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Sample records for multidetector-row ct angiography

  1. 64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model

    PubMed Central

    Holalkere, N-S; Matthes, K; Kalva, S P; Brugge, W R; Sahani, D V

    2011-01-01

    Objective In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml–1) and high-concentration contrast media (HCCM) (370 mg I ml–1) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose. Methods CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml–1), Group B (HCCM; 370 mg I ml–1) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg–1) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test. Results The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose. Conclusion 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced. PMID:21081582

  2. 64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model.

    PubMed

    Holalkere, N-S; Matthes, K; Kalva, S P; Brugge, W R; Sahani, D V

    2011-03-01

    In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml(-1)) and high-concentration contrast media (HCCM) (370 mg I ml(-1)) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose. CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml(-1)), Group B (HCCM; 370 mg I ml(-1)) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg(-1)) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test. The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose. 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced.

  3. Impaired left ventricular function has a detrimental effect on image quality in multi-detector row CT coronary angiography.

    PubMed

    Manghat, N E; Morgan-Hughes, G J; Shaw, S R; Marshall, A J; Roobottom, C A

    2008-04-01

    To determine whether there is a relationship between left ventricular (LV) haemodynamic parameters, circulation times, and arterial contrast opacification that might affect the image quality of computed tomography (CT) coronary angiography. Thirty-six patients were included in the study: 18 with cardiomyopathy (CM) and LV dilatation of suspected ischaemic aetiology [age 57.9+/-13.7 years, range 30-77 years; 14 male, four female; body mass index (BMI)=27.7+/-4.5, range 25.5-31.8] and 18 controls (age 62.3+/-9.4 years, range 47-89 years; 10 male, eight female; BMI 27.8+/-6.6; range 19.2-33.6). Coronary artery image quality was assessed using a three-point visual scale; contrast medium circulation times, aortic root contrast attenuation, and LV functional parameters were studied. Visually reduced contrast opacification impaired image quality more often in the CM group than the control group (27.4 versus 5.1%). A total of 55.6% CM patients had a contrast transit time ranging from 30-75 s; the number of "unassessable" segments increased with increasing transit time conforming to a fitted quadratic model (R2=0.74). The relationship between LV ejection fraction and contrast attenuation may also conform to a quadratic model (R2=0.71). LV haemodynamics influence coronary artery opacification using cardiac CT, and users imaging this subgroup must do so with the knowledge of this potential pitfall. The results indicate the need for further studies examining CT protocols in this clinical subgroup.

  4. Role of multidetector-row CT in assessing the source of arterial haemorrhage in patients with pelvic vascular trauma. Comparison with angiography.

    PubMed

    Pinto, A; Niola, R; Tortora, G; Ponticiello, G; Russo, G; Di Nuzzo, L; Gagliardi, N; Scaglione, M; Merola, S; Stavolo, C; Maglione, F; Romano, L

    2010-06-01

    We investigated the role of multidetector-row computed tomography (MDCT) in identifying active bleeding and its source in polytrauma patients with pelvic vascular injuries with or without associated fractures of the pelvis. From January 2003 to December 2007, 28 patients (19 men and nine women, age range 16-80 years) with acute symptoms from blunt pelvic trauma and a drop in haematocrit underwent MDCT and angiography. Conventional radiography of the pelvis was performed in all patients at the time of admission to the emergency department. MDCT was performed with a four-row unit in 15 patients and a 16-row unit in the remaining 13 patients. The study included whole-body CT to identify craniocerebral, vertebral, thoracic, abdominal and pelvic injuries. CT was performed before and after rapid infusion (4-5 ml/s) of intravenous contrast material (120 ml) using a power injector. A triphasic contrast-enhanced study was performed in all patients. MDCT images were transferred to a workstation to assess pelvic fracture, site of haematoma and active extravasation of contrast material, visibility of possible vascular injuries and associated traumatic lesions. At angiography, an abdominal and pelvic aortogram was obtained in all cases before selective catheterisation of the internal iliac arteries and superselective catheterisation of their branches for embolisation purposes. Results related to identifying the source of bleeding at MDCT were compared with sites of bleeding or vascular injury identified by selective pelvic angiography. The sensitivity and positive predictive value (PPV) of MDCT were determined. MDCT allowed us to identify pelvic bleeding in 21/28 patients (75%), with most cases being detected in the delayed contrast-enhanced phase (13/21 cases, 61.9%). Injured arteries were identified on MDCT in 12/21 cases (57%): the obturator artery (n=9), internal iliac artery (n=6), internal pudendal artery (n=6) and superior gluteal artery (n=5) were most frequently

  5. Diagnostic Imaging of Pulmonary Thromboembolism by Multidetector-row CT

    PubMed Central

    2010-01-01

    For diagnosis of pulmonary thromboembolism, multidetector-row computed tomography (CT) is a minimally invasive imaging technique that can be performed rapidly with high sensitivity and specificity, and has been increasingly employed as the imaging modality of first choice for this disease. Since deep vein thrombosis in the legs, which is important as a thrombus source, can be evaluated immediately after the diagnosis of pulmonary thromboembolism, this diagnostic method is considered to provide important information when deciding on a comprehensive therapeutic strategy for this disease. PMID:23555409

  6. Multi-detector row CT of pancreatic islet cell tumors.

    PubMed

    Horton, Karen M; Hruban, Ralph H; Yeo, Charles; Fishman, Elliot K

    2006-01-01

    Pancreatic islet cell tumors (ICTs) are neuroendocrine neoplasms that produce and secrete hormones to a variable degree. These neoplasms can present a diagnostic challenge, both clinically and radiologically. ICTs can be classified as either syndromic or nonsyndromic on the basis of their clinical manifestations. Multi-detector row computed tomography (CT) plays an important role in the diagnosis and staging of both syndromic and nonsyndromic ICTs. In general, syndromic ICTs are less than 3 cm in size. They are typically hyperenhancing and are usually best seen on CT scans obtained during the arterial phase. Nonsyndromic ICTs tend to be larger than syndromic ICTs at presentation and are more likely to be cystic or necrotic. It is important for the radiologist to be familiar with appropriate CT protocol for the evaluation of patients with suspected pancreatic ICT and to understand the variable CT appearances of these neoplasms. (c) RSNA, 2006.

  7. Classification of lung area using multidetector-row CT images

    NASA Astrophysics Data System (ADS)

    Mukaibo, Tsutomu; Kawata, Yoshiki; Niki, Noboru; Ohmatsu, Hironobu; Kakinuma, Ryutaro; Eguchi, Kenji; Kaneko, Masahiro; Moriyama, Noriyuki

    2002-05-01

    Recently, we can get high quality images in the short time for the progress of X-ray CT scanner. And the three dimensional (3-D) analysis of pulmonary organs using multidetector-row CT (MDCT) images, is expected. This paper presents a method for classifying lung area into each lobe using pulmonary MDCT images of the whole lung area. It is possible to recognize the position of nodule by classifying lung area into these lobes. The structure of lungs differs on the right one and left one. The right lung is divided into three domains by major fissure and minor fissure. And, the left lung is divided into two domains by major fissure. Watching MDCT images carefully, we find that the surroundings of fissures have few blood vessels. Therefore, lung area is classified by extraction of the domain that the distance from pulmonary blood vessels is large and connective search of these extracted domains. These extraction and search are realized by 3-D weighted Hough transform.

  8. Recent technologic advances in multi-detector row cardiac CT.

    PubMed

    Halliburton, Sandra Simon

    2009-11-01

    Recent technical advances in multi-detector row CT have resulted in lower radiation dose, improved temporal and spatial resolution, decreased scan time, and improved tissue differentiation. Lower radiation doses have resulted from the use of pre-patient z collimators, the availability of thin-slice axial data acquisition, the increased efficiency of ECG-based tube current modulation, and the implementation of iterative reconstruction algorithms. Faster gantry rotation and the simultaneous use of two x-ray sources have led to improvements in temporal resolution, and gains in spatial resolution have been achieved through application of the flying x-ray focal-spot technique in the z-direction. Shorter scan times have resulted from the design of detector arrays with increasing numbers of detector rows and through the simultaneous use of two x-ray sources to allow higher helical pitch. Some improvement in tissue differentiation has been achieved with dual energy CT. This article discusses these recent technical advances in detail.

  9. Noninvasive imaging of coronary arteries: current and future role of multi-detector row CT.

    PubMed

    Schoenhagen, Paul; Halliburton, Sandra S; Stillman, Arthur E; Kuzmiak, Stacie A; Nissen, Steven E; Tuzcu, E Murat; White, Richard D

    2004-07-01

    While invasive imaging techniques, especially selective conventional coronary angiography, will remain vital to planning and guiding catheter-based and surgical treatment of significantly stenotic coronary lesions, the comprehensive and serial assessment of asymptomatic or minimally symptomatic stages of coronary artery disease (CAD) for preventive purposes will eventually need to rely on noninvasive imaging techniques. Cardiovascular imaging with tomographic modalities, including computed tomography (CT) and magnetic resonance imaging, has great potential for providing valuable information. This review article will describe the current and future role of cardiac CT, and in particular that of multi-detector row CT, for imaging of atherosclerotic and other pathologic changes of the coronary arteries. It will describe how tomographic coronary imaging may eventually supplement traditional angiographic techniques in understanding the patterns of atherosclerotic CAD development.

  10. Automated multidetector row CT dataset segmentation with an interactive watershed transform (IWT) algorithm: Part 2. Body CT angiographic and orthopedic applications.

    PubMed

    Johnson, Pamela T; Hahn, Horst K; Heath, David G; Fishman, Elliot K

    2008-12-01

    The preceding manuscript describes the principles behind the Interactive Watershed Transform (IWT) segmentation tool. The purpose of this manuscript is to illustrate the clinical utility of this editing technique for body multidetector row computed tomography (MDCT) imaging. A series of cases demonstrates clinical applications where automated segmentation of skeletal structures with IWT is most useful. Both CT angiography and orthopedic applications are presented.

  11. Computed tomography angiography: state-of-the-art imaging using multidetector-row technology.

    PubMed

    Napoli, Alessandro; Fleischmann, Dominik; Chan, Frandics P; Catalano, Carlo; Hellinger, Jeffrey C; Passariello, Roberto; Rubin, Geoffrey D

    2004-01-01

    Multidetector-row computed tomography (MDCT) is an essential diagnostic modality for many clinical algorithms. This is particularly true with regard to the evaluation of cardiovascular disease. As a result of increased image acquisition speed, improved spatial resolution, and greater scan volume, MDCT angiography (computed tomography angiography [CTA]) has become an excellent noninvasive imaging technique, replacing intra-arterial digital subtraction angiography for most vascular territories. The clinical success of CTA depends on precise synchronization of image acquisition with optimal vascular enhancement. As technology continuously evolves, however, this task can be challenging. It remains important to have a fundamental knowledge of the principles behind technical parameters and contrast medium administration. This article reviews these essential principles, followed by an overview of current clinical applications.

  12. Relationship between noise, dose, and pitch in cardiac multi-detector row CT.

    PubMed

    Primak, Andrew N; McCollough, Cynthia H; Bruesewitz, Michael R; Zhang, Jie; Fletcher, Joel G

    2006-01-01

    In spiral computed tomography (CT), dose is always inversely proportional to pitch. However, the relationship between noise and pitch (and hence noise and dose) depends on the scanner type (single vs multi-detector row) and reconstruction mode (cardiac vs noncardiac). In single detector row spiral CT, noise is independent of pitch. Conversely, in noncardiac multi-detector row CT, noise depends on pitch because the spiral interpolation algorithm makes use of redundant data from different detector rows to decrease noise for pitch values less than 1 (and increase noise for pitch values > 1). However, in cardiac spiral CT, redundant data cannot be used because such data averaging would degrade the temporal resolution. Therefore, the behavior of noise versus pitch returns to the single detector row paradigm, with noise being independent of pitch. Consequently, since faster rotation times require lower pitch values in cardiac multi-detector row CT, dose is increased without a commensurate decrease in noise. Thus, the use of faster rotation times will improve temporal resolution, not alter noise, and increase dose. For a particular application, the higher dose resulting from faster rotation speeds should be justified by the clinical benefits of the improved temporal resolution.

  13. [Multidetector row CT in assessment of coronary artery calcification on hemodialisis].

    PubMed

    Caro, P; Delgado, R; Dapena, F; Núñez, A

    2007-01-01

    Vascular calcification is a strong predictor of cardiovascular and all-cause mortality. Coronary artery calcification is more frequent, more extensive and progresses more rapidly in CKD than in general population. They are also considered a marker of coronary heart disease, with high prevalence and functional significance. It suggests that detection and surveillance may be worthwhile in general clinical practice. New non-invasive image techniques, like Multi-detector row CT, a type of spiral scanner, assess density and volume of calcification at multiple sites and allow quantitative scoring of vascular calcification using calcium scores analogous to those from electron-beam CT. We have assessed and quantified coronary artery calcification with 16 multidetector row CT in 44 patients on hemodialysis and their relationship with several cardiovascular risk factors. Coronary artery calcification prevalence was of 84 % with mean calcium score of 1580 +/- 2010 ( r 0-9844) with calcium score > 400 in 66% of patients. It was usually multiple, affecting more than two vessels in more than 50%. In all but one patient, left anterior descending artery was involved with higher calcium score level at right coronary artery. Advanced age, male, diabetes, smoking, more morbidity, cerebrovascular disease previous, and calcium-binders phosphate and analogous vitamin D treatment would seem to be associated with coronary artery calcification. Coronary artery calcification is very frequent and extensive, usually multiple and associated to modifiable risk factors in hemodialysis patients. Multi-detector-row CT seems an effective, suitable, readily applicable method to assess and quantify coronary artery calcification.

  14. Intercostal Artery Supplying Hepatocellular Carcinoma: Demonstration of a Tumor Feeder by C-arm CT and Multidetector Row CT

    SciTech Connect

    Kim, Hyo-Cheol Chung, Jin Wook; Lee, In Joon; An, Sangbu; Seong, Nak Jong; Son, Kyu Ri; Jae, Hwan Jun; Park, Jae Hyung

    2011-02-15

    This study was designed to describe tumor feeders from the intercostal artery supplying hepatocellular carcinoma (HCC) on C-arm CT and multidetector row CT. From March 2008 to May 2009, C-arm CT of the intercostal artery was prospectively performed in 24 HCC patients. Two interventional radiologists, who performed C-arm CT, evaluated tumor feeders on C-arm CT and multidetector row CT scans by consensus. In total, 35 intercostal arteries were examined by C-arm CT. All tumor feeders except one showed a sharp upward turn at or near the costochondral junction. On axial C-arm CT images, all tumor feeders were observed as an enhancing dot in the upper intercostal space along the diaphragm. On multidetector CT scans, 17 tumor feeders were observed and 18 were not. Tumor feeders from the intercostal artery are observed as an enhancing dot along the diaphragm on C-arm CT and can be seen on multidetector row CT in approximately half of patients.

  15. Transcatheter Arterial Embolization Therapy for a Hypoplastic Pelvic Kidney with a Single Vaginal Ectopic Ureter to Control Incontinence: The Usefulness of Three-Dimensional CT Angiography Using Multidetector-Row Helical CT

    SciTech Connect

    Kudoh, Kouichi Kadota, Masataka; Nakayama, Yoshiharu; Imuta, Masanori; Yasuda, Tsuyoshi; Yamashita, Yasuyuki; Inadome, Akito; Yoshida, Masaki; Ueda, Shouichi

    2003-09-15

    A girl with continuous urinary incontinence was successfully treated by angiographic embolization of a hypoplastic pelvic kidney with a single unilateral vaginal ectopic opening of the ureter. For this intervention, CT angiography was useful for detecting the corresponding renal artery of the hypoplastic kidney.

  16. Acute appendicitis: comparison of low-dose and standard-dose unenhanced multi-detector row CT.

    PubMed

    Keyzer, Caroline; Tack, Denis; de Maertelaer, Viviane; Bohy, Pascale; Gevenois, Pierre Alain; Van Gansbeke, Daniel

    2004-07-01

    To prospectively compare low- and standard-dose unenhanced multi-detector row computed tomography (CT) in patients suspected of having acute appendicitis. Ninety-five consecutive patients underwent two unenhanced multi-detector row CT examinations with 4 x 2.5-mm collimation, 120 kVp, and 30 and 100 effective mAs. Two radiologists independently read the images obtained at each dose during two sessions. Readers recorded visualization of the appendix and presence of gas in its lumen, appendicolith, periappendiceal fat stranding, cecal wall thickening, and abscess or phlegmon to measure the diameter of the appendix and to propose diagnosis (appendicitis or alternative). Data were compared according to dose and reader, with definite diagnosis established on basis of surgical findings (n = 37) or clinical follow-up. chi(2) tests and logistic regression were used. Measurement agreements were assessed with Cohen kappa statistics. Twenty-nine patients had a definite diagnosis of appendicitis. No difference was observed between the frequency of visualization of the appendix (P =.874) neither in its mean diameter (P =.101-.696, according to readers and sessions) nor in the readers' overall diagnosis (P =.788) at each dose. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each sign were not different between doses. Fat stranding, appendicolith, and diameter were the most predictive signs, regardless of dose, yielding approximately 90% of correct diagnoses. The ability to propose a correct alternative diagnosis was not influenced by the dose. Low-dose unenhanced multi-detector row CT has similar diagnostic performance as standard-dose unenhanced multi-detector row CT for the diagnosis of acute appendicitis. Copyright RSNA, 2004

  17. Bronchial anatomy of left lung: a study of multi-detector row CT.

    PubMed

    Zhao, Xinya; Ju, Yuanrong; Liu, Cheng; Li, Jianfeng; Huang, Min; Sun, Jian; Wang, Tao

    2009-02-01

    Familiarity with prevailing pattern and variations in the bronchial tree is not only essential for the anatomist to explain bronchial variation in bronchial specimens, but also useful for guiding bronchoscopy and instructing pulmonary segmental resection. The purpose of this study was designed to demonstrate various branching patterns of left lung with 3D images, with special attention given to identify the major types at transverse thin-section CT. Two hundred and sixteen patients with routine thorax scans were enrolled. The images of bronchial tree, virtual bronchoscopy were reconstructed using post-processing technique of multi-detector row CT. We attempted to classify the segmental bronchi by interpreting the post-processing images, and identified them in transverse thin-section CT. Our results showed that the segmental bronchial ramifications of the left superior lobe were classified into three types mainly, i.e., common stem of apical and posterior segmental bronchi (64%, 138/216); trifurcation (23%, 50/216); common stem of apical and anterior segmental bronchi (10%, 22/216), and they could be identified at two typical sections of transverse thin-section CT. There were two major types in left basal segmental bronchi, i.e., bifurcation (75%, 163/216), trifurcation (18%, 39/216), and they could also be identified at two typical sections of transverse thin-section CT. In conclusion, our study have offered simplified branching patterns of bronchi and demonstrated various unusual bronchial branching patterns perfectly with 3D images, and have also revealed how to identify the main branching patterns in transverse thin-section CT.

  18. Multi-detector row CT scanning in Paleoanthropology at various tube current settings and scanning mode.

    PubMed

    Badawi-Fayad, J; Yazbeck, C; Balzeau, A; Nguyen, T H; Istoc, A; Grimaud-Hervé, D; Cabanis, E- A

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required.

  19. Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT

    SciTech Connect

    Flohr, T. G.; Stierstorfer, K.; Suess, C.; Schmidt, B.; Primak, A. N.; McCollough, C. H.

    2007-05-15

    We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the z-axis direction for a routine medical multi-detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the z-axis direction in combination with tantalum grids that are inserted in front of the multi-row detector to reduce the aperture of the detector elements both in-plane and in the z-axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of 0.4 mm (measured full width at half maximum=0.45 mm) can be reconstructed in spiral mode on a CT system with a detector configuration of 32x0.6 mm. The measured 2% value of the in-plane modulation transfer function (MTF) is 20.4 lp/cm, the measured 2% value of the longitudinal (z axis) MTF is 21.5 lp/cm. In a resolution phantom with metal line pair test patterns, spatial resolution of 20 lp/cm can be demonstrated both in the scan plane and along the z axis. This corresponds to an object size of 0.25 mm that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade-off for the clinical benefit brought about by the improved spatial resolution.

  20. Multidetector-row CT with a 64-row amorphous silicon flat panel detector

    NASA Astrophysics Data System (ADS)

    Shapiro, Edward G.; Colbeth, Richard E.; Daley, Earl T.; Job, Isaias D.; Mollov, Ivan P.; Mollov, Todor I.; Pavkovich, John M.; Roos, Pieter G.; Star-Lack, Josh M.; Tognina, Carlo A.

    2007-03-01

    A unique 64-row flat panel (FP) detector has been developed for sub-second multidetector-row CT (MDCT). The intent was to explore the image quality achievable with relatively inexpensive amorphous silicon (a-Si) compared to existing diagnostic scanners with discrete crystalline diode detectors. The FP MDCT system is a bench-top design that consists of three FP modules. Each module uses a 30 cm x 3.3 cm a-Si array with 576 x 64 photodiodes. The photodiodes are 0.52 mm x 0.52 mm, which allows for about twice the spatial resolution of most commercial MDCT scanners. The modules are arranged in an overlapping geometry, which is sufficient to provide a full-fan 48 cm diameter scan. Scans were obtained with various detachable scintillators, e.g. ceramic Gd IIO IIS, particle-in-binder Gd IIO IIS:Tb and columnar CsI:Tl. Scan quality was evaluated with a Catphan-500 performance phantom and anthropomorphic phantoms. The FP MDCT scans demonstrate nearly equivalent performance scans to a commercial 16-slice MDCT scanner at comparable 10 - 20 mGy/100mAs doses. Thus far, a high contrast resolution of 15 lp/cm and a low contrast resolution of 5 mm @ 0.3 % have been achieved on 1 second scans. Sub-second scans have been achieved with partial rotations. Since the future direction of MDCT appears to be in acquiring single organ coverage per scan, future efforts are planned for increasing the number of detector rows beyond the current 64- rows.

  1. Split-Bolus Single-Pass Multidetector-Row CT Protocol for Diagnosis of Acute Pulmonary Embolism

    PubMed Central

    Scialpi, Michele; Rebonato, Alberto; Cagini, Lucio; Brunese, Luca; Piscioli, Irene; Pierotti, Luisa; Bellantonio, Lucio; D’Andrea, Alfredo; Rotondo, Antonio

    2016-01-01

    Background: Currently computed tomography pulmonary angiography (CTPA) has become a widely accepted clinical tool in the diagnosis of acute pulmonary embolism (PE). Objectives: To report split-bolus single-pass 64-multidetector-row CT (MDCT) protocol for diagnosis of PE. Patients and Methods: MDCT split-bolus results in 40 patients suspicious of PE were analyzed in terms of image quality of target pulmonary vessels (TPVs) and occurrence and severity of flow-related artifact, flow-related artifact, false filling defect of the pulmonary veins and beam hardening streak artifacts. Dose radiation to patients was calculated. Results: MDCT split-bolus protocol allowed diagnostic images of high quality in all cases. Diagnosis of PE was obtained in 22 of 40 patients. Mean attenuation for target vessels was higher than 250 HU all cases: 361 ± 98 HU in pulmonary artery trunk (PAT); 339 ± 93 HU in right pulmonary artery (RPA); 334 ± 100 HU in left pulmonary artery (LPA). Adequate enhancement was obtained in the right atrium (RA):292 ± 83 HU; right pulmonary vein (RPV): 302 ± 91 HU, and left pulmonary vein (LPV): 291 ± 83 HU. The flow related artifacts and the beam hardening streak artifacts have been detected respectively in 4 and 25 patients. No false filling defect of the pulmonary veins was revealed. Conclusion: MDCT split-bolus technique by simultaneous opacification of pulmonary arteries and veins represents an accurate technique for diagnosis of acute PE, removes the false filling defects of the pulmonary veins, and reduces flow related artifacts. PMID:27110334

  2. Multi-detector row CT colonography: effect of collimation, pitch, and orientation on polyp detection in a human colectomy specimen.

    PubMed

    Taylor, Stuart A; Halligan, Steve; Bartram, Clive I; Morgan, Paul R; Talbot, Ian C; Fry, Nicola; Saunders, Brian P; Khosraviani, Kirosh; Atkin, Wendy

    2003-10-01

    To investigate the effects of orientation, collimation, pitch, and tube current setting on polyp detection at multi-detector row computed tomographic (CT) colonography and to determine the optimal combination of scanning parameters for screening. A colectomy specimen containing 117 polyps of different sizes was insufflated and imaged with a multi-detector row CT scanner at various collimation (1.25 and 2.5 mm), pitch (3 and 6), and tube current (50, 100, and 150 mA) settings. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal surface renderings from the 12 resultant data sets were examined by one observer for the presence and conspicuity of polyps. The results were analyzed with Poisson regression and logistic regression to determine the effects of scanning parameters and of specimen orientation on polyp detection. The percentage of polyps that were detected significantly increased when collimation (P =.008) and table feed (P =.03) were decreased. Increased tube current resulted in improved detection only of polyps with a diameter of less than 5 mm. Polyps of less than 5 mm were optimally depicted with a collimation of 1.25 mm, a pitch of 3, and a tube current setting of 150 mA; polyps with a diameter greater than 5 mm were adequately depicted with 1.25-mm collimation and with either pitch setting and any of the three tube current settings. Small polyps in the transverse segment (positioned at a 90 degrees angle to the z axis of scanning) were significantly less visible than those in parallel or oblique orientations (P <.001). The effective radiation dose, calculated with a Monte Carlo simulation, was 1.4-10.0 mSv. Detection of small polyps (<5 mm) with multi-detector row CT is highly dependent on collimation, pitch, and, to a lesser extent, tube current. Collimation of 1.25 mm, combined with pitch of 6 and tube current of 50 mA, provides for reliable detection of polyps 5 mm or larger while limiting the effective radiation dose

  3. Comparison of air kerma between C-arm CT and 64-multidetector-row CT using a phantom.

    PubMed

    Hosokawa, Seiki; Kawai, Nobuyuki; Sato, Morio; Minamiguchi, Hiroki; Nakai, Motoki; Murotani, Kazuhiro; Nishioku, Tadayoshi; Shirai, Shintaro; Sonomura, Tetsuo

    2014-05-01

    To compare air kerma after scanning a phantom with C-arm CT and with 64-multidetector row CT (64MDCT). A phantom was scanned using parameters based on data of ten patients with hepatocellular carcinoma who had C-arm CT during hepatic arteriography and 64MDCT during arterial portography. Radiation monitors were used to measure air kerma ten times at each of five points: the center (A), top (B), left side (C), bottom (D), and right side (E). For C-arm CT vs. 64MDCT, air kerma after scanning was 10.5 ± 0.2 vs. 6.4 ± 0.0 for A, 1.5 ± 0.0 vs. 11.6 ± 0.2 for B, 37.1 ± 0.2 vs. 11.1 ± 0.1 for C, 55.6 ± 1.0 vs. 10.6 ± 0.1 for D, and 40.5 ± 0.5 vs. 11.7 ± 0.1 for E, respectively. Air kerma for A, B, C, D, and E was 1.64, 0.13, 3.34, 5.24, and 3.46 times greater for C-arm CT than for 64MDCT, respectively. Using the same scanning parameters as for clinical cases, air kerma values were greater with C-arm CT than with 64MDCT; at the dorsal side of the phantom, they were 5.24 times greater with C-arm CT compared with 64MDCT.

  4. The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome

    PubMed Central

    Brown, I W; Peebles, C R; Harden, S P; Shambrook, J S

    2014-01-01

    The term “acute aortic syndrome” (AAS) encompasses several non-traumatic life-threatening pathologies of the thoracic aorta presenting in patients with a similar clinical profile. These include aortic dissection, intramural haematoma and penetrating atherosclerotic ulcers. These different pathological entities can be indistinguishable on clinical grounds alone and may be confused with other causes of chest pain, including myocardial infarction. Multidetector-row CT (MDCT) is the current modality of choice for imaging AAS with a sensitivity and specificity approaching 100%. Early diagnosis and accurate radiological classification is associated with improved clinical outcomes in AAS. We review the characteristic radiological features of the different pathologies that encompass AAS and highlight the vital role of MDCT in determining the management of these life-threatening conditions. PMID:25083552

  5. Prevalence of Temporal Bone Fractures in Patients with Mandibular Fractures Using Multidetector-Row CT.

    PubMed

    Ogura, I; Kaneda, T; Sasaki, Y; Buch, K; Sakai, O

    2015-06-01

    Temporal bone fracture after mandibular trauma is thought to be rare, and its prevalence has not been reported in the literature. The purpose of this study was to investigate the prevalence of temporal bone fractures in patients with mandibular fractures and the relationship between temporal bone fractures and the mandibular fracture location using multidetector-row computed tomography (MDCT). A prospective study was performed in 201 patients with mandibular fractures who underwent 64-MDCT scans. The mandibular fracture locations were classified as median, paramedian, angle, and condylar types. Statistical analysis for the relationship between prevalence of temporal bone fractures and mandibular fracture locations was performed using χ(2) test with Fisher's exact test. A P-value < 0.05 was considered statistically significant. The percentage of cases with temporal bone fracture was 3.0 % of all patients with mandibular fractures and 19.0 % of those with multiple mandibular fractures of paramedian and condylar type. There was a significant relationship between the incidence of temporal bone fracture and the paramedian- and condylar-type mandibular fracture (P = 0.001). Multiple mandibular fractures of paramedian and condylar type may be a stronger indicator for temporal bone fractures. This study suggests that patients with mandibular fracture, especially the paramedian and condylar type, should be examined for coexisting temporal bone fracture using MDCT.

  6. Suspected aortic dissection and other aortic disorders: multi-detector row CT in 373 cases in the emergency setting.

    PubMed

    Hayter, Robert G; Rhea, James T; Small, Andrew; Tafazoli, Faranak S; Novelline, Robert A

    2006-03-01

    To retrospectively review the authors' experience with multi-detector row computed tomography (CT) for detection of aortic dissection in the emergency setting. The investigation was institutional review board approved, did not require informed patient consent, and was HIPAA compliant. In 373 clinical evaluations in the emergency setting, 365 patients suspected of having aortic dissection and/or other aortic disorders underwent multidetector CT. Criteria for acute aortic disorder were confirmed by using surgical and pathologic diagnoses or findings at clinical follow-up and any subsequent imaging as the reference standard. Positive cases were characterized according to type of disorder interpreted. Resulting sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated by using two-way contingency tables. All cases found to be negative for acute aortic disorders were grouped according to alternative CT findings. Sixty-seven (18.0%) of the 373 cases were interpreted as positive for acute aortic disorder. One hundred twelve acute aortic disorders were identified in these 67 cases: 23 acute aortic dissections, 14 acute aortic intramural hematomas, 20 acute penetrating aortic ulcers, 44 new or enlarging aortic aneurysms, and 11 acute aortic ruptures. Three hundred five (81.8%) cases were interpreted as negative for acute aortic disorder. In 48 negative cases, multidetector CT depicted alternative findings that accounted for the clinical presentation. Of these, three included both acute aortic disorders and alternative findings, and 45 included only alternative findings. One (0.3%) case was indeterminate for acute aortic disorder. Overall, 112 findings were interpreted as positive for acute aortic disorder, an alternative finding, or both at CT. No interpretations were false-positive, one was false-negative, 67 were true-positive, and 304 were true-negative. Sensitivity, specificity, PPV, NPV, and accuracy were

  7. Use of an automatic exposure control mechanism for dose optimization in multi-detector row CT examinations: clinical evaluation.

    PubMed

    Mulkens, Tom H; Bellinck, Patrick; Baeyaert, Michel; Ghysen, Dirk; Van Dijck, Xavier; Mussen, Elvier; Venstermans, Caroline; Termote, Jean-Luc

    2005-10-01

    To prospectively compare dose reduction and image quality achieved with an automatic exposure control system that is based on both angular (x-y axis) and z-axis tube current modulation with dose reduction and image quality achieved with an angular modulation system for multi-detector row computed tomography (CT). The study protocol was approved by the institutional review board, and oral informed consent was obtained. In two groups of 200 patients, five anatomic regions (ie, the thorax, abdomen-pelvis, abdomen-liver, lumbar spine, and cervical spine) were examined with this modulation system and a six-section multi-detector row CT scanner. Data from these patients were compared with data from 200 patients who were examined with an angular modulation system. Dose reduction by means of reduction of the mean effective tube current in 600 examinations, image noise in 200 examinations performed with each modulation system, and subjective image quality scores in 100 examinations per-formed with each modulation system were compared with Wilcoxon signed rank tests. Mean dose reduction for the angular and z-axis tube current modulation system and for the angular modulation system was as follows: thorax, 20% and 14%, respectively; abdomen-liver, 38% and 18%, respectively; abdomen-pelvis, 32% and 26%, respectively; lumbar spine, 37% and 10%, respectively; and cervical spine, 68% and 16%, respectively. These differences were statistically significant (P < .05). There was no significant difference in image noise and mean image quality scores between modulation systems, with the exception of cervical spinal examinations (P < .001 for both), where the examinations with angular modulation resulted in better scores. There is good correlation between the mean effective tube current level and the body mass index of patients with the new modulation system. Correlation was as follows: thorax, 0.77; abdomen-pelvis, 0.83; abdomen-liver, 0.84; lumbar spine, 0.8; and cervical spine, 0

  8. The radiological diagnosis of fenestral otosclerosis: the utility of histogram analysis using multidetector row CT.

    PubMed

    Yamashita, Koji; Yoshiura, Takashi; Hiwatashi, Akio; Togao, Osamu; Kikuchi, Kazufumi; Inoguchi, Takashi; Kumazawa, Seiji; Honda, Hiroshi

    2014-12-01

    Bone density measurements using high-resolution CT have been reported to be useful to diagnose fenestral otosclerosis. However, small region of interest (ROI) chosen by less-experienced radiologists may result in false-negative findings. Semi-automatic analysis such as CT histogram analysis may offer improved assessment. The aim of this study was to evaluate the utility of CT histogram analysis in diagnosing fenestral otosclerosis. Temporal bone CT of consecutive patients with otosclerosis and normal controls was retrospectively analyzed. The control group consisted of the normal-hearing contralateral ears of patients with otitis media, cholesteatoma, trauma, facial nerve palsy, or tinnitus. All CT images were obtained using a 64-detector-row CT scanner with 0.5-mm collimation. AROI encompassing 10 × 10 pixels was placed in the bony labyrinth located anterior to the oval window. The mean CT value, variance and entropy were compared between otosclerosis patients and normal controls using Student's t test. The number of pixels below mean minus SD in the control (%Lowcont) and total subjects (%Lowtotal) were also compared. In addition, the area under the receiver operating characteristic curves (AUC) value for the discrimination between otosclerosis patients and normal controls was calculated. 51 temporal bones of 38 patients with otosclerosis and 30 temporal bones of 30 control subjects were included. The mean CT value was significantly lower in otosclerosis cases than in normal controls (p < 0.01). In addition, variance, entropy, %Lowcont and %Lowtotal were significantly higher in otosclerosis cases than in normal controls (p < 0.01, respectively). The AUC values for the mean CT value, %Lowcont and %Lowtotal were 0.751, 0.760 and 0.765, respectively. In conclusion, our results demonstrated that histogram analysis of CT image may be of clinical value in diagnosing otosclerosis.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  11. Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

    PubMed

    Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

    2016-04-01

    To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the

  12. Hepatocellular carcinoma: prediction of blood supply from an intercostal artery with multidetector row computed tomography.

    PubMed

    Kim, Min-Uk; Kim, Hyo-Cheol; Chung, Jin Wook; An, Sangbu; Seong, Nak Jong; Jae, Hwan Jun; Park, Jae Hyung

    2011-10-01

    To evaluate the ability of multidetector row computed tomography (CT) to detect blood supply from the intercostal artery in patients with hepatocellular carcinoma (HCC). Between January 2003 and December 2007, angiography of the intercostal artery was performed in 93 patients (76 men and 17 women, mean age 58 years) with HCC who had also undergone multidetector row CT. CT scans and digital subtraction angiograms of these patients were retrospectively reviewed by two investigators in consensus to evaluate tumor feeding vessels. Multiple logistic regression analysis was used to identify factors that predict the presence of an HCC blood supply from an intercostal artery. Tumor staining fed by an intercostal artery was noted in 65 patients (70%; 112 tumor feeding vessels) by intercostal angiography. Readers interpreted that tumor feeding vessels were evident by CT in 35 (54%) of these 65 patients with tumor staining supplied by an intercostal artery by angiography. Multiple logistic regression analysis showed that a visible tumor feeding vessel by CT (P = .003) and hepatic artery attenuation by angiography (P = .014) were significantly related to the presence of a blood supply from an intercostal artery. Visualization of a tumor feeding vessel from the intercostal artery by multidetector row CT is an important sign of parasitic supply to an HCC. Copyright © 2011 SIR. Published by Elsevier Inc. All rights reserved.

  13. Multi-detector row CT of the left atrium and pulmonary veins before radio-frequency catheter ablation for atrial fibrillation.

    PubMed

    Lacomis, Joan M; Wigginton, William; Fuhrman, Carl; Schwartzman, David; Armfield, Derek R; Pealer, Karen M

    2003-10-01

    Radio-frequency catheter ablation (RFCA) of the distal pulmonary veins and posterior left atrium is increasingly being used to treat recurrent or refractory atrial fibrillation that resists pharmacologic therapy or cardioversion. Successful RFCA of atrial fibrillation requires resolution of abnormal rhythms while minimizing complications and can be achieved with precise, preprocedural, three-dimensional (3D) anatomic delineation of the target, the atriopulmonary venous junction. Three-dimensional multi-detector row computed tomography (CT) of the pulmonary veins and left atrium provides the necessary anatomic information for successful RFCA, including (a) the number, location, and angulation of pulmonary veins and their ostial branches unobscured by adjacent cardiac and vascular anatomy, and (b) left atrial volume. The 3D multi-detector row CT scanning and postprocessing techniques used for pre-RFCA planning are straightforward. Radiologists must not only understand these techniques but must also be familiar with atrial fibrillation and the technical considerations and complications associated with RFCA of this condition. In addition, radiologists must be familiar with anatomic variants of the left atrium and distal pulmonary veins and understand the importance of these variants to the referring cardiac interventional electrophysiologist. Copyright RSNA, 2003

  14. A new 3-D diagnosis strategy for duodenal malignant lesions using multidetector row CT, CT virtual duodenoscopy, duodenography, and 3-D multicholangiography.

    PubMed

    Sata, N; Endo, K; Shimura, K; Koizumi, M; Nagai, H

    2007-01-01

    Recent advances in multidetector row computed tomography (MD-CT) technology provide new opportunities for clinical diagnoses of various diseases. Here we assessed CT virtual duodenoscopy, duodenography, and three-dimensional (3D) multicholangiography created by MD-CT for clinical diagnosis of duodenal malignant lesions. The study involved seven cases of periduodenal carcinoma (four ampullary carcinomas, two duodenal carcinomas, one pancreatic carcinoma). Biliary contrast medium was administered intravenously, followed by intravenous administration of an anticholinergic agent and oral administration of effervescent granules for expanding the upper gastrointestinal tract. Following intravenous administration of a nonionic contrast medium, an upper abdominal MD-CT scan was performed in the left lateral position. Scan data were processed on a workstation to create CT virtual duodenoscopy, duodenography, 3D multicholangiography, and various postprocessing images, which were then evaluated for their effectiveness as preoperative diagnostic tools. Carcinoma location and extent were clearly demonstrated as defects or colored low-density areas in 3-D multicholangiography images and as protruding lesions in virtual duodenography and duodenoscopy images. These findings were confirmed using multiplanar or curved planar reformation images. In conclusion, CT virtual duodenoscopy, doudenography, 3-D multicholangiography, and various images created by MD-CT alone provided necessary and adequate preoperative diagnostic information.

  15. Coronary artery calcium measurement with multi-detector row CT: in vitro assessment of effect of radiation dose.

    PubMed

    Hong, Cheng; Bae, Kyongtae T; Pilgram, Thomas K; Suh, Jongdae; Bradley, David

    2002-12-01

    The authors assessed in vitro the effect of radiation dose on coronary artery calcium quantification with multi-detector row computed tomography. A cardiac phantom with calcified cylinders was scanned at various milliampere second settings (20-160 mAs). A clear tendency was found for image noise to decrease as tube current increased (P <.001). No tendency was found for the Agatson score or calcium volume and mass errors to vary with tube current. Calcium measurements were not significantly affected by the choice of tube current. Calcium mass error was strongly correlated with calcium volume error (P <.001). The calcium mass measurement was more accurate and less variable than the calcium volume measurement.

  16. Multidetector-row computed tomography for prosthetic heart valve dysfunction: is concomitant non-invasive coronary angiography possible before redo-surgery?

    PubMed

    Tanis, Wilco; Suchá, Dominika; Laufer, Ward; Habets, Jesse; van Herwerden, Lex A; Symersky, Petr; Chamuleau, Steven; Budde, Ricardo P J

    2015-06-01

    Retrospective ECG-gated multidetector-row computed tomography (MDCT) is increasingly used for the assessment of prosthetic heart valve (PHV) dysfunction, but is also hampered by PHV-related artefacts/cardiac arrhythmias. Furthermore, it is performed without nitroglycerine or heart rate correction. The purpose was to determine whether MDCT performed before potential redo-PHV surgery is feasible for concomitant coronary artery stenosis assessment and can replace invasive coronary angiography (CAG). PHV patients with CAG and MDCT were identified. Based on medical history, two groups were created: (I) patients with no known coronary artery disease (CAD), (II) patients with known CAD. All images were scored for the presence of significant (>50 %) stenosis. CAG was the reference test. Fifty-one patients were included. In group I (n = 38), MDCT accurately ruled out significant stenosis in 19/38 (50 %) patients, but could not replace CAG in the remaining 19/38 (50 %) patients due to non-diagnostic image quality (n = 16) or significant stenosis (n = 3) detection. In group II (n = 13), MDCT correctly found no patients without significant stenosis, requiring CAG imaging in all. MDCT assessed patency in 16/19 (84 %) grafts and detected a hostile anatomy in two. MDCT performed for PHV dysfunction assessment can replace CAG (100 % accurate) in approximately half of patients without previously known CAD. • Retrospective MDCT is increasingly used for prosthetic heart valve dysfunction assessment • In case of PHV reoperation, invasive coronary angiography is also required • MDCT can replace CAG in 50 % of patients without coronary artery disease • When conclusive for coronary assessment, MDCT stenosis rule out is highly accurate • Replacing CAG saves associated risks of distant embolization of thrombi or vegetations.

  17. [Comparison of a dental cone beam CT with a multi-detector row CT on effective doses and physical image quality].

    PubMed

    Yoshida, Yutaka; Tokumori, Kenji; Okamura, Kazutoshi; Yoshiura, Kazunori

    2011-01-01

    The purpose of this study was to compare a dental cone beam computed tomography (dental CBCT) and a multi-detector row CT (MDCT) using effective doses and physical image quality. A dental mode (D-mode) and an implant mode (I-mode) were employed for calculating effective doses. Field of view (FOV) size of the MDCT was 150 mm. Three types of images were obtained using 3 different reconstruction functions: FC1 (for abdomen images), FC30 (for internal ear and bone images) and FC81 (for high resolution images). Effective doses obtained with the D-mode and with the I-mode were about 20% and 50% of those obtained with the MDCT, respectively. Resolution properties obtained with the D-mode and I-mode were superior to that of the MDCT in a high frequency range. Noise properties of the D-mode and the I-mode were better than those with FC81. It was found that the dental CBCT has better potential as compared with MDCT in both dental and implant modes.

  18. Automated multidetector row CT dataset segmentation with an interactive watershed transform (IWT) algorithm: Part 1. Understanding the IWT technique.

    PubMed

    Heath, David G; Hahn, Horst K; Johnson, Pamela T; Fishman, Elliot K

    2008-12-01

    Segmentation of volumetric computed tomography (CT) datasets facilitates evaluation of 3D CT angiography renderings, particularly with maximum intensity projection displays. This manuscript describes a novel automated bone editing program that uses an interactive watershed transform (IWT) technique to rapidly extract the skeletal structures from the volume. Advantages of this tool include efficient segmentation of large datasets with minimal need for correction. In the first of this two-part series, the principles of the IWT technique are reviewed, followed by a discussion of clinical utility based on our experience.

  19. [Reconstruction of coronary 64-multidetector-row computed tomography angiography in patients with atrial fibrillation: delete short RR intervals using electorocardiogram].

    PubMed

    Matsutani, Hideyuki; Sano, Tomonari; Kondo, Takeshi; Fujimoto, Shinichiro; Sekine, Takako; Arai, Takehiro; Morita, Hitomi; Takase, Shinichi

    2012-01-01

    The image qualities of coronary 64-multidetector-row computed tomography angiography (CCTA) in patients with atrial fibrillation (Afib) are often not enough. This study clarifies how to use electrocardiogram (ECG) -editing in Afib. We performed CCTA (Aquilion 64 with beam pitch: 0.125, 0.35 s/r) in 33 patients (M/F=24/9, age: 71±9 yr, mean heart rate: 71±12 bpm) with Afib. We injected 5 mg of verapamil into the vein when the mean HR was ≥80 bpm. First, we reconstructed images after deleting short RR (<800, 750, 700, 650, or 600). Second, we reconstructed images in 4 different methods: (1) end-systolic images with Phase Navi (automatically selecting an optimal phase) (ES-Navi), (2) Mid-diastolic images with Phase Navi (MD-Navi), (3) Mid-diastolic images reconstructed by the "R+absolute time method" [Edit-MD (R+)], and (4) Mid-diastolic images reconstructed by the "R-absolute time method" [Edit-MD (R-)]. We reconstructed 1 and 2 without ECG-editing, and 3 and 4 were reconstructed after ECG-editing without a data deficit. The quality of the images was classified into 3 ranks: no artifact (3), mild artifact (2), and severe artifact (1). The image quality point of CCTA, reconstructed after deleting RR<750, was similar to RR<800, and RR<750 was even higher than that after deleting HR<600, 650, or 700. The mean image quality point of CCTA that was reconstructed by Edit-MD (R-) or Edit-MD (R+) was significantly higher than ES-Navi or MD-Navi. The high image quality of CCTA could be reconstructed after deleting RR<750 in 76% or after deleting RR<800 in 70% of Afib. The reconstruction using Edit-MD (R-) or Edit-MD (R+) without a data deficit could provide a better quality CCTA than using PhaseNavi in Afib.

  20. Multi-detector row CT as a "one-stop" examination in the preoperative evaluation of the morphology and function of living renal donors: preliminary study.

    PubMed

    Su, Chen; Yan, Chaogui; Guo, Yan; Zhou, Xuhui; Chen, Yaqing; Liu, Mingjuan; Wang, Wenjuan; Zhang, Xiaoling

    2011-02-01

    We designed to investigate the feasibility of multi-detector row computerized tomography (CT) as a "one-stop" examination for the simultaneous preoperative evaluation of the morphology and function of living renal donors. 21 living renal donors were examined by 64-slice spiral CT with a three-phase enhancement CT scan and two inserted dynamic scans. The maximum intensity projection (MIP), multi-planar reformation (MPR), and volume reconstruction (VR) procedures were performed to compare the renal parenchyma, renal vessels, and collecting system with operational findings. The known Patlak equation was used to calculate the glomerular filtration rate (GFR); exact GFR information was acquired by single photon emission computed tomography (SPECT). Our results as following, there were 3 cases of artery variation and 3 cases of vein variation. CT findings all corresponded with the operation, and the sensitivity, positive predictive value, specialty, and negative predictive value of CT were all 100%. The r of the GFR values estimated from CT is 0.894 (left) (P < 0.001) and 0.881 (right) (P < 0.001). In conclusions, our findings demonstrate that 64-slice spiral CT may offer a "one-stop" examination to replace SPECT in the preoperative evaluation of living renal donors to simultaneously provide information regarding both anatomy and the GFR of living renal donors.

  1. Consideration of the Pathological Features of Pediatric Congenital Heart Diseases Which Are Ideally Suitable for Diagnosing With Multidetector-row CT

    PubMed Central

    Hayabuchi, Yasunobu; Inoue, Miki; Watanabe, Noriko; Sakata, Miho; Ohnishi, Tatsuya; Kagami, Shoji

    2011-01-01

    Background A lots of articles published regarding the usefulness of multidetector-row computed tomography (MDCT) in children with congenital heart disease (CHD) mostly describe that it can be an alternative to the invasive catheterization and angiography. The unique diagnostic features of this imaging modality have been largely ignored or disregarded. We described the pathological conditions that cannot be diagnosed by conventional angiography with cardiac catheterization but can be accurately diagnosed by MDCT. Methods We retrospectively reviewed non-ECG-gated MDCT images acquired from 452 children and young adults with CHD between 2005 and 2010 in our institute. In this article, we focused on the diagnostic advantages of MDCT, and indicated five pathological conditions. (1) When Blalock-Taussig shunt total occlusion prevents catheter insertion into the artificial vessel and angiography is ruled out, the peripheral pulmonary artery during the peripheral pulmonary artery can be imaged and diagnosed using MDCT based on blood flow supplied from many small collateral vessels originating from the aorta. (2) The location and protrusion of the device in the vessel after coil embolization to treat patent ductus arteriosus can be accurately visualized by virtual endoscopy using MDCT. (3) Calcification of patches, synthetic blood vessels, and other prostheses that is indistinct on conventional angiograms is clear on MDCT. (4) Simultaneous MDCT observations of the anatomical relationships between arterial and venous systems on the same image can clarify the detail diagnosis for surgical treatment. (5) Compression of the airways by the great vessels and pulmonary segmental emphysematous change can be diagnosed by MDCT. Results and Conclusions Among patients with CHD, MDCT is useful not only as a non-invasive alternative to conventional angiography, but also as a tool for specific morphological diagnoses. In the future, it will be necessary to accumulate experience in the

  2. Diagnostic accuracy of 16-slice multidetector-row CT for detection of in-stent restenosis vs detection of stenosis in nonstented coronary arteries.

    PubMed

    Kefer, Joelle M; Coche, Emmanuel; Vanoverschelde, Jean-Louis J; Gerber, Bernhard L

    2007-01-01

    The purpose of this study was to assess the diagnostic accuracy of 16-slice multidetector-row computed tomography (MDCT) for detecting in-stent restenosis. Fifty patients with 69 previously implanted coronary stents underwent 16-slice MDCT before quantitative coronary angiography (QCA). Diagnostic accuracy of MDCT for detection of in-stent restenosis defined as >50% lumen diameter stenosis (DS) in stented and nonstented coronary segments >1.5-mm diameter was computed using QCA as reference. According to QCA, 18/69 (25%) stented segments had restenosis. In addition, 33/518 (6.4%) nonstented segments had >50% DS. In-stent restenosis was correctly identified on MDCT images in 12/18 stents, and absence of restenosis was correctly identified in 50/51 stents. Stenosis in native coronary arteries was correctly identified in 22/33 segments and correctly excluded in 482/485 segments. Thus, sensitivity (67% vs 67% p=1.0), specificity (98% vs 99%, p=0.96) and overall diagnostic accuracy (90% vs 97%, p=0.68) was similarly high for detecting in-stent restenosis as for detecting stenosis in nonstented coronary segments. MDCT has similarly high diagnostic accuracy for detecting in-stent restenosis as for detecting coronary artery disease in nonstented segments. This suggests that MDCT could be clinically useful for identification of restenosis in patients after coronary stenting.

  3. Radiation dose is reduced with a single-pass whole-body multi-detector row CT trauma protocol compared with a conventional segmented method: initial experience.

    PubMed

    Ptak, Thomas; Rhea, James T; Novelline, Robert A

    2003-12-01

    Radiation dose data were collected from a calibrated multi-detector row computed tomographic (CT) scanner during trauma CT. One protocol (used with 10 case subjects) involved a single-pass continuous whole-body acquisition from cranial vertex to symphysis pubis, while the other, conventional protocol (used with 10 control subjects) involved scouting and scanning body segments (head, cervical spine, chest, abdomen, and pelvis) individually. Technical factors were kept constant within each body segment for the single-pass and the segmented protocols. Statistics included univariate analysis, two-tailed t testing to evaluate statistical significance of the summary statistic, and power and subject population contingency tables. The mean dose length product (DLP) with the single-pass protocol was 17% lower than the sum of the DLPs of each of the individual body segment scans (P <.001). Analysis of power and subject population by using a difference in mean of 500 mGy. cm and an alpha of.05 revealed a (1-beta) of higher than 0.90 for a sample of 10 patients. Thus, a whole-body single-pass trauma protocol, compared with a typical segmented acquisition protocol matched for imaging technique, resulted in reduced total radiation dose. The reduction in radiation dose is thought to represent a reduction in redundant imaging at overlap zones between body segments scanned in the segmental protocol but not in the continuous acquisition.

  4. Optimization of Z-axis automatic exposure control for multidetector row CT evaluation of neck and comparison with fixed tube current technique for image quality and radiation dose.

    PubMed

    Namasivayam, S; Kalra, M K; Pottala, K M; Waldrop, S M; Hudgins, P A

    2006-01-01

    Z-axis automatic exposure control (AEC) technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare diagnostic acceptability, noise, and radiation exposure of multidetector row CT (MDCT) of neck performed with z-axis AEC and with fixed current. Two study groups of 26 patients each underwent MDCT of neck using z-axis AEC with 8 noise index (NI), 150-440 mA, and 10 NI, 75-440 mA, respectively. A control group consisting of another 26 patients underwent MDCT of neck with fixed-current technique (300 mA). Objective noise and mean tube current-time products (mA . s) were recorded. Two radiologists evaluated images for diagnostic acceptability and subjective noise on a 5-point scale. All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with z-axis AEC (shoulder: NI 8, 20.6 +/- 6.2 HU; NI 10, 22.2 +/- 4.6 HU) than with fixed current (16.2 +/- 6 HU) (P = .01). There was no significant difference between AEC and fixed current in diagnostic acceptability and subjective noise (P = .22-.42). AEC resulted in significant radiation dose reduction (NI 8, 186.3 +/- 20.5 mA . s; NI 10, 158.1 +/- 21.2 mA x s), compared with fixed current (235 +/- 21.8 mA x s). Z-axis AEC resulted in similar subjective noise and diagnostic acceptability, with radiation dose reduction of 21% for NI of 8 and 33% for NI of 10, respectively, for MDCT evaluation of neck, compared with those of fixed current technique.

  5. Assessment of organ absorbed doses and estimation of effective doses from pediatric anthropomorphic phantom measurements for multi-detector row CT with and without automatic exposure control.

    PubMed

    Brisse, Hervé J; Robilliard, Magalie; Savignoni, Alexia; Pierrat, Noelle; Gaboriaud, Geneviève; De Rycke, Yann; Neuenschwander, Sylvia; Aubert, Bernard; Rosenwald, Jean-Claude

    2009-10-01

    This study was designed to measure organ absorbed doses from multi-detector row computed tomography (MDCT) on pediatric anthropomorphic phantoms, calculate the corresponding effective doses, and assess the influence of automatic exposure control (AEC) in terms of organ dose variations. Four anthropomorphic phantoms (phantoms represent the equivalent of a newborn, 1-, 5-, and 10-y-old child) were scanned with a four-channel MDCT coupled with a z-axis-based AEC system. Two CT torso protocols were compared: a first protocol without AEC and constant tube current-time product and a second protocol with AEC using age-adjusted noise indices. Organ absorbed doses were monitored by thermoluminescent dosimeters (LiF: Mg, Cu, P). Effective doses were calculated according to the tissue weighting factors of the International Commission on Radiological Protection (). For fixed mA acquisitions, organ doses normalized to the volume CT dose index in a 16-cm head phantom (CTDIvol16) ranged from 0.6 to 1.5 and effective doses ranged from 8.4 to 13.5 mSv. For the newborn-equivalent phantom, the AEC-modulated scan showed almost no significant dose variation compared to the fixed mA scan. For the 1-, 5- and 10-y equivalent phantoms, the use of AEC induced a significant dose decrease on chest organs (ranging from 61 to 31% for thyroid, 37 to 21% for lung, 34 to 17% for esophagus, and 39 to 10% for breast). However, AEC also induced a significant dose increase (ranging from 28 to 48% for salivary glands, 22 to 51% for bladder, and 24 to 70% for ovaries) related to the high density of skull base and pelvic bones. These dose increases should be considered before using AEC as a dose optimization tool in children.

  6. Is aortic atherothrombotic disease detected using multidetector-row CT associated with an increased risk of early ischemic lesion recurrence after acute ischemic stroke?

    PubMed

    Ko, Youngchai; Kim, Wook-Joo; Jang, Myung Suk; Yang, Mi Hwa; Park, Jung Hyun; Choi, Sang Il; Chun, Eun Ju; Lee, Soo Joo; Han, Moon-Ku; Bae, Hee-Joon

    2012-03-01

    Multidetector-row CT (MDCT) is emerging as a new tool for diagnosing aortic atherothrombotic disease (AAD). We elucidated whether MDCT-detected AAD is associated with an increased risk of early ischemic lesion recurrence on diffusion-weighted MRI after ischemic stroke. A consecutive series of patients with acute ischemic stroke confirmed using diffusion-weighted MRI who were hospitalized within 48 hours after symptom onset and underwent MDCT were identified in a prospective stroke registry database. AAD on MDCT was defined as the presence of plaque formation that was noncalcified and ≥4 mm thick, ulcerative, or soft and thrombosed (vulnerable) in the proximal aortic arch. Ischemic lesion recurrence on diffusion-weighted MRI was defined as the occurrence of any new lesion separate from the index lesion on follow-up diffusion-weighted MRI performed within 14 days after symptom onset. A total of 138 patients was selected. MDCT detected AAD in 24 of 138 (17.4%); ≥4 mm thickness in 17 of 138 (12.3%); ulcerated plaque in 20 of 138 (14.5%); and vulnerable plaque in 16 of 138 (11.6%). With respect to diffusion-weighted MRI lesion recurrence, the crude ORs (95% CIs) were as follows: AAD, 3.56 (1.43-8.89); vulnerable plaque, 3.21 (1.11-9.30); ulcerated plaque, 3.37 (1.27-8.95); and ≥4 mm thickness of the noncalcified plaque, 4.23 (1.11-16.19). These results remained significant after adjustments for potential confounders were made. This study shows that AAD detected by MDCT increases the risk of early ischemic lesion recurrence after acute ischemic stroke, thus supporting the role of MDCT in diagnosing AAD and assessing its contribution to recurrence.

  7. Evaluation of Deep Vein Thrombosis with Multidetector Row CT after Orthopedic Arthroplasty: a Prospective Study for Comparison with Doppler Sonography

    PubMed Central

    Byun, Sung Su; Kim, Youn Jeong; Chun, Yong Sun; Park, Chul Hi; Kim, Won-Hong

    2008-01-01

    Objective This prospective study evaluated the ability of indirect 16-row multidetector CT venography, in comparison with Doppler sonography, to detect deep vein thrombosis after total hip or knee replacement. Materials and Methods Sixty-two patients had undergone orthopedic replacement surgery on a total of 30 hip joints and 54 knee joints. The CT venography (scan delay time: 180 seconds; slice thickness/increment: 2/1.5 mm) and Doppler sonography were performed 8 to 40 days after surgery. We measured the z-axis length of the beam hardening artifact that degraded the image quality so that the presence of deep vein thrombosis couldn't be evaluated on the axial CT images. The incidence and location of deep vein thrombosis was analyzed. The diagnostic performance of the CT venograms was evaluated and compared with that of Doppler sonography as a standard of reference. Results The z-axis length (mean±standard deviation) of the beam hardening artifact was 4.5 ± 0.8 cm in the arthroplastic knees and 3.9 ± 2.9 cm in the arthroplastic hips. Deep vein thrombosis (DVT) was found in the popliteal or calf veins on Doppler sonography in 30 (48%) of the 62 patients. The CT venography has a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 90%, 97%, 96%, 91% and 94%, respectively. Conclusion The ability of CT venography to detect DVT was comparable to that of Doppler sonography despite of beam hardening artifact. Therefore, CT venography is feasible to use as an alternative modality for evaluating postarthroplasty patients. PMID:18253077

  8. Multidetector row computed tomography evaluation of potential living laparoscopic renal donors: the story so far.

    PubMed

    Namasivayam, Saravanan; Kalra, Mannudeep K; Small, William C; Torres, William E; Mittal, Pardeep K

    2006-01-01

    Renal transplantation is the treatment of choice for end-stage renal disease. Living related kidney donation is the major source of renal grafts due to limited availability of cadaveric kidneys. Open nephrectomy was used to harvest donor kidneys. However, the laparoscopic approach is associated with less postoperative pain and quick recovery. So, most centers now prefer a laparoscopic approach to explant donor kidneys. Laparoscopic approach is technically challenging due to limited operative visibility. Hence, accurate preoperative detection of renal arterial and venous anomalies is imperative to avoid inadvertent vascular injury and bleeding. The preoperative workup of renal donors includes clinical evaluation, laboratory tests, and imaging. Traditionally, the renal donors were evaluated with conventional imaging techniques, which included renal catheter angiography and intravenous urography. However, conventional imaging is invasive, expensive, and less accurate for evaluation of complex renal venous anomalies, small calculi, and diffuse or focal renal parenchymal lesions. The introduction of multidetector row computed tomography (MDCT) revolutionized the CT technology by enabling isotropic resolution with faster scan coverage in a single, short breath-hold. Consequently, MDCT has now replaced conventional imaging for comprehensive imaging of potential living renal donors. MDCT is a minimally invasive technique that can accurately detect urolithiasis, renal arterial and venous anomalies, renal parenchymal lesions, and urinary tract anomalies. Renal vascular anomalies detected by MDCT can help the surgeon in planning donor nephrectomy. MDCT with three-dimensional CT angiography enables accurate preoperative renal vascular mapping. This article reviews the role of MDCT in preoperative evaluation of potential laparoscopic renal donors.

  9. The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms.

    PubMed

    Brisse, H J; Brenot, J; Pierrat, N; Gaboriaud, G; Savignoni, A; De Rycke, Y; Neuenschwander, S; Aubert, B; Rosenwald, J-C

    2009-04-07

    This study assessed and compared various image quality indices in order to manage the dose of pediatric abdominal MDCT protocols and to provide guidance on dose reduction. PMMA phantoms representing average body diameters at birth, 1 year, 5 years, 10 years and 15 years of age were scanned in a four-channel MDCT with a standard pediatric abdominal CT protocol. Image noise (SD, standard deviation of CT number), noise derivative (ND, derivative of the function of noise with respect to dose) and contrast-to-noise ratio (CNR) were measured. The 'relative' low-contrast detectability (rLCD) was introduced as a new quantity to adjust LCD to the various phantom diameters on the basis of the LCD(1%) assessed in a Catphan phantom and a constant central absorbed dose. The required variations of CTDIvol(16) with respect to phantom size were analyzed in order to maintain each image quality index constant. The use of a fixed SD or CNR level leads to major dose ratios between extreme patient sizes (factor 22.7 to 44 for SD, 31.7 to 51.5 for CNR(2.8%)), whereas fixed ND and rLCD result in acceptable dose ratios ranging between factors of 2.9 and 3.9 between extreme phantom diameters. For a 5-9 mm rLCD1(%), adjusted ND values range between -0.84 and -0.11 HU mGy(-1). Our data provide guidance on dose reduction on the basis of patient dimensions and the required rLCD (e.g., to get a constant 7 mm rLCD(1%) for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol(16) values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

  10. The relevance of image quality indices for dose optimization in abdominal multi-detector row CT in children: experimental assessment with pediatric phantoms

    NASA Astrophysics Data System (ADS)

    Brisse, H. J.; Brenot, J.; Pierrat, N.; Gaboriaud, G.; Savignoni, A.; DeRycke, Y.; Neuenschwander, S.; Aubert, B.; Rosenwald, J.-C.

    2009-04-01

    This study assessed and compared various image quality indices in order to manage the dose of pediatric abdominal MDCT protocols and to provide guidance on dose reduction. PMMA phantoms representing average body diameters at birth, 1 year, 5 years, 10 years and 15 years of age were scanned in a four-channel MDCT with a standard pediatric abdominal CT protocol. Image noise (SD, standard deviation of CT number), noise derivative (ND, derivative of the function of noise with respect to dose) and contrast-to-noise ratio (CNR) were measured. The 'relative' low-contrast detectability (rLCD) was introduced as a new quantity to adjust LCD to the various phantom diameters on the basis of the LCD1% assessed in a Catphan® phantom and a constant central absorbed dose. The required variations of CTDIvol16 with respect to phantom size were analyzed in order to maintain each image quality index constant. The use of a fixed SD or CNR level leads to major dose ratios between extreme patient sizes (factor 22.7 to 44 for SD, 31.7 to 51.5 for CNR2.8%), whereas fixed ND and rLCD result in acceptable dose ratios ranging between factors of 2.9 and 3.9 between extreme phantom diameters. For a 5-9 mm rLCD1%, adjusted ND values range between -0.84 and -0.11 HU mGy-1. Our data provide guidance on dose reduction on the basis of patient dimensions and the required rLCD (e.g., to get a constant 7 mm rLCD1% for abdominal diameters of 10, 13, 16, 20 and 25 cm, tube current-time product should be adjusted in order to obtain CTDIvol16 values of 6.2, 7.2, 8.8, 11.6 and 17.7 mGy, respectively).

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-01-01

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

  13. Advances and perspectives in lung cancer imaging using multidetector row computed tomography.

    PubMed

    Coche, Emmanuel

    2012-10-01

    The introduction of multidetector row computed tomography (CT) into clinical practice has revolutionized many aspects of the clinical work-up. Lung cancer imaging has benefited from various breakthroughs in computing technology, with advances in the field of lung cancer detection, tissue characterization, lung cancer staging and response to therapy. Our paper discusses the problems of radiation, image visualization and CT examination comparison. It also reviews the most significant advances in lung cancer imaging and highlights the emerging clinical applications that use state of the art CT technology in the field of lung cancer diagnosis and follow-up.

  14. CT angiography - chest

    MedlinePlus

    Computed tomography angiography - thorax; CTA - lungs; Pulmonary embolism - CTA chest; Thoracic aortic aneurysm - CTA chest; Venous thromboembolism - CTA lung; Blood clot - CTA lung; Embolus - CTA lung; CT ...

  15. Determining contrast medium dose and rate on basis of lean body weight: does this strategy improve patient-to-patient uniformity of hepatic enhancement during multi-detector row CT?

    PubMed

    Ho, Lisa M; Nelson, Rendon C; Delong, David M

    2007-05-01

    To prospectively evaluate the use of lean body weight (LBW) as the main determinant of the volume and rate of contrast material administration during multi-detector row computed tomography of the liver. This HIPAA-compliant study had institutional review board approval. All patients gave written informed consent. Four protocols were compared. Standard protocol involved 125 mL of iopamidol injected at 4 mL/sec. Total body weight (TBW) protocol involved 0.7 g iodine per kilogram of TBW. Calculated LBW and measured LBW protocols involved 0.86 g of iodine per kilogram and 0.92 g of iodine per kilogram calculated or measured LBW for men and women, respectively. Injection rate used for the three experimental protocols was determined proportionally on the basis of the calculated volume of contrast material. Postcontrast attenuation measurements during portal venous phase were obtained in liver, portal vein, and aorta for each group and were summed for each patient. Patient-to-patient enhancement variability in same group was measured with Levene test. Two-tailed t test was used to compare the three experimental protocols with the standard protocol. Data analysis was performed in 101 patients (25 or 26 patients per group), including 56 men and 45 women (mean age, 53 years). Average summed attenuation values for standard, TBW, calculated LBW, and measured LBW protocols were 419 HU +/- 50 (standard deviation), 443 HU +/- 51, 433 HU +/- 50, and 426 HU +/- 33, respectively (P = not significant for all). Levene test results for summed attenuation data for standard, TBW, calculated LBW, and measured LBW protocols were 40 +/- 29, 38 +/- 33 (P = .83), 35 +/- 35 (P = .56), and 26 +/- 19 (P = .05), respectively. By excluding highly variable but poorly perfused adipose tissue from calculation of contrast medium dose, the measured LBW protocol may lessen patient-to-patient enhancement variability while maintaining satisfactory hepatic and vascular enhancement.

  16. Variations of the popliteal artery branching with multidetector CT angiography.

    PubMed

    Yanik, Bahar; Bulbul, Erdogan; Demirpolat, Gulen

    2015-04-01

    To date the anatomy of the popliteal artery variations using multidetector-row computed tomography angiography (MD CTA) was not assessed. The objective of this study is to establish 3D CT anatomy of the popliteal artery variations. A total of 126 lower limbs that underwent CTA using 64-detector MDCT were retrospectively reviewed. The anatomical variations of the distal popliteal artery branching were assessed. Ninety-seven lower limbs (83.6%) had the usual branching pattern (type 1 A) with tibialis anterior artery (TA) arising first followed by the tibial-peroneal trunk, which then gives rise to the tibialis posterior artery (TP) and peroneal artery. Variations in popliteal branching pattern were seen in 19 (16.4%) limbs. The commonest variation was first branch of the TP in 5 (4.4%) of the limbs (type 1 C) or high origin with anterior course of popliteus muscle of the TA in 5 (4.4%) limbs (type 2 A II). Many variations exist in the running patterns of the branching pattern of the popliteal artery. Knowledge of the branching pattern of the popliteal artery will be beneficial to radiologist for the evaluation of CT angiograms and interventional vascular procedures, and to vascular surgeons for various surgical approaches. MD CTA provides noninvasive means of assessing distal popliteal artery variations.

  17. Technical aspects of CT angiography.

    PubMed

    Kuszyk, B S; Fishman, E K

    1998-10-01

    The basic tasks of spiral CT acquisition, image processing, and image display are the foundations underlying CT angiography regardless of the anatomic region of interest. Volume rendering is a rapidly emerging image processing technique for creating three-dimensional (3D) images from CT datasets, which has important advantages over other 3D rendering techniques including maximum intensity projection and surface rendering. This articles reviews the techniques that are commonly used in CT angiography and key considerations for optimization.

  18. Volume rendering versus maximum intensity projection in CT angiography: what works best, when, and why.

    PubMed

    Fishman, Elliot K; Ney, Derek R; Heath, David G; Corl, Frank M; Horton, Karen M; Johnson, Pamela T

    2006-01-01

    The introduction and widespread availability of 16-section multi-detector row computed tomographic (CT) technology and, more recently, 64-section scanners, has greatly advanced the role of CT angiography in clinical practice. CT angiography has become a key component of state-of-the-art imaging, with applications ranging from oncology (eg, staging of pancreatic or renal cancer) to classic vascular imaging (eg, evaluation of aortic aneurysms and renal artery stenoses) as well as newer techniques such as coronary artery imaging and peripheral runoff studies. With an average of 400-1000 images in each volume data set, three-dimensional postprocessing is crucial to volume visualization. Radiologists now have workstations that provide capabilities for evaluation of these data sets by using a range of software programs and processing tools. Although different systems have unique capabilities and functionality, all provide the options of volume rendering and maximum intensity projection for image display and analysis. These two postprocessing techniques have different advantages and disadvantages when used in clinical practice, and it is important that radiologists understand when and how each technique should be used. Copyright RSNA, 2006.

  19. Dose performance of a 64-channel dual-source CT scanner.

    PubMed

    McCollough, Cynthia H; Primak, Andrew N; Saba, Osama; Bruder, Herbert; Stierstorfer, Karl; Raupach, Rainer; Suess, Christoph; Schmidt, Bernhard; Ohnesorge, Bernd M; Flohr, Thomas G

    2007-06-01

    To prospectively compare the dose performance of a 64-channel multi-detector row computed tomographic (CT) scanner and a 64-channel dual-source CT scanner from the same manufacturer. To minimize dose in the cardiac (dual-source) mode, the evaluated dual-source CT system uses a cardiac beam-shaping filter, three-dimensional adaptive noise reduction, heart rate-dependent pitch, and electrocardiographically based modulation of the tube current. Weighted CT dose index per 100 mAs was measured for the head, body, and cardiac beam-shaping filters. Kerma-length product was measured in the spiral cardiac mode at four pitch values and three electrocardiographic modulation temporal windows. Noise was measured in an anthropomorphic phantom. Data were compared with data from a 64-channel multi-detector row CT scanner. For the multi-detector row and dual-source CT systems, respectively, weighted CT dose index per 100 mAs was 14.2 and 12.2 mGy (head CT), 6.8 and 6.4 mGy (body CT), and 6.8 and 5.3 mGy (cardiac CT). In the spiral cardiac mode (no electrocardiographically based tube current modulation, 0.2 pitch), equivalent noise occurred at volume CT dose index values of 23.7 and 35.0 mGy (coronary artery calcium CT) and 58.9 and 61.2 mGy (coronary CT angiography) for multi-detector row CT and dual-source CT, respectively. The use of heart rate-dependent pitch values reduced volume CT dose index to 46.2 mGy (0.265 pitch), 34.0 mGy (0.36 pitch), and 26.6 mGy (0.46 pitch) compared with 61.2 mGy for 0.2 pitch. The use of electrocardiographically based tube current-modulation and temporal windows of 110, 210, and 310 msec further reduced volume CT dose index to 9.1-25.1 mGy, dependent on the heart rate. For electrocardiographically gated coronary CT angiography, image noise equivalent to that of multi-detector row CT can be achieved with dual-source CT at doses comparable to or up to a factor of two lower than the doses at multi-detector row CT, depending on heart rate of the patient

  20. Detection of hypervascular hepatocellular carcinoma: Comparison of multi-detector CT with digital subtraction angiography and Lipiodol CT

    PubMed Central

    Zheng, Xiao-Hua; Guan, Yong-Song; Zhou, Xiang-Ping; Huang, Juan; Sun, Long; Li, Xiao; Liu, Yuan

    2005-01-01

    AIM: The purpose of this study was to compare the diagnostic accuracy of biphasic multi-detector row helical computed tomography (MDCT), digital subtraction angiography (DSA) and Lipiodol computed tomography (CT) in detection of hypervascular hepatocellular carcinoma (HCC). METHODS: Twenty-eight patients with nodular HCC underwent biphasic MDCT examination: hepatic arterial phase (HAP) 25 s and portal venous phase (PVP) 70 s after injection of the contrast medium (1.5 mL/kg). They also underwent hepatic angiography and intra-arterial infusion of iodized oil. Lipiodol CT was performed 3-4 wk after infusion. MDCT images were compared with DSA and Lipiodol CT images for detection of hepatic nodules. RESULTS: The three imaging techniques had the same sensitivity in detecting nodules >20 mm in diameter. There was no significant difference in the sensitivity among HAP-MDCT, Lipiodol CT and DSA for nodules of 10-20 mm in diameter. For the nodules <10 mm in diameter, HAP-MDCT identified 47, Lipiodol CT detected 27 (χ2 = 11.3, P = 0.005<0.01, HAP-MDCT vs Lipiodol CT) and DSA detected 16 (χ2 = 9.09, P = 0.005<0.01 vs Lipiodol CT and χ2 = 29.03, P = 0.005<0.01vs HAP-MDCT). However, six nodules <10 mm in diameter were detected only by Lipiodol CT. CONCLUSION: MDCT and Lipiodol CT are two complementary modalities. At present, MDCT does not obviate the need for DSA and subsequent Lipiodol CT as a preoperative examination for HCC. PMID:15633215

  1. CT Angiography after 20 Years

    PubMed Central

    Rubin, Geoffrey D.; Leipsic, Jonathon; Schoepf, U. Joseph; Fleischmann, Dominik; Napel, Sandy

    2015-01-01

    Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5–15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography. PMID:24848958

  2. CT angiography - head and neck

    MedlinePlus

    ... medlineplus.gov/ency/article/007677.htm CT angiography - head and neck To use the sharing features on this page, ... create pictures of the blood vessels in the head and neck. How the Test is Performed You will be ...

  3. [Weighted-averaging multi-planar reconstruction method for multi-detector row computed tomography].

    PubMed

    Aizawa, Mitsuhiro; Nishikawa, Keiichi; Sasaki, Keita; Kobayashi, Norio; Yama, Mitsuru; Sano, Tsukasa; Murakami, Shin-ichi

    2012-01-01

    Development of multi-detector row computed tomography (MDCT) has enabled three-dimensions (3D) scanning with minute voxels. Minute voxels improve spatial resolution of CT images. At the same time, however, they increase image noise. Multi-planar reconstruction (MPR) is one of effective 3D-image processing techniques. The conventional MPR technique can adjust slice thickness of MPR images. When a thick slice is used, the image noise is decreased. In this case, however, spatial resolution is deteriorated. In order to deal with this trade-off problem, we have developed the weighted-averaging multi-planar reconstruction (W-MPR) technique to control the balance between the spatial resolution and noise. The weighted-average is determined by the Gaussian-type weighting function. In this study, we compared the performance of W-MPR with that of conventional simple-addition-averaging MPR. As a result, we could confirm that W-MPR can decrease the image noise without significant deterioration of spatial resolution. W-MPR can adjust freely the weight for each slice by changing the shape of the weighting function. Therefore, W-MPR can allow us to select a proper balance of spatial resolution and noise and at the same time produce suitable MPR images for observation of targeted anatomical structures.

  4. CT Angiography (CTA)

    MedlinePlus

    ... medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ... the extent and severity of the effects of coronary artery disease and plan for a surgical operation, such as ...

  5. Automatic liver segmentation method featuring a novel filter for multiphase multidetector-row helical computed tomography.

    PubMed

    Hirose, Tomohiro; Nitta, Norihisa; Tsudagawa, Masaru; Takahashi, Masashi; Murata, Kiyoshi

    2011-01-01

    To introduce an automatic liver segmentation method that includes a novel filter for multiphase multidetector-row helical computed tomography. We acquired 3-phase multidetector-row computed tomographic scans that included unenhanced, arterial, and portal phases. The liver was segmented using our novel adaptive linear prediction filter designed to reduce the difference between filter input and output values in the liver region and to increase these values outside the liver region. The segmentation algorithm produced a mean dice similarity coefficient (DSC) value of 91.4%. The application of our adaptive linear prediction filter was effective in automatically extracting liver regions.

  6. Clinical significance of multidetector-row computed tomography in breast surgery.

    PubMed

    Doihara, Hiroyoshi; Fujita, Takeo; Takabatake, Daisuke; Takahashi, Hirotoshi; Ogasawara, Yutaka; Shimizu, Nobuyoshi

    2006-01-01

    Several reports support the association of higher ipsilateral breast tumor recurrence rates with positive or intermediate margins compared with negative pathologic margins. Precise evaluation of tumor extension and adequate surgical margin are important factors affecting tumor recurrence after breast-conserving surgery (BCS). Many studies have reported the utility of magnetic resonance imaging (MRI) for diagnosing the tumor extension of breast cancer, but few have evaluated the utility of multidetector-row computed tomography (MDCT). The results of this study show the clinical significance of MDCT for detecting cancer extension and demonstrate the clinical role of MDCT in BCS. Subjects comprised 136 patients grouped into two categories based on whether or not tumor extension was evaluated with MDCT preoperatively. The positive surgical margin rate and breast conservation rate were analyzed in each group and the clinical role of MDCT in BCS was evaluated. Moreover, evaluation of intraductal extension was done both with MDCT and histologically, and computed tomography (CT)-pathologic correlations were examined retrospectively. Finally, the margin-positive cases were analyzed in relation to their clinical characteristics. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of the intraductal component were 71.8%, 85.7%, 82.1%, and 76.9%, respectively. The positive surgical margin rate and conservation rate are 7.46% and 81.9%, respectively, for those who were diagnosed with MDCT preoperatively; their corresponding rates without MDCT were 16.67% and 67.9%. Most margin-positive patients have remarkable lymphatic space invasion. Positive surgical margins were often recognized toward the nipple. For diagnosing the intraductal extension, MDCT shows sufficient diagnosability. Moreover, MDCT can provide appropriate information for the determination of adequate surgical margins and contribute to increases in breast conservation

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

    PubMed

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

    2016-05-28

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

  8. [Study of renal veins by multidetector-row computed tomography scans].

    PubMed

    Bouali, O; Mouttalib, S; Labarre, D; Munzer, C; Lopez, R; Lauwers, F; Moscovici, J

    2014-12-01

    To determine the prevalence of renal vein variants. To investigate the distribution of renal veins. We retrospectively reviewed spiral computed tomography (CT) scans of the abdomen performed during a two-month period. The same protocol was used for all CT scans: same multidetector-row CT scanner (Siemens(®)), 1 to 2-mm section thickness, injection of intravenous iomeprol. The study group included 121 patients, aged 21.7 to 93.4 years (mean age 60.9 ± 15.4 years). The sex ratio was 2/1, with 80 men and 41 women. Seventy-three percent of the study group (88 patients) had no variants of the renal veins. Indeed almost 40% (48 patients) had one artery and one vein on each side, with typical course, and 33% (40 patients) had course and/or number variants of the renal arteries. Variants of the right renal vein consisted in multiple veins in 20.6% (25 cases). We detected no case of multiple left renal veins, but we described variations of its course in 9.1% (11 cases): 5 cases of retroaortic left renal vein (4.1%) and 6 cases of circumaortic left renal vein (5%). Three of these 11 patients had an associated double right renal vein. The probability to have a right renal vein variant was significantly higher than a left one (OR = 2.6, P = 0.01). And we found a significantly higher risk of having a venous variant in women (OR = 2.4, P = 0.04). We detected no case of inferior vena cava variant. In our study, prevalence of a circum- or retroaortic left renal vein appeared higher than previously reported in the literature (9.1%). Knowledge of anatomical variants of renal vasculature is crucial and this study puts the emphasis on variations of course and number of renal vessels. Those variations are not so uncommon and should be known by radiologists and also by surgeons. Their knowledge has major clinical implications in practice and it contributes to the safety of renal and retroperitoneal surgery. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Radiation dose measurements in coronary CT angiography

    PubMed Central

    Sabarudin, Akmal; Sun, Zhonghua

    2013-01-01

    Coronary computed tomography (CT) angiography is associated with high radiation dose and this has raised serious concerns in the literature. Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients, thus, contributing to the implementation of dose-saving strategies. This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures. PMID:24392190

  10. Assessment of modified Blalock-Taussig shunt in children with congenital heart disease using multidetector-row computed tomography.

    PubMed

    Nabo, Manal Mohamed Helmy; Hayabuchi, Yasunobu; Inoue, Miki; Watanabe, Noriko; Sakata, Miho; Kagami, Shoji

    2010-11-01

    The purpose of this study was to assess the feasibility of multidetector-row computed tomography (MDCT) for the evaluation of modified Blalock-Taussig (B-T) shunt in children with congenital heart disease associated with reduced pulmonary blood flow. A total of 25 consecutive patients (mean age, 2.6 ± 3.6 years; range, 2 months-16 years) underwent MDCT angiography of the thorax with a 16-detector row scanner prior to cardiac catheterization. A total of 39 shunts (right, 22; left, 17) were included in the study. Conventional angiographic findings were used as the gold standard for the detection of B-T shunts. Shunt diameter was measured quantitatively and independently at four sites (the subclavian artery site, the pulmonary artery site, the widest site, and the stenotic site) on MDCT and on conventional invasive angiography. All B-T shunts were depicted on multiplanar reconstruction (MPR), maximum intensity projection (MIP), curved planar reconstruction (CPR), and three-dimensional volume-rendered (VR) images, enabling evaluation in all patients except for one with occluded shunt. There were excellent correlations between MDCT- and conventional angiography-based measurements of shunt diameter at the subclavian artery site, pulmonary artery site, and the widest site (R² = 0.46, 0.74 and 0.64, respectively; p < 0.0001 for each), although systematic overestimation was observed for MDCT (mean percentage of overestimation, 23.1 ± 32.4%). Stenotic site diameter and degree of stenosis showed a mild correlation (R² = 010 and 0.25, respectively; p < 0.01 for each). This study demonstrates that MDCT is a promising tool for the detection of lesions in B-T shunts.

  11. The clinical outcome of occult pulmonary contusion on multidetector-row computed tomography in blunt trauma patients.

    PubMed

    Deunk, Jaap; Poels, Tielke C; Brink, Monique; Dekker, Helena M; Kool, Digna R; Blickman, Johan G; van Vugt, Arie B; Edwards, Michael John Richard

    2010-02-01

    Multidetector-row computed tomography (MDCT) is a more sensitive modality as compared with conventional radiography (CR) in detecting pulmonary injuries. MDCT often detects pulmonary contusion that is not visualized by CR, defined as occult pulmonary contusion (OPC). The aim of this study was to investigate whether OPC on MDCT has implications for the outcome in blunt trauma patients. We used prospectively collected data from 1,040 adult high-energy blunt trauma patients who were primarily presented at our emergency department and who underwent CR and MDCT of the chest. All patients with pulmonary contusion were identified and divided into two groups: The "CR/computed tomography (CT) group" consisted of patients with pulmonary contusion visible on both CR and MDCT. The "CT-only" group consisted of patients with OPC, visible exclusively on MDCT. The control group consisted of blunt trauma patients without pulmonary contusion. These groups were compared with respect to difference in mortality and other outcome measures. In addition, a multivariate analysis was performed. Two hundred fifty-five patients suffered pulmonary contusion: The CT-only group consisted of 157 and the CR/CT group of 98 patients. The CT-only group did not differ from the control group with respect to mortality rate and other outcome measures. However, compared with the CR/CT group, mortality rate was significantly lower (8% versus 16%, p = 0.039) and most other outcome measures were significantly better in the CT-only group. OPC on MDCT is not associated with a worse outcome as compared with patients without pulmonary contusion. OPC has a better outcome as compared with pulmonary contusion visible on both CR and MDCT.

  12. CT angiography ofthe carotid arteries.

    PubMed

    Prokop, M; Waaijer, A; Kreuzer, S

    2004-01-01

    The introduction of multislice scanning has made CT angiography (CTA) a serious competitor to MR angiography (MRA) as a second line method for the evaluation of the carotid arteries. For optimum display of the morphology of stenoses, it is necessary to apply the thinnest possible section collimation (ideally [symbol: see text] 1.25mm). While the scan range is limited for single slice CTA, it is possible to cover the whole supraaortic circulation from the aortic arch to the intracranial vessels using multislice scanning. Timing of contrast injection is important, however, the injection technique for carotid CTA is more forgiving than for other body regions. Image evaluation is mainly based on axial sections and curved planar reformations (CPR). Other techniques only serve as an adjunct to better be able to demonstrate the findings. Most potential pitfalls can be avoided by using the appropriate technique. CTA has been shown to have a pooled sensitivity of 95% and specificity of 98% for the detection of >70% stenoses, even if only older single-slice techniques are used. Differentiation between lipid, fibrous and calcified plaques may be possible, especially with multislice scanning. Multislice CTA can in addition detect tandem stenoses in the region of the carotid origin from the aorta, the carotid siphon, and the intracranial portion of the carotids. CT is able to provide a comprehensive evaluation of patients with acute stroke by using a combined approach of pre-contrast CT to detect hemorrhage and manifest infarction, CT brain perfusion measurements to differentiate between penumbra and infarct and CTA to detect the occluded vessel as well as potential concomitant carotid abnormalities. In summary, carotid CTA has come of age and can be used to quantify stenoses more precisely than ultrasound, to detect tandem stenoses and for the workup of acute stroke patients. The learning objectives include learning how to chose acquisition parameters for carotid CTA, how to

  13. Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings

    PubMed Central

    2011-01-01

    Background Diagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT) was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography. Results Electrocardiography (ECG)-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol. Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats. Conclusions Contrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional information can be of help

  14. Improvement in the quality of the cardiac vein images by optimizing the scan protocol of multidetector-row computed tomography.

    PubMed

    Hara, Tetsuya; Yamashiro, Kohei; Okajima, Katsunori; Hayashi, Takatoshi; Kajiya, Teishi

    2009-11-01

    The present study aimed at optimizing the scan protocol for multidetector-row computed tomography (MDCT) to adequately visualize coronary veins. Circulation time (Cir.T) was defined as the time period from the injection of contrast media into the coronary artery to the pervasion of the contrast media into the coronary sinus as observed by coronary angiography. We investigated the relation between the Cir.T and echocardiographic parameters in 64 patients. The left ventricular end-diastolic diameter (LVDd) and left ventricular end-systolic diameter (LVDs) were correlated with the Cir.T (r = 0.58, P < 0.0001, and r = 0.60, P < 0.0001 respectively). In addition, the left ventricular ejection fraction (LVEF) was negatively correlated with the Cir.T (r = 0.48, P < 0.0001). The average Cir. T was longer in patients with LVEF < 35% (8.0 s vs 6.7 s; P < 0.05) or LVDd > 55 mm (7.9 s vs 6.2 s; P < 0.05) than in the other patients. The quality of the MDCT images of the coronary veins obtained at different scan timings (coronary artery phase and 10 s or 15 s after the coronary artery phase) were graded and classified into four categories (0 = worst, 3 = best) in 25 patients with LVEF < 35%. The delays of 10 and 15 s after the coronary artery phase significantly improved the mean image quality (P < 0.05). The Cir.T was prolonged in patients with low LVEF and LV dilation. An appropriate delay improved the quality of the MDCT images of the coronary veins in patients with LV dysfunction.

  15. Multicenter Evaluation Of Coronary Dual-Source CT angiography in patients with intermediate Risk of Coronary Artery Stenoses (MEDIC): study design and rationale.

    PubMed

    Marwan, Mohamed; Hausleiter, Jörg; Abbara, Suhny; Hoffmann, Udo; Becker, Christoph; Ovrehus, Kristian; Ropers, Dieter; Bathina, Ravi; Berman, Dan; Anders, Katharina; Uder, Michael; Meave, Aloha; Alexánderson, Erick; Achenbach, Stephan

    2014-01-01

    The diagnostic performance of multidetector row CT to detect coronary artery stenosis has been evaluated in numerous single-center studies, with only limited data from large cohorts with low-to-intermediate likelihood of coronary disease and in multicenter trials. The Multicenter Evaluation of Coronary Dual-Source CT Angiography in Patients with Intermediate Risk of Coronary Artery Stenoses (MEDIC) trial determines the accuracy of dual-source CT (DSCT) to identify persons with at least 1 coronary artery stenosis among patients with low-to-intermediate pretest likelihood of disease. The MEDIC trial was designed as a prospective, multicenter, international trial to evaluate the diagnostic performance of DSCT for the detection of coronary artery stenosis compared with invasive coronary angiography. The study includes 8 sites in Germany, India, Mexico, the United States, and Denmark. The study population comprises patients referred for a diagnostic coronary angiogram because of suspected coronary artery disease with an intermediate pretest likelihood as determined by sex, age, and symptoms. All evaluations are performed by blinded core laboratory readers. The primary outcome of the MEDIC trial is the accuracy of DSCT to identify the presence of coronary artery stenoses with a luminal diameter narrowing of 50% or more on a per-vessel basis. Secondary outcome parameters include per-patient and per-segment diagnostic accuracy for 50% stenoses and accuracy to identify stenoses of 70% or more. Furthermore, secondary outcome parameters include the influence of heart rate, Agatston score, body weight, body mass index, image quality, and diagnostic confidence on the accuracy to detect coronary artery stenoses >50% on a per-vessel basis. The results of the MEDIC trial will assess the clinical utility of coronary CT angiography in the evaluation of patients with intermediate pretest likelihood of coronary artery disease. Copyright © 2014 Society of Cardiovascular Computed

  16. CT angiography - abdomen and pelvis

    MedlinePlus

    Computed tomography angiography - abdomen and pelvis; CTA - abdomen and pelvis; Renal artery - CTA; Aortic - CTA; Mesenteric CTA ... belly or pelvis Masses and tumors in the abdomen or pelvis, including cancer, when needed to help ...

  17. [Extra-organic primary tumor in pelvis: correlation of multi-detector row computed tomography, anatomy and pathology].

    PubMed

    Dong, Zhihui; Yang, Zhigang; Li, Yuan; Min, Pengqiu; Zhang, Xiaochun

    2009-02-01

    The purpose of this study was to investigate the correlation between multi-detector row CT (MDCT) features, pathological findings and the anatomic basis of extra-organic primary tumors in pelvis so as to improve the document diagnosis of these entities. We retrospectively analyzed the MDCT manifestations of 20 cases with surgically and/or pathologically evidenced diagnoses of extra-organic primary tumors in pelvis. The results showed that, in 14 cases, the tumors were located in the pelvis, and 6 of them involved both pelvis and hypogastric zone. There were 8 tumors located in the peritoneal cavity of the pelvis, and 3 of them also involved the extraperitoneal space of the pelvis. In the peritoneal cavity, 2 tumors of male patients were located in the rectovesical pouch while 3 tumors of female patients were located in the rectouterine pouch. The majority of entities in these 2 pouches were germ cell tumors (3/5 cases, 60.0%). In the extraperitoneal space, 5 of 12 tumors were located in the pararectal space and 5 of them were located in the retrorectal space. The majority entities of these 10 cases were germ cell tumors (7/10 cases, 70.0%). Lymphoma mainly involved paravesical and pararectal space in disorder. Calcification occurred in 6 cases, including 4 cases of teratoma, 1 case of neurilemmoma, and 1 case of malignant teratoma. The fatty element occurred in 7 masses, including 4 cases of teratoma, 1 case of malignant teratoma, 1 case of mixed germ cell tumor, and 1 case of liposarcoma. MDCT with multi-planar reconstruction (MPR) could more clearly reveal the anatomic location of the extra-organic primary tumor in pelvis, could unveil the tumor's relationship with its surrounding organs, and could help to differentiate benign tumors from malignant tumors.

  18. Acute Ischemic Stroke: Infarct Core Estimation on CT Angiography Source Images Depends on CT Angiography Protocol

    PubMed Central

    Pulli, Benjamin; Schaefer, Pamela W.; Hakimelahi, Reza; Chaudhry, Zeshan A.; Lev, Michael H.; Hirsch, Joshua A.; González, R. Gilberto

    2012-01-01

    Purpose: To test whether the relationship between acute ischemic infarct size on concurrent computed tomographic (CT) angiography source images and diffusion-weighted (DW) magnetic resonance images is dependent on the parameters of CT angiography acquisition protocols. Materials and Methods: This retrospective study had institutional review board approval, and all records were HIPAA compliant. Data in 100 patients with anterior-circulation acute ischemic stroke and large vessel occlusion who underwent concurrent CT angiography and DW imaging within 9 hours of symptom onset were analyzed. Measured areas of hyperintensity at acute DW imaging were used as the standard of reference for infarct size. Information regarding lesion volumes and CT angiography protocol parameters was collected for each patient. For analysis, patients were divided into two groups on the basis of CT angiography protocol differences (patients in group 1 were imaged with the older, slower protocol). Intermethod agreement for infarct size was evaluated by using the Wilcoxon signed rank test, as well as by using Spearman correlation and Bland-Altman analysis. Multivariate analysis was performed to identify predictors of marked (≥20%) overestimation of infarct size on CT angiography source images. Results: In group 1 (n = 35), median hypoattenuation volumes on CT angiography source images were slightly underestimated compared with DW imaging hyperintensity volumes (33.0 vs 41.6 mL, P = .01; ratio = 0.83), with high correlation (ρ = 0.91). In group 2 (n = 65), median volume on CT angiography source images was much larger than that on DW images (94.8 vs 17.8 mL, P < .0001; ratio = 3.5), with poor correlation (ρ = 0.49). This overestimation on CT angiography source images would have inappropriately excluded from reperfusion therapy 44.4% or 90.3% of patients eligible according to DW imaging criteria on the basis of a 100-mL absolute threshold or a 20% or greater mismatch threshold, respectively

  19. Coronary CT angiography with low radiation dose.

    PubMed

    Xu, Lei; Zhang, Zhaoqi

    2010-02-01

    With the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography(CCTA) has emerged as a useful diagnostic imaging modality for the noninvasive assessment of coronary heart disease. Recently, the risks associated with ionizing radiation on CT have raised serious concerns.The main concern of exposure to ionizing radiation is the potential risk of cancer. CCTA involves much higher radiation dose with the advances in the spatial and temporal resolution of cardiac CT. Currently,various dose-saving algorithms, such as ECG (electrocardiography)-based dose modulation, reduced tube voltage, and prospective ECG gating, high-pitch helical scanning are available to lower radiation exposure during cardiac CT. Therefore, careful selection of CT scanning protocols is needed to keep the radiation exposure 'as low as reasonably achievable (ALARA)'. In this review we will discuss the radiation dose safety issues, the measurement of radiation dose and current use of dose-saving techniques in CCTA.

  20. Three-dimensional image reconstruction of an anorectal malformation with multidetector-row helical computed tomography technology.

    PubMed

    Watanabe, Yoshio; Ando, Hisami; Seo, Takahiko; Kaneko, Kentaro; Katsuno, Shinsuke; Shinohara, Tsuyoshi; Mori, Kensaku; Toriwaki, Junichiro

    2003-05-01

    The presentation of the surgical anatomy of anorectal malformation by standard anatomical figures is not suitable for individual anorectoplasty. It is essential to understand the anatomy of the pelvic muscle (striated muscle complex: SMC) including the external anal sphincter and their three-dimensional (3D) configuration in each patient. Thus, we studied the SMC three-dimensionally with multidetector-row helical computed tomography (MRH-CT) preoperatively, and evaluated its usefulness. Fourteen patients with anorectal malformations before anorectoplasty (types: high n=6, intermediate n=2, low n=6) and two patients without anorectal malformations as controls (total: male n=8, female n=8) were investigated. An image of pelvic region was prepared with a slice thickness of 0.5 mm and a reconstruction pitch of 0.5 mm. A 3D reconstruction on a conventional personal computer (PC) was made with a volume rendering method, and assisted by our own software. The SMC was analyzed with three modified modes of 3D reconstruction corresponding to the surrounding tissues. A length of the parasagittal muscle, and both the sagittal and transverse width of the vertical fibers in the SMC at the connection to the parasagittal muscle were measured on a 3D image and then compared among three different types and controls. To eliminate variations in age, a length index was used to allow comparison. The 3D configuration of the SMC was different in every case. The arranged image mode, which displayed the SMC and the pelvic bones simultaneously, enabled to use conventional knowledge in cysto-urethrography. The length of the parasagittal muscle was longest in the high type but the width of the vertical fibers was smallest. Anatomical figures of the SMC including the external anal sphincter were clearly demonstrated on a PC in every anorectal malformation by our program. A 3D reconstruction image provides positional information on the SMC for the body surface and pelvic bone at the same time

  1. Differentiation of Lymphoma Presenting as Retroperitoneal Mass and Retroperitoneal Fibrosis: Evaluation with Multidetector-row Computed Tomography

    PubMed Central

    Zhang, Shuai; Chen, Min; Li, Chun-Mei; Song, Guo-Dong; Liu, Ying

    2017-01-01

    Background: Retroperitoneal fibrosis (RPF) and lymphoma presenting as retroperitoneal mass may closely resemble each other and misdiagnosis may occur. This study investigated the differential imaging features of RPF and lymphoma which presented as a retroperitoneal soft tissue using multidetector-row computed tomography (MDCT). Methods: The 42 consecutive patients were included in this retrospective review, including 19 RPF patients (45.2%; including 13 males and 6 females; mean age: 56.7 ± 6.2 years) and 23 patients with lymphoma (54.8%; including 14 males and 9 females; mean age: 57.4 ± 12.3 years). An array of qualitative computed tomography (CT) features of lesions in 42 consecutive patients with newly diagnosed untreated RPF and lymphoma were retrospectively analyzed. The quantitative size of the lesion at the para-aortic region and attenuation in the precontrast, arterial, and portal phases were calculated in regions of interest and compared between the patients with newly diagnosed untreated RPF and with lymphoma. Receiver operating characteristic curve analysis was used to assess the potential diagnostic value of each quantitative parameter. Inter-reader concordance was also calculated. Results: Mean ages between patients with RPF and lymphoma were not significantly different (56.7 ± 6.2 years vs. 57.4 ± 12.3 years P = 0.595). Compared to those in patients with lymphoma, homogeneous enhancement (65.2% vs. 94.7%, P = 0.027) and pelvic extension (52.2% vs. 89.5%, P = 0.017) were significantly more common while the involvement of additional nodes (78.3% vs. 5.3%, P < 0.001), suprarenal extension (60.9% vs. 15.8%, P = 0.004), and aortic displacement (43.5% vs. 5.3%, P = 0.006) were significantly less common in patients with RPF. Lesion size at the para-aorta was significantly greater in patients with lymphoma, compared with RPF patients (3.9 ± 1.2 cm vs. 1.8 ± 0.6 cm; P < 0.001). The attenuation values in three phases were not significantly different

  2. Differentiation of Lymphoma Presenting as Retroperitoneal Mass and Retroperitoneal Fibrosis: Evaluation with Multidetector-row Computed Tomography.

    PubMed

    Zhang, Shuai; Chen, Min; Li, Chun-Mei; Song, Guo-Dong; Liu, Ying

    2017-03-20

    Retroperitoneal fibrosis (RPF) and lymphoma presenting as retroperitoneal mass may closely resemble each other and misdiagnosis may occur. This study investigated the differential imaging features of RPF and lymphoma which presented as a retroperitoneal soft tissue using multidetector-row computed tomography (MDCT). The 42 consecutive patients were included in this retrospective review, including 19 RPF patients (45.2%; including 13 males and 6 females; mean age: 56.7 ± 6.2 years) and 23 patients with lymphoma (54.8%; including 14 males and 9 females; mean age: 57.4 ± 12.3 years). An array of qualitative computed tomography (CT) features of lesions in 42 consecutive patients with newly diagnosed untreated RPF and lymphoma were retrospectively analyzed. The quantitative size of the lesion at the para-aortic region and attenuation in the precontrast, arterial, and portal phases were calculated in regions of interest and compared between the patients with newly diagnosed untreated RPF and with lymphoma. Receiver operating characteristic curve analysis was used to assess the potential diagnostic value of each quantitative parameter. Inter-reader concordance was also calculated. Mean ages between patients with RPF and lymphoma were not significantly different (56.7 ± 6.2 years vs. 57.4 ± 12.3 years P = 0.595). Compared to those in patients with lymphoma, homogeneous enhancement (65.2% vs. 94.7%, P = 0.027) and pelvic extension (52.2% vs. 89.5%, P = 0.017) were significantly more common while the involvement of additional nodes (78.3% vs. 5.3%, P < 0.001), suprarenal extension (60.9% vs. 15.8%, P = 0.004), and aortic displacement (43.5% vs. 5.3%, P = 0.006) were significantly less common in patients with RPF. Lesion size at the para-aorta was significantly greater in patients with lymphoma, compared with RPF patients (3.9 ± 1.2 cm vs. 1.8 ± 0.6 cm; P < 0.001). The attenuation values in three phases were not significantly different between patients with RPF and

  3. CT angiography - arms and legs

    MedlinePlus

    ... combines a CT scan with the injection of dye. This technique is able to create pictures of ... Some exams require a special dye, called contrast, to be injected into your body before the test. Contrast helps certain areas show up better on the x- ...

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

    PubMed Central

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

    2006-01-01

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

  5. Pericardial fat amount is an independent risk factor of coronary artery stenosis assessed by multidetector-row computed tomography: the Korean Atherosclerosis Study 2.

    PubMed

    Kim, Tae Hyuk; Yu, Sung Hoon; Choi, Sung Hee; Yoon, Ji Won; Kang, Seon Mee; Chun, Eun Ju; Choi, Sang Il; Shin, Hayley; Lee, Hong Kyu; Park, Kyong Soo; Jang, Hak Chul; Lim, Soo

    2011-05-01

    Pericardial fat surrounding the heart and coronary arteries might aggravate vessel wall inflammation and stimulate the progression of coronary atherosclerosis. However, there has been little comprehensive evaluation of the effects of pericardial fat on coronary artery disease (CAD). We investigated the relationship between pericardial fat volume and the severity of coronary artery stenosis assessed by computed tomography and angiography among patients with suspected CAD. Participants from the cohort of the Korean Atherosclerosis Study 2 (n = 402, mean age of 54 years, 57.0% men) underwent 64-slice multidetector-row computed tomography (MDCT) to assess pericardial fat amount, coronary artery calcium score (CACS), severity of coronary artery stenosis, and plaque characteristics. Patients with atherosclerotic lesion had significantly larger volume of pericardial fat than patients without atherosclerosis (308 ± 96 cm(3) vs. 251 ± 93 cm(3); P < 0.01). In a multivariate regression analysis adjusting for age, gender and BMI, subjects with more pericardial fat had a higher risk for significant (>50%) stenosed coronary vessels (odds ratio (OR) = 1.012; 95% confidence interval (CI) 1.001-1.030; P = 0.017). This association remained after adjusting for hypertension, diabetes, smoking status, and lipid profiles (OR = 1.007; 95% CI 1.001-1.014; P = 0.042). In conclusion, an increased pericardial fat volume was an independent risk factor for stenotic CAD and could be helpful in assessing subclinical CADs.

  6. Cardiac CT Angiography in Congestive Heart Failure.

    PubMed

    Levine, Avi; Hecht, Harvey S

    2015-06-01

    Cardiac CT angiography has become an important tool for the diagnosis and treatment of congestive heart failure. Differentiation of ischemic from nonischemic cardiomyopathy; evaluation of myocardial perfusion; characterization of hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia; and delineation of congenital heart defects and valvular abnormalities are the primary diagnostic applications. Therapeutic use includes visualization of the coronary venous anatomy for optimal implementation of cardiac resynchronization therapy and evaluation of left ventricular assist devices and transplant vasculopathy.

  7. Coronary CT angiography: Beyond morphological stenosis analysis.

    PubMed

    Sun, Zhonghua

    2013-12-26

    Rapid technological developments in computed tomography (CT) imaging technique have made coronary CT angiography an attractive imaging tool in the detection of coronary artery disease. Despite visualization of excellent anatomical details of the coronary lumen changes, coronary CT angiography does not provide hemodynamic changes caused by presence of plaques. Computational fluid dynamics (CFD) is a widely used method in the mechanical engineering field to solve complex problems through analysing fluid flow, heat transfer and associated phenomena by using computer simulations. In recent years, CFD is increasingly used in biomedical research due to high performance hardware and software. CFD techniques have been used to study cardiovascular hemodynamics through simulation tools to assist in predicting the behaviour of circulatory blood flow inside the human body. Blood flow plays a key role in the localization and progression of coronary artery disease. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of vascular geometry, thus, identifying risk factors for development of coronary artery disease. The purpose of this article is to provide an overview of the coronary CT-derived CFD applications in coronary artery disease.

  8. Hemodialysis fistula occlusion: demonstration with 64-slice CT angiography.

    PubMed

    Neyman, Edward G; Johnson, Pamela T; Fishman, Elliot K

    2006-01-01

    The speed and resolution of 64-slice CT have resulted in new applications for CT angiography (CTA) owing to rapid data acquisition during the arterial phase, improved visualization of small vessels, and lengthened anatomic coverage. Extremity CT angiography is one such region. This case report shows the utility of multislice CTA for the evaluation of hemodialysis graft dysfunction.

  9. Multiphase Multi-Detector Row Computed Tomography Imaging Characteristics of Large (>5 cm) Focal Hepatocellular Carcinoma.

    PubMed

    Blaschke, Eric M; Rao, Vijaya L; Xiong, Lingyun; Te, Helen S; Hart, John; Reddy, K Gautham; Oto, Aytekin

    2016-01-01

    The aim of this study was to describe the multiphase multi-detector row computed tomography (MDCT) imaging findings of large (>5 cm) focal hepatocellular carcinoma (HCC). Following review of the medical records of 321 patients with newly diagnosed HCC who underwent MDCT within the radiology database from January 2007 to November 2014, 27 patients (20 men and 7 women; mean age, 69 [SD, 10.1] years [range, 49-87 years]) with histologically confirmed HCC greater than 5 cm were included in this institutional review board-approved study. Multiphase, dedicated liver MDCT images of these cases were retrospectively reviewed by 2 radiologists in consensus to describe the enhancement characteristics of these lesions. Mean tumor diameter was 8.4 (SD, 2.4) cm (range, 5.2-13.5 cm). Cirrhosis was present in 16 (59%) of 27 patients. Seventeen (85%) of 20 patients with available laboratory data presented with elevated alpha-fetoprotein (median, 97 ng/mL). Twenty-three (85%) of 27 demonstrated either heterogeneous enhancement with gradual fill-in (14/27 [52%]) or peripheral enhancement with centripetal fill-in (9/27 [33%]). Twenty-two (81%) of 27 lacked washout on delayed phase images, and 21 (78%) of 27 demonstrated a pseudocapsule. Twenty-seven of 27 lesions were well defined, 8 (30%) of 27 were exophytic, 15 (56%) of 27 were unifocal, 5 (25%) of 20 cases demonstrated vascular invasion, and 7 (26%) of 27 cases presented with extrahepatic metastases. Large (>5 cm) focal HCC may present as a dominant mass with a pseudocapsule and initial heterogeneous or peripheral enhancement with gradual or centripetal fill-in without washout on multiphase MDCT. Awareness of this variant is important to allow distinction from other benign (eg, hemangioma) and malignant (eg, cholangiocarcinoma) focal liver lesions.

  10. Automated assessment of the aortic root dimensions with multidetector row computed tomography.

    PubMed

    Delgado, Victoria; Ng, Arnold C T; Schuijf, Joanne D; van der Kley, Frank; Shanks, Miriam; Tops, Laurens F; van de Veire, Nico R L; de Roos, Albert; Kroft, Lucia J M; Schalij, Martin J; Bax, Jeroen J

    2011-03-01

    Accurate aortic root measurements and evaluation of spatial relationships with coronary ostia are crucial in preoperative transcatheter aortic valve implantation assessments. Standardization of measurements may increase intraobserver and interobserver reproducibility to promote procedural success rate and reduce the frequency of procedurally related complications. This study evaluated the accuracy and reproducibility of a novel automated multidetector row computed tomography (MDCT) imaging postprocessing software, 3mensio Valves (version 4.1.sp1, Medical Imaging BV, Bilthoven, The Netherlands), in the assessment of patients with severe aortic stenosis candidates for transcatheter aortic valve implantation. Ninety patients with aortic valve disease were evaluated with 64-row and 320-row MDCT. Aortic valve annular size, aortic root dimensions, and height of the coronary ostia relative to the aortic valve annular plane were measured with the 3mensio Valves software. The measurements were compared with those obtained manually by the Vitrea2 software (Vital Images, Minneapolis, MN). Assessment of aortic valve annulus and aortic root dimensions were feasible in all the patients using the automated 3mensio Valves software. There were excellent agreements with minimal bias between automated and manual MDCT measurements as demonstrated by Bland-Altman analysis and intraclass correlation coefficients ranging from 0.97 to 0.99. The automated 3mensio Valves software had better interobserver reproducibility and required less image postprocessing time than manual assessment. Novel automated MDCT postprocessing imaging software (3mensio Valves) permits reliable, reproducible, and automated assessments of the aortic root dimensions and spatial relations with the surrounding structures. This has important clinical implications for preoperative assessments of patients undergoing transcatheter aortic valve implantation. Copyright © 2011 The Society of Thoracic Surgeons. Published by

  11. Does CT Angiography Matter for Patients with Cervical Spine Injuries?

    PubMed

    Hagedorn, John C; Emery, Sanford E; France, John C; Daffner, Scott D

    2014-06-04

    Cervical injury can be associated with vertebral artery injury. This study was performed to determine the impact of computed tomography (CT) angiography of the head and neck on planning treatment of cervical spine fracture, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast medium. This retrospective review included all patients who underwent CT of the cervical spine and CT angiography of the head and neck from January 2010 to August 2011 at one institution. Patients were divided into those with and those without cervical spine fracture seen on CT of the cervical spine. We determined if the CT angiography of the head and neck was positive for vascular injury in the patients with a cervical fracture. Vascular injury treatment and alterations in surgical fracture treatment due to positive CT angiography of the head and neck were recorded. A scan was deemed appropriate if it had been ordered per established institutional protocol. Of the 381 patients who underwent CT angiography of the head and neck, 126 had a cervical injury. Sixteen of the CT angiography studies were appropriately ordered for non-spinal indications, and twenty-three were inappropriately ordered. The CT angiography was positive for one patient for whom the imaging was off protocol and one for whom the indication was non-spinal. Nineteen patients had positive CT angiography of the head and neck; no patient underwent surgical intervention for a vascular lesion. Eleven patients underwent surgical intervention for a cervical fracture; the operative plan was changed because of vascular injury in one case. The CT angiography was positive for eleven of forty-eight patients who had sustained a C2 fracture; this group accounted for eleven of the nineteen positive CT angiography studies. Noncontiguous injuries occurred in nineteen patients; three had positive CT angiography of the head and neck. The approximate charge for the CT angiography was

  12. Computed tomography imaging and angiography - principles.

    PubMed

    Kamalian, Shervin; Lev, Michael H; Gupta, Rajiv

    2016-01-01

    The evaluation of patients with diverse neurologic disorders was forever changed in the summer of 1973, when the first commercial computed tomography (CT) scanners were introduced. Until then, the detection and characterization of intracranial or spinal lesions could only be inferred by limited spatial resolution radioisotope scans, or by the patterns of tissue and vascular displacement on invasive pneumoencaphalography and direct carotid puncture catheter arteriography. Even the earliest-generation CT scanners - which required tens of minutes for the acquisition and reconstruction of low-resolution images (128×128 matrix) - could, based on density, noninvasively distinguish infarct, hemorrhage, and other mass lesions with unprecedented accuracy. Iodinated, intravenous contrast added further sensitivity and specificity in regions of blood-brain barrier breakdown. The advent of rapid multidetector row CT scanning in the early 1990s created renewed enthusiasm for CT, with CT angiography largely replacing direct catheter angiography. More recently, iterative reconstruction postprocessing techniques have made possible high spatial resolution, reduced noise, very low radiation dose CT scanning. The speed, spatial resolution, contrast resolution, and low radiation dose capability of present-day scanners have also facilitated dual-energy imaging which, like magnetic resonance imaging, for the first time, has allowed tissue-specific CT imaging characterization of intracranial pathology.

  13. Discordance between CT and angiography in the PIOPED II study.

    PubMed

    Wittram, Conrad; Waltman, Arthur C; Shepard, Jo-Anne O; Halpern, Elkan; Goodman, Lawrence R

    2007-09-01

    To retrospectively evaluate the causes of discordant computed tomographic (CT)-angiographic readings from the Prospective Investigation of Pulmonary Embolism Diagnosis, or PIOPED, II study. Institutional review board approval was obtained for this HIPAA-compliant study. Of 1036 patients suspected of having pulmonary embolism who were examined with CT, 226 underwent angiography; 206 patients had concordant results and 20 had discordant results according to two independent readers. Of these 20 patients, 10 were men and 10 were women (mean age, 49 years). Among the 20 studies with discordant results, central readers identified seven cases as negative and 13 as positive for pulmonary embolism at CT; these findings were reversed at angiography. Side-by-side comparisons of discordant studies were performed in consensus. The time between CT and angiography and all locations of pulmonary embolism vascular territory were recorded. The McNemar binomial test was used. One patient had false-positive findings at angiography, 13 patients had false-negative findings at angiography, and two patients had false-negative findings at CT. Four patients had true-negative findings at CT; however, findings were positive for thrombus at angiography. The sensitivity for the detection of pulmonary embolism was 87% for CT and 32% for angiography (P=.007). The largest missed thrombus at angiography was subsegmental in eight patients, segmental in two patients, and lobar in three patients; at CT it was subsegmental in two patients. The mean time between CT and angiography was 40 hours+/-21 (standard deviation) (range, 10-97 hours). In the interval between CT and angiography, thrombi can remain the same, resolve, develop, or result from angiography. Copyright (c) RSNA, 2007.

  14. Significance of PQ interval in acquisition of coronary multidetector row computed tomography.

    PubMed

    Sano, Tomonari; Kondo, Takeshi; Matsutani, Hideyuki; Morita, Hitomi; Arai, Takehiro; Sekine, Takako; Takase, Shinichi; Oida, Akitsugu; Fukazawa, Hiroshi; Kodama, Takahide; Kondo, Makoto; Orihara, Tadaaki; Yamada, Norikazu; Narula, Jagat

    2009-12-01

    Since image quality obtained in the mid-diastolic [or slow filling (SF)] phase is generally superior to end-systolic image in coronary multidetector row computed tomography (MDCT), low heart rate (HR) comprises the most important factor for acquisition of high-quality images. However, despite HR <70 and optimum breath-hold, sometimes high quality images cannot be obtained in SF. We assessed the significance of PQ interval in acquisition of coronary MDCT. Of 541 consecutive patients who underwent coronary MDCT, 7 patients with incomplete breath-hold, 62 HR ≥70, and 70 arrhythmias were excluded. The remaining 402 patients (M: 222, 66±11 years), including 38 with first-degree atrioventricular block (1° AVB, PQ >200 ms) were evaluated. RR and PQ were measured on electrocardiogram and systolic and SF phase with 4-chamber cine cardiac computed tomography. SF significantly (p<0.0001) correlated with RR (SF=-471+0.720RR, r=0.887) in all subjects. The SF of without 1° AVB (292±97 ms) was significantly (p<0.0147) longer than that of with 1° AVB (251±121 ms), although RR was not significantly different between the two groups. The SF/RR of without 1° AVB (27.2±6.1%) was also significantly (p<0.0001) higher than that of with 1° AVB (22.7±8.0%). The coefficient of correlation between (RR-PQ) and SF [r=0.915, p<0.0001, SF=-362+0.742(RR-PQ)] was significantly (p<0.034) higher than that of correlation between RR and SF in all subjects. The SF of rank A image quality was significantly longer than that of rank B (p<0.0001) or rank C (p=0.0042). In critical HR (60-69 bpm), the optimum phase was ES in 7/139 patients without 1° AVB, and SF in 3/13 patients with 1° AVB (chi(2), p<0.0416). Since SF depends on (RR-PQ), if PQ is long in critical HR, it might be difficult to reconstruct high quality images in the SF phase.

  15. Fast scanning tomosynthesis for the detection of pulmonary nodules: diagnostic performance compared with chest radiography, using multidetector-row computed tomography as the reference.

    PubMed

    Yamada, Yoshitake; Jinzaki, Masahiro; Hasegawa, Ichiro; Shiomi, Eisuke; Sugiura, Hiroaki; Abe, Takayuki; Sato, Yuji; Kuribayashi, Sachio; Ogawa, Kenji

    2011-08-01

    : To evaluate the diagnostic performance of fast scanning tomosynthesis in comparison with that of chest radiography for the detection of pulmonary nodules, using multidetector-row computed tomography (MDCT) as the reference, and to assess the association of the true-positive fraction (TPF) with the size, CT attenuation value, and location of the nodules. : The institutional review board approved this study, and written informed consent was obtained from all patients. Fifty-seven patients with and 59 without pulmonary nodules underwent chest MDCT, fast scanning tomosynthesis, and radiography. The images of tomosynthesis and radiography were randomly read by 3 blinded radiologists; MDCT served as the reference standard. Free-response receiver-operating characteristic (FROC) and receiver-operating characteristic (ROC) analyses, Cochran-Armitage trend or Fisher exact test, a conditional logistic regression model, and McNemar test were used. : Both FROC and ROC analyses revealed significantly better performance (P < 0.01) of fast scanning tomosynthesis than radiography for the detection of pulmonary nodules. For fast scanning tomosynthesis, the average TPF and false-positive rate as determined by FROC analysis were 0.80 and 0.10, respectively. For both fast scanning tomosynthesis and radiography, the average TPF increased with increasing nodule size and CT attenuation values, and was lower for subpleural nodules (all P < 0.01). : The diagnostic performance of fast scanning tomosynthesis for the detection of pulmonary nodules was significantly superior to that of radiography. The TPF was affected by the size, CT attenuation value, and location of the nodule, in both fast scanning tomosynthesis and radiography.

  16. CT angiography in the abdomen: a pictorial review and update.

    PubMed

    Liu, Peter S; Platt, Joel F

    2014-02-01

    The development of multidetector CT technology and helical scanning techniques has revolutionized the use of CT for primary diagnostic evaluation of the abdominal vasculature, particularly the arterial system. CT angiography has numerous benefits relative to conventional catheter angiography, and has largely replaced catheter-based techniques in many clinical algorithms. This pictorial review and update will cover important technical principles related to modern CT angiography (including contrast delivery and dose considerations), discuss relevant anatomy and variants, and illustrate numerous arterial conditions related to the abdominal aorta and branch vessels.

  17. Comparison of CT angiography and digital subtraction angiography in the diagnosis of aortic coarctation.

    PubMed

    Miabi, Zinat; Pourfathi, Hojjat; Midia, Mehran; Midia, Ramin; Parvizi, Rezayat

    2011-01-01

    There are several methods for the diagnosis and evaluation of coarctation of the aorta. Digital Subtraction Angiography (DSA) is the standard detection method, though it entails complications and side-effects. The aim of the present study was to compare Computed Tomography (CT) angiography with DSA for diagnosing aortic coarctation. We performed a cross-sectional study of 15 patients (11 males and four females aged between two and 30 years) referred to Tabriz Shahid Madani Hospital and Imaging Center between August 2005 and February 2006 with suspected aortic coarctation. All patients were subjected to DSA and CT angiography for diagnosis of aortic coarctation. The mean age of the patients was 14.6 years; 11 were male (74.4%) and four (26.6%) were female. The DSA and CT angiography results were comparable in all patients in terms of diagnosis and the detection of complications, particularly cardiovascular complications. However, CT angiography was less time-consuming to perform than DSA (p < 0.0001). In conclusion, CT angiography, comparableto DSA, diagnosed coarctation of aorta in all the patients. However, CT angiography is a non-invasive, cost effective procedure that takes significantly less time to carry out than DSA. Therefore, CT angiography is recommended as an appropriate method for diagnosing the coarctation of aorta.

  18. Screening for carotid injury in trauma patients: image quality of 16-detector-row computed tomography angiography.

    PubMed

    Borisch, I; Boehme, T; Butz, B; Hamer, O W; Feuerbach, S; Zorger, N

    2007-09-01

    The introduction of multidetector-row computed tomography (MDCT) has revolutionized the initial management of multiply injured patients. This technology has the potential to improve the imaging of traumatic vascular injuries. To evaluate the quality of multidetector-row computed tomography angiography (MDCTA) of the carotid arteries in the setting of a routine whole-body trauma scan. 87 trauma patients underwent a routine whole-body CT scan in a 16-detector-row scanner including an MDCTA with a reconstructed axial slice thickness of 3 mm. Images were reviewed by three experienced radiologists with emphasis on image quality. Contrast density, severity, and origin of artifacts and the occurrence of vessel lesions were assessed for different vessel segments. 3642 separate vessel segments were evaluated. Contrast density was rated good or sufficient for diagnosis in 99.8%. A total of 67.3% of vessel segments were free of artifacts, while 27.9% of vessel segments showed minor artifacts not impairing diagnostic evaluation. Clinically relevant artifacts obscuring a vessel segment occurred in 4.7% and were mostly caused by dental hardware. Four dissections of the internal carotid artery were diagnosed by all three radiologists. As a rapid screening test for blunt carotid artery injury, integration of MDCTA in the routine imaging workup of trauma patients utilizing a whole-body CT trauma scan is possible and practicable. Image quality is mostly sufficient for diagnosis, but impaired in a few cases by artifacts deriving primarily from dental hardware.

  19. Coronary CT angiography: current status and continuing challenges

    PubMed Central

    Sun, Z; Choo, G H; Ng, K H

    2012-01-01

    Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease owing to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with multislice CT scanners (64 slice and higher), and in selected patients coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. With high-quality coronary CT imaging increasingly being performed, patients can benefit from an imaging modality that provides a rapid and accurate diagnosis while avoiding an invasive procedure. Despite the tremendous contributions of coronary CT angiography to cardiac imaging, study results reported in the literature should be interpreted with caution as there are some limitations existing within the study design or related to patient risk factors. In addition, some attention must be given to the potential health risks associated with the ionising radiation received during cardiac CT examinations. Radiation dose associated with coronary CT angiography has raised serious concerns in the literature, as the risk of developing malignancy is not negligible. Various dose-saving strategies have been implemented, with some of the strategies resulting in significant dose reduction. The aim of this review is to present an overview of the role of coronary CT angiography on cardiac imaging, with focus on coronary artery disease in terms of the diagnostic and prognostic value of coronary CT angiography. Various approaches for dose reduction commonly recommended in the literature are discussed. Limitations of coronary CT angiography are identified. Finally, future directions and challenges with the use of coronary CT angiography are highlighted. PMID:22253353

  20. CT angiography in the diagnosis of cardiovascular disease: a transformation in cardiovascular CT practice

    PubMed Central

    Al Moudi, Mansour; Cao, Yan

    2014-01-01

    Computed tomography (CT) angiography represents the most important technical development in CT imaging and it has challenged invasive angiography in the diagnostic evaluation of cardiovascular abnormalities. Over the last decades, technological evolution in CT imaging has enabled CT angiography to become a first-line imaging modality in the diagnosis of cardiovascular disease. This review provides an overview of the diagnostic applications of CT angiography (CTA) in cardiovascular disease, with a focus on selected clinical challenges in some common cardiovascular abnormalities, which include abdominal aortic aneurysm (AAA), aortic dissection, pulmonary embolism (PE) and coronary artery disease. An evidence-based review is conducted to demonstrate how CT angiography has changed our approach in the diagnosis and management of cardiovascular disease. Radiation dose reduction strategies are also discussed to show how CT angiography can be performed in a low-dose protocol in the current clinical practice. PMID:25392823

  1. Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology

    PubMed Central

    Arai, Y; Inaba, Y; Inoue, M; Nishiofuku, H; Anai, H; Hori, S; Sakaguchi, H; Kichikawa, K

    2014-01-01

    Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews. PMID:24968749

  2. Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology.

    PubMed

    Tanaka, T; Arai, Y; Inaba, Y; Inoue, M; Nishiofuku, H; Anai, H; Hori, S; Sakaguchi, H; Kichikawa, K

    2014-09-01

    Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews.

  3. Role of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in diagnosis and management of pancreatic cancer; comparison with multidetector row computed tomography, magnetic resonance imaging and endoscopic ultrasonography.

    PubMed

    Ergul, N; Gundogan, C; Tozlu, M; Toprak, H; Kadıoglu, H; Aydin, M; Cermik, T F

    2014-01-01

    We aimed to analyze the contribution of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging to the diagnosis and management of pancreatic cancer compared with multidetector row computed tomography (MDCT), magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS). We retrospectively scanned the data of 52 patients who were referred for FDG PET/CT imaging for evaluation of pancreatic lesions greater than 10mm. The diagnostic performances of 4 imaging methods and the impact of PET/CT on the management of pancreatic cancer were defined. Pancreatic adenocarcinoma was diagnosed in 33 of 52 patients (63%), 15 patients had benign diseases of pancreas (29%), and 4 patients were normal (8%). Sensitivity and NPV of EUS and PET/CT were equal (100%) and higher than MDCT and MRI. Specificity, PPV and NPV of PET/CT were significantly higher than MDCT. However, sensitivities of two imaging methods were not significantly different. There was no significant difference between PET/CT and MRI and EUS for these values. When the cut-off value of SUVmax was 3.2, the most effective sensitivity and specificity values were obtained. PET/CT contributed to the management of pancreatic cancer in 30% of patients. FDG PET/CT is a valuable imaging method for the diagnosis and management of pancreatic cancer, especially when applied along with EUS as first line diagnostic tools. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  4. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography: comparison with cine magnetic resonance imaging.

    PubMed

    Belge, Bénédicte; Coche, Emmanuel; Pasquet, Agnès; Vanoverschelde, Jean-Louis J; Gerber, Bernhard L

    2006-07-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134+/-51 and 67+/-56 ml) were similar to those by MR (137+/-57 and 70+/-60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55+/-21 vs. 56+/-21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3+/-1.8 vs. 8.8+/-1.9 mm and 12.7+/-3.4 vs. 13.3+/-3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54+/-30 vs. 51+/-31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR.

  5. 4D CT angiography more closely defines intracranial thrombus burden than single-phase CT angiography.

    PubMed

    Frölich, A M J; Schrader, D; Klotz, E; Schramm, R; Wasser, K; Knauth, M; Schramm, P

    2013-10-01

    In patients with acute stroke, the location and extent of intravascular thrombi correlate with clinical and imaging outcomes and have been used to predict the success of intravenous thrombolysis. We hypothesized that 4D-CTA reconstructed from whole-brain CTP more closely outlines intracranial thrombi than conventional single-phase CTA. Sixty-seven patients with anterior circulation occlusion were retrospectively analyzed. For 4D-CTA, temporal maximum intensity projections were calculated that combine all 30 spiral scans of the CTP examination through temporal fusion. Thrombus extent was assessed by a semi-quantitative clot burden score (0-10; in which 0 = complete unilateral anterior circulation occlusion and 10 = patent vasculature). In patients with sufficient collateral flow, the length of the filling defect and corresponding hyperdense middle cerebral artery sign on NCCT were measured. Clot burden on temporal maximum intensity projection (median clot burden score, 7.0; interquartile range, 5.1-8.0) was significantly lower than on single-phase CT angiography (median, 6.0; interquartile range, 4.5-7.0; P < .0001). The length of the hyperdense middle cerebral artery sign (14.30 ± 5.93 mm) showed excellent correlation with the filling defect in the middle cerebral artery on temporal maximum intensity projection (13.40 ± 6.40 mm); this filling defect was larger on single-phase CT angiography (18.08 ± 6.54 mm; P = .043). As the result of an increased sensitivity for collateral flow, 4D-CTA temporal maximum intensity projection more closely outlines intracranial thrombi than conventional single-phase CT angiography. Our findings can be helpful when planning acute neurointervention. Further research is necessary to validate our data and assess the use of 4D-CTA in predicting response to different recanalization strategies.

  6. CT angiography of intracranial aneurysms: a focus on postprocessing.

    PubMed

    Tomandl, Bernd F; Köstner, Niels C; Schempershofe, Miriam; Huk, Walter J; Strauss, Christian; Anker, Lars; Hastreiter, Peter

    2004-01-01

    Computed tomographic (CT) angiography is a well-known tool for detection of intracranial aneurysms and the planning of therapeutic intervention. Despite a wealth of existing studies and an increase in image quality due to use of multisection CT and increasingly sophisticated postprocessing tools such as direct volume rendering, CT angiography has still not replaced digital subtraction angiography as the standard of reference for detection of intracranial aneurysms. One reason may be that CT angiography is still not a uniformly standardized method, particularly with regard to image postprocessing. Several methods for two- and three-dimensional visualization can be used: multiplanar reformation, maximum intensity projection, shaded surface display, and direct volume rendering. Pitfalls of CT angiography include lack of visibility of small arteries, difficulty differentiating the infundibular dilatation at the origin of an artery from an aneurysm, the kissing vessel artifact, demonstration of venous structures that can simulate aneurysms, inability to identify thrombosis and calcification on three-dimensional images, and beam hardening artifacts produced by aneurysm clips. Finally, an algorithm for the safe and useful application of CT angiography in patients with subarachnoid hemorrhage has been developed, which takes into account the varying quality of equipment and software at different imaging centers. Copyright RSNA, 2004

  7. Coronary CT angiography with prospective ECG-triggering: an effective alternative to invasive coronary angiography

    PubMed Central

    2012-01-01

    Despite the tremendous contributions of coronary CT angiography to coronary artery disease, radiation dose associated with coronary CT angiography has raised serious concerns in the literature, as the risk of developing radiation-induced malignancy is not negligible. Various dose-saving strategies have been implemented, with some of the strategies resulting in significant dose reduction. Of these strategies, prospective ECG-triggering is one of the most effective techniques with resultant effective radiation dose similar to or even lower than that of invasive coronary angiography. Prospective ECG-triggered coronary CT angiography has been reported to have high diagnostic accuracy in the diagnosis of coronary artery disease with image quality comparable to that of retrospective ECG-gating, but with significantly reduced radiation dose. Successful performance of prospective ECG-triggering is determined by strict exclusion criteria and careful patient preparation. The aim of this article is to provide an overview of the diagnostic applications of coronary CT angiography with prospective ECG-triggering with focus on radiation dose reduction. Radiation dose measurements are discussed with aim of allowing accurate dose estimation. Diagnostic value of prospective ECG-triggered coronary CT angiography in patients with different heart rate is discussed. Finally, current status and future directions are highlighted. PMID:24282694

  8. Preduodenal portal vein in an adult--angiography and CT.

    PubMed

    Sasai, K; Sano, A; Nishizawa, S; Imanaka, K; Kuroda, Y

    1985-01-01

    We report on an adult case of preduodenal portal vein illustrated by computed tomography (CT) and angiography. These diagnostic modalities were initially performed to evaluate a coexisting pancreatic cancer. Contrast-enhanced CT demonstrated unusual positioning of the portal vein ventral to the duodenum. The superior mesenteric-portal vein, which was L-shaped and convexly caudad, strongly suggested this anomalous condition.

  9. The role of CT angiography in military trauma.

    PubMed

    Watchorn, J; Miles, R; Moore, N

    2013-01-01

    To review whole-body computed tomography (CT) angiography as an unmatched way of fully assessing battle-injured patients, and the prevalence of vascular, predominantly arterial, injuries identified. A retrospective analysis of 144 patients who underwent whole-body CT angiography in March 2011 was made. A vascular radiologist reviewed all images and imaging reports. Data gathered included positive findings from CT, anatomical region injured, mechanism of injury, time to CT, and the number of casualties per incident. One hundred and forty-four patients underwent whole-body CT of which 17% had an occult vascular injury on CT. Twenty of these injuries (56%) were in the lower limbs, excluding extravasation at the site of amputation. Improvised explosive devices (IEDs) accounted for 71% (180 of 253) of battle injuries. The median time from admission to CT was 28 min. An additional 12% longer per patient is taken on average in a multiple casualty incident. Including contrast medium administration, whole-body angiography is completed in less than 2 min (mean 116 s). A significant proportion of occult vascular injuries occur in penetrating fragmentation and blast injuries in military trauma. A low threshold for single-pass whole-body CT angiography is therefore justified. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  10. Isolation of the left subclavian artery-origin from the left pulmonary artery by way of ductus arteriosus: multidetector row computed tomographic angiographic imaging.

    PubMed

    Jesudian, Vimala; Ravikumar, Radhakrishnan; Kumar, R Suresh

    2009-05-01

    Right aortic arch with isolation of the left subclavian artery is a rare anomaly. It has been reported to occur with conotruncal anomalies and may be associated with 22q11 deletion. Multidetector-row computed tomographic angiogram images of a 15-year-old African boy with Tetralogy of Fallot who had right aortic arch and isolated left subclavian artery arising from the left pulmonary artery by way of ductus arteriosus are presented.

  11. Intracranial CT angiography obtained from a cerebral CT perfusion examination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Majoie, C. B.; Den Heeten, G. J.; Grimbergen, C. A.; Streekstra, G. J.

    2009-04-15

    CT perfusion (CTP) examinations of the brain are performed increasingly for the evaluation of cerebral blood flow in patients with stroke and vasospasm after subarachnoid hemorrhage. Of the same patient often also a CT angiography (CTA) examination is performed. This study investigates the possibility to obtain CTA images from the CTP examination, thereby possibly obviating the CTA examination. This would save the patient exposure to radiation, contrast, and time. Each CTP frame is a CTA image with a varying amount of contrast enhancement and with high noise. To improve the contrast-to-noise ratio (CNR) we combined all 3D images into one 3D image after registration to correct for patient motion between time frames. Image combination consists of weighted averaging in which the weighting factor of each frame is proportional to the arterial contrast. It can be shown that the arterial CNR is maximized in this procedure. An additional advantage of the use of the time series of CTP images is that automatic differentiation between arteries and veins is possible. This feature was used to mask veins in the resulting 3D images to enhance visibility of arteries in maximum intensity projection (MIP) images. With a Philips Brilliance 64 CT scanner (64x0.625 mm) CTP examinations of eight patients were performed on 80 mm of brain using the toggling table technique. The CTP examination consisted of a time series of 15 3D images (2x64x0.625 mm; 80 kV; 150 mAs each) with an interval of 4 s. The authors measured the CNR in images obtained with weighted averaging, images obtained with plain averaging, and images with maximal arterial enhancement. The authors also compared CNR and quality of the images with that of regular CTA examinations and examined the effectiveness of automatic vein masking in MIP images. The CNR of the weighted averaged images is, on the average, 1.73 times the CNR of an image at maximal arterial enhancement in the CTP series, where the use of plain averaging

  12. Usefulness of 40-slice multidetector row computed tomography to detect coronary disease in patients prior to cardiac valve surgery.

    PubMed

    Pouleur, Anne-Catherine; le Polain de Waroux, Jean-Benoît; Kefer, Joëlle; Pasquet, Agnès; Coche, Emmanuel; Vanoverschelde, Jean-Louis; Gerber, Bernhard L

    2007-12-01

    Preoperative identification of significant coronary artery disease (CAD) in patients prior to valve surgery requires systematic invasive coronary angiography. The purpose of this current prospective study was to evaluate whether exclusion of CAD by multi-detector CT (MDCT) might potentially avoid systematic cardiac catheterization in these patients. Eighty-two patients (53 males, 62 +/- 13 years) scheduled to undergo valve surgery underwent 40-slice MDCT before invasive quantitative coronary angiography (QCA). According to QCA, 15 patients had CAD (5 one-vessel, 6 two-vessel and 4 three-vessel disease). The remaining 67 patients had no CAD. On a per-vessel basis, MDCT correctly identified 27/29 (sensitivity 93%) vessels with and excluded 277/299 vessels (specificity 93%) without CAD. On a per-patient basis, MDCT correctly identified 14/15 patients with (sensitivity 93%) and 60/67 patients without CAD (specificity 90%). Positive and negative predictive values of MDCT were 67% and 98%. Performing invasive angiography only in patients with abnormal MDCT might have avoided QCA in 60/82 (73%). MDCT could be potentially useful in the preoperative evaluation of patients with valve disease. By selecting only those patients with coronary lesions to undergo invasive coronary angiography, it could avoid cardiac catheterization in a large number of patients without CAD.

  13. Low kV settings CT angiography (CTA) with low dose contrast medium volume protocol in the assessment of thoracic and abdominal aorta disease: a feasibility study

    PubMed Central

    Talei Franzesi, C; Fior, D; Bonaffini, P A; Minutolo, O; Sironi, S

    2015-01-01

    Objective: To assess the diagnostic quality of low dose (100 kV) CT angiography (CTA), by using ultra-low contrast medium volume (30 ml), for thoracic and abdominal aorta evaluation. Methods: 67 patients with thoracic or abdominal vascular disease underwent multidetector CT study using a 256 slice scanner, with low dose radiation protocol (automated tube current modulation, 100 kV) and low contrast medium volume (30 ml; 4 ml s−1). Density measurements were performed on ascending, arch, descending thoracic aorta, anonymous branch, abdominal aorta, and renal and common iliac arteries. Radiation dose exposure [dose–length product (DLP)] was calculated. A control group of 35 patients with thoracic or abdominal vascular disease were evaluated with standard CTA protocol (automated tube current modulation, 120 kV; contrast medium, 80 ml). Results: In all patients, we correctly visualized and evaluated main branches of the thoracic and abdominal aorta. No difference in density measurements was achieved between low tube voltage protocol (mean attenuation value of thoracic aorta, 304 HU; abdominal, 343 HU; renal arteries, 331 HU) and control group (mean attenuation value of thoracic aorta, 320 HU; abdominal, 339; renal arteries, 303 HU). Radiation dose exposure in low tube voltage protocol was significantly different between thoracic and abdominal low tube voltage studies (490 and 324 DLP, respectively) and the control group (thoracic DLP, 1032; abdomen, DLP 1078). Conclusion: Low-tube-voltage protocol may provide a diagnostic performance comparable with that of the standard protocol, decreasing radiation dose exposure and contrast material volume amount. Advances in knowledge: Low-tube-voltage-setting protocol combined with ultra-low contrast agent volume (30 ml), by using new multidetector-row CT scanners, represents a feasible diagnostic tool to significantly reduce the radiation dose delivered to patients and to preserve renal function

  14. Pulmonary artery involvement in Takayasu arteritis. PET/CT versus CT angiography.

    PubMed

    Addimanda, O; Spaggiari, L; Pipitone, N; Versari, A; Pattacini, P; Salvarani, C

    2013-01-01

    To report a patient with Takayasu arteritis in whom 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computerised tomography (CT) failed to demonstrate pulmonary artery involvement. A patient with Takayasu arteritis underwent PET/CT and CT angiography before and one year after immunosuppressive treatment. Before treatment, PET/CT showed increased FDG uptake in the aortic arch and epiaortic arteries; pulmonary arteries were not visualised. Follow-up PET/CT one year later demonstrated resolution of abnormal vascular FDG uptake. CT angiography of the chest/abdomen prior to treatment revealed circumferential thickening of the ascending aorta, aortic arch, supra-aortic branches, and left inferior intralobar pulmonary artery with normal lumen diameter (27 mm). After therapy, CT angiography revealed decreased aortic wall thickening with complete resolution of intralobar wall thickening. However, the lumen of the central pulmonary artery was increased (32 mm). PET/CT is very sensitive in depicting active vasculitis, but cannot visualise the pulmonary arteries, presumably because their diameter is below the power of detection of PET/CT. CT angiography or magnetic resonance angiography is required to evaluate pulmonary artery abnormalities.

  15. Comparison of transplenic multidetector CT portography to multidetector CT-angiography in normal dogs.

    PubMed

    Echandi, Rita L; Morandi, Federica; Daniel, William T; Paquette, Janet L; Daniel, Gregory B

    2007-01-01

    We evaluated transplenic injection of iodinated contrast medium for computed tomography (CT) assessment of the portal vasculature. Specific aims were to: (1) establish a protocol for transplenic transplenic CT portography using a 40-row multidetector scanner; (2) compare transplenic CT portography to dual-phase CT angiography in terms of image quality, opacification of the portal system, and contrast enhancement of the portal vasculature and liver; (3) compare personnel exposure during transplenic CT portography and transplenic portal scintigraphy. Seven juvenile dogs underwent transplenic portal scintigraphy, CT angiography, and transplenic CT portography. Transplenic portal scintigraphy and CT angiography were performed using previously established protocols. For transplenic CT portography, a 20- or 22 gauge needle attached to an extension set was placed into the splenic parenchyma using CT guidance. Iodinated contrast medium (175 mg I/ml) was administered, and CT acquisition was started at the time of the injection. Transplenic CT portography was simple, rapid and provided more intense enhancement of the splenic and portal veins, with a lower contrast medium dose (median dose: 525 mg I for transplenic CT portography, 7700 mg I for CT angiography), but caused inconsistent intrahepatic portal branches and parenchymal opacification due to streamlining and streak artifacts. Despite significantly lower attenuation values in the portal vein, CT angiography provided sufficient enhancement for vessel identification and more consistent parenchymal hepatic enhancement. Personnel radiation exposure rate was higher during transplenic CT portography (0.0725 mSv/min) compared with transplenic portal scintigraphy (0.000125 mSv/min). As transplenic CT portography requires an average injection time of 1 min per study; over 650 [corrected] studies must be performed before reaching the maximum permissible whole body dose of 0.05 [corrected] Sv.

  16. Penetrating neck injuries: helical CT angiography for initial evaluation.

    PubMed

    Múnera, Felipe; Soto, Jorge A; Palacio, Diana M; Castañeda, Jorge; Morales, Carlos; Sanabria, Alvaro; Gutiérrez, Juan E; García, Giovanni

    2002-08-01

    To report an experience with helical computed tomographic (CT) angiography as the initial procedure to rule out arterial lesions caused by penetrating neck injuries. During 27 months, 175 patients were referred for helical CT angiography of the neck because of clinical suspicion of arterial injuries. The protocol included a 100-mL bolus of nonionic contrast material injected at 4.5 mL/sec, with 11-second scanning delay, 3-mm collimation, and pitch of 1.3-2.0. CT images were interpreted prospectively by the emergency radiologist, and two radiologists retrospectively interpreted studies with consensus. Outcome was determined with examination of patients and their charts. The sensitivity, specificity, and positive and negative predictive values were calculated. Studies in two patients were considered inadequate for diagnosis; these patients were referred for conventional arteriography and had normal findings. In 27 patients (15.6%), arterial lesions were detected. One patient had two arterial injuries. Lesions demonstrated with helical CT angiography were arterial occlusion (n = 14), pseudoaneurysm (n = 8), pseudoaneurysm and arteriovenous fistulae (n = 4), and partial thrombosis (n = 2). The remaining 146 patients had normal arteries. On the basis of these findings, patients were treated with surgery (n = 21), endovascular intervention (n = 7), and observation alone (n = 146). Results indicate that helical CT angiography can be used as the initial method for evaluation in patients with possible arterial injuries of the neck. Copyright RSNA, 2002

  17. Diagnosis of arterial injuries caused by penetrating trauma to the neck: comparison of helical CT angiography and conventional angiography.

    PubMed

    Múnera, F; Soto, J A; Palacio, D; Velez, S M; Medina, E

    2000-08-01

    To determine the sensitivity and specificity of helical computed tomographic (CT) angiography in the diagnosis of carotid and vertebral arterial injuries caused by penetrating neck trauma. A prospective study was conducted during 24 months in 60 patients with penetrating neck trauma who were referred for conventional angiography owing to clinical suspicion of arterial injury. In the patient population, 146 arteries (77 carotid, 69 vertebral) were studied by means of conventional angiography. In all patients, conventional angiography and helical CT angiography were completed within 6 hours. Two radiologists interpreted helical CT angiographic studies by means of consensus. Conventional angiography was the standard of reference for determining the sensitivity and specificity of helical CT angiography. Conventional angiograms showed arterial injuries in 10 (17%) of 60 patients. Conventional angiographic findings were arterial occlusion (n = 4), arteriovenous fistula (n = 2), pseudoaneurysm (n = 3), pseudoaneurysm with arteriovenous fistula (n = 1), and normal arteries (n = 136). Nine of 10 arterial injuries and all normal arteries were depicted adequately at helical CT angiography. Sensitivity of helical CT angiography was 90%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 98%. The sensitivity and specificity of helical CT angiography are high for detection of major carotid and vertebral arterial injuries resulting from penetrating trauma.

  18. Electrocardiographically gated 16-section CT of the thorax: cardiac motion suppression.

    PubMed

    Hofmann, Lars K; Zou, Kelly H; Costello, Philip; Schoepf, U Joseph

    2004-12-01

    Thirty patients underwent 16-section multi-detector row computed tomographic (CT) angiography of the thorax with retrospective electrocardiographic gating. Institutional review board approval was obtained for retrospective analysis of CT scan data and records; patient informed consent was not required. Images reconstructed at six different time points (0%, 20%, 40%, 50%, 60%, 80%) within the R-R interval on the electrocardiogram were analyzed by two radiologists for diagnostic quality, to identify suitable reconstruction intervals for optimal suppression of cardiac motion. Five regions of interest (left coronary artery, aortic root, ascending and descending aorta, pulmonary arteries) were evaluated. Best image quality was achieved by referencing image reconstruction to middiastole (50%-60%) for the left coronary artery, aortic root, and ascending aorta. The pulmonary arteries are best displayed during mid- to late diastole (80%). (c) RSNA, 2004

  19. Myocardial Scar Detection by Standard CT Coronary Angiography

    PubMed Central

    Jeevarethinam, Anand; Venuraju, Shreenidhi; Mehta, Vishal Shahil; Atwal, Satvir; Raval, Usha; Rakhit, Roby; Davar, Joseph; Lahiri, Avijit

    2014-01-01

    We have described a myocardial infarct scar identified by a standard dual source CT coronary angiography (CTCA). We were able to detect the scar during the routine coronary assessment without contrast late enhancement and without additional radiation exposure. It is therefore feasible to assess chronic scar using a standard CTCA technique.

  20. Patients with Life-Threatening Arterial Renal Hemorrhage: CT Angiography and Catheter Angiography with Subsequent Superselective Embolization

    SciTech Connect

    Sommer, C. M. Stampfl, U.; Bellemann, N.; Ramsauer, S.; Loenard, B. M.; Haferkamp, A.; Hallscheidt, P.; Richter, G. M.; Kauczor, H. U.; Radeleff, B. A.

    2010-06-15

    The purpose of this study was to evaluate the technical and clinical success of superselective embolization in patients with life-threatening arterial renal hemorrhage undergoing preinterventional CT angiography. Forty-three patients with clinical signs of life-threatening arterial renal hemorrhage underwent CT angiography and catheter angiography. Superselective embolization was indicated in the case of a positive catheter angiography. Primary study goals were technical and clinical success of superselective embolization. Secondary study goals were CT angiographic and catheter angiographic image findings and clinical follow-up. The mean time interval between CT angiography and catheter angiography was 8.3 {+-} 10.3 h (range, 0.2-34.1 h). Arterial renal hemorrhage was identified with CT angiography in 42 of 43 patients (98%) and catheter angiography in 39 of 43 patients (91%) (overview angiography in 4 of 43 patients [9%], selective angiography in 16 of 43 patients [37%], and superselective angiography in 39 of 43 patients [91%]). Superselective embolization was performed in 39 of 43 patients (91%) and technically successful in 37 of 39 patients (95%). Therefore, coil embolization was performed in 13 of 37 patients (35%), liquid embolization in 9 of 37 patients (24%), particulate embolization in 1 of 37 patients (3%), and a combination in 14 of 37 patients (38%). Clinical failure occurred in 8 of 39 patients (21%) and procedure-related complications in 2 of 39 patients (5%). The 30-day mortality rate was 3%. Hemoglobin decreased significantly prior to intervention (P < 0.001) and increased significantly after intervention (P < 0.005). In conclusion, superselective embolization is effective, reliable, and safe in patients with life-threatening arterial renal hemorrhage. In contrast to overview and selective angiography, only superselective angiography allows reliable detection of arterial renal hemorrhage. Preinterventional CT angiography is excellent for detection

  1. Coronary CT Angiography-derived Fractional Flow Reserve.

    PubMed

    Tesche, Christian; De Cecco, Carlo N; Albrecht, Moritz H; Duguay, Taylor M; Bayer, Richard R; Litwin, Sheldon E; Steinberg, Daniel H; Schoepf, U Joseph

    2017-10-01

    Invasive coronary angiography (ICA) with measurement of fractional flow reserve (FFR) by means of a pressure wire technique is the established reference standard for the functional assessment of coronary artery disease (CAD) ( 1 , 2 ). Coronary computed tomographic (CT) angiography has emerged as a noninvasive method for direct assessment of CAD and plaque characterization with high diagnostic accuracy compared with ICA ( 3 , 4 ). However, the solely anatomic assessment provided with both coronary CT angiography and ICA has poor discriminatory power for ischemia-inducing lesions. FFR derived from standard coronary CT angiography (FFRCT) data sets by using any of several advanced computational analytic approaches enables combined anatomic and hemodynamic assessment of a coronary lesion by a single noninvasive test. Current technical approaches to the calculation of FFRCT include algorithms based on full- and reduced-order computational fluid dynamic modeling, as well as artificial intelligence deep machine learning ( 5 , 6 ). A growing body of evidence has validated the diagnostic accuracy of FFRCT techniques compared with invasive FFR. Improved therapeutic guidance has been demonstrated, showing the potential of FFRCT to streamline and rationalize the care of patients suspected of having CAD and improve outcomes while reducing overall health care costs ( 7 , 8 ). The purpose of this review is to describe the scientific principles, clinical validation, and implementation of various FFRCT approaches, their precursors, and related imaging tests. (©) RSNA, 2017.

  2. Advances in post-mortem CT-angiography

    PubMed Central

    Grimm, J; Dominguez, A; Vanhaebost, J; Mangin, P

    2014-01-01

    Performing a post-mortem multidetector CT (MDCT) scan has already become routine in some institutes of forensic medicine. To better visualize the vascular system, different techniques of post-mortem CT-angiography have been explored, which can essentially be divided into partial- and whole-body angiography techniques. Probably the most frequently applied technique today is the so-called multiphase post-mortem CT-angiography (MPMCTA) a standardized method for investigating the vessels of the head, thorax and abdomen. Different studies exist, describing its use for medicolegal investigations, and its advantages as well as its artefacts and pitfalls. With the aim to investigate the performance of PMCTA and to develop and validate techniques, an international working group was created in 2012 called the “Technical Working Group Post-mortem Angiography Methods” (TWGPAM). Beyond its primary perspective, the goals of this group include creating recommendations for the indication of the investigation and for the interpretation of the images and to distribute knowledge about PMCTA. This article provides an overview about the different approaches that have been developed and tested in recent years and an update about ongoing research in this field. It will explain the technique of MPMCTA in detail and give an outline of its indications, application, advantages and limitations. PMID:24234582

  3. Advances in post-mortem CT-angiography.

    PubMed

    Grabherr, S; Grimm, J; Dominguez, A; Vanhaebost, J; Mangin, P

    2014-04-01

    Performing a post-mortem multidetector CT (MDCT) scan has already become routine in some institutes of forensic medicine. To better visualize the vascular system, different techniques of post-mortem CT-angiography have been explored, which can essentially be divided into partial- and whole-body angiography techniques. Probably the most frequently applied technique today is the so-called multiphase post-mortem CT-angiography (MPMCTA) a standardized method for investigating the vessels of the head, thorax and abdomen. Different studies exist, describing its use for medicolegal investigations, and its advantages as well as its artefacts and pitfalls. With the aim to investigate the performance of PMCTA and to develop and validate techniques, an international working group was created in 2012 called the "Technical Working Group Post-mortem Angiography Methods" (TWGPAM). Beyond its primary perspective, the goals of this group include creating recommendations for the indication of the investigation and for the interpretation of the images and to distribute knowledge about PMCTA. This article provides an overview about the different approaches that have been developed and tested in recent years and an update about ongoing research in this field. It will explain the technique of MPMCTA in detail and give an outline of its indications, application, advantages and limitations.

  4. CT Angiography in Pediatric Extremity Trauma: Preoperative Evaluation Prior to Reconstructive Surgery

    PubMed Central

    Hsu, Charles S.; Hellinger, Jeffrey C.; Rubin, Geoffrey D.

    2007-01-01

    Computed tomographic angiography (CTA) is a noninvasive modality for evaluating the vascular system and planning treatment strategies. The goal of this study was to validate the clinical utility of CTA in assessment of suspected pediatric extremity traumatic vascular injury, prior to emergent and delayed reconstructive surgery. A retrospective review was performed of all operative patients under 18 years of age who underwent multidetector-row CTA for evaluation of suspected extremity vascular injury. Parameters investigated included age, type of injury, referral source, temporal relationship between the injury and the CTA, CTA findings, operations performed, intraoperative findings, and clinical outcome. Between January 2002 and September 2005, 10 pediatric patients (6 males/4 females; mean age 8 years old, range 3–17) sustained either blunt (N = 8) or penetrating (N = 2) trauma and underwent CTA of the upper (N = 5) or lower extremities (N = 5). A total of 30% (3/10) of patients were referred from the emergency department acutely, 50% (5/10) were referred from the inpatient wards subacutely, and 20% (2/10) were referred from the outpatient clinics electively. Half (N = 5) underwent CTA to evaluate need for vascular repair, whereas half (N = 5) underwent CTA to evaluate local vasculature for flap reconstruction. Overall, 40% (4/10) of CTA findings were normal, whereas 60% (6/10) revealed traumatic vascular injuries. Pertinent nonvascular findings included soft tissue defects (60%, 6/10), fractures (40%, 4/10), and contracture deformities (20%, 2/10). In all cases, procedures were completed without complications, and intraoperative findings confirmed those from CTA. At a mean follow-up of 28 months, all injuries have healed without complications. CTA is a reliable noninvasive modality to evaluate pediatric patients with suspected traumatic extremity vascular injury and to plan treatment strategies for both vascular repair and extremity

  5. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: prospective, multicentre cohort study

    PubMed Central

    Velthuis, Birgitta K; Rinkel, Gabriël J E; Algra, Ale; de Kort, Gérard A P; Witkamp, Theo D; de Ridder, Johanna C M; van Nieuwenhuizen, Koen M; de Leeuw, Frank-Erik; Schonewille, Wouter J; de Kort, Paul L M; Dippel, Diederik W; Raaymakers, Theodora W M; Hofmeijer, Jeannette; Wermer, Marieke J H; Kerkhoff, Henk; Jellema, Korné; Bronner, Irene M; Remmers, Michel J M; Bienfait, Henri Paul; Witjes, Ron J G M; Greving, Jacoba P; Klijn, Catharina J M

    2015-01-01

    Study question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This prospective diagnostic study enrolled 298 adults (18-70 years) treated in 22 hospitals in the Netherlands over six years. CT angiography was performed within seven days of haemorrhage. If the result was negative, MRI/MRA was performed four to eight weeks later. DSA was performed when the CT angiography or MRI/MRA results were inconclusive or negative. The main outcome was a macrovascular cause, including arteriovenous malformation, aneurysm, dural arteriovenous fistula, and cavernoma. Three blinded neuroradiologists independently evaluated the images for macrovascular causes of haemorrhage. The reference standard was the best available evidence from all findings during one year’s follow-up. Study answer and limitations A macrovascular cause was identified in 69 patients (23%). 291 patients (98%) underwent CT angiography; 214 with a negative result underwent additional MRI/MRA and 97 with a negative result for both CT angiography and MRI/MRA underwent DSA. Early CT angiography detected 51 macrovascular causes (yield 17%, 95% confidence interval 13% to 22%). CT angiography with MRI/MRA identified two additional macrovascular causes (18%, 14% to 23%) and these modalities combined with DSA another 15 (23%, 18% to 28%). This last extensive strategy failed to detect a cavernoma, which was identified on MRI during follow-up (reference strategy). The positive predictive value of CT angiography was 72% (60% to 82%), of additional MRI/MRA was 35% (14% to 62%), and of additional DSA was 100% (75% to 100%). None of the patients experienced complications with CT angiography or MRI/MRA; 0.6% of patients who underwent DSA experienced permanent sequelae. Not all patients with negative CT angiography and

  6. Congenital left ventricular aneurysm diagnosed by spiral CT angiography

    SciTech Connect

    Beregi, J.P.; Coulette, J.M.; Ducloux, G.

    1996-05-01

    We report a rare case of congenital left ventricular aneurysm, diagnosed by spiral CT angiography. Despite 1 s time acquisition, spiral CT, with adequate acquisition parameters and bolus injection of contrast medium, produced sufficiently good images to permit visualization of the aneurysm. Subsequently, reconstructions (shaded surface display and multiplanar reformation) were performed to demonstrate the relationship of the aneurysm with the remainder of the left ventricle, the wide neck of the aneurysm, and the absence of contractility, therein permitting differentiation from a congenital diverticulum. 6 refs., 3 figs.

  7. Noninvasive detection of vertebral artery stenosis: a comparison of contrast-enhanced MR angiography, CT angiography, and ultrasound.

    PubMed

    Khan, Sofia; Rich, Philip; Clifton, Andrew; Markus, Hugh S

    2009-11-01

    Vertebral stenosis is associated with a high risk of recurrent stroke, but noninvasive imaging techniques to identify it have lacked sensitivity. Contrast-enhanced MR angiography and CT angiography have been recently developed and appear to have better sensitivity. However, no prospective studies have compared both of these techniques with ultrasound against the gold standard of intra-arterial angiography in the same group of patients. Forty-six patients were prospectively recruited in whom intra-arterial angiography was being performed. Contrast-enhanced MR angiography, CT angiography, and duplex ultrasound were also performed. Angiographic images were analyzed blinded to patient identity by 2 experienced neuroradiologists. Contrast-enhanced MR angiography had the highest sensitivity and specificity (Radiologist 1, 0.83 and 0.91, respectively; Radiologist 2, 0.89 and 0.87) for detecting >or=50% stenosis. CT angiography had good sensitivity (Radiologist 1, 0.68; Radiologist 2, 0.58) and excellent specificity (Radiologist 1, 0.92; Radiologist 2, 0.93), whereas duplex had low sensitivity (0.44) but excellent specificity (0.95). For vertebral origin stenosis >or=50%, sensitivities were similar for contrast-enhanced MR angiography (Radiologist 1, 0.91; Radiologist 2, 0.82) but relatively higher for CT angiography (Radiologist 1, 0.82; Radiologist 2, 0.82) and duplex (0.67). Contrast-enhanced MR angiography is the most sensitive noninvasive technique to detect vertebral artery stenosis and also has high specificity. CT angiography has good sensitivity and high specificity. In contrast, ultrasound has low sensitivity and will miss many vertebral stenoses.

  8. Dynamic CT head phantom for perfusion and angiography studies

    NASA Astrophysics Data System (ADS)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  9. Diagnostic Accuracy of Fractional Flow Reserve From Anatomic CT Angiography

    PubMed Central

    Min, James K.; Leipsic, Jonathon; Pencina, Michael J.; Berman, Daniel S.; Koo, Bon-Kwon; van Mieghem, Carlos; Erglis, Andrejs; Lin, Fay Y.; Dunning, Allison M.; Apruzzese, Patricia; Budoff, Matthew J.; Cole, Jason H.; Jaffer, Farouc A.; Leon, Martin B.; Malpeso, Jennifer; John Mancini, G. B.; Park, Seung-Jung; Schwartz, Robert S.; Shaw, Leslee J.; Mauri, Laura

    2014-01-01

    Context Coronary computed tomographic (CT) angiography is a noninvasive anatomic test for diagnosis of coronary stenosis that does not determine whether a stenosis causes ischemia. In contrast, fractional flow reserve (FFR) is a physiologic measure of coronary stenosis expressing the amount of coronary flow still attainable despite the presence of a stenosis, but it requires an invasive procedure. Noninvasive FFR computed from CT (FFRCT) is a novel method for determining the physiologic significance of coronary artery disease (CAD), but its ability to identify ischemia has not been adequately examined to date. Objective To assess the diagnostic performance of FFRCT plus CT for diagnosis of hemodynamically significant coronary stenosis. Design, Setting, and Patients Multicenter diagnostic performance study involving 252 stable patients with suspected or known CAD from 17 centers in 5 countries who underwent CT, invasive coronary angiography (ICA), FFR, and FFRCT between October 2010 and October 2011. Computed tomography, ICA, FFR, and FFRCT were interpreted in blinded fashion by independent core laboratories. Accuracy of FFRCT plus CT for diagnosis of ischemia was compared with an invasive FFR reference standard. Ischemia was defined by an FFR or FFRCT of 0.80 or less, while anatomically obstructive CAD was defined by a stenosis of 50% or larger on CT and ICA. Main Outcome Measures The primary study outcome assessed whether FFRCT plus CT could improve the per-patient diagnostic accuracy such that the lower boundary of the 1-sided 95% confidence interval of this estimate exceeded 70%. Results Among study participants, 137 (54.4%) had an abnormal FFR determined by ICA. On a per-patient basis, diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of FFRCT plus CT were 73% (95% CI, 67%–78%), 90% (95% CI, 84%–95%), 54% (95% CI, 46%–83%), 67% (95% CI, 60%–74%), and 84% (95% CI, 74%–90%), respectively. Compared

  10. Incremental Value of Adenosine-induced Stress Myocardial Perfusion Imaging with Dual-Source CT at Cardiac CT Angiography1

    PubMed Central

    Rocha-Filho, Jose A.; Blankstein, Ron; Shturman, Leonid D.; Bezerra, Hiram G.; Okada, David R.; Rogers, Ian S.; Ghoshhajra, Brian; Hoffmann, Udo; Feuchtner, Gudrun; Mamuya, Wilfred S.; Brady, Thomas J.

    2010-01-01

    Purpose: First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. Materials and Methods: Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. Results: With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005). Conclusion: A combination protocol involving adenosine perfusion CT imaging and cardiac

  11. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography

    PubMed Central

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-01-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH. PMID:22932061

  12. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography.

    PubMed

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-11-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.

  13. CT Coronary Angiography: 256-Slice and 320-Detector Row Scanners

    PubMed Central

    Hsiao, Edward M.; Rybicki, Frank J.; Steigner, Michael

    2010-01-01

    Multidetector computed tomography (MDCT) has rapidly evolved from 4-detector row systems in 1998 to 256-slice and 320-detector row CT systems. With smaller detector element size and faster gantry rotation speed, spatial and temporal resolution of the 64-detector MDCT scanners have made coronary artery imaging a reliable clinical test. Wide-area coverage MDCT, such as the 256-slice and 320-detector row MDCT scanners, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle. It is hoped that these improvements will be realized with greater diagnostic accuracy of CT coronary angiography. Such scanners hold promise in performing a rapid high quality “triple rule-out” test without high contrast load, improved myocardial perfusion imaging, and even four-dimensional CT subtraction angiography. These emerging technical advances and novel applications will continue to change the way we study coronary artery disease beyond detecting luminal stenosis. PMID:20425186

  14. Multislice CT angiography in coronary artery disease: Technical developments, radiation dose and diagnostic value

    PubMed Central

    Sun, Zhonghua

    2010-01-01

    Multislice computed tomography (CT) angiography has been increasingly used in the detection and diagnosis of coronary artery disease because of its rapid technical evolution from the early generation of 4-slice CT scanners to the latest models such as 64-slice, 256-slice and 320-slice CT scanners. Technical developments of multislice CT imaging enable improved diagnostic value in the detection of coronary artery disease, and this indicates that multislice CT can be used as a reliable less-invasive alternative to invasive coronary angiography in selected patients. In addition, multislice CT angiography has played a significant role in the prediction of disease progression and cardiac events. Despite promising results reported in the literature, multislice CT has the disadvantage of having a high radiation dose which could contribute to the radiation-induced malignancy. A variety of strategies have been currently undertaken to reduce the radiation dose associated with multislice CT coronary angiography while in the meantime acquiring diagnostic images. In this article, the author will review the technical developments, radiation dose associated with multislice CT coronary angiography, and strategies to reduce radiation dose. The diagnostic and prognostic value of multislice CT angiography in coronary artery disease is briefly discussed, and future directions of multislice CT angiography in the diagnosis of coronary artery disease will also be highlighted. PMID:21160611

  15. Multidetector CT angiography for acute gastrointestinal bleeding: technique and findings.

    PubMed

    Artigas, José M; Martí, Milagros; Soto, Jorge A; Esteban, Helena; Pinilla, Inmaculada; Guillén, Eugenia

    2013-01-01

    Acute gastrointestinal bleeding is a common reason for emergency department admissions and an important cause of morbidity and mortality. Factors that complicate its clinical management include patient debility due to comorbidities; intermittence of hemorrhage; and multiple sites of simultaneous bleeding. Its management, therefore, must be multidisciplinary and include emergency physicians, gastroenterologists, and surgeons, as well as radiologists for diagnostic imaging and interventional therapy. Upper gastrointestinal tract bleeding is usually managed endoscopically, with radiologic intervention reserved as an alternative to be used if endoscopic therapy fails. Endoscopy is often less successful in the management of acute lower gastrointestinal tract bleeding, where colonoscopy may be more effective. The merits of performing bowel cleansing before colonoscopy in such cases might be offset by the resultant increase in response time and should be weighed carefully against the deficits in visualization and diagnostic accuracy that would result from performing colonoscopy without bowel preparation. In recent years, multidetector computed tomographic (CT) angiography has gained acceptance as a first-line option for the diagnosis and management of lower gastrointestinal tract bleeding. In selected cases of upper gastrointestinal tract bleeding, CT angiography also provides accurate information about the presence or absence of active bleeding, its source, and its cause. This information helps shorten the total diagnostic time and minimizes or eliminates the need for more expensive and more invasive procedures. © RSNA, 2013.

  16. Prognostic value of CT angiography in patients with inconclusive functional stress tests.

    PubMed

    de Azevedo, Clerio F; Hadlich, Marcelo S; Bezerra, Sabrina G; Petriz, João L; Alves, Rogério R; de Souza, Olga; Rati, Miguel; Albuquerque, Denilson C; Moll, Jorge

    2011-07-01

    We attempted to determine the prognostic value of coronary computed tomographic angiography (CTA) in patients with inconclusive functional stress tests. Patients with suspected coronary artery disease (CAD) and inconclusive noninvasive cardiac stress tests represent a frequent management challenge. We examined 529 consecutive patients with suspected CAD and prior inconclusive functional stress tests. All patients underwent a coronary CTA scan using a 64-slice multidetector row scanner. CAD severity by coronary CTA was categorized as: 1) no evidence of CAD; 2) nonobstructive coronary plaques (< 30%); 3) mild stenosis (30% to 49%); 4) moderate stenosis (50% to 69%); and 5) severe stenosis (≥ 70%). Patients were also categorized according to a modified Duke prognostic CAD index. Survival analyses were performed using Cox proportional hazards models adjusted for baseline risk factors and coronary artery calcium score. The primary outcome of the study was the combined endpoint of all-cause mortality and nonfatal myocardial infarction. Among patients with inconclusive stress tests, the large majority (69%) did not demonstrate significant CAD by coronary CTA. During a mean follow-up of 30.1 ± 11.1 months, there were 20 (3.8%) deaths and 17 (3.2%) nonfatal myocardial infarctions. Multivariable Cox regression analysis revealed that the presence of increasing degrees of obstructive CAD by CTA was an independent predictor of adverse events (hazard ratio [HR]: 1.66 [95% confidence interval (CI): 1.23 to 2.23], p = 0.001). Indeed, the presence of ≥ 50% coronary stenosis was associated with an increased risk of events (HR: 3.15 [95% CI: 1.26 to 7.89], p = 0.01). Likewise, the Duke prognostic CAD index was also found to be an independent predictor of events (HR: 1.54 [95% CI: 1.20 to 1.97], p = 0.001). Among patients with inconclusive functional stress tests, the noninvasive assessment of CAD severity by coronary CTA has been shown to provide incremental prognostic

  17. Investigation of temporal resolution required for CT coronary angiography

    NASA Astrophysics Data System (ADS)

    Ohashi, Kazuya; Ichikawa, Katsuhiro; Kawai, Tatsuya; Shibamoto, Yuta

    2012-03-01

    Sub-second multi-detector computed tomography systems (MDCTs) offer great potentials for improving cardiac imaging. However, since the temporal resolution of such CT systems is not sufficient, blurring and artifacts produced by fast cardiac motion are still problematic. The purposes of this study were to investigate the accurate method for measurement of temporal resolution (TR) of the cardiac CT and required TR for obtaining better CT coronary angiography (CTCA). We employed a dual source CT system (Somatom Definition, Siemens), which has various temporal resolution modes (83, 125, and 165 msec) for electro-cardiogram (ECG)-gated scanning. The temporal sensitivity profiles (TSPs) were measured by a new method using temporal impulse generated by metal ball (impulse method). The CTCA images of 200 patients with heart rates (HRs) ranging from 36 to 117 beat per minute (bpm) were visually evaluated using a 4-point scale. The 165-msec TR mode, which is mostly available on recent MDCTs, showed a sufficient image quality only at low HR (<= 60 bpm) for all 3 arteries. The image quality of 125-msec TR mode was acceptable at low to intermediate HRs (< 80 bpm) for LADs and LCXs, and insufficient for the RCAs in cases with HR more than 71 bpm. The 83-msec TR mode demonstrated excellent image quality except for cases with very quick motion of the RCAs at a high HR (>80 bpm).

  18. Simultaneous CT angiography and whole-body CT is an effective imaging approach before multiorgan retrieval.

    PubMed

    Berthier, E; Ridereau-Zins, C; Dubé, L; Tchouante, P; Nedelcu, C; Lasocki, S; Aubé, C

    2017-03-01

    To assess the role of whole-body computed tomography (CT) for determining morphological suitability before multiorgan retrieval (MOR) in brain dead patients. Fifty-one clinically brain dead patients (21 women, 30 men; mean age 61 year±15) were included in this prospective, single center study. All patients had CT angiography of the brain and whole-body CT examination. CT images were evaluated for the presence of morphological abnormalities of lungs, liver and other abdominal organs and presence of vascular anatomical variants. The results of CT examinations were compared to intraoperative findings observed during organ harvesting and/or the results of histopathological analysis of biopsy specimens. The impact of whole-body CT examination on the harvesting process was evaluated. Ninety-five percent of vascular anatomical variants that were found intraoperatively were depicted on CT. CT density measurements predicted surgical finding of steatosis in 80% of patients. Whole-body CT changed the MOR strategy in 21/51 patients (41%) including 3 MOR cancellations and 8 grafts refusals, whereas organ harvesting was continued in 10 patients after histopathological analysis was performed. Selection of potential graft donors using whole-body CT is reliable and improves graft selection during MOR. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  19. [CT - diagnosis and differential diagnosis of inflammatory acute intestinal conditions].

    PubMed

    Wiesner, W

    2011-08-24

    Multidetector-row CT has shown over the past years that it is able to provide reliable diagnoses in various acute intestinal conditions. The presented article provides an overview of primary and secondary inflammatory acute intestinal pathologies and their differential diagnoses.

  20. Multidetector CT angiography in evaluation of prosthetic heart valve dysfunction.

    PubMed

    Habets, Jesse; Mali, Willem P T M; Budde, Ricardo P J

    2012-01-01

    Prosthetic heart valves (PHVs) are commonly implanted to replace diseased native heart valves. PHV dysfunction is an infrequent but potentially life-threatening condition. In daily clinical practice, transthoracic and transesophageal echocardiography and fluoroscopy are the imaging modalities used for diagnostic evaluation of suspected PHV dysfunction. These modalities may not allow determination of the cause of PHV dysfunction, mostly because of acoustic shadowing. Multidetector computed tomographic (CT) angiography is a promising complementary technique for evaluation of PHVs, especially in patients with PHV obstruction and endocarditis. The CT image quality of PHVs mainly depends on their composition, with most causing only limited artifacts. Retrospectively electrocardiographically gated acquisition is advisable for PHV imaging because it enables dynamic leaflet evaluation and anatomic assessment in both systole and diastole. For accurate image interpretation, dedicated reconstruction in plane with and perpendicular to the PHV leaflets is mandatory. Besides PHV assessment, CT also provides information on the coronary arteries, the location and patency of bypass grafts, the dimensions of the aorta, and the distance between the sternum and right ventricle, information valuable for planning repeat surgery. To achieve the optimal diagnostic yield in PHV imaging, multidisciplinary cooperation between the departments of cardiology, cardiothoracic surgery, and radiology is crucial.

  1. Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity

    PubMed Central

    Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

    2016-01-01

    Abstract Purpose: To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. Methods: A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA. As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Results: Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP. Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. Conclusion: MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP. PMID:27399123

  2. Comparison of the diagnostic accuracy of FBP, ASiR, and MBIR reconstruction during CT angiography in the evaluation of a vessel phantom with calcified stenosis in a distal superficial femoral artery in a cadaver extremity.

    PubMed

    Tsukada, Jitsuro; Yamada, Minoru; Yamada, Yoshitake; Yamazaki, Shun; Imanishi, Nobuaki; Tamura, Kentaro; Hashimoto, Masahiro; Nakatsuka, Seishi; Jinzaki, Masahiro

    2016-07-01

    To investigate whether adaptive statistical iterative reconstruction (ASiR) or model-based iterative reconstruction (MBIR) improves the diagnostic performance of computed tomography angiography (CTA) for small-vessel calcified lesions relative to filtered back projection (FBP) using cadaver extremities and a calcified stenosis phantom. A cadaver was used in accordance with our institutional regulations, and a calcified stenosis phantom simulating 4 grades of stenosis was prepared. The phantom was inserted within the distal superficial femoral artery of the cadaver leg. Ten CT images per reconstruction type and stenosis grade were acquired using a 64-slice multidetector-row CTA.As an objective measurement, the first and second derivatives of the CT value function profiles were calculated. As a subjective measurement, 2 blinded reviewers measured the stenosis ratio using a quantitative scale. The Wilcoxon rank-sum test was used to evaluate the data. Objective measurements of both 25% and 50% stenosis differed significantly (P < 0.01) between MBIR (25/50%: 25.80/50.30 ± 3.88/3.86%) and FBP (25/50%: 35.60/83.80 ± 3.44/26.10%), whereas significant differences were not observed between ASiR and FBP.Reviewer 2's subjective measurements of 25% stenosis differed significantly (P < 0.01) between MBIR (35.13 ± 3.25%) and ASiR (40.89 ± 3.14%), and the measurements of 50% stenosis differed significantly (P < 0.01) between MBIR (reviewers 1/2, 62.36/54.78 ± 2.78/4.96%) and FBP (reviewers 1/2, 62.36/74.84 ± 2.78/18.10%). Significant differences in the subjective measurements were not observed between ASiR and FBP. MBIR improves the diagnostic performance of CTA for small-vessel calcified lesions relative to FBP.

  3. Minimizing the acquisition phase in coronary CT angiography using the second generation 320-row CT.

    PubMed

    Tomizawa, Nobuo; Kanno, Shigeaki; Maeda, Eriko; Akahane, Masaaki; Torigoe, Rumiko; Ohtomo, Kuni

    2014-07-01

    We aimed to compare the radiation dose and image quality of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second-generation 320-row CT. Eighty patients with heart rate ≤75 bpm were retrospectively included. The first 40 patients underwent scanning with a wide phase window (65-85 %), while the last 40 patients underwent scanning with a minimal phase window centered at 77 %. Subjective image quality was graded using a 4-point scale (4 = excellent). Image noise and contrast-to-noise ratio at the proximal segments were also analyzed. The mean effective dose was derived from the dose length product multiplied by a chest conversion coefficient (κ = 0.014 mSv mGy(-1) cm(-1)). Minimal phase window scanning centered at 77 % reduced the radiation dose by 30 % compared with wide phase window scanning (1.7 vs 2.4 mSv, p = 0.0009). The subjective image quality showed no significant difference (3.75 vs 3.76, p = 0.77). No significant difference was observed in the image noise, CT number, and contrast-to-noise ratio. Radiation dose could be reduced while maintaining image quality by use of a minimal phase window centered at 77 % compared with a wide phase window in coronary CT angiography using the second generation 320-row CT.

  4. Pulmonary embolism during pregnancy: diagnosis with lung scintigraphy or CT angiography?

    PubMed

    Revel, Marie-Pierre; Cohen, Stéphanie; Sanchez, Olivier; Collignon, Marie-Anne; Thiam, Rokhaya; Redheuil, Alban; Meyer, Guy; Frija, Guy

    2011-02-01

    To evaluate the rate of positive, negative, and indeterminate results and the agreement between initial and expert readings for lung scintigraphy and computed tomographic (CT) angiography performed in patients suspected of having pulmonary embolism (PE) during pregnancy. Institutional review board approval was obtained. The authors retrospectively analyzed the images from lung scintigraphy and CT angiography performed in pregnant patients during the past 9 years. Images from 46 CT angiographic examinations performed in 43 patients and 91 of 94 lung scintigraphic examinations were reviewed by experts, whose readings were then compared with the initial reports. For CT angiography, the quality of opacification was graded as good, suboptimal, or poor and intraarterial attenuation was measured. The rates of positive findings (seven of 43 patients [16%] with CT angiography and 10 of 91 patients [11%] with scintigraphy, P = .36), negative findings (28 of 43 patients [65%] with CT angiography and 64 of 91 patients [70%] with scintigraphy, P = .54), and indeterminate findings (eight of 43 patients [19%] with CT angiography and 17 of 91 patients [19%] with scintigraphy, P = .99) were similar for CT angiography and lung scintigraphy. There were four discrepancies between initial and expert readings for CT angiography (κ = 0.84; confidence interval: 0.68, 0.99) and 14 for lung scintigraphy (κ = 0.75; 95% confidence interval: 0.63, 0.87). Opacification was classified as good for only 23 of the 46 CT angiographic examinations (50%). Attenuation values were significantly different among the groups with good, suboptimal, or poor opacification. Alternative diagnoses unsuspected at chest radiography were demonstrated at CT angiography in five of the 43 patients (12%). The mean maternal radiation dose was 0.9 mSv for lung scintigraphy and 7.3 mSv for CT angiography. Lung scintigraphy and CT angiography have comparable performances for PE diagnosis during pregnancy. Interobserver

  5. From the RSNA refresher courses: CT angiography: clinical applications in the abdomen.

    PubMed

    Fishman, E K

    2001-10-01

    The development of spiral computed tomography (CT) and subsequently multidetector CT has provided unparalleled opportunities for advancement of CT technology and clinical applications. One of the most influential developments has been CT angiography, which is the use of thin-section CT combined with postprocessing of imaging data by using a variety of three-dimensional reconstruction techniques to produce vascular maps that equal or exceed those provided by classic angiography in many applications. In the evaluation of pancreatic disease, the use of multidetector CT angiography enables the radiologist to produce vascular maps that clearly show tumor invasion of vasculature and the relationship of vessels to pancreatic masses. Anatomic areas for which the three-dimensional display is especially helpful include the confluence of the portal vein and the superior mesenteric vein and the more distal portions of the portal vein. Preliminary studies indicate that CT angiography may prove beneficial in the evaluation of ischemic bowel and active Crohn disease. CT angiography has proved extremely valuable for applications such as preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation, pretreatment planning for patients considered for hepatic arterial infusion chemotherapy, and pretreatment evaluation of portal vein patency for a variety of reasons. CT angiography can also provide supplemental information in patients with cirrhosis, upper gastrointestinal tract bleeding due to varices, or primary extrahepatic neoplasms.

  6. Update on multidetector coronary CT angiography of coronary stents: in vitro evaluation of 29 different stent types with dual-source CT.

    PubMed

    Maintz, David; Burg, Matthias C; Seifarth, Harald; Bunck, Alexander C; Ozgün, Murat; Fischbach, Roman; Jürgens, Kai Uwe; Heindel, Walter

    2009-01-01

    The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70 HU). Stents were imaged in axial orientation with standard parameters: 32 x 0.6 collimation, pitch 0.24, 400 mAs, 120 kV, rotation time 0.33 s. Image reconstructions were obtained with four different convolution kernels (soft, medium-soft, standard high-resolution, stent-dedicated). To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density, and noise were measured. The stent-dedicated kernel offered best average lumen visualization (54 +/- 8.3%) and most realistic lumen attenuation (222 +/- 44 HU) at the expense of increased noise (23.9 +/- 1.9 HU) compared with standard CTA protocols (p < 0.001 for all). The magnesium stent showed the least artifacts with a lumen visibility of 90%. The majority of stents (79%) exhibited a lumen visibility of 50-59%. Less than half of the stent lumen was visible in only six stents. Stent lumen visibility largely varies depending on the stent type. Magnesium is by far more favorable a stent material with regard to CT imaging when compared with the more common materials steel, cobalt-chromium, or tantalum. The magnesium stent exhibits a lumen visibility of 90%, whereas the majority of the other stents exhibit a lumen visibility of 50-59%.

  7. Ruling out coronary artery disease with noninvasive coronary multidetector CT angiography before noncoronary cardiovascular surgery.

    PubMed

    Catalán, Paz; Leta, Rubén; Hidalgo, Alberto; Montiel, José; Alomar, Xavier; Viladés, David; Barros, Antonio; Pujadas, Sandra; Carreras, Francesc; Padró, Josep M; Cinca, Juan; Pons-Lladó, Guillem

    2011-02-01

    To assess the usefulness of preoperative coronary computed tomographic (CT) angiography in the detection of coronary artery disease (CAD) in nonselected patients scheduled to undergo noncoronary cardiovascular surgery to avoid unnecessary invasive coronary angiography (ICA). The institutional review board approved the study protocol; informed consent was given. This prospective study involved 161 consecutive patients who underwent coronary calcium scoring and coronary CT angiography before undergoing noncoronary cardiovascular surgery. Seven patients were excluded because of contraindications to CT angiography. The major indication of noncoronary cardiovascular surgery was valvular heart disease (121 patients). Follow-up was performed at a median of 20 months to define ischemic events described as acute coronary syndrome or death secondary to acute coronary syndrome, arrhythmias, or cardiac failure. Multivariate analysis was performed to determine predictors of nondiagnostic coronary CT angiography. Kaplan-Meier analysis was performed to evaluate outcome at follow-up. Twenty-one patients did not undergo surgery, which left 133 patients as the study group. Atrial fibrillation was present in 45 of 133 patients. The interquartile range of the Agatston coronary calcium score was 0-471. Coronary CT angiography was diagnostic in 108 of 133 patients. Of these, 93 of 108 had no significant CAD (≤ 50% stenosis), and noncoronary cardiovascular surgery was performed in them without preoperative ICA. No patients in this group had postoperative ischemic events at follow-up. Coronary CT angiography was nondiagnostic in 25 of 133 patients who were referred for preoperative ICA. Multivariate analysis showed Agatston score to be the only independent predictor of nondiagnostic coronary CT angiography (odds ratio = 1.002; 95% confidence interval: 1.001, 1.003; P = .001). The best Agatston score cutoff for diagnostic coronary CT angiography was 579. In nonselected patients scheduled

  8. Coronary competitive reverse flow: Imaging findings at CT angiography and correlation with invasive coronary angiography.

    PubMed

    Li, Minghua; Liu, Shuyong; Zhang, Jiayin; Lu, Zhigang; Wei, Meng; Chun, Eun-Ju; Lu, Bin

    2015-01-01

    To study the imaging features of coronary competitive reverse flow and incidence of a "reverse attenuation gradient" in coronary CT angiography (CTA) with correlation to invasive coronary angiography (ICA). Patients who had undergone coronary CTA and ICA within 2 weeks were retrospectively identified in our database and reviewed. All cases with ICA-confirmed competitive reverse flow or chronic total occlusions (CTOs) were included for further analysis. The "reverse attenuation gradient sign" was defined as a reverse intraluminal opacification gradient of vessels which showed higher opacification in more distal compared with proximal segments. ICA findings were recorded and served as the reference to identify the clinical implications of this sign. In total, 134 patients (mean age, 68.1 ± 11.3 years; range, 38-90 years; 104 men) were included in our study. ICA revealed 11 cases of coronary competitive reverse flow and 123 cases of CTO. A reverse attenuation gradient sign was present in 9 of 11 patients (82%) with coronary competitive reverse flow and 72 of 123 (59%) chronically occluded coronary arteries. Myocardial bridges, distal collateral filling, as well as direct visualization of collateral connection were all more frequent in cases with coronary competitive reverse flow group compared with cases with a CTO. The reverse attenuation gradient sign distal to an upstream coronary severe stenosis indicates the presence of competitive collateral flow. Coronary CTA is able to correctly detect coronary competitive collateral flow and differentiate it from CTOs. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  9. CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.

    PubMed

    Rubin, Geoffrey D; Leipsic, Jonathon; Joseph Schoepf, U; Fleischmann, Dominik; Napel, Sandy

    2014-06-01

    Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography.

  10. Clinical utility and cost-effectiveness of CT-angiography in the diagnosis of nontraumatic subarachnoid hemorrhage.

    PubMed

    Jabbarli, Ramazan; Shah, Mukesch; Taschner, Christian; Kaier, Klaus; Hippchen, Beate; Van Velthoven, Vera

    2014-10-01

    CT-angiography gains an increasing role in the initial diagnosis of patients with nontraumatic subarachnoid hemorrhage (SAH). However, the implementation of CT-angiography does not always exclude the necessity of conventional angiography. Our objective was to determine the practical utility and cost-effectiveness of CT-angiography. All patients with nontraumatic subarachnoid hemorrhage admitted to our university hospital after implementation of CT-angiography between June 1, 2011 and June 30, 2012 were retrospectively analyzed in regard to factors of treatment flow, radiation exposure, harms of contrast medium loading, and diagnostic costs. A control group of the same size was assembled from previously admitted SAH patients, who did not undergo pretreatment CT-angiography. Furthermore, cost-effectiveness analysis was performed. The final analysis consisted of 93 patients in each group. Of 93 patients with pretreatment CT-angiography, 74 had to undergo conventional angiography for diagnostic and/or therapeutic purposes. CT-angiography had significant impact on the reduction of collective effective radiation dose by 4.419 mSv per person (p = 0.0002) and was not associated with additional harms. Despite the significantly earlier detection of aneurysms with CT-angiography (p < 0.0001), there were no significant differences in the timing of aneurysm repair and duration of ICU and general hospital stay. There was an increase of diagnostic costs-the cost-effectiveness analysis showed, however, that benefits of CT-angiography in respect to radiation exposure and risk of conventional angiography-related complications justify the additional costs of CT-angiography. Although the implementation of CT-angiography in SAH diagnosis cannot completely replace conventional angiography, it can be approved in regard to radiation hygiene and cost-effectiveness.

  11. Incidence of Venous Thromboembolism Using 64 Channel Multidetector Row Computed Tomography-Indirect Venography and Anti-Coagulation Therapy after Total Knee Arthroplasty in Korea

    PubMed Central

    Park, Kyung-Hyun; Cheon, Sang-Ho; Lee, Ji-Ho

    2012-01-01

    Purpose This study evaluated the incidence of a venous thromboembolism (VTE) after total knee arthroplasty (TKA) using multidetector row computed tomography-indirect venography (MDCT-indirect venography) and assessed the efficacy of anti-coagulation therapy. Materials and Methods We enrolled 118 patients with 126 cases of TKA. The average age of the patients was 68.4 years. We used 64 channel MDCT-indirect venography for the detection of VTE. We treated selectively proximal deep vein thrombosis (DVT) or pulmonary thromboembolism (PTE) cases according to the results of MDCT-indirect venography. We re-evaluated the change in VTE using follow-up MDCT-indirect venography after 3 months. Results We identified VTE in 35.7%. DVT only was identified in 22.2% including 8 cases of proximal DVT and 20 cases of distal DVT. PTE without DVT was identified in 4.8%, and combined DVT and PTE in 8.7%. All patients with PTE were asymptomatic, but 4 DVT patients had signs of leg swelling. After anti-coagulation therapy, 20 patients showed complete resolution in 16 cases, improvement in 3 cases and one case showed a new distal DVT. Conclusions The incidence of VTE after primary TKA was 35.7% in Korea. Furthermore, anti-coagulation therapy for proximal DVT and PTE patients may be a useful method for preventing the occurrence of a fatal PTE. PMID:22570848

  12. Likelihood of aneurysmal subarachnoid haemorrhage in patients with normal unenhanced CT, CSF xanthochromia on spectrophotometry and negative CT angiography.

    PubMed

    Rana, A K; Turner, H E; Deans, K A

    2013-01-01

    Patients with suspected subarachnoid haemorrhage, a normal noncontrast computed tomography (CT) and cerebrospinal fluid (CSF) evidence of haemoglobin breakdown products often undergo CT angiography (CTA). If this is normal, then invasive catheter angiography may be offered. In current clinical practice, haemoglobin breakdown products are detected by spectrophotometry rather than visible xanthochromia, and CTA is performed on multidetector scanners. The aim of this study was to determine if such patients should still have a catheter angiography, given the associated risks. Patients positive for CSF spectrophotometry (n=26) were retrospectively identified from the clinical biochemistry information system and imaging data from the electronic radiology records were reviewed. Discharge letters were consulted to relate the biochemistry and radiology results to the final diagnosis. 15 patients with CT angiography were found. Nine patients had normal CT angiography. No causative aneurysms had been missed. One patient had small, coincidental aneurysms missed on initial reading of the CTA. The likelihood of a clinically significant aneurysm in a patient who is CT negative, lumbar puncture positive and CTA negative is low. Double reporting of negative CT angiograms may be advisable.

  13. Individually tailored contrast enhancement in CT pulmonary angiography

    PubMed Central

    Hendriks, Babs M F; Kok, Madeleine; Mihl, Casper; Bekkers, Sebastiaan C A M; Wildberger, Joachim E

    2016-01-01

    Objective: The purpose was to evaluate individually shaped contrast media (CM) delivery in CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE). Methods: 100 consecutive emergency patients with clinical suspicion of PE were evaluated. High-pitch CTPA was performed on a second-generation dual-source CT using the following parameters: 100 kV, 200–250 mAsref, rotation time 0.28 s, 128 × 0.6 mm col. and image reconstruction 1.0/0.8 mm (B30f). Group 1 (n = 50) then received a fixed CM bolus (300 = mgI ml−1, volume = 90 ml and flow rate = 6 ml s−1); Group 2 (n = 50) received a body weight-adapted CM bolus determined by dedicated contrast injection software. For analysis, groups were further subdivided into low-weight (40–75 kg) and high-weight (76–117 kg) groups. Technical image quality was graded using a four-point Likert scale (1 = non-diagnostic; 2 = diagnostic; 3 = good and 4 = excellent image quality) at the level of the pulmonary trunk and pulmonary arteries. Objective image quality analysis was performed by measuring contrast enhancement in Hounsfield units (HU) at the same levels. Attenuation levels > 180 HU were considered diagnostic. Results: All examinations were graded as diagnostic at each level. The individual minimum pulmonary attenuation was 184 and 270 HU for Group 1 and 2, respectively. Mean attenuation was as follows: Group 1: 475 ± 105 HU (40–75 kg) and 402 ± 115 HU (76–117 kg), p < 0.03. Group 2: 424 ± 76 HU (40–75 kg) and 418 ± 100 HU (76–117 kg), p = 0.8. For Group 2, CM volumes were: 55 ± 5 ml (40–75 kg) and 66 ± 5 ml (76–117 kg), leading to 16–51% CM reduction. Conclusion: Even under emergency conditions, individualized CM protocols can provide diagnostic and robust image quality in CTPA for PE with a substantial reduction of CM volume for lower weight patients, compared with

  14. Intravenous flat detector CT angiography for non-invasive visualisation of intracranial flow diverter: technical feasibility.

    PubMed

    Struffert, Tobias; Saake, Marc; Ott, Sabine; Engelhorn, Tobias; Gölitz, Philipp; Kloska, Stephan; Doelken, Marc; Doerfler, Arnd

    2011-08-01

    To demonstrate the feasibility of intravenous Flat Detector CT Angiography (FD-CTA) for visualisation of intracranial Flow Diverting Devices. Flow Diverting Devices are used increasingly for treatment of intracranial aneurysms. A close follow up is necessary because it becomes obvious that a significant proportion of aneurysms treated with these devices remain patent. A minimally invasive method is highly desirable. In two patients treated with flow diverters a Flat Detector CT (FD-CT) with intravenous contrast medium application was performed. Post-processing was performed using commercially available software. In both patients the lumen of the device and the lumen of the aneurysm could be clearly evaluated. Some beam hardening artefacts due to the marker wires of the device were obvious. Flat Detector CT with intravenous contrast material application to evaluate flow-diverting devices seems to be feasible. Further studies are necessary to perform comparative evaluation of FD-CTA with angiography and other techniques like MRA or conventional CT angiography.

  15. Dual-Source CT Angiography of Peripheral Arterial Stents: In Vitro Evaluation of 22 Different Stent Types

    PubMed Central

    Köhler, Michael; Burg, Matthias C.; Bunck, Alexander C.; Heindel, Walter; Seifarth, Harald; Maintz, David

    2011-01-01

    Purpose. To test different peripheral arterial stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation and image noise in dual-source multidetector row CT (DSCT) in vitro. Methods and Materials. 22 stents (nitinol, steel, cobalt-alloy, tantalum, platinum alloy) were examined in a vessel phantom. All stents were imaged in axial orientation with standard parameters. Image reconstructions were obtained with four different convolution kernels. To evaluate visualization characteristics of the stent, the lumen diameter, intraluminal density and noise were measured. Results. The mean percentage of the visible stent lumen diameter from the nominal stent diameter was 74.5% ± 5.7 for the medium-sharp kernel, 72.8% ± 6.4 for the medium, 70.8% ± 6.4 for the medium-smooth and 67.6% ± 6.6 for the smooth kernel. Mean values of lumen attenuation were 299.7HU ± 127 (medium-sharp), 273.9HU ± 68 (medium), 270.7HU ± 53 (medium-smooth) and 265.8HU ± 43. Mean image noise was: 54.6 ± 6.3, 20.5 ± 1.7, 16.3 ± 1.7, 14.0 ± 2 respectively. Conclusion. Visible stent lumen diameter varies depending on stent type and scan parameters. Lumen diameter visibility increases with the sharpness of the reconstruction kernel. Smoother kernels provide more realistic density measurements inside the stent lumen and less image noise. PMID:22091369

  16. Usefulness of CT angiography in diagnosing acute gastrointestinal bleeding: A meta-analysis

    PubMed Central

    Wu, Lian-Ming; Xu, Jian-Rong; Yin, Yan; Qu, Xin-Hua

    2010-01-01

    AIM: To analyze the accuracy of computed tomography (CT) angiography in the diagnosis of acute gastrointestinal (GI) bleeding. METHODS: The MEDLINE, EMBASE, Cancerlit, Cochrane Library database, Sciencedirect, Springerlink and Scopus, from January 1995 to December 2009, were searched for studies evaluating the accuracy of CT angiography in diagnosing acute GI bleeding. Studies were included if they compared CT angiography to a reference standard of upper GI endoscopy, colonoscopy, angiography or surgery in the diagnosis of acute GI bleeding. Meta-analysis methods were used to pool sensitivity and specificity and to construct summary receiver-operating characteristic. RESULTS: A total of 9 studies with 198 patients were included in this meta-analysis. Data were used to form 2 × 2 tables. CT angiography showed pooled sensitivity of 89% (95% CI: 82%-94%) and specificity of 85% (95% CI: 74%-92%), without showing significant heterogeneity (χ2 = 12.5, P = 0.13) and (χ2 = 22.95, P = 0.003), respectively. Summary receiver operating characteristic analysis showed an area under the curve of 0.9297. CONCLUSION: CT angiography is an accurate, cost-effective tool in the diagnosis of acute GI bleeding and can show the precise location of bleeding, thereby directing further management. PMID:20712058

  17. Three-dimensional spiral CT angiography in pancreatic surgical planning using non-tailored protocols: comparison with conventional angiography.

    PubMed

    Blomley, M J; Albrecht, T; Williamson, R C; Allison, D J

    1998-03-01

    The aim of this study was to investigate three-dimensional spiral computed tomography (3DCT) as an adjunct to routine pancreatic CT scanning, with particular regard to the identification of surgically important hepatic arterial anomalies, correlated with conventional visceral angiography. 32 patients underwent spiral CT scans prior to pancreatic surgery using established protocols. Oral contrast medium was used throughout. 150 ml of intravenous contrast medium was given at 3 ml s-1 with a 24 s spiral CT sequence starting 35 s after the start of infusion. Two protocols were employed, both with a pitch of 1:3 mm table feed/collimation (n = 17) and 5 mm table feed/collimation (n = 15). Overlapping (1 mm minimum) axial reformats were reconstructed. 3DCT shaded-surface displays of the visceral arteries were assessed for visceral arterial anomalies. Visceral angiography (n = 23) was independently correlated. Satisfactory 3D angiograms were performed in all but one patient, in whom the coeliac axis was missed. (i) 3 mm protocol: 3DCT (n = 17) showed three anomalous right hepatic arteries (ARHA), one trifurcation anomaly and one splenic artery with an aortic origin. Angiography (n = 11) confirmed these findings, although one patient with an ARHA did not have angiography. A left gastric arterial supply to the left liver was not detected. (ii) 5 mm protocol: 3DCT (n = 15) showed two cases of ARHA. While confirming these findings, angiography (n = 12) showed a third case of ARHA, in which the coeliac and superior mesenteric artery had very close origins. A left gastric supply to the left liver was also missed. It is concluded that satisfactory 3DCT is possible without changing existing scanning protocols, although narrow sections are required for the confident assessment of right hepatic arterial anomalies, and any left hepatic supply via the left gastric artery was poorly assessed in this series.

  18. Multiphase CT angiography increases detection of anterior circulation intracranial occlusion

    PubMed Central

    Yu, Amy Y. X.; Zerna, Charlotte; Assis, Zarina; Holodinsky, Jessalyn K.; Randhawa, Privia A.; Najm, Mohamed; Goyal, Mayank; Menon, Bijoy K.; Demchuk, Andrew M.; Coutts, Shelagh B.

    2016-01-01

    Objective: To evaluate whether the use of multiphase CT angiography (CTA) improves interrater agreement for intracranial occlusion detection between stroke neurology trainees and an expert neuroradiologist. Methods: A neuroradiologist and 2 stroke neurology fellows independently reviewed 100 prospectively collected single-phase and multiphase CTA scans from acute ischemic stroke patients with mild symptoms (NIH Stroke Scale score ≤5). The presence and location of a vascular occlusion(s) were documented. Interrater agreement single- and multiphase CTA was quantified using unweighted κ statistics. We assessed for any occlusions, anterior vs posterior occlusions, and pial vessel asymmetry. Results: Using multiphase CTA, the neuroradiologist detected 50 scans with anterior circulation occlusions and 15 scans with posterior circulation occlusions. Median reading time was 2 minutes per scan. Median reading time for the neurologists was 3 minutes per multiphase CTA scan. Interrater agreement was fair between the 2 neurologists and neuroradiologist when using single-phase CTA (κ = 0.45 and 0.32). Agreement improved minimally when stratified by anterior vs posterior circulation. When using multiphase CTA, agreement was high for detection of occlusion or asymmetry of pial vessels in the anterior circulation (κ = 0.80 and 0.84). Conclusions: Multiphase CTA improves diagnostic accuracy in minor ischemic stroke for detection of anterior circulation intracranial occlusion. Classification of evidence: This study provides Class II evidence that multiphase CTA, compared to single-phase CTA, improves the interrater agreement between stroke neurology trainees and an expert neuroradiologist for detecting anterior circulation intracranial vascular occlusion in patients with minor acute ischemic strokes. PMID:27385749

  19. Postmortem CT angiography: capabilities and limitations in traumatic and natural causes of death.

    PubMed

    Ross, Steffen G; Bolliger, Stephan A; Ampanozi, Garyfalia; Oesterhelweg, Lars; Thali, Michael J; Flach, Patricia M

    2014-01-01

    Whole-body postmortem computed tomographic (CT) angiography is a promising new development in forensic radiology that has the potential to improve vascular and soft-tissue imaging beyond levels currently achievable with unenhanced postmortem CT. Postmortem access to the vascular system and injection of contrast medium are different from those steps in clinical (antemortem) radiology. Because there is no circulation in a corpse that could transport or dilute a contrast medium, the injection must be performed by using a roller pump to fill the vasculature (arterial and venous) with a mixture of a water-soluble iodized contrast medium and polyethylene glycol. In contrast to a classic autopsy, postmortem CT angiography is a minimally invasive procedure. It allows the diagnosis of vascular lesions without the disruption or destruction of anatomic structures, which could result in a loss of evidence in a criminal investigation. Furthermore, postmortem CT angiography facilitates the display of vascular pathologic conditions in areas that are not typically covered with autopsy alone, such as the craniocervical junction and the small pelvis. Therefore, postmortem CT angiography adds substantial value to the classic forensic autopsy; cross-sectional data can be reevaluated objectively at any time and are fully reproducible as counterexpertise, which is as useful in the fields of forensic medicine and pathology as in clinical research. Familiarity with the capabilities of postmortem CT angiography may help radiologists working with forensic cases improve their diagnostic performance. RSNA, 2014

  20. MD CT Angiography and MR Angiography of Nonatherosclerotic Renal Artery Disease

    SciTech Connect

    Flors, Lucia; Leiva-Salinas, Carlos; Ahmad, Ehab Ali; Norton, Patrick T.; Turba, Ulku C.; Bozlar, Ugur; Hagspiel, Klaus D.

    2011-12-15

    We reviewed the computed tomographic and magnetic resonance angiographic appearances of the various nonatherosclerotic renal artery pathologies. Rapid progress in cross-sectional techniques has allowed computed tomography and magnetic resonance angiography to replace digital subtraction angiography in most circumstances. When state-of-the-art equipment and optimized protocols are used, diagnosing a wide range of nonatherosclerotic pathologies is possible.

  1. CT angiography and CT perfusion improve prediction of infarct volume in patients with anterior circulation stroke.

    PubMed

    van Seeters, Tom; Biessels, Geert Jan; Kappelle, L Jaap; van der Schaaf, Irene C; Dankbaar, Jan Willem; Horsch, Alexander D; Niesten, Joris M; Luitse, Merel J A; Majoie, Charles B L M; Vos, Jan Albert; Schonewille, Wouter J; van Walderveen, Marianne A A; Wermer, Marieke J H; Duijm, Lucien E M; Keizer, Koos; Bot, Joseph C J; Visser, Marieke C; van der Lugt, Aad; Dippel, Diederik W J; Kesselring, F Oskar H W; Hofmeijer, Jeannette; Lycklama À Nijeholt, Geert J; Boiten, Jelis; van Rooij, Willem Jan; de Kort, Paul L M; Roos, Yvo B W E M; Meijer, Frederick J A; Pleiter, C Constantijn; Mali, Willem P T M; van der Graaf, Yolanda; Velthuis, Birgitta K

    2016-04-01

    We investigated whether baseline CT angiography (CTA) and CT perfusion (CTP) in acute ischemic stroke could improve prediction of infarct presence and infarct volume on follow-up imaging. We analyzed 906 patients with suspected anterior circulation stroke from the prospective multicenter Dutch acute stroke study (DUST). All patients underwent baseline non-contrast CT, CTA, and CTP and follow-up non-contrast CT/MRI after 3 days. Multivariable regression models were developed including patient characteristics and non-contrast CT, and subsequently, CTA and CTP measures were added. The increase in area under the curve (AUC) and R (2) was assessed to determine the additional value of CTA and CTP. At follow-up, 612 patients (67.5%) had a detectable infarct on CT/MRI; median infarct volume was 14.8 mL (interquartile range (IQR) 2.8-69.6). Regarding infarct presence, the AUC of 0.82 (95% confidence interval (CI) 0.79-0.85) for patient characteristics and non-contrast CT was improved with addition of CTA measures (AUC 0.85 (95% CI 0.82-0.87); p < 0.001) and was even higher after addition of CTP measures (AUC 0.89 (95% CI 0.87-0.91); p < 0.001) and combined CTA/CTP measures (AUC 0.89 (95% CI 0.87-0.91); p < 0.001). For infarct volume, adding combined CTA/CTP measures (R (2) = 0.58) was superior to patient characteristics and non-contrast CT alone (R (2) = 0.44) and to addition of CTA alone (R (2) = 0.55) or CTP alone (R (2) = 0.54; all p < 0.001). In the acute stage, CTA and CTP have additional value over patient characteristics and non-contrast CT for predicting infarct presence and infarct volume on follow-up imaging. These findings could be applied for patient selection in future trials on ischemic stroke treatment.

  2. CT Chest with IV Contrast Compared with CT Angiography after Blunt Trauma.

    PubMed

    Zaw, Andrea A; Stewart, Donovan; Murry, Jason S; Hoang, David M; Sun, Beatrice; Ashrafian, Sogol; Hotz, Heidi; Chung, Rex; Margulies, Daniel R; Ley, Eric J

    2016-01-01

    Blunt aortic injury (BAI) after chest trauma is a potentially lethal condition. Rapid diagnosis is important to appropriately treat patients. The purpose of this study was to compare CT with intravenous contrast (CTI) to CT with angiography (CTA) in the initial evaluation of blunt chest trauma patients. This was a retrospective review of all blunt trauma patients who received a CTI or CTA during the initial evaluation at an urban Level I trauma center from January 1, 2010 to December 31, 2013. Two-hundred and eighty-one trauma patients met inclusion criteria. Most, 167/281 (59%) received CTI and 114/281 (41%) received CTA. There were no differences between cohorts in age, gender, initial heart rate, systolic blood pressure, and Glasgow Coma Scale in emergency department. Mortality rates were similar for CTI and CTA (4% vs 8%, P = 0.20). CTI identified an injury in 54 per cent compared with 46 per cent in CTA (P = 0.05). Overall, 2 per cent of patients had BAI with similar rates in CTI and CTA (2% vs 2%, P = 0.80). BAI was not missed using either CTI or CTA. Trauma patients studied with CTI had similar diagnostic findings as CTA. CTI may be preferable to CTA during the initial assessment for possible BAI because of a single contrast injection for whole body CT.

  3. CT Chest with IV Contrast Compared with CT Angiography after Blunt Trauma.

    PubMed

    Zaw, Andrea A; Stewart, Donovan; Murry, Jason S; Hoang, David M; Sun, Beatrice; Ashrafian, Sogol; Hotz, Heidi; Chung, Rex; Margulies, Daniel R; Ley, Eric J

    2015-10-01

    Blunt aortic injury (BAI) after chest trauma is a potentially lethal condition that requires rapid diagnosis for appropriate treatment. We compared CT with IV contrast (CTI) with CT with angiography (CTA) during the initial phase of care at an urban Level I trauma center from January 1, 2010 to December 31, 2013. Overall, 281 patients met inclusion criteria with 167 (59%) CTI and 114 (41%) CTA. There were no differences between cohorts in age, gender, initial heart rate, systolic blood pressure, and Glasgow Coma Scale. Mortality rates were similar for CTI and CTA (4% vs 8%, P = 0.20). CTI identified any chest injury in 54 per cent of patients compared with 46 per cent with CTA (P = 0.05). The rate of BAI was similar with CTI and CTA (2% vs 2%, P = 0.80), and neither modality was falsely negative. We conclude that CTI and CTA are similar at evaluating trauma patients for BAI, although CTI may be preferable during the initial assessment phase because the contrast injection may be combined with abdominal scanning and image time is reduced when whole-body CT is required.

  4. Surgical interventions with fatal outcome: utility of multi-phase postmortem CT angiography.

    PubMed

    Zerlauth, J-B; Doenz, F; Dominguez, A; Palmiere, C; Uské, A; Meuli, R; Grabherr, S

    2013-02-10

    Cases of fatal outcome after surgical intervention are autopsied to determine the cause of death and to investigate whether medical error caused or contributed to the death. For medico-legal purposes, it is imperative that autopsy findings are documented clearly. Modern imaging techniques such as multi-detector computed tomography (MDCT) and postmortem CT angiography, which is used for vascular system imaging, are useful tools for determining cause of death. The aim of this study was to determine the utility of postmortem CT angiography for the medico-legal death investigation. This study investigated 10 medico-legal cases with a fatal outcome after surgical intervention using multi-phase postmortem whole body CT angiography. A native CT scan was performed as well as three angiographic phases (arterial, venous, and dynamic) using a Virtangio(®) perfusion device and the oily contrast agent, Angiofil(®). The results of conventional autopsy were compared to those from the radiological investigations. We also investigated whether the radiological findings affected the final interpretation of cause-of-death. Causes of death were hemorrhagic shock, intracerebral hemorrhage, septic shock, and a combination of hemorrhage and blood aspiration. The diagnoses were made by conventional autopsy as well as by postmortem CT angiography. Hemorrhage played an important role in eight of ten cases. The radiological exam revealed the exact source of bleeding in seven of the eight cases, whereas conventional autopsy localized the source of bleeding only generally in five of the seven cases. In one case, neither conventional autopsy nor CT angiography identified the source of hemorrhage. We conclude that postmortem CT angiography is extremely useful for investigating deaths following surgical interventions. This technique helps document autopsy findings and allows a second examination if it is needed; specifically, it detects and visualizes the sources of hemorrhages in detail, which

  5. Pediatric cardiac-gated CT angiography: assessment of radiation dose.

    PubMed

    Hollingsworth, Caroline L; Yoshizumi, Terry T; Frush, Donald P; Chan, Frandics P; Toncheva, Greta; Nguyen, Giao; Lowry, Carolyn R; Hurwitz, Lynne M

    2007-07-01

    The purpose of our study was to determine a dose range for cardiac-gated CT angiography (CTA) in children. ECG-gated cardiac CTA simulating scanning of the heart was performed on an anthropomorphic phantom of a 5-year-old child on a 16-MDCT scanner using variable parameters (small field of view; 16 x 0.625 mm configuration; 0.5-second gantry cycle time; 0.275 pitch; 120 kVp at 110, 220, and 330 mA; and 80 kVp at 385 mA). Metal oxide semiconductor field effect transistor (MOSFET) technology measured 20 organ doses. Effective dose calculated using the dose-length product (DLP) was compared with effective dose determined from measured absorbed organ doses. Highest organ doses included breast (3.5-12.6 cGy), lung (3.3-12.1 cGy), and bone marrow (1.7-7.6 cGy). The 80 kVp/385 mA examination produced lower radiation doses to all organs than the 120 kVp/220 mA examination. MOSFET effective doses (+/- SD) were as follows: 110 mA: 7.4 mSv (+/- 0.6 mSv), 220 mA: 17.2 mSv (+/- 0.3 mSv), 330 mA: 25.7 mSv (+/- 0.3 mSv), 80 kVp/385 mA: 10.6 mSv (+/- 0.2 mSv). DLP effective doses for diagnostic runs were as follows: 110 mA: 8.7 mSv, 220 mA: 19 mSv, 330 mA: 28 mSv, 80 kVp/385 mA: 12 mSv. DLP effective doses exceeded MOSFET effective doses by 9.7-17.2%. Radiation doses for a 5-year-old during cardiac-gated CTA vary greatly depending on parameters. Organ doses can be high; the effective dose may reach 28.4 mSv. Further work, including determination of size-appropriate mA and image quality, is important before routine use of this technique in children.

  6. Nontraumatic subarachnoid hemorrhage management: evaluation with reduced iodine volume at CT angiography.

    PubMed

    Millon, Domitille; Derelle, Anne Laure; Omoumi, Patrick; Tisserand, Marie; Schmitt, Emmanuelle; Foscolo, Sylvain; Anxionnat, René; Bracard, Serge

    2012-07-01

    To evaluate the technical quality and the diagnostic performance of a protocol with use of low volumes of contrast medium (25 mL) at 64-detector spiral computed tomography (CT) in the diagnosis and management of adult, nontraumatic subarachnoid hemorrhage (SAH). This study was performed outside the United States and was approved by the institutional review board. Intracranial CT angiography was performed in 73 consecutive patients with nontraumatic SAH diagnosed at nonenhanced CT. Image quality was evaluated by two observers using two criteria: degree of arterial enhancement and venous contamination. The two independent readers evaluated diagnostic performance (lesion detection and correct therapeutic decision-making process) by using rotational angiographic findings as the standard of reference. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT angiography and three-dimensional rotational angiography. The intraclass correlation coefficient was calculated to assess interobserver concordance concerning aneurysm measurements and therapeutic management. All aneurysms were detected, either ruptured or unruptured. Arterial opacification was excellent in 62 cases (85%), and venous contamination was absent or minor in 61 cases (84%). In 95% of cases, CT angiographic findings allowed optimal therapeutic management. The intraclass correlation coefficient ranged between 0.93 and 0.95, indicating excellent interobserver agreement. With only 25 mL of iodinated contrast medium focused on the arterial phase, 64-detector CT angiography allowed satisfactory diagnostic and therapeutic management of nontraumatic SAH. © RSNA, 2012.

  7. Comparison of CT and angiography in assessing resectability of pancreatic carcinoma

    SciTech Connect

    Jafri, S.Z.H.; Aisen, A.M.; Glazer, G.M.; Weiss, C.A.

    1984-03-01

    A retrospective study of 27 patients with pancreatic carcinoma compared computed tomography (CT) and angiography in their ability to predict resectability of the neoplasm, using encasement of the splanchnic vessels as the criterion for nonresectability. Five patients had resectable tumor at surgery; the other 22 had unresectable disease. Tumor involvement of the splanchnic vessels was determined in 18 patients by CT examination and in 19 patients by angiography. Several other patients were found to have liver metastases, resulting in a radiologic diagnosis of nonresectability in 20 patients overall. All patients considered to have unresectable disease on the basis of either radiologic method proved to have unresectable tumor at surgery. CT is about as accurate as angiography in assessing resectability of pancreatic carcinoma.

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

    PubMed

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

    2015-01-01

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

  9. Non-invasive Detection of Aortic and Coronary Atherosclerosis in Homozygous Familial Hypercholesterolemia by 64 Slice Multi-detector Row Computed Tomography Angiography

    USDA-ARS?s Scientific Manuscript database

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector-row ...

  10. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    USDA-ARS?s Scientific Manuscript database

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  11. Novel Application of Postmortem CT Angiography for Evaluation of the Intracranial Vascular Anatomy in Cadaver Heads.

    PubMed

    van Eijk, Ruben P A; van der Zwan, Albert; Bleys, Ronald L A W; Regli, Luca; Esposito, Giuseppe

    2015-12-01

    Postmortem CT angiography is a common procedure used to visualize the entire human vasculature. For visualization of a specific organ's vascular anatomy, casting is the preferred method. Because of the permanent and damaging nature of casting, the organ cannot be further used as an experimental model after angiography. Therefore, there is a need for a minimally traumatic method to visualize organ-specific vascular anatomy. The purpose of this study was to develop and evaluate a contrast enhancement technique that is capable of visualizing the intracranial vascular anatomy while preserving the anatomic integrity in cadaver heads. Seven human heads were used in this study. Heads were prepared by cannulating the vertebral and internal carotid arteries. Contrast agent was injected as a mixture of tap water, polyethylene glycol 600, and an iodinated contrast agent. Postmortem imaging was executed on a 64-MDCT scanner. Primary image review and 3D reconstruction were performed on a CT workstation. Clear visualization of the major cerebral arteries and smaller intracranial branches was achieved. Adequate visualization was obtained for both the anterior and posterior intracranial circulation. The minimally traumatic angiography method preserved the vascular integrity of the cadaver heads. A novel application of postmortem CT angiography is presented here. The technique can be used for radiologic evaluation of the intracranial circulation in cadaver heads. After CT angiography, the specimen can be used for further experimental or laboratory testing and teaching purposes.

  12. Three-dimensional CT angiography: a new technique for imaging microvascular anatomy.

    PubMed

    Tregaskiss, Ashley P; Goodwin, Adam N; Bright, Linda D; Ziegler, Craig H; Acland, Robert D

    2007-03-01

    To date there has been no satisfactory research method for imaging microvascular anatomy in three dimensions (3D). In this article we present a new technique that allows both qualitative and quantitative examination of the microvasculature in 3D. In 10 fresh cadavers (7 females, 3 males, mean age 68 years), selected arteries supplying the abdominal wall and back were injected with a lead oxide/gelatin contrast mixture. From these regions, 30 specimens were dissected free and imaged with a 16-slice spiral computed tomographic (CT) scanner. Using three-dimensional CT (3D-CT) angiography, reconstructions of the microvasculature of each specimen were produced and examined for their qualitative content. Two calibration tools were constructed to determine (1) the accuracy of linear measurements made with CT software tools, and (2) the smallest caliber blood vessel that is reliably represented on 3D-CT reconstructions. Three-dimensional CT angiography produced versatile, high quality angiograms of the microvasculature. Correlation between measurements made with electronic calipers and CT software tools was very high (Lin's concordance coefficient, 0.99 (95% CI 0.99-0.99)). The finest caliber of vessel reliably represented on the 3D-CT reconstructions was 0.4 mm internal diameter. In summary, 3D-CT angiography is a simple, accurate, and reproducible method that imparts a much improved perception of anatomy when compared with existing research methods. Measurement tools provide accurate quantitative data to aid vessel mapping and preoperative planning. Further work will be needed to explore the full utility of 3D-CT angiography in a clinical setting.

  13. Prognostic Value of Coronary Computed Tomography (CT) Angiography and Coronary Artery Calcium Score Performed Before Revascularization

    PubMed Central

    Fujimoto, Shinichiro; Kondo, Takeshi; Kumamaru, Kanako K; Shinozaki, Tomohiro; Takamura, Kazuhisa; Kawaguchi, Yuko; Matsumori, Rie; Hiki, Makoto; Miyauchi, Katsumi; Daida, Hiroyuki; Rybicki, Frank J

    2015-01-01

    Background Cardiac events after revascularization are equally attributable to recurrence at site of culprit lesions and development of nonculprit lesions. We evaluated the hypothesis that coronary computed tomography (CT) angiography and coronary artery calcium score (CACS) performed before revascularization predicts cardiac events after treatment. Methods and Results Among 2238 consecutive patients without known coronary artery disease who underwent coronary CT angiography and CACS, 359 patients underwent revascularization within 30 days after CT; in 337 of 359 (93.9%) follow-up clinical information was available. In addition to known cardiac risk factors, CT findings were evaluated as predictors of cardiac events after revascularization: CACS and the presence of CT-verified high-risk plaque (CT-HRP). Improvement of predictive accuracy by including CT findings was evaluated from a discrimination (Harrell’s C-statistics) standpoint. During the follow-up period (median: 673, interquartile range: 47 to 1529 days), a total of 98 cardiac events occurred. Cox proportional hazard model revealed that age, diabetes, triglyceride, CACS, and nonculprit CT-HRP were significant predictors of overall cardiac events. Although not statistically significant, discriminatory power was greater for the model with CACS (C-stat: 63.2%) and the model with both CACS and CT-HRP (65.8%) compared to the model including neither CACS nor CT-HRP (60.7%). Conclusions High CACS and the presence of nonculprit CT-HRP performed before revascularization are significant predictors of cardiac events after revascularization. PMID:26296858

  14. Segmentation of brain blood vessels using projections in 3-D CT angiography images.

    PubMed

    Babin, Danilo; Vansteenkiste, Ewout; Pizurica, Aleksandra; Philips, Wilfried

    2011-01-01

    Segmenting cerebral blood vessels is of great importance in diagnostic and clinical applications, especially in quantitative diagnostics and surgery on aneurysms and arteriovenous malformations (AVM). Segmentation of CT angiography images requires algorithms robust to high intensity noise, while being able to segment low-contrast vessels. Because of this, most of the existing methods require user intervention. In this work we propose an automatic algorithm for efficient segmentation of 3-D CT angiography images of cerebral blood vessels. Our method is robust to high intensity noise and is able to accurately segment blood vessels with high range of luminance values, as well as low-contrast vessels.

  15. Anomalous left main coronary artery detected by CT angiography.

    PubMed

    Forte, Ernesto; Inglese, Marianna; Infante, Teresa; Schiano, Concetta; Napoli, Claudio; Soricelli, Andrea; Salvatore, Marco; Tedeschi, Carlo

    2016-10-01

    The growing improvements of computed tomography have made this technique more and more available for cardiac evaluation. Coronary artery anomalies (CAAs) are often incidental findings in subjects with suspected coronary artery disease (CAD) undergoing coronary angiography or computed tomography coronary angiography (CTCA). In some cases, CAAs can be clinically relevant so their identification could change radically patient management and treatment. We report the case of a 68-year-old male patient with known CAD and associated anomalous origination of the left coronary artery from the opposite sinus.

  16. A comparison of radiation doses between state-of-the-art multislice CT coronary angiography with iterative reconstruction, multislice CT coronary angiography with standard filtered back-projection and invasive diagnostic coronary angiography.

    PubMed

    Gosling, O; Loader, R; Venables, P; Roobottom, C; Rowles, N; Bellenger, N; Morgan-Hughes, G

    2010-06-01

    To accurately compare the radiation dose between prospectively gated cardiac multidetector CT (with and without iterative reconstruction) and diagnostic invasive coronary angiography using the latest International Commission on Radiological Protection 103 (ICRP) tissue weightings. A retrospective analysis of consecutive patients presenting to a university teaching hospital for investigation of coronary artery disease. Radiation doses for each technique were calculated using computational Monte Carlo modelling of a standard Cristy phantom rather than the application of previously published conversion factors. While these have frequently been used in other studies, they are based on out-dated ICRP tissue weightings (ICRP 60) and are for the whole chest rather than for structures irradiated in cardiac imaging. In order to allow a comparison, doses were calculated and expressed in terms of effective dose in millisieverts (mSv). From a population presenting for angiography within a clinical service, the median radiation dose from cardiac CT with standard filtered back-projection (84 patients, 5.4 mSv) was comparable with the dose from invasive diagnostic coronary angiography (94 patients, 6.3 mSv). The dose for cardiac CT using iterative reconstruction was significantly lower (39 patients, 2.5 mSv). The median effective dose from cardiac CT with standard filtered back-projection was comparable with the effective dose from invasive coronary angiography, even with application of the most contemporary ICRP tissue weightings and use of cardiac specific volumes. Cardiac CT scanning incorporating iterative reconstruction resulted in a significant reduction in the effective dose.

  17. Aortitis in giant cell arteritis: diagnosis with FDG PET/CT and agreement with CT angiography.

    PubMed

    Hommada, Mona; Mekinian, Arsène; Brillet, Pierre-Yves; Abad, Sébastien; Larroche, Claire; Dhôte, Robin; Fain, Olivier; Soussan, Michael

    2017-09-11

    To assess the detection rate of aortitis in giant cell arteritis (GCA) with fluorodeoxyglucose positron emission tomography/computed tomography (PET) and to compare the findings with CT angiography (CTA). Fifty-two GCA patients and 27 controls were included. GCA patients had a PET scan at diagnosis (35/52) or during relapse (17/52). Concomitant CTA was performed in 35/52 patients. Aortitis was defined as FDG uptake higher than the liver for PET and wall thickness≥3mm for CTA. Agreement between PET and CTA was evaluated by the kappa coefficient and Spearman correlation coefficient. Aortitis was diagnosed using PET in 40% (14/35) of patients at diagnosis and in 0% of controls (0/27). Agreement was perfect between PET and CT at a patient-based level, and very good at a vascular segment-based level (kappa: 0.72 to 1). PET was positive in 35% (6/17) of patients scanned during GCA relapse, showing aortitis (n=4) and/or articular uptake (n=4). Discrepancies between PET and CT were observed only in relapsing GCA (n=3). Correlation between the maximum standardized uptake value and wall thickness was moderate at diagnosis (r: 0.57 to 0.7) and not statistically significant during relapse. The detection rate of aortitis in GCA patients using PET is 40%, approximately in the range of CTA rates, suggesting that the two techniques have similar sensitivity. PET seems valuable in relapsing GCA, allowing the detection of vascular and articular activities. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Diagnostic performance of CT angiography in neck vessel trauma: systematic review and meta-analysis.

    PubMed

    Morales-Uribe, Carlos; Ramírez, Ana; Suarez-Poveda, Tatiana; Ortiz, Margarita; Sanabria, Alvaro

    2016-10-01

    This study was conducted in order to define the diagnostic performance of CT angiography for vascular injuries compared with angiography in patients with neck trauma. CT angiography is the cornerstone of diagnosis for hemodynamically stable patients with wounds suspicious of vascular trauma in the limbs, chest, or abdomen. Available evidence for the use of CT angiography in neck vascular trauma comes from small case series and few randomized controlled trials, and high-quality information does not exist regarding its performance. A protocol using the recommendations of the Cochrane Collaboration was designed. A systematic search of diagnostic studies without limits on language or time was carried out to December 2014. Studies including patients with neck trauma with retrospective or prospective data collection that assessed CT angiography compared with other methods were selected. Methodological quality was assessed using the QUADAS-2 tool. A hierarchical model ROC curve and a bivariate random effects model were used for the pooled analysis. Sixteen studies were selected and reviewed, and nine studies with 693 patients were included in this review. The overall sensitivity was 97 % (95 % CI 0.77-1.00; I (2) = 65.7 % (41.4-90.0)), while the overall specificity was 99 % (95 % CI 0.93-1.00; I (2) = 0). The hierarchic ROC curve showed an area under the curve of 0.99. Publication bias was not identified in this study. CT angiography can be stated as the gold standard for diagnosing vascular injuries in hemodynamically stable patients with neck trauma.

  19. Interobserver agreement of ASPECT score distribution for noncontrast CT, CT angiography, and CT perfusion in acute stroke.

    PubMed

    Finlayson, Olga; John, Verity; Yeung, Robert; Dowlatshahi, Dar; Howard, Peter; Zhang, Liying; Swartz, Rick; Aviv, Richard I

    2013-01-01

    The Alberta Stroke program early CT score (ASPECTS) is a semiquantative scale for estimating extent and distribution of early ischemic changes within the MCA territory in the acute stroke setting. Good interobserver agreement of total ASPECTS is demonstrated for noncontrast CT (NCCT) and other imaging modalities. Our purpose is to assess interobserver agreement for individual ASPECTS regions for different imaging modalities. One hundred and eighty-one consecutive patients presenting with acute stroke symptoms within 4.5 hours of onset were included. Four readers assigned total and individual ASPECTS for NCCT, CT angiography source images (CTA-SI), and CTP maps of cerebral blood volume (CTP-CBV). Interobserver agreement was assessed by measuring internal consistency and concordance of total and individual ASPECTS using Cronbach's α and intraclass correlation coefficient, respectively. Total ASPECTS demonstrated very good concordance and internal consistency for all 3 modalities. Intraclass correlation coefficient and Cronbach's α were 0.834 and 0.859 for NCCT, 0.876 and 0.894 for CTA, and 0.903 and 0.911 for CTP-CBV, respectively. Performance for individual ASPECTS regions was inferior to total ASPECTS, but incremental improvement in interobserver reliability was demonstrated for NCCT, CTA-SI, and CTP-CBV, respectively. Highest concordance was shown for caudate, lentiform, and M1-M3, whereas performance for internal capsule and M4-M6 was poorer. CTP-CBV demonstrates the highest interobserver agreement for individual ASPECTS regions.

  20. Surgical treatment of distal anterior cerebral artery aneurysms aided by electromagnetic navigation CT angiography.

    PubMed

    Hermann, Elvis J; Petrakakis, Ioannis; Götz, Friedrich; Lütjens, Götz; Lang, Josef; Nakamura, Makoto; Krauss, Joachim K

    2015-07-01

    The surgical treatment of distal anterior cerebral artery (DACA) aneurysms still presents a challenge for neurosurgeons because of their small size and their location in the depth of the narrow frontal interhemispheric fissure. This study aimed to investigate feasibility, safety, accuracy, and usefulness of electromagnetic (EM) navigation to aid clipping of DACA aneurysms. Eight patients (age between 2 and 68 years, mean age 49.8 years) with a DACA aneurysm underwent EM-guided neuronavigated microsurgery for clipping of the aneurysm. All patients underwent craniocervical 3D-CT angiography preoperatively. After planning the optimal approach and surgical trajectory avoiding opening of the frontal sinus, the head was fixed. Intraoperative screenshots were correlated with the microscopical view of the DACA aneurysms before clipping. EM-guided neuronavigation using CT angiography for DACA aneurysms enabled fast and accurate referencing of the patient and planning of a tailored craniotomy without opening of the frontal sinus. Intraoperative accuracy was highly reliable except in one instance due to dislocation of the dynamic reference frame (DRF). There was a good correlation between the 3D-CT angiography-based navigation data sets and the intraoperative vascular anatomy. In all patients, bridging veins were spared. The aid of EM neuronavigation was considered useful in all instances. EM-guided neuronavigation using CT angiography for surgery of DACA aneurysms is a useful tool optimizing the surgical approach directly to the aneurysm minimizing additional damage to the surrounding tissue during preparation of the aneurysm and the parent vessel.

  1. [Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps].

    PubMed

    Fansa, H; Schirmer, S; Frerichs, O; Gehl, H B

    2011-04-01

    Muscle sparing TRAM flaps and DIEA perforator flaps are standard procedures for breast reconstruction. Recently CT-angiography has been established to evaluate perforator vessels pre-operatively. CT-angiography was introduced to our department in July 2009. In a retrospective analysis data of the last 20 patients (altogether 22 flaps) before CT-angiography introduction and the following 20 (also 22 flaps) patients after introduction of CT-angiography were analysed with regard to the ratio of TRAM to DIEP flaps, and the time required to raise the flaps. The same surgeon raised all flaps. As different surgeons performed dissection of the recipient site, anastomoses, and insertion of flaps, and patients received primary (with sentinel or complete lymphadenctomy) or secondary reconstructions, only the time required harvesting the flap was compared. Thus other influences on raising the flap were eliminated. DIEP flaps were harvested with one single perforator. If perfusion or was considered not to be safe via one single perforator a muscle sparing TRAM flap (ms2) was raised. Angiography was performed using a 64-slice multi-detector CT scanner. CT-angiography did not lead to an increased rate of DIEP flaps in relation to ms2-TRAM flaps. Harvesting time of all flap types with CT-angiography on average was 121 min, without CT-angiography 135 min. This was not significantly different. However, separate analysis of DIEP flaps and ms2-TRAM flaps revealed a significant advantage of CT-angiography based harvesting of DIEP flaps of 26 min: with CT-angiography 101 min vs. 127 min without CT-angiography (p<0.028). There were no significant differences for ms2-TRAM flaps. All scans showed course and branching, diameter and size of the inferior epigastric artery. If evident the superficial inferior epigastric artery (SIEA) was marked. Dosage was 292 mGy-606 mGy×cm dependent on body weight. CTDI was 6.8-14.7 mGy. CT-angiography is a reproducible and observer independent procedure

  2. Automatic segmentation and co-registration of gated CT angiography datasets: measuring abdominal aortic pulsatility

    NASA Astrophysics Data System (ADS)

    Wentz, Robert; Manduca, Armando; Fletcher, J. G.; Siddiki, Hassan; Shields, Raymond C.; Vrtiska, Terri; Spencer, Garrett; Primak, Andrew N.; Zhang, Jie; Nielson, Theresa; McCollough, Cynthia; Yu, Lifeng

    2007-03-01

    Purpose: To develop robust, novel segmentation and co-registration software to analyze temporally overlapping CT angiography datasets, with an aim to permit automated measurement of regional aortic pulsatility in patients with abdominal aortic aneurysms. Methods: We perform retrospective gated CT angiography in patients with abdominal aortic aneurysms. Multiple, temporally overlapping, time-resolved CT angiography datasets are reconstructed over the cardiac cycle, with aortic segmentation performed using a priori anatomic assumptions for the aorta and heart. Visual quality assessment is performed following automatic segmentation with manual editing. Following subsequent centerline generation, centerlines are cross-registered across phases, with internal validation of co-registration performed by examining registration at the regions of greatest diameter change (i.e. when the second derivative is maximal). Results: We have performed gated CT angiography in 60 patients. Automatic seed placement is successful in 79% of datasets, requiring either no editing (70%) or minimal editing (less than 1 minute; 12%). Causes of error include segmentation into adjacent, high-attenuating, nonvascular tissues; small segmentation errors associated with calcified plaque; and segmentation of non-renal, small paralumbar arteries. Internal validation of cross-registration demonstrates appropriate registration in our patient population. In general, we observed that aortic pulsatility can vary along the course of the abdominal aorta. Pulsation can also vary within an aneurysm as well as between aneurysms, but the clinical significance of these findings remain unknown. Conclusions: Visualization of large vessel pulsatility is possible using ECG-gated CT angiography, partial scan reconstruction, automatic segmentation, centerline generation, and coregistration of temporally resolved datasets.

  3. Integration of 64-detector lower extremity CT angiography into whole-body trauma imaging: feasibility and early experience.

    PubMed

    Foster, Bryan R; Anderson, Stephan W; Uyeda, Jennifer W; Brooks, Jeffrey G; Soto, Jorge A

    2011-12-01

    To evaluate the image quality and clinical utility of a polytrauma computed tomographic (CT) protocol that integrates lower extremity CT angiography into multiphasic whole-body trauma CT by utilizing 64-detector CT and a single contrast material bolus. This retrospective study was institutional review board approved and HIPAA compliant. Informed consent was waived. All patients who underwent CT angiography of the lower extremities integrated with multiphasic torso CT for trauma between May 2005 and September 2009 were included. Two hundred eighty-four patients met the inclusion criteria. The mechanism of trauma was blunt injury in 228 (80.3%) of 284 patients and penetrating in 56 (19.7%) of 284 patients. CT angiography encompassed the joints proximal and distal to the injured region, with scan delay fixed at 25 seconds. Two radiologists retrospectively reviewed all the extremity CT angiograms, noting the presence of vascular injury, and measured the attenuation in the lower extremity arteries. Arterial attenuation, in Hounsfield units, was measured at multiple vascular divisions, and CT angiographic results were compared with clinical outcome, and if available, repeat lower extremity CT angiographic, conventional angiographic, or surgical findings. Sensitivity and specificity with 95% confidence intervals were calculated. Sixty-three arterial injuries were identified in 44 (15.5%) of 284 patients as follows: occlusion (n = 37), narrowing (n = 9), active extravasation (n = 14), pseudoaneurysm (n= 2), and arteriovenous fistula (n = 1). Three patients underwent conventional angiography after CT angiography. Seven patients underwent surgical therapy with all CT angiographic findings confirmed. There were no injuries subsequently identified in the subgroup with a negative result at CT angiography. Of the 864 vascular divisions in which attenuation was measured, 69 (8%) of 864 had a mean attenuation less than 150 HU. Integration of lower extremity CT angiography into

  4. Preoperative planning for endovascular aortic repair of abdominal aortic aneurysms: feasibility of nonenhanced MR angiography versus contrast-enhanced CT angiography.

    PubMed

    Goshima, Satoshi; Kanematsu, Masayuki; Kondo, Hiroshi; Kawada, Hiroshi; Kojima, Toshihisa; Sakurai, Kota; Watanabe, Haruo; Shimabukuro, Katsuya; Matsuno, Yukihiro; Ishida, Narihiro; Takemura, Hirofumi; Bae, Kyongtae T

    2013-06-01

    To compare vascular measurements to determine stent types and configurations for abdominal endovascular aneurysm repair (EVAR) by comparing results of contrast material-enhanced computed tomographic (CT) angiography and nonenhanced magnetic resonance (MR) angiography. This prospective study was institutional review board approved, and all patients provided written informed consent. Fifty patients (45 men and five women; mean age, 76.0 years) admitted for elective abdominal EVAR underwent preoperative abdominal CT angiography (triplanar reformatted images; section thickness of 1-3 mm) and nonenhanced MR angiography (triplanar two-dimensional single-shot turbo field-echo images; section thickness of 6 mm). Two observers independently completed standard measurement and device selection forms for endovascular stent planning for CT and MR angiography. Pearson and intraclass correlation coefficients were calculated to evaluate intermodality and interobserver differences. No significant difference was found in aortic neck diameter (observer 1: CT, 18.5 mm; MR, 19.0 mm; P = .43) (observer 2: CT, 19.6 mm; MR, 19.3 mm; P = .59), aortic neck diameter 15 mm distal to the lowest renal artery (observer 1: CT, 19.2 mm; MR, 19.2 mm; P = .38) (observer 2: CT, 19.6 mm; MR, 19.6 mm; P = .91), aortic neck length (observer 1: CT, 43.6 mm; MR, 43.6 mm; P = .85) (observer 2: CT, 44.4 mm; MR, 44.0 mm; P = .93), or other key vascular measurements (P = .23-.99) for preoperative planning. These included aneurysm diameter, lowest renal artery to aortic bifurcation length, aortic bifurcation diameter, common iliac artery diameters, external iliac artery diameters, length between orifices of lower renal and internal iliac arteries, and iliac artery sealing length. CT and MR angiography measurements showed very strong correlation (r = 0.92-0.99). Intraclass correlation coefficients between observers ranged from 0.90 to 0.98. Stent types and configurations determined with CT measurements remained

  5. Cerebral artery evaluation of dual energy CT angiography with dual source CT.

    PubMed

    Ma, Rui; Liu, Cheng; Deng, Kai; Song, Shao-juan; Wang, Dao-ping; Huang, Ling

    2010-05-05

    Conventional computed tomography angiography (CTA) is time consuming, user-dependent and has poor image quality in skull base region. This study assessed the feasibility of a new method, dual energy CTA for depicting the cerebral artery. Phantom scan was done with head CTA sequences on dual source CT and 64 spiral CT for radiation dose calculation. Dual energy CTA was done with dual source CT on 36 patients who were suspected of having cerebral vascular disease. Three series axial images in 0.75 mm thick, 0.4 mm increment were acquired, which were named with 80 kV, 140 kV and merged images; 80 kV and 140 kV images were transferred into dual energy software, and maximum intensity projection (MIP) image was generated quickly by dual energy bone remove (DEBR group); merged images were transferred into In Space software to acquire MIP image through manual conventional bone remove (CoBR group). Post processing time and reading time were compared. Image qualities of the two groups were compared, mainly focusing on skull base segments of internal carotid artery and bone subtraction. ANOVA and SNK tests were applied for radiation dose comparison. Student's t test and Wilcoxon rank sum test were applied for assessing differences between data for significance. Cohen's kappa was used for interobserver agreement. Radiation dose of phantom scan showed dual energy CTA was between digital bone subtraction and conventional CTA. The post processing time and reading time were much shorter in DEBR than CoBR, and image quality in skull base was much higher in DEBR than CoBR (P < 0.01). There was no significant difference for suprasellar vessels between two groups (P > 0.5). Interobserver agreement for all vessel segments was excellent (kappa = 0.97). Dual energy CTA is a reliable, new modality for depicting cerebral artery, overcoming the limitation of conventional CTA in the skull base region. It can save much time in post processing and reading than conventional CTA.

  6. Coronary CT angiography in the emergency department utilizing second and third generation dual source CT.

    PubMed

    Meyersohn, Nandini M; Szilveszter, Balint; Staziaki, Pedro V; Scholtz, Jan-Erik; Takx, Richard A P; Hoffmann, Udo; Ghoshhajra, Brian B

    Coronary computed tomography angiography (coronary CTA) allows efficient triage of low to intermediate risk patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). Techniques for coronary CTA acquisition in the ED continue to evolve with the establishment of standardized scan protocols and the introduction of newer generations of CT hardware. To evaluate qualitative and quantitative image quality and radiation dose exposure of coronary CTA acquired on 2nd versus 3rd generation dual source CT (DSCT) scanners using a standardized institutional scan protocol designed for the ED. A retrospective observational case-control study was performed of 246 ED patients referred to coronary CTA with suspicion of ACS (56.5% male; mean age 53.3 ± 11.6 years) between October 2013 and August 2015.123 consecutive patients were scanned on 3rd generation DSCT, and a cohort of 123 patients matched by age, BMI and heart rate were identified who had undergone 2nd generation DSCT imaging utilizing the same standard clinical protocol. Qualitative and quantitative image quality parameters and radiation exposures were evaluated. Qualitative image quality was significantly higher using 3rd generation DSCT as compared to 2nd generation (p < 0.001). Mean attenuation in the proximal coronary arteries was also significantly higher on 3rd generation DSCT than for 2nd generation (586 HU vs. 426 HU in the left main coronary artery (LM), p < 0.001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values, however, were lower in 3rd generation DSCT than 2nd generation (SNR 11.2 [9.9-13.4] vs 13.5 [11.0-15.5] and CNR 12.4 [10.9-14.8] vs 15.2 [12.8-17.9] in the LM, p < 0.001). Median effective dose was also lower for 3rd generation DSCT than for 2nd generation (2.9 [2.3-5.0] mSv and 3.7 mSv [2.5-5.7], respectively) although this trend did not reach statistical significance (p = 0.065). Qualitative image quality and mean CT attenuation values of the

  7. Noninvasive Imaging of Atherosclerotic Plaque Progression: Status of Coronary CT Angiography

    PubMed Central

    Sandfort, Veit; Lima, Joao A.C.; Bluemke, David A.

    2015-01-01

    The process of coronary artery disease progression is infrequently visualized. Intravascular ultrasound has been used to gain important insights but is invasive and therefore limited to high risk patients. For low to moderate risk patients, noninvasive methods may be useful to quantitatively monitor plaque progression or regression, and to understand and personalize atherosclerosis therapy. This review discusses the potential for coronary CT angiography (CCTA) to evaluate the extent and subtypes of coronary plaque. CT technology is evolving and image quality of the method approaches the level required for plaque progression monitoring. Methods to quantify plaque on CT angiography are reviewed as well as a discussion of their use in clinical trials. Limitations of CCTA compared to competing modalities include limited evaluation of plaque subcomponents and incomplete knowledge of the value of the method especially in patients with low to moderate cardiovascular risk. PMID:26156016

  8. Bone suppression in CT angiography data by region-based multiresolution segmentation

    NASA Astrophysics Data System (ADS)

    Blaffert, Thomas; Wiemker, Rafael; Lin, Zhong Min

    2003-05-01

    Multi slice CT (MSCT) scanners have the advantage of high and isotropic image resolution, which broadens the range of examinations for CT angiography (CTA). A very important method to present the large amount of high-resolution 3D data is the visualization by maximum intensity projections (MIP). A problem with MIP projections in angiography is that bones often hide the vessels of interest, especially the scull and vertebral column. Software tools for a manual selection of bone regions and their suppression in the MIP are available, but processing is time-consuming and tedious. A highly computer-assisted of even fully automated suppression of bones would considerably speed up the examination and probably increase the number of examined cases. In this paper we investigate the suppression (or removal) of bone regions in 3D CT data sets for vascular examinations of the head with a visualization of the carotids and the circle of Willis.

  9. Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

    PubMed Central

    Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

    2016-01-01

    Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted. PMID:26728701

  10. Dual-Energy CT Angiography in Peripheral Arterial Occlusive Disease

    SciTech Connect

    Brockmann, Carolin Jochum, Susanne; Sadick, Maliha; Huck, Kurt; Ziegler, Peter; Fink, Christian; Schoenberg, Stefan O.; Diehl, Steffen J.

    2009-07-15

    We sought to study the accuracy of dual-energy computed tomographic angiography (DE-CTA) for the assessment of symptomatic peripheral arterial occlusive disease of the lower extremity by using the dual-energy bone removal technique compared with a commercially available conventional bone removal tool. Twenty patients underwent selective digital subtraction angiography and DE-CTA of the pelvis and lower extremities. CTA data were postprocessed with two different applications: conventional bone removal and dual-energy bone removal. All data were reconstructed and evaluated as 3D maximum-intensity projections. Time requirements for reconstruction were documented. Sensitivity, specificity, accuracy, and concordance of DE-CTA regarding degree of stenosis and vessel wall calcification were calculated. A total of 359 vascular segments were analyzed. Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%. Best results for both postprocessing methods were achieved in the vascular segments of the upper leg. In severely calcified segments, sensitivity, specificity, and accuracy stayed above 90% by the dual-energy bone removal technique, whereas the conventional bone removal technique showed a substantial decrease of sensitivity, specificity, and accuracy. DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.

  11. CT enterography.

    PubMed

    Zamboni, Giulia A; Raptopoulos, Vassilios

    2010-04-01

    Conventional radiologic and endoscopic evaluations of the small bowel are often limited by the length, caliber, and motility of the small bowel loops. The development of new multidetector-row CT scanners, with faster scan times and isotropic spatial resolution, allows high-resolution multiphasic and multiplanar assessment of the bowel, bowel wall, and lumen. CT Enterography (CTE) is a variant of routine abdominal scanning, geared toward more sustained bowel filling with oral contrast material, and the use of multiplanar images, that can enhance gastrointestinal (GI) tract imaging. This article examines the techniques and clinical applications of CTE in comparison with CT enteroclysis, focusing on Crohn disease, obscure GI bleeding, GI tumors, acute abdominal pain, and bowel obstruction. Copyright 2010 Elsevier Inc. All rights reserved.

  12. [Postoperative imaging of synthetic coronary artery bypass graft patency by means of CT angiography].

    PubMed

    Froelich, J J; Alfke, H; Hoppe, M; Vogt, S; Vannucchi, A; Moosdorf, R; Klose, K J

    1998-08-01

    CT angiography was performed in 12 patients with insufficient autologous graft situations to evaluate postoperative patency and situation of the proximal, distal and coronary artery anastomoses of synthetic Perma-Flow coronary artery bypass grafts. Bypass grafts were evaluated postoperatively with spiral CT of the mediastinum. At a flow rate of 3 ml/s, 120 ml of contrast material were applied over a cubital vein. Slice thickness was 3 mm, maximum pitch factor 2 and image reconstruction was performed at 2 mm increment. Shaded surface displays were analysed together with axial scans for bypass evaluation. 8 out of 12 synthetic bypasses proved to be patent. One bypass was completely occluded and in three patients the distal portions of the grafts were occluded. Coronary angiography performed in one case confirmed complete bypass occlusion. Due to the occlusions, 8 distal and 12 proximal anastomoses were visible. Only 8 out of 19 side-to-side coronary artery anastomoses could be sufficiently well imaged with this technique. CT angiography is suitable for postoperative screening of synthetic coronary bypasses to determine the patency and anastomotic situations. Coronary artery anastomoses however are not sufficiently imaged and coronary angiography continues to be required.

  13. State-of-the-art in CT hardware and scan modes for cardiovascular CT

    PubMed Central

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J.; Gentry, Ralph; George, Richard T.; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm. Guy

    2013-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and the coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography (SCCT) Basic and Emerging Sciences and Technology (BEST) Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging. PMID:22551595

  14. State-of-the-art in CT hardware and scan modes for cardiovascular CT.

    PubMed

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J; Gentry, Ralph; George, Richard T; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm Guy

    2012-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography Basic and Emerging Sciences and Technology Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging.

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

    PubMed

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

    1995-03-01

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

  16. Sudden death after chest pain: feasibility of virtual autopsy with postmortem CT angiography and biopsy.

    PubMed

    Ross, Steffen G; Thali, Michael J; Bolliger, Stephan; Germerott, Tanja; Ruder, Thomas D; Flach, Patricia M

    2012-07-01

    To determine the potential of minimally invasive postmortem computed tomographic (CT) angiography combined with image-guided tissue biopsy of the myocardium and lungs in decedents who were thought to have died of acute chest disease and to compare this method with conventional autopsy as the reference standard. The responsible justice department and ethics committee approved this study. Twenty corpses (four female corpses and 16 male corpses; age range, 15-80 years), all of whom were reported to have had antemortem acute chest pain, were imaged with postmortem whole-body CT angiography and underwent standardized image-guided biopsy. The standard included three biopsies of the myocardium and a single biopsy of bilateral central lung tissue. Additional biopsies of pulmonary clots for differentiation of pulmonary embolism and postmortem organized thrombus were performed after initial analysis of the cross-sectional images. Subsequent traditional autopsy with sampling of histologic specimens was performed in all cases. Thereafter, conventional histologic and autopsy reports were compared with postmortem CT angiography and CT-guided biopsy findings. A Cohen κ coefficient analysis was performed to explore the effect of the clustered nature of the data. In 19 of the 20 cadavers, findings at postmortem CT angiography in combination with CT-guided biopsy validated the cause of death found at traditional autopsy. In one cadaver, early myocardial infarction of the papillary muscles had been missed. The Cohen κ coefficient was 0.94. There were four instances of pulmonary embolism, three aortic dissections (Stanford type A), three myocardial infarctions, three instances of fresh coronary thrombosis, three cases of obstructive coronary artery disease, one ruptured ulcer of the ascending aorta, one ruptured aneurysm of the right subclavian artery, one case of myocarditis, and one pulmonary malignancy with pulmonary artery erosion. In seven of 20 cadavers, CT-guided biopsy

  17. Hepatic perfusion abnormalities during CT angiography: Detection and interpretation

    SciTech Connect

    Freeny, P.C.; Marks, W.M.

    1986-06-01

    Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

  18. Comparative evaluation of 64-slice CT angiography and digital subtraction angiography in assessing the cervicocranial vasculature.

    PubMed

    Klingebiel, Randolf; Kentenich, Max; Bauknecht, Hans-Christian; Masuhr, Florian; Siebert, Eberhard; Busch, Markus; Bohner, Georg

    2008-01-01

    Noninvasive 64-slice computed tomography angiography (64-MSCTA) closely approximates conventional catheter angiography (DSA) in terms of detail resolution. Retrospective evaluation of cervicocranial (cc) 64-MSCTA in comparison with DSA in patients with presumptive cc vascular disorders. Twenty-four 64-MSCTA studies (32 mm detector width, slice thickness 0.5 mm, 120 kv, 150 mAs, pitch 0.75) of patients with presumptive cc vascular pathology (13 men, 11 women, mean age 38.3 +/- 11.3 yrs, range 19-54 yrs) were assessed in comparison with DSA studies without abnormal findings in age-matched patients (11 men, 13 women, mean age 39.7 +/- 11.9 yrs, range 18-54 yrs). Study readings were performed in a blinded manner by two neuroradiologists with respect to image quality and assessibility of various cc vascular segments by using a five-point scale. Radiation exposure was calculated for 64-MSCTA. Each reader assessed 384/528 different vessel segments (64-MSCTA/DSA). Superior image quality was attributed to DSA with respect to the C1 ICA-C6 ICA, A3 ACA, and P3 PCA segments as well the AICA and SCA. 64-MSCTA was scored superior for C7 ICA and V4 VA segments. A significantly increased number ofnonassessable V2- and V3 VA segments in DSA studies was noted. The effective dose for 64-MSCTA amounted to 2.2 mSv. 64-MSCTA provides near-equivalent diagnostic information of the cc vasculature as compared with DSA. According to our results, DSA should be considered primarily when peripheral vessels (A3/P3) or ICA segments close to the skull base (C2-5) are of interest, such as in primary angiitis or stenoocclusive ICA disease, respectively.

  19. Non-enhanced MR angiography of renal artery using inflow-sensitive inversion recovery pulse sequence: a prospective comparison with enhanced CT angiography.

    PubMed

    Xu, Jun-ling; Shi, Da-Peng; Li, Yong-Li; Zhang, Ji-liang; Zhu, Shao-cheng; Shen, Hao

    2011-11-01

    To prospectively evaluate the diagnostic value of non-enhanced inflow-sensitive inversion recovery (IFIR) MR angiography for the detection of renal artery stenosis (RAS), with enhanced CT angiography performed as the reference standard. Sixty consecutive patients suspected of RAS underwent both of IFIR MR and enhanced CT angiography. Subjective image quality, renal artery depiction and renal artery grading were all evaluated on artery-by-artery basis. Spearman rank correlation analysis was used to assess agreement between the two techniques. The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for RAS detection at IFIR MR angiography were calculated. One hundred twenty-six main renal arteries were visualized on enhanced CT and non-enhanced MR angiographic images, respectively. The Spearman rank correlation was 0.773 (P<.001) for renal artery depiction, 0.998 (P<.001) for renal arteries grading and 0.833 (P<.001) for RAS detection between the two modalities. The sensitivity, specificity, PPV and NPV of IFIR MR angiography for RAS detection demonstrated 100%, 99.0%, 92.0% and 100%, respectively. Non-enhanced IFIR MR angiography had high sensitivity, specificity, PPV and NPV for RAS detection. It could be the first choice of renal artery imaging methods to avoid ionizing irradiation and renal toxicity from contrast media. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Registration of ultrasound to CT angiography of kidneys: a porcine phantom study

    NASA Astrophysics Data System (ADS)

    Xiang, Jing; Gill, Sean; Nguan, Christopher; Abolmaesumi, Purang; Rohling, Robert N.

    2010-02-01

    3D ultrasound (US) to computed tomography (CT) registration is a topic of significant interest because it can potentially improve many minimally invasive procedures such as laparoscopic partial nephrectomy. Partial nephrectomy patients often receive preoperative CT angiography, which helps define the important structures of the kidney such as the vasculature. Intraoperatively, dynamic real-time imaging information can be captured using ultrasound and compared with the preoperative data. Providing accurate registration between the two modalities would enhance navigation and guidance for the surgeon. However, one of the major problems of developing and evaluating registration techniques is obtaining sufficiently accurate and realistic phantom data especially for soft tissue. We present a detailed procedure for constructing tissue phantoms using porcine kidneys, which incorporates contrast agent into the tissue such that the kidneys appear representative of in vivo human CT angiography. These phantoms are also imaged with US and resemble US images from human patients. We then perform registration on corresponding CT and US datasets using a simulation-based algorithm. The method simulates an US image from the CT, generating an intermediate modality that resembles ultrasound. This simulated US is then registered to the original US dataset. Embedded fiducial markers provide a gold standard for registration. Being able to test our registration method on realistic datasets facilitates the development of novel CT to US registration techniques such that we can generate an effective method for human studies.

  1. Failing Hemodialysis Arteriovenous Fistula and Percutaneous Treatment: Imaging with CT, MRI and Digital Subtraction Angiography

    SciTech Connect

    Cavagna, Enrico; D'Andrea, Paolo; Schiavon, Francesco; Tarroni, Giovanni

    2000-07-15

    Purpose: To evaluate failing hemodialysis arteriovenous fistulas with helical CT angiography (CTA), MR angiography (MRA), and digital subtraction angiography (DSA), and to compare the efficacy of the three techniques in detecting the number, location, grade, and extent of stenoses and in assessing the technical results of percutaneous transluminal angioplasty (PTA) and stenting.Methods: Thirteen patients with Brescia-Cimino arteriovenous fistula malfunction underwent MRA and CTA of the fistula and, within 1 week, DSA. A total of 11 PTAs were performed; in three cases an MR-compatible stent was placed. DSA served as the gold standard for comparison in all patients. The presence, site, and number of stenoses or occlusions and the technical results of percutaneous procedures were assessed with DSA, CTA, and MRA.Results: MRA underestimated a single stenosis in one patient; CTA and MRA did not overestimate any stenosis. Significant artifacts related to stent geometry and/or underlying metal were seen in MRA sequences in two cases.Conclusions: CT and MRI can provide information regarding the degree of vascular impairment, helping to stratify patients into those who can have PTA (single or multiple stenoses) versus those who require an operative procedure (occlusion). Conventional angiography can be reserved for candidates for percutaneous intervention.

  2. Mandibular arteriovenous malformation: A rare life-threatening condition depicted on multidetector CT angiography

    PubMed Central

    Dwivedi, Amit Nandan Dhar; Pandey, Anubha; Kumar, Ishan; Agarwal, Arjit

    2014-01-01

    Arteriovenous malformation (AVM) of the mandible is a rare and potentially life-threatening condition which can lead to massive hemorrhage. The following is a description where a large mandibular AVM presented with torrential bleeding following tooth extraction for caries. An orthopantomogram (OPG) was performed which was suggestive of aneurysmal bone cyst or ameloblastoma. A computed tomography (CT) angiography revealed a large mandibular AVM with submandibular extension. It is important for both clinicians and radiologist to be aware of this type of lesion that can have life-threatening complications. It is important to define the anatomical location and the feeder vessels of the entity in detail preoperatively. This communication highlights the common differential and use of multidetector CT (MDCT) angiography along with other imaging modalities to prevent a fatal hemorrhage and arrive at a correct diagnosis. PMID:24959049

  3. Estimation of myocardial volume at risk from CT angiography

    NASA Astrophysics Data System (ADS)

    Zhu, Liangjia; Gao, Yi; Mohan, Vandana; Stillman, Arthur; Faber, Tracy; Tannenbaum, Allen

    2011-03-01

    The determination of myocardial volume at risk distal to coronary stenosis provides important information for prognosis and treatment of coronary artery disease. In this paper, we present a novel computational framework for estimating the myocardial volume at risk in computed tomography angiography (CTA) imagery. Initially, epicardial and endocardial surfaces, and coronary arteries are extracted using an active contour method. Then, the extracted coronary arteries are projected onto the epicardial surface, and each point on this surface is associated with its closest coronary artery using the geodesic distance measurement. The likely myocardial region at risk on the epicardial surface caused by a stenosis is approximated by the region in which all its inner points are associated with the sub-branches distal to the stenosis on the coronary artery tree. Finally, the likely myocardial volume at risk is approximated by the volume in between the region at risk on the epicardial surface and its projection on the endocardial surface, which is expected to yield computational savings over risk volume estimation using the entire image volume. Furthermore, we expect increased accuracy since, as compared to prior work using the Euclidean distance, we employ the geodesic distance in this work. The experimental results demonstrate the effectiveness of the proposed approach on pig heart CTA datasets.

  4. Changes in Medical Management after Coronary CT Angiography.

    PubMed

    Naue, Vânia Mairi; Camargo, Gabriel; Sabioni, Letícia Roberto; Lima, Ronaldo de Souza Leão; Derenne, Maria Eduarda; Lorenzo, Andréa Rocha de; Freire, Monica Di Calafiori; Azevedo Filho, Clério Francisco; Resende, Elmiro Santos; Gottlieb, Ilan

    2015-08-07

    Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients. To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels. We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after. A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD. Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD.

  5. Changes in Medical Management after Coronary CT Angiography.

    PubMed

    Naue, Vânia Mairi; Camargo, Gabriel; Sabioni, Letícia Roberto; Lima, Ronaldo de Souza Leão; Derenne, Maria Eduarda; Lorenzo, Andréa Rocha de; Freire, Monica Di Calafiori; Azevedo Filho, Clério Francisco; Resende, Elmiro Santos; Gottlieb, Ilan

    2015-10-01

    Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients. To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels. We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after. A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD. Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD.

  6. Changes in Medical Management after Coronary CT Angiography

    PubMed Central

    Naue, Vânia Mairi; Camargo, Gabriel; Sabioni, Letícia Roberto; Lima, Ronaldo de Souza Leão; Derenne, Maria Eduarda; de Lorenzo, Andréa Rocha; Freire, Monica Di Calafiori; Azevedo Filho, Clério Francisco; Resende, Elmiro Santos; Gottlieb, Ilan

    2015-01-01

    Introduction Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients. Objective To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels. Methods We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after. Results A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD. Conclusion Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD. PMID:26559988

  7. Aneurysm of the proximal thoracic aorta simulating neoplasm: the role of CT and angiography

    SciTech Connect

    Smith, T.R.; Khoury, P.T.

    1985-05-01

    Ascending aortic and proximal transverse arch aneurysms may sometimes project to the left of midline and be difficult to distinguish from neoplasm. The authors have recently encountered three such cases that presented as possible neoplastic soft-tissue masses overlying the left upper lobe. They did not enhance on intravenous-contrast-enhanced CT scans, and in two cases the diagnosis of aneurysm was not confirmed until angiography was performed.

  8. Arteriovenous fistula complicating iliac artery pseudo aneurysm: diagnosis by CT angiography.

    PubMed

    Huawei, L; Bei, D; Huan, Z; Zilai, P; Aorong, T; Kemin, C

    2002-01-01

    Fistula formation to the inferior vena cava is a rare complication of aortic aneurysm which is often misdiagnosed clinically. In one hundred of reported arteriocaval fistulae, none was originating from the right common iliac artery. We report a case of ileo-caval fistula due to a iatrogenic pseudoaneurysm. High resolution 3D imaging using breath-hold CT angiography is highly specific in identifying the location, extent of the aortocaval fistula as well as the neighbouring anatomic structures.

  9. Individualized CT Angiography Protocols for the Evaluation of the Aorta: A Feasibility Study.

    PubMed

    Kok, Madeleine; de Haan, Michael W; Mihl, Casper; Eijsvoogel, Nienke G; Hendriks, Babs M F; Sailer, Anna M; Derks, Kris; Schnerr, Roald S; Schurink, Geert Willem H; Wildberger, Joachim E; Das, Marco

    2016-04-01

    Ionizing radiation and iodinated contrast media are potential drawbacks to repetitive follow-up CT angiography in current practice. The aim of the present study was to optimize radiation dose and contrast agent volume by using individualized CT angiography protocols. Eighty consecutive patients referred for CT angiography of the whole aorta were prospectively evaluated. Patients were divided into groups of patients with a body mass index (BMI) < 28 kg/m(2) (group 1; n = 50) and those with a BMI ≥ 28 kg/m(2) (group 2; n = 30). A control group consisted of 50 consecutive patients who were retrospectively evaluated. CT angiography parameters on a second-generation dual-source scanner were 128 × 0.6-mm collimation, pitch of 0.9, rotation time of 0.33 seconds, tube voltages of 80/100/120 kVp (group 1/group 2/control), reference tube current of 400 mA, and image reconstruction at 1-mm/0.8-mm slice thickness (kernels, B30f [control] and I30f/strength 3 [groups 1/2]). The control group received 120 mL of contrast agent (300 mgI/mL) at 4.8 mL/s; groups 1 and 2 received 44 mL and 53 mL at 3.3 mL/s and 4 mL/s, respectively. Effective dose was evaluated for each patient. Image quality was determined by qualitative image analysis at the levels of the thoracic, abdominal, and pelvic aorta as nondiagnostic, diagnostic, good, or excellent, and quantitative image analysis was performed, including attenuation values and contrast-to-noise ratio (CNR). Mean effective radiation dose values for CT angiography of the aorta were 3.7 mSv ± 0.7 in group 1, 6.7 mSv ± 1.4 in group 2, and 8.7 mSv ± 1.9 in the control group (P < .001). Mean attenuation values and CNR levels were 334 HU ± 66 and 16 ± 8, respectively, in group 1, 277 HU ± 56 and 14 ± 5 in group 2, and 305 HU ± 77 and 11 ± 4 in the control group. Iterative reconstruction algorithms resulted in 23%-57% less radiation in combination with 55%-63% less contrast agent volume compared with standard CT protocols. Copyright

  10. Visualization of an actively bleeding cortical vessel into the subdural space by CT angiography.

    PubMed

    Dalfino, John C; Boulos, Alan S

    2010-10-01

    Spontaneous subdural hematomas of arterial origin are rare with only a few published case reports in the literature. In the CT era, vessel imaging of extra-axial hematomas is not commonly performed. In this case report we present a patient with a large, spontaneous acute subdural hematoma that demonstrated active contrast extravasation from a small cortical vessel on CT angiography. During surgical evacuation the vessel was confirmed to be a small cortical artery that was bulging through the arachnoid membrane and bleeding into the subdural space. The historical, radiographic, and clinical aspects of this unusual cause of subdural hematoma are discussed.

  11. Pitfalls in image reconstruction of helical CT angiography: an experimental study.

    PubMed

    Ogata, I; Yamashita, Y; Sumi, S; Nishiharu, T; Mitsuzaki, K; Takahashi, M

    1999-01-01

    This study was undertaken to evaluate the effects of the object related factors: background tissue and the direction of vessels on the morphological reproducibility of helical CT angiography. Cylindrical tubes filled with a diluted contrast medium were prepared to obtain vascular phantoms. The scan was performed within various background tissues. For the evaluation of the direction of the vessels, two types of vascular phantoms were prepared. The phantoms were scanned by varying beam collimations and scan pitches. Reconstructed CT images were markedly affected by the background tissue. The reconstructed images were also affected by the direction of vessels.

  12. Radiologic Damage Control: Evaluation of a Combined CT and Angiography Suite with a Pivoting Table

    SciTech Connect

    Kos, Xavier; Fanchamps, Jean-Marc; Trotteur, Genevieve; Dondelinger, Robert F.

    1999-03-15

    Purpose: To evaluate retrospectively the integrated diagnostic and therapeutic management of severely polytraumatized patients using a combined computed tomography (CT) and angiography suite with a single pivoting table. Methods: Eleven patients, aged 16-74 years (median 30 years), were managed with spiral CT and angiography without patient transfer. Four patients were unstable, seven had received blood transfusions (2-18 units) and six were intubated. In 10 patients in whom active bleeding was demonstrated (splenic 5, hepatic 2, renal 2, left inferior epigastric artery 1), hemostatic embolization was obtained. Results: Total procedure time did not exceed 80 min. Immediate hemostasis was achieved in all patients. Recurrent bleeding from the liver required additional embolization in one patient. Median length of stay in the intensive care unit was 4 days and median hospital stay was 27 days. All patients survived without significant sequelae. Conclusion: The use of a combined CT-angiography suite enables rapid diagnostic investigation and hemostatic embolization in actively bleeding trauma patients.

  13. Management of acute chest pain: A major role for coronary CT angiography.

    PubMed

    Pernès, J-M; Dupouy, P; Labbé, R; Sotirov, Y; Pongas, D; Mansour, H; Gaux, J-C

    2015-11-01

    Most patients presenting with acute chest pain (ACP) at the emergency unit do not have any marked electrocardiogram abnormalities or known history of heart disease. Identifying the few patients who have, or will actually develop acute coronary syndrome in this group that is considered to be at low risk, is an actual clinical challenge for emergency department physicians. In these patients, the goal of complementary non-invasive morphological or functional imaging tests is to exclude heart disease. The diagnostic values of coronary CT angiography include a sensitivity of 96% and a negative likelihood ratio of 0.09, which are highly contributory to the diagnosis, and the integration of this imaging test into a decision tree algorithm appears to be the least expensive strategy with the best cost/effective ratio. Coronary CT angiography is indicated in the presence of ACP associated with an inconclusive electrocardiogram, in the absence of any other obvious diagnoses, when the ultrasensitive troponin assay is negative or the dynamic changes are modest, slow and/or inconclusive. Ideally, coronary CT angiography should be performed within 3 to 48hours after the initial consultation. Copyright © 2015 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  14. Integrated assessment of coronary anatomy and myocardial perfusion using a retractable SPECT camera combined with 64-slice CT: initial experience.

    PubMed

    Thilo, Christian; Schoepf, U Joseph; Gordon, Leonie; Chiaramida, Salvatore; Serguson, Jill; Costello, Philip

    2009-04-01

    We evaluated a prototype SPECT system integrated with multidetector row CT (MDCT) for obtaining complementary information on coronary anatomy and hemodynamic lesion significance. Twenty-five consecutive patients with known or suspected coronary artery disease (CAD) underwent routine SPECT myocardial perfusion imaging (MPI). All patients also underwent repeat MPI with a mobile SPECT unit which could be attached to a 64-slice MDCT system. Coronary CT angiography (cCTA) was performed without repositioning the patient. Investigational MPI was compared with routine MPI for detection of myocardial perfusion defects (PD). Two observers diagnosed presence or absence of CAD based on MPI alone, cCTA alone, and based on combined MPI and cCTA with fused image display. In 22/24 patients investigative MPI corresponded with routine MPI (r = 0.80). Stenosis >or= 50% at cCTA was detected in 6/24 patients. Six out of 24 patients had PD at regular MPI. Three of these six patients had no significant stenosis at cCTA. Three out of 19 patients with normal MPI studies had significant stenosis at cCTA. Our initial experience indicates that the integration of SPECT MPI with cCTA is technically feasible and enables the comprehensive evaluation of coronary artery anatomy and myocardial perfusion with a single instrumental setup.

  15. Preoperative visualization of the artery of Adamkiewicz by dual-phase CT angiography in patients with aortic aneurysm.

    PubMed

    Amako, Mau; Yamamoto, Yoshiaki; Nakamura, Katsumi; Tobinaga, Satoru; Nakamura, Eiji; Hosokawa, Yukio; Ohno, Tomokazu; Akashi, Hidetoshi; Aoyagi, Shigeaki; Tanaka, Hiroyuki

    2011-01-01

    To improve our ability to visualize the Adamkiewicz artery (AKA), we developed a modified intravenous CT angiography technique, which we refer to as right atrial CT (RA-CT) angiography. In this study, AKA detection rate and visualization of the arterial continuity from the aorta to the anterior spinal cord artery (ASA) was evaluated using RA-CT angiography.We performed RA-CT angiography in 110 patients with abdominal, thoracic descending, or thoracoabdominal aortic aneurysms. In RA-CT angiography, contrast medium with a high iodine concentration (370 mg/dl) was injected twice into the right atrium at a high injection rate (8.0 ml/sec), and two CT scans, starting at 20 sec after the first injection and at 35 sec after the second injection, respectively, were performed. All CT images were obtained using an 8- or 16-detector CT scanner at a slice thickness of 0.625 mm. The AKA was defined as the largest radiculomedullary artery with a characteristic hairpin turn, and with continuity from the aorta to the ASA.The AKA with hairpin turn was detected in all patients (100%), and continuity from the aorta to the ASA was confirmed in 99 of the 110 patients (90.0%). The AKA arose between Th8 and L1 in 86 of these patients (86.8%), and originated from the left side in 71 patients (71.7%).RA-CT angiography may be useful for visualizing the AKA and the arterial continuity from the aorta to the ASA in patients with aortic aneurysm, although the use of more advanced CT machines will provide safe and easy identification of the AKA and arterial continuity with a small amount of contrast medium and a single scan.

  16. Peripheral arterial occlusive disease: diagnostic performance and effect on therapeutic management of 64-section CT angiography.

    PubMed

    Napoli, Alessandro; Anzidei, Michele; Zaccagna, Fulvio; Cavallo Marincola, Beatrice; Zini, Chiara; Brachetti, Giulia; Cartocci, Gaia; Fanelli, Fabrizio; Catalano, Carlo; Passariello, Roberto

    2011-12-01

    To evaluate the diagnostic performance and effect on therapeutic management of 64-section computed tomographic (CT) angiography in the assessment of steno-occlusive disease in patients with peripheral arterial disease (PAD), with conventional digital subtraction angiography (DSA) as the reference standard. The study protocol was approved by the institutional review board, and written informed consent was obtained from all patients. A total of 212 patients with symptomatic PAD underwent CT angiography and subsequent DSA. For stenosis analysis (≥ 70% stenosis), the arterial bed was divided into 35 segments and evaluated by three readers. Interobserver agreement was determined with generalized κ statistics. Accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. In addition, according to the TransAtlantic Inter-Society Consensus (TASC) Document on Management of Peripheral Arterial Disease guidelines, treatment recommendations based on CT angiographic and DSA findings were compared. McNemar test was used to prove significant differences between CT angiographic and DSA findings. A total of 7420 arterial segments were evaluated, with excellent agreement between readers (κ ≥ 0.928). On a segmental basis, both sensitivity and specificity for stenosis of 70% or more were at least 96% (3072 of 3113 segments and 4141 of 4279 segments, respectively), with an accuracy of 98% (7213 of 7392 segments), a PPV of 96% (3072 of 3187 segments), an NPV of 99% (3141 of 3187 segments), a PLR of 36.7, and an NLR of 0.013. There was no significant difference between CT angiographic and DSA findings (P = .62-.87). In accordance with TASC II guidelines, 49 patients were referred for conservative treatment, 87 underwent endovascular procedures, 38 underwent surgery, and 17 received hybrid treatment. Therapy recommendations based on CT angiographic findings

  17. Centerline correction of incorrectly segmented coronary arteries in CT angiography

    NASA Astrophysics Data System (ADS)

    Fu, Ling; Kang, Yan

    2013-03-01

    For computer-aided diagnosis of cardiovascular diseases, accurately extracted centerlines of coronary arteries are important. However, centerlines extracted from incorrectly segmented vessels are usually unsatisfactory. For this reason, we propose two automatic centerline correction methods in this paper. First, a method based on the local volume comparison and the morphological comparison is presented to remove false centerlines from over-segmented tissues. Second, another method based on the judgment of vessel identity and the gradient-SDF (source distance field) calculation is presented to add missing centerlines of under-segmented vessels. We have validated the proposed centerline correction methods on real CT angiographic datasets of coronary arteries. The quantitative evaluation results show that the proposed methods can effectively correct centerline errors arising from erroneous vessel segmentation in most cases.

  18. Automated coronary CT angiography plaque-lumen segmentation

    NASA Astrophysics Data System (ADS)

    Cline, Harvey E.; Krishnan, Karthik; Napel, Sandy; Rubin, Geoffrey D.; Turner, Wesley D.; Avila, Ricardo S.

    2009-02-01

    We are investigating the feasibility of a computer-aided detection (CAD) system to assist radiologists in diagnosing coronary artery disease in ECG gated cardiac multi-detector CT scans having calcified plaque. Coronary artery stenosis analysis is challenging if calcified plaque or the iodinated blood pool hides viable lumen. The research described herein provides an improved presentation to the radiologist by removing obscuring calcified plaque and blood pool. The algorithm derives a Gaussian estimate of the point spread function (PSF) of the scanner responsible for plaque blooming by fitting measured CTA image profiles. An initial estimate of the extent of calcified plaque is obtained from the image evidence using a simple threshold. The Gaussian PSF estimate is then convolved with the initial plaque estimate to obtain an estimate of the extent of the blooming artifact and this plaque blooming image is subtracted from the CT image to obtain an image largely free of obscuring plaque. In a separate step, the obscuring blood pool is suppressed using morphological operations and adaptive region growing. After processing by our algorithm, we are able to project the segmented plaque-free lumen to form synthetic angiograms free from obstruction. We can also analyze the coronary arteries with vessel tracking and centerline extraction to produce cross sectional images for measuring lumen stenosis. As an additional aid to radiologists, we also produce plots of calcified plaque and lumen cross-sectional area along selected blood vessels. The method was validated using digital phantoms and actual patient data, including in one case, a validation against the results of a catheter angiogram.

  19. Four- and Eight-Channel Aortoiliac CT Angiography: A Comparative Study

    SciTech Connect

    Karcaaltincaba, Musturay Foley, Dennis

    2005-04-15

    Purpose. To compare performance parameters, contrast material load and radiation dose in a patient cohort having aortoiliac CT angiography using 4- and 8-channel multidetector CT (MDCT) systems. Methods. Eighteen patients with abdominal aortic aneurysms underwent initial 4-channel and follow-up 8-channel MDCT angiography. Both the 4- and 8-channel MDCT systems utilized a matrix detector of 16 x 1.25 mm rows. Scan coverage included the abdominal aorta and iliac arteries to the level of the proximal femoral arteries. For 4-channel MDCT, nominal slice thickness and beam pitch were 1.25 mm and 1.5, respectively, and for 8-channel MDCT they were 1.25 mm and 1.35 or 1.65 respectively. Scan duration, iodinated contrast material load and mean aortoiliac attenuation were compared retrospectively. Comparative radiation dose measurements for 4- and 8-channel MDCT were obtained using a multiple scan average dose technique on an abdominal phantom. Results. Compared with 4-channel MDCT, 8-channel MDCT aortoiliac angiography was performed with equivalent collimation, decreased contrast load (mean 45% decrease: 144 ml versus 83 ml of 300 mg iodine/ml contrast material) and decreased acquisition time (mean 51% shorter: 34.4 sec versus 16.9 sec) without a significant change in mean aortic enhancement (299 HU versus 300 HU, p > 0.05). Radiation dose was 2 rad for the 4-channel system and 2/1.5 rad for the 8-channel system at 1.35/1.65 pitch respectively. Conclusion. Compared with 4-channel MDCT, aortoiliac CT angiography with 8-channel MDCT produces equivalent z-axis resolution with decreased contrast load and acquisition time without increased radiation exposure.

  20. Multidetector CT coronary angiography for patient triage to invasive coronary angiography: Performance and cost in ambulatory patients with equivocal or suspected inaccurate noninvasive stress tests.

    PubMed

    Menon, Madhav; Lesser, John R; Hara, Hidehiko; Birkett, Richard; Knickelbine, Thomas; Longe, Terry; Flygenring, Bjorn; Henry, Jason; Schwartz, Robert

    2009-03-01

    Multidetector-CT angiography (MDCTA) differs from noninvasive stress tests by directly imaging coronary anatomy. The utility of MDCTA for invasive triage is undefined however. We evaluated MDCTA triage to invasive coronary angiography in outpatients with indeterminate or suspected inaccurate stress tests, and estimated cost savings by MDCTA in this role. Consecutive MDCTA patients were retrospectively compared with noninvasive stress tests if performed within 6 months of MDCTA. Twelve-month clinical follow up was obtained for patients not undergoing invasive angiography, and cost using MDCTA for triage to invasive coronary angiography was calculated. MDCTA was performed in 385 patients who had noninvasive stress testing. Stress tests include included treadmill (n = 37), stress echo (n = 178), and nuclear perfusion imaging (n = 170). Invasive angiography was performed in 57 (14.8%). MDCTA compared to CA showed positive and negative predictive values of 94%/100% respectively for lesions found by invasive QCA. Stress testing compared to MDCTA showed positive/negative predictive values of 100%/67% for treadmill exercise, 60%/54% for stress echo, and 59%/55% of nuclear perfusion examinations respectively. One year clinical follow up in 314 patients showed no coronary events in 98% (309) of patients. Triage to invasive angiography by MDCTA showed a 4-fold cost reduction. MDCTA shows excellent performance as a triage for invasive angiography in patients with stress tests that are equivocal or thought inaccurate. A negative CTA confers good 12-month prognosis. Substantial cost savings may accrue using MDCTA in this triage role.

  1. Early Experience Studying Cerebral Aneurysms with Rotational and Three-dimensional Angiography and Review of CT and MR Angiography Literature

    PubMed Central

    Castaño-Duque, C.H.; Ruscalleda-Nadal, J.; De Juan-Delago, M.; Guardia-Mas, E.; San Roman-Manzanera, L.; Bartomeus-Jene, F.; Molet-Teixido, J.; Tresserras-Ribo, P.; Pares-Muñoz, P.; Clavel Laria, P.

    2002-01-01

    Summary From september 2000 to september 2001, 32 consecutive patients with ruptured intracranial aneurysms were examined with rotational and 3D reconstruction angiography using an Integris V5000 Philips Medical System: 39 aneurysms were detected. After a selective cerebral artery was catheterized with a 5F or 4F-catheter, 35 ml of contrast medium was intra-arterially administered at a rate of 4 ml/s and a 180° rotational angiography was performed in eight seconds. This information was transferred to a computer (Silicon Graphics Octane) with software (Integris 3D-RA, Philips Integris Systems) and a three-dimensional reconstruction was made. The information provided by Angio-3D was useful for evaluating the parent artery, aneurysmal sac, aneurysmal neck and arterial branches. It was also very useful in selecting the therapeutic method. For open surgery, this technique provides preoperative images that are useful for planning microsurgical approaches, especially in cases of large aneurysm showing complex surrounding arteries. For endovascular embolization, various anatomic characteristics of the aneurysm such as neck and sac size, shape, lobularity, parent artery and arterial branches adjacent to the aneurysmal neck must be demonstrated. This is very important to determine the best projection for embolization and to avoid multiple series. This is also essential in the choice of the first coil to create a good basket producing total occlusion. Microaneurysms are demonstrated well with this technique whereas this is difficult to do with conventional arteriography. The Angio-RM and Angio-CT literature show a lower sensitivity and specificity in comparasion with our experience with 3D IA-ROT-DSA. For this reason, we believe that 3D IA-ROT-DSA is now the gold standard for patients presenting intracranial aneurysms. PMID:20594499

  2. Correlation between abdominal perforator vessels identified with preoperative CT angiography and intraoperative fluorescent angiography in the microsurgical breast reconstruction patient.

    PubMed

    Pestana, Ivo A; Zenn, Michael R

    2014-01-01

    CT angiography (CTA) has become a reliable method of perforator vessel identification. Indocyanine green fluorescent angiography (ICGLA) produces a real-time image of large- and small-caliber blood vessels. The aim of this prospective study was to compare ICGLA with CTA to evaluate its reliability of vessel identification and correlation to perforator vessel size and number determined preoperatively by CTA. The effect of both imaging techniques on flap design or intraoperative plan was also evaluated. Over a 1-year period, patients presenting for free-tissue transfer breast reconstruction underwent preoperative CTA mapping of abdominal perforators followed by intraoperative ICGLA. Using visualization software, scaling factors were calculated so CTA and ICGLA data could be compared. Eighteen patients (24 breast reconstructions) were included. Larger CTA perforator size was associated with larger actual size (P = 0.04). The largest CTA perforator or largest actual perforator was used 78% of the time. Increasing body mass index was not associated with larger CTA perforator size (P = 0.67) or more intense ICGLA blushes (P = 0.13). No significant correlation was found between CTA perforator location and ICGLA skin blush location, size, or intensity. CTA or SPY guided intraoperative procedure adjustments in 72% of patients. ICGLA identified poor soft-tissue perfusion and guided flap resection in 46% of patients. ICGLA skin blush location, size, and intensity do not correlate with CTA-identified perforating vessel location or actual perforating vessel size. Despite this, the ICGLA information was useful for evaluation of soft-tissue perfusion and flap design.

  3. [Comparative assessment of ct-bypass angiography and invasive coronary angiography in patients after coronary bypass surgery in the late postoperative period].

    PubMed

    Men'kov, I A; Trufanov, G E; Zhelezniak, I S; Rud', S D; Kniazev, E A

    2013-10-01

    The aim of the study was to evaluate the diagnostic accuracy of ct-bypass angiography in the evaluation of significant stenosis and occlusion of grafts, recipient and nongrafted vessels in patients after coronary bypass surgery in the late postoperative period. Ct-bypass angiography was performed on 64-slice ct scanner with a slice thickness of 0.5 mm and a gantry rotation time of 0.4 s. All results were compared with quantitative invasive coronary angiography. 43 patients with 113 grafts were included in the study. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy for the evaluation of significant stenosis were 94%, 95%, 88%, 98%, 95%, respectively. Diagnostic accuracy for the evaluation of significant stenosis in the recipient and nongrafted vessels were 91% and 90%, respectively. The diagnostic accuracy for the evaluation graft occlusion, recipient and nongrafted vessels was 100%, 100% and 98%, respectively. Ct-bypass angiography allows accurate non-invasive assessment of significant stenosis and occlusion of coronary bypass grafts and native coronary arteries in patients after coronary bypass surgery in the late postoperative period.

  4. Coronary computed tomography angiography: overview of technical aspects, current concepts, and perspectives.

    PubMed

    Chartrand-Lefebvre, Carl; Cadrin-Chênevert, Alexandre; Bordeleau, Edith; Ugolini, Patricia; Ouellet, Robert; Sablayrolles, Jean-Louis; Prenovault, Julie

    2007-04-01

    Multidetector-row electrocardiogram (ECG)-gated cardiac computed tomography (CT) will probably be a major noninvasive imaging option in the near future. Recent developments indicate that this new technology is improving rapidly. This article presents an overview of the current concepts, perspectives, and technical capabilities in coronary CT angiography (CTA). We have reviewed the recent literature on the different applications of this technology; of particular note are the many studies that have demonstrated the high negative predictive value (NPV) of coronary CTA, when performed under optimal conditions, for significant stenoses in native coronary arteries. This new technology's level of performance allows it to be used to evaluate the presence of calcified plaques, coronary bypass graft patency, and the origin and course of congenital coronary anomalies. Despite a high NPV, the robustness of the technology is limited by arrhythmias, the requirement of low heart rates, and calcium-related artifacts. Some improvements are needed in the imaging of coronary stents, especially the smaller stents, and in the detection and characterization of noncalcified plaques. Further studies are needed to more precisely determine the role of CTA in various symptomatic and asymptomatic patient groups. Clinical testing of 64-slice scanners has recently begun. As the technology improves, so does the spatial and temporal resolution. To date, this is being achieved through the development of systems with an increased number of detectors and shorter gantry rotation time, as well as the development of systems equipped with 2 X-ray tubes and the eventual development of flat-panel technology. Thus further improvement of image quality is expected.

  5. Value of CT angiography in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy

    PubMed Central

    Meng, Xiang-Jun; Mi, Qi-Wu; Hu, Tao; Zhong, Wei-De

    2015-01-01

    ABSTRACT Purpose: To evaluate the clinical value of computed tomography angiography (CTA) in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy (PCNL). Materials and Methods: A total of 158 patients with renal or ureter stones who had undergone mini-percutaneous nephrolithotomy were retrospectively enrolled into this study from May of 2011 to April of 2014. Group 1 (65 patients) underwent computed tomography angiography, and Group 2 (93 patients) underwent non-contrast CT. The clinical characteristics of the patients and hemorrhagic complications were recorded. The hematologic complications (transfusion rate, and preoperative and postoperative hemoglobin values) were assessed. Results: There were no statistically significant differences in age, body mass index(BMI), stone diameter, operative time, stone-free rate, and hospital stay between the 2 groups. In group 2, 1 patient (1.1%) developed a renal arteriovenous fistula and was treated with embolus therapy. In addition, Group 2 showed significantly drop in hemoglobin (3.6 g/dL vs. 2.4 g/dL, respectively; P <0.001) and more transfusions (9.7% vs. 1.5%, respectively; P <0.05) compared with Group 1. Conclusion: The study showed that patients who underwent computed tomography angiography prior to percutaneous nephrolithotomy had lower drop of hemoglobin and needed less transfusions. These findings may suggest that the use of computed tomography angiography may reduce the risk of bleeding during percutaneous nephrolithotomy. PMID:26401861

  6. Postmortem whole-body CT angiography: evaluation of two contrast media solutions.

    PubMed

    Ross, Steffen; Spendlove, Danny; Bolliger, Stephan; Christe, Andreas; Oesterhelweg, Lars; Grabherr, Silke; Thali, Michael J; Gygax, Erich

    2008-05-01

    The objective of our study was to establish a standardized procedure for postmortem whole-body CT-based angiography with lipophilic and hydrophilic contrast media solutions and to compare the results of these two methods. Minimally invasive postmortem CT angiography was performed on 10 human cadavers via access to the femoral blood vessels. Separate perfusion of the arterial and venous systems was established with a modified heart-lung machine using a mixture of an oily contrast medium and paraffin (five cases) and a mixture of a water-soluble contrast medium with polyethylene glycol (PEG) 200 in the other five cases. Imaging was executed with an MDCT scanner. The minimally invasive femoral approach to the vascular system provided a good depiction of lesions of the complete vascular system down to the level of the small supplying vessels. Because of the enhancement of well-vascularized tissues, angiography with the PEG-mixed contrast medium allowed the detection of tissue lesions and the depiction of vascular abnormalities such as pulmonary embolisms or ruptures of the vessel wall. The angiographic method with a water-soluble contrast medium and PEG as a contrast-agent dissolver showed a clearly superior quality due to the lack of extravasation through the gastrointestinal vascular bed and the enhancement of soft tissues (cerebral cortex, myocardium, and parenchymal abdominal organs). The diagnostic possibilities of these findings in cases of antemortem ischemia of these tissues are not yet fully understood.

  7. Learning-based automatic detection of severe coronary stenoses in CT angiographies

    NASA Astrophysics Data System (ADS)

    Melki, Imen; Cardon, Cyril; Gogin, Nicolas; Talbot, Hugues; Najman, Laurent

    2014-03-01

    3D cardiac computed tomography angiography (CCTA) is becoming a standard routine for non-invasive heart diseases diagnosis. Thanks to its high negative predictive value, CCTA is increasingly used to decide whether or not the patient should be considered for invasive angiography. However, an accurate assessment of cardiac lesions using this modality is still a time consuming task and needs a high degree of clinical expertise. Thus, providing automatic tool to assist clinicians during the diagnosis task is highly desirable. In this work, we propose a fully automatic approach for accurate severe cardiac stenoses detection. Our algorithm uses the Random Forest classi cation to detect stenotic areas. First, the classi er is trained on 18 CT cardiac exams with CTA reference standard. Then, then classi cation result is used to detect severe stenoses (with a narrowing degree higher than 50%) in a 30 cardiac CT exam database. Features that best captures the di erent stenoses con guration are extracted along the vessel centerlines at di erent scales. To ensure the accuracy against the vessel direction and scale changes, we extract features inside cylindrical patterns with variable directions and radii. Thus, we make sure that the ROIs contains only the vessel walls. The algorithm is evaluated using the Rotterdam Coronary Artery Stenoses Detection and Quantication Evaluation Framework. The evaluation is performed using reference standard quanti cations obtained from quantitative coronary angiography (QCA) and consensus reading of CTA. The obtained results show that we can reliably detect severe stenosis with a sensitivity of 64%.

  8. Multidetector CT and three-dimensional CT angiography of upper extremity arterial injury.

    PubMed

    Fritz, Jan; Efron, David T; Fishman, Elliot K

    2015-06-01

    Successful management of upper extremity arterial injury requires fast and accurate diagnosis. The rate of limb preservation depends on the location, severity, and time of ischemia. Indications for diagnostic imaging depend on the mechanism and type of injury, clinical signs, cardiovascular stability, and clinical suspicion. Because of ease of access, speed, and high accuracy for this diagnosis, multidetector computed tomographic (MDCT) angiography is often used as the first line imaging modality. MDCT systems with 64 slice configuration and more afford high temporal and spatial high-resolution, isotropic data acquisition and integration with whole-body trauma MDCT protocols. The use of individual injection timing protocols ensures high diagnostic image quality. Several strategies are available to reduce radiation exposure. Direct MDCT angiography findings of arterial injuries include active extravasation, luminal narrowing, lack of luminal contrast opacification, filling defect, arteriovenous fistula, and pseudoaneurysm. Important descriptors are location and length of defect, degree of luminal narrowing, and presence of distal arterial supply reconstitution. Proximal arterial injuries include the subclavian, axillary, and brachial arteries. Distal arterial injuries include the ulnar and radial arteries, as well as the palmar arterial arches. Concomitant venous injury, musculoskeletal injury, and nerve damage are common. In this exhibit, we outline the role of MDCT angiography in the diagnosis and management of upper extremity arterial injury, discuss strategies for MDCT angiography acquisition and concepts of data visualization, and illustrate various types of injuries.

  9. Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model

    SciTech Connect

    Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola

    2012-01-15

    Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

  10. Pitfalls in post-mortem CT-angiography--intravascular contrast induces post-mortem pericardial effusion.

    PubMed

    Berger, Nicole; Martinez, Rosita; Winklhofer, Sebastian; Flach, Patricia M; Ross, Steffen; Ampanozi, Garyfalia; Gascho, Dominic; Thali, Michael J; Ruder, Thomas D

    2013-11-01

    We present a case where multi-phase post-mortem computed tomography angiography (PMCTA) induced a hemorrhagic pericardial effusion during the venous phase of angiography. Post-mortem non-contrast CT (PMCT) suggested the presence of a ruptured aortic dissection. This diagnosis was confirmed by PMCTA after pressure controlled arterial injection of contrast. During the second phase of multi-phase PMCTA the presence of contrast leakage from the inferior cava vein into the pericardial sac was noted. Autopsy confirmed the post-mortem nature of this vascular tear. This case teaches us an important lesson: it underlines the necessity to critically analyze PMCT and PMCTA images in order to distinguish between artifacts, true pathologies and iatrogenic findings. In cases with ambiguous findings such as the case reported here, correlation of imaging findings with autopsy is elementary.

  11. Prediction of outcome in patients with suspected acute ischaemic stroke with CT perfusion and CT angiography: the Dutch acute stroke trial (DUST) study protocol

    PubMed Central

    2014-01-01

    Background Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We present the study protocol of the Dutch acute Stroke Trial (DUST). The DUST aims to assess the prognostic value of CT perfusion and CT angiography in predicting stroke outcome, in addition to patient characteristics and non-contrast CT. For this purpose, individualised prediction models for clinical outcome after stroke based on the best predictors from patient characteristics and CT imaging will be developed and validated. Methods/design The DUST is a prospective multi-centre cohort study in 1500 patients with suspected acute ischaemic stroke. All patients undergo non-contrast CT, CT perfusion and CT angiography within 9 hours after onset of the neurological deficits, and, if possible, follow-up imaging after 3 days. The primary outcome is a dichotomised score on the modified Rankin Scale, assessed at 90 days. A score of 0–2 represents good outcome, and a score of 3–6 represents poor outcome. Three logistic regression models will be developed, including patient characteristics and non-contrast CT (model A), with addition of CT angiography (model B), and CT perfusion parameters (model C). Model derivation will be performed in 60% of the study population, and model validation in the remaining 40% of the patients. Additional prognostic value of the models will be determined with the area under the curve (AUC) from the receiver operating characteristic (ROC) curve, calibration plots, assessment of goodness-of-fit, and likelihood ratio tests. Discussion This study will provide insight in the added prognostic value of CTP and CTA parameters in outcome prediction of acute stroke patients. The prediction models that will be developed in this study may help guide future

  12. Feasibility of dual-source cardiac CT angiography with high-pitch scan protocols.

    PubMed

    Hausleiter, Jörg; Bischoff, Bernhard; Hein, Franziska; Meyer, Tanja; Hadamitzky, Martin; Thierfelder, Carsten; Allmendinger, Thomas; Flohr, Thomas G; Schömig, Albert; Martinoff, Stefan

    2009-01-01

    Cardiac CT angiography (CCTA) has become a frequently used diagnostic tool in clinical practice, but concern remains about the radiation exposure. Because of the second x-ray acquisition system, dual-source CT systems might allow for high-pitch CT data acquisition and thus for examination of the whole heart during a single heart beat, with the potential for radiation dose reduction. We assessed the feasibility of a high-pitch scan mode with a dual-source CT system. High-pitch modes were used in patients undergoing CCTA with a dual-source CT system. Diagnostic image quality for cardiac structures and coronary arteries was assessed. Radiation dose was estimated from the scanner-generated dose-length product (DLP). CCTA was performed in 14 patients during a single heart beat applying a pitch value of 3.4. Mean heart rate during examination was 56.4+/-8.1 beats/min. Diagnostic image quality for the assessment of larger cardiac structures was obtained in all patients, whereas diagnostic image quality could be achieved in 82% of all coronary segments. With a mean DLP of 145+/-47 mGy x cm, the resulting estimated radiation dose was 2.0+/-0.7 mSv. This proof-of-concept study shows the ability of dual-source CT scanners to scan the whole heart during one single heart beat at low radiation dose.

  13. Diagnostic performance of 320-detector CT coronary angiography in patients with atrial fibrillation: preliminary results.

    PubMed

    Xu, Lei; Yang, Lin; Fan, Zhanming; Yu, Wei; Lv, Biao; Zhang, Zhaoqi

    2011-05-01

    To evaluate the feasibility, diagnostic accuracy, and radiation dose of CT coronary angiography (CTCA) in patients with atrial fibrillation (AF) using 320-detector CT. Thirty-seven patients with persistent AF and suspected coronary artery disease (CAD) were enrolled. All patients underwent both 320-detector CTCA and conventional coronary angiography (CCA). CT image quality and the presence of significant (≥ 50%) stenosis were evaluated by two radiologists blinded to the results of CCA. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using CCA as the reference standard. Differences in detection of coronary artery stenosis between 320-detector CTCA and CCA were evaluated with McNemar's test. Patient radiation dose was calculated by multiplying dose length product by conversion coefficient of 0.017. In total 474 evaluated coronary segments, 459 (96.8%) segments were diagnostically evaluable. On per-segment analysis, sensitivity, specificity, PPV and NPV were 90.0% (18 of 20), 99.3% (436 of 439), 85.7% (18 of 21) and 99.5% (436 of 438). No significant difference was found between 320-detector CTCA and CCA on the detection of significant stenosis (P = 1.000). Effective doses of 320-detector CTCA was 13.0 ± 4.7 mSv. 320-detector CTCA is feasible and accurate in excluding CAD in patients with AF.

  14. Preoperative dual-phase 3D CT angiography assessment of the right hepatic artery before gastrectomy.

    PubMed

    Yamashita, Keishi; Sakuramoto, Shinichi; Mieno, Hiroaki; Shibata, Tomotaka; Nemoto, Masayuki; Katada, Natsuya; Kikuchi, Shiro; Watanabe, Masahiko

    2014-10-01

    In the current study, we evaluated the efficacy of dual-phase three-dimensional (3D) CT angiography (CTA) in the assessment of the vascular anatomy, especially the right hepatic artery (RHA), before gastrectomy. The study initially included 714 consecutive patients being treated for gastric cancer. A dual-phase contrast-enhanced CT scan using 32-multi detector-row CT was performed for all patients. Among the 714 patients, 3D CTA clearly identified anomalies with the RHA arising from the superior mesenteric artery (SMA) in 49 cases (6.9 %). In Michels' classification type IX, the common hepatic artery (CHA) originates only from the SMA. Such cases exhibit defective anatomy for the CHA in conjunction with the celiac-splenic artery system, resulting in direct exposure of the portal vein beneath the #8a lymph node station, which was retrospectively confirmed by video in laparoscopic gastrectomy cases. Fused images of both 3D angiography and venography were obtained, and could have predicted the risk preoperatively, and the surgical finding confirmed its usefulness. Preoperative evaluations using 3D CTA can provide more accurate information about the vessel anatomy. The fused images from 3D CTA have the potential to reduce the intraoperative risks for injuries to critical vessel, such as the portal vein, during gastrectomy.

  15. Prevalence of non-cardiovascular findings on CT angiography in children with congenital heart disease.

    PubMed

    Malik, Archana; Hellinger, Jeffrey C; Servaes, Sabah; Schwartz, Mathew C; Keller, Marc S; Epelman, Monica

    2017-03-01

    CT angiography is gaining broader acceptance in the evaluation of children with known or suspected congenital heart disease. These studies include non-cardiovascular structures such as the mediastinum, lung parenchyma and upper abdominal organs. It is important to inspect all these structures for potential abnormalities that might be clinically important and, in some cases, may impact care plans. To determine the prevalence of non-cardiovascular findings in CT angiography of children with congenital heart disease. During 28 months, 300 consecutive children (170 males; mean age: 7.1 years, age range: 6 h-26 years), referred from a tertiary pediatric cardiology center, underwent clinically indicated CT angiography to evaluate known or suspected congenital heart disease. Slightly more than half (n = 169) of the patients were postoperative or post-intervention. Examinations were retrospectively reviewed, and non-cardiovascular findings were recorded and tabulated by organ system, congenital heart disease and operative procedure in conjunction with outcomes from medical charts. Non-cardiovascular findings were identified in 83% (n = 250 / 300) of the studies for a total of 857 findings. In 221 patients (n = 73.7% of 300) a total of 813 non-cardiovascular findings were clinically significant, while in 9.7% (n = 29 / 300) of patients, 5.1% (n = 44 / 857) of the findings were nonsignificant. In 38.3% (n = 115 / 300) of patients with significant non-cardiovascular pathology, the findings were unexpected and directly impacted patient care plans. Commonly involved organs with non-cardiovascular findings were the lungs with 280 non-cardiovascular findings in 176 / 300 (58.7%) of patients, the airway with 139 non-cardiovascular findings in 103 / 300 (34.3%) of patients and the liver with 108 non-cardiovascular findings in 72 / 300 (24.0%) of patients. Syndromic associations were noted in 22% (n = 66 / 300) of the

  16. Three-dimensional CT angiography of anatomic variations in the pulmonary arterial tree.

    PubMed

    Fourdrain, Alex; De Dominicis, Florence; Blanchard, Chloé; Iquille, Jules; Lafitte, Sophie; Beuvry, Pierre-Louis; Michel, David; Merlusca, Geoni; Havet, Eric; Berna, Pascal

    2017-08-30

    Anatomic variations of the pulmonary arterial tree can cause technical difficulties during pulmonary lobectomy in general and video-assisted thoracic surgery (VATS). Using CT angiography and 3D reconstruction, we sought to identify anatomic variations of the pulmonary arterial tree and assess their respective frequencies. We retrospectively studied 88 pulmonary arterial trees in 44 patients having undergone VATS lobectomy for lung cancer over an 18-month period in Amiens University Hospital's Department of Thoracic Surgery. Each CT angiography with 3D reconstruction of the pulmonary arterial tree was performed by two experienced operators, according to a standardized procedure. On the right side, the upper lobe was supplied with blood by a mediastinal artery in 100% of cases and by one or more fissural arteries in 88.6%. The middle lobe was usually supplied by two arteries (54.5%). The upper segment of the right lower lobe was usually supplied by a single artery (90.9%). We identified 11 variations in the vasculature of the basal segments. On the left side, the upper lobe was supplied by four arteries in 50% of cases, three culminal arteries (50%), and a fissural lingular artery (77.3%). The upper segment of the left lower lobe was usually supplied by a single artery (65.9%). We identified 15 anatomic variations in the vasculature of the basal segments. We observed that the origin of the apical artery of the right lower lobe was proximal to the origin of the middle lobe artery in 38.6% of cases. The origin of the apical artery of the left lower lobe artery was proximal to the origin of the lingular fissural artery in 65.9% of cases. The findings of the present CT angiography/3D reconstruction study agreed with the reference works on the anatomy of the pulmonary arterial tree and defined the frequency of anatomic variations. It is essential to assess the anatomy of the pulmonary arterial tree before VATS lobectomy.

  17. Coronary artery calcium scoring does not add prognostic value to standard 64-section CT angiography protocol in low-risk patients suspected of having coronary artery disease.

    PubMed

    Kwon, Sung Woo; Kim, Young Jin; Shim, Jaemin; Sung, Ji Min; Han, Mi Eun; Kang, Dong Won; Kim, Ji-Ye; Choi, Byoung Wook; Chang, Hyuk-Jae

    2011-04-01

    To evaluate the prognostic outcome of cardiac computed tomography (CT) for prediction of major adverse cardiac events (MACEs) in low-risk patients suspected of having coronary artery disease (CAD) and to explore the differential prognostic values of coronary artery calcium (CAC) scoring and coronary CT angiography. Institutional review committee approval and informed consent were obtained. In 4338 patients who underwent 64-section CT for evaluation of suspected CAD, both CAC scoring and CT angiography were concurrently performed by using standard scanning protocols. Follow-up clinical outcome data regarding composite MACEs were procured. Multivariable Cox proportional hazards models were developed to predict MACEs. Risk-adjusted models incorporated traditional risk factors for CAC scoring and coronary CT angiography. During the mean follow-up of 828 days ± 380, there were 105 MACEs, for an event rate of 3%. The presence of obstructive CAD at coronary CT angiography had independent prognostic value, which escalated according to the number of stenosed vessels (P < .001). In the receiver operating characteristic curve (ROC) analysis, the superiority of coronary CT angiography to CAC scoring was demonstrated by a significantly greater area under the ROC curve (AUC) (0.892 vs 0.810, P < .001), whereas no significant incremental value for the addition of CAC scoring to coronary CT angiography was established (AUC = 0.892 for coronary CT angiography alone vs 0.902 with addition of CAC scoring, P = .198). Coronary CT angiography is better than CAC scoring in predicting MACEs in low-risk patients suspected of having CAD. Furthermore, the current standard multisection CT protocol (coronary CT angiography combined with CAC scoring) has no incremental prognostic value compared with coronary CT angiography alone. Therefore, in terms of determining prognosis, CAC scoring may no longer need to be incorporated in the cardiac CT protocol in this population. © RSNA, 2011.

  18. CT Angiography of the Aorta: Prospective Evaluation of Individualized Low-Volume Contrast Media Protocols.

    PubMed

    Higashigaito, Kai; Schmid, Tabea; Puippe, Gilbert; Morsbach, Fabian; Lachat, Mario; Seifert, Burkhardt; Pfammatter, Thomas; Alkadhi, Hatem; Husarik, Daniela B

    2016-09-01

    Purpose To prospectively develop individualized low-volume contrast media (CM) protocols adapted to tube voltage in patients undergoing computed tomographic (CT) angiography of the aorta. Materials and Methods The study was approved by the institutional review board and local ethics committee. All patients provided written informed consent. CT angiography was performed by using automated attenuation-based tube voltage selection (ATVS) (range, 70-150 kVp; 10-kVp increments). Iodine attenuation curves from an ex vivo experiment in a phantom were used to design CM protocols for CT angiography of the thoracoabdominal aorta in 129 consecutive patients (hereafter, cohort A). Further modified CM protocols based on results in cohort A were designed with the aim of homogeneous vascular attenuation of 300-350 HU across tube voltages and were applied to another 61 consecutive patients (cohort B). Three independent blinded radiologists assessed subjective image quality, and one reader determined objective image quality. The Kruskal-Wallis test was performed to test for differences in subjective image quality, and linear regression was performed to test for differences in objective image quality between the automatically selected tube voltages. Results Experiments revealed tube voltage-dependent iodine attenuation curves, which were used to determine the CM protocols in cohort A; these ranged from 68 mL at 110 kVp to 45 mL at 80 kVp. In both cohorts, ATVS selected 80 kVp in 62 patients, 90 kVp in 84, 100 kVp in 33, and 110 kVp in 11. In cohort A, image quality that was satisfactory or better was attained in 126 (98%) of 129 patients who had no significant differences in subjective image quality between tube voltages (P = .106) but who did have significant differences in attenuation and contrast-to-noise ratio (CNR) (P < .001 for both). In cohort B, the further-modified CM protocol (from 33 mL at 80 kVp to 68 mL at 110 kVp) yielded image quality that was satisfactory or better

  19. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT.

    PubMed

    Badea, Cristian T; Hedlund, Laurence W; Johnson, G Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.

  20. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT

    PubMed Central

    Badea, Cristian T.; Hedlund, Laurence W.; Johnson, G. Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging. PMID:27006920

  1. Diagnostic performance of helical CT angiography in trauma to large arteries of the extremities.

    PubMed

    Soto, J A; Múnera, F; Cardoso, N; Guarín, O; Medina, S

    1999-01-01

    The purpose of this work was to assess the performance of helical CT angiography (CTA) in the diagnosis of injuries to large arteries of the extremities. We performed helical CTA on 45 consecutive patients referred for conventional angiography for evaluation of suspected arterial injuries after sustaining trauma to the extremities (13 upper, 32 lower). Two radiologists interpreted the helical CTA studies independently. Diagnostic performance parameters evaluated included sensitivity, specificity, receiver operating characteristic (ROC) curves, and interobserver agreement (kappa statistics). Conventional angiography was used as the standard of reference for determination of final diagnoses. Forty-three of 45 patients (96%) had diagnostic helical CTA examinations. Final diagnoses in these 43 patients were arterial occlusion (n = 7), partial obstruction (n = 3), pseudoaneurysm (n = 5), arteriovenous fistula (n = 1), pseudoaneurysm and arteriovenous fistula (n = 3), and normal findings (n = 24). Sensitivity and specificity were 90% [95% confidence interval (CI), 80-99] and 100% (95% CI, 99-100), respectively, for Reader 1 and 100% (95% CI, 99-100) and 100% (95% CI, 99-100), respectively, for Reader 2. ROC curve analysis revealed high diagnostic performance, with areas under the curve of >0.9 for both readers. Interobserver agreement was 0.9. The diagnostic performance of helical CTA for detection of major injuries of large arteries of the extremities is high.

  2. Acceptance of Combined Coronary CT Angiography and Myocardial CT Perfusion versus Conventional Coronary Angiography in Patients with Coronary Stents—Intraindividual Comparison

    PubMed Central

    Martus, Peter; Laule, Michael; Dewey, Marc; Schönenberger, Eva

    2015-01-01

    Objectives To evaluate how well patients with coronary stents accept combined coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) compared with conventional coronary angiography (CCA). Background While combined CTA and CTP may improve diagnostic accuracy compared with CTA alone, patient acceptance of CTA/CTP remains to be defined. Methods A total of 90 patients with coronary stents prospectively underwent CTA/CTP (both with contrast agent, CTP with adenosine) and CCA as part of the CARS-320 study. In this group, an intraindividual comparison of patient acceptance of CTA, CTP, and CCA was performed. Results CTP was experienced to be significantly more painful than CTA (p<0.001) and was associated with a higher frequency of dyspnea (p<0.001). Comparison of CTA/CTP with CCA revealed no significant differences in terms of pain (p = 0.141) and comfort (p = 0.377). Concern before CTA/CTP and CCA and overall satisfaction were likewise not significantly different (p = 0.097 and p = 0.123, respectively). Nevertheless, about two thirds (n = 60, 68%) preferred CTA/CTP to CCA (p<0.001). Moreover, patients felt less helpless during CTA/CTP than during CCA (p = 0.026). Lack of invasiveness and absence of pain were the most frequently mentioned advantages of CTA/CTP over CCA in our patient population. Conclusions CCA and combined CTA/CTP are equally well accepted by patients; however, more patients prefer CTA/CTP. CTP was associated with more intense pain than CTA and more frequently caused dyspnea than CTA alone. Trial Registration ClinicalTrials.gov NCT00967876 PMID:26327127

  3. Yield of CT Pulmonary Angiography in the Emergency Department When Providers Override Evidence-based Clinical Decision Support.

    PubMed

    Yan, Zihao; Ip, Ivan K; Raja, Ali S; Gupta, Anurag; Kosowsky, Joshua M; Khorasani, Ramin

    2017-03-01

    Purpose To determine the frequency of, and yield after, provider overrides of evidence-based clinical decision support (CDS) for ordering computed tomographic (CT) pulmonary angiography in the emergency department (ED). Materials and Methods This HIPAA-compliant, institutional review board-approved study was performed at a tertiary care, academic medical center ED with approximately 60 000 annual visits and included all patients who were suspected of having pulmonary embolism (PE) and who underwent CT pulmonary angiography between January 1, 2011, and August 31, 2013. The requirement to obtain informed consent was waived. Each CT order for pulmonary angiography was exposed to CDS on the basis of the Wells criteria. For patients with a Wells score of 4 or less, CDS alerts suggested d-dimer testing because acute PE is highly unlikely in these patients if d-dimer levels are normal. The yield of CT pulmonary angiography (number of positive PE diagnoses/total number of CT pulmonary angiographic examinations) was compared in patients in whom providers overrode CDS alerts (by performing CT pulmonary angiography in patients with a Wells score ≤4 and a normal d-dimer level or no d-dimer testing) (override group) and those in whom providers followed Wells criteria (CT pulmonary angiography only in patients with Wells score >4 or ≤4 with elevated d-dimer level) (adherent group). A validated natural language processing tool identified positive PE diagnoses, with subsegmental and/or indeterminate diagnoses removed by means of chart review. Statistical analysis was performed with the χ(2) test, the Student t test, and logistic regression. Results Among 2993 CT pulmonary angiography studies in 2655 patients, 563 examinations had a Wells score of 4 or less but did not undergo d-dimer testing and 26 had a Wells score of 4 or less and had normal d-dimer levels. The yield of CT pulmonary angiography was 4.2% in the override group (25 of 589 studies, none with a normal d

  4. From 3D to 4D: Integration of temporal information into CT angiography studies.

    PubMed

    Haubenreisser, Holger; Bigdeli, Amir; Meyer, Mathias; Kremer, Thomas; Riester, Thomas; Kneser, Ulrich; Schoenberg, Stefan O; Henzler, Thomas

    2015-12-01

    CT angiography is the current clinical standard for the imaging many vascular illnesses. This is traditionally done with a single arterial contrast phase. However, advances in CT technology allow for a dynamic acquisition of the contrast bolus, thus adding temporal information to the examination. The aim of this article is to highlight the clinical possibilities of dynamic CTA using 2 examples. The accuracy of the detection and quantification of stenosis in patients with peripheral arterial occlusive disease, especially in stadium III and IV, is significantly improved when performing dynamic CTA examinations. The post-interventional follow-up of examinations of EVAR benefit from dynamic information, allowing for a higher sensitivity and specificity, as well as allowing more accurate classification of potential endoleaks. The described radiation dose for these dynamic examinations is low, but this can be further optimized by using lower tube voltages. There are a multitude of applications for dynamic CTA that need to be further explored in future studies.

  5. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

    PubMed Central

    Vavere, Andrea L.; Rochitte, Carlos E.; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A.; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E.; Lima, João A. C.

    2012-01-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its noninvasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective “CORE-64” trial (“Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors”). This multi-centre trialwas unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. PMID:18998142

  6. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64.

    PubMed

    Miller, Julie M; Dewey, Marc; Vavere, Andrea L; Rochitte, Carlos E; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A; Bush, David E; Lardo, Albert C; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E; Lima, João A C

    2009-04-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its non-invasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective "CORE-64" trial ("Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors"). This multi-centre trial was unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows.

  7. Spiral CT angiography in diagnosis of cerebral aneurysms of cases with acute subarachnoid hemorrhage.

    PubMed

    Uysal, Ender; Yanbuloğlu, Bariş; Ertürk, Mehmet; Kilinç, Bekir M; Başak, Muzaffer

    2005-06-01

    To investigate the diagnostic accuracy of spiral CT angiography (CTA) in detection of cerebral aneurysms in cases with acute subarachnoid hemorrhage (SAH). Spiral CT angiography and DSA examinations were performed in 32 cases due to non-traumatic SAH. CTA data were obtained by maximum intensity projection (MIP) method. CTA and DSA findings were evaluated and compared in terms of existence of aneurysm, size and location. In 32 patients, DSA detected 34 aneurysms with diameters ranging from 3 to 13 mm while four cases were free of aneurysms. With CTA, an aneurysm at anterior communicating artery location could not be demonstrated. In all other cases CTA correlated well with DSA in detecting the site, size and orientation of the aneurysms. It was found that CTA sensitivity was 97% and specificity was 100% in diagnosis of intracranial aneurysms. Spiral CTA is a highly accurate, cheap and non-invasive imaging method in diagnosis of intracranial aneurysms in cases with SAH and can be used as a safe alternative method to DSA when emergency surgery is needed.

  8. Use of Dyna-CT Angiography in Neuroendovascular Decision-Making

    PubMed Central

    Namba, K.; Niimi, Y.; Song, J.K.; Berenstein, A.

    2009-01-01

    Summary A successful neuroendovascular procedure depends on accurate anatomical understanding of a target vessel in relation to surrounding anatomical structures or endovascular devices, such as coils and stents. During an endovascular procedure, with conventional or three dimensional (3D) rotational angiography, this type of information is extremely difficult to obtain in a timely manner. To overcome this drawback, a DynaCT was combined with low dose contrast injection to create CT angiography (CTA)-like images (DynaCTA). The images obtained were similar to those of conventional CTA but with better quality in analyzing vessels to surrounding anatomical structures and endovascular devices while the patient was on the table. The authors present three illustrative cases in which information added by the DynaCTA helped improve understanding of anatomy, and affected our clinical decision-making. Although better quality images may be obtained by other imaging modalities or careful angiographic interpretations, DynaCTA can be an easy and effective rescue technique worth keeping in mind in clarifying the relation of a vessel to surrounding anatomy. PMID:20465931

  9. A multidetector CT angiography study of variations in the circle of Willis in a Chinese population.

    PubMed

    Li, Qi; Li, Jialun; Lv, Fajin; Li, Kewei; Luo, Tianyou; Xie, Peng

    2011-03-01

    The circle of Willis is a major collateral circulation that has an important role in ischemic events. The purpose of our study was to investigate the collateral circulation in a Chinese population with 64-section multidetector CT angiography (CTA). A total of 170 patients who underwent 64-section CT angiography at The First Affiliated Hospital of Chongqing Medical University were included in our study. The morphological variations in the anterior and posterior circle of Willis were assessed in each patient. A total of 160 patients were included in the final analysis, of whom 126 (79%) demonstrated a complete anterior circle of Willis, and 50 (31%) had a complete posterior circle of Willis. A complete circle of Willis was seen in 43 of 160 participants (27%). A fetal-type posterior circle of Willis was seen in 15 (9.4%) patients. This is the first report of a CTA study of collateral circulation in a Chinese population. A higher prevalence of compromised posterior collaterals was observed in this Chinese population compared to Western and Japanese populations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Accurate, fully-automated registration of coronary arteries for volumetric CT digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Razeto, Marco; Mohr, Brian; Arakita, Kazumasa; Schuijf, Joanne D.; Fuchs, Andreas; Kühl, J. Tobias; Chen, Marcus Y.; Kofoed, Klaus F.

    2014-03-01

    Diagnosis of coronary artery disease with Coronary Computed Tomography Angiography (CCTA) is complicated by the presence of signi cant calci cation or stents. Volumetric CT Digital Subtraction Angiography (CTDSA) has recently been shown to be e ective at overcoming these limitations. Precise registration of structures is essential as any misalignment can produce artifacts potentially inhibiting clinical interpretation of the data. The fully-automated registration method described in this paper addresses the problem by combining a dense deformation eld with rigid-body transformations where calci cations/stents are present. The method contains non-rigid and rigid components. Non-rigid registration recovers the majority of motion artifacts and produces a dense deformation eld valid over the entire scan domain. Discrete domains are identi ed in which rigid registrations very accurately align each calci cation/stent. These rigid-body transformations are combined within the immediate area of the deformation eld using a distance transform to minimize distortion of the surrounding tissue. A recent interim analysis of a clinical feasibility study evaluated reader con dence and diagnostic accuracy in conventional CCTA and CTDSA registered using this method. Conventional invasive coronary angiography was used as the reference. The study included 27 patients scanned with a second-generation 320-row CT detector in which 41 lesions were identi ed. Compared to conventional CCTA, CTDSA improved reader con dence in 13/36 (36%) of segments with severe calci cation and 3/5 (60%) of segments with coronary stents. Also, the false positive rate of CTDSA was reduced compared to conventional CCTA from 18% (24/130) to 14% (19/130).

  11. Automatic alignment of myocardial perfusion PET and 64-slice coronary CT angiography on hybrid PET/CT

    PubMed Central

    Nakazato, Ryo; Dey, Damini; Alexánderson, Erick; Meave, Aloha; Jiménez, Moisés; Romero, Edgar; Jácome, Rodrigo; Peña, Marco; Berman, Daniel S.; Slomka, Piotr J.

    2012-01-01

    Background Hybrid PET/CT allows acquisition of cardiac PET and coronary CT angiography (CCTA) in one session. However, PET and CCTA, are acquired with differing breathing protocols and require software registration. We aimed to validate automatic correction for breathing misalignment between PET and CCTA acquired on hybrid scanner. Methods Single-session hybrid PET/CT studies of rest/stress 13N-ammonia PET and CCTA in 32 consecutive patients were considered. Automated registration of PET left ventricular (LV) surfaces with CCTA volumes was evaluated by comparison to expert manual alignment by 2 observers. Results The average initial misalignment between the position of LV on PET and CCTA was 27.2±11.8mm, 13.3±11.5mm, and 14.3±9.1mm in x, y, and z axes on rest, and 26.3±10.2mm, 11.1±9.5mm, and 11.7±7.1mm in x, y, and z axes on stress. The automated PET-CCTA co-registration had 95% agreement as judged visually. Compared to expert manual alignment, the translation errors of the algorithm were 5.3±2.8mm (rest) and 6.0±3.5mm (stress). 3D visualization of combined coronary vessel anatomy and hypoperfusion from PET could be made without further manual adjustments. Conclusion Software co-registration of CCTA and PET myocardial perfusion imaging on hybrid PET/CT scanners is necessary, but can be performed automatically, facilitating integrated 3D display on PET/CT. PMID:22419224

  12. A retrospective comparison of smart prep and test bolus multi-detector CT pulmonary angiography protocols

    SciTech Connect

    Suckling, Tara; Smith, Tony; Reed, Warren

    2013-06-15

    Optimal arterial opacification is crucial in imaging the pulmonary arteries using computed tomography (CT). This poses the challenge of precisely timing data acquisition to coincide with the transit of the contrast bolus through the pulmonary vasculature. The aim of this quality assurance exercise was to investigate if a change in CT pulmonary angiography (CTPA) scanning protocol resulted in improved opacification of the pulmonary arteries. Comparison was made between the smart prep protocol (SPP) and the test bolus protocol (TBP) for opacification in the pulmonary trunk. A total of 160 CTPA examinations (80 using each protocol) performed between January 2010 and February 2011 were assessed retrospectively. CT attenuation coefficients were measured in Hounsfield Units (HU) using regions of interest at the level of the pulmonary trunk. The average pixel value, standard deviation (SD), maximum, and minimum were recorded. For each of these variables a mean value was then calculated and compared for these two CTPA protocols. Minimum opacification of 200 HU was achieved in 98% of the TBP sample but only 90% of the SPP sample. The average CT attenuation over the pulmonary trunk for the SPP was 329 (SD = ±21) HU, whereas for the TBP it was 396 (SD = ±22) HU (P = 0.0017). The TBP also recorded higher maximum (P = 0.0024) and minimum (P = 0.0039) levels of opacification. This study has found that a TBP resulted in significantly better opacification of the pulmonary trunk than the SPP.

  13. Blunt polytrauma: evaluation with 64-section whole-body CT angiography.

    PubMed

    Dreizin, David; Munera, Felipe

    2012-01-01

    Blunt polytrauma remains a leading cause of death and disability worldwide. With the major advances in computed tomography (CT) technology over the past decade, whole-body CT is increasingly recognized as the emerging standard for providing rapid and accurate diagnoses within the narrow therapeutic window afforded to trauma victims with multiple severe injuries. With a single continuous acquisition, whole-body CT angiography is able to demonstrate all potentially injured organs, as well as vascular and bone structures, from the circle of Willis to the symphysis pubis. As its use becomes more widespread, the large volume of information inherent to whole-body CT poses new challenges to radiologists in providing efficient and timely interpretation. An awareness of trauma scoring systems and injury mechanisms is essential to maintain an appropriate level of suspicion in the search for multiple injuries, and the use of multiplanar reformation and three-dimensional postprocessing techniques is important to maximize efficiency in the search. Knowledge of the key injuries that require urgent surgical or percutaneous intervention, including major vascular injuries and active hemorrhage, diaphragmatic rupture, unstable spinal fractures, pancreatic injuries with ductal involvement, and injuries to the mesentery and hollow viscera, is also necessary. RSNA, 2012

  14. Clinical evaluation of dual-energy bone removal in CT angiography of the head and neck: comparison with conventional bone-subtraction CT angiography.

    PubMed

    Deng, K; Liu, C; Ma, R; Sun, C; Wang, X-m; Ma, Z-T; Sun, X-l

    2009-05-01

    To evaluate the bone-subtraction effect of dual-energy bone removal in computed tomography angiography (CTA) of the head and neck in comparison with conventional bone-subtraction CTA. The study comprised 52 patients who were divided into two groups at random, and examined using dual-source CT for head and neck CTA. Dual-energy bone removal CTA and conventional bone-subtraction CTA were applied to each of the two groups, respectively. The bone subtraction was performed automatically in both methods. Vascular structures, as well as brain tissue remained visible. The subtracted images were further processed with maximum intensity projection (MIP) and volume-rendering technique (VRT) for image evaluation. Two experienced radiologists reviewed the resulting subtracted and non-subtracted volume data with respect to the delineation and detection of image quality and vascular pathology. The means of the weighted CT dose index (CTDIvol) for bone-removal dual-energy CTA and conventional bone-subtraction CTA were 20.56+/-0.01 mGy and 25.57+/-0.56 mGy, respectively. There was a significant difference between them. The percentage of carotid and vertebral arteries and all other vessels that could be successfully assessed with these two methods were 87.8, 68, and 83%, and 93.5, 91.8, and 92.6%, respectively. There were no significant differences in the visualization of the carotid arteries; however, there were significant differences in the visualization of the vertebral arteries. Compared with conventional bone-subtraction CTA, dual-energy bone-removal CTA had a lower radiation dose. It eliminated most bones in the head and neck successfully; however, the bone subtraction effect around the vertebral artery was unsatisfactory. Dual-energy bone-removal CTA provides a new method for detecting vascular diseases in routine clinical work.

  15. Prediction of fluoroscopic angulations for transcatheter aortic valve implantation by CT angiography: influence on procedural parameters.

    PubMed

    Hell, Michaela M; Biburger, Lukas; Marwan, Mohamed; Schuhbaeck, Annika; Achenbach, Stephan; Lell, Michael; Uder, Michael; Arnold, Martin

    2017-05-01

    Repeated angiograms to achieve an exactly orthogonal visualization of the aortic valve plane can substantially contribute to the total contrast amount required for transcatheter aortic valve implantation (TAVI). We investigated whether pre-procedural identification of an optimal fluoroscopic projection by cardiac computed tomography (CT) can significantly reduce the amount of a procedure-related contrast agent compared with angiographic determination of suitable angulations. Eighty consecutive patients (81 ± 5 years, 55% male) with symptomatic severe aortic valve stenosis and normal renal function who underwent cardiac CT prior to TAVI were prospectively randomized. In 40 patients, a CT-predicted suitable angulation was used for the first aortic angiogram (CT cohort); in the other 40 patients, the first aortogram was acquired at LAO 10°/cranial 10 (angiography cohort). Additional aortograms were performed if no satisfactory view of the aortic valve plane was obtained. The number of aortograms needed to achieve a satisfactory fluoroscopic projection (1.2 ± 0.6 vs. 3.2 ± 1.7; P < 0.001) and the total amount of contrast agent per TAVI procedure were significantly lower in the CT cohort (95 ± 21 vs. 125 ± 36 mL; P < 0.001). Incidence of acute kidney injury was not significantly different. There was no significant difference regarding radiation dose, time of procedure, degree of post-procedural aortic regurgitation, complications and 30-day mortality between the cohorts. Pre-procedural identification of a suitable fluoroscopic projection by cardiac CT significantly reduces a procedural contrast agent volume required for TAVI.

  16. Prospectively ECG gated CT pulmonary angiography versus helical ungated CT pulmonary angiography: impact on cardiac related motion artifacts and patient radiation dose.

    PubMed

    Shuman, William P; Leipsic, Jonathon A; Busey, Janet M; Green, Douglas E; Pipavath, Sudhakar N; Hague, Cameron J; Koprowicz, Kent M

    2012-09-01

    To compare prospectively ECG gated CT pulmonary angiography (CTPA) with routine helical ungated CTPA for cardiac related motion artifacts and patient radiation dose. Twenty patients with signs and symptoms suspicious for pulmonary embolism and who had a heart rate below 85 were scanned with prospectively ECG gated CTPA. These gated exams were matched for several clinical parameters to exams from twenty similar clinical patients scanned with routine ungated helical CTPA. Three blinded independent reviewers subjectively evaluated all exams for overall pulmonary artery enhancement and for several cardiac motion related artifacts, including vessel blurring, intravascular shading, and double line. Reviewers also measured pulmonary artery intravascular density and image noise. Patient radiation dose for each technique was compared. Fourteen clinical prospectively ECG gated CTPA exams from a second institution were evaluated for the same parameters. Prospectively ECG gated CTPA resulted in significantly decreased motion-related image artifact scores in lung segments adjacent to the heart compared to ungated CTPA. Measured image noise was not significantly different between the two types of CTPA exams. Effective dose was 28% less for prospectively ECG gated CTPA (4.9 mSv versus 6.8 mSv, p=0.02). Similar results were found in the prospectively ECG gated exams from the second institution. Compared to routine helical ungated CTPA, prospectively ECG gated CTPA may result in less cardiac related motion artifact in lung segments adjacent to the heart and significantly less patient radiation dose. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

    PubMed Central

    Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

    2013-01-01

    Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

  18. Low-dose CT pulmonary angiography on a 15-year-old CT scanner: a feasibility study

    PubMed Central

    Kaup, Moritz; Gruber-Rouh, Tatjana; Scholtz, Jan E; Albrecht, Moritz H; Bucher, Andreas; Frellesen, Claudia; Vogl, Thomas J

    2016-01-01

    Background Computed tomography (CT) low-dose (LD) imaging is used to lower radiation exposure, especially in vascular imaging; in current literature, this is mostly on latest generation high-end CT systems. Purpose To evaluate the effects of reduced tube current on objective and subjective image quality of a 15-year-old 16-slice CT system for pulmonary angiography (CTPA). Material and Methods CTPA scans from 60 prospectively randomized patients (28 men, 32 women) were examined in this study on a 15-year-old 16-slice CT scanner system. Standard CT (SD) settings were 100 kV and 150 mAs, LD settings were 100 kV and 50 mAs. Attenuation of the pulmonary trunk, various anatomic landmarks, and image noise were quantitatively measured; contrast-to-noise ratios (CNR) and signal-to-noise ratios (SNR) were calculated. Three independent blinded radiologists subjectively rated each image series using a 5-point grading scale. Results CT dose index (CTDI) in the LD series was 66.46% lower compared to the SD settings (2.49 ± 0.55 mGy versus 7.42 ± 1.17 mGy). Attenuation of the pulmonary trunk showed similar results for both series (SD 409.55 ± 91.04 HU; LD 380.43 HU ± 93.11 HU; P = 0.768). Subjective image analysis showed no significant differences between SD and LD settings regarding the suitability for detection of central and peripheral PE (central SD/LD, 4.88; intra-class correlation coefficients [ICC], 0.894/4.83; ICC, 0.745; peripheral SD/LD, 4.70; ICC, 0.943/4.57; ICC, 0.919; all P > 0.4). Conclusion The LD protocol, on a 15-year-old CT scanner system without current high-end hardware or post-processing tools, led to a dose reduction of approximately 67% with similar subjective image quality and delineation of central and peripheral pulmonary arteries. PMID:28286671

  19. Clinical outcome and imaging follow-up in acute stroke patients with normal perfusion CT and normal CT angiography.

    PubMed

    Eckert, Bernd; Küsel, Tobias; Leppien, Andreas; Michels, Peter; Müller-Jensen, Axel; Fiehler, Jens

    2011-02-01

    Acute stroke multimodal CT imaging (MMCT: non-enhanced CT, CT angiography, and CT perfusion (CTP)) may show normal results despite persistent clinical stroke. We prospectively evaluated the sensitivity/specificity of MMCT infarct detection and the clinical outcome in patients with normal MMCT findings. From April 2007 to April 2008, all patients with acute hemispheric stroke within 6 h of symptom onset who underwent complete MMCT and MRI follow-up imaging were included. MMCT analysis included occlusion type, early infarct hypodensities (EIH), mean transit time (MTT), and cerebral blood volume (CBV) maps according to Alberta Stroke Program Early CT Score (ASPECTS). Clinical assessment included symptom onset to CT scan (≤3 h/>3 h), the National Institute of Health Stroke Scale score (admission/discharge), and the modified Rankin scale (mRS) 90 days after stroke onset. One hundred seven were included (mean age, 68.4 years; ≤3 h, n = 84; >3 h, n = 23; intravenous thrombolysis (IVT), n = 51; ≤3 h, n = 40; >3 h, n = 11). In patients with normal MMCT on admission (n = 54), follow-up MRT detected brain infarctions in 23 patients (lacunar strokes, n = 16; infratentorial strokes, n = 4; territorial infarction, n = 3). Sensitivity/specificity/positive predictive value/negative predictive value of any infarct detection was 69.5%/99.8%/99.9%/57.2% and of a any territorial infarct detection was 93.9%/99.9%/99.9%/93.6%, respectively. In univariate regression analysis (time to CT scan, ≤3 h/>3 h; IVT: yes/no; ASPECTS EIH/CBV/MTT, 10/<10), only the evidence of normal CTP (ASPECTS MTT = 10) had a statistically significant impact (p = 0.02) on a good outcome (mRS 0.1). MMCT sensitivity in acute lacunar or infratentorial stroke was poor. But, we found a high specifity and a fairly good sensitivity in territorial infarct detection. In acute stroke patients with normal MMCT findings on admission, a good clinical prognosis can be

  20. Blunt craniocervical artery injury in cervical spine lesions: the value of CT angiography.

    PubMed

    Fleck, Steffen Kristian; Langner, Soenke; Baldauf, Joerg; Kirsch, Michael; Rosenstengel, Christian; Schroeder, Henry W

    2010-10-01

    The awareness of traumatic craniocervical artery injuries has increased over the last years, and the detection rate varies in published trauma series. These injuries are often associated with cervical spinal and cranial trauma. The purpose of this prospective study was to determine the frequency and injury characteristics of blunt traumatic cervical artery injuries in patients suffering from cervical spine injuries by using a standardized CT angiography (CTA) protocol of the craniocervical vessels. Over a period of 32 months (February 2006 to September 2008), we prospectively evaluated 53 patients with osseous cervical spine injuries. Of these, 41 patients were screened for blunt craniocervical vessel injuries using CT angiography in 718 consecutive patients requiring a whole-body trauma CT due to the mechanism of their injury and injury patterns. All examinations were performed using a 16-row multi-slice computed tomography (Sensation 16, Siemens, Erlangen, Germany). Initially, a scan of the neurocranium angulated in orbito-meatal orientation was acquired. Then, a CT angiography of the craniocervical vessels with 40 ml of iodinated contrast agent (flow 4 ml/s; 40 ml saline flush, flow 4 ml/s) was performed starting at the level of Th2 up to the roof of the lateral ventricles. The scan was started using bolus tracking. Finally, a contrast-enhanced spiral thoraco-abdominal scan was performed with a delay of 20 s after administering a second contrast bolus of 60 ml. Besides, 11 patients with already detected isolated cervical spine injury, who were not initially involved in the whole-body trauma imaging protocol, underwent a secondary CT angiography with 60 ml of contrast agent (flow 4 ml/s; 40 ml saline flush, flow 4 ml/s), starting at the level of Th2 up to the roof of the lateral ventricles. The craniocervical vessels were analyzed in the source images, with the use of maximum-intensity projections and curved multi-planar reconstructions. Alternatively, a duplex

  1. INCIDENTAL AND NONINCIDENTAL CANINE THYROID TUMORS ASSESSED BY MULTIDETECTOR ROW COMPUTED TOMOGRAPHY: A SINGLE-CENTRE CROSS SECTIONAL STUDY IN 4520 DOGS.

    PubMed

    Bertolini, Giovanna; Drigo, Michele; Angeloni, Luca; Caldin, Marco

    2017-02-09

    Thyroid nodules are common in dogs and are increasingly likely to be detected with the increased use of advanced imaging modalities. An unsuspected, nonpalpable, asymptomatic lesion, defined as a thyroid incidentaloma, may be discovered on an imaging study unrelated to the thyroid gland. The objective of this single-center cross-sectional study was to assess the prevalence and computed tomography (CT) characteristics of incidental and nonincidental thyroid tumors in a large population of dogs, using prospective recruitment of patients undergoing CT examination for various reasons during the period of 2005-2015. Unilateral or bilateral thyroid masses were detected in 96/4520 dogs (prevalence, 2.12%; 95% confidence interval [CI], 1.70-2.54%). Seventy-nine (82.3%) lesions were malignant and 17 (17.7%) were benign. Masses were discovered incidentally in 34/96 dogs (overall prevalence of incidentaloma, 0.76%; 95% CI, 0.51-1.02), and 24 (70.6%) of these 34 masses were thyroid carcinomas. Among the CT variables assessed, mineralization, vascular invasion, and tissue invasion were detected only in malignant tumors. Intratumoral vascularization was significantly associated with the presence of thyroid malignancy (P < 0.001). Although incidental thyroid nodules in dogs are relatively rare, they are often malignant. Findings indicated that the neck should be thoroughly assessed in middle-aged and old patients undergoing body CT for various reasons. Thyroid nodules detected incidentally on CT should be sampled to avoid missing thyroid cancer.

  2. Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to "triage" patients' treatment.

    PubMed

    Agid, R; Lee, S K; Willinsky, R A; Farb, R I; terBrugge, K G

    2006-11-01

    To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm.

  3. "Role of CT Coronary Angiography in Recanalization of Chronic Total Occlusion"

    PubMed Central

    Roy, Sanjeeb; Sharma, Jugal

    2015-01-01

    Chronic total occlusion (CTO) is considered as the most challenging frontier in interventional cardiology and the last one to be conquered. With availability of state of the art hardware, wires and catheters in particular and increased skills of the operators, the success rate for recanalization of CTO by percutaneous catheter intervention (PCI) has improved. Yet the complications rate and longterm adverse events are high, mostly due to failure in tracking or navigation of hardware through the occluded CTO segment, prolonged exposure to radiation and high doses of contrast used. Therefore, proper selection of patient is of utmost importance. One of the major challenges for successful CTO recanalization is satisfactory visualization of the occluded CTO segment. Conventional invasive catheterization fails to fill the gap and the shortcomings and handicaps of such invasive imaging can be resolved with the use of non-invasive CT coronary angiography (CTCA). CTCA helps to better define the morphological features of the occluded CTO segment, which are established predictors of success, like the actual length of the occluded segment and any calcification or tortuosity in its course. Integration of reconstructed three-dimensional CT coronary images with twodimensional fluoroscopic images, offers directional guide to select the best angiographic plane for visualization of angiographically “missing segment”. With advances in CT technology, CTCA has now become an established technology for pre-procedure evaluation of CTO segment, thereby help in planning and execution of successful PCI.

  4. Accurate registration of coronary arteries for volumetric CT digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Razeto, Marco; Matthews, James; Masood, Saad; Steel, Jill; Arakita, Kazumasa

    2013-03-01

    In the diagnosis of coronary artery disease with coronary computed tomography angiography, accurate evaluation remains challenging in the presence of calcifications or stents. Volumetric CT Digital Subtraction Angiography is a novel method that may become a powerful tool to overcome these limitations. However, precise registration of structures is essential, as even small misalignments can produce striking and disruptive bright and dark artefacts. Moreover, for clinical acceptance, the tool should require minimal user interaction and fast turnaround, thereby raising several challenges. In this paper we address the problem with a registration method based on a global non- rigid step, followed by local rigid refinement. In our quantitative analysis based on 10 datasets, each consisting of a pair of pre- and post-contrast scans of the same patient, we achieve an average Target Registration Error of 0.45 mm. Runtimes are less than 90 seconds for the global step, while each local refinement takes less than 15 seconds to run. Initial clinical evaluation shows good results in cases of moderate calcification, and indicates that around 50% of severely calcified and previously non-interpretable cases have been made interpretable by application of our method.

  5. The Role of Multi-slice Spiral CT Angiography in Patient Management After Endovascular Therapy

    SciTech Connect

    Peloschek, P. Sailer, J.; Loewe, C.; Schillinger, M.; Lammer, J.

    2006-10-15

    Objectives. To bring out the role of multi-slice spiral CT angiography (MS-CTA) in patient management after endovascular therapy of subclavian artery stenosis. Methods. Twenty-one consecutive patients with clinically suspected restenosis after endovascular treatment of subclavian artery stenosis or occlusion were included in the study. Eleven patients had been treated with percutaneous transluminal angioplasty (PTA) alone and 10 with PTA and stenting. The mean follow-up period after PTA or stenting was 57 ({+-}27 SD) months. CTA was performed using a bolus-triggered high-resolution protocol with biphasic intravenous contrast medium injection. Axial images and curved planar reformations (CPRs) were rated by three readers with regard to patency of supra-aortic vessels. Imaging findings were correlated with a standardized clinical assessment. Results. All examinations were of diagnostic quality. Of 21 referred patients, 7 had significant reobstruction of the treated subclavian artery. Six of the 7 patients with significant restenosis on CTA were treated conservatively (antiplatelet agents), despite 2 of them being symptomatic on the standardized clinical assessment, which showed a sensitivity and specificity of 86% in predicting stenosis. One patient was treated with PTA and stent deployment because of strong subjective suffering. Conclusion. MS-CTA is useful for exclusion or quantification of clinically suspected restenosis in carefully selected patients after endovascular therapy where ultrasound is inconclusive and/or contrast-enhanced magnetic resonance angiography is contraindicated.

  6. Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation.

    PubMed

    Carbone, Iacopo; Cannata, David; Algeri, Emanuela; Galea, Nicola; Napoli, Alessandro; De Zorzi, Andrea; Bosco, Giovanna; D'Agostino, Rita; Menezes, Leon; Catalano, Carlo; Passariello, Roberto; Francone, Marco

    2011-09-01

    Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. The study group comprised 12 patients (age 17.6 ± 2.9 years, mean ± SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 ± 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 ± 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.

  7. Marked reduction of effective radiation dose in patients undergoing CT coronary angiography using prospective ECG gating.

    PubMed

    Freeman, Anthony; Learner, Ruth; Eggleton, Simon; Lambros, John; Friedman, Daniel

    2011-08-01

    Coronary CT angiography (CCTA) is a rapidly evolving technology which can characterise and image sub clinical atherosclerotic plaque and visualise anatomy and quantitate stenosis. Concern about radiation exposure has limited the uptake of this technology. The aim of this study was to review the radiation dose data in 2298 consecutive patients referred to a single centre in an Australian outpatient setting over 27 months using all available radiation dose reduction strategies. Prospective ECG gating ("step and shoot") was used preferentially in 2025 patients with a mean effective dose of 3.39 ± 1.84 mSv (range 0.86-12.6 mSv). For clinical reasons only 273 patients required retrospective ECG gating, mean dose 19.21 ± 5.58 mSv (range 2.4-34.9 mSv) resulting in an 85.7% reduction in dose for the majority of patients with the low dose technique. In conclusion, most patients referred for routine CCTA can be studied with a radiation dose comparable to invasive X-ray angiography and less than radionuclide myocardial perfusion imaging. Copyright © 2011 Australasian Society of Cardiac and Thoracic Surgeons and the Cardiac Society of Australia and New Zealand. Published by Elsevier B.V. All rights reserved.

  8. Is urgent CT angiography necessary in cases of acute lower gastrointestinal bleeding?

    PubMed

    Díaz, A Martín; Rodríguez, L Fernández; de Gracia, M Martí

    Acute lower gastrointestinal bleeding usually presents as hematochezia, rectal bleeding or melena and represents 1-2% of the medical appointments in the Emergency Services. Mortality reaches the 30-40% and it is highly related with the severity and associated comorbidity. Most clinical practice guidelines include colonoscopy at some point in the diagnostic and therapeutic process (urgent for severe cases and ambulatory for mild ones) and look for predictors of severity. In the last years, there have been numerous studies where is clear the relevance and complementarity of advanced diagnostic imaging techniques, gradually incorporated as an alternative or second step in severe cases. Therefore, we have made a review of current scientific evidence to establish a clinical prediction rule for optimal indication of CT angiography in these patients. However, future studies providing greater robustness and level of evidence are necessary. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Myopericarditis diagnosed by a 64-slice coronary CT angiography "triple rule out" protocol

    PubMed Central

    Ku, Bon S.; Halpern, Ethan J.

    2010-01-01

    We report a case of myopericarditis in a 30-year-old male complaining of shortness of breath. In an emergency department (ED) setting, the symptoms of myopericarditis may overlap with many disease entities and can be a challenging diagnosis to make. However, with the use of a 64-section coronary CT angiography in a “triple rule out” (TRO) protocol, we were able to detect a large pericardial effusion surrounding the heart and moderate global hypokinesis in the setting of normal-sized heart chambers and normal coronary arteries. We were further able to exclude pulmonary embolism and thoracic dissection. This is the first reported case of diagnosing myopericarditis using a TRO protocol. It demonstrates the usefulness of TRO in making an emergent diagnosis of myopericarditis while excluding other life-threatening diseases that can lead to earlier appropriate ED disposition and care. PMID:21373320

  10. Automatic segmentation of vertebral arteries in CT angiography using combined circular and cylindrical model fitting

    NASA Astrophysics Data System (ADS)

    Lee, Min Jin; Hong, Helen; Chung, Jin Wook

    2014-03-01

    We propose an automatic vessel segmentation method of vertebral arteries in CT angiography using combined circular and cylindrical model fitting. First, to generate multi-segmented volumes, whole volume is automatically divided into four segments by anatomical properties of bone structures along z-axis of head and neck. To define an optimal volume circumscribing vertebral arteries, anterior-posterior bounding and side boundaries are defined as initial extracted vessel region. Second, the initial vessel candidates are tracked using circular model fitting. Since boundaries of the vertebral arteries are ambiguous in case the arteries pass through the transverse foramen in the cervical vertebra, the circle model is extended along z-axis to cylinder model for considering additional vessel information of neighboring slices. Finally, the boundaries of the vertebral arteries are detected using graph-cut optimization. From the experiments, the proposed method provides accurate results without bone artifacts and eroded vessels in the cervical vertebra.

  11. Cardiac CT angiography in the emergency room: Apical hypertrophic cardiomyopathy presenting as acute coronary syndrome.

    PubMed

    Turner, Michael C; Kerut, Edmund K; Mckinnie, James; Davis, Michael; Hinton, Christine

    2017-03-07

    A 59-year-old male presented to the emergency room with symptoms of chest tightness and palpitations. Following conversion of atrial fibrillation to sinus rhythm, he had deep symmetrical T-wave changes on his electrocardiogram. Symptoms resolved almost immediately, and his initial troponin was negative. He underwent cardiac CT angiography utilizing an emergency room triage protocol which resulted in a diagnosis of nonobstructive coronary artery disease and apical hypertrophic cardiomyopathy. Following a hospital stay of less than 24 hours, he was discharged to outpatient follow-up on medical management and has remained asymptomatic over 6 months. This case presentation illustrates an example of the diversity of pathology that presents in emergency rooms with symptoms consistent with acute coronary syndrome.

  12. Multidetector CT angiography influences the choice of treatment for blunt carotid artery injury

    PubMed Central

    Beliaev, Andrei M; Civil, Ian

    2014-01-01

    A 43-year-old woman presented with a 2 h history of left neck pain after striking her neck against a marble bench while playing with her son. The patient was screened for blunt cerebrovascular injury (BCVI) and a left carotid bruit was identified. Subsequently, she underwent multidetector CT angiography (MCTA) of the aortic arch and neck vessels, which demonstrated a flow-limiting dissection of the left common carotid artery (CCA). The patient was started on heparin infusion and underwent an emergency operation. At surgery, a circumferential intimal dissection was excised and the arteriotomy defect closed with an autologous venous patch. This case emphasises the importance of adequately examining patients with direct injury to the neck, screening relevant patients for BCVI and investigating them with MCTA that influences the choice of a treatment option. PMID:25103313

  13. Diagnostic accuracy of contrast-enhanced MR angiography and unenhanced proton MR imaging compared with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension.

    PubMed

    Rajaram, Smitha; Swift, Andrew J; Capener, David; Telfer, Adam; Davies, Christine; Hill, Catherine; Condliffe, Robin; Elliot, Charles; Hurdman, Judith; Kiely, David G; Wild, Jim M

    2012-02-01

    To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) and the added benefit of unenhanced proton MR angiography compared with CT pulmonary angiography (CTPA) in patients with chronic thromboembolic disease (CTE). A 2 year retrospective study of 53 patients with chronic thromboembolic pulmonary hypertension who underwent CTPA and MRI for suspected pulmonary hypertension and a control group of 36 patients with no CT evidence of pulmonary embolism. The MRI was evaluated for CTE and the combined diagnostic accuracy of ce-MRA and unenhanced proton MRA was determined. CE-MRA generated lung perfusion maps were also assessed. The overall sensitivity and specificity of CE-MRA in diagnosing proximal and distal CTE were 98% and 94%, respectively. The sensitivity improved from 50% to 88% for central vessel disease when CE-MRA images were analysed with unenhanced proton MRA. The CE-MRA identified more stenoses (29/18), post-stenosis dilatation (23/7) and occlusions (37/29) compared with CTPA. The CE-MRA perfusion images showed a sensitivity of 92% for diagnosing CTE. CE-MRA has high sensitivity and specificity for diagnosing CTE. The sensitivity of CE-MRA for visualisation of adherent central and lobar thrombus significantly improves with the addition of unenhanced proton MRA which delineates the vessel wall.

  14. Coronary CT angiography outperforms calcium imaging in the triage of acute coronary syndrome.

    PubMed

    Dedic, Admir; Ten Kate, Gert-Jan; Neefjes, Lisan A; Rossi, Alexia; Dharampal, Anoeshka; Rood, Pleunie P M; Galema, Tjebbe W; Schultz, Carl; Ouhlous, Mohamed; Moelker, Adriaan; de Feyter, Pim J; Nieman, Koen

    2013-08-20

    In this prospective study we determine the diagnostic value of coronary CT angiography (CTA) and calcium imaging in low to intermediate risk acute chest pain patients. One hundred and eleven consecutive patients (57 ± 11 years, 71 males) presenting to the emergency department with chest pain suggestive of acute coronary syndrome (ACS), but without indication for immediate catheter angiography, underwent both coronary CTA and calcium imaging without disclosure of the findings to the treating physicians. ACS was diagnosed in 19 patients (17%). Coronary calcium was present in 71 patients (64%). Coronary CTA identified 74 (67%) patients with coronary plaque and 36 (32%) patients with obstructive (≥ 50%) plaque. The sensitivity and specificity of the calcium scan were: 89% and 41%. The sensitivity and specificity of coronary CTA were: 100% and 40% based on the presence of any plaque and 89% and 79% based on the presence of >50% stenosis. C-statistics of the GRACE risk score (0.77 [95% CI 0.66-0.89]) improved after addition of coronary CTA (0.93 [0.88-0.98], p<0.01), though not after addition of calcium scores (0.81 [0.71-0.91], p=0.52). Follow-up at 3 months revealed four late revascularizations (no deaths or myocardial infarctions), all of whom had obstructive CAD with calcium on CT at presentation. Coronary CTA outperforms calcium imaging in the triage of patients suspected of developing ACS. Absence of plaque on coronary CTA allows safe discharge. Coronary CTA has incremental value to clinical risk scores and has the potential to reduce unnecessary hospital admissions. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  15. Nonstenotic carotid plaque on CT angiography in patients with cryptogenic stroke

    PubMed Central

    Coutinho, Jonathan M.; Derkatch, Sheldon; Potvin, Alphonse R.J.; Tomlinson, George; Kiehl, Tim-Rasmus; Silver, Frank L.

    2016-01-01

    Objective: To determine whether large (≥3 mm thick) but nonstenotic (<50%) carotid artery atherosclerotic plaque predominantly occurs ipsilateral rather than contralateral to cryptogenic stroke. Methods: This was a cross-sectional observational study. Using a stroke registry, we identified consecutive patients with anterior circulation embolic stroke of undetermined source (ESUS). Using CT angiography, we measured carotid plaque size (thickness, mm) and carotid artery stenosis (North American Symptomatic Carotid Endarterectomy Trial method) for each patient. We dichotomized plaque size at several predefined thresholds and calculated the frequency of plaque size above each threshold ipsilateral vs contralateral to stroke. Results: We included 85 patients with ESUS. Plaque with thickness ≥5 mm was present ipsilateral to stroke in 11% of patients, and contralateral in 1% (9/85 vs 1/85; p = 0.008). Plaque with thickness ≥4 mm was present ipsilateral to stroke in 19% of patients, and contralateral in 5% (16/85 vs 4/85; p = 0.002). Plaque with thickness ≥3 mm was present ipsilateral to stroke in 35% of patients, and contralateral in 15% (30/85 vs 13/85; p = 0.001). There was no difference in percentage stenosis ipsilateral vs contralateral to stroke (p = 0.98), and weak correlation between plaque size and stenosis (R2 = 0.26, p < 0.001). Conclusions: Large but nonstenotic carotid artery plaque is considerably more common ipsilateral than contralateral to cryptogenic stroke, suggesting that nonstenotic plaque is an underrecognized cause of stroke. We measured plaque size using CT angiography, a method that could be easily implemented in clinical practice. PMID:27412144

  16. Deformable known component model-based reconstruction for coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Tilley, S.; Xu, S.; Mathews, A.; McVeigh, E. R.; Stayman, J. W.

    2017-03-01

    Purpose: Atherosclerosis detection remains challenging in coronary CT angiography for patients with cardiac implants. Pacing electrodes of a pacemaker or lead components of a defibrillator can create substantial blooming and streak artifacts in the heart region, severely hindering the visualization of a plaque of interest. We present a novel reconstruction method that incorporates a deformable model for metal leads to eliminate metal artifacts and improve anatomy visualization even near the boundary of the component. Methods: The proposed reconstruction method, referred as STF-dKCR, includes a novel parameterization of the component that integrates deformation, a 3D-2D preregistration process that estimates component shape and position, and a polyenergetic forward model for x-ray propagation through the component where the spectral properties are jointly estimated. The methodology was tested on physical data of a cardiac phantom acquired on a CBCT testbench. The phantom included a simulated vessel, a metal wire emulating a pacing lead, and a small Teflon sphere attached to the vessel wall, mimicking a calcified plaque. The proposed method was also compared to the traditional FBP reconstruction and an interpolation-based metal correction method (FBP-MAR). Results: Metal artifacts presented in standard FBP reconstruction were significantly reduced in both FBP-MAR and STF- dKCR, yet only the STF-dKCR approach significantly improved the visibility of the small Teflon target (within 2 mm of the metal wire). The attenuation of the Teflon bead improved to 0.0481 mm-1 with STF-dKCR from 0.0166 mm-1 with FBP and from 0.0301 mm-1 with FBP-MAR - much closer to the expected 0.0414 mm-1. Conclusion: The proposed method has the potential to improve plaque visualization in coronary CT angiography in the presence of wire-shaped metal components.

  17. Removal of bone in CT angiography by multiscale matched mask bone elimination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Streekstra, G. J.; Straten, M. van; Majoie, C. B. L. M.; Heeten, G. J. den; Grimbergen, C. A.

    2007-10-15

    For clear visualization of vessels in CT angiography (CTA) images of the head and neck using maximum intensity projection (MIP) or volume rendering (VR) bone has to be removed. In the past we presented a fully automatic method to mask the bone [matched mask bone elimination (MMBE)] for this purpose. A drawback is that vessels adjacent to bone may be partly masked as well. We propose a modification, multiscale MMBE, which reduces this problem by using images at two scales: a higher resolution than usual for image processing and a lower resolution to which the processed images are transformed for use in the diagnostic process. A higher in-plane resolution is obtained by the use of a sharper reconstruction kernel. The out-of-plane resolution is improved by deconvolution or by scanning with narrower collimation. The quality of the mask that is used to remove bone is improved by using images at both scales. After masking, the desired resolution for the normal clinical use of the images is obtained by blurring with Gaussian kernels of appropriate widths. Both methods (multiscale and original) were compared in a phantom study and with clinical CTA data sets. With the multiscale approach the width of the strip of soft tissue adjacent to the bone that is masked can be reduced from 1.0 to 0.2 mm without reducing the quality of the bone removal. The clinical examples show that vessels adjacent to bone are less affected and therefore better visible. Images processed with multiscale MMBE have a slightly higher noise level or slightly reduced resolution compared with images processed by the original method and the reconstruction and processing time is also somewhat increased. Nevertheless, multiscale MMBE offers a way to remove bone automatically from CT angiography images without affecting the integrity of the blood vessels. The overall image quality of MIP or VR images is substantially improved relative to images processed with the original MMBE method.

  18. Flat panel detector-based cone-beam volume CT angiography imaging: system evaluation.

    PubMed

    Ning, R; Chen, B; Yu, R; Conover, D; Tang, X; Ning, Y

    2000-09-01

    Preliminary evaluation of recently developed large-area flat panel detectors (FPDs) indicates that FPDs have some potential advantages: compactness, absence of geometric distortion and veiling glare with the benefits of high resolution, high detective quantum efficiency (DQE), high frame rate and high dynamic range, small image lag (< 1%), and excellent linearity (approximately 1%). The advantages of the new FPD make it a promising candidate for cone-beam volume computed tomography (CT) angiography (CBVCTA) imaging. The purpose of this study is to characterize a prototype FPD-based imaging system for CBVCTA applications. A prototype FPD-based CBVCTA imaging system has been designed and constructed around a modified GE 8800 CT scanner. This system is evaluated for a CBVCTA imaging task in the head and neck using four phantoms and a frozen rat. The system is first characterized in terms of linearity and dynamic range of the detector. Then, the optimal selection of kVps for CBVCTA is determined and the effect of image lag and scatter on the image quality of the CBVCTA system is evaluated. Next, low-contrast resolution and high-contrast spatial resolution are measured. Finally, the example reconstruction images of a frozen rat are presented. The results indicate that the FPD-based CBVCT can achieve 2.75-lp/mm spatial resolution at 0% modulation transfer function (MTF) and provide more than enough low-contrast resolution for intravenous CBVCTA imaging in the head and neck with clinically acceptable entrance exposure level. The results also suggest that to use an FPD for large cone-angle applications, such as body angiography, further investigations are required.

  19. Correlation between myocardial scintigraphy and CT angiography in the evaluation of coronary disease.

    PubMed

    Azevedo, Jader Cunha de; Ferreira Junior, Diógenes de Souza; Vieira, Felipe Carvalhinho; Prezotti, Laís Santos; Simões, Luciana Silveira; Nacif, Marcelo Souto; Rochitte, Carlos Eduardo; Oliveira Junior, Amarino de Carvalho; Mesquita, Evandro Tinoco; Mesquita, Cláudio Tinoco

    2013-03-01

    Coronary multidetector CT angiography (CTA) has shown good accuracy for detection of coronary stenosis. Although this is a promising technique for the evaluation of CAD, its correlation with the functional expression of the disease is not yet well established. To evaluate whether the presence of CAD and the degree of coronary stenosis assessed by CT angiography are associated with changes in the Myocardial Perfusion Scintigraphy (MPS). This is a retrospective observational study, which included 99 consecutive patients with known or suspected CAD. MPS and CTA were conducted. We compared the presence of perfusion defects by MPS with the presence of CAD and the degree of luminal obstruction by CTA. For statistical analysis, Student's t-test, ANOVA, and Chi-square (or Fisher's exact test for n <5) tests were used. Multivariate analysis was performed using logistic regression: the level of significance was 5%. Mean age was 62 ± 11.4 years, with 46 (71.7%) men. The variable analysis was performed per patient (n = 99) and per coronary irrigation territory (n = 297). Of the 67 territories that had significant CAD by CTA, 44.8% had abnormal MPS. Considering the degree of stenosis, abnormal MPS was present in 18.7% of the territories with no significant stenosis, 45.28% of the territories with moderate stenosis, and 42.8% of the territories with severe injuries. CTA is a good method for exclusion of CAD. However, its use to evaluate the severity of stenosis and its functional impact has not shown good correlation.

  20. New insights on COPD imaging via CT and MRI

    PubMed Central

    Sverzellati, N; Molinari, F; Pirronti, T; Bonomo, L; Spagnolo, P; Zompatori, M

    2007-01-01

    Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD. PMID:18229568

  1. Simultaneous extraction of centerlines, stenosis, and thrombus detection in renal CT angiography

    NASA Astrophysics Data System (ADS)

    Subramanyan, Krishna; Durgan, Jacob; Hodgkiss, Thomas D.; Chandra, Shalabh

    2004-05-01

    The Renal Artery Stenosis (RAS) is the major cause of renovascular hypertension and CT angiography has shown tremendous promise as a noninvasive method for reliably detecting renal artery stenosis. The purpose of this study was to validate the semi-automated methods to assist in extraction of renal branches and characterizing the associated renal artery stenosis. Automatically computed diagnostic images such as straight MIP, curved MPR, cross-sections, and diameters from multi-slice CT are presented and evaluated for its acceptance. We used vessel-tracking image processing methods to extract the aortic-renal vessel tree in a CT data in axial slice images. Next, from the topology and anatomy of the aortic vessel tree, the stenosis, and thrombus section and branching of the renal arteries are extracted. The results are presented in curved MPR and continuously variable MIP images. In this study, 15 patients were scanned with contrast on Mx8000 CT scanner (Philips Medical Systems), with 1.0 mm thickness, 0.5mm slice spacing, and 120kVp and a stack of 512x512x150 volume sets were reconstructed. The automated image processing took less than 50 seconds to compute the centerline and borders of the aortic/renal vessel tree. The overall assessment of manual and automatically generated stenosis yielded a weighted kappa statistic of 0.97 at right renal arteries, 0.94 at the left renal branches. The thrombus region contoured manually and semi-automatically agreed upon at 0.93. The manual time to process each case is approximately 25 to 30 minutes.

  2. Phantom-based standardization of CT angiography images for spot sign detection.

    PubMed

    Morotti, Andrea; Romero, Javier M; Jessel, Michael J; Hernandez, Andrew M; Vashkevich, Anastasia; Schwab, Kristin; Burns, Joseph D; Shah, Qaisar A; Bergman, Thomas A; Suri, M Fareed K; Ezzeddine, Mustapha; Kirmani, Jawad F; Agarwal, Sachin; Shapshak, Angela Hays; Messe, Steven R; Venkatasubramanian, Chitra; Palmieri, Katherine; Lewandowski, Christopher; Chang, Tiffany R; Chang, Ira; Rose, David Z; Smith, Wade; Hsu, Chung Y; Liu, Chun-Lin; Lien, Li-Ming; Hsiao, Chen-Yu; Iwama, Toru; Afzal, Mohammad Rauf; Cassarly, Christy; Greenberg, Steven M; Martin, Renee' Hebert; Qureshi, Adnan I; Rosand, Jonathan; Boone, John M; Goldstein, Joshua N

    2017-07-20

    The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

  3. Interleaving cerebral CT perfusion with neck CT angiography. Part II: clinical implementation and image quality.

    PubMed

    Oei, Marcel T H; Meijer, Frederick J A; van der Woude, Willem-Jan; Smit, Ewoud J; van Ginneken, Bram; Manniesing, Rashindra; Prokop, Mathias

    2017-06-01

    Feasibility evaluation of the One-Step Stroke Protocol, which is an interleaved cerebral computed tomography perfusion (CTP) and neck volumetric computed tomography angiography (vCTA) scanning technique using wide-detector computed tomography, and to assess the image quality of vCTA. Twenty patients with suspicion of acute ischaemic stroke were prospectively scanned and evaluated with a head and neck CTA and with the One-Step Stroke Protocol. Arterial enhancement and contrast-to-noise ratio (CNR) in the carotid arteries was assessed. Three observers scored artefacts and image quality of the cervical arteries. The total z-coverage was evaluated. Mean enhancement in the carotid bifurcation was rated higher in the vCTA (595 ± 164 HU) than CTA (441 ± 117 HU). CNR was rated higher in vCTA. Image quality scores showed no significant difference in the region of the carotid bifurcation between vCTA and CTA. Lower neck image quality scores were slightly lower for vCTA due to artefacts, although not rated as diagnostically relevant. In ten patients, the origin of the left common carotid artery was missed by 1.6 ± 0.8 cm. Mean patient height was 1.8 ± 0.09 m. Carotid bifurcation and origin of vertebral arteries were covered in all patients. The One-Step Stroke Protocol is feasible with good diagnostic image quality of vCTA, although full z-coverage is limited in tall patients. • Interleaving cerebral CTP with neck CTA (One-Step Stroke Protocol) is feasible • Diagnostic quality of One-Step Stroke Protocol neck CTA is similar to conventional CTA • One-Step Stroke Protocol neck CTA suffers from streak artefacts in the lower neck • A limitation of One-Step Stroke Protocol CTA is lack of coverage in tall patients • Precise planning of One-Step Stroke Protocol neck CTA is necessary in tall patients.

  4. Multimodality evaluation of dural arteriovenous fistula with CT angiography, MR with arterial spin labeling, and digital subtraction angiography: case report.

    PubMed

    Alexander, Matthew; McTaggart, Ryan; Santarelli, Justin; Fischbein, Nancy; Marks, Michael; Zaharchuk, Greg; Do, Huy

    2014-01-01

    Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed.

  5. The effect of equipment set up on patient radiation dose in conventional and CT angiography of the renal arteries.

    PubMed

    Kemerink, G J; De Haan, M W; Vasbinder, G B C; Frantzen, M J; Schultz, F W; Zoetelief, J; Jansen, J Th M; Van Engelshoven, J M A

    2003-09-01

    Patient radiation dose in angiography of the renal arteries was assessed and optimized after installing new radiological equipment. In three separate studies (n=50, 25 and 20) patient exposure was monitored in detail. For the first study default factory settings were used, for the second the number of digital subtraction angiography (DSA) images was halved and the X-ray beam filtering during fluoroscopy was increased, and for the third study filtering during DSA was increased as well. Standard projections were derived and used in Monte Carlo simulations to derive dose conversion coefficients to calculate effective dose from the dose-area product (DAP). Dose conversion coefficients were also calculated for CT angiography (CTA). Using default factory settings on the new angiography system, DAP, number of images and effective dose were much higher than on the replaced unit. For the studies given above, DAP was reduced from 144 Gy cm(2) to 65 Gy cm(2) to 32 Gy cm(2), and effective dose from 22 mSv to 11 mSv to 9.1 mSv, respectively. Effective dose due to CTA was 5.2 mSv. It is concluded that modern angiography systems, resulting in high customer satisfaction, may readily cause much higher patient exposure than older systems. These doses may also be much higher than necessary. Optimization before putting such systems into use is absolutely essential. Internationally accepted recommendations for image quality and technique factors in angiography would be of great help.

  6. Radiation dose reduction in time-resolved CT angiography using highly constrained back projection reconstruction

    PubMed Central

    Supanich, Mark; Tao, Yinghua; Nett, Brian; Pulfer, Kari; Hsieh, Jiang; Turski, Patrick; Mistretta, Charles; Rowley, Howard; Chen, Guang-Hong

    2010-01-01

    Recently dynamic, time-resolved three-dimensional computed tomography angiography (CTA) has been introduced to the neurological imaging community. However, the radiation dose delivered to patients in time-resolved CTA protocol is a high and potential risk associated with the ionizing radiation dose. Thus, minimizing the radiation dose is highly desirable for time-resolved CTA. In order to reduce the radiation dose delivered during dynamic, contrast-enhanced CT applications, we introduce here the CT formulation of HighlY constrained back PRojection (HYPR) imaging. We explore the radiation dose reduction approaches of both acquiring a reduced number of projections for each image and lowering the tube current used during acquisition. We then apply HYPR image reconstruction to produce image sets at a reduced patient dose and with low image noise. Numerical phantom experiments and retrospective analysis of in vivo canine studies are used to assess the accuracy and quality of HYPR reduced dose image sets and validate our approach. Experimental results demonstrated that a factor of 6–8 times radiation dose reduction is possible when the HYPR algorithm is applied to time-resolved CTA exams. PMID:19567941

  7. Probabilistic boosting trees for automatic bone removal from CT angiography images

    NASA Astrophysics Data System (ADS)

    Militzer, Arne; Vega-Higuera, Fernando

    2009-02-01

    In CT angiography images, osseous structures occluding vessels pose difficulties for physicians during diagnosis. Simple thresholding techniques for removing bones fail due to overlapping CT values of vessels filled with contrast agent and osseous tissue, while manual delineation is slow and tedious. Thus, we propose to automatically segment bones using a trainable classifier to label image patches as bone or background. The image features provided to the classifier are based on grey value statistics and gradients. In contrast to most existing methods, osseous tissue segmentation in our algorithm works without any prior knowledge of the body region depicted in the image. This is achieved by using a probabilistic boosting tree, which is capable of automatically decomposing the input space. The whole system works by partitioning the image using a watershed transform, classifying image regions as bone or background and refining the result by means of a graph-based procedure. Additionally, an intuitive way of manually refining the segmentation result is incorporated. The system was evaluated on 15 CTA datasets acquired from various body regions, showing an average correct recognition of bone regions of 80% at a false positive rate of 0.025% of the background voxels.

  8. In vivo dosimetry for estimation of effective doses in multislice CT coronary angiography

    SciTech Connect

    De Denaro, M.; Bregant, P.; Severgnini, M.; De Guarrini, F.

    2007-10-15

    In vivo dosimetry represents a technique that has been widely employed to evaluate the dose to the patient mainly in radiotherapy. Considering the increment in dose to the population due to new high-dose multislice CT examinations, such as coronary angiography, it is becoming important to more accurately know the dose to the patient. The desire to know patient dose extends even to radiological examinations. Thermoluminescent dosimeters are considered the gold standard for in vivo dosimetry, but their use is time consuming. A rapid, less labor-intensive method has been developed to perform in vivo dosimetry using radiochromic film positioned next to the patient's skin. Multislice CT scanners allow the estimation of the effective dose to the patient from the dose length product (DLP) parameter, the value of which is displayed on the acquisition console, simply multiplying the DLP by published conversion factors. The method represents only an approximation based on standard size circular phantoms and neglects the actual size of the patient. More accurate evaluations can be carried out using software-based Monte Carlo simulations. However, these methods do not consider possible dose reduction techniques, such as automatic tube-current modulation. For 22 patients effective doses measured by in vivo dosimetry and calculated by software were compared. The technique of using in vivo dosimetry measured with radiochromic film appears a promising procedure for improving the assessment of the effective dose to the patient.

  9. Remote-rendered 3D CT angiography (3DCTA) as an intraoperative aid in cerebrovascular neurosurgery.

    PubMed

    Wilkinson, E P; Shahidi, R; Wang, B; Martin, D P; Adler, J R; Steinberg, G K

    1999-01-01

    To assess the viability and utility of network-based rendering in the treatment of patients with cerebral aneurysms, we implemented an intraoperative rendering system and protocol using both three-dimensional CT angiography (3DCTA) and perspective volume rendering (PVR). A Silicon Graphics InfiniteReality engine was connected via a Fast Ethernet network to a workstation in the neurosurgical operating room. A protocol was developed to isolate bone and vessels using an appropriate transfer function. Three-dimensional CT angiogram images were volume rendered and transmitted to the workstation using a bandwidth-conserving remote rendering system, and were rotated, cut using clipping planes, and viewed using normal and perspective views. Twelve patients with intracranial aneurysms were examined at surgery using this system. Rendering performance at optimal operating bandwidths (50-60 Mb/s) was excellent, with regeneration of a high-resolution image in less than 1 s. Network performance varied in two cases, slowing image regeneration. Surgeons found the images to be useful as an adjunct to conventional imaging in understanding the morphology of complex aneurysms and their relationship to the skull base. Intraoperative volume rendering using 3DCTA is achievable over a network, can reduce hardware costs by amortizing hardware among multiple users, and provides useful imaging information during the surgical treatment of cerebral aneurysms. Future operating suites may incorporate network-transmitted three-dimensional images as additional sources of imaging information. Copyright 1999 Wiley-Liss, Inc.

  10. Accuracy of the Alberta Stroke Program Early CT Score during the first 3 hours of middle cerebral artery stroke: comparison of noncontrast CT, CT angiography source images, and CT perfusion.

    PubMed

    Lin, K; Rapalino, O; Law, M; Babb, J S; Siller, K A; Pramanik, B K

    2008-05-01

    The Alberta Stroke Program Early CT Score (ASPECTS) is a reliable method of delineating the extent of middle cerebral artery (MCA) stroke. Our aim was to retrospectively compare the accuracy of ASPECTS on noncontrast CT, CT angiography (CTA) source images, and CT perfusion maps of cerebral blood volume (CBV) during the first 3 hours of middle cerebral artery (MCA) stroke. First-time patients with MCA stroke who presented <3 hours from symptom onset and were evaluated by noncontrast CT/CTA/CT perfusion, had confirmed acute nonlacunar MCA infarct on diffusion-weighted MR imaging (DWI) within 7 days, and had follow-up angiography were included. Patients were excluded for persistent MCA occlusion or stenosis. Two raters through consensus assigned an ASPECTS on the noncontrast CT, CTA source images, and the section-selective (2 x 12 mm coverage) CT perfusion CBV maps. ASPECTS on follow-up DWI served as the reference standard. For each CT technique, the detection rates of regional infarction, the mean ASPECTS, and the linear correlation to final ASPECTS were determined and compared. P values <.05 were considered significant. Twenty-eight patients satisfied the criteria with DWI performed at a mean of 50.3 hours (range, 22-125 hours) post-CT imaging. Of 280 ASPECTS regions, 100 were infarcted on DWI. The accuracy of noncontrast CT, CTA source images, and CT perfusion CBV for detecting regional infarct was 80.0%, 84.3%, and 96.8%, respectively (P < .0001). The mean ASPECTSs of noncontrast CT, CTA source images, CT perfusion CBV, and DWI were 8.4 +/- 1.8, 8.0 +/- 1.8, 6.8 +/- 1.9, and 6.5 +/- 1.8, respectively. The mean noncontrast CT and CTA source image ASPECTS was different from that of DWI (P < .05). Correlation of noncontrast CT, CTA source images, and CT perfusion CBV ASPECTS with final ASPECTS was r(2) = 0.34, r(2) = 0.42, and r(2) = 0.91, respectively. In a retrospective cohort of MCA infarcts imaged <3 hours from stroke onset, ASPECTS was most accurately determined

  11. Diversity and Determinants of the Three-dimensional Anatomical Axis of the Heart as Revealed Using Multidetector-row Computed Tomography.

    PubMed

    Mori, Shumpei; Anderson, Robert H; Tahara, Natsuko; Izawa, Yu; Toba, Takayoshi; Fujiwara, Sei; Shimoyama, Shinsuke; Watanabe, Yoshiaki; Nishii, Tatsuya; Kono, Atsushi K; Hirata, Ken-Ichi

    2017-06-01

    The location of the heart within the thorax varies significantly between individuals. The resultant diversity of the anatomical cardiac long axis, however, and its determinants, have yet to be systematically investigated. We enrolled 100 consecutive patients undergoing coronary arterial computed tomographic angiography, decomposing the vector of the anatomical cardiac long axis by projecting it to horizontal, frontal, and sagittal planes. The projected vectors on each plane were then converted into three rotation angles using coordinate transformation. We then measured the extent of aortic wedging, using the vertical distance between the inferior margins of the non-adjacent aortic sinus and the epicardium. We took the aortic root rotation angle to be zero when an "en face" view of the right coronary aortic sinus was obtained in the frontal view, defining leftward rotation to be positive. The mean horizontal, frontal, and sagittal rotation angles were 48.7° ± 9.5°, 52.3° ± 12.0°, and 34.0° ± 11.2°, respectively. The mean extent of aortic wedging, and the aortic root rotation angle, were 42.7 ± 9.8 mm, and 5.3° ± 16.4°. Horizontal rotation of the anatomical axis was associated with leftward and ventral rotation, and vice versa. Multivariate analysis showed aortic root rotation to be associated with horizontal cardiac rotation, while aortic wedging is associated with frontal and sagittal cardiac rotation. We have quantified the marked individual variation observed in the anatomical axis of the living heart, identifying the different mechanisms involved in producing the marked three-dimensional diversity of the living heart. Anat Rec, 300:1083-1092, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. Differentiation of Malignant and Benign Incidental Breast Lesions Detected by Chest Multidetector-Row Computed Tomography: Added Value of Quantitative Enhancement Analysis

    PubMed Central

    Lin, Yu-Pang; Hsu, Hsian-He; Ko, Kai-Hsiung; Chu, Chi-Ming; Chou, Yu-Ching; Chang, Wei-Chou; Chang, Tsun-Hou

    2016-01-01

    To retrospectively determine the association between breast lesion morphology and malignancy and to determine the optimal value of lesion enhancement (HU, Hounsfield units) to improve the diagnostic accuracy of breast cancer in patients with incidental breast lesions (IBLs). A total of 97 patients with 102 IBLs detected from July 2009 to December 2012 were enrolled in this study. Two radiologists analyzed CT images for the presence of malignancy based on the morphology of the lesions alone and in combination with an enhancement value (HU) analysis. There were 36 malignant and 66 benign IBLs. When the morphology and enhancement values were combined, the sensitivity, specificity, and accuracy were 92%, 97%, and 95%, respectively, for reader 1 and 89%, 94%, and 92%, respectively, for reader 2. The addition of HU values led to correct changes in the diagnosis; specifically, the accuracy of the diagnosis of reader 1 and reader 2 improved by 6.9% and 11.8%, respectively. The addition of the enhancement value (HU) to the CT morphology improved the diagnostic accuracy in the differentiation of malignant from benign IBLs by using the region of interest (ROI) to measure the HU within the most suspicious part of the lesion. PMID:27128524

  13. Performance of turbo high-pitch dual-source CT for coronary CT angiography: first ex vivo and patient experience.

    PubMed

    Morsbach, Fabian; Gordic, Sonja; Desbiolles, Lotus; Husarik, Daniela; Frauenfelder, Thomas; Schmidt, Bernhard; Allmendinger, Thomas; Wildermuth, Simon; Alkadhi, Hatem; Leschka, Sebastian

    2014-08-01

    To evaluate image quality, maximal heart rate allowing for diagnostic imaging, and radiation dose of turbo high-pitch dual-source coronary computed tomographic angiography (CCTA). First, a cardiac motion phantom simulating heart rates (HRs) from 60-90 bpm in 5-bpm steps was examined on a third-generation dual-source 192-slice CT (prospective ECG-triggering, pitch 3.2; rotation time, 250 ms). Subjective image quality regarding the presence of motion artefacts was interpreted by two readers on a four-point scale (1, excellent; 4, non-diagnostic). Objective image quality was assessed by calculating distortion vectors. Thereafter, 20 consecutive patients (median, 50 years) undergoing clinically indicated CCTA were included. In the phantom study, image quality was rated diagnostic up to the HR75 bpm, with object distortion being 1 mm or less. Distortion increased above 1 mm at HR of 80-90 bpm. Patients had a mean HR of 66 bpm (47-78 bpm). Coronary segments were of diagnostic image quality for all patients with HR up to 73 bpm. Average effective radiation dose in patients was 0.6 ± 0.3 mSv. Our combined phantom and patient study indicates that CCTA with turbo high-pitch third-generation dual-source 192-slice CT can be performed at HR up to 75 bpm while maintaining diagnostic image quality, being associated with an average radiation dose of 0.6 mSv. • CCTA is feasible with the turbo high-pitch mode. • Turbo high-pitch CCTA provides diagnostic image quality up to 73 bpm. • The radiation dose of high-pitch CCTA is 0.6 mSv on average.

  14. Computerized luminal analysis for detection of non-calcified plaques in coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Patel, Smita; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Kazerooni, Ella

    2014-03-01

    Non-calcified plaque (NCP) detection in coronary CT angiography (cCTA) is challenging due to the low CT number of NCP, the large number of coronary arteries and multiple phase CT acquisition. We are developing computer-vision methods for automated detection of NCPs in cCTA. A data set of 62 cCTA scans with 87 NCPs was collected retrospectively from patient files. Multiscale coronary vessel enhancement and rolling balloon tracking were first applied to each cCTA volume to extract the coronary artery trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A topological soft-gradient (TSG) detection method was developed to prescreen for both positive and negative remodeling candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. A quantitative luminal analysis was newly designed for feature extraction and false positive (FP) reduction. We extracted 9 geometric features and 6 gray-level features, to quantify the differences between NCPs and FPs. The gray-level features included 4 features to measure local statistical characteristics and 2 asymmetry features to measure the asymmetric spatial location of gray-level density along the vessel centerline. The geometric features included a radius differential feature and 8 features extracted from two transformed volumes: the volumetric shape indexing and the gradient direction mapping volumes. With a machine learning algorithm and feature selection method, useful features were selected and combined into an NCP likelihood measure to differentiate TPs from FPs. With the NCP likelihood measure as a decision variable in the receiver operating characteristic (ROC) analysis, the area under the curve achieved a value of 0.85+/-0.01, indicating that the luminal analysis is effective in reducing FPs for NCP detection.

  15. Procedural success of CTO recanalization: Comparison of the J-CTO score determined by coronary CT angiography to invasive angiography.

    PubMed

    Li, Yuehua; Xu, Nan; Zhang, Jiayin; Li, Minghua; Lu, Zhigang; Wei, Meng; Lu, Bin; Zhang, Yang

    2015-01-01

    The J-CTO score is based on invasive angiography, combines several parameters of chronic total coronary occlusions (CTO), and is well established to predict the likelihood of success of percutaneous recanalization. The purpose of this study was to evaluate and validate a J-CTOCT score derived from coronary computed tomography angiography (coronary CTA). Between April 2011 and December 2014, 159 consecutive patients were retrospectively included. All had at least one CTO in invasive angiography, had coronary CTA performed at an interval of no more than one week from invasive angiography, and had an attempt at percutaneous coronary intervention (PCI) following coronary CTA In parallel to the angiographic J-CTO score, the J-CTOCT score was determined by awarding one point each for a blunt vessel stump, bending > 45°, occlusion length ≥ 20 mm, presence of calcium covering > 50% of any vessel cross-section within the occlusion, or a previously failed attempt at PCI. a. Both scores were compared regarding their ability to predict successful recanalization. A total of 171 CTO lesions were analyzed. Intraobserver (k = 0.814, p < 0.001) and interobserver agreement (k = 0.771, p < 0.001) for calculation of the J-CTOCT score were close. The mean occlusion length measured by coronary CTA was significantly shorter than in invasive angiography (27.6 ± 14.8 mm vs. 37.2 ± 18.8 mm, p < 0.001). The J-CTOCT score (mean: 1.9 ± 1.4) correlated closely to the angiographic J-CTO score (mean: 1.8 ± 1.3, r = 0.856, p < 0.001), and in 122/171 lesions (71%), the scores were identical. Both J-CTOCT score (area under curve: 0.882, p < 0.001) and angiographic J-CTO score (area under curve: 0.868, p < 0.001) yielded similarly high predictive value for successful guidewire crossing within 30 min (p = 0.496). While the length of coronary occlusions in coronary CTA is significantly shorter than in invasive angiography, a J-CTOCT score determined by coronary CTA closely correlates to the

  16. Coronary CT angiography in patients with high calcium score: evaluation of plaque characteristics and diagnostic accuracy.

    PubMed

    Park, Mi Jung; Jung, Jung Im; Choi, Yun-Seok; Ann, Soe Hee; Youn, Ho-Joong; Jeon, Gyeong Nyeo; Choi, Ho Cheol

    2011-12-01

    Our aim was to evaluate the plaque characteristics of coronary arteries related to significant stenosis with coronary CT angiography (CCTA) and to discuss the diagnostic accuracy of CCTA in patients with high calcium scores. After institutional review board approval, 110 patients (63 men; mean age: 67.1 ± 7.9 years) with Agatston scores >400 were retrospectively reviewed. Patients underwent Agatston calcium scoring and 64-slice CCTA, in addition to invasive coronary angiography (CAG). The composition (calcified, mixed, and non-calcified) and configuration (concentric, eccentric) of coronary artery plaques were analyzed on a per-segment basis by CCTA. We analyzed the differences in plaque composition and configuration between significant (≥ 50%) and non-significant (<50%) stenosis. Additionally, the diagnostic accuracy of stenosis according to plaque composition was evaluated by CCTA, using CAG as a reference method. Significant differences in plaque composition and configurations were observed between the two groups. In cases of significant stenosis, the proportions of concentric, mixed, and non-calcified plaques were significantly higher than those of eccentric and calcified plaques (P < 0.001). The sensitivity and positive predictive value of mixed (97.4, 87.6%) and non-calcified plaques (97.8, 95.7%) were significantly higher than those of calcified plaques (87.6, 67.2%). Although CCTA has limited value due to low diagnostic accuracy of calcified plaques, knowledge about the high frequencies of mixed and non-calcified plaques in significant stenosis help to make an accurate assessment of CAD with CCTA in patients with high calcium scores.

  17. CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

    PubMed

    Pallesen, Lars P; Khomenko, Andrei; Dzialowski, Imanuel; Barlinn, Jessica; Barlinn, Kristian; Zerna, Charlotte; van der Hoeven, Erik Jrj; Algra, Ale; Kapelle, L Jaap; Michel, Patrik; Bodechtel, Ulf; Demchuk, Andrew M; Schonewille, Wouter; Puetz, Volker

    2017-02-01

    Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. <8) and Pons-Midbrain Index (<3 vs. ≥3) with mortality and favourable outcome (modified Rankin Scale score 0-3) at one month. Results Of 619 patients in the Basilar Artery International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

  18. Multislice CT Angiography in Renal Artery Stent Evaluation: Prospective Comparison with Intra-Arterial Digital Subtraction Angiography

    SciTech Connect

    Raza, Syed A.; Chughtai, Aamer R.; Wahba, Mona; Cowling, Mark G.; Taube, David; Wright, Andrew R.

    2004-01-15

    Purpose: To assess the role of multislice computed tomography angiography (MCTA) in the evaluation of renal artery stents, using intra-arterial digital subtraction angiography (DSA) as the gold standard. Methods: Twenty consecutive patients (15 men, 5 women) with 23 renal artery stents prospectively underwent both MCTA and DSA. Axial images, multiplanar reconstructions and maximum intensity projection images were used for diagnosis. The MCTA and DSA images were each interpreted without reference to the result of the other investigation. Results:The three cases of restenosis on DSA were detected correctly by MCTA; in 19 cases where MCTA showed a fully patent stent, the DSA was also negative. Sensitivity and negative predictive value (NPV) of MCTA were therefore 100%. In four cases, MCTA showed apparently minimal disease which was not shown on DSA. These cases are taken as false positive giving a specificity of 80% and a positive predictive value of 43%. Conclusion: The high sensitivity and NPV suggest MCTA may be useful as a noninvasive screen for renal artery stentrestenosis. MCTA detected mild disease in a few patients which was not confirmed on angiography.

  19. Contrast media volume optimization in high-pitch dual-source CT coronary angiography: feasibility study.

    PubMed

    Yang, Wen Jie; Chen, Ke Min; Liu, Bo; Pang, Li Fang; Zhang, Huan; Pan, Zi Lai; Yan, Fu Hua

    2013-01-01

    To investigate the feasibility of contrast media (CM) volume reduction in dual-source coronary computed tomography angiography high-pitch mode without affecting coronary artery enhancement. Eighty patients were involved in a preliminary experiment with a default injection protocol (60 ml of CM). The age, BMI, test bolus (TB) enhancement peak and the CT values of coronary artery for each patient were recorded and the key factors for determining coronary artery enhancement were investigated. Based on the results of the preliminary experiment, 120 patients were involved in the main experiment with a new injection protocol. For each patient, the CT values and noise of left coronary sinus (LCS), and the distal segment of right coronary artery were measured. In the preliminary experiment, the peak enhancement of TB correlated most strongly with the HU values of coronary artery. Consequently, the new injection protocol was devised to catalog patients into four groups (30, 40, 50 and 60 ml) of CM based on their TB peak enhancement. In the main experiment, the 30 ml CM injection group whose peak attenuation of TB were the highest (30 vs. 40,50,60 ml: 323.0 ± 27.5 vs. 264.2 ± 11.9, 242.1 ± 8.8, 206.2 ± 18.2 HU, p < 0.05), obtained the highest attenuation of LCS (30 vs. 40,50,60 ml: 365.0 ± 41.2 vs. 341.8 ± 40.0, 326.9 ± 34.7, 312.5 ± 38.2 HU p < 0.05). Contrast optimization is feasible in high-pitch DSCT coronary angiography. Certain patients may receive 30 ml of CM without affecting vessel enhancement.

  20. Prognostic Value of Combined CT Angiography and Myocardial Perfusion Imaging versus Invasive Coronary Angiography and Nuclear Stress Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events: The CORE320 Multicenter Study.

    PubMed

    Chen, Marcus Y; Rochitte, Carlos E; Arbab-Zadeh, Armin; Dewey, Marc; George, Richard T; Miller, Julie M; Niinuma, Hiroyuki; Yoshioka, Kunihiro; Kitagawa, Kakuya; Sakuma, Hajime; Laham, Roger; Vavere, Andrea L; Cerci, Rodrigo J; Mehra, Vishal C; Nomura, Cesar; Kofoed, Klaus F; Jinzaki, Masahiro; Kuribayashi, Sachio; Scholte, Arthur J; Laule, Michael; Tan, Swee Yaw; Hoe, John; Paul, Narinder; Rybicki, Frank J; Brinker, Jeffrey A; Arai, Andrew E; Matheson, Matthew B; Cox, Christopher; Clouse, Melvin E; Di Carli, Marcelo F; Lima, João A C

    2017-07-01

    Purpose To compare the prognostic importance (time to major adverse cardiovascular event [MACE]) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not

  1. Is CT angiography of the pulmonary arteries indicated in patients with high clinical probability of pulmonary embolism?

    PubMed

    Martínez Montesinos, L; Plasencia Martínez, J M; García Santos, J M

    2017-06-30

    When a diagnostic test confirms clinical suspicion, the indicated treatment can be administered. A problem arises when the diagnostic test does not confirm the initially suspected diagnosis; when the suspicion is grounded in clinically validated predictive rules and is high, the problem is even worse. This situation arises in up to 40% of patients with high suspicion for acute pulmonary embolism, raising the question of whether CT angiography of the pulmonary arteries should be done systematically. This paper reviews the literature about this issue and lays out the best evidence about the relevant recommendations for patients with high clinical suspicion of acute pulmonary embolism and negative findings on CT angiography. It also explains the probabilistic concepts derived from Bayes' theorem that can be useful for ascertaining the most appropriate approach in these patients. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Triple-rule-out CT angiography for evaluation of acute chest pain and possible acute coronary syndrome.

    PubMed

    Halpern, Ethan J

    2009-08-01

    Triple-rule-out (TRO) computed tomographic (CT) angiography can provide a cost-effective evaluation of the coronary arteries, aorta, pulmonary arteries, and adjacent intrathoracic structures for the patient with acute chest pain. TRO CT is most appropriate for the patient who is judged to be at low to intermediate risk for acute coronary syndrome (ACS) and whose symptoms may also be attributed to acute pathologic conditions of the aorta or pulmonary arteries. Although a regular cardiac rhythm remains an important factor in coronary CT image quality, newer CT scanners with 64 or more detector rows afford rapid electrocardiographically (ECG) gated imaging to provide high-quality TRO CT studies in patients with a heart rate of up to 80 beats per minute. Injection of iodinated contrast material (< or = 100 mL) is tailored to provide simultaneous high levels of arterial enhancement in the coronary arteries and aorta (> 300 HU) and in the pulmonary arteries (> 200 HU). To limit radiation exposure, the TRO CT examination does not include the entire chest but is constrained to incorporate the aortic arch down through the heart. Scanning parameters, including prospective ECG tube current modulation and prospective ECG gating with the "step-and-shoot" technique, are tailored to reduce radiation exposure (optimally, 5-9 mSv). When performed with appropriate attention to timing and technique, TRO CT provides coronary image quality equal to that of dedicated coronary CT angiography and pulmonary arterial images that are free of motion artifact related to cardiac pulsation. In an appropriately selected emergency department patient population, TRO CT can safely eliminate the need for further diagnostic testing in over 75% of patients.

  3. Cirsoid Aneurysm of Coronary Arteries Associated with Arterioventricular Fistula Evaluated by 64-Multidetector CT Coronary Angiography: Depiction of a Case

    SciTech Connect

    Marrone, Gianluca Mamone, Giuseppe; Milazzo, Mariapina; Caruso, Settimo; Baravoglia, Cesar Hernandez; Vitulo, Patrizio; Gridelli, Bruno; Luca, Angelo

    2009-05-15

    A female patient with severe pulmonary hypertension was admitted for lung transplant evaluation. As an incidental finding, the chest CT showed diffuse and dilated coronaries, not detected at previous echocardiography. A coronary CT angiography was then performed using a 64-multidetector computed tomography (MDCT) scanner to better evaluate the coronary tree. The images obtained after postprocessing demonstrated tremendously aneurysmatic and tortuous coronary arteries and the presence of a septal branch deepening into the myocardium and penetrating the right ventricle cavity, forming an abnormal arterioventricular fistula. A causal relation between the aneurysms and the fistula is suspected.

  4. Clinical outcomes after investigation for pulmonary embolism using CT angiography and venography.

    PubMed

    Darze, Eduardo S; Braghiroli, João F M; Almeida, Ricardo V; Araújo, Enio P; Toscano, Sergio M; Araújo-Neto, César Augusto

    2012-08-01

    The diagnosis of pulmonary embolism (PE) still requires long work-up periods and multiple tests. We aim to assess clinical outcomes after a negative investigation using a combined protocol of CT pulmonary angiography and CT venography (CTA/CTV) as a sole diagnostic test in unselected patients with suspected PE. This retrospective cohort study enrolled consecutive patients with suspected PE who were investigated with a combined CTA/CTV protocol. Patients who had an initially negative investigation and were not anticoagulated were followed for 6 months for the occurrence of recurrent venous thromboembolic events. Out of 425 patients with suspected PE, 62 (14.6%) had venous thromboembolism diagnosed on the initial CTA/CTV. The mean age was 56 ± 19 years and 61% of the population fell into the low clinical probability category. Isolated deep vein thrombosis represented 21% of all venous thromboembolic events, and when considering the whole population, CTV was associated with an increment in diagnostic yield of 3.1%. Our cohort was composed of 320 patients with initially negative CTA/CTVs and who were not anticoagulated. After 6 months of follow up, only three patients presented with recurrent thromboembolic events (0.9%; 95% CI -0.1% - 2.0%) and none was fatal. There were no PE-related deaths. Our study suggests that a diagnostic strategy that utilizes CTA/CTV as a sole diagnostic test can safely rule out PE in a low to moderate risk population and is associated with favorable outcomes with a negative predictive value of 99.1%.

  5. Electrocardiogram-gated coronary CT angiography dose estimates using ImPACT.

    PubMed

    Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Koshida, Kichiro; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Toyama, Hiroshi; Kato, Ryoichi

    2016-07-01

    The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), prospective CTA, continuous CTA/cardiac function analysis (CFA), and CTA/CFA modulation. Accordingly, we clarified the CT dose index (CTDI) to determine the relationship between heart rate (HR) and X-ray exposure. As a secondary objective, we compared radiation doses using modified ImPACT, a whole-body dosimetry phantom study, and the k-factor method to verify the validity of the dose results obtained with modified ImPACT. The effective dose determined for the reference person (4.66 mSv at 60 beats per minute (bpm) and 33.43 mSv at 90 bpm) were approximately 10% less than those determined for the phantom study (5.28 mSv and 36.68 mSv). The effective doses according to the k-factor (0.014 mSv·mGy-1·cm-1; 2.57 mSv and 17.10 mSv) were significantly lower than those obtained with the other two methods. In the present study, we have shown that ImPACT, when modified for cardiac applications, can assess both absorbed and effective doses. The results of our dose comparison indicate that modified ImPACT dose assessment is a promising and practical method for evaluating coronary CTA. PACS number(s): 87.57.Q-, 87.59.Dj, 87.57.uq. © 2016 The Authors.

  6. Electrocardiogram-gated coronary CT angiography dose estimates using ImPACT.

    PubMed

    Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Koshida, Kichiro; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Toyama, Hiroshi; Kato, Ryouichi

    2016-07-08

    The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), prospective CTA, continuous CTA/cardiac function analysis (CFA), and CTA/CFA modulation. Accordingly, we clarified the CT dose index (CTDI) to determine the relationship between heart rate (HR) and X-ray exposure. As a secondary objective, we compared radiation doses using modified ImPACT, a whole-body dosimetry phantom study, and the k-factor method to verify the validity of the dose results obtained with modified ImPACT. The effective dose determined for the reference person (4.66 mSv at 60 beats per minute (bpm) and 33.43 mSv at 90bpm) were approximately 10% less than those determined for the phantom study (5.28 mSv and 36.68 mSv). The effective doses according to the k-factor (0.014 mSv•mGy-1•cm-1; 2.57 mSv and 17.10 mSv) were significantly lower than those obtained with the other two methods. In the present study, we have shown that ImPACT, when modified for cardiac applications, can assess both absorbed and effective doses. The results of our dose comparison indicate that modified ImPACT dose assessment is a promising and practical method for evaluating coronary CTA.

  7. Development and Validation of Intracranial Thrombus Segmentation on CT Angiography in Patients with Acute Ischemic Stroke

    PubMed Central

    Santos, Emilie M. M.; Marquering, Henk A.; Berkhemer, Olvert A.; van Zwam, Wim H.; van der Lugt, Aad; Majoie, Charles B.; Niessen, Wiro J.

    2014-01-01

    Background and Purpose Thrombus characterization is increasingly considered important in predicting treatment success for patients with acute ischemic stroke. The lack of intensity contrast between thrombus and surrounding tissue in CT images makes manual delineation a difficult and time consuming task. Our aim was to develop an automated method for thrombus measurement on CT angiography and validate it against manual delineation. Materials and Methods Automated thrombus segmentation was achieved using image intensity and a vascular shape prior derived from the segmentation of the contralateral artery. In 53 patients with acute ischemic stroke due to proximal intracranial arterial occlusion, automated length and volume measurements were performed. Accuracy was assessed by comparison with inter-observer variation of manual delineations using intraclass correlation coefficients and Bland–Altman analyses. Results The automated method successfully segmented the thrombus for all 53 patients. The intraclass correlation of automated and manual length and volume measurements were 0.89 and 0.84. Bland-Altman analyses yielded a bias (limits of agreement) of −0.4 (−8.8, 7.7) mm and 8 (−126, 141) mm3 for length and volume, respectively. This was comparable to the best interobserver agreement, with an intraclass correlation coefficients of 0.90 and 0.85 and a bias (limits of agreement) of −0.1 (−11.2, 10.9) mm and −17 (−216, 185) mm3. Conclusions The method facilitates automated thrombus segmentation for accurate length and volume measurements, is relatively fast and requires minimal user input, while being insensitive to high hematocrit levels and vascular calcifications. Furthermore, it has the potential to assess thrombus characteristics of low-density thrombi. PMID:25032691

  8. Assessment of intracranial collaterals on CT angiography in anterior circulation acute ischemic stroke.

    PubMed

    Yeo, L L L; Paliwal, P; Teoh, H L; Seet, R C; Chan, B P; Ting, E; Venketasubramanian, N; Leow, W K; Wakerley, B; Kusama, Y; Rathakrishnan, R; Sharma, V K

    2015-02-01

    Intracranial collaterals influence the prognosis of patients treated with intravenous tissue plasminogen activator in acute anterior circulation ischemic stroke. We compared the methods of scoring collaterals on pre-tPA brain CT angiography for predicting functional outcomes in acute anterior circulation ischemic stroke. Two hundred consecutive patients with acute anterior circulation ischemic stroke treated with IV-tPA during 2010-2012 were included. Two independent neuroradiologists evaluated intracranial collaterals by using the Miteff system, Maas system, the modified Tan scale, and the Alberta Stroke Program Early CT Score 20-point methodology. Good and extremely poor outcomes at 3 months were defined by modified Rankin Scale scores of 0-1 and 5-6 points, respectively. Factors associated with good outcome on univariable analysis were younger age, female sex, hypertension, diabetes mellitus, atrial fibrillation, small infarct core (ASPECTS ≥8), vessel recanalization, lower pre-tPA NIHSS scores, and good collaterals according to Tan methodology, ASPECTS methodology, and Miteff methodology. On multivariable logistic regression, only lower NIHSS scores (OR, 1.186 per point; 95% CI, 1.079-1.302; P = .001), recanalization (OR, 5.599; 95% CI, 1.560-20.010; P = .008), and good collaterals by the Miteff method (OR, 3.341; 95% CI, 1.203-5.099; P = .014) were independent predictors of good outcome. Poor collaterals by the Miteff system (OR, 2.592; 95% CI, 1.113-6.038; P = .027), Maas system (OR, 2.580; 95% CI, 1.075-6.187; P = .034), and ASPECTS method ≤5 points (OR, 2.685; 95% CI, 1.156-6.237; P = .022) were independent predictors of extremely poor outcomes. Only the Miteff scoring system for intracranial collaterals is reliable for predicting favorable outcome in thrombolyzed acute anterior circulation ischemic stroke. However, poor outcomes can be predicted by most of the existing methods of scoring intracranial collaterals. © 2015 by American Journal of

  9. Spontaneous obliteration of MRI-silent cerebral angiomatosis revealed by CT angiography in a patient with Sturge-Weber syndrome.

    PubMed

    Aguglia, Umberto; Latella, Maria Adele; Cafarelli, Franco; Le Piane, Emilio; Gangemi, Antonio; Labate, Angelo; Gambardella, Antonio; Quattrone, Aldo

    2008-01-15

    Type I Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome characterized by facial port wine stain and ipsilateral leptomeningeal angiomatosis. It is commonly complicated by glaucoma and neurological disturbances including seizures, hemiparesis, transient stroke-like deficits, and behavioral problems. Gadolinium-enhanced MRI is the study of choice for demonstrating the leptomeningeal angiomatosis, and is particularly useful for making the diagnosis. Cerebral hematoma and spontaneous obliteration of cerebral angiomatosis have never been reported in SWS. We describe a patient with type I SWS in which a hemorrhage in the left temporal lobe was caused by an underlying angiomatosis. No arteriovenous malformations were detected by brain CT or gadolinium-enhanced MRI, whereas a small angiomatous nidus draining into an ectasic venous collector near the hematoma was disclosed by brain CT angiography. Carotid angiography, performed 3 years after the hemorrhage, demonstrated the spontaneous obliteration of the angioma. This description expands the phenotypic spectrum of type I SWS in which the occurrence of cerebral hemorrhage and MRI-silent cerebral angiomatosis should be included, and emphasizes the need of performing a brain CT angiography in SWS patients whose routine neuroimaging studies fail to detect potentially harmful vessel malformation.

  10. Value of CT angiography in anterior circulation large vessel occlusive stroke: Imaging findings, pearls, and pitfalls.

    PubMed

    Power, Sarah; McEvoy, Sinead H; Cunningham, Jane; Ti, Joanna P; Looby, Seamus; O'Hare, Alan; Williams, David; Brennan, Paul; Thornton, John

    2015-07-01

    Hyperacute stroke imaging is playing an increasingly important role in determining management decisions in acute stroke patients, particularly patients with large vessel occlusive stroke who may benefit from endovascular intervention. CT angiography (CTA) is an important tool in the work-up of the acute stroke patient. It reliably detects large occlusive thrombi in proximal cerebral arteries and is a quick and highly accurate method in identifying candidates for endovascular stroke treatment. In this article we review the imaging findings on CTA in acute large vessel occlusive stroke using a pictorial case based approach. We retrospectively reviewed CTA studies in 48 patients presenting with acute anterior circulation large vessel occlusive stroke who were brought for intra-arterial acute stroke intervention. We discuss and illustrate patterns of proximal intracranial arterial occlusion, collateralization to the occluded territory, as well as reviewing some important pearls, pitfalls and teaching points in CTA assessment of the acute stroke patient. Performed from the level of the aortic arch CTA also gives valuable information regarding the state of other vessels in the acute stroke patient, identifying additional significant vascular stenoses or occlusions, and as we illustrate, can demonstrate other clinically significant findings which may impact on patient management and outcome. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Dose reduction with iterative reconstruction for coronary CT angiography: a systematic review and meta-analysis

    PubMed Central

    Willemink, Martin J; De Ruiter, Quirina M B; De Jong, Pim A; Schilham, Arnold M R; Krestin, Gabriel P; Leiner, Tim; Budde, Ricardo P J

    2016-01-01

    Objective: To investigate the achievable radiation dose reduction for coronary CT angiography (CCTA) with iterative reconstruction (IR) in adults and the effects on image quality. Methods: PubMed and EMBASE were searched, and original articles concerning IR for CCTA in adults using prospective electrocardiogram triggering were included. Primary outcome was the effective dose using filtered back projection (FBP) and IR. Secondary outcome was the effect of IR on objective and subjective image quality. Results: The search yielded 1616 unique articles, of which 10 studies (1042 patients) were included. The pooled routine effective dose with FBP was 4.2 mSv [95% confidence interval (CI) 3.5–5.0]. A dose reduction of 48% to a pooled effective dose of 2.2 mSv (95% CI 1.3–3.1) using IR was reported. Noise, contrast-to-noise ratio and subjective image quality were equal or improved in all but one study, whereas signal-to-noise ratio was decreased in two studies with IR at reduced dose. Conclusion: IR allows for CCTA acquisition with an effective dose of 2.2 mSv with preserved objective and subjective image quality. PMID:26562096

  12. Contraindications and side effects of commonly used medications in coronary CT angiography.

    PubMed

    Khan, Mansoor; Cummings, Kristopher W; Gutierrez, Fernando R; Bhalla, Sanjeev; Woodard, Pamela K; Saeed, Ibrahim M

    2011-03-01

    For certain clinical applications, coronary CT angiography (CCTA) has become a useful tool for the noninvasive evaluation of coronary artery atherosclerosis. To optimize image quality in CCTA, medications are often given prior to scanning to slow the heart rate or distend the arteries. These medications have side effects and are contraindicated in certain patient populations. Metoprolol is the ß-blocker of choice in CCTA, and it has been shown to be effective in achieving the goal heart rate of less than 65 beats per minute for CCTA and in minimizing variability of heart rate. It is contraindicated in patients with hypotension or high degree AV block, and it must be used with caution in patients with asthma or obstructive pulmonary disease, patients with decompensated heart failure, and those with vasospastic or vasoocclusive disease. Diltiazem, the calcium channel blocker of choice in CCTA, is a reasonable alternative for heart control, particularly in patients with asthma or bronchospastic disease, and patients with orthotopic heart transplants that have been sympathetically denervated. Sublingual nitroglycerin is especially useful in order to dilate distal arteries to improve stenosis visibility. However, it is contraindicated in patients on erectile dysfunction medications and those with severe anemia. It must be used cautiously in patients with aortic stenosis or other preload-dependant cardiac pathologies.

  13. Improving visualization of intracranial arteries at the skull base for CT angiography with calcified plaques

    NASA Astrophysics Data System (ADS)

    Huang, Adam; Lee, Chung-Wei; Yang, Chung-Yi; Liu, Hon-Man

    2010-03-01

    Bony structures at the skull base were the main obstacle to detection and estimation of arterial stenoses and aneurysms for CT angiography in the brain. Direct subtraction and the matched mask bone elimination (MMBE) have become two standard methods for removing bony structures. However, clinicians regularly find that calcified plaques at or near the carotid canal cannot be removed satisfactorily by existing methods. The blood-plaque boundary tends to be blurred by subtraction operation while plaque size is constantly overestimated by the bone mask dilation operation in the MMBE approach. In this study, we propose using the level of enhancement to adjust the MMBE bone mask more intelligently on the artery- and tissue-bone/plaque boundaries. The original MMBE method is only applied to the tissue-bone boundary voxels; while the artery-bone/blood-plaque boundary voxels, identified by a higher enhancement level, are processed by direct subtraction instead. A dataset of 6 patients (3 scanned with a regular dose and 3 scanned with a reduced dose) with calcified plaques at or near the skull base is used to examine our new method. Preliminary results indicate that the visualization of intracranial arteries with calcified plaques at the skull base can be improved effectively and efficiently.

  14. Automatic detection of plaques with severe stenosis in coronary vessels of CT angiography

    NASA Astrophysics Data System (ADS)

    Dinesh, M. S.; Devarakota, Pandu; Kumar, Jitendra

    2010-03-01

    Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of coronary arteries and is the leading cause of death worldwide. Computed tomography angiography (CTA) has been proved to be very useful for accurate noninvasive diagnosis and quantification of plaques. However, the existing methods to measure the stenosis in the plaques are not accurate enough in mid and distal segments where the vessels become narrower. To alleviate this, we propose a method that consists of three stages namely, automatic extraction of coronary vessels; vessels straightening; lumen extraction and stenosis evaluation. In the first stage, the coronary vessels are segmented using a parametric approach based on circular vessel model at each point on the centerline. It is assumed that centerline information is available in advance. Vessel straightening in the second stage performs multi-planar reformat (MPR) to straighten the curved vessels. MPR view of a vessel helps to visualize and measure the plaques better. On the straightened vessel, lumen and vessel wall are segregated using a nearest neighbor classification. To detect the plaques with severe stenosis in the vessel lumen, we propose a "Diameter Luminal Stenosis" method for analyzing the smaller segments of the vessel. Proposed measurement technique identifies the segments that have plaques and reports the top three severely stenosed segments. Proposed algorithm is applied on 24 coronary vessels belonging to multiple cases acquired from Sensation 64 - slice CT and initial results are promising.

  15. Feasibility of low contrast media volume in CT angiography of the aorta.

    PubMed

    Seehofnerová, Anna; Kok, Madeleine; Mihl, Casper; Douwes, Dave; Sailer, Anni; Nijssen, Estelle; de Haan, Michiel J W; Wildberger, Joachim E; Das, Marco

    2015-01-01

    Using smaller volumes of contrast media (CM) in CT angiography (CTA) is desirable in terms of cost reduction and prevention of contrast-induced nephropathy (CIN). The purpose was to evaluate the feasibility of low CM volume in CTA of the aorta. 77 patients referred for CTA of the aorta were scanned using a standard MDCT protocol at 100 kV. A bolus of 50 ml CM (Iopromide 300 mg Iodine/ml) at a flow rate of 6 ml/s was applied (Iodine delivery rate IDR = 1.8 g/s; Iodine load 15 g) followed by a saline bolus of 40 ml at the same flow rate. Scan delay was determined by the test bolus method. Subjective image quality was assessed and contrast enhancement was measured at 10 anatomical levels of the aorta. Diagnostic quality images were obtained for all patients, reaching a mean overall contrast enhancement of 324 ± 28 HU. Mean attenuation was 350 ± 60 HU at the thoracic aorta and 315 ± 83 HU at the abdominal aorta. A straightforward low volume CM protocol proved to be technically feasible and led to CTA examinations reaching diagnostic image quality of the aorta at 100 kV. Based on these findings, the use of a relatively small CM bolus can be incorporated into routine clinical imaging.

  16. Utilization of CT Pulmonary Angiography in Suspected Pulmonary Embolism in a Major Urban Emergency Department

    PubMed Central

    Shujaat, Adil; Shapiro, Janet M.

    2013-01-01

    Objectives. We conducted a study to answer 3 questions: (1) is CT pulmonary angiography (CTPA) overutilized in suspected pulmonary embolism (PE)? (2) What alternative diagnoses are provided by CTPA? (3) Can CTPA be used to evaluate right ventricular dilatation (RVD)? Methods. We retrospectively reviewed the clinical information of 231 consecutive emergency department patients who underwent CTPA for suspected PE over a one-year period. Results. The mean age of our patients was 53 years, and 58.4% were women. The prevalence of PE was 20.7%. Among the 136 patients with low clinical probability of PE, a d-dimer test was done in 54.4%, and it was normal in 24.3%; none of these patients had PE. The most common alternative findings on CTPA were emphysema (7.6%), pneumonia (7%), atelectasis (5.5%), bronchiectasis (3.8%), and congestive heart failure (3.3%). The sensitivity and negative predictive value of CTPA for (RVD) was 92% and 80%, respectively. Conclusions. PE could have been excluded without CTPA in ~1 out of 4 patients with low clinical probability of PE, if a formal assessment of probability and d-dimer test had been done. In patients without PE, CTPA did not provide an alternative diagnosis in 65%. In patients with PE, CTPA showed the potential to evaluate RVD. PMID:24078873

  17. Evaluation of intracranial aneurysms with CT angiography: current status and future direction

    NASA Astrophysics Data System (ADS)

    Sato, Yutaka; Sickels, William; Quets, Jerome; Crosby, Daniel; Chang, Shereen; Cook-Granroth, Janice; Hoffman, Eric A.

    1997-05-01

    Purpose: To develop a valid, reliable and accurate system of measurement of intracranial aneurysm geometry using volumetric data obtained by CT angiography. Materials and methods: A simple model of lateral saccular aneurysm was created. Three models were prepared with different size of aneurysm sac and neck. Volumetric data was acquired using a Toshiba Xpress SX helical scanner. Geometry of an aneurysm model obtained by workstation linked to the scanner applying volume rendering display and dedicated UNIX based computer applying MPR based method. These results were compared with actual caliper measurements of the model. A clinical case of lateral aneurysm arising from the supraclinoid internal carotid artery was also studied. Results: Both the volume rendered image based method and MPR based method provided accurate geometric information of an aneurysm sac and its neck. Conclusions: Volume rendering technique requires editing by a well-informed operator and subjective, while the MPR based method is more objective and better suited for quantitative analysis. Using these mutually complimentary tools, critical geometric information of an aneurysm can be extracted from volumetric data provided by CTA.

  18. Aortic valve stenosis: non-invasive preoperative evaluation using 64-slice CT angiography.

    PubMed

    Ciolina, F; Sedati, P; Zaccagna, F; Galea, N; Noce, V; Miraldi, F; Cavarretta, E; Francone, M; Carbone, I

    2015-10-01

    In patients affected by aortic valve stenosis (AS) it is mandatory to rule out coronary artery disease (CAD). The role of retrospectively ECG-gated 64-slice CT angiography (64-SCTA) was assessed in patients with AS referred for surgical valve replacement. Forty-two patients with AS underwent ECG-gated 64-SCTA of thoracic aorta, including the heart and coronary arteries, before surgical valve replacement. Images were evaluated by two independent readers and compared with surgical findings in terms of aortic valve calcification grading, valvular morphology, aortic valve annulus and sino-tubular junction diameters, and valvular area planimetry. Quantitative evaluation of cusps opening was also performed. Finally, the presence of CAD, thoracic aortic aneurysm and left ventricle hypertrophy were assessed. Visualization of the aortic valve without motion artefacts was possible in 38 patients (90.5%). Valvular morphology was correctly assessed in all cases (100%). 64-SCTA correctly determined aortic valve calcification grading and the aortic valve annulus and sinotubular junction diameters in 100% of cases. The aortic valve planimetric area was assessed in 38 cases (90.5%). Ascending aortic aneurysms requiring surgical replacement were detected in 12 patients (28.6%). Significant left ventricle hypertrophy was found in 30 patients (71%). Preoperative evaluation of patients undergoing surgical replacement for AS with 64-SCTA is feasible. 64-SCTA can rule out CAD and evaluate the status of the aortic valve and thoracic aorta in the same examination, obtaining relevant information for surgical planning.

  19. A fast 3D region growing approach for CT angiography applications

    NASA Astrophysics Data System (ADS)

    Ye, Zhen; Lin, Zhongmin; Lu, Cheng-chang

    2004-05-01

    Region growing is one of the most popular methods for low-level image segmentation. Many researches on region growing have focused on the definition of the homogeneity criterion or growing and merging criterion. However, one disadvantage of conventional region growing is redundancy. It requires a large memory usage, and the computation-efficiency is very low especially for 3D images. To overcome this problem, a non-recursive single-pass 3D region growing algorithm named SymRG is implemented and successfully applied to 3D CT angiography (CTA) applications for vessel segmentation and bone removal. The method consists of three steps: segmenting one-dimensional regions of each row; doing region merging to adjacent rows to obtain the region segmentation of each slice; and doing region merging to adjacent slices to obtain the final region segmentation of 3D images. To improve the segmentation speed for very large volume 3D CTA images, this algorithm is applied repeatedly to newly updated local cubes. The next new cube can be estimated by checking isolated segmented regions on all 6 faces of the current local cube. This local non-recursive 3D region-growing algorithm is memory-efficient and computation-efficient. Clinical testings of this algorithm on Brain CTA show this technique could effectively remove whole skull, most of the bones on the skull base, and reveal the cerebral vascular structures clearly.

  20. In Vivo Small Animal Imaging using Micro-CT and Digital Subtraction Angiography

    PubMed Central

    Badea, C.T.; Drangova, M.; Holdsworth, D.W.; Johnson, G.A.

    2009-01-01

    Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review in vivo X-ray based small animal imaging, with a focus on in vivo micro-computed tomography (micro-CT) and digital subtraction angiography (DSA). We present the principles, technologies, image quality parameters and types of applications. We show that both methods can be used not only to provide morphological, but also functional information, such as cardiac function estimation or perfusion. Compared to other modalities, x-ray based imaging is usually regarded as being able to provide higher throughput at lower cost and adequate resolution. The limitations are usually associated with the relatively poor contrast mechanisms and potential radiation damage due to ionizing radiation, although the use of contrast agents and careful design of studies can address these limitations. We hope that the information will effectively address how x-ray based imaging can be exploited for successful in vivo preclinical imaging. PMID:18758005

  1. Value of monoenergetic low-kV dual energy CT datasets for improved image quality of CT pulmonary angiography.

    PubMed

    Apfaltrer, Paul; Sudarski, Sonja; Schneider, David; Nance, John W; Haubenreisser, Holger; Fink, Christian; Schoenberg, Stefan O; Henzler, Thomas

    2014-02-01

    High vessel attenuation and high contrast-to-noise ratio (CNR) are prerequisites for high diagnostic confidence in CT pulmonary angiography (CTPA). This study evaluated the impact of calculated monoenergetic dual-energy (DE) CTPA datasets on vessel attenuation and CNR. 50 Patients (24 men, mean age 68 ± 14 years) who underwent DE-CTPA were retrospectively included in this study. The 80 and 140-kV DE polyenergetic image data were used to calculate virtual monoenergetic image datasets in 10 kiloelectron volt (keV) increments from 40 to 120 keV. Vessel and soft tissue attenuation and image noise were measured in various regions of interest and the CNR was subsequently calculated. Differences in vessel attenuation and CNR were compared between the different monoenergetic datasets. The best monoenergetic dataset was then compared to the standard 120-kV polyenergetic dataset. Vessel attenuation and CNR of 70-keV CTPA datasets were superior to all other monoenergetic image datasets (all p<0.05). 70-keV monoenergetic datasets provided a statistically significant 12% increase in mean vessel attenuation compared to standard 120-kV polyenergetic datasets (384 ± 117 HU vs. 342 ± 106 HU, respectively; p<0.0001) and a statistically significant 18% increase in mean CNR (29 ± 13 vs. 24 ± 11 respectively; p<0.0001). Virtual 70-keV monoenergetic CTPA image datasets significantly increase vessel attenuation and CNR of DE-CTPA studies, suggesting that clinical application of low-keV monoenergetic reconstructions may allow a decrease in the amount of iodinated contrast required for adequate image quality in DE-CTPA examinations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    NASA Astrophysics Data System (ADS)

    Gu, Jin; Shi, He-Shui; Han, Ping; Yu, Jie; Ma, Gui-Na; Wu, Sheng

    2016-10-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose.

  3. Rotational micro-CT using a clinical C-arm angiography gantry

    SciTech Connect

    Patel, V.; Hoffmann, K. R.; Ionita, C. N.; Keleshis, C.; Bednarek, D. R.; Rudin, S.

    2008-10-15

    Rotational angiography (RA) gantries are used routinely to acquire sequences of projection images of patients from which 3D renderings of vascular structures are generated using Feldkamp cone-beam reconstruction algorithms. However, these systems have limited resolution (<4 lp/mm). Micro-computed tomography (micro-CT) systems have better resolution (>10 lp/mm) but to date have relied either on rotating object imaging or small bore geometry for small animal imaging, and thus are not used for clinical imaging. The authors report here the development and use of a 3D rotational micro-angiography (RMA) system created by mounting a micro-angiographic fluoroscope (MAF) [35 {mu}m pixel, resolution >10 lp/mm, field of view (FOV)=3.6 cm] on a standard clinical FPD-based RA gantry (Infinix, Model RTP12303J-G9E, Toshiba Medical Systems Corp., Tustin, CA). RA image sequences are obtained using the MAF and reconstructed. To eliminate artifacts due to image truncation, lower-dose (compared to MAF acquisition) full-FOV (FFOV) FPD RA sequences (194 {mu}m pixel, FOV=20 cm) were also obtained to complete the missing data. The RA gantry was calibrated using a helical bead phantom. To ensure high-quality high-resolution reconstruction, the high-resolution images from the MAF were aligned spatially with the lower-dose FPD images, and the pixel values in the FPD image data were scaled to match those of the MAF. Images of a rabbit with a coronary stent placed in an artery in the Circle of Willis were obtained and reconstructed. The MAF images appear well aligned with the FPD images (average correlation coefficient before and after alignment: 0.65 and 0.97, respectively) Greater details without any visible truncation artifacts are seen in 3D RMA (MAF-FPD) images than in those of the FPD alone. The FWHM of line profiles of stent struts (100 {mu}m diameter) are approximately 192{+-}21 and 313{+-}38 {mu}m for the 3D RMA and FPD data, respectively. In addition, for the dual-acquisition 3D RMA

  4. Impact of Multislice CT Angiography on Planning of Radiological Catheter Placement for Hepatic Arterial Infusion Chemotherapy

    SciTech Connect

    Sone, Miyuki Kato, Kenichi; Hirose, Atsuo; Nakasato, Tatsuhiko; Tomabechi, Makiko; Ehara, Shigeru; Hanari, Takao

    2008-01-15

    The objective of this study was to assess prospectively the role of multislice CT angiography (MSCTA) on planning of radiological catheter placement for hepatic arterial infusion chemotherapy (HAIC). Forty-six patients with malignant liver tumors planned for HAIC were included. In each patient, both MSCTA and intra-arterial digital subtraction angiography (DSA) were performed, except one patient who did not undergo DSA. Comparison of MSCTA and DSA images was performed for the remaining 45 patients. Detectability of anatomical variants of the hepatic artery, course of the celiac trunk, visualization scores of arterial branches and interobserver agreement, presence of arterial stenosis, and technical outcome were evaluated. Anatomical variations of the hepatic artery were detected in 19 of 45 patients (42%) on both modalities. The course of the celiac trunk was different in 12 patients. The visualization scores of celiac arterial branches on MSCTA/DSA were 3.0 {+-} 0/2.9 {+-} 0.2 in the celiac trunk, 3.0 {+-} 0/2.9 {+-} 0.3 in the common hepatic artery, 2.9 {+-} 0.2/2.9 {+-} 0.3 in the proper hepatic artery, 2.9 {+-} 0.3/2.9 {+-} 0.4 in the right hepatic artery, 2.8 {+-} 0.4/2.9 {+-} 0.4 in the left hepatic artery, 2.9 {+-} 0.2/2.9 {+-} 0.3 in the gastroduodenal artery, 2.1 {+-} 0.8/2.2 {+-} 0.9 in the right gastric artery, and 2.7 {+-} 0.8/2.6 {+-} 0.8 in the left gastric artery. No statistically significant differences exist between the two modalities. Interobserver agreement for MSCTA was equivalent to that for DSA. Two patients showed stenosis of the celiac trunk on both modalities. Based on these imaging findings, technical success was accomplished in all patients. In conclusion, MSCTA is accurate in assessing arterial anatomy and abnormalities. MSCTA can provide adequate information for planning of radiological catheter placement for HAIC.

  5. Impact of multislice CT angiography on planning of radiological catheter placement for hepatic arterial infusion chemotherapy.

    PubMed

    Sone, Miyuki; Kato, Kenichi; Hirose, Atsuo; Nakasato, Tatsuhiko; Tomabechi, Makiko; Ehara, Shigeru; Hanari, Takao

    2008-01-01

    The objective of this study was to assess prospectively the role of multislice CT angiography (MSCTA) on planning of radiological catheter placement for hepatic arterial infusion chemotherapy (HAIC). Forty-six patients with malignant liver tumors planned for HAIC were included. In each patient, both MSCTA and intra-arterial digital subtraction angiography (DSA) were performed, except one patient who did not undergo DSA. Comparison of MSCTA and DSA images was performed for the remaining 45 patients. Detectability of anatomical variants of the hepatic artery, course of the celiac trunk, visualization scores of arterial branches and interobserver agreement, presence of arterial stenosis, and technical outcome were evaluated. Anatomical variations of the hepatic artery were detected in 19 of 45 patients (42%) on both modalities. The course of the celiac trunk was different in 12 patients. The visualization scores of celiac arterial branches on MSCTA/DSA were 3.0 +/- 0/2.9 +/- 0.2 in the celiac trunk, 3.0 +/- 0/2.9 +/- 0.3 in the common hepatic artery, 2.9 +/- 0.2/2.9 +/- 0.3 in the proper hepatic artery, 2.9 +/- 0.3/2.9 +/- 0.4 in the right hepatic artery, 2.8 +/- 0.4/2.9 +/- 0.4 in the left hepatic artery, 2.9 +/- 0.2/2.9 +/- 0.3 in the gastroduodenal artery, 2.1 +/- 0.8/2.2 +/- 0.9 in the right gastric artery, and 2.7 +/- 0.8/2.6 +/- 0.8 in the left gastric artery. No statistically significant differences exist between the two modalities. Interobserver agreement for MSCTA was equivalent to that for DSA. Two patients showed stenosis of the celiac trunk on both modalities. Based on these imaging findings, technical success was accomplished in all patients. In conclusion, MSCTA is accurate in assessing arterial anatomy and abnormalities. MSCTA can provide adequate information for planning of radiological catheter placement for HAIC.

  6. Minimally invasive autopsy employing post-mortem CT and targeted coronary angiography: evaluation of its application to a routine Coronial service.

    PubMed

    Roberts, Ian S D; Traill, Zoe C

    2014-01-01

    Post-mortem imaging is a potential alternative to traditional medicolegal autopsy. We investigate the reduction in number of invasive autopsies required by use of post-mortem CT ± coronary angiography. A total of 120 adult deaths referred to the Coroner were investigated by CT, with coronary angiography employed only for the second series of 60 cases, in order to determine the added value of angiography. The confidence of imaging cause of death was classified as definite (no autopsy), probable, possible or unascertained. Invasive autopsy was not required in 38% of cases without coronary angiography and 70% of cases with angiography. Full autopsy, including brain dissection, was required in only 9% of cases. There was complete agreement between autopsy and radiological causes of death in the cases with a 'probable' imaging cause of death, indicating that cases for which imaging provides an accurate cause of death without autopsy were identified correctly. In two patients, CT demonstrated unsuspected fractures, not detected at subsequent autopsy. A two-thirds reduction in the number of invasive coronial autopsies can be achieved by use of post-mortem CT plus coronary angiography. At the same time, use of post-mortem CT may improve accuracy of diagnosis, particularly for traumatic deaths. © 2013 John Wiley & Sons Ltd.

  7. Automatic coronary artery calcium scoring in cardiac CT angiography using paired convolutional neural networks.

    PubMed

    Wolterink, Jelmer M; Leiner, Tim; de Vos, Bob D; van Hamersvelt, Robbert W; Viergever, Max A; Išgum, Ivana

    2016-12-01

    The amount of coronary artery calcification (CAC) is a strong and independent predictor of cardiovascular events. CAC is clinically quantified in cardiac calcium scoring CT (CSCT), but it has been shown that cardiac CT angiography (CCTA) may also be used for this purpose. We present a method for automatic CAC quantification in CCTA. This method uses supervised learning to directly identify and quantify CAC without a need for coronary artery extraction commonly used in existing methods. The study included cardiac CT exams of 250 patients for whom both a CCTA and a CSCT scan were available. To restrict the volume-of-interest for analysis, a bounding box around the heart is automatically determined. The bounding box detection algorithm employs a combination of three ConvNets, where each detects the heart in a different orthogonal plane (axial, sagittal, coronal). These ConvNets were trained using 50 cardiac CT exams. In the remaining 200 exams, a reference standard for CAC was defined in CSCT and CCTA. Out of these, 100 CCTA scans were used for training, and the remaining 100 for evaluation of a voxel classification method for CAC identification. The method uses ConvPairs, pairs of convolutional neural networks (ConvNets). The first ConvNet in a pair identifies voxels likely to be CAC, thereby discarding the majority of non-CAC-like voxels such as lung and fatty tissue. The identified CAC-like voxels are further classified by the second ConvNet in the pair, which distinguishes between CAC and CAC-like negatives. Given the different task of each ConvNet, they share their architecture, but not their weights. Input patches are either 2.5D or 3D. The ConvNets are purely convolutional, i.e. no pooling layers are present and fully connected layers are implemented as convolutions, thereby allowing efficient voxel classification. The performance of individual 2.5D and 3D ConvPairs with input sizes of 15 and 25 voxels, as well as the performance of ensembles of these Conv

  8. Declining radiation dose of coronary computed tomography angiography: German cardiac CT registry experience 2009-2014.

    PubMed

    Schmermund, Axel; Marwan, Mohamed; Hausleiter, Jörg; Barth, Sebastian; Bruder, Oliver; Kerber, Sebastian; Korosoglou, Grigorius; Leber, Alexander; Moshage, Werner; Schröder, Stephen; Schneider, Steffen; Senges, Jochen; Achenbach, Stephan

    2017-07-19

    Coronary computed tomography angiography (CTA) is increasingly used as a test to rule out coronary artery disease (CAD) in patients with a low to intermediate pre-test probability of the disease. We used the database of the German CT registry, collected between 2009 and 2014 in a broad patient population, to analyze contemporary radiation dose associated with coronary CTA in clinical practice. The prospective observational registry included a total of 7061 patients ≥18 years, referred to 12 participating centers for a clinically indicated cardiac CT examination. All centers were cardiology units well experienced in CTA and used multi-slice CT scanners with at least 64 rows. Coronary CTA was performed in a subset of 5001 patients, 59.6 ± 11.8 years, body mass index (BMI) 26.9 ± 4.5 kg/m(2), 38% females. Three time periods with approximately equal numbers of patients were created (01/09-03/10, 04/10-03/11, 04/11-07/14). The dose-length product of all examinations and derived effective dose in mSv (conversion factor k = 0.014) as well as the influence of patient characteristics on dose were compared for the three time periods. BMI and proportion of female patients remained stable over time, and mean heart rate decreased from 60.3 ± 9.0 to 58.5 ± 9.3 bpm from the first to the last time period (p < 0.001). Overall, the mean effective dose of coronary CTA was 3.6 mSv (Q1 1.8 mSv, Q3 7.4 mSv). Within the three time periods, it declined from 5.6 (2.7, 8.6) mSv during the first to 4.8 (2.1, 8.2) mSv during the second and 2.5 (1.3, 4.6) mSv during the last time period (p < 0.001). Paralleling the decline in radiation dose over time, the proportion of prospectively ECG-triggered examinations increased (68, 79, 83%; p < 0.001), and the proportion of examinations with retrospective gating and no tube current modulation decreased (5.3, 4.0, 1.6%; p < 0.001). Tube current (mAs) and voltage (kV) both decreased over time. In multivariable analysis

  9. Pediatric body MR angiography.

    PubMed

    Krishnamurthy, Rajesh; Muthupillai, Raja; Chung, Taylor

    2009-02-01

    Vascular pathology in children is commonplace and involves every organ system; however, the powerful, noninvasive, and rapid three-dimensional imaging capability offered by MR angiography is underutilized in children. The success of pediatric MR angiography depends on modifying the MR angiography on the basis of patient size, hemodynamic status, and clinical indications in children, and requires an adequate understanding of pediatric-specific hardware, software, and equipment requirements. This article provides an overview of general pediatric MR angiography techniques, common indications for body MR angiography in children, and the complementary role of MR angiography to other vascular imaging modalities in children, including CT angiography, Doppler ultrasound, and catheter angiography.

  10. Recanalization and clinical outcome of occlusion sites at baseline CT angiography in the Interventional Management of Stroke III trial.

    PubMed

    Demchuk, Andrew M; Goyal, Mayank; Yeatts, Sharon D; Carrozzella, Janice; Foster, Lydia D; Qazi, Emmad; Hill, Michael D; Jovin, Tudor G; Ribo, Marc; Yan, Bernard; Zaidat, Osama O; Frei, Donald; von Kummer, Rüdiger; Cockroft, Kevin M; Khatri, Pooja; Liebeskind, David S; Tomsick, Thomas A; Palesch, Yuko Y; Broderick, Joseph P

    2014-10-01

    To use baseline computed tomographic (CT) angiography to analyze imaging and clinical end points in an Interventional Management of Stroke III cohort to identify patients who would benefit from endovascular stroke therapy. The primary clinical end point was 90-day dichotomized modified Rankin Scale (mRS) score. Secondary end points were 90-day mRS score distribution and 24-hour recanalization. Prespecified subgroup was baseline proximal occlusions (internal carotid, M1, or basilar arteries). Exploratory analyses were subsets with any occlusion and specific sites of occlusion (two-sided α = .01). Of 656 subjects, 306 (47%) underwent baseline CT angiography or magnetic resonance angiography. Of 306, 282 (92%) had arterial occlusions. At baseline CT angiography, proximal occlusions (n = 220) demonstrated no difference in primary outcome (41.3% [62 of 150] endovascular vs 38% [27 of 70] intravenous [IV] tissue-plasminogen activator [tPA]; relative risk, 1.07 [99% confidence interval: 0.67, 1.70]; P = .70); however, 24-hour recanalization rate was higher for endovascular treatment (n = 167; 84.3% [97 of 115] endovascular vs 56% [29 of 52] IV tPA; P < .001). Exploratory subgroup analysis for any occlusion at baseline CT angiography did not demonstrate significant differences between endovascular and IV tPA arms for primary outcome (44.7% [85 of 190] vs 38% [35 of 92], P = .29), although ordinal shift analysis of full mRS distribution demonstrated a trend toward more favorable outcome (P = .011). Carotid T- or L-type occlusion (terminal internal carotid artery [ICA] with M1 middle cerebral artery and/or A1 anterior cerebral artery involvement) or tandem (extracranial or intracranial) ICA and M1 occlusion subgroup also showed a trend favoring endovascular treatment over IV tPA alone for primary outcome (26% [12 of 46] vs 4% [one of 23], P = .047). Significant differences were identified between treatment arms for 24-hour recanalization in proximal occlusions; carotid T

  11. Radiation dose of CT coronary angiography in clinical practice: objective evaluation of strategies for dose optimization.

    PubMed

    Yerramasu, Ajay; Venuraju, Shreenidhi; Atwal, Satvir; Goodman, Dennis; Lipkin, David; Lahiri, Avijit

    2012-07-01

    CT coronary angiography (CTCA) is an evolving modality for the diagnosis of coronary artery disease. Radiation burden associated with CTCA has been a major concern in the wider application of this technique. It is important to reduce the radiation dose without compromising the image quality. To estimate the radiation dose of CTCA in clinical practice and evaluate the effect of dose-saving algorithms on radiation dose and image quality. Effective radiation dose was measured from the dose-length product in 616 consecutive patients (mean age 58 ± 12 years; 70% males) who underwent clinically indicated CTCA at our institution over 1 year. Image quality was assessed subjectively using a 4-point scale and objectively by measuring the signal- and contrast-to-noise ratios in the coronary arteries. Multivariate linear regression analysis was used to identify factors independently associated with radiation dose. Mean effective radiation dose of CTCA was 6.6 ± 3.3 mSv. Radiation dose was significantly reduced by dose saving algorithms such as 100 kV imaging (-47%; 95% CI, -44% to -50%), prospective gating (-35%; 95% CI, -29% to -40%) and ECG controlled tube current modulation (-23%; 95% CI, -9% to -34%). None of the dose saving algorithms were associated with a significant reduction in mean image quality or the frequency of diagnostic scans (P = non-significant for all comparisons). Careful application of radiation-dose saving algorithms in appropriately selected patients can reduce the radiation burden of CTCA significantly, without compromising the image quality. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure

    PubMed Central

    Saw, Jacqueline; Fahmy, Peter; DeJong, Peggy; Lempereur, Mathieu; Spencer, Ryan; Tsang, Michael; Gin, Kenneth; Jue, John; Mayo, John; McLaughlin, Patrick; Nicolaou, Savvas

    2015-01-01

    Aims Left atrial appendage (LAA) device imaging after endovascular closure is important to assess for device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion. Cardiac CT angiography (CCTA) is well suited to assess these non-invasively. Methods and results We report our consecutive series of non-valvular atrial fibrillation patients who underwent CCTA post-LAA closure with Amplatzer Cardiac Plug (ACP), Amulet (second generation ACP), or WATCHMAN devices. Patients underwent CCTA typically 1–6 months post-implantation. Prospective cardiac-gated CCTA was performed with Toshiba 320-detector or Siemens 2nd generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation™. GFR <30 mL/min/1.73 m2 was an exclusion. We assessed for device thrombus, residual LAA leak, device embolization, position, pericardial effusion, optimal implantation, and device lobe dimensions. Forty-five patients underwent CCTA at median 97 days post-LAA closure (18 ACP, 9 Amulet, 18 WATCHMAN). Average age was 75.5 ± 8.9 years, mean CHADS2 score 3.1 ± 1.3, and CHADS-VASc score 4.9 ± 1.6. All had contraindications to oral anticoagulation. Post-procedure, 41 (91.1%) were discharged on DAPT. There was one device embolization (ACP, successfully retrieved percutaneously) and one thrombus (WATCHMAN, resolved with 3 months of warfarin). There were two pericardial effusions, both pre-existing and not requiring intervention. Residual leak (patency) was seen in 28/44 (63.6%), and the mechanisms of leak were readily identified by CCTA (off-axis device, gaps at orifice, or fabric leak). Mean follow-up was 1.2 ± 1.1year, with no death, stroke, or systemic embolism. Conclusion CCTA appears to be a feasible alternative to transoesophageal echocardiography for post-LAA device surveillance to evaluate for device thrombus, residual leak, embolization, position, and pericardial effusion. PMID:25851318

  13. Alternative diagnoses based on CT angiography of the chest in patients with suspected pulmonary thromboembolism

    PubMed Central

    Ferreira, Eleci Vaz; Gazzana, Marcelo Basso; Sarmento, Muriel Bossle; Guazzelli, Pedro Arends; Hoffmeister, Mariana Costa; Guerra, Vinicius André; Seligman, Renato; Knorst, Marli Maria

    2016-01-01

    Objective : To determine the prevalence of alternative diagnoses based on chest CT angiography (CTA) in patients with suspected pulmonary thromboembolism (PTE) who tested negative for PTE, as well as whether those alternative diagnoses had been considered prior to the CTA. Methods : This was a cross-sectional, retrospective study involving 191 adult patients undergoing CTA for suspected PTE between September of 2009 and May of 2012. Chest X-rays and CTAs were reviewed to determine whether the findings suggested an alternative diagnosis in the cases not diagnosed as PTE. Data on symptoms, risk factors, comorbidities, length of hospital stay, and mortality were collected. Results : On the basis of the CTA findings, PTE was diagnosed in 47 cases (24.6%). Among the 144 patients not diagnosed with PTE via CTA, the findings were abnormal in 120 (83.3%). Such findings were consistent with an alternative diagnosis that explained the symptoms in 75 patients (39.3%). Among those 75 cases, there were only 39 (20.4%) in which the same alterations had not been previously detected on chest X-rays. The most common alternative diagnosis, made solely on the basis of the CTA findings, was pneumonia (identified in 20 cases). Symptoms, risk factors, comorbidities, and the in-hospital mortality rate did not differ significantly between the patients with and without PTE. However, the median hospital stay was significantly longer in the patients with PTE than in those without (18.0 and 9.5 days, respectively; p = 0.001). Conclusions : Our results indicate that chest CTA is useful in cases of suspected PTE, because it can confirm the diagnosis and reveal findings consistent with an alternative diagnosis in a significant number of patients. PMID:26982039

  14. Coronary artery plaque formation at coronary CT angiography: morphological analysis and relationship to hemodynamics.

    PubMed

    Enrico, Benedetta; Suranyi, Pal; Thilo, Christian; Bonomo, Lorenzo; Costello, Philip; Schoepf, U Joseph

    2009-04-01

    We aimed to demonstrate that coronary CT angiography (cCTA) can be used to non-invasively study the effect of hemodynamic factors in the pathophysiology of plaque formation. cCTA data of 73 patients were analyzed. All detected plaques were classified according to location (bifurcation, non-branching segment), configuration (eccentric, concentric), orientation (myocardial, lateral, epicardial side of the vessel wall), and composition (calcified, mixed, non-calcified). Bifurcation lesions were further characterized using the Medina classification. Of 382 plaques, 8.1% were in the LM, 46.3% in the LAD, 18.3% in the LCx, and 25.9% in the RCA. Also, 25.1% were completely calcified, 72.3% were mixed, and 2.6% were purely non-calcified. Of the plaques, 51.3% were bifurcation lesions. The most frequent (40%) Medina pattern was 1.1.0 (lesion starts before, extends beyond bifurcation, sparing the side branch). Eighty percent of plaques were eccentric. A significant (p < 0.01) majority (55%) were on the myocardial side, while 17.3% were lateral, and 27.7% epicardial. Of all non-calcified and mixed plaques, 45.1% (p < 0.01) were myocardial, whereas only 14.3% were lateral, 20.6% epicardial, and 19.9% concentric. We conclude that cCTA can non-invasively study the effect of vascular hemodynamics, such as turbulent flow (bifurcations) and low shear stress (myocardial vessel wall), on the distribution and composition of atherosclerotic plaque deposition.

  15. CT angiography spot sign in intracerebral hemorrhage predicts active bleeding during surgery.

    PubMed

    Brouwers, H Bart; Raffeld, Miriam R; van Nieuwenhuizen, Koen M; Falcone, Guido J; Ayres, Alison M; McNamara, Kristen A; Schwab, Kristin; Romero, Javier M; Velthuis, Birgitta K; Viswanathan, Anand; Greenberg, Steven M; Ogilvy, Christopher S; van der Zwan, Albert; Rinkel, Gabriel J E; Goldstein, Joshua N; Klijn, Catharina J M; Rosand, Jonathan

    2014-09-02

    To determine whether the CT angiography (CTA) spot sign marks bleeding complications during and after surgery for spontaneous intracerebral hemorrhage (ICH). In a 2-center study of consecutive spontaneous ICH patients who underwent CTA followed by surgical hematoma evacuation, 2 experienced readers (blinded to clinical and surgical data) reviewed CTAs for spot sign presence. Blinded raters assessed active intraoperative and postoperative bleeding. The association between spot sign and active intraoperative bleeding, postoperative rebleeding, and residual ICH volumes was evaluated using univariable and multivariable logistic regression. A total of 95 patients met inclusion criteria: 44 lobar, 17 deep, 33 cerebellar, and 1 brainstem ICH; ≥1 spot sign was identified in 32 patients (34%). The spot sign was the only independent marker of active bleeding during surgery (odds ratio [OR] 3.4; 95% confidence interval [CI] 1.3-9.0). Spot sign (OR 4.1; 95% CI 1.1-17), female sex (OR 6.9; 95% CI 1.7-37), and antiplatelet use (OR 4.6; 95% CI 1.2-21) were predictive of postoperative rebleeding. Larger residual hematomas and postoperative rebleeding were associated with higher discharge case fatality (OR 3.4; 95% CI 1.1-11) and a trend toward increased case fatality at 3 months (OR 2.9; 95% CI 0.9-8.8). The CTA spot sign is associated with more intraoperative bleeding, more postoperative rebleeding, and larger residual ICH volumes in patients undergoing hematoma evacuation for spontaneous ICH. The spot sign may therefore be useful to select patients for future surgical trials. © 2014 American Academy of Neurology.

  16. Automatic detection of significant and subtle arterial lesions from coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Kang, Dongwoo; Slomka, Piotr; Nakazato, Ryo; Cheng, Victor Y.; Min, James K.; Li, Debiao; Berman, Daniel S.; Kuo, C.-C. Jay; Dey, Damini

    2012-02-01

    Visual analysis of three-dimensional (3D) Coronary Computed Tomography Angiography (CCTA) remains challenging due to large number of image slices and tortuous character of the vessels. We aimed to develop an accurate, automated algorithm for detection of significant and subtle coronary artery lesions compared to expert interpretation. Our knowledge-based automated algorithm consists of centerline extraction which also classifies 3 main coronary arteries and small branches in each main coronary artery, vessel linearization, lumen segmentation with scan-specific lumen attenuation ranges, and lesion location detection. Presence and location of lesions are identified using a multi-pass algorithm which considers expected or "normal" vessel tapering and luminal stenosis from the segmented vessel. Expected luminal diameter is derived from the scan by automated piecewise least squares line fitting over proximal and mid segments (67%) of the coronary artery, considering small branch locations. We applied this algorithm to 21 CCTA patient datasets, acquired with dual-source CT, where 7 datasets had 17 lesions with stenosis greater than or equal to 25%. The reference standard was provided by visual and quantitative identification of lesions with any >=25% stenosis by an experienced expert reader. Our algorithm identified 16 out of the 17 lesions confirmed by the expert. There were 16 additional lesions detected (average 0.13/segment); 6 out of 16 of these were actual lesions with <25% stenosis. On persegment basis, sensitivity was 94%, specificity was 86% and accuracy was 87%. Our algorithm shows promising results in the high sensitivity detection and localization of significant and subtle CCTA arterial lesions.

  17. Removal of bone in CT angiography of the cervical arteries by piecewise matched mask bone elimination

    SciTech Connect

    Straten, Marcel van; Venema, Henk W.; Streekstra, Geert J.; Majoie, Charles B.L.M.; Heeten, Gerard J. den; Grimbergen, Cornelis A.

    2004-10-01

    In maximum intensity projection (MIP) images of CT angiography (CTA) scans, the arteries are often obscured by bone. A bone removal method is presented that uses an additional, nonenhanced scan to create a mask of the bone by thresholding and dilation. After registration of the CTA scan and the additional scan, the bone in the CTA scan is masked. As the cervical area contains bones that can move with respect to each other, these bones are separated first using a watershed algorithm, and then registered individually. A phantom study was performed to evaluate and quantify the tradeoff between the removal of the bone and the preservation of the arteries contiguous to the bone. The influence of algorithm parameters and scan parameters was studied. The method was clinically evaluated with data sets of 35 patients. Best results were obtained with a threshold of 150 HU and a dilation of 8 in-plane voxels and two out-of-plane voxels. The mean width of the soft tissue layer, which is also masked, was approximately 1 mm. The mAs value of the nonenhanced scan could be reduced from 250 mAs to 65 mAs without a loss of quality. In 32 cases the bones were registered correctly and removed completely. In three cases the bone separation was not completely successful, and consequently the bone was not completely removed. The piecewise matched mask bone elimination method proved to be able to obtain MIP images of the cervical arteries free from overprojecting bone in a fully automatic way and with only a slight increase of radiation dose.

  18. Optimizing radiation dose by using advanced modelled iterative reconstruction in high-pitch coronary CT angiography.

    PubMed

    Gordic, Sonja; Desbiolles, Lotus; Sedlmair, Martin; Manka, Robert; Plass, André; Schmidt, Bernhard; Husarik, Daniela B; Maisano, Francesco; Wildermuth, Simon; Alkadhi, Hatem; Leschka, Sebastian

    2016-02-01

    To evaluate the potential of advanced modeled iterative reconstruction (ADMIRE) for optimizing radiation dose of high-pitch coronary CT angiography (CCTA). High-pitch 192-slice dual-source CCTA was performed in 25 patients (group 1) according to standard settings (ref. 100 kVp, ref. 270 mAs/rot). Images were reconstructed with filtered back projection (FBP) and ADMIRE (strength levels 1-5). In another 25 patients (group 2), high-pitch CCTA protocol parameters were adapted according to results from group 1 (ref. 160 mAs/rot), and images were reconstructed with ADMIRE level 4. In ten patients of group 1, vessel sharpness using full width at half maximum (FWHM) analysis was determined. Image quality was assessed by two independent, blinded readers. Interobserver agreements for attenuation and noise were excellent (r = 0.88/0.85, p < 0.01). In group 1, ADMIRE level 4 images were most often selected (84%, 21/25) as preferred data set; at this level noise reduction was 40% compared to FBP. Vessel borders showed increasing sharpness (FWHM) at increasing ADMIRE levels (p < 0.05). Image quality in group 2 was similar to that of group 1 at ADMIRE levels 2-3. Radiation dose in group 2 (0.3 ± 0.1 mSv) was significantly lower than in group 1 (0.5 ± 0.3 mSv; p < 0.05). In a selected population, ADMIRE can be used for optimizing high-pitch CCTA to an effective dose of 0.3 mSv. • Advanced modeled IR (ADMIRE) reduces image noise up to 50% as compared to FBP. • Coronary artery vessel borders show an increasing sharpness at higher ADMIRE levels. • High-pitch CCTA with ADMIRE is possible at a radiation dose of 0.3 mSv.

  19. Lowering heart rate with an optimised breathing protocol for prospectively ECG-triggered CT coronary angiography

    PubMed Central

    Husmann, L; Herzog, B A; Pazhenkottil, A P; Buechel, R R; Nkoulou, R; Ghadri, J R; Valenta, I; Burger, I A; Gaemperli, O; Wyss, C A; Kaufmann, P A

    2011-01-01

    Objectives The aim was to prospectively characterise the effect of the level of breath-hold on heart rate in CT coronary angiography (CTCA) with prospective electrocardiogram (ECG) triggering and its impact on coronary artery attenuation. Methods 260 patients (86 women; mean age 59 ± 11 years) underwent 64-slice CTCA using prospective ECG triggering. Prior to CTCA, heart rates were recorded during 15 s of breath-hold at three different levels of inspiration (normal, intermediate and deep). The inspiration level with the lowest heart rate was chosen for actual CTCA scanning. Coronary artery attenuation was measured, and the presence of backflow of contrast material into the inferior vena cava (as an indicator of increased intrathoracic pressure) was recorded. Results The mean heart rate at breath-hold was significantly different for the three inspiration levels (normal, 60 ± 8 bpm; intermediate, 59 ± 8 bpm; deep, 57 ± 7 bpm; p<0.001). The maximum heart rate reduction in each patient at breath-hold averaged 5.3 ± 5.1 bpm, and was observed at a normal inspiration depth in 23 (9%) patients, at an intermediate inspiration depth in 102 (39%) patients and at deep inspiration in 135 (52%) patients. Overall, there was no association between the level of breath-hold and coronary vessel attenuation (p-value was not significant). However, the backflow of contrast material into the inferior vena cava (n = 26) was found predominantly at deep inspiration levels (p<0.001), and, when it occurred, it was associated with reduced coronary attenuation compared with patients with no backflow (p<0.05). Conclusion The breath-hold level to best reduce heart rate for CTCA should be individually assessed prior to scanning because a mean heart rate reduction of 5 bpm can be achieved. PMID:21849364

  20. CT Angiography Spot Sign, Hematoma Expansion, and Outcome in Primary Pontine Intracerebral Hemorrhage.

    PubMed

    Morotti, Andrea; Jessel, Michael J; Brouwers, H Bart; Falcone, Guido J; Schwab, Kristin; Ayres, Alison M; Vashkevich, Anastasia; Anderson, Christopher D; Viswanathan, Anand; Greenberg, Steven M; Gurol, M Edip; Romero, Javier M; Rosand, Jonathan; Goldstein, Joshua N

    2016-08-01

    The computed tomography angiography (CTA) spot sign is a validated predictor of hematoma expansion and poor outcome in supratentorial intracerebral hemorrhage (ICH), but patients with brainstem ICH have typically been excluded from the analyses. We investigated the frequency of spot sign and its relationship with hematoma expansion and outcome in patients with primary pontine hemorrhage (PPH). We performed a retrospective analysis of PPH cases obtained from a prospectively collected cohort of consecutive ICH patients who underwent CTA. CTA first-pass readings for spot sign presence were analyzed by two trained readers. Baseline and follow-up hematoma volumes on non-contrast CT scans were assessed by semi-automated computer-assisted volumetric analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive and negative likelihood ratio, and accuracy of spot sign for prediction of in-hospital mortality were calculated. 49 subjects met the inclusion criteria of whom 11 (22.4 %) showed a spot sign. In-hospital mortality was higher in spot sign-positive versus spot sign-negative subjects (90.9 vs 47.4 %, p = 0.020). Spot sign showed excellent specificity (95 %) and PPV (91 %) in predicting in-hospital mortality. Absolute hematoma growth, defined as parenchymal and intraventricular hematoma expansion of any amount, was significantly higher in spot sign-positive versus spot sign-negative subjects (13.72 ± 20.93 vs 3.76 ± 8.55 mL, p = 0.045). As with supratentorial ICH, the CTA spot sign is a common finding and is associated with higher risk of hematoma expansion and mortality in PPH. This marker may assist clinicians in prognostic stratification.

  1. Cardiac CT Angiography (CCTA) predicts left atrial appendage occluder device size and procedure outcome.

    PubMed

    Goitein, Orly; Fink, Noam; Hay, Ilan; Di Segni, Elio; Guetta, Victor; Goitein, David; Brodov, Yafim; Konen, Eli; Glikson, Michael

    2017-05-01

    To investigate the role of cardiac CT angiography (CCTA) in predicting optimal left atrial appendage (LAA) occluder size and procedure outcome. Thirty-six patients underwent pre-procedural CCTA. CCTA and TEE LAA orifice diameters and perimeters were compared with the implanted device size. CCTA 3D configuration was correlated with procedure outcome. Watchman™ device (N = 18): diameters were 21 ± 4, 26 ± 5 and 25 ± 3 mm for TEE, CCTA and inserted device, respectively. Average perimeters were 61 ± 10, 74 ± 8 and 78 ± 11 mm for TEE, CCTA and inserted device, respectively. Better agreement with the device size was found for CCTA compared to TEE (Bland-Altman). ACP™ device (N = 15): diameters were 20 ± 5, 25 ± 4 and 23 ± 4 for TEE, CCTA and inserted device, respectively. Average perimeters were 58 ± 11, 72 ± 15 and 72 ± 13 mm for TEE, CCTA and inserted device, respectively. Excellent correlation and agreement with the device size was found for CCTA compared to TEE. CCTA perimeter >100 mm and "cactus" 3D configuration had a specificity of 96 and 81% respectively for procedure failure. CCTA LAA ostial perimeter predicted better the optimal occluder size as compared with the currently used LAA TEE diameter. Moreover, CCTA 3D data may help in predicting potential complications.

  2. Duplex ultrasonography for the detection of vertebral artery stenosis: A comparison with CT angiography.

    PubMed

    Rozeman, Anouk D; Hund, Hajo; Westein, Michel; Wermer, Marieke J H; Lycklama À Nijeholt, Geert J; Boiten, Jelis; Schimsheimer, Robert-Jan; Algra, Ale

    2017-08-01

    Vertebrobasilar stenosis is frequent in patients with posterior circulation stroke and it increases risk of recurrence. We investigated feasibility of duplex ultrasonography (DUS) for screening for extracranial vertebral artery stenosis and compared it with CT angiography (CTA). We gathered data on 337 consecutive patients who had DUS because of posterior circulation stroke or TIA. Matching CTA studies were retrieved and used as reference. Stenosis on CTA was considered "significant" if >50%, at DUS if Peak Systolic Velocity (PSV) > 140 cm/s for the V1 segment and PSV > 125 cm/s for the V2 segment. We determined the area under the ROC curve (AUROC). In addition, we calculated which PSV cut-off value resulted in highest sensitivity with acceptable specificity. DUS was able to make an adequate measurement in 378 of 674 V1 segments and 673 of 674 V2 segments. DUS detected a significant stenosis in 52 of 378 V1 segments; 12 were confirmed by CTA (AUROC 0.73, 95% Confidence Interval 0.63-0.83). The optimal DUS PSV cut-off value for this segment was 90 cm/s. For the V2 segment there were too few stenoses to allow reliable assessment of diagnostic characteristics of DUS. Although DUS has a fair AUROC for detecting significant stenosis, adequate assessment of the V1 segment is often not possible due to anatomic difficulties. Assessment of the V2 segment is feasible but yielded few stenoses. Hence, we consider usefulness of DUS for screening of extracranial vertebral artery stenosis limited.

  3. Pulmonary embolism in pregnancy: comparison of pulmonary CT angiography and lung scintigraphy.

    PubMed

    Ridge, Carole A; McDermott, Shaunagh; Freyne, Bridget J; Brennan, Donal J; Collins, Conor D; Skehan, Stephen J

    2009-11-01

    The purpose of this study was to retrospectively compare the diagnostic adequacy of lung scintigraphy with that of pulmonary CT angiography (CTA) in the care of pregnant patients with suspected pulmonary embolism. Patient characteristics, radiology report content, additional imaging performed, final diagnosis, and diagnostic adequacy were recorded for pregnant patients consecutively referred for lung scintigraphy or pulmonary CTA according to physician preference. Measurements of pulmonary arterial enhancement were performed on all pulmonary CTA images of pregnant patients. Lung scintigraphy and pulmonary CTA studies deemed inadequate for diagnosis at the time of image acquisition were further assessed, and the cause of diagnostic inadequacy was determined. The relative contribution of the inferior vena cava to the right side of the heart was measured on nondiagnostic CTA images and compared with that on CTA images of age-matched nonpregnant women, who were the controls. Twenty-eight pulmonary CTA examinations were performed on 25 pregnant patients, and 25 lung scintigraphic studies were performed on 25 pregnant patients. Lung scintigraphy was more frequently adequate for diagnosis than was pulmonary CTA (4% vs 35.7%) (p = 0.0058). Pulmonary CTA had a higher diagnostic inadequacy rate among pregnant than nonpregnant women (35.7% vs 2.1%) (p < 0.001). Transient interruption of contrast material by unopacified blood from the inferior vena cava was identified in eight of 10 nondiagnostic pulmonary CTA studies. We found that lung scintigraphy was more reliable than pulmonary CTA in pregnant patients. Transient interruption of contrast material by unopacified blood from the inferior vena cava is a common finding at pulmonary CTA of pregnant patients.

  4. [A comparison of ventilation/perfusion single photon emission CT and CT pulmonary angiography for diagnosis of pulmonary embolism].

    PubMed

    Meng, Jing-jing; Zhang, Li-jun; Wang, Qian; Fang, Wei; Dai, Hao-jie; Yan, Jue; Wang, Tie; Yao, Zhi-ming; He, Jia; Li, Mei; Mi, Hong-zhi; Jiao, Jian; Zheng, Yu-min

    2013-03-01

    To assess the diagnostic accuracy of ventilation/perfusion (V/Q) single photon emission CT (SPECT) as compared to computed tomographic pulmonary angiography (CTPA) for pulmonary embolism (PE). In this prospective multicenter study, 111 patients in whom acute or sub-acute PE was clinically confirmed or suspected were enrolled. The patients underwent one-day method V/Q lung scan (including SPECT and planar imaging) within 3 days before and after completion of CTPA. The European Association of Nuclear Medicine (EANM) guidelines for ventilation/perfusion scintigraphy (2009) reference was used as the evaluation criteria of V/Q SPECT imaging. The refined modified prospective investigation of pulmonary embolism diagnosis (RM-PIOPED) criteria was used for evaluation of planar imaging. According to the direct and indirect signs of PE, the imaging of CTPA was evaluated. All patients were followed for at least 6 months. A diagnosis was finally made by consensus of respiratory physicians, radiologists and nuclear medicine physicians based on the clinical data, laboratory tests, imaging features and follow-up results. The difference among diagnostic methods was evaluated for significance using chi-square test. The receiver operator characteristic (ROC) curve was drawn according to the results of the 3 diagnostic tests. The area under ROC curve (AUC) was calculated and compared. P < 0.05 was considered statistically significant. Among the 111 patients, PE was confirmed in 80, and excluded in 31. The diagnostic sensitivity/specificity/accuracy of V/Q SPECT, planar imaging, and CTPA were 85.9%/93.5%/88.1%, 75.7%/92.9%/81.4%, and 85.5%/90.0%/86.8%, respectively. By ROC curve analysis, the AUC values of V/Q SPECT, planar imaging and CTPA were 0.898, 0.838, and 0.877, respectively; with 95% confidence intervals [CI] 0.831 to 0.966, 0.759 to 0.917, and 0.801 to 0.954, respectively. The area of the fitted smooth ROC curve was statistically significant (P < 0.05) as compared with the

  5. Nonlinear registration of serial coronary CT angiography (CCTA) for assessment of changes in atherosclerotic plaque

    SciTech Connect

    Woo, Jonghye; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Sundaramoorthi, Ganesh; Nakazato, Ryo; Berman, Daniel S.; Germano, Guido; Kuo, C.-C. Jay; Slomka, Piotr J.

    2010-02-15

    Purpose: Coronary CT angiography (CCTA) is a high-resolution three-dimensional imaging technique for the evaluation of coronary arteries in suspected or confirmed coronary artery disease (CAD). Coregistration of serial CCTA scans would allow precise superimposition of images obtained at two different points in time, which could aid in recognition of subtle changes and precise monitoring of coronary plaque progression or regression. To this end, the authors aimed at developing a fully automatic nonlinear volume coregistration for longitudinal CCTA scan pairs. Methods: The algorithm combines global displacement and local deformation using nonlinear volume coregistration with a volume-preserving constraint. Histogram matching of intensities between two serial scans is performed prior to nonlinear coregistration with dense nonparametric local deformation in which sum of squared differences is used as a similarity measure. The approximate segmentation of coronary arteries obtained from commercially available software provides initial anatomical landmarks for the coregistration algorithm that help localize and emphasize the structure of interest. To avoid possible bias caused by incorrect segmentation, the authors convolve the Gaussian kernel with the segmented binary coronary tree mask and define an extended weighted region of interest. A multiresolution approach is employed to represent coarse-to-fine details of both volumes and the energy function is optimized using a gradient descent method. The authors applied the algorithm in ten paired CCTA datasets (20 scans in total) obtained within 10.7{+-}5.7 months from each other on a dual source CT scanner to monitor progression of CAD. Results: Serial CCTA coregistration was successful in 9/10 cases as visually confirmed. The global displacement and local deformation of target registration error obtained from four anatomical landmarks were 2.22{+-}1.15 and 1.56{+-}0.74 mm, respectively, and the inverse consistency error of

  6. Optimal table feed in run-off CT angiography in patients with abdominal aortic aneurysms.

    PubMed

    Werncke, T; von Falck, C; Wittmann, M; Elgeti, T; Wacker, F K; Meyer, B C

    2013-09-01

    To assess the influence of different table feeds (TFs) on vascular enhancement and image quality in patients with an abdominal aortic aneurysm (AAA) undergoing computed tomography (CT) angiography of the lower extremities (run-off CTA). Seventy-nine patients (71 ± 8 years) with an AAA (>30 mm) who underwent run-off CTA between January 2004 and August 2011 were included in this retrospective institutional review board-approved study. Run-off CTA was conducted using 16- and 64-row CT. The range of TFs was 30-86 mm/s and was categorised in quartiles TF1 (32.6 ± 1.9 mm/s), TF2 (38.9 ± 0.9 mm/s), TF3 (43.9 ± 3.1 mm/s) and TF4 (57.4 ± 10.5 mm/s). Image quality was rated independently by two radiologists and vessel enhancement was assessed. Image quality was diagnostic at all aortic, pelvic and almost all thigh levels. Below the knee, the number of diagnostic levels was highest for TF1 and decreased to TF4. Arterial enhancement between the aorta and fibular trunk was not different in all TF groups, P > 0.05. At the calf and foot strongest arterial enhancement was noted for TF1 and TF2 and decreased to TF4, P < 0.01. Results indicate that the highest image quality of run-off CTA in patients with an AAA may be obtained using table feeds measuring 30-35 mm/s. • CTA has become a key investigation for peripheral vascular disease. • Run-off CTA is more complex in patients with an abdominal aortic aneurysm. • Run-off CTA is feasible with a short bolus of intravenous contrast medium. • A constant 30-35 mm/s table feed provides the highest likelihood of diagnostic images.

  7. CT perfusion with angiography as a substitute for both conventional digital subtraction angiography and acetazolamide-challenged SPECT in the follow-up of postbypass patients.

    PubMed

    Park, Jung Cheol; Kim, Jeong Eun; Kang, Hyun-Seung; Sohn, Chul-Ho; Lee, Dong Soo; Oh, Chang Wan; Han, Moon Hee

    2010-01-01

    We evaluated the clinical usefulness of CT perfusion (CTP) with angiography (CTA) as an alternative to digital subtraction angiography (DSA) and acetazolamide (ACZ)-challenged single-photon emission computed tomography (SPECT) in the follow-up evaluation of hemodynamic changes and bypass patency after bypass surgery in chronic cerebral ischemic diseases. Thirty-five patients who underwent superficial temporal artery/middle cerebral artery bypass surgery for chronic cerebral ischemic diseases were retrospectively enrolled. We assessed the relationship between CTP parameters [cerebral blood volume, cerebral blood flow (CBF), mean transit time (MTT), affected-to-unaffected hemisphere (ATU) ratio of perfusion parameters and MTT differences between hemispheres] and SPECT parameters (regional CBF and cerebrovascular reserve) and compared the preoperative CTP parameters with the postoperative ones. For the bypass patency, we compared CTA with DSA. MTT showed the best correlation with CVR of SPECT (r = -0.343; p < 0.001). ATU ratio (r = -0.547; p < 0.001) and ATU differences (r = -0.592; p < 0.001) of MTT correlated well with the ATU ratio of rCBF on ACZ-challenged SPECT. Significant improvement of perfusion parameters could be demonstrated in the affected vascular territory with postoperative CTP. The CTA findings were consistent with those of DSA in 96% of the cases. The examination-related complication rate was 0, 2.8 and 8.6% for CT studies, DSA and SPECT, respectively. CTP performed simultaneously with CTA seems to be a safe and efficient substitute for DSA and ACZ-challenged SPECT in the follow-up evaluation after bypass surgery in patients with chronic cerebral ischemic diseases. Copyright © 2010 S. Karger AG, Basel.

  8. CT Angiography of Peripheral Arterial Disease by 256-Slice Scanner: Accuracy, Advantages and Disadvantages Compared to Digital Subtraction Angiography.

    PubMed

    Mishra, Atul; Jain, Narendra; Bhagwat, Anand

    2017-07-01

    Peripheral arterial occlusive disease (PAOD) may cause disabling claudication or critical limb ischemia. Multidetector computed tomography (CT) technology has evolved to the level of 256-slice CT scanners which has significantly improved the spatial and temporal resolution of the images. This has provided the capability of chasing the contrast bolus at a fast speed enabling angiographic imaging of long segments of the body. These images can be reconstructed in various planes and various modes for detailed analysis of the peripheral vascular diseases which helps in making treatment decision. The aim of this retrospective study was to compare the CT angiograms (CTAs) of all cases of PAOD done by 256-slice CT scanner at a tertiary care vascular center and comparing these images with the digital subtraction angiograms (DSAs) of these patients. The retrospective study included 53 patients who underwent both CTA and DSA at our center over a period of 3 years from March 2013 to March 2016. The CTA showed high sensitivity (93%) and specificity (92.7%) for overall assessment of degree of stenosis in a vascular segment in cases of aortic and lower limb occlusive disease. The assessment of lesions of infrapopliteal segment was comparatively inferior (sensitivity 91.6%, accuracy 73.3%, and positive predictive value 78.5%), more so in the presence of significant calcification. The advantages of CTA were its noninvasive nature, ability to image large area of body, almost no adverse effects to the patients, and better assessment of vessel wall disease. However, the CTA assessment of collaterals was inferior with a sensitivity of only 62.7% as compared to DSA. Overall, 256-slice CTA provides fast and accurate imaging of vascular tree which can restrict DSA only in few selected cases as a problem-solving tool where clinico-radiological mismatch is present.

  9. Detection of carotid artery stenosis using histological specimens: a comparison of CT angiography, magnetic resonance angiography, digital subtraction angiography and Doppler ultrasonography.

    PubMed

    Netuka, David; Belšán, Tomáš; Broulíková, Karolina; Mandys, Václav; Charvát, František; Malík, Josef; Coufalová, Lucie; Bradáč, Ondřej; Ostrý, Svatopluk; Beneš, Vladimír

    2016-08-01

    Carotid endarterectomy (CEA) is accepted as a primary modality to treat carotid stenosis. The accuracy of measuring carotid stenosis is important for indication of the CEA procedure. Different diagnostic tools have been developed and used in the past 2 decades for the diagnosis of carotid stenosis. Only a few studies, however, have focused on the comparison of different diagnostic tools to histological findings of carotid plaque. Patients with internal carotid artery (ICA) stenosis were investigated primarily by computed tomography angiography (CTA). Digital subtraction angiography (DSA), Doppler ultrasonography (DUS) and magnetic resonance angiography (MRA) were performed as well. Atherosclerotic plaque specimens were transversally cut into smaller segments and histologically processed. The slides were scanned and specimens showing maximal stenosis were determined; the minimal diameter and the diameter of the whole plaque were measured. High quality histological specimen and histological measurement was considered to be the prerequisite for inclusion into the analysis. The preoperative findings were compared with histological measurement. CTA and histological measurements were obtained from 152 patients. DSA measurements were available in 138 of these cases, MRA in 107 and DUS in 88. A comparison between preoperative and histological findings was performed. In addition, correlation coefficients were computed and tested. A significant correlation was found for each of the diagnostic procedures. The strongest correlation coefficient and the best allocation of stenosis into clinical significant groups (<50 %, 50-69 %, ≥70 %) was observed for CTA. Mean differences in the whole cohort between preoperative and histological measurements were as follows: CTA underestimated histological measurement by 2.4 % (based on European Carotid Surgery Trial [ECST] methodology) and 11.9 % (based on North American Symptomatic Carotid Endarterectomy Trial [NASCET] methodology

  10. ESTIMATION OF CARDIAC CT ANGIOGRAPHY RADIATION DOSE TOWARD THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVEL FOR CCTA IN IRAN.

    PubMed

    Hosseini Nasab, Seyed Mohammad Bagher; Shabestani-Monfared, Ali; Deevband, Mohammad Reza; Paydar, Reza; Nabahati, Mehrdad

    2016-08-29

    In recent years, with the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography (CCTA) has emerged as a useful diagnostic imaging modality as a non-invasive assessment of coronary heart disease. CT produces a larger radiation dose than other imaging tests and cardiac CT involves higher radiation dose with the advances in the spatial and temporal resolution. The aims of this study are patient dose assessment and establishment of national diagnostic reference level for CCTA in Iran. A questionnaire was sent to CCTA centers. Data for patient and CT protocols were obtained. The volumetric CT dose index (CTDIvol), dose length product (DLP) and total DLP were considered in the 32 cm standard body phantom. Calculation of estimated effective dose (ED) was obtained by multiplying the DLP by a conversion factor [k = 0.014 mSv (mGy·cm)(-1)]. Mean value of CTDIvol and DLP for CCTA was 50 mGy and 825 mGy·cm. The third quartile (75th) of the distribution of mean CTDIvol (66.54 mGy) and DLP (1073 mGy·cm) values was expressed as the diagnostic reference level (DRL) for CCTA in Iran. The median of ED was 10.26 mSv and interquartile range of ED was 7.08-15.03 mSv. A large variety in CTDIvol and DLP among CT scanner and different sites due to variability in CT parameter is noted. It seems that training could help to reduce patient's dose.

  11. Stent Lumen Visibility in Single-energy CT Angiography: Does Tube Potential Matter?

    PubMed

    Boos, Johannes; Kröpil, Patric; Lanzman, Rotem Shlomo; Aissa, Joel; Schleich, Christoph; Antoch, Gerald; Thomas, Christoph

    2016-06-01

    There has been a trend toward lowering tube potential in computed tomography angiography (CTA) examinations to reduce radiation dose or contrast medium dose. The aim of this study was to evaluate the influence of tube potential on peripheral artery in-stent lumen visibility in CTA examinations. Nine different peripheral artery stents were placed in a vessel phantom (inner diameter: 5 mm, surrounded by water) and scanned consecutively using a 128-row CT scanner with 70, 80, 100, 120, and 140 kV and two different concentrations of contrast medium to simulate contrast-enhanced blood. Medium-smooth and ultra-sharp reconstruction kernels with filtered back projection (B30f, B46f) and iterative reconstruction technique (I30f, I46f) were used. Visible in-stent lumen diameter and artifact width were evaluated using a semiautomatic software tool. All stents were scanned with digital angiography, which was regarded as the reference standard. Averaged over all stents, visible in-stent lumen diameter ranged from 1.30 ± 0.21 mm (CM2/70 kV/I30f) to 3.13 ± 0.32 mm (CM1/120 kV/I46f). In-stent lumen diameters were significantly higher for 120 and 140 kV compared to 70 kV (2.39 ± 0.73 and 2.39 ± 0.66 mm vs 1.99 ± 0.69 mm; P = 0.01 and P = 0.005). Ultra-sharp reconstruction kernels lead to significantly better in-stent lumen visibility than smooth reconstruction kernels (B46f: 2.74 ± 0.34 mm vs B30f: 1.57 ± 0.36 mm; P < 0.001, respectively). Furthermore, in-stent lumen visibility was improved for iterative reconstructions compared to filtered back projection (I46f: 2.93 ± 0.30 mm vs B46f: 2.74 ± 0.34 mm; P < 0.001). Contrast medium concentration did not influence in-stent lumen visibility. Despite all known benefits of low kV CTA protocols, the use of a very low tube potential may hamper in-stent lumen visibility. A sharp kernel may be of value when evaluating the inner lumen of vascular stents

  12. Detection of Symptomatic Carotid Plaque Using Source Data from MR and CT Angiography: A Correlative Study

    PubMed Central

    Gupta, Ajay; Baradaran, Hediyeh; Mtui, Edward E.; Kamel, Hooman; Pandya, Ankur; Giambrone, Ashley; Iadecola, Costantino; Sanelli, Pina C.

    2016-01-01

    Background Carotid plaque MRI has been a useful method to characterize vulnerable atherosclerotic plaque elements. Recent investigations have suggested that source images from CT angiography (CTA) and MR angiography (MRA) can identify the simple high-risk features of symptom-producing carotid artery plaque. We studied the correlation and relative diagnostic accuracies of CTA and MRA source images in detecting symptomatic carotid artery plaque. Methods Subjects were eligible if they had carotid stenosis between 50 and 99% and had MRA and CTA exams performed within 10 days of one another. We measured the soft (non-calcified) plaque and hard (calcified) plaque thickness on CTA axial source images and intraplaque high-intensity signal (IHIS) on 3D-time-of-flight MRA source images in subjects. We assessed whether a correlation existed between increasing CTA soft plaque thicknesses and the presence of MRA IHIS using the Student's t-test. We calculated the differences in sensitivity and specificity measures of CTA and MRA source-imaging data with the occurrence of recent ipsilateral stroke or transient ischemic attack (TIA) as the reference standard. We also performed logistic regression analyses to evaluate the predictive strength of plaque showing both IHIS and increased CTA soft plaque thickness in predicting symptomatic disease status. Results Of 1994 screened patients, 48 arteries met the final inclusion criteria with MRA and CTA performed within 10 days of one another. The mean and median time between CTA and MRA exams were 2.0 days and 1 day, respectively. A total of 34 of 48 stenotic vessels (70.8%) were responsible for giving rise to ipsilateral stroke or TIA. CTA mean soft plaque thickness was significantly greater (4.47 vs. 2.30 mm, p < 0.0001) in patients with MRA-defined IHIS, while CTA hard plaque thickness was significantly greater (2.09 vs. 1.16 mm, p = 0.0134) in patients without MRA evidence of IHIS. CTA soft plaque thickness measurements were more

  13. Sensitivity of EUS and ERCP Endoscopic Procedures in the Detection of Pancreatic Cancer During Preoperative Staging Correlated with CT and CT Angiography Imaging Methods

    PubMed Central

    Vukobrat-Bijedic, Zora; Husic-Selimovic, Azra; Bijedic, Nina; Gornjakovic, Srdjan; Sofic, Amela; Gogov, Bisera; Bjelogrlic, Ivana; Mehmedovic, Amila; Glavas, Sanjin

    2014-01-01

    The goal: The goal of this work was to give advantage to EUS as endoscopic method in diagnosis and following therapeutic treatment of pancreatic cancer in relation to radiological methods of CT and CTA. Material and Methods: The study included 49 patients, 20 women and 29 men hospitalized at the Clinic for gastroenterohepatology, due to suspicion on pancreatic cancer during observed 2 years period. All cancers were histologically and cytologically confirmed. The patients underwent ERCP as a mandatory part of staging and all patients underwent endoscopic ultrasound as well as CT or CT angiography. Results: Testing of differences was carried out using Fisher’s exact test in open-source software R. The following characteristics were tested: involvement of the blood vessels, lymph nodes, metastases, tumor size and duodenum infiltration. Results showed statistically significant difference at the 0.05 level for EUS, CT and CT angiography. Risk ratio showed that EUS is less effective in detecting infiltration of blood vessels within a malignant process then CTA where RR=0.52, CI 0.2–1.38, p-value=0.33. EUS and CTA are equal in the diagnosis of enlarged lymph nodes affected by malignancy where RR=1.3, CI 0.75–1.42, p-value=0.09. Comparison according to distant metastases showed that EUS is less effective compared to CT in approximately 30% of cases. In the diagnosis of duodenal infiltration EUS is in 5% of cases less accurate than the CT with the RR=0.95, CI 0.27–3.32, p-value=0.76, but the CTA method is more efficient because the comparison of EUS and CTA showed RR=12.52, CI 0.2–1.38, p-value=0.33. EUS as a diagnostic method is dominant in determining the size of malignant lesions located in the pancreas as compared to CT and CTA. Conclusion: EUS as endoscopic method compared to CT and CTA is one of the more invasive methods of examination but due to its ability to be performed immediately, to locate a changes smaller than 5 mm and the target biopsy option, to

  14. Atherosclerotic Plaque Tissue: Noninvasive Quantitative Assessment of Characteristics with Software-aided Measurements from Conventional CT Angiography.

    PubMed

    Sheahan, Malachi; Ma, Xiaonan; Paik, David; Obuchowski, Nancy A; St Pierre, Samantha; Newman, William P; Rae, Guenevere; Perlman, Eric S; Rosol, Michael; Keith, James C; Buckler, Andrew J

    2017-08-31

    Purpose To (a) evaluate whether plaque tissue characteristics determined with conventional computed tomographic (CT) angiography could be quantitated at higher levels of accuracy by using image processing algorithms that take characteristics of the image formation process coupled with biologic insights on tissue distributions into account by comparing in vivo results and ex vivo histologic findings and (b) assess reader variability. Materials and Methods Thirty-one consecutive patients aged 43-85 years (average age, 64 years) known to have or suspected of having atherosclerosis who underwent CT angiography and were referred for endarterectomy were enrolled. Surgical specimens were evaluated with histopathologic examination to serve as standard of reference. Two readers used lumen boundary to determine scanner blur and then optimized component densities and subvoxel boundaries to best fit the observed image by using semiautomatic software. The accuracy of the resulting in vivo quantitation of calcification, lipid-rich necrotic core (LRNC), and matrix was assessed with statistical estimates of bias and linearity relative to ex vivo histologic findings. Reader variability was assessed with statistical estimates of repeatability and reproducibility. Results A total of 239 cross sections obtained with CT angiography and histologic examination were matched. Performance on held-out data showed low levels of bias and high Pearson correlation coefficients for calcification (-0.096 mm(2) and 0.973, respectively), LRNC (1.26 mm(2) and 0.856), and matrix (-2.44 mm(2) and 0.885). Intrareader variability was low (repeatability coefficient ranged from 1.50 mm(2) to 1.83 mm(2) among tissue characteristics), as was interreader variability (reproducibility coefficient ranged from 2.09 mm(2) to 4.43 mm(2)). Conclusion There was high correlation and low bias between the in vivo software image analysis and ex vivo histopathologic quantitative measures of atherosclerotic plaque tissue

  15. Combination of a low tube voltage technique with the hybrid iterative reconstruction (iDose) algorithm at coronary CT angiography

    PubMed Central

    Funama, Yoshinori; Taguchi, Katsuyuki; Utsunomiya, Daisuke; Oda, Seitaro; Yanaga, Yumi; Yamashita, Yasuyuki; Awai, Kazuo

    2011-01-01

    We compare the performance of low-tube voltage with the hybrid iterative reconstruction (iDose) with standard- and low-tube voltage with the filtered backprojection (FBP) using phantoms at CT coronary angiography (CTCA). At CTCA, application of the combined low-tube voltage with iDose resulted in significant image quality improvements compared to the low-tube voltage with FBP. Image quality was the same or better despite a reduction in the radiation dose by 76% compared with standard-tube voltage with FBP. PMID:21765305

  16. Extent of hypoattenuation on CT angiography source images in basilar artery occlusion: prognostic value in the Basilar Artery International Cooperation Study.

    PubMed

    Puetz, Volker; Khomenko, Andrei; Hill, Michael D; Dzialowski, Imanuel; Michel, Patrik; Weimar, Christian; Wijman, Christine A C; Mattle, Heinrich P; Engelter, Stefan T; Muir, Keith W; Pfefferkorn, Thomas; Tanne, David; Szabo, Kristina; Kappelle, L Jaap; Algra, Ale; von Kummer, Ruediger; Demchuk, Andrew M; Schonewille, Wouter J

    2011-12-01

    The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) quantifies the extent of early ischemic changes in the posterior circulation with a 10-point grading system. We hypothesized that pc-ASPECTS applied to CT angiography source images predicts functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). BASICS was a prospective, observational registry of consecutive patients with acute symptomatic basilar artery occlusion. Functional outcome was assessed at 1 month. We applied pc-ASPECTS to CT angiography source images of patients with CT angiography for confirmation of basilar artery occlusion. We calculated unadjusted and adjusted risk ratios (RRs) of pc-ASPECTS dichotomized at ≥8 versus <8. Primary outcome measure was favorable outcome (modified Rankin Scale scores 0-3). Secondary outcome measures were mortality and functional independence (modified Rankin Scale scores 0-2). Of 158 patients included, 78 patients had a CT angiography source images pc-ASPECTS≥8. Patients with a pc-ASPECTS≥8 more often had a favorable outcome than patients with a pc-ASPECTS<8 (crude RR, 1.7; 95% CI, 0.98-3.0). After adjustment for age, baseline National Institutes of Health Stroke Scale score, and thrombolysis, pc-ASPECTS≥8 was not related to favorable outcome (RR, 1.3; 95% CI, 0.8-2.2), but it was related to reduced mortality (RR, 0.7; 95% CI, 0.5-0.98) and functional independence (RR, 2.0; 95% CI, 1.1-3.8). In post hoc analysis, pc-ASPECTS dichotomized at ≥6 versus <6 predicted a favorable outcome (adjusted RR, 3.1; 95% CI, 1.2-7.5). pc-ASPECTS on CT angiography source images independently predicted death and functional independence at 1 month in the CT angiography subgroup of patients in the BASICS registry.

  17. Giant-cell arteritis: concordance study between aortic CT angiography and FDG-PET/CT in detection of large-vessel involvement.

    PubMed

    de Boysson, Hubert; Dumont, Anael; Liozon, Eric; Lambert, Marc; Boutemy, Jonathan; Maigné, Gwénola; Martin Silva, Nicolas; Sultan, Audrey; Ly, Kim Heang; Aide, Nicolas; Manrique, Alain; Bienvenu, Boris; Aouba, Achille

    2017-07-24

    The purpose of our study was to assess the concordance of aortic CT angiography (CTA) and FDG-PET/CT in the detection of large-vessel involvement at diagnosis in patients with giant-cell arteritis (GCA). We created a multicenter cohort of patients with GCA diagnosed between 2010 and 2015, and who underwent both FDG-PET/CT and aortic CTA before or in the first ten days following treatment introduction. Eight vascular segments were studied on each procedure. We calculated concordance between both imaging techniques in a per-patient and a per-segment analysis, using Cohen's kappa concordance index. We included 28 patients (21/7 women/men, median age 67 [56-82]). Nineteen patients had large-vessel involvement on PET/CT and 18 of these patients also presented positive findings on CTA. In a per-segment analysis, a median of 5 [1-7] and 3 [1-6] vascular territories were involved on positive PET/CT and CTA, respectively (p = 0.03). In qualitative analysis, i.e., positivity of the procedure suggesting a large-vessel involvement, the concordance rate between both procedures was 0.85 [0.64-1]. In quantitative analysis, i.e., per-segment analysis in both procedures, the global concordance rate was 0.64 [0.54-0.75]. Using FDG-PET/CT as a reference, CTA showed excellent sensitivity (95%) and specificity (100%) in a per-patient analysis. In a per-segment analysis, sensitivity and specificity were 61% and 97.9%, respectively. CTA and FDG-PET/CT were both able to detect large-vessel involvement in GCA with comparable results in a per-patient analysis. However, PET/CT showed higher performance in a per-segment analysis, especially in the detection of inflammation of the aorta's branches.

  18. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure.

    PubMed

    Saw, Jacqueline; Fahmy, Peter; DeJong, Peggy; Lempereur, Mathieu; Spencer, Ryan; Tsang, Michael; Gin, Kenneth; Jue, John; Mayo, John; McLaughlin, Patrick; Nicolaou, Savvas

    2015-11-01

    Left atrial appendage (LAA) device imaging after endovascular closure is important to assess for device thrombus, residual leak, positioning, surrounding structures, and pericardial effusion. Cardiac CT angiography (CCTA) is well suited to assess these non-invasively. We report our consecutive series of non-valvular atrial fibrillation patients who underwent CCTA post-LAA closure with Amplatzer Cardiac Plug (ACP), Amulet (second generation ACP), or WATCHMAN devices. Patients underwent CCTA typically 1-6 months post-implantation. Prospective cardiac-gated CCTA was performed with Toshiba 320-detector or Siemens 2nd generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation™. GFR <30 mL/min/1.73 m(2) was an exclusion. We assessed for device thrombus, residual LAA leak, device embolization, position, pericardial effusion, optimal implantation, and device lobe dimensions. Forty-five patients underwent CCTA at median 97 days post-LAA closure (18 ACP, 9 Amulet, 18 WATCHMAN). Average age was 75.5 ± 8.9 years, mean CHADS2 score 3.1 ± 1.3, and CHADS-VASc score 4.9 ± 1.6. All had contraindications to oral anticoagulation. Post-procedure, 41 (91.1%) were discharged on DAPT. There was one device embolization (ACP, successfully retrieved percutaneously) and one thrombus (WATCHMAN, resolved with 3 months of warfarin). There were two pericardial effusions, both pre-existing and not requiring intervention. Residual leak (patency) was seen in 28/44 (63.6%), and the mechanisms of leak were readily identified by CCTA (off-axis device, gaps at orifice, or fabric leak). Mean follow-up was 1.2 ± 1.1year, with no death, stroke, or systemic embolism. CCTA appears to be a feasible alternative to transoesophageal echocardiography for post-LAA device surveillance to evaluate for device thrombus, residual leak, embolization, position, and pericardial effusion. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015

  19. Current trends in patients with chronic total occlusions undergoing coronary CT angiography

    PubMed Central

    Opolski, Maksymilian P; Hartaigh, Bríain ó; Berman, Daniel S; Budoff, Matthew J; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Chang, Hyuk-Jae; Chinnaiyan, Kavitha; Chow, Benjamin J W; Hadamitzky, Martin; Hausleiter, Joerg; Feuchtner, Gudrun; Kim, Yong-Jin; Kaufmann, Philipp A; Leipsic, Jonathon; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J; Villines, Todd C; Min, James K

    2015-01-01

    Objective Data describing the prevalence, characteristics and management of coronary chronic total occlusions (CTOs) in patients undergoing coronary CT angiography (CCTA) have not been reported. The purpose of this study was to determine the prevalence, characteristics and treatment strategies of CTO identified by CCTA. Methods We identified 23 745 patients who underwent CCTA for suspected coronary artery disease (CAD) from the prospective international CCTA registry. Baseline clinical data were collected, and allocation to early coronary revascularisation performed within 90 days of CCTA was determined. Multivariable hierarchical mixed-effects logistic regression reporting OR with 95% CI was performed. Results The prevalence of CTO was 1.4% (342/23 745) in all patients and 6.2% in patients with obstructive CAD (≥50% stenosis). The presence of CTO was independently associated with male sex (OR 3.12, 95% CI 2.39 to 4.08, p<0.001), smoking (OR 2.02, 95% CI 1.55 to 2.64, p<0.001), diabetes (OR 1.60, 95% CI 1.22 to 2.11, p=0.001), typical angina (OR 1.51, 95% CI 1.12 to 2.06, p=0.008), hypertension (OR 1.47, 95% CI 1.14 to 1.88, p=0.003), family history of CAD (OR 1.30, 95% CI 1.01 to 1.67, p=0.04) and age (OR 1.06, 95% CI 1.05 to 1.07, p<0.001). Most patients with CTO (61%) were treated medically, while 39% underwent coronary revascularisation. In patients with severe CAD (≥70% stenosis), CTO independently predicted revascularisation by coronary artery bypass grafting (OR 3.41, 95% CI 2.06 to 5.66, p<0.001), but not by percutaneous coronary intervention (p=0.83). Conclusions CTOs are not uncommon in a contemporary CCTA population, and are associated with age, gender, angina status and CAD risk factors. Most individuals with CTO undergoing CCTA are managed medically with higher rates of surgical revascularisation in patients with versus without CTO. Trial registration number ClinicalTrials.gov identifier NCT01443637. PMID:26076936

  20. Evaluation of individually body weight adapted contrast media injection in coronary CT-angiography.

    PubMed

    Mihl, Casper; Kok, Madeleine; Altintas, Sibel; Kietselaer, Bas L J H; Turek, Jakub; Wildberger, Joachim E; Das, Marco

    2016-04-01

    Contrast media (CM) injection protocols should be customized to the individual patient. Aim of this study was to determine if software tailored CM injections result in diagnostic enhancement of the coronary arteries in computed tomography angiography (CTA) and if attenuation values were comparable between different weight categories. 265 consecutive patients referred for routine coronary CTA were scanned on a 2nd generation dual-source CT. Group 1 (n=141) received an individual CM bolus based on weight categories (39-59 kg; 60-74 kg; 75-94 kg; 95-109 kg) and scan duration ('high-pitch: 1s; "dual-step prospective triggering": 7s), as determined by contrast injection software (Certegra™ P3T, Bayer, Berlin, Germany). Group 2 (n=124) received a standard fixed CM bolus; Iopromide 300 mgI/ml; volume: 75 ml; flow rate: 7.2 ml/s. Contrast enhancement was measured in all proximal and distal coronary segments. Subjective and objective image quality was evaluated. Statistical analysis was performed using SPSS (IBM, version 20.0). For group 1, mean attenuation values of all segments were diagnostic (>325 HU) without statistical significant differences between different weight categories (p>0.17), proximal vs. distal: 449 ± 65-373 ± 58 HU (39-59 kg); 443 ± 69-367 ± 81 HU (60-74 kg); 427 ± 59-370 ± 61 HU (75-94 kg); 427 ± 73-347 ± 61 HU (95-109 kg). Mean CM volumes were: 55 ± 6 ml (39-59 kg); 61 ± 7 ml (60-74 kg); 71 ± 8 ml (75-94 kg); 84 ± 9 ml (95-109 kg). For group 2, mean attenuation values were not all diagnostic with differences between weight categories (p<0.01), proximal vs. distal: 611 ± 142-408 ± 69 HU (39-59 kg); 562 ± 135-389 ± 98 HU (60-74 kg); 481 ± 83-329 ± 81 HU (75-94 kg); 420 ± 73-305 ± 35 HU (95-109 kg). Comparable image noise and image quality were found between groups (p ≥ 0.330). Individually tailored CM injection protocols yield diagnostic attenuation and a more homogeneous enhancement pattern between different weight groups. CM

  1. Automated quantification of epicardial adipose tissue using CT angiography: evaluation of a prototype software.

    PubMed

    Spearman, James V; Meinel, Felix G; Schoepf, U Joseph; Apfaltrer, Paul; Silverman, Justin R; Krazinski, Aleksander W; Canstein, Christian; De Cecco, Carlo Nicola; Costello, Philip; Geyer, Lucas L

    2014-02-01

    This study evaluated the performance of a novel automated software tool for epicardial fat volume (EFV) quantification compared to a standard manual technique at coronary CT angiography (cCTA). cCTA data sets of 70 patients (58.6 ± 12.9 years, 33 men) were retrospectively analysed using two different post-processing software applications. Observer 1 performed a manual single-plane pericardial border definition and EFVM segmentation (manual approach). Two observers used a software program with fully automated 3D pericardial border definition and EFVA calculation (automated approach). EFV and time required for measuring EFV (including software processing time and manual optimization time) for each method were recorded. Intraobserver and interobserver reliability was assessed on the prototype software measurements. T test, Spearman's rho, and Bland-Altman plots were used for statistical analysis. The final EFVA (with manual border optimization) was strongly correlated with the manual axial segmentation measurement (60.9 ± 33.2 mL vs. 65.8 ± 37.0 mL, rho = 0.970, P < 0.001). A mean of 3.9 ± 1.9 manual border edits were performed to optimize the automated process. The software prototype required significantly less time to perform the measurements (135.6 ± 24.6 s vs. 314.3 ± 76.3 s, P < 0.001) and showed high reliability (ICC > 0.9). Automated EFVA quantification is an accurate and time-saving method for quantification of EFV compared to established manual axial segmentation methods. • Manual epicardial fat volume quantification correlates with risk factors but is time-consuming. • The novel software prototype automates measurement of epicardial fat volume with good accuracy. • This novel approach is less time-consuming and could be incorporated into clinical workflow.

  2. An Aneurysmal Left Circumflex Artery-to-Right Atrium Fistula in a Patient with Ischemic Symptoms: Accurate Diagnosis with Dual-Source CT Angiography

    SciTech Connect

    Oncel, Dilek Oncel, Guray

    2008-07-15

    In this report, we present a 55-year-old female patient with a left circumflex artery-to-right atrial fistula associated with a huge saccular aneurysm. She had undergone conventional angiography due to ischemic symptoms. In conventional angiography, a very dilated and tortuous vessel originating from the circumflex artery and continuous with a huge saccular aneurysm was visualized but the drainage site could not be demonstrated. With dual-source CT coronary angiography, the exact anatomy of this fistula was demonstrated and surgery was planned.

  3. Feasibility of extended-coverage perfusion and dynamic computer tomography (CT) angiography using toggling-table technique on 64-slice CT.

    PubMed

    Horiguchi, Jun; Kiura, Yoshihiro; Tanaka, Junpei; Fukuda, Hiroshi; Kiguchi, Masao; Fujioka, Chikako; Kurisu, Kaoru; Awai, Kazuo

    2011-07-01

    The major drawbacks of brain computed tomography (CT) perfusion are limited coverage in the z-axis, radiation exposure and the use of contrast medium, all of which increase when CT angiography (CTA) is performed with double acquisitions. The purpose of this study was to investigate the feasibility of the 'toggling-table' technique using a 40-mm detector. The clinical usefulness of CT perfusion and 4D-CTA (time-resolved 3D-CTA), as well as the time taken and radiation exposure, were assessed in 14 non-ischemic patients clinically indicated for CT perfusion and CTA. A perfusion map and 4D-CTA was successfully achieved in all patients. The total time needed for scanning and processing was approximately 30 min per examination. The 80-mm CT perfusion coverage and 4D-CTA images were advantageous for analyses of the anatomy and widely distributed lesions. The estimated effective radiation dose was 2.22 mSv, and the amount of contrast media was 40 mL. The 'toggling-table' technique acts as a 'one-stop-shop' protocol for perfusion mapping and 4D-CTA over a wide area, following a single contrast injection and scan. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  4. Duret hemorrhage: demonstration of ruptured paramedian pontine branches of the basilar artery on minimally invasive, whole body postmortem CT angiography.

    PubMed

    Chew, Ka Lip; Baber, Yeliena; Iles, Linda; O'Donnell, Christopher

    2012-12-01

    A 25 year old male died suddenly and unexpectedly. Postmortem CT scanning revealed marked raised intracranial pressure with brainstem compression due to subarachnoid, subdural and parenchymal hemorrhage. A hyperdense mass at the termination of the right internal carotid artery was thought to represent an aneurysm. Postmortem, whole body CT angiography failed to fill the aneurysm but did demonstrate multiple central pontine linear enhancing structures in continuity with the mid basilar artery and small foci of contrast leak into the adjacent mid pontine parenchyma. Autopsy confirmed subarachnoid hemorrhage, a thrombosed and ruptured proximal right middle cerebral artery aneurysm and Duret hemorrhages in the mid pons. This finding supports the theory that Duret hemorrhages occur as a result of perforating pontine branch of the basilar arterial rupture but does not exclude the contribution of venous congestion.

  5. Cone-Beam CT with Flat-Panel-Detector Digital Angiography System: Early Experience in Abdominal Interventional Procedures

    SciTech Connect

    Hirota, Shozo Nakao, Norio; Yamamoto, Satoshi; Kobayashi, Kaoru; Maeda, Hiroaki; Ishikura, Reiichi; Miura, Koui; Sakamoto, Kiyoshi; Ueda, Ken; Baba, Rika

    2006-12-15

    We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200{sup o} rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.

  6. Spiral CT During Selective Accessory Renal Artery Angiography: Assessment of Vascular Territory Before Aortic Stent-Grafting

    SciTech Connect

    Dorffner, Roland; Thurnher, Siegfried; Prokesch, Rupert; Youssefzadeh, Soraya; Hoelzenbein, Thomas; Lammer, Johannes

    1998-03-15

    We evaluated the vascular territory of accessory renal arteries in cases where the vessel might be overlapped by an aortic stent-graft. Spiral CT during selective accessory renal artery angiography was performed in four patients with abdominal aortic aneurysms (including one with a horseshoe kidney). The volume of the vascular territory of each renal artery was measured using a software program provided by the CT unit manufacturer. The supernumerary renal arteries perfused 32%, 37%, 15%, and 16% of the total renal mass, respectively. In two patients, stent-grafts were implanted, which resulted in occlusion of the supernumerary renal artery. The volume of the renal infarction was equal to the volume perfused by the artery as calculated before implantation of the stent-graft.The method proposed is accurate for estimating the size of the expected renal infarction. It might help to determine whether placement of a stent-graft is acceptable.

  7. Automated selection of the optimal cardiac phase for single-beat coronary CT angiography reconstruction

    SciTech Connect

    Stassi, D.; Ma, H.; Schmidt, T. G.; Dutta, S.; Soderman, A.; Pazzani, D.; Gros, E.; Okerlund, D.

    2016-01-15

    Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, making it suited for prospectively gated studies where only a subset of phases are available. Methods: An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three

  8. [Imaging techniques in the preoperative diagnosis of soft tissue tumors. A comparison of MRT, CT, sonography, angiography and conventional x-rays].

    PubMed

    Roeren, T; Gindele, A; Grosspietsch, C; Dueck, M; Kauffmann, G W

    1992-12-01

    In a study on 51 patients with histologically confirmed soft tissue tumors (STT), we retrospectively evaluated the preoperative use of imaging procedures (MRI, CT, ultrasound, angiography, plain film) for identification of tumor size, delineation, and determination of malignancy and tissue type. The findings were correlated with intraoperative findings and histological diagnosis. The overall diagnostic method of choice for preoperative imaging of STT is MRI, followed by CT. Ultrasound, although sensitive, lacks the required specificity. Angiography and plain film can only be used for specific indications, as they generally do not make it possible to stage the tumor. Combining our results with those from the more recent literature, we propose a diagnostic algorithm according to which MRI would generally be performed for preoperative staging of STT. CT and plain film should only be used if bony infiltration is suspected; angiography is indicated for planning intraarterial chemotherapy or embolization or if vascular infiltration is probable.

  9. Whole-body CT trauma imaging with adapted and optimized CT angiography of the craniocervical vessels: do we need an extra screening examination?

    PubMed

    Langner, S; Fleck, S; Kirsch, M; Petrik, M; Hosten, N

    2008-11-01

    Blunt carotid and vertebral artery injury (BCVI) is rare but potentially devastating. The objective of our study was to prospectively evaluate the usefulness of a dedicated and optimized CT angiography (CTA) protocol of the craniocervical vessels as part of a whole-body CT work-up of patients with multiple trauma in a population of patients with blunt trauma. From February 2006 to July 2007, a total of 368 consecutive patients with trauma were evaluated. All examinations were performed on a 16-row multisection CT (MSCT) scanner. CTA was performed from the level of the T2 vertebra to the roof of the lateral ventricles with 40 mL of iodinated contrast agent. Images were reconstructed with use of the angiography and bone window settings to evaluate vessels and bones. Of all eligible patients imaged, 100 had injuries to the head and neck including 35 skull base fractures (9.5%), 24 maxillofacial (6.5%), and 11 cervical spine fractures (3%). CTA was diagnostic in all patients. BCVI was diagnosed in 6 cases (6 lesions of the internal carotid artery, 3 lesions of the vertebral artery); among them were 2 who did not meet the screening criteria. No patient with negative results on CTA subsequently had development of neurologic deficits suspicious for BCVI. This study confirms that optimized craniocervical CTA can be easily integrated into a whole-body CT protocol for patients with multiple trauma. No additional screening technique is necessary to identify clinically relevant vascular injuries. Earlier recognition enables earlier treatment and may decrease mortality and morbidity rates of these rare but potentially devastating injuries.

  10. Effect of heart rate on CT angiography using the enhanced cardiac model of the 4D NCAT

    NASA Astrophysics Data System (ADS)

    Segars, W. P.; Taguchi, K.; Fung, G. S. K.; Fishman, E. K.; Tsui, B. M. W.

    2006-03-01

    We investigate the effect of heart rate on the quality and artifact generation in coronary artery images obtained using multi-slice computed tomography (MSCT) with the purpose of finding the optimal time resolution for data acquisition. To perform the study, we used the 4D NCAT phantom, a computer model of the normal human anatomy and cardiac and respiratory motions developed in our laboratory. Although capable of being far more realistic, the 4D NCAT cardiac model was originally designed for low-resolution imaging research, and lacked the anatomical detail to be applicable to high-resolution CT. In this work, we updated the cardiac model to include a more detailed anatomy and physiology based on high-resolution clinical gated MSCT data. To demonstrate its utility in high-resolution dynamic CT imaging research, the enhanced 4D NCAT was then used in a pilot simulation study to investigate the effect of heart rate on CT angiography. The 4D NCAT was used to simulate patients with different heart rates (60-120 beats/minute) and with various cardiac plaques of known size and location within the coronary arteries. For each simulated patient, MSCT projection data was generated with data acquisition windows ranging from 100 to 250 ms centered within the quiet phase (mid-diastole) of the heart using an analytical CT projection algorithm. CT images were reconstructed from the projection data, and the contrast of the plaques was then measured to assess the effect of heart rate and to determine the optimal time resolution required for each case. The 4D NCAT phantom with its realistic model for the cardiac motion was found to provide a valuable tool from which to optimize CT cardiac applications. Our results indicate the importance of optimizing the time resolution with regard to heart rate and plaque location for improved CT images at a reduced patient dose.

  11. Invited review-Computed tomographic angiography (CTA) of the thoracic cardiovascular system in companion animals.

    PubMed

    Drees, Randi; François, Christopher J; Saunders, Jimmy H

    2014-01-01

    Computed tomographic angiography (CTA) of the thoracic cardiovascular system is offering new diagnostic opportunities in companion animal patients with the increasing availability of multidetector-row computed tomographic (MDCT) units in veterinary facilities. Optimal investigation of the systemic, pulmonary, and coronary circulation provides unique challenges due to the constant movement of the heart, the small size of several of the structures of interest, and the dependence of angiographic quality on various contrast bolus design and patient factors. Technical and practical aspects of thoracic cardiovascular CTA are reviewed in light of the currently available veterinary literature and future opportunities given utilizing MDCT in companion animal patients with suspected thoracic cardiovascular disease. © 2014 American College of Veterinary Radiology.

  12. Right heart on multidetector CT

    PubMed Central

    Gopalan, D

    2011-01-01

    Right ventricular function plays an integral role in the pathogenesis and outcome of many cardiovascular diseases. Imaging the right ventricle has long been a challenge because of its complex geometry. In recent years there has been a tremendous expansion in multidetector row CT (MDCT) and its cardiac applications. By judicious modification of contrast medium protocol, it is possible to achieve good opacification of the right-sided cardiac chambers, thereby paving the way for exploring the overshadowed right heart. This article will describe the key features of right heart anatomy, review MDCT acquisition techniques, elaborate the various morphological and functional information that can be obtained, and illustrate some important clinical conditions associated with an abnormal right heart. PMID:22723537

  13. Head-to-head comparison between (18)F-FDOPA PET/CT and MR/CT angiography in clinically recurrent head and neck paragangliomas.

    PubMed

    Heimburger, Céline; Veillon, Francis; Taïeb, David; Goichot, Bernard; Riehm, Sophie; Petit-Thomas, Julie; Averous, Gerlinde; Cavalcanti, Marcela; Hubelé, Fabrice; Chabrier, Gerard; Namer, Izzie Jacques; Charpiot, Anne; Imperiale, Alessio

    2017-06-01

    Head and neck paragangliomas (HNPGLs) can relapse after primary treatment. Optimal imaging protocols have not yet been established for posttreatment evaluation. The aim of the present study was to assess the diagnostic value of (18)F-FDOPA PET/CT and MR/CT angiography (MRA/CTA) in HNPGL patients with clinical relapse during their follow-up. Sixteen consecutive patients presenting with local pain, tinnitus, dysphagia, hoarse voice, cranial nerve involvement, deafness, or retrotympanic mass appearing during follow-up after the initial treatment of HNPGLs were retrospectively evaluated. Patients underwent both (18)F-FDOPA PET/CT and MRA (15 patents) or CTA (1 patent). Both methods were first assessed under blinded conditions and afterwards correlated. Head and neck imaging abnormalities without histological confirmation were considered true-positive results based on a consensus between radiologists and nuclear physicians and on further (18)F-FDOPA PET/CT and/or MRA. (18)F-FDOPA PET/CT and MRA/CTA were concordant in 14 patients and in disagreement in 2 patients. (18)F-FDOPA PET/CT and MRA/CTA identified, respectively, 12 and 10 presumed recurrent HNPGLs in 12 patients. The two lesions diagnosed by PET/CT only were confirmed during follow-up by otoscopic examination and MRA performed 29 and 17 months later. (18)F-FDOPA PET/CT images were only slightly influenced by the posttreatment sequelae, showing a better interobserver reproducibility than MRA/CTA. Finally, in 2 of the 16 studied patients, (18)F-FDOPA PET/CT detected two additional synchronous primary HNPGLs. (18)F-FDOPA PET/CT is highly sensitive in posttreatment evaluation of patients with HNPGLs, and also offers better interobserver reproducibility than MRA/CTA and whole-body examination. We therefore suggest that (18)F-FDOPA PET/CT is performed as the first diagnostic imaging modality in symptomatic patients with suspicion of HNPGL relapse after primary treatment when (68)Ga-labeled somatostatin analogues are

  14. Demonstration of liver metastases on postmortem whole body CT angiography following inadvertent systemic venous infusion of the contrast medium.

    PubMed

    O'Donnell, Chris; Hislop-Jambrich, Jacqueline; Woodford, Noel; Baker, Melissa

    2012-03-01

    An 86-year-old woman was hospitalized for breathlessness and a large right-sided pleural effusion. Approximately 1 h after thoracentesis, she developed a hemothorax resulting in hypotension and death. Routine postmortem CT scanning showed a large volume right hemothorax and a markedly enlarged liver. In an attempt to determine the origin of bleeding prior to autopsy, a postmortem CT angiogram was performed. Following inadvertent cannulation of the left long saphenous vein and infusion of ∼1,700 mL of a polyethylene glycol 200 and iodine-based radiographic contrast solution into systemic veins using a mechanical pump, CT scanning revealed a dense hepatic "parenchogram" containing multiple large, filling defects indicative of metastases. These were confirmed at autopsy. Microscopic evaluation of the liver using hematoxylin and eosin staining showed marked histological artifact characterized by centrilobular sinusoidal expansion although histology of the adenocarcinoma metastases was typical and apparently unaffected by the contrast solution. Postmortem CT angiography using an aqueous radiographic contrast agent in the so-called venous phase seems to be useful for the identification of hepatic parenchymal metastatic disease although it does cause histological artifact.

  15. Multi-phase post-mortem CT-angiography: a pathologic correlation study on cardiovascular sudden death

    PubMed Central

    Turillazzi, Emanuela; Frati, Paola; Pascale, Natascha; Pomara, Cristoforo; Grilli, Giampaolo; Viola, Rocco Valerio; Fineschi, Vittorio

    2016-01-01

    Multi-phase post-mortem CT-angiography (MPMCTA) has the great potential to increase the quality of the post-mortem investigation, especially in the area of sudden death; however, its role as routine complement to the pathology toolbox is still questioned as it needs to be further standardized. The aim of this study is to investigate the contribution of MPMCTA in cases of sudden unexplained death in adults and in particular in sudden cardiovascular death. Sixty-eight sudden unexpected deaths of adults were investigated at our institution between 2012 and 2013. Ten cases underwent MPMCTA and autopsy and were included in the study. Before the angiographic step by complete filling of the vascular system, prior to any manipulation of the body, a non-contrast CT-scan was carried out. Image reconstructions were performed on a CT workstation (Vitrea) and two radiologists experienced with post mortem imaging interpreted the MPMCTA findings. In all 10 cases, we could state a good correlation between combination of post-mortem CT and MPMCTA and autopsy procedures, confirming a high diagnostic sensitivity. With this case series we want to illustrate the advantages offered by performing MPMCTA when facing a sudden death, regardless of specific suspicion for acute coronary syndrome or other vascular or ischemic disease. PMID:27928228

  16. Carotid and cerebral CT angiography using low volume of iodinated contrast material and low tube voltage.

    PubMed

    Kayan, M; Demirtas, H; Türker, Y; Kayan, F; Çetinkaya, G; Kara, M; Orhan Çelik, A; Umul, A; Yılmaz, Ö; Recep Aktaş, A

    2016-11-01

    To evaluate image quality of carotid computed tomography angiography (CTA) using a low voltage (80kV) and low amount of iodinated contrast material. A total of 101 patients referred for carotid CTA were randomly assigned to receive a specific protocol. In group A patients received intravenous administration of contrast material at a dose of 1mL/kg and CTA examinations were performed at 100kV. In group B, patients received intravenous administration of contrast material at a dose of 0.5mL/kg and CTA examinations were performed at 80kV. The same nonionic iodinated contrast material containing 370mg of iodine per mL was used in both groups. Attenuation values were measured from the center of specific arterial segments using regions of interest. Attenuation values above 300HU were accepted as significant. Institutional review board approval was obtained. A total of 50 patients were included in group A (38 men, 12 women; mean age, 63.56 years±13.18 [SD]) and 51 patients in group B (33 men, 18 women; mean age, 59.60 years±16.63 [SD]). A total of 1615 arterial segments (1515 common carotid artery-middle cerebral artery and 101 aortic arches) were analyzed. Venous contamination was not observed in either group. The mean attenuation values of all arterial segments in both groups were greater than 300HU. Mean arterial attenuation value in group B (499.22HU±97.25 [SD]) was significantly greater than in group A (374.36HU±73.79 [SD]) (P<0.01). Hemodynamically significant stenosis (grade III stenosis or >70%) was detected in 2 segments in group A and in 3 segments in group B, while grade IV stenosis (occlusion) was detected in 2 segments in group B. Distal common carotid artery dissection was detected in 1 patient and aortic dissection was detected in 1 patient in group B. Total dose-length product (DLP) value was significantly greater in group A (225.74mGy·cm±21.80 [SD]) than in group B (116.60mGy·cm±21.22 [SD]) (P<0.01). The mean tube current was similar in group A

  17. CT angiography of renal arteriovenous fistulae: a report of two cases.

    PubMed

    Abdel-Gawad, Ehab A; Housseini, Ahmed M; Cherry, Kenneth J; Bonatti, Hugo; Maged, Ismaeel M; Norton, Patrick T; Hagspiel, Klaus D

    2009-01-01

    Renal arteriovenous fistulas (AVFs) are rare abnormal communications between the arterial and venous circulations that can be congenital or acquired. We describe the multidetector computed tomography angiography (MDCTA) appearance of 2 cases of renal AVF, one with the cirsoid and one with the aneurysmal subtype, and the impact of these findings on therapeutic decision making and treatment follow-up.

  18. Automatic selection of an optimal systolic and diastolic reconstruction windows for dual-source CT coronary angiography

    NASA Astrophysics Data System (ADS)

    Seifarth, H.; Puesken, M.; Wienbeck, S.; Maintz, D.; Heindel, W.; Juergens, K.-U.

    2008-03-01

    Purpose: To assess the performance of a motion map algorithm to automatically determine the optimal systolic and diastolic reconstruction window for coronary CT Angiography using Dual Source CT. Materials and Methods: Dual Source coronary CT angiography data sets (Somatom Definition, Siemens Medical Solutions) from 50 consecutive patients were included in the analysis. Optimal systolic and diastolic reconstruction windows were determined using a motion map algorithm (BestPhase, Siemens Medical Solutions). Additionally data sets were reconstructed in 5% steps throughout the RR-interval. For each major vessel (RCA, LAD and LCX) an optimal systolic and diastolic reconstruction window was manually determined by two independent readers using volume rendering displays. Image quality was rated using a five-point scale (1 = no motion artifacts, 5 = severe motion artifacts over entire length of the vessel). Results: The mean heart rate during the scan was 72.4bpm (+/-15.8bpm). Median systolic and diastolic reconstruction windows using the BestPhase algorithm were at 37% and 73% RR. The median manually selected systolic reconstruction window was 35 %, 30% and 35% for RCA, LAD, and LCX. For all vessels the median observer selected diastolic reconstruction window was 75%. Mean image quality using the BestPhase algorithm was 2.4 +/-0.9 for systolic reconstructions and 1.9 +/-1.1 for diastolic reconstructions. Using the manual approach, the mean image quality was 1.9 +/-0.5 and 1.7 +/-0.8 respectively. There was a significant difference in image quality between automatically and manually determined systolic reconstructions (p<0.01) but there was no significant difference in image quality in diastolic reconstructions. Conclusion: Automatic determination of the optimal reconstruction interval using the BestPhase algorithm is feasible and yields reconstruction windows similar to observer selected reconstruction windows. In diastolic reconstructions overall image quality is similar

  19. Cerebral Angiography for Evaluation of Patients with CT Angiogram-Negative Subarachnoid Hemorrhage: An 11-Year Experience.

    PubMed

    Heit, J J; Pastena, G T; Nogueira, R G; Yoo, A J; Leslie-Mazwi, T M; Hirsch, J A; Rabinov, J D

    2016-02-01

    CT angiography is increasingly used to evaluate patients with nontraumatic subarachnoid hemorrhage given its high sensitivity for aneurysms. We investigated the yield of digital subtraction angiography among patients with SAH or intraventricular hemorrhage and a negative CTA. An 11-year, single-center retrospective review of all consecutive patients with CTA-negative SAH was performed. Noncontrast head CT, CTA, DSA, and MR imaging studies were reviewed by 2 experienced interventional neuroradiologists and 1 neuroradiologist. Two hundred thirty patients (mean age, 54 years; 51% male) with CTA-negative SAH were identified. The pattern of SAH was diffuse (40%), perimesencephalic (31%), sulcal (31%), isolated IVH (6%), or identified by xanthochromia (7%). Initial DSA yield was 13%, including vasculitis/vasculopathy (7%), aneurysm (5%), arteriovenous malformation (0.5%), and dural arteriovenous fistula (0.5%). An additional 6 aneurysms/pseudoaneurysms (4%) were identified by follow-up DSA, and a single cavernous malformation (0.4%) was identified by MRI. No cause of hemorrhage was identified in any patient presenting with isolated intraventricular hemorrhage or xanthochromia. Diffuse SAH was due to aneurysm rupture (17%); perimesencephalic SAH was due to aneurysm rupture (3%) or vasculitis/vasculopathy (1.5%); and sulcal SAH was due to vasculitis/vasculopathy (32%), arteriovenous malformation (3%), or dural arteriovenous fistula (3%). DSA identifies vascular pathology in 13% of patients with CTA-negative SAH. Aneurysms or pseudoaneurysms are identified in an additional 4% of patients by repeat DSA following an initially negative DSA. All patients with CT-negative SAH should be considered for DSA. The pattern of SAH may suggest the cause of hemorrhage, and aneurysms should specifically be sought with diffuse or perimesencephalic SAH. © 2016 by American Journal of Neuroradiology.

  20. Flat-detector computed tomography with intravenous contrast material application in experimental aneurysms: comparison with multislice CT and conventional angiography.

    PubMed

    Struffert, Tobias; Doelken, Marc; Adamek, Edyta; Schwarz, Marc; Engelhorn, Tobias; Kloska, Stephan; Ott, Sabine; Doerfler, Arnd

    2010-05-01

    Despite limited soft tissue resolution flat-detector computed tomography (FD-CT) provides substantial superior spatial resolution in comparison with multislice computed tomography (MS-CT). This may add value in the visualization of small vascular structures if intravenous contrast application leads to substantial opacification and visibility of intracranial vessels or aneurysms. To evaluate the feasibility of visualization of vascular structures by FD-CT angiography (FD-CTA) after intravenous contrast injection compared with MS-CTA and intra-arterial digital subtracted angiography (IADSA) in an animal model. Aneurysms were created in the right common carotid artery in six New Zealand White Rabbits using the elastase technique. Imaging was performed using FD-CTA, MS-CTA (injection of 1 ml/kg body weight) and IADSA. Anonymized volume rendering reconstruction (VRT), maximum intensity projection (MIP), and multiplanar reconstruction (MPR) images were reconstructed and evaluated by two experienced reviewers for aneurysm geometry and vascular structure anatomy using standard tools of a dedicated workstation. Aneurysms could be successfully created in all animals. Measurements of aneurysm geometry (aneurysm height, width, neck width) and vascular structures (brachiocephalic trunk, carotid artery diameter and plane) were nearly identical in all three modalities. Intra- and inter-observer correlations of the different parameters showed high r values between 0.83 and 0.99. Our results show the feasibility of FD-CTA in comparison with MS-CTA and IADSA in an animal model. Despite limited soft tissue resolution, opacification of vascular structures with sufficient contrast to the surrounding structures was possible in all animals. Vascular structures appeared better delineated in FD-CTA than in MS-CTA, probably due to the superior spatial resolution.

  1. Evaluation of the relationship between extremity soft tissue sarcomas and adjacent major vessels using contrast-enhanced multidetector CT and three-dimensional volume-rendered CT angiography: a preliminary study.

    PubMed

    Li, YangKang; Zheng, Yu; Lin, JianBang; Cai, AiQun; Zhou, XiuGuo; Wei, XiaoLong; Cheng, Ying; Liu, GuoRui

    2013-10-01

    Accurate description of the relationship between extremity soft tissue sarcoma and the adjacent major vessels is crucial for successful surgery. In addition to magnetic resonance imaging (MRI) or in patients who cannot undergo MRI, two-dimensional (2D) postcontrast computed tomography (CT) images and three-dimensional (3D) volume-rendered CT angiography may be valuable alternative imaging techniques for preoperative evaluation of extremity sarcomas. To preoperatively assess extremity sarcomas using multidetector CT (MDCT), with emphasis on postcontrast MDCT images and 3D volume-rendered MDCT angiography in evaluating the relationship between tumors and adjacent major vessels. MDCT examinations were performed on 13 patients with non-metastatic extremity sarcomas. Conventional CT images and 3D volume-rendered CT angiography were evaluated, with focus on the relationship between tumors and adjacent major vessels. Kappa consistency statistics were performed with surgery serving as the reference standard. The relationship between sarcomas and adjacent vessels was described as one of three patterns: proximity, adhesion, and encasement. Proximity was seen in five cases on postcontrast CT images or in eight cases on volume-rendered images. Adhesion was seen in three cases on both postcontrast CT images and volume-rendered images. Encasement was seen in five cases on postcontrast CT images or in two cases on volume-rendered images. Compared to surgical results, postcontrast CT images had 100% sensitivity, 83.3% specificity, 87.5% positive predictive value, 100% negative predictive value, and 92.3% accuracy in the detection of vascular invasion (κ = 0.843, P = 0.002). 3D volume-rendered CT angiography had 71.4% sensitivity, 100% specificity, 100% positive predictive value, 75% negative predictive value, and 84.6% accuracy in the detection of vascular invasion (κ = 0.698, P = 0.008). On volume-rendered images, all cases with adhesion or encasement had arterial stenosis and

  2. Predictors of Vertebral Artery Injury in Isolated C2 Fractures Based on Fracture Morphology Using CT Angiography.

    PubMed

    Durand, David; Wu, Xiao; Kalra, Vivek B; Abbed, Khalid M; Malhotra, Ajay

    2015-06-15

    Retrospective database analysis. To determine C2 fracture patterns associated with vertebral artery injury (VAI) as assessed by computed tomography angiography. The incidence of C2 fracture hospitalizations has increased significantly in the last decade. The vertebral arteries are susceptible to injury as each courses through the C2 transverse foramen. Early screening for VAI to institute antithrombotic treatment is critical to prevent ischemic neurological sequelae. Imaging-based fracture classification schemes to determine which patterns are predictors of VAI in isolated C2 fractures using computed tomography angiography have not been described. Cervical spine computed tomographic (CT) scans at a level I trauma center were reviewed for isolated C2 fractures from 2004 to 2014 under institutional board review approval. Exclusion criteria included penetrating injury or additional cervical/occipital fractures. Fractures were classified using multiplanar CT scans into type I/II/IIa/III spondylolisthesis, type I/IIA/IIB/IIC/III dens, transverse foramen (displacement/comminution/intraforaminal fragments), and miscellaneous vertebral body fractures. Corresponding CT angiograms were assessed for VAI on the basis of the Denver grading criteria. Fisher exact test and Student t test were performed to determine predictors of VAI on the basis of fracture type. Sixty-seven patients met inclusion criteria. Fracture pattern analysis revealed that the majority were dens fractures (50.8%) and traumatic spondylolisthesis (41.8%); 29.9% had miscellaneous coronal/sagittal fractures and 22.4% were a combination.VAI was identified in 37.3% of patients with isolated C2 fractures, and 88% of patients had transverse foramen involvement. Fracture patterns significantly associated with VAI were type III dens and transverse foramen fractures with intraforaminal fragments, with or without comminution. The C2 fracture pattern most associated with VAI was comminuted transverse foramen fracture

  3. Diagnostic accuracy of three-dimensional contrast-enhanced MR angiography at 3-T for acute pulmonary embolism detection: comparison with multidetector CT angiography.

    PubMed

    Zhang, Long Jiang; Luo, Song; Yeh, Benjamin M; Zhou, Chang Sheng; Tang, Chun Xiang; Zhao, Yan'e; Li, Lin; Zheng, Ling; Huang, Wei; Lu, Guang Ming

    2013-10-12

    Three-dimensional contrast-enhanced MR pulmonary angiography (MRPA) is a suitable option for pulmonary embolism (PE) detection. However, there have been few reports on the diagnostic accuracy of MRPA for PE detection in a 3-T MR system. The purpose of this study was to evaluate the accuracy of MRPA in a 3-T MR system to detect acute PE with multidetector CT pulmonary angiography (CTPA) as reference standard. Twenty-seven patients (18 males and 9 females, mean age 38.9±14.4 years) underwent both MRPA and CTPA within 3 days (range, 0-3 days) for evaluating PE. Pulmonary emboli in MRPA were independently analyzed on a per-patient and per-lobe basis by two radiologists. CTPA was regarded as reference standard, which was evaluated by another two radiologists in consensus. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for PE detection were calculated. Weighted κ values were calculated to evaluate agreement between readers. Twenty-four patients had PE in 55 lung lobes in CTPA, while 3 patients had no PE detected. Readers 1 and 2 correctly detected 47 and 46 lung lobes having clots in 24 and 23 patients, corresponding to sensitivities, specificities, PPV, NPV, and accuracies of 100%, 100%, 100%, 100%, 100%; 100%, 66.7%, 96.0%, 100%, 96.4% on a per-patient basis and 85.5%, 100%, 100%, 90.9%, 94.1%; 83.6%, 93.7%, 90.2%, 89.2%, 89.6% on a per-lobe basis; respectively. Excellent inter-reader agreement (κ values=1.00 and 0.934; both P<0.001) were found for detecting PE on a per-patient and per-lobe analysis. Three-dimensional contrast-enhanced MRPA with a 3-T MR system is a suitable alternative modality to CTPA to detect PE on a per-patient basis based on this small cohort study. © 2013.

  4. Incremental prognostic utility of coronary CT angiography for asymptomatic patients based upon extent and severity of coronary artery calcium: results from the COronary CT Angiography EvaluatioN For Clinical Outcomes InteRnational Multicenter (CONFIRM) Study

    PubMed Central

    Cho, Iksung; Chang, Hyuk-Jae; Ó Hartaigh, Bríain; Shin, Sanghoon; Sung, Ji Min; Lin, Fay Y.; Achenbach, Stephan; Heo, Ran; Berman, Daniel S.; Budoff, Matthew J.; Callister, Tracy Q.; Al-Mallah, Mouaz H.; Cademartiri, Filippo; Chinnaiyan, Kavitha; Chow, Benjamin J.W.; Dunning, Allison M.; DeLago, Augustin; Villines, Todd C.; Hadamitzky, Martin; Hausleiter, Joerg; Leipsic, Jonathon; Shaw, Leslee J.; Kaufmann, Philipp A.; Cury, Ricardo C.; Feuchtner, Gudrun; Kim, Yong-Jin; Maffei, Erica; Raff, Gilbert; Pontone, Gianluca; Andreini, Daniele; Min, James K.

    2015-01-01

    Aim Prior evidence observed no predictive utility of coronary CT angiography (CCTA) over the coronary artery calcium score (CACS) and the Framingham risk score (FRS), among asymptomatic individuals. Whether the prognostic value of CCTA differs for asymptomatic patients, when stratified by CACS severity, remains unknown. Methods and results From a 12-centre, 6-country observational registry, 3217 asymptomatic individuals without known coronary artery disease (CAD) underwent CACS and CCTA. Individuals were categorized by CACS as: 0–10, 11–100, 101–400, 401–1000, >1000. For CCTA analysis, the number of obstructive vessels—as defined by the per-patient presence of a ≥50% luminal stenosis—was used to grade the extent and severity of CAD. The incremental prognostic value of CCTA over and above FRS was measured by the likelihood ratio (LR) χ2, C-statistic, and continuous net reclassification improvement (NRI) for prediction, discrimination, and reclassification of all-cause mortality and non-fatal myocardial infarction. During a median follow-up of 24 months (25th–75th percentile, 17–30 months), there were 58 composite end-points. The incremental value of CCTA over FRS was demonstrated in individuals with CACS >100 (LRχ2, 25.34; increment in C-statistic, 0.24; NRI, 0.62, all P < 0.001), but not among those with CACS ≤100 (all P > 0.05). For subgroups with CACS >100, the utility of CCTA for predicting the study end-point was evident among individuals whose CACS ranged from 101 to 400; the observed predictive benefit attenuated with increasing CACS. Conclusion Coronary CT angiography provides incremental prognostic utility for prediction of mortality and non-fatal myocardial infarction for asymptomatic individuals with moderately high CACS, but not for lower or higher CACS. PMID:25205531

  5. Optimization of kiloelectron volt settings in cerebral and cervical dual-energy CT angiography determined with virtual monoenergetic imaging.

    PubMed

    Schneider, David; Apfaltrer, Paul; Sudarski, Sonja; Nance, John W; Haubenreisser, Holger; Fink, Christian; Schoenberg, Stefan O; Henzler, Thomas

    2014-04-01

    Dual-energy computed tomography (DECT) offers various fields of application, especially in angiography using virtual monoenergetic imaging. The aim of this study was to evaluate objective image quality indices of calculated low-kiloelectron volt monoenergetic DECT angiographic cervical and cerebral data sets compared to virtual 120-kV polyenergetic images. Forty-one patients (21 men, mean age 58 ± 14) who underwent DECT angiography of the cervical (n = 7) or cerebral vessels (n = 34) were retrospectively included in this study. Data acquired with the 80 and 140 kVp tube using dual-source CT technology were subsequently used to calculate low-kiloelectron volt monoenergetic image data sets ranging from 120 to 40 keV (at 10-keV intervals per patient). Vessel and soft tissue attenuation and image noise were measured in various regions of interest, and contrast-to-noise ratio (CNR) was subsequently calculated. Differences in image attenuation and CNR were compared between the different monoenergetic data sets and virtual 120-kV polyenergetic images. For cervical angiography, 60-keV monoenergetic data sets resulted in the greatest improvements in vessel attenuation and CNR compared to virtual 120-kV polyenergetic data sets (+40%, +16%; all P < .01). Also for cerebral vessel assessment, 60-keV monoenergetic data sets provided the greatest improvement in vessel attenuation and CNR (+40%, +9%; all P < .01) compared to virtual 120-kV polyenergetic data sets. 60-keV monoenergetic image data significantly improve vessel attenuation and CNR of cervical and cerebral DECT angiographic studies. Future studies have to evaluate whether the technique can lead to an increased diagnostic accuracy or should be used for dose reduction of iodinated contrast material. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  6. Noninvasive FFR derived from coronary CT angiography in the management of coronary artery disease: technology and clinical update

    PubMed Central

    Nakanishi, Rine; Budoff, Mathew J

    2016-01-01

    After a decade of clinical use of coronary computed tomographic angiography (CCTA) to evaluate the anatomic severity of coronary artery disease, new methods of deriving functional information from CCTA have been developed. These methods utilize the anatomic information provided by CCTA in conjunction with computational fluid dynamics to calculate fractional flow reserve (FFR) values from CCTA image data sets. Computed tomography-derived FFR (CT-FFR) enables the identification of lesion-specific drop noninvasively. A three-dimensional CT-FFR modeling technique, which provides FFR values throughout the coronary tree (HeartFlow FFRCT analysis), has been validated against measured FFR and is now approved by the US Food and Drug Administration for clinical use. This technique requires off-site supercomputer analysis. More recently, a one-dimensional computational analysis technique (Siemens cFFR), which can be performed on on-site workstations, has been developed and is currently under investigation. This article reviews CT-FFR technology and clinical evidence for its use in stable patients with suspected coronary artery disease. PMID:27382296

  7. Evaluation of radiation dose of triple rule-out coronary angiography protocols with different scan length using 256-slice CT

    NASA Astrophysics Data System (ADS)

    Tsai, Chia-Jung; Lee, Jason J. S.; Chen, Liang-Kuang; Mok, Greta S. P.; Hsu, Shih-Ming; Wu, Tung-Hsin

    2011-10-01

    Triple rule-out coronary CT angiography (TRO-CTA) is a new approach for providing noninvasive visualization of coronary arteries with simultaneous evaluation of pulmonary arteries, thoracic aorta and other intrathoracic structures. The increasing use of TRO-CTA examination with longer scan length is associated with the concerns about radiation dose and their corresponding cancer risk. The purpose of this study is to evaluate organ dose and effective dose for the TRO-CTA examination with 2 scan lengths: TRO std and TRO ext, using 256-slice CT. TRO-CTA examinations were performed on a 256-slice CT scanner without ECG-based tube current modulation. Absorbed organ doses were measured using an anthropomorphic phantom and thermal-luminance dosimeters (TLDs). Effective dose was determined by taking a sum of the measured absorbed organ doses multiplied with the tissue weighting factor based on ICRP-103, and compared to that calculated using the dose-length product (DLP) method. We obtained high organ doses in the thyroid, esophagus, breast, heart and lung in both TRO-CTA protocols. Effective doses of the TRO std and TRO ext protocols with the phantom method were 26.37 and 42.49 mSv, while those with the DLP method were 19.68 and 38.96 mSv, respectively. Our quantitative dose information establishes a relationship between radiation dose and scanning length, and can provide a practical guidance to best clinical practice.

  8. Single Phase Dual-energy CT Angiography: One-stop-shop Tool for Evaluating Aneurysmal Subarachnoid Hemorrhage.

    PubMed

    Ni, Qian Qian; Tang, Chun Xiang; Zhao, Yan E; Zhou, Chang Sheng; Chen, Guo Zhong; Lu, Guang Ming; Zhang, Long Jiang

    2016-05-25

    Aneurysmal subarachnoid hemorrhages have extremely high case fatality in clinic. Early and rapid identifications of ruptured intracranial aneurysms seem to be especially important. Here we evaluate clinical value of single phase contrast-enhanced dual-energy CT angiograph (DE-CTA) as a one-stop-shop tool in detecting aneurysmal subarachnoid hemorrhage. One hundred and five patients who underwent true non-enhanced CT (TNCT), contrast-enhanced DE-CTA and digital subtraction angiography (DSA) were included. Image quality and detectability of intracranial hemorrhage were evaluated and compared between virtual non-enhanced CT (VNCT) images reconstructed from DE-CTA and TNCT. There was no statistical difference in image quality (P > 0.05) between VNCT and TNCT. The agreement of VNCT and TNCT in detecting intracranial hemorrhage reached 98.1% on a per-patient basis. With DSA as reference standard, sensitivity and specificity on a per-patient were 98.3% and 97.9% for DE-CTA in intracranial aneurysm detection. Effective dose of DE-CTA was reduced by 75.0% compared to conventional digital subtraction CTA. Thus, single phase contrast-enhanced DE-CTA is optimal reliable one-stop-shop tool for detecting intracranial hemorrhage with VNCT and intracranial aneurysms with DE-CTA with substantial radiation dose reduction compared with conventional digital subtraction CTA.

  9. [Evaluation of the variable-speed injection method for three-dimensional CT angiography of the trunk].

    PubMed

    Muroga, Koji; Hatcho, Atsushi; Terasawa, Kazuaki

    2005-01-20

    In three-dimensional CT angiography (3DCTA) studies, the CT values within blood vessels ideally should be uniform because the reproducibility and detectability of the morphological characteristics of blood vessels change depending on the threshold value selected. The time-density curve (TDC) therefore should be maintained at a certain level. However, conventional contrast medium injectors have a fixed injection speed, and the injection speed must therefore be changed in a stepwise manner. This means that it is not possible to maintain the TDC precisely. However, recent advances in the performance capabilities of contrast medium injectors allow the injection speed to be changed continuously with a user-selectable injection-speed ratio, permitting studies to be performed using the so-called "variable-speed injection method". We have conducted studies using this new method to determine the optimal injection speed ratio that permits the TDC to be maintained at the desired level. Our results showed that an injection-speed ratio of 0.5 permits the TDC to be maintained at the optimal level, improving the reproducibility and detectability of blood vessel morphology in 3DCTA studies. In addition, when contrast medium injection was terminated at a time point > or =50% of the preset contrast medium injection time, the mean CT value was not adversely affected (i.e., was not significantly reduced), making it possible to reduce the amount of contrast medium administered to the patient.

  10. Automated quantitative Rb-82 3D PET/CT myocardial perfusion imaging: normal limits and correlation with invasive coronary angiography.

    PubMed

    Nakazato, Ryo; Berman, Daniel S; Dey, Damini; Le Meunier, Ludovic; Hayes, Sean W; Fermin, Jimmy S; Cheng, Victor Y; Thomson, Louise E J; Friedman, John D; Germano, Guido; Slomka, Piotr J

    2012-04-01

    We aimed to characterize normal limits and to determine the diagnostic accuracy for an automated quantification of 3D 82-Rubidium (Rb-82) PET/CT myocardial perfusion imaging (MPI). We studied 125 consecutive patients undergoing Rb-82 PET/CT MPI, including patients with suspected coronary artery disease (CAD) and invasive coronary angiography, and 42 patients with a low likelihood (LLk) of CAD. Normal limits for perfusion and function were derived from LLk patients. QPET software was used to quantify perfusion abnormality at rest and stress expressed as total perfusion deficit (TPD). Relative perfusion databases did not differ in any of the 17 segments between males and females. The areas under the receiver operating characteristic curve for detection of CAD were 0.86 for identification of ≥50% and ≥70% stenosis. The sensitivity/specificity was 86%/86% for detecting ≥50% stenosis and 93%/77% for ≥70% stenosis, respectively. In regard to normal limits, mean rest and stress left ventricular ejection fraction (LVEF) were 67% ± 10% and 75% ± 9%, respectively. Mean transient ischemic dilation ratio was 1.06 ± 0.14 and mean increase in LVEF with stress was 7.4% ± 6.1% (95th percentile of 0%). Normal limits have been established for 3D Rb-82 PET/CT analysis with QPET software. Fully automated quantification of myocardial perfusion PET data shows high diagnostic accuracy for detecting obstructive CAD.

  11. Unusual Malignant Coronary Artery Anomaly: Results of Coronary Angiography, MR Imaging, and Multislice CT

    SciTech Connect

    Apitzsch, Jonas; Kuehl, Harald P.; Muehlenbruch, Georg; Mahnken, Andreas H.

    2010-04-15

    We report the case of a man with an uncommon anomaly of the origin and course of the left coronary artery. Clinical, coronary angiography, magnetic resonance imaging, and multislice computed tomography findings of this intermittently symptomatic 49 year-old patient with the rare anomaly of his left coronary artery stemming from the right sinus of Valsalva and taking an interarterial and intraseptal course are presented. The diagnostic value of the different imaging modalities is discussed.

  12. Development of new risk score for pre-test probability of obstructive coronary artery disease based on coronary CT angiography.

    PubMed

    Fujimoto, Shinichiro; Kondo, Takeshi; Yamamoto, Hideya; Yokoyama, Naoyuki; Tarutani, Yasuhiro; Takamura, Kazuhisa; Urabe, Yoji; Konno, Kumiko; Nishizaki, Yuji; Shinozaki, Tomohiro; Kihara, Yasuki; Daida, Hiroyuki; Isshiki, Takaaki; Takase, Shinichi

    2015-09-01

    Existing methods to calculate pre-test probability of obstructive coronary artery disease (CAD) have been established using selected high-risk patients who were referred to conventional coronary angiography. The purpose of this study is to develop and validate our new method for pre-test probability of obstructive CAD using patients who underwent coronary CT angiography (CTA), which could be applicable to a wider range of patient population. Using consecutive 4137 patients with suspected CAD who underwent coronary CTA at our institution, a multivariate logistic regression model including clinical factors as covariates calculated the pre-test probability (K-score) of obstructive CAD determined by coronary CTA. The K-score was compared with the Duke clinical score using the area under the curve (AUC) for the receiver-operating characteristic curve. External validation was performed by an independent sample of 319 patients. The final model included eight significant predictors: age, gender, coronary risk factor (hypertension, diabetes mellitus, dyslipidemia, smoking), history of cerebral infarction, and chest symptom. The AUC of the K-score was significantly greater than that of the Duke clinical score for both derivation (0.736 vs. 0.699) and validation (0.714 vs. 0.688) data sets. Among patients who underwent coronary CTA, newly developed K-score had better pre-test prediction ability of obstructive CAD compared to Duke clinical score in Japanese population.

  13. Detection of cerebral aneurysms in nontraumatic subarachnoid haemorrhage: role of multislice CT angiography in 130 consecutive patients.

    PubMed

    El Khaldi, M; Pernter, P; Ferro, F; Alfieri, A; Decaminada, N; Naibo, L; Bonatti, G

    2007-02-01

    The leading cause of a nontraumatic subarachnoid haemorrhage is rupture of an intracranial aneurysm. The aim of this study was to assess the usefulness of multislice computed tomography angiography (CTA) in identifying and evaluating cerebral aneurysms by comparing it with intra-arterial digital subtraction angiography (DSA) and intraoperative findings. During a 20-month period (June 2004 and February 2006), 130 patients with a CT diagnosis of nontraumatic acute subarachnoid haemorrhage were prospectively recruited to this study and underwent 16-detector CTA and DSA (57 men, 73 women; mean age 59.5 years). Twenty-five patients who underwent DSA alone postclipping were excluded. CTA and DSA were evaluated by the performing radiologist to assess the presence of one or more aneurysms and their morphological characteristics. CTA detected 133 aneurysms, whereas DSA identified 134: the aneurysm missed by CTA was 2 mm in size. CTA is fast and relatively noninvasive, and its sensitivity appears similar to that of DSA in detecting and evaluating intracranial aneurysms, even those smaller than 3 mm. This study confirms the value of CTA as the primary imaging technique in subarachnoid haemorrhage, with DSA reserved for selected patients.

  14. Automatic Coronary Artery Segmentation Using Active Search for Branches and Seemingly Disconnected Vessel Segments from Coronary CT Angiography

    PubMed Central

    Shim, Hackjoon; Jeon, Byunghwan; Jang, Yeonggul; Hong, Youngtaek; Jung, Sunghee; Ha, Seongmin; Chang, Hyuk-Jae

    2016-01-01

    We propose a Bayesian tracking and segmentation method of coronary arteries on coronary computed tomographic angiography (CCTA). The geometry of coronary arteries including lumen boundary is estimated in Maximum A Posteriori (MAP) framework. Three consecutive sphere based filtering is combined with a stochastic process that is based on the similarity of the consecutive local neighborhood voxels and the geometric constraint of a vessel. It is also founded on the prior knowledge that an artery can be seen locally disconnected and consist of branches which may be seemingly disconnected due to plaque build up. For such problem, an active search method is proposed to find branches and seemingly disconnected but actually connected vessel segments. Several new measures have been developed for branch detection, disconnection check and planar vesselness measure. Using public domain Rotterdam CT dataset, the accuracy of extracted centerline is demonstrated and automatic reconstruction of coronary artery mesh is shown. PMID:27536939

  15. Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing.

    PubMed

    Yu, Sheng; Kumamaru, Kanako K; George, Elizabeth; Dunne, Ruth M; Bedayat, Arash; Neykov, Matey; Hunsaker, Andetta R; Dill, Karin E; Cai, Tianxi; Rybicki, Frank J

    2014-12-01

    In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. The classification tasks include: PE present vs. absent, acute PE vs. others, central PE vs. others, and subsegmental PE vs. others. Statistical learning algorithms were trained with features extracted using the NLP tool and gold standard labels obtained via chart review from two radiologists. The areas under the receiver operating characteristic curves (AUC) for the four tasks were 0.998, 0.945, 0.987, and 0.986, respectively. We compared our classifiers with bag-of-words Naive Bayes classifiers, a standard text mining technology, which gave AUC 0.942, 0.765, 0.766, and 0.712, respectively.

  16. Agreement between SPECT V/Q scan and CT angiography in patients with high clinical suspicion of PE.

    PubMed

    Mahdavi, Ramyar; Caronia, Jonathan; Fayyaz, Jazeela; Panagopoulos, Georgia; Lessnau, Klaus D; Scharf, Stephen C; Mina, Bushra; Allred, Charles; DiFabrizio, Larry

    2013-11-01

    To track agreement between single positron emission computed tomography (SPECT) V/Q and CT angiography in patients with high clinical suspicion of pulmonary embolism (PE). If significant agreement occurs, a case could be made for more frequent use of chest radiography followed by SPECT V/Q scanning given its lower risk profile. Diagnosis of PE can be difficult. CT pulmonary angiography (CTA) is the preferred initial test, but may be indeterminate, is a significant source of ionizing radiation, and is contraindicated in renal insufficiency. SPECT ventilation/perfusion imaging (V/Q) is therefore preferred in certain patients. Two thousand nine hundred and twenty patients admitted to a tertiary care hospital in New York City were screened and 100 consecutive high-risk patients who required both CTA and V/Q for an initial indeterminate or negative imaging test despite a high pre-test probability were identified. The agreement between these tests was evaluated. There was no significant agreement between CTA and V/Q when positive, negative and indeterminate results were included (K = 0.18, SE = 0.09, p = 0.051). However, in the presence of a positive finding on either test, there was substantial agreement between the two (K = 0.62, SE = 0.27, p = 0.02). In 30 cases in which CTA was indeterminate, V/Q was diagnostic 93 % of the time. In 12 cases in which V/Q was indeterminate, CTA was diagnostic 83 % of the time and negative in 100 % of those cases. In the presence of an indeterminate CTA in patients with high clinical suspicion of PE, SPECT V/Q often provides a diagnosis.

  17. Diagnostic accuracy of 128-slice dual-source CT coronary angiography: a randomized comparison of different acquisition protocols.

    PubMed

    Neefjes, Lisan A; Rossi, Alexia; Genders, Tessa S S; Nieman, Koen; Papadopoulou, Stella L; Dharampal, Anoeshka S; Schultz, Carl J; Weustink, Annick C; Dijkshoorn, Marcel L; Ten Kate, Gert-Jan R; Dedic, Admir; van Straten, Marcel; Cademartiri, Filippo; Hunink, M G Myriam; Krestin, Gabriël P; de Feyter, Pim J; Mollet, Nico R

    2013-03-01

    To compare the diagnostic performance and radiation exposure of 128-slice dual-source CT coronary angiography (CTCA) protocols to detect coronary stenosis with more than 50 % lumen obstruction. We prospectively included 459 symptomatic patients referred for CTCA. Patients were randomized between high-pitch spiral vs. narrow-window sequential CTCA protocols (heart rate below 65 bpm, group A), or between wide-window sequential vs. retrospective spiral protocols (heart rate above 65 bpm, group B). Diagnostic performance of CTCA was compared with quantitative coronary angiography in 267 patients. In group A (231 patients, 146 men, mean heart rate 58 ± 7 bpm), high-pitch spiral CTCA yielded a lower per-segment sensitivity compared to sequential CTCA (89 % vs. 97 %, P = 0.01). Specificity, PPV and NPV were comparable (95 %, 62 %, 99 % vs. 96 %, 73 %, 100 %, P > 0.05) but radiation dose was lower (1.16 ± 0.60 vs. 3.82 ± 1.65 mSv, P < 0.001). In group B (228 patients, 132 men, mean heart rate 75 ± 11 bpm), per-segment sensitivity, specificity, PPV and NPV were comparable (94 %, 95 %, 67 %, 99 % vs. 92 %, 95 %, 66 %, 99 %, P > 0.05). Radiation dose of sequential CTCA was lower compared to retrospective CTCA (6.12 ± 2.58 vs. 8.13 ± 4.52 mSv, P < 0.001). Diagnostic performance was comparable in both groups. Sequential CTCA should be used in patients with regular heart rates using 128-slice dual-source CT, providing optimal diagnostic accuracy with as low as reasonably achievable (ALARA) radiation dose.

  18. Dual-energy CT angiography of abdomen with routine concentration contrast agent in comparison with conventional single-energy CT with high concentration contrast agent.

    PubMed

    He, Jingzhen; Wang, Qing; Ma, Xiangxing; Sun, Zhiyuan

    2015-02-01

    To compare the quantitative and subjective image quality in abdominal angiography between dual-energy CT (DECT) at the routine concentration of iodinated contrast agent (300mg/mL) and conventional 120-kVp single-energy CT (SECT) at the high concentration of contrast agent (370mg/mL). Abdominal computed tomography angiography (CTA) was performed in 104 patients, including 56 with conventional 120-kVp SECT at the high concentration of contrast agent and 48 with DECT at the routine concentration of contrast agent. The monochromatic images at the optimal kiloelectron-voltage (keV) of DECT that demonstrated the best contrast-to-noise ratio were reconstructed. The signal intensity and noise in abdominal arteries were comparatively analyzed between DECT and SECT. The image quality and visibility of the branch orders of superior mesenteric artery and renal arteries were further assessed. The radiation doses were recorded. Compared with SECT, DECT demonstrated higher signal intensity, signal-to-noise ratio, and contrast-to-noise ratio (all P<0.01) with moderately increased noise (40%, P<0.01) in all abdominal arteries. The image quality of DECT was superior to that of SECT (P<0.01) as evaluated with a subjective five-point scale system. Visualization of the branches of superior mesenteric artery and renal arteries was also better by DECT (P<0.01) than SECT. The radiation dose of DECT was slight higher than that of SECT (P<0.0001). DECT with image reconstruction at the optimal keV provides a high-quality angiographic technique, which allows use of a lower concentration of contrast agent compared with conventional 120-kVp SECT. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Selective deblurring for improved calcification visualization and quantification in carotid CT angiography: validation using micro-CT.

    PubMed

    Rollano-Hijarrubia, Empar; Manniesing, Rashindra; Niessen, Wiro J

    2009-03-01

    Visualization and quantification of small structures with computed tomography (CT) is hampered by the limited spatial resolution of the system. Histogram-based selective deblurring (HiSD) is a deconvolution method that restores small high-density structures, i.e., calcifications, of a CT image, using the high-intensity voxel information of the deconvolved image, while preserving the original hounsfield Units (HUs) in the remaining tissues. In this study, high resolution micro-CT data are used to validate the potential of HiSD to improve calcium visualization and quantification in the carotid arteries on in vivo contrast-enhanced CTA data. The evaluation is performed qualitatively and quantitatively on 15 atherosclerotic plaques obtained from ten different patients. HiSD in combination with vessel segmentation significantly improves calcification visualization and quantification on in vivo contrast-enhanced CT images. Calcification blur is reduced, while avoiding noise amplification and edge-ringing artifacts in the surrounding tissues. Calcification quantification errors are reduced by 23.5% on average.

  20. Asbestos Surveillance Program Aachen (ASPA): initial results from baseline screening for lung cancer in asbestos-exposed high-risk individuals using low-dose multidetector-row CT.

    PubMed

    Das, Marco; Mühlenbruch, Georg; Mahnken, Andreas H; Hering, K G; Sirbu, H; Zschiesche, W; Knoll, Lars; Felten, Michael K; Kraus, Thomas; Günther, Rolf W; Wildberger, Joachim E

    2007-05-01

    The purpose of this study was to assess the prevalence of lung cancer in a high-risk asbestos-exposed cohort using low-dose MDCT. Of a population of 5,389 former power-plant workers, 316 were characterized as individuals at highest risk for lung cancer according to a lung-cancer risk model including age, asbestos exposure and smoking habits. Of these 316, 187 (mean age: 66.6 years) individuals were included in a prospective trial. Mean asbestos exposure time was 29.65 years and 89% were smokers. Screening was performed on a 16-slice MDCT (Siemens) with low-dose technique (10/20 mAs(eff.); 1 mm/0.5 mm increment). In addition to soft copy PACS reading analysis on a workstation with a dedicated lung analysis software (LungCARE; Siemens) was performed. One strongly suspicious mass and eight cases of histologically proven lung cancer were found plus 491 additional pulmonary nodules (average volume: 40.72 ml, average diameter 4.62 mm). Asbestos-related changes (pleural plaques, fibrosis) were visible in 80 individuals. Lung cancer screening in this high-risk cohort showed a prevalence of lung cancer of 4.28% (8/187) at baseline screening with an additional large number of indeterminate pulmonary nodules. Low-dose MDCT proved to be feasible in this highly selected population.

  1. Computerized detection of non-calcified plaques in coronary CT angiography: topological soft-gradient detection method for plaque prescreening

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Patel, Smita; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Kazerooni, Ella

    2013-03-01

    Non-calcified plaque (NCP) detection in coronary CT angiography (cCTA) is challenging due to the low CT number of NCP, the large number of coronary arteries and multiple phase CT acquisition. We are developing computervision methods for automated detection of NCPs in cCTA. A data set of 62 cCTA scans with 87 NCPs was collected retrospectively from patient files. Multiscale coronary vessel enhancement and rolling balloon tracking were first applied to each cCTA volume to extract the coronary artery trees. Each extracted vessel was reformatted to a straightened volume composed of cCTA slices perpendicular to the vessel centerline. A new topological soft-gradient (TSG) detection method was developed to prescreen for both positive and negative remodeling candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. Nineteen features were designed to describe the relative location along the coronary artery, shape, distribution of CT values, and radial gradients of each NCP candidate. With a machine learning algorithm and a two-loop leave-one-case-out training and testing resampling method, useful features were selected and combined into an NCP likelihood measure to differentiate TPs from FPs. The detection performance was evaluated by FROC analysis. Our TSG method achieved a sensitivity of 96.6% with 35.4 FPs/scan at prescreening. Classification with the NCP likelihood measure reduced the FP rates to 13.1, 10.0 and 6.7 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. These results demonstrated that the new TSG method is useful for computerized detection of NCPs in cCTA.

  2. CT angiography of the kidney using routine CT and the latest Gemstone Spectral Imaging combination of different noise indexes: image quality and radiation dose.

    PubMed

    Zhao, Yongxia; Wu, Yanmin; Zuo, Ziwei; Cheng, Shujie

    2017-05-01

    The objective of our study was to compare the image quality and radiation dose of computed tomography angiography (CTA) of the kidney in patients with different body mass indexes using routine CT and the latest Gemstone Spectral Imaging (GSI) combination of different noise indexes (NI) with the adaptive statistical iterative reconstruction 2.0 algorithm (ASiR 2.0). A total of 120 patients who had undergone a CTA of the kidney were divided into four groups (A, B, C and D), with 30 patients in each group. Group A underwent a routine CT examination, while groups B, C and D underwent GSI with different noise indexes. All images were restructured using ASiR 2.0. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all images were calculated when the kidney CTA was completed. Each subjective image evaluation used a 5-point scoring method and was conducted by two independent radiologists. The CT dose index of volume (CTDIvol) and dose-length product (DLP) were recorded, and the mean value was calculated. The DLP was converted to the effective dose (ED). All data were compared with one-way ANOVA. The SNR, CNR and subjective image quality in group A were significantly lower than in groups B, C and D (P < 0.01). There were no significant differences in SNR, CNR and subjective image quality among groups B, C and D. The ED of group D decreased by 47.81 and 18.59% relative to groups A and B, respectively (P < 0.01). The latest GSI with different NI values can more effectively reduce the radiation dose than can the routine CT scan mode for a kidney CTA while still maintaining diagnostic image quality.

  3. Pseudoaneurysm of the Superficial Femoral Artery in Behcet's Disease with Spontaneous Thrombosis Followed by CT Angiography

    SciTech Connect

    Yoshida, Satoru; Akiba, Hidenari; Tamakawa, Mituharu; Takeda, Miki; Yama, Naoya; Hareyama, Masato; Morita, Kazuo; Masuda, Atsushi; Shimamoto, Kazuaki

    1998-07-15

    A 25-year-old man developed sudden pain and a pulsating mass in the left thigh. A diagnosis of Behcet's disease was made because of four major symptoms. Laboratory data indicated active inflammation. Emergency spiral computed tomographic angiography (CTA) showed an aneurysm of the left superficial femoral artery (SFA). Under steroid therapy, follow-up spiral CTA showed spontaneous occlusion of the aneurysm. In the active phase of arteritis, spiral CTA is useful for the diagnosis of arterial lesions to avoid the arterial puncture of conventional arteriography.

  4. CT pulmonary angiography of adult pulmonary vascular diseases: Technical considerations and interpretive pitfalls.

    PubMed

    Taslakian, Bedros; Latson, Larry A; Truong, Mylene T; Aaltonen, Eric; Shiau, Maria C; Girvin, Francis; Alpert, Jeffrey B; Wickstrom, Maj; Ko, Jane P

    2016-11-01

    Computed tomography pulmonary angiography (CTPA) has become the primary imaging modality for evaluating the pulmonary arteries. Although pulmonary embolism is the primary indication for CTPA, various pulmonary vascular abnormalities can be detected in adults. Knowledge of these disease entities and understanding technical pitfalls that can occur when performing CTPA are essential to enable accurate diagnosis and allow timely management. This review will cover a spectrum of acquired abnormalities including pulmonary embolism due to thrombus and foreign bodies, primary and metastatic tumor involving the pulmonary arteries, pulmonary hypertension, as well as pulmonary artery aneurysms and stenoses. Additionally, methods to overcome technical pitfalls and interventional treatment options will be addressed.

  5. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience

    SciTech Connect

    Ierardi, Anna Maria; Duka, Ejona; Radaelli, Alessandro; Rivolta, Nicola; Piffaretti, Gabriele; Carrafiello, Gianpaolo

    2016-01-15

    AimTo evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease.Materials and MethodsBetween September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated.ResultsImage co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02–63.75 Gycm2). The mean total procedure time was 32.2 min (range 27–38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20–40 mL).ConclusionsIF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration.

  6. Fusion of CT Angiography or MR Angiography with Unenhanced CBCT and Fluoroscopy Guidance in Endovascular Treatments of Aorto-Iliac Steno-Occlusion: Technical Note on a Preliminary Experience.

    PubMed

    Ierardi, Anna Maria; Duka, Ejona; Radaelli, Alessandro; Rivolta, Nicola; Piffaretti, Gabriele; Carrafiello, Gianpaolo

    2016-01-01

    To evaluate the feasibility of image fusion (IF) of pre-procedural arterial-phase CT angiography or MR angiography with intra-procedural fluoroscopy for road-mapping in endovascular treatment of aorto-iliac steno-occlusive disease. Between September and November, 2014, we prospectively evaluated 5 patients with chronic aorto-iliac steno-occlusive disease, who underwent endovascular treatment in the angiography suite. Fusion image road-mapping was performed using angiographic phase CT images or MR images acquired before and intra-procedural unenhanced cone-beam CT. Radiation dose of the procedure, volume of intra-procedural iodinated contrast medium, fluoroscopy time, and overall procedural time were recorded. Reasons for potential fusion imaging inaccuracies were also evaluated. Image co-registration and fusion guidance were feasible in all procedures. Mean radiation dose of the procedure was 60.21 Gycm2 (range 55.02-63.75 Gycm2). The mean total procedure time was 32.2 min (range 27-38 min). The mean fluoroscopy time was 12 min and 3 s. The mean procedural iodinated contrast material dose was 24 mL (range 20-40 mL). IF gives Interventional Radiologists the opportunity to use new technologies in order to improve outcomes with a significant reduction of contrast media administration.

  7. Spontaneous rupture of a middle colic artery aneurysm arising from superior mesenteric artery dissection: Diagnosis by color Doppler ultrasonography and CT angiography.

    PubMed

    Yoo, Bo Reum; Han, Hyun Young; Cho, Young Kwon; Park, Suk Jin

    2012-05-01

    Both middle colic artery (MCA) aneurysm and spontaneous dissection of the superior mesenteric artery (SMA) are rare. We report the first case of concomitancy of both conditions, diagnosed by ultrasonography and CT angiography. A 56-year-old man with abrupt abdominal pain and hypovolemic shock was diagnosed initially with ruptured MCA aneurysm by color Doppler ultrasonography. Computed tomography and angiography confirmed MCA aneurysm and showed that it was arising from the false lumen of an SMA dissection and was probably associated with segmental arterial mediolysis. The MCA aneurysm was treated successfully by transcatheter coil embolization, and the SMA dissection was treated conservatively.

  8. Helical CT Angiography of Abdominal Aortic Aneurysms Treated with Suprarenal Stent Grafting: A Pictorial Essay

    SciTech Connect

    Sun Zhonghua

    2003-06-15

    The endovascular repair of abdominal aorticaneurysm (AAA) with stent grafts is rapidly becoming an important alternative to open repair. Suprarenal stent grafting, recently modified from conventional infrarenal stent grafting, is a technique for the purpose of treating patients with inappropriate aneurysm necks.Unlike open repair, the success of endoluminal repair cannot be ascertained by means of direct examination and thus relies on imaging results. The use of conventional angiography for arterial imaging has become less dominant, while helical computed tomography angiography(CTA) has become the imaging modality of choice for both preoperative assessment and postoperative followup after treatment with stent graft implants. There is an increasing likelihood that radiologists will become more and more involved in the procedure of aortic stent grafting and in giving the radiological report on these patients treated with stent grafts. It is necessary for radiologists to be familiar with the imaging findings, including common and uncommon appearances following aortic stent grafting. The purpose of this pictorial essay is to describe and present normal and abnormal imaging appearances following aortic stent grafting based on helical CTA.

  9. Coronary CT Angiography as a Diagnostic and Prognostic Tool: Perspectives from the SCOT-HEART Trial.

    PubMed

    Doris, Mhairi; Newby, David E

    2016-02-01

    Coronary artery disease is the leading cause of death worldwide. Many trials to date have investigated the diagnostic accuracy of coronary computed tomography angiography (CCTA) when compared to the gold standard diagnostic test, invasive coronary angiography. However, whether the use of a non-invasive anatomical test, such as CCTA, can translate into improved patient risk stratification, management and outcome has yet to be established. The Scottish COmputed Tomography of the HEART (SCOT-HEART) trial sought to address these questions and determined whether CCTA, when used in addition to standard care, could aid the diagnosis, further investigation and treatment of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. In this trial, CCTA clarified the diagnosis of angina due to coronary heart disease in a quarter of patients and this led to major alterations in treatment and management that appeared to reduce the risk of subsequent coronary heart disease death or non-fatal myocardial infarction. The SCOT-Heart trial has established that CCTA is a valuable diagnostic test in patients with suspected angina pectoris due to coronary heart disease and leads to greater clarity, more focused appropriate treatments and better coronary heart disease outcomes.

  10. Subtraction CT angiography for the detection of intracranial aneurysms: A meta-analysis

    PubMed Central

    FENG, TIAN-YING; HAN, XUE-FENG; LANG, RUI; WANG, FEI; WU, QIONG

    2016-01-01

    The aim of this meta-analysis was to investigate the accuracy of subtraction computed tomography angiography (CTA) for diagnosing intracranial aneurysms. A systematic literature search up to January 1, 2013 was performed in PubMed. Two independent reviewers selected 8 studies that compared subtraction CTA with digital subtraction angiography. Data from the studies were used to construct a 2×2 contingency table on a per-patient basis in ≥5 diseased and 5 non-diseased patients, with additional data on a per-aneurysm basis. Overall, subtraction CTA had a pooled sensitivity of 99% [95% confidence interval (CI), 95–100%] and specificity of 94% (95% CI, 86–97%) for detecting and ruling out cerebral aneurysms, respectively, on a per-patient basis. On a per-aneurysm basis, the pooled sensitivity was 96% (95% CI, 90–99%), and the specificity was 91% (95% CI, 85–95%). In conclusion, subtraction CTA is a highly sensitive, specific and non-invasive method for the diagnosis and evaluation of intracranial aneurysms. PMID:27168830

  11. Whole-brain CT perfusion combined with CT angiography for ischemic complications following microsurgical clipping and endovascular coiling of ruptured intracranial aneurysms.

    PubMed

    Cheng, Xiao Qing; Chen, Qian; Zhou, Chang Sheng; Li, Jian Rui; Zhang, Zong Jun; Zhang, Long Jiang; Huang, Wei; Lu, Guang Ming

    2016-04-01

    Ischemic complications associated with microsurgical clipping and endovascular coiling affects the outcome of patients with intracranial aneurysms. We prospectively evaluated 58 intracranial aneurysm patients who had neurological deterioration or presented with poor grade (Hunt-Hess grades III and IV), aneurysm size >13 mm and multiple aneurysms after clipping or coiling. Thirty patients had ischemic complications (52%) as demonstrated by whole-brain CT perfusion (WB-CTP) combined with CT angiography (CTA). Half of these 30 patients had treatment-associated reduction in the diameter of the parent vessels (n=6), ligation of the parent vessels or perforating arteries (n=2), and unexplained or indistinguishable vascular injury (n=7); seven of these 15 (73%) patients suffered infarction. The remaining 15 patients had disease-associated cerebral ischemia caused by generalized vasospasm (n=6) and focal vessel vasospasm (n=9); six of these 15 (40%) patients developed infarction. Three hemodynamic patterns of ischemic complications were found on WB-CTP, of which increased time to peak, time to delay and mean transit time associated with decreased cerebral blood flow and cerebral blood volume were the main predictors of irreversible ischemic lesions. In conclusion, WB-CTP combined with CTA can accurately determine the cause of neurological deterioration and classify ischemic complications. This combined approach may be helpful in assessing hemodynamic patterns and monitoring operative outcomes.

  12. Detection of coronary artery stenoses by low-dose, prospectively ECG-triggered, high-pitch spiral coronary CT angiography.

    PubMed

    Achenbach, Stephan; Goroll, Tobias; Seltmann, Martin; Pflederer, Tobias; Anders, Katharina; Ropers, Dieter; Daniel, Werner G; Uder, Michael; Lell, Michael; Marwan, Mohamed

    2011-04-01

    We sought to evaluate the diagnostic accuracy of a new prospectively electrocardiogram (ECG)-triggered high-pitch scan mode for coronary computed tomography angiography (CTA), which allows an effective dose of less than 1 mSv. Coronary CTA provides increasingly reliable image quality, but the associated radiation exposure can be high. Seventy-five patients with suspected coronary artery disease and in sinus rhythm were screened for participation. After exclusion of 25 patients for body weight >100 kg or failure to lower heart rate to ≤ 60 beats/min, 50 patients were studied by prospectively ECG-triggered high-pitch spiral computed tomography (CT). Coronary CTA was performed using a dual-source CT system with 2 × 128 × 0.6-mm collimation, 0.28-s rotation time, a pitch of 3.4, 100-kVp tube voltage, and current of 320 mA. Data acquisition was prospectively triggered at 60% of the R-R interval and completed within 1 cardiac cycle. Diagnostic accuracy for detection of coronary artery stenoses ≥ 50% diameter stenosis was determined by comparison to invasive coronary angiography. Per-patient diagnostic performance was the primary form of analysis. In all 50 patients (34 males, 59 ± 12 years of age), imaging was successful. For the detection of 16 patients with at least 1 coronary artery stenosis, CT demonstrated a sensitivity of 100% (95% confidence interval [CI]: 79% to 100%) and specificity of 82% (95% CI: 65% to 93%). The positive predictive value was 72% (95% CI: 49% to 89%) and the negative predictive value was 100% (95% CI: 87% to 100%). Sensitivity was 100% (95% CI: 88% to 100%) and specificity was 94% (95% CI: 89% to 97%) on a per-vessel basis. Per-segment sensitivity was 92% (95% CI: 80% to 97%), and specificity was 98% (95% CI: 96% to 98%). Mean dose-length product for coronary CTA was 54 ± 6 mGy · cm, the effective dose was 0.76 ± 0.08 mSv (0.64 to 0.95 mSv). In nonobese patients with a low and stable heart rate, prospectively ECG-triggered high

  13. Impact on image quality and radiation exposure in coronary CT angiography: 100 kVp versus 120 kVp.

    PubMed

    Ripsweden, Jonaz; Brismar, Torkel B; Holm, Jon; Melinder, Annika; Mir-Akbari, Habib; Nilsson, Tage; Nyman, Ulf; Rasmussen, Elsbeth; Rück, Andreas; Cederlund, Kerstin

    2010-10-01

    The risk of radiation-induced cancer has become a major concern with the increasing use of computed tomography (CT). To compare image quality and radiation doses when decreasing X-ray tube peak kilovoltage (kVp) from 120 to 100 kVp in patients undergoing coronary CT angiography (CCTA). Patients referred for evaluation of suspected coronary artery disease (CAD) underwent 64-channel detector CCTA using a tube voltage of either 120 kVp (n = 46) or 100 kVp (n = 82). The individual volume CT dose index (CTDI(vol)) and dose length product (DLP) were recorded and effective radiation dose was estimated on the basis of DLP. Subjective image quality was assessed by two radiologists on per-patient based consensus. Vascular density and image noise were quantified in the left main coronary artery (LMCA) and proximal ascending aorta (AA). Mean density in the adjacent perivascular tissue was also quantified. Contrast-to-noise ratio (CNR) was calculated. Corresponding invasive coronary angiography (ICA) was performed, which constituted the gold standard. Mean values in the 100/120 kVp cohorts regarding CNR in the LMCA were 12.7/16.0 (P<0.0001)) and in the AA 13.2/17.2 (P<0.0001), CTDI(vol) 34.4/57.4 mGy (a 40% reduction, P<0.0001), DLP 578/1125 mGy × cm (P<0.0001), and estimated effective dose 9.6/20.2 mSv (P<0.0001). There was no statistically significant difference in subjective image quality between the two cohorts. The sensitivity to detect significant coronary stenoses was 88% (120 kVp) and 84% (100 kVp) and the specificity was 71% (120 kVp) and 74% (100 kVp), respectively. By reduction of tube voltage from 120 to 100 kVp at CCTA, while keeping all other scanning parameters unchanged, the radiation dose to the patient can be almost halved while keeping the diagnostic image quality at a clinically acceptable level.

  14. The value of CT cardiac angiography and CT calcium score testing in a modern cardiology service in New Zealand: a report of a single centre eight-year experience from 5,237 outpatient procedures.

    PubMed

    Ellis, Chris; Gamble, Greg; Edwards, Colin; van Pelt, Niels; Gabriel, Ruvin; Lowe, Boris; Christiansen, Jonathan; To, Andrew; Winch, Helen; Osborne, Mark; Ormiston, John; Legget, Malcolm

    2016-12-02

    Computed tomographic (CT) cardiac angiography is of increasing value in several areas of patient management in cardiology. We assessed the ability of CT cardiac angiography to effectively 'rule out' severe coronary stenoses in patients presenting with 'atypical' symptoms and/or an equivocal stress test, which offers a new approach to the management of coronary artery disease. We also examined the use of the CT calcium score test in cardiovascular (CVS) risk assessment. From a large single centre (Mercy Hospital) in Auckland, using a prospectively acquired, comprehensive database, we audited the entire eight-year experience of 5,169 patients (7/8/06 to 31/1/14) who underwent 5,237 64-slice computed tomographic (CT) cardiac angiogram or CT calcium score tests (GE Lightspeed scanner). From 5,169 patients there were 5,237 CT procedures. The mean patient age was 57 (SD 10) years; 42% patients were female. Of the 3,603 (69%) full CT cardiac angiogram scans, 3,509 (67%) included a calcium score test. One thousand four hundred and eighty-three (28%) of scans were a calcium score test only. Of the 3,603 (69%) full CT cardiac angiogram scans, it was possible to 'rule out' significant coronary atheroma (stenosis ≥50%) in 2,947 (82%) of these procedures. Of the 4,903 (94%) patients who had a CT calcium score test, in whom we could calculate the NZ Framingham-based CVS risk, it was possible to reassign 532 (22%) of these patients who were previously thought to be at 'low risk' to be at a higher CVS risk. CT cardiac angiography has become established in the modern management of cardiology patients. It has particular value as a tool to 'rule out' severe coronary stenoses, and as a tool to give a more accurate assessment of CVS risk. It adds significant value to the care of many patients within an established cardiology practice.

  15. Coronary CT angiography: IVUS image fusion for quantitative plaque and stenosis analyses

    NASA Astrophysics Data System (ADS)

    Marquering, Henk A.; Dijkstra, Jouke; Besnehard, Quentin J. A.; Duthé, Julien P. M.; Schuijf, Joanne D.; Bax, Jeroen J.; Reiber, Johan H. C.

    2008-03-01

    Rationale and Objective: Due to the limited temporal and spatial resolution, coronary CT angiographic image quality is not optimal for robust and accurate stenosis quantification, and plaque differentiation and quantification. By combining the high-resolution IVUS images with CT images, a detailed representation of the coronary arteries can be provided in the CT images. Methods: The two vessel data sets are matched using three steps. First, vessel segments are matched using anatomical landmarks. Second, the landmarks are aligned in cross-sectional vessel images. Third, the semi-automatically detected IVUS lumen contours are matched to the CTA data, using manual interaction and automatic registration methods. Results: The IVUS-CTA fusion tool facilitates the unique combined view of the high-resolution IVUS segmentation of the outer vessel wall and lumen-intima transitions on the CT images. The cylindrical projection of the CMPR image decreases the analysis time with 50 percent. The automatic registration of the cross-vessel views decreases the analyses time with 85 percent. Conclusions: The fusion of IVUS images and their segmentation results with coronary CT angiographic images provide a detailed view of the lumen and vessel wall of coronary arteries. The automatic fusion tool makes such a registration feasible for the development and validation of analysis tools.

  16. Cardiovascular CT angiography in neonates and children: image quality and potential for radiation dose reduction with iterative image reconstruction techniques.

    PubMed

    Tricarico, Francesco; Hlavacek, Anthony M; Schoepf, U Joseph; Ebersberger, Ullrich; Nance, John W; Vliegenthart, Rozemarijn; Cho, Young Jun; Spears, J Reid; Secchi, Francesco; Savino, Giancarlo; Marano, Riccardo; Schoenberg, Stefan O; Bonomo, Lorenzo; Apfaltrer, Paul

    2013-05-01

    To evaluate image quality (IQ) of low-radiation-dose paediatric cardiovascular CT angiography (CTA), comparing iterative reconstruction in image space (IRIS) and sinogram-affirmed iterative reconstruction (SAFIRE) with filtered back-projection (FBP) and estimate the potential for further dose reductions. Forty neonates and children underwent low radiation CTA with or without ECG synchronisation. Data were reconstructed with FBP, IRIS and SAFIRE. For ECG-synchronised studies, half-dose image acquisitions were simulated. Signal noise was measured and IQ graded. Effective dose (ED) was estimated. Mean absolute and relative image noise with IRIS and full-dose SAFIRE was lower than with FBP (P < 0.001), while SNR and CNR were higher (P < 0.001). Image noise was also lower and SNR and CNR higher in half-dose SAFIRE studies compared with full-and half-dose FBP studies (P < 0.001). IQ scores were higher for IRIS, full-dose SAFIRE and half-dose SAFIRE than for full-dose FBP and higher for half-dose SAFIRE than for half-dose FBP (P < 0.05). Median weight-specific ED was 0.3 mSv without and 1.36 mSv with ECG synchronisation. The estimated ED of half-dose SAFIRE studies was 0.68 mSv. IR improves image noise, SNR, CNR and subjective IQ compared with FBP in low-radiation-dose paediatric CTA and allows further dose reductions without compromising diagnostic IQ. • Iterative reconstruction techniques significantly improve non-invasive cardiovascular CT in children. • Using half traditional radiation dose image quality is higher with iterative reconstruction. • Iterative reconstruction techniques may allow further radiation reductions in paediatric cardiovascular CT.

  17. Alberta Stroke Program Early CT Score applied to CT angiography source images is a strong predictor of futile recanalization in acute ischemic stroke.

    PubMed

    Kawiorski, Michal M; Martínez-Sánchez, Patricia; García-Pastor, Andrés; Calleja, Patricia; Fuentes, Blanca; Sanz-Cuesta, Borja E; Lourido, Daniel; Marín, Begoña; Díaz-Otero, Fernando; Vicente, Agustina; Sierra-Hidalgo, Fernando; Ruiz-Ares, Gerardo; Díez-Tejedor, Exuperio; Fandiño, Eduardo; Alonso de Leciñana, María

    2016-05-01

    Reliable predictors of poor clinical outcome despite successful revascularization might help select patients with acute ischemic stroke for thrombectomy. We sought to determine whether baseline Alberta Stroke Program Early CT Score (ASPECTS) applied to CT angiography source images (CTA-SI) is useful in predicting futile recanalization. Data are from the FUN-TPA study registry (ClinicalTrials.gov; NCT02164357) including patients with acute ischemic stroke due to proximal arterial occlusion in anterior circulation, undergoing reperfusion therapies. Baseline non-contrast CT and CTA-SI-ASPECTS, time-lapse to image acquisition, occurrence, and timing of recanalization were recorded. Outcome measures were NIHSS at 24 h, symptomatic intracranial hemorrhage, modified Rankin scale score, and mortality at 90 days. Futile recanalization was defined when successful recanalization was associated with poor functional outcome (death or disability). Included were 110 patients, baseline NIHSS 17 (IQR 12; 20), treated with intravenous thrombolysis (IVT; 45 %), primary mechanical thrombectomy (MT; 16 %), or combined IVT + MT (39 %). Recanalization rate was 71 %, median delay of 287 min (225; 357). Recanalization was futile in 28 % of cases. In an adjusted model, baseline CTA-SI-ASPECTS was inversely related to the odds of futile recanalization (OR 0.5; 95 % CI 0.3-0.7), whereas NCCT-ASPECTS was not (OR 0.8; 95 % CI 0.5-1.2). A score ≤5 in CTA-SI-ASPECTS was the best cut-off to predict futile recanalization (sensitivity 35 %; specificity 97 %; positive predictive value 86 %; negative predictive value 77 %). CTA-SI-ASPECTS strongly predicts futile recanalization and could be a valuable tool for treatment decisions regarding the indication of revascularization therapies.

  18. Lethal hemorrhage from a ureteric-arterial-enteric fistula diagnosed by postmortem CT angiography.

    PubMed

    Rashid, Saiful Nizam bin Abdul; Bouwer, Heinrich; O'Donnell, Chris

    2012-12-01

    Fistula formation following pelvic surgery and radiotherapy, including ureteric-arterial fistulas (UAF), is well documented, however, ureteric-arterial-enteric fistula is extremely rare. Conventional autopsy is usually required for the definitive diagnosis of pelvic vascular fistulas although an accurate diagnosis can still be complicated and challenging. The role of post-mortem computed tomography (PMCT) as an adjunct to conventional autopsy is well documented in the literature. One of the limitations of PMCT is the diagnosis of vascular conditions. Post-mortem computed tomography angiography (PMCTA) is a recently introduced technique that can assist in detecting such pathology. We present a case of post-radiotherapy ureteric-arterial-enteric fistula presenting as massive rectal and vaginal bleeding diagnosed prior to autopsy on PMCTA. The role of PMCTA in the diagnosis of such a UAF has not previously been reported in the literature.

  19. Scintigraphic Evidence for Overdiagnosis of Small PE on CT Pulmonary Angiography.

    PubMed

    Lu, Yang

    2017-03-01

    A 68-year-old man with recent history of a fall presented with dyspnea on exertion, and underwent computed tomography pulmonary angiography (CTPA) for possible pulmonary embolism (PE). The CTPA was first read by the radiology resident as nondiagnostic for segmental PE. Subsequent planar perfusion (Q) images were normal; meanwhile, the attending radiologist revised the CTPA results as subsegmental PE in the left upper lobe. Further Q-SPECT images were obtained and fused with CTPA for clarification, which showed normal perfusion in the region of PE. The patient was monitored without anticoagulation treatment and remained uneventful for 12 months. This case illustrates that CTPA can lead to overdiagnosis and overtreatment of nonocclusive subsegmental PE.

  20. Laparoscopic resection aided by preoperative 3-D CT angiography for rectosigmoid colon cancer associated with a horseshoe kidney: A case report.

    PubMed

    Maeda, Yoshiaki; Shinohara, Toshiki; Nagatsu, Akihisa; Futakawa, Noriaki; Hamada, Tomonori

    2014-11-01

    We herein report a case of laparoscopic high anterior resection with D3 lymph node dissection for rectosigmoid colon cancer with a horseshoe kidney. A 65-year-old Japanese man referred to our hospital for rectosigmoid colon cancer was found to have a horseshoe kidney on a CT scan. On 3-D CT angiography, an aberrant renal artery was visualized feeding the renal isthmus that arises from the aorta just below the root of the inferior mesenteric artery (IMA). Laparoscopic anterior rectal resection with D3 lymph node dissection was performed. During the operation, the IMA, left ureter, left gonadal vessels and hypogastric nerve plexus could be seen passing over the horseshoe kidney isthmus. With the aid of preoperative 3-D CT angiography, the root of the IMA was identified on the temporal side of the isthmus and divided safely just above the hypogastric nerve. As a horseshoe kidney is often accompanied by aberrant renal arteries and/or abnormal running of the ureter, 3-D CT angiography is useful for determining the location of these structures and avoiding intraoperative injury.

  1. Study of Normal Branching Pattern of the Coeliac Trunk and its Variations Using CT Angiography

    PubMed Central

    Selvaraj, Lakshana

    2015-01-01

    Introduction Blood vessel anomalies are always interesting from embryological view and of considerable significance from a clinical or a surgical standpoint. Vascular anomalies are usually asymptomatic; they may cause problems in patients undergoing diagnostic angiography or any operative procedure. The length and course of the coeliac artery are variable and its branches frequently arise separately from the main trunk. Several other branches may additionally arise from the coeliac trunk, for example, inferior phrenic arteries, the dorsal pancreatic artery, and the middle colic artery. Aim The present study was undertaken to analyse the vertebral level of origin of coeliac artery, its branching pattern and the associated variations using computed tomographic angiography in 75 subjects. Results The results obtained were analysed and classified based on Adachi’s and Lipshutz’s classification method. The results were also compared with various other studies cited in the literature. The level of origin was found to be at the inter-vertebral disc between T12 and L1 in a majority of the cases (70.6%). It was also found that the coeliac trunk trifurcates in majority of the cases i.e. 90.6%. Trifurcation was of two types, classical and non-classical, the classical trunk being the commonest type. Variations included bifurcation of the trunk (8%) with Left gastric artery arising directly from the aorta, in a few cases (1.3%) Common hepatic artery arose as a separate trunk from the aorta. Conclusion A comprehensive knowledge of this arterial anatomy and variations will be very useful when planning abdominal surgeries and image-guided interventions. The success of procedures such as liver transplantation, intestinal anastomosis, intra-arterial chemotherapy, chemo-embolization, and radio-embolization requires a detailed knowledge of the coeliac artery and its anatomical variants, which are extremely common, to avoid iatrogenic injuries and to prevent complications. PMID

  2. SYNTAX Score Derived From Coronary CT Angiography for Prediction of Complex Percutaneous Coronary Interventions.

    PubMed

    Shalev, Aryeh; Nakazato, Ryo; Arsanjani, Reza; Nakanishi, Rine; Park, Hyung-Bok; Otaki, Yuka; Cheng, Victor Y; Gransar, Heidi; LaBounty, Troy M; Hayes, Sean W; Berman, Daniel S; Min, James K

    2016-11-01

    SYNTAX score is a useful metric determined at the time of invasive coronary angiography (ICA) to assess the complexity of coronary artery disease, and improves prediction of complications at the time of percutaneous complex intervention (PCI). We aimed to determine whether SYNTAX score can be reliably determined from coronary computed tomography angiography (CCTA) and whether a CCTA-derived SYNTAX score can predict complex PCI. SYNTAX scores were calculated on per-patient, per-vessel, and per-segment basis in 154 consecutive patients who underwent CCTA and ICA. PCI complexity in 113 patients who underwent intervention was defined by total fluoroscopy time and contrast volume. Compared to ICA, CCTA detected 285 of 302 (94%) obstructive lesions in 230 vessels, for which PCI was performed for 154 lesions in 131 vessels. Overall, on a per-patient basis, ICA-derived SYNTAX score was lower in comparison to CCTA-derived score (10.2 ± 8.0 vs 10.9 ± 8.3, P = 0.001). As compared to lesions in the lowest CCTA-derived segmental SYNTAX tertile, lesions in the highest tertile required longer fluoroscopy time (17.5 ± 12 min vs 11.5 ± 7.9 min, P = 0.01) and greater contrast volume (215.4 ± 125.5 mL vs 144.3 ± 49 mL, P = 0.02). SYNTAX scores derived from CCTA are concordant with those derived from ICA and correspond with complex PCI. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  3. CT angiographic analysis of carotid artery stenosis: comparison of manual assessment, semiautomatic vessel analysis, and digital subtraction angiography.

    PubMed

    Silvennoinen, H M; Ikonen, S; Soinne, L; Railo, M; Valanne, L

    2007-01-01

    To compare multisection CT angiography (CTA) analyzed with source/maximum intensity projection (MIP) images as well as semiautomated vessel analysis software with intra-arterial digital subtraction angiography (DSA) in detection and grading of carotid artery bifurcation stenosis. Consecutive patients with sonography evidence of a marked internal carotid artery stenosis underwent both carotid CTA and DSA (37 patients, 73 vessels). In CTA, the grade of stenosis was determined using axial source and MIP images as well as vessel analysis. The scans were blind-analyzed by 2 neuroradiologists using the NASCET criteria. Correlation of CTA source/MIP images versus DSA estimates of stenosis (R = 0.95) was higher than for the vessel analysis method versus DSA (R = 0.89). Compared with DSA, CTA source/MIP images underestimated high (78.2% versus 86.4%, P < .05) and moderate grades of stenosis (57.3% versus 63.1%, P < .05) to a lesser extent than the vessel analysis method (68.5% versus 83.5% and 51.8% versus 63.1%, P < .05). For a high-grade stenosis, sensitivity