performance of real-time follow-up of oral and maxillofacial surgical procedures. This article discusses the advantages and disadvantages of introducing this new technology in the clinical routine. PMID:25565229

  10. Three-dimensional computed tomographic evaluation of Le Fort III distraction osteogenesis with an external device in syndromic craniosynostosis.

    PubMed

    Wery, M F; Nada, R M; van der Meulen, J J; Wolvius, E B; Ongkosuwito, E M

    2015-03-01

    There is little anteroposterior growth of the midface in patients with syndromic craniosynostosis who are followed up over time without intervention. A Le Fort III with distraction osteogenesis can be done to correct this. This is a controlled way in which to achieve appreciable stable advancement of the midface without the need for bone grafting, but the vector of the movement is not always predictable. The purpose of this study was to evaluate the 3-dimensional effect of Le Fort III distraction osteogenesis with an external frame. Ten patients (aged 7-19 years) who had the procedure were included in the study. The le Fort III procedure and the placement of the external frame were followed by an activation period and then a 3-month retention period. Computed tomographic (CT) images taken before and after operation were converted and loaded into 3-dimensional image rendering software and compared with the aid of a paired sample t test and a colour-coded qualitative analysis. Comparison of the CT data before and after distraction indicated that the amount of midface advancement was significant. Le Fort III distraction osteogenesis is an effective way to advance the midface. However, the movement during osteogenesis is not always exactly in the intended direction, and a secondary operation is often necessary. Three-dimensional evaluation over a longer period of time is necessary. PMID:25605236

  11. Complimentary Imaging Modalities for Investigating Obscure Gastrointestinal Bleeding: Capsule Endoscopy, Double-Balloon Enteroscopy, and Computed Tomographic Enterography.

    PubMed

    Chu, Ye; Wu, Sheng; Qian, Yuting; Wang, Qi; Li, Juanjuan; Tang, Yanping; Bai, Tingting; Wang, Lifu

    2016-01-01

    Objectives. The complimentary value of computed tomographic enterography (CTE) and double-balloon enteroscopy (DBE) combined with capsule endoscopy (CE) was evaluated in the diagnosis of obscure gastrointestinal bleeding (OGIB). Methods. Patients who received CE examinations at Ruijin Hospital between July 2007 and July 2014 with the indication of OGIB were identified, and those who also underwent DBE and/or CTE were included. Their clinical information was retrieved, and results from each test were compared with findings from the other two examinations. Results. The overall diagnostic yield of CE was comparable with DBE (73.9% versus 60.9%) but was significantly higher than the yield of CTE (87% versus 25%, p < 0.001). The diagnostic yield of angiodysplasia at CE was significantly higher than CTE (73% versus 8%, p < 0.001) and DBE (39.1% versus 17.4%, p = 0.013), while no significant difference was found between the three approaches for small bowel tumors. DBE and CTE identified small bowel diseases undetected or undetermined by CE. Conversely, CE improved diagnosis in the cases with negative CTE and DBE, and findings at initial CE directed further diagnosis made by DBE. Conclusions. Combination of the three diagnostic platforms provides complementary value in the diagnosis of OGIB. PMID:26858753

  12. Renal ultrasonographic and computed tomographic appearance, volume, and function of cats with autosomal dominant polycystic kidney disease.

    PubMed

    Reichle, Jean K; DiBartola, Stephen P; Léveillé, Renée

    2002-01-01

    The purpose of this study was to describe the ultrasonographic (US) and computed tomographic (CT) appearance of autosomal dominant polycystic kidney disease (ADPKD) in cats; to compare renal volume in cats with ADPKD (n = 5; mean age 59 +/- 10 months)) and normal cats (n = 5; mean age 66 +/- 10 months) using 2 imaging modalities, US and CT; and to calculate cyst volume using CT. Glomerular filtration rate (GFR) was determined by 2 methods: 99mTc-diethylene-triaminepentaacetic acid (99mTc-DPTA) scintigraphic uptake and 99-Tc-DTPA plasma clearance. Sonographically, ADPKD affected kidneys were characterized by multiple anechoic to hypoechoic, round to irregularly shaped structures with variation in size. Affected kidneys had indistinct corticomedullary junctions and foci of mineralization. Intravenous (IV) contrast medium administration allowed more definitive identification of cysts with CT, and identification of distortion of renal pelves by cysts. A significant difference (Welch ANOVA, P = 0.05) was detected between the US-estimated renal volumes of normal and affected cats. No statistically significant differences were detected in CT volume (between the normal and affected cats, or between US and CT volume measurements) or the 2 GFR methods. In this group of clinically normal, middle-aged ADPKD cats, renal function was within normal limits and not significantly different than normal. PMID:12175002

  13. Complimentary Imaging Modalities for Investigating Obscure Gastrointestinal Bleeding: Capsule Endoscopy, Double-Balloon Enteroscopy, and Computed Tomographic Enterography

    PubMed Central

    Chu, Ye; Wu, Sheng; Qian, Yuting; Wang, Qi; Li, Juanjuan; Tang, Yanping; Bai, Tingting; Wang, Lifu

    2016-01-01

    Objectives. The complimentary value of computed tomographic enterography (CTE) and double-balloon enteroscopy (DBE) combined with capsule endoscopy (CE) was evaluated in the diagnosis of obscure gastrointestinal bleeding (OGIB). Methods. Patients who received CE examinations at Ruijin Hospital between July 2007 and July 2014 with the indication of OGIB were identified, and those who also underwent DBE and/or CTE were included. Their clinical information was retrieved, and results from each test were compared with findings from the other two examinations. Results. The overall diagnostic yield of CE was comparable with DBE (73.9% versus 60.9%) but was significantly higher than the yield of CTE (87% versus 25%, p < 0.001). The diagnostic yield of angiodysplasia at CE was significantly higher than CTE (73% versus 8%, p < 0.001) and DBE (39.1% versus 17.4%, p = 0.013), while no significant difference was found between the three approaches for small bowel tumors. DBE and CTE identified small bowel diseases undetected or undetermined by CE. Conversely, CE improved diagnosis in the cases with negative CTE and DBE, and findings at initial CE directed further diagnosis made by DBE. Conclusions. Combination of the three diagnostic platforms provides complementary value in the diagnosis of OGIB. PMID:26858753

  14. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    PubMed Central

    Kim, Jae Hun; Hwang, Jae Joon; Lee, Jung-Hee

    2016-01-01

    Purpose The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions. PMID:27358821

  15. Magnetic resonance and computed tomographic features of 4 cases of canine congenital thoracic vertebral anomalies

    PubMed Central

    Berlanda, Michele; Zotti, Alessandro; Brandazza, Giada; Poser, Helen; Calò, Pietro; Bernardini, Marco

    2011-01-01

    Magnetic resonance and computed tomography features of 4 cases of canine congenital vertebral anomalies (CVAs) are discussed. Two of the cases represent unusual presentations for such anomalies that commonly affect screw-tail or toy breeds. Moreover, the combination of CVAs and a congenital peritoneo-pericardial diaphragmatic hernia has never before been imaged. PMID:22654139

  16. Magnetic resonance and computed tomographic features of 4 cases of canine congenital thoracic vertebral anomalies.

    PubMed

    Berlanda, Michele; Zotti, Alessandro; Brandazza, Giada; Poser, Helen; Calò, Pietro; Bernardini, Marco

    2011-12-01

    Magnetic resonance and computed tomography features of 4 cases of canine congenital vertebral anomalies (CVAs) are discussed. Two of the cases represent unusual presentations for such anomalies that commonly affect screw-tail or toy breeds. Moreover, the combination of CVAs and a congenital peritoneo-pericardial diaphragmatic hernia has never before been imaged. PMID:22654139

  17. Improved vessel morphology measurements in contrast-enhanced multi-detector computed tomography coronary angiography with non-linear post-processing.

    PubMed

    Ferencik, Maros; Lisauskas, Jennifer B; Cury, Ricardo C; Hoffmann, Udo; Abbara, Suhny; Achenbach, Stephan; Karl, W Clem; Brady, Thomas J; Chan, Raymond C

    2006-03-01

    Multi-detector computed tomography (MDCT) permits detection of coronary plaque. However, noise and blurring impair accuracy and precision of plaque measurements. The aim of the study was to evaluate MDCT post-processing based on non-linear image deblurring and edge-preserving noise suppression for measurements of plaque size. Contrast-enhanced MDCT coronary angiography was performed in four subjects (mean age 55 +/- 5 years, mean heart rate 54 +/- 5 bpm) using a 16-slice scanner (Siemens Sensation 16, collimation 16 x 0.75 mm, gantry rotation 420 ms, tube voltage 120 kV, tube current 550 mAs, 80 mL of contrast). Intravascular ultrasound (IVUS; 40 MHz probe) was performed in one vessel in each patient and served as a reference standard. MDCT vessel cross-sectional images (1 mm thickness) were created perpendicular to centerline and aligned with corresponding IVUS images. MDCT images were processed using a deblurring and edge-preserving noise suppression algorithm. Then, three independent blinded observers segmented lumen and outer vessel boundaries in each modality to obtain vessel cross-sectional area and wall area in the unprocessed MDCT cross-sections, post-processed MDCT cross-sections and corresponding IVUS. The wall area measurement difference for unprocessed and post-processed MDCT images relative to IVUS was 0.4 +/- 3.8 mm2 and -0.2 +/- 2.2 mm2 (p < 0.05), respectively. Similarly, Bland-Altman analysis of vessel cross-sectional area from unprocessed and post-processed MDCT images relative to IVUS showed a measurement difference of 1.0 +/- 4.4 and 0.6 +/- 4.8 mm2, respectively. In conclusion, MDCT permitted accurate in vivo measurement of wall area and vessel cross-sectional area as compared to IVUS. Post-processing to reduce blurring and noise reduced variability of wall area measurements and reduced measurement bias for both wall area and vessel cross-sectional area. PMID:16442768

  18. Fermionic computation is non-local tomographic and violates monogamy of entanglement

    NASA Astrophysics Data System (ADS)

    D'Ariano, G. M.; Manessi, F.; Perinotti, P.; Tosini, A.

    2014-07-01

    We show that the computational model based on local fermionic modes in place of qubits does not satisfy local tomography and monogamy of entanglement, and has mixed states with maximal entanglement of formation. These features directly follow from the parity superselection rule. We generalize quantum superselection rules to general probabilistic theories as sets of linear constraints on the convex set of states. We then provide a link between the cardinality of the superselection rule and the degree of holism of the resulting theory.

  19. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-file Systems

    PubMed Central

    Prabhakar, Attiguppe R; Yavagal, Chandrashekar; Naik, Saraswathi V

    2016-01-01

    ABSTRACT Background: Primary root canals are considered to be most challenging due to their complex anatomy. "Wave one" and "one shape" are single-file systems with reciprocating and rotary motion respectively. The aim of this study was to evaluate and compare dentin thickness, centering ability, canal transportation, and instrumentation time of wave one and one shape files in primary root canals using a cone beam computed tomographic (CBCT) analysis. Study design: This is an experimental, in vitro study comparing the two groups. Materials and methods: A total of 24 extracted human primary teeth with minimum 7 mm root length were included in the study. Cone beam computed tomographic images were taken before and after the instrumentation for each group. Dentin thickness, centering ability, canal transportation, and instrumentation times were evaluated for each group. Results: A significant difference was found in instrumentation time and canal transportation measures between the two groups. Wave one showed less canal transportation as compared with one shape, and the mean instrumentation time of wave one was significantly less than one shape. Conclusion: Reciprocating single-file systems was found to be faster with much less procedural errors and can hence be recommended for shaping the root canals of primary teeth. How to cite this article: Prabhakar AR, Yavagal C, Dixit K, Naik SV. Reciprocating vs Rotary Instrumentation in Pediatric Endodontics: Cone Beam Computed Tomographic Analysis of Deciduous Root Canals using Two Single-File Systems. Int J Clin Pediatr Dent 2016;9(1):45-49. PMID:27274155

  20. Value of two-phase dynamic multidetector computed tomography in differential diagnosis of post-inflammatory strictures from esophageal cancer

    PubMed Central

    Karmazanovsky, Grigory G; Buryakina, Svetlana A; Kondratiev, Evgeny V; Yang, Qin; Ruchkin, Dmitry V; Kalinin, Dmitry V

    2015-01-01

    AIM: To characterize the computed tomography (CT) findings in patients with post-inflammatory esophageal strictures (corrosive and peptic) and reveal the optimal scanning phase protocols for distinguishing post-inflammatory esophageal stricture and esophageal cancer. METHODS: Sixty-five patients with esophageal strictures of different etiology were included in this study: 24 patients with 27 histopathologically confirmed corrosive strictures, 10 patients with 12 peptic strictures and 31 patients with esophageal cancer were evaluated with a two-phase dynamic contrast-enhanced MDCT. Arterial and venous phases at 10 and 35 s after the attenuation of 200 HU were obtained at the descending aorta, with a delayed phase at 6-8 min after the start of injection of contrast media. For qualitative analysis, CT scans of benign strictures were reviewed for the presence/absence of the following features: “target sign”, luminal mass, homogeneity of contrast medium uptake, concentric wall thickening, conically shaped suprastenotic dilatation, smooth boundaries of stenosis and smooth mucous membrane at the transition to stenosis, which were compared with a control group of 31 patients who had esophageal cancer. The quantitative analysis included densitometric parameter acquisition using regions-of-interest measurement of the zone of stenosis and normal esophageal wall and the difference between those measurements (ΔCT) at all phases of bolus contrast enhancement. Esophageal wall thickening, length of esophageal wall thickening and size of the regional lymph nodes were also evaluated. RESULTS: The presence of a concentric esophageal wall, conically shaped suprastenotic dilatation, smooth upper and lower boundaries, “target sign” and smooth mucous membrane at the transition to stenosis were suggestive of a benign cause, with sensitivities of 92.31%, 87.17%, 94.87%, 76.92% and 82.05%, respectively, and specificities of 70.96%, 89.66%, 80.65%, 96.77% and 93.55%, respectively

  1. Sector computed tomographic spine scanning in the diagnosis of lumbar nerve root entrapment

    SciTech Connect

    Risius, B.; Modic, M.T.; Hardy, R.W. Jr.; Duchesneau, P.M.; Weinstein, M.A.

    1982-04-01

    The diagnosis of lumbar nerve root entrapment was made by sector computed tomography (CT) scanning in 25 patients whose myelograms were normal at the site of the CT scan abnormalities. Sector CT scanning demonstrates preoperatively which neural foramina are narrow. This information, correlated with the patient's history and physical examination, indicates which foramina should be operated on and prevents unnecessary exploration of normal neutral foramina. CT findings were confirmed surgically in 14 patients. Eleven of these 14 patients had excellent postoperative results and remain pain free.

  2. Computed tomographic detection of sinusitis responsible for intracranial and extracranial infections

    SciTech Connect

    Carter, B.L.; Bankoff, M.S.; Fisk, J.D.

    1983-06-01

    Computed tomography (CT) is now used extensively for the evaluation of orbital, facial, and intracranial infections. Nine patients are presented to illustrate the importance of detecting underlying and unsuspected sinusitis. Prompt treatment of the sinusitis is essential to minimize the morbidity and mortality associated with complications such as brain abscess, meningitis, orbital cellulitis, and osteomyelitis. A review of the literature documents the persistence of these complications despite the widespread use of antibiotic therapy. Recognition of the underlying sinusitis is now possible with CT if the region of the sinuses is included and bone-window settings are used during the examination of patients with orbital and intracranial infection.

  3. Tomographic images of breast tissues obtained by Compton scattering: An analytical computational study

    NASA Astrophysics Data System (ADS)

    Antoniassi, M.; Poletti, M. E.; Brunetti, A.

    2015-11-01

    In this work, we studied by analytical simulation the potential of a Compton scatter technique for breast imaging application. A Compton scattering tomography system was computationally simulated in order to provide the projection data (scattering signal) for the image reconstructions. The simulated projections generated by the analytical proposed method were validated through comparison with those obtained by Monte Carlo simulation. Electron density images were obtained from the scattering signal using a reconstruction algorithm implemented for the system geometry. Finally, the quality of the reconstructed images was evaluated for different sample sizes, beam energies, and tissue compositions (glandularities).

  4. Cone Beam Computed Tomographic Evaluation and Diagnosis of Mandibular First Molar with 6 Canals

    PubMed Central

    Pasha, Shiraz; Chaitanya, Bathula Vimala; Somisetty, Kusum Valli

    2016-01-01

    Root canal treatment of tooth with aberrant root canal morphology is very challenging. So thorough knowledge of both the external and internal anatomy of teeth is an important aspect of root canal treatment. With the advancement in technology it is imperative to use modern diagnostic tools such as magnification devices, CBCT, microscopes, and RVG to confirm the presence of these aberrant configurations. However, in everyday endodontic practice, clinicians have to treat teeth with atypical configurations for root canal treatment to be successful. This case report presents the management of a mandibular first molar with six root canals, four in mesial and two in distal root, and also emphasizes the use and importance of Cone Beam Computed Tomography (CBCT) as a diagnostic tool in endodontics. PMID:26904310

  5. Carcinoma of the larynx and hypopharynx: computed tomographic-histopathologic correlations

    SciTech Connect

    Silverman, P.M.; Bossen, E.H.; Fisher, S.R.; Cole, T.B.; Korobkin, M.; Halvorsen, R.A.

    1984-06-01

    Twenty consecutive patients underwent computed tomography (CT) prior to total laryngectomy in order to assess the accuracy of CT scanning in the evaluation of carcinoma of the larynx and hypopharynx. CT scans were prospectively interpreted and the extent of tumor was recorded graphically at five major levels of the larynx. The extent of tumor was similarly evaluated on whole-mount histologic sections of the laryngeal specimens prepared in the horizontal plane similar to the CT scans. The results were compared to assess the ability of CT to identify tumor extent accurately. Despite good correlation of gross tumor extent between histologic specimens and TC scanning, specific pitfalls in CT diagnosis were identified. Overestimation of tumor extent was caused by edematous changes in six patients and tumor-associated inflammatory changes in three patients. In seven patients, mass effect from adjacent bulky tumor significantly distorted normal structures, mimicking tumor involvement.

  6. Meckel cave: computed tomographic study. Part I. Normal anatomy. Part II. Pathology

    SciTech Connect

    Kapila, A.; Chakeres, D.W.; Blanco, E.

    1984-08-01

    A formalin-fixed cadaver head with air filling the cisternal and ventricular spaces was scanned by high-resolution computed tomography (CT) in multiple planes (axial, coronal, and sagittal) through the Meckel cave. Correlation of the CT appearance of the Meckel cave was made with an anatomic dissection and whole-head band saw cross-sections. CT techniques allowed consistent and accurate definition of the Meckel cave, the fifth cranial nerve, and adjacent anatomic structures. CT findings of 13 patients with lesions of the Meckel cave are also reviewed, including six trigeminal schwannomas, three meningiomas, two secondary tumors, one glioma, and one congenital fatty tumor. Surgical confirmation was present in 11 cases. Diagnosis and determination of the extent of Meckel cave lesions is possible with the use of high-resolution CT.

  7. Multicolor Computed Tomographic Molecular Imaging with Non-crystalline High Metal Density Nanobeacons

    PubMed Central

    Pan, Dipanjan; Schirra, Carsten O.; Wickline, Samuel A; Lanza, Gregory M

    2014-01-01

    Computed tomography (CT) is one of the most frequently pursued radiology technologies applied in the clinics today and in the preclinical field of biomedical imaging. Myriad advancement has been made to make this technique more powerful with improved signal sensitivity, rapid image acquisition and faster reconstruction. Synergistic development of novel nanoparticles has been adopted as the next generation CT contrasts agents for imaging specific biological markers. Nanometer-sized agents are anticipated to play a critical part in the prospect of medical diagnostics owing to their capabilities of targeting specific biological markers, extended blood circulation time and defined biological clearance. This review paper introduces the readers to the fundamental design principles of nanoparticulate CT contrast agents with a special emphasis on the molecular Imaging with non-crystalline high metal density nanobeacons. PMID:24470291

  8. Intracranial lesions in the acquired immunodeficiency syndrome: radiological (computed tomographic) features

    SciTech Connect

    Elkin, C.M.; Leon, E.; Grenell, S.L.; Leeds, N.E.

    1985-01-18

    Computed tomography (CT) delineates the presence or absence of intracerebral focal lesions in most instances. The presence of contrast enhancement, cerebral atrophy, and an intracranial mass are important in consideration of the differential diagnosis and in establishing the diagnosis. Initially the authors utilized a double dose of contrast medium in all patients after single-dose study, but little additional information was obtained. A second dose of contrast medium is now administered only to evaluate further a suspected lesion. Angiography can confirm the location of the lesion(s) and the cortical veins before biopsy. Of one hundred patients with AIDS examined, 33% had neurological symptoms excluding headache and herpes zoster. All patients with neurological symptoms were studied with noncontrast and contrast CT scanning. Twenty-seven patients in the group had abnormal scans. In 13, the abnormality was limited to a diffuse atrophic appearance, while in 14, focal lesions were identified. Representative cases are discussed and illustrated.

  9. Computed Tomographic Features in a Case of Bilateral Neoplastic Cryptorchidism with Suspected Torsion in a Dog

    PubMed Central

    Stokowski, Scott; Ruth, Jeffrey; Lanz, Otto; Ziglioli, Vincent

    2016-01-01

    An 11-year-old male German Shepherd dog presented for inappetence and weight loss. Physical examination and initial bloodwork revealed palpable abdominal masses, mild non-regenerative anemia, and thrombocytopenia. Survey radiography and abdominal ultrasonography confirmed the presence of bilateral abdominal masses and lymphadenopathy. Contrast-enhanced computed tomography (CT) was performed in order to further investigate the origin of the intraabdominal masses, confirming two enlarged cryptorchid testes, one of which had an associated CT “whirl sign.” Histopathology of the testes and lymph nodes revealed bilateral malignant Sertoli cell tumors and seminomas with lymph node metastasis of both neoplasms. The purpose of this case report is to discuss the benefits of CT in the diagnosis of cryptorchid testes and describe an additional organ that may display CT “whirl sign.” PMID:27200365

  10. Hyperspectral datacube estimations of binary stars with the Computed Tomographic Imaging Spectrometer (CTIS)

    NASA Astrophysics Data System (ADS)

    Scholl, James F.; Hege, E. Keith; O'Connell, Daniel G.; Dereniak, Eustace L.

    2010-08-01

    Using mathematical techniques recently adapted for the analysis of hyperspectral imaging systems such as the CTIS, we have performed datacube reconstructions for a number of binary star systems. The CTIS images in the visible (420nm to 720nm) wavelength range were obtained in 2001 using the 3.67m Advanced Electro Optical System (AEOS) of the Maui Space Surveillance System (MSSS). These methods used an analytical model of the CTIS to construct an imaging system operator from optical, focal plane array and Computer Generated Holographic (CGH) disperser parameters in the CTIS. We used the adjoint of this operator to construct matched filtered estimates of the datacubes from the image data. In these reconstructions we are able to simultaneously obtain information on the geometry and relative photometry of the binary systems as well as the spectrum for each component of the system.

  11. Computed tomographic assessment of maxillary sinus wall thickness in edentulous patients.

    PubMed

    Yang, S-M; Park, S-I; Kye, S-B; Shin, S-Y

    2012-06-01

    Posterior maxillary region is considered to be the most challenging area for dental implant placement. Lateral window opening is the gold standard procedure for maxillary sinus augmentation in this area. The purpose of this study is to evaluate lateral wall thickness of the maxillary sinus for sinus augmentation using computed tomography (CT) in edentulous patients. Computed tomography images of 302 patients were analysed. Using the maxillary sinus floor as the reference point in edentulous regions, lateral wall thickness was measured on CT scans. After drawing a tangent line at the lowest point of the sinus floor, another perpendicular line to the tangent line was drawn at the same point of the sinus floor. Thickness of the lateral wall of the maxillary sinus was measured using 10DR implant software at 3 (R1), 10 (R2) and 15 mm (R3) from the sinus floor. The mean thickness of the lateral wall of the maxillary sinus from the first premolar to second molar was 1·69 ± 0·71, 1·50 ± 0·72, 1·77 ± 0·78 and 1·89 ± 0·85 mm, respectively. The thickness differed significantly at the R2 and R3 points. Women had thinner lateral walls at the R1 and R2 points at the premolars than did men. At the R2 and R3 points at the second premolar, the mean thickness of smokers was larger than that of non-smokers. There were no significant differences on age or reasons for tooth loss. The changes in the thickness of the lateral wall at different reference points were observed, and CT examinations may help make lateral window without membrane perforation. PMID:22471834

  12. Development of an electrical impedance computed tomographic two-phase flows analyzer. Final report

    SciTech Connect

    Ovacik, L.; Jones, O.C.

    1998-08-01

    This report summarizes the work on the research project on this cooperative program between DOE and Hitachi, Ltd. Major advances were made in the computational reconstruction of images from electrical excitation and response data with respect to existing capabilities reported in the literature. A demonstration is provided of the imaging of one or more circular objects within the measurement plane with demonstrated linear resolution of six parts in two hundred. At this point it can be said that accurate excitation and measurement of boundary voltages and currents appears adequate to obtain reasonable images of the real conductivity distribution within a body and the outlines of insulating targets suspended within a homogeneous conducting medium. The quality of images is heavily dependent on the theoretical and numerical implementation of imaging algorithms. The overall imaging system described has the potential of being both fast and cost effective in comparison with alternative methods. The methods developed use multiple plate-electrode excitation in conjunction with finite element block decomposition, preconditioned voltage conversion, layer approximation of the third dimension and post processing of boundary measurements to obtain optimal boundary excitations. Reasonably accurate imaging of single and multiple targets of differing size, location and separation is demonstrated and the resulting images are better than any others found in the literature. Recommendations for future effort include the improvement in computational algorithms with emphasis on internal conductivity shape functions and the use of adaptive development of quadrilateral (2-D) or tetrahedral or hexahedral (3-D) elements to coincide with large discrete zone boundaries in the fields, development of a truly binary model and completion of a fast imaging system. Further, the rudimentary methods shown herein for three-dimensional imaging need improving.

  13. Use of Coronary Computed Tomographic Angiography to Guide Management of Patients With Coronary Disease

    PubMed Central

    Williams, Michelle C.; Hunter, Amanda; Shah, Anoop S.V.; Assi, Valentina; Lewis, Stephanie; Smith, Joel; Berry, Colin; Boon, Nicholas A.; Clark, Elizabeth; Flather, Marcus; Forbes, John; McLean, Scott; Roditi, Giles; van Beek, Edwin J.R.; Timmis, Adam D.; Newby, David E.

    2016-01-01

    Background In a prospective, multicenter, randomized controlled trial, 4,146 patients were randomized to receive standard care or standard care plus coronary computed tomography angiography (CCTA). Objectives The purpose of this study was to explore the consequences of CCTA-assisted diagnosis on invasive coronary angiography, preventive treatments, and clinical outcomes. Methods In post hoc analyses, we assessed changes in invasive coronary angiography, preventive treatments, and clinical outcomes using national electronic health records. Results Despite similar overall rates (409 vs. 401; p = 0.451), invasive angiography was less likely to demonstrate normal coronary arteries (20 vs. 56; hazard ratios [HRs]: 0.39 [95% confidence interval (CI): 0.23 to 0.68]; p < 0.001) but more likely to show obstructive coronary artery disease (283 vs. 230; HR: 1.29 [95% CI: 1.08 to 1.55]; p = 0.005) in those allocated to CCTA. More preventive therapies (283 vs. 74; HR: 4.03 [95% CI: 3.12 to 5.20]; p < 0.001) were initiated after CCTA, with each drug commencing at a median of 48 to 52 days after clinic attendance. From the median time for preventive therapy initiation (50 days), fatal and nonfatal myocardial infarction was halved in patients allocated to CCTA compared with those assigned to standard care (17 vs. 34; HR: 0.50 [95% CI: 0.28 to 0.88]; p = 0.020). Cumulative 6-month costs were slightly higher with CCTA: difference $462 (95% CI: $303 to $621). Conclusions In patients with suspected angina due to coronary heart disease, CCTA leads to more appropriate use of invasive angiography and alterations in preventive therapies that were associated with a halving of fatal and non-fatal myocardial infarction. (Scottish COmputed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590) PMID:27081014

  14. Evidence for dysanapsis using computed tomographic imaging of the airways in older ex-smokers

    PubMed Central

    Guenette, Jordan A.; Yuan, Ren; Holy, Lukas; Mayo, John R.; McWilliams, Annette M.; Lam, Stephen; Coxson, Harvey O.

    2009-01-01

    We sought to determine the relationship between lung size and airway size in men and women of varying stature. We also asked if men and women matched for lung size would still have differences in airway size and if so where along the pulmonary airway tree would these differences exist. We used computed tomography to measure airway luminal areas of the large and central airways. We determined airway luminal areas in men (n = 25) and women (n = 25) who were matched for age, body mass index, smoking history, and pulmonary function and in a separate set of men (n = 10) and women (n = 11) who were matched for lung size. Men had greater values for the larger airways and many of the central airways. When male and female subjects were pooled there were significant associations between lung size and airway size. Within the male and female groups the magnitudes of these associations were decreased or nonsignificant. In males and females matched for lung size women had significantly smaller airway luminal areas. The larger conducting airways in females are significantly smaller than those of males even after controlling for lung size. PMID:19762522

  15. Computed tomographic imaging of dogs with primary laryngeal or tracheal airway obstruction.

    PubMed

    Stadler, Krystina; Hartman, Susan; Matheson, Jodi; O'Brien, Robert

    2011-01-01

    Seventeen dogs with clinical signs attributable to nonneoplastic obstruction of the larynx, trachea, or large bronchi underwent computed tomography (CT) imaging. In 16 of the 17 dogs, CT was performed without general anesthesia using a positioning device. Fifteen of these 16 dogs were imaged without sedation or general anesthesia. Three-dimensional (3D) internal rendering was performed on each image set based on lesion localization determined by routine image planes. Visual laryngeal examination, endoscopy, video fluoroscopy, and necropsy were used for achieving the cause of the upper airway obstruction. The CT and 3D internal rendering accurately indicated the presence and cause of upper airway obstruction in all dogs. CT findings indicative of laryngeal paralysis included failure to abduct the arytenoid cartilages, narrowed rima glottis, and air-filled laryngeal ventricles. Laryngeal collapse findings depended on the grade of collapse and included everted laryngeal saccules, collapse of the cuneiform processes and corniculate processes, and narrowed rima glottis. Trachea abnormalities included hypoplasia, stenosis, or collapse syndrome. The CT findings in tracheal hypoplasia consisted of a severely narrowed lumen throughout the entire length. Tracheal stenosis was represented by a circumferential decrease in tracheal lumen size limited to one region. Tracheal collapse syndrome was diagnosed by severe asymmetric narrowing. Lobar bronchi collapse appeared in CT images as a narrowed asymmetric lumen diameter. CT imaging of unanesthetized dogs with upper airway obstruction compares favorably with traditional definitive diagnostic methods. PMID:21447037

  16. Computed tomographic evaluation of cervical vertebral canal and spinal cord morphometry in normal dogs

    PubMed Central

    Seo, Eunjeong; Choi, Jihye; Choi, Mincheol

    2014-01-01

    The height, width, and cross-sectional area of the vertebral canal and spinal cord along with the area ratio of spinal cord to vertebral canal in the cervical vertebra were evaluated in images obtained using computed tomography (CT). Measurements were taken at the cranial, middle, and caudal point of each cervical vertebra in eight clinically normal small breed dogs (two shih tzu, two miniature schnauzers, and four mixed breed), 10 beagles, and four German shepherds. CT myelography facilitated the delineation of the epidural space, subarachnoid space, and spinal cord except at the caudal portion of the 7th cervical vertebra. The spinal cord had a tendency to have a clear ventral border in the middle portion of the vertebral canal and lateral borders near both end plates. The height, width, and area of the vertebral canal and spinal cord in the cervical vertebra were increased as the size of dog increased. However, the ratio of the spinal cord area to vertebral canal area in the small dogs was higher than that of the larger dogs. Results of the present study could provide basic and quantitative information for CT evaluation of pathologic lesions in the cervical vertebra and spinal cord. PMID:24136210

  17. Three-dimensional segmentation of the tumor mass in computed tomographic images of neuroblastoma

    NASA Astrophysics Data System (ADS)

    Deglint, Hanford J.; Rangayyan, Rangaraj M.; Boag, Graham S.

    2004-05-01

    Tumor definition and diagnosis require the analysis of the spatial distribution and Hounsfield unit (HU) values of voxels in computed tomography (CT) images, coupled with a knowledge of normal anatomy. Segmentation of the tumor in neuroblastoma is complicated by the fact that the mass is almost always heterogeneous in nature; furthermore, viable tumor, necrosis, fibrosis, and normal tissue are often intermixed. Rather than attempt to separate these tissue types into distinct regions, we propose to explore methods to delineate the normal structures expected in abdominal CT images, remove them from further consideration, and examine the remaining parts of the images for the tumor mass. We explore the use of fuzzy connectivity for this purpose. Expert knowledge provided by the radiologist in the form of the expected structures and their shapes, HU values, and radiological characteristics are also incorporated in the segmentation algorithm. Segmentation and analysis of the tissue composition of the tumor can assist in quantitative assessment of the response to chemotherapy and in the planning of delayed surgery for resection of the tumor. The performance of the algorithm is evaluated using cases acquired from the Alberta Children's Hospital.

  18. On-Site Geologic Core Analysis Using a Portable X-ray ComputedTomographic System

    SciTech Connect

    Freifeld, Barry M.; Kneafsey, Timothy J.; Rack, Frank

    2004-03-01

    X-ray computed tomography (CT) is an established techniquefor nondestructively characterizing geologic cores. CT providesinformation on sediment structure, diagenetic alteration, fractures, flowchannels and barriers, porosity, and fluid-phase saturation. A portableCT imaging system has been developed specifically for imaging whole-roundcores at the drilling site. The new system relies upon carefully designedradiological shielding to minimize the size and weight of the resultinginstrument. Specialized x-ray beam collimators and filters maximizesystem sensitivity and performance. The system has been successfullydeployed on the research vessel Joides Resolution for Ocean DrillingProgram's Leg 204 and 210, within the Ocean Drilling Program'srefrigerated Gulf Coast Core Repository, as well as on the Hot Ice #1drilling platform located near the Kuparuk Field, Alaska. A methodologyfor performingsimple densiometry measurements, as well as scanning forgross structural features, will be presented using radiographs from ODPLeg 204. Reconstructed CT images from Hot Ice #1 will demonstrate the useof CT for discerning core textural features. To demonstrate the use of CTto quantitatively interpret dynamic processes, we calculate 95 percentconfidence intervals for density changes occurring during a laboratorymethane hydrate dissociation experiment. The field deployment of a CTrepresents a paradigm shift in core characterization, opening up thepossibility for rapid systematic characterization of three-dimensionalstructural features and leading to improved subsampling andcore-processing procedures.

  19. Gross, Histologic, and Computed Tomographic Anatomy of the Lacrimal System of Snakes

    PubMed Central

    Souza, Nicole M.; Maggs, David J.; Park, Shin Ae; Puchalski, Sarah; Reilly, Christopher M.; Paul-Murphy, Joanne; Murphy, Christopher J.

    2014-01-01

    Objective To describe the lacrimal system of snakes using contrast micro-computed tomography (micro-CT) with 3-dimensional reconstruction, fluorescein passage (“Jones”) testing, histology, and gross dissection. Animals studied One Royal Python and 19 snake cadavers representing 10 species. Procedures Direct observation following injection of fluorescein into the subspectacular space, micro-CT following injection of 3 contrast agents into the subspectacular space, gross dissection following injection of latex into the subspectacular space, and histopathology. Results Injection of fluorescein confirmed patency but not course of the lacrimal duct. Barium enabled clear visualization of the lacrimal duct whereas two iodinated contrast agents proved inadequate. Collectively, micro-CT, anatomic dissections, and histology suggest tears are produced by a single, large, serous, retrobulbar gland, released into the subspectacular space via several ductules, and drained through a single punctum originating in the ventronasal subspectacular space and the lacrimal duct taking one of 3 routes of variable tortuosity before opening into the oral cavity in close association with the opening of the duct of the vomeronasal organ. Conclusions The ophidian lacrimal duct has a generally tortuous course and the details of its anatomy is species variable. The tortuous course of the duct likely predisposes snakes to duct occlusion and must be considered when planning medical and surgical interventions in snakes with pseudobuphthalmos and subspectacular abscessation. PMID:24862081

  20. Shaping Ability of Single-file Systems with Different Movements: A Micro-computed Tomographic Study

    PubMed Central

    Santa-Rosa, Joedy; de Sousa-Neto, Manoel Damião; Versiani, Marco Aurelio; Nevares, Giselle; Xavier, Felipe; Romeiro, Kaline; Cassimiro, Marcely; Leoni, Graziela Bianchi; de Menezes, Rebeca Ferraz; Albuquerque, Diana

    2016-01-01

    Introduction: This study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (MB) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (WaveOne with reciprocating motion and OneShape with rotary movement), using micro-computed tomography (micro-CT). Methods and Materials: Ten MB roots with single canals were included, uniformly distributed into two groups (n=5). The samples were prepared with a WaveOne or OneShape files. The shaping ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The Kolmogorov-Smirnov and t-tests were used for statistical analysis. The level of significance was set at 0.05. Results: Instrumentation of canals increased their surface area and volume. Canal transportation occurred in coronal, middle and apical thirds and no statistical difference was observed between the two systems (P>0.05). In apical third, significant differences were found between groups in canal roundness (in 3 mm level) and perimeter (in 3 and 4 mm levels) (P<0.05). Conclusion: The WaveOne and One Shape single-file systems were able to shape curved root canals, producing minor changes in the canal curvature. PMID:27471537

  1. Computed tomographic arthrography of the intercarpal ligaments of the equine carpus.

    PubMed

    Gray, Sarah N; Puchalski, Sarah M; Galuppo, Larry D

    2013-01-01

    Injuries of the intercarpal ligaments are an important cause of lameness in performance horses. The purpose of this prospective cadaver study was to determine whether computed tomography (CT) arthrography would be a feasible method for visualizing and characterizing intercarpal ligaments in the horse. One cadaver limb from each of eight nonlame horses was collected immediately after euthanasia. For each limb, overlapping 2.0 mm CT images were acquired before and after injection of iodinated contrast medium into the antebrachiocarpal joint, middle carpal joint, and carpal sheath. Spin echo magnetic resonance imaging (MRI) sequences were acquired in three planes using a 1.5 Tesla MRI scanner in three limbs. Following MRI, colored resin was injected into the synovial structures of these three limbs, limbs were frozen, and anatomic sections were obtained in three planes. Findings from CT arthrograms were compared to findings from precontrast CT, MRI, anatomic slices, and arthroscopy. Medial and lateral palmar intercarpal ligaments, radiocarpal and transverse intercarpal ligaments, and palmar carpal ligament were visible in CT arthrograms of all limbs. The proximal and distal entheses of all ligaments were readily identifiable. Findings indicated that CT arthrography is feasible for visualizing intercarpal ligaments and may be a useful adjunct imaging technique for diagnosing lameness due to suspected carpal ligament injury in horses. PMID:23489249

  2. Computed tomographic findings in dogs and cats with temporomandibular joint disorders: 58 cases (2006–2011)

    PubMed Central

    Arzi, Boaz; Cissell, Derek D.; Verstraete, Frank J. M.; Kass, Philip H.; DuRaine, Grayson D.; Athanasiou, Kyriacos A.

    2013-01-01

    Objective To describe CT findings in dogs and cats with temporomandibular joint (TMJ) disorders. Design Retrospective case-series. Animals 41 dogs and 17 cats. Procedures Medical records and CT images of the skull were reviewed for dogs and cats that were examined at a dentistry and oral surgery specialty practice between 2006 and 2011. Results Of 142 dogs and 42 cats evaluated, 41 dogs and 17 cats had CT findings consistent with a TMJ disorder. In dogs, the most common TMJ disorder was osteoarthritis; however, in most cases, there were other TMJ disorders present in addition to osteoarthritis. Osteoarthritis was more frequently identified at the medial aspect rather than the lateral aspect of the TMJ, whereas the frequency of osteoarthritic involvement of the dorsal and ventral compartments did not differ significantly. In cats, fractures were the most common TMJ disorder, followed by osteoarthritis. Clinical signs were observed in all dogs and cats with TMJ fractures, dysplasia, ankylosis, luxation, and tumors; however, only 4 of 15 dogs and 2 of 4 cats with osteoarthritis alone had clinical signs. Conclusions and Clinical Relevance Results indicated that TMJ disorders are frequently present in combination. Osteoarthritis was the most common TMJ disorder in dogs and the second most common TMJ disorder in cats. Computed tomography should be considered as a tool for the diagnosis of TMJ disorders in dogs and cats with suspected orofacial disorders and pain. PMID:23234284

  3. COMPUTED TOMOGRAPHIC ANATOMY AND CHARACTERISTICS OF RESPIRATORY ASPERGILLOSIS IN JUVENILE WHOOPING CRANES

    PubMed Central

    Kelley, Cristin; Pinkerton, Marie E.; Hartup, Barry K.

    2015-01-01

    Respiratory diseases are a leading cause of morbidity and mortality in captivity reared, endangered whooping cranes (Grus americana). Objectives of this retrospective, case series, cross‐sectional study were to describe computed tomography (CT) respiratory anatomy in a juvenile whooping crane without respiratory disease, compare CT characteristics with gross pathologic characteristics in a group of juvenile whooping cranes with respiratory aspergillosis, and test associations between the number of CT tracheal bends and bird sex and age. A total of 10 juvenile whooping cranes (one control, nine affected) were included. Seven affected cranes had CT characteristics of unilateral extrapulmonary bronchial occlusion or wall thickening, and seven cranes had luminal occlusion of the intrapulmonary primary or secondary bronchi. Air sac membrane thickening was observed in three cranes in the cranial and caudal thoracic air sacs, and air sac diverticulum opacification was observed in four cranes. Necropsy lesions consisted of severe, subacute to chronic, focally extensive granulomatous pathology of the trachea, primary bronchi, lungs, or air sacs. No false positive CT scan results were documented. Seven instances of false negative CT scan results occurred; six of these consisted of subtle, mild air sacculitis including membrane opacification or thickening, or the presence of small plaques found at necropsy. The number of CT tracheal bends was associated with bird age but not sex. Findings supported the use of CT as a diagnostic test for avian species with respiratory disease and tracheal coiling or elongated tracheae where endoscopic evaluation is impractical. PMID:26592357

  4. COMPUTED TOMOGRAPHIC ANATOMY AND CHARACTERISTICS OF RESPIRATORY ASPERGILLOSIS IN JUVENILE WHOOPING CRANES.

    PubMed

    Schwarz, Tobias; Kelley, Cristin; Pinkerton, Marie E; Hartup, Barry K

    2016-01-01

    Respiratory diseases are a leading cause of morbidity and mortality in captivity reared, endangered whooping cranes (Grus americana). Objectives of this retrospective, case series, cross-sectional study were to describe computed tomography (CT) respiratory anatomy in a juvenile whooping crane without respiratory disease, compare CT characteristics with gross pathologic characteristics in a group of juvenile whooping cranes with respiratory aspergillosis, and test associations between the number of CT tracheal bends and bird sex and age. A total of 10 juvenile whooping cranes (one control, nine affected) were included. Seven affected cranes had CT characteristics of unilateral extrapulmonary bronchial occlusion or wall thickening, and seven cranes had luminal occlusion of the intrapulmonary primary or secondary bronchi. Air sac membrane thickening was observed in three cranes in the cranial and caudal thoracic air sacs, and air sac diverticulum opacification was observed in four cranes. Necropsy lesions consisted of severe, subacute to chronic, focally extensive granulomatous pathology of the trachea, primary bronchi, lungs, or air sacs. No false positive CT scan results were documented. Seven instances of false negative CT scan results occurred; six of these consisted of subtle, mild air sacculitis including membrane opacification or thickening, or the presence of small plaques found at necropsy. The number of CT tracheal bends was associated with bird age but not sex. Findings supported the use of CT as a diagnostic test for avian species with respiratory disease and tracheal coiling or elongated tracheae where endoscopic evaluation is impractical. PMID:26592357

  5. X-ray Computed Tomographic Investigation of the Porosity and Morphology of Plasma Electrolytic Oxidation Coatings.

    PubMed

    Zhang, Xun; Aliasghari, Sepideh; Němcová, Aneta; Burnett, Timothy L; Kuběna, Ivo; Šmíd, Miroslav; Thompson, George E; Skeldon, Peter; Withers, Philip J

    2016-04-01

    Plasma electrolytic oxidation (PEO) is of increasing interest for the formation of ceramic coatings on metals for applications that require diverse coating properties, such as wear and corrosion resistance, low thermal conductivity, and biocompatibility. Porosity in the coatings can have an important impact on the coating performance. However, the quantification of the porosity in coatings can be difficult due to the wide range of pore sizes and the complexity of the coating morphology. In this work, a PEO coating formed on titanium is examined using high resolution X-ray computed tomography (X-ray CT). The observations are validated by comparisons of surface views and cross-sectional views of specific coating features obtained using X-ray CT and scanning electron microscopy. The X-ray CT technique is shown to be capable of resolving pores with volumes of at least 6 μm(3). Furthermore, the shapes of large pores are revealed and a correlation is demonstrated between the locations of the pores, nodules on the coating surface, and depressions in the titanium substrate. The locations and morphologies of the pores, which constitute 5.7% of the coating volume, indicate that they are generated by release of oxygen gas from the molten coating. PMID:26974706

  6. Abdominal computed tomographic scan-merits and demerits over ultrasonography: evaluation of 70 cases.

    PubMed

    Obajimi, M O; Ogunseyinde, A O; Agunloye, A M

    2002-06-01

    Computed tomography (CT) and Ultrasonography (USS) are commonly used to ascertain the cause of abdominal symptoms. In a retrospective study of 70 Nigerian patients who had abdominal ultrasonography prior to abdominal CT scans, the most frequent clinical feature was abdominal pain, which was reported in 20.8% of the patients. The prevalent ultrasonographic finding was hepatomegaly (12.2%) while bowel displacement was the most frequently reported CT finding (18.3%). There was no correlation between USS and CT findings in 11 patients (15.7%). There was some agreement in the findings of both tests in 75.7% of cases. Additional findings were noted in 38 (54.3%) of the latter group of patients on CT scans. Hundred percent agreement was reported in both imaging techniques in 5 radiological findings namely: dilated gall bladder, renal cysts, ascites, adrenal mass and utero-cervical mass. These findings suggest a high yield of diagnostic accuracy from abdominal sonography and increased diagnostic details provided by CT imaging. Our overall impression is that the diagnostic information provided by the two techniques are complimentary. PMID:12518911

  7. Computed Tomographic presentation of obstructive jejunal adenocarcinoma associated with celiac disease and incomplete intestinal malrotation

    PubMed Central

    Ines, Marzouk Moussa; Ennaifer, Rym; Omrani, Sahir; Ahlem, Lahmar Boufaroua; Ouji, Rym; Hendaoui, Lotfi

    2015-01-01

    Introduction Small bowel adenocarcinoma is a rare entity most frequently observed with celiac disease. This is the first case report on the association of celiac disease, small bowel adenocarcinoma and intestinal malrotation. Case report A 40 year-old male patient diagnosed with celiac disease since the age of 5 years complained of epigastric pain and vomiting for three days. Computed tomography (CT) showed a significant gastroduodenal dilatation with thickened intestinal wall proximal to the duodenojejunal flexure. The lumen contained a food bezoar in the center. The duodenojejunal angle was abnormally on the right side of the abdomen and the superior mesenteric vein was anterior to the superior mesenteric artery. Endoscopy after aspiration found a hemi-circumferential and irregular mass which bled at the contact of fibroscope. Biopsies showed an adenocarcinoma and small bowel resection was performed. Discussion Celiac disease is associated with a high risk of small bowel cancer. The association of incomplete intestinal malrotation, duodenojejunal flexure tumor and celiac disease made the surgery challenging. Conclusion Patients with celiac disease should be carefully monitored and endoscopic or radiologic investigations should be carried out in patients with any doubtful symptoms. PMID:26670410

  8. Automatic segmentation of the ribs, the vertebral column, and the spinal canal in pediatric computed tomographic images.

    PubMed

    Banik, Shantanu; Rangayyan, Rangaraj M; Boag, Graham S

    2010-06-01

    We propose methods to perform automatic identification of the rib structure, the vertebral column, and the spinal canal in computed tomographic (CT) images of pediatric patients. The segmentation processes for the rib structure and the vertebral column are initiated using multilevel thresholding and the results are refined using morphological image processing techniques with features based on radiological and anatomical prior knowledge. The Hough transform for the detection of circles is applied to a cropped edge map that includes the thoracic vertebral structure. The centers of the detected circles are used to derive the information required for the opening-by-reconstruction algorithm used to segment the spinal canal. The methods were tested on 39 CT exams of 13 patients; the results of segmentation of the vertebral column and the spinal canal were assessed quantitatively and qualitatively by comparing with segmentation performed independently by a radiologist. Using 13 CT exams of six patients, including a total of 458 slices with the vertebra from different sections of the vertebral column, the average Hausdorff distance was determined to be 3.2 mm with a standard deviation (SD) of 2.4 mm; the average mean distance to the closest point (MDCP) was 0.7 mm with SD = 0.6 mm. Quantitative analysis was also performed for the segmented spinal canal with three CT exams of three patients, including 21 slices with the spinal canal from different sections of the vertebral column; the average Hausdorff distance was 1.6 mm with SD = 0.5 mm, and the average MDCP was 0.6 mm with SD = 0.1 mm. PMID:19219504

  9. Utility of an advanced digital electronic stethoscope in the diagnosis of coronary artery disease compared with coronary computed tomographic angiography.

    PubMed

    Makaryus, Amgad N; Makaryus, John N; Figgatt, Alan; Mulholland, Dan; Kushner, Harvey; Semmlow, John L; Mieres, Jennifer; Taylor, Allen J

    2013-03-15

    The detection of coronary artery microbruits, subaudible bruits too faint to be heard through standard auscultation, may provide an alternative means to diagnose coronary artery disease (CAD). The aim of this study was to test the accuracy of a novel digital electronic stethoscope, the Cardiac Sonospectrographic Analyzer (CSA; SonoMedica model 3.0, SonoMedica, Inc., Vienna, Virginia, United States Food and Drug Administration 510[k] cleared) to diagnose CAD compared to gold-standard diagnosis using cardiac computed tomographic (CT) angiography. In this blinded, single-site study, adults previously referred for CT imaging were selected. Patients underwent CT and CSA evaluations. CSA exams entailed recording heart sounds at 9 positions on the chest for 40 seconds at each position. An algorithm then processed these data to generate a microbruit score. The CT scans were read blinded to patients' microbruit scores. Sensitivity and specificity of the CSA in detecting CAD compared to CT imaging were estimated using standard receiver-operating characteristic curves calculated from logistic regression models. A total of 161 patients, aged 57 ± 13 years (range 22 to 85), 53% with hypertension and 40% with obesity (body mass index ≥30 kg/m(2)), completed the protocol and had evaluable CT and CSA examinations. The overall sensitivity of the CSA to identify >50% stenosis in any major epicardial coronary artery as determined by CT imaging was 89.5% (p <0.0001). Gender-specific models based on smaller sample sizes had slightly poorer results and lower specificity among men with heavy chest hair. In conclusion, the CSA showed high sensitivity and specificity for the detection of significant early CAD in an outpatient setting and represents a new noninvasive device for detecting abnormal coronary blood flow as occurs in CAD. PMID:23290309

  10. Comparative analysis of fluorescent angiography, computed tomographic angiography and magnetic resonance angiography for planning autologous breast reconstruction

    PubMed Central

    Chae, Michael P.; Hunter-Smith, David J.

    2015-01-01

    Background The high incidence of breast cancer and growing number of breast cancer patients undergoing mastectomy has led to breast reconstruction becoming an important part of holistic treatment for these patients. In planning autologous reconstructions, preoperative assessment of donor site microvascular anatomy with advanced imaging modalities has assisted in the appropriate selection of flap donor site, individual perforators, and lead to an overall improvement in flap outcomes. In this review, we compare the accuracy of fluorescent angiography, computed tomographic angiography (CTA), and magnetic resonance angiography (MRA) and their impact on clinical outcomes. Methods A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE was undertaken. Results Fluorescent angiography is technically limited by its inability to evaluate deep-lying perforators and hence, it has a minimal role in the preoperative setting. However, it may be useful intraoperatively in evaluating microvascular anastomotic patency and the mastectomy skin perfusion. CTA is currently widely considered the standard, due to its high accuracy and reliability. Multiple studies have demonstrated its ability to improve clinical outcomes, such as operative length and flap complications. However, concerns surrounding exposure to radiation and nephrotoxic contrast agents exist. MRA has been explored, however despite recent advances, the image quality of MRA is considered inferior to CTA. Conclusions Preoperative imaging is an essential component in planning autologous breast reconstruction. Fluorescent angiography presents minimal role as a preoperative imaging modality, but may be a useful intraoperative adjunct to assess the anastomosis and the mastectomy skin perfusion. Currently, CTA is the gold standard preoperatively. MRA has a role, particularly for women of younger age, iodine allergy, and renal impairment. PMID

  11. Original Protocol Using Computed Tomographic Angiography for Diagnosis of Brain Death: A Better Alternative to Standard Two-Phase Technique?

    PubMed

    Sawicki, Marcin; Sołek-Pastuszka, Joanna; Jurczyk, Krzysztof; Skrzywanek, Piotr; Guziński, Maciej; Czajkowski, Zenon; Mańko, Witold; Burzyńska, Małgorzata; Safranow, Krzysztof; Poncyljusz, Wojciech; Walecka, Anna; Rowiński, Olgierd; Walecki, Jerzy; Bohatyrewicz, Romuald

    2015-01-01

    BACKGROUND The application of computed tomographic angiography (CTA) for the diagnosis of brain death (BD) is limited because of the low sensitivity of the commonly used two-phase method consisting of assessing arterial and venous opacification at the 60th second after contrast injection. The hypothesis was that a reduction in the scanning delay might increase the sensitivity of the test. Therefore, an original technique using CTA was introduced and compared with catheter angiography as a reference. MATERIAL AND METHODS In a prospective multicenter trial, 84 clinically brain-dead patients were examined using CTA and catheter angiography. The sensitivities of original CTA technique, involving an arterial assessment at the 25th second and a venous assessment at the 40th second, and the standard CTA, involving an arterial and venous assessment at the 60th second, were compared to catheter angiography. RESULTS Catheter angiography results were consistent with the clinical diagnosis of BD in all cases. In comparison to catheter angiography, the sensitivity of original CTA technique was 0.93 (95%CI, 0.85-0.97; p<0.001) and 0.57 (95%CI, 0.46-0.68; p<0.001) for the standard protocol. The differences were statistically significant (p=0.03 for original CTA and p<0.001 for standard CTA). Decompressive craniectomy predisposes to a false-negative CTA result with a relative risk of 3.29 (95% CI, 1.76-5.81; p<0.001). CONCLUSIONS Our original technique using CTA for the assessment of the cerebral arteries during the arterial phase and the deep cerebral veins with a delay of 15 seconds is a highly sensitive test for the diagnosis of BD. This method may be a better alternative to the commonly used technique. PMID:26250464

  12. COMPUTED TOMOGRAPHIC APPEARANCE OF MELANOMAS IN THE EQUINE HEAD: 13 CASES.

    PubMed

    Dixon, Jonathon; Smith, Ken; Perkins, Justin; Sherlock, Ceri; Mair, Tim; Weller, Renate

    2016-05-01

    Melanomas are one of the most common neoplasms in the horse and are frequently found in the head region. There is a genetic predisposition in horses with a gray hair coat. Computed tomography (CT) is frequently used in referral practice to evaluate the equine head but there are few reports describing the CT appearance of melanomas in this location. The aim of this retrospective, case series study was to describe characteristics in a group of horses with confirmed disease. Case records from two referral hospitals were reviewed, and 13 horses were identified that had undergone CT of the head, with a diagnosis of melanoma based on cytology, histopathology, or visual assessment of black (melanotic) tissue. A median of 11 melanomas was identified per horse (range 3-60), with a total of 216 masses. Melanomas were found most frequently in the parotid salivary gland, guttural pouches, surrounding the larynx and pharynx and adjacent to the hyoid apparatus. In noncontrast CT images, all melanomas were hyperattenuating (median; 113.5 Hounsfield units (HU), IQR; 26 HU) compared to masseter musculature (median; 69 HU, IQR; 5.5 HU). Fifty-six (25.9%) masses were partially mineralized and 41 (19.4%) included hypoattenuating areas. Histopathological assessment of these melanomas suggested that the hyperattenuation identified was most likely a result of abundant intracytoplasmic melanin pigment. Melanomas of the equine head appeared to have consistent CT features that aided detection of mass lesions and their distribution, although histopathological analysis or visual confirmation should still be obtained for definitive diagnosis. PMID:26799704

  13. ASSOCIATION BETWEEN COMPUTED TOMOGRAPHIC CHARACTERISTICS AND FRACTURES FOLLOWING STEREOTACTIC RADIOSURGERY IN DOGS WITH APPENDICULAR OSTEOSARCOMA.

    PubMed

    Kubicek, Lyndsay; Vanderhart, Daniel; Wirth, Kimberly; An, Qi; Chang, Myron; Farese, James; Bova, Francis; Sudhyadhom, Atchar; Kow, Kelvin; Bacon, Nicholas J; Milner, Rowan

    2016-05-01

    The objective of this observational, descriptive, retrospective study was to report CT characteristics associated with fractures following stereotactic radiosurgery in canine patients with appendicular osteosarcoma. Medical records (1999 and 2012) of dogs that had a diagnosis of appendicular osteosarcoma and undergone stereotactic radiosurgery were reviewed. Dogs were included in the study if they had undergone stereotactic radiosurgery for an aggressive bone lesion with follow-up information regarding fracture status, toxicity, and date and cause of death. Computed tomography details, staging, chemotherapy, toxicity, fracture status and survival data were recorded. Overall median survival time (MST) and fracture rates of treated dogs were calculated. CT characteristics were evaluated for association with time to fracture. Forty-six dogs met inclusion criteria. The median overall survival time was 9.7 months (95% CI: 6.9-14.3 months). The fracture-free rates at 3, 6, and 9 months were 73%, 44%, and 38% (95% CI: 60-86%, 29-60%, and 22-54%), respectively. The region of bone affected was significantly associated with time to fracture. The median time to fracture was 4.2 months in dogs with subchondral bone involvement and 16.3 months in dogs without subchondral bone involvement (P-value = 0.027, log-rank test). Acute and late skin effects were present in 58% and 16% of patients, respectively. Findings demonstrated a need for improved patient selection for this procedure, which can be aided by CT-based prognostic factors to predict the likelihood of fracture. PMID:26916056

  14. Computerized detection of pulmonary embolism in computed tomographic pulmonary angiography (CTPA): improvement of vessel segmentation

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Kuriakose, Jean W.; Chughtai, Aamer; Hadjiiski, Lubomir M.; Wei, Jun; Patel, Smita; Kazerooni, Ella A.

    2011-03-01

    Vessel segmentation is a fundamental step in an automated pulmonary embolism (PE) detection system. The purpose of this study is to improve the segmentation scheme for pulmonary vessels affected by PE and other lung diseases. We have developed a multiscale hierarchical vessel enhancement and segmentation (MHES) method for pulmonary vessel tree extraction based on the analysis of eigenvalues of Hessian matrices. However, it is difficult to segment the pulmonary vessels accurately when the vessel is occluded by PEs and/or surrounded by lymphoid tissues or lung diseases. In this study, we developed a method that combines MHES with level set refinement (MHES-LSR) to improve vessel segmentation accuracy. The level set was designed to propagate the initial object contours to the regions with relatively high gray-level, high gradient, and high compactness as measured by the smoothness of the curvature along vessel boundaries. Two and eight CTPA scans were randomly selected as training and test data sets, respectively. Forty volumes of interest (VOI) containing "representative" vessels were manually segmented by a radiologist experienced in CTPA interpretation and used as reference standard. The results show that, for the 32 test VOIs, the average percentage volume error relative to the reference standard was improved from 31.7+/-10.9% using the MHES method to 7.7+/-4.7% using the MHES-LSR method. The correlation between the computer-segmented vessel volume and the reference standard was improved from 0.954 to 0.986. The accuracy of vessel segmentation was improved significantly (p<0.05). The MHES-LSR method may have the potential to improve PE detection.

  15. Shaping ability of rotatory or reciprocating instruments in curved canals: a micro-computed tomographic study.

    PubMed

    Jardine, Alexander Pompermayer; Rosa, Ricardo Abreu da; Santini, Manuela Favarin; Zaccara, Ivana Maria; Só, Marcus Vinicius Reis; Kopper, Patrícia Maria Poli

    2016-06-14

    This study aimed to compare apical transportation, centering ratio, and working time during root canal preparation with Wizard Navigator (WN), WaveOne (WO), or ProTaper Universal (PT) and to describe deformation and fracture of these instruments. Thirty-six mesiobuccal roots from maxillary molars were micro-computed tomography (micro-CT) scanned and then sorted into three groups (n = 12): Wizard Navigator (WN), WaveOne (WO), and ProTaper Universal (PT). The root canals were prepared using WN, WO, or PT; the time of each canal preparation was timed; and the specimens were micro-CT re-scanned. The instruments were submitted to scanning electron microscopy (SEM) before and after their use. The data on canal transportation at 1, 2, 3, 4 and 5 mm and preparation time were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney U test. The centering ratio was analyzed by ANOVA, followed by Tukey's test. Both instrument deformation and fracture were described. Apical transportation was similar among groups at 1, 2, 3 and 4 mm. The WO group showed higher canal transportation at 5mm than the other groups (p = 0.03). There was no significant difference in centering ratio among the groups. Preparation time in the WO group was significantly lower than in the other groups (p = 0.004). Small differences were observed in the surface area of all instruments. The WN, WO, and PT groups had a similar centering ratio without procedural errors or significant structural changes. At 5 mm from the apex, the WO group showed the largest canal transportation toward the furcation and root canal preparation was faster than in the WN and PT groups. PMID:27305517

  16. Coronary computed tomographic angiography: current role in the diagnosis and management of coronary artery disease

    PubMed Central

    Bowman, Andrew W.; Kantor, Birgit; Gerber, Thomas C.

    2009-01-01

    Advances in computed tomography (CT) technology allow images to be obtained with high spatial and temporal resolution. These features now permit noninvasive coronary CT angiography (CCTA). Many studies addressing proof of concept, feasibility, and clinical robustness have been published since CCTA was first described. More recently, the scientific evaluation of CCTA has rightly focused less on technical aspects and more on multicenter trials of the diagnostic value of CCTA and on head-to-head comparisons with other noninvasive modalities for the detection of coronary artery disease (CAD), such as stress myocardial perfusion imaging (MPI) with radionuclides. Recent peer-reviewed publications that compare CCTA to invasive, selective coronary angiography (SCA) or MPI, or that address radiation protection issues related to CCTA, were reviewed and summarized. Overall, there is high agreement between CCTA and both SCA and MPI for the presence of CAD. However, CCTA can over- or underestimate the severity of CAD compared to SCA as a reference standard. Initial studies that compared CCTA to MPI found their accuracies for determining the presence of high-grade luminal obstructions comparable. Limitations of CCTA include inability to reliably assess the coronary artery lumen dimensions in patients with large amounts of coronary artery calcium, artifacts caused by coronary and respiratory motion, and the need for ionizing radiation and intravenous administration of iodinated contrast material. Various dose reduction methods for CCTA now exist that may substantially lower patient dose to levels less than those of SCA or MPI. Although current expert consensus does not call for CCTA to be a first-line test for CAD, particularly for screening in asymptomatic individuals, current data suggest a promising role in the evaluation of symptomatic patients for possible CAD. PMID:19694220

  17. EFFECTS OF FLUID AND COMPUTED TOMOGRAPHIC TECHNICAL FACTORS ON CONSPICUITY OF CANINE AND FELINE NASAL TURBINATES

    PubMed Central

    Uosyte, Raimonda; Shaw, Darren J; Gunn-Moore, Danielle A; Fraga-Manteiga, Eduardo; Schwarz, Tobias

    2015-01-01

    Turbinate destruction is an important diagnostic criterion in canine and feline nasal computed tomography (CT). However decreased turbinate visibility may also be caused by technical CT settings and nasal fluid. The purpose of this experimental, crossover study was to determine whether fluid reduces conspicuity of canine and feline nasal turbinates in CT and if so, whether CT settings can maximize conspicuity. Three canine and three feline cadaver heads were used. Nasal slabs were CT-scanned before and after submerging them in a water bath; using sequential, helical, and ultrahigh resolution modes; with images in low, medium, and high frequency image reconstruction kernels; and with application of additional posterior fossa optimization and high contrast enhancing filters. Visible turbinate length was measured by a single observer using manual tracing. Nasal density heterogeneity was measured using the standard deviation (SD) of mean nasal density from a region of interest in each nasal cavity. Linear mixed-effect models using the R package ‘nlme’, multivariable models and standard post hoc Tukey pair-wise comparisons were performed to investigate the effect of several variables (nasal content, scanning mode, image reconstruction kernel, application of post reconstruction filters) on measured visible total turbinate length and SD of mean nasal density. All canine and feline water-filled nasal slabs showed significantly decreased visibility of nasal turbinates (P < 0.001). High frequency kernels provided the best turbinate visibility and highest SD of aerated nasal slabs, whereas medium frequency kernels were optimal for water-filled nasal slabs. Scanning mode and filter application had no effect on turbinate visibility. PMID:25867935

  18. The VetMousetrap: a device for computed tomographic imaging of the thorax of awake cats.

    PubMed

    Oliveira, Cintia R; Ranallo, Frank N; Pijanowski, Gerald J; Mitchell, Mark A; O'Brien, Mauria A; McMichael, Maureen; Hartman, Susan K; Matheson, Jodi S; O'Brien, Robert T

    2011-01-01

    The VetMousetrap, a novel device that allows computed tomography (CT) of awake cats and provides a clinically supportive environment, is described. Ten normal cats were used to test the device for ambient internal oxygen, carbon dioxide levels, and temperature. Twenty-two awake normal cats were imaged using a 16-multislice helical CT unit to evaluate dose-equivalent protocols. Two different X-ray tube potentials (kV), 80 and 120, and two different helical pitches, 0.562 and 1.75, were evaluated. The signal intensity of the pulmonary parenchyma (SIlung), signal intensity of background (SIbackgr), contrast, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated. Three evaluators ranked the images for sharpness of liver margins, motion, helical, and windmill artifacts. CT was successfully completed in 20 of 22 cats. No artifacts directly related to the device were detected. Overall, 75 of 80 (94%) examinations were judged to have absent or minimal motion artifact. A statistically significant difference was found for SNR (P = 0.001) and CNR (P = 0.001) between all protocols. The higher pitch protocols had significantly lower noise and higher SNR and CNR, lower motion artifact but greater helical artifacts. A protocol using 80 kV, 130 mA, 0.5s, and 0.562 pitch with 1.25mm slice thickness, and 0.625 mm slice reconstruction interval is recommended. The VetMousetrap appears to provide the opportunity for diagnostic CT imaging of the thorax of awake cats. PMID:21322386

  19. Computed tomographic features of feline sino-nasal and sino-orbital aspergillosis.

    PubMed

    Barrs, V R; Beatty, J A; Dhand, N K; Talbot, J J; Bell, E; Abraham, L A; Chapman, P; Bennett, S; van Doorn, T; Makara, M

    2014-08-01

    Feline upper respiratory tract aspergillosis (URTA) occurs as two distinct anatomical forms, namely, sino-nasal aspergillosis (SNA) and sino-orbital aspergillosis (SOA). An emerging pathogen, Aspergillus felis, is frequently involved. The pathogenesis of URTA, in particular the relationship between the infecting isolate and outcome, is poorly understood. In this study, computed tomography was used to investigate the route of fungal infection and extension in 16 cases (SNA n = 7, SOA n = 9) where the infecting isolate had been identified by molecular testing. All cases had nasal cavity involvement except for one cat with SNA that had unilateral frontal sinus changes. There was a strong association between the infecting species and anatomic form (P = 0.005). A. fumigatus infections remained within the sino-nasal cavity, while cryptic species infections were associated with orbital and paranasal soft-tissue involvement and with orbital lysis. Cryptic species were further associated with a mass in the nasal cavity, paranasal sinuses or nasopharynx. Orbital masses showed heterogeneous contrast enhancement, with central coalescing hypoattenuating foci and peripheral rim enhancement. Severe, cavitated turbinate lysis, typical of canine SNA, was present only in cats with SNA. These findings support the hypothesis that the nasal cavity is the portal of entry for fungal spores in feline URTA and that the route of extension to involve the orbit is via direct naso-orbital communication from bone lysis. Additionally, a pathogenic role for A. wyomingensis and a sinolith in a cat with A. udagawae infection are reported for the first time. PMID:24685469

  20. Clinical Application of High-Resolution Computed Tomographic Imaging Features of Community-Acquired Pneumonia

    PubMed Central

    Nie, Yunqiang; Li, Cuiyun; Zhang, Jingling; Wang, Hui; Han, Ping; Lv, Xin; Xu, Xinyi; Guo, Miao

    2016-01-01

    Background This article discusses the value of high-resolution computed tomography (HRCT) in the diagnosis and treatment of pulmonary infections. Lung infection caused by pathogens is an important cause of death. Traditional methods to treat lung infection involved empirical antibiotic therapy. Thin-slice CT scanning is widely used in the clinical setting, and HRCT scan can very clearly show alveolar and bronchiolar involvement of infection. Material/Methods In total, 178 patients with community-acquired pneumonia (CAP) were enrolled. All the patients underwent CT scan, qualified sputum, and blood samples for culture or immunological biochemical tests. CT imaging features, pathogenic bacteria, and treatment results were used for statistical analysis. Results In 77 patients with lobar consolidation, the rate of detection was 43.26% (77/178), and in 101 patients with lobular pneumonia it was 56.74% (101/178). In 51 patients, pathogenic bacteria were detected (28.65%, 51/178). Sixteen of 33 patients detected with bacteria had cavities (48.5%, 16/33) and 35 of 145 patients detected with bacteria had no cavities (24.1%, 35/145). The difference between the 2 groups was statistically significant (χ2=7.795, P=0.005). According to the pathogenic bacteria, 38 patients were cured (74.51%, 38/51), and according to the CT imaging features 81 patients were cured (71.05%, 81/114). No statistically significant difference was found between them (χ2=0.209, P=0.647). Conclusions Treatment effect of CAP based on HRCT findings is not inferior to treatment effect guided by microbial characterization. PMID:27031210

  1. Comparison of computed tomographic findings in pulmonary mucormycosis and invasive pulmonary aspergillosis.

    PubMed

    Jung, J; Kim, M Y; Lee, H J; Park, Y S; Lee, S-O; Choi, S-H; Kim, Y S; Woo, J H; Kim, S-H

    2015-07-01

    Because there are no available molecular markers for pulmonary mucormycosis (PM), which has low culture sensitivity, early diagnosis and treatment rely heavily on imaging modes such as computed tomography (CT). However, there are limited data comparing CT findings for PM with those for invasive pulmonary aspergillosis (IPA). Adult patients who met the modified criteria for proven and probable PM (over an 11-year period) and IPA (over a 6-year period, owing to the availability of the galactomannan assay) according to the modified European Organization for Research and Treatment of Cancer/Mycosis Study Group definitions were retrospectively enrolled. IPA cases were selected at a 1 : 4 (PM/IPA) ratio. Thoracic CT scans were reviewed by two experienced radiologists blinded to the patients' demographics and clinical outcomes. A total of 24 patients with PM, including 20 (83%) with proven PM and four (17%) with probable PM, and 96 patients with IPA, including 12 (13%) with proven IPA and 84 (87%) with probable IPA, were eventually analysed. The reverse halo sign was more common in patients with PM (54%) than in those with IPA (6%, p < 0.001), whereas some airway-invasive features, such as clusters of centrilobular nodules, peribronchial consolidations, and bronchial wall thickening, were more common in patients with IPA (IPA 52% vs. PM 29%, p 0.04; IPA 49% vs. PM 21%, p 0.01; IPA 34% vs. PM 4%, p 0.003, respectively). The reverse halo sign was more common, and airway-invasive features were less common, in patients with PM than in those with IPA. These findings may help physicians to initiate Zygomycetes-active antifungal treatment earlier. PMID:25882362

  2. Setup Variations in Radiotherapy of Esophageal Cancer: Evaluation by Daily Megavoltage Computed Tomographic Localization

    SciTech Connect

    Chen, Y.-J. . E-mail: yichen@coh.org; Han Chunhui; Liu An; Schultheiss, Timothy E.; Kernstine, Kemp H.; Shibata, Stephen; Vora, Nayana L.; Pezner, Richard D.; Wong, Jeffrey Y.C.

    2007-08-01

    Purpose: To use pretreatment megavoltage computed tomography (MVCT) scans to evaluate setup variations in anterior-posterior (AP), lateral, and superior-inferior (SI) directions and rotational variations, including pitch, roll, and yaw, for esophageal cancer patients treated with helical tomotherapy. Methods and Materials: Ten patients with locally advanced esophageal cancer treated by combined chemoradiation using helical tomotherapy were selected. After patients were positioned using their skin tattoos/marks, MVCT scans were performed before every treatment and automatically registered to planning kilovoltage CT scans according to bony landmarks. Image registration data were used to adjust patient setups before treatment. A total of 250 MVCT scans were analyzed. Correlations between setup variations and body habitus, including height, weight, relative weight change, body surface area, and patient age, were evaluated. Results: The standard deviations for systematic setup corrections in AP, lateral, and SI directions and pitch, roll, and yaw rotations were 1.5, 3.7, and 4.8 mm and 0.5 deg., 1.2 deg., and 0.8 deg., respectively. The appropriate averages of random setup variations in AP, lateral, and SI directions and pitch, roll, and yaw rotations were 2.9, 5.2, and 4.4 mm, and 1.0 deg., 1.2 deg., and 1.1 deg., respectively. Setup variations were stable throughout the entire course of radiotherapy in all three translational and three rotational displacements, with little change in magnitude. No significant correlations were found between setup variations and body habitus variables. Conclusions: Daily MVCT scans before each treatment can effectively detect setup errors and thereby reduce planning target volume (PTV) margins. This will reduce radiation dose to critical organs and may translate into lower treatment-related toxicities.

  3. THE EFFECT OF ANGLE SLICE ACQUISITION ON COMPUTED TOMOGRAPHIC CERVICAL VERTEBRAL COLUMN MORPHOMETRY IN GREAT DANES.

    PubMed

    Jurkoshek, Amanda M; da Costa, Ronaldo C; Martin-Vaquero, Paula

    2015-01-01

    Computed tomography (CT) scans can be acquired with the transverse images aligned either parallel to the endplates or perpendicular to the vertebral canal. The purpose of this prospective cross-sectional study was to determine the effect of angle acquisition on CT morphometric evaluation of the cervical vertebral column of Great Danes with and without cervical spondylomyelopathy. Twenty-eight Great Danes (13 normal, 15 affected) were sampled. For each dog, a set of CT images was acquired with the transverse slices aligned parallel to the endplates and another one with the transverse images aligned perpendicular to the vertebral canal. For each different set, transverse slices from the cranial, middle, and caudal aspects of the individual vertebral bodies C2-C7 were measured. Height, width, transverse area, right dorsal to left ventral height (RDLV), and left dorsal to right ventral height (LDRV) were recorded by a single observer at each location. For both affected and control dogs, significant differences between the measurements obtained from the two sets of transverse images were found only at the cranial aspect of the vertebrae (P = 0.005, P < 0.001, P < 0.001, P = 0.005, and P = 0.010 for height, width, area, RDLV, and LDRV, respectively). Measurements for the middle and caudal aspects did not differ. The funnel-shape morphology of the cervical vertebral foramina in Great Danes with stenosis of their cranial aspect may be responsible for the significant differences found. Considering that the morphometric parameters were significantly affected by CT slice angle in the current study, authors recommend that a standardized scanning protocol be followed when morphometric evaluations using CT are planned. PMID:25872964

  4. EFFECTS OF FLUID AND COMPUTED TOMOGRAPHIC TECHNICAL FACTORS ON CONSPICUITY OF CANINE AND FELINE NASAL TURBINATES.

    PubMed

    Uosyte, Raimonda; Shaw, Darren J; Gunn-Moore, Danielle A; Fraga-Manteiga, Eduardo; Schwarz, Tobias

    2015-01-01

    Turbinate destruction is an important diagnostic criterion in canine and feline nasal computed tomography (CT). However decreased turbinate visibility may also be caused by technical CT settings and nasal fluid. The purpose of this experimental, crossover study was to determine whether fluid reduces conspicuity of canine and feline nasal turbinates in CT and if so, whether CT settings can maximize conspicuity. Three canine and three feline cadaver heads were used. Nasal slabs were CT-scanned before and after submerging them in a water bath; using sequential, helical, and ultrahigh resolution modes; with images in low, medium, and high frequency image reconstruction kernels; and with application of additional posterior fossa optimization and high contrast enhancing filters. Visible turbinate length was measured by a single observer using manual tracing. Nasal density heterogeneity was measured using the standard deviation (SD) of mean nasal density from a region of interest in each nasal cavity. Linear mixed-effect models using the R package 'nlme', multivariable models and standard post hoc Tukey pair-wise comparisons were performed to investigate the effect of several variables (nasal content, scanning mode, image reconstruction kernel, application of post reconstruction filters) on measured visible total turbinate length and SD of mean nasal density. All canine and feline water-filled nasal slabs showed significantly decreased visibility of nasal turbinates (P < 0.001). High frequency kernels provided the best turbinate visibility and highest SD of aerated nasal slabs, whereas medium frequency kernels were optimal for water-filled nasal slabs. Scanning mode and filter application had no effect on turbinate visibility. PMID:25867935

  5. Computed Tomographic Evaluation of K3 Rotary and Stainless Steel K File Instrumentation in Primary Teeth

    PubMed Central

    Kavitha, Swaminathan; Thomas, Eapen; Anadhan, Vasanthakumari; Vijayakumar, Rajendran

    2016-01-01

    Introduction The intention of root canal preparation is to reduce infected content and create a root canal shape allowing for a well condensed root filling. Therefore, it is not necessary to remove excessive dentine for successful root canal preparation and concern must be taken not to over instrument as perforations can occur in the thin dentinal walls of primary molars. Aim This study was done to evaluate the time preparation, the risk of lateral perforation and dentine removal of the stainless steel K file and K3 rotary instrumentation in primary teeth. Materials and Methods Seventy-five primary molars were selected and divided into three groups. Using spiral computed tomography the teeth were scanned before instrumentation. Teeth were prepared using a stainless steel K file for manual technique. All the canals were prepared up to file size 35. In K3 rotary files (.02 taper) instrumentation was done up to 35 size file. In K3 rotary files (.04 taper) the instrumentation was done up to 25 size file and simultaneously the instrumentation time was recorded. The instrumented teeth were once again scanned and the images were compared with the images of the uninstrumented canals. Statistical Analysis Data was statistically analysed using Kruskal Wallis One-way ANOVA, Mann-Whitney U-Test and Pearson’s Chi-square Test. Results K3 rotary files (.02 taper) removed a significantly less amount of dentine, required less instrumentation time than a stainless steel K file. Conclusion K3 files (.02 taper) generated less dentine removal than the stainless steel K file and K3 files (.04 taper). K3 rotary files (.02 taper) were more effective for root canal instrumentation in primary teeth. PMID:26894166

  6. 3D printing of preclinical X-ray computed tomographic data sets.

    PubMed

    Doney, Evan; Krumdick, Lauren A; Diener, Justin M; Wathen, Connor A; Chapman, Sarah E; Stamile, Brian; Scott, Jeremiah E; Ravosa, Matthew J; Van Avermaete, Tony; Leevy, W Matthew

    2013-01-01

    Three-dimensional printing allows for the production of highly detailed objects through a process known as additive manufacturing. Traditional, mold-injection methods to create models or parts have several limitations, the most important of which is a difficulty in making highly complex products in a timely, cost-effective manner.(1) However, gradual improvements in three-dimensional printing technology have resulted in both high-end and economy instruments that are now available for the facile production of customized models.(2) These printers have the ability to extrude high-resolution objects with enough detail to accurately represent in vivo images generated from a preclinical X-ray CT scanner. With proper data collection, surface rendering, and stereolithographic editing, it is now possible and inexpensive to rapidly produce detailed skeletal and soft tissue structures from X-ray CT data. Even in the early stages of development, the anatomical models produced by three-dimensional printing appeal to both educators and researchers who can utilize the technology to improve visualization proficiency. (3, 4) The real benefits of this method result from the tangible experience a researcher can have with data that cannot be adequately conveyed through a computer screen. The translation of pre-clinical 3D data to a physical object that is an exact copy of the test subject is a powerful tool for visualization and communication, especially for relating imaging research to students, or those in other fields. Here, we provide a detailed method for printing plastic models of bone and organ structures derived from X-ray CT scans utilizing an Albira X-ray CT system in conjunction with PMOD, ImageJ, Meshlab, Netfabb, and ReplicatorG software packages. PMID:23542702

  7. COMPUTED TOMOGRAPHIC APPEARANCE OF THE TEMPOROMANDIBULAR JOINT IN 1018 ASYMPTOMATIC HORSES: A MULTI-INSTITUTION STUDY.

    PubMed

    Carmalt, James L; Kneissl, Sibylle; Rawlinson, Jennifer E; Zwick, Timo; Zekas, Lisa; Ohlerth, Stefanie; Bienert-Zeit, Astrid

    2016-05-01

    Published descriptions of nonseptic arthritis of the equine temporomandibular joint (TMJ) are rare and large studies investigating variations in the TMJ for asymptomatic horses are lacking. The objectives of this cross-sectional, retrospective, multi-institutional study were to describe anatomical variations in the TMJ detected using computed tomography (CT) in an equid population asymptomatic for TMJ disease and determine whether these variations were associated with patient signalment, reason for CT examination, or CT slice width. Medical records at eight hospitals were searched for horses that had head/neck CT scans and no clinical signs of TMJ disease. Age, breed, sex, clinical presentation, and CT slice width data were recorded. Alterations in CT contour and density of the mandibular condyles, mandibular fossae, and TMJ intra-articular discs were described for each horse. Generalized logistic regression was used to test associations between anatomical variations and horse age. A total of 1018 horses were sampled. Anatomical variations were found in TMJ CT images for 40% of horses and 29% of joints. These were dichotomous with regard to age. Horses <1 year old commonly had alterations in the shape and density of the mandibular condyle. Older horses commonly had spherical hypodensities within the mandibular condyles consistent with bone cysts; and hyperdense regions of the intra-articular disc consistent with dystrophic mineralization. Findings indicated that TMJ anatomic variations were common in CT images of younger and older horses asymptomatic for TMJ disease. Future studies are needed to more definitively characterize these CT variations using gross pathology and histopathology. PMID:26773281

  8. Evaluation of condylar positions in patients with temporomandibular disorders: A cone-beam computed tomographic study

    PubMed Central

    Imanimoghaddam, Mahrokh; Madani, Azam Sadat; Mahdavi, Pirooze; Bagherpour, Ali; Darijani, Mansoreh

    2016-01-01

    Purpose This study was performed to compare the condylar position in patients with temporomandibular joint disorders (TMDs) and a normal group by using cone-beam computed tomography (CBCT). Materials and Methods In the TMD group, 25 patients (5 men and 20 women) were randomly selected among the ones suffering from TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The control group consisted of 25 patients (8 men and 17 women) with normal temporomandibular joints (TMJs) who were referred to the radiology department in order to undergo CBCT scanning for implant treatment in the posterior maxilla. Linear measurements from the superior, anterior, and posterior joint spaces between the condyle and glenoid fossa were made through defined landmarks in the sagittal view. The inclination of articular eminence was also determined. Results The mean anterior joint space was 2.3 mm in the normal group and 2.8 mm in the TMD group, respectively. The results showed that there was a significant correlation between the superior and posterior joint spaces in both the normal and TMD groups, but it was only in the TMD group that the correlation coefficient among the dimensions of anterior and superior spaces was significant. There was a significant correlation between the inclination of articular eminence and the size of the superior and posterior spaces in the normal group. Conclusion The average dimension of the anterior joint space was different between the two groups. CBCT could be considered a useful diagnostic imaging modality for TMD patients. PMID:27358820

  9. Cranial computed tomographic findings in Nigerian women with metastatic breast cancer

    PubMed Central

    Obajimi, Millicent O.; Ogbole, Godwin Inalegwu; Adeniji-Sofoluwe, Adenike T.; Adeleye, Amos O.; Elumelu, Theresa N.; Oluwasola, Abideen O.; Akute, O. O.

    2013-01-01

    Introduction: Brain metastases (BM) occur in up to one-fifth of patients with metastatic breast cancer (MBC). Imaging plays a key role in diagnosis. The pattern and distribution of these changes are also crucial to their management. These patterns have not been fully studied in Nigerian women. Materials and Methods: Retrospective analysis of the findings on the cranial Computed Tomography (CT) scans performed in 59 breast cancer patients with suspected BM treated at the University Teaching Hospital in Ibadan, between 2005 and 2010. The imaging features were evaluated in relation to their clinical characteristics. Results: In the 59 patients studied (mean age 50.9 years ± 11.75 SD), headache (40.7%) and hemiparesis/hemiplegia (16.9%) were the commonest clinical presentation. Lytic skull lesions were seen in 15 patients (25.4%), most commonly in the parietal bones. Thirty-nine patients (66.1%), had parenchymal brain lesions, and only 8 (20.5%) of these were single lesions. Most of the lesions were isodense (19/39; 51.4%) the parietal lobe was the most common site with 50.8% (30/59) occurrence and the leptomeninges the least with 13.6% (8/59). Orbital or sellar region involvement occurred in only two patients. The size of the lesions, was <2 cm in 17 (28.8%), 2-5 cm in 14 (23.7%) and >5 cm in 5 patients. Sixteen (27.1%) patients were free of any lesion either in the skull or brain. Patient presenting with multiple brain lesions were more likely to have skull lesions though this was not statistically significant (P = 0.584). Conclusion: The brain continues to be a sanctuary site for breast cancer metastases and CT imaging remains an invaluable tool in the clinical evaluation and therapeutic management of Nigerian women with BM from MBC. It also appears that the demographic and imaging findings in these patients are similar to other racial groups. PMID:23798799

  10. Clamshell tomograph

    DOEpatents

    Derenzo, Stephen E.; Budinger, Thomas F.

    1984-01-01

    In brief, the invention is a tomograph modified to be in a clamshell configuration so that the ring or rings may be moved to multiple sampling positions. The tomograph includes an array of detectors arranged in successive adjacent relative locations along a closed curve in a first position in a selected plane, and means for securing the detectors in the relative locations in a first sampling position. The securing means is movable in the plane in two sections and pivotable at one p The U.S. Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California.

  11. Comparative evaluation of the cadaveric, radiographic and computed tomographic anatomy of the heads of green iguana (Iguana iguana) , common tegu ( Tupinambis merianae) and bearded dragon ( Pogona vitticeps)

    PubMed Central

    2012-01-01

    Background Radiology and computed tomography are the most commonly available diagnostic tools for the diagnosis of pathologies affecting the head and skull in veterinary practice. Nevertheless, accurate interpretation of radiographic and CT studies requires a thorough knowledge of the gross and the cross-sectional anatomy. Despite the increasing success of reptiles as pets, only a few reports over their normal imaging features are currently available. The aim of this study is to describe the normal cadaveric, radiographic and computed tomographic features of the heads of the green iguana, tegu and bearded dragon. Results 6 adult green iguanas, 4 tegus, 3 bearded dragons, and, the adult cadavers of : 4 green iguana, 4 tegu, 4 bearded dragon were included in the study. 2 cadavers were dissected following a stratigraphic approach and 2 cadavers were cross-sectioned for each species. These latter specimens were stored in a freezer (−20°C) until completely frozen. Transversal sections at 5 mm intervals were obtained by means of an electric band-saw. Each section was cleaned and photographed on both sides. Radiographs of the head of each subject were obtained. Pre- and post- contrast computed tomographic studies of the head were performed on all the live animals. CT images were displayed in both bone and soft tissue windows. Individual anatomic structures were first recognised and labelled on the anatomic images and then matched on radiographs and CT images. Radiographic and CT images of the skull provided good detail of the bony structures in all species. In CT contrast medium injection enabled good detail of the soft tissues to be obtained in the iguana whereas only the eye was clearly distinguishable from the remaining soft tissues in both the tegu and the bearded dragon. Conclusions The results provide an atlas of the normal anatomical and in vivo radiographic and computed tomographic features of the heads of lizards, and this may be useful in interpreting any

  12. Tomographic diagnostics of nonthermal plasmas

    NASA Astrophysics Data System (ADS)

    Denisova, Natalia

    2009-10-01

    In the previous work [1], we discussed a ``technology'' of tomographic method and relations between the tomographic diagnostics in thermal (equilibrium) and nonthermal (nonequilibrium) plasma sources. The conclusion has been made that tomographic reconstruction in thermal plasma sources is the standard procedure at present, which can provide much useful information on the plasma structure and its evolution in time, while the tomographic reconstruction of nonthermal plasma has a great potential at making a contribution to understanding the fundamental problem of substance behavior in strongly nonequilibrium conditions. Using medical terminology, one could say, that tomographic diagnostics of the equilibrium plasma sources studies their ``anatomic'' structure, while reconstruction of the nonequilibrium plasma is similar to the ``physiological'' examination: it is directed to study the physical mechanisms and processes. The present work is focused on nonthermal plasma research. The tomographic diagnostics is directed to study spatial structures formed in the gas discharge plasmas under the influence of electrical and gravitational fields. The ways of plasma ``self-organization'' in changing and extreme conditions are analyzed. The analysis has been made using some examples from our practical tomographic diagnostics of nonthermal plasma sources, such as low-pressure capacitive and inductive discharges. [0pt] [1] Denisova N. Plasma diagnostics using computed tomography method // IEEE Trans. Plasma Sci. 2009 37 4 502.

  13. Role of multidetector computed tomography in the diagnosis and management of patients attending the rapid access chest pain clinic, The Scottish computed tomography of the heart (SCOT-HEART) trial: study protocol for randomized controlled trial

    PubMed Central

    2012-01-01

    Background Rapid access chest pain clinics have facilitated the early diagnosis and treatment of patients with coronary heart disease and angina. Despite this important service provision, coronary heart disease continues to be under-diagnosed and many patients are left untreated and at risk. Recent advances in imaging technology have now led to the widespread use of noninvasive computed tomography, which can be used to measure coronary artery calcium scores and perform coronary angiography in one examination. However, this technology has not been robustly evaluated in its application to the clinic. Methods/design The SCOT-HEART study is an open parallel group prospective multicentre randomized controlled trial of 4,138 patients attending the rapid access chest pain clinic for evaluation of suspected cardiac chest pain. Following clinical consultation, participants will be approached and randomized 1:1 to receive standard care or standard care plus ≥64-multidetector computed tomography coronary angiography and coronary calcium score. Randomization will be conducted using a web-based system to ensure allocation concealment and will incorporate minimization. The primary endpoint of the study will be the proportion of patients diagnosed with angina pectoris secondary to coronary heart disease at 6 weeks. Secondary endpoints will include the assessment of subsequent symptoms, diagnosis, investigation and treatment. In addition, long-term health outcomes, safety endpoints, such as radiation dose, and health economic endpoints will be assessed. Assuming a clinic rate of 27.0% for the diagnosis of angina pectoris due to coronary heart disease, we will need to recruit 2,069 patients per group to detect an absolute increase of 4.0% in the rate of diagnosis at 80% power and a two-sided P value of 0.05. The SCOT-HEART study is currently recruiting participants and expects to report in 2014. Discussion This is the first study to look at the implementation of computed

  14. [Multislice computed tomographic angiography in the assessment of central veins for endovascular treatment planning: comparison with phlebography].

    PubMed

    Patanè, Domenico; Morale, Walter; Malfa, Pierantonio; Seminara, Giuseppe; L'Anfusa, Giuseppe; Spanti, Demetrio; Incardona, Concetta; Mandalà, Maria Luisa; Di Landro, Domenico

    2010-01-01

    The dysfunction of a vascular access for hemodialysis and its loss may depend on drainage difficulties of the superficial or deep venation due to hemodynamically significant stenosis or obstruction of a central vein, which generally involve the innominate-subclavian veins or superior vena cava. These alterations are often neglected due to their central and deep location; when there is hemodynamic compensation, they may remain asymptomatic. For these reasons every suspect clinical sign for central vein stenosis (gross arm syndrome or venous hypertension in an arteriovenous fistula) must not be ignored, as timely intervention is essential for functional recovery of the vessel and for the protection of the arteriovenous fistula. The modern imaging techniques ensure thorough diagnostic assessment, while the possibilities of endovascular treatment with interventional radiology allow, in a large proportion of cases, optimal minimally invasive treatment, but above all the recovery of venation in a hemodialyzed patient. We report our experience with multislice computed tomographic angiography (MS-CTA) and reconstruction software for treatment planning of central vein stenosis or obstruction. Forty-nine patients were studied with MS-CTA (GE 16). Images were acquired in the venous phase (120-180 seconds after contrast medium injection) followed by digital vascular reconstruction (AutoBone for bone removal, vessel analysis for caliber and length measurements, thin and curved MIP, MPR). Within a week control phlebography was performed. The venous tree was divided into seven segments and analyzed in a double-blind fashion with a distinction between patent segments, 50-70% stenosis, >70% stenosis, occlusion, and collateral vascular beds. There was excellent correspondence in all the examined segments for patency, >70% stenosis, and occlusion, with high sensitivity (98%), specificity (99.3%), and diagnostic accuracy (99.1%). The binomial test demonstrated a highly significant

  15. Uncommon Complex Anomaly of Inferior Vena Cava and Left Iliac Vein Demonstrated by Multidetector-Row CT Angiography

    PubMed Central

    Ogul, Hayri; Yuce, Ihsan; Yalcin, Ahmet; Karaca, Leyla; Okur, Aylin; Kantarci, Mecit

    2014-01-01

    Retroperitoneal venous anomalies have clinical importance in retroperitoneal and pelvic surgery. Multidetector-row computed tomography (CT) angiography is an important imaging method to be preferred in evaluating vascular structures in this locality. We describe a complex retroperitoneal venous anomaly with a multidetector-row CT angiography. PMID:25437601

  16. Tomographic bioluminescence imaging by use of a combined optical-PET (OPET) system: a computer simulation feasibility study

    NASA Astrophysics Data System (ADS)

    Alexandrakis, George; Rannou, Fernando R.; Chatziioannou, Arion F.

    2005-09-01

    The feasibility and limits in performing tomographic bioluminescence imaging with a combined optical-PET (OPET) system were explored by simulating its image formation process. A micro-MRI based virtual mouse phantom was assigned appropriate tissue optical properties to each of its segmented internal organs at wavelengths spanning the emission spectrum of the firefly luciferase at 37 °C. The TOAST finite-element code was employed to simulate the diffuse transport of photons emitted from bioluminescence sources in the mouse. OPET measurements were simulated for single-point, two-point and distributed bioluminescence sources located in different organs such as the liver, the kidneys and the gut. An expectation maximization code was employed to recover the intensity and location of these simulated sources. It was found that spectrally resolved measurements were necessary in order to perform tomographic bioluminescence imaging. The true location of emission sources could be recovered if the mouse background optical properties were known a priori. The assumption of a homogeneous optical property background proved inadequate for describing photon transport in optically heterogeneous tissues and led to inaccurate source localization in the reconstructed images. The simulation results pointed out specific methodological challenges that need to be addressed before a practical implementation of OPET-based bioluminescence tomography is achieved.

  17. Computed tomographic observations pertinent to intracranial venous thrombotic and occulsive disease in childhood: state of the art, some new data, and hypotheses

    SciTech Connect

    Segall, H.D.; Ahmadi, J.; McComb, J.G.; Zee, C.S.; Becker, T.S.; Han, J.S.

    1982-05-01

    Selected topics are discussed and new observations recorded regarding computed tomographic (CT) evaluation of intracranial venous thrombotic and occlusive disease in childhood. High density of the vein of Galen and adjacent venous sinuses (relative to brain) can be seen normally in children. A number of potential pitfalls in the diagnosis of superior sagittal sinus thrombosis are also disclosed. A case of cavernous sinus thrombosis with abnormal CT changes is included. In addition, the normal CT appearance of the cavernous sinus is described. In some cases, filling defects occur which appear to correlate with normal cranial nerves. An unusual case of venous sinus occlusion by neoplasm (sarcoma) is presented. Finally, new findings in the Sturge-Weber syndrome are analyzed. Enhancement of the brain in this condition may have its basis in altered circulation resulting from fundamental venous abnormalities.

  18. Validation of a technique for integration of a digital dental model into stereophotogrammetric images of the face using cone-beam computed tomographic data.

    PubMed

    Codari, Marina; Pucciarelli, Valentina; Tommasi, Davide G; Sforza, Chiarella

    2016-06-01

    We wanted to find and validate a new way to visualise patients' faces and their dental arches non-invasively. The stereophotogrammetric images of the faces and the digitised dental casts of seven healthy subjects were analysed. Point-based and surface-based recording techniques matched the facial image with those of the mandibular and maxillary dental arches in their relative positions. The cone-beam computed tomographic (CT) images of the same subjects were analysed retrospectively. Twenty-eight dentofacial distances were obtained on cone-beam CT images and on the recorded facial and dental surfaces. The median (IQR) distances of more than 96% of the measurements did not differ significantly. PMID:26852270

  19. Computed tomographic, magnetic resonance imaging, and cross-sectional anatomic features of the manus in a normal American black bear (Ursus americanus).

    PubMed

    Ober, C P; Freeman, L E

    2010-06-01

    The purpose of this study was to provide a detailed description of cross-sectional anatomic structures of the manus of a black bear cadaver and correlate anatomic findings with corresponding features in computed tomographic (CT) and magnetic resonance (MR) images. CT, MR imaging, and transverse sectioning were performed on the thoracic limb of a cadaver female black bear which had no evidence of lameness or thoracic limb abnormality prior to death. Features in CT and MR images corresponding to clinically important anatomic structures in anatomic sections were identified. Most of the structures identified in transverse anatomic sections were also identified using CT and MR imaging. Bones, muscles and tendons were generally easily identified with both imaging modalities, although divisions between adjacent muscles were rarely visible with CT and only visible sometimes with MR imaging. Vascular structures could not be identified with either imaging modality. PMID:20500743

  20. X-Ray Tomographic Reconstruction

    SciTech Connect

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  1. Tomographic image via background subtraction using an x-ray projection image and a priori computed tomography

    SciTech Connect

    Zhang Jin; Yi Byongyong; Lasio, Giovanni; Suntharalingam, Mohan; Yu, Cedric

    2009-10-15

    Kilovoltage x-ray projection images (kV images for brevity) are increasingly available in image guided radiotherapy (IGRT) for patient positioning. These images are two-dimensional (2D) projections of a three-dimensional (3D) object along the x-ray beam direction. Projecting a 3D object onto a plane may lead to ambiguities in the identification of anatomical structures and to poor contrast in kV images. Therefore, the use of kV images in IGRT is mainly limited to bony landmark alignments. This work proposes a novel subtraction technique that isolates a slice of interest (SOI) from a kV image with the assistance of a priori information from a previous CT scan. The method separates structural information within a preselected SOI by suppressing contributions to the unprocessed projection from out-of-SOI-plane structures. Up to a five-fold increase in the contrast-to-noise ratios (CNRs) was observed in selected regions of the isolated SOI, when compared to the original unprocessed kV image. The tomographic image via background subtraction (TIBS) technique aims to provide a quick snapshot of the slice of interest with greatly enhanced image contrast over conventional kV x-ray projections for fast and accurate image guidance of radiation therapy. With further refinements, TIBS could, in principle, provide real-time tumor localization using gantry-mounted x-ray imaging systems without the need for implanted markers.

  2. Scenes from the past: initial investigation of early jurassic vertebrate fossils with multidetector CT.

    PubMed

    Bolliger, Stephan A; Ross, Steffen; Thali, Michael J; Hostettler, Bernhard; Menkveld-Gfeller, Ursula

    2012-01-01

    The study of fossils permits the reconstruction of past life on our planet and enhances our understanding of evolutionary processes. However, many fossils are difficult to recognize, being encased in a lithified matrix whose tedious removal is required before examination is possible. The authors describe the use of multidetector computed tomography (CT) in locating, identifying, and examining fossil remains of crocodilians (Mesosuchia) embedded in hard shale, all without removing the matrix. In addition, they describe how three-dimensional (3D) reformatted CT images provided details that were helpful for extraction and preparation. Multidetector CT can help experienced paleontologists localize and characterize fossils in the matrix of a promising rock specimen in a nondestructive manner. Moreover, with its capacity to generate highly accurate 3D images, multidetector CT can help determine whether the fossils warrant extraction and can assist in planning the extraction process. Thus, multidetector CT may well become an invaluable tool in the field of paleoradiology. PMID:22977034

  3. Multiplanar and three-dimensional multi-detector row CT of thoracic vessels and airways in the pediatric population.

    PubMed

    Siegel, Marilyn J

    2003-12-01

    Multi-detector row computed tomography (CT) has changed the approach to imaging of thoracic anatomy and disease in the pediatric population. At the author's institution, multi-detector row CT with multiplanar and three-dimensional reconstruction has become an important examination in the evaluation of systemic and pulmonary vasculature and the tracheobronchial tree. In some clinical situations, multi-detector row CT with reformatted images is obviating conventional angiography, which is associated with higher radiation doses and longer sedation times. Although multi-detector row CT with multiplanar and three-dimensional reconstruction is expanding the applications of CT of the thorax, its role as a diagnostic tool still needs to be better defined. The purposes of this article are to describe how to perform multi-detector row CT with multiplanar and three-dimensional reconstruction in young patients, to discuss various reconstruction techniques available, and to discuss applications in the evaluation of vascular and airways diseases. PMID:14563904

  4. Comparative evaluation of the cadaveric and computed tomographic features of the coelomic cavity in the green iguana (Iguana iguana), black and white tegu (Tupinambis merianae) and bearded dragon (Pogona vitticeps).

    PubMed

    Banzato, T; Selleri, P; Veladiano, I A; Zotti, A

    2013-12-01

    Contrast-enhanced computed tomographic studies of the coelomic cavity in four green iguanas, four black and white tegus and four bearded dragons were performed using a conventional CT scanner. Anatomical reference cross sections were obtained from four green iguana, four black and white tegu and six bearded dragon cadavers; the specimens were stored in a -20°C freezer for 24 h then sliced into 5-mm intervals. The frozen sections were cleaned with water and photographed on both sides. The individual anatomical structures were identified by means of the available literature; these were labelled first on the anatomical images and then matched to the corresponding computed tomography images. The results provide an atlas of the normal cross-sectional and computed tomographic anatomy of the coelomic cavity in the green iguana, the black and white tegu and the bearded dragon, which is useful in the interpretation of any imaging modality. PMID:23410482

  5. Multidetector CT for Penetrating Torso Trauma: State of the Art.

    PubMed

    Dreizin, David; Munera, Felipe

    2015-11-01

    The use of computed tomography (CT) for hemodynamically stable victims of penetrating torso trauma continues to increase but remains less singular to the work-up than in blunt trauma. Research in this area has focused on the incremental benefits of CT within the context of evolving diagnostic algorithms and in conjunction with techniques such as laparoscopy, endoscopy, and angiographic intervention. This review centers on the current state of multidetector CT as a triage tool for penetrating torso trauma and the primacy of trajectory evaluation in diagnosis, while emphasizing diagnostic challenges that have lingered despite tremendous technological advances since CT was first used in this setting 3 decades ago. As treatment strategies have also changed considerably over the years in parallel with advances in CT, current management implications of organ-specific injuries depicted at multidetector CT are also discussed. PMID:26492022

  6. A unique case of Turner syndrome accompanying prolactinoma and unexpected elongated styloid process: Clinical and cone-beam computed tomographic features

    PubMed Central

    Tatli, Ufuk; Yazicioglu, Iffet; Evlice, Ahmet; Oztunc, Haluk

    2013-01-01

    Turner syndrome (TS) is one of the most common chromosomal abnormalities, with an estimated frequency among female live births of 1/2,000-3,000. The syndrome is characterized by the partial or complete absence of one X chromosome (45,X karyotype). We reported a unique case of a 40-year-old woman with TS accompanying unexpected elongated styloid process specific to Eagle syndrome (ES) and followed up-prolactinoma. The present article is the first report to define the cone-beam computed tomographic (CBCT) features of TS accompanying ES. Patients with TS carry various risks that make treatment more complicated; thus advanced imaging techniques for proper treatment and follow-up are extremely important. In the light of CBCT examination, craniofacial abnormalities specific to TS and accompanying syndromes such as the crowding of teeth especially in the maxillary anterior region caused by maxillary narrowness, micrognatic maxilla and mandible, relative mandibular retrusion, malocclusion, open-bite, and an elongated styloid process (length of 32.7 mm) on the right side were illustrated in detail. PMID:23807938

  7. Cone Beam Computed Tomographic Analyses of the Position and Course of the Mandibular Canal: Relevance to the Sagittal Split Ramus Osteotomy

    PubMed Central

    Sekerci, Ahmet Ercan; Sahman, Halil

    2014-01-01

    Purpose. The aim of this study was to document the position and course of the mandibular canal through the region of the mandibular angle and body in dental patients, using cone beam computed tomographic imaging. Methods. The position and course of the mandibular canal from the region of the third molar to the first molar were measured at five specific locations in the same plane: at three different positions just between the first and second molars; between the second and third molars; and just distal to the third molar. Results. The study sample was composed of 500 hemimandibles from 250 dental patients with a mean age of 26.32. Significant differences were found between genders, distances, and positions. B decreased significantly from the anterior positions to the posterior positions in both females and males. The mean values of S and CB increased significantly from the posterior positions to the anterior positions in both females and males. Conclusion. Because the sagittal split ramus osteotomy is a technically difficult procedure, we hope that the findings of the present study will help the surgeon in choosing the safest surgical technique for the treatment of mandibular deformities. PMID:24719896

  8. Diagnosis and follow-up of neonatal tetralogy of Fallot and hemitruncus with discontinuous pulmonary arteries noninvasively using awake ultra low-dose computed tomographic angiography.

    PubMed

    Wheeler, Adam; Vu, Dan; Renella, Pierangelo

    2016-09-01

    We present a case of an ex-30 week premature male infant diagnosed postnatally with Tetralogy of Fallot, hemitruncus, and discontinuous pulmonary arteries (PAs) at 6 days of life. The patient was diagnosed by echocardiography, and the diagnosis was confirmed on subsequent dual-energy chest CT angiogram. In our patient, the left PA arose directly from the aorta, whereas the right PA originated normally from the right ventricular outflow tract. At 9 days of life, he underwent successful surgical palliation with placement of a modified Blalock-Taussig (aortopulmonary) shunt from the base of the left subclavian artery to the anomalously connected left PA along with anastomosis together of the right and left branch PAs to establish continuity with the main PA. Such cases have been described and are rare. The specific aim of this case report is to illustrate the added benefit of dual-energy electrocardiographically-triggered computed tomographic angiography (CTA) along with standard echocardiography. In addition, high quality images useful in preoperative planning were obtained noninvasively using an ultra low radiation dose without the need for sedation. The information obtained proved essential for confirmation of the diagnosis, preoperative planning, and post-surgical monitoring of branch PA development. PMID:27594935

  9. Accompanying artery of sciatic nerve as recipient vessel for free-flap transfer: a computed tomographic angiography study and case reports.

    PubMed

    Miyamoto, Shimpei; Fukunaga, Yutaka; Fujiki, Masahide; Nakatni, Fumihiko; Tanzawa, Yoshikazu; Sakuraba, Minoru

    2015-05-01

    Suitable recipient vessels for free-flap transfer are hard to find in the posterior thigh. To investigate the versatility of accompanying artery of sciatic nerve as a recipient vessel in this region, we performed computed tomographic angiographic study of 20 consecutive healthy thighs in 10 patients. The presence and internal diameter of the accompanying artery were studied. The accompanying artery of the sciatic nerve was present in 11 thighs (55%) and the internal diameter of the artery at the mid-thigh level ranged from 2.1 to 3.2 mm. We used this artery as a recipient vessel for free flaps transferred to reconstruct extensive thigh defects in three patients with sarcomas. In all patients the flaps survived without vascular compromise. No sensory or motor dysfunction in the sciatic nerve distribution occurred in any patients. We believe that the accompanying artery of the sciatic nerve may be a recipient vessel for free-flap transfer in selected patients. PMID:25196891

  10. 3-D volumetric computed tomographic scoring as an objective outcome measure for chronic rhinosinusitis: Clinical correlations and comparison to Lund-Mackay scoring

    PubMed Central

    Pallanch, John; Yu, Lifeng; Delone, David; Robb, Rich; Holmes, David R.; Camp, Jon; Edwards, Phil; McCollough, Cynthia H.; Ponikau, Jens; Dearking, Amy; Lane, John; Primak, Andrew; Shinkle, Aaron; Hagan, John; Frigas, Evangelo; Ocel, Joseph J.; Tombers, Nicole; Siwani, Rizwan; Orme, Nicholas; Reed, Kurtis; Jerath, Nivedita; Dhillon, Robinder; Kita, Hirohito

    2014-01-01

    Background We aimed to test the hypothesis that 3-D volume-based scoring of computed tomographic (CT) images of the paranasal sinuses was superior to Lund-Mackay CT scoring of disease severity in chronic rhinosinusitis (CRS). We determined correlation between changes in CT scores (using each scoring system) with changes in other measures of disease severity (symptoms, endoscopic scoring, and quality of life) in patients with CRS treated with triamcinolone. Methods The study group comprised 48 adult subjects with CRS. Baseline symptoms and quality of life were assessed. Endoscopy and CT scans were performed. Patients received a single systemic dose of intramuscular triamcinolone and were reevaluated 1 month later. Strengths of the correlations between changes in CT scores and changes in CRS signs and symptoms and quality of life were determined. Results We observed some variability in degree of improvement for the different symptom, endoscopic, and quality-of-life parameters after treatment. Improvement of parameters was significantly correlated with improvement in CT disease score using both CT scoring methods. However, volumetric CT scoring had greater correlation with these parameters than Lund-Mackay scoring. Conclusion Volumetric scoring exhibited higher degree of correlation than Lund-Mackay scoring when comparing improvement in CT score with improvement in score for symptoms, endoscopic exam, and quality of life in this group of patients who received beneficial medical treatment for CRS. PMID:24106202

  11. Computed tomographic angiography of the superficial cerebral venous anastomosis based on volume rendering, multi-planar reconstruction, and integral imaging display.

    PubMed

    Fang, Qiong; Chen, Feng; Jiang, Anhong; Huang, Yanping; Deng, Xuefei

    2015-12-01

    As damage to the superficial cerebral venous anastomosis may create catastrophic complications even after successful surgery, it is important to visualize and determine the normal features of the venous anastomosis with computed tomographic angiography. A total of 90 patients underwent a 64-detector row helical CT scan of head. The superficial cerebral venous anastomosis was reconstructed by volume rendering, multi-planar reconstruction, and integral display algorithm. In particular, we examined the vein of Trolard, the vein of Labbe, and the vein of Sylvian, in order to analyze the venous anastomosis. The superficial cerebral venous anastomosis varied across different individuals, and in this study, six types of anastomosis were found. In 28 % of patients, no venous anastomosis was found in the unilateral cerebral hemisphere. The display rate of the vein of Trolard, the vein of Labbe, and the vein of Sylvian in contributing to venous anastomosis was 70, 80, and 91 %, respectively. The number of vein of Trolard and vein of Labbe on the left side was greater than that of those on the right side. We implemented the 64-detector row helical CT as a rapid and noninvasive method to investigate the superficial cerebral venous anastomosis in our group of patients. We performed substantial image processing for the visualization of the superficial cerebral venous anastomosis; this would not only enable the early diagnosis of cerebral venous disease, but also protect the cerebral vein during neurosurgical intervention. PMID:26577709

  12. Comparison of computed tomographic angiography versus rubidium-82 positron emission tomography for the detection of patients with anatomical coronary artery disease

    PubMed Central

    Chow, Benjamin JW; Dennie, Carole; Hoffmann, Udo; So, Derek; deKemp, Robert A; Ruddy, Terrence D; Beanlands, Rob S

    2007-01-01

    BACKGROUND: The present study compared computed tomo-graphic coronary angiography (CTA) and positron emission tomography (PET) for the detection of significant anatomical coronary artery stenosis as defined by conventional invasive coronary angiography (CICA). METHODS: The study protocol was approved by the local ethics board, and informed consent was obtained from all patients. Of the 26 patients (mean age 57±9 years, 18 men) who prospectively underwent CTA and rubidium-82 PET before CICA, 24 patients had a history of chest pain. Images were interpreted by expert readers and assessed for the presence of anatomically significant coronary stenosis (50% luminal diameter stenosis or greater) or myocardial perfusion defects. Diagnostic test characteristics were analyzed using patient-based, territory-based, vessel-based and segment-based analyses. RESULTS: In the 24 patients referred for chest pain, CTA had similar sensitivity to PET, but was more specific (sensitivity 95% [95% CI 72% to 100%] versus 95% [95% CI 72% to 100%], respectively; specificity 100% [95% CI 46% to 100%] versus 60% [95% CI 17% to 93%], respectively) in the detection of patients with anatomical coronary artery stenosis of 50% or greater. On a per-segment basis of all 26 patients, CTA had a sensitivity, specificity, positive predictive value and negative predictive value of 72%, 99%, 91% and 95%, respectively, in all coronary segments. CONCLUSIONS: Coronary CTA has a similar sensitivity and specificity to rubidium-82 PET for the identification of patients with significant anatomical coronary artery disease. PMID:17703259

  13. Intraspinal collateral circulation to the artery of Adamkiewicz detected with intra-arterial injected computed tomographic angiography.

    PubMed

    Domoto, Satoru; Kimura, Fumiko; Asakura, Toshihisa; Nakazawa, Ken; Koike, Hiroyuki; Niinami, Hiroshi

    2016-06-01

    When the intercostal and lumbar arteries are occluded by plaque or thrombus, spinal cord perfusion depends on collateral circulation. Some reports have demonstrated collateral circulation to the artery of Adamkiewicz via computed tomography and magnetic resonance angiographies. However, intraspinal collateral circulation to the artery of Adamkiewicz along the spinal cord has not been reported previously. Here, we report two patients with intraspinal collateral circulation to the artery of Adamkiewicz along the spinal cord that was detected with intra-arterial injected computed tomography angiography. PMID:26365662

  14. Correlative multiple porosimetries for reservoir sandstones with adoption of a new reference-sample-guided computed-tomographic method

    PubMed Central

    Jin, Jae Hwa; Kim, Junho; Lee, Jeong-Yil; Oh, Young Min

    2016-01-01

    One of the main interests in petroleum geology and reservoir engineering is to quantify the porosity of reservoir beds as accurately as possible. A variety of direct measurements, including methods of mercury intrusion, helium injection and petrographic image analysis, have been developed; however, their application frequently yields equivocal results because these methods are different in theoretical bases, means of measurement, and causes of measurement errors. Here, we present a set of porosities measured in Berea Sandstone samples by the multiple methods, in particular with adoption of a new method using computed tomography and reference samples. The multiple porosimetric data show a marked correlativeness among different methods, suggesting that these methods are compatible with each other. The new method of reference-sample-guided computed tomography is more effective than the previous methods when the accompanied merits such as experimental conveniences are taken into account. PMID:27445105

  15. Correlative multiple porosimetries for reservoir sandstones with adoption of a new reference-sample-guided computed-tomographic method

    NASA Astrophysics Data System (ADS)

    Jin, Jae Hwa; Kim, Junho; Lee, Jeong-Yil; Oh, Young Min

    2016-07-01

    One of the main interests in petroleum geology and reservoir engineering is to quantify the porosity of reservoir beds as accurately as possible. A variety of direct measurements, including methods of mercury intrusion, helium injection and petrographic image analysis, have been developed; however, their application frequently yields equivocal results because these methods are different in theoretical bases, means of measurement, and causes of measurement errors. Here, we present a set of porosities measured in Berea Sandstone samples by the multiple methods, in particular with adoption of a new method using computed tomography and reference samples. The multiple porosimetric data show a marked correlativeness among different methods, suggesting that these methods are compatible with each other. The new method of reference-sample-guided computed tomography is more effective than the previous methods when the accompanied merits such as experimental conveniences are taken into account.

  16. Histological and computed tomographic evaluation of a parasitic conjoined twin in hybrid catfish (Ictalurus punctatus [Rafinesque] X Ictalurus furcatus [Lesueur]).

    PubMed

    Leach, C A; Thomas, M W; Cooley, A J; Waldbieser, G C; Bosworth, B G; Torrans, E L; Khoo, L H

    2014-06-01

    There is growing use of hybrid catfish (Ictalurus punctatus ♀ X Ictalurus furcatus ♂) in commercial aquaculture to utilize hybrid vigour to improve production A conjoined twin specimen found during the course of production studies by the United States Department of Agriculture Catfish Genetic Research Unit (USDA-CGRU) was submitted to the Aquatic Research and Diagnostic Laboratory (ARDL). After preliminary inspection, it was transported to Mississippi State University, College of Veterinary Medicine for further evaluation. The specimen was examined using both computed radiography and computed tomography antemortem. Following humane euthanasia, the specimen was examined both grossly and histologically. Tissues from both fish were also submitted for genetic analysis to determine whether twins were derived from the same egg. This report records the presentation and examination of a pair of conjoined hybrid catfish (I. punctatus X Ictalurus furcatus). PMID:23991936

  17. Correlative multiple porosimetries for reservoir sandstones with adoption of a new reference-sample-guided computed-tomographic method.

    PubMed

    Jin, Jae Hwa; Kim, Junho; Lee, Jeong-Yil; Oh, Young Min

    2016-01-01

    One of the main interests in petroleum geology and reservoir engineering is to quantify the porosity of reservoir beds as accurately as possible. A variety of direct measurements, including methods of mercury intrusion, helium injection and petrographic image analysis, have been developed; however, their application frequently yields equivocal results because these methods are different in theoretical bases, means of measurement, and causes of measurement errors. Here, we present a set of porosities measured in Berea Sandstone samples by the multiple methods, in particular with adoption of a new method using computed tomography and reference samples. The multiple porosimetric data show a marked correlativeness among different methods, suggesting that these methods are compatible with each other. The new method of reference-sample-guided computed tomography is more effective than the previous methods when the accompanied merits such as experimental conveniences are taken into account. PMID:27445105

  18. COMBINATION OF COMPUTED TOMOGRAPHIC IMAGING CHARACTERISTICS OF MEDIAL RETROPHARYNGEAL LYMPH NODES AND NASAL PASSAGES AIDS DISCRIMINATION BETWEEN RHINITIS AND NEOPLASIA IN CATS.

    PubMed

    Nemanic, Sarah; Hollars, Katelyn; Nelson, Nathan C; Bobe, Gerd

    2015-01-01

    Feline nasal diseases are a diagnostic challenge. The objective of this retrospective, cross-sectional study was to determine whether computed tomography (CT) imaging characteristics of the medial retropharyngeal lymph nodes (MRPLN), alone or in combination with CT imaging characteristics of the nasal passages, could aid in differentiation between rhinitis and nasal neoplasia. Cats were recruited from record archives at two veterinary facilities during the period of 2008-2012. Selection criteria were presentation for chronic nasal discharge, contrast-enhanced CT of the head that included the MRPLN, and rhinoscopic nasal biopsy resulting in diagnosis of rhinitis or neoplasia. For each CT scan, two board-certified veterinary radiologists recorded MRPLN size, attenuation, heterogeneity, contrast-medium enhancement, margination, shape, presence of a lymph node hilus, perinodal fat, turbinate lysis, paranasal bone lysis, and nasal mass. Both readers were unaware of patient information at the time of CT interpretation. Thirty-four cats with rhinitis and 22 cats with neoplasia were included. Computed tomographic characteristics significantly associated with neoplasia included abnormal MRPLN hilus (OR 5.1), paranasal bone lysis (OR 5.6), turbinate lysis (5.6), mass (OR 26.1), MRPLN height asymmetry (OR 4.5), and decreased MRPLN precontrast heterogeneity (OR 7.0). The combined features predictive of neoplasia were a nasal mass with abnormal hilus (OR 47.7); lysis of turbinates/paranasal bones with abnormal MRPLN hilus (OR 16.2). Findings supported the hypothesis that combining CT features of the nasal passages and MRPLN aided in differentiating rhinitis from neoplasia in cats. PMID:26194153

  19. Cardiac Multi-detector CT Segmentation Based on Multiscale Directional Edge Detector and 3D Level Set.

    PubMed

    Antunes, Sofia; Esposito, Antonio; Palmisano, Anna; Colantoni, Caterina; Cerutti, Sergio; Rizzo, Giovanna

    2016-05-01

    Extraction of the cardiac surfaces of interest from multi-detector computed tomographic (MDCT) data is a pre-requisite step for cardiac analysis, as well as for image guidance procedures. Most of the existing methods need manual corrections, which is time-consuming. We present a fully automatic segmentation technique for the extraction of the right ventricle, left ventricular endocardium and epicardium from MDCT images. The method consists in a 3D level set surface evolution approach coupled to a new stopping function based on a multiscale directional second derivative Gaussian filter, which is able to stop propagation precisely on the real boundary of the structures of interest. We validated the segmentation method on 18 MDCT volumes from healthy and pathologic subjects using manual segmentation performed by a team of expert radiologists as gold standard. Segmentation errors were assessed for each structure resulting in a surface-to-surface mean error below 0.5 mm and a percentage of surface distance with errors less than 1 mm above 80%. Moreover, in comparison to other segmentation approaches, already proposed in previous work, our method presented an improved accuracy (with surface distance errors less than 1 mm increased of 8-20% for all structures). The obtained results suggest that our approach is accurate and effective for the segmentation of ventricular cavities and myocardium from MDCT images. PMID:26319010

  20. Association of achondroplasia with Down syndrome: difficulty in prenatal diagnosis by sonographic and 3-D helical computed tomographic analyses.

    PubMed

    Kaga, Akimune; Murotsuki, Jun; Kamimura, Miki; Kimura, Masato; Saito-Hakoda, Akiko; Kanno, Junko; Hoshi, Kazuhiko; Kure, Shigeo; Fujiwara, Ikuma

    2015-05-01

    Achondroplasia and Down syndrome are relatively common conditions individually. But co-occurrence of both conditions in the same patient is rare and there have been no reports of fetal analysis of this condition by prenatal sonographic and three-dimensional (3-D) helical computed tomography (CT). Prenatal sonographic findings seen in persons with Down syndrome, such as a thickened nuchal fold, cardiac defects, and echogenic bowel were not found in the patient. A prenatal 3-D helical CT revealed a large head with frontal bossing, metaphyseal flaring of the long bones, and small iliac wings, which suggested achondroplasia. In a case with combination of achondroplasia and Down syndrome, it may be difficult to diagnose the co-occurrence prenatally without typical markers of Down syndrome. PMID:25385298

  1. Use of Coronary Computed Tomographic Angiography Findings to Modify Statin and Aspirin Prescription in Patients With Acute Chest Pain.

    PubMed

    Pursnani, Amit; Celeng, Csilla; Schlett, Christopher L; Mayrhofer, Thomas; Zakroysky, Pearl; Lee, Hang; Ferencik, Maros; Fleg, Jerome L; Bamberg, Fabian; Wiviott, Stephen D; Truong, Quynh A; Udelson, James E; Nagurney, John T; Hoffmann, Udo

    2016-02-01

    Coronary CT angiography (CCTA) is used in patients with low-intermediate chest pain presenting to the emergency department for its reliability in excluding acute coronary syndrome (ACS). However, its influence on medication modification in this setting is unclear. We sought to determine whether knowledge of CCTA-based coronary artery disease (CAD) was associated with change in statin and aspirin prescription. We used the CCTA arm of the Rule Out Myocardial Infarction using Computed Angiographic Tomography II multicenter, randomized control trial (R-II) and comparison cohort from the observational Rule Out Myocardial Infarction using Computed Angiographic Tomography I cohort (R-I). In R-II, subjects were randomly assigned to CCTA to guide decision making, whereas in R-I patients underwent CCTA with results blinded to caregivers and managed according to standard care. Our final cohort consisted of 277 subjects from R-I and 370 from R-II. ACS rate was similar (6.9% vs 6.2% respectively, p = 0.75). For subjects with CCTA-detected obstructive CAD without ACS, initiation of statin was significantly greater after disclosure of CCTA results (0% in R-I vs 20% in R-II, p = 0.009). Conversely, for subjects without CCTA-detected CAD, aspirin prescription was lower with disclosure of CCTA results (16% in R-I vs 4.8% in R-II, p = 0.001). However, only 68% of subjects in R-II with obstructive CAD were discharged on statin and 65% on aspirin. In conclusion, physician knowledge of CCTA results leads to improved alignment of aspirin and statin with the presence and severity of CAD although still many patients with CCTA-detected CAD are not discharged on aspirin or statin. Our findings suggest opportunity for practice improvement when CCTA is performed in the emergency department. PMID:26762723

  2. Quantitative Ex-Vivo Micro-Computed Tomographic Imaging of Blood Vessels and Necrotic Regions within Tumors

    PubMed Central

    Downey, Charlene M.; Singla, Arvind K.; Villemaire, Michelle L.; Buie, Helen R.; Boyd, Steven K.; Jirik, Frank R.

    2012-01-01

    Techniques for visualizing and quantifying the microvasculature of tumors are essential not only for studying angiogenic processes but also for monitoring the effects of anti-angiogenic treatments. Given the relatively limited information that can be gleaned from conventional 2-D histological analyses, there has been considerable interest in methods that enable the 3-D assessment of the vasculature. To this end, we employed a polymerizing intravascular contrast medium (Microfil) and micro-computed tomography (micro-CT) in combination with a maximal spheres direct 3-D analysis method to visualize and quantify ex-vivo vessel structural features, and to define regions of hypoperfusion within tumors that would be indicative of necrosis. Employing these techniques we quantified the effects of a vascular disrupting agent on the tumor vasculature. The methods described herein for quantifying whole tumor vascularity represent a significant advance in the 3-D study of tumor angiogenesis and evaluation of novel therapeutics, and will also find potential application in other fields where quantification of blood vessel structure and necrosis are important outcome parameters. PMID:22848565

  3. Anatomical, radiographical and computed tomographic study of the limbs skeleton of the Euphrates soft shell turtle (Rafetus euphraticus).

    PubMed

    Asadi Ahranjani, Behnaz; Shojaei, Bahador; Tootian, Zahra; Masoudifard, Madjid; Rostami, Amir

    2016-01-01

    Euphrates turtle is the only soft shell turtle of Iran, and unfortunately is in danger of extinction due to multiple reasons. Imaging techniques, in addition to their importance in diagnosis of injuries to animals, have been used as non-invasive methods to provide normal anatomic views. A few studies have been conducted to understand body structure of the Euphrates turtle. Since there is only general information about the anatomy of turtle limbs, the normal skeleton of the Euphrates limbs was studied. For this purpose four adult Euphrates turtles were used. Digital radiographic examination was performed by computed radiographic (CR) in dorsoventral (DV) and lateral (L) positions. Spiral CT-scanning was done and 3D images of the bones were reconstructed for anatomical evaluation. For skeletal preparation, the skeleton was cleaned by a combination of boiling and mealworm methods and limbs' bones were examined anatomically. In the present study, simultaneous anatomic, radiographic and CT studies of bones in individual turtles made us possible to describe bones anatomically and provided comparable and complementary conditions to represent the abilities of the radiography and CT for better understanding of the anatomy. Arrangement and the number of carpal and tarsal bones are used in turtles' classification. Among the studied species, Euphrates turtle carpal and tarsal bones show the most similarities to the Apolone spinifera. PMID:27482356

  4. A Systematic Review of Protocols for the Three-Dimensional Morphologic Assessment of Abdominal Aortic Aneurysms Using Computed Tomographic Angiography

    SciTech Connect

    Ghatwary, Tamer M. H.; Patterson, Benjamin O.; Karthikesalingam, Alan; Hinchliffe, Robert J.; Loftus, Ian M.; Morgan, Robert; Thompson, Matt M.; Holt, Peter J. E.

    2013-02-15

    The morphology of infrarenal abdominal aortic aneurysms (AAAs) directly influences the perioperative outcome and long-term durability of endovascular aneurysm repair. A variety of methods have been proposed for the characterization of AAA morphology using reconstructed three-dimensional (3D) computed tomography (CT) images. At present, there is lack of consensus as to which of these methods is most applicable to clinical practice or research. The purpose of this review was to evaluate existing protocols that used 3D CT images in the assessment of various aspects of AAA morphology. An electronic search was performed, from January 1996 to the end of October 2010, using the Embase and Medline databases. The literature review conformed to PRISMA statement standards. The literature search identified 604 articles, of which 31 studies met inclusion criteria. Only 15 of 31 studies objectively assessed reproducibility. Existing published protocols were insufficient to define a single evidence-based methodology for preoperative assessment of AAA morphology. Further development and expert consensus are required to establish a standardized and validated protocol to determine precisely how morphology relates to outcomes after endovascular aneurysm repair.

  5. Infrared thermography of the pig thorax: an assessment of selected regions of interest by computed tomographical and anatomical parameters.

    PubMed

    Menzel, A; Siewert, C; Gasse, H; Seifert, H; Hoeltig, D; Hennig-Pauka, I

    2015-04-01

    Current methods of diagnosis of respiratory diseases in swine are invasive, time-consuming and expensive. Infrared thermography (IRT) of the thorax might provide a new method of high specificity to select swine affected with lung alterations for further diagnostics. In this study, layer thickness of different tissues was determined in frozen thorax slices (FTS) by computed tomography (CT) and then related to skin temperatures measured by IRT in healthy pigs. The aim was to determine appropriate regions of interest (ROI) for evaluation of IRT images. Organ layer thicknesses measured in CT images correspond to those measured in FTS. Temperature differences between lung ROIs and abdomen ROIs were positively correlated with lung layer thickness at certain localizations, and negatively correlated with the thickness of the thorax wall and of inner organ layers. Reference values of differences between skin temperatures were established for two ROIs on the thorax with potential practical use for lung health status determination. Respective ROIs were located on vertical lines crossing the 7th (right) and the 10th (left) thoracic vertebrae. The presence of ribs affected skin temperature significantly. PMID:24712373

  6. Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

    PubMed Central

    Bouhemad, Bélaid; Richecoeur, Jack; Lu, Qin; Malbouisson, Luiz M; Cluzel, Philippe; Rouby, Jean-Jacques

    2003-01-01

    Background Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications. PMID:12617742

  7. Computer Tomographic Illustration of the Development of the Pulmonary Function in Bovine Neonates until the Twenty-First Day Postnatum

    PubMed Central

    Bostedt, H.; Richter, A.

    2013-01-01

    The aim of this study was to analyze the development of the lung in newborn calves. The sample consisted of 28 Holstein Friesians calves which were examined clinically, and their chest segment was measured with computed tomography. The tests were performed on the first, sixth, and twelfth hours of life and after the first, second, and third weeks. Also, blood gases and blood counts were determined. Besides Kolmogorov-Smirnov tests, analyses of variance, t-tests (on a significance level of P < 0.05), and correlation analyses were used. The most significant changes occurred between birth and the first hour. However, there were significant differences in the gas filling between cranial and caudal and between dorsal and ventral parenchyma segments. This difference remained over the entire study period. At the end of the first week between 85 and 93% were involved in gas exchange. Only after the completion of the second week of life, the air supply was achieved throughout the whole lung. The pO2, pCO2, and pH values confirmed this. This study shows that a healthy bovine neonate needs about 2 weeks before all lung units are integrated into the gas exchange. This explains why calves in unfavorable environments often suffer from pulmonary affections. PMID:24175112

  8. Quantitative computed tomographic evaluation of femoral bone mineral content in renal osteodystrophy compared with radial photon absorptiometry

    SciTech Connect

    Sakurai, K.; Marumo, F.; Iwanami, S.; Uchida, H.; Matsubayashi, T.

    1989-05-01

    The computed tomography (CT) numbers of cortical bone at the level of 20 cm (CT20) and of spongiosa in the lateral condyle at the level of 2 cm (CT02) from the distal end of the femur were obtained by a quantitative CT method and compared with the bone mineral density of mostly cortical bone within the radius (BMD) by photon absorptiometry. The study included 47 patients with chronic renal failure not dialyzed or induced to regular hemodialysis within 4 weeks of the study (group 1), 28 patients on regular hemodialysis for more than one month (group 2), and ten healthy volunteers (group 3). The measures of bone mineral content (BMC), namely CT20, CT02, and BMD, were compared in terms of their abilities to distinguish members in the various groups. For group 1 and group 3, the greatest variation in BMC was in the difference in CT02, which was primarily a measurement of the BMC of spongiosa. For groups 1 and 2, the greatest variation was in the difference in BMD, which was primarily a measurement of the BMC of cortex. The reproducibility of CT02 was estimated as almost equal to the difference in CT02 values at intervals of 10 months' duration of hemodialysis. The results indicated that CT02 was a useful measurement for evaluating the progress in the early stage of the renal osteodystrophy, and it is recommended that the bone mineral measurement with this QCT method should be performed once or twice a year.

  9. Anatomical, radiographical and computed tomographic study of the limbs skeleton of the Euphrates soft shell turtle (Rafetus euphraticus)

    PubMed Central

    Asadi Ahranjani, Behnaz; Shojaei, Bahador; Tootian, Zahra; Masoudifard, Madjid; Rostami, Amir

    2016-01-01

    Euphrates turtle is the only soft shell turtle of Iran, and unfortunately is in danger of extinction due to multiple reasons. Imaging techniques, in addition to their importance in diagnosis of injuries to animals, have been used as non-invasive methods to provide normal anatomic views. A few studies have been conducted to understand body structure of the Euphrates turtle. Since there is only general information about the anatomy of turtle limbs, the normal skeleton of the Euphrates limbs was studied. For this purpose four adult Euphrates turtles were used. Digital radiographic examination was performed by computed radiographic (CR) in dorsoventral (DV) and lateral (L) positions. Spiral CT-scanning was done and 3D images of the bones were reconstructed for anatomical evaluation. For skeletal preparation, the skeleton was cleaned by a combination of boiling and mealworm methods and limbs’ bones were examined anatomically. In the present study, simultaneous anatomic, radiographic and CT studies of bones in individual turtles made us possible to describe bones anatomically and provided comparable and complementary conditions to represent the abilities of the radiography and CT for better understanding of the anatomy. Arrangement and the number of carpal and tarsal bones are used in turtles’ classification. Among the studied species, Euphrates turtle carpal and tarsal bones show the most similarities to the Apolone spinifera. PMID:27482356

  10. Dual-Source Computed Tomographic Temporal Resolution Provides Higher Image Quality Than 64-Detector Temporal Resolution at Low Heart Rates

    PubMed Central

    Araoz, Philip A.; Kirsch, Jacobo; Primak, Andrew N.; Braun, Natalie N.; Saba, Osama; Williamson, Eric E.; Harmsen, W. Scott; Mandrekar, Jayawant N.; McCollough, Cynthia H.

    2010-01-01

    Objective To compare coronary image quality at temporal resolutions associated with dual-source computed tomography (DSCT; 83 milliseconds) and 64–detector row scanning (165 milliseconds). Methods In 30 patients with a heart rate of less than 70 beats per minute, DSCT coronary angiograms were reconstructed at 83- and 165-millisecond temporal resolutions over different cardiac phases. A blinded observer graded coronary quality. Results The typical DSCT temporal resolution (83 milliseconds) showed a significantly greater quality at end-systole for all coronary vessels and at end-diastole for the right coronary and left anterior descending coronary arteries. For all vessels, the end-diastole produced the highest quality for both temporal resolutions. Conclusions Imaging at 83 milliseconds creates superior quality at end-systole for all coronary vessels and at end-diastole for the right coronary and left anterior descending coronary arteries. At low heart rates, end-diastole produces the highest quality at both temporal resolutions. PMID:20118724

  11. In vivo X-Ray Computed Tomographic Imaging of Soft Tissue with Native, Intravenous, or Oral Contrast

    PubMed Central

    Wathen, Connor A.; Foje, Nathan; van Avermaete, Tony; Miramontes, Bernadette; Chapaman, Sarah E.; Sasser, Todd A.; Kannan, Raghuraman; Gerstler, Steven; Leevy, W. Matthew

    2013-01-01

    X-ray Computed Tomography (CT) is one of the most commonly utilized anatomical imaging modalities for both research and clinical purposes. CT combines high-resolution, three-dimensional data with relatively fast acquisition to provide a solid platform for non-invasive human or specimen imaging. The primary limitation of CT is its inability to distinguish many soft tissues based on native contrast. While bone has high contrast within a CT image due to its material density from calcium phosphate, soft tissue is less dense and many are homogenous in density. This presents a challenge in distinguishing one type of soft tissue from another. A couple exceptions include the lungs as well as fat, both of which have unique densities owing to the presence of air or bulk hydrocarbons, respectively. In order to facilitate X-ray CT imaging of other structures, a range of contrast agents have been developed to selectively identify and visualize the anatomical properties of individual tissues. Most agents incorporate atoms like iodine, gold, or barium because of their ability to absorb X-rays, and thus impart contrast to a given organ system. Here we review the strategies available to visualize lung, fat, brain, kidney, liver, spleen, vasculature, gastrointestinal tract, and liver tissues of living mice using either innate contrast, or commercial injectable or ingestible agents with selective perfusion. Further, we demonstrate how each of these approaches will facilitate the non-invasive, longitudinal, in vivo imaging of pre-clinical disease models at each anatomical site. PMID:23711461

  12. Radiation dose and physical image quality in 128-section dual-source computed tomographic coronary angiography: a phantom study.

    PubMed

    Matsubara, Kosuke; Koshida, Haruka; Sakuta, Keita; Takata, Tadanori; Horii, Junsei; Iida, Hiroji; Koshida, Kichiro; Ichikawa, Katsuhiro; Matsui, Osamu

    2012-01-01

    One-hundred-and-twenty-eight-section dual X-ray source computed tomography (CT) systems have been introduced into clinical practice and have been shown to increase temporal resolution. Higher temporal resolution allows low-dose spiral mode at a high pitch factor during CT coronary angiography. We evaluated radiation dose and physical image qualities in CT coronary angiography by applying high-pitch spiral, step-and-shoot, and low-pitch spiral modes to determine the optimal acquisition mode for clinical situations. An anthropomorphic phantom, small dosimeters, a calibration phantom, and a microdisc phantom were used to evaluate the radiation doses absorbed by thoracic organs, noise power spectrums, in-plane and z-axis modulation transfer functions, slice sensitivity profiles, and number of artifacts for the three acquisition modes. The high-pitch spiral mode had the advantage of a small absorbed radiation dose, but provided low image quality. The low-pitch spiral mode resulted in a high absorbed radiation dose of approximately 200 mGy for the heart. Although the absorbed radiation dose was lower in the step-and-shoot mode than in the low-pitch spiral mode, the noise power spectrum was inferior. The quality of the in-plane modulation transfer function differed, depending on spatial frequency. Therefore, the step-and-shoot mode should be applied initially because of its low absorbed radiation dose and superior image quality. PMID:22955662

  13. A Pilot Evaluation of a 4-Dimensional Cone-Beam Computed Tomographic Scheme Based on Simultaneous Motion Estimation and Image Reconstruction

    SciTech Connect

    Dang, Jun; Gu, Xuejun; Pan, Tinsu; Wang, Jing

    2015-02-01

    Purpose: To evaluate the performance of a 4-dimensional (4-D) cone-beam computed tomographic (CBCT) reconstruction scheme based on simultaneous motion estimation and image reconstruction (SMEIR) through patient studies. Methods and Materials: The SMEIR algorithm contains 2 alternating steps: (1) motion-compensated CBCT reconstruction using projections from all phases to reconstruct a reference phase 4D-CBCT by explicitly considering the motion models between each different phase and (2) estimation of motion models directly from projections by matching the measured projections to the forward projection of the deformed reference phase 4D-CBCT. Four lung cancer patients were scanned for 4 to 6 minutes to obtain approximately 2000 projections for each patient. To evaluate the performance of the SMEIR algorithm on a conventional 1-minute CBCT scan, the number of projections at each phase was reduced by a factor of 5, 8, or 10 for each patient. Then, 4D-CBCTs were reconstructed from the down-sampled projections using Feldkamp-Davis-Kress, total variation (TV) minimization, prior image constrained compressive sensing (PICCS), and SMEIR. Using the 4D-CBCT reconstructed from the fully sampled projections as a reference, the relative error (RE) of reconstructed images, root mean square error (RMSE), and maximum error (MaxE) of estimated tumor positions were analyzed to quantify the performance of the SMEIR algorithm. Results: The SMEIR algorithm can achieve results consistent with the reference 4D-CBCT reconstructed with many more projections per phase. With an average of 30 to 40 projections per phase, the MaxE in tumor position detection is less than 1 mm in SMEIR for all 4 patients. Conclusion: The results from a limited number of patients show that SMEIR is a promising tool for high-quality 4D-CBCT reconstruction and tumor motion modeling.

  14. Protein-Poly(amino acid) Nanocore-Shell Mediated Synthesis of Branched Gold Nanostructures for Computed Tomographic Imaging and Photothermal Therapy of Cancer.

    PubMed

    Sasidharan, Sisini; Bahadur, Dhirendra; Srivastava, Rohit

    2016-06-29

    Anisotropic noble metal nanoparticles especially branched gold nanoparticles with a large absorption cross-section and high molar extinction coefficient have promising applications in biomedical field. However, sophisticated and cumbersome methodologies of synthesis along with toxic precursors pose serious concern for its use. Herein, we report the synthesis of branched gold nanostructures from protein (albumin) nanoparticles by a simple reduction method. Albumin nanoparticles were synthesized by a modified desolvation technique with poly-l-arginine (cationic poly amino acid) substituting the conventional toxic cross-linker, glutaraldehyde. In silico molecular docking was carried out to study the interaction of poly-l-arginine with albumin which revealed its binding to Pocket 1B of the A-chain of albumin. The poly-l-arginine-albumin core-shell nanoparticles of ∼100 nm in size served as a base for attachment of gold ions and its reduction to form 140 nm sized branched gold nanostructures conjugated with glutathione. These gold nanostructures exhibited near-infrared absorption λmax at 800 nm with extreme compatibility toward non cancerous (NIH 3T3), oral epithelial carcinoma (KB) cell lines, and human blood (red blood cells, platelets, and coagulation mechanisms) even up to a high concentration of 250 μg/mL. These structures demonstrated superior computed tomographic (CT) contrast ability and marked photothermal cytotoxicity on KB cells. This study reports for the first time a method to develop blood and cell compatible branched gold nanostructures from protein nanoparticles as a dual CT diagnostic and photothermal therapeutic agent. PMID:27243100

  15. Impaired fasting glucose is associated with increased severity of subclinical coronary artery disease compared to patients with diabetes and normal fasting glucose: evaluation by coronary computed tomographic angiography

    PubMed Central

    Gurudevan, Swaminatha; Garg, Pankaj; Malik, Shaista; Khattar, Ramni; Saremi, Farhood; Hecht, Harvey; DeMaria, Anthony; Narula, Jagat

    2016-01-01

    Objective This study was designed to evaluate the severity of subclinical atherosclerosis in patients with asymptomatic impaired fasting glucose (IFG) compared to those with diabetes mellitus (DM) and normal fasting glucose (NFG), as measured by coronary computed tomographic angiography (CCTA). Design Subjects were divided into three groups: NFG (<100 mg/dL), IFG (100–125 mg/dL) and DM. Coronary artery calcium on non-contrast CT and plaque analysis on CCTA were performed. Setting University hospital, single centre. Participants 216 asymptomatic participants prospectively underwent CCTA for the evaluation of coronary artery disease (CAD). Primary and secondary outcome measures Atherosclerotic plaque burden in IFG compared to NFG patients. Results 2664 segments were analysed in 120 NFG, 44 IFG and 52 DM participants. The mean calcium scores were 178±395, 259±510 and 414±836 for NFG, IFG and DM, respectively (p=0·037). The mean plaque burdens in the NFG, IFG and DM groups were 0.31±0.45, 0.50±0.69 and 0.68±0.69, respectively (p=0·0007). A greater proportion of patients with DM (19/52, 36.5%) and IFG (13/44, 29.5%) had obstructive CAD compared to those with NFG (16/120, 13.3%) (p=0.0015). The number of segments with severe disease was significantly higher in the DM (60/637, 9.4%) and IFG (42/539, 7.8%) groups compared to that in the NFG group (34/1488, 2.3%) (p=0.0001). Conclusions (1) IFG and DM have significantly higher, but comparable, calcium scores, plaque burden and obstructive CAD compared to NFG in asymptomatic individuals. (2) Pending corroboration by other reports, more intensive efforts may be devoted to the evaluation and treatment of patients with IFG. PMID:27531720

  16. Downstream Testing and Subsequent Procedures After Coronary Computed Tomographic Angiography Following Coronary Stenting in Patients ≥65 Years of Age

    PubMed Central

    Mudrick, Daniel; Kaltenbach, Lisa A.; Shah, Bimal; Lytle, Barbara; Masoudi, Frederick A.; Mark, Daniel B.; Federspiel, Jerome J.; Cowper, Patricia A.; Green, Cynthia; Douglas, Pamela S.

    2013-01-01

    Limited data are available on the use of coronary computed tomography angiography (CCTA) in patients who have received percutaneous coronary intervention (PCI). To evaluate patterns of cardiac testing including CCTA after PCI, we created a retrospective observational data set linking the National Cardiovascular Data Registry® CathPCI Registry® baseline data with longitudinal inpatient and outpatient Medicare claims data for patients who received coronary stenting between November 1, 2005 and December 31, 2007. Among 192,009 PCI patients (median age 74 years), the first test after coronary stenting was CCTA for 553 (0.3%), stress testing for 89,900 (46.8%), and coronary angiography for 22,308 (11.6%); 79,248 (41.3%) had no further testing. Patients referred to CCTA first had generally similar or lower baseline risk than those referred for stress testing or catheterization first. Compared to patients with stress testing first after PCI, patients who underwent CCTA first had higher unadjusted rates of subsequent noninvasive testing (10% vs. 3%), catheterization (26% vs. 15%), and revascularization (13% vs. 8%) within 90 days of initial post-PCI testing (p<0.0001 for all). In conclusion, despite similar or lesser risk profiles, patients initially evaluated with CCTA after PCI had more downstream testing and revascularization than patients initially evaluated with stress testing. It is unclear whether these differences derive from patient selection, the performance of CCTA relative to other testing strategies, or the association of early CCTA adoption with distinct patterns of care. PMID:22651883

  17. Evaluation of an X-Ray Dose Profile Derived from an Optically Stimulated Luminescent Dosimeter during Computed Tomographic Fluoroscopy.

    PubMed

    Hasegawa, Hiroaki; Sato, Masanori; Tanaka, Hiroshi

    2015-01-01

    The purpose of this study was to evaluate scatter radiation dose to the subject surface during X-ray computed tomography (CT) fluoroscopy using the integrated dose ratio (IDR) of an X-ray dose profile derived from an optically stimulated luminescent (OSL) dosimeter. We aimed to obtain quantitative evidence supporting the radiation protection methods used during previous CT fluoroscopy. A multislice CT scanner was used to perform this study. OSL dosimeters were placed on the top and the lateral side of the chest phantom so that the longitudinal direction of dosimeters was parallel to the orthogonal axis-to-slice plane for measurement of dose profiles in CT fluoroscopy. Measurement of fluoroscopic conditions was performed at 120 kVp and 80 kVp. Scatter radiation dose was evaluated by calculating the integrated dose determined by OSL dosimetry. The overall percent difference of the integrated doses between OSL dosimeters and ionization chamber was 5.92%. The ratio of the integrated dose of a 100-mm length area to its tails (-50 to -6 mm, 50 to 6 mm) was the lowest on the lateral side at 80 kVp and the highest on the top at 120 kVp. The IDRs for different measurement positions were larger at 120 kVp than at 80 kVp. Similarly, the IDRs for the tube voltage between the primary X-ray beam and scatter radiation was larger on the lateral side than on the top of the phantom. IDR evaluation suggested that the scatter radiation dose has a high dependence on the position and a low dependence on tube voltage relative to the primary X-ray beam for constant dose rate fluoroscopic conditions. These results provided quantitative evidence supporting the radiation protection methods used during CT fluoroscopy in previous studies. PMID:26151914

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

    DOE R&D Accomplishments Database

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

    2002-02-28

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

  19. Stent sizing strategies in renal artery stenting: the comparison of conventional invasive renal angiography with renal computed tomographic angiography

    PubMed Central

    Michalowska, Ilona; Pregowski, Jerzy; Janaszek-Sitkowska, Hanna; Lech, Katarzyna; Kabat, Marek; Staruch, Adam; Januszewicz, Andrzej; Witkowski, Adam

    2016-01-01

    Introduction Randomized trials comparing invasive treatment of renal artery stenosis with standard pharmacotherapy did not show substantial benefit from revascularization. One of the potential reasons for that may be suboptimal procedure technique. Aim To compare renal stent sizing using two modalities: three-dimensional renal computed tomography angiography (CTA) versus conventional angiography. Material and methods Forty patients (41 renal arteries), aged 65.1 ±8.5 years, who underwent renal artery stenting with preprocedural CTA performed within 6 months, were retrospectively analyzed. In CTA analysis, reference diameter (CTA-D) and lesion length (CTA_LL) were measured and proposed stent diameter and length were recorded. Similarly, angiographic reference diameter (ANGIO_D) and lesion length (ANGIO_LL) as well as proposed stent dimensions were obtained by visual estimation. Results The median CTA_D was 0.5 mm larger than the median ANGIO_D (p < 0.001). Also, the proposed stent diameter in CTA evaluation was 0.5 mm larger than that in angiography (p < 0.0001). The median CTA_LL was 1 mm longer than the ANGIO_LL (p = NS), with significant correlation of these variables (r = 0.66, p < 0.0001). The median proposed stent length with CTA was equal to that proposed with angiography. The median diameter of the implanted stent was 0.5 mm smaller than that proposed in CTA (p < 0.0005) and identical to that proposed in angiography. The median length of the actual stent was longer than that proposed in angiography (p = 0.0001). Conclusions Renal CTA has potential advantages as a tool adjunctive to angiography in appropriate stent sizing. Careful evaluation of the available CTA scans may be beneficial and should be considered prior to the planned procedure. PMID:27279870

  20. Phantom and Clinical Study of Differences in Cone Beam Computed Tomographic Registration When Aligned to Maximum and Average Intensity Projection

    SciTech Connect

    Shirai, Kiyonori; Nishiyama, Kinji; Katsuda, Toshizo; Teshima, Teruki; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo

    2014-01-01

    Purpose: To determine whether maximum or average intensity projection (MIP or AIP, respectively) reconstructed from 4-dimensional computed tomography (4DCT) is preferred for alignment to cone beam CT (CBCT) images in lung stereotactic body radiation therapy. Methods and Materials: Stationary CT and 4DCT images were acquired with a target phantom at the center of motion and moving along the superior–inferior (SI) direction, respectively. Motion profiles were asymmetrical waveforms with amplitudes of 10, 15, and 20 mm and a 4-second cycle. Stationary CBCT and dynamic CBCT images were acquired in the same manner as stationary CT and 4DCT images. Stationary CBCT was aligned to stationary CT, and the couch position was used as the baseline. Dynamic CBCT was aligned to the MIP and AIP of corresponding amplitudes. Registration error was defined as the SI deviation of the couch position from the baseline. In 16 patients with isolated lung lesions, free-breathing CBCT (FBCBCT) was registered to AIP and MIP (64 sessions in total), and the difference in couch shifts was calculated. Results: In the phantom study, registration errors were within 0.1 mm for AIP and 1.5 to 1.8 mm toward the inferior direction for MIP. In the patient study, the difference in the couch shifts (mean, range) was insignificant in the right-left (0.0 mm, ≤1.0 mm) and anterior–posterior (0.0 mm, ≤2.1 mm) directions. In the SI direction, however, the couch position significantly shifted in the inferior direction after MIP registration compared with after AIP registration (mean, −0.6 mm; ranging 1.7 mm to the superior side and 3.5 mm to the inferior side, P=.02). Conclusions: AIP is recommended as the reference image for registration to FBCBCT when target alignment is performed in the presence of asymmetrical respiratory motion, whereas MIP causes systematic target positioning error.

  1. Evaluation of an X-Ray Dose Profile Derived from an Optically Stimulated Luminescent Dosimeter during Computed Tomographic Fluoroscopy

    PubMed Central

    Hasegawa, Hiroaki; Sato, Masanori; Tanaka, Hiroshi

    2015-01-01

    The purpose of this study was to evaluate scatter radiation dose to the subject surface during X-ray computed tomography (CT) fluoroscopy using the integrated dose ratio (IDR) of an X-ray dose profile derived from an optically stimulated luminescent (OSL) dosimeter. We aimed to obtain quantitative evidence supporting the radiation protection methods used during previous CT fluoroscopy. A multislice CT scanner was used to perform this study. OSL dosimeters were placed on the top and the lateral side of the chest phantom so that the longitudinal direction of dosimeters was parallel to the orthogonal axis-to-slice plane for measurement of dose profiles in CT fluoroscopy. Measurement of fluoroscopic conditions was performed at 120 kVp and 80 kVp. Scatter radiation dose was evaluated by calculating the integrated dose determined by OSL dosimetry. The overall percent difference of the integrated doses between OSL dosimeters and ionization chamber was 5.92%. The ratio of the integrated dose of a 100-mm length area to its tails (−50 to −6 mm, 50 to 6 mm) was the lowest on the lateral side at 80 kVp and the highest on the top at 120 kVp. The IDRs for different measurement positions were larger at 120 kVp than at 80 kVp. Similarly, the IDRs for the tube voltage between the primary X-ray beam and scatter radiation was larger on the lateral side than on the top of the phantom. IDR evaluation suggested that the scatter radiation dose has a high dependence on the position and a low dependence on tube voltage relative to the primary X-ray beam for constant dose rate fluoroscopic conditions. These results provided quantitative evidence supporting the radiation protection methods used during CT fluoroscopy in previous studies. PMID:26151914

  2. Comparison of gross and histopathologic findings with quantitative computed tomographic bone density in the distal third metacarpal bone of racehorses.

    PubMed

    Drum, Martha G; Kawcak, Christopher E; Norrdin, Robert W; Park, Richard D; McIlwraith, C Wayne; Les, Clifford M

    2007-01-01

    Comparison of subchondral bone density determined by quantitative computed tomography (CT) with gross and histopathologic changes have not been made in horses. The goal of this study was to determine if mean quantitative CT density and mean voxel standard deviation are associated with the presence and severity of osteochondral lesions in the palmar aspect of the distal third metacarpal bone in racing horses. Metacarpophalangeal joints from nine racehorses were imaged using CT and scored for gross damage. Four-millimeter-thick sagittal and 30 degrees palmar dorsal plane sections were cut, decalcified and stained with hematoxylin and eosin from the distal third metacarpal bone. Microscopic osteochondral lesions and subchondral remodeling were scored on a scale of 0-3. Percent subchondral bone, expressed as the ratio of bone volume to tissue volume, was also measured. Mean quantitative CT density and mean voxel standard deviation were measured from three-dimensional models of CT images comparable with histologic sections. Mean quantitative CT density was not associated with lesion severity or number of lesions. A weak correlation between mean quantitative CT density and gross score was found, but mean quantitative CT density was not predictive for gross score. Mean voxel standard deviation was not correlated with gross or histopathologic measures, but was predictive of mild osteochondral lesions. Results support the association of subchondral remodeling with the development of palmar metacarpal lesions. However, there was not a strong correlation between mean quantitative CT density or mean voxel standard deviation and histopathologic lesions of the distal third metacarpal bone. PMID:18018722

  3. Development of a portable x-ray computed tomographic imaging system for drill-site investigation of recovered core

    SciTech Connect

    Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Pruess, Jacob

    2003-05-01

    A portable x-ray computed tomography (CT) system was constructed for imaging core at drill sites. Performing drill-site-based x-ray scanning and CT analysis permits rapid evaluation of core properties (such as density, lithologic structure, and macroporosity distribution) and allows for real-time decision making for additional core-handling procedures. Because of the speed with which scanning is performed, systematic imaging and electronic cataloging of all retrieved core is feasible. Innovations (such as a novel clamshell shielding arrangement integrated with system interlocks) permit safe operation of the x-ray system in a busy core handling area. The minimization of the volume encapsulated with shielding reduces the overall system weight and facilitates instrument portability. The x-ray system as originally fabricated had a 110 kV x-ray source with a fixed 300-micron focal spot size. A 15 cm image intensifier with a cesium iodide phosphor input screen was coupled to a CCD for image capture. The CT system has since been modified with a 130 kV micro-focal x-ray source. With the x-ray system's variable focal spot size, high-resolution studies (10-micron resolution) can be performed on core plugs and coarser (100-micron resolution) images can be acquired of whole drill cores. The development of an aluminum compensator has significantly improved the dynamic range and accuracy of the system. An x-ray filter has also been incorporated, permitting rapid acquisition of multi-energy scans for more quantitative analysis of sample mineralogy. The x-ray CT system has operated reliably under extreme field conditions, which have varied from shipboard to arctic.

  4. COMPARISON BETWEEN COMPUTED TOMOGRAPHIC CHARACTERISTICS OF THE MIDDLE EAR IN NONBRACHYCEPHALIC AND BRACHYCEPHALIC DOGS WITH OBSTRUCTIVE AIRWAY SYNDROME.

    PubMed

    Salgüero, Raquel; Herrtage, Michael; Holmes, Mark; Mannion, Paddy; Ladlow, Jane

    2016-03-01

    Prevalence of subclinical middle ear lesions in dogs that undergo computed tomography (CT) and magnetic resonance imaging of the head has been reported up to 41%. A predisposition in brachycephalics has been suggested, however evidence-based studies are lacking. Aims of this retrospective cross-sectional study were to compare CT characteristics of the middle ear in groups of nonbrachycephalic and brachycephalic dogs that underwent CT of the head for conditions unrelated to ear disease, and test associations between thickness of the soft palate and presence of subclinical middle ear lesions. One observer recorded CT findings for each dog without knowledge of group status. A total of 65 dogs met inclusion criteria (25 brachycephalic, 40 nonbrachycephalic). Brachycephalic dogs had a significantly thicker bulla wall (P = 2.38 × 10(-26) ) and smaller luminal volume (P = 5.74 × 10(-20) ), when compared to nonbrachycephalic dogs. Soft palate thickness was significantly greater in the brachycephalic group (P = 2.76 × 10(-9) ). Nine of 25 brachycephalic dogs had material in the lumen of the tympanic cavity, compared to zero of 45 of nonbrachycephalics. Within the brachycephalic group, a significant difference in mean soft palate thickness was identified for dogs with material in the middle ear (12.2 mm) vs. air-filled bullae (9 mm; P = 0.016). Findings from the current study supported previous theories that brachycephalic dogs have a greater prevalence of subclinical middle ear effusion and smaller bulla luminal size than nonbrachycephalic dogs. Authors recommend that the bulla lumen volume formula previously developed for mesaticephalic dogs, (-0.612 + 0.757 [lnBW]) be adjusted to 1/3(-0.612 + 0.757 [lnBW]) for brachycephalic breeds. PMID:26765680

  5. DOSIMETRIC CONSEQUENCES OF USING CONTRAST-ENHANCED COMPUTED TOMOGRAPHIC IMAGES FOR INTENSITY-MODULATED STEREOTACTIC BODY RADIOTHERAPY PLANNING.

    PubMed

    Yoshikawa, Hiroto; Roback, Donald M; Larue, Susan M; Nolan, Michael W

    2015-01-01

    Potential benefits of planning radiation therapy on a contrast-enhanced computed tomography scan (ceCT) should be weighed against the possibility that this practice may be associated with an inadvertent risk of overdosing nearby normal tissues. This study investigated the influence of ceCT on intensity-modulated stereotactic body radiotherapy (IM-SBRT) planning. Dogs with head and neck, pelvic, or appendicular tumors were included in this retrospective cross-sectional study. All IM-SBRT plans were constructed on a pre- or ceCT. Contours for tumor and organs at risk (OAR) were manually constructed and copied onto both CT's; IM-SBRT plans were calculated on each CT in a manner that resulted in equal radiation fluence. The maximum and mean doses for OAR, and minimum, maximum, and mean doses for targets were compared. Data were collected from 40 dogs per anatomic site (head and neck, pelvis, and limbs). The average dose difference between minimum, maximum, and mean doses as calculated on pre- and ceCT plans for the gross tumor volume was less than 1% for all anatomic sites. Similarly, the differences between mean and maximum doses for OAR were less than 1%. The difference in dose distribution between plans made on CTs with and without contrast enhancement was tolerable at all treatment sites. Therefore, although caution would be recommended when planning IM-SBRT for tumors near "reservoirs" for contrast media (such as the heart and urinary bladder), findings supported the use of ceCT with this dose calculation algorithm for both target delineation and IM-SBRT treatment planning. PMID:26242716

  6. Comparison of clinical, radiographic, computed tomographic, and magnetic resonance imaging methods for early prediction of canine hip laxity and dysplasia.

    PubMed

    Ginja, Mário M D; Ferreira, António J; Jesus, Sandra S; Melo-Pinto, Pedro; Bulas-Cruz, José; Orden, Maria A; San-Roman, Fidel; Llorens-Pena, Maria P; Gonzalo-Orden, José M

    2009-01-01

    The purpose of the study was to use two palpation methods (Bardens and Ortolani), a radiographic distraction view, three computed tomography (CT) measurements (dorsolateral subluxation score, the lateral center-edge angle, and acetabular ventroversion angle) and two magnetic resonance (MR) imaging hip studies (synovial fluid and acetabular depth indices) in the early monitoring of hip morphology and laxity in 7-9 week old puppies; and in a follow-up study to compare their accuracy in predicting later hip laxity and dysplasia. The MR imaging study was performed with the dog in dorsal recumbency and the CT study with the animal in a weight-bearing position. There was no association between clinical laxity with later hip laxity or dysplasia. The dorsolateral subluxation score and the lateral center-edge angle were characterized by a weak negative correlation with later radiographic passive hip laxity (-0.26 < r < -0.38, P < 0.05) but its association with hip dysplasia was not significant. There was an association between early radiographic passive hip laxity and synovial fluid index with later passive hip laxity (0.41 < r < 0.55, P < 0.05) and this was significantly different in dysplastic vs. nondysplastic hips (P < 0.05). There was no association between the remaining variables and later hip laxity or dysplasia. The overlapping ranges of early passive hip laxity and synovial fluid index for hip dysplasia grades and the moderate correlations with the later passive hip laxity make the results of these variables unreliable for use in predicting hip laxity and dysplasia susceptibility. PMID:19400458

  7. Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study

    PubMed Central

    Kim, Dokyung; Jin, Myoung-Uk

    2016-01-01

    Objectives The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery. Materials and Methods Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.0 mm on the cross-sectional view of CBCT. Results The second molar apex and apical 3 mm were located significantly deeper relative to the buccal bone surface compared with the first molar (p < 0.01). For the mandibular second molars, the distance from the buccal bone surface to the root apex was significantly shorter in patients over 70 years of age (p < 0.05). Furthermore, this distance was significantly shorter when the first molar was missing compared to nonmissing cases (p < 0.05). For the mandibular first molars, the distance to the distal root apex of one distal-rooted tooth was significantly greater than the distance to the disto-buccal root apex (p < 0.01). In mandibular second molar, the distance to the apex of C-shaped roots was significantly greater than the distance to the mesial root apex of non-C-shaped roots (p < 0.01). Conclusions For apical surgery in mandibular molars, the distance from the buccal bone surface to the apex and apical 3 mm is significantly affected by the location, patient age, an adjacent missing anterior tooth, and root configuration. PMID:27508159

  8. Use of computed X-ray tomographic data for analyzing the thermodynamics of a dissociating porous sand/hydrate mixture

    SciTech Connect

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

    2002-02-28

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

  9. The internal cranial morphology of an armoured dinosaur Euoplocephalus corroborated by X-ray computed tomographic reconstruction

    PubMed Central

    Miyashita, Tetsuto; Arbour, Victoria M; Witmer, Lawrence M; Currie, Philip J

    2011-01-01

    Internal cranial anatomy is a challenging area to study in fossilized skulls because of small sample sizes and varied post-mortem preservational alterations. This difficulty has led to the lack of correspondence between results obtained from direct osteological observation and from more indirect reconstruction methods. This paper presents corroborating evidence from direct osteological observation and from reconstruction based on computed X-ray tomography (CT) on the internal cranial anatomy of the ankylosaurid dinosaur Euoplocephalus tutus. A remarkable specimen of Euoplocephalus preserves rarely observed internal cranial structures such as vascular impressions in the nasal cavity, olfactory turbinates and possible impressions of conchae. Comparison with fossils and CT models of other taxa and other Euoplocephalus specimens adds osteological evidence for the previously reconstructed nasal cavity in this dinosaur and revises the previously described braincase morphology. A new interpretation of the ethmoidal homology identifies a mesethmoid, sphenethmoid and ectethmoid. These ethmoidal ossifications are continuous with the mineralized walls of the nasal cavity. The location of the olfactory fenestra provides further evidence that the olfactory regions of the nasal cavity are pushed to the sides of the main airway. This implies that the function of the vascular impressions in the nasal cavity and the looping of the cavity are not related to olfaction. A byproduct of the elongate, looping airway is a dramatic increase in surface area of the nasal respiratory mucosa, which in extant species has been linked to heat and water balance. A role in vocalization as a resonating chamber is another possible function of the looping and elongation of the nasal cavity. Olfaction remains as a possible function for the enlarged olfactory region, suggesting that multiple functions account for different parts of the ankylosaurid nasal cavity that underwent substantial modification

  10. Extrahepatic, nonneoplastic, fat-containing lesions of the abdominopelvic cavity: spectrum of lesions, significance, and typical appearance on multidetector computed tomography.

    PubMed

    Kani, Kimia Khalatbari; Moshiri, Mariam; Bhargava, Puneet; Kolokythas, Orpheus

    2012-01-01

    Fat may be noted in a diffuse or focal manner in a variety of nonneoplastic abdominopelvic conditions. The specific signature of macroscopic fat on computed tomography along with the usually characteristic findings of these entities makes the diagnosis of most of these conditions relatively straightforward. In the intestinal tract, the "fat halo sign" usually arises in the context of subacute to chronic bowel wall inflammation. Excess fat in the renal sinus may occur with renal sinus lipomatosis or "replacement lipomatosis of the kidney." Some cases of "pancreatic lipomatosis" may culminate in steatopancreatitis and ultimately neoplastic transformations. "Fibrofatty mesenteric proliferation" is a characteristic feature of Crohn disease. In the setting of the acute abdomen, accurate diagnosis of fat-containing lesions (epiploic appendagitis or omental infarction) from other causes of the acute abdomen is critical. Mesenteric panniculitis is 1 of the causes of the "misty mesentery." Juxtacaval fat deposition is a benign process that has the potential to be confused with more serious conditions. More diffuse fat deposition (abdominal or pelvic lipomatosis) has the potential to become symptomatic by causing mass effect upon the adjacent structures. Fat can also be seen in a variety of postoperative/iatrogenic conditions or abdominal wall/diaphragmatic hernias. PMID:22285003

  11. Gd-EOB-DTPA-enhanced 3.0-Tesla MRI findings for the preoperative detection of focal liver lesions: Comparison with iodine-enhanced multi-detector computed tomography

    NASA Astrophysics Data System (ADS)

    Park, Hyong-Hu; Goo, Eun-Hoe; Im, In-Chul; Lee, Jae-Seung; Kim, Moon-Jib; Kwak, Byung-Joon; Chung, Woon-Kwan; Dong, Kyung-Rae

    2012-12-01

    The safety of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) has been confirmed, but more study is needed to assess the diagnostic accuracy of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in patients with a hepatocellular carcinoma (HCC) for whom surgical treatment is considered or with a metastatic hepatoma. Research is also needed to examine the rate of detection of hepatic lesions compared to multi-detector computed tomography (MDCT), which is used most frequently to localize and characterize a HCC. Gd-EOB-DTPA-enhanced MRI and iodine-enhanced MDCT imaging were compared for the preoperative detection of focal liver lesions. The clinical usefulness of each method was examined. The current study enrolled 79 patients with focal liver lesions who preoperatively underwent MRI and MDCT. In these patients, there was less than one month between the two diagnostic modalities. Imaging data were taken before and after contrast enhancement in both methods. To evaluate the images, we analyzed the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) in the lesions and the liver parenchyma. To compare the sensitivity of the two methods, we performed a quantitative analysis of the percentage signal intensity of the liver (PSIL) on a high resolution picture archiving and communication system (PACS) monitor (paired-samples t-test, p < 0.05). The enhancement was evaluated based on a consensus of four observers. The enhancement pattern and the morphological features during the arterial and the delayed phases were correlated between the Gd-EOB-DTPA-enhanced MRI findings and the iodine-enhanced MDCT by using an adjusted x2 test. The SNRs, CNRs, and PSIL all had a greater detection rate in Gd-EOB-DTPA enhanced MRI than in iodine-enhanced MDCT. Hepatocyte-selective uptake was observed 20 minutes after the injection in the focal nodular hyperplasia (FNH, 9/9), adenoma (9/10), and highly-differentiated HCC (grade G1, 27/30). Rim

  12. A model for quantitative correction of coronary calcium scores on multidetector, dual source, and electron beam computed tomography for influences of linear motion, calcification density, and temporal resolution: A cardiac phantom study

    SciTech Connect

    Greuter, M. J. W.; Groen, J. M.; Nicolai, L. J.; Dijkstra, H.; Oudkerk, M.

    2009-11-15

    Purpose: The objective of this study is to quantify the influence of linear motion, calcification density, and temporal resolution on coronary calcium determination using multidetector computed tomography (MDCT), dual source CT (DSCT), and electron beam tomography (EBT) and to find a quantitative method which corrects for the influences of these parameters using a linear moving cardiac phantom. Methods: On a robotic arm with artificial arteries with four calcifications of increasing density, a linear movement was applied between 0 and 120 mm/s (step of 10 mm/s). The phantom was scanned five times on 64-slice MDCT, DSCT, and EBT using a standard acquisition protocol. The average Agatston, volume, and mass scores were determined for each velocity, calcification, and scanner. Susceptibility to motion was quantified using a cardiac motion susceptibility (CMS) index. Resemblance to EBT and physical volume and mass was quantified using a {Delta} index. Results: Increasing motion artifacts were observed at increasing velocities on all scanners, with increasing severity from EBT to DSCT to 64-slice MDCT. The calcium score showed a linear dependency on motion from which a correction factor could be derived. This correction factor showed a linear dependency on the mean calcification density with a good fit for all three scoring methods and all three scanners (0.73{<=}R{sup 2}{<=}0.95). The slope and offset of this correction factor showed a linear dependency on temporal resolution with a good fit for all three scoring methods and all three scanners (0.83{<=}R{sup 2}{<=}0.98). CMS was minimal for EBT and increasing values were observed for DSCT and highest values for 64-slice MDCT. CMS was minimal for mass score and increasing values were observed for volume score and highest values for Agatston score. For all densities and scoring methods DSCT showed on average the closest resemblance to EBT calcium scores. When using the correction factor, CMS index decreased on average by

  13. Multidetector Computed Tomography-Based Microstructural Analysis Reveals Reduced Bone Mineral Content and Trabecular Bone Changes in the Lumbar Spine after Transarterial Chemoembolization Therapy for Hepatocellular Carcinoma

    PubMed Central

    Takasu, Miyuki; Yamagami, Takuji; Nakamura, Yuko; Komoto, Daisuke; Kaichi, Yoko; Tani, Chihiro; Date, Shuji; Kiguchi, Masao; Awai, Kazuo

    2014-01-01

    Purpose It is well recognized that therapeutic irradiation can result in bone damage. However, long-term bone toxicity associated with computed tomography (CT) performed during interventional angiography has received little attention. The purpose of this study was to determine the prevalence of osteoporosis and trabecular microstructural changes in patients after transarterial chemoembolization (TACE) for hepatocellular carcinoma therapy using an interventional-CT system. Materials and Methods Spinal microarchitecture was examined by 64-detector CT in 81 patients who underwent TACE, 35 patients with chronic hepatitis, and 79 controls. For each patient, the volumetric CT dose index (CTDIv) during TACE (CTDIv (TACE)), the dose-length product (DLP) during TACE (DLP (TACE)), and CTDIv and DLP of routine dynamic CT scans (CTDIv (CT) and DLP (CT), respectively), were calculated as the sum since 2008. Using a three dimensional (3D) image analysis system, the tissue bone mineral density (tBMD) and trabecular parameters of the 12th thoracic vertebra were calculated. Using tBMD at a reported cutoff value of 68 mg/cm3, the prevalence of osteoporosis was assessed. Results The prevalence of osteoporosis was significantly greater in the TACE vs. the control group (39.6% vs. 18.2% for males, P<0.05 and 60.6% vs. 34.8% for females, P<0.01). Multivariate regression analysis demonstrated that sex, age, and CTDIv (CT) significantly affected the risk of osteoporosis. Of these indices, CTDIv (CT) had the highest area under the curve (AUC) (0.735). Correlation analyses of tBMD with cumulative radiation dose revealed weak correlations between tBMD and CTDIv (CT) (r2 = 0.194, P<0.001). Conclusion The prevalence of osteoporosis was significantly higher in post TACE patients than in control subjects. The cumulative radiation dose related to routine dynamic CT studies was a significant contributor to the prevalence of osteoporosis. PMID:25329933

  14. Tomographic Imaging: Visualization of the Unseeable

    NASA Astrophysics Data System (ADS)

    Pan, Xiaochuan

    2009-03-01

    Tomographic imaging is a noninvasive approach to acquiring information within the subject under study, and it plays an increasingly important role in the improvement of health care by providing valuable information for diagnosis of diseases, for guidance of disease treatment and therapy, and for assessment/monitoring of treatment response. It has also found a wide variety of applications in other disciplines, ranging from molecular imaging to material sciences to security scan to paleontology. Over the last 30 years, biomedical imaging has involved into an important discipline in its own right. Physics and mathematics form the foundation of advanced tomographic imaging. Computed tomography (CT) and magnetic resonance imaging (MRI) represent two well-known tomographic imaging modalities. In this talk, I will first introduce the basic physics and mathematics principles on which some of the advanced tomographic imaging techniques such as CT are based, with an emphasis on what and how physical signals are detected, how they are used for producing images, and what physical information is that can be extracted from these images. I will then touch upon some of the recent exciting advances in tomographic imaging technology, followed by a brief discussion of some of the important applications of advanced tomographic imaging in medicine and other areas.

  15. Spatial filtering improved tomographic PIV

    NASA Astrophysics Data System (ADS)

    Discetti, Stefano; Natale, Andrea; Astarita, Tommaso

    2013-04-01

    Tomographic reconstruction accuracy is of fundamental importance to obtain reliable three-dimensional three-components velocity field measurements when implementing tomographic particle image velocimetry. Algebraic methods (Herman and Lent 1976) are quite well established to handle the problem in case of high spatial frequency spots on a dark background imaged by a limited number of simultaneous views; however, their efficacy is limited in case of dense distributions to be reconstructed. In the present work, an easy implementable modified version of the commonly used multiplicative algebraic reconstruction technique is proposed, allowing a remarkable improvement of the tomographic reconstruction quality only slightly increasing the computational cost. The technique is based on artificial diffusion applied by Gaussian smoothing after each iteration of the reconstruction procedure. Numerical simulations show that the increase in the reconstruction quality leads to a significant reduction of the modulation effects in the velocity measurement due to the coherent ghost particles motion. An experimental application in fractal grid turbulence highlights an improvement of the signal strength and a reduction of the uncertainty in the velocity measurement.

  16. Regional Mapping of Aortic Wall Stress by Using Deformable, Motion-coherent Modeling based on Electrocardiography-gated Multidetector CT Angiography: Feasibility Study.

    PubMed

    Mileto, Achille; Heye, Tobias J; Makar, Ryan A; Hurwitz, Lynne M; Marin, Daniele; Boll, Daniel T

    2016-07-01

    Purpose To investigate the feasibility of deformable, motion-coherent modeling based on electrocardiography-gated multidetector computed tomographic (CT) angiography of the thoracic aorta and to evaluate whether quantifiable information on aortic wall stress as a function of patient-specific cardiovascular parameters can be gained. Materials and Methods For this institutional review board-approved, HIPAA-compliant study, thoracic electrocardiography-gated dual-source multidetector CT angiographic images were used from 250 prospectively enrolled patients (150 men, 100 women; mean age, 79 years). On reconstructed 50-phase CT angiographic images, aortic strain and deformation were determined at seven cardiac and aortic locations. One-way analysis of variance was used by assessing the magnitude for longitudinal and axial strain and axial deformation, as well as time-resolved peak and maxima count for longitudinal strain and axial deformation. Interdependencies between aortic strain and deformation with extracted hemodynamic parameters were evaluated. Results With increasing heart rates, there was a significant decrease in longitudinal strain (P = .009, R(2) = 0.95) and a decrease in the number of longitudinal strain peaks (P < .001, R(2) = 0.79); however, a significant increase in axial deformation (P < .001, R(2) = 0.31) and axial strain (P = .009, R(2) = 0.61) was observed. Increasing aortic blood velocity led to increased longitudinal strain (P = .018, R(2) = 0.42) and longitudinal strain peak counts (P = .011, R(2) = 0.48). Pronounced motion in the longitudinal direction limited motion in the axial plane (P < .019, R(2) = 0.29-0.31). Conclusion The results of this study render a clinical basis and provide proof of principle for the use of deformable, motion-coherent modeling to provide quantitative information on physiological motion of the aorta under various hemodynamic circumstances. (©) RSNA, 2016 Online supplemental material is available for this article

  17. Advances in Multidetector CT Diagnosis of Pediatric Pulmonary Thromboembolism

    PubMed Central

    Thacker, Paul G.

    2016-01-01

    Although pediatric pulmonary thromboembolism is historically believed to be rare with relatively little information available in the medical literature regarding its imaging evaluation, it is more common than previously thought. Thus, it is imperative for radiologists to be aware of the most recent advances in its imaging information, particularly multidetector computed tomography (MDCT), the imaging modality of choice in the pediatric population. The overarching goal of this article is to review the most recent updates on MDCT diagnosis of pediatric pulmonary thromboembolism. PMID:26957904

  18. Characteristics of high-risk coronary plaques identified by computed tomographic angiography and associated prognosis: a systematic review and meta-analysis.

    PubMed

    Thomsen, Camilla; Abdulla, Jawdat

    2016-02-01

    To clarify the potential role of coronary computed tomographic angiography (CCTA) in characterizing and prognosticating high-risk coronary plaques. A systematic review and meta-analysis were conducted to compare high-risk vs. low-risk plaques and culprit vs. non-culprit lesions in patients with acute coronary syndrome (ACS) vs. stable angina (SA). High-risk plaques were defined by at least one of the following features: non-calcified plaque (NCP), the presence of spotty calcified plaque (SCP), or increased remodelling index (RI). Results of included studies were pooled as odds ratios (OR) or weighted mean differences (WMD) with 95% confidence interval (CI). Eighteen eligible studies provided data to compare plaque types, plaque volume, and RI. Six studies provided data on ACS events in vulnerable high-risk vs. low-risk calcified plaques after 35 ± 2 months of follow-up. ACS patients had significantly higher number of NCP and SCP compared with SA patients with OR = 1.96 (1.47-2.60; 95% CI) P = 0.0001 and OR = 4.5 (2.98-6.83; 95% CI) P = 0.0001, respectively. Total plaque volume in ACS was not larger than SA: WMD = 22.9 (-22.1 to 67; 95% CI) mm(3), P = 0.32, but NCP volume was significantly larger: WMD = 28.8 (10.9-46.7; 95% CI) mm(3), P = 0.002. RI was higher in culprit lesions in ACS compared with SA and compared with non-culprit lesions in ACS patients: WMD = 0.48 (0.25-0.70; 95% CI) P = 0.0001 and 0.19 (0.07-0.30) P = 0.0001, respectively. The associated risk of future ACS was significantly higher in high-risk than in low-risk plaques: OR = 12.1 (5.24-28.1; 95% CI) P = 0.0001. CCTA can non-invasively characterize high-risk vulnerable coronary plaques and can predict future ACS events in patients with high-risk plaques. PMID:26690951

  19. Comparing the diagnostic accuracy of contrast-enhanced computed tomographic angiography and gadolinium-enhanced magnetic resonance angiography for the assessment of hemodynamically significant transplant renal artery stenosis.

    PubMed

    Gaddikeri, Santhosh; Mitsumori, Lee; Vaidya, Sandeep; Hippe, Daniel S; Bhargava, Puneet; Dighe, Manjiri K

    2014-01-01

    To compare diagnostic accuracy of contrast-enhanced computed tomographic angiography (CTA) and gadolinium-enhanced magnetic resonance angiography (MRA) for the assessment of hemodynamically significant transplant renal artery stenosis (TRAS). After institutional review board approval, records of 27 patients with TRAS confirmed on digital subtraction angiography (DSA) were retrospectively reviewed. A total of 13 patients had MRA and 14 had CTA before DSA. Two board-certified fellowship-trained radiologists, one each from interventional radiology and body imaging blindly reviewed the DSA and CTA or MRA data, respectively. Sensitivity (SN), specificity (SP), positive predictive value, and negative predictive value of MRA and CTA were estimated using 50% stenosis as the detection threshold for significant TRAS. These parameters were compared between modalities using the Fisher exact test. Bias between MRA or CTA imaging and DSA was tested using the Wilcoxon signed-rank test. Two patients were excluded from the MRA group owing to susceptibility artifacts obscuring the TRAS. The correlation between MRA and DSA measurements of stenosis was r = 0.57 (95% CI:-0.02, 0.87; P = 0.052) and between CTA and DSA measurements was r = 0.63 (95% CI: 0.14, 0.87; P = 0.015); the difference between the 2 techniques was not significant (P = 0.7). Both imaging modalities tended to underestimate the degree of stenosis when compared with DSA. MRA group (SN and SP: 56% and 100%, respectively) and CTA group (SN and SP: 81% and 67%, respectively). There were no significant differences in detection performance between modalities (P>0.3 for all measures). We did not find that either modality had any advantage over the other in terms of measuring or detecting significant stenosis. Accordingly, MRA may be preferred over CTA after positive color Doppler ultrasound screening when not contraindicated owing to lack of ionizing radiation or nephrotoxic iodinated contrast. However, susceptibility of

  20. Scanning tomographic acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Hua

    2002-11-01

    This paper provides an overview of the design and development of the scanning tomographic acoustic microscopy (STAM). This research effort spans over a period of more than 12 years, which successfully elevated the acoustic microscopy from the traditional intensity-mapping mode to the level of holographic and tomographic imaging. The tomographic imaging capability of STAM was developed on the platform of the scanning laser acoustic microscope (SLAM), which operates in a coherent transmission mode with plane-wave illumination and scanning laser wavefield detection. The image formation techniques were based on the backward propagation method implemented in the plane-to-plane format. In this paper, the key elements of the design and development, including the modification of the data-acquisition hardware, implementation of image reconstruction algorithms for multiple-frequency and multiple-angle tomography, and the high-precision phase-correction and image registration techniques for the superposition of coherent sub-images, will be discussed. Results of full-scale experiments will also be included to demonstrate the capability of holographic and tomographic image formation in microscopic scale.

  1. CHIMERA Multidetector at Laboratori Nazionali del Sud

    SciTech Connect

    Aiello, S.; Anzalone, A.; Baldo, M.; Barna, R.; Campisi, M.g.; Cardella, G.; Cavallaro, Sl., Amico, V.D.; De Filippo, E.; DePasquale, D.; Femino, S.; Geraci, E.; Giustolisi, F.; Guazzoni, P.; Iacono-Manno, C.M.; Italiano, A.; Lanzalone, G.; Lanzano, G.; LoNigro, S.; Lombardo, U.; Manfredi, G.; Pagano, A.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Sambataro, S.; Sperduto, M.L.; Sutera, C.M.; Zetta, L.

    2000-12-31

    The installation of CHIMERA multidetector, designed in order to study central collisions in heavy ion reactions at intermediate energy, is going on at LNS and the first experiment with the forward part (688 telescopes) is running since May 1999. The aim of this contribution is to present the status of the project.

  2. Computed tomographic colonography compared with colonoscopy or barium enema for diagnosis of colorectal cancer in older symptomatic patients: two multicentre randomised trials with economic evaluation (the SIGGAR trials).

    PubMed Central

    Halligan, Steve; Dadswell, Edward; Wooldrage, Kate; Wardle, Jane; von Wagner, Christian; Lilford, Richard; Yao, Guiqing L; Zhu, Shihua; Atkin, Wendy

    2015-01-01

    BACKGROUND Computed tomographic colonography (CTC) is a relatively new diagnostic test that may be superior to existing alternatives to investigate the large bowel. OBJECTIVES To compare the diagnostic efficacy, acceptability, safety and cost-effectiveness of CTC with barium enema (BE) or colonoscopy. DESIGN Parallel randomised trials: BE compared with CTC and colonoscopy compared with CTC (randomisation 2 : 1, respectively). SETTING A total of 21 NHS hospitals. PARTICIPANTS Patients aged ≥ 55 years with symptoms suggestive of colorectal cancer (CRC). INTERVENTIONS CTC, BE and colonoscopy. MAIN OUTCOME MEASURES For the trial of CTC compared with BE, the primary outcome was the detection rate of CRC and large polyps (≥ 10 mm), with the proportion of patients referred for additional colonic investigation as a secondary outcome. For the trial of CTC compared with colonoscopy, the primary outcome was the proportion of patients referred for additional colonic investigation, with the detection rate of CRC and large polyps as a secondary outcome. Secondary outcomes for both trials were miss rates for cancer (via registry data), all-cause mortality, serious adverse events, patient acceptability, extracolonic pathology and cost-effectiveness. RESULTS A total of 8484 patients were registered and 5384 were randomised and analysed (BE trial: 2527 BE, 1277 CTC; colonoscopy trial: 1047 colonoscopy, 533 CTC). Detection rates in the BE trial were 7.3% (93/1277) for CTC, compared with 5.6% (141/2527) for BE (p = 0.0390). The difference was due to better detection of large polyps by CTC (3.6% vs. 2.2%; p = 0.0098), with no significant difference for cancer (3.7% vs. 3.4%; p = 0.66). Significantly more patients having CTC underwent additional investigation (23.5% vs. 18.3%; p = 0.0003). At the 3-year follow-up, the miss rate for CRC was 6.7% for CTC (three missed cancers) and 14.1% for BE (12 missed cancers). Significantly more patients randomised to CTC

  3. Partially coherent lensfree tomographic microscopy⋄

    PubMed Central

    Isikman, Serhan O.; Bishara, Waheb; Ozcan, Aydogan

    2012-01-01

    Optical sectioning of biological specimens provides detailed volumetric information regarding their internal structure. To provide a complementary approach to existing three-dimensional (3D) microscopy modalities, we have recently demonstrated lensfree optical tomography that offers high-throughput imaging within a compact and simple platform. In this approach, in-line holograms of objects at different angles of partially coherent illumination are recorded using a digital sensor-array, which enables computing pixel super-resolved tomographic images of the specimen. This imaging modality, which forms the focus of this review, offers micrometer-scale 3D resolution over large imaging volumes of, for example, 10–15 mm3, and can be assembled in light weight and compact architectures. Therefore, lensfree optical tomography might be particularly useful for lab-on-a-chip applications as well as for microscopy needs in resource-limited settings. PMID:22193016

  4. Medical ultrasonic tomographic system

    NASA Technical Reports Server (NTRS)

    Heyser, R. C.; Lecroissette, D. H.; Nathan, R.; Wilson, R. L.

    1977-01-01

    An electro-mechanical scanning assembly was designed and fabricated for the purpose of generating an ultrasound tomogram. A low cost modality was demonstrated in which analog instrumentation methods formed a tomogram on photographic film. Successful tomogram reconstructions were obtained on in vitro test objects by using the attenuation of the fist path ultrasound signal as it passed through the test object. The nearly half century tomographic methods of X-ray analysis were verified as being useful for ultrasound imaging.

  5. Kinky tomographic reconstruction

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.; Bilisoly, R.L.

    1996-05-01

    We address the issue of how to make decisions about the degree of smoothness demanded of a flexible contour used to model the boundary of a 2D object. We demonstrate the use of a Bayesian approach to set the strength of the smoothness prior for a tomographic reconstruction problem. The Akaike Information Criterion is used to determine whether to allow a kink in the contour.

  6. Field-portable lensfree tomographic microscope†

    PubMed Central

    Isikman, Serhan O.; Bishara, Waheb; Sikora, Uzair; Yaglidere, Oguzhan; Yeah, John; Ozcan, Aydogan

    2011-01-01

    We present a field-portable lensfree tomographic microscope, which can achieve sectional imaging of a large volume (~20 mm3) on a chip with an axial resolution of <7 μm. In this compact tomographic imaging platform (weighing only ~110 grams), 24 light-emitting diodes (LEDs) that are each butt-coupled to a fibre-optic waveguide are controlled through a cost-effective micro-processor to sequentially illuminate the sample from different angles to record lensfree holograms of the sample that is placed on the top of a digital sensor array. In order to generate pixel super-resolved (SR) lensfree holograms and hence digitally improve the achievable lateral resolution, multiple sub-pixel shifted holograms are recorded at each illumination angle by electromagnetically actuating the fibre-optic waveguides using compact coils and magnets. These SR projection holograms obtained over an angular range of ~50° are rapidly reconstructed to yield projection images of the sample, which can then be back-projected to compute tomograms of the objects on the sensor-chip. The performance of this compact and light-weight lensfree tomographic microscope is validated by imaging micro-beads of different dimensions as well as a Hymenolepis nana egg, which is an infectious parasitic flatworm. Achieving a decent three-dimensional spatial resolution, this field-portable on-chip optical tomographic microscope might provide a useful toolset for telemedicine and high-throughput imaging applications in resource-poor settings. PMID:21573311

  7. Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFRCT: outcome and resource impacts study

    PubMed Central

    Douglas, Pamela S.; Pontone, Gianluca; Hlatky, Mark A.; Patel, Manesh R.; Norgaard, Bjarne L.; Byrne, Robert A.; Curzen, Nick; Purcell, Ian; Gutberlet, Matthias; Rioufol, Gilles; Hink, Ulrich; Schuchlenz, Herwig Walter; Feuchtner, Gudrun; Gilard, Martine; Andreini, Daniele; Jensen, Jesper M.; Hadamitzky, Martin; Chiswell, Karen; Cyr, Derek; Wilk, Alan; Wang, Furong; Rogers, Campbell; De Bruyne, Bernard

    2015-01-01

    Aims In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. Methods and results At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFRCT (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFRCT-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFRCT arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53–69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFRCT results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFRCT) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFRCT arms. Conclusions Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD. PMID:26330417

  8. Multi-detector row CT of pancreatic islet cell tumors.

    PubMed

    Horton, Karen M; Hruban, Ralph H; Yeo, Charles; Fishman, Elliot K

    2006-01-01

    Pancreatic islet cell tumors (ICTs) are neuroendocrine neoplasms that produce and secrete hormones to a variable degree. These neoplasms can present a diagnostic challenge, both clinically and radiologically. ICTs can be classified as either syndromic or nonsyndromic on the basis of their clinical manifestations. Multi-detector row computed tomography (CT) plays an important role in the diagnosis and staging of both syndromic and nonsyndromic ICTs. In general, syndromic ICTs are less than 3 cm in size. They are typically hyperenhancing and are usually best seen on CT scans obtained during the arterial phase. Nonsyndromic ICTs tend to be larger than syndromic ICTs at presentation and are more likely to be cystic or necrotic. It is important for the radiologist to be familiar with appropriate CT protocol for the evaluation of patients with suspected pancreatic ICT and to understand the variable CT appearances of these neoplasms. PMID:16549609

  9. Multidetector CT diagnosis of massive hemobilia due to gallbladder polyposis in a child with metachromatic leukodystrophy.

    PubMed

    Wanner, Matthew R; Karmazyn, Boaz; Fan, Rong

    2015-12-01

    Hemobilia secondary to gallbladder polyposis is rare in children but has been reported in a few children with metachromatic leukodystrophy. We present a case with preoperative multidetector computed tomography (MDCT) diagnosis of massive hemobilia caused by gallbladder polyposis in a patient with metachromatic leukodystrophy. Our report highlights the importance of both awareness of the association of gallbladder polyposis with other syndromes such as metachromatic leukodystrophy as well as the possibility of this entity presenting with life-threatening bleeding. PMID:26160127

  10. Scanning Tomographic Acoustic Microscopy

    NASA Astrophysics Data System (ADS)

    Wade, G.; Meyyappan, A.

    1988-07-01

    The technology for "seeing" with sound has an important and interesting history. Some of nature's creatures have been using sound waves for many millenia to image otherwise unobservable objects. The human species, lacking this natural ability, have overcome this deficiency by developing several different ultrasonic imaging techniques. acoustic microscopy is one such technique, which produces high resolution images of detailed structure of small objects in a non-destructive fashion. Two types of acoustic microscopes have evolved for industrial exploitation. They are the scanning laser acoustic microscope (SLAM) and the scanning acoustic microscope (SAM). In this paper, we review the principles of SLAM and describe how we use elements of SLAM to realize the scanning tomographic acoustic microscope (STAM). We describe the data acquisition process and the image reconstruction procedure. We also describe techniques to obtain projection data from different angles of wave incidence enabling us to reconstruct different planes of a complex specimen tomo-graphically. Our experimental results show that STAM is capable of producing high-quality high-resolution subsurface images.

  11. Dynamic three-dimensional echocardiographic imaging of congenital heart defects in infants and children by computer-controlled tomographic parallel slicing using a single integrated ultrasound instrument.

    PubMed

    Fulton, D R; Marx, G R; Pandian, N G; Romero, B A; Mumm, B; Krauss, M; Wollschläger, H; Ludomirsky, A; Cao, Q L

    1994-03-01

    Three-dimensional cardiac reconstruction generated from transesophageal interrogation can be performed using an integrated unit that captures, processes, and postprocesses tomographic parallel slices of the heart. This probe was used for infants and young children in the transthoracic position to evaluate the feasibility of producing three-dimensional cardiac images with capability for real-time dynamic display. Twenty-two infants and children (range 1 day-3.5 years) underwent image acquisition using a 16 mm 5 MHz 64 element probe placed over the precordium. Two infants were also imaged from the subcostal position. Data was obtained and stored over a single cardiac cycle after acceptable cardiac and respiratory gating intervals were met. The transducer was advanced in 0.5-1 mm increments over the cardiac structures using identical acquisition criteria. The images were reconstructed from the stored digital cubic format and could be oriented in any desired plane. In 9 of the 22 infants the images obtained were of optimal quality. The images obtained displayed normal cardiac structures emphasizing depth relationships as well as visualization of planes not generally demonstrated by two-dimensional imaging. Several lesions were also depicted in a unique fashion using this technique. Though the method employed was limited by movement artifact and reconstruction time, the quality of the three-dimensional display was excellent and enhanced by real-time demonstration. The transthoracic approach was successful in capturing sufficient data to create three-dimensional images, which may have further application in more accurate diagnosis of complex cardiac abnormalities and generation of planes of view which could duplicate surgical visualization of a lesion. Further assessment of the technique in infants with congenital heart disease is warranted. PMID:10146717

  12. Multidetector CT of the female pelvis.

    PubMed

    Siddall, Kristina A; Rubens, Deborah J

    2005-11-01

    In the emergency room setting, multidetector detector CT (MDCT) offers rapid, noninvasive, multiplanar evaluation of female patients who have acute pelvic pain. MDCT has been integrated into several of the major trauma centers, and its use may surpass the use of ultrasound in the trauma evaluation of the pregnant patient. In the nonemergent setting, MDCT can be used to stage gynecologic malignancy and to evaluate tumor recurrence. Multiplanar MDCT has received some acceptance for evaluation of small primary tumor volume and small metastatic implants. MDCT also has a role in the evaluation of pelvic varices and suspected pelvic congestion syndrome. PMID:16253664

  13. Coronary Computed Tomography Angiography of Spontaneous Coronary Artery Dissection: A Case Report and Review of the Literature

    PubMed Central

    Torres-Ayala, Stephanie C.; Maldonado, Jose; Scott Bolton, J.; Bhalla, Sanjeev

    2015-01-01

    Patient: Male, 23 Final Diagnosis: Spontaneous coronary artery dissection Symptoms: Chest discomfort • chest pain Medication: — Clinical Procedure: Coronary computed tomography angiography Specialty: Radiology Objective: Rare disease Background: Multidetector computed tomography (MDCT) has gained wide acceptance in the evaluation of the cardiovascular system. Of particular clinical interest is its ability to non-invasively evaluate coronary arteries in patients presenting to the emergency room. In acute coronary syndromes, myocardial ischemia is most often caused by atherosclerosis. We present a case of a rare cause of acute coronary syndrome, spontaneous coronary artery dissection (SCAD), which was initially evaluated with MDCT and followed by intravascular ultrasound (IVUS) and invasive coronary angiography (ICA). We discuss the findings and role of each modality with particular attention to coronary computed tomographic angiography (CCTA) in the diagnosis and management of SCAD. As the use of CCTA in the emergency department continues to rise, radiologists must become familiar with CT appearance of SCAD. Case Report: We report the multidetector computed tomography (MDCT), intravascular ultrasound (IVUS), and invasive coronary angiography (ICA) findings in a case of spontaneous coronary artery dissection of the left anterior descending artery in a previously healthy 23-year-old man. The role of coronary computed tomographic angiography (CCTA) in diagnosis and management of this potentially life-threatening condition is discussed. Conclusions: In the clinical setting of acute coronary syndrome, SCAD must be a consideration, particularly in young patients without clear risk factors for coronary artery disease and in women in the peripartum period. CCTA is a very helpful diagnostic tool to diagnose the condition in a non-invasive manner and to follow up after treatment. PMID:25738889

  14. Heterogeneous Microinfarcts Caused by Coronary Microemboli: Evaluation with Multidetector CT and MR Imaging in a Swine Model1

    PubMed Central

    Saloner, David; Martin, Alastair J.; Ursell, Philip C.; Saeed, Maythem

    2010-01-01

    Purpose: To directly compare the sensitivity of 64-section multidetector computed tomography (CT) with that of 1.5-T magnetic resonance (MR) imaging in the depiction and measurement of heterogeneous 7–8-week-old microinfarcts and the quantification of regional left ventricular (LV) function and perfusion in the territory of coronary intervention in a swine model. Materials and Methods: Approval was obtained from the institutional animal committee. An x-ray/MR system was used to catheterize the left anterior descending (LAD) coronary artery with x-ray guidance and to delineate the perfusion territory. The vessel was selectively microembolized in six pigs with small-diameter embolic material (40–120 µm, 250000 count). At 7–8 weeks after microembolization, multidetector CT and MR imaging were used to assess LV function, first-pass perfusion, and delayed contrast enhancement in remote myocardium and microinfarct scars. Histochemical staining with triphenyltetrazolium chloride (TTC) was used to confirm and quantify heterogeneous microinfarct scars. The two-tailed Wilcoxon signed rank test was used to detect differences between modalities and myocardial regions. Results: The LAD territory was 32.4% ± 3.8(stadard error of the mean) of the LV mass. Multidetector CT and MR imaging have similar sensitivity in the detection of regional and global LV dysfunction and extent of microinfarct. The mean LV end-diastolic volume, end-systolic volume, and ejection fraction were 93 mL ± 8, 46 mL ± 4, and 50% ± 3, respectively, on multidetector CT images and 92 mL ± 8, 48 mL ± 5, and 48% ± 3, respectively, on MR images (P ≥ .05). The extent of heterogeneous microinfarct was not significantly different between multidetector CT (6.3% ± 0.8 of the LV mass), MR imaging (6.6% ± 0.5 of the LV mass), and TTC staining (7.0% ± 0.6 of the LV mass). First-pass multidetector CT and MR imaging demonstrated significant regional differences (P < .05) in time to peak between the

  15. When Planning Screw Fracture Fixation Why the 5.5 mm Screw is the Goldilocks Screw. An Observational Computer Tomographic Study of Fifth Metatarsal Bone Anatomy in a Sample of Patients

    PubMed Central

    Iselin, Lukas D.; Ramawat, Sunil; Hanratty, Brian; Klammer, Georg; Stavrou, Peter

    2015-01-01

    Abstract We wanted to verify our clinical experience that the 5.5 mm screw was ideal in the majority of fifth metatarsal fracture fixation. The size of a screw is important for the successful surgical treatment of these fractures in order to obtain the maximal stability while reducing the risk for iatrogenic fracture. A sample of patients undergoing computer tomographic imaging of the foot for investigation other than fifth metatarsal pathology were recruited. The parameters of the fifth metatarsal bone anatomy were measured. These parameters of the 5.5 mm screw were correlated with this data. The upper parameter (the diameter of the threads) was 5.5 and the lower parameter (the diameter of the shank) was 4.0 mm. Twenty seven patients were recruited. The proximal third internal diameter ranged from 3.6 to 7.0 mm with a mean of 5.0 mm. 93% of the metatarsals could easily accommodate the 5.5 mm screw. Two of the metatarsals had an internal diameter of < 4 mm (7%). It is our belief that the 5.5 mm screw may be used safely in the majority of patients with fifth metatarsal fractures. PMID:25950685

  16. Gynecologic electrical impedance tomograph

    NASA Astrophysics Data System (ADS)

    Korjenevsky, A.; Cherepenin, V.; Trokhanova, O.; Tuykin, T.

    2010-04-01

    Electrical impedance tomography extends to the new and new areas of the medical diagnostics: lungs, breast, prostate, etc. The feedback from the doctors who use our breast EIT diagnostic system has induced us to develop the 3D electrical impedance imaging device for diagnostics of the cervix of the uterus - gynecologic impedance tomograph (GIT). The device uses the same measuring approach as the breast imaging system: 2D flat array of the electrodes arranged on the probe with handle is placed against the body. Each of the 32 electrodes of the array is connected in turn to the current source while the rest electrodes acquire the potentials on the surface. The current flows through the electrode of the array and returns through the remote electrode placed on the patient's limb. The voltages are measured relative to another remote electrode. The 3D backprojection along equipotential surfaces is used to reconstruct conductivity distribution up to approximately 1 cm in depth. Small number of electrodes enables us to implement real time imaging with a few frames per sec. rate. The device is under initial testing and evaluation of the imaging capabilities and suitability of usage.

  17. A comparative evaluation of root canal area increase using three different nickel-titanium rotary systems: An ex vivo cone-beam computed tomographic analysis

    PubMed Central

    Deka, Adrija; Bhuyan, A.C.; Bhuyan, Darpana

    2015-01-01

    Background and Objectives: The present study was undertaken to compare and evaluate the area increase of root canals with ProTaper, iRaCe and Revo-S systems using cone beam computed tomography for analysis. Materials and Methodology: Forty five extracted human mandibular premolars having single canal and straight root were collected. Teeth were randomly assigned to three groups (n=15). Samples were decoronized by maintaining root length at 14 mm. Pre-instrumentation cone beam computed tomography scan was done after stabilizing the samples on wax blocks. The working length was determined at 1 mm short from the apical foramen by using a ISO 15 K-file tip protruding at apical foramen. Preparation was carried out according to the manufacturer's instructions. Finally, canals were instrumented upto 30/.06 apically for each group. After each instrumentation, root canals were irrigated with 2ml of 3% sodium hypochlorite solution followed by 2 ml of 17% EDTA solution. Final irrigation was done with 5ml of saline. Post instrumentation cone beam computed tomography scans of all samples in the 3 groups were acquired. Results: Mean percentage of area increase in different thirds of the canal was highest for ProTaper followed by i-RaCe and Revo-s system which was statistically significant. Interpretation and Conclusion: Root canal area increase was highest for ProTaper followed by i-Race and Revo-S systems. PMID:25684917

  18. Validity of Acute Stroke Lesion Volume Estimation by Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomographic Score Depends on Lesion Location in 496 Patients With Middle Cerebral Artery Stroke

    PubMed Central

    Schröder, Julian; Cheng, Bastian; Ebinger, Martin; Köhrmann, Martin; Wu, Ona; Kang, Dong-Wha; Liebeskind, David S.; Tourdias, Thomas; Singer, Oliver C.; Christensen, Soren; Campbell, Bruce; Luby, Marie; Warach, Steven; Fiehler, Jens; Fiebach, Jochen B.; Gerloff, Christian; Thomalla, Götz

    2016-01-01

    Background and Purpose Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) has been used to estimate diffusion-weighted imaging (DWI) lesion volume in acute stroke. We aimed to assess correlations of DWI-ASPECTS with lesion volume in different middle cerebral artery (MCA) subregions and reproduce existing ASPECTS thresholds of a malignant profile defined by lesion volume ≥100 mL. Methods We analyzed data of patients with MCA stroke from a prospective observational study of DWI and fluid-attenuated inversion recovery in acute stroke. DWI-ASPECTS and lesion volume were calculated. The population was divided into subgroups based on lesion localization (superficial MCA territory, deep MCA territory, or both). Correlation of ASPECTS and infarct volume was calculated, and receiver-operating characteristics curve analysis was performed to identify the optimal ASPECTS threshold for ≥100-mL lesion volume. Results A total of 496 patients were included. There was a significant negative correlation between ASPECTS and DWI lesion volume (r=−0.78; P<0.0001). With regards to lesion localization, correlation was weaker in deep MCA region (r=−0.19; P=0.038) when compared with superficial (r=−0.72; P<0.001) or combined superficial and deep MCA lesions (r=−0.72; P<0.001). Receiver-operating characteristics analysis revealed ASPECTS≤6 as best cutoff to identify ≥100-mL DWI lesion volume; however, positive predictive value was low (0.35). Conclusions ASPECTS has limitations when lesion location is not considered. Identification of patients with malignant profile by DWI-ASPECTS may be unreliable. ASPECTS may be a useful tool for the evaluation of noncontrast computed tomography. However, if MRI is used, ASPECTS seems dispensable because lesion volume can easily be quantified on DWI maps. PMID:25316278

  19. Tomographic multiphase flow measurement.

    PubMed

    Sætre, C; Johansen, G A; Tjugum, S A

    2012-07-01

    Measurement of multiphase flow of gas, oil and water is not at all trivial and in spite of considerable achievements over the past two decades, important challenges remain (Corneliussen et al., 2005). These are related to reducing measurement uncertainties arising from variations in the flow regime, improving long term stability and developing new means for calibration, adjustment and verification of the multiphase flow meters. This work focuses on the first two issues using multi gamma beam (MGB) measurements for identification of the type of flow regime. Further gamma ray tomographic measurements are used for reference of the gas/liquid distribution. For the MGB method one Am-241 source with principal emission at 59.5 keV is used because this relatively low energy enables efficient collimation and thereby shaping of the beams, as well as compact detectors. One detector is placed diametrically opposite the source whereas the second is positioned to the side so that this beam is close to the pipe wall. The principle is then straight forward to compare the measured intensities of these detectors and through that identify the flow pattern, i.e. the instantaneous cross-sectional gas-liquid distribution. The measurement setup also includes Compton scattering measurements, which can provide information about the changes in the water salinity for flow segments with high water liquid ratio and low gas fractions. By measuring the transmitted intensity in short time slots (<100 ms), rapid regime variations are revealed. From this we can select the time sections suitable for salinity measurements. Since the salinity variations change at the time scale of hours, a running average can be performed to increase the accuracy of the measurements. Recent results of this work will be presented here. PMID:22341954

  20. Central odontogenic fibroma (simple type) in a four-year-old boy: atypical cone-beam computed tomographic appearance with periosteal reaction

    PubMed Central

    Anbiaee, Najme; Sanaei, Alireza

    2015-01-01

    Central odontogenic fibroma (COF) is a rare benign tumor that accounts for 0.1% of all odontogenic tumors. A case of COF (simple type) of the mandible in a four-year-old boy is described in this report. The patient showed asymptomatic swelling in the right inferior border of the lower jaw for one week. A panoramic radiograph showed a poorly-defined destructive unilocular radiolucent area. Cone-beam computed tomography showed expansion and perforation of the adjacent cortical bone plates. A periosteal reaction with the Codman triangle pattern was clearly visible in the buccal cortex. Since the tumor had destroyed a considerable amount of bone, surgical resection was performed. No recurrence was noted. PMID:26125006

  1. Renal Collecting System Anatomy in Living Kidney Donors by Computed Tomographic Urography: Protocol Accuracy Compared to Intravenous Pyelographic and Surgical Findings

    PubMed Central

    Tarzamni, Mohammad Kazem; Nezami, Nariman; Zomorrodi, Afshar; Fathi-Noroozlou, Samad; Piri, Reza; Naghavi-Behzad, Mohammad; Mojadidi, Mohammad Khalid; Bijan, Bijan

    2016-01-01

    Objectives: To evaluate the accuracy of triple-bolus computed tomography urography (CTU) as a surrogate of intravenous pyelography (IVP) for determining the anatomy of the urinary collecting system in living kidney donors. Materials and Methods: In an analytic descriptive cross-sectional study, 36 healthy kidney donors were recruited during 12 months. Preoperative IVP and CTU were utilized to evaluate kidneys’ anatomy; major and minor calyces and variation were used as anatomical indices to compare the accuracy of CTU and IVP; the images were then compared to surgical findings. Results: Thirty-six kidney donors (92% male; mean age: 28 ± 6 years) were enrolled in this study. The kappa coefficient value was significant and almost perfect for the CTU and IVP findings in detecting the pattern of calyces (kappa coefficient 0.92, asymptotic 95% confidence interval 0.86–0.97). Anatomic variations or anomalies of the urinary collecting system included the bifid pelvis (5.6%), duplication (8.3%), and extra-renal pelvis (2.8%). Both the sensitivity and specificity of CTU in the detection of the anatomy and variations were 100%; the sensitivity and specificity of IVP were 83.3% and 100%, respectively. Conclusions: The triple-bolus preoperative CTU can be considered an alternative to IVP for assessing the anatomy of the urinary collecting system. PMID:26958431

  2. Three-Dimensional Computed Tomographic Analysis for Comminution of Pertrochanteric Femoral Fracture: Comminuted Anterior Cortex as a Predictor of Cutting Out

    PubMed Central

    Tsukada, Sachiyuki; Wakui, Motohiro; Yoshizawa, Hiroshi; Miyao, Masunao; Honma, Takeshi

    2016-01-01

    Background: Fixed angle sliding hip screw devices allow controlled impaction between the head neck fragment and the femoral shaft fragment in the surgical treatment of pertrochanteric fractures. This study was performed to evaluate the frequency and pattern of comminution at the fracture site, which may prevent the intended impaction. Materials and Methods: Three-dimensional computed tomography was used to investigate 101 pertrochanteric fractures treated with fixed angle sliding hip screw devices, with emphasis on the comminuted cortex. A comminuted fracture was defined as a fracture that had a third fracture fragment at the main fracture line. Results: There were 40 fractures without comminution and 61 with comminution. All 61 comminuted fractures had a comminuted posterior cortex, and 3 of 61 fractures also had comminution at the anterior cortex. The prevalence of cutting out of the implant from the femoral head was significantly higher in cases involving comminution at both the posterior and anterior cortices than in cases involving comminution only at the posterior cortex (66.7 % and 3.4 %, p < 0.0001). Conclusion: The posterior cortex was comminuted in 60.4% of pertrochanteric fractures and the anterior cortex in 3.0%. Intended impaction at the fracture site could not be obtained at any cortex in cases with comminution at both the anterior and posterior cortices; comminution at the anterior cortex may be a predictor of cutting out. PMID:27347234

  3. Screw Placement and Osteoplasty Under Computed Tomographic-Fluoroscopic Guidance in a Case of Advanced Metastatic Destruction of the Iliosacral Joint

    SciTech Connect

    Trumm, Christoph Gregor; Rubenbauer, Bianca; Piltz, Stefan; Reiser, Maximilian F.; Hoffmann, Ralf-Thorsten

    2011-02-15

    We present a case of combined surgical screw placement and osteoplasty guided by computed tomography-fluoroscopy (CTF) in a 68-year-old man with unilateral osteolytic destruction and a pathological fracture of the iliosacral joint due to a metastasis from renal cell carcinoma. The patient experienced intractable lower back pain that was refractory to analgesia. After transarterial particle and coil embolization of the tumor-feeding vessels in the angiography unit, the procedure was performed under general anesthesia by an interdisciplinary team of interventional radiologists and trauma surgeons. Under intermittent single-shot CTF, two K wires were inserted into the left iliosacral joint from a lateral transiliac approach at the S1 level followed by two self-tapping surgical screws. Continuous CTF was used for monitoring of the subsequent polymethylmethacrylate injection through two vertebroplasty cannulas for further stabilization of the screw threads within the osteolytic sacral ala. Both the screw placement and cement injection were successful, with no complications occurring during or after the procedure. With additional nonsteroidal anti-inflammatory and opioid medication, the patient reported a marked decrease in his lower back pain and was able to move independently again at the 3-month follow-up assessment. In our patient with intolerable back pain due to tumor destruction and consequent pathological fracture of the iliosacral joint, CTF-guided iliosacral screw placement combined with osteoplasty was successful with respect to joint stabilization and a reduction in the need for analgesic therapy.

  4. Hydrodynamic and dispersion behavior in a non-porous silica monolith through fluid dynamic study of a computational mimic reconstructed from sub-micro-tomographic scans.

    PubMed

    Loh, Kai-Chee; Vasudevan, Vivek

    2013-01-25

    An analysis of the transport properties of the bulk homogeneous core of a commercially available silica monolith (Chromolith(®)) is presented via direct numerical simulations in a topological model reconstructed from 3D nanotomographic scans at isotropic resolutions of 390 nm, 290 nm and 190 nm. The pore and skeleton size distributions were calculated from image analysis and a representative unit cell from each resolution was reconstructed to simulate the hydrodynamic transport properties using Computational Fluid Dynamics (CFD). A 30 μm × 30 μm × 30 μm unit cell extracted at 190 nm resolution was found to be representative of hydrodynamic permeability. Numerical peak parking simulations yielded an axial external obstruction factor (γ(e)) of 0.8. Mass transfer characteristics of a large non-penetrating molecule (BSA) were evaluated under non-retained conditions so as to elucidate the eddy dispersion contribution to total HETP. Transverse and axial dispersion length scales in the reconstructed model were resolved and related to the structural heterogeneities in the silica monolith. Deviations of simulated HETP from experimental measurements were attributed to a transcolumn dispersion contribution, which amounted to about 90% of the total HETP. The presented approach provides great scope to analyze the contributions of pore network topology to separation performance of silica monoliths (and other porous media) in HPLC applications. A significant reduction in simulation time and memory resources has been observed due to the lower scanning resolution, without significant loss in prediction accuracy. PMID:23290336

  5. Pulmonary Findings on Computed Tomography in Asymptomatic Total Joint Arthroplasty Patients.

    PubMed

    Vigdorchik, Jonathan M; Riesgo, Aldo M; Lincoln, Denis; Markel, David C

    2016-08-01

    An increase in the diagnosis of pulmonary embolus (PE) in the early postoperative period has been attributed to the use of multidetector 64-slice computed tomographic (CT) scans. It was suspected that this finding was the result of marrow or fat emboli that are commonly associated with arthroplasty rather than a true venous thromboembolic phenomenon. The purpose of this study was to determine the baseline pulmonary findings in asymptomatic patients after total joint arthroplasty (TJA). Over a 1-year period, an institutional review board-approved prospective study of 20 asymptomatic patients using a multidetector 64-slice CT scanner was performed. Overall, 15 TKAs and 5 total hip arthroplasties were included for analysis. All of the CT scans were negative for PE. There were no signs of microemboli or fat emboli on any scan. No patient went on to develop a PE at 2 years postoperatively. Despite the fact that emboli are created during TJA, if emboli are seen on a CT scan postoperatively, they should be assumed to be real events with clinical sequelae. If pulmonary symptoms develop postoperatively, they should not simply be assumed to be the result of fat or marrow embolism. PMID:26551068

  6. Coronary dominance and prognosis in patients undergoing coronary computed tomographic angiography: results from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry

    PubMed Central

    Gebhard, Catherine; Fuchs, Tobias A.; Stehli, Julia; Gransar, Heidi; Berman, Daniel S.; Budoff, Matthew J.; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Chinnaiyan, Kavitha M.; Chow, Benjamin J. W.; Cury, Ricardo C.; Delago, Augustin; Gomez, Millie J.; Hadamitzky, Martin; Hausleiter, Joerg; Hindoyan, Niree; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison M.; Min, James K.; Kaufmann, Philipp A.

    2015-01-01

    Aims Coronary computed tomographic angiography (CCTA) has become an important tool for non-invasive diagnosis of coronary artery disease (CAD). Coronary dominance can be assessed by CCTA; however, the predictive value of coronary dominance is controversially discussed. The aim of this study was to evaluate the prevalence and prognosis of coronary dominance in a large prospective, international multicentre cohort of patients undergoing CCTA. Methods and results The study population consisted of 6382 patients with or without CAD (47% females, 53% males, mean age 56.9 ± 12.3 years) who underwent CCTA and were followed over a period of 60 months. Right or left coronary dominance was determined. Right dominance was present in 91% (n = 5817) and left in 9% (n = 565) of the study population. At the end of follow-up, outcome in patients with obstructive CAD (>50% luminal stenosis) and right dominance was similar compared with patients with left dominance [hazard ratio (HR) 0.46, 95% CI 0.16–1.32, P = 0.15]. Furthermore, no differences were observed for the type of coronary dominance in patients with non-obstructive CAD (HR 0.95, 95% CI 0.41–2.21, P = 0.8962) or normal coronary arteries (HR 1.04, 95% CI 0.68–1.59, P = 0.9). Subgroup analysis in patients with left main disease revealed an elevated hazard of the combined endpoint for left dominance (HR 6.45, 95% CI 1.66–25.0, P = 0.007), but not for right dominance. Conclusion In our study population, survival after 5 years of follow-up did not differ significantly between patients with left or right coronary dominance. Thus, assessment of coronary vessel dominance by CCTA may not enhance risk stratification in patients with normal coronary arteries or obstructive CAD, but may add prognostic information for specific subpopulations. PMID:25744341

  7. Optimization of tomographic reconstruction workflows on geographically distributed resources.

    PubMed

    Bicer, Tekin; Gürsoy, Dogˇa; Kettimuthu, Rajkumar; De Carlo, Francesco; Foster, Ian T

    2016-07-01

    New technological advancements in synchrotron light sources enable data acquisitions at unprecedented levels. This emergent trend affects not only the size of the generated data but also the need for larger computational resources. Although beamline scientists and users have access to local computational resources, these are typically limited and can result in extended execution times. Applications that are based on iterative processing as in tomographic reconstruction methods require high-performance compute clusters for timely analysis of data. Here, time-sensitive analysis and processing of Advanced Photon Source data on geographically distributed resources are focused on. Two main challenges are considered: (i) modeling of the performance of tomographic reconstruction workflows and (ii) transparent execution of these workflows on distributed resources. For the former, three main stages are considered: (i) data transfer between storage and computational resources, (i) wait/queue time of reconstruction jobs at compute resources, and (iii) computation of reconstruction tasks. These performance models allow evaluation and estimation of the execution time of any given iterative tomographic reconstruction workflow that runs on geographically distributed resources. For the latter challenge, a workflow management system is built, which can automate the execution of workflows and minimize the user interaction with the underlying infrastructure. The system utilizes Globus to perform secure and efficient data transfer operations. The proposed models and the workflow management system are evaluated by using three high-performance computing and two storage resources, all of which are geographically distributed. Workflows were created with different computational requirements using two compute-intensive tomographic reconstruction algorithms. Experimental evaluation shows that the proposed models and system can be used for selecting the optimum resources, which in turn can

  8. Effect of age on bone mineral density and micro architecture in the radius and tibia of horses: An Xtreme computed tomographic study

    PubMed Central

    Fürst, A; Meier, D; Michel, S; Schmidlin, A; Held, L; Laib, A

    2008-01-01

    Background The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone. Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex. Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis. Results Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia. Conclusion The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses. PMID:18221526

  9. Three-dimensional micro-computed tomographic evaluation of periodontal regeneration: a human report of intrabony defects treated with Bio-Oss collagen.

    PubMed

    Nevins, Marc L; Camelo, Marcelo; Rebaudi, Alberto; Lynch, Samuel E; Nevins, Myron

    2005-08-01

    This study utilized three-dimensional micro-computed tomography (micro-CT) to evaluate the regenerative response to Bio-Oss Collagen when used alone or in combination with a Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. The micro-CT observations are compared to the clinical, radiographic, and histologic results, which have been previously reported. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. Bio-Oss Collagen was then used to fill the defects, and in two cases a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. A mean pocket depth reduction of 5.75 mm and mean clinical attachment level gain of 5.25 mm were recorded. The histologic evaluation demonstrated the formation of a complete new attachment apparatus with new cementum, periodontal ligament, and alveolar bone at the level of and coronal to the calculus reference notch. Micro-CT evaluation confirmed the histologic results and demonstrated the absence of ankylosis or root resorption for all specimens. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to facilitate regeneration of the periodontal attachment apparatus when placed in intrabony defects. Micro-CT observations confirmed the histologic results and enhanced the three-dimensional understanding of periodontal wound healing. The results indicate that micro-CT may be useful for three-dimensional evaluation of periodontal regenerative procedures. PMID:16089044

  10. Utilization of Cone-Beam Computed Tomographic Angiography in Planning for Gamma Knife Radiosurgery of Arteriovenous Malformations: A Case Series and Early Report

    PubMed Central

    Safain, Mina G.; Rahal, Jason P.; Raval, Ami; Rivard, Mark J.; Mignano, John; Wu, Julian; Malek, Adel M.

    2014-01-01

    Background The effectiveness of Gamma Knife radiosurgery (GKR) for cerebral arteriovenous malformations (AVM) is predicated on inclusion of the entire nidus while excluding normal tissue. As such, GKR may be limited by the resolution and accuracy of the imaging modality used in targeting. Objective We present the first case series to demonstrate the feasibility of utilizing ultra-high-resolution C-arm cone beam computed tomography angiography (CBCT-A) in AVM targeting. Methods From June 2009 to June 2013, CBCT-A was utilized for targeting of all patients with AVMs treated with GKR at our institution. Patients underwent Leksell stereotactic head frame placement followed by catheter-based biplane 2-D digital subtraction angiography (DSA), 3-D rotational angiography (3DRA), as well as CBCT-A. The CBCT-A dataset was used for stereotactic planning for GKR. Patients were followed up at 1, 3, 6, and 12 months, and then annually thereafter. Results CBCT-A-based targeting was used in twenty-two consecutive patients. CBCT-A provided detailed spatial resolution and sensitivity of nidal angioarchitecture enabling treatment. The average radiation dose to the margin of the AVM nidus corresponding to the 50% percent isodose line was 15.6 Gy. No patient had treatment-associated hemorrhage. At early follow-up (mean=16 months), 84% of patients had a decreasing or obliterated AVM nidus. Conclusion CBCT-A-guided radiosurgery is feasible and useful because it provides sufficient detailed resolution and sensitivity for imaging brain AVMs. PMID:24584136

  11. Cone beam computed tomographic analysis of maxillary premolars and molars to detect the relationship between periapical and marginal bone loss and mucosal thickness of maxillary sinus

    PubMed Central

    Sekerci, Ahmet-Ercan; Köse, Emre; Sisman, Yildiray

    2015-01-01

    Background This study assessed the relationship between mucosal thickness (MT) of the maxillary sinus and periodontal bone loss (PBL) and periapical condition of related teeth. We also aimed to identify the association between root apices and the inferior wall of the maxillary sinus using Cone beam computed tomography (CBCT). Material and Methods In this study, CBCT images of 205 patients with 410 maxillary sinuses were examined, retrospectively. A total of 582 maxillary molars and 587 premolars were observed. The relationship of each root with maxillary sinus and apical lesions of these roots were classified, PBL was examined and the situations of adjacent teeth were estimated. The effect of these conditions on sinus mucosal thickness (MT) was evaluated. Results There was a significant correlation between MT of maxillary sinus and both PBL and age (r = 0.52, p=0.000 and r = 0.111, p= 0.002, respectively). The frequency of MT increased as the severity of apical lesion enlarged. A positive correlation was found between MT and degree of PBL and periapical lesions. To reveal the association between MT and pulpoperiapical condition bivariate correlation was done and a significant relationship between the pulpoperiapical condition and MT was found (r = 0.17, p=0.000). Conclusions This retrospective study showed that MT of the maxillary sinus was common among patients with PBL and MT was significantly associated with PBL and apical lesions. The relationship of maxillary sinus to adjacent teeth had also positive correlation with MT. CBCT imaging enabled better evaluation of maxillary sinus, posterior teeth and surrounding structures compared to other imaging tools. Key words:Maxillary sinus mucosal thickness, apical periodontitis, periodontal bone loss, CBCT. PMID:26241459

  12. Computer-Aided Tomographic Analysis of Interstitial Lung Disease (ILD) in Patients with Systemic Sclerosis (SSc). Correlation with Pulmonary Physiologic Tests and Patient-Centred Measures of Perceived Dyspnea and Functional Disability

    PubMed Central

    Salaffi, Fausto; Carotti, Marina; Di Donato, Eleonora; Di Carlo, Marco; Ceccarelli, Luca; Giuseppetti, Gianmarco

    2016-01-01

    ), patient-centred measures of perceived dyspnea and functional disability. Computer-aided tomographic analysis is computationally efficient, and in combination with physiologic and patient-centred measures, it could allow a means for accurately assessing and monitoring the disease progression or response to therapy. PMID:26930658

  13. Misty mesentery: a pictorial review of multidetector-row CT findings.

    PubMed

    Filippone, A; Cianci, R; Di Fabio, F; Storto, M L

    2011-04-01

    The term "misty mesentery" indicates a pathological increase in mesenteric fat attenuation at computed tomography (CT). It is frequently observed on multidetector CT (MDCT) scans performed during daily clinical practice and may be caused by various pathological conditions, including oedema, inflammation, haemorrhage, neoplastic infiltration or sclerosing mesenteritis. In patients suffering from acute abdominal disease, misty mesentery may be considered a feature of the underlying disease. Otherwise, it may represent an incidental finding on MDCT performed for other reasons. This article describes the MDCT features of misty mesentery in different diseases in order to provide a rational approach to the differential diagnosis. PMID:21311992

  14. Correlation of Lung Collapse and Gas Exchange - A Computer Tomographic Study in Sheep and Pigs with Atelectasis in Otherwise Normal Lungs

    PubMed Central

    Hammermüller, Sören; Costa, Eduardo L. V.; Spieth, Peter M.; Hepp, Pierre; Carvalho, Alysson R.; Kraßler, Jens; Wrigge, Hermann; Amato, Marcelo B. P.; Reske, Andreas W.

    2015-01-01

    Background Atelectasis can provoke pulmonary and non-pulmonary complications after general anaesthesia. Unfortunately, there is no instrument to estimate atelectasis and prompt changes of mechanical ventilation during general anaesthesia. Although arterial partial pressure of oxygen (PaO2) and intrapulmonary shunt have both been suggested to correlate with atelectasis, studies yielded inconsistent results. Therefore, we investigated these correlations. Methods Shunt, PaO2 and atelectasis were measured in 11 sheep and 23 pigs with otherwise normal lungs. In pigs, contrasting measurements were available 12 hours after induction of acute respiratory distress syndrome (ARDS). Atelectasis was calculated by computed tomography relative to total lung mass (Mtotal). We logarithmically transformed PaO2 (lnPaO2) to linearize its relationships with shunt and atelectasis. Data are given as median (interquartile range). Results Mtotal was 768 (715–884) g in sheep and 543 (503–583) g in pigs. Atelectasis was 26 (16–47) % in sheep and 18 (13–23) % in pigs. PaO2 (FiO2 = 1.0) was 242 (106–414) mmHg in sheep and 480 (437–514) mmHg in pigs. Shunt was 39 (29–51) % in sheep and 15 (11–20) % in pigs. Atelectasis correlated closely with lnPaO2 (R2 = 0.78) and shunt (R2 = 0.79) in sheep (P-values<0.0001). The correlation of atelectasis with lnPaO2 (R2 = 0.63) and shunt (R2 = 0.34) was weaker in pigs, but R2 increased to 0.71 for lnPaO2 and 0.72 for shunt 12 hours after induction of ARDS. In both, sheep and pigs, changes in atelectasis correlated strongly with corresponding changes in lnPaO2 and shunt. Discussion and Conclusion In lung-healthy sheep, atelectasis correlates closely with lnPaO2 and shunt, when blood gases are measured during ventilation with pure oxygen. In lung-healthy pigs, these correlations were significantly weaker, likely because pigs have stronger hypoxic pulmonary vasoconstriction (HPV) than sheep and humans. Nevertheless, correlations improved also

  15. Expansion of the Multi-Link Frontier™ Coronary Bifurcation Stent: Micro-Computed Tomographic Assessment in Human Autopsy and Porcine Heart Samples

    PubMed Central

    Kralev, Stefan; Haag, Benjamin; Spannenberger, Jens; Lang, Siegfried; Brockmann, Marc A.; Bartling, Soenke; Marx, Alexander; Haase, Karl-Konstantin; Borggrefe, Martin; Süselbeck, Tim

    2011-01-01

    Background Treatment of coronary bifurcation lesions remains challenging, beyond the introduction of drug eluting stents. Dedicated stent systems are available to improve the technical approach to the treatment of these lesions. However dedicated stent systems have so far not reduced the incidence of stent restenosis. The aim of this study was to assess the expansion of the Multi-Link (ML) Frontier™ stent in human and porcine coronary arteries to provide the cardiologist with useful in-vitro information for stent implantation and selection. Methodology/Principal Findings Nine ML Frontier™ stents were implanted in seven human autopsy heart samples with known coronary artery disease and five ML Frontier™ stents were implanted in five porcine hearts. Proximal, distal and side branch diameters (PD, DD, SBD, respectively), corresponding opening areas (PA, DA, SBA) and the mean stent length (L) were assessed by micro-computed tomography (micro-CT). PD and PA were significantly smaller in human autopsy heart samples than in porcine heart samples (3.54±0.47 mm vs. 4.04±0.22 mm, p = 0.048; 10.00±2.42 mm2 vs. 12.84±1.38 mm2, p = 0.034, respectively) and than those given by the manufacturer (3.54±0.47 mm vs. 4.03 mm, p = 0.014). L was smaller in human autopsy heart samples than in porcine heart samples, although data did not reach significance (16.66±1.30 mm vs. 17.30±0.51 mm, p = 0.32), and significantly smaller than that given by the manufacturer (16.66±1.30 mm vs. 18 mm, p = 0.015). Conclusions/Significance Micro-CT is a feasible tool for exact surveying of dedicated stent systems and could make a contribution to the development of these devices. The proximal diameter and proximal area of the stent system were considerably smaller in human autopsy heart samples than in porcine heart samples and than those given by the manufacturer. Special consideration should be given to the stent deployment procedure (and to the follow-up) of dedicated

  16. 3-dimensional strain fields from tomographic measurements

    NASA Astrophysics Data System (ADS)

    Haldrup, K.; Nielsen, S. F.; Mishnaevsky, L., Jr.; Beckmann, F.; Wert, J. A.

    2006-08-01

    Understanding the distributions of strain within solid bodies undergoing plastic deformations has been of interest for many years in a wide range of disciplines, ranging from basic materials science to biology. However, the desire to investigate these strain fields has been frustrated by the inaccessibility of the interior of most samples to detailed investigation without destroying the sample in the process. To some extent, this has been remedied by the development of advanced surface measurement techniques as well as computer models based on Finite Element methods. Over the last decade, this situation has changed by the introduction of a range of tomographic methods based both on advances in computer technology and in instrumentation, advances which have opened up the interior of optically opaque samples for detailed investigations. We present a general method for assessing the strain in the interior of marker-containing specimens undergoing various types of deformation. The results are compared with Finite Element modelling.

  17. Important Advances in Technology and Unique Applications to Cardiovascular Computed Tomography

    PubMed Central

    Chaikriangkrai, Kongkiat; Choi, Su Yeon; Nabi, Faisal; Chang, Su Min

    2014-01-01

    For the past decade, multidetector cardiac computed tomography and its main application, coronary computed tomography angiography, have been established as a noninvasive technique for anatomical assessment of coronary arteries. This new era of coronary artery evaluation by coronary computed tomography angiography has arisen from the rapid advancement in computed tomography technology, which has led to massive diagnostic and prognostic clinical studies in various patient populations. This article gives a brief overview of current multidetector cardiac computed tomography systems, developing cardiac computed tomography technologies in both hardware and software fields, innovative radiation exposure reduction measures, multidetector cardiac computed tomography functional studies, and their newer clinical applications beyond coronary computed tomography angiography. PMID:25574342

  18. Important advances in technology and unique applications to cardiovascular computed tomography.

    PubMed

    Chaikriangkrai, Kongkiat; Choi, Su Yeon; Nabi, Faisal; Chang, Su Min

    2014-01-01

    For the past decade, multidetector cardiac computed tomography and its main application, coronary computed tomography angiography, have been established as a noninvasive technique for anatomical assessment of coronary arteries. This new era of coronary artery evaluation by coronary computed tomography angiography has arisen from the rapid advancement in computed tomography technology, which has led to massive diagnostic and prognostic clinical studies in various patient populations. This article gives a brief overview of current multidetector cardiac computed tomography systems, developing cardiac computed tomography technologies in both hardware and software fields, innovative radiation exposure reduction measures, multidetector cardiac computed tomography functional studies, and their newer clinical applications beyond coronary computed tomography angiography. PMID:25574342

  19. On the tomographic description of classical fields

    NASA Astrophysics Data System (ADS)

    Ibort, A.; López-Yela, A.; Man'ko, V. I.; Marmo, G.; Simoni, A.; Sudarshan, E. C. G.; Ventriglia, F.

    2012-03-01

    After a general description of the tomographic picture for classical systems, a tomographic description of free classical scalar fields is proposed both in a finite cavity and the continuum. The tomographic description is constructed in analogy with the classical tomographic picture of an ensemble of harmonic oscillators. The tomograms of a number of relevant states such as the canonical distribution, the classical counterpart of quantum coherent states and a new family of so-called Gauss-Laguerre states, are discussed. Finally the Liouville equation for field states is described in the tomographic picture offering an alternative description of the dynamics of the system that can be extended naturally to other fields.

  20. Expediting model-based optoacoustic reconstructions with tomographic symmetries

    SciTech Connect

    Lutzweiler, Christian; Deán-Ben, Xosé Luís; Razansky, Daniel

    2014-01-15

    Purpose: Image quantification in optoacoustic tomography implies the use of accurate forward models of excitation, propagation, and detection of optoacoustic signals while inversions with high spatial resolution usually involve very large matrices, leading to unreasonably long computation times. The development of fast and memory efficient model-based approaches represents then an important challenge to advance on the quantitative and dynamic imaging capabilities of tomographic optoacoustic imaging. Methods: Herein, a method for simplification and acceleration of model-based inversions, relying on inherent symmetries present in common tomographic acquisition geometries, has been introduced. The method is showcased for the case of cylindrical symmetries by using polar image discretization of the time-domain optoacoustic forward model combined with efficient storage and inversion strategies. Results: The suggested methodology is shown to render fast and accurate model-based inversions in both numerical simulations andpost mortem small animal experiments. In case of a full-view detection scheme, the memory requirements are reduced by one order of magnitude while high-resolution reconstructions are achieved at video rate. Conclusions: By considering the rotational symmetry present in many tomographic optoacoustic imaging systems, the proposed methodology allows exploiting the advantages of model-based algorithms with feasible computational requirements and fast reconstruction times, so that its convenience and general applicability in optoacoustic imaging systems with tomographic symmetries is anticipated.

  1. [Fascioliasis hepatis--computed tomographic aspect].

    PubMed

    Goebel, N; Markwalder, K; Siegenthaler, W

    1984-12-01

    In a patient with liver fascioliasis (already excreting eggs with the faeces) a CT scan of the liver showed after i. v. contrast injection a relatively characteristic aspect with multiple, small, hypodense areas, partly in formations of bunches of grapes, partly in a street-like arrangement towards the portal vein - bile duct - areas. 9 months later the hypodense lesions had markedly decreased. PMID:6518725

  2. Single-shot ultrafast tomographic imaging by spectral multiplexing

    NASA Astrophysics Data System (ADS)

    Matlis, N. H.; Axley, A.; Leemans, W. P.

    2012-10-01

    Computed tomography has profoundly impacted science, medicine and technology by using projection measurements scanned over multiple angles to permit cross-sectional imaging of an object. The application of computed tomography to moving or dynamically varying objects, however, has been limited by the temporal resolution of the technique, which is set by the time required to complete the scan. For objects that vary on ultrafast timescales, traditional scanning methods are not an option. Here we present a non-scanning method capable of resolving structure on femtosecond timescales by using spectral multiplexing of a single laser beam to perform tomographic imaging over a continuous range of angles simultaneously. We use this technique to demonstrate the first single-shot ultrafast computed tomography reconstructions and obtain previously inaccessible structure and position information for laser-induced plasma filaments. This development enables real-time tomographic imaging for ultrafast science, and offers a potential solution to the challenging problem of imaging through scattering surfaces.

  3. CT-guided Irreversible Electroporation in an Acute Porcine Liver Model: Effect of Previous Transarterial Iodized Oil Tissue Marking on Technical Parameters, 3D Computed Tomographic Rendering of the Electroporation Zone, and Histopathology

    SciTech Connect

    Sommer, C. M.; Fritz, S.; Vollherbst, D.; Zelzer, S.; Wachter, M. F. Bellemann, N. Gockner, T. Mokry, T. Schmitz, A.; Aulmann, S.; Stampfl, U.; Pereira, P.; Kauczor, H. U.; Werner, J.; Radeleff, B. A.

    2015-02-15

    PurposeTo evaluate the effect of previous transarterial iodized oil tissue marking (ITM) on technical parameters, three-dimensional (3D) computed tomographic (CT) rendering of the electroporation zone, and histopathology after CT-guided irreversible electroporation (IRE) in an acute porcine liver model as a potential strategy to improve IRE performance.MethodsAfter Ethics Committee approval was obtained, in five landrace pigs, two IREs of the right and left liver (RL and LL) were performed under CT guidance with identical electroporation parameters. Before IRE, transarterial marking of the LL was performed with iodized oil. Nonenhanced and contrast-enhanced CT examinations followed. One hour after IRE, animals were killed and livers collected. Mean resulting voltage and amperage during IRE were assessed. For 3D CT rendering of the electroporation zone, parameters for size and shape were analyzed. Quantitative data were compared by the Mann–Whitney test. Histopathological differences were assessed.ResultsMean resulting voltage and amperage were 2,545.3 ± 66.0 V and 26.1 ± 1.8 A for RL, and 2,537.3 ± 69.0 V and 27.7 ± 1.8 A for LL without significant differences. Short axis, volume, and sphericity index were 16.5 ± 4.4 mm, 8.6 ± 3.2 cm{sup 3}, and 1.7 ± 0.3 for RL, and 18.2 ± 3.4 mm, 9.8 ± 3.8 cm{sup 3}, and 1.7 ± 0.3 for LL without significant differences. For RL and LL, the electroporation zone consisted of severely widened hepatic sinusoids containing erythrocytes and showed homogeneous apoptosis. For LL, iodized oil could be detected in the center and at the rim of the electroporation zone.ConclusionThere is no adverse effect of previous ITM on technical parameters, 3D CT rendering of the electroporation zone, and histopathology after CT-guided IRE of the liver.

  4. Relationship between lung function and quantitative computed tomographic parameters of airway remodeling, air trapping, and emphysema in patients with asthma and chronic obstructive pulmonary disease: A single-center study

    PubMed Central

    Hartley, Ruth A.; Barker, Bethan L.; Newby, Chris; Pakkal, Mini; Baldi, Simonetta; Kajekar, Radhika; Kay, Richard; Laurencin, Marie; Marshall, Richard P.; Sousa, Ana R.; Parmar, Harsukh; Siddiqui, Salman; Gupta, Sumit; Brightling, Chris E.

    2016-01-01

    Background There is a paucity of studies comparing asthma and chronic obstructive pulmonary disease (COPD) based on thoracic quantitative computed tomographic (QCT) parameters. Objectives We sought to compare QCT parameters of airway remodeling, air trapping, and emphysema between asthmatic patients and patients with COPD and explore their relationship with airflow limitation. Methods Asthmatic patients (n = 171), patients with COPD (n = 81), and healthy subjects (n = 49) recruited from a single center underwent QCT and clinical characterization. Results Proximal airway percentage wall area (%WA) was significantly increased in asthmatic patients (62.5% [SD, 2.2]) and patients with COPD (62.7% [SD, 2.3]) compared with that in healthy control subjects (60.3% [SD, 2.2], P < .001). Air trapping measured based on mean lung density expiratory/inspiratory ratio was significantly increased in patients with COPD (mean, 0.922 [SD, 0.037]) and asthmatic patients (mean, 0.852 [SD, 0.061]) compared with that in healthy subjects (mean, 0.816 [SD, 0.066], P < .001). Emphysema assessed based on lung density measured by using Hounsfield units below which 15% of the voxels lie (Perc15) was a feature of COPD only (patients with COPD: mean, −964 [SD, 19.62] vs asthmatic patients: mean, −937 [SD, 22.7] and healthy subjects: mean, −937 [SD, 17.1], P < .001). Multiple regression analyses showed that the strongest predictor of lung function impairment in asthmatic patients was %WA, whereas in the COPD and asthma subgrouped with postbronchodilator FEV1 percent predicted value of less than 80%, it was air trapping. Factor analysis of QCT parameters in asthmatic patients and patients with COPD combined determined 3 components, with %WA, air trapping, and Perc15 values being the highest loading factors. Cluster analysis identified 3 clusters with mild, moderate, or severe lung function impairment with corresponding decreased lung density (Perc15 values) and increased air

  5. Diagnosing pulmonary embolism: new computed tomography applications.

    PubMed

    Nikolaou, Konstantin; Thieme, Sven; Sommer, Wieland; Johnson, Thorsten; Reiser, Maximilian F

    2010-05-01

    Computed tomographic pulmonary angiography has become the standard of care for the evaluation of patients with suspected pulmonary embolism (PE). In addition to the direct depiction or exclusion of a pulmonary embolus in suspected PE, a number of predictive markers have been established to evaluate the patient's prognosis in acute and in chronic PE. An accurate risk stratification based on CT findings is crucial because optimal management, monitoring, and therapeutic strategies depend on the prognosis. With the recent introduction of the so-called "dual-source" CT scanners, that is, a scanner consisting of 2 tubes and 2 detectors mounted orthogonally to each other, different tube voltages can be used simultaneously, resulting in different energies of the emitted x-ray spectra (dual-energy CT; DECT). Initial results have shown that DECT is capable of iodine mapping of the pulmonary parenchyma, reliably depicting the segmental defects in iodine distribution in locations corresponding to embolic vessel occlusions. This study deals with a number of actual topics on PE imaging with multidetector CT and DECT, including the discussion of the relevant imaging findings to assess the patient's prognosis, the potential and additional benefit of dual-energy information on the parenchymal iodine distribution, the optimization of scan protocols including low-radiation dose chest pain protocols, and the discussion on future perspectives of CT in PE patients, such as the role of computer-aided diagnostic tools or the potential of ventilation imaging with DECT. PMID:20463534

  6. Search for continuous gravitational waves: Metric of the multidetector F-statistic

    SciTech Connect

    Prix, Reinhard

    2007-01-15

    We develop a general formalism for the parameter-space metric of the multidetector F-statistic, which is a matched-filtering detection statistic for continuous gravitational waves. We find that there exists a whole family of F-statistic metrics, parametrized by the (unknown) amplitude parameters of the gravitational wave. The multidetector metric is shown to be expressible in terms of noise-weighted averages of single-detector contributions, which implies that the number of templates required to cover the parameter space does not scale with the number of detectors. Contrary to using a longer observation time, combining detectors of similar sensitivity is therefore the computationally cheapest way to improve the sensitivity of coherent wide-parameter searches for continuous gravitational waves. We explicitly compute the F-statistic metric family for signals from isolated spinning neutron stars, and we numerically evaluate the quality of different metric approximations in a Monte Carlo study. The metric predictions are tested against the measured mismatches and we identify regimes in which the local metric is no longer a good description of the parameter-space structure.

  7. Trapping volumetric measurement by multidetector CT in chronic obstructive pulmonary disease: Effect of CT threshold

    SciTech Connect

    Wang, Xiaohua; Yuan, Huishu; Duan, Jianghui; Du, Yipeng; Shen, Ning; He, Bei

    2013-08-15

    Purpose: The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD).Methods: Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and expiratory phase. CT thresholds of −950 Hu in inspiration and −950 to −890 Hu in expiration were used, after which trapping volumetric measurements were made using computer software. Trapping volume percentage (Vtrap%) under the different CT thresholds in the expiratory phase and below −950 Hu in the inspiratory phase was compared and correlated with lung function.Results: Mean Vtrap% was similar under −930 Hu in the expiratory phase and below −950 Hu in the inspiratory phase, being 13.18 ± 9.66 and 13.95 ± 6.72 (both lungs), respectively; this difference was not significant (P= 0.240). Vtrap% under −950 Hu in the inspiratory phase and below the −950 to −890 Hu threshold in the expiratory phase was moderately negatively correlated with the ratio of forced expiratory volume in one second to forced vital capacity and the measured value of forced expiratory volume in one second as a percentage of the predicted value.Conclusions: Trapping volumetric measurement with multidetector CT is a promising method for the quantification of COPD. It is important to know the effect of various CT thresholds on trapping volumetric measurements.

  8. Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist.

    PubMed

    Dreizin, David; Nam, Arthur J; Tirada, Nikki; Levin, Martin D; Stein, Deborah M; Bodanapally, Uttam K; Mirvis, Stuart E; Munera, Felipe

    2016-01-01

    After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016. PMID:27618328

  9. Advanced Ultrasonic Tomograph of Children's Bones

    NASA Astrophysics Data System (ADS)

    Lasaygues, Philippe; Lefebvre, Jean-Pierre; Guillermin, Régine; Kaftandjian, Valérie; Berteau, Jean-Philippe; Pithioux, Martine; Petit, Philippe

    This study deals with the development of an experimental device for performing ultrasonic computed tomography (UCT) on bone in pediatric degrees. The children's bone tomographs obtained in this study, were based on the use of a multiplexed 2-D ring antenna (1 MHz and 3 MHz) designed for performing electronic and mechanical scanning. Although this approach is known to be a potentially valuable means of imaging objects with similar acoustical impedances, problems arise when quantitative images of more highly contrasted media such as bones are required. Various strategies and various mathematical procedures for modeling the wave propagation based on Born approximations have been developed at our laboratory, which are suitable for use with pediatric cases. Inversions of the experimental data obtained are presented.

  10. Tomographic reconstruction of polar plumes

    NASA Astrophysics Data System (ADS)

    Auchère, F.; Guennou, C.; Barbey, N.

    2012-06-01

    We present a tomographic reconstruction of polar plumes as observed in the Extreme Ultraviolet in January 2010. Plumes are elusive structures visible in polar coronal holes that may play an important role in the acceleration of the solar wind. However, despite numerous observations, little is irrefutably known about them. Because of line of sight effects, even their geometry is subject to debate. Are they genuine cylindrical features of the corona or are they only chance alignments along the line of sight? Tomography provides a means to reconstruct the volume of an optically thin object from a set of observations taken from different vantage points. In the case of the Sun, these are typically obtained by using a solar rotation worth of images, which limits the ability to reconstruct short lived structures. We present here a tomographic inversion of the solar corona obtained using only 6 days of data. This is achieved by using simultaneously three space telescopes (EUVI/STEREO and SWAP/PROBA2) in a very specific orbital configuration. The result is the shortest possible tomographic snapshot of polar plumes. The 3D reconstruction shows both quasi-cylindrical plumes and a network pattern that can mimic them by line of sight superimpositions. This suggests that the controversy on plume geometry is due to the coexistence of both types of structures.

  11. Image processing pipeline for synchrotron-radiation-based tomographic microscopy.

    PubMed

    Hintermüller, C; Marone, F; Isenegger, A; Stampanoni, M

    2010-07-01

    With synchrotron-radiation-based tomographic microscopy, three-dimensional structures down to the micrometer level can be visualized. Tomographic data sets typically consist of 1000 to 1500 projections of 1024 x 1024 to 2048 x 2048 pixels and are acquired in 5-15 min. A processing pipeline has been developed to handle this large amount of data efficiently and to reconstruct the tomographic volume within a few minutes after the end of a scan. Just a few seconds after the raw data have been acquired, a selection of reconstructed slices is accessible through a web interface for preview and to fine tune the reconstruction parameters. The same interface allows initiation and control of the reconstruction process on the computer cluster. By integrating all programs and tools, required for tomographic reconstruction into the pipeline, the necessary user interaction is reduced to a minimum. The modularity of the pipeline allows functionality for new scan protocols to be added, such as an extended field of view, or new physical signals such as phase-contrast or dark-field imaging etc. PMID:20567088

  12. Tomographic imaging in civil engineering infrastructure

    NASA Astrophysics Data System (ADS)

    Gheshlaghi, Farshad

    This research was to assess the potential of tomographic imaging in a variety of geotechnical processes, with emphasis on matrix-based inversion algorithms. While most prior research in tomography has been based on simulated data, this research centers on case histories gathered under well-controlled, yet realistic field conditions. The goal is to invert a velocity image which reflects the state or evolution of a given soil parameter (e.g., stress, pore pressure, ion concentration) using a set of picked travel times. In general, it is assumed that "picked travel times" correspond to paths of shortest travel path (Fermat's principle). If the velocity contrast in the medium is more than 15 to 20 percent, rays bend toward higher velocity regions. In this case, entries in the coefficient matrix depend on a prior estimate of the velocity field. Therefore, the relation between pixel velocities and travel times is non-linear in general. This non-linear inversion problem can be solved by employing iterative solutions with ray tracing. Ray tracing methods can be categorized as: one-point methods, two-point methods, and whole-field methods. The computational time demand for ray tracing methods for each category is evaluated based on the number of segmental travel time calculations. The computational efficiency of the ray tracing methods is also compared for fundamental cases. Prior experience with simulated data has shown that the quality of inversion is unrealistically good when compared to inversions with real data. In part, this reflects the compatibility of forward simulation algorithms with hypotheses made in the inversion stage. A central goal of this thesis is to assess the potential of inversion with real data. A database of case histories has been compiled for this purpose. Part of this study is dedicated to the testing of pre-processing strategies in each case history. It is shown that data pre-processing can be employed to provide foresight about the medium, and

  13. Value and Accuracy of Multidetector Computed Tomography in Obstructive Jaundice

    PubMed Central

    Mathew, Rishi Philip; Moorkath, Abdunnisar; Basti, Ram Shenoy; Suresh, Hadihally B.

    2016-01-01

    Summary Background Objective; To find out the role of MDCT in the evaluation of obstructive jaundice with respect to the cause and level of the obstruction, and its accuracy. To identify the advantages of MDCT with respect to other imaging modalities. To correlate MDCT findings with histopathology/surgical findings/Endoscopic Retrograde CholangioPancreatography (ERCP) findings as applicable. Material/Methods This was a prospective study conducted over a period of one year from August 2014 to August 2015. Data were collected from 50 patients with clinically suspected obstructive jaundice. CT findings were correlated with histopathology/surgical findings/ERCP findings as applicable. Results Among the 50 people studied, males and females were equal in number, and the majority belonged to the 41–60 year age group. The major cause for obstructive jaundice was choledocholithiasis. MDCT with reformatting techniques was very accurate in picking a mass as the cause for biliary obstruction and was able to differentiate a benign mass from a malignant one with high accuracy. There was 100% correlation between the CT diagnosis and the final diagnosis regarding the level and type of obstruction. MDCT was able to determine the cause of obstruction with an accuracy of 96%. Conclusions MDCT with good reformatting techniques has excellent accuracy in the evaluation of obstructive jaundice with regards to the level and cause of obstruction. PMID:27429673

  14. Quantum correlations and tomographic representation

    NASA Astrophysics Data System (ADS)

    Man'ko, O. V.; Chernega, V. N.

    2013-07-01

    We review the probabilistic representation of quantum mechanics within which states are described by the probability distribution rather than by the wavefunction and density matrix. Uncertainty relations have been obtained in the form of integral inequalities containing measurable optical tomograms of quantum states. Formulas for the transition probabilities and purity parameter have been derived in terms of the tomographic probability distributions. Inequalities for Shannon and Rényi entropies associated with quantum tomograms have been obtained. A scheme of the star product of tomograms has been developed.

  15. Linear adaptive noise-reduction filters for tomographic imaging: Optimizing for minimum mean square error

    SciTech Connect

    Sun, W Y

    1993-04-01

    This thesis solves the problem of finding the optimal linear noise-reduction filter for linear tomographic image reconstruction. The optimization is data dependent and results in minimizing the mean-square error of the reconstructed image. The error is defined as the difference between the result and the best possible reconstruction. Applications for the optimal filter include reconstructions of positron emission tomographic (PET), X-ray computed tomographic, single-photon emission tomographic, and nuclear magnetic resonance imaging. Using high resolution PET as an example, the optimal filter is derived and presented for the convolution backprojection, Moore-Penrose pseudoinverse, and the natural-pixel basis set reconstruction methods. Simulations and experimental results are presented for the convolution backprojection method.

  16. Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

    NASA Astrophysics Data System (ADS)

    Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

    2016-04-01

    In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and

  17. Algebraic filter approach for fast approximation of nonlinear tomographic reconstruction methods

    NASA Astrophysics Data System (ADS)

    Plantagie, Linda; Batenburg, Kees Joost

    2015-01-01

    We present a computational approach for fast approximation of nonlinear tomographic reconstruction methods by filtered backprojection (FBP) methods. Algebraic reconstruction algorithms are the methods of choice in a wide range of tomographic applications, yet they require significant computation time, restricting their usefulness. We build upon recent work on the approximation of linear algebraic reconstruction methods and extend the approach to the approximation of nonlinear reconstruction methods which are common in practice. We demonstrate that if a blueprint image is available that is sufficiently similar to the scanned object, our approach can compute reconstructions that approximate iterative nonlinear methods, yet have the same speed as FBP.

  18. Mapping of Visual Receptive Fields by Tomographic Reconstruction

    PubMed Central

    Pipa, Gordon; Chen, Zhe; Neuenschwander, Sergio; Lima, Bruss; Brown, Emery N.

    2014-01-01

    The moving bar experiment is a classic paradigm for characterizing the receptive field (RF) properties of neurons in primary visual cortex (V1). Current approaches for analyzing neural spiking activity recorded from these experiments do not take into account the point process nature of these data and the circular geometry of the stimulus presentation. We present a novel analysis approach to mapping V1 receptive fields that combines point process generalized linear models (PPGLM) with tomographic reconstruction computed by filtered-back projection. We use the method to map the RF sizes and orientations of 251 V1 neurons recorded from two macaque monkeys during a moving bar experiment. Our cross-validated goodness-of-fit analyses show that the PPGLM provides a more accurate characterization of spike train data than analyses based on rate functions computed by the methods of spike triggered averages or first-order Wiener-Volterra kernel. Our analysis leads to a new definition of RF size as the spatial area over which the spiking activity is significantly greater than baseline activity. Our approach yields larger RF sizes and sharper orientation tuning estimates. The tomographic reconstruction paradigm further suggests an efficient approach to choosing the number of directions and the number of trials per direction in designing moving bar experiments. Our results demonstrate that standard tomographic principles for image reconstruction can be adapted to characterize V1 RFs and that two fundamental properties, size and orientation, may be substantially different from what is currently reported. PMID:22734491

  19. A preliminary design study for improving performance in tomographic assays

    SciTech Connect

    Estep, R.J.

    1994-03-01

    The authors recently introduced the tomographic-gamma-scanner (TGS) method for assaying transuranic (TRU) waste and special nuclear material (SNM) in 55-gal drums. The TGS combines low-resolution emission and transmission tomography to obtain attenuation-corrected images of the radionuclide distribution inside a drum. In a low-resolution tomographic assay device, it is desirable to have as flat an efficiency profile as possible. Using computer simulations, they have demonstrated that a flat response in the vertical direction can be obtained by using a diamond-shaped collimator, and that this flatness of response translates into improved assay accuracy. Similarly, they have shown that the use of a continuous-motion scan protocol reduces horizontal efficiency variations.

  20. Evaluation of a Multicore-Optimized Implementation for Tomographic Reconstruction

    PubMed Central

    Agulleiro, Jose-Ignacio; Fernández, José Jesús

    2012-01-01

    Tomography allows elucidation of the three-dimensional structure of an object from a set of projection images. In life sciences, electron microscope tomography is providing invaluable information about the cell structure at a resolution of a few nanometres. Here, large images are required to combine wide fields of view with high resolution requirements. The computational complexity of the algorithms along with the large image size then turns tomographic reconstruction into a computationally demanding problem. Traditionally, high-performance computing techniques have been applied to cope with such demands on supercomputers, distributed systems and computer clusters. In the last few years, the trend has turned towards graphics processing units (GPUs). Here we present a detailed description and a thorough evaluation of an alternative approach that relies on exploitation of the power available in modern multicore computers. The combination of single-core code optimization, vector processing, multithreading and efficient disk I/O operations succeeds in providing fast tomographic reconstructions on standard computers. The approach turns out to be competitive with the fastest GPU-based solutions thus far. PMID:23139768

  1. Cirsoid Aneurysm of Coronary Arteries Associated with Arterioventricular Fistula Evaluated by 64-Multidetector CT Coronary Angiography: Depiction of a Case

    SciTech Connect

    Marrone, Gianluca Mamone, Giuseppe; Milazzo, Mariapina; Caruso, Settimo; Baravoglia, Cesar Hernandez; Vitulo, Patrizio; Gridelli, Bruno; Luca, Angelo

    2009-05-15

    A female patient with severe pulmonary hypertension was admitted for lung transplant evaluation. As an incidental finding, the chest CT showed diffuse and dilated coronaries, not detected at previous echocardiography. A coronary CT angiography was then performed using a 64-multidetector computed tomography (MDCT) scanner to better evaluate the coronary tree. The images obtained after postprocessing demonstrated tremendously aneurysmatic and tortuous coronary arteries and the presence of a septal branch deepening into the myocardium and penetrating the right ventricle cavity, forming an abnormal arterioventricular fistula. A causal relation between the aneurysms and the fistula is suspected.

  2. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  3. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  4. High resolution tomographic instrument development

    NASA Astrophysics Data System (ADS)

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefitted greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  5. Tomographic Adaptive Optics and Turbulence Profiling

    NASA Astrophysics Data System (ADS)

    Morris, Tim

    2015-04-01

    The use of tomographic adaptive optics is fundamental to fulfilling scientific goals for many proposed instruments at major observatories. Tomographic AO uses knowledge of the atmospheric C2n profile and to date, the majority of the profiles used to design and simulate these systems have come from external turbulence profilers. The C2n profile resolution required for accurate predictions of ELT instrumentation exceeds that of existing instrumentation and here we define the requirements on these profilers for ELT support. However, tomographic AO systems can also measure C2n profiles and we highlight several cases where external profilers can provide critical functionality to support on-sky operations.

  6. Spin scan tomographic array-based imager.

    PubMed

    Hovland, Harald

    2014-12-29

    This work presents a novel imaging device based on tomographic reconstruction. Similar in certain aspects to the earlier presented tomographic scanning (TOSCA) principle, it provides several important enhancements. The device described generates a stream of one-dimensional projections from a linear array of thin stripe detectors onto which the (circular) image of the scene is rotated. A two-dimensional image is then reproduced from the one-dimensional signals using tomographic processing techniques. A demonstrator is presented. Various aspects of the design and construction are discussed, and resulting images and movies are presented. PMID:25607168

  7. Multimodality tomographic scintimammography with PET, PECI, and SPECT: initial evaluation

    NASA Astrophysics Data System (ADS)

    Krol, Andrzej; Feiglin, David H.; Thomas, Frank D.; Hellwig, Bradford J.; Gagne, George M.

    2002-04-01

    We compared tomographic scintimammography performed using single photon emission computed tomography (SPECT), positron emission coincidence imaging (PECI) and positron emission tomography (PET). A female thorax phantom was used. Activities of the myocardium, thorax and breasts were adjusted to emulate the count rate observed with patients. Hollow plastic spheres, imitating hot lesions (1.5-20ml), filled with radioactive saline were inserted in the center of each breast. Specific activities of internal organs were adjusted to emulate the count rate observed with patients. SPECT data were acquired with Tc-99m using gamma cameras with NaI(Tl) detectors. A modified FBP (CODE) reconstruction algorithm was used to render SPECT tomographic images. PECI (Siemens E.CAM with NaI(Tl)) and PET (GE Advance with BGO) data were acquired using F-18 FDG. Vendor supplied reconstruction algorithms were used. The reconstructed hot lesions contrast and resolution were investigated. Image quality obtained can be ranked as follows: (1) PET(BGO), (2) PECI(NaI), (3) SPECT(NaI) In conclusion, assuming comparable uptake values of Tc-99m-sestamibi and F-18 FDG, PET seems to be a superior methodology in visualization of breast lesion as compared to SPECT and PECI. All these tomographic methods appear to be promising adjunct to x-ray mammography in difficult to interpret cases.

  8. Scanning tomographic acoustic microscopy: principles and recent developments (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Wade, G.; Meyyappan, A.

    1987-09-01

    Acoustic Microscopy is an important branch of non-destructive evaluation which provides high resolution for imaging the detailed structure of a small object. When an acoustic microscope operates in the transmission mode, the micrograph is simply a shadowgraph of all the structures encountered by the acoustic wave passing through the object. Because of diffraction and overlapping, the resultant images are difficult to comprehend in the case of specimens of substantial thickness and structural complexity. We used the principles of diffraction tomography and acoustical holography along with digital calcuations of wavefield propagation to overcome this problem. We have described in previously-published work how a scanning laser acoustic microscope (SLAM) can be modified to obtain data for subsurface tomographic imaging. In this paper, we review the principles of scanning tomographic acoustic microscopy (STAM). The required modification of SLAM to obtain STAM and the reconstruction process are described. We show how we are able to accurately acquire the complex-amplitude information necessary for image reconstruction. We demonstrate the power of this technique by comparing digitally-computed images thus obtained with analogue images of a conventional SLAM. The results show that high-quality, high-resolution subsurface images can be obtained from experimentally acquired data. We also describe techniques to obtain projection data from different angles of wave incidence enabling us to tomographically reconstruct different planes of a complex specimen in microscopic detail. With these modifications in place, STAM should shortly become a powerful tool in non-destructive evaluation.

  9. Novel Ultrasound Tomograph for Anatomical Inspection

    NASA Astrophysics Data System (ADS)

    Rouyer, Julien; Lasaygues, Philippe; Mensah, Serge

    A device for ultrasound computed tomography (UCT) is introduced here. An half-ring transducer array was designed in conformity with the breast anatomy and the cancer growth region to perform an early detection. The array comprises 1,024 elements set in a 190-degree circular arc with a radius of 100 mm. The nominal frequency is 3 MHz with a 79% -6 dB bandwidth. The front-end electronics incorporate 32 independent transmit/receive parallel channels and a 32-to-1,024 multiplexer unit. The acquisition circuitries have a variable sampling frequency of up to 80 MHz and a precision of 12 bits. Arbitrary waveforms are synthesized to improve the signal-to-noise ratio and to increase the in-depth resolution. Tomographic acquisitions were realized in diffraction mode using a restricted aperture. The backscattered field was recorded in the case of a string phantom (0.08-mm diameter steel threads) and a breast-shaped phantom containing inclusions. Data were processed with dedicated correction tools processes such as pulse compression. Objects were reconstructed with the ellipsoidal back-projection method.

  10. Tomographic phase microscopy using optical tweezers

    NASA Astrophysics Data System (ADS)

    Habaza, Mor; Gilboa, Barak; Roichman, Yael; Shaked, Natan T.

    2015-07-01

    We review our technique for tomographic phase microscopy with optical tweezers [1]. This tomographic phase microscopy approach enables full 3-D refractive-index reconstruction. Tomographic phase microscopy measures quantitatively the 3- D distribution of refractive-index in biological cells. We integrated our external interferometric module with holographic optical tweezers for obtaining quantitative phase maps of biological samples from a wide range of angles. The close-tocommon- path, off-axis interferometric system enables a full-rotation tomographic acquisition of a single cell using holographic optical tweezers for trapping and manipulating with a desired array of traps, while acquiring phase information of a single cell from all different angles and maintaining the native surrounding medium. We experimentally demonstrated two reconstruction algorithms: the filtered back-projection method and the Fourier diffraction method for 3-D refractive index imaging of yeast cells.

  11. Computer-aided assessment of cardiac computed tomographic images

    NASA Astrophysics Data System (ADS)

    King, Martin; Giger, Maryellen; Suzuki, Kenji; Pan, Xiaochuan

    2007-03-01

    The accurate interpretation of cardiac CT images is commonly hindered by the presence of motion artifacts. Since motion artifacts commonly can obscure the presence of coronary lesions, physicians must spend much effort analyzing images at multiple cardiac phases in order to determine which coronary structures are assessable for potential lesions. In this study, an artificial neural network (ANN) classifier was designed to assign assessability indices to calcified plaques in individual region-of-interest (ROI) images reconstructed at multiple cardiac phases from two cardiac scans obtained at heart rates of 66 bpm and 90 bpm. Six individual features (volume, circularity, mean intensity, margin gradient, velocity, and acceleration) were used for analyzing images. Visually-assigned assessability indices were used as a continuous truth, and jack-knife analysis with four testing sets was used to evaluate the performance of the ANN classifier. In a study in which all six features were inputted into the ANN classifier, correlation coefficients of 0.962 +/- 0.006 and 0.935 +/- 0.023 between true and ANN-assigned assessability indices were obtained for databases corresponding to 66 bpm and 90 bpm, respectively.

  12. Scenes from the past: multidetector CT of Egyptian mummies of the Redpath Museum.

    PubMed

    Wade, Andrew D; Garvin, Gregory J; Hurnanen, Jaana H; Williams, Licd Lana; Lawson, Barbara; Nelson, Andrew J; Tampieri, Donatella

    2012-01-01

    As a nondestructive method of historical and anthropologic inquiry, imaging has played an important role in mummy studies over the past several decades. Recent technologic advances have made multidetector computed tomography (CT) an especially useful means for deepening the present understanding of ancient cultures by examining preserved human remains. In April 2011, three ancient Egyptian human mummies from the Redpath Museum of McGill University were examined with 320-section multidetector CT as part of the IMPACT Radiological Mummy Database project headquartered at the University of Western Ontario. Whole-body scanning was performed with a section thickness of 0.5 mm and a peak voltage of 120 kVp, and the raw CT datasets were postprocessed by using smooth body and high-resolution bone convolution filters. Two of the mummies were scanned at different energy levels (80 and 135 keV). The high-resolution CT scans revealed the details of mummification and allowed observations about the socioeconomic and health status of the human subjects based on both the mummification technique used and the appearance of the remains, particularly the bones and teeth. The paleopathologic information obtained from the scans confirmed some findings in studies performed in the same mummies in the late 19th and 20th centuries. The CT scans also demonstrated a high degree of variability in Egyptian mortuary practice, variability that is not generally recognized in the literature. Unusual features that were observed included a relatively uncommon retained heart in mummy RM2718, retained lungs in a mummy from which the heart had been extracted (RM2720), and a cartonnage plaque placed over the left abdomen of a mummy that had been eviscerated transperineally (RM2717). PMID:22787004

  13. A maximum entropy reconstruction technique for tomographic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Bilsky, A. V.; Lozhkin, V. A.; Markovich, D. M.; Tokarev, M. P.

    2013-04-01

    This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART.

  14. Lifetime-based tomographic multiplexing

    NASA Astrophysics Data System (ADS)

    Raymond, Scott B.; Boas, David A.; Bacskai, Brian J.; Kumar, Anand T. N.

    2010-07-01

    Near-infrared (NIR) fluorescence tomography of multiple fluorophores has previously been limited by the bandwidth of the NIR spectral regime and the broad emission spectra of most NIR fluorophores. We describe in vivo tomography of three spectrally overlapping fluorophores using fluorescence lifetime-based separation. Time-domain images are acquired using a voltage-gated, intensified charge-coupled device (CCD) in free-space transmission geometry with 750 nm Ti:sapphire laser excitation. Lifetime components are fit from the asymptotic portion of fluorescence decay curve and reconstructed separately with a lifetime-adjusted forward model. We use this system to test the in vivo lifetime multiplexing suitability of commercially available fluorophores, and demonstrate lifetime multiplexing in solution mixtures and in nude mice. All of the fluorophores tested exhibit nearly monoexponential decays, with narrow in vivo lifetime distributions suitable for lifetime multiplexing. Quantitative separation of two fluorophores with lifetimes of 1.1 and 1.37 ns is demonstrated for relative concentrations of 1:5. Finally, we demonstrate tomographic imaging of two and three fluorophores in nude mice with fluorophores that localize to distinct organ systems. This technique should be widely applicable to imaging multiple NIR fluorophores in 3-D.

  15. Tomographic PIV: particles versus blobs

    NASA Astrophysics Data System (ADS)

    Champagnat, Frédéric; Cornic, Philippe; Cheminet, Adam; Leclaire, Benjamin; Le Besnerais, Guy; Plyer, Aurélien

    2014-08-01

    We present an alternative approach to tomographic particle image velocimetry (tomo-PIV) that seeks to recover nearly single voxel particles rather than blobs of extended size. The baseline of our approach is a particle-based representation of image data. An appropriate discretization of this representation yields an original linear forward model with a weight matrix built with specific samples of the system’s point spread function (PSF). Such an approach requires only a few voxels to explain the image appearance, therefore it favors much more sparsely reconstructed volumes than classic tomo-PIV. The proposed forward model is general and flexible and can be embedded in a classical multiplicative algebraic reconstruction technique (MART) or a simultaneous multiplicative algebraic reconstruction technique (SMART) inversion procedure. We show, using synthetic PIV images and by way of a large exploration of the generating conditions and a variety of performance metrics, that the model leads to better results than the classical tomo-PIV approach, in particular in the case of seeding densities greater than 0.06 particles per pixel and of PSFs characterized by a standard deviation larger than 0.8 pixels.

  16. A PC-controlled microwave tomographic scanner for breast imaging

    NASA Astrophysics Data System (ADS)

    Padhi, Shantanu; Howard, John; Fhager, A.; Bengtsson, Sebastian

    2011-01-01

    This article presents the design and development of a personal computer based controller for a microwave tomographic system for breast cancer detection. The system uses motorized, dual-polarized antennas and a custom-made GUI interface to control stepper motors, a wideband vector network analyzer (VNA) and to coordinate data acquisition and archival in a local MDSPlus database. Both copolar and cross-polar scattered field components can be measured directly. Experimental results are presented to validate the various functionalities of the scanner.

  17. A fast multi-resolution approach to tomographic PIV

    NASA Astrophysics Data System (ADS)

    Discetti, Stefano; Astarita, Tommaso

    2012-03-01

    Tomographic particle image velocimetry (Tomo-PIV) is a recently developed three-component, three-dimensional anemometric non-intrusive measurement technique, based on an optical tomographic reconstruction applied to simultaneously recorded images of the distribution of light intensity scattered by seeding particles immersed into the flow. Nowadays, the reconstruction process is carried out mainly by iterative algebraic reconstruction techniques, well suited to handle the problem of limited number of views, but computationally intensive and memory demanding. The adoption of the multiplicative algebraic reconstruction technique (MART) has become more and more accepted. In the present work, a novel multi-resolution approach is proposed, relying on the adoption of a coarser grid in the first step of the reconstruction to obtain a fast estimation of a reliable and accurate first guess. A performance assessment, carried out on three-dimensional computer-generated distributions of particles, shows a substantial acceleration of the reconstruction process for all the tested seeding densities with respect to the standard method based on 5 MART iterations; a relevant reduction in the memory storage is also achieved. Furthermore, a slight accuracy improvement is noticed. A modified version, improved by a multiplicative line of sight estimation of the first guess on the compressed configuration, is also tested, exhibiting a further remarkable decrease in both memory storage and computational effort, mostly at the lowest tested seeding densities, while retaining the same performances in terms of accuracy.

  18. 64 Slice multi-detector row cardiac CT.

    PubMed

    Pannu, Harpreet K; Johnson, Pamela T; Fishman, Elliot K

    2009-01-01

    Cardiac imaging is feasible with multi-detector row (MDCT) scanners. Coronary arterial anatomy and both non-calcified and calcified plaques are depicted at CT coronary angiography. Vessel wall pathology and luminal diameter are depicted, and secondary myocardial changes may also be seen. Diagnostic capacity has increased with technological advancement, and preliminary investigations confirm the utility of 64-MDCT in low- and intermediate-risk patients who present to the emergency department with acute chest pain. The clinical indications, 64-MDCT technique, and MDCT findings in coronary artery disease are reviewed. PMID:18941811

  19. Multidetector CT of pulmonary cavitation: filling in the holes.

    PubMed

    Mortensen, K H; Babar, J L; Balan, A

    2015-04-01

    Pulmonary cavitation causes significant morbidity and mortality. Early diagnosis of the presence and aetiology of a cavity is therefore crucial in order to avoid further demise in both the localized pulmonary and systemic disorders that may manifest with pulmonary cavity formation. Multidetector CT has become the principal diagnostic technique for detecting pulmonary cavitation and its complications. This review provides an overview of the aetiologies and their imaging findings using this technique. Combining a literature review with case illustration, a synopsis of the different imaging features and constellations is provided, which may suggest a particular cause and aid the differentiation from diseases with similar findings. PMID:25623513

  20. Tomographic methods in flow diagnostics

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.

    1993-01-01

    This report presents a viewpoint of tomography that should be well adapted to currently available optical measurement technology as well as the needs of computational and experimental fluid dynamists. The goals in mind are to record data with the fastest optical array sensors; process the data with the fastest parallel processing technology available for small computers; and generate results for both experimental and theoretical data. An in-depth example treats interferometric data as it might be recorded in an aeronautics test facility, but the results are applicable whenever fluid properties are to be measured or applied from projections of those properties. The paper discusses both computed and neural net calibration tomography. The report also contains an overview of key definitions and computational methods, key references, computational problems such as ill-posedness, artifacts, missing data, and some possible and current research topics.

  1. Steering in spin tomographic probability representation

    NASA Astrophysics Data System (ADS)

    Man'ko, V. I.; Markovich, L. A.

    2016-09-01

    The steering property known for two-qubit state in terms of specific inequalities for the correlation function is translated for the state of qudit with the spin j = 3 / 2. Since most steering detection inequalities are based on the correlation functions we introduce analogs of such functions for the single qudit systems. The tomographic probability representation for the qudit states is applied. The connection between the correlation function in the two-qubit system and the single qudit is presented in an integral form with an intertwining kernel calculated explicitly in tomographic probability terms.

  2. 21 CFR 892.1740 - Tomographic x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tomographic x-ray system. 892.1740 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1740 Tomographic x-ray system. (a) Identification. A tomographic x-ray system is an x-ray device intended to be used to produce radiologic images...

  3. A tomographic technique for aerodynamics at transonic speeds

    NASA Technical Reports Server (NTRS)

    Lee, G.

    1985-01-01

    Computer aided tomography (CAT) provides a means of noninvasively measuring the air density distribution around an aerodynamic model. This technique is global in that a large portion of the flow field can be measured. A test of the applicability of CAT to transonic velocities was studied. A hemispherical-nose cylinder afterbody model was tested at a Mach number of 0.8 with a new laser holographic interferometer at the 2- by 2-Foot Transonic Wind Tunnel. Holograms of the flow field were taken and were reconstructed into interferograms. The fringe distribution (a measure of the local densities) was digitized for subsequent data reduction. A computer program based on the Fourier-transform technique was developed to convert the fringe distribution into three-dimensional densities around the model. Theoretical aerodynamic densities were calculated for evaluating and assessing the accuracy of the data obtained from the tomographic method.

  4. Tomographic Gamma Scanner Experience: Three Cases

    SciTech Connect

    Mercer, David J.

    2014-06-30

    This is a summary of field applications of tomographic gamma scanning (TGS). Three cases are shown: enriched uranium scanning at Rocky Flats, heat-source plutonium at LANL, and plutonium-bearing pyrochemical salts at Rocky Flats. Materials are taken from the references shown below.

  5. A TOMOGRAPHIC TECHNIQUE FOR MAGNETIZED BEAM MATCHING.

    SciTech Connect

    MONTAG,C.ET AL.

    2004-07-05

    To maintain low electron beam temperatures in the proposed RHIC electron cooler, careful matching of the magnetized beam from the source to the cooler solenoid is mandatory. We propose a tomographic technique to diagnose matching conditions. First simulation results will be presented.

  6. Tomographic Image Compression Using Multidimensional Transforms.

    ERIC Educational Resources Information Center

    Villasenor, John D.

    1994-01-01

    Describes a method for compressing tomographic images obtained using Positron Emission Tomography (PET) and Magnetic Resonance (MR) by applying transform compression using all available dimensions. This takes maximum advantage of redundancy of the data, allowing significant increases in compression efficiency and performance. (13 references) (KRN)

  7. Computed tomography of the sacrum: 1. normal anatomy

    SciTech Connect

    Whelan, M.A.; Gold, R.P.

    1982-12-01

    The sacrum of a disarticulated pelvis was scanned with a Pfizer 0450 computed tomographic scanner using contiguous 5 mm sections to display the normal computed tomographic anatomy of the sacrum. These anatomic sections were then compared with normal sacrums. In analyzing the computed tomographic anatomy, emphasis was placed on the central canal and sacral foramina, in that these landmarks are important in determining not only the presence but also the type of pathology involving the sacrum.

  8. Cam-type deformities: Concepts, criteria, and multidetector CT features.

    PubMed

    Mellado, J M; Radi, N

    2015-01-01

    Interpreting imaging studies of a painful hip requires detailed knowledge of the regional anatomy. Some variants of the proximal femur, such as cam-type deformities, can course asymptomatically or cause femoroacetabular impingement. The principal numerical criterion for defining cam-type deformities, the alpha angle, has some limitations. In this article, we review the anatomic variants of the anterior aspect of the proximal femur, focusing on cam-type deformities. Using diagrams and multidetector CT images, we describe the parameters that are useful for characterizing these deformities in different imaging techniques. We also discuss the potential correspondence of imaging findings of cam-type deformities with the terms coined by anatomists and anthropologists to describe these phenomena. PMID:25660594

  9. Toroid cavity/coil NMR multi-detector

    DOEpatents

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  10. Cardiac Conduction System: Delineation of Anatomic Landmarks With Multidetector CT

    PubMed Central

    Saremi, Farhood; Torrone, Maria; Yashar, Nooshin

    2009-01-01

    Major components of the cardiac conduction system including the sinoatrial node (SAN), atrioventricular node (AVN), the His Bundle, and the right and left bundle branches are too small to be directly visualized by multidetector CT (MDCT) given the limited spatial resolution of current scanners. However, the related anatomic landmarks and variants of this system a well as the areas with special interest to electrophysiologists can be reliably demonstrated by MDCT. Some of these structures and landmarks include the right SAN artery, right atrial cavotricuspid isthmus, Koch triangle, AVN artery, interatrial muscle bundles, and pulmonary veins. In addition, MDCT has an imperative role in demarcating potential arrhythmogenic structures. The aim of this review will be to assess the extent at which MDCT can outline the described anatomic landmarks and therefore provide crucial information used in clinical practice. PMID:19898655

  11. Performance of analytical methods for tomographic gamma scanning

    SciTech Connect

    Prettyman, T.H.; Mercer, D.J.

    1997-06-01

    The use of gamma-ray computerized tomography for nondestructive assay of radioactive materials has led to the development of specialized analytical methods. Over the past few years, Los Alamos has developed and implemented a computer code, called ARC-TGS, for the analysis of data obtained by tomographic gamma scanning (TGS). ARC-TGS reduces TGS transmission and emission tomographic data, providing the user with images of the sample contents, the activity or mass of selected radionuclides, and an estimate of the uncertainty in the measured quantities. The results provided by ARC-TGS can be corrected for self-attenuation when the isotope of interest emits more than one gamma-ray. In addition, ARC-TGS provides information needed to estimate TGS quantification limits and to estimate the scan time needed to screen for small amounts of radioactivity. In this report, an overview of the analytical methods used by ARC-TGS is presented along with an assessment of the performance of these methods for TGS.

  12. Initial results from the Donner 600 crystal positron tomograph

    SciTech Connect

    Derenzo, S.E.; Huesman, R.H.; Cahoon, J.L.; Geyer, A.; Uber, D.; Vuletich, T.; Budinger, T.F.

    1986-10-01

    We describe a positron tomograph using a single ring of 600 close-packed 3 mm wide bismuth germanate (BGO) crystals coupled to 14 mm phototubes. The phototube preamplifier circuit derives a timing pulse from the first photoelectron, and sends it to address and coincidence circuits only if the integrated pulse height is within a pre-set window. The timing delays and pulse height windows for all 600 detectors and the coincidence timing windows are computer adjustable. An orbiting positron source is used for transmission measurements and a look-up table is used to reject scattered and random coincidences that do not pass through the source. Data can be acquired using a stationary mode for 1.57 mm lateral sampling or the two-position clam sampling mode for 0.79 mm lateral sampling. High maximum data rates are provided by 45 parallel coincidence circuits and 4 parallel histogram memory units. With two-position sampling and 1.57 mm bins, the reconstructed point spread function (PSF) of a 0.35 mm diam /sup 22/Na wire source at the center of the tomograph is circular with 2.9 mm full-width at half-maximum (fwhm) and the PSF at a distance of 8 cm from the center is elliptical with a radial fwhm of 4.0 mm and tangential fwhm of 3.0 mm. 12 refs., 6 figs., 3 tabs.

  13. Homogenized Tomographic Models: a Tool for Efficient Numerical Modeling of Seismic Wave Propagation

    NASA Astrophysics Data System (ADS)

    Landes, M.; Capdeville, Y.; Shapiro, N.; Guilbert, J.

    2013-12-01

    Full seismic waveforms are frequently used to characterize details of seismic sources and to discriminate their origin. Prediction of realistic waveforms requires developing algorithms for fast and reliable simulation of seismic wave propagation in 3D models of Earth. Classical 3D seismic tomographic models often use a layered parameterization. However, computing exact wave propagation in layered models may result in mesh complexity and long computing time. These difficulties become crucial when considering regional scales with operational interests. The aim of our study is to develop a parameterization of seismic tomographic models adapted for efficient numerical modeling of the wave propagation within a given frequency range. We use a 'homogenization' approach to construct models smoothed at scale naturally imposed by their propagation characteristics at target frequencies. We start with defining a basis of continuous and smooth functions with a Principal Component Analysis based on the statistic of the homogenized CUB2 tomographic model. Then, we invert surface phase and the group velocities deduced from global tomographic maps with a Monte Carlo method to generate smooth depth profiles with a controlled number of unknowns at all grid points. The set of these profiles form a smooth 3D seismic velocity model designed for numerical wave propagation.

  14. Influence of z overscanning on normalized effective doses calculated for pediatric patients undergoing multidetector CT examinations

    SciTech Connect

    Tzedakis, Antonis; Damilakis, John; Perisinakis, Kostas; Karantanas, Apostolos; Karabekios, Spiros; Gourtsoyiannis, Nicholas

    2007-04-15

    The purpose of this study was to evaluate the effect of z overscanning on normalized effective dose for pediatric patients undergoing multidetector-computed tomography (CT) examinations. Five commercially available mathematical anthropomorphic phantoms representing newborn, 1-, 5-, 10-, and 15-year-old patients and the Monte Carlo N-Particle (MCNP, version 4C2) radiation transport code were employed in the current study to simulate pediatric CT exposures. For all phantoms, axial and helical examinations at 120 kV tube voltage were simulated. Scans performed at 80 kV were also simulated. Sex-specific normalized effective doses were estimated for four standard CT examinations i.e., head-neck, chest, abdomen-pelvis, and trunk, for all pediatric phantoms. Data for both axial and helical mode acquisition were obtained. In the helical mode, z overscanning was taken into account. The validity of the Monte Carlo results was verified by comparison with dose data obtained using thermoluminescence dosimetry and a physical pediatric anthropomorphic phantom simulating a 10-year-old child. In all cases normalized effective dose values were found to increase with increasing z overscanning. The percentage differences in normalized data between axial and helical scans may reach 43%, 70%, 36%, and 26% for head-neck, chest, abdomen-pelvis, and trunk studies, respectively. Normalized data for female pediatric patients was in general higher compared to male patients for all ages, examined regions, and z overscanning values. For both male and female children, the normalized effective dose values were reduced as the age was increased. For the same typical exposure conditions, dose values decreased when lower tube voltage was used; for a 1-year-old child, for example, the effective dose was 3.8 times lower when 80 kV instead of 120 kV was used. Normalized data for the estimation of effective dose to pediatric patients undergoing standard axial and helical CT examinations on an

  15. Influence of z overscanning on normalized effective doses calculated for pediatric patients undergoing multidetector CT examinations.

    PubMed

    Tzedakis, Antonis; Damilakis, John; Perisinakis, Kostas; Karantanas, Apostolos; Karabekios, Spiros; Gourtsoyiannis, Nicholas

    2007-04-01

    The purpose of this study was to evaluate the effect of z overscanning on normalized effective dose for pediatric patients undergoing multidetector-computed tomography (CT) examinations. Five commercially available mathematical anthropomorphic phantoms representing newborn, 1-, 5-, 10-, and 15-year-old patients and the Monte Carlo N-Particle (MCNP, version 4C2) radiation transport code were employed in the current study to simulate pediatric CT exposures. For all phantoms, axial and helical examinations at 120 kV tube voltage were simulated. Scans performed at 80 kV were also simulated. Sex-specific normalized effective doses were estimated for four standard CT examinations i.e., head-neck, chest, abdomen-pelvis, and trunk, for all pediatric phantoms. Data for both axial and helical mode acquisition were obtained. In the helical mode, z overscanning was taken into account. The validity of the Monte Carlo results was verified by comparison with dose data obtained using thermoluminescence dosimetry and a physical pediatric anthropomorphic phantom simulating a 10-year-old child. In all cases normalized effective dose values were found to increase with increasing z overscanning. The percentage differences in normalized data between axial and helical scans may reach 43%, 70%, 36%, and 26% for head-neck, chest, abdomen-pelvis, and trunk studies, respectively. Normalized data for female pediatric patients was in general higher compared to male patients for all ages, examined regions, and z overscanning values. For both male and female children, the normalized effective dose values were reduced as the age was increased. For the same typical exposure conditions, dose values decreased when lower tube voltage was used; for a 1-year-old child, for example, the effective dose was 3.8 times lower when 80 kV instead of 120 kV was used. Normalized data for the estimation of effective dose to pediatric patients undergoing standard axial and helical CT examinations on an

  16. Contrast enhanced multi-detector CT and MR findings of a well-differentiated pancreatic vipoma

    PubMed Central

    Camera, Luigi; Severino, Rosa; Faggiano, Antongiulio; Masone, Stefania; Mansueto, Gelsomina; Maurea, Simone; Fonti, Rosa; Salvatore, Marco

    2014-01-01

    Pancreatic vipoma is an extremely rare tumor accounting for less than 2% of endocrine pancreatic neoplasms with a reported incidence of 0.1-0.6 per million. While cross-sectional imaging findings are usually not specific, exact localization of the tumor by means of either computed tomography (CT) or magnetic resonance (MR) is pivotal for surgical planning. However, cross-sectional imaging findings are usually not specific and further characterization of the tumor may only be achieved by somatostatin-receptor scintigraphy (SRS). We report the case of a 70 years old female with a two years history of watery diarrhoea who was found to have a solid, inhomogeneously enhancing lesion at the level of the pancreatic tail at Gadolinium-enhanced MR (Somatom Trio 3T, Siemens, Germany). The tumor had been prospectively overlooked at a contrast-enhanced multi-detector CT (Aquilion 64, Toshiba, Japan) performed after i.v. bolus injection of only 100 cc of iodinated non ionic contrast media because of a chronic renal failure (3.4 mg/mL) but it was subsequently confirmed by SRS. The patient first underwent a successful symptomatic treatment with somatostatin analogues and was then submitted to a distal pancreasectomy with splenectomy to remove a capsulated whitish tumor which turned out to be a well-differentiated vipoma at histological and immuno-histochemical analysis. PMID:25349667

  17. Detection, visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT.

    PubMed

    van Ooijen, Peter M A; Dorgelo, Joost; Zijlstra, Felix; Oudkerk, Matthijs

    2004-12-01

    Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT. PMID:15452665

  18. Multi-detector CT features of acute intestinal ischemia and their prognostic correlations

    PubMed Central

    Moschetta, Marco; Telegrafo, Michele; Rella, Leonarda; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe

    2014-01-01

    Acute intestinal ischemia is an abdominal emergency occurring in nearly 1% of patients presenting with acute abdomen. The causes can be occlusive or non occlusive. Early diagnosis is important to improve survival rates. In most cases of late or missed diagnosis, the mortality rate from intestinal infarction is very high, with a reported value ranging from 60% to 90%. Multi-detector computed tomography (MDCT) is a fundamental imaging technique that must be promptly performed in all patients with suspected bowel ischemia. Thanks to the new dedicated reconstruction program, its diagnostic potential is much improved compared to the past and currently it is superior to that of any other noninvasive technique. The increased spatial and temporal resolution, high-quality multi-planar reconstructions, maximum intensity projections, vessel probe, surface-shaded volume rending and tissue transition projections make MDCT the gold standard for the diagnosis of intestinal ischemia, with reported sensitivity, specificity, positive and negative predictive values of 64%-93%, 92%-100%, 90%-100% and 94%-98%, respectively. MDCT contributes to appropriate treatment planning and provides important prognostic information thanks to its ability to define the nature and extent of the disease. The purpose of this review is to examine the diagnostic and prognostic role of MDCT in bowel ischemia with special regard to the state of art new reconstruction software. PMID:24876917

  19. Bayesian tomographic reconstruction of microsystems

    NASA Astrophysics Data System (ADS)

    Salem, Sofia Fekih; Vabre, Alexandre; Mohammad-Djafari, Ali

    2007-11-01

    The microtomography by X ray transmission plays an increasingly dominating role in the study and the understanding of microsystems. Within this framework, an experimental setup of high resolution X ray microtomography was developed at CEA-List to quantify the physical parameters related to the fluids flow in microsystems. Several difficulties rise from the nature of experimental data collected on this setup: enhanced error measurements due to various physical phenomena occurring during the image formation (diffusion, beam hardening), and specificities of the setup (limited angle, partial view of the object, weak contrast). To reconstruct the object we must solve an inverse problem. This inverse problem is known to be ill-posed. It therefore needs to be regularized by introducing prior information. The main prior information we account for is that the object is composed of a finite known number of different materials distributed in compact regions. This a priori information is introduced via a Gauss-Markov field for the contrast distributions with a hidden Potts-Markov field for the class materials in the Bayesian estimation framework. The computations are done by using an appropriate Markov Chain Monte Carlo (MCMC) technique. In this paper, we present first the basic steps of the proposed algorithms. Then we focus on one of the main steps in any iterative reconstruction method which is the computation of forward and adjoint operators (projection and backprojection). A fast implementation of these two operators is crucial for the real application of the method. We give some details on the fast computation of these steps and show some preliminary results of simulations.

  20. Tomographic Errors From Wavefront Healing

    NASA Astrophysics Data System (ADS)

    Malcolm, A. E.; Trampert, J.

    2008-12-01

    Despite recent advances in full-waveform modeling ray theory is still, for good reasons, the preferred method in global tomography. It is well known that ray theory is most accurate for anomalies that are large compared to the wavelength. Exactly what errors result from the failure of this assumption is less well understood, in spite of the fact that anomalies found in the Earth from ray-based tomography methods are often outside the regime in which ray theory is known to be valid. Using the spectral element method, we have computed exact delay times and compared them to ray-theoretical traveltimes for two classic anomalies, one large and disk-shaped near the core mantle boundary, and the other a plume-like structure extending throughout the mantle. Wavefront healing is apparent in the traveltime anomalies generated by these structures; its effects are strongly asymmetric between P and S arrivals due to wavelength differences and source directionality. Simple computations in two dimensions allow us to develop the intuition necessary to understand how diffractions around the anomalies explain these results. When inverting the exact travel time anomalies with ray theory we expect wavefront healing to have a strong influence on the resulting structures. We anticipate that the asymmetry will be of particular importance in anomalies in the bulk velocity structure.

  1. Video-rate tomographic phase microscopy

    PubMed Central

    Fang-Yen, Christopher; Choi, Wonshik; Sung, Yongjin; Holbrow, Charles J.; Dasari, Ramachandra R.; Feld, Michael S.

    2011-01-01

    Tomographic phase microscopy measures the 3-D refractive index distribution of cells and tissues by combining the information from a series of angle-dependent interferometric phase images. In the original device, the frame rate was limited to 0.1 frames per second (fps) by the technique used to acquire phase images, preventing measurements of moving or rapidly changing samples. We describe an improved tomographic phase microscope in which phase images are acquired via a spatial fringe pattern demodulation method, enabling a full tomogram acquisition rate of 30 fps. In addition, in this system the refractive index is calculated by a diffraction tomography algorithm that accounts for the effects of diffraction in the 3-D reconstruction. We use the instrument to quantitatively monitor rapid changes in refractive index within defined subregions of cells due to exposure to acetic acid or changes in medium osmolarity. PMID:21280892

  2. Tomographic techniques for the study of exceptionally preserved fossils

    PubMed Central

    Sutton, Mark D

    2008-01-01

    Three-dimensional fossils, especially those preserving soft-part anatomy, are a rich source of palaeontological information; they can, however, be difficult to work with. Imaging of serial planes through an object (tomography) allows study of both the inside and outside of three-dimensional fossils. Tomography may be performed using physical grinding or sawing coupled with photography, through optical techniques of serial focusing, or using a variety of scanning technologies such as neutron tomography, magnetic resonance imaging and most usefully X-ray computed tomography. This latter technique is applicable at a variety of scales, and when combined with a synchrotron X-ray source can produce very high-quality data that may be augmented by phase-contrast information to enhance contrast. Tomographic data can be visualized in several ways, the most effective of which is the production of isosurface-based ‘virtual fossils’ that can be manipulated and dissected interactively. PMID:18426749

  3. The electronics for the Donner 600-Crystal Positron Tomograph

    SciTech Connect

    Cahoon, J.L.; Huesman, R.H.; Derenzo, S.E.; Geyer, A.B.; Uber, D.C.; Turko, B.T.; Budinger, T.F.

    1986-02-01

    The data acquisition system, designed for the Donner 600-Crystal Positron Tomograph, is described. Coincidence timing resolution of less than five nanoseconds full width at half maximum and data rates in excess of one million events per second are achieved by using high-speed emitter coupled logic circuits, first-in first-out memory to derandomize data flow, and parallel architecture to increase throughput. These data rates allow the acquisition of adequate transmission data in a reasonable amount of time. Good timing resolution minimizes accidental coincidences and permits data rates greater than 100,000 image-forming events per second for high-speed dynamic emission tomography. Additional scatter and accidental rejection are accomplished for transmission data by using an orbiting source and a look-up table for valid events. Calibration of this complex electronic system is performed automatically under computer control.

  4. Electronics for the Donner 600-Crystal Positron Tomograph

    SciTech Connect

    Cahoon, J.L.; Huesman, R.H.; Derenzo, S.E.; Geyer, A.B.; Uber, D.C.; Turko, B.T.; Budinger, T.F.

    1985-10-01

    The data acquisition system, designed for the Donner 600-Crystal Positron Tomograph, is described. Coincidence timing resolution of less than five nanoseconds full width at half maximum and data rates in excess of one million events per second are achieved by using high-speed emitter coupled logic circuits, first-in first-out memory to derandomize data flow, and parallel architecture to increase throughput. These data rates allow the acquisition of adequate transmission data in a reasonable amount of time. Good timing resolution minimizes accidental coincidences and permits data rates greater than 100,000 image-forming events per second for high-speed dynamic emission tomography. Additional scatter and accidental rejection are accomplished for transmission data by using an orbiting source and a look-up table for valid events. Calibration of this complex electronic system is performed automatically under computer control. 4 refs., 5 figs.

  5. PRINCIPLES OF TOMOGRAPHICAL IMAGING WITH LIMITED-ANGLE INPUT

    SciTech Connect

    Tam, K. C.; Perez-Mendez, V.

    1980-09-01

    The theory of tomographical imaging with limited-angular input is discussed , from which two reconstruction algorithms are derived. The existence of missing information due to incomplete angular coverage is demonstrated. and an iteration algorithm to recover this information from a priori knowledge on the finite extent of the object developed. Smoothing algorithms to stabilize reconstructions in the presence of noise are given. The effects of digitization and finite truncation of the reconstruction region in numerical computation are also analysed. It is shown that the limited-angle problem is governed by a set of eigenvalues whose spectrum is determined by the imaging angle and the finite extent of the object. The distortion on a point source caused by the missing information is calculated; from the results some properties of the iteration scheme, such as spatial uniformity, are derived.

  6. On the tomographic picture of quantum mechanics

    NASA Astrophysics Data System (ADS)

    Ibort, A.; Man'ko, V. I.; Marmo, G.; Simoni, A.; Ventriglia, F.

    2010-06-01

    We formulate necessary and sufficient conditions for a symplectic tomogram of a quantum state to determine the density state. We establish a connection between the (re)construction by means of symplectic tomograms with the construction by means of Naimark positive definite functions on the Weyl-Heisenberg group. This connection is used to formulate properties which guarantee that tomographic probabilities describe quantum states in the probability representation of quantum mechanics.

  7. Addition of Tomographic Capabilities to NMIS

    SciTech Connect

    Mullens, J.A.

    2003-03-11

    This paper describes tomographic capabilities for the Nuclear Materials Identification System (NMIS). The tomographic capabilities add weapons component spatial and material properties information that result in a more detailed item signature (template) and provide more information for physical attributes analyses. The Nuclear Materials Identification System (NMIS) is used routinely to confirm the identity of HEU components in sealed containers. It does this through a radiation signature acquired by shining a {sup 252}Cf source through the container and measuring the radiation at four detectors stacked vertically on the other side. This measurement gives a gamma and neutron radiation transmission profile of the weapons component, mixed with the radiation production due to the induced fissions in the fissile materials. This information is sufficient to match an ''unknown'' weapons component signature to a template signature from a reference item when measuring under controlled conditions. Tomography measures the interior of an item by making transmission measurements from all angles around the item, whereas NMIS makes the measurements from a single angle. Figure 1 is a standard example of tomographic reconstruction, the Shepp-Logan human brain phantom. The measured quantity is attenuation so high values (white) are highly attenuating areas.

  8. Tomographic imaging using poissonian detector data

    DOEpatents

    Aspelmeier, Timo; Ebel, Gernot; Hoeschen, Christoph

    2013-10-15

    An image reconstruction method for reconstructing a tomographic image (f.sub.j) of a region of investigation within an object (1), comprises the steps of providing detector data (y.sub.i) comprising Poisson random values measured at an i-th of a plurality of different positions, e.g. i=(k,l) with pixel index k on a detector device and angular index l referring to both the angular position (.alpha..sub.l) and the rotation radius (r.sub.l) of the detector device (10) relative to the object (1), providing a predetermined system matrix A.sub.ij assigning a j-th voxel of the object (1) to the i-th detector data (y.sub.i), and reconstructing the tomographic image (f.sub.j) based on the detector data (y.sub.i), said reconstructing step including a procedure of minimizing a functional F(f) depending on the detector data (y.sub.i) and the system matrix A.sub.ij and additionally including a sparse or compressive representation of the object (1) in an orthobasis T, wherein the tomographic image (f.sub.j) represents the global minimum of the functional F(f). Furthermore, an imaging method and an imaging device using the image reconstruction method are described.

  9. Tomographic /sup 67/Ga citrate scanning: useful new surveillance for metastatic melanoma

    SciTech Connect

    Kirkwood, J.M.; Myers, J.E.; Vlock, D.R.; Neumann, R.; Ariyan, S.; Gottschalk, A.; Hoffer, P.

    1982-11-01

    Conventional gallium scans are not useful to evaluate patients with metastatic melanoma. We evaluated a new method of tomographic gallium imaging. One hundred fourteen tomographic scans were obtained in a prospective surveillance study of 67 patients over a 3-year period. Scans were evaluated and compared to findings of independent clinical evaluations. Sensitivity of gallium identification of tumor involving peripheral lymph nodes and soft tissues, abdomen, mediastinum, and osseous sites was 68% to 100%; overall sensitivity of this technique is 82% with specificity of 99% in 570 organ system assessments. Analysis of discordant findings when a site was clinically occult but gallium-positive showed gallium uptake to be true-positive in six of seven lymphatic sites, three of three lung and mediastinal sites, six of six abdominal sites, but in no brain or bone sites. Gallium lesions identified by computed tomographic scans proved to be false-positive at one lymphatic and one bone site, and false-negative at four otherwise clinically evident lymph node and soft tissue sites, seven pulmonary sites, and four brain sites. Gallium tomographic scanning provides a composite assessment of melanoma and may eliminate the need for other studies.

  10. 21 CFR 892.1740 - Tomographic x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1740 Tomographic x-ray system. (a) Identification. A tomographic x-ray system is an...

  11. Projection approach to complexity reduction in tomographic alignment of extremely large telescopes.

    PubMed

    Piatrou, Piotr; Chanan, Gary

    2012-02-20

    We describe a complexity reduction approach intended to solve the tomographic alignment problem for the Thirty Meter Telescope by means of its alignment and phasing system (APS) with little loss of information. This approach is computationally efficient enough to perform detailed Monte-Carlo simulations of the APS on a standard PC. We present sample simulations to model error propagation through the system and to build a preliminary APS alignment error budget. PMID:22358159

  12. RTOG Sarcoma Radiation Oncologists Reach Consensus on Gross Tumor Volume and Clinical Target Volume on Computed Tomographic Images for Preoperative Radiotherapy of Primary Soft Tissue Sarcoma of Extremity in Radiation Therapy Oncology Group Studies

    SciTech Connect

    Wang Dian; Bosch, Walter; Roberge, David; Finkelstein, Steven E.; Petersen, Ivy; Haddock, Michael; Chen, Yen-Lin E.; Saito, Naoyuki G.; Kirsch, David G.; Hitchcock, Ying J.; Wolfson, Aaron H.; DeLaney, Thomas F.

    2011-11-15

    Objective: To develop a Radiation Therapy Oncology Group (RTOG) atlas delineating gross tumor volume (GTV) and clinical target volume (CTV) to be used for preoperative radiotherapy of primary extremity soft tissue sarcoma (STS). Methods and Materials: A consensus meeting was held during the RTOG meeting in January 2010 to reach agreement about GTV and CTV delineation on computed tomography (CT) images for preoperative radiotherapy of high-grade large extremity STS. Data were presented to address the local extension of STS. Extensive discussion ensued to develop optimal criteria for GTV and CTV delineation on CT images. Results: A consensus was reached on appropriate CT-based GTV and CTV. The GTV is gross tumor defined by T1 contrast-enhanced magnetic resonance images. Fusion of magnetic resonance and images is recommended to delineate the GTV. The CTV for high-grade large STS typically includes the GTV plus 3-cm margins in the longitudinal directions. If this causes the field to extend beyond the compartment, the field can be shortened to include the end of a compartment. The radial margin from the lesion should be 1.5 cm, including any portion of the tumor not confined by an intact fascial barrier, bone, or skin surface. Conclusion: The consensus on GTV and CTV for preoperative radiotherapy of high-grade large extremity STS is available as web-based images and in a descriptive format through the RTOG. This is expected to improve target volume consistency and allow for rigorous evaluation of the benefits and risks of such treatment.

  13. Computed tomographic imaging of subchondral fatigue cracks in the distal end of the third metacarpal bone in the thoroughbred racehorse can predict crack micromotion in an ex-vivo model.

    PubMed

    Dubois, Marie-Soleil; Morello, Samantha; Rayment, Kelsey; Markel, Mark D; Vanderby, Ray; Kalscheur, Vicki L; Hao, Zhengling; McCabe, Ronald P; Marquis, Patricia; Muir, Peter

    2014-01-01

    Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic injury were studied. Limbs were radiographed and examined using CT. Parasagittal subchondral fatigue crack dimensions were measured on CT images using image analysis software. MC3 bones with fatigue cracks were tested using five cycles of compressive loading at -7,500N (38 condyles, 18 horses). Crack motion was recorded using an extensometer. Mechanical testing was validated using bones with 3 mm and 5 mm deep parasagittal subchondral slots that modeled naturally occurring fatigue cracks. After testing, subchondral crack density was determined histologically. Creation of parasagittal subchondral slots induced significant micromotion during loading (p<0.001). In our biomechanical model, we found a significant positive correlation between extensometer micromotion and parasagittal crack area derived from reconstructed CT images (SR = 0.32, p<0.05). Correlations with transverse and frontal plane crack lengths were not significant. Histologic fatigue damage was not significantly correlated with crack dimensions determined by CT or extensometer micromotion. Bones with parasagittal crack area measurements above 30 mm2 may have a high risk of crack propagation and condylar fracture in vivo because of crack micromotion. In conclusion, our results suggest that CT could be used to quantify subchondral fatigue crack dimensions in racing Thoroughbred horses in-vivo to assess risk of

  14. Computed Tomographic Imaging of Subchondral Fatigue Cracks in the Distal End of the Third Metacarpal Bone in the Thoroughbred Racehorse Can Predict Crack Micromotion in an Ex-Vivo Model

    PubMed Central

    Dubois, Marie-Soleil; Morello, Samantha; Rayment, Kelsey; Markel, Mark D.; Vanderby, Ray; Kalscheur, Vicki L.; Hao, Zhengling; McCabe, Ronald P.; Marquis, Patricia; Muir, Peter

    2014-01-01

    Articular stress fracture arising from the distal end of the third metacarpal bone (MC3) is a common serious injury in Thoroughbred racehorses. Currently, there is no method for predicting fracture risk clinically. We describe an ex-vivo biomechanical model in which we measured subchondral crack micromotion under compressive loading that modeled high speed running. Using this model, we determined the relationship between subchondral crack dimensions measured using computed tomography (CT) and crack micromotion. Thoracic limbs from 40 Thoroughbred racehorses that had sustained a catastrophic injury were studied. Limbs were radiographed and examined using CT. Parasagittal subchondral fatigue crack dimensions were measured on CT images using image analysis software. MC3 bones with fatigue cracks were tested using five cycles of compressive loading at -7,500N (38 condyles, 18 horses). Crack motion was recorded using an extensometer. Mechanical testing was validated using bones with 3 mm and 5 mm deep parasagittal subchondral slots that modeled naturally occurring fatigue cracks. After testing, subchondral crack density was determined histologically. Creation of parasagittal subchondral slots induced significant micromotion during loading (p<0.001). In our biomechanical model, we found a significant positive correlation between extensometer micromotion and parasagittal crack area derived from reconstructed CT images (SR = 0.32, p<0.05). Correlations with transverse and frontal plane crack lengths were not significant. Histologic fatigue damage was not significantly correlated with crack dimensions determined by CT or extensometer micromotion. Bones with parasagittal crack area measurements above 30 mm2 may have a high risk of crack propagation and condylar fracture in vivo because of crack micromotion. In conclusion, our results suggest that CT could be used to quantify subchondral fatigue crack dimensions in racing Thoroughbred horses in-vivo to assess risk of

  15. FM&TI (Forward Modeling & Tomographic Inversion) approach in passive and active seismic studies

    NASA Astrophysics Data System (ADS)

    Koulakov, Ivan

    2010-05-01

    Seismic tomography is like a photography taken by a camera with deformed and blurred lenses. Amplitudes and shapes of seismic patterns derived at tomographic images are often strongly biased with respect to real structures in the Earth. In particular, tomography usually provides continuous velocity distributions, while the major velocity changes in the Earth often occur on first order interfaces. While working with noisy data, one has to apply strong damping which makes impossible retrieving realistic amplitudes of anomalies. Uneven ray sampling may cause variable damping effect: within one model, one may obtain over- and underdamped solutions in different parts of the study area. Lack of some ray orientations may cause smearing of seismic patterns. Due to these and other reasons, quantitative values reported in most tomographic studies, although supported by pseudo-formal criteria (e.g. trade-off curves), do not often represent the reality. We propose an approach which is used to construct a realistic structure of the Earth based on a combination of forward modeling and tomographic inversion. Based on available a-priori information we construct a synthetic model with realistic patterns. Then we compute synthetic times and invert them using the same tomographic code with the same parameters as in the case of observed data processing. The reconstruction result is compared with the tomographic image of observed data inversion. For the parts where discrepancy is observed, we correct the synthetic model and repeat the forward modeling and inversion again. After several trials we obtain similar results of synthetic and observed data inversion. In this case we claim that the derived synthetic model adequately represents the real structure of the Earth. In the talk, several examples of applying this approach at various scales for different data schemes are presented: (1) few real and synthetic examples of active source refraction travel time data; (2) local earthquake

  16. Tomographic PIV measurements of flow patterns in a nasal cavity with geometry acquisition

    NASA Astrophysics Data System (ADS)

    Im, Sunghyuk; Heo, Go Eun; Jeon, Young Jin; Sung, Hyung Jin; Kim, Sung Kyun

    2014-01-01

    The flow patterns inside a scaled transparent model of a nasal cavity were measured by tomographic particle image velocimetry (PIV) with three-dimensional (3D) geometry acquisition. The model was constructed using transparent silicone. The refractive index of the working fluid was matched to the index of silicone by mixing water and glycerol. Four cameras and a double-pulse laser system were used for tomographic PIV. Red fluorescent particles and long-pass filters were used to obtain a high signal-to-noise ratio. The complex geometry of the 3D nasal model was acquired by accumulating triangulated 3D particle positions, obtained through a least square-based triangulation method. Certain morphological operations, such as the opening and closing of the nasal cavity, were used to improve the quality of acquired nasal geometry data. The geometry information was used to distinguish the fluid from the solid regions during the tomographic reconstruction procedure. The quality of the model geometry acquisition and tomographic reconstruction algorithms was evaluated using a synthetic image test. Synthetic images were generated by fitting a computational model (stereolithography file) to the virtual 3D coordinates and by randomly seeding particles inside the nasal region. A perspective transformation matrix of each camera was used to generate the synthetic images based on the experimental configuration of the camera. The synthetic image test showed that the voxel reconstruction quality could be improved by applying acquired model geometry in the tomographic reconstruction step. The nasal geometry was acquired and a flow velocity field was determined by cross-correlating the reconstructed 3D voxel intensities.

  17. Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

    PubMed

    Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

    2016-04-01

    Purpose To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Materials and Methods Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Results Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was

  18. Three-dimensional mapping of soil chemical characteristics at micrometric scale: Statistical prediction by combining 2D SEM-EDX data and 3D X-ray computed micro-tomographic images

    NASA Astrophysics Data System (ADS)

    Hapca, Simona

    2015-04-01

    Many soil properties and functions emerge from interactions of physical, chemical and biological processes at microscopic scales, which can be understood only by integrating techniques that traditionally are developed within separate disciplines. While recent advances in imaging techniques, such as X-ray computed tomography (X-ray CT), offer the possibility to reconstruct the 3D physical structure at fine resolutions, for the distribution of chemicals in soil, existing methods, based on scanning electron microscope (SEM) and energy dispersive X-ray detection (EDX), allow for characterization of the chemical composition only on 2D surfaces. At present, direct 3D measurement techniques are still lacking, sequential sectioning of soils, followed by 2D mapping of chemical elements and interpolation to 3D, being an alternative which is explored in this study. Specifically, we develop an integrated experimental and theoretical framework which combines 3D X-ray CT imaging technique with 2D SEM-EDX and use spatial statistics methods to map the chemical composition of soil in 3D. The procedure involves three stages 1) scanning a resin impregnated soil cube by X-ray CT, followed by precision cutting to produce parallel thin slices, the surfaces of which are scanned by SEM-EDX, 2) alignment of the 2D chemical maps within the internal 3D structure of the soil cube, and 3) development, of spatial statistics methods to predict the chemical composition of 3D soil based on the observed 2D chemical and 3D physical data. Specifically, three statistical models consisting of a regression tree, a regression tree kriging and cokriging model were used to predict the 3D spatial distribution of carbon, silicon, iron and oxygen in soil, these chemical elements showing a good spatial agreement between the X-ray grayscale intensities and the corresponding 2D SEM-EDX data. Due to the spatial correlation between the physical and chemical data, the regression-tree model showed a great potential

  19. Semigroups of tomographic probabilities and quantum correlations

    NASA Astrophysics Data System (ADS)

    Man'ko, V. I.

    2008-08-01

    Semigroups of stochastic and bistochastic matrices constructed by means of spin tomograms or tomographic probabilities and their relations to the problem of Bell's inequalities and entanglement are reviewed. The probability determining the quantum state of spins and the probability densities determining the quantum states of particles with continuous variables are considered. Entropies for semigroups of stochastic and bisctochastic matrices are studied, in view of both the Shannon information entropy and its generalization like Rényi entropy. Qubit portraits of qudit states are discussed in the connection with the problem of Bell's inequality violation for entangled states.

  20. Medical imaging with a microwave tomographic scanner.

    PubMed

    Jofre, L; Hawley, M S; Broquetas, A; de los Reyes, E; Ferrando, M; Elias-Fusté, A R

    1990-03-01

    A microwave tomographic scanner for biomedical applications is presented. The scanner consists of a 64 element circular array with a useful diameter of 20 cm. Electronically scanning the transmitting and receiving antennas allows multiview measurements with no mechanical movement. Imaging parameters are appropriate for medical use: a spatial resolution of 7 mm and a contrast resolution of 1% for a measurement time of 3 s. Measurements on tissue-simulating phantoms and volunteers, together with numerical simulations, are presented to assess the system for absolute imaging of tissue distribution and for differential imaging of physiological, pathological, and induced changes in tissues. PMID:2329003

  1. Medical tomograph system using ultrasonic transmission

    NASA Technical Reports Server (NTRS)

    Heyser, Richard C. (Inventor); Nathan, Robert (Inventor)

    1978-01-01

    Ultrasonic energy transmission in rectilinear array scanning patterns of soft tissue provides projection density values of the tissue which are recorded as a function of scanning position and angular relationship, .theta., of the subject with a fixed coordinate system. A plurality of rectilinear scan arrays in the same plane for different angular relationships .theta..sub.1 . . . .theta..sub.n thus recorded are superimposed. The superimposition of intensity values thus yields a tomographic image of an internal section of the tissue in the scanning plane.

  2. Model-based Tomographic Reconstruction Literature Search

    SciTech Connect

    Chambers, D H; Lehman, S K

    2005-11-30

    In the process of preparing a proposal for internal research funding, a literature search was conducted on the subject of model-based tomographic reconstruction (MBTR). The purpose of the search was to ensure that the proposed research would not replicate any previous work. We found that the overwhelming majority of work on MBTR which used parameterized models of the object was theoretical in nature. Only three researchers had applied the technique to actual data. In this note, we summarize the findings of the literature search.

  3. Tomographic PIV Study of Hairpin Vortices

    NASA Astrophysics Data System (ADS)

    Sabatino, Daniel; Rossmann, Tobias

    2014-11-01

    Tomographic PIV is used in a free surface water channel to quantify the flow behavior of hairpin vortices that are artificially generated in a laminar boundary layer. Direct injection from a 32:1 aspect ratio slot at low blowing ratios (0 . 1 < BR < 0 . 2) is used to generate an isolated hairpin vortex in a thick laminar boundary layer (485 < Reδ* < 600). Due to the large dynamic range of length and velocity scales (the resulting vortices have advection velocities 5X greater than their tangential velocities), a tailored optical arrangement and specialized post processing techniques are required to fully capture the small-scale behavior and long-time development of the flow field. Hairpin generation and evolution are presented using the λ2 criterion derived from the instantaneous, three-dimensional velocity field. The insight provided by the tomographic data is also compared to the conclusions drawn from 2D PIV and passive scalar visualizations. Finally, the three-dimensional behavior of the measured velocity field is correlated with that of a simultaneously imaged, passive scalar dye that marks the boundary of the injected fluid, allowing the examination of the entrainment behavior of the hairpin. Supported by the National Science Foundation under Grant CBET-1040236.

  4. Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT

    SciTech Connect

    Flohr, T. G.; Stierstorfer, K.; Suess, C.; Schmidt, B.; Primak, A. N.; McCollough, C. H.

    2007-05-15

    We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the z-axis direction for a routine medical multi-detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the z-axis direction in combination with tantalum grids that are inserted in front of the multi-row detector to reduce the aperture of the detector elements both in-plane and in the z-axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of 0.4 mm (measured full width at half maximum=0.45 mm) can be reconstructed in spiral mode on a CT system with a detector configuration of 32x0.6 mm. The measured 2% value of the in-plane modulation transfer function (MTF) is 20.4 lp/cm, the measured 2% value of the longitudinal (z axis) MTF is 21.5 lp/cm. In a resolution phantom with metal line pair test patterns, spatial resolution of 20 lp/cm can be demonstrated both in the scan plane and along the z axis. This corresponds to an object size of 0.25 mm that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade-off for the clinical benefit brought about by the improved spatial resolution.

  5. Multi-detector row CT scanning in Paleoanthropology at various tube current settings and scanning mode.

    PubMed

    Badawi-Fayad, J; Yazbeck, C; Balzeau, A; Nguyen, T H; Istoc, A; Grimaud-Hervé, D; Cabanis, E- A

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required. PMID:16211320

  6. New absorbed dose measurement with cylindrical water phantoms for multidetector CT.

    PubMed

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hioki, Kazunari; Tomiyama, Yuuki; Yamashita, Yusuke

    2015-06-01

    The aim of this study was to develop new dosimetry with cylindrical water phantoms for multidetector computed tomography (MDCT). The ionization measurement was performed with a Farmer ionization chamber at the center and four peripheral points in the body-type and head-type cylindrical water phantoms. The ionization was converted to the absorbed dose using a (60)Co absorbed-dose-to-water calibration factor and Monte Carlo (MC) -calculated correction factors. The correction factors were calculated from MDCT (Brilliance iCT, 64-slice, Philips Electronics) modeled with GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. The spectrum of incident x-ray beams and the configuration of a bowtie filter for MDCT were determined so that calculated photon intensity attenuation curves for aluminum (Al) and calculated off-center ratio (OCR) profiles in air coincided with those measured. The MC-calculated doses were calibrated by the absorbed dose measured at the center in both cylindrical water phantoms. Calculated doses were compared with measured doses at four peripheral points and the center in the phantom for various beam pitches and beam collimations. The calibration factors and the uncertainty of the absorbed dose determined using this method were also compared with those obtained by CTDIair (CT dose index in air). Calculated Al half-value layers and OCRs in air were within 0.3% and 3% agreement with the measured values, respectively. Calculated doses at four peripheral points and the centers for various beam pitches and beam collimations were within 5% and 2% agreement with measured values, respectively. The MC-calibration factors by our method were 44-50% lower than values by CTDIair due to the overbeaming effect. However, the calibration factors for CTDIair agreed within 5% with those of our method after correction for the overbeaming effect. Our method makes it possible to directly measure the absorbed dose for MDCT and is more robust and accurate than the

  7. New absorbed dose measurement with cylindrical water phantoms for multidetector CT

    NASA Astrophysics Data System (ADS)

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hioki, Kazunari; Tomiyama, Yuuki; Yamashita, Yusuke

    2015-06-01

    The aim of this study was to develop new dosimetry with cylindrical water phantoms for multidetector computed tomography (MDCT). The ionization measurement was performed with a Farmer ionization chamber at the center and four peripheral points in the body-type and head-type cylindrical water phantoms. The ionization was converted to the absorbed dose using a 60Co absorbed-dose-to-water calibration factor and Monte Carlo (MC) -calculated correction factors. The correction factors were calculated from MDCT (Brilliance iCT, 64-slice, Philips Electronics) modeled with GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. The spectrum of incident x-ray beams and the configuration of a bowtie filter for MDCT were determined so that calculated photon intensity attenuation curves for aluminum (Al) and calculated off-center ratio (OCR) profiles in air coincided with those measured. The MC-calculated doses were calibrated by the absorbed dose measured at the center in both cylindrical water phantoms. Calculated doses were compared with measured doses at four peripheral points and the center in the phantom for various beam pitches and beam collimations. The calibration factors and the uncertainty of the absorbed dose determined using this method were also compared with those obtained by CTDIair (CT dose index in air). Calculated Al half-value layers and OCRs in air were within 0.3% and 3% agreement with the measured values, respectively. Calculated doses at four peripheral points and the centers for various beam pitches and beam collimations were within 5% and 2% agreement with measured values, respectively. The MC-calibration factors by our method were 44-50% lower than values by CTDIair due to the overbeaming effect. However, the calibration factors for CTDIair agreed within 5% with those of our method after correction for the overbeaming effect. Our method makes it possible to directly measure the absorbed dose for MDCT and is more robust and accurate than the

  8. Regional brain glucose metabolism in chronic schizophrenia. A positron emission transaxial tomographic study

    SciTech Connect

    Farkas, T.; Wolf, A.P.; Jaeger, J.; Brodie, J.D.; Christman, D.R.; Fowler, J.S.

    1984-03-01

    Thirteen diagnosed schizophrenics and 11 normal controls were studied with a method using the PETT III positron emission tomograph (PET) and fluorodeoxyglucose labeled with fluorine 18. Each subject also had a computed tomographic (CT) scan. For each subject, two brain levels, one through the basal ganglia and one through the semioval center, were analyzed for the mean regional metabolic glucose rate. Specifically, relationships between frontal and posterior regions were evaluated. The CT scans of matching levels were superimposed on the functional PET images to provide anatomic criteria for region of interest selection. While no whole-slice metabolic differences were apparent between groups, schizophrenics had significantly lower activity in the frontal lobes, relative to posterior regions. The medicated and drug-free groups did not differ from one another in these regards. Trait v state dependency of the phenomenon was analyzed, and several technological limitations were considered.

  9. Tomographic capabilities of the new GEM based SXR diagnostic of WEST

    NASA Astrophysics Data System (ADS)

    Jardin, A.; Mazon, D.; O'Mullane, M.; Mlynar, J.; Loffelmann, V.; Imrisek, M.; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.; Bourdelle, C.; Malard, P.

    2016-07-01

    The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, influence of noise as well as computational time.

  10. Evaluation of the channelized Hotelling observer for signal detection in 2D tomographic imaging

    NASA Astrophysics Data System (ADS)

    LaRoque, Samuel J.; Sidky, Emil Y.; Edwards, Darrin C.; Pan, Xiaochuan

    2007-03-01

    Signal detection by the channelized Hotelling (ch-Hotelling) observer is studied for tomographic application by employing a small, tractable 2D model of a computed tomography (CT) system. The primary goal of this manuscript is to develop a practical method for evaluating the ch-Hotelling observer that can generalize to larger 3D cone-beam CT systems. The use of the ch-Hotelling observer for evaluating tomographic image reconstruction algorithms is also demonstrated. For a realistic model for CT, the ch-Hotelling observer can be a good approximation to the ideal observer. The ch-Hotelling observer is applied to both the projection data and the reconstructed images. The difference in signal-to-noise ratio for signal detection in both of these domains provides a metric for evaluating the image reconstruction algorithm.

  11. Computed tomographic evaluation of mouth breathers among paediatric patients

    PubMed Central

    Farid, MM; Metwalli, N

    2010-01-01

    Objectives Mouth breathing causes many serious problems in the paediatric population. It has been maintained that enlarged adenoids are principally responsible for mouth breathing. This study was designed to evaluate whether other mechanical obstacles might predispose the child to mouth breathing. Methods 67 children with ages ranging from 10 to 15 years were studied and grouped into mouth-breathers and nose-breathers. The children first underwent axial CT scans of the brain for which they were originally referred. In addition, they were subjected to a limited coronal CT examination of the paranasal sinuses. Congenital anatomical variations as well as inflammatory changes were assessed. Results 87% of mouth-breathing children had hypertrophied adenoids, 77% had maxillary sinusitis, 74% had pneumatized middle concha, 55% had a deviated nasal septum, 55% had hypertrophied inferior conchae, 45% had ethmoidal sinusitis and 23% showed frontal sinusitis. Such changes were significantly less prevalent in nose-breathers. 12.9% of mouth-breathing children did not have adenoids. Of these children, only 3.3% had one or more congenital or inflammatory change whereas the other 9.6% showed a completely normal CT scan signifying the incidence of habitual non-obstructive mouth breathing. Conclusions It is clear that adenoids have a dominant role in causing mouth breathing. Yet, we recommend that paediatricians should assess other mechanical obstacles if mouth breathing was not corrected after adenoidectomy. Further research should be performed to test the validity of correction of such factors in improving the quality of life of mouth-breathing children. PMID:20089737

  12. Childhood Psychosis and Computed Tomographic Brain Scan Findings.

    ERIC Educational Resources Information Center

    Gillberg, Christopher; Svendsen, Pal

    1983-01-01

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

  13. [Intracerebral tuberculoma. Clinical and x-ray computed tomographic characteristics].

    PubMed

    Ruelle, A; Boccardo, M; Lasio, G

    1984-01-01

    Intracranial tuberculomas have become uncommon in industrial nations, while they still have a high incidence in underdeveloped countries. Four cases of intracerebral supratentorial tuberculomas are reported in this paper. Clinical findings suggestive of tuberculosis were present in only one case. The other cases were thought to be gliomas or metastases and the diagnosis was made only after surgery. The CT scan provided a good image of the lesions whose characteristics, however, were diagnostically confusing. When a tuberculoma is suspected, medical therapy alone should be administered initially. Surgery should be resorted to in cases of markedly increased intracranial pressure. PMID:6571449

  14. Computed tomographic characteristics of odontogenic neoplasms in dogs.

    PubMed

    Amory, Joseph T; Reetz, Jennifer A; Sánchez, Melissa D; Bradley, Charles W; Lewis, John R; Reiter, Alexander M; Mai, Wilfried

    2014-01-01

    Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board-certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty-three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass-associated tooth displacement in 85.2% (23/27). Mass-associated cyst-like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra-osseous (10/15) or intra-osseous (5/15) masses. Intra-osseous canine acanthomatous ameloblastomas were more likely to have mass-associated cyst-like structures and were subjectively more aggressive when compared with extra-osseous canine acanthomatous ameloblastomas. Amyloid-producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst-like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra-osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass-associated tooth destruction was appreciated more often with dental radiographs and extra-oral tumor extension was identified more often with CT. PMID:24102949

  15. Spontaneous intracranial haemorrhage: computed tomographic patterns in Accra.

    PubMed

    Obajimi, M O; Nyame, P K; Jumah, K B; Wiredu, E K

    2002-01-01

    The diagnosis of stroke and the ability to distinguish the subtypes is central in the management of patients. This CT study has confirmed an increased prevalence of stroke (CVA) among Ghanaians. It has also reaffirmed a relatively higher incidence (52.9%) of spontaneous intracranial haemorrhage over cerebral infarcts among the 1,172 stroke patients studied. The study points to a male preponderance and a mean age of 55.7 years. Parenchymal haemorrhage was found to be the commonest variety of these haemorrhages. It occurred in 83.6% of cases while primary subarachnoid haemorrhage was reported in only 8.1% of cases. Ventricular extension of the parenchymal haemorrhage was reported in 22.7% of cases. The latter were mostly unilateral and on the left side especially in the parietal lobe (70.9%), subdural haemorrhage like the parenchymal variety was also reported to be more on the left, mainly unilateral and acute. Haemorrhages in the cerebellum and pons which are normally difficult to diagnose were also outlined with ease in the CT images. Other CT findings in these patients include parilesional oedema and mass effect found in 87.10% and 77.4% respectively. PMID:12081348

  16. The tuning algorithms used by the Donner 600 Crystal Tomograph

    SciTech Connect

    Moses, W.W.; Derenzo, S.E.; Geyer, A.B.; Huesman, R.H.; Uber, D.C.

    1988-11-01

    We describe the computer algorithms used to adjust the energy thresholds and timing delays in the Donner 600 Crystal Tomograph. These thresholds and delays are adjusted using 1890 computer controlled digital to analog converters (DAC's) and a orbiting positron source. The energy threshold for each crystal is adjusted by measuring the counting rate of each crystal-crystal coincidence as a function of the DAC settings that control a pulse height window for the crystal in question. The DAC settings that correspond to the 511 keV photopeak are noted, thus determining the conversion from DAC setting to energy, and allowing the DAC's to be set to any desired energy window. The DAC settings controlling the timing delay for each channel are systematically adjusted to maximize the overall event rate. As these 1890 adjustments are coupled, we discuss the convergence of the tuning algorithms, and also report on the photomultiplier tube gain and timing variations over a period of 18 months. 7 refs., 6 figs.

  17. The tuning algorithms used by the Donner 600 crystal tomograph

    SciTech Connect

    Moses, W.W.; Derenzo, S.E.; Geyer, A.B.; Huesman, R.H.; Uber, D.C.

    1989-02-01

    The authors describe the computer algorithms used to adjust the energy thresholds and timing delays in the Donner 600 Crystal Tomograph. These thresholds and delays are adjusted using 1890 computer controlled digital to analog converters (DAC's) and a orbiting positron source. The energy threshold for each crystal is adjusted by measuring the counting rate of each crystal-crystal coincidence as a function of the DAC settings that control a pulse height window for the crystal in question. The DAC settings that correspond to the 511 keV photopeak are noted, thus determining the conversion from DAC setting to energy, and allowing the DAC's to be set to any desired energy window. The DAC settings controlling the timing delay for each channel are systematically adjusted to maximize the overall event rate. As these 1890 adjustments are coupled, the authors discuss the convergence of the tuning algorithms, and also report on the photomultiplier tube gain and timing variations over a period of 18 months.

  18. Tomographic bioluminescence imaging by an iteratively re-weighted minimization

    NASA Astrophysics Data System (ADS)

    Wu, Ping; Liu, Kai; Xue, Zhenwen; Guo, Wei; Qin, Chenghu; Tian, Jie

    2012-03-01

    Tomographic bioluminescence imaging (TBI), with visible light emission in living organisms, is an effective way of molecular imaging, which allows for the study of ongoing tumor biological processes in vivo and non-invasively. This newly developed technology enables three-dimensional accuracy localization and quantitative analysis of the target tumor cells in small animal via reconstructing the images acquired by the high-resolution imaging system. Due to the difficulty of reconstruction, which is often referred to an ill-posed inverse problem, continuous efforts are still made to find more practical and efficient approaches. In this paper, an iteratively re-weighted minimization (IRM) has been applied to reconstruct the entire source distribution, which is known as sparse signals, inside the target tissue with the limited outgoing photon density on its boundary. By introducing a weight function into the objective function, we convert the lp norm problem into a more simple form of l2 norm to reduce the computational complexity. The weight function is updated in each iterative step to compute the final optimal solution more efficiently. This method is proved to be robust to different parameters, and mouse experiments are conducted to validate the feasibility of IRM approach, which is also reliable at whole-body imaging.

  19. Pancreatic pseudoaneurysm in a child with hereditary pancreatitis: diagnosis with multidetector CT angiography.

    PubMed

    Ahmed, Hossam K; Hagspiel, Klaus D; McGahren, Eugene D; Angle, John F; Leung, Daniel A; Spinosa, David J; Matsumoto, Alan H; Rodgers, Bradley M

    2004-08-01

    Pseudoaneurysm formation is a serious vascular complication of pancreatitis. It most commonly affects splenic and gastroduodenal arteries. We report a rare case of superior mesenteric artery pseudoaneurysm in a child with hereditary pancreatitis. Multidetector CT angiography allowed the comprehensive assessment of the aneurysm and allowed accurate surgical planning obviating the need for catheter angiography. PMID:15107963

  20. Study of statistical properties of hybrid statistic in coherent multidetector