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Sample records for computed tomography perfusion

  1. Brain perfusion: computed tomography applications

    International Nuclear Information System (INIS)

    Miles, K.A.

    2004-01-01

    Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

  2. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  3. Myocardial perfusion with multi-detector computed tomography: quantitative evaluation

    International Nuclear Information System (INIS)

    Carrascosa, Patricia M.; Vallejos, J.; Capunay, Carlos M.; Deviggiano, A.; Carrascosa, Jorge M.

    2007-01-01

    The objective of this work is to evaluate the skill of multidetector computer tomography, to quantify the different patterns of intensification during the evaluation of the myocardial perfusion. 45 patients were studied with suspicion of cardiovascular disease. Multi-detector computed tomography was utilized on patients at rest and in effort with pharmacological stress, after the administration of dipyridamole. Also they were evaluated using nuclear medicine [es

  4. Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography

    DEFF Research Database (Denmark)

    Rochitte, Carlos E; George, Richard T; Chen, Marcus Y

    2014-01-01

    AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed...... emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA...... tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon...

  5. Hyperperfusion on Perfusion Computed Tomography Following Revascularization for Acute Stroke

    International Nuclear Information System (INIS)

    Nguyen, T.B.; Lum, C.; Eastwood, J.D.; Stys, P.K.; Hogan, M.; Goyal, M.

    2005-01-01

    Purpose: To describe the findings of hyperperfusion on perfusion computed tomography (CT) in four patients following revascularization for acute stroke. Material and Methods: In 2002-2003, among a series of 6 patients presenting with an acute stroke and treated with intra-arterial thrombolysis, we observed the presence of hyperperfusion in 3 patients on the follow-up CT perfusion. We included an additional patient who was treated with intravenous thrombolysis and who had hyperperfusion on the follow-up CT perfusion. We retrospectively analyzed their CT perfusion maps. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were compared between the affected territory and the normal contralateral hemisphere. Results: In the four patients, the mean CBV and CBF were 3.6±2.0 ml/100 g and 39±25 ml/100 g/min in the affected territory compared to the normal side (mean CBV 2.7±2.1 ml/100 g, mean CBF = 27±23 ml/100 g/min). There was no intracranial hemorrhage in the hyperperfused territories. At follow-up CT, some hyperperfused brain areas progressed to infarction, while others retained normal white to gray matter differentiation. Conclusion: CT perfusion can demonstrate hyperperfusion, which can be seen in an ischemic brain territory following recanalization

  6. Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Kühl, Jørgen Tobias; Kjaer, Andreas

    2017-01-01

    INTRODUCTION: Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion usi...

  7. Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

    Science.gov (United States)

    Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy. © The Author(s) 2014.

  8. Computed tomography perfusion imaging denoising using Gaussian process regression

    International Nuclear Information System (INIS)

    Zhu Fan; Gonzalez, David Rodriguez; Atkinson, Malcolm; Carpenter, Trevor; Wardlaw, Joanna

    2012-01-01

    Brain perfusion weighted images acquired using dynamic contrast studies have an important clinical role in acute stroke diagnosis and treatment decisions. However, computed tomography (CT) images suffer from low contrast-to-noise ratios (CNR) as a consequence of the limitation of the exposure to radiation of the patient. As a consequence, the developments of methods for improving the CNR are valuable. The majority of existing approaches for denoising CT images are optimized for 3D (spatial) information, including spatial decimation (spatially weighted mean filters) and techniques based on wavelet and curvelet transforms. However, perfusion imaging data is 4D as it also contains temporal information. Our approach using Gaussian process regression (GPR), which takes advantage of the temporal information, to reduce the noise level. Over the entire image, GPR gains a 99% CNR improvement over the raw images and also improves the quality of haemodynamic maps allowing a better identification of edges and detailed information. At the level of individual voxel, GPR provides a stable baseline, helps us to identify key parameters from tissue time-concentration curves and reduces the oscillations in the curve. GPR is superior to the comparable techniques used in this study. (note)

  9. Possibilities of differentiation of solitary focal liver lesions by computed tomography perfusion

    Directory of Open Access Journals (Sweden)

    Irmina Sefić Pašić

    2015-08-01

    Full Text Available Aim To evaluate possibilities of computed tomography (CT perfusion in differentiation of solitary focal liver lesions based on their characteristic vascularization through perfusion parameters analysis. Methods Prospective study was conducted on 50 patients in the period 2009-2012. Patients were divided in two groups: benign and malignant lesions. The following CT perfusion parameters were analyzed: blood flow (BF, blood volume (BV, mean transit time (MTT, capillary permeability surface area product (PS, hepatic arterial fraction (HAF, and impulse residual function (IRF. During the study another perfusion parameter was analyzed: hepatic perfusion index (HPI. All patients were examined on Multidetector 64-slice CT machine (GE with application of perfusion protocol for liver with i.v. administration of contrast agent. Results In both groups an increase of vascularization and arterial blood flow was noticed, but there was no significant statistical difference between any of 6 analyzed parameters. Hepatic perfusion index values were increased in all lesions in comparison with normal liver parenchyma. Conclusion Computed tomography perfusion in our study did not allow differentiation of benign and malignant liver lesions based on analysis of functional perfusion parameters. Hepatic perfusion index should be investigated in further studies as a parameter for detection of possible presence of micro-metastases in visually homogeneous liver in cases with no lesions found during standard CT protocol

  10. Hepatic blood perfusion estimated by dynamic contrast-enhanced computed tomography in pigs

    DEFF Research Database (Denmark)

    Winterdahl, Michael; Sørensen, Michael; Keiding, Inger Susanne

    2012-01-01

    The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates.......The aim of this study was to determine whether dynamic contrast-enhanced computed tomography (DCE-CT) and the slope method can provide absolute measures of hepatic blood perfusion from the hepatic artery (HA) and portal vein (PV) at experimentally varied blood flow rates....

  11. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yeung, Timothy P C [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Yartsev, Slav [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Lee, Ting-Yim [Robarts Research Institute, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Imaging, The University of Western Ontario, London Health Sciences Centre, Victoria Hospital, Ontario, Canada, N6A 5W9 (Australia); Lawson Health Research Institute, St. Joseph' s Health Care London, Ontario, Canada, N6A 4V2 (Canada); Wong, Eugene [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Physics and Astronomy, The University of Western Ontario, Ontario, Canada, N6A 3K7 (Canada); He, Wenqing [Department of Statistical and Actuarial Sciences, The University of Western Ontario, Ontario, Canada, N6A 5B7 (Canada); Fisher, Barbara; VanderSpek, Lauren L [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Macdonald, David [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada); Department of Clinical Neurological Sciences, The University of Western Ontario, London Health Sciences Centre, University Hospital, Ontario, Canada, N6A 5A5 (Canada); Bauman, Glenn, E-mail: glenn.bauman@lhsc.on.ca [London Regional Cancer Program, London Health Sciences Centre, Ontario, Canada, N6A 4L6 (Canada); Department of Medical Biophysics, The University of Western Ontario, Ontario, Canada, N6A 5C1 (Canada); Department of Oncology, The University of Western Ontario, London Health Sciences Centre, London Regional Cancer Program, Ontario, Canada, N6A 4L6 (Canada)

    2014-02-15

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity.

  12. Relationship of computed tomography perfusion and positron emission tomography to tumour progression in malignant glioma

    International Nuclear Information System (INIS)

    Yeung, Timothy P C; Yartsev, Slav; Lee, Ting-Yim; Wong, Eugene; He, Wenqing; Fisher, Barbara; VanderSpek, Lauren L; Macdonald, David; Bauman, Glenn

    2014-01-01

    Introduction: This study aimed to explore the potential for computed tomography (CT) perfusion and 18-Fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting sites of future progressive tumour on a voxel-by-voxel basis after radiotherapy and chemotherapy. Methods: Ten patients underwent pre-radiotherapy magnetic resonance (MR), FDG-PET and CT perfusion near the end of radiotherapy and repeated post-radiotherapy follow-up MR scans. The relationships between these images and tumour progression were assessed using logistic regression. Cross-validation with receiver operating characteristic (ROC) analysis was used to assess the value of these images in predicting sites of tumour progression. Results: Pre-radiotherapy MR-defined gross tumour; near-end-of-radiotherapy CT-defined enhancing lesion; CT perfusion blood flow (BF), blood volume (BV) and permeability-surface area (PS) product; FDG-PET standard uptake value (SUV); and SUV:BF showed significant associations with tumour progression on follow-up MR imaging (P < 0.0001). The mean sensitivity (±standard deviation), specificity and area under the ROC curve (AUC) of PS were 0.64 ± 0.15, 0.74 ± 0.07 and 0.72 ± 0.12 respectively. This mean AUC was higher than that of the pre-radiotherapy MR-defined gross tumour and near-end-of-radiotherapy CT-defined enhancing lesion (both AUCs = 0.6 ± 0.1, P ≤ 0.03). The multivariate model using BF, BV, PS and SUV had a mean AUC of 0.8 ± 0.1, but this was not significantly higher than the PS only model. Conclusion: PS is the single best predictor of tumour progression when compared to other parameters, but voxel-based prediction based on logistic regression had modest sensitivity and specificity

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

    OpenAIRE

    Cabeda, Est?van Vieira; Falc?o, Andr?a Maria Gomes; Soares Jr., Jos?; Rochitte, Carlos Eduardo; Nomura, C?sar Higa; ?vila, Luiz Francisco Rodrigues; Parga, Jos? Rodrigues

    2015-01-01

    Abstract Background: Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB). Objective: To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and comp...

  14. Computed Tomography Perfusion Imaging for the Diagnosis of Hepatic Alveolar Echinococcosis

    Science.gov (United States)

    Sade, Recep; Kantarci, Mecit; Genc, Berhan; Ogul, Hayri; Gundogdu, Betul; Yilmaz, Omer

    2018-01-01

    Objective: Alveolar echinococcosis (AE) is a rare life-threatening parasitic infection. Computed tomography perfusion (CTP) imaging has the potential to provide both quantitative and qualitative information about the tissue perfusion characteristics. The purpose of this study was the examination of the characteristic features and feasibility of CTP in AE liver lesions. Material and Methods: CTP scanning was performed in 25 patients who had a total of 35 lesions identified as AE of the liver. Blood flow (BF), blood volume (BV), portal venous perfusion (PVP), arterial liver perfusion (ALP), and hepatic perfusion indexes (HPI) were computed for background liver parenchyma and each AE lesion. Results: Significant differences were detected between perfusion values of the AE lesions and background liver tissue. The BV, BF, ALP, and PVP values for all components of the AE liver lesions were significantly lower than the normal liver parenchyma (p<0.01). Conclusions: We suggest that perfusion imaging can be used in AE of the liver. Thus, the quantitative knowledge of perfusion parameters are obtained via CT perfusion imaging. PMID:29531482

  15. Perfusion imaging with single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Holman, B.L.; Hill, T.C.

    1987-01-01

    SPECT with perfusion tracers is useful in a number of circumstances: (1) In acute cerebral infarction while the CT scan may be normal for several days after onset of symptoms, the uptake of SPECT perfusion tracers will be altered immediately after the onset of the stroke. Even when the CT scan has become abnormal, the physiologic abnormality may exceed the anatomic abnormality. One may, therefore be able to measure the extent of the reversibly ischemic tissue early enough to justify more agressive therapeutic interventions. (2) For endarterectomy and other surgical and medical therapies serial measurements of regional cerebral perfusion with SPECT may provide a readily available tool to assess their efficacy. (3) SPECT perfusion imaging may become the method of choice for the diagnosis and evaluation of Alzheimer's disease. (4) In patients with epilepsy, the extent and location of the abnormally perfused focus may be important to medical and surgical management. Follow-up examination may be useful in documenting the effectiveness of therapy

  16. Single photon emission computed tomography study of human pulmonary perfusion: preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Carratu, L; Sofia, M [Naples Univ. (Italy). Facolta di Medicina e Chirurgia; Salvatore, M; Muto, P; Ariemma, G [Istituto Nazionale per la Prevenzione, Lo Studio e La Cura dei Tumori Fondazione Pascale, Naples (Italy); Lopez-Majano, V [Cook County Hospital, Chicago, IL (USA). Nuclear Medicine Div.

    1984-02-01

    Single photon emission computed tomography (SPECT) was performed with /sup 99/Tcsup(m)-albumin macroaggregates to study human pulmonary perfusion in healthy subjects and patients with respiratory diseases such as chronic obstructive pulmonary disease (COPD) and lung neoplasms. The reconstructed SPECT data was displayed in coronal, transverse, sagittal plane sections and compared to conventional perfusion scans. The SPECT data gave more complicated anatomical information about the extent of damage and morphology of the pulmonary vascular bed. In healthy subjects and COPD patients, qualitative and quantitative assessment of pulmonary perfusion could be obtained from serial SPECT scans with respect to distribution and relative concentration of the injected radiopharmaceutical. Furthermore, SPECT of pulmonary perfusion has been useful in detecting the extent of damage to the pulmonary circulation. This is useful for the preoperative evaluation and staging of lung cancer.

  17. The Comparison of Computed Tomography Perfusion, Contrast-Enhanced Computed Tomography and Positron-Emission Tomography/Computed Tomography for the Detection of Primary Esophageal Carcinoma.

    Science.gov (United States)

    Genc, Berhan; Kantarci, Mecit; Sade, Recep; Orsal, Ebru; Ogul, Hayri; Okur, Aylin; Aydin, Yener; Karaca, Leyla; Eroğlu, Atilla

    2016-01-01

    The purpose of this study was to investigate the efficiency of computed tomography perfusion (CTP), contrast-enhanced computed tomography (CECT) and 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron-emission tomography (PET/CT) in the diagnosis of esophageal cancer. This prospective study consisted of 33 patients with pathologically confirmed esophageal cancer, 2 of whom had an esophageal abscess. All the patients underwent CTP, CECT and PET/CT imaging and the imaging findings were evaluated. Sensitivity, specificity and positive and negative predictive values were calculated for each of the 3 imaging modalities relative to the histological diagnosis. Thirty-three tumors were visualized on CTP, 29 on CECT and 27 on PET/CT. Six tumors were stage 1, and 2 and 4 of these tumors were missed on CECT and PET/CT, respectively. Significant differences between CTP and CECT (p = 0.02), and between CTP and PET/CT (p = 0.04) were found for stage 1 tumors. Values for the sensitivity, specificity and positive and negative predictive values on CTP were 100, 100, 100 and 100%, respectively. Corresponding values on CECT were 93.94, 0, 93.94 and 0%, respectively, and those on PET/CT were 87.88, 0, 93.55 and 0%, respectively. Hence, the sensitivity, specificity and positive and negative predictive values of CTP were better than those of CECT and PET/CT. CTP had an advantage over CECT and PET/CT in detecting small lesions. CTP was valuable, especially in detecting stage 1 tumors. © 2016 S. Karger AG, Basel.

  18. Computed Tomography Perfusion Usefulness in Early Imaging Diagnosis of Herpes Simplex Virus Encephalitis

    International Nuclear Information System (INIS)

    Marco de Lucas, E.; Mandly, Gonzalez A.; Gutierrez, A.; Sanchez, E.; Arnaiz, J.; Piedra, T.; Rodriguez, E.; Diez, C.

    2006-01-01

    An early diagnosis is crucial in herpes simplex virus encephalitis patients in order to institute acyclovir therapy and reduce mortality rates. Magnetic resonance imaging (MRI) is considered the gold standard for evaluation of these patients, but is frequently not available in the emergency setting. We report the first case of a computed tomography (CT) perfusion study that helped to establish a prompt diagnosis revealing abnormal increase of blood flow in the affected temporoparietal cortex at an early stage

  19. Transmural myocardial perfusion gradients in relation to coronary artery stenoses severity assessed by cardiac multidetector computed tomography

    DEFF Research Database (Denmark)

    Linde, Jesper James; Kühl, Jørgen Tobias; Hove, Jens Dahlgaard

    2015-01-01

    To assess the relationship between epicardial coronary artery stenosis severity and the corresponding regional transmural perfusion at rest and during adenosine stress, using multidetector computed tomography (MDCT). We evaluated the relationship between the severity of coronary artery diameter...

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

    DEFF Research Database (Denmark)

    Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Graumann, Ole

    2017-01-01

    The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention...... of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings...

  1. Perfusion Computed Tomography for the Assessment of Myocardial Viability — a Case Series

    Directory of Open Access Journals (Sweden)

    Morariu Mirabela

    2016-06-01

    Full Text Available Myocardial viability plays an important role in preventing the development of left ventricular remodeling following an acute myocardial infarction. A preserved viability in the infarcted area has been demonstrated to be associated with a lower amplitude of the remodeling process, while the extent of the non-viable myocardium is directly correlated with the amplitude of the remodeling process. A number of methods are currently in use for the quantification of the viable myocardium, and some of them are based on the estimation of myocardial perfusion during pharmacologic stress. 64-slice Multi-detector Computed Tomography (MDCT during vasodilator stress test, associated with CT Coronary Angiography (CCTA has a high diagnostic accuracy in evaluating myocardial perfusion. In this article, we present a sequence of 3 clinical cases that presented with symptoms of myocardial ischemia, who underwent 64-slice MDCT imaging at rest and during adenosine stress test, in order to assess the extent of the hypoperfused myocardial areas. Coronary artery anatomy and the Coronary Calcium Score was assessed for all 3 patients by performing CT Coronary Angiography. The combination of CT Angiography and adenosine stress CT myocardial perfusion imaging can accurately detect atherosclerosic lesions that cause perfusion abnormalities, compared with the combination of invasive angiography and single-photon emission computed tomography (SPECT.

  2. Hepatic computed tomography perfusion. Comparison of maximum slope and dual-input single-compartment methods

    International Nuclear Information System (INIS)

    Kanda, Tomonori; Yoshikawa, Takeshi; Ohno, Yoshiharu; Kanata, Naoki; Koyama, Hisanobu; Nogami, Munenobu; Takenaka, Daisuke; Sugimura, Kazuro

    2010-01-01

    The aim of the study was to compare two analytical methods-maximum slope (MS) and the dualinput single-compartment model (CM)-in computed tomography (CT) measurements of hepatic perfusion and to assess the effects of extrahepatic systemic factors. A total of 109 patients underwent hepatic CT perfusion. The scans were conducted at the hepatic hilum 7-77 s after administration of contrast material. Hepatic arterial perfusion (HAP) and portal perfusion (HPP) (ml/min/100 ml) and the arterial perfusion fraction (APF, %) were calculated with the two methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors, including age, sex, risk of cardiovascular disease, compensation for respiratory misregistration, arrival time of contrast material at the abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction. The mean HAPs, HPPs, and APFs were, respectively, 31.4, 104.2, and 23.9 for MS and 27.1, 141.3, and 22.1 for CM. HAP and APF showed significant (P<0.0001) and moderate correlation (γ=0.417 and 0.548) and HPP showed poor correlation (γ=0.172) between the two methods. While MS showed weak correlations (γ=-0.39 to 0.34; P<0.001 to <0.02) between multiple extrahepatic factors and perfusion values, CM showed weak correlation only between the patients' sex and HAP (γ=0.31, P=0.001). Hepatic perfusion values estimated by the two methods are not interchangeable. CM is less susceptible to extrahepatic systemic factors. (author)

  3. Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A. (Dept. of Radiology and Diagnostic Imaging, and Dept. of General and Vascular Surgery, Nicolaus Copernicus Univ., Collegium Medicum, Bydgoszcz (Poland))

    2009-02-15

    Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

  4. Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

    International Nuclear Information System (INIS)

    Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A.

    2009-01-01

    Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

  5. Evaluation of brain perfusion in Alzheimer disease with perfusion computed tomography and comparison to elderly patient without dementia.

    Science.gov (United States)

    Yildirim, Tülin; Karakurum Göksel, Başak; Demir, Şenay; Tokmak, Naime; Tan, Meliha

    2016-04-19

    The aim of this study was to evaluate perfusion computed tomography (PCT) findings in patients with Alzheimer disease and to compare them with those of patients without dementia. PCT was performed in 35 patients: 20 with Alzheimer disease (mean age, 69.7 ± 5.5 years) and 15 control subjects (mean age, 67.5 ± 3.5 years). Control subjects were elderly individuals with no cognitive problems who were admitted with headaches. All PCT examinations were performed on a 4-slice CT unit. The PCT analysis software program was used to calculate regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional time-to-peak (rTTP) values in the bilateral frontal, temporal, and occipital cortices, and bilateral lentiform nucleus. rCBF values in the bilateral frontal and temporal cortices and bilateral lentiform nucleus were significantly lower in the patients with Alzheimer disease than in the control subjects. There were no significant differences in rCBV values between Alzheimer disease and the control group. rTTP values in all cortical areas and bilateral lentiform nucleus were significantly higher in the patients with Alzheimer disease than in the control subjects. PCT is a rapid and reliable imaging modality for evaluating brain perfusion in Alzheimer disease.

  6. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography

    DEFF Research Database (Denmark)

    Vavere, Andrea L; Simon, Gregory G; George, Richard T

    2013-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability...... to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess...... the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8...

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

    Science.gov (United States)

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

    2018-03-01

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

  8. Use of ultrafast computed tomography to quantitate regional myocardial perfusion: a preliminary report

    International Nuclear Information System (INIS)

    Rumberger, J.A.; Feiring, A.J.; Lipton, M.J.; Higgins, C.B.; Ell, S.R.; Marcus, M.L.

    1987-01-01

    The purpose of this study was to assess the potential for rapid acquisition computed axial tomography (Imatron C-100) to quantify regional myocardial perfusion. Myocardial and left ventricular cavity contrast clearance curves were constructed after injecting nonionic contrast (1 ml/kg over 2 to 3 seconds) into the inferior vena cava of six anesthetized, closed chest dogs (n = 14). Independent myocardial perfusion measurements were obtained by coincident injection of radiolabeled microspheres into the left atrium during control, intermediate and maximal myocardial vasodilation with adenosine (0.5 to 1.0 mg/kg per min, intravenously, respectively). At each flow state, 40 serial short-axis scans of the left ventricle were taken near end-diastole at the midpapillary muscle level. Contrast clearance curves were generated and analyzed from the left ventricular cavity and posterior papillary muscle regions after excluding contrast recirculation and minimizing partial volume effects. The area under the curve (gamma variate function) was determined for a region of interest placed within the left ventricular cavity. Characteristics of contrast clearance data from the posterior papillary muscle region that were evaluated included the peak myocardial opacification, area under the contrast clearance curve and a contrast clearance time defined by the full width/half maximal extent of the clearance curve. Myocardial perfusion (microspheres) ranged from 35 to 450 ml/100 g per min (mean 167 +/- 125)

  9. Single-photon emission computed tomography for the assessment of ventricular perfusion and function

    International Nuclear Information System (INIS)

    Gonzalez, Patricio; Dussaillant, Gaston; Gutierrez, Daniela; Berrocal, Isabel; Alay, Rita; Otarola, Sonia

    2013-01-01

    Background: Single-photon emission computed tomography (SPECT) can be used as a non-invasive tool for the assessment of coronary perfusion. Aim: To assess ventricular perfusion and function by SPECT in patients with single vessel coronary artery disease. Material and Methods: Among patients with indications for a coronary artery angiography, those with significant lesions in one vessel, were selected for the study. Within 24 hours, cardiac SPECT examinations on basal conditions and after high doses of dipyridamole, were performed. SPECT data from 38 patients with a low probability of coronary artery disease was used for comparisons. Results:Ten patients aged 61 ± 8 years (seven men) were studied. Visual analysis of SPECT revealed signs suggestive of ischemia in eight patients. The remaining two patients did not have perfusion disturbances. SPECT detected eight of ten abnormal vessels reported in the coronary artery angiography. There were two false negative results Summed stress, summed rest and summed difference scores were 9.78 ± 6.51, 3.22 ± 5.07 and 6.33 ± 4.97, respectively. The ejection fractions under stress and at rest were 53 ± 11.7% and 61 ± 15.7% respectively (p ≤ 0.01). The figures for the control group were 69.1 ± 13.5% and 75.2 ± 12.04% respectively (significantly different from patients). Two patients had a summed motion score above 14.9. Likewise, two patients had a summed thickening score above 10.9. Conclusions: SPECT detected 80% of coronary lesions found during coronary artery angiography. Visual analysis of perfusion is highly reliable for diagnosis. Quantitative parameters must be considered only as reference parameters

  10. Cerebral perfusion computed tomography deconvolution via structure tensor total variation regularization

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Dong; Zhang, Xinyu; Bian, Zhaoying, E-mail: zybian@smu.edu.cn, E-mail: jhma@smu.edu.cn; Huang, Jing; Zhang, Hua; Lu, Lijun; Lyu, Wenbing; Feng, Qianjin; Chen, Wufan; Ma, Jianhua, E-mail: zybian@smu.edu.cn, E-mail: jhma@smu.edu.cn [Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515 (China); Zhang, Jing [Department of Radiology, Tianjin Medical University General Hospital, Tianjin 300052 (China)

    2016-05-15

    Purpose: Cerebral perfusion computed tomography (PCT) imaging as an accurate and fast acute ischemic stroke examination has been widely used in clinic. Meanwhile, a major drawback of PCT imaging is the high radiation dose due to its dynamic scan protocol. The purpose of this work is to develop a robust perfusion deconvolution approach via structure tensor total variation (STV) regularization (PD-STV) for estimating an accurate residue function in PCT imaging with the low-milliampere-seconds (low-mAs) data acquisition. Methods: Besides modeling the spatio-temporal structure information of PCT data, the STV regularization of the present PD-STV approach can utilize the higher order derivatives of the residue function to enhance denoising performance. To minimize the objective function, the authors propose an effective iterative algorithm with a shrinkage/thresholding scheme. A simulation study on a digital brain perfusion phantom and a clinical study on an old infarction patient were conducted to validate and evaluate the performance of the present PD-STV approach. Results: In the digital phantom study, visual inspection and quantitative metrics (i.e., the normalized mean square error, the peak signal-to-noise ratio, and the universal quality index) assessments demonstrated that the PD-STV approach outperformed other existing approaches in terms of the performance of noise-induced artifacts reduction and accurate perfusion hemodynamic maps (PHM) estimation. In the patient data study, the present PD-STV approach could yield accurate PHM estimation with several noticeable gains over other existing approaches in terms of visual inspection and correlation analysis. Conclusions: This study demonstrated the feasibility and efficacy of the present PD-STV approach in utilizing STV regularization to improve the accuracy of residue function estimation of cerebral PCT imaging in the case of low-mAs.

  11. Assessment of tumor vascularization with functional computed tomography perfusion imaging in patients with cirrhotic liver disease.

    Science.gov (United States)

    Li, Jin-Ping; Zhao, De-Li; Jiang, Hui-Jie; Huang, Ya-Hua; Li, Da-Qing; Wan, Yong; Liu, Xin-Ding; Wang, Jin-E

    2011-02-01

    Hepatocellular carcinoma (HCC) is a common malignant tumor in China, and early diagnosis is critical for patient outcome. In patients with HCC, it is mostly based on liver cirrhosis, developing from benign regenerative nodules and dysplastic nodules to HCC lesions, and a better understanding of its vascular supply and the hemodynamic changes may lead to early tumor detection. Angiogenesis is essential for the growth of primary and metastatic tumors due to changes in vascular perfusion, blood volume and permeability. These hemodynamic and physiological properties can be measured serially using functional computed tomography perfusion (CTP) imaging and can be used to assess the growth of HCC. This study aimed to clarify the physiological characteristics of tumor angiogenesis in cirrhotic liver disease by this fast imaging method. CTP was performed in 30 volunteers without liver disease (control subjects) and 49 patients with liver disease (experimental subjects: 27 with HCC and 22 with cirrhosis). All subjects were also evaluated by physical examination, laboratory screening and Doppler ultrasonography of the liver. The diagnosis of HCC was made according to the EASL criteria. All patients underwent contrast-enhanced ultrasonography, pre- and post-contrast triple-phase CT and CTP study. A mathematical deconvolution model was applied to provide hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic arterial index (HAI), hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP) data. The Mann-Whitney U test was used to determine differences in perfusion parameters between the background cirrhotic liver parenchyma and HCC and between the cirrhotic liver parenchyma with HCC and that without HCC. In normal liver, the HAP/HVP ratio was about 1/4. HCC had significantly higher HAP and HAI and lower HPP than background liver parenchyma adjacent to the HCC. The value of HBF at the tumor

  12. Computed Tomography Perfusion Alberta Stroke Program Early Computed Tomography Score Is Associated with Hemorrhagic Transformation after Acute Cardioembolic Stroke

    Directory of Open Access Journals (Sweden)

    Lan Liu

    2017-11-01

    Full Text Available Alberta Stroke Program Early Computed Tomography (CT score (ASPECTS has been applied to CT perfusion (CTP with good interrater agreement to predict early ischemic stroke, and it can be useful in decision making in acute ischemic stroke. The aim of the present study was to assess the predictive value of CTP ASPECTS of hemorrhagic transformation (HT in acute cardioembolic stroke. This is a single-enter, retrospective study. All patients hospitalized with acute cardioembolic stroke from January 2008 to September 2013 were included. ASPECTS of baseline non-contrast CT, CTP maps of cerebral blood volume (CBV, cerebral blood flow, and mean transit time were collected from 52 consecutive patients with less than 12-h anterior circulation ischemic stroke. MRI scan was performed within 72 h of symptom onset after index stroke including T2*-weighted gradient echo to identify HT. For bleeding risk assessment, CTP and diffusion-weighted imaging ASPECTS were categorized into 0–7 or 8–10. Baseline characteristics, ASPCETS scores and HT were compared. Eighteen (34.6% patients had HT and four (7.7% developed symptomatic HT. On univariate analysis, the proportion of patients with CBV-ASPECTS 0–7 was significantly higher in HT patients as compared to patients without HT (44 versus 9%, P = 0.005. CBV ASPECTS 0–7 remained independent prognostic factors for HT after adjustment for clinical baseline variables. CBV ASPECTS could be of value to predict HT risk after acute cardioembolic stroke and may be a quick risk assessment approach before reperfusion therapy.

  13. Hyperacute stroke patients and catheter thrombolysis therapy. Correlation between computed tomography perfusion maps and final infarction

    International Nuclear Information System (INIS)

    Naito, Yukari; Tanaka, Shigeko; Inoue, Yuichi; Ota, Shinsuke; Sakaki, Saburo; Kitagaki, Hajime

    2008-01-01

    We investigated the correlation between abnormal perfusion areas by computed tomography perfusion (CTP) study of hyperacute stroke patients and the final infarction areas after intraarterial catheter thrombolysis. CTP study using the box-modulation transfer function (box-MTF) method based on the deconvolution analysis method was performed in 22 hyperacute stroke patients. Ischemic lesions were immediately treated with catheter thrombolysis after CTP study. Among them, nine patients with middle cerebral artery (MCA) occlusion were investigated regarding correlations of the size of the prolonged mean transit time (MTT) area, the decreased cerebral blood volume (CBV) area, and the final infarction area. Using the box-MTF method, the prolonged MTT area was almost identical to the final infarction area in the case of catheter thrombolysis failure. The decreased CBV areas resulted in infarction or hemorrhage, irrespective of the outcome of recanalization after catheter thrombolysis. The prolonged MTT areas, detected by the box-MTF method of CTP in hyperacute stroke patients, included the area of true prolonged MTT and the tracer delay. The prolonged MTT area was almost identical to the final infarction area when recanalization failed. We believe that a tracer delay area also indicates infarction in cases of thrombolysis failure. (author)

  14. Cerebral blood volume imaging by flat detector computed tomography in comparison to conventional multislice perfusion CT

    International Nuclear Information System (INIS)

    Struffert, Tobias; Kloska, Stephan; Engelhorn, Tobias; Doerfler, Arnd; Deuerling-Zheng, Yu; Boese, Jan; Zellerhoff, Michael; Schwab, Stefan

    2011-01-01

    We tested the hypothesis that Flat Detector computed tomography (FD-CT) with intravenous contrast medium would allow the calculation of whole brain cerebral blood volume (CBV) mapping (FD-CBV) and would correlate with multislice Perfusion CT (PCT). Twenty five patients were investigated with FD-CBV and PCT. Correlation of the CBV maps of both techniques was carried out with measurements from six anatomical regions from both sides of the brain. Mean values of each region and the correlation coefficient were calculated. Bland-Altman analysis was performed to compare the two different imaging techniques. The image and data quality of both PCT and FD-CBV were suitable for evaluation in all patients. The mean CBV values of FD-CBV and PCT showed only minimal differences with overlapping standard deviation. The correlation coefficient was 0.79 (p < 0.01). Bland-Altman analysis showed a mean difference of -0.077 ± 0.48 ml/100 g between FD-CBV and PCT CBV measurements, indicating that FD-CBV values were only slightly lower than those of PCT. CBV mapping with intravenous contrast medium using Flat Detector CT compared favourably with multislice PCT. The ability to assess cerebral perfusion within the angiographic suite may improve the management of ischaemic stroke and evaluation of the efficacy of dedicated therapies. (orig.)

  15. Automated prediction of tissue outcome after acute ischemic stroke in computed tomography perfusion images

    Science.gov (United States)

    Vos, Pieter C.; Bennink, Edwin; de Jong, Hugo; Velthuis, Birgitta K.; Viergever, Max A.; Dankbaar, Jan Willem

    2015-03-01

    Assessment of the extent of cerebral damage on admission in patients with acute ischemic stroke could play an important role in treatment decision making. Computed tomography perfusion (CTP) imaging can be used to determine the extent of damage. However, clinical application is hindered by differences among vendors and used methodology. As a result, threshold based methods and visual assessment of CTP images has not yet shown to be useful in treatment decision making and predicting clinical outcome. Preliminary results in MR studies have shown the benefit of using supervised classifiers for predicting tissue outcome, but this has not been demonstrated for CTP. We present a novel method for the automatic prediction of tissue outcome by combining multi-parametric CTP images into a tissue outcome probability map. A supervised classification scheme was developed to extract absolute and relative perfusion values from processed CTP images that are summarized by a trained classifier into a likelihood of infarction. Training was performed using follow-up CT scans of 20 acute stroke patients with complete recanalization of the vessel that was occluded on admission. Infarcted regions were annotated by expert neuroradiologists. Multiple classifiers were evaluated in a leave-one-patient-out strategy for their discriminating performance using receiver operating characteristic (ROC) statistics. Results showed that a RandomForest classifier performed optimally with an area under the ROC of 0.90 for discriminating infarct tissue. The obtained results are an improvement over existing thresholding methods and are in line with results found in literature where MR perfusion was used.

  16. Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E.; El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria; Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke; Kroft, Lucia J.; Younis, Imad Al; Reiber, Johan H.; Scholte, Arthur J.

    2013-01-01

    Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 ± 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS ≥2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p 2 = 20.7) and lesion length (χ 2 = 26.0) to the clinical variables and the visual assessment (χ 2 = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have incremental value over baseline variables and visually assessed significant stenosis. Potentially, QCT can refine assessment of CAD, which may be of potential use for identification of patients with myocardial ischaemia. (orig.)

  17. Prognostic implications of atrial fibrillation in patients undergoing myocardial perfusion single-photon emission computed tomography.

    Science.gov (United States)

    Abidov, Aiden; Hachamovitch, Rory; Rozanski, Alan; Hayes, Sean W; Santos, Marcia M; Sciammarella, Maria G; Cohen, Ishac; Gerlach, James; Friedman, John D; Germano, Guido; Berman, Daniel S

    2004-09-01

    The aim of this research was to determine whether presence of atrial fibrillation (AF) provides incremental prognostic information relative to myocardial perfusion single-photon emission computed tomography (MPS) with respect to risk of cardiac death (CD). The prognostic significance of AF in patients undergoing MPS is not known. A total of 16,048 consecutive patients undergoing MPS were followed-up for a mean of 2.21 +/- 1.15 years for the development of CD. Of those, 384 patients (2.4%) had AF. Cox proportional hazards method was used to compare clinical and perfusion data for the prediction of CD in patients with and without AF. Atrial fibrillation was a significant predictor of CD in patients with normal (1.6% per year vs. 0.4% per year in non-AF patients), mildly abnormal (6.3% per year vs. 1.2% per year), and severely abnormal MPS (6.4% per year vs. 3.7% per year) (p < 0.001 for all). By multivariable analysis, AF patients had worse survival (p = 0.001) even after adjustment for the variables most predictive of CD: age, diabetes, shortness of breath, use of vasodilator stress, rest heart rate, and the nuclear variables. In the 4,239 patients with left ventricular ejection fraction evaluated by gated MPS, AF demonstrated incremental prognostic value not only over clinical and nuclear variables, but also over left ventricular ejection in predicting CD (p = 0.014). The presence of AF independently increases the risk of cardiac events over perfusion and function variables in patients undergoing MPS. Patients with AF have a high risk of CD, even when MPS is only mildly abnormal. Whether patients with AF and mildly abnormal MPS constitute a group more deserving of early referral to cardiac catheterization is a question warranting further study.

  18. Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke.

    Science.gov (United States)

    Sporns, Peter; Schmidt, Rene; Minnerup, Jens; Dziewas, Rainer; Kemmling, André; Dittrich, Ralf; Zoubi, Tarek; Heermann, Philipp; Cnyrim, Christian; Schwindt, Wolfram; Heindel, Walter; Niederstadt, Thomas; Hanning, Uta

    2016-01-01

    Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone. © 2016 S. Karger AG, Basel.

  19. The role of perfusion computed tomography in the prediction of cerebral hyperperfusion syndrome.

    Directory of Open Access Journals (Sweden)

    Chien Hung Chang

    Full Text Available Hyperperfusion syndrome (HPS following carotid angioplasty with stenting (CAS is associated with significant morbidity and mortality. At present, there are no reliable parameters to predict HPS. The aim of this study was to clarify whether perfusion computed tomography (CT is a feasible and reliable tool in predicting HPS after CAS.We performed a retrospective case-control study of 54 patients (11 HPS patients and 43 non-HPS with unilateral severe stenosis of the carotid artery who underwent CAS. We compared the prevalence of vascular risk factors and perfusion CT parameters including regional cerebral blood volume (rCBV, regional cerebral blood flow (rCBF, and time to peak (TTP within seven days prior to CAS. Demographic information, risk factors for atherosclerosis, and perfusion CT parameters were evaluated by multivariable logistic regression analysis. The rCBV index was calculated as [(ipsilateral rCBV - contralateral rCBV/contralateral rCBV], and indices of rCBF and TTP were similarly calculated. We found that eleven patients had HPS, including five with intracranial hemorrhages (ICHs of whom three died. After a comparison with non-HPS control subjects, independent predictors of HPS included the severity of ipsilateral carotid artery stenosis, 3-hour mean systolic blood pressure (3 h SBP after CAS, pre-stenting rCBV index >0.15 and TTP index >0.22.The combination of severe ipsilateral carotid stenosis, 3 h SBP after CAS, rCBV index and TTP index provides a potential screening tool for predicting HPS in patients with unilateral carotid stenosis receiving CAS. In addition, adequate management of post-stenting blood pressure is the most important treatable factor in preventing HPS in these high risk patients.

  20. Dynamic iterative beam hardening correction (DIBHC) in myocardial perfusion imaging using contrast-enhanced computed tomography.

    Science.gov (United States)

    Stenner, Philip; Schmidt, Bernhard; Allmendinger, Thomas; Flohr, Thomas; Kachelrie, Marc

    2010-06-01

    In cardiac perfusion examinations with computed tomography (CT) large concentrations of iodine in the ventricle and in the descending aorta cause beam hardening artifacts that can lead to incorrect perfusion parameters. The aim of this study is to reduce these artifacts by performing an iterative correction and by accounting for the 3 materials soft tissue, bone, and iodine. Beam hardening corrections are either implemented as simple precorrections which cannot account for higher order beam hardening effects, or as iterative approaches that are based on segmenting the original image into material distribution images. Conventional segmentation algorithms fail to clearly distinguish between iodine and bone. Our new algorithm, DIBHC, calculates the time-dependent iodine distribution by analyzing the voxel changes of a cardiac perfusion examination (typically N approximately 15 electrocardiogram-correlated scans distributed over a total scan time up to T approximately 30 s). These voxel dynamics are due to changes in contrast agent. This prior information allows to precisely distinguish between bone and iodine and is key to DIBHC where each iteration consists of a multimaterial (soft tissue, bone, iodine) polychromatic forward projection, a raw data comparison and a filtered backprojection. Simulations with a semi-anthropomorphic dynamic phantom and clinical scans using a dual source CT scanner with 2 x 128 slices, a tube voltage of 100 kV, a tube current of 180 mAs, and a rotation time of 0.28 seconds have been carried out. The uncorrected images suffer from beam hardening artifacts that appear as dark bands connecting large concentrations of iodine in the ventricle, aorta, and bony structures. The CT-values of the affected tissue are usually underestimated by roughly 20 HU although deviations of up to 61 HU have been observed. For a quantitative evaluation circular regions of interest have been analyzed. After application of DIBHC the mean values obtained deviate by

  1. Analysis of blood flow in a third ventricular ependymoma and an olfactory bulb meningioma by usisng perfusion computed tomography

    International Nuclear Information System (INIS)

    Kishimoto, M.; Yamada, K.; Seok, J.S.; Shimizu, J.; Kobayashi, Y.; Akiba, Y.; Morishita, Y.; Iwasa, A.; Iwasaki, T.; Miyake, Y.

    2008-01-01

    Brain perfusion computed tomography (CT) scanning was performed in a mongrel dog and a golden retriever that were diagnosed with third ventricular tumor and olfactory bulb tumor, respectively, by contrast-enhanced CT. The tumors were pathologically diagnosed as ependymoma and meningioma, respectively. Perfusion CT results revealed that the ependymoma in this study had a lower blood flow, higher blood volume, and greater transit time of blood than the adjacent brain tissue. Further, the meningioma in this study had a higher blood flow, higher blood volume, and greater transit time of blood than the adjacent brain tissue. Perfusion CT can potentially be used for the grading of brain tumors and narrowing differential diagnosis, provided the perfusion CT data of animals are accumulated

  2. Differentiation of myocardial ischemia and infarction assessed by dynamic computed tomography perfusion imaging and comparison with cardiac magnetic resonance and single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Miyagawa, Masao; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon, Ehime (Japan); Uetani, Teruyoshi; Kono, Tamami; Ogimoto, Akiyoshi [Ehime University Graduate School of Medicine, Department of Cardiology, Pulmonology, Hypertension and Nephrology, Toon, Ehime (Japan); Soma, Tsutomu [FUJIFILM RI Pharma Co., Ltd., QMS Group, Quality Assurance Department, Tokyo (Japan); Graduate School of Medicine, University of Tokyo, Department of Radiology, Tokyo (Japan); Murase, Kenya [Osaka University Graduate School of Medicine, Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Osaka (Japan); Iwaki, Hirotaka [Ehime University Graduate School of Medicine, Center for Clinical Research Data and Biostatistics, Toon, Ehime (Japan)

    2016-11-15

    To evaluate the feasibility of myocardial blood flow (MBF) by computed tomography from dynamic CT perfusion (CTP) for detecting myocardial ischemia and infarction assessed by cardiac magnetic resonance (CMR) or single-photon emission computed tomography (SPECT). Fifty-three patients who underwent stress dynamic CTP and either SPECT (n = 25) or CMR (n = 28) were retrospectively selected. Normal and abnormal perfused myocardium (ischemia/infarction) were assessed by SPECT/CMR using 16-segment model. Sensitivity and specificity of CT-MBF (mL/g/min) for detecting the ischemic/infarction and severe infarction were assessed. The abnormal perfused myocardium and severe infarction were seen in SPECT (n = 90 and n = 19 of 400 segments) and CMR (n = 223 and n = 36 of 448 segments). For detecting the abnormal perfused myocardium, sensitivity and specificity were 80 % (95 %CI, 71-90) and 86 % (95 %CI, 76-91) in SPECT (cut-off MBF, 1.23), and 82 % (95 %CI, 76-88) and 87 % (95 %CI, 80-92) in CMR (cut-off MBF, 1.25). For detecting severe infarction, sensitivity and specificity were 95 % (95 %CI, 52-100) and 72 % (95 %CI, 53-91) in SPECT (cut-off MBF, 0.92), and 78 % (95 %CI, 67-97) and 80 % (95 %CI, 58-86) in CMR (cut-off MBF, 0.98), respectively. Dynamic CTP has a potential to detect abnormal perfused myocardium and severe infarction assessed by SPECT/CMR using comparable cut-off MBF. (orig.)

  3. Safety of ventilation/perfusion single photon emission computed tomography for pulmonary embolism diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Le Roux, Pierre-Yves; Palard, Xavier; Robin, Philippe; Abgral, Ronan; Querellou, Solene; Salaun, Pierre-Yves [Universite Europeenne de Bretagne, Brest (France); Universite de Brest, Brest (France); CHRU de la Cavale Blanche, Service de medecine nucleaire, Brest (France); Delluc, Aurelien; Couturaud, Francis [Universite Europeenne de Bretagne, Brest (France); Universite de Brest, Brest (France); CHRU de la Cavale Blanche, Departement de medecine interne et de pneumologie, Brest (France); Le Gal, Gregoire [Universite Europeenne de Bretagne, Brest (France); University of Ottawa, Ottawa Hospital Research Institute, Ottawa (Canada); CHRU de la Cavale Blanche, Departement de medecine interne et de pneumologie, Brest (France); Universite de Brest, Brest (France)

    2014-10-15

    The aim of this management outcome study was to assess the safety of ventilation/perfusion single photon emission computed tomography (V/Q SPECT) for the diagnosis of pulmonary embolism (PE) using for interpretation the criteria proposed in the European Association of Nuclear Medicine (EANM) guidelines for V/Q scintigraphy. A total of 393 patients with clinically suspected PE referred to the Nuclear Medicine Department of Brest University Hospital from April 2011 to March 2013, with either a high clinical probability or a low or intermediate clinical probability but positive D-dimer, were retrospectively analysed. V/Q SPECT were interpreted by the attending nuclear medicine physician using a diagnostic cut-off of one segmental or two subsegmental mismatches. The final diagnostic conclusion was established by the physician responsible for patient care, based on clinical symptoms, laboratory test, V/Q SPECT and other imaging procedures performed. Patients in whom PE was deemed absent were not treated with anticoagulants and were followed up for 3 months. Of the 393 patients, the prevalence of PE was 28 %. V/Q SPECT was positive for PE in 110 patients (28 %) and negative in 283 patients (72 %). Of the 110 patients with a positive V/Q SPECT, 78 (71 %) had at least one additional imaging test (computed tomography pulmonary angiography or ultrasound) and the diagnosis of PE was eventually excluded in one patient. Of the 283 patients with a negative V/Q SPECT, 74 (26 %) patients had another test. The diagnosis of PE was finally retained in one patient and excluded in 282 patients. The 3-month thromboembolic risk in the patients not treated with anticoagulants was 1/262: 0.38 % (95 % confidence interval 0.07-2.13). A diagnostic management including V/Q SPECT interpreted with a diagnostic cut-off of ''one segmental or two subsegmental mismatches'' appears safe to exclude PE. (orig.)

  4. Safety of ventilation/perfusion single photon emission computed tomography for pulmonary embolism diagnosis

    International Nuclear Information System (INIS)

    Le Roux, Pierre-Yves; Palard, Xavier; Robin, Philippe; Abgral, Ronan; Querellou, Solene; Salaun, Pierre-Yves; Delluc, Aurelien; Couturaud, Francis; Le Gal, Gregoire

    2014-01-01

    The aim of this management outcome study was to assess the safety of ventilation/perfusion single photon emission computed tomography (V/Q SPECT) for the diagnosis of pulmonary embolism (PE) using for interpretation the criteria proposed in the European Association of Nuclear Medicine (EANM) guidelines for V/Q scintigraphy. A total of 393 patients with clinically suspected PE referred to the Nuclear Medicine Department of Brest University Hospital from April 2011 to March 2013, with either a high clinical probability or a low or intermediate clinical probability but positive D-dimer, were retrospectively analysed. V/Q SPECT were interpreted by the attending nuclear medicine physician using a diagnostic cut-off of one segmental or two subsegmental mismatches. The final diagnostic conclusion was established by the physician responsible for patient care, based on clinical symptoms, laboratory test, V/Q SPECT and other imaging procedures performed. Patients in whom PE was deemed absent were not treated with anticoagulants and were followed up for 3 months. Of the 393 patients, the prevalence of PE was 28 %. V/Q SPECT was positive for PE in 110 patients (28 %) and negative in 283 patients (72 %). Of the 110 patients with a positive V/Q SPECT, 78 (71 %) had at least one additional imaging test (computed tomography pulmonary angiography or ultrasound) and the diagnosis of PE was eventually excluded in one patient. Of the 283 patients with a negative V/Q SPECT, 74 (26 %) patients had another test. The diagnosis of PE was finally retained in one patient and excluded in 282 patients. The 3-month thromboembolic risk in the patients not treated with anticoagulants was 1/262: 0.38 % (95 % confidence interval 0.07-2.13). A diagnostic management including V/Q SPECT interpreted with a diagnostic cut-off of ''one segmental or two subsegmental mismatches'' appears safe to exclude PE. (orig.)

  5. The New Frontier of Cardiac Computed Tomography Angiography: Fractional Flow Reserve and Stress Myocardial Perfusion.

    Science.gov (United States)

    Pontone, Gianluca; Muscogiuri, Giuseppe; Andreini, Daniele; Guaricci, Andrea I; Guglielmo, Marco; Mushtaq, Saima; Baggiano, Andrea; Conte, Edoardo; Beltrama, Virginia; Annoni, Andrea; Formenti, Alberto; Mancini, Elisabetta; Rabbat, Mark G; Pepi, Mauro

    2016-12-01

    The increased number of patients with coronary artery disease (CAD) in developed countries is of great clinical relevance and involves a large burden of the healthcare system. The management of these patients is focused on relieving symptoms and improving clinical outcomes. Therefore the ideal test would provide the correct diagnosis and actionable information. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography (ICA), but their diagnostic yield remains low with limited accuracy when compared to obstructive CAD at the time of ICA or invasive fractional flow reserve (FFR). Invasive FFR is considered the gold standard for the evaluation of functionally relevant CAD. Therefore, an urgent need for non-invasive techniques that evaluate both the functional and morphological severity of CAD is growing. Coronary computed tomography angiography (CCTA) has emerged as a unique non-invasive technique providing coronary artery anatomic imaging. More recently, the evaluation of FFR with CCTA (FFR CT ) has demonstrated high diagnostic performance compared to invasive FFR. Additionally, stress myocardial computed tomography perfusion (CTP) represents a novel tool for the diagnosis of ischemia with high diagnostic accuracy. Compared to nuclear imaging and cardiac magnetic resonance imaging, both FFR CT and stress-CTP, allow us to integrate the anatomical evaluation of coronary arteries with the functional relevance of coronary artery lesions having the potential to revolutionize the diagnostic paradigm of suspected CAD. FFR CT and stress-CTP could be assimilated in diagnostic pathways of patients with stable CAD and will likely result in a decrease of invasive diagnostic procedures and costs. The current review evaluates the technical aspects and clinical experience of FFR CT and stress-CTP in the evaluation of functionally relevant CAD discussing the strengths and weaknesses of each approach.

  6. Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of The Netherlands, Utrecht (Netherlands); El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Kroft, Lucia J. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Reiber, Johan H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical imaging systems B.V., Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2013-08-15

    Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 {+-} 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS {>=}2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p < 0.001, and OR 1.07, 95 % CI 1.00-1.45, p = 0.032, respectively) after correcting for clinical variables and visually assessed significant stenosis. The addition of quantitatively assessed significant stenosis ({chi} {sup 2} = 20.7) and lesion length ({chi} {sup 2} = 26.0) to the clinical variables and the visual assessment ({chi} {sup 2} = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have

  7. A benchmarking tool to evaluate computer tomography perfusion infarct core predictions against a DWI standard.

    Science.gov (United States)

    Cereda, Carlo W; Christensen, Søren; Campbell, Bruce Cv; Mishra, Nishant K; Mlynash, Michael; Levi, Christopher; Straka, Matus; Wintermark, Max; Bammer, Roland; Albers, Gregory W; Parsons, Mark W; Lansberg, Maarten G

    2016-10-01

    Differences in research methodology have hampered the optimization of Computer Tomography Perfusion (CTP) for identification of the ischemic core. We aim to optimize CTP core identification using a novel benchmarking tool. The benchmarking tool consists of an imaging library and a statistical analysis algorithm to evaluate the performance of CTP. The tool was used to optimize and evaluate an in-house developed CTP-software algorithm. Imaging data of 103 acute stroke patients were included in the benchmarking tool. Median time from stroke onset to CT was 185 min (IQR 180-238), and the median time between completion of CT and start of MRI was 36 min (IQR 25-79). Volumetric accuracy of the CTP-ROIs was optimal at an rCBF threshold of benchmarking tool can play an important role in optimizing CTP software as it provides investigators with a novel method to directly compare the performance of alternative CTP software packages. © The Author(s) 2015.

  8. Quantification of leg muscle perfusion using thallium-201 single photon emission computed tomography

    International Nuclear Information System (INIS)

    Oshima, M.; Akanabe, H.; Sakuma, S.; Yano, T.; Nishikimi, N.; Shionoya, S.

    1989-01-01

    The purpose of this study is to quantify leg muscle perfusion with 201 Tl single photon emission computed tomography (SPECT). Six normal controls and 21 patients with peripheral arterial disease underwent this examination. Thallium-201 leg SPECT of both stress and redistribution was performed using a dual-headed digital gamma camera. Each slice of transverse images was normalized with pixels and whole-body counts. In normal controls, the activity of posterior tibial muscle components was significantly higher than that of anterior tibial muscle components (p less than 0.001). In 14 components, where patients had insignificant lesions, profile curves were normal in 10 (71%). In 62 components, where patients had arteriographically significant lesions, stress profile curves were abnormal in 57 (92%) compared with normal controls. Approximately, in half (28/62) components which had significant lesions, profile curves showed redistribution after 3 hr compared with normal redistribution curves. In three patients who underwent successful bypass graftings, the activity of each muscle component returned to a normal range

  9. Arterio-portal shunts in the cirrhotic liver: perfusion computed tomography for distinction of arterialized pseudolesions from hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Karolinska Institutet, Division of Medical Imaging and Technology. Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Marquez, Herman P.; Gordic, Sonja; Alkadhi, Hatem [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Leidner, Bertil; Aspelin, Peter; Brismar, Torkel B. [Karolinska Institutet, Division of Medical Imaging and Technology. Department of Clinical Science, Intervention and Technology (CLINTEC), Stockholm (Sweden); Klotz, Ernst [Computed Tomography and Radiation Oncology, Siemens Healthcare, Forchheim (Germany)

    2017-03-15

    To determine perfusion computed tomography (P-CT) findings for distinction of arterial pseudolesions (APL) from hepatocellular carcinoma (HCC) in the cirrhotic liver. 32 APL and 21 HCC in 20 cirrhotic patients (15 men; 65 ± 10 years), who underwent P-CT for evaluation of HCC pre- (N = 9) or post- (N = 11) transarterial chemoembolization, were retrospectively included using CT follow-up as the standard of reference. All 53 lesions were qualitatively (visual) and quantitatively (perfusion parameters) analysed according to their shape (wedge, irregular, nodular), location (not-/adjunct to a fistula), arterial liver perfusion (ALP), portal venous liver perfusion (PLP), hepatic perfusion index (HPI). Accuracy for diagnosis of HCC was determined using receiver operating characteristics. 18/32 (56 %) APL were wedge shaped, 10/32 (31 %) irregular and 4/32 (12 %) nodular, while 11/21 (52 %) HCC were nodular or 10/21 (48 %) irregular, but never wedge shaped. Significant difference between APL and HCC was seen for lesion shape in pretreated lesions (P < 0.001), and for PLP and HPI in both pre- and post-treated lesions (all, P < 0.001). Diagnostic accuracy for HCC was best for combined assessment of lesion configuration and PLP showing an area under the curve of 0.901. Combined assessment of lesion configuration and portal venous perfusion derived from P-CT allows best to discriminate APL from HCC with high diagnostic accuracy. (orig.)

  10. Myocardial perfusion assessment by dual-energy computed tomography in patients with intermediate to high likelihood of coronary artery disease

    International Nuclear Information System (INIS)

    De Zam, M.C.; Capunay, C.; Rodriguez Granillo, G.A.; Deviggiano, A.; Campisi, R.; Munain, M. López de; Vallejos, J.; Carrascosa, P.M.

    2015-01-01

    Objectives. We sought to explore the feasibility and diagnostic performance of dual-energy computed tomography (DECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease (CAD), and to assess the impact of beam hardening artifacts (HAE). Methods. The present prospective study involved patients with known or suspected CAD referred for myocardial perfusion imaging by single-photon emission computed tomography (SPECT). Twenty patients were included in the study protocol, and scanned using DECT imaging (n = 20). The same pharmacological stress was used for DECT and SPECT scans. Results. A total of 680 left ventricular segments were evaluated by DECT and SPECT. The contrast to noise ratio was 8.8±2.9. The diagnostic performance of DECT was very good in identifying perfusion defects [area under ROC curve (AUC) of DECT 0.90 (0.86-0.94)] compared with SPECT, and remained unaffected when including only segments affected by beam hardening artifacts (BHA) [AUC= DECT 0.90 (0.84-0.96)]. Conclusions. In this pilot investigation, myocardial perfusion assessment by DECT imaging in patients with intermediate to high likelihood of CAD was feasible and remained unaffected by the presence of BHA. (authors) [es

  11. Diagnostic accuracy of combined coronary angiography and adenosine stress myocardial perfusion imaging using 320-detector computed tomography: pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Nasis, Arthur; Ko, Brian S.; Leung, Michael C.; Antonis, Paul R.; Wong, Dennis T.; Kyi, Leo; Cameron, James D.; Meredith, Ian T.; Seneviratne, Sujith K. [Southern Health and Monash University, Monash Cardiovascular Research Centre, Monash Heart, Department of Medicine Monash Medical Centre (MMC), Melbourne (Australia); Nandurkar, Dee; Troupis, John M. [MMC, Southern Health, Department of Diagnostic Imaging, Melbourne (Australia)

    2013-07-15

    To determine the diagnostic accuracy of combined 320-detector row computed tomography coronary angiography (CTA) and adenosine stress CT myocardial perfusion imaging (CTP) in detecting perfusion abnormalities caused by obstructive coronary artery disease (CAD). Twenty patients with suspected CAD who underwent initial investigation with single-photon-emission computed tomography myocardial perfusion imaging (SPECT-MPI) were recruited and underwent prospectively-gated 320-detector CTA/CTP and invasive angiography. Two blinded cardiologists evaluated invasive angiography images quantitatively (QCA). A blinded nuclear physician analysed SPECT-MPI images for fixed and reversible perfusion defects. Two blinded cardiologists assessed CTA/CTP studies qualitatively. Vessels/territories with both >50 % stenosis on QCA and corresponding perfusion defect on SPECT-MPI were defined as ischaemic and formed the reference standard. All patients completed the CTA/CTP protocol with diagnostic image quality. Of 60 vessels/territories, 17 (28 %) were ischaemic according to QCA/SPECT-MPI criteria. Sensitivity, specificity, PPV, NPV and area under the ROC curve for CTA/CTP was 94 %, 98 %, 94 %, 98 % and 0.96 (P < 0.001) on a per-vessel/territory basis. Mean CTA/CTP radiation dose was 9.2 {+-} 7.4 mSv compared with 13.2 {+-} 2.2 mSv for SPECT-MPI (P < 0.001). Combined 320-detector CTA/CTP is accurate in identifying obstructive CAD causing perfusion abnormalities compared with combined QCA/SPECT-MPI, achieved with lower radiation dose than SPECT-MPI. (orig.)

  12. Diagnostic accuracy of combined coronary angiography and adenosine stress myocardial perfusion imaging using 320-detector computed tomography: pilot study

    International Nuclear Information System (INIS)

    Nasis, Arthur; Ko, Brian S.; Leung, Michael C.; Antonis, Paul R.; Wong, Dennis T.; Kyi, Leo; Cameron, James D.; Meredith, Ian T.; Seneviratne, Sujith K.; Nandurkar, Dee; Troupis, John M.

    2013-01-01

    To determine the diagnostic accuracy of combined 320-detector row computed tomography coronary angiography (CTA) and adenosine stress CT myocardial perfusion imaging (CTP) in detecting perfusion abnormalities caused by obstructive coronary artery disease (CAD). Twenty patients with suspected CAD who underwent initial investigation with single-photon-emission computed tomography myocardial perfusion imaging (SPECT-MPI) were recruited and underwent prospectively-gated 320-detector CTA/CTP and invasive angiography. Two blinded cardiologists evaluated invasive angiography images quantitatively (QCA). A blinded nuclear physician analysed SPECT-MPI images for fixed and reversible perfusion defects. Two blinded cardiologists assessed CTA/CTP studies qualitatively. Vessels/territories with both >50 % stenosis on QCA and corresponding perfusion defect on SPECT-MPI were defined as ischaemic and formed the reference standard. All patients completed the CTA/CTP protocol with diagnostic image quality. Of 60 vessels/territories, 17 (28 %) were ischaemic according to QCA/SPECT-MPI criteria. Sensitivity, specificity, PPV, NPV and area under the ROC curve for CTA/CTP was 94 %, 98 %, 94 %, 98 % and 0.96 (P < 0.001) on a per-vessel/territory basis. Mean CTA/CTP radiation dose was 9.2 ± 7.4 mSv compared with 13.2 ± 2.2 mSv for SPECT-MPI (P < 0.001). Combined 320-detector CTA/CTP is accurate in identifying obstructive CAD causing perfusion abnormalities compared with combined QCA/SPECT-MPI, achieved with lower radiation dose than SPECT-MPI. (orig.)

  13. Computed tomography myocardial perfusion vs {sup 15}O-water positron emission tomography and fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Michelle C.; Dweck, Marc R.; Golay, Saroj K. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); Mirsadraee, Saeed; Weir, Nicholas W.; Fletcher, Alison; Lucatelli, Christophe; Reid, John H. [University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); MacGillivray, Tom; Van Beek, Edwin J.R.; Newby, David E. [University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Edinburgh (United Kingdom); University of Edinburgh, Clinical Research Imaging Centre, Edinburgh (United Kingdom); Cruden, Nicholas L.; Henriksen, Peter A.; Uren, Neal [Edinburgh Heart Centre, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); McKillop, Graham; Patel, Dilip [Department of Radiology, Royal Infirmary of Edinburgh, Edinburgh (United Kingdom); Lima, Joao A.C. [Johns Hopkins Hospital, Departments of Medicine and Radiology, Baltimore, MD (United States)

    2017-03-15

    Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with {sup 15}O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR). 51 patients (63 (61-65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by ''snapshot'' adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80. PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32-2.20) vs 3.11 (2.44-3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32-2.20) vs 3.12 (2.44-3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71-76) vs 86 (84-88) HU, P < 0.001 and 101 (96-106) vs 111 (107-114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR. CT myocardial attenuation density correlates with {sup 15}O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD. (orig.)

  14. Correlation of angina pectoris and perfusion decrease by collateral circulation in single-vessel coronary chronic total occlusion using myocardial perfusion single-photon emssion computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Geon; Park, Ki Seong; Kang, Sae Ryung [Chonnam National University Hospital, Gwangju (Korea, Republic of); and others

    2016-03-15

    To evaluate the perfusion decrease in donor myocardium by collateral circulation and its correlation with angina pectoris in patients with chronic total occlusion (CTO) using myocardial perfusion single-photon emission computed tomography (MPS). Thirty-six patients with single-vessel CTO without any other stenosis were included. All patients underwent MPS and coronary angiography (CAG) within 2 months. Total 72 donor arteries were evaluated for the grades of collaterals to the CTO artery using the Rentrop grading system on CAG. Perfusion defects and perfusion scores in donor and CTO territories were analyzed on MPS. Myocardial perfusion of donor and CTO territories were evaluated according to the presence of angina pectoris and the grades of collateral circulation. When the CTO territory was ischemic, symptomatic patients showed higher summed difference scores in the CTO territory compared to asymptomatic patients (3.5 ± 2.4 vs. 1.5 ± 0.8 for symptomatic and asymptomatic groups respectively; p = 0.034). However, when the CTO territory was nonischemic, symptomatic patients showed higher summed stress scores (SSS, 4.3 ± 2.9 vs. 1.6 ± 1.2; p = 0.032) and summed rest scores (SRS, 4.2 ± 2.5 vs. 1.5 ± 1.1; p = 0.003) in the donor territories. On the per-vessel analysis, perfusion defects in donor territories were more frequent (0 % vs. 53 % vs. 86 % for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p < 0.001) and showed higher SSS (0.0 ± 0.0, 1.3 ± 1.6 and 2.1 ± 1.1 for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p = 0.001) and SRS (0.0 ± 0.0, 1.0 ± 1.4 and 1.7 ± 1.2; p = 0.003) at higher Rentrop grades, but their patterns were variable. Angina pectoris was related to either ischemia of the myocardium beyond CTO or a perfusion decrease in the donor myocardium. The perfusion decrease in donor myocardium positively correlated with the collateral grades.

  15. Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: Evaluation by perfusion computed tomography

    International Nuclear Information System (INIS)

    Koyasu, Sho; Isoda, Hiroyoshi; Tsuji, Yoshihisa; Yamamoto, Hiroshi; Matsueda, Kazuhiro; Watanabe, Yuji; Chiba, Tsutomu; Togashi, Kaori

    2012-01-01

    Purpose: Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT. Materials and methods: Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively. Results: Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92). Conclusion: Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.

  16. Hematocrit and Serum Hemoglobin Do Not Influence Values in Computed Tomography Perfusion of Patients With Acute Ischemic Stroke.

    Science.gov (United States)

    Karwacki, Grzegorz Marek; Benz, Matthias Richard; Tyndall, Anthony Joseph; Ulmer, Stephan

    There is a correlation between both serum hemoglobin (HGB) and hematocrit (HCT) and attenuation values of vessels in noncontrast-enhanced computed tomography (NECT), which could influence calculated perfusion maps in CT perfusion. We retrospectively included 45 patients, who presented with acute new neurological symptoms and underwent NECT and CT perfusion (128-row multi detector scanner, coverage: 6.9 cm craniocaudally; 80 kV; 200 mAs; temporal resolution: 2 seconds using 40 mL Ultravist 370 at a flow rate of 5 mL/s) on admission and a follow-up MRI within 1 week of admission. Hematocrit, HGB, and attenuation values did not differ between patients with stroke and controls. A statistically significant correlation was found between HCT and HGB and attenuation values in the internal carotid artery or middle cerebral artery on NECT (P Hematocrit and HGB do not influence calculated perfusion maps. There is no need for HCT/HGB-adjusted cerebral blood volume thresholds in stroke patients.

  17. Incremental value of myocardial perfusion over coronary angiography by spectral computed tomography in patients with intermediate to high likelihood of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Carrascosa, Patricia M., E-mail: investigacion@diagnosticomaipu.com.ar; Deviggiano, Alejandro; Capunay, Carlos; Campisi, Roxana; López Munain, Marina de; Vallejos, Javier; Tajer, Carlos; Rodriguez-Granillo, Gaston A.

    2015-04-15

    Highlights: •We evaluated myocardial perfusion by dual energy computed tomography (DECT). •We included patients with intermediate to high likelihood of coronary artery disease. •Stress myocardial perfusion by DECT had a reliable accuracy for the detection of ischemia. •Stress myocardial perfusion with DECT showed an incremental value over anatomical evaluation. •DECT imaging was associated to a significant reduction in radiation dose compared to SPECT. -- Abstract: Purpose: We sought to explore the diagnostic performance of dual energy computed tomography (DECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease (CAD). Materials and methods: Consecutive patients with known or suspected CAD referred for myocardial perfusion imaging by single-photon emission computed tomography (SPECT) constituted the study population and were scanned using a DECT scanner equipped with gemstone detectors for spectral imaging, and a SPECT. The same pharmacological stress was used for both scans. Results: Twenty-five patients were prospectively included in the study protocol. The mean age was 63.4 ± 10.6 years. The total mean effective radiation dose was 7.5 ± 1.2 mSv with DECT and 8.2 ± 1.7 mSv with SPECT (p = 0.007). A total of 425 left ventricular segments were evaluated by DECT, showing a reliable accuracy for the detection of reversible perfusion defects [area under ROC curve (AUC) 0.84 (0.80–0.87)]. Furthermore, adding stress myocardial perfusion provided a significant incremental value over anatomical evaluation alone by computed tomography coronary angiography [AUC 0.70 (0.65–0.74), p = 0.003]. Conclusions: In this pilot investigation, stress myocardial perfusion by DECT demonstrated a significant incremental value over anatomical evaluation alone by CTCA for the detection of reversible perfusion defects.

  18. Diagnostic performance of coronary CT angiography, stress dual-energy CT perfusion, and stress perfusion single-photon emission computed tomography for coronary artery disease: Comparison with combined invasive coronary angiography and stress perfusion cardiac MRI

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hyun Woo; Ko, Sung Min; Hwang, Hweung Kon; So, Young; Yi, Jeong Geun [Konkuk University Medical Center, Research Institute of Biomedical Science, Konkuk University School of Medicine, Seoul (Korea, Republic of); Lee, Eun Jeong [Dept. of Nuclear Medicine, Seoul Medical Center, Seoul (Korea, Republic of)

    2017-06-15

    To investigate the diagnostic performance of coronary computed tomography angiography (CCTA), stress dual-energy computed tomography perfusion (DE-CTP), stress perfusion single-photon emission computed tomography (SPECT), and the combinations of CCTA with myocardial perfusion imaging (CCTA + DE-CTP and CCTA + SPECT) for identifying coronary artery stenosis that causes myocardial hypoperfusion. Combined invasive coronary angiography (ICA) and stress perfusion cardiac magnetic resonance (SP-CMR) imaging are used as the reference standard. We retrospectively reviewed the records of 25 patients with suspected coronary artery disease, who underwent CCTA, DE-CTP, SPECT, SP-CMR, and ICA. The reference standard was defined as ≥ 50% stenosis by ICA, with a corresponding myocardial hypoperfusion on SP-CMR. For per-vascular territory analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 96, 96, 68, 93, and 68%, respectively, and specificities were 72, 75, 89, 85, and 94%, respectively. The areas under the receiver operating characteristic curve (AUCs) were 0.84 ± 0.05, 0.85 ± 0.05, 0.79 ± 0.06, 0.89 ± 0.04, and 0.81 ± 0.06, respectively. For per-patient analysis, the sensitivities of CCTA, DE-CTP, SPECT, CCTA + DE-CTP, and CCTA + SPECT were 100, 100, 89, 100, and 83%, respectively; the specificities were 14, 43, 57, 43, and 57%, respectively; and the AUCs were 0.57 ± 0.13, 0.71 ± 0.11, 0.73 ± 0.11, 0.71 ± 0.11, and 0.70 ± 0.11, respectively. The combination of CCTA and DE-CTP enhances specificity without a loss of sensitivity for detecting hemodynamically significant coronary artery stenosis, as defined by combined ICA and SP-CMR.

  19. Single photon emission computed tomography of technetium-99m tetrofosmin myocardial perfusion imaging in patients with systemic lupus erythematosus-A preliminary report

    International Nuclear Information System (INIS)

    Lin, Jen-Jhy; Hsu, Hsiu-Bao; Sun, Shung-Shung; Kao, Chia-Hung; Ho, Shung-Tai

    2003-01-01

    The purpose of this study was to evaluate the utility of single-photon emission computed tomography (SPECT) of technetium-99m tetrofosmin (Tc-99m TF) myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus (SLE). Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardial perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TF myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs. (author)

  20. A comparison of perfusion computed tomography and contrast enhanced computed tomography on radiation target volume delineation using rabbit VX2 brain tumor model

    International Nuclear Information System (INIS)

    Sun Changjin; Luo Yunxiu; Yu Jinming; Lu Haibo; Li Chao; Zhang Dekang; Huang Jianming; Wang Jie; Lang Jinyi

    2010-01-01

    Objective: To compare the accuracy of blood volume perfusion imaging (perfusion CT)with contrast enhanced 64-slice spiral computed tomography (CECT) in the evaluation of gross tumor volume (GTV) and clinical target volume (CTV) using rabbits with VX2 brain tumor. Methods: Perfusion CT and CECT were performed in 20 rabbits with VX2 brain tumor. The GTV and CTV calculated with the maximal and minimal diameter of each tumor in the blood volume (BV) maps and CECT were measured and compared to those in pathological specimens. Results: The mean value of the maximal and minimal diameter of GTV was (8.19 ± 2.29) mm and (4.83 ± 1.31) mm in pathological specimens, (11.98 ±3.29) mm and (7.03±1.82) mm in BV maps, while (6.36±3.85) mm and (3.17±1.93) mm in CECT images, which were significantly different (pathological specimen vs. BV map, t = 7.17, P =0.000;pathological specimen vs. CECT, t = 8.37, P = 0.000, respectively). The mean value of the maximal and minimal diameter of CTV in pathologic specimens was (12.87 ± 3.74) mm and (7.71 ± 2.15) mm, which was significantly different from that of GTV and CTV in CECT (t = - 3. 18, P = 0. 005 and t = - 4.24, P =0.000; t= -11.59,P=0.000 and t= -9.39, P=0.000), while similar with that of GTV in BV maps (t = - 1.95,P = 0. 067; t = - 2. 06, P = 0. 054). For CECT, the margin from GTV to CTV was 81.83% ±40.33% for the maximal diameter and 276.73% ± 131.46% for the minimal. While for BV maps, the margin was 7.93% ± 17. 84% and 12.52% ± 27. 83%, which was significant different from that for CECT images (t=7.36, P=0. 000 and t= -8.78, P=0.000). Conclusions: Compared with CECT, the BV map from 64-slice spiral CT perfusion imaging might have higher accuracy in target volume delineation for brain tumor. (authors)

  1. SPET brain perfusion imaging in mild traumatic brain injury without loss of consciousness and normal computed tomography.

    Science.gov (United States)

    Abu-Judeh, H H; Parker, R; Singh, M; el-Zeftawy, H; Atay, S; Kumar, M; Naddaf, S; Aleksic, S; Abdel-Dayem, H M

    1999-06-01

    We present SPET brain perfusion findings in 32 patients who suffered mild traumatic brain injury without loss of consciousness and normal computed tomography. None of the patients had previous traumatic brain injury, CVA, HIV, psychiatric disorders or a history of alcohol or drug abuse. Their ages ranged from 11 to 61 years (mean = 42). The study was performed in 20 patients (62%) within 3 months of the date of injury and in 12 (38%) patients more than 3 months post-injury. Nineteen patients (60%) were involved in a motor vehicle accident, 10 patients (31%) sustained a fall and three patients (9%) received a blow to the head. The most common complaints were headaches in 26 patients (81%), memory deficits in 15 (47%), dizziness in 13 (41%) and sleep disorders in eight (25%). The studies were acquired approximately 2 h after an intravenous injection of 740 MBq (20.0 mCi) of 99Tcm-HMPAO. All images were acquired on a triple-headed gamma camera. The data were displayed on a 10-grade colour scale, with 2-pixel thickness (7.4 mm), and were reviewed blind to the patient's history of symptoms. The cerebellum was used as the reference site (100% maximum value). Any decrease in cerebral perfusion in the cortex or basal ganglia less than 70%, or less than 50% in the medial temporal lobe, compared to the cerebellar reference was considered abnormal. The results show that 13 (41%) had normal studies and 19 (59%) were abnormal (13 studies performed within 3 months of the date of injury and six studies performed more than 3 months post-injury). Analysis of the abnormal studies revealed that 17 showed 48 focal lesions and two showed diffuse supratentorial hypoperfusion (one from each of the early and delayed imaging groups). The 12 abnormal studies performed early had 37 focal lesions and averaged 3.1 lesions per patient, whereas there was a reduction to--an average of 2.2 lesions per patient in the five studies (total 11 lesions) performed more than 3 months post-injury. In the

  2. Contrast enhancement by arterial perfusion during computed tomography (computed tomographic arteriography) of the pancreatic disease

    International Nuclear Information System (INIS)

    Takaki, Yukiari

    1983-01-01

    Computed tomographic arteriography (CTA) was performed on 52 cases of pancreatic disease in which was suspected clinically, and in which other method failed to yield a definitive diagnosis. For CTA, 65% meglumine diatrizoate 20 ml, diluted 1:3, was injected via a catherter inserted in an artery connected with the pancreas and the change with time of the pacreas CT number was studied. The normal pancreas stains deeply and the best contrast enhancement was obtained between 17 to 21 seconds after instillation of contrast medium. In the CTA findings in pancreatic cancer, low density areas with irregular internal structures are characteristic, and these characteristics were seen even in minute pancreatic cancers which could not be recognized by CT or the intravenous bolus injection method. On the other hand, in chronic pancreatitis, even when differentiation from pancreatic cancer is difficult with arterial and venous encasement in angiography, as long as the chronic pancreatitis is not very advanced ischemic changes are not seen, and this permits differentiation form normal pancreas. This also facilitates differentiation between pancreatitis and pancreatic cancer. In the intravenous bolus injection method, the chronological change of contrast enhancement in the pancreas was studied and the best contrast enhancement was obtained after 60 to 120 seconds. This method revealed no findings peculiar to pancreatic cancer. Based on the above, CTA was found to be useful for making in contributing to establishing a definitive diagnosis, detecting minute pancreatic cancer and to differentiate pancreatic cancer from chronic pancreatitis. (author)

  3. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tokihiro, E-mail: toyamamoto@ucdavis.edu [Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, California 95817 (United States); Kent, Michael S.; Wisner, Erik R. [Department of Surgical and Radiological Sciences, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Johnson, Lynelle R.; Stern, Joshua A. [Department of Medicine and Epidemiology, University of California Davis School of Veterinary Medicine, Davis, California 95616 (United States); Qi, Lihong [Department of Public Health Sciences, University of California Davis, Davis, California 95616 (United States); Fujita, Yukio [Department of Radiation Oncology, Tokai University, Isehara, Kanagawa 259-1193 (Japan); Boone, John M. [Department of Radiology, University of California Davis School of Medicine, Sacramento, California 95817 (United States)

    2016-07-15

    Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

  4. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model.

    Science.gov (United States)

    Yamamoto, Tokihiro; Kent, Michael S; Wisner, Erik R; Johnson, Lynelle R; Stern, Joshua A; Qi, Lihong; Fujita, Yukio; Boone, John M

    2016-07-01

    Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t-test. The mean TRE

  5. Single-energy computed tomography-based pulmonary perfusion imaging: Proof-of-principle in a canine model

    International Nuclear Information System (INIS)

    Yamamoto, Tokihiro; Kent, Michael S.; Wisner, Erik R.; Johnson, Lynelle R.; Stern, Joshua A.; Qi, Lihong; Fujita, Yukio; Boone, John M.

    2016-01-01

    Purpose: Radiotherapy (RT) that selectively avoids irradiating highly functional lung regions may reduce pulmonary toxicity, which is substantial in lung cancer RT. Single-energy computed tomography (CT) pulmonary perfusion imaging has several advantages (e.g., higher resolution) over other modalities and has great potential for widespread clinical implementation, particularly in RT. The purpose of this study was to establish proof-of-principle for single-energy CT perfusion imaging. Methods: Single-energy CT perfusion imaging is based on the following: (1) acquisition of end-inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast agents, (2) deformable image registration (DIR) for spatial mapping of those two CT image data sets, and (3) subtraction of the precontrast image data set from the postcontrast image data set, yielding a map of regional Hounsfield unit (HU) enhancement, a surrogate for regional perfusion. In a protocol approved by the institutional animal care and use committee, the authors acquired CT scans in the prone position for a total of 14 anesthetized canines (seven canines with normal lungs and seven canines with diseased lungs). The elastix algorithm was used for DIR. The accuracy of DIR was evaluated based on the target registration error (TRE) of 50 anatomic pulmonary landmarks per subject for 10 randomly selected subjects as well as on singularities (i.e., regions where the displacement vector field is not bijective). Prior to perfusion computation, HUs of the precontrast end-inspiratory image were corrected for variation in the lung inflation level between the precontrast and postcontrast end-inspiratory CT scans, using a model built from two additional precontrast CT scans at end-expiration and midinspiration. The authors also assessed spatial heterogeneity and gravitationally directed gradients of regional perfusion for normal lung subjects and diseased lung subjects using a two-sample two-tailed t

  6. Role of myocardial perfusion single photon emission computed tomography in pediatric cardiology practice

    Directory of Open Access Journals (Sweden)

    Sundaram P

    2009-01-01

    Full Text Available Diagnostic and prognostic power of myocardial perfusion imaging in patients with coronary artery disease has been demonstrated with planar imaging which was further improvised with addition of gated SPECT and newer Technetium labeled myocardial perfusion tracers like SestaMIBI, Tetrofosmin. Myocardial perfusion abnormalities at rest and after stress are considered to be the best predictors of cardiac event-free survival in adults with ischemic heart disease. This article highlights various myocardial perfusion imaging (MPIradiopharmaceuticals, exercise procedures, pharmacological stress protocols, indications for MPI and myocardial perfusion patterns in children with some of the common congenital and acquired heart diseases.

  7. Differences in cerebral perfusion deficits in mild traumatic brain injury and depression using single-photon emission computed tomography.

    Science.gov (United States)

    Romero, Kristoffer; Black, Sandra E; Feinstein, Anthony

    2014-01-01

    Numerous studies have shown decreased perfusion in the prefrontal cortex following mild traumatic brain injury (mTBI). However, similar hypoperfusion can also be observed in depression. Given the high prevalence of depressive symptoms following mTBI, it is unclear to what extent depression influences hypoperfusion in TBI. Mild TBI patients without depressive symptoms (mTBI-noD, n = 39), TBI patients with depressive symptoms (mTBI-D, n = 13), and 15 patients with major depressive disorder (MDD), but no TBI were given 99m T-ECD single-photon emission computed tomography (SPECT) scans within 2 weeks of injury. All subjects completed tests of information processing speed, complex attention, and executive functioning, and a self-report questionnaire measuring symptoms of psychological distress. Between-group comparisons of quantified SPECT perfusion were undertaken using univariate and multivariate (partial least squares) analyses. mTBI-D and mTBI-noD groups did not differ in terms of cerebral perfusion. However, patients with MDD showed hypoperfusion compared to both TBI groups in several frontal (orbitofrontal, middle frontal, and superior frontal cortex), superior temporal, and posterior cingulate regions. The mTBI-D group showed poorer performance on a measure of complex attention and working memory compared to both the mTBI-noD and MDD groups. These results suggest that depressive symptoms do not affect SPECT perfusion in the sub-acute phase following a mild TBI. Conversely, MDD is associated with hypoperfusion primarily in frontal regions.

  8. Effect of intravenous contrast agent volume on colorectal cancer vascular parameters as measured by perfusion computed tomography

    International Nuclear Information System (INIS)

    Goh, V.; Bartram, C.; Halligan, S.

    2009-01-01

    Aim: To determine the effect of two different contrast agent volumes on quantitative and semi-quantitative vascular parameters as measured by perfusion computed tomography (CT) in colorectal cancer. Materials and methods: Following ethical approval and informed consent, eight prospectively recruited patients with proven colorectal adenocarcinoma underwent two separate perfusion CT studies on the same day after (a) 100 ml and (b) 50 ml of a 340 mg/ml iodinated contrast medium, respectively. Quantitative (blood volume, blood flow, permeability surface area product) and semi-quantitative (peak enhancement, time to peak enhancement) tumour vascular parameters were determined using commercial software based on distributed parameter analysis and compared using t-testing. Results: Tumour blood volume, blood flow, and permeability surface area product were not substantially different following the injection of 100 ml and 50 ml contrast medium: 6.12 versus 6.23 ml/100 g tissue; 73.4 versus 71.3 ml/min/100 g tissue; 15.6 versus 15.3 ml/min/100 g tissue for 100 and 50 ml, respectively; p > 0.05. Tumour peak enhancement and time to peak were significantly greater following the injection of 100 ml versus 50 ml contrast medium: 41.2 versus 28.5 HU; 16.1 versus 11.8 s for 100 ml and 50 ml, respectively; p = 0.002; p = 0.0003. Conclusion: Quantitative parameters do not appear to change substantially with a higher contrast agent volume suggesting a combined diagnostic staging-perfusion CT study following a single injection is feasible for colorectal cancer

  9. Comparison between perfusion computed tomography and dynamic contrast-enhanced magnetic resonance imaging in assessing glioblastoma microvasculature

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Zhong Zheng, E-mail: jzz2397@163.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Shi, Wei, E-mail: sw740104@hotmail.com [Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu (China); Shi, Jin Long, E-mail: shij_ns@163.com [Department of Neurosurgery, Affiliated Hospital of Nantong University, 20 Xisi Road, Nantong 226001, Jiangsu (China); Shen, Dan Dan, E-mail: 1021121084@qq.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Gu, Hong Mei, E-mail: guhongmei71@163.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China); Zhou, Xue Jun, E-mail: 56516400@qq.com [Department of Radiology, Affiliated Hospital of Nantong University, No. 20 Xisi Road Nantong 226001, Jiangsu (China)

    2017-02-15

    Purpose: Perfusion computed tomography (PCT) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provide independent measurements of biomarkers related to tumor perfusion. The aim of this study was to compare the two techniques in assessing glioblastoma microvasculature. Materials and methods: Twenty-five patients diagnosed with glioblastoma (14 males and 11 females; 51 ± 11 years old, ranging from 33 to 70 years) were includede in this prospective study. All patients underwent both PCT and DCE-MRI. Imaging was performed on a 256-slice CT scanner and a 3-T MRI system. PCT yielded permeability surface-area product (PS) using deconvolution physiological models; meanwhile, DCE-MRI determined volume transfer constant (K{sup trans}) using the Tofts-Kermode compartment model. All cases were submitted to surgical intervention, and CD105-microvascular density (CD105-MVD) was measured in each glioblastoma specimen. Then, Spearman’s correlation coefficients and Bland-Altman plots were obtained for PS, K{sup trans} and CD105-MVD. P < 0.05 was considered statistically significant. Results: Tumor PS and K{sup trans} values were correlated with CD105-MVD (r = 0.644, P < 0.001; r = 0.683, P < 0.001). In addition, PS was correlated with K{sup trans} in glioblastoma (r = 0.931, P < 0.001). Finally, Bland-Altman plots showed no significant differences between PS and K{sup trans} (P = 0.063). Conclusion: PCT and DCE-MRI measurements of glioblastoma perfusion biomarkers have similar results, suggesting that both techniques may have comparable utility. Therefore, PCT may serve as an alternative modality to DCE-MRI for the in vivo evaluation of glioblastoma microvasculature.

  10. Brain perfusion single photon emission computed tomography in major psychiatric disorders: From basics to clinical practice

    International Nuclear Information System (INIS)

    Santra, Amburanjan; Kumar, Rakesh

    2014-01-01

    Brain single photon emission computed tomography (SPECT) is a well-established and reliable method to assess brain function through measurement of regional cerebral blood flow (rCBF). It can be used to define a patient's pathophysiological status when neurological or psychiatric symptoms cannot be explained by anatomical neuroimaging findings. Though there is ample evidence validating brain SPECT as a technique to track human behavior and correlating psychiatric disorders with dysfunction of specific brain regions, only few psychiatrists have adopted brain SPECT in routine clinical practice. It can be utilized to evaluate the involvement of brain regions in a particular patient, to individualize treatment on basis of SPECT findings, to monitor the treatment response and modify treatment, if necessary. In this article, we have reviewed the available studies in this regard from existing literature and tried to present the evidence for establishing the clinical role of brain SPECT in major psychiatric illnesses

  11. Brain perfusion single photon emission computed tomography in children after acute encephalopathy

    International Nuclear Information System (INIS)

    Kurihara, Mana; Nakae, Yoichiro; Kohagizawa, Toshitaka; Eto, Yoshikatsu

    2005-01-01

    We studied single photon emission computed tomography (SPECT) of 15 children with acute encephalopathy after more than 1 year from the onset, using technetium-99 m-L, L-ethyl cystinate dimer ( 99m Tc-ECD) and a three-dementional stereotaxic region of interest template. Regional cerebral blood flow was evaluated and divided in three groups according to the severity of disability: absent or mild, moderate, and severe. There was no abnormality on SPECT in the patients without disability or with mild disability. Diffuse hypoperfusion was shown in the groups with moderate and severe disability. The patients with severe disability showed hypoperfusion in the pericallosal, frontal and central areas which was more pronounced than in the patients with moderate disability. (author)

  12. Metaanalysis of Diagnostic Performance of Computed Coronary Tomography Angiography, Computed Tomography Perfusion and Computed Tomography-Fractional Flow Reserve in Functional Myocardial Ischemia Assessment versus Invasive Fractional Flow Reserve

    Science.gov (United States)

    Gonzalez, Jorge A.; Lipinski, Michael J.; Flors, Lucia F.; Shaw, Peter; Kramer, Christopher M.; Salerno, Michael

    2015-01-01

    We sought to compare the diagnostic performance of computed coronary tomography angiography (CCTA), computed tomography perfusion (CTP) and computed tomography fractional flow reserve (CT-FFR) for assessing the functional significance of coronary stenosis as defined by invasive fractional flow reserve (FFR), in patients with known or suspected coronary artery disease. CCTA has proven clinically useful for excluding obstructive CAD due to its high sensitivity and negative predictive value (NPV), however the ability of CTA to identify functionally significant CAD has remained challenging. We searched PubMed/Medline for studies evaluating CCTA, CTP or CT-FFR for the non-invasive detection of obstructive CAD as compared to catheter-derived FFR as the reference standard. Pooled sensitivity, specificity, PPV, NPV, likelihood ratios (LR), odds ratio (OR) of all diagnostic tests were assessed. Eighteen studies involving a total of 1535 patients were included. CTA demonstrated a pooled sensitivity of 0.92, specificity 0.43, PPV of 0.56 and NPV of 0.87 on a per-patient level. CT-FFR and CTP increased the specificity to 0.72 and 0.77 respectively (P=0.004 and P=0.0009)) resulting in higher point estimates for PPV 0.70 and 0.83 respectively. There was no improvement in the sensitivity. The CTP protocol involved more radiation (3.5 mSv CCTA VS 9.6 mSv CTP) and a higher volume of iodinated contrast (145 mL). In conclusion, CTP and CT-FFR improve the specificity of CCTA for detecting functionally significant stenosis as defined by invasive FFR on a per-patient level; both techniques could advance the ability to non-invasively detect the functional significance of coronary lesions. PMID:26347004

  13. Perfusion single photon emission computed tomography of myocardium with 99mTc-tetra-phosmine (Myoview)

    International Nuclear Information System (INIS)

    Khusainova, Sh.K.; Zholdybaj, Zh.; Potapov, A.V.; Karaev, O.S.; Akhmetova, G.R.

    2003-01-01

    The aim of the work is study of diagnostic valuation of myocardium scintigraphy with help of the 99m Tc-tetrophosmin, Myoview in determination of latent coronary blood-circulation destabilization in liquidators of the Chernobyl accident (LChA) and persons living in the Semipalatinsk test site (STS) region. The perfusion myocardium scintigraphy was made to 71 patients (5 women and 66 men) from those - 33 LChA and 37 - residents of STS region. The examination was carried out in 'ADAC Genesys Epic' apparatus (USA). Mean age of the patients was 46.3±2.3 years old. In the result of examination the left ventricle myocardium perfusion reduction on 30 % and more was revealed. The distribution of radiopharmaceutical by the myocardium parts were relatively proportional both with pharmacologic load (ATF, dipiridamol) and the rest in 48 (67.7 %) patients. So, the 99m Tc-tetrophosmin, Myoview pharmaceutical allows with high rate estimate the myocardium perfusion and get a high qualitative images, that permits to identify localization, character and distribution of myocardium perfusion reduction in the revealed areas. In the result of myocardine scintigraphy with the pharmacologic load trial conducting the both the latent coronary blood-circulation destabilization forms and the incoming ones were differentiated

  14. Perfusion computed tomography for detection of hepatocellular carcinoma in patients with liver cirrhosis

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael A.; Kartalis, Nikolaos; Grigoriadis, Aristeidis; Loizou, Louiza; Leidner, Bertil; Aspelin, Peter; Brismar, Torkel B. [Karolinska Institute, Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Stockholm (Sweden); Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Staal, Per [Karolinska University Hospital, Department of Hepatology, Stockholm (Sweden)

    2015-11-15

    To evaluate the diagnostic performance of dynamic perfusion CT (P-CT) for detection of hepatocellular carcinoma (HCC) in the cirrhotic liver. Twenty-six cirrhotic patients (19 men, aged 69 ± 10 years) with suspicion of HCC prospectively underwent P-CT of the liver using the 4D spiral-mode (100/80 kV; 150/175mAs/rot) of a dual-source system. Two readers assessed: (1) arterial liver-perfusion (ALP), portal-venous liver-perfusion (PLP) and hepatic perfusion-index (HPI) maps alone; and (2) side-by-side with maximum-intensity-projections of arterial time-points (art-MIP) for detection of HCC using histopathology and imaging follow-up as standard of reference. Another reader quantitatively assessed perfusion maps of detected lesions. A total of 48 HCCs in 21/26 (81 %) patients with a mean size of 20 ± 10 mm were detected by histopathology (9/48, 19 %) or imaging follow-up (39/48, 81 %). Detection rates (Reader1/Reader2) of HPI maps and side-by-side analysis of HPI combined with arterial MIP were 92/88 % and 98/96 %, respectively. Positive-predictive values were 63/63 % and 68/71 %, respectively. A cut-off value of ≥85 % HPI and ≥99 % HPI yielded a sensitivity and specificity of 100 %, respectively, for detection of HCC. P-CT shows a high sensitivity for detection of HCC in the cirrhotic liver. Quantitative assessment has the potential to reduce false-positive findings improving the specificity of HCC diagnosis. (orig.)

  15. 99mTc-Hexamethyl Propyleneamine Oxime Brain Perfusion Single Photon Emission Computed Tomography in Characterization of Dementia: An Initial Experience in Indian Clinical Practice

    International Nuclear Information System (INIS)

    Santra, Amburanjan; Sinha, Gaurav Kumar; Neogi, Rajarshi; Thukral, Ramesh Kumar

    2014-01-01

    There is a growing health burden in developing countries due to recent trends of increasing incidence of neurodegenerative diseases. To reduce the healthcare cost and effective management of dementia illness, early diagnosis, accurate differentiation and their progression assessment is becoming crucially important. We are utilizing 99m Tc-d, l-hexamethyl propyleneamine oxime (HMPAO) brain perfusion single photon emission computed tomography (SPECT) to characterize dementia on the basis of perfusion patterns and observed significant improvement in their management. Eleven patients (median age of 60 years range of 53-83 years) with clinical suspicion of dementia underwent 99m Tc-HMPAO brain perfusion SPECT. SPECT-computed tomography acquisition done, data are reconstructed, reviewed in three view and further processed in “neurogam” to get voxel based analysis and the comparison with age based normal database and surface mapping. Final diagnosis was done with clinical correlation. Four patients are diagnosed as Alzheimer's disease, two as frontotemporal dementia, one as dementia of Lewy bodies, two as vascular dementia and two as pseudodementia. All imaging findings are well-correlated with clinical background. Brain perfusion SPECT with HMPAO was very helpful to us in characterizing the patients of dementia by its perfusion pattern

  16. TU-A-9A-10: Verification of Photoacoustic Computed Tomography Perfusion Imaging Using DCE-CT

    International Nuclear Information System (INIS)

    Roth, A; Krutulis, M; Verleker, A; Stantz, K

    2014-01-01

    Purpose: We propose to verify quantifiable perfusion information generated by a Photoacoustic Computed Tomography (PCT) scanner using Dynamic Contrast-Enhanced CT (DCE-CT), and to investigate physicsbased models of acoustic properties of tissue and photon transport to improve quantification. These corrections first necessitate a skin identifying algorithms to reduce speed-of-sound blurring and empirical photon correction methods. Methods: Xenograft mice (n=5) of breast cancer was imaged using DCE-CT which was followed by DCE-PCT. To obtain CT perfusion data, each mouse was i.v. injected (0.2mL Isovue @0.5mL/min) and subsequent radio-opaque time curves fit to a 2-compartmental model on a voxel-wise basis. For DCE-PCT, different concentrations of ICG (250, 125, and 62.5 micro-Molar) were injected at the same rate, but also acquired at different sampling rates (3, 6, and 12 seconds). The time intensity curves from PCT were fit to a 1-compartmental model on a voxel by voxel basis. The images were coregistered (Oncentra) based on the structural similarities of the tumor vasculature after which we compared both the contrastenhanced dynamics and the vascular physiology. Results: Moderate to high doses of ICG impact the washin phase of the PCT contrast due to photon losses as a function of depth. A semi-automatic algorithm has been developed to identify the skin margin, and subsequent MC and empirical models of photon transport and variations in speed-of-sound are being evaluated. Conclusion: From our results we find that there is a need to apply photon and speed-of-sound corrections to our PCT data to improve the quantifiable image data at depth in the tumor for PCT. The dose and injection rate may help in reducing large systematic effects. Our project is partially funded by a NIH SBIR grant

  17. Advanced Gastric Cancer and Perfusion Imaging Using a Multidetector Row Computed Tomography: Correlation with Prognostic Determinants

    International Nuclear Information System (INIS)

    Zhang, Huan; Pan, Zilai; Du, Lianjun; Yan, Chao; Ding, Bei; Song, Qi; Ling, Huawei; Chen, Kemin

    2008-01-01

    Objective : To investigate the relationship between the perfusion CT features and the clinicopathologically determined prognostic factors in advanced gastric cancer cases. Materials and Methods : A perfusion CT was performed on 31 patients with gastric cancer one week before surgery using a 16-channel multi-detector CT (MDCT) instrument. The data were analyzed with commercially available software to calculate tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS). The microvessel density (MVD), was evaluated by immunohistochemical staining of the surgical specimens with anti-CD34. All of the findings were analyzed prospectively and correlated with the clinicopathological findings, which included histological grading, presence of lymph node metastasis, serosal involvement, distant metastasis, tumor, node, metastasis (TNM) staging, and MVD. The statistical analyses used included the Student's t-test and the Spearman rank correlation were performed in SPSS 11.5. Result : The mean perfusion values and MVD for tumors were as follows: BF (48.14+/-16.46 ml/100 g/min), BV (6.70+/-2.95 ml/100 g), MTT (11.75+/-4.02 s), PS (14.17+/-5.23 ml/100 g/min) and MVD (41.7+/-11.53). Moreover, a significant difference in the PS values was found between patients with or without lymphatic involvement (p = 0.038), as well as with different histological grades (p 0.04) and TNM stagings (p = 0.026). However, BF, BV, MTT, and MVD of gastric cancer revealed no significant relationship with the clinicopathological findings described above (p > 0.05). Conclusion : The perfusion CT values of the permeable surface could serve as a useful prognostic indicator in patients with advanced gastric cancer

  18. Advanced Gastric Cancer and Perfusion Imaging Using a Multidetector Row Computed Tomography: Correlation with Prognostic Determinants

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huan; Pan, Zilai; Du, Lianjun; Yan, Chao; Ding, Bei; Song, Qi; Ling, Huawei; Chen, Kemin [Jiaotong University, Jiaotong (China)

    2008-04-15

    Objective : To investigate the relationship between the perfusion CT features and the clinicopathologically determined prognostic factors in advanced gastric cancer cases. Materials and Methods : A perfusion CT was performed on 31 patients with gastric cancer one week before surgery using a 16-channel multi-detector CT (MDCT) instrument. The data were analyzed with commercially available software to calculate tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS). The microvessel density (MVD), was evaluated by immunohistochemical staining of the surgical specimens with anti-CD34. All of the findings were analyzed prospectively and correlated with the clinicopathological findings, which included histological grading, presence of lymph node metastasis, serosal involvement, distant metastasis, tumor, node, metastasis (TNM) staging, and MVD. The statistical analyses used included the Student's t-test and the Spearman rank correlation were performed in SPSS 11.5. Result : The mean perfusion values and MVD for tumors were as follows: BF (48.14+/-16.46 ml/100 g/min), BV (6.70+/-2.95 ml/100 g), MTT (11.75+/-4.02 s), PS (14.17+/-5.23 ml/100 g/min) and MVD (41.7+/-11.53). Moreover, a significant difference in the PS values was found between patients with or without lymphatic involvement (p = 0.038), as well as with different histological grades (p 0.04) and TNM stagings (p = 0.026). However, BF, BV, MTT, and MVD of gastric cancer revealed no significant relationship with the clinicopathological findings described above (p > 0.05). Conclusion : The perfusion CT values of the permeable surface could serve as a useful prognostic indicator in patients with advanced gastric cancer.

  19. Hemimegalencephaly: a rare cause of hemihypoperfusion on 99m technetium-ethyl cysteinate dimer brain perfusion single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Damle, Nishikant A.; Singhal, Abhinav; Mukherjee, Anirban; Sahoo, Manas Kumar; Tripathi, Madhavi; Bal, Chandrasekhar

    2013-01-01

    Hemimegalencephaly is a rare congenital neuronal migration disorder that can presents with the equally rare finding of hemihypoperfusion on brain perfusion single-photon emission computed tomography (SPECT). It is an extremely rare cause of intractable epilepsy. Technetium-99m ethyl cysteinate dimer (ECD) brain perfusion SPECT is useful in excluding other foci of hypoperfusion in the contralateral since hemispherectomy has been suggested to be the treatment of choice. Furthermore, hemimegalencephaly may present with hyper as well as hypoperfusion on ECD SPECT. We present the case of an 11-year-old male child with intractable seizures who showed hemihypoperfusion in the hemimegalecephalic hemisphere. (author)

  20. Computed Tomography Perfusion of the liver: Assessment of Pure Portal Blood Flow Studied with CT Perfusion During Superior Mesenteric Arterial Portography

    International Nuclear Information System (INIS)

    Kojima, H.; Tanigawa, N.; Komemushi, A.; Kariya, S.; Sawada, S.

    2004-01-01

    Purpose: To quantitatively assess the portal component of hepatic blood flow using computed tomography (CT) perfusion studies during superior mesenteric arterial portography. Material and Methods: Thirty-four patients with hepatocellular carcinoma and liver cirrhosis (LC) and 13 patients with liver metastasis without chronic liver disease were enrolled in this study. Ten milliliters of a non-ionic contrast medium (150 mgI) was injected at a rate of 5 ml/s via a catheter placed in the superior mesenteric artery. Single-slice cine CT images at the level of the main trunk or the right/left main trunk of the portal vein were acquired over 40 s. The deconvolution method was then used on these CT images to measure blood flow (BF), blood volume (BV), and mean transit time (MTT) in (a) liver parenchyma in patients with HCC and liver cirrhosis; (b) liver parenchyma in patients with liver metastasis without cirrhosis; (c) directly in the HCC; and (d) directly in one of the metastases. Results: In 34 LC patients (a), BF, BV, and MTT in the liver parenchyma were 44.7±24.5 ml/min/100 g, 3.9±2.4 ml/100 g, and 10.9±5.5 s, respectively. In 13 patients without cirrhosis (b), BF, BV, and MTT in the liver parenchyma were 89.6±52.0 ml/min/100 g, 6.3 ±3.2 ml/100 g, and 8.7±3.6 sec, respectively. A significant difference in BF and BV was seen in patients with liver cirrhosis compared to those without cirrhosis. BF, BV, and MTT measured directly in HCC (c) were 6.5±4.5 ml/min/100 g, 0.4±0.4 ml/100 g, and 3.0±3.1 sec respectively, and BF, BV, and MTT in liver metastases (d) were 19.3 ± 21.7 ml/min/100 g, 0.6±0.8 ml/100 g, and 1.8±1.6 s, respectively. Conclusion: CT perfusion studies during superior mesenteric arterial portography allow quantitative assessment of pure portal blood flow in the liver

  1. Brain perfusion imaging using a Reconstruction-of-Difference (RoD) approach for cone-beam computed tomography

    Science.gov (United States)

    Mow, M.; Zbijewski, W.; Sisniega, A.; Xu, J.; Dang, H.; Stayman, J. W.; Wang, X.; Foos, D. H.; Koliatsos, V.; Aygun, N.; Siewerdsen, J. H.

    2017-03-01

    Purpose: To improve the timely detection and treatment of intracranial hemorrhage or ischemic stroke, recent efforts include the development of cone-beam CT (CBCT) systems for perfusion imaging and new approaches to estimate perfusion parameters despite slow rotation speeds compared to multi-detector CT (MDCT) systems. This work describes development of a brain perfusion CBCT method using a reconstruction of difference (RoD) approach to enable perfusion imaging on a newly developed CBCT head scanner prototype. Methods: A new reconstruction approach using RoD with a penalized-likelihood framework was developed to image the temporal dynamics of vascular enhancement. A digital perfusion simulation was developed to give a realistic representation of brain anatomy, artifacts, noise, scanner characteristics, and hemo-dynamic properties. This simulation includes a digital brain phantom, time-attenuation curves and noise parameters, a novel forward projection method for improved computational efficiency, and perfusion parameter calculation. Results: Our results show the feasibility of estimating perfusion parameters from a set of images reconstructed from slow scans, sparse data sets, and arc length scans as short as 60 degrees. The RoD framework significantly reduces noise and time-varying artifacts from inconsistent projections. Proper regularization and the use of overlapping reconstructed arcs can potentially further decrease bias and increase temporal resolution, respectively. Conclusions: A digital brain perfusion simulation with RoD imaging approach has been developed and supports the feasibility of using a CBCT head scanner for perfusion imaging. Future work will include testing with data acquired using a 3D-printed perfusion phantom currently and translation to preclinical and clinical studies.

  2. Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

    Directory of Open Access Journals (Sweden)

    Gianluca Pontone

    2015-01-01

    Full Text Available Coronary artery disease (CAD is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT, functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach.

  3. Whole tumour first-pass perfusion using a low-dose method with 64-section multidetector row computed tomography in oesophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Chen Tianwu; Yang Zhigang; Dong Zhihui; Li Yuan; Yao Jin; Wang Qiling; Qian Lingling

    2011-01-01

    Purpose: To propose a low-dose method at tube current-time product of 50 mAs for whole tumour first-pass perfusion of oesophageal squamous cell carcinoma using 64-section multidetector row computed tomography (MDCT), and to assess the original image quality and accuracy of perfusion parameters. Materials and methods: Fifty-nine consecutive patients with confirmed oesophageal squamous cell carcinomas were enrolled into our study, and underwent whole tumour first-pass perfusion scan with 64-section MDCT at 50 mAs. Image data were statistically reviewed focusing on original image quality demonstrated by image-quality scores and signal-to-noise (S/N) ratios; and perfusion parameters including perfusion (PF, in ml/min/ml), peak enhanced density (PED, in HU), time to peak (TTP, in seconds) and blood volume (BV, in ml/100 g) for the tumour. To test the interobserver agreement of perfusion measurements, perfusion analyses were repeatedly performed. Results: Original image-quality scores were 4.71 ± 0.49 whereas S/N ratios were 5.21 ± 2.05, and the scores were correlated with the S/N ratios (r = 0.465, p < 0.0001). Mean values for PF, PED, TTP and BV of the tumour were 33.27 ± 24.15 ml/min/ml, 24.06 ± 9.87 HU, 29.42 ± 8.61 s, and 12.45 ± 12.22 ml/100 g, respectively. Intraclass correlation coefficient between the replicated measurements of each perfusion parameter was greater than 0.99, and mean difference of the replicated measurements of each parameter was close to zero. Conclusion: Whole tumour first-pass perfusion with 64-section MDCT at low-dose radiation could be reproducible to assess microcirculation in oesophageal squamous cell carcinoma without compromising subjective original image quality of the tumour.

  4. Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

    International Nuclear Information System (INIS)

    Koome, Miriam; Thevathasan, Arthur; Yan, Bernard; Churilov, Leonid; Chen, Ziyuan; Chen, Ziyi; Naylor, Jillian; Kwan, Patrick

    2016-01-01

    Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT). We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T max , cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined. Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T max (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T max (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T max 0.65. CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT. (orig.)

  5. Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Koome, Miriam; Thevathasan, Arthur; Yan, Bernard [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Churilov, Leonid [University of Melbourne, Florey Neuroscience Institutes, Austin Health, Melbourne (Australia); Chen, Ziyuan [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Tsinghua University, School of Medicine, Beijing (China); Chen, Ziyi [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Sun Yat-Sen University, First Affiliated Hospital, Guangdong (China); Naylor, Jillian; Kwan, Patrick [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); The University of Melbourne, Department of Medicine, Melbourne (Australia)

    2016-06-15

    Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT). We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T{sub max}, cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined. Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T{sub max} (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T{sub max} (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T{sub max} 0.65. CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT. (orig.)

  6. Performance of Thallium-201 Electrocardiography-gated Myocardial Perfusion Single Photon Emission Computed Tomography to Assess Left Ventricular Function

    Directory of Open Access Journals (Sweden)

    Guang-Uei Hung

    2005-05-01

    Full Text Available This study evaluated the performance of gated single photon emission computed tomography (SPECT with thallium-201 (201Tl in assessing left ventricular ejection fraction (LVEF, end-diastolic volume (EDV, and end-systolic volume (ESV in Taiwanese by determining repeatability and correlation with two-dimensional (2D echocardiography. A total of 18 patients underwent two sequential gated SPECT acquisitions within 30 minutes in the resting state to assess repeatability. Another 28 patients who underwent gated SPECT and 2D echocardiography within 7 days were included for comparison. The two sequential measurements were well correlated with respect to LVEF, EDV, and ESV (r = 0.97, 0.95, and 0.97, respectively, all p < 0.0001. Bland-Altman analysis revealed that two standard deviations of the absolute difference between the two sequential measurements for LVEF, EDV, and ESV were 6.4%, 16.8 mL, and 8.6 mL, respectively. For LVEF, EDV, and ESV, correlations between redistribution 201Tl-gated SPECT and echocardiography were also excellent (all r = 0.83, p < 0.0001. LVEF was similar with 201Tl-gated SPECT and echocardiography, but EDV and ESV were significantly higher with echocardiography (p < 0.05. Our study revealed that 201Tl-gated SPECT has high repeatability and excellent correlation with echocardiography for the assessment of LVEF and volumes in Taiwanese. These results support the clinical application of gated SPECT in routine 201Tl myocardial perfusion imaging in Taiwanese.

  7. Perfusion computed tomography imaging of abdominal aortic aneurysms may be of value for patient specific rupture risk estimation.

    Science.gov (United States)

    Kontopodis, Nikolaos; Galanakis, Nikolaos; Tsetis, Dimitrios; Ioannou, Christos V

    2017-04-01

    Abdominal aortic aneurysm (AAA) continues to pose a significant cause of unexpected mortality in the developed countries with its incidence constantly rising. The indication of elective surgical repair is currently based on the maximum diameter and growth rate criteria which represent an oversimplification of the Law of Laplace stating that the stress exerted in a cylinder or sphere is proportional to its radius. These criteria fail to capture the complex pathophysiology of the aneurismal disease thus often leading to therapeutic inaccuracies (treating large AAAs with a very low actual rupture risk while observing smaller ones with a much greater risk). Aneurysmal disease is mainly a degenerative process leading to loss of structural integrity of the diseased aortic wall which cannot withhold the stresses due to systemic pressurization. Moreover aortic wall degeneration has been shown to be a localized phenomenon and rupture depends on the pointwise comparison of strength and stress rather than a global aortic wall weakening. Ex-vivo mechanical studies have related vessel wall hypoxia to loss of structural endurance and reduced wall strength. Therefore a module to capture in vivo variation of aortic wall blood supply and oxygenation would be of value for the evaluation of AAA rupture risk. Perfusion computed tomography (PCT) imaging represents a novel technique which has been already used to estimate tissue vascularity in several clinical conditions but not aneurismal disease. We hypothesize that PCT could be used as an adjunct tool during AAA diagnostics in order to evaluate aortic wall oxygenation in vivo, therefore providing a possible means to identify weak spots making the lesion amenable to rupture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Interventional model establishment and computed tomography perfusion imaging for early diagnosis of acute cerebral infarction in dogs

    International Nuclear Information System (INIS)

    Shi Haibin; Liu Sheng; Ji Libiao; Li Lingsun; Huang Jun

    2005-01-01

    Objective: To establish interventionally a new canine model of focal cerebral infarction suitable to the study of imaging diagnosis and thrombolytic therapy, and to evaluate the application of computed tomography perfusion (CTP) in super acute ischemic cerebrovascular disease. Methods: Ten beagle adult dogs with self white thrombi of venous blood, injected into the left internal carotid arteries through 4F headhunter catheter selectively were created under fluoroscopic guidance. The cerebral angiography was performed before and after the embolization and the patency of the occluded cerebral arteries was observed with angiography at 1, 2 and 5 hours after the procedure. The CTP was performed at 2 hours after embolization. These dogs were sacrificed and their cerebra were taken out for pathologic study at 24th hour. Results: The occlusions of middle cerebral artery were shown angiographically in all 10 dogs with additional other cerebral arteries occlusion in 4. All occluded arteries were not recanalized at 2 hours after embolization, but the occluded arteries of 2 canines were partly recanalized at 5 hours. The regional cerebral blood flow (rCBF) was decreased to 48.3% ± 13.2% (33.7%-69.2%) in CTP of 9 canines showing no significant difference between digital subtraction angiography (DSA) and CTP (P>0.05). All dogs were survived at 24 hours without any severe complications. The cerebral infarction was found in deep part of cerebrum of all dogs. Conclusions: The establishment of acute cerebral infarction model in dogs with interventional technique is simple, micro invasive and reliable, for investigating CTP as a fast, accurate and no invasive method in evaluating the canine super acute ischemic cerebrovascular disease. (authors)

  9. Comparison of 4-Dimensional Computed Tomography Ventilation With Nuclear Medicine Ventilation-Perfusion Imaging: A Clinical Validation Study

    International Nuclear Information System (INIS)

    Vinogradskiy, Yevgeniy; Koo, Phillip J.; Castillo, Richard; Castillo, Edward; Guerrero, Thomas; Gaspar, Laurie E.; Miften, Moyed; Kavanagh, Brian D.

    2014-01-01

    Purpose: Four-dimensional computed tomography (4DCT) ventilation imaging provides lung function information for lung cancer patients undergoing radiation therapy. Before 4DCT-ventilation can be implemented clinically it needs to be validated against an established imaging modality. The purpose of this work was to compare 4DCT-ventilation to nuclear medicine ventilation, using clinically relevant global metrics and radiologist observations. Methods and Materials: Fifteen lung cancer patients with 16 sets of 4DCT and nuclear medicine ventilation-perfusion (VQ) images were used for the study. The VQ-ventilation images were acquired in planar mode using Tc-99m-labeled diethylenetriamine-pentaacetic acid aerosol inhalation. 4DCT data, spatial registration, and a density-change-based model were used to compute a 4DCT-based ventilation map for each patient. The percent ventilation was calculated in each lung and each lung third for both the 4DCT and VQ-ventilation scans. A nuclear medicine radiologist assessed the VQ and 4DCT scans for the presence of ventilation defects. The VQ and 4DCT-based images were compared using regional percent ventilation and radiologist clinical observations. Results: Individual patient examples demonstrate good qualitative agreement between the 4DCT and VQ-ventilation scans. The correlation coefficients were 0.68 and 0.45, using the percent ventilation in each individual lung and lung third, respectively. Using radiologist-noted presence of ventilation defects and receiver operating characteristic analysis, the sensitivity, specificity, and accuracy of the 4DCT-ventilation were 90%, 64%, and 81%, respectively. Conclusions: The current work compared 4DCT with VQ-based ventilation using clinically relevant global metrics and radiologist observations. We found good agreement between the radiologist's assessment of the 4DCT and VQ-ventilation images as well as the percent ventilation in each lung. The agreement lessened when the data were

  10. Collateral circulation on perfusion-computed tomography-source images predicts the response to stroke intravenous thrombolysis.

    Science.gov (United States)

    Calleja, A I; Cortijo, E; García-Bermejo, P; Gómez, R D; Pérez-Fernández, S; Del Monte, J M; Muñoz, M F; Fernández-Herranz, R; Arenillas, J F

    2013-05-01

    Perfusion-computed tomography-source images (PCT-SI) may allow a dynamic assessment of leptomeningeal collateral arteries (LMC) filling and emptying in middle cerebral artery (MCA) ischaemic stroke. We described a regional LMC scale on PCT-SI and hypothesized that a higher collateral score would predict a better response to intravenous (iv) thrombolysis. We studied consecutive ischaemic stroke patients with an acute MCA occlusion documented by transcranial Doppler/transcranial color-coded duplex, treated with iv thrombolysis who underwent PCT prior to treatment. Readers evaluated PCT-SI in a blinded fashion to assess LMC within the hypoperfused MCA territory. LMC scored as follows: 0, absence of vessels; 1, collateral supply filling ≤ 50%; 2, between> 50% and < 100%; 3, equal or more prominent when compared with the unaffected hemisphere. The scale was divided into good (scores 2-3) vs. poor (scores 0-1) collaterals. The predetermined primary end-point was a good 3-month functional outcome, while early neurological recovery, transcranial duplex-assessed 24-h MCA recanalization, 24-h hypodensity volume and hemorrhagic transformation were considered secondary end-points. Fifty-four patients were included (55.5% women, median NIHSS 10), and 4-13-23-14 patients had LMC score (LMCs) of 0-1-2-3, respectively. The probability of a good long-term outcome augmented gradually with increasing LMCs: (0) 0%; (1) 15.4%; (2) 65.2%; (3) 64.3%, P = 0.004. Good-LMCs was independently associated with a good outcome [OR 21.02 (95% CI 2.23-197.75), P = 0.008]. Patients with good LMCs had better early neurological recovery (P = 0.001), smaller hypodensity volumes (P < 0.001) and a clear trend towards a higher recanalization rate. A higher degree of LMC assessed by PCT-SI predicts good response to iv thrombolysis in MCA ischaemic stroke patients. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  11. Pulmonary Perfusion Changes as Assessed by Contrast-Enhanced Dual-Energy Computed Tomography after Endoscopic Lung Volume Reduction by Coils.

    Science.gov (United States)

    Lador, Frédéric; Hachulla, Anne-Lise; Hohn, Olivia; Plojoux, Jérôme; Ronot, Maxime; Montet, Xavier; Soccal, Paola M

    2016-01-01

    Endoscopic lung volume reduction by coils (LVRC) is a recent treatment approach for severe emphysema. Furthermore, dual-energy computed tomography (DECT) now offers a combined assessment of lung morphology and pulmonary perfusion. The aim of our study was to assess the impact of LVRC on pulmonary perfusion with DECT. Seventeen patients (64.8 ± 6.7 years) underwent LVRC. DECT was performed prior to and after LVRC. For each patient, lung volumes and emphysema quantification were automatically calculated. Then, 6 regions of interest (ROIs) on the iodine perfusion map were drawn in the anterior, mid, and posterior right and left lungs at 4 defined levels. The ROI values were averaged to obtain lung perfusion as assessed by the lung's iodine concentration (CLung, μg·cm-3). The CLung values were normalized using the left atrial iodine concentration (CLA) to take into account differences between successive DECT scans. The 6-min walk distance (6MWD) improved significantly after the procedure (p = 0.0002). No lung volume changes were observed between successive DECT scans for any of the patients (p = 0.32), attesting the same suspended inspiration. After LVRC, the emphysema index was significantly reduced in the treated lung (p = 0.0014). Lung perfusion increased significantly adjacent to the treated areas (CLung/CLA from 3.4 ± 1.7 to 5.6 ± 2.2, p < 0.001) and in the ipsilateral untreated areas (from 4.1 ± 1.4 to 6.6 ± 1.7, p < 0.001), corresponding to a mean 65 and 61% increase in perfusion, respectively. No significant difference was observed in the contralateral upper and lower areas (from 4.4 ± 1.9 to 4.8 ± 2.1, p = 0.273, and from 4.9 ± 2.0 to 5.2 ± 1.7, p = 0.412, respectively). A significant correlation between increased 6MWD and increased perfusion was found (p = 0.0027, R2 = 0.3850). Quantitative analysis based on DECT acquisition revealed that LVRC results in a significant increase in perfusion in the coil-free areas adjacent to the treated ones, as

  12. Computed tomography

    International Nuclear Information System (INIS)

    Wells, P.; Davis, J.; Morgan, M.

    1994-01-01

    X-ray or gamma-ray transmission computed tomography (CT) is a powerful non-destructive evaluation (NDE) technique that produces two-dimensional cross-sectional images of an object without the need to physically section it. CT is also known by the acronym CAT, for computerised axial tomography. This review article presents a brief historical perspective on CT, its current status and the underlying physics. The mathematical fundamentals of computed tomography are developed for the simplest transmission CT modality. A description of CT scanner instrumentation is provided with an emphasis on radiation sources and systems. Examples of CT images are shown indicating the range of materials that can be scanned and the spatial and contrast resolutions that may be achieved. Attention is also given to the occurrence, interpretation and minimisation of various image artefacts that may arise. A final brief section is devoted to the principles and potential of a range of more recently developed tomographic modalities including diffraction CT, positron emission CT and seismic tomography. 57 refs., 2 tabs., 14 figs

  13. Value of Myocardial Perfusion Assessment With Coronary Computed Tomography Angiography in Patients With Recent Acute-Onset Chest Pain

    DEFF Research Database (Denmark)

    Sørgaard, Mathias H; Linde, Jesper J; Kühl, J Tobias

    2018-01-01

    was the frequency of coronary revascularization among patients referred for invasive coronary angiography (ICA) based on index computed tomography evaluation. Secondary endpoints were invasive procedural complications at index-related ICA, post-index cardiac death, hospital admittance because of recurrence of chest...

  14. In vivo quantitative assessment of myocardial structure, function, perfusion and viability using cardiac micro-computed tomography

    NARCIS (Netherlands)

    E.D. van Deel (Elza); Y. Ridwan (Yanto); van Vliet, J.N. (J. Nicole); Belenkov, S. (Sasha); J. Essers (Jeroen)

    2016-01-01

    textabstractThe use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most

  15. Quantification of myocardial area at risk in the absence of collateral flow: the validation of angiographic scores by myocardial perfusion single-photon emission computed tomography.

    Science.gov (United States)

    Rodríguez-Palomares, José F; Alonso, Albert; Martí, Gerard; Aguadé-Bruix, Santiago; González-Alujas, M T; Romero-Farina, Guillermo; Candell-Riera, Jaume; García del Blanco, Bruno; Evangelista, Artur; García-Dorado, David

    2013-02-01

    Our study aimed to compare the area at risk (AAR) determined by single-photon emission computed tomography (SPECT) with the Bypass Angioplasty Revascularization Investigation (BARI) and modified Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) angiographic scores in the setting of patients undergoing coronary angioplasty for either unstable angina or an STEMI. Radionuclide myocardial perfusion imaging prior to reperfusion has classically been the most widely practised technique for assessing the AAR and has been successfully used to compare the efficacy of various reperfusion strategies in patients with an ST-segment elevation myocardial infarction (STEMI). The BARI and modified APPROACH scores are angiographic methods widely used to provide a rapid estimation of the AAR; however, they have not been directly validated with myocardial perfusion single-photon emission computed tomography (SPECT). Fifty-five patients with no previous myocardial infarction who underwent coronary angioplasty for single-vessel disease (unstable angina: n = 25 or an STEMI: n = 30) with no evidence of collaterals (Rentrop Collateral Score collateral flow, BARI and APPROACH scores constitute valid methods for AAR estimation in current clinical practice, with more accurate results when used for the LAD territory; both are useful not only in STEMI patients but also in patients with unstable angina.

  16. Epileptic patterns of local cerebral metabolism and perfusion in man determined by emission computed tomography of 18FDG and 13NH3

    International Nuclear Information System (INIS)

    Kuhl, D.E.; Engel, J. Jr.; Phelps, M.E.; Selin, C.

    1979-01-01

    Seventeen patients with partial epilepsy had EEG monitoring concurrent with cerebral emission computed tomography (ECT) after 18 F-fluorodeoxyglucose ( 18 FDG) and 13 N-ammonia were given intravenously as indicators of local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. In 12 of 15 patients who had unilateral or focal electrical abnormalities, interictal 18 FDG scan patterns clearly showed localized regions of decreased (20% to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization. These hypometabolic zones appeared normal on x-ray computed tomography in all but three patients and were unchanged on scans repeated on different days. In 5 of 6 patients who underwent temporal lobectomy, the interictal 18 FDG scan correctly detected the pathologically confirmed lesion as a hypometabolic zone, and removal of the lesion site resulted in marked clinical improvement. In contrast, the ictal 18 FDG scan patterns clearly showed foci of increased (82% to 130%) LCMR/sub glc/, which correlated temporally and anatomically with ictal EEG spike foci and were within the zones of interictal hypometabolism (3 studies in 2 patients). 13 NH 3 distributions paralleled 18 FDG increases and decreases in abnormal zones, but 13 NH 3 differences were of lesser magnitude. When the relationship of 13 NH 3 uptake to local blood flow found in dog brain was applied as a correction to the patients' 13 NH 3 scan data, local alterations in perfusion and glucose utilization were usually matched, both in the interictal and ictal states

  17. Computed tomography

    International Nuclear Information System (INIS)

    Andre, M.; Resnick, D.

    1988-01-01

    Computed tomography (CT) has matured into a reliable and prominent tool for study of the muscoloskeletal system. When it was introduced in 1973, it was unique in many ways and posed a challenge to interpretation. It is in these unique features, however, that its advantages lie in comparison with conventional techniques. These advantages will be described in a spectrum of important applications in orthopedics and rheumatology

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  19. Illustrated computer tomography

    International Nuclear Information System (INIS)

    Takahashi, S.

    1983-01-01

    This book provides the following information: basic aspects of computed tomography; atlas of computed tomography of the normal adult; clinical application of computed tomography; and radiotherapy planning and computed tomography

  20. Non-invasive diagnostic workup of patients with suspected stable angina by combined computed tomography coronary angiography and magnetic resonance perfusion imaging

    International Nuclear Information System (INIS)

    Kirschbaum, S.W.; Nieman, K.; Springeling, T.

    2011-01-01

    The background of this study was to evaluate additional adenosine magnetic resonance perfusion (MRP) imaging in the diagnostic workup of patients with suspected stable angina with computed tomography coronary angiography (CTCA) as first-line diagnostic modality. Two hundred and thirty symptomatic patients (male, 52%; age, 56 year) with suspected stable angina underwent CTCA. In patients with a stenosis of >50% as visually assessed, MRP was performed and the quantitative myocardial perfusion reserve index (MPRI) was calculated. Coronary flow reserve (CFR) using invasive coronary flow measurements served as the standard of reference. CTCA showed non-significant coronary artery disease (CAD) in 151/230 (66%) patients and significant CAD in 79/230 patients (34%), of whom 50 subsequently underwent MRP and CFR. MRP showed reduced perfusion in 32 patients (64%), which was confirmed by CFR in 27 (84%). All 18 cases of normal MRP (36%) were confirmed by CFR. The positive likelihood ratio of MRP for the presence of functional significant disease in patients with a lesion on CTCA was 4.49 (95% confidence interval [CI] 2.12-9.99). The negative likelihood ratio was 0.05 (95% CI 0.01-0.34). CTCA as first-line diagnostic modality excluded coronary artery disease in a high percentage of patients referred for diagnostic workup of suspected stable angina. MRP made a significant contribution to the detection of functional significant lesions in patients with a positive CTCA. (author)

  1. Assessment of the brain areas perfused by superselective intra-arterial chemotherapy using single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime. Technical note

    Energy Technology Data Exchange (ETDEWEB)

    Namba, Hiroki; Iwadate, Yasuo; Saegusa, Takashi; Sueyoshi, Kanji [Chiba Cancer Center Hospital (Japan); Kobayashi, Shigeki; Sato, Akira; Watanabe, Yoshiro

    1994-12-01

    The brain areas perfused by superselective intra-arterial (i.a.) chemotherapy were assessed using single photon emission computed tomography (SPECT) with technetium-99m-hexamethyl-propyleneamine oxime ({sup 99m}Tc-HMPAO). A superselective catheter was introduced into the anterior, middle, or posterior cerebral artery of patients with malignant glioma for i.a. chemotherapy. {sup 99m}Tc-HMPAO was subsequently injected via the same catheter used for chemotherapy, and a higher dose of {sup 99m}Tc-HMPAO was injected intravenously to obtain adequate background brain images. Comparison of the SPECT images with magnetic resonance images could confirm complete perfusion of the tumor tissue. In two patients with malignant glioma, regions of interest were selected in the peritumoral brain area and a reference brain area, and the radioactivity was measured. The concentration of {sup 99m}Tc-HMPAO was about 50 times higher in tissue perfused by superselective injection into anterior or middle cerebral artery compared to intravenous injection. {sup 99m}Tc-HMPAO SPECT is readily available in many institutions and the information provided is useful for planning more effective and safe i.a. chemotherapy. (author).

  2. A pilot trial on pulmonary emphysema quantification and perfusion mapping in a single-step using contrast-enhanced dual-energy computed tomography.

    Science.gov (United States)

    Lee, Choong Wook; Seo, Joon Beom; Lee, Youngjoo; Chae, Eun Jin; Kim, Namkug; Lee, Hyun Joo; Hwang, Hye Jeon; Lim, Chae-Hun

    2012-01-01

    To know whether contrast-enhanced dual-energy computed tomography angiography (DECTA) can be used for simultaneous assessment of emphysema quantification and regional perfusion evaluation. We assessed 27 patients who had pulmonary emphysema and no pulmonary embolism on visual assessment of CT images, among 584 consecutive patients who underwent DECTA for the evaluation of pulmonary embolism. Virtual noncontrast (VNC) images were generated by modifying the "Liver VNC" application in a dedicated workstation. Using in-house software, the low-attenuation area below 950HU (LAA950), the 15th percentile attenuation (15pctlVNC) and the mean lung attenuation (MeanVNC) were calculated. The "Lung PBV" application was used to assess perfusion, and the low-iodine area below 5HU (LIA5), the 15th percentile iodine (15pctlIodine), and the mean iodine value (MeanIodine) were calculated from iodine map images. The correlation between VNC parameters and pulmonary function test data (available in 22 patients) and the correlation between VNC and iodine map parameters (all included 27 patients) were assessed. Color-coded map of VNC image were compared with iodine map images for the evaluation of regional heterogeneity. We observed moderate correlations between LAA950 and predicted %FEV1 (rs = -0.47, P VNC images. We observed moderate correlations between quantitative parameters on VNC images and pulmonary function test data, and also observed moderate correlations between the severity of parenchymal destruction, as determined from VNC images, and perfusion status, as determined from iodine maps. Therefore, the contrast-enhanced DECTA can be used for the emphysema quantification and regional perfusion evaluation by using the VNC images and iodine map, simultaneously.

  3. A segmentectomy of the right upper lobe has an advantage over a right upper lobectomy regarding the preservation of the functional volume of the right middle lobe. Analysis by perfusion single-photon emission computed tomography/computed tomography

    International Nuclear Information System (INIS)

    Yoshimoto, Kentaro; Nomori, Hiroaki; Mori, Takeshi; Ohba, Yasuomi; Shibata, Hidekatsu; Tashiro, Kuniyuki; Shiraishi, Shinya; Kobayashi, Toshiaki

    2010-01-01

    To evaluate the advantages of a segmentectomy of the right upper lobe (RUL) over a right upper (RU) lobectomy regarding the preservation of the functional volume of the right middle lobe (RML), the postoperative forced expiratory volume in one second (FEV 1 ) of the RML was compared between an RU lobectomy and an RUL segmentectomy, by using a coregistered perfusion single-photon emission computed tomography and computed tomography (SPECT/CT). The pulmonary function tests and perfusion SPECT/CT were conducted before and after surgery (RU lobectomy: 7; RUL segmentectomy: 13). The FEV 1 of the RML before and after surgery was calculated from the data of the pulmonary function test and SPECT/CT. In the RU lobectomy group, the percentage change of FEV 1 was 71%±12%, which was significantly lower in comparison to 92%±9% in the RUL segmentectomy group (P=0.001). In the lobectomy group, the preoperative FEV 1 of the RML was 0.17±0.101 which decreased significantly to 0.06±0.061 after surgery (P=0.009). In the segmentectomy group, FEV 1 of the RML before and after the surgery were 0.23±0.101 and 0.20±0.111, of which the difference was not significant. An RUL segmentectomy has an advantage over an RU lobectomy regarding the preservation of pulmonary function, due to a greater preservation of not only the lung tissue, but also the FEV 1 of the RML. (author)

  4. Epileptic patterns of local cerebral metabolism and perfusion in man determined by emission computed tomography of /sup 18/FDG and /sup 13/NH/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, D.E.; Engel, J. Jr.; Phelps, M.E.; Selin, C.

    1979-01-01

    Seventeen patients with partial epilepsy had EEG monitoring concurrent with cerebral emission computed tomography (ECT) after /sup 18/F-fluorodeoxyglucose (/sup 18/FDG) and /sup 13/N-ammonia were given intravenously as indicators of local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. In 12 of 15 patients who had unilateral or focal electrical abnormalities, interictal /sup 18/FDG scan patterns clearly showed localized regions of decreased (20% to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization. These hypometabolic zones appeared normal on x-ray computed tomography in all but three patients and were unchanged on scans repeated on different days. In 5 of 6 patients who underwent temporal lobectomy, the interictal /sup 18/FDG scan correctly detected the pathologically confirmed lesion as a hypometabolic zone, and removal of the lesion site resulted in marked clinical improvement. In contrast, the ictal /sup 18/FDG scan patterns clearly showed foci of increased (82% to 130%) LCMR/sub glc/, which correlated temporally and anatomically with ictal EEG spike foci and were within the zones of interictal hypometabolism (3 studies in 2 patients). /sup 13/NH/sub 3/ distributions paralleled /sup 18/FDG increases and decreases in abnormal zones, but /sup 13/NH/sub 3/ differences were of lesser magnitude. When the relationship of /sup 13/NH/sub 3/ uptake to local blood flow found in dog brain was applied as a correction to the patients' /sup 13/NH/sub 3/ scan data, local alterations in perfusion and glucose utilization were usually matched, both in the interictal and ictal states.

  5. Differentiating between visual hallucination-free dementia with Lewy bodies and corticobasal syndrome on the basis of neuropsychology and perfusion single-photon emission computed tomography.

    Science.gov (United States)

    Misch, Michael R; Mitchell, Sara; Francis, Philip L; Sherborn, Kayla; Meradje, Katayoun; McNeely, Alicia A; Honjo, Kie; Zhao, Jiali; Scott, Christopher Jm; Caldwell, Curtis B; Ehrlich, Lisa; Shammi, Prathiba; MacIntosh, Bradley J; Bilbao, Juan M; Lang, Anthony E; Black, Sandra E; Masellis, Mario

    2014-01-01

    Dementia with Lewy bodies (DLB) and Corticobasal Syndrome (CBS) are atypical parkinsonian disorders with fronto-subcortical and posterior cognitive dysfunction as common features. While visual hallucinations are a good predictor of Lewy body pathology and are rare in CBS, they are not exhibited in all cases of DLB. Given the clinical overlap between these disorders, neuropsychological and imaging markers may aid in distinguishing these entities. Prospectively recruited case-control cohorts of CBS (n =31) and visual hallucination-free DLB (n =30), completed neuropsychological and neuropsychiatric measures as well as brain perfusion single-photon emission computed tomography and structural magnetic resonance imaging (MRI). Perfusion data were available for forty-two controls. Behavioural, perfusion, and cortical volume and thickness measures were compared between the groups to identify features that serve to differentiate them. The Lewy body with no hallucinations group performed more poorly on measures of episodic memory compared to the corticobasal group, including the delayed and cued recall portions of the California Verbal Learning Test (F (1, 42) =23.1, P reproduction of the Wechsler Memory Scale-Revised (F (1, 36) =9.7, P =0.004). The Lewy body group also demonstrated reduced perfusion in the left occipital pole compared to the corticobasal group (F (1,57) =7.4, P =0.009). At autopsy, the Lewy body cases all demonstrated mixed dementia with Lewy bodies, Alzheimer's disease and small vessel arteriosclerosis, while the corticobasal cases demonstrated classical corticobasal degeneration in five, dementia with agyrophilic grains + corticobasal degeneration + cerebral amyloid angiopathy in one, Progressive Supranuclear Palsy in two, and Frontotemporal Lobar Degeneration-Ubiquitin/TAR DNA-binding protein 43 proteinopathy in one. MRI measures were not significantly different between the patient groups. Reduced perfusion in the left occipital region and worse

  6. No detectable nephrotoxic side effect using a dimer, non-ionic contrast media in cerebral perfusion computed tomography in case of suspected brain ischemia

    International Nuclear Information System (INIS)

    Petrik, M.; Weigel, C.; Kirsch, M.; Hosten, N.

    2005-01-01

    Purpose: In suspected brain ischemia, the perfusion cerebral computed tomography (cCT) should be performed with the lowest amount of contrast media to avoid a contrast media induced nephropathy (CIN) even if the patient already is in renal failure. We were interested to find the best parameters for this examination. Material and methods: From February 2000 to March 2003, 138 patients (58 females, 80 males, mean age 66.8 years) underwent cCT-perfusion immediately after the admission to our stroke unit. Of these patients, 62% (n=86) had normal renal function and 38% (n=52) renal failure (up to 381 μmol/l basic serum creatinine). We varied volume (20-80 ml), flow (5 vs. 7.2. ml/s) and concentration (270 vs. 320 ml/mg iodine) of a dimer, non-ionic contrast media (Visipaque registered ) to establish 5 groups. So we got patients receiving 6 g, 12 g, 16 g, 19 g and 25 g of iodine. After generating the perfusion maps, two radiologists reviewed the quality of the maps and scored it (1-5). We measured the serum creatinine before contrast application and at follow up cCt (days 3 and 7). Results: The quality of the maps increases with increasing amount of iodine. However, the diagnostic result was not significantly better using more than about 16 g of iodine (e.g., 60 ml-7.2 ml/s - 270 mg/ml) in cCT-perfusion studies. Only one patient had a pathologic increase in serum creatinine (day 1: 93; day 4: 146 μmol/l) but died at day 5 because of massive co-morbidity and septic pneumonia. No CIN occurred even in the patient group with pre-existent renal failure. Conclusions: About 60 ml contrast media and a moderate flow rate of about 7 ml/s ensure good results in perfusion-cCT, even if the patients have poor blood circulation or arteriosclerosis. The use of a dimer, non-ionic contrast media (range of 6-25 g iodine) seems to minimize the risk of CIN in the daily routine. (orig.)

  7. Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation

    Energy Technology Data Exchange (ETDEWEB)

    Neill, Johanne [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); The Prince Charles Hospital, Brisbane (Australia); Prvulovich, Elizabeth M.; Bomanji, Jamshed B. [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); Fish, Matthews B. [Sacred Heart Medical Center (SHMC), Springfield, OR (United States); Berman, Daniel S.; Slomka, Piotr J. [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Sharir, Tali [Procardia Maccabi Healthcare Services (PMHS), Tel Aviv (Israel); Martin, William H. [Vanderbilt University Medical Center (VUMC), Nashville, TN (United States); DiCarli, Marcelo F. [Brigham and Women' s Hospital (BWH), Boston, MA (United States); Ziffer, Jack A. [Baptist Hospital of Miami (BHM), Miami, FL (United States); Shiti, Dalia [Spectrum-Dynamics, Caesarea (Israel); Ben-Haim, Simona [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); Chaim Sheba Medical Center, Department of Nuclear Medicine, Tel-Hashomer (Israel)

    2013-07-15

    High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings. The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS {>=}3 or coronary territorial SSS {>=}2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5 % and coronary territorial TPD {>=}3 % were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; {>=}50 % was considered significant. Of the 50 patients, 13 (26 %) had no stenosis, 22 (44 %) had single-vessel disease, 6 (12 %) had double-vessel disease and 9 (18 %) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's {rho} 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92 % (35/38), 83 % (10/12) and 90 % (45/50) vs. 84 % (32/38), 50 % (6/12) and 76 % (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89 % (31/35), 57 % (8/14) and 80 % (39/49) vs. 86 % (31/36), 77 % (10/13) and 84 % (41/49), respectively. HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual

  8. Prediction of left main or 3-vessel disease using myocardial perfusion reserve on dynamic thallium-201 single-photon emission computed tomography with a semiconductor gamma camera.

    Science.gov (United States)

    Shiraishi, Shinya; Sakamoto, Fumi; Tsuda, Noriko; Yoshida, Morikatsu; Tomiguchi, Seiji; Utsunomiya, Daisuke; Ogawa, Hisao; Yamashita, Yasuyuki

    2015-01-01

    Myocardial perfusion imaging (MPI) may fail to detect balanced ischemia. We evaluated myocardial perfusion reserve (MPR) using Tl dynamic single-photon emission computed tomography (SPECT) and a novel cadmium zinc telluride (CZT) camera for predicting 3-vessel or left main coronary artery disease (CAD). METHODS AND RESULTS: A total of 55 consecutive patients with suspected CAD underwent SPECT-MPI and coronary angiography. The MPR index was calculated using the standard 2-compartment kinetic model. We analyzed the utility of MPR index, other SPECT findings, and various clinical variables. On multivariate analysis, MPR index and history of previous myocardial infarction (MI) predicted left main and 3-vessel disease. The area under the receiver operating characteristic curve was 0.81 for MPR index, 0.699 for history of previous MI, and 0.86 for MPR index plus history of previous MI. MPR index ≤1.5 yielded the highest diagnostic accuracy. Sensitivity, specificity, and accuracy were 86%, 78%, and 80%, respectively, for MPR index, 64%, 76%, 73% for previous MI, and 57%, 93%, and 84% for MPR index plus history of previous MI. Quantification of MPR using dynamic SPECT and a novel CZT camera may identify balanced ischemia in patients with left main or 3-vessel disease.

  9. The Effect of Heart Rate on Exposure Window and Best Phase for Stress Perfusion Computed Tomography: Lessons From the CORE320 Study.

    Science.gov (United States)

    Steveson, Chloe; Schuijf, Joanne D; Vavere, Andrea L; Mather, Richard T; Caton, Teresa; Mehra, Vishal; Betoko, Aisha; Cox, Christopher; Lima, Joao Ac; George, Richard T

    The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. Of the 368 patients included in the analysis, 93% received oral β blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P stress scan was 5.3 mSv (IQR, 3.8-6.1). Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and β-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.

  10. Cerebral perfusion inhomogeneities in schizophrenia demonstrated with single photon emission computed tomography and Tc99m-hexamethylpropyleneamineoxim

    International Nuclear Information System (INIS)

    Bajc, M.; Basic, M.; Topuzovic, N.; Babic, C.; Medved, V.

    1989-01-01

    Cerebral blood flow was measured in relative terms with Tc99m-hexamethylpropyleneamineoxim (HMPAO) and single photon emission computed tomography (SPECT) in 28 female schizophrenic patients (20 acute and 8 chronic) classified according to DSM-III. Eleven normals served as controls. The acute patients were classified according to positive and negative symptoms. Patients with predominantly positive symptoms showed by and large normal and homogeneous cerebral isotope uptake. Those with negative symptoms, and the chronic patients, showed inhomogeneous tracer uptake with multiple regions of hypoperfusion in slices 4-6 cm above the orbitomeatal line. The findings support in principle the notion that schizophrenia with negative or chronic symptoms does not affect the whole brain homogeneously. Brain imaging with Tc99m-HMPAO and SPECT might be used to distinguish various types of schizophrenia. (author)

  11. Myocardial perfusion assessed by contrast echocardiography and single photon emission computed tomography in the evaluation of patients with acute chest pain and normal electrocardiogram

    International Nuclear Information System (INIS)

    Soares, J. Jr.; Ferreira, S.M.A.; Matias, W. Jr.; Giorgi, M.C.P.; Izaki, M.; Luz, P.L.; Ramires, J.A.F.; Meneghetti, J.C.

    2002-01-01

    Aim : Evaluation of diagnostic accuracy of myocardial contrast echocardiography (MCE) in comparison with single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia in patients with acute chest pain. Material and Methods : Eighteen patients (pts) with chest pain lasting ≥30 minutes, occurring within 6 hours of emergency room presentation and a normal or no diagnostic electrocardiogram were studied. Pts underwent rest MCE and SPECT. For both exams myocardial perfusion was assessed in the same 7 segments (apical, anterior, inferior, anteroseptal, inferoseptal, lateral and posterior) of left ventricle. A total of 126 segments were analyzed. Images were classified as positive for ischemia if they had a perfusion defect. Coronary angiography was performed if MCE or SPECT images were classified as positive for ischemia or by clinical indication. Otherwise the patients underwent stress SPECT. Significant coronary artery disease (CAD) was defined as ≥70% stenosis in a major coronary artery or its branches. Final diagnosis of an acute coronary event (ACE) was established in the presence of positive findings in MCE or SPECT in addition to significant CAD in the corresponding territory. Kappa statistics were calculated to evaluate the concordance between MCE and SPECT. κ values of ≤0.4, >0.4 and >0.7 indicate fair, good and excellent agreement, respectively. Results: Thirteen out of 18 pts underwent coronary angiography (seven pts had positive findings on SPECT, 2 on MCE, 2 on both exams and 1 had clinical indication). Significant CAD was detected on six. Five pts underwent stress SPECT and no perfusion defect was detected. Therefore, six pts (33.3%) had an ACE and 12 (66.6%) had not. There were no statistical differences between groups according to age, gender, duration of pain, free pain interval, presence of risk factors and antecedents. Concordance between MCE and SPECT for evaluation of perfusion defects showed a ? coefficient of 0

  12. [Acute stent thrombosis and reverse transient left ventricular dilatation after performing a single-photon emission computed tomography myocardial perfusion].

    Science.gov (United States)

    Miranda, B; Pizzi, M N; Aguadé-Bruix, S; Domingo, E; Candell-Riera, J

    2015-01-01

    A 63-year-old male patient with a history of stent implantation in the left anterior descending three months before. Due to the presentation of vegetative symptoms, he was referred for gated-SPECT myocardial perfusion. During acquisition of the resting images he presented chest pain and ST segment elevation, so that urgent cardiac catheterization was performed, showing stent thrombosis. Rest perfusion imaging showed a defect in anterior and apical perfusion, more severe and extensive than in the stress images, with striking left ventricular dilatation and a fall in the ejection fraction related to the acute ischemia phenomenon. Intense exercise is associated with a transient activation of the coagulation system and hemodynamic changes that might induce thrombosis, especially in recently implanted coronary stents that probably still have not become completely endothelialized. Copyright © 2014 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  13. Prediction of Clinical Outcome After Acute Ischemic Stroke: The Value of Repeated Noncontrast Computed Tomography, Computed Tomographic Angiography, and Computed Tomographic Perfusion.

    Science.gov (United States)

    Dankbaar, Jan W; Horsch, Alexander D; van den Hoven, Andor F; Kappelle, L Jaap; van der Schaaf, Irene C; van Seeters, Tom; Velthuis, Birgitta K

    2017-09-01

    Early prediction of outcome in acute ischemic stroke is important for clinical management. This study aimed to compare the relationship between early follow-up multimodality computed tomographic (CT) imaging and clinical outcome at 90 days in a large multicenter stroke study. From the DUST study (Dutch Acute Stroke Study), patients were selected with (1) anterior circulation occlusion on CT angiography (CTA) and ischemic deficit on CT perfusion (CTP) on admission, and (2) day 3 follow-up noncontrast CT, CTP, and CTA. Follow-up infarct volume on noncontrast CT, poor recanalization on CTA, and poor reperfusion on CTP (mean transit time index ≤75%) were related to unfavorable outcome after 90 days defined as modified Rankin Scale 3 to 6. Four multivariable models were constructed: (1) only baseline variables (model 1), (2) model 1 with addition of infarct volume, (3) model 1 with addition of recanalization, and (4) model 1 with addition of reperfusion. Area under the curves of the receiver operating characteristic curves of the models were compared using the DeLong test. A total of 242 patients were included. Poor recanalization was found in 21%, poor reperfusion in 37%, and unfavorable outcome in 44%. The area under the curve of the receiver operating characteristic curve without follow-up imaging was 0.81, with follow-up noncontrast CT 0.85 ( P =0.02), CTA 0.86 ( P =0.01), and CTP 0.86 ( P =0.01). All 3 follow-up imaging modalities improved outcome prediction compared with no imaging. There was no difference between the imaging models. Follow-up imaging after 3 days improves outcome prediction compared with prediction based on baseline variables alone. CTA recanalization and CTP reperfusion do not outperform noncontrast CT at this time point. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00880113. © 2017 American Heart Association, Inc.

  14. Differences in cerebral perfusion deficits in mild traumatic brain injury and depression using single photon emission computed tomography

    Directory of Open Access Journals (Sweden)

    Kristoffer eRomero

    2014-08-01

    Full Text Available Background: Numerous studies have shown decreased perfusion in the prefrontal cortex following mild traumatic brain injury (mTBI. However, similar hypoperfusion can also be observed in depression. Given the high prevalence of depressive symptoms following mTBI, it is unclear to what extent depression influences hypoperfusion in TBI.Methods: Mild TBI patients without depressive symptoms (mTBI-noD, n = 39, TBI patients with depressive symptoms (mTBI-D, n = 13, and 15 patients with major depressive disorder, but no TBI (MDD were given 99-m T-ECD SPECT scans within 2 weeks of injury. All subjects completed tests of information processing speed, complex attention, and executive functioning, and a self-report questionnaire measuring symptoms of psychological distress. Between group comparisons of quantified SPECT perfusion were undertaken, using univariate and multivariate (partial least squares analyses.Results: mTBI-D and mTBI-noD groups did not differ in terms of cerebral perfusion. However, patients with MDD showed hypoperfusion in several frontal (orbitofrontal, middle frontal, and superior frontal cortex, superior temporal, and posterior cingulate regions. The mTBI-D group showed poorer performance on a measure of complex attention and working memory, compared to both the mTBI-noD and MDD groups.Conclusions: These results suggest that depressive symptoms do not affect SPECT perfusion in the sub-acute phase following a mild TBI. Conversely, MDD is associated with hypoperfusion primarily in frontal regions.

  15. Sex- and age-related differences of myocardial perfusion at rest assessed with multidetector computed tomography

    DEFF Research Database (Denmark)

    Byrne, Christina; Kühl, J Tobias; Zacho, Mette

    2013-01-01

    The clinical presentation of ischemic heart disease in women differs from men, which could reflect sex-related differences of normal physiology. Cardiac CT angiography provides a noninvasive method to assess both regional and transmural myocardial perfusion in addition to coronary atherosclerosis....

  16. Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

    Science.gov (United States)

    Nardini, Giordano; Di Girolamo, Nicola; Leopardi, Stefania; Paganelli, Irene; Zaghini, Anna; Origgi, Francesco C; Vignoli, Massimo

    2014-05-13

    Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

  17. Assessment of prognostic value of semiquantitative parameters on gated single photon emission computed tomography myocardial perfusion scintigraphy in a large middle eastern population

    International Nuclear Information System (INIS)

    Chavoshi, Maryam; Fard-Esfahani, Armaghan; Fallahi, Babak; Emami-Ardekani, Alireza; Beiki, Davood; Hassanzadeh-Rad, Arman; Eftekhari, Mohammad

    2005-01-01

    Coronary artery disease is the leading cause of mortality worldwide. The goal of this study is to determine the prognostic value of semiquantitative parameters of electrocardiogram-gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in a large Middle Eastern (Iranian) population. This study was a prospective study including all patients referred to our center for myocardial perfusion scan. The patients were followed annually up to 24 months and their survival information was collected. From 1148 patients, 473 (41.2%) men and 675 (58.8%) women, 40.6% had normal MPI, 13.3% near normal and 46.1% abnormal MPI. After follow-up of 929 patients, 97.4% of patients were alive, and 2.6% succumbed to cardiac deaths. Abnormal ejection fraction was related with cardiac events (P = 0.001), but neither transient ischemic dilation (TID) (P = 0.09) nor lung/heart ratio (P = 0.92) showed such relationship. Association between summed difference score (SDS) and soft cardiac events (P < 0.001) was significant. Summed motion score (SMS) and summed thickening score (STS) showed a significant relation with hard cardiac events, including myocardial infarction and cardiac death (P < 0.001 and P = 0.001, respectively). Totally, risk of all cardiac events was significantly higher in abnormal MPI group than normal group (P < 0.001, 0.02, and 0.025, respectively). No significant relationship was found between TID and total cardiac events (P = 0.478). Semiquantitative variables derived from gated SPECT MPI have independent prognostic value. Rate of total cardiac events is higher in patients with higher summed stress score and SDS. Total and hard cardiac events are higher in upper scores of functional parameters (SMS and STS). Total cardiac events are higher in patients with lower left ventricular ejection fraction

  18. Ischemic Volume and Neurological Deficit: Correlation of Computed Tomography Perfusion with the National Institutes of Health Stroke Scale Score in Acute Ischemic Stroke.

    Science.gov (United States)

    Furlanis, Giovanni; Ajčević, Miloš; Stragapede, Lara; Lugnan, Carlo; Ridolfi, Mariana; Caruso, Paola; Naccarato, Marcello; Ukmar, Maja; Manganotti, Paolo

    2018-04-30

    The National Institutes of Health Stroke Scale (NIHSS) is the most adopted stroke patients' evaluation tool in emergency settings to assess the severity of stroke and to determine the patients' eligibility for specific treatments. Computed tomography perfusion (CTP) is crucial to identify salvageable tissue that can benefit from the reperfusion treatment. The aim of this study is to identify the relation between the NIHSS scores and the hypoperfused volumes evaluated by CTP in patients with hyperacute ischemic stroke. This retrospective study was conducted on 105 patients with ischemic stroke who underwent NIHSS assessment and CTP in the hyperacute phase. Hypoperfused volume was evaluated by CTP maps processed with semi-automatic algorithm. An analysis was conducted to determine the degree of correlation between the NIHSS scores and the ischemic lesion volumes and to investigate the relation between the anterior and the posterior circulation strokes, as well as between the right and the left hemispheric strokes. A significant correlation was found between ischemic volume and NIHSS score at baseline (r = .82; P correlation was identified in the anterior circulation stroke (r = .76; P correlated for the left and the right hemispheric strokes (r = .83 and .81; P correlation between the baseline NIHSS score and the ischemic volume estimated by CTP. We confirmed that NIHSS is a reliable predictor of perfusion deficits in acute ischemic stroke. CTP allows fast imaging assessment in the hyperacute phase. The results highlight the importance of these diagnostic tools in the assessment of stroke severity and in acute decision-making. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  19. Differences in cerebral perfusion deficits in mild traumatic brain injury and depression using single photon emission computed tomography

    OpenAIRE

    Kristoffer eRomero; Sandra E Black; Sandra E Black; Anthony eFeinstein

    2014-01-01

    Background: Numerous studies have shown decreased perfusion in the prefrontal cortex following mild traumatic brain injury (mTBI). However, similar hypoperfusion can also be observed in depression. Given the high prevalence of depressive symptoms following mTBI, it is unclear to what extent depression influences hypoperfusion in TBI.Methods: Mild TBI patients without depressive symptoms (mTBI-noD, n = 39), TBI patients with depressive symptoms (mTBI-D, n = 13), and 15 patients with major depr...

  20. Single-photon emission computed tomography myocardial perfusion imaging-assessed stress perfusion defect severity is associated with mortality independent of ethnicity in an Asian population.

    Science.gov (United States)

    Chin, Chee Tang; Gao, Fei; Keng, Felix Y J; Shah, Bimal R; Koh, Angela S; Tan, Ru San; Chua, Terrance S J

    2014-12-01

    Ischemic heart disease is growing by epidemic proportions in Asia. Among patients in Western populations with similar myocardial perfusion imaging (MPI) ischemia severity, ethnicity is independently associated with mortality. We aimed to determine the differential prognostic value of MPI abnormality severity among three major Asian ethnic groups. From 16,921 consecutive patients, we used summed stress score to define increasing abnormal scan severity groups (minimal, mild, moderate, and severe) among Chinese, Indian, and Malay patients. We determined mortality from the national death registry. Using multivariable Cox regression models, we examined the association between ethnicity and mortality. Chinese patients were older than Indians or Malays. Annual all-cause death rates increased with increasing abnormal scan severity in all three ethnicities. After adjustment, ethnicity was not associated with mortality. With Chinese as the reference group, adjusted hazard ratio and 95% CI for Malays and Indians were 1.29 (0.95-1.77) and 1.06 (0.74-1.50) in the minimally abnormal scan group, and 1.20 (0.75-1.91) and 0.82 (0.47-1.45) in the severely abnormal scan group, respectively. Mortality risk is related to the severity of scan abnormality and is independent of ethnicity in Asians. Our findings emphasize the continued utility of MPI in guiding risk stratification in Asia.

  1. Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael A.; Kartalis, Nikolaos; Aspelin, Peter; Albiin, Nils; Brismar, Torkel B. [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Leidner, Bertil; Svensson, Anders [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden)

    2014-01-15

    To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. (orig.)

  2. Correlating Computed Tomography Perfusion Changes in the Pharyngeal Constrictor Muscles During Head-and-Neck Radiotherapy to Dysphagia Outcome

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Minh Tam, E-mail: mitruong@bu.edu [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Department of Radiology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Lee, Richard [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Saito, Naoko [Department of Radiology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Qureshi, Muhammad M. [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Ozonoff, Al [Department of Biostatistics, Boston University School of Public Health, Boston, MA (United States); Romesser, Paul B. [Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States); Wang, Jimmy; Sakai, Osamu [Department of Radiology, Boston Medical Center and Boston University School of Medicine, Boston, MA (United States)

    2012-02-01

    Purpose: To measure changes in perfusion of the pharyngeal constrictor muscles (PCM) using CT perfusion (CTP) imaging during a course of definitive radiotherapy (RT) in head-and-neck cancer (HNC) patients and correlate with dysphagia outcome after RT. Methods and Materials: Fifteen HNC patients underwent CTP imaging of the PCM at baseline and Weeks 2, 4, and 6 during RT and 6 weeks after RT. Blood flow and blood volume were measured in the PCM, and percentage change from baseline scan was determined. A single physician-based assessment of dysphagia was performed every 3 months after RT using the Common Terminology Criteria for Adverse Events, version 3.0 grading system. Results: With a median follow-up of 28 months (range, 6-44 months), Grade 3 dysphagia was present in 7 of 15 patients, and 8 patients experienced Grade 0-2 dysphagia. The CTP parameters at Week 2 of RT demonstrated an increase in mean PCM blood flow of 161.9% vs. 12.3% (p = 0.007) and an increase in mean PCM blood volume of 96.6% vs. 8.7% (p = 0.039) in patients with 6-month post-RT Grade 3 dysphagia and Grade 0-2 dysphagia, respectively. On multivariate analysis, when adjusting for smoking history, tumor volume, and baseline dysphagia status, an increase in blood flow in the second week of RT was significant for 3- and 6-month Grade 3 dysphagia (p < 0.05). Conclusions: Perfusion changes in the PCM during Week 2 of RT in the PCM may predict the severity of dysphagia after HNC RT.

  3. Comparison between fragmented QRS and Q waves in myocardial scar detection using myocardial perfusion single photon emission computed tomography.

    Science.gov (United States)

    Dabbagh Kakhki, Vahid Reza; Ayati, Narjess; Zakavi, Seyed Rasoul; Sadeghi, Ramin; Tayyebi, Mohammad; Shariati, Farzaneh

    2015-01-01

    Accurate diagnosis of myocardial infarction (MI) is of paramount importance in patient management, which necessitates the development of efficient and accurate diagnostic methods. Q wave is not present in all patients with MI, and its prevalence is declining. Recently, fragmented QRS (fQRS) complex has been introduced as a marker of prior MI. To investigate diagnostic value of fQRS compared to Q wave. We included 500 consecutive patients with known or suspected coronary artery disease who underwent two days of gated myocardial perfusion imaging using dipyridamole pharmacologic stress. Electrocardiogram (ECG) was evaluated to detect fQRS as well as Q-wave. Finally, subjects were compared in terms of ventricular perfusion and function indices. A total of 207 men and 269 women with mean age of 57.06 ± 12 years were studied. ECG analysis showed that 14.3% of the patients had both fQRS and Q waves, 30.7% had fQRS, and 3.8% had Q waves. Fixed myocardial perfusion defect was noted in 22.3% of patients according to MPIs. Sensitivity, specificity, and positive and negative predictive values for myocardial scar detection were 78%, 65%, 39%, and 91%, respectively, for fQRS and 61%, 94%, 76%, and 89%, respectively, for Q wave. Although fQRS had lower specificity compared to Q wave in the detection of myocardial scar, due to higher sensitivity and negative predictive value can be an invaluable diagnostic index. There is also an incremental value for fQRS in association with Q-wave in myocardial scar assessment.

  4. Increased accuracy of single photon emission computed tomography (SPECT myocardial perfusion scintigraphy using iterative reconstruction of images

    Directory of Open Access Journals (Sweden)

    Stević Miloš

    2016-01-01

    Full Text Available Background/Aim. Filtered back projection (FBP is a common way of processing myocardial perfusion imaging (MPI studies. There are artifacts in FBP which can cause falsepositive results. Iterative reconstruction (IR is developed to reduce false positive findings in MPI studies. The aim of this study was to evaluate the difference in the number of false positive findings in MPI studies, between FBP and IR processing. Methods. We examined 107 patients with angina pectoris with MPI and coronary angiography (CAG, 77 man and 30 woman, aged 32−82. MPI studies were processed with FBP and with IR. Positive finding at MPI was visualization of the perfusion defect. Positive finding at CAG was stenosis of coronary artery. Perfusion defect at MPI without coronary artery stenosis at CAG was considered like false positive. The results were statistically analyzed with bivariate correlation, and with one sample t-test. Results. There were 20.6% normal, and 79.4% pathologic findings at FBP, 30.8% normal and 69.2% pathologic with IR and 37.4% normal and 62.6% pathologic at CAG. FBP produced 19 false-positive findings, at IR 11 false positive findings. The correlation between FBP and CAG was 0.658 (p < 0.01 and between IR and CAG 0.784 (p < 0.01. The number of false positive findings at MPI with IR was significantly lower than at FBP (p < 0.01. Conclusion. Our study shows that IR processing MPI scintigraphy has less number of false positive findings, therefore it is our choice for processing MPI studies.

  5. Correlating Computed Tomography Perfusion Changes in the Pharyngeal Constrictor Muscles During Head-and-Neck Radiotherapy to Dysphagia Outcome

    International Nuclear Information System (INIS)

    Truong, Minh Tam; Lee, Richard; Saito, Naoko; Qureshi, Muhammad M.; Ozonoff, Al; Romesser, Paul B.; Wang, Jimmy; Sakai, Osamu

    2012-01-01

    Purpose: To measure changes in perfusion of the pharyngeal constrictor muscles (PCM) using CT perfusion (CTP) imaging during a course of definitive radiotherapy (RT) in head-and-neck cancer (HNC) patients and correlate with dysphagia outcome after RT. Methods and Materials: Fifteen HNC patients underwent CTP imaging of the PCM at baseline and Weeks 2, 4, and 6 during RT and 6 weeks after RT. Blood flow and blood volume were measured in the PCM, and percentage change from baseline scan was determined. A single physician-based assessment of dysphagia was performed every 3 months after RT using the Common Terminology Criteria for Adverse Events, version 3.0 grading system. Results: With a median follow-up of 28 months (range, 6–44 months), Grade 3 dysphagia was present in 7 of 15 patients, and 8 patients experienced Grade 0–2 dysphagia. The CTP parameters at Week 2 of RT demonstrated an increase in mean PCM blood flow of 161.9% vs. 12.3% (p = 0.007) and an increase in mean PCM blood volume of 96.6% vs. 8.7% (p = 0.039) in patients with 6-month post-RT Grade 3 dysphagia and Grade 0–2 dysphagia, respectively. On multivariate analysis, when adjusting for smoking history, tumor volume, and baseline dysphagia status, an increase in blood flow in the second week of RT was significant for 3- and 6-month Grade 3 dysphagia (p < 0.05). Conclusions: Perfusion changes in the PCM during Week 2 of RT in the PCM may predict the severity of dysphagia after HNC RT.

  6. Differences in Cerebral Perfusion Deficits in Mild Traumatic Brain Injury and Depression Using Single-Photon Emission Computed Tomography

    OpenAIRE

    Romero, Kristoffer; Black, Sandra E.; Feinstein, Anthony

    2014-01-01

    Background: Numerous studies have shown decreased perfusion in the prefrontal cortex following mild traumatic brain injury (mTBI). However, similar hypoperfusion can also be observed in depression. Given the high prevalence of depressive symptoms following mTBI, it is unclear to what extent depression influences hypoperfusion in TBI. Methods: Mild TBI patients without depressive symptoms (mTBI-noD, n = 39), TBI patients with depressive symptoms (mTBI-D, n = 13), and 15 patients with major ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography (CT) - Head Sponsored by ...

  8. Diagnostic value of thallium-201 myocardial perfusion IQ-SPECT without and with computed tomography-based attenuation correction to predict clinically significant and insignificant fractional flow reserve

    Science.gov (United States)

    Tanaka, Haruki; Takahashi, Teruyuki; Ohashi, Norihiko; Tanaka, Koichi; Okada, Takenori; Kihara, Yasuki

    2017-01-01

    Abstract The aim of this study was to clarify the predictive value of fractional flow reserve (FFR) determined by myocardial perfusion imaging (MPI) using thallium (Tl)-201 IQ-SPECT without and with computed tomography-based attenuation correction (CT-AC) for patients with stable coronary artery disease (CAD). We assessed 212 angiographically identified diseased vessels using adenosine-stress Tl-201 MPI-IQ-SPECT/CT in 84 consecutive, prospectively identified patients with stable CAD. We compared the FFR in 136 of the 212 diseased vessels using visual semiquantitative interpretations of corresponding territories on MPI-IQ-SPECT images without and with CT-AC. FFR inversely correlated most accurately with regional summed difference scores (rSDS) in images without and with CT-AC (r = −0.584 and r = −0.568, respectively, both P system can predict FFR at an optimal cut-off of <0.80, and we propose a novel application of CT-AC to MPI-IQ-SPECT for predicting clinically significant and insignificant FFR even in nonobese patients. PMID:29390486

  9. Suspected acute pulmonary emboli: cost-effectiveness of chest helical computed tomography versus a standard diagnostic algorithm incorporating ventilation-perfusion scintigraphy

    International Nuclear Information System (INIS)

    Larcos, G.; Chi, K.K.G.; Berry, G.; Westmead Hospital, Sydney, NSW; Shiell, A.

    2000-01-01

    There is a controversy regarding the investigation of patients with suspected acute pulmonary embolism (PE). To compare the cost-effectiveness of alternative methods of diagnosing acute PE, chest helical computed tomography (CT) alone and in combination with venous ultrasound (US) of legs and pulmonary angiography (PA) were compared to a conventional algorithm using ventilation-perfusion (V/Q) scintigraphy supplemented in selected cases by US and PA. A decision-analytical model was constructed to model the costs and effects of the three diagnostic strategies in a hypothetical cohort of 1000 patients each. Transition probabilities were based on published data. Life years gained by each strategy were estimated from published mortality rates. Schedule fees were used to estimate costs. The V/Q protocol is both more expensive and more effective than CT alone resulting in 20.1 additional lives saved at a (discounted) cost of $940 per life year gained. An additional 2.5 lives can be saved if CT replaces V/Q scintigraphy in the diagnostic algorithm but at a cost of $23,905 per life year saved. It resulted that the more effective diagnostic strategies are also more expensive. In patients with suspected PE, the incremental cost-effectiveness of the V/Q based strategy over CT alone is reasonable in comparison with other health interventions. The cost-effectiveness of the supplemented CT strategy is more questionable. Copyright (2000) The Australasian College of Physicians

  10. What is Computed Tomography?

    Science.gov (United States)

    ... Imaging Medical X-ray Imaging What is Computed Tomography? Share Tweet Linkedin Pin it More sharing options ... Chest X ray Image back to top Computed Tomography (CT) Although also based on the variable absorption ...

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  12. Computed tomography

    International Nuclear Information System (INIS)

    Boyd, D.P.

    1989-01-01

    This paper reports on computed tomographic (CT) scanning which has improved computer-assisted imaging modalities for radiologic diagnosis. The advantage of this modality is its ability to image thin cross-sectional planes of the body, thus uncovering density information in three dimensions without tissue superposition problems. Because this enables vastly superior imaging of soft tissues in the brain and body, CT scanning was immediately successful and continues to grow in importance as improvements are made in speed, resolution, and cost efficiency. CT scanners are used for general purposes, and the more advanced machines are generally preferred in large hospitals, where volume and variety of usage justifies the cost. For imaging in the abdomen, a scanner with a rapid speed is preferred because peristalsis, involuntary motion of the diaphram, and even cardiac motion are present and can significantly degrade image quality. When contrast media is used in imaging to demonstrate scanner, immediate review of images, and multiformat hardcopy production. A second console is reserved for the radiologist to read images and perform the several types of image analysis that are available. Since CT images contain quantitative information in terms of density values and contours of organs, quantitation of volumes, areas, and masses is possible. This is accomplished with region-of- interest methods, which involve the electronic outlining of the selected region of the television display monitor with a trackball-controlled cursor. In addition, various image- processing options, such as edge enhancement (for viewing fine details of edges) or smoothing filters (for enhancing the detectability of low-contrast lesions) are useful tools

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  14. Emission computed tomography

    International Nuclear Information System (INIS)

    Ott, R.J.

    1986-01-01

    Emission Computed Tomography is a technique used for producing single or multiple cross-sectional images of the distribution of radionuclide labelled agents in vivo. The techniques of Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are described with particular regard to the function of the detectors used to produce images and the computer techniques used to build up images. (UK)

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

  17. Differentiation between malignant and benign solitary pulmonary nodules: Use of volume first-pass perfusion and combined with routine computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Fei, E-mail: shanfeiqz@gmail.com [Department of Radiology, Third Affiliated Hospital of Suzhou University, 185, Juqian Road, Changzhou, Zip Code: 213003 (China); Zhang, Zhiyong, E-mail: zhangzy@fudan.edu.cn [Department of Radiology, Zhongshan Hospital Fudan University, 180, Fenglin Road, Shanghai, Zip Code: 200032 (China); Xing, Wei, E-mail: suzhxingwei@126.com [Department of Radiology, Third Affiliated Hospital of Suzhou University, 185, Juqian Road, Changzhou, Zip Code: 213003 (China); Qiu, Jianguo, E-mail: step9999@sina.com [Department of Radiology, Third Affiliated Hospital of Suzhou University, 185, Juqian Road, Changzhou, Zip Code: 213003 (China); Yang, Shan, E-mail: yang.shan@zs-hospital.sh.cn [Department of Radiology, Zhongshan Hospital Fudan University, 180, Fenglin Road, Shanghai, Zip Code: 200032 (China); Wang, Jian, E-mail: wang.jian@zs-hospital.sh.cn [Department of Radiology, Zhongshan Hospital Fudan University, 180, Fenglin Road, Shanghai, Zip Code: 200032 (China); Jiang, Yaping, E-mail: jiang.yaping@zs-hospital.sh.cn [Department of Radiology, Zhongshan Hospital Fudan University, 180, Fenglin Road, Shanghai, Zip Code: 200032 (China); Chen, Gang, E-mail: chen.gang@zs-hospital.sh.cn [Department of Radiology, Zhongshan Hospital Fudan University, 180, Fenglin Road, Shanghai, Zip Code: 200032 (China)

    2012-11-15

    Purpose: To evaluate the capability of first-pass volume perfusion computed tomography (PCT) for differentiation of solitary pulmonary nodules (SPNs) and to compare that of combination of PCT and routine CT with CT alone for the differentiation. Materials and methods: Our institutional review board approved this study and informed consent was obtained. With nine excluded, 65 consecutive patients having a SPN with histopathologic proof or follow-up underwent a 30 s PCT using the deconvolution model were evaluated. Kruskal-Wallis tests and receiver operating characteristics (ROC) analysis were underwent. Four radiologists assessed nodules independently and retrospectively. Diagnostic capability was compared for CT alone and PCT plus CT. ROC analysis, McNemar test, and weighted kappa statistics were performed. Results: Significant differences were found in parameters between malignant and benign nodules (p < 0.0001 for blood flow, blood volume, and permeability surface area product), SPNs were more likely to be malignant by using threshold values of more than 55 ml/100 g/min, 2.5 ml/100 g, and 10 ml/100 g/min, respectively. PCT plus CT was significantly better in overall sensitivity (93%, p = 0.004) and accuracy (94%, p = 0.003) compared to CT alone, not specificity (96%). Area under the curve for ROC analyses of PCT plus CT was significantly larger than that of CT alone (p = 0.018). Mean weighted kappa for PCT plus CT was 0.715, that for CT alone was 0.447. Conclusion: Volume first-pass PCT can distinguish SPNs. Using PCT plus routine CT may be more sensitive and accurate for differentiating malignant from benign nodules than CT alone and allows more confidence and constancy.

  18. Quantitative perfusion computed tomography measurements of cerebral hemodynamics: Correlation with digital subtraction angiography identified primary and secondary cerebral collaterals in internal carotid artery occlusive disease

    International Nuclear Information System (INIS)

    Cheng Xiaoqing; Tian Jianming; Zuo Changjing; Liu Jia; Zhang Qi; Lu Guangming

    2012-01-01

    Background: The aim of the present study was to assess hemodynamic variations in symptomatic unilateral internal carotid artery occlusion (ICAO) patients with primary collateral flow via circle of Willis or secondary collateral flow via ophthalmic artery and/or leptomeningeal collaterals. Methods: Thirty-eight patients with a symptomatic unilateral ICAO were enrolled in the study. Based on digital subtraction angiography (DSA) findings, patients were classified into 2 groups: primary collateral (n = 14) and secondary collateral (n = 24) groups. Collateral flow hemodynamics were investigated with perfusion computed tomography (PCT) by measuring the cerebral blood flow (CBF), cerebral blood volume (CBV) and time to peak (TTP) in the hemispheres ipsilateral and contralateral to ICAO. Based on the measurements, the ipsilateral to contralateral ratio for each parameter was calculated and compared. Results: Irrespective of the collateral patterns, ipsilateral CBF was not significantly different from that of the contralateral hemisphere (P = 0.285); ipsilateral CBV and TTP was significantly increased compared with those of the contralateral hemisphere (P = 0.000 and P = 0.000 for CBV and TTP, respectively). Furthermore, patients with secondary collaterals had significantly larger ipsilateral-to-contralateral ratios for both CBV (rCBV, P = 0.0197) and TTP (rTTP, P = 0.000) than those of patients with only primary collaterals. These two groups showed no difference in ipsilateral-to-contralateral ratio for CBF (rCBF, P = 0.312). Conclusion: Patients with symptomatic unilateral ICAO in our study were in an autoregulatory vasodilatation status. Moreover, secondary collaterals in ICAO patients were correlated with ipsilateral CBV and delayed TTP that suggested severe hemodynamic impairment, presumably increasing the risk of ischemic events.

  19. Factors affecting accuracy of ventricular volume and ejection fraction measured by gated Tl-201 myocardial perfusion single photon emission computed tomography

    International Nuclear Information System (INIS)

    Pai, Moon Sun; Yang, You Jung; Im, Ki Chun; Hong, Il Ki; Yun, Sung Cheol; Kang, Duk Hyun; Song, Jae Kwan; Moon, Dae Hyuk

    2005-01-01

    Systemic errors in the gated single photon emission computed tomography (SPECT) measurement of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) may occur. We evaluated whether patient-related factors affected the accuracy of EDV, ESV, and EF measured by electrocardiogram-gated Tl-201 SPECT. A total of 518 patients without perfusion defects on Tl-201 SPECT or coronary artery disease were studied. EDV, ESV, and EF were measured from echocardiography and adenosine stress/redistribution gated Tl-201 SPECT using commercially available software packages (QGS and 4D-MSPECT). We identified factors affecting the accuracy of gated SPECT via multiple linear regression analysis of the differences between echocardiography and gated SPECT. Gated SPECT analyzed with QGS underestimated EDV and ESV, and overestimated EF, but 4D-MSPECT overestimated all those values (p<0.001). Independent variables that increased the difference in EDV between echocardiography and gated SPECT were decreasing LV end-diastolic wall thickness, decreasing body surface area, female sex and increasing EDV (p< 0.001). Those for ESV were decreasing LV end-systolic wall thickness, female sex, and decreasing ESV (p<0.001). Increasing end-systolic wall thickness, male sex and decreasing age were independent determinants associated with an increased difference in EF (p< 0.001). Adenosine stress SPECT showed significantly higher EDV and ESV values and a lower EF than did redistribution SPECT (p< 0.001). In determination of EF, QGS demonstrated a smaller bias than did 4D-MSPECT. However, in men with LV hypertrophy, 4D-MSPECT was superior to QGS. Systemic error by gated Tl-201 SPECT is determined by individual patient-characteristics

  20. Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography

    International Nuclear Information System (INIS)

    Ng, Q.-S.; Goh, Vicky; Milner, Jessica; Padhani, Anwar R.; Saunders, Michele I.; Hoskin, Peter J.

    2007-01-01

    Purpose: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). Methods and Materials: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. Results: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. Conclusion: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center

  1. Differentiation between malignant and benign solitary pulmonary nodules: Use of volume first-pass perfusion and combined with routine computed tomography

    International Nuclear Information System (INIS)

    Shan, Fei; Zhang, Zhiyong; Xing, Wei; Qiu, Jianguo; Yang, Shan; Wang, Jian; Jiang, Yaping; Chen, Gang

    2012-01-01

    Purpose: To evaluate the capability of first-pass volume perfusion computed tomography (PCT) for differentiation of solitary pulmonary nodules (SPNs) and to compare that of combination of PCT and routine CT with CT alone for the differentiation. Materials and methods: Our institutional review board approved this study and informed consent was obtained. With nine excluded, 65 consecutive patients having a SPN with histopathologic proof or follow-up underwent a 30 s PCT using the deconvolution model were evaluated. Kruskal–Wallis tests and receiver operating characteristics (ROC) analysis were underwent. Four radiologists assessed nodules independently and retrospectively. Diagnostic capability was compared for CT alone and PCT plus CT. ROC analysis, McNemar test, and weighted kappa statistics were performed. Results: Significant differences were found in parameters between malignant and benign nodules (p < 0.0001 for blood flow, blood volume, and permeability surface area product), SPNs were more likely to be malignant by using threshold values of more than 55 ml/100 g/min, 2.5 ml/100 g, and 10 ml/100 g/min, respectively. PCT plus CT was significantly better in overall sensitivity (93%, p = 0.004) and accuracy (94%, p = 0.003) compared to CT alone, not specificity (96%). Area under the curve for ROC analyses of PCT plus CT was significantly larger than that of CT alone (p = 0.018). Mean weighted kappa for PCT plus CT was 0.715, that for CT alone was 0.447. Conclusion: Volume first-pass PCT can distinguish SPNs. Using PCT plus routine CT may be more sensitive and accurate for differentiating malignant from benign nodules than CT alone and allows more confidence and constancy.

  2. Impaired coronary flow reserve is the most important marker of viable myocardium in the myocardial segment-based analysis of dual-isotope gated myocardial perfusion single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Lee, Won Woo; So, Young; Kim, Ki Bong; Lee, Dong Soo

    2014-01-01

    The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), 201 Tl perfusion status at rest, 201 Tl 24 hours redistribution and systolic wall thickening of 99m Tc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p 201 Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

  3. Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block; Perfusao miocardica de estresse com dipiridamol por tomografia computadorizada em pacientes com bloqueio de ramo esquerdo

    Energy Technology Data Exchange (ETDEWEB)

    Cabeda, Estevan Vieira; Rochitte, Carlos Eduardo; Nomura, Cesar Higa; Parga, Jose Rodrigues; Avila, Luiz Francisco Rodrigues; Falcao, Andrea Maria Gomes; Soares Junior, Jose [Instituto do Coracao (InCor), Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

    2015-12-15

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

  4. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.

    1986-01-01

    Computed tomography is regarded by many as a complicated union of sophisticated x-ray equipment and computer technology. This book overcomes these complexities. The rigid technicalities of the machinery and the clinical aspects of computed tomography are discussed including the preparation of patients, both physically and mentally, for scanning. Furthermore, the author also explains how to set up and run a computed tomography department, including advice on how the room should be designed

  5. Impact of intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction on left ventricular perfusion and function: a 6-month follow-up gated 99mTc-MIBI single-photon emission computed tomography study

    International Nuclear Information System (INIS)

    Lipiec, Piotr; Krzeminska-Pakula, Maria; Plewka, Michal; Kasprzak, Jaroslaw D.; Kusmierek, Jacek; Plachcinska, Anna; Szuminski, Remigiusz; Robak, Tadeusz; Korycka, Anna

    2009-01-01

    We investigated the impact of intracoronary injection of autologous mononuclear bone marrow cells (BMC) in patients with acute ST elevation myocardial infarction (STEMI) on left ventricular volumes, global and regional systolic function and myocardial perfusion. The study included 39 patients with first anterior STEMI treated successfully with primary percutaneous coronary intervention. They were randomly assigned to the treatment group or the control group in a 2:1 ratio. The patients underwent baseline gated single-photon emission computed tomography (G-SPECT) 3-10 days after STEMI with quantitative and qualitative analysis of left ventricular perfusion and systolic function. On the following day, patients from the BMC treatment group were subjected to bone marrow aspiration, mononuclear BMC isolation and intracoronary injection. No placebo procedure was performed in the control group. G-SPECT was repeated 6 months after STEMI. Baseline and follow-up G-SPECT studies were available for 36 patients. At 6 months in the BMC group we observed a significantly enhanced improvement in the mean extent of the perfusion defect, the left ventricular perfusion score index, the infarct area perfusion score and the infarct area wall motion score index compared to the control group (p=0.01-0.04). However, the changes in left ventricular volume, ejection fraction and the left ventricular wall motion score index as well as the relative changes in the infarct area wall motion score index did not differ significantly between the groups. Intracoronary injection of autologous mononuclear BMC in patients with STEMI improves myocardial perfusion at 6 months. The benefit in infarct area systolic function is less pronounced and there is no apparent improvement of global left ventricular systolic function. (orig.)

  6. An Exploratory Study Into the Role of Dynamic Contrast-Enhanced Magnetic Resonance Imaging or Perfusion Computed Tomography for Detection of Intratumoral Hypoxia in Head-and-Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Newbold, Kate [Royal Marsden Hospital, Sutton (United Kingdom); Castellano, Isabel [Institute of Cancer Research, London (United Kingdom); Charles-Edwards, Elizabeth [Institute of Cancer Research, Sutton, Surrey (United Kingdom); Mears, Dorothy; Sohaib, Aslam [Royal Marsden Hospital, Sutton (United Kingdom); Leach, Martin [Institute of Cancer Research, Sutton, Surrey (United Kingdom); Rhys-Evans, Peter; Clarke, Peter; Fisher, Cyril [Royal Marsden Hospital, London (United Kingdom); Harrington, Kevin [Institute of Cancer Research, London (United Kingdom); Royal Marsden Hospital, London (United Kingdom); Nutting, Christopher [Royal Marsden Hospital, London (United Kingdom)

    2009-05-01

    Purpose: Hypoxia in patients with head-and-neck cancer (HNC) is well established and known to cause radiation resistance and treatment failure in the management of HNC. This study examines the role of parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and perfusion computed tomography (CT) as surrogate markers of intratumoral hypoxia, defined by using the exogenous marker of hypoxia pimonidazole and the endogenous marker carbonic anhydrase 9 (CA9). Methods and Materials: Patients with HNC underwent preoperative DCE-MRI, perfusion CT, and pimonidazole infusion. Imaging parameters were correlated with pimonidazole and CA9 staining. The strength of correlations was tested by using a two-tailed Spearman's rank correlation coefficient. Results: Twenty-three regions of interest were analyzed from the 7 patients who completed the DCE-MRI studies. A number of statistically significant correlations were seen between DCE-MRI parameters (volume transfer between blood plasma and extracellular extravascular space [EES], volume of EES, rate constant between EES and blood plasma, time at arrival of contrast inflow, time to peak, average gradient, and time to onset) and areas with a pimonidazole score of 4. In the case of CA9 staining, only a weak correlation was shown with wash-in rate. There were no significant correlations between perfusion CT parameters and pimonidazole staining or CA9 expression. Conclusion: Intratumoral hypoxia in patients with HNC may be predicted by using DCE-MRI; however, perfusion CT requires further investigation.

  7. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... are the limitations of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed ... nasal cavity by small openings. top of page What are some common uses of the procedure? CT ...

  8. Emission computed tomography

    International Nuclear Information System (INIS)

    Budinger, T.F.; Gullberg, G.T.; Huesman, R.H.

    1979-01-01

    This chapter is devoted to the methods of computer assisted tomography for determination of the three-dimensional distribution of gamma-emitting radionuclides in the human body. The major applications of emission computed tomography are in biological research and medical diagnostic procedures. The objectives of these procedures are to make quantitative measurements of in vivo biochemical and hemodynamic functions

  9. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special ... the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) ... are the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a ...

  11. Perfusion computed tomography-guided intravenous thrombolysis for acute ischemic stroke beyond 4.5 hours: a case-control study.

    Science.gov (United States)

    García-Bermejo, Pablo; Calleja, Ana I; Pérez-Fernández, Santiago; Cortijo, Elisa; del Monte, José M; García-Porrero, Miguel; Fe Muñoz, M; Fernández-Herranz, Rosario; Arenillas, Juan F

    2012-01-01

    Extending the therapeutic window of intravenous thrombolysis for acute ischemic stroke beyond the established 4.5-hour limit is of critical importance in order to increase the proportion of thrombolysed stroke patients. In this setting, the capacity of MRI to select acute stroke patients for reperfusion therapies in delayed time windows has been and is being tested in clinical trials. However, whether the more available and cost-effective perfusion computed tomography (PCT) may be useful to select candidates for delayed intravenous thrombolysis remains largely unexplored. We aimed to evaluate the safety and efficacy of PCT-guided intravenous thrombolysis beyond 4.5 h after stroke onset. We prospectively studied all consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA) in our stroke unit between January 2008 and December 2010. Patients treated within 0- 4.5 h were treated according to non-contrast CT (NCCT) criteria. Beyond 4.5 h, patients received intravenous tPA according to PCT criteria, i.e. an infarct core on cerebral blood volume (CBV) maps not exceeding one third of the middle cerebral artery (MCA) territory and tissue at risk as defined by mean transit time-CBV mismatch greater than 20%. Predetermined primary endpoints were symptomatic hemorrhagic transformation and favorable long-term outcome, while early neurological improvement and MCA recanalization were considered secondary endpoints. Statistical analysis included bivariate comparisons between the two groups for each endpoint and logistic regression models when significance was found in bivariate analyses. This study was approved by our local ethics committee. A total of 245 patients received intravenous thrombolysis. After the groups were matched by baseline National Institutes of Health Stroke Scale score, 172 patients treated at 4.5 h were finally included. Early and late groups were comparable regarding baseline variables; only cardioembolic etiology

  12. Diagnosing coronary artery disease after a positive coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Nissen, L; Winther, S; Westra, J

    2018-01-01

    Aims: Perfusion scans after coronary computed tomography angiography (CCTA) in patients with suspected coronary artery disease (CAD) may reduce unnecessary invasive coronary angiographies (ICAs). However, the diagnostic accuracy of perfusion scans after primary CCTA is unknown. The aim...

  13. Computer tomography in otolaryngology

    International Nuclear Information System (INIS)

    Gradzki, J.

    1981-01-01

    The principles of design and the action of computer tomography which was applied also for the diagnosis of nose, ear and throat diseases are discussed. Computer tomography makes possible visualization of the structures of the nose, nasal sinuses and facial skeleton in transverse and eoronal planes. The method enables an accurate evaluation of the position and size of neoplasms in these regions and differentiation of inflammatory exudates against malignant masses. In otology computer tomography is used particularly in the diagnosis of pontocerebellar angle tumours and otogenic brain abscesses. Computer tomography of the larynx and pharynx provides new diagnostic data owing to the possibility of obtaining transverse sections and visualization of cartilage. Computer tomograms of some cases are presented. (author)

  14. Comparison of conventional and cadmium-zinc-telluride single-photon emission computed tomography for analysis of thallium-201 myocardial perfusion imaging: an exploratory study in normal databases for different ethnicities.

    Science.gov (United States)

    Ishihara, Masaru; Onoguchi, Masahisa; Taniguchi, Yasuyo; Shibutani, Takayuki

    2017-12-01

    The aim of this study was to clarify the differences in thallium-201-chloride (thallium-201) myocardial perfusion imaging (MPI) scans evaluated by conventional anger-type single-photon emission computed tomography (conventional SPECT) versus cadmium-zinc-telluride SPECT (CZT SPECT) imaging in normal databases for different ethnic groups. MPI scans from 81 consecutive Japanese patients were examined using conventional SPECT and CZT SPECT and analyzed with the pre-installed quantitative perfusion SPECT (QPS) software. We compared the summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for the two SPECT devices. For a normal MPI reference, we usually use Japanese databases for MPI created by the Japanese Society of Nuclear Medicine, which can be used with conventional SPECT but not with CZT SPECT. In this study, we used new Japanese normal databases constructed in our institution to compare conventional and CZT SPECT. Compared with conventional SPECT, CZT SPECT showed lower SSS (p < 0.001), SRS (p = 0.001), and SDS (p = 0.189) using the pre-installed SPECT database. In contrast, CZT SPECT showed no significant difference from conventional SPECT in QPS analysis using the normal databases from our institution. Myocardial perfusion analyses by CZT SPECT should be evaluated using normal databases based on the ethnic group being evaluated.

  15. Computed Tomographic Perfusion Improves Diagnostic Power of Coronary Computed Tomographic Angiography in Women

    DEFF Research Database (Denmark)

    Penagaluri, Ashritha; Higgins, Angela Y.; Vavere, Andrea L

    2016-01-01

    laboratories. Prevalence of flow-limiting CAD defined by invasive coronary angiography equal to 50% or greater with an associated single-photon emission computed tomography myocardial perfusion imaging defect was 45% (114/252) and 23% (30/129) in males and females, respectively. Patient-based diagnostic......Background-Coronary computed tomographic angiography (CTA) and myocardial perfusion imaging (CTP) is a validated approach for detection and exclusion of flow-limiting coronary artery disease (CAD), but little data are available on gender-specific performance of these modalities. In this study, we...... aimed to evaluate the diagnostic accuracy of combined coronary CTA and CTP in detecting flow-limiting CAD in women compared with men.  Methods and Results-Three hundred and eighty-one patients who underwent both CTA-CTP and single-photon emission computed tomography myocardial perfusion imaging...

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ... Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... white on the x-ray; soft tissue, such as organs like the heart or liver, shows up ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... of the Sinuses? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... white on the x-ray; soft tissue, such as organs like the heart or liver, shows up ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info About Us News Physician Resources Professions Site Index A-Z Computed Tomography ( ...

  4. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the ...

  5. Cardiac functional mapping for thallium-201 myocardial perfusion, washout, wall motion and phase using single-photon emission computed tomography (SPECT)

    International Nuclear Information System (INIS)

    Nakajima, Kenichi; Bunko, Hisashi; Taniguchi, Mitsuru; Taki, Junichi; Tonami, Norihisa; Hisada, Kinichi; Hirano, Takako; Wani, Hidenobu.

    1986-01-01

    A method for three-dimensional functional mapping of Tl-201 myocardial uptake, washout, wall motion and phase was developed using SPECT. Each parameter was mapped using polar display in the same format. Normal values were determined in Tl-201 exercise study in 16 patients. Myocardial counts were lower in the septum and inferior wall and the difference of counts between anterior and inferior walls were greater in man compared with the perfusion pattern in woman. Washout was slower at septum and inferior wall in man, and slightly slower at inferior wall in woman. In gated blood-pool tomography, length-based and count-based Fourier analyses were applied to calculate the parameters of contraction and phase. The results of both Fourier analyses generally agreed; however, the area of abnormality was slightly different. Phase maps were useful for the assessment of asynergy as well as in patients with conduction disorders. These cardiac functional maps using SPECT were considered to be effective for the understanding of three-dimensional informations of cardiac function. (author)

  6. Intra-observer and inter-observer agreements for the measurement of dual-input whole tumor computed tomography perfusion in patients with lung cancer: Influences of the size and inner-air density of tumors.

    Science.gov (United States)

    Wang, Qingle; Zhang, Zhiyong; Shan, Fei; Shi, Yuxin; Xing, Wei; Shi, Liangrong; Zhang, Xingwei

    2017-09-01

    This study was conducted to assess intra-observer and inter-observer agreements for the measurement of dual-input whole tumor computed tomography perfusion (DCTP) in patients with lung cancer. A total of 88 patients who had undergone DCTP, which had proved a diagnosis of primary lung cancer, were divided into two groups: (i) nodules (diameter ≤3 cm) and masses (diameter >3 cm) by size, and (ii) tumors with and without air density. Pulmonary flow, bronchial flow, and pulmonary index were measured in each group. Intra-observer and inter-observer agreements for measurement were assessed using intraclass correlation coefficient, within-subject coefficient of variation, and Bland-Altman analysis. In all lung cancers, the reproducibility coefficient for intra-observer agreement (range 26.1-38.3%) was superior to inter-observer agreement (range 38.1-81.2%). Further analysis revealed lower agreements for nodules compared to masses. Additionally, inner-air density reduced both agreements for lung cancer. The intra-observer agreement for measuring lung cancer DCTP was satisfied, while the inter-observer agreement was limited. The effects of tumoral size and inner-air density to agreements, especially between two observers, should be emphasized. In future, an automatic computer-aided segment of perfusion value of the tumor should be developed. © 2017 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  7. Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Park, Sang Hyub [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2017-11-15

    Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy. (orig.)

  8. Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Park, Sang Hyub

    2017-01-01

    Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy. (orig.)

  9. Myocardial perfusion at rest in patients with Diabetes Mellitus Type 1 compared with healthy controls assessed with Multi Detector Computed Tomography

    DEFF Research Database (Denmark)

    Byrne, Christina; Jensen, Tonny; Hjortkjær, Henrik Øder

    2015-01-01

    AIM: Type 1 diabetes mellitus (T1DM) is associated with an increased risk of ischemic heart disease (IHD). The relative contribution of structural and functional abnormalities of the coronary circulation determining clinically manifested IHD remains unknown. The aim of this study was to assess...... artery atherosclerosis were evaluated with 320-multidetector computed tomography angiography in 57 asymptomatic T1DM patients and 114 sex and age matched controls. RESULTS: In both groups median age was 53 years (p5,p95: 42,67) and 59.6% were men. Median duration of diabetes in the T1DM group was 35...

  10. Function's evaluation, perfusion and metabolism by positron emission tomography associated with multislice tomography (PET/CT) in patient with previous diagnosis to myocardial necrosis

    International Nuclear Information System (INIS)

    Campisi, Roxana; Aramayo, Natalia; Osorio, Amilcar

    2010-01-01

    A 64-years-old male patient with previous diagnosis of myocardial necrosis as assessed by myocardial perfusion gated single photon emission computed tomography (gSPECT) with 3-vessel-disease, left ventricular dysfunction and symptomatic by epigastric pain. The patient was referred for myocardial viability assessment by positron emission tomography (PET) to define clinical management decision. (authors) [es

  11. Diagnostic value of thallium-201 myocardial perfusion IQ-SPECT without and with computed tomography-based attenuation correction to predict clinically significant and insignificant fractional flow reserve: A single-center prospective study.

    Science.gov (United States)

    Tanaka, Haruki; Takahashi, Teruyuki; Ohashi, Norihiko; Tanaka, Koichi; Okada, Takenori; Kihara, Yasuki

    2017-12-01

    The aim of this study was to clarify the predictive value of fractional flow reserve (FFR) determined by myocardial perfusion imaging (MPI) using thallium (Tl)-201 IQ-SPECT without and with computed tomography-based attenuation correction (CT-AC) for patients with stable coronary artery disease (CAD).We assessed 212 angiographically identified diseased vessels using adenosine-stress Tl-201 MPI-IQ-SPECT/CT in 84 consecutive, prospectively identified patients with stable CAD. We compared the FFR in 136 of the 212 diseased vessels using visual semiquantitative interpretations of corresponding territories on MPI-IQ-SPECT images without and with CT-AC.FFR inversely correlated most accurately with regional summed difference scores (rSDS) in images without and with CT-AC (r = -0.584 and r = -0.568, respectively, both P system can predict FFR at an optimal cut-off of reserved.

  12. The natural history of misery perfusion in positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Shinji; Fujii, Kiyotaka; Matsushima, Toshio; Fukui, Masashi; Sadoshima, Shouzou; Kuwabara, Yasuo (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1992-03-01

    This report reviews the natural courses of misery perfusion in 5 patients with atherosclerotic cerebrovascular occlusion diseases. Cases 1 showed partial improvement and Case 2 showed deterioration of misery perfusion on positron emission tomography (PET). These 2 patients did not show any clinical changes during the follow-up periods. Case 3 showed remarkable improvement of misery perfusion during the 2-year follow-ups, but his neurological condition worsened. The EC-IC bypass improved both in PET and clinical symptoms. Case 4 had a stroke at the region of misery perfusion in PET. Case 5 had a lacunar infarction 2 years after the EC-IC bypass on the opposite side. PET taken one month before the stroke did not show any signs of hypoperfusion in the area of the lacunar infarction. Misery perfusion seems not to be a static but a dynamic condition that can develop into cerebral infarction by some hemodynamic stresses. Cerebral cortical or lobar infarction may occur in the region of severe misery perfusion. EC-IC bypass may prevent impending infarction of the cerebral cortex by improving the regional cerebral blood flow. However, EC-CI bypass will not prevent the lacunar infarction of the basal ganglia or internal capsule. (author).

  13. Pulmonary vascular volume ratio measured by cardiac computed tomography in children and young adults with congenital heart disease: comparison with lung perfusion scintigraphy.

    Science.gov (United States)

    Goo, Hyun Woo; Park, Sang Hyub

    2017-11-01

    Lung perfusion scintigraphy is regarded as the gold standard for evaluating differential lung perfusion ratio in congenital heart disease. To compare cardiac CT with lung perfusion scintigraphy for estimated pulmonary vascular volume ratio in patients with congenital heart disease. We included 52 children and young adults (median age 4 years, range 2 months to 28 years; 31 males) with congenital heart disease who underwent cardiac CT and lung perfusion scintigraphy without an interim surgical or transcatheter intervention and within 1 year. We calculated the right and left pulmonary vascular volumes using threshold-based CT volumetry. Then we compared right pulmonary vascular volume percentages at cardiac CT with right lung perfusion percentages at lung perfusion scintigraphy by using paired t-test and Bland-Altman analysis. The right pulmonary vascular volume percentages at cardiac CT (66.3 ± 14.0%) were significantly smaller than the right lung perfusion percentages at lung perfusion scintigraphy (69.1 ± 15.0%; P=0.001). Bland-Altman analysis showed a mean difference of -2.8 ± 5.8% and 95% limits of agreement (-14.1%, 8.5%) between these two variables. Cardiac CT, in a single examination, can offer pulmonary vascular volume ratio in addition to pulmonary artery anatomy essential for evaluating peripheral pulmonary artery stenosis in patients with congenital heart disease. However there is a wide range of agreement between cardiac CT and lung perfusion scintigraphy.

  14. Meta-Analysis of Stress Myocardial Perfusion Imaging

    Science.gov (United States)

    2017-06-06

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

  15. A semi-automated volumetric software for segmentation and perfusion parameter quantification of brain tumors using 320-row multidetector computed tomography: a validation study

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Soo Young; Suh, Sangil; Ryoo, Inseon; Park, Arim; Seol, Hae Young [Korea University Guro Hospital, Department of Radiology, Seoul (Korea, Republic of); Noh, Kyoung Jin [Soonchunhyang University, Department of Electronic Engineering, Asan (Korea, Republic of); Shim, Hackjoon [Toshiba Medical Systems Korea Co., Seoul (Korea, Republic of)

    2017-05-15

    We developed a semi-automated volumetric software, NPerfusion, to segment brain tumors and quantify perfusion parameters on whole-brain CT perfusion (WBCTP) images. The purpose of this study was to assess the feasibility of the software and to validate its performance compared with manual segmentation. Twenty-nine patients with pathologically proven brain tumors who underwent preoperative WBCTP between August 2012 and February 2015 were included. Three perfusion parameters, arterial flow (AF), equivalent blood volume (EBV), and Patlak flow (PF, which is a measure of permeability of capillaries), of brain tumors were generated by a commercial software and then quantified volumetrically by NPerfusion, which also semi-automatically segmented tumor boundaries. The quantification was validated by comparison with that of manual segmentation in terms of the concordance correlation coefficient and Bland-Altman analysis. With NPerfusion, we successfully performed segmentation and quantified whole volumetric perfusion parameters of all 29 brain tumors that showed consistent perfusion trends with previous studies. The validation of the perfusion parameter quantification exhibited almost perfect agreement with manual segmentation, with Lin concordance correlation coefficients (ρ {sub c}) for AF, EBV, and PF of 0.9988, 0.9994, and 0.9976, respectively. On Bland-Altman analysis, most differences between this software and manual segmentation on the commercial software were within the limit of agreement. NPerfusion successfully performs segmentation of brain tumors and calculates perfusion parameters of brain tumors. We validated this semi-automated segmentation software by comparing it with manual segmentation. NPerfusion can be used to calculate volumetric perfusion parameters of brain tumors from WBCTP. (orig.)

  16. Endocardial-epicardial distribution of myocardial perfusion reserve assessed by multidetector computed tomography in symptomatic patients without significant coronary artery disease

    DEFF Research Database (Denmark)

    Kühl, Jørgen Tobias; George, Richard T; Mehra, Vishal C

    2016-01-01

    (MPR) in humans. We aimed to test the hypothesis that MPR in all myocardial layers is determined by age, gender, and cardiovascular risk profile in patients with ischaemic symptoms or equivalent but without obstructive coronary artery disease (CAD). METHODS AND RESULTS: A total of 149 patients enrolled...... in endocardial-epicardial distribution of perfusion reserve may be demonstrated with static CT perfusion. Low MPR in all myocardial layers was observed specifically in obese patients....

  17. Computed Tomography (CT) Perfusion as an Early Predictive Marker for Treatment Response to Neoadjuvant Chemotherapy in Gastroesophageal Junction Cancer and Gastric Cancer - A Prospective Study

    DEFF Research Database (Denmark)

    Lundsgaard Hansen, Martin; Fallentin, Eva; Lauridsen, Carsten

    2014-01-01

    OBJECTIVES: To evaluate whether early reductions in CT perfusion parameters predict response to pre-operative chemotherapy prior to surgery for gastroesophageal junction (GEJ) and gastric cancer. MATERIALS AND METHODS: Twenty-eight patients with adenocarcinoma of the gastro-esophageal junction (GEJ......-operative chemotherapy in GEJ and gastric cancer. As a single diagnostic test, CT Perfusion only has moderate sensitivity and specificity in response assessment of pre-operative chemotherapy making it insufficient for clinical decision purposes....

  18. A semi-automated volumetric software for segmentation and perfusion parameter quantification of brain tumors using 320-row multidetector computed tomography: a validation study.

    Science.gov (United States)

    Chae, Soo Young; Suh, Sangil; Ryoo, Inseon; Park, Arim; Noh, Kyoung Jin; Shim, Hackjoon; Seol, Hae Young

    2017-05-01

    We developed a semi-automated volumetric software, NPerfusion, to segment brain tumors and quantify perfusion parameters on whole-brain CT perfusion (WBCTP) images. The purpose of this study was to assess the feasibility of the software and to validate its performance compared with manual segmentation. Twenty-nine patients with pathologically proven brain tumors who underwent preoperative WBCTP between August 2012 and February 2015 were included. Three perfusion parameters, arterial flow (AF), equivalent blood volume (EBV), and Patlak flow (PF, which is a measure of permeability of capillaries), of brain tumors were generated by a commercial software and then quantified volumetrically by NPerfusion, which also semi-automatically segmented tumor boundaries. The quantification was validated by comparison with that of manual segmentation in terms of the concordance correlation coefficient and Bland-Altman analysis. With NPerfusion, we successfully performed segmentation and quantified whole volumetric perfusion parameters of all 29 brain tumors that showed consistent perfusion trends with previous studies. The validation of the perfusion parameter quantification exhibited almost perfect agreement with manual segmentation, with Lin concordance correlation coefficients (ρ c ) for AF, EBV, and PF of 0.9988, 0.9994, and 0.9976, respectively. On Bland-Altman analysis, most differences between this software and manual segmentation on the commercial software were within the limit of agreement. NPerfusion successfully performs segmentation of brain tumors and calculates perfusion parameters of brain tumors. We validated this semi-automated segmentation software by comparing it with manual segmentation. NPerfusion can be used to calculate volumetric perfusion parameters of brain tumors from WBCTP.

  19. Acute effect of electroconvulsive therapy on brain perfusion assessed by Tc99m-hexamethylpropyleneamineoxim and single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bajc, M.; Basic, M.; Topuzovic, N.; Babic, D.; Ivancevic, D. (Department of Nuclear Medicine, University Hospital Rebro, Zagreb (Yugoslavia)); Medved, V. (Psychiatric Clinic, University Hospital Rebro, Zagreb (Yugoslavia))

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured in relative terms with Tc99m-hexamethylpropyleneamineoxim and single photon emission computed tomography in 11 patients undergoing electroconvulsive therapy (ECT). The patients suffered from major depressive disorder (n=8) or schizoaffective disorders (n=3). rCBF was measured under general anesthesia 3 days prior to the ECT treatment and coinciding with the ECT stimualtion. ECT caused a redistribution of the tracers uptake. The uptake became more pronounced in frontal parts of the brain and in the basal ganglia than in posterior parts of the cortex, and the thalamus. This selective effect of ECT on rCBF may be related to catecholaminergic projections to anterior parts of the brain. (author).

  20. Acute effect of electroconvulsive therapy on brain perfusion assessed by Tc99m-hexamethylpropyleneamineoxim and single photon emission computed tomography

    International Nuclear Information System (INIS)

    Bajc, M.; Basic, M.; Topuzovic, N.; Babic, D.; Ivancevic, D.; Medved, V.

    1989-01-01

    Regional cerebral blood flow (rCBF) was measured in relative terms with Tc99m-hexamethylpropyleneamineoxim and single photon emission computed tomography in 11 patients undergoing electroconvulsive therapy (ECT). The patients suffered from major depressive disorder (n=8) or schizoaffective disorders (n=3). rCBF was measured under general anesthesia 3 days prior to the ECT treatment and coinciding with the ECT stimualtion. ECT caused a redistribution of the tracers uptake. The uptake became more pronounced in frontal parts of the brain and in the basal ganglia than in posterior parts of the cortex, and the thalamus. This selective effect of ECT on rCBF may be related to catecholaminergic projections to anterior parts of the brain. (author)

  1. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  2. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  5. Computed tomography in traumatology

    International Nuclear Information System (INIS)

    Heller, M.; Jend, H.H.

    1986-01-01

    This volume offers a critical review and assessment of new avenues opened up by computed tomography in traumatology. Over 200 illustrations, including numerous CT scans, aid the physician engaged emergency care and postoperative treatment of accident victims. Technical prerequisites, special techniques of investigation, pathomorphology of organ changes conditioned by trauma, diagnostic leading symptoms and signs, and diagnostics of iatrogenic injuries and lesions are presented

  6. Computed tomography system

    International Nuclear Information System (INIS)

    Lambert, T.W.; Blake, J.E.

    1981-01-01

    This invention relates to computed tomography and is particularly concerned with determining the CT numbers of zones of interest in an image displayed on a cathode ray tube which zones lie in the so-called level or center of the gray scale window. (author)

  7. Chest computed tomography

    DEFF Research Database (Denmark)

    Loeve, Martine; Krestin, Gabriel P.; Rosenfeld, Margaret

    2013-01-01

    are not suitable to study CF lung disease in young children. Chest computed tomography (CT) holds great promise for use as a sensitive surrogate endpoint in CF. A large body of evidence has been produced to validate the use of chest CT as primary endpoint to study CF lung disease. However, before chest CT can...

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  10. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.J.

    1986-01-01

    This book is directed towards giving radiographers an introduction to and basic knowledge of computerized tomography. The technical section discusses gantries and x-ray production, computer and disc drive image display, storage, artefacts quality assurance and design of departments. The clinical section includes patient preparation, radiotherapy planning, and interpretation of images from various areas of the anatomy. (U.K.)

  11. Quantitative cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, M.; Dueber, C.; Wolff, P.; Erbel, R.; Hoffmann, T.

    1985-06-01

    The scope and limitations of quantitative cardiac CT have been evaluated in a series of experimental and clinical studies. The left ventricular muscle mass was estimated by computed tomography in 19 dogs (using volumetric methods, measurements in two axes and planes and reference volume). There was good correlation with anatomical findings. The enddiastolic volume of the left ventricle was estimated in 22 patients with cardiomyopathies; using angiography as a reference, CT led to systematic under-estimation. It is also shown that ECG-triggered magnetic resonance tomography results in improved visualisation and may be expected to improve measurements of cardiac morphology.

  12. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is ... a CT scan. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  13. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

    NARCIS (Netherlands)

    Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

    2016-01-01

    Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

  14. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  15. Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting

    NARCIS (Netherlands)

    Szarmach, Arkadiusz; Halena, Grzegorz; Buczny, Jacek; Studniarek, Michał; Markiet, Karolina; Szurowska, Edyta; Retkowski, Mariusz; Piskunowicz, Maciej

    BACKGROUND: CT perfusion of the brain allows functional evaluation of cerebral blood flow. Patients with chronic internal carotid artery (ICA) stenosis may suffer from malperfusion. Improvement of cerebral blood flow and remission of neurological symptoms indicate the effectiveness of treatment of

  16. TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T; Boone, J [University of California Davis School of Medicine, Sacramento, CA (United States); Kent, M; Wisner, E [University of California Davis School of Veterinary Medicine, Davis, CA (United States); Fujita, Y [Tokai University, Isehara (Japan)

    2015-06-15

    Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R{sup 2}=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral

  17. TU-CD-BRA-08: Single-Energy Computed Tomography-Based Pulmonary Perfusion Imaging: Proof-Of-Principle in a Canine Model

    International Nuclear Information System (INIS)

    Yamamoto, T; Boone, J; Kent, M; Wisner, E; Fujita, Y

    2015-01-01

    Purpose: Pulmonary perfusion imaging has provided significant insights into pulmonary diseases, and can be useful in radiotherapy. The purpose of this study was to prospectively establish proof-of-principle in a canine model for single-energy CT-based perfusion imaging, which has the potential for widespread clinical implementation. Methods: Single-energy CT perfusion imaging is based on: (1) acquisition of inspiratory breath-hold CT scans before and after intravenous injection of iodinated contrast medium, (2) deformable image registration (DIR) of the two CT image data sets, and (3) subtraction of the pre-contrast image from post-contrast image, yielding a map of Hounsfield unit (HU) enhancement. These subtraction image data sets hypothetically represent perfused blood volume, a surrogate for perfusion. In an IACUC-approved clinical trial, we acquired pre- and post-contrast CT scans in the prone posture for six anesthetized, mechanically-ventilated dogs. The elastix algorithm was used for DIR. The registration accuracy was quantified using the target registration errors (TREs) for 50 pulmonary landmarks in each dog. The gradient of HU enhancement between gravity-dependent (ventral) and non-dependent (dorsal) regions was evaluated to quantify the known effect of gravity, i.e., greater perfusion in ventral regions. Results: The lung volume difference between the two scans was 4.3±3.5% on average (range 0.3%–10.1%). DIR demonstrated an average TRE of 0.7±1.0 mm. HU enhancement in lung parenchyma was 34±10 HU on average and varied considerably between individual dogs, indicating the need for improvement of the contrast injection protocol. HU enhancement in ventral (gravity-dependent) regions was found to be greater than in dorsal regions. A population average ventral-to-dorsal gradient of HU enhancement was strong (R"2=0.94) and statistically significant (p<0.01). Conclusion: This canine study demonstrated relatively accurate DIR and a strong ventral

  18. Detection of hemodynamic impairment using magnetic resonance angiography in patients with internal carotid artery stenoocclusive disease. Comparison with quantitative brain perfusion single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Hirooka, Ryonoshin; Ogasawara, Kuniaki

    2008-01-01

    Cerebrovascular reactivity (CVR) to acetazolamideis a key parameter in determining the severity of hemodynamic impairment in patients with major cerebral artery occlusive disease. The aim of the present study is to validate the accuracy of magnetic resonance angiography (MRA) for detecting hemodynamic impairment by correlating detectability of the middle cerebral artery obtained by MRA with CVR measured by single-photon emission computed tomography (SPECT) in patients with internal carotid artery (ICA) occlusive disease. Ninety-four patients with chronic ICA occlusion underwent single slab three-dimensional time-of-flight MRA and SPECT. SPECT-CVR was calculated by measured cerebral blood flow before and after acetazolamide challenge. CVR was significantly lower in patients without detection of any portion (M1, M2 or M3) of the MCA than in those with detection of all portions. When SPECT-CVR lower than the mean- 2 standard deviation (SD) obtained in normal subjects was defined as reduced and the SPECT-CVR was assumed as the true determinant of hemodynamic impairment, MRA provided 92% sensitivity and 73% specificity, with 96% negative predictive value for detecting patients with reduced CVR. The present MRA method is effective for the identification of patients with hemodynamic impairment. (author)

  19. Computed Tomography. Chapter 11

    Energy Technology Data Exchange (ETDEWEB)

    Geleijns, J. [Leiden University Medical Centre, Leiden (Netherlands)

    2014-09-15

    After its clinical introduction in 1971, computed tomography (CT) developed from an X ray modality that was limited to axial imaging of the brain in neuroradiology into a versatile 3-D whole body imaging modality for a wide range of applications, including oncology, vascular radiology, cardiology, traumatology and interventional radiology. CT is applied for diagnosis and follow-up studies of patients, for planning of radiotherapy, and even for screening of healthy subpopulations with specific risk factors.

  20. Computed Tomography Status

    Science.gov (United States)

    Hansche, B. D.

    1983-01-01

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

  1. Mathematics of Computed Tomography

    Science.gov (United States)

    Hawkins, William Grant

    A review of the applications of the Radon transform is presented, with emphasis on emission computed tomography and transmission computed tomography. The theory of the 2D and 3D Radon transforms, and the effects of attenuation for emission computed tomography are presented. The algebraic iterative methods, their importance and limitations are reviewed. Analytic solutions of the 2D problem the convolution and frequency filtering methods based on linear shift invariant theory, and the solution of the circular harmonic decomposition by integral transform theory--are reviewed. The relation between the invisible kernels, the inverse circular harmonic transform, and the consistency conditions are demonstrated. The discussion and review are extended to the 3D problem-convolution, frequency filtering, spherical harmonic transform solutions, and consistency conditions. The Cormack algorithm based on reconstruction with Zernike polynomials is reviewed. An analogous algorithm and set of reconstruction polynomials is developed for the spherical harmonic transform. The relations between the consistency conditions, boundary conditions and orthogonal basis functions for the 2D projection harmonics are delineated and extended to the 3D case. The equivalence of the inverse circular harmonic transform, the inverse Radon transform, and the inverse Cormack transform is presented. The use of the number of nodes of a projection harmonic as a filter is discussed. Numerical methods for the efficient implementation of angular harmonic algorithms based on orthogonal functions and stable recursion are presented. The derivation of a lower bound for the signal-to-noise ratio of the Cormack algorithm is derived.

  2. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Kelman, A.L.; Peterson, T.E.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. The tracks are supported on rollers which carry the substantial weight. Explicit engineering details are presented especially of the ball bearing races used in the rotation. (U.K.)

  3. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Brandt, R.T.; Hein, P.W.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. The tracks are supported on rollers which carry the substantial weight. Explicit engineering details are presented. (U.K.)

  4. Prognostic value of myocardial perfusion single-photon emission computed tomography for the prediction of future cardiac events in a Japanese population. A middle-term follow-up study

    International Nuclear Information System (INIS)

    Matsumoto, Naoya; Sato, Yuichi; Suzuki, Yasuyuki

    2007-01-01

    The prognostic value of rest 201 Tl/stress 99m Tc-tetrofosmin myocardial perfusion single-photon emission computed tomography (SPECT) for the prediction of future hard cardiac events, including acute myocardial infarction (AMI), unstable angina (UAP) and cardiac death, and the implications for risk stratification has not yet been defined in a Japanese population. The 1,988 patients who underwent rest 201 Tl/stress 99m Tc-tetrofosmin SPECT were identified and followed up for the occurrence of AMI, UAP and cardiac death. The mean follow-up interval was 26.9±15.8 months. The 142 patients were revascularized within 60 days after SPECT and they were censored from the prognostic analysis. Summed stress score (SSS), summed rest score and summed difference score (SDS) were calculated using a 5-point scoring (Normal: 0, No uptake: 4) and a 20-segment model; 22 cases of myocardial infarction, 31 of UAP and 22 cardiac deaths occurred (1.2%, 1.7% and 1.2%, respectively). Multivariate Cox regression analysis showed that hypertension (Wald 6.37, p<0.05) and SDS (Wald 8.77, p<0.01) were independent predictors of AMI and UAP. Advanced age (Wald 16.0, p<0.001), SSS (Wald 10.9, p<0.01) and SDS (Wald 4.58, p<0.05) were independent predictors of cardiac death. Myocardial perfusion SPECT yields prognostic information toward the identification of acute coronary syndrome and cardiac death. (author)

  5. Prognostic value of myocardial perfusion single photon emission computed tomography for major adverse cardiac cerebrovascular and renal events in patients with chronic kidney disease: results from first year of follow-up of the Gunma-CKD SPECT multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji [Department of Cardiovascular Medicine, Gunma Prefectural Cardiovascular Center, Maebashi (Japan); Sato, Makito [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Tatebayashi Kosei Hospital, Department of Internal Medicine, Gunma (Japan); Sano, Hirokazu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Isesaki Municipal Hospital, Department of Cardiovascular Medicine, Isesaki (Japan); Ueda, Tetsuya [Fujioka General Hospital, Division of Cardiology, Fujioka (Japan); Sasaki, Toyoshi [Takasaki General Medical Center, Division of Cardiology, Takasaki (Japan); Nakahara, Takehiro; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Higuchi, Tetsuya; Tsushima, Yoshito [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi (Japan)

    2016-02-15

    Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. We examined whether stress myocardial perfusion single photon emission computed tomography (SPECT) provides reliable prognostic markers for these patients. In this multicenter, prospective cohort trial from the Gunma-CKD SPECT study protocol, patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml per 1.73 m{sup 2}] undergoing stress {sup 99m}Tc-tetrofosmin SPECT for suspected or possible ischemic heart disease were initially followed for 1 year, with the following study endpoints: primary, the occurrence of cardiac deaths (CDs), and secondary, major adverse cardiac, cerebrovascular, and renal events (MACCREs). The summed stress score (SSS), summed rest score, and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Left ventricular end-diastolic volume, end-systolic volume (ESV), and ejection fraction were measured using electrocardiogram-gated SPECT. During the first year of follow-up, 69 of 299 patients experienced MACCREs (CD, n = 7; non-fatal myocardial infarction, n = 3; hospitalization for heart failure, n = 13; cerebrovascular accident, n = 1; need for revascularization, n = 38; and renal failure, i.e., hemodialysis initiation, n = 7). ESV and SSS were associated with CDs (p < 0.05), and eGFR and SDS were associated with MACCREs (p < 0.05), in multivariate logistic analysis. Patients with high ESV and high SSS had a significantly higher CD rate during the first year than the other CKD patient subgroups (p < 0.05). Patients with low eGFR and high SDS had a significantly higher MACCRE rate than the other subgroups (p < 0.05). Myocardial perfusion SPECT can provide reliable prognostic markers for patients with CKD. (orig.)

  6. Prognostic value of myocardial perfusion single photon emission computed tomography for major adverse cardiac cerebrovascular and renal events in patients with chronic kidney disease: results from first year of follow-up of the Gunma-CKD SPECT multicenter study

    International Nuclear Information System (INIS)

    Kasama, Shu; Toyama, Takuji; Sato, Makito; Sano, Hirokazu; Ueda, Tetsuya; Sasaki, Toyoshi; Nakahara, Takehiro; Kurabayashi, Masahiko; Higuchi, Tetsuya; Tsushima, Yoshito

    2016-01-01

    Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. We examined whether stress myocardial perfusion single photon emission computed tomography (SPECT) provides reliable prognostic markers for these patients. In this multicenter, prospective cohort trial from the Gunma-CKD SPECT study protocol, patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml per 1.73 m 2 ] undergoing stress 99m Tc-tetrofosmin SPECT for suspected or possible ischemic heart disease were initially followed for 1 year, with the following study endpoints: primary, the occurrence of cardiac deaths (CDs), and secondary, major adverse cardiac, cerebrovascular, and renal events (MACCREs). The summed stress score (SSS), summed rest score, and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Left ventricular end-diastolic volume, end-systolic volume (ESV), and ejection fraction were measured using electrocardiogram-gated SPECT. During the first year of follow-up, 69 of 299 patients experienced MACCREs (CD, n = 7; non-fatal myocardial infarction, n = 3; hospitalization for heart failure, n = 13; cerebrovascular accident, n = 1; need for revascularization, n = 38; and renal failure, i.e., hemodialysis initiation, n = 7). ESV and SSS were associated with CDs (p < 0.05), and eGFR and SDS were associated with MACCREs (p < 0.05), in multivariate logistic analysis. Patients with high ESV and high SSS had a significantly higher CD rate during the first year than the other CKD patient subgroups (p < 0.05). Patients with low eGFR and high SDS had a significantly higher MACCRE rate than the other subgroups (p < 0.05). Myocardial perfusion SPECT can provide reliable prognostic markers for patients with CKD. (orig.)

  7. Multislice computed tomography coronary angiography

    NARCIS (Netherlands)

    F. Cademartiri (Filippo)

    2005-01-01

    markdownabstract__Abstract__ Computed Tomography (CT) imaging is also known as "CAT scanning" (Computed Axial Tomography). Tomography is from the Greek word "tomos" meaning "slice" or "section" and "graphia" meaning "describing". CT was invented in 1972 by British engineer Godfrey Hounsfield

  8. Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease

    Energy Technology Data Exchange (ETDEWEB)

    Bisdas, Sotirios [JWG University Hospital, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Nemitz, Ole; Becker, Hartmut; Donnerstag, Frank [Hannover Medical School, Department of Neuroradiology, Hannover (Germany); Berding, Georg [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Weissenborn, Karin; Ahl, Bjoern [Hannover Medical School, Department of Neurology, Hannover (Germany)

    2006-10-15

    Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [{sup 15}O]H{sub 2}O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics. (orig.)

  9. Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease

    International Nuclear Information System (INIS)

    Bisdas, Sotirios; Nemitz, Ole; Becker, Hartmut; Donnerstag, Frank; Berding, Georg; Weissenborn, Karin; Ahl, Bjoern

    2006-01-01

    Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [ 15 O]H 2 O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics. (orig.)

  10. Voxelwise comparison of perfusion parameters estimated using dynamic contrast enhanced (DCE) computed tomography and DCE-magnetic resonance imaging in locally advanced cervical cancer

    International Nuclear Information System (INIS)

    Kallehauge; Jesper; Nielsen, Thomas; Haack, Soeren

    2013-01-01

    Purpose: Dynamic contrast enhanced (DCE) imaging has gained interest as an imaging modality for assessment of tumor characteristics and response to cancer treatment. However, for DCE-magnetic resonance imaging (MRI) tissue contrast enhancement may vary depending on imaging sequence and temporal resolution. The aim of this study is to compare DCE-MRI to DCE-computed tomography (DCE-CT) as the gold standard. Material and methods: Thirteen patients with advanced cervical cancer were scanned once prior to chemo-radiation and during chemo-radiation with DCE-CT and -MRI in immediate succession. A total of 22 paired DCE-CT and -MRI scans were acquired for comparison. Kinetic modeling using the extended Tofts model was applied to both image series. Furthermore the similarity of the spatial distribution was evaluated using a G analysis. The correlation between the two imaging techniques was evaluated using Pe arson's correlation and the parameter means were compared using a Student's t-test (p trans (r = 0.9), flux rate constant k ep (r = 0.77), extracellular volume fraction v e (r = 0.58) and blood plasma volume fraction v p (r = 0.83). All quantitative parameters were found to be significantly different as estimated by DCE-CT and -MRI. The G analysis in normalized maps revealed that 45 % of the voxels failed to find a voxel with the corresponding value allowing for an uncertainty of 3 mm in position and 3 % in value (G 3,3 ). By reducing the criteria, the G-failure rates were: G 3,5 (37 % failure), G 3,10 (26% failure) and at G 3,15 (19 % failure). Conclusion: Good to excellent correlations but significant bias was found between DCE-CT and -MRI. Both the Pearson's correlation and the G analysis proved that the spatial information was similar when analyzing the two sets of DCE data using the extended Tofts model. Improvement of input function sampling is needed to improve kinetic quantification using DCE-MRI

  11. Computed tomography device

    International Nuclear Information System (INIS)

    Ohhashi, A.

    1985-01-01

    A computed tomography device comprising a subtraction unit which obtains differential data strings representing the difference between each time-serial projection data string of a group of projection data strings corresponding to a prospective reconstruction image generated by projection data strings acquired by a data acquisition system, a convolution unit which convolves each time-serial projection data string of the group of projection data strings corresponding to the prospective reconstruction image, and a back-projection unit which back-projects the convolved data strings

  12. Method for computed tomography

    International Nuclear Information System (INIS)

    Wagner, W.

    1980-01-01

    In transversal computer tomography apparatus, in which the positioning zone in which the patient can be positioned is larger than the scanning zone in which a body slice can be scanned, reconstruction errors are liable to occur. These errors are caused by incomplete irradiation of the body during examination. They become manifest not only as an incorrect image of the area not irradiated, but also have an adverse effect on the image of the other, completely irradiated areas. The invention enables reduction of these errors

  13. Dosimetry in computed tomography

    International Nuclear Information System (INIS)

    Andisco, D.; Blanco, S.; Buzzia, A.E.

    2014-01-01

    Objective: The amount of computed tomography (CT) studies that are performed each year in the world is growing exponentially mainly due to the incorporation of multislice CT that allows studies in a few seconds. But, despite the benefit received by patients with the diagnosis, radiation dose is a concern in the professional community and it has be reduced as much as reasonably possible. This article describes the main dosimetric CT units used in order to work with this practice easily, using the values that provide modern equipment and internationally known reference levels. (authors) [es

  14. Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography in patients with major cerebral artery steno-occlusive diseases

    International Nuclear Information System (INIS)

    Saito, Hideo; Ogasawara, Kuniaki; Suzuki, Taro; Kuroda, Hiroki; Kobayashi, Masakazu; Yoshida, Kenji; Kubo, Yoshitaka; Ogawa, Akira

    2011-01-01

    Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography (SPECT) were prospectively investigated in 100 patients with major cerebral artery, atherosclerotic, and steno-occlusive diseases. All patients underwent two SPECT studies (with and without acetazolamide challenge) at an interval of 2 or 3 days, received a questionnaire immediately after each SPECT study, and returned the answered questionnaire within 7 days after the study. None of the 100 patients studied experienced any symptoms during the SPECT study without acetazolamide challenge. Sixty-three patients (63%) developed symptoms during the SPECT study with acetazolamide challenge, such as headache, nausea, dizziness, tinnitus, numbness of the extremities, motor weakness of the extremities, and general malaise 1-3 hours (mean 1.6 hours) after administration of acetazolamide, and these symptoms lasted for 0.5-72 hours (mean 7.9 hours). Multivariate statistical analysis revealed that younger age (95% confidence interval [CI] 0.896-0.980, p=0.0047) and female sex (95% CI 1.178-16.129, p=0.0274) were significantly associated with development of symptoms with acetazolamide challenge. The incidences of the development of symptoms with acetazolamide challenge were 91% (21/23) and 41% (12/29) in subgroups of women <70 years and men ≥70 years, respectively. Patients should be informed of such adverse effects of intravenous acetazolamide administration prior to the acetazolamide challenge test for evaluation of cerebrovascular reactivity. (author)

  15. Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography in patients with major cerebral artery steno-occlusive diseases

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Hideo; Ogasawara, Kuniaki; Suzuki, Taro; Kuroda, Hiroki; Kobayashi, Masakazu; Yoshida, Kenji; Kubo, Yoshitaka; Ogawa, Akira [Iwate Medical Univ., School of Medicine, Morioka, Iwate (Japan)

    2011-07-15

    Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography (SPECT) were prospectively investigated in 100 patients with major cerebral artery, atherosclerotic, and steno-occlusive diseases. All patients underwent two SPECT studies (with and without acetazolamide challenge) at an interval of 2 or 3 days, received a questionnaire immediately after each SPECT study, and returned the answered questionnaire within 7 days after the study. None of the 100 patients studied experienced any symptoms during the SPECT study without acetazolamide challenge. Sixty-three patients (63%) developed symptoms during the SPECT study with acetazolamide challenge, such as headache, nausea, dizziness, tinnitus, numbness of the extremities, motor weakness of the extremities, and general malaise 1-3 hours (mean 1.6 hours) after administration of acetazolamide, and these symptoms lasted for 0.5-72 hours (mean 7.9 hours). Multivariate statistical analysis revealed that younger age (95% confidence interval [CI] 0.896-0.980, p=0.0047) and female sex (95% CI 1.178-16.129, p=0.0274) were significantly associated with development of symptoms with acetazolamide challenge. The incidences of the development of symptoms with acetazolamide challenge were 91% (21/23) and 41% (12/29) in subgroups of women <70 years and men {>=}70 years, respectively. Patients should be informed of such adverse effects of intravenous acetazolamide administration prior to the acetazolamide challenge test for evaluation of cerebrovascular reactivity. (author)

  16. Mesenteric panniculitis: computed tomography aspects

    International Nuclear Information System (INIS)

    Moreira, Luiza Beatriz Melo; Alves, Jose Ricardo Duarte; Marchiori, Edson; Pinheiro, Ricardo Andrade; Melo, Alessandro Severo Alves de; Noro, Fabio

    2001-01-01

    Mesenteric panniculitis is an inflammatory process that represents the second stage of a rare progressive disease involving the adipose tissue of the mesentery. Imaging methods used in the diagnosis of mesenteric panniculitis include barium studies, ultrasonography, computed tomography and magnetic resonance imaging. Computed tomography is important for both, diagnosis and evaluation of the extension of the disease and treatment monitoring. Computed tomography findings may vary according to the stage of the disease and the amount of inflammatory material or fibrosis. There is also good correlation between the computed tomography and anatomical pathology findings. The authors studied 10 patients with mesenteric panniculitis submitted to computed tomography. Magnetic resonance imaging was also performed in one patient. In all patients, computed tomography revealed a heterogeneous mass in the mesentery with density of fat, interspersed with areas of soft tissue density and dilated vessels. (author)

  17. The neutron computer tomography

    International Nuclear Information System (INIS)

    Matsumoto, G.; Krata, S.

    1983-01-01

    The method of computer tomography (CT) was applied for neutrons instead of X-rays. The neutron radiography image of samples was scanned by microphotometer to get the transmission data. This process was so time-consuming that the number of incident angles to samples could not be increased. The transmission data was processed by FACOM computer and CT image was gained. In the experiment at the Japan Research Reactor No. 4 at Tokai-mura with 18 projection angles, the resolution of paraffin in the aluminum block was less than 0.8 mm. In the experiment at Van de Graaf accelerator of Nagoya University, this same resolution was 1.2 mm because of the angle distribution of neutron beam. This experiment is the preliminary one, the facility which utilizes neutron television and video-recorder will be necessary for the next stage. (Auth.)

  18. Gantry for computed tomography

    International Nuclear Information System (INIS)

    Kelman, A.L.; O'Dell, W.R.; Brook, R.F.; Hein, P.W.; Brandt, R.T.

    1981-01-01

    A novel design of gantry for use in computed tomography is described in detail. In the new gantry, curved tracks are mounted to the laterally spaced apart sides of the frame which rotates and carries the detector and X-ray source. This permits the frame to be tilted either side of vertical enabling angular slices of body layers to be viewed and allows simplification of the algorithm which the computer uses for image reconstruction. A failsafe, solenoid brake is described which can lock the shaft against rotation. The gantry also contains a hoist mechanism which aids maintenance of the heavy X-ray tube and/or detector arrays. Explicit engineering details are presented. (U.K.)

  19. Computed tomography in facial trauma

    International Nuclear Information System (INIS)

    Zilkha, A.

    1982-01-01

    Computed tomography (CT), plain radiography, and conventional tomography were performed on 30 patients with facial trauma. CT demonstrated bone and soft-tissue involvement. In all cases, CT was superior to tomography in the assessment of facial injury. It is suggested that CT follow plain radiography in the evaluation of facial trauma

  20. Comparison of ventilation-perfusion single-photon emission computed tomography (V/Q SPECT) versus dual-energy CT perfusion and angiography (DECT) after 6 months of pulmonary embolism (PE) treatment

    Energy Technology Data Exchange (ETDEWEB)

    Meysman, M., E-mail: marc.meysman@uzbrussel.be [Respiratory Division, Department of Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Everaert, H., E-mail: nucgeth@gmail.com [Department of Nuclear Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Buls, N., E-mail: nico.buls@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Nieboer, K., E-mail: koenraad.nieboer@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Mey, J. de, E-mail: Johan.deMey@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel (VUB), Brussels (Belgium)

    2015-09-15

    Highlights: • Incomplete resolution of pulmonary emboli occurs frequently. • Residual V/Q-SPECT defects correspond in the majority of cases with defects seen on DECT. • Some (11.1%) defects on V/Q-SPECT are not present on comparable DECT images. - Abstract: Background: The natural evolution of treated symptomatic pulmonary embolism shows often incomplete resolution of pulmonary thrombi. The prevalence of perfusion defects depend on the image modality used. This study directly compares V/Q SPECT with DECT. Methods: A single-center prospective observational cohort study of patients with intermediate risk PE, reassessed at the end of treatment with V/Q SPECT. Abnormal V/Q SPECT images were compared with DECT. Results: We compared DECT en V/Q SPECT in 28 consecutive patients with persistent V/Q mismatch on V/Q SPECT, 13 men and 15 woman, mean age 60 (+17), range 23–82 year. One patient was excluded from the final analysis due to inferior quality DECT. In 18/27 (66.7%) the results were concordant between CTPA (persistent embolus visible), DECT (segmentary defects on iodine map) and V/Q SPECT (segmentary ventilation–perfusion mismatch). In 3/18 (11.1% of the total group) the partialy matched V/Q SPECT defect could be explained on DECT lung images by lung infarction. In 6/27 (22.1%) only hypoperfusion was seen on DECT iodine map. In 3/27 (11.1%) results were discordant between V/Q SPECT and DECT images. Conclusion: Six months after diagnosis of first or recurrent PE, residual pulmonary perfusion-defects encountered on V/Q-SPECT corresponds in the majority of patients with chronic thromboembolic disease seen on DECT. In 22.1% of patients V/Q SPECT mismatch only corresponds with hypoperfusion on iodine map DECT scan. Some (11.1%) of the chronic thromboembolic lesions seen on V/Q SPECT can not be explained by DECT results.

  1. Comparison of myocardial Perfusion imaging by thallium-201 single-photon emission computed tomography with SUNY4001 (adenosine) and exercise. Crossover clinical trial at multi-center

    International Nuclear Information System (INIS)

    Nishimura, Shigeyuki; Nishimura, Tsunehiko; Yamazaki, Junichi

    2004-01-01

    We compared the ischemic diagnosis ability and adverse events of 201 Tl myocardial perfusion imaging with SUNY4001 (adenosine) stress to that with exercise (ergometer) stress both on random crossover trial. Thirty one known or suspected chronic stable angina patients who are able to exercise and 10 healthy volunteers were enrolled for the trial. The early and delayed images were obtained by SPECT imaging. The concordance of diagnoses [ischemia vs. no ischemia] between the two types of stresses was 97.3% (36/37) [Kappa: 0.9068]. The sensitivity and specificity based on the exercise test were 100% (6/6) and 96.8% (30/31) respectively. The incidence of adverse events caused by SUNY4001 and the exercise were 44.7% (17/38) and 52.6% (20/38), respectively. Major adverse events caused by SUNY4001 were blood pressure (BP) decrease, flushing and headache. And those by exercise were ST decrease, dyspnea and chest pain. None of the adverse events required the intervention or caused life-threatening complication in the trial. The trial showed that the ischemic diagnosis ability and safety of 201 Tl scintigraphy with SUNY4001 stress are almost equal to those of the exercise stress that is considered as the standard stress method. We concluded that 201 Tl imaging with SUNY4001 is safe and useful for detecting ischemic heart disease, especially for patients unable to exercise adequately. (author)

  2. Proton computed tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1978-01-01

    The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible

  3. Positron emission computed tomography

    International Nuclear Information System (INIS)

    Grover, M.; Schelbert, H.R.

    1985-01-01

    Regional mycardial blood flow and substrate metabolism can be non-invasively evaluated and quantified with positron emission computed tomography (Positron-CT). Tracers of exogenous glucose utilization and fatty acid metabolism are available and have been extensively tested. Specific tracer kinetic models have been developed or are being tested so that glucose and fatty acid metabolism can be measured quantitatively by Positron-CT. Tracers of amino acid and oxygen metabolism are utilized in Positron-CT studies of the brain and development of such tracers for cardiac studies are in progress. Methods to quantify regional myocardial blood flow are also being developed. Previous studies have demonstrated the ability of Positron-/CT to document myocardial infarction. Experimental and clinical studies have begun to identify metabolic markers of reversibly ischemic myocardium. The potential of Positron-CT to reliably detect potentially salvageable myocardium and, hence, to identify appropriate therapeutic interventions is one of the most exciting applications of the technique

  4. Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Miori, E-mail: miori@mx6.et.tiki.ne.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Tsuji, Yoshihisa, E-mail: y.tsuji@extra.ocn.ne.jp [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Katabami, Nana; Shimizu, Junichiro; Lee, Ki-Ja [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Iwasaki, Toshiroh [Department of Veterinary Internal Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8, Fuchu 183-8509 (Japan); Miyake, Yoh-Ichi [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan); Yazumi, Shujiro [Digestive Disease Center, Kitano Hospital, 2-4-20 Ougi-machi, Kita-ku, Osaka 530-8480 (Japan); Chiba, Tsutomu [Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Shogoinkawara-cho 54, Sakyo-ku 606-8507 (Japan); Yamada, Kazutaka, E-mail: kyamada@obihiro.ac.jp [Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro 080-8555 (Japan)

    2011-01-15

    Objective: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. Methods: We examined nine beagles injected with iohexol (200 mgI kg{sup -1}) at 5.0 ml s{sup -1}. The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. Results: The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 {+-} 1.6) was shorter than the appearance time (14.1 {+-} 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. Conclusion: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

  5. Measurement of canine pancreatic perfusion using dynamic computed tomography: Influence of input-output vessels on deconvolution and maximum slope methods

    International Nuclear Information System (INIS)

    Kishimoto, Miori; Tsuji, Yoshihisa; Katabami, Nana; Shimizu, Junichiro; Lee, Ki-Ja; Iwasaki, Toshiroh; Miyake, Yoh-Ichi; Yazumi, Shujiro; Chiba, Tsutomu; Yamada, Kazutaka

    2011-01-01

    Objective: We investigated whether the prerequisite of the maximum slope and deconvolution methods are satisfied in pancreatic perfusion CT and whether the measured parameters between these algorithms are correlated. Methods: We examined nine beagles injected with iohexol (200 mgI kg -1 ) at 5.0 ml s -1 . The abdominal aorta and splenic and celiac arteries were selected as the input arteries and the splenic vein, the output veins. For the maximum slope method, we determined the arterial contrast volume of each artery by measuring the area under the curve (AUC) and compared the peak enhancement time in the pancreas with the contrast appearance time in the splenic vein. For the deconvolution method, the artery-to-vein collection rate of contrast medium was calculated. We calculated the pancreatic tissue blood flow (TBF), tissue blood volume (TBV), and mean transit time (MTT) using both algorithms and investigated their correlation based on vessel selection. Results: The artery AUC significantly decreased as it neared the pancreas (P < 0.01). In all cases, the peak time of the pancreas (11.5 ± 1.6) was shorter than the appearance time (14.1 ± 1.6) in the splenic vein. The splenic artery-vein combination exhibited the highest collection rate (91.1%) and was the only combination that was significantly correlated between TBF, TBV, and MTT in both algorithms. Conclusion: Selection of a vessel nearest to the pancreas is considered as a more appropriate prerequisite. Therefore, vessel selection is important in comparison of the semi-quantitative parameters obtained by different algorithms.

  6. Computer tomography of the neurocranium.

    Science.gov (United States)

    Liliequist, B; Forssell, A

    1976-07-01

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

  7. [Computed tomography of the heart

    DEFF Research Database (Denmark)

    Kristensen, T.S.; Kofoed, K.F.; der, Recke P. von

    2009-01-01

    Noninvasive evaluation of the coronary arteries by multi-detector row computed tomography is a promising new alternative to conventional invasive coronary angiography. This article describes the technical background, methods, limitations and clinical applications and reviews current literature...... that compares the diagnostic accuracy of multi-detector row computed tomography with that of coronary angiography Udgivelsesdato: 2009/4/6...

  8. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    International Nuclear Information System (INIS)

    Hacker, M.; Hack, N.; Tiling, R.; Jakobs, T.; Nikolaou, K.; Becker, C.; Ziegler, F. von; Knez, A.; Koenig, A.; Klauss, V.

    2007-01-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 ± 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  9. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, M.; Hack, N.; Tiling, R. [Klinikum Grosshadern (Germany). Dept. of Nuclear Medicine; Jakobs, T.; Nikolaou, K.; Becker, C. [Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Ziegler, F. von; Knez, A. [Klinikum Grosshadern (Germany). Dept. of Cardiology; Koenig, A.; Klauss, V. [Medizinische Poliklinik-Innenstadt, Univ. of Munich (Germany). Dept. of Cardiology

    2007-07-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting ''obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 {+-} 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  10. Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

    Science.gov (United States)

    Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

    2014-05-01

    The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

  11. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams Blood Clots CT Perfusion of the Head CT Angiography ( ...

  12. Computed tomography apparatus

    International Nuclear Information System (INIS)

    Fairbairn, I.A.

    1984-01-01

    In fan-beam computed tomography apparatus, timing reference pulses, normally occurring at intervals t, for data transfer and reset of approx. 500 integrators in the signal path from the detector array, are generated from the scan displacement, e.g. using a graticule and optical sensor to relate the measurement paths geometrically to the body section. Sometimes, a slow scan rate is required to provide a time-averaged density image, e.g. for planning irradiation therapy, and then the sensed impulses will occur at extended intervals and can cause integrator overload. An improvement is described which provides a pulse generator which responds to a reduced scan rate by generating a succession of further transfer and reset pulses at intervals approximately equal to t starting a time t after each timing reference pulse. Then, using an adding device and RAM, all the transferred signals integrated in the interval t' between two successive slow scan reference pulses are accumulated in order to form a corresponding measurement signal. (author)

  13. Computed tomography intravenous cholangiography

    International Nuclear Information System (INIS)

    Nascimento, S.; Murray, W.; Wilson, P.

    1997-01-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors)

  14. Computed tomography of the pancreas

    International Nuclear Information System (INIS)

    Kolmannskog, F.; Kolbenstvedt, A.; Aakhus, T.; Bergan, A.; Fausa, O.; Elgjo, K.

    1980-01-01

    The findings by computed tomography in 203 cases of suspected pancreatic tumours, pancreatitis or peripancreatic abnormalities were evaluated. The appearances of the normal and the diseased pancreas are described. Computed tomography is highly accurate in detecting pancreatic masses, but can not differentiate neoplastic from inflammatory disease. The only reliable signs of pancreatic carcinoma are a focal mass in the pancreas, together with liver metastasis. When a pancreatic mass is revealed by computed tomography, CT-guided fine-needle aspiration biopsy of the pancreas is recommended. Thus the need for more invasive diagnostic procedures and explorative laparotomy may be avoided in some patients. (Auth.)

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... is Children's CT? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... is used to evaluate: complications from infections such as pneumonia a tumor that arises in the lung ...

  16. Computed tomography of drill cores

    International Nuclear Information System (INIS)

    Taylor, T.

    1985-08-01

    A preliminary computed tomography evaluation of drill cores of granite and sandstone has generated geologically significant data. Density variations as small as 4 percent and fractures as narrow as 0.1 mm were easily detected

  17. Children's (Pediatric) CT (Computed Tomography)

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    Full Text Available ... Children's (Pediatric) CT (Computed Tomography) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  18. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  19. Computed Tomography (CT) -- Head

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    Full Text Available ... tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  20. Computed Tomography (CT) -- Head

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    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Brain Tumors Radiation Therapy for ... Tomography (CT) - Head Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... top of page Additional Information and Resources RTAnswers.org Radiation Therapy for Head and Neck Cancer top ... Tomography (CT) - Sinuses Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ...

  2. Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning

    NARCIS (Netherlands)

    Kunst, P. W.; Vonk Noordegraaf, A.; Hoekstra, O. S.; Postmus, P. E.; de Vries, P. M.

    1998-01-01

    Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of

  3. Neuroanatomy of cranial computed tomography

    International Nuclear Information System (INIS)

    Kretschmann, H.J.; Weinrich, W.

    1985-01-01

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

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ... ray beam follows a spiral path. A special computer program processes this large volume of data to ...

  9. Single photon emission computed tomography in children with idiopathic seizures

    International Nuclear Information System (INIS)

    Hara, Masafumi; Takahashi, Mutsumasa; Kojima, Akihiro; Shimomura, Osamu; Kinoshita, Rumi; Tomiguchi, Seiji; Taku, Keiichi; Miike, Teruhisa

    1991-01-01

    Single photon emission computed tomography (SPECT) with N-isoprophyl-p [ 123 I]-iodoamphetamine (IMP), X-ray computed tomography (X-CT), and magnetic resonance imaging (MRI) were performed in 20 children with idiopathic seizures. In children with idiopathic seizures, SPECT could detect the abnormal sites at the highest rate (45%) compared with CT (10%) and MRI (12%), but the abnormal sites on SPECT correlated poorly with the foci on electroencephalograph (EEG). Idiopathic epilepsy with hypoperfusion on SPECT was refractory to treatment and was frequently associated with mental and/or developmental retardation. Perfusion defects on SPECT scans probably affect the development and maturation of the brain in children. (author)

  10. Computed tomography in renal trauma

    International Nuclear Information System (INIS)

    Brueck, W.; Eisenberger, F.; Buck, J.

    1981-01-01

    In a group of 19 patients suffering from flank trauma and gross hematuria the diagnostic value of angiography was compared with that of computed tomography. The cases that underwent both tests were found to have the some diagnosis of rupture of the kidney. Typical CT-findings in kidney rupture are demonstrated. Whereas angiography presents an exact picture of the arterial system of the kidney, including its injures computed tomography reveals the extent of organ lesons by showing extra- and intrarenal hematomas. If surgery is planned angiography is still mandatory, whereby the indication is largely determined by the clinical findings. Computed tomography as a non-invasive method is equally suitable for follow-ups. (orig.) [de

  11. Computed tomography of pulmonary nodules

    International Nuclear Information System (INIS)

    Nakata, Hajime; Honda, Hiroshi; Nakayama, Chikashi; Kimoto, Tatsuya; Nakayama, Takashi

    1983-01-01

    We have evaluated the value of computed tomography (CT) in distinguishing benign and malignant pulmonary nodules. CT was performed on 30 cases of solitary pulmonary nodules consisting of 17 primary lung cancers, 3 metastatic tumors and 10 benign nodules. The CT number was calculated for each lesion. Three benign nodules showed CT numbers well above the range of malignant nodules, and only in one of them was calcification visible on conventional tomography. In 6 benign nodules, the CT numbers overlapped those of malignant lesion and could not be differentiated. Thus the measurement of CT number can be useful to confirm the benign nature of certain nodules when calcification is unclear or not visible on conventional tomography. As for the morphological observation of the nodule, CT was not superior to conventional tomography and its value seems to be limited. (author)

  12. Emission computed tomography

    International Nuclear Information System (INIS)

    Phelps, M.E.

    1977-01-01

    Although there are many common aspects to x-ray transmission and radionuclide emission (ECT) computerized tomography, there are added difficulties and a number of particular factors which form the basis of ECT. The relationship between the physical factors, system design, methodologic approach and assumptions of ECT is discussed. The instrumentation design and application strategies in ECT at this time are diverse and in a rapid stage of development. The approaches are divided into two major categories of Single Photon Counting (SPC) employing scanner and camera concepts with radionuclides of 99 /sup m/Tc, 201 Tl, 123 I etc., and Annihilation Coincidence Detection (ACD) of positron-emitting radionuclides. Six systems in the former and ten systems in the latter category, with examples of typical studies, illustrate the different approaches

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... diagnose sinusitis . evaluate sinuses that are filled with fluid or thickened sinus membranes . detect the presence of ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  15. Computed Tomography (CT) -- Head

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    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  16. Computed Tomography (CT) -- Head

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  17. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... many types of tissue as well as the lungs, bones, and blood vessels. CT examinations are fast ...

  18. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... accurate. A major advantage of CT is its ability to image bone, soft tissue and blood vessels ...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy ...

  1. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... of the Sinuses? CT is usually the first test ordered when a sinus tumor is suspected. If ...

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT imaging is sometimes compared to looking into ...

  4. Computed Tomography (CT) -- Head

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    Full Text Available ... to reduce the risk of an allergic reaction. These medications must be taken 12 hours prior to ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ...

  5. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... to reduce the risk of an allergic reaction. These medications must be taken 12 hours prior to ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ...

  6. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... to you, revolve around you during the imaging process. You will be alone in the exam room ...

  7. Computed Tomography (CT) -- Head

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  8. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  9. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they ...

  10. Computed Tomography (CT) -- Head

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    Full Text Available ... path. A special computer program processes this large volume of data to create two-dimensional cross-sectional ... time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they ...

  11. Computed Tomography (CT) -- Head

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    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  12. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  13. Computed Tomography (CT) -- Head

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... cause blurring of the images and degrade the quality of the examination the same way that it ...

  14. Computed Tomography (CT) -- Sinuses

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    Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... artifacts on the images. This loss of image quality can resemble the blurring seen on a photograph ...

  15. Computed tomography of the heart using thallium-201 in children

    International Nuclear Information System (INIS)

    Treves, S.; Hill, T.C.; VanPraagh, R.; Holman, B.L.

    1979-01-01

    Thallium-201 emission computed tomography (ECT) was performed in 3 pediatric patients in whom conventional scintigraphy was normal but there was a strong clinical suspicion of myocardial disease. Abnormalities in the distribution of myocardial perfusion appeared sharply delineated with ECT compared to normal conventional gamma camera scintigraphy. Single photon ECT provides a three dimensional reconstruction which results in greater enhancement since activity in overlying structures does not interfere. Its widespread use is limited only by the cost of the imaging device

  16. Application of C-arm computed tomography in cardiology

    International Nuclear Information System (INIS)

    Rieber, J.; Rohkohl, C.; Lauritsch, G.; Rittger, H.; Meissner, O.

    2009-01-01

    C-arm computed tomography is currently being introduced into cardiac imaging and offers the potential for three-dimensional imaging of the cardiac anatomy within the interventional environment. This detailed view is necessary to support complex interventional strategies, such as transcutaneous valve replacement, interventional therapy of atrial fibrillation, implantation of biventricular pacemakers and assessment of myocardial perfusion. Currently, the major limitation of this technology is its insufficient temporal resolution which limits the visualization of fast moving parts of the heart. (orig.) [de

  17. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... information about radiation dose. There always is a risk of complications from general anesthesia or sedation. Every measure will be taken to ... in X-Ray and CT Exams Contrast Materials Anesthesia Safety Children and Radiation Safety ... (Pediatric) CT (Computed Tomography) Videos related to Children's (Pediatric) ...

  18. Computed tomography in hepatic echinococcosis

    International Nuclear Information System (INIS)

    Choliz, J.D.; Olaverri, F.J.L.; Casas, T.F.; Zubieta, S.O.

    1982-01-01

    Computed tomography (CT) was used to evaluate 50 cases of hydatid disease of the liver. It was definite in 49 cases and negative in one case. Pre- and postcontrast scans were performed. CT may reveal the exact location and extension of cysts and possible complications. However, a false-negative case was found in a hydatid cyst located in a fatty liver

  19. Computer tomography in Caisson's disease

    International Nuclear Information System (INIS)

    Horvath, F.; Csobaly, S.; Institute for Advanced Training of Physicians, Budapest

    1981-01-01

    Computer tomography was performed on 20 patients with the early stages of Caisson osteoarthropathy, as well as in other patients with chronic bone infarcts. From their results the authors have formed the opinion that CT is valuable, not only in the diagnosis of early cases, but that it can provide significant information concerning the osteopathy and bone infarcts. (orig.) [de

  20. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... CT (Computed Tomography) Sponsored by Please note RadiologyInfo.org is not a medical facility. Please contact your ... links: For the convenience of our users, RadiologyInfo .org provides links to relevant websites. RadiologyInfo.org , ACR ...

  1. Laryngopyocele: signs on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nazaroglu, Hasan E-mail: hnazarog@dicle.edu.tr; Oezates, Mustafa; Uyar, Asur; Deger, Emin; Simsek, Masum

    2000-01-01

    A laryngocele is an air-filled dilation of the saccule of the larynx. An infected laryngocele is called a laryngopyocele. Our experience with a case of laryngopyocele with signs on computed tomography before and after antibiotic therapy is presented since laryngopyocele is more unusual.

  2. Laryngopyocele: signs on computed tomography

    International Nuclear Information System (INIS)

    Nazaroglu, Hasan; Oezates, Mustafa; Uyar, Asur; Deger, Emin; Simsek, Masum

    2000-01-01

    A laryngocele is an air-filled dilation of the saccule of the larynx. An infected laryngocele is called a laryngopyocele. Our experience with a case of laryngopyocele with signs on computed tomography before and after antibiotic therapy is presented since laryngopyocele is more unusual

  3. X-ray Computed Tomography.

    Science.gov (United States)

    Michael, Greg

    2001-01-01

    Describes computed tomography (CT), a medical imaging technique that produces images of transaxial planes through the human body. A CT image is reconstructed mathematically from a large number of one-dimensional projections of a plane. The technique is used in radiological examinations and radiotherapy treatment planning. (Author/MM)

  4. Industrial applications of computed tomography

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Kruth, J. -P.

    2014-01-01

    The number of industrial applications of Computed Tomography(CT) is large and rapidly increasing. After a brief market overview, the paper gives a survey of state of the art and upcoming CT technologies, covering types of CT systems, scanning capabilities, and technological advances. The paper...

  5. Positron computed tomography with fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Hervouet, T.; Kraeber-Bodere, F.; Lamy, T.; Le Gouil, S.; Devillers, A.; Bodet-Milin, C.; Ansquer, C.; Cheze-le Rest, C.; Metges, J.P.; Teyton, P.; Lozach, P.; Volant, A.; Bizais, Y.; Visvikis, D.; Morel, O.; Girault, S.; Soulie, P.; Dupoiron, D.; Berthelot, C.; Lorimier, G.; Jallet, P.; Garin, E.; Prigent, F.; Lesimple, T.; Barge, M.L.; Rousseau, C.; Devillers, A.; Bernard, A.M.; Bouriel, C.; Bridji, B.; Resche, R.; Banayan, S.; Claret, M.; Ninet, J.; Janier, M.; Billotey, C.; Garin, E.; Devillers, A.; Becker, S.; Lecloirec, J.; Boucher, E.; Raoul, J.L.; Rolland, V.; Oudoux, A.; Valette, F.; Dupas, B.; Moreau, P.; Champion, L.; Anract, P.; Wartski, M.; Laurence, V.; Goldwasser, F.; Pecking, A.P.; Alberini, J.L.; Brillouet, S.; Caselles, O.; Allal, B.; Zerdoud, S.; Gansel, M.G.; Thomas, F.; Dierrickx, L.; Delord, J.P.; Marchand, C.; Resche, I.; Mahe, M.A.

    2006-01-01

    Several oral communications present the interest of positron computed tomography with fluorodeoxyglucose in the detection of cancers, or for the follow up of cancers treatments in order to detect early possible relapses.PET FDG is also used to optimize the definition of target volume in order to avoid side effects and to get a better control of the illness. (N.C.)

  6. Viewing Welds By Computer Tomography

    Science.gov (United States)

    Pascua, Antonio G.; Roy, Jagatjit

    1990-01-01

    Computer tomography system used to inspect welds for root penetration. Source illuminates rotating welded part with fan-shaped beam of x rays or gamma rays. Detectors in circular array on opposite side of part intercept beam and convert it into electrical signals. Computer processes signals into image of cross section of weld. Image displayed on video monitor. System offers only nondestructive way to check penetration from outside when inner surfaces inaccessible.

  7. Cranial computed tomography in psychiatry

    International Nuclear Information System (INIS)

    Falkai, P.; Bogerts, B.

    1993-01-01

    Computed tomography has gained importance as a diagnostic tool in psychiatry to exclude structural brain pathology, but has passed on its role in research to magnetic resonance tomography. It helps to distinguish between senile dementia of Alzheimer type and multi-infarct dementia. The enlargement of the ventricular system and cortical sulci is well established in schizophrenic and affective psychosis. Some alcohol addicts show a considerable degree of cerebral atrophy, only exceeded by demented patients, but this condition is potentially reversible. To screen psychiatric patients by CT is recommendable, as 2-10% of hospitalized psychiatric patients have structural brain disease. (orig.) [de

  8. Myocardial perfusion 320-row multidetector computed tomography-guided treatment strategy for the clinical management of patients with recent acute-onset chest pain: Design of the CArdiac cT in the treatment of acute CHest pain (CATCH)-2 randomized controlled trial.

    Science.gov (United States)

    Sørgaard, Mathias; Linde, Jesper J; Hove, Jens D; Petersen, Jan R; Jørgensen, Tem B S; Abdulla, Jawdat; Heitmann, Merete; Kragelund, Charlotte; Hansen, Thomas Fritz; Udholm, Patricia M; Pihl, Christian; Kühl, J Tobias; Engstrøm, Thomas; Jensen, Jan Skov; Høfsten, Dan E; Kelbæk, Henning; Kofoed, Klaus F

    2016-09-01

    Patients admitted with chest pain are a diagnostic challenge because the majority does not have coronary artery disease (CAD). Assessment of CAD with coronary computed tomography angiography (CCTA) is safe, cost-effective, and accurate, albeit with a modest specificity. Stress myocardial computed tomography perfusion (CTP) has been shown to increase the specificity when added to CCTA, without lowering the sensitivity. This article describes the design of a randomized controlled trial, CATCH-2, comparing a clinical diagnostic management strategy of CCTA alone against CCTA in combination with CTP. Patients with acute-onset chest pain older than 50 years and with at least one cardiovascular risk factor for CAD are being prospectively enrolled to this study from 6 different clinical sites since October 2013. A total of 600 patients will be included. Patients are randomized 1:1 to clinical management based on CCTA or on CCTA in combination with CTP, determining the need for further testing with invasive coronary angiography including measurement of the fractional flow reserve in vessels with coronary artery lesions. Patients are scanned with a 320-row multidetector computed tomography scanner. Decisions to revascularize the patients are taken by the invasive cardiologist independently of the study allocation. The primary end point is the frequency of revascularization. Secondary end points of clinical outcome are also recorded. The CATCH-2 will determine whether CCTA in combination with CTP is diagnostically superior to CCTA alone in the management of patients with acute-onset chest pain. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Evaluation of myocardial ischemia by multiple detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2015-01-15

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  10. Protean appearance of craniopharyngioma on computed tomography

    International Nuclear Information System (INIS)

    Danziger, A.; Price, H.I.

    1979-01-01

    Craniopharyngiomas present a diverse appearance on computed tomography. Histological diagnosis is not always possible, but computed tomography is of great assistance in the delineation of the tumour as well as of the degree of associated hydrocephalus. Computed tomography also enables rapid non-invasive follow-up after surgery or radiotherapy, or both

  11. Industrial applications of computer tomography

    International Nuclear Information System (INIS)

    Sheng Kanglong; Qiang Yujun; Yang Fujia

    1992-01-01

    Industrial computer tomography (CT) and its application is a rapidly developing field of high technology. CT systems have been playing important roles in nondestructive testing (NDT) of products and equipment for a number of industries. Recently, the technique has advanced into the area of industrial process control, bringing even greater benefit to mankind. The basic principles and typical structure of an industrial CT system Descriptions are given of some successful CT systems for either NDT application or process control purposes

  12. Computed tomography of projectile injuries

    International Nuclear Information System (INIS)

    Jeffery, A.J.; Rutty, G.N.; Robinson, C.; Morgan, B.

    2008-01-01

    Computed tomography (CT) is a gold standard in clinical imaging but forensic professions have been slow to embrace radiological advances. Forensic applications of CT are now exponentially expanding, replacing other imaging methods. As post-mortem cross-sectional imaging increases, radiologists will fall under increasing pressure to interpret complex forensic cases involving both living and deceased patients. This review presents a wide variety of weapon and projectile types aiding interpretation of projectile injuries both in forensic and clinical practice

  13. Computed tomography in osteoid osteoma

    International Nuclear Information System (INIS)

    Vicens, J.L.; Aubspin, D.; Buchon, R.; Schoenenberger, P.; Flageat, J.

    1989-01-01

    Four cases of suspected osteoid osteoma were evaluated by computed tomography (CT). The role of CT was related, as a key diagnostic tool: radionuclide imaging is helpful in directing subsequent CT scans, which allows the study of complex anatomical sites (spine) or the analysis of atypical lesions (invisible nidus, sclerosis or lytic lesions, double nidus...). CT provides the surgeon with the exact location and extent of the lesion, and thus, CT may allow a more limited surgical resection of the involved bone [fr

  14. The value of computed tomography in ''sciatica''

    International Nuclear Information System (INIS)

    Boehm-Jurkovic, H.; Hammer, B.

    1981-01-01

    13 cases of therapy-resistant lumboischialgia without herniated disk, caused in 12 cases by a tumour and in 1 case by an abscess, were examined by computed tomography of the lumbar and pelvic region. This method is indicated immediately after insufficient results of conventional X-ray methods (including tomography) and of lumbosacral radiculography. The computed tomography is indispensable also in patients with ''sciatica'' with a known malignoma. The information given by computed tomography is essential for the therapy planning. (author)

  15. Computed tomography of the ossicles

    International Nuclear Information System (INIS)

    Chakeres, D.W.; Weider, D.J.

    1985-01-01

    Otologists and otolaryngologists have described in detail the disorders which are unique to the ossicles. However the anatomy and spectrum of pathology and anatomy of the ossicles are not familiar to most radiologists. Recent advances in computed tomography (CT) and a systematic approach to evaluation now allow accurate identification of even subtle abnormalities of the ossicles. We present the normal anatomy, ossicular abnormalities, and indications for computed tomographic study. Because of the greater diagnostic capability of CT, the radiologist's role has increased in evaluation and treatment planning of patients with suspected ossicular abnormalities. (orig.)

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

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 19,2016 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

  17. The history of computed tomography

    International Nuclear Information System (INIS)

    Bull, J.

    1980-01-01

    New scientific discoveries are often made by the synthetising of other discoveries. Computed tomography is such an example. The three necessary elements were: 1/ the fact that certain simple crystals scintillate when exposed to X-rays, 2/ the advent of electronics and 3/ that of computers. The fact that X-rays cause crystals to scintillate was learnt very shortly after Roentgen's discovery, electronics and computers coming very much later. To put all these together and apply them to diagnostic radiology, and at the same time dismiss the concept so firmly ingrained in everyone's mind that an X-ray picture must be produced on photographic film, required a genius. (orig./VJ) [de

  18. Computed tomography of stress fracture

    International Nuclear Information System (INIS)

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-01-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic. (orig.)

  19. Duodenal diverticulitis. computed tomography findings

    International Nuclear Information System (INIS)

    Sanchez, E.; Martin, S.; Garcia, J.; Dominguez, A.

    2001-01-01

    Duodenal diverticular occur very frequently among the general public. However, duodenal diverticulitis is a very uncommon clinical entity, the diagnosis of which requires radiological studies since the clinical signs cam mimic a great number of disease processes with different treatments. We present a case of duodenal diverticulitis in which the diagnosis according to ultrasound and computed tomography (CT) studies was confirmed intraoperatively. We also review the few cases of this entity reported in the literature. The CT findings are highly suggestive of duodenal diverticulitis given their similarity to those associated with diverticulitis at other sites. (Author) 5 refs,

  20. Mathematical foundations of computed tomography

    International Nuclear Information System (INIS)

    Smith, K.T.; Keinert, F.

    1985-01-01

    Along with a review of some of the mathematical foundations of computed tomography, the article contains new results on derivation of reconstruction formulas in a general setting encompassing all standard formulas; discussion and examples of the role of the point spread function with recipes for producing suitable ones; formulas for, and examples of, the reconstruction of certain functions of the attenuation coefficient, e.g., sharpened versions of it, some of them with the property that reconstruction at a point requires only the attenuation along rays meeting a small neighborhood of the point

  1. High speed computer assisted tomography

    International Nuclear Information System (INIS)

    Maydan, D.; Shepp, L.A.

    1980-01-01

    X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large x-ray tube having a circular anode (3) surrounds the patient area. A movable electron gun (8) orbits adjacent to the anode. The anode directs into the patient area xrays which are delimited into a fan beam by a pair of collimating rings (21). After passing through the patient, x-rays are detected by an array (22) of movable detectors. Detector subarrays (23) are synchronously movable out of the x-ray plane to permit the passage of the fan beam

  2. Brain metastases: computed tomography assessment

    International Nuclear Information System (INIS)

    Gordillo, Victoria; Yagual, Glenda; Vinueza, Clayreth

    1998-01-01

    Intracranial metastatic tumor is relatively frequent in patients with cancer from other origin. Its location and type of metastasis varies in relation to its linage from the primary tumor. And the sequence goes from the most frequent: lung and breast cancer, melanoma, GU tract, leukemia, GI tract, head and neck tumor. Computed tomography findings are extremely varied and non specific, so there are no radiologic characteristics even from the primary tumor. We reviewed 29 TC studies in the Radiology department of ION-SOLCA, from patients with diagnosis of brain metastasis, our findings showed the great variability in the radio-diagnosis imaging. (The author)

  3. Computed tomography of stress fracture

    International Nuclear Information System (INIS)

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-01-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic

  4. Whole-body computed tomography

    International Nuclear Information System (INIS)

    Wegener, O.H.

    1992-01-01

    The vast literature on whole-body CT is presented in this bibliography which is published as a self-contained supplement to the monography entitled whole-body CT. For this documentation, the following journals have been scanned back to the year 1980: Journal of Computer Assisted Tomography (JCAT), Fortschritte auf dem Gebiet der Roentgenstrahlen (RoeFo), Radiology, American Journal of Roentgenology (AJR), Der Radiologe, Neuroradiology, and American Journal of Neuroradiology (AJNR). The supplement includes keyword indexes that can be searched for terms indicating body organs, body regions, or certain lesions. The author index offers an additional access to the publication wanted. (orig./MG) [de

  5. Dose determination in computed tomography

    International Nuclear Information System (INIS)

    Descamps, C.; Garrigo, E.; Venencia, D.; Gonzalez, M.; Germanier, A.

    2011-10-01

    In the last years the methodologies to determine the dose in computed tomography have been revised. In this work was realized a dosimetric study about the exploration protocols used for simulation of radiotherapy treatments. The methodology described in the Report No. 111 of the American Association of Medical Physiques on a computed tomograph of two cuts was applied. A cylindrical phantom of water was used with dimensions: 30 cm of diameter and 50 cm of longitude that simulates the absorption and dispersion conditions of a mature body of size average. The doses were determined with ionization chamber and thermoluminescent dosimetry. The results indicate that the dose information that provides the tomograph underestimates the dose between 32 and 35%.

  6. Computed tomography of the spine

    International Nuclear Information System (INIS)

    Isherwood, I.; Antoun, N.M.

    1984-01-01

    Until the advent of Computed Tomography (CT), axial studies of the spine were limited in the main to gross bony anatomy and to conventional transaxial tomography (TAT). Others studied the upper cervical cord in transverse section during gas myelography and encephalography. The potential role of CT in the evaluation of spinal anatomy and disease was recognized, however, at an early stage in the development of the general purpose CT scanner. CT is not organ specific and therefore provides a uniformly thin (1.5-13 mm) axial section displaying detailed spinal topographical anatomy against a background of paravertebral muscles, vascular structures and body cavity organs. The relationships of the apophyseal joints to the spinal canal and intervertebral foramina are particularly well displayed. The study of neural tissue and pathology within the spinal canal is facilitated by the use of a non-ionic water-soluble contrast medium (viz. metrizamide) in the subarachnoid spaces. The high sensitivity of CT to very small changes in X-ray attenuation permits studies to be continued over several hours. The digital derivation of the sequential CT transaxial sections enables not only interrogation of data and quantitative studies to be made but also makes possible computer-generated reconstructions in other planes

  7. Motion artifacts in computed tomography

    International Nuclear Information System (INIS)

    Yang, C.K.

    1979-01-01

    In the year 1972, the first Computed Tomography Scanner (or CT) was introduced and caused a revolution in the field of Diagnostic Radiology. A tomogram is a cross-sectional image of a three-dimensional object obtained through non-invasive measurements. The image that is presented is very similar to what would be seen if a thin cross-sectional slice of the patient was examined. In Computed Tomography, x-rays are passed through the body of a patient in many different directions and their attenuation is detected. By using some mathematical theorems, the attenuation information can be converted into the density of the patient along the x-ray path. Combined with modern sophisticated computer signal processing technology, a cross-sectional image can be generated and displayed on a TV monitor. Usually a good CT image relies on the patient not moving during the x-ray scanning. However, for some unconscious or severely ill patients, this is very difficult to achieve. Thus, the motion during the scan causes the so-called motion artifacts which distort the displayed image and sometimes these motion artifacts make diagnosis impossible. Today, to remove or avoid motion artifacts is one of the major efforts in developing new scanner systems. In this thesis, a better understanding of the motion artifacts problem in CT scaning is gained through computer simulations, real scanner experiments and theoretical analyses. The methods by which the distorted image can be improved are simulated also. In particular, it is assumed that perfect knowledge of the patient motion is known since this represents the theoretical limit on how well the distorted image can be improved

  8. Batch Computed Tomography Analysis of Projectiles

    Science.gov (United States)

    2016-05-01

    ARL-TR-7681 ● MAY 2016 US Army Research Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt, Chris M...Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt and Matthew S Bratcher Weapons and Materials Research...values to account for projectile variability in the ballistic evaluation of armor. 15. SUBJECT TERMS computed tomography , CT, BS41, projectiles

  9. Computed tomography in acute ischemic stroke

    International Nuclear Information System (INIS)

    Loevblad, Karl-Olof; Baird, Alison E.

    2010-01-01

    Stroke remains the third most important cause of mortality in industrialized countries; this has prompted research for improvements in both diagnostic and therapeutic strategies for patients with signs of acute cerebral ischemia. Over the last decade, there has been a parallel in progress in techniques in both diagnostic and therapeutic options. While previously only used for excluding hemorrhage, imaging now has the possibility to detect ischemia, vascular occlusion, as well as detect tissue at risk in one setting. It should also allow to monitor treatment and predict/exclude therapeutic complications. Parallel to advances in magnetic resonance imaging of stroke, computed tomography has improved immensely over the last decade due to the development of CT scanners that are faster and that allow to acquire studies such as CT perfusion or CT angiography in a reliable way. CT can detect many signs that might help us detect impending signs of massive infarction, but we still lack the experience to use these alone to prevent a patient from benefitting from possible therapy. (orig.)

  10. Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning.

    Science.gov (United States)

    Kunst, P W; Vonk Noordegraaf, A; Hoekstra, O S; Postmus, P E; de Vries, P M

    1998-11-01

    Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximates to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of radionuclide imaging. Following routine ventilation (81mKr) and perfusion scanning (99mTc-MAA), EIT measurements were performed at the third and the sixth intercostal level in 14 patients with lung cancer. A correlation (r = 0.98, p RC) was calculated for estimating the left-right division with EIT. The RC for the ventilation measurements was 94% and 96% for the perfusion measurements. The correlation analysis for reproducibility of the EIT measurements was 0.95 (p < 0.001) for the ventilation and 0.93 (p < 0.001) for the perfusion measurements. In conclusion, EIT can be regarded as a promising technique to estimate the left-right division of pulmonary perfusion and ventilation.

  11. Measuring Weld Profiles By Computer Tomography

    Science.gov (United States)

    Pascua, Antonio G.; Roy, Jagatjit

    1990-01-01

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

  12. Noninvasive coronary angioscopy using electron beam computed tomography and multidetector computed tomography

    NARCIS (Netherlands)

    van Ooijen, PMA; Nieman, K; de Feyter, PJ; Oudkerk, M

    2002-01-01

    With the advent of noninvasive coronary imaging techniques like multidetector computed tomography and electron beam computed tomography, new representation methods such as intracoronary visualization. have been introduced. We explore the possibilities of these novel visualization techniques and

  13. An introduction to emission computed tomography

    International Nuclear Information System (INIS)

    Williams, E.D.

    1985-01-01

    This report includes salient features of the theory and an examination of practical considerations for someone who is using or introducing tomography, selecting equipment for it or wishing to develop a clinical application. Emphasis is on gamma camera tomography. The subject is dealt with under the following headings: emission computed and gamma camera tomography and the relationship to other medical imaging techniques, the tomographic reconstruction technique theory, rotating gamma camera tomography, attenuation correction and quantitative reconstruction, other single photon tomographic techniques, positron tomography, image display, clinical application of single photon and positron tomography, and commercial systems for SPECT. Substantial bibliography. (U.K.)

  14. Computed tomography of surface related radionuclide distributions ('BONN'-tomography)

    International Nuclear Information System (INIS)

    Bockisch, A.; Koenig, R.

    1989-01-01

    A method called the 'BONN' tomography is described to produce planar projections of circular activity distributions using standard single photon emission computed tomography. The clinical value of the method is demonstrated for bone scans of the jaw, thorax, and pelvis. Numerical or projection-related problems are discussed. (orig.) [de

  15. Computed tomography of splenic trauma

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey, R.B.; Laing, F.C.; Federle, M.P.; Goodman, P.C.

    1981-12-01

    Fifty patients with abdominal trauma and possible splenic injury were evaluated by computed tomography (CT). CT correctly diagnosed 21 of 22 surgically proved traumatic sesions of the spleen (96%). Twenty-seven patients had no evidence of splenic injury. This was confirmed at operation in 1 patient and clinical follow-up in 26. There were one false negative and one false positive. In 5 patients (10%), CT demonstrated other clinically significant lesions, including hepatic or renal lacerations in 3 and large retroperitoneal hematomas in 2. In adolescents and adults, CT is an accurate, noninvasive method of rapidly diagnosing splenic trauma and associated injuries. Further experience is needed to assess its usefulness in evaluating splenic injuries in infants and small children.

  16. Computed tomography of splenic trauma

    International Nuclear Information System (INIS)

    Jeffrey, R.B.; Laing, F.C.; Federle, M.P.; Goodman, P.C.

    1981-01-01

    Fifty patients with abdominal trauma and possible splenic injury were evaluated by computed tomography (CT). CT correctly diagnosed 21 of 22 surgically proved traumatic sesions of the spleen (96%). Twenty-seven patients had no evidence of splenic injury. This was confirmed at operation in 1 patient and clinical follow-up in 26. There were one false negative and one false positive. In 5 patients (10%), CT demonstrated other clinically significant lesions, including hepatic or renal lacerations in 3 and large retroperitoneal hematomas in 2. In adolescents and adults, CT is an accurate, noninvasive method of rapidly diagnosing splenic trauma and associated injuries. Further experience is needed to assess its usefulness in evaluating splenic injuries in infants and small children

  17. Computed tomography in sport injuries

    International Nuclear Information System (INIS)

    Reiser, M.; Rupp, N.

    1984-01-01

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability. (orig.)

  18. Computed tomography in sport injuries

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M; Rupp, N

    1984-01-01

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability.

  19. Computed tomography in hepatic trauma

    International Nuclear Information System (INIS)

    Moon, K.L. Jr.; Federle, M.P.

    1983-01-01

    Twenty-five patients with hepatic injury from blunt upper abdominal trauma were examined by computed tomography (CT). The spectrum of CT findings was recorded, and the size of the hepatic laceration and the associated hemoperitoneum were correlated with the mode of therapy used in each case (operative vs nonoperative). While the need for surgery correlated roughly with the size of the hepatic laceration, the size of the associated hemoperitoneum was an important modifying factor. Fifteen patients with hepatic lacerations but little or no hemoperitoneum were managed nonoperatively. CT seems to have significant advantages over hepatic scintigraphy, angiography, and diagnostic peritoneal lavage. By combining inforamtion on the clinical state of the patient and CT findings, therapy of hepatic injury can be individualized and the incidence of nontherapeutic laparotomies decreased

  20. Computed tomography of cryogenic cells

    International Nuclear Information System (INIS)

    Schneider, Gerd; Anderson, E.; Vogt, S.; Knochel, C.; Weiss, D.; LeGros, M.; Larabell, C.

    2001-01-01

    Due to the short wavelengths of X-rays and low numerical aperture of the Fresnel zone plates used as X-ray objectives, the depth of field is several microns. Within the focal depth, imaging a thick specimen is to a good approximation equivalent to projecting the specimen absorption. Therefore, computed tomography based on a tilt series of X-ray microscopic images can be used to reconstruct the local linear absorption coefficient and image the three-dimensional specimen structure. To preserve the structural integrity of biological objects during image acquisition, microscopy is performed at cryogenic temperatures. Tomography based on X-ray microscopic images was applied to study the distribution of male specific lethal 1 (MSL-1), a nuclear protein involved in dosage compensation in Drosophila melanogaster, which ensures that males with single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. Tomographic reconstructions of X-ray microscopic images were used to compute the local three-dimensional linear absorption coefficient revealing the arrangement of internal structures of Drosophila melanogaster cells. Combined with labelling techniques, nanotomography is a new technique to study the 3D distribution of selected proteins inside whole cells. We want to improve this technique with respect to resolution and specimen preparation. The resolution in the reconstruction can be significantly improved by reducing the angular step size to collect more viewing angles, which requires an automated data acquisition. In addition, fast-freezing with liquid ethane instead of cryogenic He gas will be applied to improve the vitrification of the hydrated samples. We also plan to apply cryo X-ray nanotomography in order to study different types of cells and their nuclear protein distributions

  1. The contribution of single photon emission computed tomography in the clinical assessment of Alzheimer type dementia

    International Nuclear Information System (INIS)

    Boudousq, V.; Collombier, L.; Kotzki, P.O.

    1999-01-01

    Interest of brain single-photon emission computed tomography to support clinical diagnosis of Alzheimer-type dementia is now established. Numerous studies have reported a decreased perfusion in the association cortex of the parietal lobe and the posterior temporal regions. In patients with mild cognitive complaints, the presence of focal hypoperfusion may increase substantially the probability of the disease. In addition, emission tomography emerges as a helpful tool in situation in which there is diagnostic doubt. In this case, the presence of temporo-parietal perfusion deficit associated with hippocampal atrophy on MRI or X-ray computed tomography contributes to diagnostic accuracy. However, some studies suggest that emission tomography may be useful for preclinical prediction of Alzheimer's disease and to predict cognitive decline. (author)

  2. Radiological protection in computed tomography and cone beam computed tomography.

    Science.gov (United States)

    Rehani, M M

    2015-06-01

    The International Commission on Radiological Protection (ICRP) has sustained interest in radiological protection in computed tomography (CT), and ICRP Publications 87 and 102 focused on the management of patient doses in CT and multi-detector CT (MDCT) respectively. ICRP forecasted and 'sounded the alarm' on increasing patient doses in CT, and recommended actions for manufacturers and users. One of the approaches was that safety is best achieved when it is built into the machine, rather than left as a matter of choice for users. In view of upcoming challenges posed by newer systems that use cone beam geometry for CT (CBCT), and their widened usage, often by untrained users, a new ICRP task group has been working on radiological protection issues in CBCT. Some of the issues identified by the task group are: lack of standardisation of dosimetry in CBCT; the false belief within the medical and dental community that CBCT is a 'light', low-dose CT whereas mobile CBCT units and newer applications, particularly C-arm CT in interventional procedures, involve higher doses; lack of training in radiological protection among clinical users; and lack of dose information and tracking in many applications. This paper provides a summary of approaches used in CT and MDCT, and preliminary information regarding work just published for radiological protection in CBCT. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  3. Computed tomography and three-dimensional imaging

    International Nuclear Information System (INIS)

    Harris, L.D.; Ritman, E.L.; Robb, R.A.

    1987-01-01

    Presented here is a brief introduction to two-, three-, and four-dimensional computed tomography. More detailed descriptions of the mathematics of reconstruction and of CT scanner operation are presented elsewhere. The complementary tomographic imaging methods of single-photon-emission tomography (SPECT) positron-emission tomography (PET), nuclear magnetic resonance (NMR) imaging, ulltrasound sector scanning, and ulltrasound computer-assisted tomography [UCAT] are only named here. Each imaging modality ''probes'' the body with a different energy form, yielding unique and useful information about tomographic sections through the body

  4. Single photon emission computed tomography in AIDS dementia complex

    International Nuclear Information System (INIS)

    Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

    1988-01-01

    Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

  5. Computed tomography of obstructive jaundice

    International Nuclear Information System (INIS)

    Suh, Jung Hek; Lee, Joong Suk; Chun, Beung He; Suh, Soo Jhi

    1982-01-01

    It is well known that the computed tomography (CT) is very useful in the evaluation of obstructive jaundice. We have studied 55 cases of obstructive jaundice with whole body scanner from Jun.1980 to Jun. 1981. The results were as follows: 1. The sex distribution was 36 males and 19 females, and 40 cases of obstructive jaundice were seen in fifth, sixth, and seventh decades. 2. Causes of obstructive jaundice were 25 cases of pancreas cancer, 8 cases of common duct cancer, 4 cases of gallbladder cancer, 4 cases of ampulla vater cancer, 12 cases of common duct stone, and 2 cases of common duct stricture. 3. Levels of obstruction were 8 cases of hepatic portion, 15 cases of suprapancreatic portion, 28 cases of pancreatic portion, and 4 cases of ampullary portion. 4. In tumorous condition, CT demonstrated metastasis of other organs, 9 cases of the liver, 1 case of the lung, 3 cases of the pancreas, 3 cases of the common bile duct, 1 case of the stomach, and 12 cases of adjacent lymph nodes. 5. Associated diseases were 12 cases of intrahepatic stone, 4 cases of clonorchiasis, 2 cases of pancreas pseudocyst, 1 cases of hydronephrosis, and 1 case of renal cyst

  6. Errors in abdominal computed tomography

    International Nuclear Information System (INIS)

    Stephens, S.; Marting, I.; Dixon, A.K.

    1989-01-01

    Sixty-nine patients are presented in whom a substantial error was made on the initial abdominal computed tomography report. Certain features of these errors have been analysed. In 30 (43.5%) a lesion was simply not recognised (error of observation); in 39 (56.5%) the wrong conclusions were drawn about the nature of normal or abnormal structures (error of interpretation). The 39 errors of interpretation were more complex; in 7 patients an abnormal structure was noted but interpreted as normal, whereas in four a normal structure was thought to represent a lesion. Other interpretive errors included those where the wrong cause for a lesion had been ascribed (24 patients), and those where the abnormality was substantially under-reported (4 patients). Various features of these errors are presented and discussed. Errors were made just as often in relation to small and large lesions. Consultants made as many errors as senior registrar radiologists. It is like that dual reporting is the best method of avoiding such errors and, indeed, this is widely practised in our unit. (Author). 9 refs.; 5 figs.; 1 tab

  7. X-ray computed tomography

    International Nuclear Information System (INIS)

    Kalender, Willi A

    2006-01-01

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  8. Computed tomography of epileptic children

    International Nuclear Information System (INIS)

    Kurihara, Mana; Yamashita, Sumimasa; Miyake, Shota; Yamada, Michiko; Iwamoto, Hiroko

    1986-01-01

    The aim of this study was to analyze the changes seen on cranial computed tomography (CT) of epileptic children, especially in the area of the temporal horn. The subjects were 242 epileptic children excluding those with encephalitis, brain tumor, neurocutaneous syndromes, degenerative disease, hydrocephalus etc. The control subjects were 195 children without any neurological disease and symptoms. CT scan were taken with a TCT-60A whole body scanner, and 14 check points were evaluated excluding the temporal horn. 195 epileptic children (N-group) and all control children were normal at 14 check points. Next, the areas of the temporal horns and adjoining hemispheres of the epileptic children (N-group) and control children were examined with Muto-Tablet-Desitizer. The temporal horn ratio ((area of temporal horn/area of ipsilateral hemisphere) x 100) was greater in younger children of the control group, and it was higher in epileptic than in control children. Enlargement of the temporal horn was seen in 1 % of the controls and in 35 % of the 125 epileptic children with normal measurements at 14 points on CT scans (p < 0.01). The frequency of enlargement of temporal horns was not variable among different epileptic types. In the epileptic children with normal CT scans except for enlargement of temporal horns behavioral disturbances were 6 boys and 5 had enlarged temporal horns (bilateral 1 case, left side 1 case, right side 3 cases). (author)

  9. Computed Tomography of Interacerebral Hemorrhage

    International Nuclear Information System (INIS)

    Kim, Seung Hyeon; Lee, Jong Beum; Lee, Yong Chul; Lee, Kwan Seh; Park, Soo Soung

    1983-01-01

    Computed tomography (CT) is the most accurate and reliable method for the diagnosis of intracerebral and intraventricular hemorrhage. The precise anatomic extent of the nematoma, associated cerebral edema, ventricular deformity and displacement, and hydrocephalus are all readily assessed. Aside from head trauma, the principal cause of intracerebral hematoma is hypertensive vascular disease. Although hematomas from various causes may present similar CT appearances frequently the correct etiology may be suggested by consideration of patient's age, clinical history, and the location of the hematoma. The analytical study was performed in 180 cases of intracerebral hemorrhages by CT from October 1981 to January 1983. The results were as follows; 1. The most prevalent age group was 6th decade (37.2%). Male was prevalent to female at the ration of 1.6 to 1. 2. The most common symptom and sign was mental disturbance (48.7%), motor weakness (23%), headache (10.6%), nausea and vomiting (9.8%). 3. The causes of hemorrhage were hypertension (53.9%), head trauma (30.6%), aneurysm (6.1%) and A-V malformation (7.2%). 4. The frequent locations of hemorrhage were basal ganglia and thalamus (40.4%), lobes (35%), ventricles (21.8%). 5. The distribution of hemorrhage was intracerebral hemorrhage (65.6%), intracerebral and intraventricular hemorrhage (30.3%), intraventricular hemorrhage (4.4%).

  10. Recent Developments in Computed Tomography

    International Nuclear Information System (INIS)

    Braunstein, D.; Dafni, E.; Levene, S.; Malamud, G.; Shapiro, O.; Shechter, G.; Zahavi, O.

    1999-01-01

    Computerized Tomography. has become, during the past few years, one of the mostly used apparatus in X-ray diagnosis. Its clinical applications has penetrated to various fields, like operational guidance, cardiac imaging, computer aided surgery etc. The first second-generation CT scanners consisted of a rotate-rotate system detectors array and an X-ray tube. These scanners were capable of acquiring individual single slices, the duration of each being several seconds. The slow scanning rate, and the then poor computers power, limited the application range of these scanners, to relatively stable organs, short body coverage at given resolutions. Further drawbacks of these machines were weak X-ray sources and low efficiency gas detectors. In the late 80's the first helical scanners were introduced by Siemens. Based on a continuous patient couch movement during gantry rotation, much faster scans could be obtained, increasing significantly the volume coverage at a given time. In 1992 the first dual-slice scanners, equipped with high efficiency solid state detectors were introduced by Elscint. The acquisition of data simultaneously from two detector arrays doubled the efficiency of the scan. Faster computers and stronger X-ray sources further improved the performance, allowing for a new range of clinical applications. Yet, the need for even faster machines and bigger volume coverage led to further R and D efforts by the leading CT manufacturers. In order to accomplish the most demanding clinical needs, innovative 2 dimensional 4-rows solid-state detector arrays were developed, together with faster rotating machines and bigger X-ray tubes, all demanding extremely accurate and robust mechanical constructions. Parallel, multi-processor custom computers were made, in order to allow the on-line reconstruction of the growing amounts of raw data. Four-slice helical scanners, rotating at 0.5 sec per cycle are being tested nowadays in several clinics all over the world. This talk

  11. Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Disseminated Cryptococcosis.

    Science.gov (United States)

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

    2017-01-01

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

  12. Pulmonary ventilation/perfusion single photon emission tomography – Initial experience of a Nuclear Medicine Department

    Directory of Open Access Journals (Sweden)

    J. G. Santos

    2016-01-01

    Full Text Available Introduction: Lung ventilation/perfusion scintigraphy with planar images (V/QS-planar is very useful for the diagnosis and follow-up of pulmonary thromboembolism (PTE. Acquiring tomographic images (V/QS-SPECT is a recent development with potential to increase the technique's accuracy. The purpose of this work is to evaluate the added benefits of V/QS-SPECT studies as opposed to traditional planar imaging. Patients and methods: We prospectively revised 53 V/QS-planar and V/QS-SPECT exams, performed according to the European Association of Nuclear Medicine guidelines. We evaluated the exams independently, by consensus of two Nuclear Medicine physicians. For both methods, we gave each lung a score expressing the dimension and extension of perfusion defects with normal ventilation. For each lung, we compared the scores with the paired Wilcoxon test, estimating the 95% confidence interval (95CI for the respective difference. Results: We performed V/QS-SPECT exams without technical difficulties. The paired Wilcoxon test estimated the score difference to be −0.75 (95CI of −1.0 to −0.5; p-value = 9.6 × 10−7, expressing a statistically significant difference of about 1 subsegmental defect between both methods, with V/QS-SPECT detecting more defects. Discussion: The results demonstrate that V/QS-SPECT identifies a slightly larger number of perfusion defects than V/QS-planar, suggesting a higher sensitivity of this technique. However, more studies are necessary to evaluate the clinical meaning of this fact. Conclusion: V/QS-SPECT demonstrates a higher capability to identify perfusion defects. This method looks promising, allowing for a greater role of this exam in pulmonary thromboembolism diagnosis and follow-up. Keywords: Pulmonary thromboembolism, Lung, Scintigraphy, Single-photon emission-computed tomography (SPECT

  13. Computed tomography of the facial canal

    International Nuclear Information System (INIS)

    Kiuchi, Sousuke

    1983-01-01

    The radiological details of the facial canal was investigated by computed tomography. In the first part of this study, dry skulls were used to delineate the full course of the facial canal by computed tomography. In the second part of this study, the patients with chronic otitis media and secondary cholesteatoma were evaluated. The labyrinthine and tympanic parts of the canal were well demonstrated with the axial scanning, and the mastoid part with the coronal scanning. Moreover, computed tomography showed excellent delineation of the middle ear contents. In patients with secondary cholesteatoma, the destructions of the intratympanic course of the bony facial canal were also assessed preoperatively. (author)

  14. Attenuation Correction Strategies for Positron Emission Tomography/Computed Tomography and 4-Dimensional Positron Emission Tomography/Computed Tomography

    OpenAIRE

    Pan, Tinsu; Zaidi, Habib

    2013-01-01

    This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4 dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list mode data acquisition in 4 dimensional PET and introduces 4 dimensional CT popular in thoracic treatment planning to 4 dimensional PET/CT. ...

  15. Orbital computed tomography for exophthalmos

    International Nuclear Information System (INIS)

    Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo

    1987-01-01

    Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos

  16. Computed tomography of cerebrovascular accidents

    International Nuclear Information System (INIS)

    Lee, Jong Deuk; Moon, Yang In; Lim, Se Hwan; Lee, Cheorl Woo; Kim, Byung Chan; Won, Jong Jin

    1989-01-01

    Computed tomography (CT) is an accurate and noninvasive method in the evaluation of cerebrovascular accidents (CVA) for detection of nature, location, extension and associated changes. Retrospective analysis was done in 402 patients of clinically suspected CVA who were performed CT in our hospital from December 1985 to December 1987. The results were as follows; 1. The analysis of CT findings in 402 patients showed 321 cases of CVA, 79 cases of normal findings, and 2 cases of brain tumors. 2. Among 321 cases of CVA, intracerebral hemorrhage was noted in 158 cases, cerebral infarction in 126 cases, and subarachnoid hemorrhage in 37 cases. 3. The common sites of cerebral hemorrhage were basal ganglia in 99 cases, especially putamen, thalamus in 32 cases, and cerebrum, cerebellum in 11 cases respectively. Cerebral infarction was found chiefly at the areas distributed by the middle cerebral artery: cerebral lobe 55 cases and basal ganglia 51 cases. The aneurysm was the most common cause of subarachnoid hemorrhage, and its common site was posterior communicating artery and middle cerebral artery areas. 4. The common shape of cerebral infarction was oval in basal ganglia and wedged in the cerebral lobes. The contrast enhancement of the cerebral infarction was observed in 10% of cases between the 3rd days and 2nd weeks after onset, and was usually gyral patients (77.7%). 5. The aneurysm was noted as enhancing nodule on contrast CT in all 14 cases. In conclusion, the most common cause of CVA is intracerebral hemorrhage in Iri, Korea. High resolution contrast enhanced CT can be used in the diagnosis of the ruptured cerebral aneurysm without the aid of cerebral angiography

  17. Computed tomography of cerebrovascular accidents

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Deuk; Moon, Yang In; Lim, Se Hwan; Lee, Cheorl Woo; Kim, Byung Chan; Won, Jong Jin [Wonkwang University School of Medicine, Iri (Korea, Republic of)

    1989-10-15

    Computed tomography (CT) is an accurate and noninvasive method in the evaluation of cerebrovascular accidents (CVA) for detection of nature, location, extension and associated changes. Retrospective analysis was done in 402 patients of clinically suspected CVA who were performed CT in our hospital from December 1985 to December 1987. The results were as follows; 1. The analysis of CT findings in 402 patients showed 321 cases of CVA, 79 cases of normal findings, and 2 cases of brain tumors. 2. Among 321 cases of CVA, intracerebral hemorrhage was noted in 158 cases, cerebral infarction in 126 cases, and subarachnoid hemorrhage in 37 cases. 3. The common sites of cerebral hemorrhage were basal ganglia in 99 cases, especially putamen, thalamus in 32 cases, and cerebrum, cerebellum in 11 cases respectively. Cerebral infarction was found chiefly at the areas distributed by the middle cerebral artery: cerebral lobe 55 cases and basal ganglia 51 cases. The aneurysm was the most common cause of subarachnoid hemorrhage, and its common site was posterior communicating artery and middle cerebral artery areas. 4. The common shape of cerebral infarction was oval in basal ganglia and wedged in the cerebral lobes. The contrast enhancement of the cerebral infarction was observed in 10% of cases between the 3rd days and 2nd weeks after onset, and was usually gyral patients (77.7%). 5. The aneurysm was noted as enhancing nodule on contrast CT in all 14 cases. In conclusion, the most common cause of CVA is intracerebral hemorrhage in Iri, Korea. High resolution contrast enhanced CT can be used in the diagnosis of the ruptured cerebral aneurysm without the aid of cerebral angiography.

  18. Orbital computed tomography for exophthalmos

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo [College of Medicine, Pusan National University, Busan (Korea, Republic of)

    1987-06-15

    Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos.

  19. Image quality in coronary computed tomography angiography

    DEFF Research Database (Denmark)

    Precht, Helle; Gerke, Oke; Thygesen, Jesper

    2018-01-01

    Background Computed tomography (CT) technology is rapidly evolving and software solution developed to optimize image quality and/or lower radiation dose. Purpose To investigate the influence of adaptive statistical iterative reconstruction (ASIR) at different radiation doses in coronary CT...

  20. Evaluation of computed tomography for obstructive jaundice

    International Nuclear Information System (INIS)

    Matsuoka, Shoji; Toda, Hiroshi; Suzuki, Toshihiko

    1980-01-01

    Findings of computed tomography were reviewed in 54 cases where obstructive jaundice was suggested by liver function studies and computed tomography was done with the diagnosis subsequently confirmed by surgery. Dilatation of the intrahepatic bile duct was found in 49 (91%) of the cases and the site of obstruction was determined in 44 cases (82%). The cause was shown in 28 cases (52%). By disease, the cause was correctly diagnosed with gallbladder in 40%, bile duct cancer in 46%, pancreas cancer in 71%, and choledocal cyst in 100%, but cholelithiasis was diagnosed correctly in only 17%. Further, non-calcium cholelithiasis is very difficult to diagnose by computed tomography. Computed tomography is a useful tool for diagnosis of obstructive jaundice as a noninvasive means of evaluating the patient; however, concomitand use of other diagnostic studies is essential for greater accuracy of diagnosis. (author)

  1. Computed tomography and/or ventriculography

    International Nuclear Information System (INIS)

    Wende, S.; Kishikawa, T.; Huewel, N.; Kazner, E.; Grumme, T.; Lanksch, W.

    1982-01-01

    It is discussed if in intracranial tumors, especially in tumors of the posterior cranial fossa, a CT and/or a ventriculography should be practiced. We have made investigations of 134 patients, 93 of whom were children up to 14 years of age. Each case was undertaken computed tomography as well as ventriculography. The results are clearly demonstrating the superiority of computed tomography compared with ventriculography. Ventriculography is a surgical intervention stressing the patients, side-effects may occur, and sometimes serious complications are caused. Modern computed tomography is producing pictures of high quality, which are highly sufficient for neurosurgical intervention. Very rarely additional angiography has to be performed. The diagnosis of intracranial tumors can fully be established by computed tomography, whereas ventriculography is no longer necessary. (orig.) [de

  2. Examination of weld defects by computed tomography

    Directory of Open Access Journals (Sweden)

    M. Jovanović

    2012-04-01

    Full Text Available Defects in metal arc gas (MAG welds made in S235JR low carbon steel of 6 mm thickness were examined. A sample containing lack of fusion (LOF and pores was examined by computed tomography – CT. The computed tomography examination was performed in order to define LOF size and position as well as dimensions and distribution of accompanying pores in the weld metal.

  3. Dose optimization in computed tomography: ICRP 87

    International Nuclear Information System (INIS)

    2007-01-01

    The doses given in the use of computed tomography scans are studied, aiming to calibrate the limits of irradiation in patients who need these tests. Furthermore, a good value of computed tomography should be guaranteed by physicians and radiologists for people not being irradiated unfairly, reducing doses and unnecessary tests. A critical evaluation by an ethics committee is suggested for cases where the test is performed for medical research without a cause [es

  4. Quantitative computed tomography evaluation of pulmonary disease

    DEFF Research Database (Denmark)

    McEvoy, Fintan; Buelund, Lene Elisabeth; Strathe, Anders Bjerring

    2009-01-01

    Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present.......Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present....

  5. Computed tomography in abnormalities of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Visser, J.D.; Jonkers, A.; Klasen, H.J. (Rijksuniversiteit Groningen (Netherlands). Academisch Ziekenhuis); Hillen, B. (Rijksuniversiteit Groningen (Netherlands). Lab. voor Anatomie en Embryologie)

    1982-06-26

    The value of computed tomography in the assessment of abnormalities of the hip is demonstrated with the aid of an anatomical preparation and in patients with, respectively, congenital dislocation of a hip, dislocation of the hip in spina bifida, an acetabular fracture and a Ewing tumour. The anteversion of the acetabulum and femur and the instability index of the hip joint can be measured by means of computed tomography.

  6. Development of emission computed tomography in Japan

    International Nuclear Information System (INIS)

    Tanaka, E.

    1984-01-01

    Two positron emission computed tomography (PCT) devices developed in Japan are described. One is for head and the other for wholebody. The devices show fairly quantitative images with slight modifications of the existing algorithms because they were developed based on filtered back-projection. The PCT device seems to be better than the single photon emission computed tomography (SPECT) since it provides adequade compensation for photon attenuation in patients. (M.A.C.) [pt

  7. Perfusion- and pattern-based quantitative CT indexes using contrast-enhanced dual-energy computed tomography in diffuse interstitial lung disease: relationships with physiologic impairment and prediction of prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jung Won [Sungkyunkwan University School of Medicine, Department of Radiology, Kangbuk Samsung Hospital, Seoul (Korea, Republic of); Bae, Jang Pyo; Kim, Namkug; Chang, Yongjun; Seo, Joon Beom [University of Ulsan College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lee, Ho Yun; Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Chung, Man Pyo; Park, Hye Yun [Sungkyunkwan University School of Medicine, Department of Pulmonology, Samsung Medical Center, Seoul (Korea, Republic of)

    2016-05-15

    To evaluate automated texture-based segmentation of dual-energy CT (DECT) images in diffuse interstitial lung disease (DILD) patients and prognostic stratification by overlapping morphologic and perfusion information of total lung. Suspected DILD patients scheduled for surgical biopsy were prospectively included. Texture patterns included ground-glass opacity (GGO), reticulation and consolidation. Pattern- and perfusion-based CT measurements were assessed to extract quantitative parameters. Accuracy of texture-based segmentation was analysed. Correlations between CT measurements and pulmonary function test or 6-minute walk test (6MWT) were calculated. Parameters of idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) and non-IPF/UIP were compared. Survival analysis was performed. Overall accuracy was 90.47 % for whole lung segmentation. Correlations between mean iodine values of total lung, 50-97.5th (%) attenuation and forced vital capacity or 6MWT were significant. Volume of GGO, reticulation and consolidation had significant correlation with DLco or SpO{sub 2} on 6MWT. Significant differences were noted between IPF/UIP and non-IPF/UIP in 6MWT distance, mean iodine value of total lung, 25-75th (%) attenuation and entropy. IPF/UIP diagnosis, GGO ratio, DILD extent, 25-75th (%) attenuation and SpO{sub 2} on 6MWT showed significant correlations with survival. DECT combined with pattern analysis is useful for analysing DILD and predicting survival by provision of morphology and enhancement. (orig.)

  8. Computed tomography of intraventricular hemorrhage

    International Nuclear Information System (INIS)

    Cho, Bum Shin; Shin, Kyoung Hee; Hahm, Chang Kok

    1982-01-01

    Computed tomography (CT) is a new non-invasive diagnostic imaging method, which has ability to differentiate C.S.F., hematoma, and even edematous brain from normal brain tissue. Prior to the introduction of the CT, the diagnosis of the intraventricular hemorrhage in living patients was difficult and was confirmed by surgery of autopsy. Intracranial hemorrhages are visible on the CT with density higher than brain tissue in acute phase. CT is an accurate method for detecting of intraventricular hemorrhage including detection of nature, location, amount, and associated changes. CT is also useful as a guidance and in the evaluation of fate of the hematomas by easily performable follow up studies. The causes of the intraventricular hemorrhages are hypertension, rupture of aneurysm, arteriovenous malformation, head trauma, brain tumor, and others. This study included evaluation of CT of 69 patients who show the high density in cerebral ventricular system during the period of 31 months from Feb. 1979 to Aug. 1981 in the Department of Radiology, College of Medicine, Hanyang University. The results were as follows. 1. Age distribution of the total 69 patient was broad ranging from 1 month to 80 years. 28% of patients were in the 6th decade. The mate to female ratio was 2 : 1. 2. The consciousness of patients at CT study: Those were conscious in 11 cases, stuporous in 41 cases and unconscious in 17 cases. 3. The causes of intraventricular hemorrhages were hypertension in 28 cases, head trauma in 12 cases, aneurysm in 4 cases, tumor in 2 cases and others in 23 cases. 4. 9 cases showed intraventricular hematomas only, other 60 cases showed associated intracranial hematomas: Those were intracerebral hematomas in 53 cases including 30 cases of basal ganglial and thalamic hematomas, subarachnoid hemorrhage in 17 cases, epidural hematomas in 3 cases, and subdural hematomas in 2 cases. 5. All cases of the intraventricular hematomas except one sowed hematoma in the lateral

  9. Computed tomography in subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Lee, Seung Ro; Chang, Kee Hyun; Choi, Byung Ihn; Han, Man Chung; Sim, Bo Sung

    1981-01-01

    Computed Tomography has become increasingly important diagnostic method as the initial examination in the diagnosis of subarachnoid hemorrhage with direct detection of extravasated blood in basal cistern and cortical sulci. Furthermore, CT provides better and exact visualization of the presence, localization, extent and degree of intracerebral, intraventricular and subdural hemorrhage, infarction, hydrocephalus and rebleeding which may be associated with subarachnoid hemorrhage, and also could detect the causative lesions with contrast enhancement in many cases. The purpose of the paper is to describe the CT findings of subarachnoid hemorrhage due to various causes and to evaluate the diagnostic accuracy of CT in subarachnoid hemorrhage. Authors analysed a total of 153 cases with subarachnoid hemorrhage confirmed by lumbar puncture at Seoul National University Hospital from March 1979 to April 1981, with special emphasis on CT findings. All of the cases took CT scan and 125 cases of them angiography. The results are as follows: 1. Most prevalent age group was 4th to 6th decades (78%). The ratio of male to female was 1.1: 1. 2. Of 125 cases with angiography, aneurysm was a major cause (68%). Others were arterio-venous malformation (9.6%), Moya-moya disease (4%) and unknown (18.4%). 3. Of all 153 cases with CT scan, hemorrhage was demonstrated in 98 cases (64.1%); SAH in 72 cases (47.1%), ICH in 65 cases (42.5%), IVH in 34 cases (22.2%) and SDH in 1 case (0.7%). SAH combined with ICH was a major group (34.7%) in SAH. Detection rate of SAH was 68.3% within the first 7 days and 5.8% after 7 dyas. 4. In aneurysms, SAH was detected in 60 of 85 cases (70.6%); 88.1% within the first 7 dyas and 5.6% after 7 dyas. Anterior communicating artery was the most common site of the aneurysms (40%), in which detection rate of SAH was 100% within the first 7 days. SAH was combined with ICH in 38.3%. 5. On CT, SAH of unilateral Sylvian fissure was pathognomonic for ruptured MCA

  10. Computed Tomography evaluation of maxillofacial injuries

    Directory of Open Access Journals (Sweden)

    V Natraj Prasad

    2017-01-01

    Full Text Available Background & Objectives: The maxillofacial region, a complex anatomical structure, can be evaluated by conventional (plain films, Tomography, Multidetector Computed Tomography, Three-Dimensional Computed Tomography, Orthopantomogram and Magnetic Resonance Imaging. The study was conducted with objective of describing various forms of maxillofacial injuries, imaging features of different types of maxillofacial fractures and the advantage of using Three- Dimensional Computed Tomography reconstructed image. Materials & Methods: A hospital based cross-sectional study was conducted among 50 patients during April 2014 to September 2016 using Toshiba Aquilion Prime 160 slice Multi Detector Computed Tomography scanner.Results: The maxillofacial fractures were significantly higher in male population (88% than female population (12 %. Road traffic accidents were the most common cause of injury others being physical assault and fall from height. It was most common in 31-40 years (26% and 21-30 (24% years age group. Maxillary sinus was the commonest fracture (36% followed by nasal bone and zygomatic bone (30%, mandible and orbital bones (28%. Soft tissue swelling was the commonest associated finding. Three dimensional images (3 D compared to the axial scans missed some fractures. However, the extension of the complex fracture lines and degree of displacement were more accurately assessed. Complex fractures found were Le fort (6% and naso-orbito-ethmoid (4% fractures.Conclusion: The proper evaluation of complex anatomy of the facial bones requires Multidetector Computed Tomography which offers excellent spatial resolution enabling multiplanar reformations and three dimensional reconstructions for enhanced diagnostic accuracy and surgical planning.

  11. Positron emission tomography/computed tomography scanning for ...

    African Journals Online (AJOL)

    Background: Although the site of nosocomial sepsis in the critically ill ventilated patient is usually identifiable, it may remain occult, despite numerous investigations. The rapid results and precise anatomical location of the septic source using positron emission tomography (PET) scanning, in combination with computed ...

  12. Computed tomography of cartilaginous tumours

    International Nuclear Information System (INIS)

    Marincek, B.; Triller, J.; Robotti, G.; Gumppenberg, S. von

    1984-01-01

    The compound tomography (CT) morphology of cartilaginous tumors and the utility of CT in their diagnostic work-up is presented on the basis of 19 cases. CT provided unique informations regarding definition of tumor extent and tumor relationship to adjacent structures particularly in the axial skeleton. CT has diminished the indications for angiography in cartilaginous tumors. (orig.) [de

  13. Computed tomography arterial portography for assessment of portal vein injury after blunt hepatic trauma.

    Science.gov (United States)

    Fu, Chen Ju; Wong, Yon Cheong; Tsang, Yuk Ming; Wang, Li Jen; Chen, Huan Wu; Ku, Yi Kang; Wu, Cheng Hsien; Chen, Huan Wen; Kang, Shih Ching

    2015-01-01

    Intrahepatic portal vein injuries secondary to blunt abdominal trauma are difficult to diagnose and can result in insidious bleeding. We aimed to compare computed tomography arterial portography (CTAP), reperfusion CTAP (rCTAP), and conventional computed tomography (CT) for diagnosing portal vein injuries after blunt hepatic trauma. Patients with blunt hepatic trauma, who were eligible for nonoperative management, underwent CTAP, rCTAP, and CT. The number and size of perfusion defects observed using the three methods were compared. A total of 13 patients (seven males/six females) with a mean age of 34.5±14.1 years were included in the study. A total of 36 hepatic segments had perfusion defects on rCTAP and CT, while there were 47 hepatic segments with perfusion defects on CTAP. The size of perfusion defects on CT (239 cm3; interquartile range [IQR]: 129.5, 309.5) and rCTAP (238 cm3; IQR: 129.5, 310.5) were significantly smaller compared with CTAP (291 cm3; IQR: 136, 371) (both, P = 0.002). Perfusion defects measured by CTAP were significantly greater than those determined by either rCTAP or CT in cases of blunt hepatic trauma. This finding suggests that CTAP is superior to rCTAP and CT in evaluating portal vein injuries after blunt liver trauma.

  14. The clinical value of adenosine triphosphate stress myocardial perfusion tomography for detecting coronary artery disease

    International Nuclear Information System (INIS)

    Yao Zhiming; He Qing; Qu Wanying; Yu Xue; Han Lijun; Yu Zhiguo; Li Wei; Zeng Xuezhai; Zhu Ming; Zhao Hongshan

    2002-01-01

    Objective: To study the clinical value of adenosine triphosphate stress myocardial perfusion tomography imaging (ATP-MPI) in detection of coronary artery disease (CAD). Methods: There were 278 patients underwent ATP-MPI, 51 patients of them also underwent coronary angiography (CAG). Seventy-three patients underwent stress-rest myocardial perfusion tomography imaging with multi-stage submaximal exercise test (ST-MPI) and CAG serving as control group. Results: 1) Side effects: there were 11 different symptoms and atrioventricular conduction block (10 patients), sinoatrial conduction block (2 patients) occurred during ATP stress. Allopathy or interruption of ATP stress did not happen. 2) The sensitivity and specificity of ATP-MPI in detection of CAD were 97.1% and 82.4%, respectively, and those in detection of ≥50% narrowing coronary artery were 91.0% and 94.7%, respectively. 3) In patients without myocardial infarction, the sensitivity and specificity of ATP-MPI in detection of myocardial ischemia were comparable to those of ST-MPI. Conclusion: ATP-MPI is an accurate, safe modality and is comparable to ST-MPI in the detection of CAD

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  16. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which rotates around the patient. The computer that processes the imaging information and monitor are located in ... follows a spiral path. A special computer program processes this series of pictures, or slices of the ...

  17. Computer axial tomography in geosciences

    International Nuclear Information System (INIS)

    Duliu, Octavian G.

    2002-01-01

    Computer Axial Tomography (CAT) is one of the most adequate non-invasive techniques for the investigation of the internal structure of a large category of objects. Initially designed for medical investigations, this technique, based on the attenuation of X- or gamma-ray (and in some cases neutrons), generates digital images which map the numerical values of the linear attenuation coefficient of a section or of the entire volume of the investigated sample. Shortly after its application in medicine, CAT has been successfully used in archaeology, life sciences, and geosciences as well as for the industrial materials non-destructive testing. Depending on the energy of the utilized radiation as well as on the effective atomic number of the sample, CAT can provide with a spatial resolution of 0.01 - 0.5 mm, quantitative as well as qualitative information concerning local density, porosity or chemical composition of the sample. At present two types of axial Computer Tomographs (CT) are in use. One category, consisting of medical as well as industrial CT is equipped with X-ray tubes while the other uses isotopic gamma-ray sources. CT provided with intense X-ray sources (equivalent to 12-15 kCi or 450-550 TBq) has the advantage of an extremely short running time (a few seconds and even less) but presents some disadvantages known as beam hardening and absorption edge effects. These effects, intrinsically related to the polychromatic nature of the X-rays generated by classical tubes, need special mathematical or physical corrections. A polychromatic X-ray beam can be made almost monochromatic by means of crystal diffraction or by using adequate multicomponent filters, but these devices are costly and considerably diminish the output of X-ray generators. In the case of CT of the second type, monochromatic gamma-rays generated by radioisotopic sources, such as 169 Yb (50.4 keV), 241 Am (59 keV), 192 Ir (310.5 and 469.1 keV ) or 137 Cs (662.7 keV), are used in combination with

  18. The dream of a one-stop-shop : Meta-analysis on myocardial perfusion CT

    NARCIS (Netherlands)

    Pelgrim, Gert Jan; Dorrius, Monique; Xie, Xueqian; den Dekker, Martijn A. M.; Schoepf, U. Joseph; Henzler, Thomas; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

    2015-01-01

    Purpose: To determine the diagnostic performance of computed tomography (CT) perfusion techniques for the detection of functionally relevant coronary artery disease (CAD) in comparison to reference standards, including invasive coronary angiography (ICA), single photon emission computed tomography

  19. Indication for dental computed tomography. Case reports

    International Nuclear Information System (INIS)

    Schom, C.; Engelke, W.; Kopka, L.; Fischer, U.; Grabbe, E.

    1996-01-01

    Based on case reports, common indications for dental computed tomography are demonstrated and typical findings are analysed. From a group of 110 patients who had a reformatted computed tomography of the maxilla and mandibula, 10 typical cases were chosen as examples and are presented with a detailed description of the findings. The most important indication was the analysis of the morphology of the alveolar ridge needed in presurgical planning for osseointegrated implants as well as in special cases of postsurgical control. Apart from implantology, the method could be used in cases of mandibular cysts and bony destructions. In conclusion, dental computed tomography has become established mainly in implantology. It can provide valuable results in cases where a demonstration of the bone in all dimensions and free of overlappings and distortions is needed. (orig.) [de

  20. Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

    Science.gov (United States)

    Yao, Junjie; Xia, Jun; Maslov, Konstantin I.; Nasiriavanaki, Mohammadreza; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

    2012-01-01

    We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood-brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively decoupled by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area had a clear vascular pattern and spread wider than the somatosensory region. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism. PMID:22940116

  1. Computed tomography in malignant primary bone tumours

    International Nuclear Information System (INIS)

    Kersjes, W.; Harder, T.; Haeffner, P.

    1990-01-01

    The importance of computed tomography is examined in malignant primary bone tumours using a strongly defined examination group of 13 Patients (six Ewing's-sarcomas, five osteosarcomas, one chondrosarcoma and one spindle-shaped cell sarcoma). Computed tomography is judged superior compared to plain radiographs in recognition of bone marrow infiltration and presentation of parosteal tumour parts as well as in analysis of tissue components of tumours, CT is especially suitable for therapy planning and evaluating response to therapy. CT does not provide sufficient diagnostic information to determine dignity and exact diagnosis of bone tumours. (orig.) [de

  2. Computed tomography of sacro-iliac joints

    International Nuclear Information System (INIS)

    Miquel, A.; Laredo, J.D.

    1995-01-01

    Actual technologies to explore sacro-iliac joints are conventional radiography, computed tomography , scintigraphy and nuclear magnetic resonance imaging. Standards films are sufficient, except in beginning sacro-iliac septic inflammations where the computed tomography is superior. Two problems are generally posed for the radiologist, to differentiate a septic arthritis from a rheumatic pathology An other problem in diagnosis is to make the difference between a degenerative arthropathy (which does not need a further investigation) and an infectious rheumatic pathology where more exploration is necessary. 28 refs., 3 tabs., 13 figs

  3. The Western Denmark Cardiac Computed Tomography Registry

    DEFF Research Database (Denmark)

    Nielsen, Lene Hüche; Nørgaard, Bjarne Linde; Tilsted, Hans-Henrik

    2014-01-01

    BACKGROUND: As a subregistry to the Western Denmark Heart Registry (WDHR), the Western Denmark Cardiac Computed Tomography Registry (WDHR-CCTR) is a clinical database established in 2008 to monitor and improve the quality of cardiac computed tomography (CT) in Western Denmark. OBJECTIVE: We...... examined the content, data quality, and research potential of the WDHR-CCTR. METHODS: We retrieved 2008-2012 data to examine the 1) content; 2) completeness of procedure registration using the Danish National Patient Registry as reference; 3) completeness of variable registration comparing observed vs...

  4. Computed tomography versus invasive coronary angiography

    DEFF Research Database (Denmark)

    Napp, Adriane E.; Haase, Robert; Laule, Michael

    2017-01-01

    Objectives: More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate...... angiography (ICA) is the reference standard for detection of CAD.• Noninvasive computed tomography angiography excludes CAD with high sensitivity.• CT may effectively reduce the approximately 2 million negative ICAs in Europe.• DISCHARGE addresses this hypothesis in patients with low-to-intermediate pretest...

  5. Physics of x-ray computed tomography

    International Nuclear Information System (INIS)

    Akutagawa, W.M.; Huth, G.C.

    1976-01-01

    Sections are included on theoretical limits of x-ray computed tomography and the relationship of these limits to human organ imaging and specific disease diagnosis; potential of x-ray computed tomography in detection of small calcified particles in early breast cancer detection; early lung cancer measurement and detection; advanced materials for ionizing radiation detection; positron system with circular ring transaxial tomographic camera; contrast mechanism of transmission scanner and algorithms; and status of design on a 200 keV scanning proton microprobe

  6. Computed tomography in dementia of Alzheimer type

    International Nuclear Information System (INIS)

    Tsunoda, Masahiko; Fujii, Tsutomu; Tanii, Yasuyuki

    1990-01-01

    Computed tomography (CT) examinations of 7 patients with dementia of Alzheimer type were reviewed and correlated with clinical stages. The findings of CT were also compared with those of single photon emission computed tomography (SPECT). There was no positive correlation between the degree of cerebral atrophy on CT and clinical stage. Cerebral atrophy seemed to be influenced by aging, ill duration, and the degree of dementia. The cerebral/cerebellar uptake ratio of RI on SPECT was significantly decreased with the progression of clinical stage. SPECT seemed to reflect the degree of dementia, irrespective of ages and ill duration. (N.K.)

  7. ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI): a report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group and the American Society of Nuclear Cardiology endorsed by the American Heart Association.

    Science.gov (United States)

    Brindis, Ralph G; Douglas, Pamela S; Hendel, Robert C; Peterson, Eric D; Wolk, Michael J; Allen, Joseph M; Patel, Manesh R; Raskin, Ira E; Hendel, Robert C; Bateman, Timothy M; Cerqueira, Manuel D; Gibbons, Raymond J; Gillam, Linda D; Gillespie, John A; Hendel, Robert C; Iskandrian, Ami E; Jerome, Scott D; Krumholz, Harlan M; Messer, Joseph V; Spertus, John A; Stowers, Stephen A

    2005-10-18

    Under the auspices of the American College of Cardiology Foundation (ACCF) and the American Society of Nuclear Cardiology (ASNC), an appropriateness review was conducted for radionuclide cardiovascular imaging (RNI), specifically gated single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). The review assessed the risks and benefits of the imaging test for several indications or clinical scenarios and scored them based on a scale of 1 to 9, where the upper range (7 to 9) implies that the test is generally acceptable and is a reasonable approach, and the lower range (1 to 3) implies that the test is generally not acceptable and is not a reasonable approach. The mid range (4 to 6) implies that the test may be generally acceptable and may be a reasonable approach for the indication. The indications for this review were primarily drawn from existing clinical practice guidelines and modified based on discussion by the ACCF Appropriateness Criteria Working Group and the Technical Panel members who rated the indications. The method for this review was based on the RAND/UCLA approach for evaluating appropriateness, which blends scientific evidence and practice experience. A modified Delphi technique was used to obtain first- and second-round ratings of 52 clinical indications. The ratings were done by a Technical Panel with diverse membership, including nuclear cardiologists, referring physicians (including an echocardiographer), health services researchers, and a payer (chief medical officer). These results are expected to have a significant impact on physician decision making and performance, reimbursement policy, and future research directions. Periodic assessment and updating of criteria will be undertaken as needed.

  8. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... so that the x-ray beam follows a spiral path. A special computer program processes this series ... Sometimes ultrasound is substituted for CT as a method of imaging in these procedures in children. A ...

  9. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ... diabetes, kidney disease or thyroid problems. Any of these conditions may influence the decision on whether contrast ...

  10. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... through the body, recording an image on photographic film or a special image recording plate . Bones appear ...

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... images can be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT images of internal organs, bones, soft tissue and blood vessels provide greater detail ...

  12. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... which are then displayed on a monitor. Special software can also generate three-dimensional (3-D) images ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ...

  13. Paradoxical emboli: demonstration using helical computed tomography of the pulmonary artery associated with abdominal computed tomography

    International Nuclear Information System (INIS)

    Delalu, P.; Ferretti, G.R.; Bricault, I.; Ayanian, D.; Coulomb, M.

    2000-01-01

    We report the case of a 60-year-old woman with a recent history of a cerebrovascular accident. Because of clinical suspicion of pulmonary embolism and negative Doppler ultrasound findings of the lower limbs, spiral computed tomography of the pulmonary artery was performed and demonstrated pulmonary emboli. We emphasize the role of computed tomography of the abdomen, performed 3 min after the thoracic acquisition, which showed an unsuspected thrombus within the abdominal aorta and the left renal artery with infarction of the left kidney. Paradoxical embolism was highly suspected on computed tomography data and confirmed by echocardiography which demonstrated a patent foramen ovale. (orig.)

  14. Computed Tomography Study Of Complicated Bacterial Meningitis ...

    African Journals Online (AJOL)

    To monitor the structural intracranial complications of bacterial meningitis using computed tomography (CT) scan. Retrospective study of medical and radiological records of patients who underwent CT scan over a 4 year period. AUniversityTeachingHospital in a developing country. Thirty three patients with clinically and ...

  15. Computed tomography - old ideas and new technology

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmann, Dominik; Boas, F.E. [Stanford University, School of Medicine, Department of Radiology, Stanford, CA (United States)

    2011-03-15

    Several recently introduced 'new' techniques in computed tomography - iterative reconstruction, gated cardiac CT, multiple-source, and dual-energy CT - actually date back to the early days of CT. We review the historic origins and evolution of these techniques, which may provide some insight into the latest innovations in commercial CT systems. (orig.)

  16. Computed tomography in the evaluation of trauma

    International Nuclear Information System (INIS)

    Federle, M.P.; Brant-Zawadzki, M.

    1982-01-01

    This book is intended to be the current standard for computed tomography in the evaluation of trauma. It summarizes two years of experience at San Francisco General Hospital. The book is organized into seven chapters, covering head, maxillofacial, laryngeal, spinal, chest, abdominal, acetabular, and pelvic trauma. Extremity trauma is not discussed

  17. Computed tomography (CT) and diastematomyelia's diagnosis

    International Nuclear Information System (INIS)

    Santos, M.B. dos; Luca, V. de; Ferreira, M.A.S.; Barros, A.P. de

    1982-01-01

    After a case of diastematomyelia observed at the University Hospital (Federal University of Rio de Janeiro, Brazil) a review is done of the pertaining literature, and the contribution of the computed tomography for the diagnosis of this disease is emphasized. (Author) [pt

  18. Computed tomography evaluation of petrous bone fractures ...

    African Journals Online (AJOL)

    Background: Petrous bone trauma is the sequel of blunt head injury and can have life threatening complications resulting in immediate mortality. Early detection and good knowledge of the Computed Tomography (CT) findings ensure prompt treatment of both fractures and complications. Objective: To document the ...

  19. Appropriateness of computed tomography and magnetic resonance ...

    African Journals Online (AJOL)

    Introduction. Computed tomography (CT) and magnetic resonance imaging (MRI) are an essential part of modern healthcare. Marked increases in clinical demand for these imaging modalities are straining healthcare expenditure and threatening health system sustainability. The number of CT and MRI scans requested in ...

  20. Comparison on Computed Tomography using industrial items

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    2014-01-01

    In a comparison involving 27 laboratories from 8 countries, measurements on two common industrial items, a polymer part and a metal part, were carried out using X-ray Computed Tomography. All items were measured using coordinate measuring machines before and after circulation, with reference...

  1. Computed tomography of intussusception in adult

    International Nuclear Information System (INIS)

    Jeon, Hae Jeong; Ahn, Byeong Yeob; Cha, Soon Joo; Seol, Hae Young; Chung, Kyoo Byung; Suh, Won Hyuck

    1984-01-01

    Intussusception is rare in adult and usually caused by organic lesions, although there is a significant number of so-called idiopathic cases. The diagnosis of intussusception have been made by plain abdomen, barium enema and small bowel series. But recently ultrasound and computed tomography make a contribution to diagnose intussusception. Computed tomography is not the primary means for evaluating a gastrointestinal tract abnormality but also provides valuable information in evaluating disorders affecting the hollow viscera of the alimentary tract. Computed tomography image of intussusception demonstrates a whirl like pattern of bowel loops separated by fatty stripe correlating of the intestinal walls. Abdominal ultrasonogram was used as the initial diagnostic test in 2 cases out of total 4 cases, with abdominal mass of unknown cause. It revealed a typical pattern, composed of a round or oval mass with central dense echoes and peripheral poor echoes. We report 4 all cases of intussusception in adult who were performed by computed tomography and/or ultrasound. All cases were correlated with barium enema examination and/or surgical reports.

  2. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    An interlaboratory comparison on industrial X-ray Computed Tomography (CT) was organized by the Centre for Geometrical Metrology (CGM), Department of Mechanical Engineering, Technical University of Denmark (DTU) and carried out within the project “Centre for Industrial Application of CT scanning...

  3. Computed Tomography in the Modern Slaughterhouse

    DEFF Research Database (Denmark)

    Mosbech, Thomas Hammershaimb

    of technology. Recently, the use of X-ray computed tomography (CT) coupled with methods from image analysis has been introduced as a powerful means to optimise production, by providing detailed information on the raw materials. This thesis covers two aspects of the application of CT in the modern abattoir...

  4. Analysis of airways in computed tomography

    DEFF Research Database (Denmark)

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...

  5. Investigation of measuring strategies in computed tomography

    DEFF Research Database (Denmark)

    Müller, Pavel; Hiller, Jochen; Cantatore, Angela

    2011-01-01

    Computed tomography has entered the industrial world in 1980’s as a technique for non-destructive testing and has nowadays become a revolutionary tool for dimensional metrology, suitable for actual/nominal comparison and verification of geometrical and dimensional tolerances. This paper evaluates...

  6. Computed tomography in severe protein energy malnutrition.

    OpenAIRE

    Househam, K C; de Villiers, J F

    1987-01-01

    Computed tomography of the brain was performed on eight children aged 1 to 4 years with severe protein energy malnutrition. Clinical features typical of kwashiorkor were present in all the children studied. Severe cerebral atrophy or brain shrinkage according to standard radiological criteria was present in every case. The findings of this study suggest considerable cerebral insult associated with severe protein energy malnutrition.

  7. Computed tomography of the iliopsoas muscle

    International Nuclear Information System (INIS)

    Nino-Murcia, M.; Wechsler, R.J.; Brennan, R.E.

    1983-01-01

    Computed tomography (CT) is an ideal method for the imaging of the psoas muscle. The authors present 13 cases of patients with psoas abnormalities diagnosed by CT. The CT features of the different pathologic entities and comparison of CT with other imaging modalities are discussed. (orig.)

  8. Cone beam computed tomography in veterinary dentistry

    NARCIS (Netherlands)

    van Thielen, B.; Siguenza, F.; Hassan, B.

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal

  9. Computed tomography of tuberculous meningitis

    International Nuclear Information System (INIS)

    Sato, Noriko; Sato, Hiromi; Kawaguchi, Tetsuro; Fujita, Katsuzo; Tanaka, Makoto

    1982-01-01

    Recently, tuberculous meningitis has become rather rare except in areas where tuberculosis is still endemic. Six adolescents and young adults with tuberculous meningitis were evaluated by means of serial computerized tomography (CT), and the results were correlated with the findings of surgical specimens or autopsies. All cases showed meningeal irritation and fever at onset. CSF cultures revealed the presence of tuberculous bacilli. Four cases advanced rapidly to the clinical stage III and expired in a short period-between two weeks to one month from onset. On initial CT scanning, the disappearance of the basal cistern was a characteristic finding in all these cases. With the progression, an enhancement of the basal cistern on contrast injection, a localized hypodensity in adjacent parenchyma, and symmetrical ventricular dilatation appeared. Two autopsied cases showed tuberculous granulomas with purulent materials, thickened meninges, and caseous necrosis in the parenchyma around the basal cistern. The other two cases progressed rather slowly. CT findings at Stage II showed multiple enhanced spots in the basal subcortical area following contrast injection. Tuberculous granulomas were identified in these parts by means of explorative craniotomy. The authors point out the pathognomonic CT findings of tuberculous meningitis and emphasize the necessity of serial CT for the early detection and management of tuberculous meningitis. (author)

  10. Misty mesentery: computed tomography findings

    International Nuclear Information System (INIS)

    Ahualli, Jorge; Mendez Uriburu, Luis; Ravera, Maria L.; Cikman, Pablo

    2008-01-01

    An alteration in the density of the mesenteric adipose tissue is often the principal clue of underlying mesenteric and bowel disease. The term 'Misty Mesentery' describes the computed tomographic appearance of mesenteric fat infiltrated by inflammatory cells, fluid (edema, lymph, and/or blood), tumor, and fibrosis. (author) [es

  11. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed ...

  12. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... detectors rotate around the patient. At the same time, the examination table is moving through the scanner, so that the x-ray beam follows a spiral path. A special computer program processes this series of pictures, or slices of the body, to ...

  13. Computed Tomography in Forensic Medicine

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2015-01-01

    was not used. Autopsies were performed according to the Danish government's official guidelines. PMCT and autopsy findings were interpreted independent of each other. Diagnoses, including the cause of death and histology findings, were registered in a computer database (SPSS) together with information about...

  14. Computed tomography in Alexander's disease

    Energy Technology Data Exchange (ETDEWEB)

    Holland, I M; Kendall, B E

    1980-10-01

    Two cases of biopsy-proven Alexander's disease are described with computed tomographic changes which, in our experience and on survey of the literature, have not occurred in any other condition. Such changes in a child with a progressive condition consistent with Alexander's disease, strongly support the diagnosis.

  15. Computed tomography of limy bile

    International Nuclear Information System (INIS)

    Yamamoto, Shinichiro; Kimoto, Masatoshi; Gunge, Nobuharu; Sano, Kaizo; Yamashita, Sachiko; Hirano, Yutaka

    1983-01-01

    The computed tomographic appearance of three cases of limy bile was reported. The CT findings consist of uniform high density within gallbladder, niveau formation between limy bile and noncalcified bile. Sagittal reconstruction of CT images was especially useful in the differentiation of limy bile and gallstones. (author)

  16. Thermoluminescent dosimetry in computed tomography

    International Nuclear Information System (INIS)

    Lara C, A.; Rivera M, T.; Osorio V, M.; Hernandez O, O.

    2016-10-01

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  17. Thermoluminescent dosimetry in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lara C, A.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria, Av. Legaria 694, Col. Irrigacion, 11500 Ciudad de Mexico (Mexico); Osorio V, M. [ISSSTE, Centro Medico Nacional 20 de Noviembre, Felix Cuevas 540, Col. del Valle, 03100 Ciudad de Mexico (Mexico); Hernandez O, O., E-mail: armando_lara_cam@yahoo.com.mx [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Ciudad de Mexico (Mexico)

    2016-10-15

    In this work we studied the dosimetry performed on CT scan in two different equipment, SOMATOM and Phillips, with 16 and 64 slice respectively. We used 51 pellets of lithium fluoride doped with magnesium and titanium (LiF: Mg, Ti) also knows as TLD-100 due to its physical properties and its easy of use, in this study, first analysis a batch of 56 pellets, but only 53 pellets were optimal for this study, cesium-137 was used as source irradiation, then proceeded to calibrate the batch with X-rays source, measuring the corresponding dose in a Farmers ionization chamber, then, we obtained a calibration curve, and we used as reference to calculation of the applied dose, finally designing ergonomic mesh, were it was deposited a TLD 100, placed in a regions of interest were made to each scan type. Once characterized our material proceeded to testing in 30 patients, which were irradiated with X-ray tube, whose operation was performed at 80, 120 kV with a current of 100, 300 and 400 m A according to scanning protocol. Overall we measured dose of 5 mGy to 53 mGy, these measurements reflect significant dose to can induced cancer, due previous reports published, that doses greater than 20 mGy there is a risk of developing cancer in the long term, but in practice when it assigned a medical diagnosis, there are no dose limits due to benefits patients, however, IAEA publish recommendations that allow us to carry out optimum handling of ionizing radiation, among these is the quality control of the tomography equipment that helps greatly reduce patient dose. (Author)

  18. The clinical significance of abnormal 99Tcm-MIBI myocardial perfusion tomography in patients with hypertension

    International Nuclear Information System (INIS)

    Yang Yongzhen; Li Zhaoping; Liu Yimin; Zhang Weifang; Zhang Yanyan; Zhang Songlin; Wang Xin; Mao Yuan

    2000-01-01

    Objective: To evaluate the clinical significance of abnormal myocardial perfusion tomography in the hypertensive patients with normal coronary angiography. Methods: Qualitative diagnosis, the average counts ratio of lateral to septal segments (L/S) and the ratio of stress L/S to rest L/S from stress and rest 99 Tc m -sestamibi myocardial perfusion tomography (MPT), and every clinical characteristic and the results from other examinations were compared between hypertensive patients (HP) and normotensive controls (NC). Every risk factor leading to coronary artery disease and related indexes in patients with positive MPT were compared with the results of patients with negative MPT. Results: 1) The positive rate of MPT in HP was obviously higher than that of NC,which was 61.9% vs 9.1%, respectively. Most focuses of MPT were reversible defects (RD), a few of them accompanied by reverse reversible defects (RRD). There were many more angina pectoris and heart arrhythmia attacks in HP than in NC. 2) The ratio of stress L/S to rest L/S of HP was lower than that of NC (P<0.05). 3) The ratio of stress L/S to rest L/S of the patients with positive MPT in HP significantly decreased compared with that of the patients with negative MPT (P<0.01). There were more patients being addicted to smoking and drinking in those with a positive than in those with a negative MPT (53.8% versus 12.5%, P<0.05). 4) The abnormal defects of MPT in HP were almost seen in any segment of left ventricle and most of the patients had no left ventricular hypertrophy, but did smoke and drink. Conclusions: 1)Abnormal MPT exist in the HP with normal coronary angiography and not necessarily with left ventricular hypertrophy. 2)The long-term addiction of smoking and drinking was one of the risk factors leading to arouse myocardial ischemia in HP

  19. Cerebral candidiasis. Computed tomography appearance

    International Nuclear Information System (INIS)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-01-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  20. Cerebral candidiasis. Computed tomography appearance

    Energy Technology Data Exchange (ETDEWEB)

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  1. Microfocus computed tomography in medicine

    Science.gov (United States)

    Obodovskiy, A. V.

    2018-02-01

    Recent advances in the field of high-frequency power schemes for X-ray devices allow the creation of high-resolution instruments. At the department of electronic devices and Equipment of the St. Petersburg State Electrotechnical University, a model of a microfocus computer tomograph was developed. Used equipment allows to receive projection data with an increase up to 100 times. A distinctive feature of the device is the possibility of implementing various schemes for obtaining projection data.

  2. Computed tomography of thymic abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, P.; Candardjis, G.

    1987-05-01

    Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis.

  3. Computed tomography of thymic abnormalities

    International Nuclear Information System (INIS)

    Schnyder, P.; Candardjis, G.

    1987-01-01

    Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis. (orig.)

  4. Orbital computed tomography: technical aspects

    International Nuclear Information System (INIS)

    Beck, T.J.; Rosenbaum, A.E.; Miller, N.R.

    1982-01-01

    Computed tomographic scanning has revolutionized the diagnosis and management of orbital disease. The best use of this methodology requires knowledge of the principles and appropriate attention to scanning protocols. Computed tomographic scanning of the orbit is a demanding technique requiring thin sections through planes precisely positioned from the topographical anatomy. Ideally, orbital CT should include both transverse axial and coronal sections: The pathological condition and its plane of growth will influence the selection of the optimal plane or section. Coronal sections may be obtained either directly or indirectly by computer reconstruction from contiguous transverse images. Sagittal or oblique sections or both also are useful and may be obtained directly or indirectly. Difficulty in patient positioning may preclude direct sagittal imaging, however. The use of intravenous contrast enhancement is not necessary as a routine technique unless a mass is identified or suspected. Where surgical resection or biopsy of a space-occupying lesion is contemplated, contrast enhancement can be valuable in assessing relative vascularity and aiding diagnostic specificity. It should be continually emphasized that CT is a powerful technology which, in orbital diagnosis, produces the highest yield when clinician and radiologist collaborate in the radiodiagnostic workup. The clinical information supplied by the referring ophthalmologist is used by the radiologist both in the selection of the appropriate techniques for investigation and in striving to achieve the most specific conclusion

  5. Proton computed tomography images with algebraic reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzi, M. [Physics and Astronomy Department, University of Florence, Florence (Italy); Civinini, C.; Scaringella, M. [INFN - Florence Division, Florence (Italy); Bonanno, D. [INFN - Catania Division, Catania (Italy); Brianzi, M. [INFN - Florence Division, Florence (Italy); Carpinelli, M. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Cirrone, G.A.P.; Cuttone, G. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Presti, D. Lo [INFN - Catania Division, Catania (Italy); Physics and Astronomy Department, University of Catania, Catania (Italy); Maccioni, G. [INFN – Cagliari Division, Cagliari (Italy); Pallotta, S. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Randazzo, N. [INFN - Catania Division, Catania (Italy); Romano, F. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Sipala, V. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Talamonti, C. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Vanzi, E. [Fisica Sanitaria, Azienda Ospedaliero-Universitaria Senese, Siena (Italy)

    2017-02-11

    A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175 MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to ~1% and spatial resolutions <1 mm, achieved within processing times of ~15′ for a 512×512 pixels image prove that this technique will be beneficial if used instead of X-CT in hadron-therapy.

  6. Measuring techniques in emission computed tomography

    International Nuclear Information System (INIS)

    Jordan, K.; Knoop, B.

    1988-01-01

    The chapter reviews the historical development of the emission computed tomography and its basic principles, proceeds to SPECT and PET, special techniques of emission tomography, and concludes with a comprehensive discussion of the mathematical fundamentals of the reconstruction and the quantitative activity determination in vivo, dealing with radon transformation and the projection slice theorem, methods of image reconstruction such as analytical and algebraic methods, limiting conditions in real systems such as limited number of measured data, noise enhancement, absorption, stray radiation, and random coincidence. (orig./HP) With 111 figs., 6 tabs [de

  7. Computed tomography of the skeletal system

    International Nuclear Information System (INIS)

    Maas, R.; Heller, M.

    1990-01-01

    Patients showing severe multiple injuries, require special care and attention in the hospital. In these cases, the range of the diagnostic measures taken subsequent to computed tomography of the cranium must be broadened to include examinations of the vertebral column and pelvic ring for traumatic lesions. Radiological routine procedures are discussed wit hthe view of throwing some light on the problems involved incomputed tomography of the vertebral disks. In degenerative processes associated with spinal stenosis and hypertrophic facets it has been found that angular-sagittal-reconstruction may be quite useful. Computed tomography provides valuable information on morphological factors and has great discriminating power in the diagnosis of skeletal tumours of the extremities. Quantitative computed tomography offers unprecedented possibilities in the diagnosis and treatment of osteoporosis. Here, particular care must be taken to avoid inaccuracies of measurement as a result of incorrectly performed examinations. In malignant bone tumours the method of dynamic scanning permits the success or failure of any radiotherapeutic or chemical measures taken to be evaluated at an early stage. The success or failure of any radiotherapeutic or chemical measures taken to to treat malignant bone tumours can be evaluated at an early stage using the method on dynamic scanning. (orig.) [de

  8. Comparison between conventional tomography and computer tomography in diseases of the sacroiliac joints

    International Nuclear Information System (INIS)

    Moritz, J.D.; Ganter, H.; Winter, C.; Evangelisches Krankenhaus, Giessen

    1990-01-01

    16 patients with diseases of the sacroiliac joints were examined both with computer tomography and with conventional tomography. Both techniques were characterized by a high sensitivity. Computer tomography was superior in exactly delineating the extent of the pathologic changes. In conventional tomography the joint surface was more blurred, erosions were larger, and signs of ankylosis were more expanded, so that the joints seemed to be more altered in 8 cases than demonstrated by computer tomography. Very accurate changes like subchondral cysts were recognized only in the computer tomograms. In all cases in which anteroposterior radiographs revealed no clear result, the authors recommend to additionally employ computer tomography. (orig.) [de

  9. Detection of regional derangements in myocardial metabolism by positron computed tomography in Duchenne's muscular dystrophy

    International Nuclear Information System (INIS)

    Henze, E.; Schelbert, H.R.; Perloff, J.K.; Schwaiger, M.; Phelps, M.E.

    1982-01-01

    Duchenne's Muscular Dystrophy is unique in genetically targeting for disease a specific region of myocardium: the postero-basal left ventricular wall. Postmortem examinations revealed focal fibrous degenerations in the postero-basal segment, while the coronary arteries were usually not affected. A predystrophic metabolic fault has been postulated for this region. This hypothesis was tested with positron computed tomography as a new means for the noninvasive study of regional myocadial perfusion and metabolism and to determine the incidence of regional and global left ventricular dysfunction and perfusion abnormalities using Thallium-201 and gated blood pool imaging. Myocardial perfusion was evaluated with N-13 ammonia while regional myocardial glucose uptake was studied with the glucose analog F-18 DG. The sensitivity of each diagnostic test for detecting cardiac involvement in Duchenne's Muscular Dystrophy was evaluated. It was highest for ammonia and glucose imaging and it was low for Thallium and radionuclide blood pool imaging

  10. Computed tomography in diagnostics of effluent otitis media

    International Nuclear Information System (INIS)

    Imomova, L.S.; Norboev, Z.; Kalandarov, S.Ch.

    2011-01-01

    This article is devoted to computed tomography in diagnostics of effluent otitis media. The purpose of present work is to assess the possibilities of computed tomography method of temporal bone in the diagnostics of otitis media.

  11. Computed tomography of the menisci

    International Nuclear Information System (INIS)

    Wagner-Manslau, C.; Rupp, N.; Paar, O.; Rodammer, G.

    1988-01-01

    Thirty patients were examined with CT of the menisci. All findings were confirmed by arthroscopy. One false positive diagnosis of a torn meniscus was made, caused by partial volume effect. In seven patients with irregular degenerative changes of the menisci, the abnormality could be clearly demonstrated. One meniscus ganglion was shown. Seven meniscus lesions, which were not shown by arthrography or arthroscopy, were clearly demonstrated by CT. The computer tomographic demonstration of menisci can replace knee arthrography as the examination of choice and should be performed before carrying out arthroscopy. (orig.) [de

  12. Introducing Seismic Tomography with Computational Modeling

    Science.gov (United States)

    Neves, R.; Neves, M. L.; Teodoro, V.

    2011-12-01

    Learning seismic tomography principles and techniques involves advanced physical and computational knowledge. In depth learning of such computational skills is a difficult cognitive process that requires a strong background in physics, mathematics and computer programming. The corresponding learning environments and pedagogic methodologies should then involve sets of computational modelling activities with computer software systems which allow students the possibility to improve their mathematical or programming knowledge and simultaneously focus on the learning of seismic wave propagation and inverse theory. To reduce the level of cognitive opacity associated with mathematical or programming knowledge, several computer modelling systems have already been developed (Neves & Teodoro, 2010). Among such systems, Modellus is particularly well suited to achieve this goal because it is a domain general environment for explorative and expressive modelling with the following main advantages: 1) an easy and intuitive creation of mathematical models using just standard mathematical notation; 2) the simultaneous exploration of images, tables, graphs and object animations; 3) the attribution of mathematical properties expressed in the models to animated objects; and finally 4) the computation and display of mathematical quantities obtained from the analysis of images and graphs. Here we describe virtual simulations and educational exercises which enable students an easy grasp of the fundamental of seismic tomography. The simulations make the lecture more interactive and allow students the possibility to overcome their lack of advanced mathematical or programming knowledge and focus on the learning of seismological concepts and processes taking advantage of basic scientific computation methods and tools.

  13. Computed tomography of tibial plateau fractures

    International Nuclear Information System (INIS)

    Rafii, M.; Firooznia, H.; Golimbu, C.; Bonamo, J.

    1984-01-01

    Twenty patients with tibial plateau fractures were studied by conventional tomography and computed tomography (CT) in order to determine the role and feasibility of CT in management of such patients. CT resulted in less discomfort to the patient and provided optimal visualization of the plateau defect and the split fragments. It proved more accurate than conventional tomography in assessing depressed and split fractures when they involved the anterior or posterior border of the plateau and in demonstrating the extent of fracture comminution. Split fragments with an oblique plane of fracture also were seen better by CT. The degree of fracture depression and separation as measured by the computerized technique was often more accurate than measurements obtained from conventional tomograms

  14. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer.

    Science.gov (United States)

    Bartholomä, Mark D; He, Huamei; Pacak, Christina A; Dunning, Patricia; Fahey, Frederic H; McGowan, Francis X; Cowan, Douglas B; Treves, S Ted; Packard, Alan B

    2013-11-01

    Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an (18)F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on (18)F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of (18)F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake (18)F-labeled rhodamine B by cardiomyocytes. A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100-150 μCi of (18)F-labeled rhodamine B diethylene glycol ester ([(18)F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [(18)F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Small-animal PET showed intense and uniform uptake of [(18)F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [(18)F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ~40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [(18)F]RhoBDEGF in the mitochondria of rat cardiomyocytes. Fluorine-18

  15. Biological characterization of F-18-labeled rhodamine B, a potential positron emission tomography perfusion tracer

    International Nuclear Information System (INIS)

    Bartholomä, Mark D.; He, Huamei; Pacak, Christina A.; Dunning, Patricia; Fahey, Frederic H.; McGowan, Francis X.; Cowan, Douglas B.; Treves, S. Ted; Packard, Alan B.

    2013-01-01

    Introduction: Myocardial infarction is the leading cause of death in western countries, and positron emission tomography (PET) plays an increasing role in the diagnosis and treatment planning for this disease. However, the absence of an 18 F-labeled PET myocardial perfusion tracer hampers the widespread use of PET in myocardial perfusion imaging (MPI). We recently reported a potential MPI agent based on 18 F-labeled rhodamine B. The goal of this study was to more completely define the biological properties of 18 F-labeled rhodamine B with respect to uptake and localization in an animal model of myocardial infarction and to evaluate the uptake 18 F-labeled rhodamine B by cardiomyocytes. Methods: A total of 12 female Sprague Dawley rats with a permanent ligation of the left anterior descending artery (LAD) were studied with small-animal PET. The animals were injected with 100–150 μCi of 18 F-labeled rhodamine B diethylene glycol ester ([ 18 F]RhoBDEGF) and imaged two days before ligation. The animals were imaged again two to ten days post-ligation. After the post-surgery scans, the animals were euthanized and the hearts were sectioned into 1 mm slices and myocardial infarct size was determined by phosphorimaging and 2,3,5-triphenyltetrazolium chloride staining (TTC). In addition, the uptake of [ 18 F]RhoBDEGF in isolated rat neonatal cardiomyocytes was determined by fluorescence microscopy. Results: Small-animal PET showed intense and uniform uptake of [ 18 F]RhoBDEGF throughout the myocardium in healthy rats. After LAD ligation, well defined perfusion defects were observed in the PET images. The defect size was highly correlated with the infarct size as determined ex vivo by phosphorimaging and TTC staining. In vitro, [ 18 F]RhoBDEGF was rapidly internalized into rat cardiomyocytes with ∼ 40 % of the initial activity internalized within the 60 min incubation time. Fluorescence microscopy clearly demonstrated localization of [ 18 F]RhoBDEGF in the mitochondria

  16. Sparse Image Reconstruction in Computed Tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...... applications. This thesis takes a systematic approach toward establishing quantitative understanding of conditions for sparse reconstruction to work well in CT. A general framework for analyzing sparse reconstruction methods in CT is introduced and two sets of computational tools are proposed: 1...... contributions to a general set of computational characterization tools. Thus, the thesis contributions help advance sparse reconstruction methods toward routine use in...

  17. Computed tomography of pelvic fractures

    Energy Technology Data Exchange (ETDEWEB)

    Kimoto, Makoto; Hashimoto, Keiji; Hiraki, Yoshio

    1984-12-01

    Plain x-ray and computed tomographic (CT) findings were compared in 7 patients with pelvic fractures (2 males and 5 females) aged between 35 and 50 year. Plain x-rays had a higher sensitivity than CT in detecting fractures of the ischiatic and pubic ramuses, and deviation of bone fragments. CT was superior to plain x-rays near the acetabulum and in detecting deviation of bone fragments. Although there were no differences between the two modalities in detecting fractures of the wing of ilium, CT was more useful than plain x-rays in visualizing deviation of bone fragments. CT clearly visualized not only fractures but also injuries of the soft tissues, such as pelvic viscera and muscles, and the presence of hematoma. CT seems to be a useful method for observing the condition and process of pelvic injuries and for deciding treatment protocols.

  18. 21 CFR 892.1200 - Emission computed tomography system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1200 Emission computed tomography system. (a) Identification. An emission computed tomography system is a device intended to detect the...

  19. Cone beam computed tomography in endodontic

    Energy Technology Data Exchange (ETDEWEB)

    Durack, Conor; Patel, Shanon [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  20. Cone beam computed tomography in endodontic

    International Nuclear Information System (INIS)

    Durack, Conor; Patel, Shanon

    2012-01-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  1. Emission computed tomography: methodology and applications

    International Nuclear Information System (INIS)

    Reivich, M.; Alavi, A.; Greenberg, J.; Fowler, J.; Christman, D.; Rosenquist, A.; Rintelmann, W.; Hand, P.; MacGregor, R.; Wolf, A.

    1980-01-01

    A technique for the determination of local cerebral glucose metabolism using positron emission computed tomography is described as an example of the development of use of this methodology for the study of these parameters in man. The method for the determination of local cerebral glucose metabolism utilizes 18 F-2-fluoro-2-deoxyglucose ([ 18 F]-FDG). In this method [ 18 F]-FDG is used as a tracer for the exchange of glucose between plasma and brain and its phosphorylation by hexokinase in the tissue. The labelled product of metabolism, [ 18 F]-FDG phosphate, is essentially trapped in the tissue over the time course of the measurement. The studies demonstrate the potential usefulness of emission computed tomography for the measurement of various biochemical and physiological parameters in man. (Auth.)

  2. Computed tomography of chest wall abscess

    International Nuclear Information System (INIS)

    Ikezoe, Junpei; Morimoto, Shizuo; Akira, Masanori

    1986-01-01

    Inflammatory lesions of the chest wall become less common because of the improvement of antibiotics and chemotherapeutic agents. Over a 5-year period, 7 patients with chest wall inflammatory diseases underwent chest computed tomography. These were 2 tuberculous pericostal abscesses, 2 empyema necessitatis, 1 spinal caries, and 2 bacterial chest wall abscesses (unknown organisms). Computed tomography (CT) helped in demonstrating the density, border, site, and extent of the lesions. CT images also demonstrated the accompaning abnormalities which included bone changes, pleural calcification, or old tuberculous changes of the lung. CT was very effective to demonstrate the communicating portions from the inside of the bony thorax to the outside of the bony thorax in 2 empyema necessitatis. (author)

  3. Soil structure changes evaluated with computed tomography

    International Nuclear Information System (INIS)

    Pires, Luiz Fernando

    2010-01-01

    The objective of this work was to evaluate in millimetric scale changes in soil bulk density and porosity, using the gamma-ray computed tomography in soil samples with disturbed structure due to wetting and drying (W-D) cycles. Soil samples with 98.1 cm 3 were sieved using a 2 mm mesh and homogeneously packed in PVC cylinders. Soil samples were submitted to 1, 2, and 3 W-D cycles. Control samples were not submitted to W-D cycles. After repetitions of W-D cycles, soil sample porosity decreased and soil layers became denser. Computed tomography allowed a continuous analysis of soil bulk density and also soil porosity along millimetric (0.08 cm) layers, what cannot be provided by traditional methods used in soil physics. (author)

  4. Possibilities of computer tomography in multiple sclerosis

    International Nuclear Information System (INIS)

    Vymazal, J.; Bauer, J.

    1983-01-01

    Computer tomography was performed in 41 patients with multiple sclerosis, the average age of patients being 40.8 years. Native examinations were made of 17 patients, examinations with contrast medium of 19, both methods were used in the examination of 5 patients. In 26 patients, i.e. in almost two-thirds, cerebral atrophy was found, in 11 of a severe type. In 9 patients atrophy affected only the hemispheres, in 16 also the stem and cerebellum. The stem and cerebellum only were affected in 1 patient. Hypodense foci were found in 21 patients, i.e. more than half of those examined. In 9 there were multiple foci. In most of the 19 examined patients the hypodense changes were in the hemispheres and only in 2 in the cerebellum and brain stem. No hyperdense changes were detected. The value and possibilities are discussed of examinations by computer tomography multiple sclerosis. (author)

  5. Basic principle of cone beam computed tomography

    International Nuclear Information System (INIS)

    Choi, Yong Suk; Kim, Gyu Tae; Hwang, Eui Hwan

    2006-01-01

    The use of computed tomography for dental procedures has increased recently. Cone beam computed tomography(CBCT) systems have been designed for imaging hard tissues of the dentomaxillofacial region. CBCT is capable of providing high resolution in images of high diagnostic quality. This technology allows for 3-dimensional representation of the dentomaxillofacial skeleton with minimal distortion, but at lower equipment cost, simpler image acquisition and lower patient dose. Because this technology produces images with isotropic sub-millimeter spatial resolution, it is ideally suited for dedicated dentomaxillofacial imaging. In this paper, we provide a brief overview of cone beam scanning technology and compare it with the fan beam scanning used in conventional CT and the basic principles of currently available CBCT systems

  6. Contrast-induced nephropathy after computed tomography

    Directory of Open Access Journals (Sweden)

    Luciano da Silva Selistre

    2015-03-01

    Full Text Available Introduction: Contrast induced nephropathy is the third most prevalent preventable cause of acute kidney injury in hospitalized patients. It defined as an absolute increase in serum creatinine ≥ 0.5 mg/dL and relative ≥ 25% increase. Objective: We studied the risk factors to intravenous injection contrast nephropathy after computed tomography. Methods: We studied 400 patients prospectively. Results: The incidence of contrast induced nephropathy, with an absolute or a relative increase were 4.0% and 13.9%, respectively. Diabetes and cardiac failure were independent risk factors for CIN a relative increase de serum creatinine (O.R.: 3.5 [95% CI: 1.92-6.36], p < 0.01, 2.61 [95% CI: 1.14-6.03%], p < 0.05, respectively. Conclusions: We showed association between uses of intravenous injection contrast after computed tomography with acute injury renal, notably with diabetes and heart failure.

  7. Xenon as an adjunct in computed tomography

    International Nuclear Information System (INIS)

    Kendall, B.E.; Radue, E.W.; Zilkha, E.; Loh, L.

    1979-01-01

    Nonradioactive xenon was used for enhancement in computed tomography in a series of 18 patients requiring general anesthesia. The method and results are described. The properties of xenon are radically different from those of intravenous iodides, and the enhancement patterns demonstrate different aspects of both normal and abnormal tissues. In our limited experience, it has been of value in those isodense and low attenuation lesions that have not enhanced after intravenous Conray. (orig.) 891 MG/orig. 892 MB [de

  8. Computed tomography of the eye and orbit

    International Nuclear Information System (INIS)

    Hammerschlag, S.B.; Hesselink, J.R.; Weber, A.L.

    1982-01-01

    This book is the product of the evolution of computed tomography (CT) into subspecialization and the need for one source of information for the busy radiologist. The authors have succeeded in providing a readable overview of orbital CT as well as a reference book. The book is divided into seven major catagories of pathology (Neurofibromatosis, Primary Orbital Neoplasms, Secondary and Metastic Tumors of the Orbit, Vascular Disorders, Inflammatory Disease, Occular Lesions, and Trauma) after separate discussions of anatomy and technique

  9. Computed tomography in gastrointestinal stromal tumors

    International Nuclear Information System (INIS)

    Ghanem, Nadir; Altehoefer, Carsten; Winterer, Jan; Schaefer, Oliver; Springer, Oliver; Kotter, Elmar; Langer, Mathias; Furtwaengler, Alex

    2003-01-01

    The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary (n=20) and (n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST ( 5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly

  10. Computed tomography in opportunistic lung infections

    International Nuclear Information System (INIS)

    Hartelius, H.

    1988-01-01

    Chest radiography in two teenage boys, one with Wiscott-Aldrich's syndrome and one with acute lymphatic leucemia in remission showed increased interstitial pattern. In both computed tomography (CT) of the lungs showed heavy interstitial pneumonia, rather different in appearance but in both cases equal to the CT findings in opportunistic lung infections known from immunoincompetent patients with for instance pneumocystis carinii and/or cytomegalo virus infections. In both patients the CT findings led to lung biopsy establishing the etiologic agent. (orig.)

  11. Cranial computed tomography of the neurofibromatosis

    International Nuclear Information System (INIS)

    Fukuda, Teruo; Inoue, Yuichi; Shibakiri, Ippei

    1981-01-01

    The computed tomography (CT) was performed in 10 cases of neurofibromatosis. The CT scan showed the abnormal findings in 8 cases out of 10. Skull lesions were noted in 3 cases and intracranial tumors were found in 5 among which multiple neoplasms were seen in 3. Although reported cases were not large enough in number, the incidence and variety of the tumors were similar to others reported before CT era. (author)

  12. Computed tomography manifestations of peritoneal diseases

    International Nuclear Information System (INIS)

    Gordon, K.; Lee, W.K.; Hennessy, O.

    2005-01-01

    The peritoneal cavity is a potential space that is divided by the peritoneal reflections into various complex subspaces. It can be involved in many disease processes including developmental, inflammatory, neoplastic and traumatic conditions. Computed tomography is highly sensitive and consistent in detecting peritoneal pathology. This pictorial essay aims to emphasize and illustrate the CT features of the spectrum of peritoneal diseases. Copyright (2005) Blackwell Science Pty Ltd

  13. Encapsulating peritonitis: computed tomography and surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kadow, Juliana Santos; Fingerhut, Carla Jeronimo Peres; Fernandes, Vinicius de Barros; Coradazzi, Klaus Rizk Stuhr; Silva, Lucas Marciel Soares; Penachim, Thiago Jose, E-mail: vinicius.barros.fernandes@gmail.com [Pontificia Universidade Catolica de Campinas (PUC-Campinas), Campinas, SP (Brazil). Hospital e Maternidade Celso Pierro

    2014-07-15

    Sclerosing encapsulating peritonitis is a rare and frequently severe entity characterized by total or partial involvement of small bowel loops by a membrane of fibrous tissue. The disease presents with nonspecific clinical features of intestinal obstruction, requiring precise imaging diagnosis to guide the treatment. The present report emphasizes the importance of computed tomography in the diagnosis of this condition and its confirmation by surgical correlation. (author)

  14. Computed tomography after radical pancreaticoduodenectomy (Whipple's procedure)

    International Nuclear Information System (INIS)

    Smith, S.L.; Hampson, F.; Duxbury, M.; Rae, D.M.; Sinclair, M.T.

    2008-01-01

    Whipple's procedure (radical pancreaticoduodenectomy) is currently the only curative option for patients with periampullary malignancy. The surgery is highly complex and involves multiple anastomoses. Complications are common and can lead to significant postoperative morbidity. Early detection and treatment of complications is vital, and high-quality multidetector computed tomography (MDCT) is currently the best method of investigation. This review outlines the surgical technique and illustrates the range of normal postoperative appearances together with the common complications

  15. Fatty kidney diagnosed by mortem computed tomography

    DEFF Research Database (Denmark)

    Leth, P. M.

    2016-01-01

    Subnuclear vacuolization of the renal tubular epithelium is indicative of diabetic and alcoholic ketoacidosis and has also been proposed as a postmortem marker for hypothermia. We present for the first time a fatal case of ketoacidosis in combination with exposure where a suspicion of these diagn...... of these diagnoses was raised by a marked radiolucency of the kidneys at post-mortem computed tomography (PMCT). © 2015 Elsevier Ltd....

  16. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Meeder, J.G.; Blanksma, P.K.; Wall, E.E. van der; Anthonio, R.L.; Willemsen, A.T.M.; Pruim, J.; Vaalburg, W.; Lie, K.I.

    1996-01-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116±17 ml/min/100 g vs 96±20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02±0.15 vs 1.18±0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%±4.2% vs 13.5%±1.9%, P <0.05) and during cold pressor stimulation (17.0%±3.2% vs 13.9%±1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab

  17. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Meeder, J.G. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Blanksma, P.K. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Wall, E.E. van der [Department of Cardiology, University Hospital, Leiden (Netherlands); Anthonio, R.L. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Willemsen, A.T.M. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Pruim, J. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Vaalburg, W. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Lie, K.I. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands)

    1996-11-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116{+-}17 ml/min/100 g vs 96{+-}20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02{+-}0.15 vs 1.18{+-}0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%{+-}4.2% vs 13.5%{+-}1.9%, P <0.05) and during cold pressor stimulation (17.0%{+-}3.2% vs 13.9%{+-}1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab.

  18. Physics and instrumentation of emission computed tomography

    International Nuclear Information System (INIS)

    Links, J.M.

    1986-01-01

    Transverse emission computed tomography can be divided into two distinct classes: single photon emission computed tomography (SPECT) and positron emission tomography (PET). SPECT is usually accomplished with specially-adapted scintillation cameras, although dedicated SPECT scanners are available. The special SPECT cameras are standard cameras which are mounted on gantries that allow 360 degree rotation around the long axis of the head or body. The camera stops at a number of angles around the body (usually 64-128), acquiring a ''projection'' image at each stop. The data from these projections are used to reconstruct transverse images with a standard ''filtered back-projection'' algorithm, identical to that used in transmission CT. Because the scintillation camera acquires two-dimensional images, a simple 360 degree rotation around the patient results in the acquisition of data for a number of contiguous transverse slices. These slices, once reconstructed, can be ''stacked'' in computer memory, and orthogonal coronal and sagittal slices produced. Additionally, reorienting algorithms allow the generation of slices that are oblique to the long axis of the body

  19. Computed tomography in intracranial malignant lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, S; Odake, G; Fujimoto, M; Yamaki, T; Mizukawa, N [Kyoto Prefectural Univ. of Medicine (Japan)

    1978-09-01

    Malignant lymphoma of the central nervous system has been found more and more often in recent years, partly because of the increased use of radiation and such drugs as steroids and antibiotics. However, the definite diagnosis of this disease is difficult until histological verification has been done by operation or autopsy. Since the revolutionary development of computed tomography, however, several reports have been presented, on the computed tomography of malignant lymphoma of the thorax and abdomen. Nevertheless, only a few cases of intracranial malignant lymphoma have been reported. The purpose of this paper, using four patients, is to emphasize the value of computed tomography in the diagnosis of intracranial malignant lymphoma. The characteristic CT findings of intracranial malignant lymphoma may be summarized follows: (1) the tumors are demonstrated to be well-defined, nodular-shaped, and homogenous isodensity - or slightly high-density - lesions in plain scans, and the tumors homogenously increase in density upon contrast enhancement; (2) the disease always has multifocal intracranial lesions, which are shown simultaneously or one after another, and (3) perifocal edema is prominent around the tumors in the cerebral hemisphere.

  20. Inter laboratory comparison on Industrial Computed Tomography

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science......, Technology and Innovation. The comparison aims to collect information about measurement performance in state-of the-art industrial CT (Computed Tomography) scanning. Since CT scanning has entered the field of manufacturing and coordinate metrology, evaluation of uncertainty of measurement with assessment...

  1. Basic principles of cone beam computed tomography.

    Science.gov (United States)

    Abramovitch, Kenneth; Rice, Dwight D

    2014-07-01

    At the end of the millennium, cone-beam computed tomography (CBCT) heralded a new dental technology for the next century. Owing to the dramatic and positive impact of CBCT on implant dentistry and orthognathic/orthodontic patient care, additional applications for this technology soon evolved. New software programs were developed to improve the applicability of, and access to, CBCT for dental patients. Improved, rapid, and cost-effective computer technology, combined with the ability of software engineers to develop multiple dental imaging applications for CBCT with broad diagnostic capability, have played a large part in the rapid incorporation of CBCT technology into dentistry. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Computed tomography-controlled stereotactic surgery

    International Nuclear Information System (INIS)

    Matsumoto, Keizo; Shichijo, Fumio; Gyoten, Tetsuya; Tomida, Keisuke; Miyake, Hajime

    1986-01-01

    A single use of coordinate system of computed tomography (CT) scanner is utilized for CT-controlled stereotactic surgery. Depth, direction and readjustment of target trajectory were defined by known values of cursor number in CT images and numbers of the sliding table indicator. We loaded calculation formulas into hand held computer to obtain immediate answers. Stereotactic apparatus consisted two main parts: the patient's head fixation and probe holder. Surgery was performed in cases of hypertensive intracerebral hemorrhage for evacuation of the hematomas successfully. Target accuracy was satisfactory. With further advance of this surgery, automatic stereotactic control with a special robot machine seeing possible. (author)

  3. Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

    International Nuclear Information System (INIS)

    Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2013-01-01

    It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

  4. Applications of X-ray Computed Tomography and Emission Computed Tomography

    International Nuclear Information System (INIS)

    Seletchi, Emilia Dana; Sutac, Victor

    2005-01-01

    Computed Tomography is a non-destructive imaging method that allows visualization of internal features within non-transparent objects such as sedimentary rocks. Filtering techniques have been applied to circumvent the artifacts and achieve high-quality images for quantitative analysis. High-resolution X-ray computed tomography (HRXCT) can be used to identify the position of the growth axis in speleothems by detecting subtle changes in calcite density between growth bands. HRXCT imagery reveals the three-dimensional variability of coral banding providing information on coral growth and climate over the past several centuries. The Nuclear Medicine imaging technique uses a radioactive tracer, several radiation detectors, and sophisticated computer technologies to understand the biochemical basis of normal and abnormal functions within the brain. The goal of Emission Computed Tomography (ECT) is to accurately determine the three-dimensional radioactivity distribution resulting from the radiopharmaceutical uptake inside the patient instead of the attenuation coefficient distribution from different tissues as obtained from X-ray Computer Tomography. ECT is a very useful tool for investigating the cognitive functions. Because of the low radiation doses associated with Positron Emission Tomography (PET), this technique has been applied in clinical research, allowing the direct study of human neurological diseases. (authors)

  5. Positron emission tomography/computed tomography imaging and rheumatoid arthritis.

    Science.gov (United States)

    Wang, Shi-Cun; Xie, Qiang; Lv, Wei-Fu

    2014-03-01

    Rheumatoid arthritis (RA) is a phenotypically heterogeneous, chronic, destructive inflammatory disease of the synovial joints. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the upgraded glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography/computed tomography with fluorine-18 fluorodeoxyglucose ((18) F-FDG PET/CT) is available to delineate inflammation with high sensitivity. Recently, several studies have indicated that FDG uptake in affected joints reflects the disease activity of RA. In addition, usage of FDG PET for the sensitive detection and monitoring of the response to treatment has been reported. Combined FDG PET/CT enables the detailed assessment of disease in large joints throughout the whole body. These unique capabilities of FDG PET/CT imaging are also able to detect RA-complicated diseases. Therefore, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in RA. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  6. Therapy response evaluation with positron emission tomography-computed tomography.

    Science.gov (United States)

    Segall, George M

    2010-12-01

    Positron emission tomography-computed tomography with F-18-fluorodeoxyglucose is widely used for evaluation of therapy response in patients with solid tumors but has not been as readily adopted in clinical trials because of the variability of acquisition and processing protocols and the absence of universal response criteria. Criteria proposed for clinical trials are difficult to apply in clinical practice, and gestalt impression is probably accurate in individual patients, especially with respect to the presence of progressive disease and complete response. Semiquantitative methods of determining tissue glucose metabolism, such as standard uptake value, can be a useful descriptor for levels of tissue glucose metabolism and changes in response to therapy if technical quality control measures are carefully maintained. The terms partial response, complete response, and progressive disease are best used in clinical trials in which the terms have specific meanings and precise definitions. In clinical practice, it may be better to use descriptive terminology agreed upon by imaging physicians and clinicians in their own practice. Copyright © 2010. Published by Elsevier Inc.

  7. Mathematics in computed tomography and related techniques

    International Nuclear Information System (INIS)

    Sawicka, B.

    1992-01-01

    The mathematical basis of computed tomography (CT) was formulated in 1917 by Radon. His theorem states that the 2-D function f(x,y) can be determined at all points from a complete set of its line integrals. Modern methods of image reconstruction include three approaches: algebraic reconstruction techniques with simultaneous iterative reconstruction or simultaneous algebraic reconstruction; convolution back projection; and the Fourier transform method. There is no one best approach. Because the experimental data do not strictly satisfy theoretical models, a number of effects have to be taken into account; in particular, the problems of beam geometry, finite beam dimensions and distribution, beam scattering, and the radiation source spectrum. Tomography with truncated data is of interest, employing mathematical approximations to compensate for the unmeasured projection data. Mathematical techniques in image processing and data analysis are also extensively used. 13 refs

  8. Quantification of MRI measured myocardial perfusion reserve in healthy humans: A comparison with positron emission tomography

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Hove, J.D.; Kofoed, K.F.

    2008-01-01

    Purpose: To validate a noninvasive quantitative MRI technique, the K-i perfusion method, for myocardial perfusion in humans using N-13-ammonia PET as a reference method. Materials and Methods: Ten healthy males (64 +/- 8 years) were examined with combined PET and MRI perfusion imaging at rest and...

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

    Science.gov (United States)

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

    1980-09-01

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

  10. Positron computed tomography: current state, clinical results and future trends

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-09-01

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

  11. Positron computed tomography: current state, clinical results and future trends

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  12. RELIABILITY OF POSITRON EMISSION TOMOGRAPHY-COMPUTED TOMOGRAPHY IN EVALUATION OF TESTICULAR CARCINOMA PATIENTS.

    Science.gov (United States)

    Nikoletić, Katarina; Mihailović, Jasna; Matovina, Emil; Žeravica, Radmila; Srbovan, Dolores

    2015-01-01

    The study was aimed at assessing the reliability of 18F-fluorodeoxyglucose positron emission tomography-computed tomography scan in evaluation of testicular carcinoma patients. The study sample consisted of 26 scans performed in 23 patients with testicular carcinoma. According to the pathohistological finding, 14 patients had seminomas, 7 had nonseminomas and 2 patients had a mixed histological type. In 17 patients, the initial treatment was orchiectomy+chemotherapy, 2 patients had orchiectomy+chemotherapy+retroperitoneal lymph node dissection, 3 patients had orchiectomy only and one patient was treated with chemotherapy only. Abnormal computed tomography was the main cause for the oncologist to refer the patient to positron emission tomography-computed tomography scan (in 19 scans), magnetic resonance imaging abnormalities in 1 scan, high level oftumor markers in 3 and 3 scans were perforned for follow-up. Positron emission tomography-computed tomography imaging results were compared with histological results, other imaging modalities or the clinical follow-up of the patients. Positron emission tomography-computed tomography scans were positive in 6 and negative in 20 patients. In two patients, positron emission tomography-computed tomography was false positive. There were 20 negative positron emission omography-computed tomography scans perforned in 18 patients, one patient was lost for data analysis. Clinically stable disease was confirmed in 18 follow-up scans performed in 16 patients. The values of sensitivty, specificity, accuracy, and positive- and negative predictive value were 60%, 95%, 75%, 88% and 90.5%, respectively. A hgh negative predictive value obtained in our study (90.5%) suggests that there is a small possibility for a patient to have future relapse after normal positron emission tomography-computed tomography study. However, since the sensitivity and positive predictive value of the study ire rather low, there are limitations of positive

  13. Total variation-based neutron computed tomography

    Science.gov (United States)

    Barnard, Richard C.; Bilheux, Hassina; Toops, Todd; Nafziger, Eric; Finney, Charles; Splitter, Derek; Archibald, Rick

    2018-05-01

    We perform the neutron computed tomography reconstruction problem via an inverse problem formulation with a total variation penalty. In the case of highly under-resolved angular measurements, the total variation penalty suppresses high-frequency artifacts which appear in filtered back projections. In order to efficiently compute solutions for this problem, we implement a variation of the split Bregman algorithm; due to the error-forgetting nature of the algorithm, the computational cost of updating can be significantly reduced via very inexact approximate linear solvers. We present the effectiveness of the algorithm in the significantly low-angular sampling case using synthetic test problems as well as data obtained from a high flux neutron source. The algorithm removes artifacts and can even roughly capture small features when an extremely low number of angles are used.

  14. Regional myocardial perfusion assessed by N-13 labeled ammonia and positron emission computerized axial tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.J.; Huang, S.C.; Selin, C.E.; Kuhl, D.E.

    1978-01-01

    The usefulness of 13 NH 3 as an indicator of regional myocardial perfusion suitable for positron emission computerized axial tomography (PCT) has been suggested. However, the relationship between myocardial blood flow and uptake of 13 NH 3 has not been examined quantitatively. It was therefore the purpose of the current investigation to quantitate the relationship of myocardial 13 NH 3 tissue concentration to myocardial blood flow and to examine its suitability for PCT imaging. Twelve open chest dogs were studied. In 8 of the dogs 25 imaging procedures with 13 NH 3 and PCT were performed. In the remaining four dogs the relationship between flow and myocardial 13 NH 3 tissue concentration was assessed by in vitro techniques. The PCT technique provided high quality cross-sectional images of the distribution of 13 NH 3 in left ventricular myocardium. No significant redistribution of 13 NH 3 in myocardium occurred with time. Alterations in regional myocardial blood flow resulted in changes of the regional distribution of 13 NH 3 that were readily appreciated on the PCT images

  15. Cross-sectional anatomy for computed tomography

    International Nuclear Information System (INIS)

    Farkas, M.L.

    1988-01-01

    This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations

  16. Computed tomography scans of metastatic hepatic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Fukuda, Haruyuki; Nemoto, Yutaka [Osaka City Univ. (Japan). Faculty of Medicine

    1984-01-01

    Computed tomography scans of 114 metastatic hepatic tumors were reviewed. Central low density was found in 82 cases (71.9%) and seems to be characteristic to metastatic hepatic tumors. Dynamic CT was performed on 34 cases, and 21 (61.8%) of these had ring enhancement at the arterial phase. Most of metastatic hepatic tumors could be differentiated from hepatocellular carcinoma. However, metastatic hepatic tumors from renal cell carcinoma, renal rhabdomyosarcoma, malignant melanoma and leiomyosarcoma could not be differentiated from hepatocellular carcinoma, even with use of dynamic study.

  17. Computed tomography appearances of sclerosing encapsulating peritonitis

    International Nuclear Information System (INIS)

    George, C.; Al-Zwae, K.; Nair, S.; Cast, J.E.I.

    2007-01-01

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP

  18. An industrial application of computer assisted tomography

    International Nuclear Information System (INIS)

    Tonner, P.D.; Tosello, G.

    1984-10-01

    Computer assisted tomography (CAT) scanning is a nondestructive testing technique used to obtain quantitatively accurate mappings of the distribution of linear attenuation coefficients inside an object. To demonstrate the potential of the technique for accurately locating defects in three dimensions a sectioned 5 cm gate valve, with a shrink cavity made visible by the sectioning, was tomographically imaged using a Co-60 source. The tomographic images revealed a larger cavity below the sectioned surface. The position of this cavity was located with an in-plane and axial precision of approximately +- 1 mm. The volume of the cavity was estimated to be approximately 40 mm 3

  19. Application of protons to computer tomography

    International Nuclear Information System (INIS)

    Hanson, K.M.; Bradbury, J.N.; Cannon, T.M.; Hutson, R.L.; Laubacher, D.B.; Macek, R.; Paciotti, M.A.; Taylor, C.A.

    1977-01-01

    It was demonstrated that the application of protons to computed tomography can result in a significant dose advantage relative to x rays. Thus, at the same dose as is delivered by contemporary commercial x-ray scanners, a proton scanner could produce reconstructions with a factor of 2 or more improvement in density resolution. Whether such an improvement can result in significantly better diagnoses of human disease is an open question which can only be answered by the implementation of a proton scanner in a clinical situation

  20. Contrast media on abdominal computed tomography

    International Nuclear Information System (INIS)

    Skalpe, I.O.; Oestensen, H.M.

    1984-01-01

    Abdominal computed tomography was performed in 55 patients before and after intravenous injection of 60 ml of a non-ionic (iohexol) or an ionic (metrizoate) contrast medium. The adverse effects were recorded and a series of measurements of attenuation values before and after the contrast medium injection was performed in the aorta and in hepatic and renal parenchyma. Only minor adverse effects were seen with both contrast media, but iohexol was clearly better tolerated than metrizoate. No difference in the enhancement properties was found between the two contrast media. (orig.)

  1. Computed tomography appearances of sclerosing encapsulating peritonitis

    Energy Technology Data Exchange (ETDEWEB)

    George, C. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)]. E-mail: cheriangeorge@hotmail.com; Al-Zwae, K. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Nair, S. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom); Cast, J.E.I. [Department of Radiology, Hull Royal Infirmary, Hull (United Kingdom)

    2007-08-15

    Sclerosing encapsulating peritonitis (SEP) is a serious complication of peritoneal dialysis (PD) characterized by thickened peritoneal membranes, which lead to decreased ultra-filtration and intestinal obstruction. Its early clinical features are nonspecific, and it is often diagnosed late following laparotomy and peritoneal biopsy, when the patient develops small bowel obstruction, which can be a life-threatening complication. However, this is changing with increasing awareness of computed tomography (CT) findings in SEP. CT can yield an early, non-invasive diagnosis that may improve patient outcome. We present a review of the CT appearances of SEP.

  2. Computed tomography of the spine: Diagnostic exercises

    International Nuclear Information System (INIS)

    Kricun, R.; Kricun, M.E.

    1987-01-01

    The authors' aim is to provide diagnostic challenges and information to improve the readers' ability to interpret computed tomography (CT) scans of the spine. The entire vertebral column and adjacent soft-tissue structures are covered. The authors discuss normal findings, and congenital, traumatic, inflammatory, neoplastic, degenerative, idiopathic, and postoperative findings. Sixty-six case examples are presented, followed by description of the findings. Additional examples are given, and drawings and photographs of specimens are used to illustrate and clarify the pathologic conditions. Other modalities, including their advantages and disadvantages, are illustrated and discussed where appropriate. The relative merits of these modalities are presented

  3. Computed tomography features of small bowel volvulus

    International Nuclear Information System (INIS)

    Loh, Y.H.; Dunn, G.D.

    2000-01-01

    Small bowel volvulus is a cause of acute abdomen and commonly occurs in neonates and young infants. Although it is rare in adults in the Western world,' it is a relatively common surgical emergency in the Middle East, India and Central Africa. It is associated with a mortality rate of 10-67% and, hence, it is important to make an early diagnosis to expedite surgical intervention. Computed tomography has become an important imaging modality in diagnosis and a number of signs have been recognized in a handful of documented case reports. We describe a case of small bowel volvulus that illustrates these important CT signs. Copyright (1999) Blackwell Science Pty Ltd

  4. Computed tomography in neuronal ceroid lipofuscinosis

    International Nuclear Information System (INIS)

    Valavanis, A.; Schubiger, O.; Hayek, J.; Friede, R.L

    1981-01-01

    The computed tomography (CT) findings in a verified case of neutronal ceroid lipofuscinosis (NCL) are presented. CT revealed diffuse and severe cerebral atrophy, reflected by generalized subarachnoid space enlargement and symmetric ventricular dilatation. There was no evidence of abnormalities of the white matter. The CT features in our case of NCL correspond perfectly with the neuropathologic changes of the disease mentioned in the literature. Furthermore, CT is of considerable help in differentiating between those inherited metabolic brain diseases characterized primarily by white matter involvement and those presenting predominantly with changes of grey matter. (orig.) [de

  5. Unusual causes of obstructive jaundice. Computed tomography

    International Nuclear Information System (INIS)

    Rodriguez, E.; Pombo, F.; Cao, I.; Fernandez, R.; Riba da, M.

    1998-01-01

    The purpose of this study is to present selected computed tomography (CT) images showing unusual causes of obstructive jaundice. We reviewed retrospectively the Ct findings of obstructive jaundice in 227 patients. The most common causes of biliary obstruction were adenocarcinoma of the pancreatic head (n=77) and cholangiocarcinoma (n=65). In 13 cases (5.7%), the etiology of obstructive jaundice was unusual or exceptional: tuberculous adenitis (n=3), obstruction of afferent loop (n=2)signet ring cell adenocarcinoma (n=3); in duodenum, gallbladder and papilla of Water), Mirizzi syndrome (n=1), adenocarcinoma of the hepatic flexure (n=1), choledochal cyst (n=1) and pancreatic lymphoma (n=1). (Author) 13 refs

  6. Electrocardiographic gating in positron emission computed tomography

    International Nuclear Information System (INIS)

    Hoffman, E.J.; Phelps, M.E.; Wisenberg, G.; Schelbert, H.R.; Kuhl, D.E.

    1979-01-01

    Electrocardiographic (ECG) synchronized multiple gated data acquisition was employed with positron emission computed tomography (ECT) to obtain images of myocardial blood pool and myocardium. The feasibility and requirements of multiple gated data acquisition in positron ECT were investigated for 13NH3, ( 18 F)-2-fluoro-2-D-deoxyglucose, and ( 11 C)-carboxyhemoglobin. Examples are shown in which image detail is enhanced and image interpretation is facilitated when ECG gating is employed in the data collection. Analysis of count rate data from a series of volunteers indicates that multiple, statistically adequate images can be obtained under a multiple gated data collection format without an increase in administered dose

  7. Ground-glass opacity: High-resolution computed tomography and 64-multi-slice computed tomography findings comparison

    International Nuclear Information System (INIS)

    Sergiacomi, Gianluigi; Ciccio, Carmelo; Boi, Luca; Velari, Luca; Crusco, Sonia; Orlacchio, Antonio; Simonetti, Giovanni

    2010-01-01

    Objective: Comparative evaluation of ground-glass opacity using conventional high-resolution computed tomography technique and volumetric computed tomography by 64-row multi-slice scanner, verifying advantage of volumetric acquisition and post-processing technique allowed by 64-row CT scanner. Methods: Thirty-four patients, in which was assessed ground-glass opacity pattern by previous high-resolution computed tomography during a clinical-radiological follow-up for their lung disease, were studied by means of 64-row multi-slice computed tomography. Comparative evaluation of image quality was done by both CT modalities. Results: It was reported good inter-observer agreement (k value 0.78-0.90) in detection of ground-glass opacity with high-resolution computed tomography technique and volumetric Computed Tomography acquisition with moderate increasing of intra-observer agreement (k value 0.46) using volumetric computed tomography than high-resolution computed tomography. Conclusions: In our experience, volumetric computed tomography with 64-row scanner shows good accuracy in detection of ground-glass opacity, providing a better spatial and temporal resolution and advanced post-processing technique than high-resolution computed tomography.

  8. Computed tomography in the diagnosis of pericardial heart disease

    International Nuclear Information System (INIS)

    Isner, J.M.; Carter, B.L.; Bankoff, M.S.; Konstam, M.A.; Salem, D.N.

    1982-01-01

    To evaluate the use of computed tomography (CT) in the diagnosis of pericardial heart disease, 53 patients were prospectively studied by computed tomography of the chest and cardiac ultrasound. A diagnostic-quality CT study was done for all patients; a technically satisfactory ultrasound examination was not possible in six patients. Of 47 patients in whom both chest scans and satisfactory ultrasound studies were obtained, computed tomography showed pericardial thickening not shown by ultrasound in five patients. Estimated size of pericardial effusion was the same for both computed tomography and ultrasound. Computed tomography provided quantifiable evaluation of the composition of pericardial fluid in seven patients with either hemopericardium or purulent pericarditis. Neoplastic pericardial heart disease was detected by CT scan in four of the 53 patients. Computed tomography of the chest provides a sensitive evaluation of the pericardium and quality of pericardial effusion, and is a valuable adjunct in patients in whom cardiac ultrasound is technically unsatisfactory

  9. Computed tomography by reconstruction. Brain CT scanning. I. Basic physics, equipment, normal aspects, artefacts

    International Nuclear Information System (INIS)

    Chiras, J.; Palmieri, P.; Saudinos, J.; Salamon, G.

    1980-01-01

    The authors describe the physical basis, apparatus, normal images, and artefacts of computed tomography by reconstruction. Radio-anatomical sections enable clear comprehension of the computed tomography images. Other methods using computer reconstruction are outlined: tomography by Compton effect, tomography by positrons, tomography by gamma emission, tomography by protons, tomography by nuclear magnetic resonance [fr

  10. Speeding up image reconstruction in computed tomography

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Computed tomography (CT) is a technique for imaging cross-sections of an object using X-ray measurements taken from different angles. In last decades a significant progress has happened there: today advanced algorithms allow fast image reconstruction and obtaining high-quality images even with missing or dirty data, modern detectors provide high resolution without increasing radiation dose, and high-performance multi-core computing devices are there to help us solving such tasks even faster. I will start with CT basics, then briefly present existing classes of reconstruction algorithms and their differences. After that I will proceed to employing distinctive architectural features of modern multi-core devices (CPUs and GPUs) and popular program interfaces (OpenMP, MPI, CUDA, OpenCL) for developing effective parallel realizations of image reconstruction algorithms. Decreasing full reconstruction time from long hours up to minutes or even seconds has a revolutionary impact in diagnostic medicine and industria...

  11. Comparison of computed tomography dose reporting software

    International Nuclear Information System (INIS)

    Abdullah, A.; Sun, Z.; Pongnapang, N.; Ng, K. H.

    2008-01-01

    Computed tomography (CT) dose reporting software facilitates the estimation of doses to patients undergoing CT examinations. In this study, comparison of three software packages, i.e. CT-Expo (version 1.5, Medizinische Hochschule, Hannover (Germany)), ImPACT CT Patients Dosimetry Calculator (version 0.99x, Imaging Performance Assessment on Computed Tomography, www.impactscan.org) and WinDose (version 2.1a, Wellhofer Dosimetry, Schwarzenbruck (Germany)), has been made in terms of their calculation algorithm and the results of calculated doses. Estimations were performed for head, chest, abdominal and pelvic examinations based on the protocols recommended by European guidelines using single-slice CT (SSCT) (Siemens Somatom Plus 4, Erlangen (Germany)) and multi-slice CT (MSCT) (Siemens Sensation 16, Erlangen (Germany)) for software-based female and male phantoms. The results showed that there are some differences in final dose reporting provided by these software packages. There are deviations of effective doses produced by these software packages. Percentages of coefficient of variance range from 3.3 to 23.4 % in SSCT and from 10.6 to 43.8 % in MSCT. It is important that researchers state the name of the software that is used to estimate the various CT dose quantities. Users must also understand the equivalent terminologies between the information obtained from the CT console and the software packages in order to use the software correctly. (authors)

  12. Computed tomography of juvenile nasopharyngeal angiofibroma

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheong Hee; Yoo, Shi Joon; Lee, Yul; Chang, Kee Hyun; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1985-02-15

    It is well known that computed tomography (CT) is useful in detecting accurately the location, extent, erosion and relationship of angiofibroma to surrounding structures such as pterygopalation fossa. It is well known that computed tomography (CT) is useful in detecting accurately the location, sphenoid sinus, and etc. CT of 20 patients with juvenile angiofibroma, which were examined for 5 yeas from February, 1979 to May, 1984 at Department of Radiology, Seoul National University Hospital, were retrospectively analyzed. The results were as follows: 1. All 20 patients of juvenile angiofibroma had tumors in nasopharynx and posterior nasal cavity showing homogeneously dense-enhancing soft tissue mass on CT. There was extension of the tumor from nasopharynx and posterior nasal cavity into paranasal sinus (60%, 12/20), pterygopalatine fossa (55%, 11/20), infratemporal fossa (30%, 6/20), posterior orbit (10%, 2/20) and cranial cavity (15%, 3/20). 2. Angiogrpahy usually adds little diagnostic information, but is still needed to identify the precise source of blood supply to the tumor, and to perform the pre-operative embolization. The use of CT has deferred angiography until just before surgery, permitting embolization at optimal time. 3. CT is almost always necessary to reveal accurately the full extent of the tumor, especially intracranial space in the axial and coronal planes with contrast enhancement. CT is useful both in diagnosis as a guide to angiography and in planning the adequate therapy of juvenile angiofibroma.

  13. Evaluation of valvular heart diseases with computed tomography

    International Nuclear Information System (INIS)

    Tomoda, Haruo; Hoshiai, Mitsumoto; Matsuyama, Seiya

    1982-01-01

    Forty-two patients with valvular heart diseases were studied with a third-generation computed tomographic system. The cardiac chambers (the atria and ventricles) were evaluated semiquantitatively, and valvular calcification was easily detected with computed tomography. Computed tomography was most valuable in revealing left atrial thrombi which were not identified by other diagnostic procedures in some cases. (author)

  14. A Clinical Evaluation Of Cone Beam Computed Tomography

    Science.gov (United States)

    2016-06-01

    A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY by Bryan James Behm, D.D.S. Lieutenant, Dental Corps United States Navy A thesis... COMPUTED TOMOGRAPHY " is appropriately acknowledged and, beyond brief excerpts, is with the permission of the copyright owner. ~mes Behm Endodontic...printed without the expressed written permission of the author. IV ABSTRACT A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY BRYAN JAMES

  15. Characteristics and applications of a flat panel computer tomography system

    International Nuclear Information System (INIS)

    Knollmann, F.; Valencia, R.; Obenauer, S.; Buhk, J.H.

    2006-01-01

    Purpose: to assess a new flat panel volume computed tomography (FP-VCT) with very high isotropic spatial resolution as well as high Z-axis coverage. Materials and Methods: The prototype of an FP-VCT scanner with a detector cell size of 0.2 mm was used for numerous phantom studies, specimen examinations, and animal research projects. Results: The high spatial resolution of the new system can be used to accurately determine solid tumor volume, thus allowing for earlier assessment of the therapeutic response. In animal experimentation, whole-body perfusion mapping of mice is feasible. The high spatial resolution also improves the classification of coronary artery atherosclerotic plaques in the isolated post mortem human heart. With the depiction of intramyocardial segments of the coronary arteries, investigations of myocardial collateral circulation are feasible. In skeletal applications, an accurate analysis of the smallest bony structures, e.g., petrous bone and dental preparations, can be successfully performed, as well as investigations of repetitive studies of fracture healing and the treatment of osteoporosis. Conclusion: The introduction of FP-VCT opens up new applications for CT, including the field of molecular imaging, which are highly attractive for future clinical applications. Present limitations include limited temporal resolution and necessitate further improvement of the system. (orig.)

  16. Computed tomography of post-traumatic orbito-palpebral emphysema

    International Nuclear Information System (INIS)

    Nose, Harumi; Kohno, Keiko

    1981-01-01

    Two cases of orbito-palpebral emphysema are described. Both having a history of recent facial trauma, emphysema occurred after blowing the nose. They were studied by computed tomography and plain x-ray film, including tomograms of the orbit. The emphysema was revealed by computed tomography and x-ray film, but more clearly by the former technique. The fracture lines of the orbit were revealed in only one case by x-ray film, but in both cases by computed tomography. The authors stress that computed tomography is the best technique for the study of orbital emphysema. (author)

  17. Fusion imaging of computed tomographic pulmonary angiography and SPECT ventilation/perfusion scintigraphy: initial experience and potential benefit

    International Nuclear Information System (INIS)

    Harris, Benjamin; Bailey, Dale; Roach, Paul; Bailey, Elizabeth; King, Gregory

    2007-01-01

    The objective of this study was to examine the feasibility of fusing ventilation and perfusion data from single-photon emission computed tomography (SPECT) ventilation perfusion (V/Q) scintigraphy together with computed tomographic pulmonary angiography (CTPA) data. We sought to determine the accuracy of this fusion process. In addition, we correlated the findings of this technique with the final clinical diagnosis. Thirty consecutive patients (17 female, 13 male) who had undergone both CTPA and SPECT V/Q scintigraphy during their admission for investigation of potential pulmonary embolism were identified retrospectively. Image datasets from these two modalities were co-registered and fused using commercial software. Accuracy of the fusion process was determined subjectively by correlation between modalities of the anatomical boundaries and co-existent pleuro-parenchymal abnormalities. In all 30 cases, SPECT V/Q images were accurately fused with CTPA images. An automated registration algorithm was sufficient alone in 23 cases (77%). Additional linear z-axis scaling was applied in seven cases. There was accurate topographical co-localisation of vascular, parenchymal and pleural disease on the fused images. Nine patients who had positive CTPA performed as an initial investigation had co-localised perfusion defects on the subsequent fused CTPA/SPECT images. Three of the 11 V/Q scans initially reported as intermediate could be reinterpreted as low probability owing to co-localisation of defects with parenchymal or pleural pathology. Accurate fusion of SPECT V/Q scintigraphy to CTPA images is possible. This technique may be clinically useful in patients who have non-diagnostic initial investigations or in whom corroborative imaging is sought. (orig.)

  18. Computed Tomography Technology: Development and Applications for Defence

    International Nuclear Information System (INIS)

    Baheti, G. L.; Saxena, Nisheet; Tripathi, D. K.; Songara, K. C.; Meghwal, L. R.; Meena, V. L.

    2008-01-01

    Computed Tomography(CT) has revolutionized the field of Non-Destructive Testing and Evaluation (NDT and E). Tomography for industrial applications warrants design and development of customized solutions catering to specific visualization requirements. Present paper highlights Tomography Technology Solutions implemented at Defence Laboratory, Jodhpur (DLJ). Details on the technological developments carried out and their utilization for various Defence applications has been covered.

  19. Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability

    International Nuclear Information System (INIS)

    Soustiel, Jean F.; Mor, Nadav; Zaaroor, Menashe; Goldsher, Dorith

    2006-01-01

    There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis. A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol. MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV. The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account. (orig.)

  20. Prognostic value of stress myocardial perfusion positron emission tomography: results from a multicenter observational registry.

    Science.gov (United States)

    Dorbala, Sharmila; Di Carli, Marcelo F; Beanlands, Rob S; Merhige, Michael E; Williams, Brent A; Veledar, Emir; Chow, Benjamin J W; Min, James K; Pencina, Michael J; Berman, Daniel S; Shaw, Leslee J

    2013-01-15

    The primary objective of this multicenter registry was to study the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) and the improved classification of risk in a large cohort of patients with suspected or known coronary artery disease (CAD). Limited prognostic data are available for MPI with PET. A total of 7,061 patients from 4 centers underwent a clinically indicated rest/stress rubidium-82 PET MPI, with a median follow-up of 2.2 years. The primary outcome of this study was cardiac death (n = 169), and the secondary outcome was all-cause death (n = 570). Net reclassification improvement (NRI) and integrated discrimination analyses were performed. Risk-adjusted hazard of cardiac death increased with each 10% myocardium abnormal with mildly, moderately, or severely abnormal stress PET (hazard ratio [HR]: 2.3 [95% CI: 1.4 to 3.8; p = 0.001], HR: 4.2 [95% CI: 2.3 to 7.5; p statistic 0.805 [95% CI: 0.772 to 0.838] to 0.839 [95% CI: 0.809 to 0.869]) and risk reclassification for cardiac death (NRI 0.116 [95% CI: 0.021 to 0.210]), with smaller improvements in risk assessment for all-cause death. In patients with known or suspected CAD, the extent and severity of ischemia and scar on PET MPI provided powerful and incremental risk estimates of cardiac death and all-cause death compared with traditional coronary risk factors. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  1. Computed tomography angiography in acute stroke (revisiting the 4Ps of imaging).

    Science.gov (United States)

    Varadharajan, Shriram; Saini, Jitender; Acharya, Ullas V; Gupta, Arun Kumar

    2016-02-01

    Imaging in acute stroke has traditionally focussed on the 4Ps-parenchyma, pipes, perfusion, and penumbra-and has increasingly relied upon advanced techniques including magnetic resonance imaging to evaluate such patients. However, as per European Magnetic Resonance Forum estimates, the availability of magnetic resonance imaging scanners for the general population in India (0.5 per million inhabitants) is quite low as compared to Europe (11 per million) and United States (35 per million), with most of them only present in urban cities. On the other hand, computed tomography (CT) is more widely available and has reduced scanning duration. Computed tomography angiography of cervical and intracranial vessels is relatively simpler to perform with extended coverage and can provide all pertinent information required in such patients. This imaging review will discuss relevant imaging findings on CT angiography in patients with acute ischemic stroke through illustrated cases. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. 123I-IMP single photon emission computed tomography (SPECT) study in childhood epilepsy

    International Nuclear Information System (INIS)

    Hara, Masafumi; Shimomura, Osamu; Kojima, Akihiro; Izunaga, Hiroshi; Tomiguchi, Seiji; Hirota, Yoshihisa; Taku, Keiichi; Miike, Teruhisa; Takahashi, Mutsumasa

    1990-01-01

    N-isopropyl-p[ 123 I]-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), X-ray computed tomography (X-CT) and magnetic resonance imaging (MRI) were performed in 18 children with idiopathic seizures. In children with idiopathic seizures SPECT identified abnormal lesions in the highest rate (50%) compared with X-CT (11%) and MRI (13%), but the findings of SPECT poorly correlated with the foci on electroencephalography (EEG). Idiopathic epilepsy with abnormal uptake on SPECT was refractory to medical treatments and frequently associated with mental and/or developmental retardation. Perfusion defects identified on SPECT probably influenced the development of the brains in children. IMP SPECT is useful in the diagnosis and medical treatment in children with seizures. (author)

  3. [Contribution of X-ray computed tomography in the evaluation of kidney performance].

    Science.gov (United States)

    Lemoine, Sandrine; Rognant, Nicolas; Collet-Benzaquen, Diane; Juillard, Laurent

    2012-07-01

    X-ray computer assisted tomography scanner is an imaging method based on the use of X-ray attenuation in tissue. This attenuation is proportional to the density of the tissue (without or after contrast media injection) in each pixel image of the image. Spiral scanner, the electron beam computed tomography (EBCT) scanner and multidetector computed tomography scanner allow renal anatomical measurements, such as cortical and medullary volume, but also the measurement of renal functional parameters, such as regional renal perfusion, renal blood flow and glomerular filtration rate. These functional parameters are extracted from the modeling of the kinetics of the contrast media concentration in the vascular space and the renal tissue, using two main mathematical models (the gamma variate model and the Patlak model). Renal functional imaging allows measuring quantitative parameters on each kidney separately, in a non-invasive manner, providing significant opportunities in nephrology, both for experimental and clinical studies. However, this method uses contrast media that may alter renal function, thus limiting its use in patients with chronic renal failure. Moreover, the increase irradiation delivered to the patient with multi detector computed tomography (MDCT) should be considered. Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  4. Computed tomography findings in convergent strabismus fixus

    International Nuclear Information System (INIS)

    Ohta, Michitaka; Iwashige, Hiroyasu; Hayashi, Takao; Maruo, Toshio

    1995-01-01

    X-ray computed tomography (CT) of the eyeball and orbit revealed the cause of eye movement disorder in convergent strabismus fixus. The findings suggest that the disease can be diagnosed and treated at an early stage. Twelve cases of progressive esotropia with high myopia and 20 cases with normal visual acuity served as subjects in this study. The CT slice was parallel to the German horizontal plane, and the lens and medial and lateral rectus muscles were scanned. The average axial length of the affected eyes was significantly longer than in normal eyes. In progressive esotropia, the characteristic CT findings are an elongated eyeball, mechanical contact between the eyeball and lateral wall of the orbit, and a downward displacement of the lateral rectus muscle. Thus, it is reasonable to conclude that eye movement disorder in convergent strabismus fixus results from weakness of the lateral rectus muscle which has been displaced downward due to compression of the eyeball against the orbital wall. (author)

  5. Technological Evolution on Computed Tomography and Radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Bruno Barros; Ribeiro, Nuno Carrilho [Servico de Radiologia, Hospital de Curry Cabral, Rua da Beneficencia, 8, 1069-166 Lisboa (Portugal)

    2006-05-15

    Computed Tomography (CT) has been available since the 70s and has experienced a dramatic technical evolution. Multi-detector technology is our current standard, offering capabilities unthinkable only a decade ago. Yet, we must nor forget the ionizing nature of CT's scanning energy (X-rays). It represents the most important cause of medical-associated radiation exposure to the general public, with a trend to increase. It is compulsory to intervene with the objective of dose reduction, following ALARA policies. Currently there are some technical advances that allow dose reduction, without sacrificing diagnostic image capabilities. However, human intervention is also essential. We must keep investment on education so that CT exams are don when they are really useful in clinical decision. Alternative techniques should also be considered. Image quality must not be searched disregarding the biological effects of radiation. Generally, it is possible to obtain clinically acceptable images with lower dose protocols. (author)

  6. Computed tomography of the traumatized abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Young Woon; Baik, Seung Kug; Lee, Jong Yul; Choi, Han Yong; Kim, Bong Ki [Wallace Memotial Baptist Hospital, Pusan (Korea, Republic of)

    1989-02-15

    Forty-seven patients with abdominal and retroperitoneal injuries were examined by computed tomography(CT). We analyzed the results of 47 patients who were confirmed of abdominal injuries by operation, clinical follow up, and repeated radiologic examinations. 1. the type of trauma was blunt in 38 patients (81%) and penerating in 9 patients (19%) 2. There were 14 splenic, 11 renal, 9 hepatic, 6 retroperitoneal, 4 pancreatic, and 3 alimentary tract injuries. 3. The patients who had been treated by conservative management were 23.4% (surgical treatment,76.6%). 4. The six ratio was 4.9 : 1.0 (male ; female). 5. CT has major advantage over plain radiography, radionuclide imaging, and angiography in assessment of trauma-induced injuries.

  7. Computed tomography of the traumatized abdomen

    International Nuclear Information System (INIS)

    Yoon, Young Woon; Baik, Seung Kug; Lee, Jong Yul; Choi, Han Yong; Kim, Bong Ki

    1989-01-01

    Forty-seven patients with abdominal and retroperitoneal injuries were examined by computed tomography(CT). We analyzed the results of 47 patients who were confirmed of abdominal injuries by operation, clinical follow up, and repeated radiologic examinations. 1. the type of trauma was blunt in 38 patients (81%) and penerating in 9 patients (19%) 2. There were 14 splenic, 11 renal, 9 hepatic, 6 retroperitoneal, 4 pancreatic, and 3 alimentary tract injuries. 3. The patients who had been treated by conservative management were 23.4% (surgical treatment,76.6%). 4. The six ratio was 4.9 : 1.0 (male ; female). 5. CT has major advantage over plain radiography, radionuclide imaging, and angiography in assessment of trauma-induced injuries

  8. Multidetector Computed Tomography and Neuroendocrine Pancreaticoduodenal Tumors

    International Nuclear Information System (INIS)

    Rappeport, E.D.; Palnaes Hansen, C.; Kjaer, A.; Knigge, U.

    2006-01-01

    Purpose: To investigate the accuracy of dedicated pancreatic multidetector computed tomography (MDCT) in the diagnosis of neuroendocrine pancreaticoduodenal tumors (NPTs). Material and Methods: MDCT and other imaging studies in patients with suspected NPTs were identified. Thirty dedicated MDCT studies were done in 23 patients. Fourteen patients (16 operations) subsequently had surgery. Imaging reports were reviewed and findings compared with surgical findings and findings in other imaging studies. Results: Patients with surgery : 19 NPTs (16 extrapancreatic gastrinomas and 3 pancreatic NPTs) were identified at surgery. MDCT identified 16 and somatostatin receptor scintigraphy (SRS) 11 out of 19 tumors. Endoscopic ultrasound detected 11 out of 14 NPTs. Patients without surgery : In 4 out of 9 patients, no NPTs were identified at MDCT. Conclusion: Dedicated MDCT of the pancreas can identify many NPTs, including small duodenal and periduodenal tumors, and the detection rate is better than reported in the older literature on CT

  9. Quality control in quantitative computed tomography

    International Nuclear Information System (INIS)

    Jessen, K.A.; Joergensen, J.

    1989-01-01

    Computed tomography (CT) has for several years been an indispensable tool in diagnostic radiology, but it is only recently that extraction of quantitative information from CT images has been of practical clinical value. Only careful control of the scan parameters, and especially the scan geometry, allows useful information to be obtained; and it can be demonstrated by simple phantom measurements how sensitive a CT system can be to variations in size, shape and position of the phantom in the gantry aperture. Significant differences exist between systems that are not manifested in normal control of image quality and general performance tests. Therefore an actual system has to be analysed for its suitability for quantitative use of the images before critical clinical applications are justified. (author)

  10. Technological Evolution on Computed Tomography and Radioprotection

    International Nuclear Information System (INIS)

    Leite, Bruno Barros; Ribeiro, Nuno Carrilho

    2006-01-01

    Computed Tomography (CT) has been available since the 70s and has experienced a dramatic technical evolution. Multi-detector technology is our current standard, offering capabilities unthinkable only a decade ago. Yet, we must nor forget the ionizing nature of CT's scanning energy (X-rays). It represents the most important cause of medical-associated radiation exposure to the general public, with a trend to increase. It is compulsory to intervene with the objective of dose reduction, following ALARA policies. Currently there are some technical advances that allow dose reduction, without sacrificing diagnostic image capabilities. However, human intervention is also essential. We must keep investment on education so that CT exams are don when they are really useful in clinical decision. Alternative techniques should also be considered. Image quality must not be searched disregarding the biological effects of radiation. Generally, it is possible to obtain clinically acceptable images with lower dose protocols. (author)

  11. The temporomandibular joint in computed tomography

    International Nuclear Information System (INIS)

    Pomaroli, A.; Lener, M.

    1988-01-01

    The first part describes details of the temporomandibular joint (TMJ) which are of interest for the examination by computed tomography. In the second part three new planes of reference for scanning of the ventral, middle or dorsal part of the joint are presented. CT examinations were made of 14 TMJ of corpses to identify the medial or ventral parts of the articular disc, medial wall of the articular capsule and medial or triangular recessus to achieve this were scanned the corpses with opened and closed mouth, as well as with closed sets of teeth using a sort of hypomochlion in the molar region to distract the TMJ. More over we applicated different contrast mediums like air and niob. (orig.) [de

  12. Neutron stimulated emission computed tomography: Background corrections

    International Nuclear Information System (INIS)

    Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

    2007-01-01

    Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

  13. Computed tomography study of otitis media

    International Nuclear Information System (INIS)

    Bahia, Paulo Roberto Valle; Marchiori, Edson

    1997-01-01

    The findings of computed tomography (CT) of 89 patients clinically suspected of having otitis media were studied in this work. Such results were compared to clinical diagnosis, otoscopy, surgical findings and previous data. Among the results of our analysis, we studied seven patients with acute otitis media and 83 patients with chronic otitis media. The patients with acute otitis media have undergone CT examinations to evaluate possible spread to central nervous system. The diagnosis of cholesteatoma, its extension and complications were the main indication. for chronic otitis media study. The main findings of the cholesteatomatous otitis were the occupation of the epitympanun, the bony wall destruction and the ossicular chain erosion. The CT demonstrated a great sensibility to diagnose the cholesteatoma. (author)

  14. Diagnosis of cerebral disorders using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, K [Tokyo Women' s Medical Coll. (Japan)

    1980-01-01

    Computed tomography (CT), which makes differential diagnosis of cerebral disorders possible, was applied in the diagnosis of hypertensive intracerebral hemorrhage, cerebral thrombosis, subarachnoid hemorrhage, and cerebrovascular Moyamoya disease. CT findings of hypertensive intracerebral hemorrhage showed the localization, volume, and direction of hematoma, and the classification of hematoma according to CT findings was highly correlated to the clinical symptoms of the patients. CT findings of cerebral thrombosis showed the extension of the lesion to be a low density area, but there were many cases in which they did not show a low density area immediately after an attack. CT findings of subarachnoid hemorrhage were very useful in the diagnosis of intracerebral hematoma, ventricular hematoma, and intracranial hematoma secondary to this disease. However, it was very difficult to diagnose cerebrovascular Moyamoya disease by means of CT.

  15. Diagnosis of cerebral disorders using computed tomography

    International Nuclear Information System (INIS)

    Kitamura, Koichi

    1980-01-01

    Computed tomography (CT), which makes differential diagnosis of cerebral disorders possible, was applied in the diagnosis of hypertensive intracerebral hemorrhage, cerebral thrombosis, subarachnoid hemorrhage, and cerebrovascular Moyamoya disease. CT findings of hypertensive intracerebral hemorrhage showed the localization, volume, and direction of hematoma, and the classification of hematoma according to CT findings was highly correlated to the clinical symptoms of the patients. CT findings of cerebral thrombosis showed the extension of the lesion to be a low density area, but there were many cases in which they did not show a low density area immediately after an attack. CT findings of subarachnoid hemorrhage were very useful in the diagnosis of intracerebral hematoma, ventricular hematoma, and intracranial hematoma secondary to this disease. However, it was very difficult to diagnose cerebrovascular Moyamoya disease by means of CT. (Nishio, M.)

  16. The dynamic micro computed tomography at SSRF

    Science.gov (United States)

    Chen, R.; Xu, L.; Du, G.; Deng, B.; Xie, H.; Xiao, T.

    2018-05-01

    Synchrotron radiation micro-computed tomography (SR-μCT) is a critical technique for quantitative characterizing the 3D internal structure of samples, recently the dynamic SR-μCT has been attracting vast attention since it can evaluate the three-dimensional structure evolution of a sample. A dynamic μCT method, which is based on monochromatic beam, was developed at the X-ray Imaging and Biomedical Application Beamline at Shanghai Synchrotron Radiation Facility, by combining the compressed sensing based CT reconstruction algorithm and hardware upgrade. The monochromatic beam based method can achieve quantitative information, and lower dose than the white beam base method in which the lower energy beam is absorbed by the sample rather than contribute to the final imaging signal. The developed method is successfully used to investigate the compression of the air sac during respiration in a bell cricket, providing new knowledge for further research on the insect respiratory system.

  17. Computed tomography of the pituitary gland

    International Nuclear Information System (INIS)

    Bonneville, J.F.; Cattin, F.; Dietemann, J.L.

    1986-01-01

    This book is written entirely to include the imaging of the pituitary gland by computed tomography (CT). The first three chapters illustrated technical aspects of scanning, anatomic depiction of the gland by CT, and the use of dynamic CT scanning for detecting and displaying abnormalities. The chapters discuss and illustrate various types of pathologic processes in and around the pituitary gland. One short but very helpful chapter demonstrates potential pitfalls due to the combination of anatomic variants and the geometry of CT sections. Some illustrations of disease processed are depicted by magnetic resonance imaging. All major types of pituitary diseases are illustrated. Lists of readily available English-language references are available. A small subject index is provided at the end of the book in which the illustrations are identified by use of a special numeric front

  18. Ward nurses' knowledge of computed tomography scanning.

    Science.gov (United States)

    Majeed, M A; Nayeemuddin, M; Christie, M

    Patients benefit from and are reassured by advance information on procedures that they are to undergo. Ward nurses should have adequate knowledge of radiological investigations to ensure proper patient preparation and good interdepartmental communication to avoid delays and cancellations. This study was conducted to assess the ward nurses' knowledge of the process of computed tomography (CT) scanning. One hundred and twenty qualified nurses were asked to complete a questionnaire regarding CT scanning. The findings revealed a suboptimal level of awareness about the process. This is probably due to lack of formal teaching for nurses on the wards in regards the different radiological procedures and patient preparation. There is a strong case for better educational talks on rapidly changing radiological techniques for ward staff to ensure high-quality patient care.

  19. Computed tomography study of Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Arai, H; Kobayashi, K; Ikeda, Y; Nagao, Y; Ogihara, R; Kosaka, K

    1983-01-01

    Computed tomography (CT) was used to study cerebral atrophy in 18 patients with clinically diagnosed Alzheimer's disease of presenile type and in 14 healthy age-matched subjects as controls. Using the computerized planimetric method, Subarachnoid Space Volume Index and Ventricle Volume Index were calculated as the measure of cortical atrophy and ventricular dilatation respectively. From the results the following conclusions were drawn: 1. The cerebral atrophy in Alzheimer patients could be attributable to the disease processes rather than to physiological aging of the brain. 2. The degree of atrophy increases in parallel with the progress of the clinical stage, and the cortical atrophy is already apparent at an early stage, whereas the ventricular dilatation becomes pronounced at later stages. 3. CT could be one of the most useful clinical tests available for the diagnosis of Alzheimer's disease.

  20. Practical techniques for pediatric computed tomography

    International Nuclear Information System (INIS)

    Fitz, C.R.; Harwood-Nash, D.C.; Kirks, D.R.; Kaufman, R.A.; Berger, P.E.; Kuhn, J.P.; Siegel, M.J.

    1983-01-01

    Dr. Donald Kirks has assembled this section on Practical Techniques for Pediatric Computed Tomography. The material is based on a presentation in the Special Interest session at the 25th Annual Meeting of the Society for Pediatric Radiology in New Orleans, Louisiana, USA in 1982. Meticulous attention to detail and technique is required to ensure an optimal CT examination. CT techniques specifically applicable to infants and children have not been disseminated in the radiology literature and in this respect it may rightly be observed that ''the child is not a small adult''. What follows is a ''cookbook'' prepared by seven participants and it is printed in Pediatric Radiology, in outline form, as a statement of individual preferences for pediatric CT techniques. This outline gives concise explanation of techniques and permits prompt dissemination of information. (orig.)