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Sample records for multidetector-row ct angiography

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

    PubMed Central

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

    2014-01-01

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

  2. 64 Slice multi-detector row cardiac CT.

    PubMed

    Pannu, Harpreet K; Johnson, Pamela T; Fishman, Elliot K

    2009-01-01

    Cardiac imaging is feasible with multi-detector row (MDCT) scanners. Coronary arterial anatomy and both non-calcified and calcified plaques are depicted at CT coronary angiography. Vessel wall pathology and luminal diameter are depicted, and secondary myocardial changes may also be seen. Diagnostic capacity has increased with technological advancement, and preliminary investigations confirm the utility of 64-MDCT in low- and intermediate-risk patients who present to the emergency department with acute chest pain. The clinical indications, 64-MDCT technique, and MDCT findings in coronary artery disease are reviewed. PMID:18941811

  3. Multiplanar and three-dimensional multi-detector row CT of thoracic vessels and airways in the pediatric population.

    PubMed

    Siegel, Marilyn J

    2003-12-01

    Multi-detector row computed tomography (CT) has changed the approach to imaging of thoracic anatomy and disease in the pediatric population. At the author's institution, multi-detector row CT with multiplanar and three-dimensional reconstruction has become an important examination in the evaluation of systemic and pulmonary vasculature and the tracheobronchial tree. In some clinical situations, multi-detector row CT with reformatted images is obviating conventional angiography, which is associated with higher radiation doses and longer sedation times. Although multi-detector row CT with multiplanar and three-dimensional reconstruction is expanding the applications of CT of the thorax, its role as a diagnostic tool still needs to be better defined. The purposes of this article are to describe how to perform multi-detector row CT with multiplanar and three-dimensional reconstruction in young patients, to discuss various reconstruction techniques available, and to discuss applications in the evaluation of vascular and airways diseases. PMID:14563904

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed

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

    2006-01-01

    Pancreatic islet cell tumors (ICTs) are neuroendocrine neoplasms that produce and secrete hormones to a variable degree. These neoplasms can present a diagnostic challenge, both clinically and radiologically. ICTs can be classified as either syndromic or nonsyndromic on the basis of their clinical manifestations. Multi-detector row computed tomography (CT) plays an important role in the diagnosis and staging of both syndromic and nonsyndromic ICTs. In general, syndromic ICTs are less than 3 cm in size. They are typically hyperenhancing and are usually best seen on CT scans obtained during the arterial phase. Nonsyndromic ICTs tend to be larger than syndromic ICTs at presentation and are more likely to be cystic or necrotic. It is important for the radiologist to be familiar with appropriate CT protocol for the evaluation of patients with suspected pancreatic ICT and to understand the variable CT appearances of these neoplasms. PMID:16549609

  6. 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.

  7. [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. PMID:18336102

  8. Detection, visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT.

    PubMed

    van Ooijen, Peter M A; Dorgelo, Joost; Zijlstra, Felix; Oudkerk, Matthijs

    2004-12-01

    Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT. PMID:15452665

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

    PubMed

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

    2005-12-01

    The purpose of this study was to determine the optimal tube current setting and scanning mode for hominid fossil skull scanning, using multi-detector row computed tomography (CT). Four fossil skulls (La Ferrassie 1, Abri Pataud 1, CroMagnon 2 and Cro-Magnon 3) were examined by using the CT scanner LightSpeed 16 (General Electric Medical Systems) with varying dose per section (160, 250, and 300 mAs) and scanning mode (helical and conventional). Image quality of two-dimensional (2D) multiplanar reconstructions, three-dimensional (3D) reconstructions and native images was assessed by four reviewers using a four-point grading scale. An ANOVA (analysis of variance) model was used to compare the mean score for each sequence and the overall mean score according to the levels of the scanning parameters. Compared with helical CT (mean score=12.03), the conventional technique showed sustained poor image quality (mean score=4.17). With the helical mode, we observed a better image quality at 300 mAs than at 160 in the 3D sequences (P=0.03). Whereas in native images, a reduction in the effective tube current induced no degradation in image quality (P=0.05). Our study suggests a standardized protocol for fossil scanning with a 16 x 0.625 detector configuration, a 10 mm beam collimation, a 0.562:1 acquisition mode, a 0.625/0.4 mm slice thickness/reconstruction interval, a pitch of 5.62, 120 kV and 300 mAs especially when a 3D study is required. PMID:16211320

  10. 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.

  11. 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

  12. Misty mesentery: a pictorial review of multidetector-row CT findings.

    PubMed

    Filippone, A; Cianci, R; Di Fabio, F; Storto, M L

    2011-04-01

    The term "misty mesentery" indicates a pathological increase in mesenteric fat attenuation at computed tomography (CT). It is frequently observed on multidetector CT (MDCT) scans performed during daily clinical practice and may be caused by various pathological conditions, including oedema, inflammation, haemorrhage, neoplastic infiltration or sclerosing mesenteritis. In patients suffering from acute abdominal disease, misty mesentery may be considered a feature of the underlying disease. Otherwise, it may represent an incidental finding on MDCT performed for other reasons. This article describes the MDCT features of misty mesentery in different diseases in order to provide a rational approach to the differential diagnosis. PMID:21311992

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

    PubMed

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

    2016-04-01

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

  14. Optimised z-axis coverage at multidetector-row CT in adults suspected of acute appendicitis

    PubMed Central

    Brassart, N; Winant, C; Tack, D; Gevenois, P A; De Maertelaer, V

    2013-01-01

    Objective: To compare diagnostic performances of two reduced z-axis coverages to full coverage of the abdomen and pelvis for the diagnosis of acute appendicitis and alternative diseases at unenhanced CT. Methods: This study included 152 adults suspected of appendicitis who were enrolled in two ethical committee-approved previous prospective trials. Based on scans covering the entire abdomen and pelvis (set L), two additional sets of images were generated, each with reduced z-axis coverages: (1) from the top of the iliac crests to the pubis (set S) and (2) from the diaphragmatic crus to the pubis (set M). Two readers independently coded the visualisation of the appendix, measured its diameter and proposed a diagnosis (appendicitis or alternative). Final diagnosis was based on surgical findings or clinical follow-up. Fisher exact and McNemar tests and logistic regression were used. Results: 46 patients had a definite diagnosis of appendicitis and 53 of alternative diseases. The frequency of appendix visualisation was lower for set S than set L for both readers (89% and 84% vs 95% and 91% by Readers A and B, respectively; p=0.021 and 0.022). The probability of giving a correct diagnosis was lower for set S (68%) than set L (78%; odds ratio, 0.611; p=0.008) for both readers, without significant difference between sets L and M (77%, p=0.771); z-axis coverage being reduced by 25% for set M. Conclusion: Coverage from diaphragmatic crus to pubis, but not focused on pelvis only, can be recommended in adults suspected of appendicitis. Advances in knowledge: In suspected appendicitis, CT-coverage can be reduced from diaphragmatic crus to pubis. PMID:23690436

  15. Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT

    PubMed Central

    Cho, S H; Sung, Y M; Kim, M S

    2012-01-01

    Objective The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. Methods 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. Results 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Conclusion Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images. PMID:22514102

  16. Diagnosis of Small-Bowel Diseases: Prospective Comparison of Multi-Detector Row CT Enterography with MR Enterography.

    PubMed

    Masselli, Gabriele; Di Tola, Marco; Casciani, Emanuele; Polettini, Elisabetta; Laghi, Francesca; Monti, Riccardo; Bernieri, Maria Giulia; Gualdi, Gianfranco

    2016-05-01

    Purpose To prospectively compare the accuracies of computed tomographic (CT) enterography and magnetic resonance (MR) enterography for the detection and characterization of small-bowel diseases. Materials and Methods The institutional review board approved the study protocol, and informed consent was obtained from all participants. From June 2009 to July 2013, 150 consecutive patients (81 men and 69 women; mean age, 38.8 years; range, 18-74 years), who were suspected of having a small-bowel disease on the basis of clinical findings and whose previous upper and lower gastrointestinal endoscopy findings were normal, underwent CT and MR enterography. Two independent readers reviewed CT and MR enterographic images for the presence of small-bowel diseases, for differentiating between inflammatory and noninflammatory diseases, and for extraenteric complications. The histopathologic findings of surgical (n = 23) and endoscopic (n = 32) biopsy specimens were used as the reference standard; the results of video-capsule endoscopy (n = 36) and clinical follow-up (n = 59) were used only to confirm the absence of small-bowel disease. Results MR and CT enterography were successfully performed in all 150 patients. Overall sensitivity, specificity, and accuracy, respectively, in identifying patients with small-bowel lesions were 75.9% (41 of 54), 94.8% (91 of 96), and 88.0% (132 of 150) for CT enterography and 92.6% (50 of 54), 99.0% (95 of 96), and 96.7% (145 of 150) for MR enterography. The sensitivity of MR enterography was significantly higher than that of CT enterography for the detection of both overall small-bowel diseases (P = .0159) and neoplastic diseases (P = .0412) but not for the detection of inflammatory diseases (P > .99) or noninflammatory and nonneoplastic diseases (P = .6171). Conclusion MR enterography is more accurate than CT enterography in the detection of small-bowel diseases; MR enterography was more accurate in detecting neoplastic diseases in particular

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

    PubMed Central

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

    2008-01-01

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

  18. CT Angiography (CTA)

    MedlinePlus

    ... CT Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ...

  19. 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).

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Eren, Suat

    2010-01-01

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

  2. 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

  3. 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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  6. Combined anatomical and functional imaging using coronary CT angiography and myocardial perfusion SPECT in symptomatic adults with abnormal origin of a coronary artery.

    PubMed

    Uebleis, C; Groebner, M; von Ziegler, F; Becker, A; Rischpler, C; Tegtmeyer, R; Becker, C; Lehner, S; Haug, A R; Cumming, P; Bartenstein, P; Franz, W M; Hacker, M

    2012-10-01

    There has been a lack of standardized workup guidelines for patients with congenital abnormal origin of a coronary artery from the opposite sinus (ACAOS). We aimed to evaluate the use of cardiac hybrid imaging using multi-detector row CT (MDCT) for coronary CT angiography (Coronary CTA) and stress-rest myocardial perfusion SPECT (MPS) for comprehensive diagnosis of symptomatic adult patients with ACAOS. Seventeen symptomatic patients (12 men; 54 ± 13 years) presenting with ACAOS underwent coronary CTA and MPS. Imaging data were analyzed by conventional means, and with additional use of 3D image fusion to allocate stress induced perfusion defects (PD) to their supplying coronary arteries. An anomalous RCA arose from the left anterior sinus in eight patients, an abnormal origin from the right sinus was detected in nine patients (5 left coronary arteries, LCA and 4 LCx). Five of the 17 patients (29%) demonstrated a reversible PD in MPS. There was no correlation between the anatomical variants of ACAOS and the presence of myocardial ischemia. Image fusion enabled the allocation of reversible PD to the anomalous vessel in three patients (two cases in the RCA and the other in the LCA territory); PD in two patients were allocated to the territory of artery giving rise to the anomalies, rather than the anomalies themselves. In a small cohort of adult symptomatic patients with ACAOS anomaly there was no relation found between the specific anatomical variant and the appearance of stress induced myocardial ischemia using cardiac hybrid imaging. PMID:22147107

  7. Coronary vasospasm during CT angiography.

    PubMed

    Nakahara, Takehiro; Toyama, Takuji; Tsushima, Yoshito; Kurabayashi, Masahiko

    2014-01-01

    A 71-year-old man, a heavy smoker, was admitted for evaluation of "chest oppression" after every dinner. Cardiac CT with a beta-blocker showed coronary stenosis in the left circumflex. Although adenosine triphosphate-stress perfusion single-photon emission CT revealed no ischemia, Holter electrocardiography belatedly indicated an ST elevation associated with his symptoms while smoking. He was diagnosed to have vasospastic angina. Cardiac CT without a beta-blocker showed thin diffuse plaque and negative remolding without any significant stenosis at the same site. Asian patients have a tendency to develop vasospastic angina. Although beta-blockers are recommended for cardiac CT, the routine administration of beta-blockers in cardiac CT may have some risk for such cases. PMID:25065860

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

    PubMed Central

    Sliesarenko, Sergii V.

    2015-01-01

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

  9. 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. PMID:27432657

  10. 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

  11. Coronary CT angiography: current status and continuing challenges.

    PubMed

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

    2012-05-01

    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

  12. 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

  13. 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

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

    PubMed

    Sun, Zhonghua; Al Moudi, Mansour; Cao, Yan

    2014-10-01

    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

  15. 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

  16. [The features of adults' coronary artery anomalies shown by 64-multi-detector rows CT].

    PubMed

    Yuan, Zhentuan; Yu, Jianqun; Zhang, Youyi; Yuan, Hongmei

    2009-06-01

    To analyze the adults' coronary artery anomalies revealed by 64-MDCT, we retrospectively analyzed 34 cases of coronary artery anomalies (26 males and 8 females, averagely aged 53. 4 years with a range from 30 to 72 years). Multi-plannar reconstruction (MPR), maximum intensity projection (MIP), surface shadow display (SSD) and volume rendering (VR) were used to demonstrate the anomalous coronary artery. We found 4 cases of RCA from the left coronary sinus, 8 cases with secondary RCA, 1 case with high locations of left main (LM) segments from left sinus of valves, 1 case with LAD originated from main pulmonary artery, 3 cases with separate origin of LAD and LCX. Ten cases with myocardial bridge were shown (9 cases in LAD, 1 case in LCX); coronary fistula was seen in 2 cases (one was RCA-RA fistula, another was LAD-RV fistula), coronary aneurysm was found in 2 cases. Three cases in RCA were short and small. In conclusion, 64-MDCT is a good choice for diagnosing the anomalous coronary artery. PMID:19634659

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

    PubMed

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

    2015-07-01

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

  18. Coronary thrombus detected by cardiac CT angiography before cardiac catheterization.

    PubMed

    Slim, Ahmad M; Slim, Jennifer N; Haney, Brian R; Shry, Eric A

    2010-11-01

    A patient presented with a complaint of pleuritic chest discomfort with elevated cardiac biomarkers. After a cardiac magnetic resonance imaging scan for the suspicion of myopericarditis showed a potential myocardial infarct, a coronary CT scan was performed. This revealed a thrombus of the left anterior descending artery. Cardiac catheterization confirmed the findings, and a small clot was removed. To our knowledge, this is the first reported case of coronary thrombus being detected by CT angiography with cardiac catheterization correlation. Coronary CT angiography has been increasingly used to evaluate acute chest pain with a negative predictive value close to 100%. In a young patient with suspicion of myopericarditis, CT angiography proved to be useful in diagnosing thrombus in the coronary tree. PMID:20463613

  19. CT angiography in complex upper extremity reconstruction.

    PubMed

    Bogdan, M A; Klein, M B; Rubin, G D; McAdams, T R; Chang, J

    2004-10-01

    Computed tomography angiography is a new technique that provides high-resolution, three-dimensional vascular imaging as well as excellent bone and soft tissue spatial relationships. The purpose of this study was to examine the use of computed tomography angiography in planning upper extremity reconstruction. Seventeen computed tomography angiograms were obtained in 14 patients over a 20-month period. All studies were obtained on an outpatient basis with contrast administered through a peripheral vein. All the studies demonstrated the pertinent anatomy and the intraoperative findings were as demonstrated in all cases. Information from two studies significantly altered pre-operative planning. The average charge for computed tomography angiography was 1,140 dollars, compared to 3,900 dollars for traditional angiography. PMID:15336751

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

  5. Comprehensive plaque assessment by coronary CT angiography.

    PubMed

    Maurovich-Horvat, Pál; Ferencik, Maros; Voros, Szilard; Merkely, Béla; Hoffmann, Udo

    2014-07-01

    Most acute coronary syndromes are caused by sudden luminal thrombosis due to atherosclerotic plaque rupture or erosion. Preventing such an event seems to be the only effective strategy to reduce mortality and morbidity of coronary heart disease. Coronary lesions prone to rupture have a distinct morphology compared with stable plaques, and provide a unique opportunity for noninvasive imaging to identify vulnerable plaques before they lead to clinical events. The submillimeter spatial resolution and excellent image quality of modern computed tomography (CT) scanners allow coronary atherosclerotic lesions to be detected, characterized, and quantified. Large plaque volume, low CT attenuation, napkin-ring sign, positive remodelling, and spotty calcification are all associated with a high risk of acute cardiovascular events in patients. Computation fluid dynamics allow the calculation of lesion-specific endothelial shear stress and fractional flow reserve, which add functional information to plaque assessment using CT. The combination of morphologic and functional characteristics of coronary plaques might enable noninvasive detection of vulnerable plaques in the future. PMID:24755916

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Biodegradable Iodinated Polydisulfides as Contrast Agents for CT Angiography

    PubMed Central

    Jin, Erlei; Zheng-Rong, Lu

    2014-01-01

    Current clinical CT contrast agents are mainly small molecular iodinated compounds, which often suffer from short blood pool retention for more comprehensive cardiovascular CT imaging and may cause contrast-induced nephropathy. In this work, we prepared polydisulfides containing a traditional iodinated CT contrast agent in order to optimize the pharmacokinetics of the agent and improve its safety. Initially acting as a macromolecular agent and achieving sharp blood vessel delineation, the polydisulfides can be reduced by endogenous thiols via disulfide-thiol exchange reaction to oligomers that can be readily excreted via renal filtration. Short polyethylene glycol (PEG) chain was also introduced to the polymers to further modify the in vivo properties of the agents. Strong and prolonged vascular enhancement has been generated with two new agents in mice (5–10 times higher blood pool enhancement than iodinaxol). The polydisulfide agents gradually degraded and excreted via renal filtration. The gradual excretion process could prevent contrast induced nephropathy. These results suggest that the biodegradable macromolecular CT contrast agents are promising safe and effective blood contrast agents for CT angiography and image-guided interventions. PMID:24768156

  11. 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).

  12. Hilar cholangiocarcinoma. An evaluation of subtypes with CT and angiography.

    PubMed

    Yamashita, Y; Takahashi, M; Kanazawa, S; Charnsangavej, C; Wallace, S

    1992-07-01

    Sixty-seven patients had hilar cholangiocarcinomas which were divided into 3 types based on tumor morphology as observed on cholangiography and CT. The pathology, vascularity, and pattern of tumor spread of these types were compared. Most of the infiltrative tumors (n = 44) were scirrhous adenocarcinomas, which on CT showed poor or no contrast enhancement with frequent lymph node metastases and liver atrophy. At angiography, there was vascular encasement in 52%, in rare cases neovascularity, and tumor stain. The exophytic type (n = 19) was divided into 2 subgroups depending on the main location of the tumor. The nodular subtype (n = 16) was mainly inside the liver and somewhat hypervascular similar to peripheral cholangiocarcinoma, often with intrahepatic metastases. The periductal subtype (n = 3) was hypovascular, similar to the infiltrative cholangiocarcinoma, and had a tendency to spread along the portal vein. The intraductal type (n = 4) was observed as a filling defect on cholangiography. CT revealed an intraluminal low density mass. Histologically, they were papillary adenocarcinomas. The radiologic types of hilar cholangiocarcinoma showed different characteristics with regard to pathologic findings, vascularity, and pattern of spread. PMID:1321653

  13. Preoperative Gross Classification of Gastric Adenocarcinoma: Comparison of Double Contrast-Enhanced Ultrasound and Multi-Detector Row CT.

    PubMed

    Yan, Caoxin; Bao, Xiaofeng; Shentu, Weihui; Chen, Jian; Liu, Chunmei; Ye, Qin; Wang, Liuhong; Tan, Yangbin; Huang, Pintong

    2016-07-01

    The aim of this study was to compare the accuracy of multi-detector computed tomography (MDCT) with double contrast-enhanced ultrasound (DCEUS), in which intravenous microbubbles are used alongside oral contrast-enhanced ultrasound, in determining the gross classification of patients with gastric carcinoma (GC). Altogether, 239 patients with GC proved by histology after endoscopic biopsy were included in this study. DCEUS and MDCT were performed pre-operatively. The diagnostic accuracies of DCEUS and MDCT in determining the gross classification were calculated and compared. The overall accuracy of DCEUS in determining the gross appearance of GC was higher than that of MDCT (84.9% vs. 79.9%, p < 0.001). There was no significant difference in accuracy between DCEUS and MDCT for Borrmann I and IV classifications of advanced gastric cancer (χ(2), p = 0.323 for Borrmann type I, p = 0.141 for Borrmann type IV). The accuracy of DCEUS for early GC and Borrmann II and III classifications of GC was higher than that of MDCT (χ(2), p = 0.000 for all). DCEUS may be regarded as a valuable complementary tool to MDCT in determining the gross appearance of gastric adenocarcinoma pre-operatively. PMID:27072076

  14. Pancreatic pseudoaneurysm in a child with hereditary pancreatitis: diagnosis with multidetector CT angiography.

    PubMed

    Ahmed, Hossam K; Hagspiel, Klaus D; McGahren, Eugene D; Angle, John F; Leung, Daniel A; Spinosa, David J; Matsumoto, Alan H; Rodgers, Bradley M

    2004-08-01

    Pseudoaneurysm formation is a serious vascular complication of pancreatitis. It most commonly affects splenic and gastroduodenal arteries. We report a rare case of superior mesenteric artery pseudoaneurysm in a child with hereditary pancreatitis. Multidetector CT angiography allowed the comprehensive assessment of the aneurysm and allowed accurate surgical planning obviating the need for catheter angiography. PMID:15107963

  15. 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. PMID:24848958

  16. Segmental Comparison of Peripheral Arteries by Doppler Ultrasound and CT Angiography

    PubMed Central

    Swaminathan, Ram Kumar; Ganesan, Prakash; Mayavan, Manibharathi

    2016-01-01

    Introduction Diseases of peripheral arterial system are one of the common causes of limb pain, especially in elderly patients. Here we analyse non invasive imaging of peripheral arterial segments. Aim Aim of the study was to compare arterial diseases of extremities using Doppler ultrasound and CT angiography, and to find the better non-invasive modality of choice. Materials and Methods Fifty patients {14 patients with upper limb complaints (15 upper limbs) and 36 patients with lower limb complaints (72 lower limbs)} of peripheral arterial disease underwent Doppler ultrasound (USG) and CT Angiogram (CTA). Arterial systems divided into anatomic segments and luminal narrowing were compared using gray scale Doppler ultrasound and axial images of arterial phase of CT angiogram. Using statistical methods, sensitivity, specificity and accuracy of Doppler ultrasound and CT angiography were determined. Results Six hundred and nineteen arterial segments were studied with CT angiography and Doppler ultrasound. Of which 226 diseased segments were identified in CT angiography. Doppler overestimated narrowing by one grade in 47 segments, by two grade in 11 segments, by three grades in 30 segments and by four grades in 22 segments; underestimated by one grade in 28 segments, by two grades in 9 segments, by three grades in 5 segments and by four grades in 3 segments. Significant statistical difference exists between Doppler USG and CT angiography. Doppler showed good correlation with CT angiography in 74%, but, Doppler overestimated stenosis grade in a significant percentage. The sensitivity, specificity and accuracy of Doppler USG compared with CT angiography was 93.36%, 82.44%, and 86.42%. Conclusion Duplex Doppler can be the first investigation in excluding peripheral arterial disease, especially for evaluation of infra inguinal region of lower limbs and from second part of the subclavian artery in upper limbs. PMID:27042556

  17. Semiautomatic bone removal technique from CT angiography data

    NASA Astrophysics Data System (ADS)

    Alyassin, Abdal M.; Avinash, Gopal B.

    2001-07-01

    Cortical bone is the major barrier in visualizing the 3-D blood vessel tree from CT Angiography [CTA] data. Thus, we have developed a novel semi-automatic technique that removes the cortical bone and retains the clinical diagnostic information such as blood vessels, aneurysms, and calcifications. The technique is based on a methodical composite set of filters that use region-growing, adaptive, and morphological filtering algorithms. While using only voxel intensity value and region size information, this technique retains most of the CTA data untouched. We have implemented this method on 10 CTA abdomen and head data sets. The accuracy of the method was tested and proved successful by visual inspection of all segmented slices. The segmented CTA data were also visualized in 3-D with different Ray Casting Volume Rendering techniques (e.g. Maximum Intensity Projection). The blood vessels along with other diagnostic information were clearly visualized in 3-D without the obstruction of bone. The segmentation technique ran under one second per slice (image size is 512x512x2 bytes) on a PC with 550 MHz processor.

  18. Combined hepatocellular and cholangiocarcinoma of the liver: sonography, CT, angiography, and iodized-oil CT with pathologic correlation.

    PubMed

    Choi, B I; Han, J K; Kim, Y I; Kim, H C; Park, J H; Kim, C W; Han, M C

    1994-01-01

    To evaluate the characteristics of combined hepatocellular and cholangiocarcinoma of the liver by imaging techniques, six patients (five male and one female), aged 46-60 years, with proved combined tumors were selected for this study from the review of 500 resected specimens of liver tumors. Images obtained from sonography, computed tomography (CT), angiography, and CT after intraarterial injection of iodized oil (iodized-oil CT) were retrospectively reviewed and correlated with the appearance of pathologic specimens. Sonographic findings were round or ovoid hypoechoic masses with central hyperechoic area (target appearance) in all patients. On CT scans, tumors were relatively well-defined low-and/or iso-attenuation masses in all patients. Angiography showed hypovascular masses in five patients. In one patient, the tumor appeared as a hypovascular mass with a central hypervascular area. On iodized-oil CT scans, all patients showed partial retention of iodized oil in tumors. Echogenicity in tumors at sonography or attenuation in tumors at CT could not be correlated with histologic difference in tumors at pathologic specimens. However, the hypervascular area at angiography and the compact retention areas of iodized oil at iodized-oil CT corresponded to portions of hepatocellular carcinoma within the combined tumor. On the basis of our results, imaging features, including target appearance at sonography, hypovascular mass with central hypervascular portions at angiography, and partial retention of iodized oil in tumors at iodized-oil CT, might be helpful in making accurate diagnosis of these rare tumors. PMID:8161902

  19. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography

    PubMed Central

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-01-01

    Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment. PMID:23563677

  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. Patterns of Opacification in Coronary CT Angiography: Contrast Differences and Gradients

    PubMed Central

    Rybicki, Frank J.; Juan, Yu-Hsiang; Saboo, Sachin S.; George, Elizabeth; Bhivasankar, Rani; Mitsouras, Dimitrios

    2014-01-01

    Iodinated contrast delivery is a key component of coronary CT angiography. However, the purpose of contrast delivery has been limited to morphology alone. Specifically, iodine opacification of the coronary lumen has been used to separate it from the coronary artery wall and lesions within the coronary arteries. Because contrast is delivered to the coronary arteries according to the coronary blood flow, there is flow information encoded within the contrast opacification which, depending on CT hardware and acquisition protocol, can be recognized in coronary CT angiography. In addition, metrics related to flow have been identified and studied. They include coronary contrast opacification differences and contrast opacification gradients. PMID:25258657

  2. 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

  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

    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. PMID:26802856

  4. 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. PMID:26463312

  5. 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

  6. Bilateral alien hand syndrome in cerebrovascular disease: CT, MR, CT angiography, and 99mTc-HMPAO-SPECT findings.

    PubMed

    Serrano-Vicente, Justo; Duran-Barquero, Carmen; Garcia-Bernardo, Lucia; Dominguez-Grande, Maria Luz; Infante-Torre, Jose Rafael; Rayo-Madrid, Juan Ignacio

    2015-03-01

    We report a 65-year-old man with a right cerebral infarction that occurred 15 years ago and a residual left hemiparesis that began with progressive contralateral hemiparesis. During the hospitalization, the patient developed a bilateral alien hand syndrome. Urgent CT, MR, CT angiography, and brain perfusion SPECT were performed that revealed an old right cerebral infarction and a new ischemic lesion in left parietal lobe and adjacent brain territories. PMID:25546190

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

    PubMed

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

    2006-08-01

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

  8. 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.

  9. Effects of Dual-Energy CT with Non-Linear Blending on Abdominal CT Angiography

    PubMed Central

    Wang, Chaoqin; Jiang, Xiaochen; Xu, Ge

    2014-01-01

    Objective To determine whether non-linear blending technique for arterial-phase dual-energy abdominal CT angiography (CTA) could improve image quality compared to the linear blending technique and conventional 120 kVp imaging. Materials and Methods This study included 118 patients who had accepted dual-energy abdominal CTA in the arterial phase. They were assigned to Sn140/80 kVp protocol (protocol A, n = 40) if body mass index (BMI) < 25 or Sn140/100 kVp protocol (protocol B, n = 41) if BMI ≥ 25. Non-linear blending images and linear blending images with a weighting factor of 0.5 in each protocol were generated and compared with the conventional 120 kVp images (protocol C, n = 37). The abdominal vascular enhancements, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and radiation dose were assessed. Statistical analysis was performed using one-way analysis of variance test, independent t test, Mann-Whitney U test, and Kruskal-Wallis test. Results Mean vascular attenuation, CNR, SNR and subjective image quality score for the non-linear blending images in each protocol were all higher compared to the corresponding linear blending images and 120 kVp images (p values ranging from < 0.001 to 0.007) except for when compared to non-linear blending images for protocol B and 120 kVp images in CNR and SNR. No significant differences were found in image noise among the three kinds of images and the same kind of images in different protocols, but the lowest radiation dose was shown in protocol A. Conclusion Non-linear blending technique of dual-energy CT can improve the image quality of arterial-phase abdominal CTA, especially with the Sn140/80 kVp scanning. PMID:25053901

  10. 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

  11. 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

  12. Intraarterial CT Angiography Using Ultra Low Volume of Iodine Contrast – Own Experiences

    PubMed Central

    Garcarek, Jerzy; Kurcz, Jacek; Guziński, Maciej; Banasik, Mirosław; Miś, Marcin; Gołębiowski, Tomasz

    2015-01-01

    Summary Background High volume of intravenous contrast in CT-angiography may result in contrast-induced nephropathy. Intraarterial ultra-low volume of contrast medium results in its satisfactory blood concentration with potentially good image quality. The first main purpose was to assess the influence of the method on function of transplanted kidney in patients with impaired graft function. The second main purpose of the study was to evaluate the usefulness of this method for detection of gastrointestinal and head-and-neck haemorrhages. Material/Methods Between 2010 and 2013 intraarterial CT-angiography was performed in 56 patients, including 28 with chronic kidney disease (CKD). There were three main subgroups: 18 patients after kidney transplantation, 10 patients with gastrointestinal hemorrhage, 8 patients with head-and-neck hemorrhage. Contralateral or ipsilateral inguinal arterial approach was performed. The 4-French vascular sheaths and 4F-catheters were introduced under fluoroscopy. Intraarterial CT was performed using 64-slice scanner. The scanning protocol was as follows: slice thickness 0.625 mm, pitch 1.3, gantry rotation 0.6 sec., scanning delay 1–2 sec. The extent of the study was established on the basis of scout image. In patients with CKD 6–8 mL of Iodixanol (320 mg/mL) diluted with saline to 18–24 mL was administered at a speed of 4–5 mL/s. Results Vasculature was properly visualized in all patients. In patients with impaired renal function creatinine/eGFR levels remained stable in all but one case. Traditional arteriography failed and CT-angiography demonstrated the site of bleeding in 3 of 10 patients with symptoms of gastrointestinal bleeding (30%). In 8 patients with head-and-neck bleeding CT-angiography did not prove beneficial when compared to traditional arteriography. Conclusions 1. Ultra-low contrast intraarterial CT-angiography does not deteriorate the function of transplanted kidneys in patients with impaired graft function. 2. 3

  13. Stereological estimation of left-ventricular volumetric and functional parameters from multidetector-row computed tomography data.

    PubMed

    Mazonakis, Michalis; Pagonidis, Konstantin; Schlosser, Thomas; Hunold, Peter; Damilakis, John; Barkhausen, Jörg; Gourtsoyiannis, Nicholas

    2008-07-01

    This study aims to optimize the stereological method for estimating left-ventricular (LV) parameters from retrospectively electrocardiography-gated 16-row MDCT and to compare stereological estimations with those by MRI. MDCT was performed in 17 consecutive patients with known or suspected coronary disease. Stereological measurements based on point counting were optimized by determining the appropriate distance between grid points. LV parameters were evaluated by standard CT analysis using a semi-automatic segmentation method. Two independent observers evaluated the reproducibility of the stereological method. End-diastolic volume (EDV) and end-systolic volume (ESV) estimations with a coefficient of error below 5% were obtained in a mean time of 2.3 +/- 0.5 min with a point spacing of 25 and 15 pixels, respectively. The intra- and interobserver variability for estimating LV parameters was 2.6-4.4 and 4.9-8.2%, respectively. MRI estimations were highly correlated with those by standard CT analysis (R > 0.82) and stereology (R > 0.84). Stereological method significantly overestimated EDV and ESV compared to MRI (EDV: P = 0.0011; ESV: P = 0.0013), whereas for stroke volume (SV) and ejection fraction (EF), no difference was observed (P > 0.05). For standard CT analysis and MRI, significant differences were found except for SV and EF (EDV: P = 0.0008; ESV: P = 0.0004; EF: P = 0.051; SV: P = 0.064). The time-efficient optimized stereological method enables the reproducible evaluation of LV function from MDCT. PMID:18351349

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  16. 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.

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

    PubMed

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

    2015-01-01

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

  18. 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.

  19. 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.

  20. [Conservative management of renal haemangioma: value of a synergistic combination of flexible ureteroscopy and CT angiography].

    PubMed

    Mallet, Richard; Game, Xavier; Lefi, Mounir; Mouzin, Marc; Malavaud, Bernard; Otal, Philippe; Joffre, Francis; Rischmann, Pascal

    2007-02-01

    Renal haemangioma (RH) is a rare congenital vascular lesion that is frequently responsible for macroscopic haematuria. This lesion is difficult to diagnose preoperatively despite progress in imaging techniques. These diagnostic difficulties account for the high rate of radical treatment (nephrectomy or nephro-ureterectomy) due to a suspicion of renal carcinoma or upper urinary tract tumour. However, conservative diagnostic and therapeutic management can be performed by a combination of CT angiography, flexible ureteroscopy and selective embolization. PMID:17373249

  1. 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.

  2. 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

  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. 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

  5. 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.

  6. 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.

  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. Reduced iodine load with CT coronary angiography using dual-energy imaging: A prospective randomized trial compared with standard coronary CT angiography

    PubMed Central

    Raju, Rekha; Thompson, Angus G.; Lee, Kristy; Precious, Bruce; Yang, Tae-Hyun; Berger, Adam; Taylor, Carolyn; Heilbron, Brett; Nguyen, Giang; Earls, James; Min, James; Carrascosa, Patricia; Murphy, Darra; Hague, Cameron; Leipsic, Jonathon A.

    2014-01-01

    Background There is concern regarding the administration of iodinated contrast to patients with impaired renal function because of the increased risk of contrast-induced nephropathy. Objective Evaluate image quality and feasibility of a protocol with a reduced volume of iodinated contrast and utilization of dual-energy coronary CT angiography (DECT) vs a standard iodinated contrast volume coronary CT angiography protocol (SCCTA). Methods A total of 102 consecutive patients were randomized to SCCTA (n = 53) or DECT with rapid kVp switching (n = 49). Eighty milliliters and 35 mL of iodinated contrast were administered in the SCCTA and DECT cohorts, respectively. Two readers measured signal and noise in the coronary arteries; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A 5-point signal/noise Likert scale was used to evaluate image quality; scores of <3 were nondiagnostic. Agreement was assessed through kappa analyses. Results Demographics and radiation dose were not significantly different; there was no difference in CNR between both cohorts (P = .95). A significant difference in SNR between the groups (P = .02) lost significance (P = .13) when adjusted for body mass index. The median Likert score was inferior for DECT for reader 1 (3.6 ± 0.6 vs 4.3 ± 0.6; P < .001) but not reader 2 (4.1 ± 0.6 vs 4.3 ± 0.5; P = .06). Agreement in diagnostic interpretability in the DECT and SCCTA groups was 91% (95% confidence interval, 86%–100%) and 96% (95% confidence interval, 90%–100%), respectively. Conclusion DECT resulted in inferior image quality scores but demonstrated comparable SNR, CNR, and rate of diagnostic interpretability without a radiation dose penalty while allowing for >50% reduction in contrast volume compared with SCCTA. PMID:25151920

  9. Usefulness of multidetector CT angiography for anomalous origin of coronary artery

    PubMed Central

    Ishisone, Takenori; Satoh, Mamoru; Okabayashi, Hitoshi; Nakamura, Motoyuki

    2014-01-01

    A 17-year-old man underwent clinical evaluation of exercise-induced syncope. Routine exercise stress test did not show any myocardial ischaemic changes or arrhythmias on the ECG recording. However, multidetector CT (MDCT) angiography of the coronary arteries revealed an abnormal origin of the left coronary artery from the right coronary sinus. The participants’ symptoms were diagnosed as cardiogenic syncope possibly due to transient stenosis of the left main coronary artery caught between the functionally distended aortic root and the pulmonary trunk during exercise. After successful patch coronary angioplasty, his symptoms disappeared completely even during a similar degree of strenuous exercise. It is important for clinicians not to overlook possible coronary artery anomalies during management of patients with exercise-induced syncope. MDCT coronary angiography may be a useful and non-invasive tool to establish diagnosis and a surgical approach to rectify congenital coronary artery anomalies. PMID:25150237

  10. Imaging Quality Evaluation of Low Tube Voltage Coronary CT Angiography Using Low Concentration Contrast Medium

    PubMed Central

    Zhang, Zaixian; Wang, Qingguo; Zheng, Linfeng; Feng, Yan; Zhou, Zhiguo; Zhang, Guixiang; Li, Kangan

    2015-01-01

    Purpose To compare the image quality of prospectively ECG-gated low voltage coronary computed tomography angiography (CTA) with an administration of low concentration contrast medium. Method and Materials A total of 101 patients, each with a heart rate below 65 beats per minute (BPM), underwent a prospectively ECG-gated axial scan in CT coronary angiography on a 64-slice CT scanner. All patients were allocated in three groups (group A: n=31, 80kVp, 300 mgI/ml; group B: n=34, 100kVp, 300 mgI/ml; group C: n=36, 120kVp, 370 mgI/ml). The CT attenuation values of aortic root (AR), left main coronary artery (LMA), right main coronary artery (RMA) and chest subcutaneous fat tissue were measured. The contrast-to-noise ratio (CNR) of AR, LMA and RMA were calculated according to the formulas below. The values of computed tomography dose index (CTDI) and dose-length product (DLP) were recorded. Image quality was assessed on a 5-point scale. The results were compared using the one-way ANOVA and rank sum tests. Results The values of CNR and SNR for vessels in group A and group B were not significantly different from group C (each p > 0.05). The effective radiation dose in group A (1.51±0.70 mSv) and group B (2.59±1.24 mSv) were both lower than group C (4.92±2.82 mSv) (each p < 0.05). There was no significant difference among the image quality scores of group A (4.10±0.41), group B (3.90±0.48) and group C (4.04±0.36) (each P > 0.05). Conclusion Low tube voltage coronary CT angiography using low concentration contrast medium does not affect the imaging quality for assessing the coronary arteries compared with high voltage coronary CT angiography using high concentration contrast medium. Meanwhile low concentration contrast medium allowed 47-69% of radiation dose reduction. PMID:25811785

  11. High-Pitch CT Pulmonary Angiography in Third Generation Dual-Source CT: Image Quality in an Unselected Patient Population

    PubMed Central

    Sabel, Bastian O.; Buric, Kristijan; Karara, Nora; Thierfelder, Kolja M.; Dinkel, Julien; Sommer, Wieland H.; Meinel, Felix G.

    2016-01-01

    Objectives To investigate the feasibility of high-pitch CT pulmonary angiography (CTPA) in 3rd generation dual-source CT (DSCT) in unselected patients. Methods Forty-seven patients with suspected pulmonary embolism underwent high-pitch CTPA on a 3rd generation dual-source CT scanner. CT dose index (CTDIvol) and dose length product (DLP) were obtained. Objective image quality was analyzed by calculating signal-to-noise-ratio (SNR) and contrast-to-noise ratio (CNR). Subjective image quality on the central, lobar, segmental and subsegmental level was rated by two experienced radiologists. Results Median CTDI was 8.1 mGy and median DLP was 274 mGy*cm. Median SNR was 32.9 in the central and 31.9 in the segmental pulmonary arteries. CNR was 29.2 in the central and 28.2 in the segmental pulmonary arteries. Median image quality was “excellent” in central and lobar arteries and “good” in subsegmental arteries according to both readers. Segmental arteries varied between “excellent” and “good”. Image quality was non-diagnostic in one case (2%), beginning in the lobar arteries. Thirteen patients (28%) showed minor motion artifacts. Conclusions In third-generation dual-source CT, high-pitch CTPA is feasible for unselected patients. It yields excellent image quality with minimal motion artifacts. However, compared to standard-pitch cohorts, no distinct decrease in radiation dose was observed. PMID:26872262

  12. Preoperative imaging of liver metastases. Comparison of angiography, CT scan, and ultrasonography.

    PubMed Central

    Gunvén, P; Makuuchi, M; Takayasu, K; Moriyama, N; Yamasaki, S; Hasegawa, H

    1985-01-01

    Thirty-one patients with mostly colorectal cancer metastases to the liver had preoperative selective/superselective angiograms (24 cases), computed tomography (CT) [26 cases, mostly enhanced by contrast administered by a peripheral vein (9), the common hepatic artery (9), or the portal vein (5)], and ultrasonography (26 cases). Intraoperative ultrasonography and palpation and examination of the resected specimens revealed 113 tumors. CT detected almost half of the masses smaller than 1 cm, and ultrasonography and angiography about one-third of lesions 1-2 cm in size. Ultrasonography was less powerful for examination of the posterior segment of the liver. CT and ultrasonography placed the tumors into subsegments more accurately than did angiography. Almost 40% of the preoperative plans had to be changed: in two-thirds by extended resections and in one-third by a change from curative to palliative intent. Most changes were due to extrahepatic tumor growth, often within areas screened before surgery. The use of all three imaging modalities for liver metastases is recommended for preoperative planning. PMID:3901943

  13. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    PubMed Central

    Behroozi, Hamid; Davoodi, Mohammad; Aghasi, Shahriar

    2015-01-01

    Background: The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. Objectives: The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Patients and Methods: Eighty-one patients (41 males and 40 females) who were diagnosed with suspected coronary artery disease and were referred to Golestan Hospital, Imaging Department were recruited. Inclusion criteria were based on the protocol of multi-slice CT coronary angiography. The radiation dose to the thyroid and pelvis regions was measured using thermo luminescent dosimeters (TLDs). Results: The mean radiation dose to the thyroid in male and female subjects was 0.32 mSv and 0.41 mSv, respectively (P = 0.032) (total mean, 0.36 mSv). The mean radiation dose to the pelvis in male and female subjects was 81 μSv and 112 μSv, respectively (P = 0.026) (total mean, 96.5 μSv), Conclusions: The total mean radiation dose to the thyroid and gonads was 0.36 mSv, and 96.5 μSv, respectively for the subjects. These values were high for one organ in a single study. Gender can affect the radiation dose to the thyroid and gonads. This can be attributed to the anatomical characteristic differences of the male and female subjects. PMID:26060556

  14. 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

  15. 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

  16. High-pitch spiral acquisition: a new scan mode for coronary CT angiography.

    PubMed

    Achenbach, Stephan; Marwan, Mohamed; Schepis, Tiziano; Pflederer, Tobias; Bruder, Herbert; Allmendinger, Thomas; Petersilka, Martin; Anders, Katharina; Lell, Michael; Kuettner, Axel; Ropers, Dieter; Daniel, Werner G; Flohr, Thomas

    2009-01-01

    Coronary CT angiography allows high-quality imaging of the coronary arteries when state-of-the-art CT systems are used. However, radiation exposure has been a concern. We describe a new scan mode that uses a very high-pitch spiral acquisition, "Flash Spiral," which has been developed specifically for low-dose imaging with dual-source CT. The scan mode uses a pitch of 3.2 to acquire a spiral CT data set, while covering the entire volume of the heart in one cardiac cycle. Data acquisition is prospectively triggered by the electrocardiogram and starts in late systole to be completed within one cardiac cycle. Images are reconstructed with a temporal resolution that corresponds to one-quarter of the gantry rotation time. Throughout the data set, subsequent images are reconstructed at later time instants in the cardiac cycle. In a patient with a heart rate of 49 beats/min, the Flash Spiral scan mode was used with a first-generation dual-source CT system and allowed artifact-free visualization of the coronary arteries with a radiation exposure of 1.7 mSv for a 12-cm scan range at 120 kVp tube voltage. PMID:19332343

  17. 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

  18. Evaluation of popliteal arteries with CT angiography in popliteal artery entrapment syndrome

    PubMed Central

    Papaioannou, S; Tsitouridis, K; Giataganas, G; Rodokalakis, G; Kyriakou, V; Papastergiou, Ch; Arvaniti, M; Tsitouridis, I

    2009-01-01

    Background: Popliteal artery entrapment is an uncommon clinical entity that occurs due to compression of the popliteal artery by adjacent muscle and tendinous structures. Early diagnosis should be established through a combined approach of careful physical examination and history-taking, duplex ultrasonography, and CT angiography. Patients and methods: We have studied retrospectively 16 patients of popliteal artery entrapment syndrome, 9 men and 7 women. All patients were scanned with a scanner Picker PQ 5000 after bolus injection of nonionic contrast medium and they all underwent a two-part examination first, with the knee in a neutral position, and, second, with the knee hyperextended. Results: At the second phase of the examination 3 patients showed normal findings, 10 patients have shown mild stenosis of the popliteal artery or more severe stenosis due to compression, 2 patients have exhibited bilateral stenosis and 1 patient has also showed popliteal venous compression Conclusion: CT angiography images and three-dimensional images are useful not only for depiction of the arterial changes but also identification of the abnormal anatomic structures responsible for the entrapment. PMID:19240818

  19. 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).

  20. 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.

  1. Dose management in CT facility

    PubMed Central

    Tsapaki, V; Rehani, M

    2007-01-01

    Computed Tomography (CT) examinations have rapidly increased in number over the last few years due to recent advances such as the spiral, multidetector-row, CT fluoroscopy and Positron Emission Tomography (PET)-CT technology. This has resulted in a large increase in collective radiation dose as reported by many international organisations. It is also stated that frequently, image quality in CT exceeds the level required for confident diagnosis. This inevitably results in patient radiation doses that are higher than actually required, as also stressed by the US Food and Drug Administration (FDA) regarding the CT exposure of paediatric and small adult patients. However, the wide range in exposure parameters reported, as well as the different CT applications reveal the difficulty in standardising CT procedures. The purpose of this paper is to review the basic CT principles, outline the recent technological advances and their impact in patient radiation dose and finally suggest methods of radiation dose optimisation. PMID:21614279

  2. Cerebral vascular malformations: Time-resolved CT angiography compared to DSA

    PubMed Central

    Lum, Cheemun; Chakraborty, Santanu; dos Santos, Marlise P

    2015-01-01

    Purpose The purpose of this article is to prospectively test the hypothesis that time-resolved CT angiography (TRCTA) on a Toshiba 320-slice CT scanner enables the same characterization of cerebral vascular malformation (CVM) including arteriovenous malformation (AVM), dural arteriovenous fistula (DAVF), pial arteriovenous fistula (PAVF) and developmental venous anomaly (DVA) compared to digital subtraction angiography (DSA). Materials and methods Eighteen (eight males, 10 females) consecutive patients (11 AVM, four DAVF, one PAVF, and two DVA) underwent 19 TRCTA (Aquillion one, Toshiba) for suspected CVM diagnosed on routine CT or MRI. One patient with a dural AVF underwent TRCTA and DSA twice before and after treatment. Of the 18 patients, 13 were followed with DSA (Artis, Siemens) within two months of TRCTA. Twenty-three sequential volume acquisitions of the whole head were acquired after injection of 50 ml contrast at the rate of 4 ml/sec. Two patients with DVA did not undergo DSA. Two TRCTA were not assessed because of technical problems. TRCTAs were independently reviewed by two neuroradiologists and DSA by two other neuroradiologists and graded according to the Spetzler-Martin classification, Borden classification, overall diagnostic quality, and level of confidence. Weighted kappa coefficients (k) were calculated to compare reader’s assessment of DSA vs TRCTA. Results There was excellent (k = 0.83 and 1) to good (k = 0.56, 0.61, 0.65 and 0.67) agreement between the different possible pairs of neuroradiologists for the assessment of vascular malformations. Conclusion TRCTA may be a sufficient noninvasive substitute for conventional DSA in certain clinical situations. PMID:26246101

  3. 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

  4. CT of nontraumatic thoracic aortic emergencies.

    PubMed

    Bhalla, Sanjeev; West, O Clark

    2005-10-01

    Computed tomography (CT), especially multidetector row CT (MDCT), is often the preferred imaging test used for evaluation of nontraumatic thoracic aortic abnormalities. Unenhanced images, usually followed by contrast-enhanced arterial imaging, allow for rapid detailed aortic assessment. Understanding the spectrum of acute thoracic aortic conditions which may present similarly (aortic dissection, aneurysm rupture, penetrating atherosclerotic ulcer, intramural hematoma) will ensure that patients are diagnosed and treated appropriately. Familiarity with imaging protocols and potential mimics will prevent confusion of normal anatomy and variants with aortic disease. PMID:16274000

  5. The Diagnostic Performance of Coronary CT Angiography for the Assessment of Coronary Stenosis in Calcified Plaque

    PubMed Central

    Xu, Yi; Zhu, Xiao-Mei; Zhang, Yu-Dong; Shi, Hai-Bin; Yu, Rong-Bin

    2016-01-01

    Purpose To prospectively evaluate the diagnostic performance of coronary CT angiography (CCTA) for the assessment of coronary stenosis in a calcified plaque, by using conventional coronary angiography (CAG) as a standard reference. Materials and Methods Eight hundred and ninety-four patients were known to have or have been suspicious of having coronary artery disease, underwent CCTA and conventional coronary angiography (CAG). All the images acquired were assessed. The calcified plaque in CCTA was classified into four types (I-IV) according to the ratio of calcified plaque volume to vessel circumference (RVTC). Overall diagnostic accuracy was made under receiver operating characteristic curve (AUC) analysis. CAG was used as the standard reference. Results A total of 12845 segments were evaluated in 894 patients, among which 4955 calcified plaques were detected on 3645(28.4%) segments by CCTA. The overall AUC, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.939, 97.8%, 90.1%, 71.2% and 99.4%, respectively. In type I-II calcification, CCTA had high diagnostic performance in AUC (type I: 0.983; type II: 0.976), sensitivity (96.7%; 98.1%), specificity (99.8%; 97.0%), PPV (95.7%; 90.1%), NPV (99.8%; 99.5%) and accuracy (99.6%; 97.3%). In type III-IV calcification, CCTA has high performance in sensitivity (type III: 97.6%; type IV: 97.9%) and NPV (98.3%; 98.7%), moderate performance in AUC (0.877; 0.829), while remarkable decrease in specificity (78.7%; 67.9%), PPV (71.0%; 56.2%) and accuracy (84.9%; 76.8%). Conclusion CCTA has highest accuracy in diagnosing the coronary artery stenosis of type I-II calcified plaques, but has a significant decrease in specificity, PPV and accuracy in type III-IV calcified plaque. PMID:27149622

  6. 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

  7. Contrast agent comparison for three-dimensional micro-CT angiography: A cadaveric study.

    PubMed

    Kingston, Mitchell J; Perriman, Diana M; Neeman, Teresa; Smith, Paul N; Webb, Alexandra L

    2016-07-01

    Barium sulfate and lead oxide contrast media are frequently used for cadaver-based angiography studies. These contrast media have not previously been compared to determine which is optimal for the visualisation and measurement of blood vessels. In this study, the lower limb vessels of 16 embalmed Wistar rats, and four sets of cannulae of known diameter, were injected with one of three different contrast agents (barium sulfate and resin, barium sulfate and gelatin, and lead oxide combined with milk powder). All were then scanned using micro-computed tomography (CT) angiography and 3-D reconstructions generated. The number of branching generations of the rat lower limb vessels were counted and compared between the contrast agents using ANOVA. The diameter of the contrast-filled cannulae, were measured and used to calculate the accuracy of the measurements by comparing the bias and variance of the estimates. Intra- and inter-observer reliability were calculated using intra-class correlation coefficients. There was no significant difference (mean difference [MD] 0.05; MD 95% confidence interval [CI] -0.83 to 0.93) between the number of branching generations for barium sulfate-resin and lead oxide-milk powder. Barium sulfate-resin demonstrated less bias and less variance of the estimates (MD 0.03; standard deviation [SD] 1.96 mm) compared to lead oxide-milk powder (MD 0.11; SD 1.96 mm) for measurements of contrast-filled cannulae scanned at high resolution. Barium sulfate-resin proved to be more accurate than lead oxide-milk powder for high resolution micro-CT scans and is preferred due to its non-toxicity. This technique could be applied to any embalmed specimen model. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27075920

  8. 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.

  9. Relationship of hepatic steatosis severity and coronary artery disease characteristics assessed by coronary CT angiography.

    PubMed

    Tomizawa, Nobuo; Inoh, Shinichi; Nojo, Takeshi; Nakamura, Sunao

    2016-06-01

    The objective of this study was to investigate the relationship between the severity of hepatic steatosis and coronary artery disease characteristics assessed by coronary computed tomography (CT) angiography. This retrospective analysis consisted of 2028 patients. Hepatic steatosis was evaluated by liver attenuation on unenhanced CT and the patients were divided into four groups (≥60 HU, 54-59 HU, 43-53 HU, ≤42 HU). Coronary calcification was calculated using the Agatston method. Obstructive disease was defined as ≥50 % stenosis assessed by CT. A high-risk plaque was defined by a remodeling index >1.1 and low attenuation (<30 HU). Patients with a segment involvement score >4 were determined to have extensive disease. Logistic regression analysis was performed to study multivariate associations. Severity of hepatic steatosis was associated with coronary calcification (p = 0.02), obstructive disease (p < 0.0001), presence of a high-risk plaque (p = 0.0001) and extensive disease (p = 0.001) in the univariate analysis. However, the relationships were attenuated in the multivariate analysis with the exception of obstructive disease (p = 0.04). Liver attenuation of <54 HU was significantly associated with obstructive coronary artery disease independent of conventional risk factors such as age, sex, diabetes mellitus, hypertension, dyslipidemia and smoking (hepatic attenuation 43-53 HU, odds ratio 1.52, 95 % confidence interval 1.11-2.10, p = 0.01; ≤42 HU, odds ratio 1.65, 95 % confidence interval 1.10-2.45, p = 0.02). Although conventional risk factors were stronger predictors of coronary calcification and plaque formation, the severity of hepatic steatosis remained an independent risk factor for obstructive coronary artery disease. Coronary CT angiography may play a potential role in risk stratification for patients with hepatic steatosis. PMID:26831056

  10. 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. PMID:23746119

  11. 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.

  12. Radiation Dose from Single-Heartbeat Coronary CT Angiography Performed with a 320–Detector Row Volume Scanner1

    PubMed Central

    Elliston, Carl D.; Arai, Andrew E.; Chen, Marcus Y.; Mather, Richard; Pearson, Gregory D. N.; DeLaPaz, Robert L.; Nickoloff, Edward; Dutta, Ajoy; Brenner, David J.

    2010-01-01

    Purpose: To determine radiation doses from coronary computed tomographic (CT) angiography performed by using a 320–detector row volume scanner and evaluate how the effective dose depends on scan mode and the calculation method used. Materials and Methods: Radiation doses from coronary CT angiography performed by using a volume scanner were determined by using metal-oxide–semiconductor field-effect transistor detectors positioned in an anthropomorphic phantom physically and radiographically simulating a male or female human. Organ and effective doses were determined for six scan modes, including both 64-row helical and 280-row volume scans. Effective doses were compared with estimates based on the method most commonly used in clinical literature: multiplying dose-length product (DLP) by a general conversion coefficient (0.017 or 0.014 mSv·mGy−1·cm−1), determined from Monte Carlo simulations of chest CT by using single-section scanners and previous tissue-weighting factors. Results: Effective dose was reduced by up to 91% with volume scanning relative to helical scanning, with similar image noise. Effective dose, determined by using International Commission on Radiological Protection publication 103 tissue-weighting factors, was 8.2 mSv, using volume scanning with exposure permitting a wide reconstruction window, 5.8 mSv with optimized exposure and 4.4 mSv for optimized 100-kVp scanning. Estimating effective dose with a chest conversion coefficient resulted in a dose as low as 1.8 mSv, substantially underestimating effective dose for both volume and helical coronary CT angiography. Conclusion: Volume scanning markedly decreases coronary CT angiography radiation doses compared with those at helical scanning. When conversion coefficients are used to estimate effective dose from DLP, they should be appropriate for the scanner and scan mode used and reflect current tissue-weighting factors. © RSNA, 2010 PMID:20177085

  13. Diagnostic Performance of Transluminal Attenuation Gradient and Noninvasive Fractional Flow Reserve Derived from 320-Detector Row CT Angiography to Diagnose Hemodynamically Significant Coronary Stenosis: An NXT Substudy.

    PubMed

    Ko, Brian S; Wong, Dennis T L; Nørgaard, Bjarne L; Leong, Darryl P; Cameron, James D; Gaur, Sara; Marwan, Mohamed; Achenbach, Stephan; Kuribayashi, Sachio; Kimura, Takeshi; Meredith, Ian T; Seneviratne, Sujith K

    2016-04-01

    Purpose To compare the diagnostic performance of 320-detector row computed tomography (CT) coronary angiography-derived computed fractional flow reserve (FFR; FFRCT), transluminal attenuation gradient (TAG; TAG320), and CT coronary angiography alone to diagnose hemodynamically significant stenosis as determined by invasive FFR. Materials and Methods This substudy of the prospective NXT study (no. NCT01757678) was approved by each participating institution's review board, and informed consent was obtained from all participants. Fifty-one consecutive patients who underwent 320-detector row CT coronary angiographic examination and invasive coronary angiography with FFR measurement were included. Independent core laboratories determined coronary artery disease severity by using CT coronary angiography, TAG320, FFRCT, and FFR. TAG320 is defined as the linear regression coefficient between luminal attenuation and axial distance from the coronary ostium. FFRCT was computed from CT coronary angiography data by using computational fluid dynamics technology. Diagnostic performance was evaluated and compared on a per-vessel basis by the area under the receiver operating characteristic (ROC) curve (AUC). Results Among 82 vessels, 24 lesions (29%) had ischemia by FFR (FFR ≤ 0.80). FFRCT exhibited a stronger correlation with invasive FFR compared with TAG320 (Spearman ρ, 0.78 vs 0.47, respectively). Overall per-vessel accuracy, sensitivity, specificity, and positive and negative predictive values for TAG320 (<15.37) were 78%, 58%, 86%, 64%, and 83%, respectively; and those of FFRCT were 83%, 92%, 79%, 65%, and 96%, respectively. ROC curve analysis showed a significantly larger AUC for FFRCT (0.93) compared with that for TAG320 (0.72; P = .003) and CT coronary angiography alone (0.68; P = .008). Conclusion FFRCT computed from 320-detector row CT coronary angiography provides better diagnostic performance for the diagnosis of hemodynamically significant coronary stenoses

  14. Dual Energy CT Angiography of Peripheral Arterial Disease: Feasibility of Using Lower Contrast Medium Volume

    PubMed Central

    Almutairi, Abdulrahman; Sun, Zhonghua; Poovathumkadavi, Abduljaleel; Assar, Tarek

    2015-01-01

    Objective One of the main drawbacks associated with Dual Energy Computed Tomography Angiography (DECTA) is the risk of developing contrast medium-induced nephropathy (CIN). The aim of the present study was firstly, to design an optimal CT imaging protocol by determining the feasibility of using a reduced contrast medium volume in peripheral arterial DECTA, and secondly, to compare the results with those obtained from using routine contrast medium volume. Methods Thirty four patients underwent DECTA for the diagnosis of peripheral arterial disease. They were randomly divided into two groups: Group 1 (routine contrast volume group) with n = 17, injection rate 4–5 ml/s, and 1.5 ml/kg of contrast medium, and Group 2 ((low contrast volume group), with n = 17, injection rate 4–5ml/s, and contrast medium volume 0.75 ml/kg. A fast kilovoltage—switching 64-slice CT scanner in the dual-energy mode was employed for the study. A total of 6 datasets of monochromatic images at 50, 55, 60, 65, 70 and 75 keV levels were reconstructed with adaptive statistical iterative reconstruction (ASIR) at 50%. A 4-point scale was the tool for qualitative analysis of results. The two groups were compared and assessed quantitatively for image quality on the basis of signal-to-noise ratio (SNR) and contrast-to-noise-ratio (CNR). Radiation and contrast medium doses were also compared. Results The overall mean CT attenuation and mean noise for all lower extremity body parts was significantly lower for the low volume contrast group (p<0.001), and varied significantly between groups (p = 0.001), body parts (p<0.001) and keVs (p<0.001). The interaction between group body parts was significant with CT attenuation and CNR (p = 0.002 and 0.003 respectively), and marginally significant with SNR (p = 0.047), with minimal changes noticed between the two groups. Group 2 (low contrast volume group) displayed the lowest image noise between 65 and 70 keV, recorded the highest SNR and CNR at 65 keV, and

  15. 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.

  16. 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

    2016-01-01

    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 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. PMID:27455500

  17. 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.

  18. Descriptive anatomy of the dominant septal perforators using Dual Source Coronary CT Angiography.

    PubMed

    Brinjikji, Waleed; Harris, Scott R; Froemming, Adam T; Christensen, Kevin N; Lachman, Nirusha; Araoz, Philip A

    2010-01-01

    Although clinical outcomes for septal ablation in treating left ventricular outflow tract obstructions are generally favorable, a variety of complications have been reported including a high incidence of right bundle branch block. These complications may be attributed to anatomic variability of the dominant septal perforator. We used Dual Source CT Coronary Angiography (DS-CTA) to determine the location of the termination point of the dominant septal perforator as well as the distance of the termination point from the mitral annulus in patients undergoing DS-CTA. One-hundred-fourteen DS-CTA scans were retrospectively reviewed by two observers by consensus. The left ventricle was divided into anterior wall, anterioseptum, and inferioseptum. For each segment, the myocardium was divided into three layers (1) right ventricular side, (2) mid portion, and (3) left ventricular side. The zone of termination of the dominant septal perforator was identified as well as the distance of the termination point from the mitral annulus. The dominant septal perforator terminated in the right ventricular side of the anterioseptum in 86 of the 118 visualized terminations (73%) and in the left ventricular anterior wall in 6 visualized terminations (5%). On average, the dominant septal perforator terminated 26.3 +/- 8.6 mm from the mitral annulus. In the majority of cases, the dominant septal perforator terminates in the right ventricular side of anterioseptum. In addition, there is great variability in the distribution of the termination point of the dominant septal perforator from the mitral annulus. PMID:19918876

  19. 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

  20. 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.

  1. 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

  2. Can 3D-CT angiography (3D-CTA) replace conventional catheter angiography in ruptured aneurysm surgery? Our experience with 162 cases.

    PubMed

    Matsumoto, Masato; Kasuya, Hiromichi; Sato, Taku; Endo, Yuji; Sakuma, Jun; Suzuki, Kyouichi; Sasaki, Tatsuya; Kodama, Namio

    2007-12-01

    In this communication, we studied whether 3D-CT angiography (3D CTA) gives us enough information for a safe operation without those from conventional catheter angiography (CCA) in patients with ruptured aneurysms. Between December 1996 and September 2005, we treated 162 consecutive patients with ruptured aneurysms in the acute stage based on 3D-CTA findings. One hundred sixty-two ruptured aneurysms, including 64 associated unruptured aneurysms, were detected using 3D-CTA. CCA was performed in nine (5.6%) of the 162 patients after 3D-CTA. They were four dissecting vertebral artery aneurysms, two basilar tip aneurysms, one basilar artery-superior cerebellar artery (BA-SCA), one previously clipped BA-SCA and one internal carotid-posterior communicating artery aneurysm. All ruptured aneurysms confirmed at surgery were treated successfully. The lack of information on CCA did not lead any neurological deficits or difficulties in the surgical procedure. 3D-CTA was of high diagnostic value compatible with CCA and yielded important information such as the configuration of the aneurysmal sac and neck, calcification in the aneurysmal wall, and the aneurysms' anatomic relation with adjacent vessels and bone structures. We suggest that 3D-CTA can replace CCA in the diagnosis of ruptured aneurysms and that most of ruptured aneurysms can be operated by using only 3D-CTA without CCA. PMID:18402288

  3. Coronary CT Angiography as a Diagnostic and Prognostic Tool: Perspective from a Multicenter Randomized Controlled Trial: PROMISE.

    PubMed

    Bittner, Daniel O; Ferencik, Maros; Douglas, Pamela S; Hoffmann, Udo

    2016-05-01

    The PROMISE (Prospective multicenter imaging study for evaluation of chest pain) trial compared the effectiveness of coronary CT angiography and functional testing as initial diagnostic test for patients with suspicion for stable coronary artery disease (CAD). With 10,003 patients randomized at 193 sites, the PROMISE trial provides a snapshot of real-world care for this very common presentation. Over a median follow-up of 25 months, PROMISE did not find significant differences in major clinical events (composite endpoint 164 vs. 151, HR 1.04 (0.83-1.29); p = 0.75) between the two strategies. Other major findings were the large discrepancy between estimates of pre-test likelihood and observed prevalence for obstructive CAD (≥50 %) and the proportion of noninvasive tests positive for ischemia or obstructive CAD (53 vs. 11 %; respectively) and the better efficiency of coronary computed tomography angiography (CTA) to select patients for invasive coronary angiography (ICA) who had obstructive CAD (72 vs. 48 % for coronary CTA and functional testing, respectively). Radiation exposure was higher in the CT arm compared to all functional testing but lower than for nuclear perfusion stress testing. Improvement of patient selection for diagnostic testing and risk stratification will be keys to increase efficacy and efficiency of management of patients with suspicion for stable CAD. PMID:26995403

  4. 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

  5. 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.

  6. Removal of bone in CT angiography of the cervical arteries by piecewise matched mask bone elimination.

    PubMed

    van Straten, Marcel; Venema, Henk W; Streekstra, Geert J; Majoie, Charles B L M; den Heeten, Gerard J; 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. PMID:15543801

  7. High-Pitch Coronary CT Angiography at 70 kVp With Low Contrast Medium Volume

    PubMed Central

    Zhang, Long Jiang; Qi, Li; De Cecco, Carlo N.; Zhou, Chang Sheng; Spearman, James V.; Schoepf, U. Joseph; Lu, Guang Ming

    2014-01-01

    Abstract The purpose of this article is to evaluate image quality and radiation dose of prospectively electrocardiogram (ECG)-triggered high-pitch coronary computed tomography angiography (CCTA) at 70 kVp and 30 mL contrast medium. One hundred fifty patients with a heart rate ≤70 beats per minute (bpm) underwent CCTA using a second-generation dual-source computed tomography (CT) scanner and were randomized into 3 groups according to tube voltage and contrast medium volume (370 mg/mL iodine concentration) (100 kVp group, 100 kVp/60 mL, n = 55; 80 kVp group, 80 kVp/60 mL, n = 44; 70 kVp group, 70 kVp/30 mL, n = 51). Objective and subjective image quality along with the effect of heart rate (HR) and body mass index (BMI) was evaluated and compared between the groups. Radiation dose was estimated for each patient. CT attenuation and image noise were higher in the 80 and 70 kVp groups than in the 100 kVp group (all P < 0.001). Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were lower in the 70 kVp group than in the 80 and 100 kVp groups (all P < 0.05). There was no difference for subjective image quality between the groups (P > 0.05). HR did not affect subjective image quality (all P > 0.05), while patients with BMI <23 kg/m2 had higher image quality than patients with BMI ≥23 kg/m2 (P < 0.05). Compared with the 100 kVp group, the radiation dose of the 70 kVp group was reduced by 75%. In conclusion, prospectively ECG-triggered high-pitch 70 kVp/30 mL CCTA can obtain diagnostic image quality with lower radiation dose in selected patients with BMI <23 kg/m2 compared with 80/100 kVp/60 mL CCTA. PMID:25396334

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. Principle and applications of dual source CT

    NASA Astrophysics Data System (ADS)

    Flohr, Thomas

    2008-08-01

    Dual source CT (DSCT) has the potential to solve remaining limitations of conventional multi-detector row CT (MDCT)-scanners, such as insufficient temporal resolution for ECG-controlled cardiac imaging. A DSCT is equipped with two X-ray tubes and two corresponding detectors that are mounted onto the rotating gantry with an angular offset of 90°. The key benefit of DSCT for cardiac scanning is improved temporal resolution equivalent to a quarter of the gantry rotation time (83 ms at 0.33 s rotation time). Additionally, both X-ray tubes can be operated at different kV- and mA-settings, enabling the acquisition of dual energy data. The acquisition of dual energy CT data can add functional information to the morphological information based on different X-ray attenuation coefficients that is usually obtained in a CT examination.

  13. 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.

  14. The safe practice of CT coronary angiography in adult patients in UK imaging departments.

    PubMed

    Harden, S P; Bull, R K; Bury, R W; Castellano, E A; Clayton, B; Hamilton, M C K; Morgan-Hughes, G J; O'Regan, D; Padley, S P G; Roditi, G H; Roobottom, C A; Stirrup, J; Nicol, E D

    2016-08-01

    Computed tomography coronary angiography is increasingly used in imaging departments in the investigation of patients with chest pain and suspected coronary artery disease. Due to the routine use of heart rate controlling medication and the potential for very high radiation doses during these scans, there is a need for guidance on best practice for departments performing this examination, so the patient can be assured of a good quality scan and outcome in a safe environment. This article is a summary of the document on 'Standards of practice of computed tomography coronary angiography (CTCA) in adult patients' published by the Royal College of Radiologists (RCR) in December 2014. PMID:27207375

  15. Finding the Gatekeeper to the Cardiac Catheterization Laboratory: Coronary CT Angiography or Stress Testing?

    PubMed

    Marwick, Thomas H; Cho, Iksung; Ó Hartaigh, Bríain; Min, James K

    2015-06-30

    Functional capacity is a robust predictor of clinical outcomes, and stress testing is used in current practice paradigms to guide referral to invasive coronary angiography. However, invasive coronary angiography is driven by ongoing symptoms, as well as risk of adverse outcomes. The limitations of current functional testing-based paradigms might be avoided by using coronary computed tomographic angiography (CCTA) for exclusion of obstructive coronary artery disease. The growth of CCTA has been supported by comparative prognostic evidence with CCTA and functional testing, as well as radiation dose reduction. Use of CCTA for physiological evaluation of coronary lesion-specific ischemia may facilitate evaluation of moderate stenoses, designation of the culprit lesion, and prediction of benefit from revascularization. The potential of CCTA to serve as an effective gatekeeper to invasive coronary angiography will depend, in part, on the adoption of these new developments, as well as definition of the benefit of detecting high-risk plaque for guiding the management of selected patients. PMID:26112200

  16. Noninvasive FFR derived from coronary CT angiography in the management of coronary artery disease: technology and clinical update.

    PubMed

    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

  17. Single Phase Dual-energy CT Angiography: One-stop-shop Tool for Evaluating Aneurysmal Subarachnoid Hemorrhage

    PubMed Central

    Ni, Qian Qian; Tang, Chun Xiang; Zhao, Yan E; Zhou, Chang Sheng; Chen, Guo Zhong; Lu, Guang Ming; Zhang, Long Jiang

    2016-01-01

    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. PMID:27222163

  18. 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.

  19. 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

  20. Non-coronary abnormalities of the left heart: CT angiography findings.

    PubMed

    Öztürk, Ersin; Kafadar, Cahit; Tutar, Süleyman; Bozlar, Uğur; Hagspiel, Klaus D

    2016-09-01

    Cardiac computed tomography (CT) is most commonly performed for the evaluation of the coronary arteries; however, non-coronary cardiac pathologies are frequently detected on these scans. In cases where magnetic resonance imaging cannot be used, cardiac CT can serve as the first-line imaging modality to evaluate many non-coronary cardiac pathologies. In this article, we discuss congenital non-coronary abnormalities of the left heart and their cardiac CT imaging features. PMID:27609435

  1. 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. PMID:24770610

  2. 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.

  3. Congenital subcutaneous arteriovenous malformation in a puppy: diagnosis with CT angiography.

    PubMed

    Proks, Pavel; Stehlik, Ladislav; Paninarova, Michaela; Irova, Katarina; Lorenzova, Jana; Necas, Alois

    2015-10-01

    A 4-month-old, 20 kg, intact male, cane corso dog was presented with a slowly growing subcutaneous lesion on the left caudoventral abdominal wall. Ultrasound and computed tomography angiography revealed a subcutaneous plexus of aberrant tortuous vessels directly connected with the superficial branch of the deep circumflex iliac artery and vein. The arteriovenous malformation (AVM) was successfully surgically removed. Early recognition and surgical removal of AVM can have excellent cosmetic results and prevents potential cardiovascular complications. PMID:26175066

  4. 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

  5. Analysis of coronary arterial calcification components with coronary CT angiography using single-source dual-energy CT with fast tube voltage switching.

    PubMed

    Matsui, Kazuhiro; Machida, Haruhiko; Mitsuhashi, Tetsuya; Omori, Hisako; Nakaoka, Takashi; Sakura, Hiroshi; Ueno, Eiko

    2015-03-01

    Clinical cardiac applications of single-source dual-energy computed tomography (DECT) have recently been introduced. This study aimed to analyze the components of coronary arterial calcification (CAC) in vivo by material decomposition achieved with DECT. We reconstructed computed tomography (CT) angiography images for 51 consecutive patients with CACs who had undergone electrocardiography-gated coronary CT angiography by single-source DECT with fast tube voltage switching. We placed regions of interest (ROIs) within the CAC with margins of at least 0.5 mm to minimize partial volume averaging. We compared histograms for the effective atomic number (EAN) and the median, mean, and maximum EANs for each CAC with the theoretical EANs for possible CAC components, including hydroxyapatite (HA), calcium oxalate monohydrate (COM), and dicalcium phosphate dehydrate. We also investigated the in vivo EAN for COM and in vitro EAN for HA by our phantom experiment. Analysis of the CAC components was feasible in 177 ROIs from 28 patients. The median EAN was 13.8 ± 0.8 (95% confidence interval 13.7-13.9), which is similar to the theoretical EAN for COM (13.8). The EAN for HA in vitro was 16.5 ± 0.1, which was slightly higher than the theoretical EAN value for HA (16.1). Notably, the median EAN in 144 ROIs (81.4%) was between 11.2 and 14.4, which is the reported range of the in vivo EAN for COM. Our results suggest that COM might be a more frequent CAC component than previously reported. PMID:25407480

  6. Differential associations between blood biomarkers of inflammation, oxidation, and lipid metabolism with varying forms of coronary atherosclerotic plaque as quantified by coronary CT angiography

    PubMed Central

    Truong, Quynh A.; Koenig, Wolfgang; Schlett, Christopher L.; Nasir, Khurram; Butler, Javed; Kurtz, Emily; Nikolaou, Konstantin; Hoffmann, Udo; Januzzi, James L.

    2011-01-01

    Although epidemiologic data link biomarkers of cardiovascular risk with incident and prevalent coronary artery disease, exact anatomic relationships between biomarkers and coronary atherosclerosis as measured by coronary CT angiography remain unclear. Patients with acute chest pain who ultimately had no evidence of acute coronary syndrome underwent contrast-enhanced 64-slice coronary CT angiography to determine presence, extent and composition of coronary atherosclerotic plaque. We determined the differences in levels of blood biomarkers measured at the time of the CT scan between different CT-based atherosclerotic plaque groups. Among 313 patients (mean age: 51.6 ± 11 years, 62% male) high-sensitivity C-reactive protein (hs-CRP) and matrix metalloproteinase-2 were associated with the extent of calcified plaque (P = 0.03 and P<0.001), while hs-CRP and apolipoprotein A1 were associated with the extent of non-calcified plaque (P = 0.03 and P = 0.004; respectively). Despite a generally lower risk profile, subjects with exclusively non-calcified plaque had significantly higher levels of hs-CRP and oxidized low-density lipoprotein (P = 0.01 and P = 0.03; respectively) and lower levels of adiponectin (P = 0.03) when compared to subjects with calcified plaque (n = 130, 42%). Biomarkers reflecting inflammation, vascular remodeling, oxidation, and lipoprotein metabolism maybe associated with different patterns of coronary atherosclerosis as quantified by coronary CT angiography. PMID:21222039

  7. State of the art low-dose CT angiography of the body.

    PubMed

    Alkadhi, Hatem; Schindera, Sebastian T

    2011-10-01

    This review summarizes current evidence based on pertinent literature on low-dose computed tomography angiography (CTA) of the body. Various strategies for optimizing CTA protocols with the aim to lower the radiation dose while maintaining the diagnostic accuracy of the examination are summarized. To date, various publications have demonstrated that CTA of the body can be performed at a low radiation dose while providing high quality information. Nevertheless, a number of questions still need to be answered, including the optimal combination of tube voltage and tube current settings, as well as the appropriate protocol parameters in relation to the body physiognomy and the specific body region imaged. PMID:21330084

  8. 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.

  9. Use of CT angiography in the diagnosis of total anomalous venous return.

    PubMed

    Lakshminrusimha, S; Wynn, R J; Youssfi, M; Pabalan, M J; Bommaraju, M; Kirmani, K; Carrion, V

    2009-06-01

    Total anomalous pulmonary venous return (TAPVR) is an uncommon cause of cyanotic congenital heart disease in the neonatal period. This diagnosis is often made by echocardiography. We present two cases where echocardiography was not confirmatory. Computerized tomography (CT) scan of the chest and abdomen with contrast was performed instead of cardiac catheterization to establish the diagnosis. We suggest that CT with contrast is a noninvasive modality to obtain anatomic details of pulmonary venous drainage in TAPVR when echocardiography is inconclusive. PMID:19474817

  10. Coronary artery anomalies in adults: imaging at dual source CT coronary angiography.

    PubMed

    Laspas, Fotios; Roussakis, Arkadios; Mourmouris, Christos; Kritikos, Nikolaos; Efthimiadou, Roxani; Andreou, John

    2013-04-01

    Congenital abnormalities of the coronary arteries have an incidence of 1%, and most of these are benign. However, a small number are associated with myocardial ischaemia and sudden death. Various imaging modalities are available for coronary artery assessment. Recently, multi-detector CT has emerged as an accurate diagnostic tool for defining coronary artery anomalies. The purpose of this pictorial essay is to review the dual source CT appearance of congenital anomalies of the coronary arteries in adults. PMID:23551776

  11. 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.

  12. 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

  13. Intracoronary transluminal attenuation gradient in coronary CT angiography for determining coronary artery stenosis.

    PubMed

    Choi, Jin-Ho; Min, James K; Labounty, Troy M; Lin, Fay Y; Mendoza, Dorinna D; Shin, Dae Hee; Ariaratnam, Nikki S; Koduru, Sunaina; Granada, Juan F; Gerber, Thomas C; Oh, Jae K; Gwon, Hyeon-Cheol; Choe, Yeon Hyeon

    2011-11-01

    Coronary computed tomography angiography (CTA) assessment of calcified or complex coronary lesions is frequently challenging. Transluminal attenuation gradient (TAG), defined as the linear regression coefficient between luminal attenuation and axial distance, has a potential to evaluate the degree of coronary stenosis. We examined the value of TAG in determining the stenosis severity on 64-slice coronary CTA. The value of TAG of 370 major coronary arteries was measured from 7,263 intervals of 5-mm length. Compared with coronary CTA and invasive coronary angiography, TAG decreased consistently and significantly with maximum stenosis severity on a per-vessel basis, from -1.91 ± 4.25 Hounsfield units/10 mm for diameter stenosis of 0% to 49% to -13.37 ± 9.81 Hounsfield units/10 mm for diameter stenosis of 100% (p < 0.0001). Adding TAG to the interpretation of coronary CTA improved diagnostic accuracy (p = 0.001), especially in vessels with calcified lesions (N = 127; net reclassification improvement 0.095; p = 0.046). TAG appears to be able to contribute to improved classification of coronary artery stenosis severity in coronary CTA, especially in severely calcified lesions. PMID:22093264

  14. Quantitative Assessment of Left Ventricular Function and Myocardial Mass: A Comparison of Coronary CT Angiography with Cardiac MRI and Echocardiography

    PubMed Central

    Kara, Bedia; Nayman, Alaaddin; Guler, Ibrahim; Gul, Enes Elvin; Koplay, Mustafa; Paksoy, Yahya

    2016-01-01

    Summary Background The purpose of this study was to compare the left ventricular parameters obtained from multi-detector row computed tomography (MDCT) studies with two-dimensional echocardiography (2DE), and magnetic resonance imaging (MRI), which is accepted as the gold standard in the evaluation of left ventricular functions. The study also aimed to evaluate whether or not there is a relationship between the MR-Argus and CMR tools software programs which are used in post-process calculations of data obtained by MRI. Material/Methods Forty patients with an average age of 51.4±14.9 years who had been scanned with cardiac MDCT were evaluated with cardiac MRI and 2DE. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), cardiac output (CO), and myocardial mass values calculated by MDCT, MRI, and 2DE were compared with each other. Two different MR software programs were used to compare left ventricular functions. The CMR tools LV tutorials method is accepted as the gold standard because it can be used in three-dimensional functional evaluation. The Pearson Correlation and Bland-Altman analysis were performed to compare the results from the two MR methods (MR-Argus and CMR tools) and the results from both the MDCT and the 2DE with the CMR tools results. Results Strong positive correlations for EF values were found between the MDCT and CMR tools (r=0.702 p<0.001), and between the MR-Argus and CMR tools (r=0.746 p<0.001). The correlation between the 2DE and CMR tools (r=0.449 p<0.004), however, was only moderate. Similar results were obtained for the other parameters. The strongest correlation for ESV, EDV, and EF was between the two MR software programs. The correlation coefficient between the MDCT and CMR tools is close to the correlation coefficient between the two software programs. While the correlation between 2DE and CMR tools was satisfactory for ESV, EDV, and CO values, it was at a moderate level for the other parameters. Conclusions Left ventricular functional analysis can be performed easily and reliably with cardiac MDCT used for coronary artery evaluation and it also gives more accurate results than 2DE. PMID:27026794

  15. Low-Dose High-Pitch CT Angiography of the Supraaortic Arteries Using Sinogram-Affirmed Iterative Reconstruction

    PubMed Central

    Beitzke, Dietrich; Nolz, Richard; Unterhumer, Sylvia; Plank, Christina; Weber, Michael; Schernthaner, Rüdiger; Schöpf, Veronika; Wolf, Florian; Loewe, Christian

    2014-01-01

    Objective To prospectively evaluate image quality and radiation dose using a low-dose computed tomography angiography protocol and iterative image reconstruction for high-pitch dual-source CT-angiography (DSCTA) of the supraaortic arteries. Material and Methods DSCTA was performed in 42 patients, using either 120 kVp tube voltage, 120 mAS tube current, 2.4 pitch and filtered back projection, or 100 kVp tube voltage, 100 mAs tube current, 3.2 pitch, and sinogram affirmed iterative reconstruction. Measurements of vessel attenuation, of the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were performed to objectively evaluate image quality. Two readers evaluated subjective image quality and image noise, using a four-point scale. Effective dose was used to compare the differences in radiation dose. Results Low-dose protocol application showed significantly higher vessel opacification (p = 0.013), and non-significantly higher CNR and SNR values. There was no difference in the subjective image quality and image noise reading between the protocols. Effective dose was significantly lower using the low-dose protocol (1.29±0.21 mSv vs. 2.92±0.72 mSv; p<0.001). Conclusion The combined use of reduced tube voltage, reduced tube current, and iterative reconstruction reduces radiation dose by 55.4% in high-pitch DSCTA of the supraaortic arteries without impairment of image quality. PMID:24919195

  16. Clinical value of multidetector CT coronary angiography as a preoperative screening test before non‐coronary cardiac surgery

    PubMed Central

    Russo, Vincenzo; Gostoli, Valentina; Lovato, Luigi; Montalti, Maurizio; Marzocchi, Antonio; Gavelli, Giampaolo; Branzi, Angelo; Bartolomeo, Roberto Di; Fattori, Rossella

    2007-01-01

    Objective Myocardial scintigraphy and/or conventional angiography (CA) are often performed before cardiac surgery in an attempt to identify unsuspected coronary artery disease which might result in significant cardiac morbidity and mortality. Multidetector CT coronary angiography (MDCTCA) has a recognised high negative predictive value and may provide a non‐invasive alternative in this subset of patients. The aim of this study was to evaluate the clinical value of MDCTCA as a preoperative screening test in candidates for non‐coronary cardiac surgery. Methods 132 patients underwent MDCTCA (Somatom Sensation 16 Cardiac, Siemens) in the assessment of the cardiac risk profile before surgery. Coronary arteries were screened for ⩾50% stenosis. Patients without significant stenosis (Group 1) underwent surgery without any adjunctive screening tests while all patients with coronary lesions ⩾50% at MDCTCA (Group 2) underwent CA. Results 16 patients (12.1%) were excluded due to poor image quality. 72 patients without significant coronary stenosis at MDCTCA were submitted to surgery. 30 out of 36 patients with significant (⩾50%) coronary stenosis at MDCTCA and CA underwent adjunctive bypass surgery or coronary angioplasty. In 8 patients, MDCTCA overestimated the severity of the coronary lesions (>50% MDCTCA, <50% CA). No severe cardiovascular perioperative events such as myocardial ischaemia, myocardial infarction or cardiac failure occurred in any patient in Group 1. Conclusions MDCTCA seems to be effective as a preoperative screening test prior to non‐coronary cardiac surgery. In this era of cost containment and optimal care of patients, MDCTCA is able to provide coronary vessel and ventricular function evaluation and may become the method of choice for the assessment of a cardiovascular risk profile prior to major surgery. PMID:17164488

  17. PROMISE of Coronary CT Angiography: Precise and Accurate Diagnosis and Prognosis in Coronary Artery Disease.

    PubMed

    Thomas, Dustin M; Branch, Kelley R; Cury, Ricardo C

    2016-04-01

    Coronary computed tomography angiography (CCTA) is a rapidly growing and powerful diagnostic test that offers a great deal of precision with respect to diagnosing coronary artery disease (CAD). Guideline statements for patients with stable ischemic heart disease have recommended CCTA for only a limited portion of intermediate-risk patients who have relative or absolute contraindications for exercise or vasodilator stress testing. The publication of two large, prospective randomized clinical trials, the Prospective Multicenter Imaging Study for Evaluation of Chest Pain and the Scottish Computed Tomography of the Heart Trial are likely to expand these indications. These new data from large trials, in addition to other studies, show that CCTA is highly sensitive for the detection of CAD, identifies high-risk patients for cardiac events based on extent or plaque morphology of CAD that would not be identified by other noninvasive means, and provides significantly greater diagnostic certainty for proper treatment, including referral for invasive coronary angiography with revascularization more appropriately. Superior diagnostic accuracy and prognostic data with CCTA, when compared with other functional stress tests, may result in a reduction in unnecessary downstream testing and cost savings. In addition, newer CCTA applications hold the promise of providing a complete evaluation of a patient's coronary anatomy as well as a per-vessel ischemic evaluation. This review focuses on the interval knowledge obtained from newer data on CCTA in patients with stable ischemic heart disease, primarily focusing on the contributions of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain and the Scottish Computed Tomography of the Heart Trial. PMID:27043808

  18. Infant Cardiac CT Angiography with 64-Slice and 256-Slice CT: Comparison of Radiation Dose and Image Quality Using a Pediatric Phantom

    PubMed Central

    Mok, Greta S. P.; Wu, Tung-Hsin

    2012-01-01

    Background The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age. Methodology/Principal Findings Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocardiogram-gated helical (RGH) and prospectively electrocardiogram-gated axial (PGA) techniques in 64-slice and 256-slice CT scanners. The thermoluminescent dosimeters (TLD) were used for direct organ dose measurement, while dose-length product and effective mAs were also used to estimate the patient dose. For image quality, noise and signal-to-noise-ratio (SNR) were assessed based on regions-of-interest drawn on the reconstructed CT images, and were compared with the proposed cardiac image quantum index (CIQI). Estimated dose results were in accordant to the measured doses. The NG scan showed the best image quality in terms of noise and SNR. The PGA scan had better image quality than the RGH scan with 83.70% dose reduction. Noise and SNR were also corresponded to the proposed CIQI. Conclusions/Significance The PGA scan protocol was a good choice in balancing radiation exposure and image quality for infant cardiac CTA. We also suggested that the effective mAs and the CIQI were suitable in assessing the tradeoffs between radiation dose and image quality for cardiac CTA in infants. These results are useful for future implementation of dose reduction strategies in pediatric cardiac CTA protocols. PMID:23185380

  19. Patient radiation dose in prospectively gated axial CT coronary angiography and retrospectively gated helical technique with a 320-detector row CT scanner

    SciTech Connect

    Seguchi, Shigenobu; Aoyama, Takahiko; Koyama, Shuji; Fujii, Keisuke; Yamauchi-Kawaura, Chiyo

    2010-11-15

    Purpose: The aim of this study was to evaluate radiation dose to patients undergoing computed tomography coronary angiography (CTCA) for prospectively gated axial (PGA) technique and retrospectively gated helical (RGH) technique. Methods: Radiation doses were measured for a 320-detector row CT scanner (Toshiba Aquilion ONE) using small sized silicon-photodiode dosimeters, which were implanted at various tissue and organ positions within an anthropomorphic phantom for a standard Japanese adult male. Output signals from photodiode dosimeters were read out on a personal computer, from which organ and effective doses were computed according to guidelines published in the International Commission on Radiological Protection Publication 103. Results: Organs that received high doses were breast, followed by lung, esophagus, and liver. Breast doses obtained with PGA technique and a phase window width of 16% at a simulated heart rate of 60 beats per minute were 13 mGy compared to 53 mGy with RGH technique using electrocardiographically dependent dose modulation at the same phase window width as that in PGA technique. Effective doses obtained in this case were 4.7 and 20 mSv for the PGA and RGH techniques, respectively. Conversion factors of dose length product to the effective dose in PGA and RGH were 0.022 and 0.025 mSv mGy{sup -1} cm{sup -1} with a scan length of 140 mm. Conclusions: CTCA performed with PGA technique provided a substantial effective dose reduction, i.e., 70%-76%, compared to RGH technique using the dose modulation at the same phase windows as those in PGA technique. Though radiation doses in CTCA with RGH technique were the same level as, or some higher than, those in conventional coronary angiography (CCA), the use of PGA technique reduced organ and effective doses to levels less than CCA except for breast dose.

  20. Application of Prospective ECG-Gated High-Pitch 128-Slice Dual-Source CT Angiography in the Diagnosis of Congenital Extracardiac Vascular Anomalies in Infants and Children

    PubMed Central

    Wang, Ximing; Duan, Yanhua; Xu, Wenjian; Li, Haiou; Cao, Ting; Liu, Xuejun; Ji, Xiaopeng; Cheng, Zhaoping; Wang, Anbiao

    2014-01-01

    Purpose To investigate the value of prospective ECG-gated high-pitch 128-slice dual-source CT (DSCT) angiography in the diagnosis of congenital extracardiac vascular anomalies in infants and children in comparison with transthoracic echocardiography (TTE). Methods Eighty consecutive infants or children clinically diagnosed of congenital heart disease and suspected with extracardiac vascular anomaly were enrolled, and 75 patients were finally included in this prospective study. All patients underwent prospective ECG-gated high-pitch DSCT angiography after TTE with an interval of 1–7 days. The diagnostic accuracy and sensitivity of high-pitch DSCT angiography and TTE were compared according to the surgical/CCA findings. The image quality of DSCT was assessed using a five-point scale. The effective radiation dose (ED) was calculated. Results A total of 17 congenital heart diseases and 162 separate extracardiac vascular anomalies were confirmed by surgical/CCA findings in 75 patients. The diagnostic accuracy of high-pitch DSCT angiography and TTE was 99.67% and 97.89%, respectively. The sensitivity of high-pitch DSCT angiography and TTE was 97.53% and 79.62%, respectively. There was significant difference regarding to the diagnostic accuracy and the sensitivity between high-pitch DSCT angiography and TTE (χ2 = 23.561 and 28.013, P<0.05). The agreement on the image quality scoring of DSCT between the two observers was excellent (κ = 0.81), and the mean score of image quality was 4.1±0.7. The mean ED of DSCT was 0.29±0.08 mSv. Conclusions Prospective ECG-gated high-pitch 128-slice DSCT angiography with low radiation dose and high diagnostic accuracy has higher sensitivity compared to TTE in the detection of congenital extracardiac vascular anomalies in infants and children. PMID:25546178

  1. SU-E-I-31: Differences Observed in Radiation Doses Across 2 Similar CT Scanners From Adult Brain-Neck CT Angiography

    SciTech Connect

    Fujii, K; McMillan, K; Bostani, M; Cagnon, C; McNitt-Gray, M

    2015-06-15

    Purpose: The aim of this study is to evaluate the difference in radiation doses from adult Brain-Neck CT angiography (CTA) between two CT scanners. Methods: We collected CT dose index data (CTDIvol, DLP) from adult Brain-Neck CTA performed with two CT scanners (Sensation 64 (S64) and Definition AS (AS), Siemens Healthcare) performed at two of our facilities from Jan 1st to Dec 31th, 2014. X-ray dose management software (Radmetrics, Bayer Healthcare) was used to mine these data. All exams were performed with Tube Current Modulation (Care Dose 4D), tube voltage of 120 kVp, quality reference mAs of 300, beam collimation of 64*0.6 mm. The rotation time was set to 0.5 sec for S64 and 1.0 sec for AS. We also scanned an anthropomorphic skull and chest phantom under routine Brain-Neck CTA protocol with the two scanners and extracted the tube current values from the raw projection data. Results: The mean CTDIvol and DLP in Brain-Neck CTA was 72 mGy and 2554 mGy*cm for AS, which was substantially larger than the mean values of 46 mGy and 1699 mGy*cm for S64. The maximum tube current was 583 mA for most cases on the S64 while the maximum was 666 mA for AS even though the rotation time set for AS was 1.0 sec. Measurements obtained with the anthropomorphic phantom showed that the tube current reached 583 mA at the shoulder region for S64 while it reached to 666 mA for AS. Conclusion: The results of this study showed that substantially different CT doses can Result from Brain-Neck CTA protocols even when similar scanners and similar settings are used. Though both scanners have a similar maximum mA rating, differences in mA were observed through the shoulders, resulting in substantially different CTDIvol values.

  2. Statistical iterative reconstruction for streak artefact reduction when using multidetector CT to image the dento-alveolar structures

    PubMed Central

    Hayakawa, Y; Kober, C

    2014-01-01

    Objectives: When metallic prosthetic appliances and dental fillings exist in the oral cavity, the appearance of metal-induced streak artefacts is not avoidable in CT images. The aim of this study was to develop a method for artefact reduction using the statistical reconstruction on multidetector row CT images. Methods: Adjacent CT images often depict similar anatomical structures. Therefore, reconstructed images with weak artefacts were attempted using projection data of an artefact-free image in a neighbouring thin slice. Images with moderate and strong artefacts were continuously processed in sequence by successive iterative restoration where the projection data was generated from the adjacent reconstructed slice. First, the basic maximum likelihood–expectation maximization algorithm was applied. Next, the ordered subset–expectation maximization algorithm was examined. Alternatively, a small region of interest setting was designated. Finally, the general purpose graphic processing unit machine was applied in both situations. Results: The algorithms reduced the metal-induced streak artefacts on multidetector row CT images when the sequential processing method was applied. The ordered subset–expectation maximization and small region of interest reduced the processing duration without apparent detriments. A general-purpose graphic processing unit realized the high performance. Conclusions: A statistical reconstruction method was applied for the streak artefact reduction. The alternative algorithms applied were effective. Both software and hardware tools, such as ordered subset–expectation maximization, small region of interest and general-purpose graphic processing unit achieved fast artefact correction. PMID:24754471

  3. Cerebral Arteries Extraction using Level Set Segmentation and Adaptive Tracing for CT Angiography

    SciTech Connect

    Zhang Yong; Zhou Xiaobo; Srinivasan, Ranga; Wong, Stephen T. C.; Young, Geoff

    2007-11-02

    We propose an approach for extracting cerebral arteries from partial Computed Tomography Angiography (CTA). The challenges of extracting cerebral arteries from CTA come from the fact that arteries are usually surrounded by bones and veins in the lower portion of a CTA volume. There exists strong intensity-value overlap between vessels and surrounding objects. Besides, it is inappropriate to assume the 2D cross sections of arteries are circle or ellipse, especially for abnormal vessels. The navigation of the arteries could change suddenly in the 3D space. In this paper, a method based on level set segmentation is proposed to target this challenging problem. For the lower portion of a CTA volume, we use geodesic active contour method to detect cross section of arteries in the 2D space. The medial axis of the artery is obtained by adaptively tracking along its navigation path. This is done by finding the minimal cross section from cutting the arteries under different angles in the 3D spherical space. This method is highly automated, with minimum user input of providing only the starting point and initial navigation direction of the arteries of interests.

  4. Segmentation of the thrombus of giant intracranial aneurysms from CT angiography scans with lattice Boltzmann method.

    PubMed

    Chen, Yu; Navarro, Laurent; Wang, Yan; Courbebaisse, Guy

    2014-01-01

    Computed Tomography Angiography (CTA) plays an essential role in the diagnosis, treatment evaluation, and monitoring of cerebral aneurysms. Segmentation of CTA medical images of giant intracranial aneurysms (GIA) provides quantitative measurements of thrombus and aneurysms geometrical characteristics allowing 3D reconstruction. In fact, GIA demonstrated neuroradiological features and propensity of partial or total spontaneous intra-aneurysmal thrombosis generating a thrombus. Despite intensive researches on medical image segmentation, aneurysm (Lumen, Thrombus, and Parent Blood Vessels) segmentation remains as a difficult problem that has not been yet resolved. In this paper, we proposed a Lattice Boltzmann Geodesic Active Contour Method (LBGM) for aneurysm segmentation in CTA images in order to estimate both the volumes of the thrombus and the aneurysm. Although the noise in the CTA images is very strong and the edges of the thrombus are not so different than the surrounding tissues, the aneurysms are segmented effectively. Based on these results, a method using a dome-neck aspect ratio (AR) parameter for the evaluation of the Spontaneous Thrombosis (ST) phenomena demonstrates the promising potentiality of this LBGM for clinical applications. PMID:24077409

  5. Barber Pole Sign in CT Angiography, Adult Presentation of Midgut Malrotation: A Case Report.

    PubMed

    Garcelan-Trigo, Juan Arsenio; Tello-Moreno, Manuel; Rabaza-Espigares, Manuel Jesus; Talavera-Martinez, Ildefonso

    2015-07-01

    Adult midgut volvulus is a challenging diagnosis because of its low incidence and nonspecific symptoms. Diagnostic delay and long-term complaints are frequent in this clinical scenario. We reported a patient referred to our diagnostic imaging unit with intermittent abdominal pain, bloating and episodic vomiting for several years. He underwent barium gastrointestinal transit and abdominal ultrasound, which revealed severe gastric dilatation, food retention and slow transit until a depressed duodenojejunal flexure, with malrotation of the midgut and jejunal loops being located in the right upper quadrant. Computed tomography angiography was performed, showing rotation of the small intestine around the mesentery root, suggestive of midgut malrotation. In addition, an abnormal twisted disposition of superior mesenteric artery with corkscrew appearance was seen, shaping the pole-barber sign which was evident in volume rendering three-dimensional reconstructions. The patient underwent scheduled surgical treatment without any complication and had good outcome after hospital discharge and follow-up. Computed tomography plays an important role in evaluation of adult midgut volvulus. In addition, angiographic reconstructions can help us to assess the anatomic disposition of mesenteric vascular supply. Both of these assessments are useful in preoperative management. PMID:26557278

  6. Quantification of coronary artery Stenosis by Area Stenosis from cardiac CT angiography.

    PubMed

    Jiayin Zhou; Weimin Huang; Yanling Chi; Yuping Duan; Liang Zhong; Xiaodan Zhao; Junmei Zhang; Wei Xiong; Ru San Tan; Kyaw Kyar Toe

    2015-08-01

    Non-invasive cardiac computed tomography angiography (CTA) is widely used to assess coronary artery stenosis and give clinical decision-making support to clinicians. The severity of stenosis lesion is commonly graded by a range of percent Diameter Stenosis (DS), which can introduce false positive diagnoses or over-estimation, triggering unnecessary further procedures. In this paper, a system and the associate methods to quantify stenosis by the percent Area Stenosis (AS) from cardiac CTA is presented. In the process, coronary artery tree is segmented and the centerline is extracted by Hessian filtering and the minimal path method. After a serial of 2D cross-sectional artery images along the artery centerline are obtained, lumen areas are segmented by ellipse-fitting with deformable models, and consequently to compute the lesion's AS. Experimental results on 5 CTA data sets show that compared to DS, AS better correlates to the reference standard for stenosis quantification, suggesting the efficacy of the proposed system. PMID:26736357

  7. Effect of Bismuth Breast Shielding on Radiation Dose and Image Quality in Coronary CT Angiography

    PubMed Central

    Einstein, Andrew J.; Elliston, Carl D.; Groves, Daniel W.; Cheng, Bin; Wolff, Steven D.; Pearson, Gregory D. N.; Peters, M. Robert; Johnson, Lynne L.; Bokhari, Sabahat; Johnson, Gary W.; Bhatia, Ketan; Pozniakoff, Theodore; Brenner, David J.

    2011-01-01

    Background Coronary computed tomographic angiography (CCTA) is associated with high radiation dose to the female breasts. Bismuth breast shielding offers the potential to significantly reduce dose to the breasts and nearby organs, but the magnitude of this reduction and its impact on image quality and radiation dose have not been evaluated. Methods Radiation doses from CCTA to critical organs were determined using metal-oxide-semiconductor field-effect transistors positioned in a customized anthropomorphic whole-body dosimetry verification phantom. Image noise and signal were measured in regions of interest (ROIs) including the coronary arteries. Results With bismuth shielding, breast radiation dose was reduced 46–57% depending on breast size and scanning technique, with more moderate dose reduction to the heart, lungs, and esophagus. However, shielding significantly decreased image signal (by 14.6 HU) and contrast (by 28.4 HU), modestly but significantly increased image noise in ROIs in locations of coronary arteries, and decreased contrast-to-noise ratio by 20.9%.. Conclusions While bismuth breast shielding can significantly decrease radiation dose to critical organs, it is associated with an increase in image noise, decrease in contrast-to-noise, and changes tissue attenuation characteristics in the location of the coronary arteries. PMID:22068687

  8. Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial

    PubMed Central

    Park, Eun-Ah; Kang, Doo Kyoung; Kim, Sung Jin; Kim, Young-Ju; Kim, Yookyung; Sung, Yon Mi; Song, Soon-Young; Oh, Yu-Whan; Yong, Hwan Seok; Lee, Heon; Jeon, Eui-Yong; Jin, Gong-Yong; Choi, Byoung Wook; Choi, Sang-Il

    2016-01-01

    Objective This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Materials and Methods Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. Results A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Conclusion Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine. PMID:27134522

  9. Investigation of Suspected Pulmonary Embolism at Hutt Valley Hospital with CT Pulmonary Angiography: Current Practice and Opportunities for Improvement.

    PubMed

    Kennedy, Nick; Jayathissa, Sisira; Healy, Paul

    2015-01-01

    Aims. To study the use of CT pulmonary angiography (CTPA) at Hutt Hospital and investigate the use of pretest probability scoring in the assessment of patients with suspected pulmonary embolism (PE). Methods. We studied patients with suspected PE that underwent CTPA between January and May 2012 and collected data on demographics, use of pretest probability scoring, and use of D Dimer and compared our practice with the British Thoracic Society (BTS) guideline. Results. 105 patients underwent CTPA and 15% of patients had PE. 13% of patients had a Wells score prior to their scan. Wells score calculated by researchers revealed 54%, 36%, and 8% patients had low, medium, and high risk pretest probabilities and 8%, 20%, and 50% of these patients had positive scans. D Dimer was performed in 58% of patients and no patients with a negative D Dimer had a PE. Conclusion. The CTPA positive rate was similar to other contemporary studies but lower than previous New Zealand studies and some international guidelines. Risk stratification of suspected PE using Wells score and D Dimer was underutilised. A number of scans could have been safely avoided by using accepted guidelines reducing resources use and improving patient safety. PMID:26556556

  10. Volume Changes of Experimental Carotid Sidewall Aneurysms Due to Embolization with Liquid Embolic Agents: A Multidetector CT Angiography Study

    SciTech Connect

    Dudeck, O. Okuducu, A. F.; Jordan, O.; Tesmer, K.; Pech, M.; Weigang, E.; Ruefenacht, D. A.; Doelker, E.; Felix, R.

    2006-12-15

    Iodine-containing polyvinyl alcohol polymer (I-PVAL) is a novel precipitating liquid embolic that allows for artifact-free evaluation of CT angiography (CTA). As accurate aneurysm volumetry can be performed with multidetector CTA, we determined volumes of experimental aneurysms before, immediately after, and 4 weeks after embolization of 14 porcine experimental carotid sidewall aneurysms with this liquid embolic. An automated three-dimensional software measurement tool was used for volumetric analysis of volume-rendering CTA data. Furthermore, intra-aneurysmal pressure changes during liquid embolization were measured in four silicone aneurysms and potential polymer volume changes within 4 weeks were assessed in vitro. Liquid embolic injection was performed during temporary balloon occlusion of the aneurysm neck, resulting in a mean occlusion rate of 98.3%. Aneurysms enlarged significantly during embolization by 61.1 {+-} 28.9%, whereas a significant shrinkage of 5.6 {+-} 2.7% was observed within the follow-up period. Histologic analysis revealed an inflammatory foreign body reaction with partial polymer degradation. In silicone aneurysm models, intra-aneurysmal pressure remained unchanged during liquid embolic injection, whereas balloon inflation resulted in a mean pressure increase of 31.2 {+-} 0.7%. No polymer shrinkage was observed in vitro. The aneurysm enlargement noted was presumably due to pressure elevation after balloon inflation, which resulted in dilatation of the weak venous wall of the newly constructed aneurysm-another shortcoming of this experimental aneurysm model. The volume decrease after 4 weeks expressed partial polymer degradation.

  11. Document-level classification of CT pulmonary angiography reports based on an extension of the ConText algorithm.

    PubMed

    Chapman, Brian E; Lee, Sean; Kang, Hyunseok Peter; Chapman, Wendy W

    2011-10-01

    In this paper we describe an application called peFinder for document-level classification of CT pulmonary angiography reports. peFinder is based on a generalized version of the ConText algorithm, a simple text processing algorithm for identifying features in clinical report documents. peFinder was used to answer questions about the disease state (pulmonary emboli present or absent), the certainty state of the diagnosis (uncertainty present or absent), the temporal state of an identified pulmonary embolus (acute or chronic), and the technical quality state of the exam (diagnostic or not diagnostic). Gold standard answers for each question were determined from the consensus classifications of three human annotators. peFinder results were compared to naive Bayes' classifiers using unigrams and bigrams. The sensitivities (and positive predictive values) for peFinder were 0.98(0.83), 0.86(0.96), 0.94(0.93), and 0.60(0.90) for disease state, quality state, certainty state, and temporal state respectively, compared to 0.68(0.77), 0.67(0.87), 0.62(0.82), and 0.04(0.25) for the naive Bayes' classifier using unigrams, and 0.75(0.79), 0.52(0.69), 0.59(0.84), and 0.04(0.25) for the naive Bayes' classifier using bigrams. PMID:21459155

  12. Age-related differences in image quality of prospectively ECG-triggered axial and helical scans for coronary CT angiography.

    PubMed

    Takase, Makoto; Fujimoto, Shinichiro; Takamura, Kazuhisa; Yamashita, Haruyo; Uno, Kenji; Aoki, Shigeki

    2016-07-01

    We investigated the underlying reasons for the occurrence of misalignment artifacts in prospectively ECG-triggered axial coronary CT angiography scans. In this study we analyzed 56 consecutive patients scanned in axial mode and 66 consecutive patients scanned in helical mode. Predictors for the occurrence of misalignment artifacts were evaluated by multivariable logistic regression analysis for those patients scanned in the axial mode; advanced age was identified as the sole independent predictor (odds ratio: 1.088; 95 % CI: 1.012-1.170; p = 0.0228). In a comparison with the patients scanned in the helical mode, the image quality score for patients aged 65 years or older was significantly higher in helical mode than in axial mode (2.6 ± 0.5 and 2.4 ± 0.7, respectively; p = 0.0313). Misalignment artifacts in the image are more common in the elderly than in younger. Helical mode should be preferred in this older patient population to allow for good diagnostic image quality. PMID:26984733

  13. Diagnostic quality of CT pulmonary angiography in pulmonary thromboembolism: A comparison of three different kV values

    PubMed Central

    Yilmaz, Ömer; Üstün, Esma Dilek; Kayan, Mustafa; Kayan, Fatmanur; Aktaş, Aykut Recep; Unlu, Elif Nisa; Degirmenci, Bumin; Cetin, Meltem

    2013-01-01

    Background Our purpose was to evaluate the effectiveness of different kilovolt (kV) uses in computed tomography pulmonary angiography (CTPA) in the diagnosis of pulmonary thromboembolism (PTE). We also aimed to establish the optimal kV value and investigate the possibility of obtaining appropriate imaging quality with minimal radiation dose. Material/Methods We compared 120, 100, and 80 kV CTPA for 90 patients in whom PTE was clinically considered. The examinations were carried out using a 128 multislice CT device (Definition AS, Siemens Medical Solutions, Forchheim, Germany). Each kV value was used on 30 patients in 3 groups. Patients in all groups were compared with respect to the mean radiation dose they received, pulmonary arterial attenuation values, image quality, and motion artefacts. Results With respect to pulmonary arterial attenuation values, imaging with 80 kV yielded significantly higher values (p<0.05). However, no difference was found between 120 kV, 100 kV, and 80 kV with respect to image quality. Similarly, no significant difference was detected between the groups with respect to pulmonary artery contrasting and motion artefacts. Statistically significant differences were present in DLP values and effective dose among all 3 groups (p<0.001). Conclusions Using 80 kV as the low value in CTPA imaging for patients pre-diagnosed with PTE will increase the density of pulmonary arteries and decrease the amount of radiation received. PMID:24169688

  14. Reduced z-axis technique for CT Pulmonary angiography in pregnancy--validation for practical use and dose reduction.

    PubMed

    Shahir, Kaushik; McCrea, Jonathan M; Lozano, Luis Antonio Sosa; Goodman, Lawrence R

    2015-12-01

    The aim of this study is to determine the feasibility of using reduced scan range CT pulmonary angiography technique in pregnancy for pulmonary embolism (PE) and to quantify resulting dose reduction. This was a retrospective study. Eighty-four CTPA exams performed on pregnant women during 2004-2012. The scans were modified to create reduced anatomic coverage scans extending from aortic arch to base of heart. These were separately evaluated by two radiologists for PE and non-PE abnormalities. The results were then compared by the third radiologist with original radiology report and scans. Radiation dose reduction was evaluated prospectively in 36 patients as part of a quality control project. Two patients had PE and were successfully identified on reduced z-axis scans. Thirty-two exams were normal; rest had 60 pertinent and 16 had incidental findings. There were four incidental findings which included three benign thyroid nodules and one benign small lung nodule which were missed. None of these affected clinical outcome or management. There was 71 % radiation dose reduction. No PE or any important diagnoses are missed using reduced z-axis CTPA in pregnancy. There is a substantial radiation dose reduction. Hence, this technique is highly recommended in pregnancy. PMID:26304188

  15. Tearing of the left iliac vessels in lumbar surgery revealed by multiphase post-mortem CT-angiography (MPMCTA).

    PubMed

    Vilariño Villaverde, Raquel; Bruguier, Christine; Zerlauth, Jean-Baptiste; De Froidmont, Sébastien; Grabherr, Silke

    2016-05-01

    Lumbar surgery is regularly applied in cases of discal hernia and acquired lumbar stenosis. In this report, we present a case of a laceration in the left common iliac artery and iliac vein during a lumbar surgery and discuss the literature concerning this kind of event. In the present case, the surgical procedure was followed by a sudden decrease in blood pressure, and the surgeon discovered an intra-abdominal haemorrhage that led to the patient's death. Postmortem investigation confirmed the intra-abdominal haemorrhage and revealed a laceration of the proximal portion of the left common iliac artery and left iliac vein. The source of bleeding could be detected especially thanks to multi-phase postmortem CT angiography (MPMCTA), which was performed prior to autopsy. We also found a haemorrhagic path through the intervertebral disc between the L4-L5 vertebrae, caused by the surgeon's instrument (pituitary rongeur). To date, a few cases have been described of iatrogenic death resulting from a tear in the iliac vessels during lumbar surgery, but not from the postmortem perspective. Such investigations have recently been modernized thanks to the introduction of forensic imaging. In particular, MPMCTA offers new possibilities in postmortem investigations and can be considered the new gold standard for investigating deaths related to medical intervention. Here we describe the first case of a death during lumbar surgery using this new method. PMID:27161923

  16. Validity of the size-specific dose estimate in adults undergoing coronary CT angiography: comparison with the volume CT dose index.

    PubMed

    Kidoh, Masafumi; Utsunomiya, Daisuke; Oda, Seitaro; Funama, Yoshinori; Yuki, Hideaki; Nakaura, Takeshi; Kai, Noriyuki; Nozaki, Takeshi; Yamashita, Yasuyuki

    2015-12-01

    Size-specific dose estimate (SSDE) takes into account the patient size but remains to be fully validated for adult coronary computed tomography angiography (CCTA). We investigated the appropriateness of SSDE for accurate estimation of patient dose by comparing the SSDE and the volume CT dose index (CTDIvol) in adult CCTA. This prospective study received institutional review board approval, and informed consent was obtained from each patient. We enrolled 37 adults who underwent CCTA with a 320-row CT. High-sensitivity metal oxide semiconductor field effect transistor dosimeters were placed on the anterior chest. CTDIvol reported by the scanner based on a 32-cm phantom was recorded. We measured chest diameter to convert CTDIvol to SSDE. Using linear regression, we then correlated SSDE with the mean measured skin dose. We also performed linear regression analyses between the skin dose/CTDIvol and the body mass index (BMI), and the skin dose/SSDE and BMI. There was a strong linear correlation (r = 0.93, P < 0.001) between SSDE (mean 37 ± 22 mGy) and mean skin dose (mean 17.7 ± 10 mGy). There was a moderate negative correlation between the skin dose/CTDIvol and BMI (r = 0.45, P < 0.01). The skin dose/SSDE was not affected by BMI (r = 0.06, P > 0.76). SSDE yields a more accurate estimation of the radiation dose without estimation errors attributable to the body size of adult patients undergoing CCTA. PMID:26440660

  17. The role of coronary CT angiography in diagnosis of patent foramen ovale

    PubMed Central

    Kara, Kemal; Sivrioğlu, Ali Kemal; Öztürk, Ersin; İncedayı, Mehmet; Sağlam, Muzaffer; Arıbal, Serkan; Işılak, Zafer; Mutlu, Hakan

    2016-01-01

    PURPOSE We aimed to examine the incidence of patent foramen ovale (PFO) and atrial septal aneurysms (ASA) in the Turkish population using coronary computed tomography angiography (CTA); assess the feasibility of coronary CTA for PFO diagnosis by conducting a comparison with transthoracic echocardiography (TTE); and determine the diagnostic role and characteristics of the interatrial tunnel, free flap valve (FFV), and shunts. METHODS The present study was conducted retrospectively and included a sample of 782 patients. Coronary CTA results for all patients were evaluated for the following parameters: the presence of PFO, the degree of contrast jet (if present due to PFO), ASA existence, free flap valve (FFV) length, and PFO tunnel diameters (1 and 2). Coronary CTA and TTE results for PFO detection were also compared for 19 patients who underwent both procedures. RESULTS PFO was present in 118 patients (15%). In 19 patients who underwent both CTA and TTE, the shunt was present in 15 patients on TTE compared with nine patients on CTA. The sensitivity and specificity of CTA for shunt existence were 53% (8/15) and 75% (3/4), respectively. FFV was observed on CTA in 118 patients (15%). No significant relationship was observed between shunt existence and FFV length (P = 0.148), or between shunt existence and tunnel diameter-1 (P = 0.638) or diameter-2 (P = 0.058). ASAs were present in 16 patients (2%), while accompanying PFO was present in three patients (2.4%). CONCLUSION Coronary CTA constitutes a more practical and efficient alternative to TTE for PFO diagnosis. Further, it allows the clear visualization of anatomical details of the interatrial tunnel, shunts, and associated abnormalities and detects ASAs. PMID:27152642

  18. MicroCT angiography detects vascular formation and regression in skin wound healing.

    PubMed

    Urao, Norifumi; Okonkwo, Uzoagu A; Fang, Milie M; Zhuang, Zhen W; Koh, Timothy J; DiPietro, Luisa A

    2016-07-01

    Properly regulated angiogenesis and arteriogenesis are essential for effective wound healing. Tissue injury induces robust new vessel formation and subsequent vessel maturation, which involves vessel regression and remodeling. Although formation of functional vasculature is essential for healing, alterations in vascular structure over the time course of skin wound healing are not well understood. Here, using high-resolution ex vivo X-ray micro-computed tomography (microCT), we describe the vascular network during healing of skin excisional wounds with highly detailed three-dimensional (3D) reconstructed images and associated quantitative analysis. We found that relative vessel volume, surface area and branching number are significantly decreased in wounds from day 7 to days 14 and 21. Segmentation and skeletonization analysis of selected branches from high-resolution images as small as 2.5μm voxel size show that branching orders are decreased in the wound vessels during healing. In histological analysis, we found that the contrast agent fills mainly arterioles, but not small capillaries nor large veins. In summary, high-resolution microCT revealed dynamic alterations of vessel structures during wound healing. This technique may be useful as a key tool in the study of the formation and regression of wound vessels. PMID:27009591

  19. A motion-compensated scheme for helical cone-beam reconstruction in cardiac CT angiography

    SciTech Connect

    Stevendaal, U. van; Berg, J. von; Lorenz, C.; Grass, M.

    2008-07-15

    Since coronary heart disease is one of the main causes of death all over the world, cardiac computed tomography (CT) imaging is an application of very high interest in order to verify indications timely. Due to the cardiac motion, electrocardiogram (ECG) gating has to be implemented into the reconstruction of the measured projection data. However, the temporal and spatial resolution is limited due to the mechanical movement of the gantry and due to the fact that a finite angular span of projections has to be acquired for the reconstruction of each voxel. In this article, a motion-compensated reconstruction method for cardiac CT is described, which can be used to increase the signal-to-noise ratio or to suppress motion blurring. Alternatively, it can be translated into an improvement of the temporal and spatial resolution. It can be applied to the entire heart in common and to high contrast objects moving with the heart in particular, such as calcified plaques or devices like stents. The method is based on three subsequent steps: As a first step, the projection data acquired in low pitch helical acquisition mode together with the ECG are reconstructed at multiple phase points. As a second step, the motion-vector field is calculated from the reconstructed images in relation to the image in a reference phase. Finally, a motion-compensated reconstruction is carried out for the reference phase using those projections, which cover the cardiac phases for which the motion-vector field has been determined.

  20. The role of coronary CT angiography in chronic total occlusion intervention

    PubMed Central

    Cheung, Stephen C W; Lim, Michael C L; Chan, Carmen W S

    2010-01-01

    Revascularisation by percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) is often a technically challenging procedure. The manipulation of wires and devices through a CTO during PCI without any means to visually identify vessel-wall boundaries involves an inherent risk of complications such as arterial dissection, perforation and cardiac tamponade. With the tremendous advances in multidetector CT technology and the popularity of utilising coronary CT angiogram (CCTA) for a workup of chest pain patients, an increasing number of CTO cases are being encountered. Therefore, the primary goal of CCTA for imaging in CTOs involves identifying the presence and locations of CTO as well as predicting the potential clinical benefits derived from revascularisation of the occluded segment. The secondary goal includes preprocedural planning to shorten procedure times, visualisation of the procedure in predicting the ease with which a CTO can be crossed and the frequency of procedure-related complications such as contrast nephropathy and radiation skin injury. Apart from these, CCTA also plays a role in postprocedural assessment of the revascularised arterial segments and long-term follow-up on the patency of coronary stents.

  1. Pre-existing oral contrast from lanthanum carbonate: a confounding factor in CT mesenteric angiography

    PubMed Central

    Bull, M D; Shrimanker, R; Thomas, M R M; Mulgrew, C J

    2012-01-01

    A 69-year-old male was referred from the renal unit to radiology for investigation of bleeding per rectum. A CT mesenteric angiogram was performed. However, it was noted on the pre-contrast images that the large bowel contained positive oral contrast media. The procedure was abandoned as it would have been difficult to see extravasation of intravenous contrast from a bleeding point in the large bowel. The initial belief was that either the patient had been given oral contrast by ward staff on the assumption that it would be needed, or had had a recent radiological study requiring contrast, which was still present. Neither was the case; it emerged that the patient was taking Fosrenol (Shire Pharmaceuticals, Wayne, PA), a lanthanum carbonate medication used in the treatment of hyperphosphataemia. Lanthanum is densely radio-opaque and appears as positive bowel contrast on CT and plain radiography studies. When considering radiological studies specifically requiring the absence of oral contrast, it is important to be aware of the patient's drug history to avoid non-diagnostic scans with the associated radiation exposure. PMID:22457410

  2. Accuracy of multislice CT angiography for the assessment of in-stent restenoses in the iliac arteries at reduced dose: a phantom study

    PubMed Central

    Perisinakis, K; Manousaki, E; Zourari, K; Tsetis, D; Tzedakis, A; Papadakis, A; Karantanas, A; Damilakis, J

    2011-01-01

    Objective We investigated the potential of low-dose CT angiography for accurate assessment of in-stent restenoses (ISRs) of the iliac artery. Method A Rando anthropomorphic phantom (Alderson Research Labs, Stanford, CA), custom-made wax simulating hyperplastic tissue and a nitinol stent were used to simulate a patient with clinically relevant iliac artery ISRs. The cylindrical lumen was filled with a solution of iodine contrast medium diluted in saline, representing a patient's blood during CT angiography. The phantom was subjected to standard- and low-dose angiographic exposures using a modern multidetector (MD) CT scanner. The percentage of ISR was determined using the profile along a line normal to the lumen axis on reconstructed images of 2 and 5 mm slice thickness. Percentage ISRs derived using the standard- and low-dose protocols were compared. In a preliminary study, seven patients with stents were subjected to standard- and low-dose MDCT angiography during follow-up. The resulting images were assessed and compared by two experienced radiologists. Results The accuracy in measuring the percentage ISR was found to be better than 12% for all simulated stenoses. The differences between percentage ISRs measured on images obtained at 120 kVp/160 mAs and 80 kVp/80 mAs were below 6%. Patient image sets acquired using low-exposure factors were judged to be of satisfactory diagnostic quality. The assessment of ISR did not differ significantly between image sets acquired using the standard factors and those acquired using the low-exposure factors, although the mean reduction in patient effective dose was 48%. Conclusion A reduction in exposure factors during MDCT angiography of the iliac artery is possible without affecting the accuracy in the determination of ISRs. PMID:21325364

  3. Coronary CT angiography (cCTA): automated registration of coronary arterial trees from multiple phases.

    PubMed

    Hadjiiski, Lubomir; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Kazerooni, Ella; Wei, Jun; Patel, Smita

    2014-08-21

    Coronary computed tomography angiography (cCTA) is a commonly used imaging modality for the evaluation of coronary artery disease. cCTA is generally reconstructed in multiple cardiac phases because different coronary arteries may be better visualized in some phases than in others due to the periodic cardiac motion. We are developing an automated registration method for coronary arterial trees from multiple-phase cCTA that has potential application in building a 'best-quality' tree to facilitate image analysis and detection of stenotic plaques. Given the segmented left or right coronary arterial (LCA or RCA) trees from the multiple phases as input, the adjacent phase pairs, where displacements are relatively small, are registered by a specifically designed method based on a cubic B-spline with fast localized optimization (CBSO). For the phase pairs with large displacements, a global registration using an affine transform with quadratic terms and nonlinear simplex optimization (AQSO) is followed by a local registration using CBSO to refine the AQSO registered volumes. 26 LCA and 26 RCA trees with six cCTA phases from 26 patients were used for registration evaluation. The average distances for the tree pairs between the adjacent phases with small displacements before and after CBSO registration were 0.96  ±  0.79 and 0.76  ±  0.61 mm respectively for LCA, and 0.93  ±  0.97 and 0.64  ±  0.43 mm, respectively for RCA. The average distance differences before and after registration were statistically significant (p < 0.001) for both LCA and RCA trees. The average distances for the distant phases with large displacements before registration, after AQSO registration, and finally after the CBSO registration were 2.85  ±  1.46, 1.62  ±  0.76, and 0.97  ±  0.43 mm, respectively for LCA, and 4.03  ±  2.36, 2.18  ±  1.11, and 0.97  ±  0.44 mm, respectively for RCA. The average distance differences

  4. Coronary CT angiography (cCTA): automated registration of coronary arterial trees from multiple phases

    NASA Astrophysics Data System (ADS)

    Hadjiiski, Lubomir; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Kazerooni, Ella; Wei, Jun; Patel, Smita

    2014-08-01

    Coronary computed tomography angiography (cCTA) is a commonly used imaging modality for the evaluation of coronary artery disease. cCTA is generally reconstructed in multiple cardiac phases because different coronary arteries may be better visualized in some phases than in others due to the periodic cardiac motion. We are developing an automated registration method for coronary arterial trees from multiple-phase cCTA that has potential application in building a ‘best-quality’ tree to facilitate image analysis and detection of stenotic plaques. Given the segmented left or right coronary arterial (LCA or RCA) trees from the multiple phases as input, the adjacent phase pairs, where displacements are relatively small, are registered by a specifically designed method based on a cubic B-spline with fast localized optimization (CBSO). For the phase pairs with large displacements, a global registration using an affine transform with quadratic terms and nonlinear simplex optimization (AQSO) is followed by a local registration using CBSO to refine the AQSO registered volumes. 26 LCA and 26 RCA trees with six cCTA phases from 26 patients were used for registration evaluation. The average distances for the tree pairs between the adjacent phases with small displacements before and after CBSO registration were 0.96  ±  0.79 and 0.76  ±  0.61 mm respectively for LCA, and 0.93  ±  0.97 and 0.64  ±  0.43 mm, respectively for RCA. The average distance differences before and after registration were statistically significant (p < 0.001) for both LCA and RCA trees. The average distances for the distant phases with large displacements before registration, after AQSO registration, and finally after the CBSO registration were 2.85  ±  1.46, 1.62  ±  0.76, and 0.97  ±  0.43 mm, respectively for LCA, and 4.03  ±  2.36, 2.18  ±  1.11, and 0.97  ±  0.44 mm, respectively for RCA. The average distance differences between every two

  5. Automatic multiscale enhancement and segmentation of pulmonary vessels in CT pulmonary angiography images for CAD applications

    SciTech Connect

    Zhou Chuan; Chan, H.-P.; Sahiner, Berkman; Hadjiiski, Lubomir M.; Chughtai, Aamer; Patel, Smita; Wei Jun; Ge Jun; Cascade, Philip N.; Kazerooni, Ella A.

    2007-12-15

    The authors are developing a computerized pulmonary vessel segmentation method for a computer-aided pulmonary embolism (PE) detection system on computed tomographic pulmonary angiography (CTPA) images. Because PE only occurs inside pulmonary arteries, an automatic and accurate segmentation of the pulmonary vessels in 3D CTPA images is an essential step for the PE CAD system. To segment the pulmonary vessels within the lung, the lung regions are first extracted using expectation-maximization (EM) analysis and morphological operations. The authors developed a 3D multiscale filtering technique to enhance the pulmonary vascular structures based on the analysis of eigenvalues of the Hessian matrix at multiple scales. A new response function of the filter was designed to enhance all vascular structures including the vessel bifurcations and suppress nonvessel structures such as the lymphoid tissues surrounding the vessels. An EM estimation is then used to segment the vascular structures by extracting the high response voxels at each scale. The vessel tree is finally reconstructed by integrating the segmented vessels at all scales based on a 'connected component' analysis. Two CTPA cases containing PEs were used to evaluate the performance of the system. One of these two cases also contained pleural effusion disease. Two experienced thoracic radiologists provided the gold standard of pulmonary vessels including both arteries and veins by manually tracking the arterial tree and marking the center of the vessels using a computer graphical user interface. The accuracy of vessel tree segmentation was evaluated by the percentage of the 'gold standard' vessel center points overlapping with the segmented vessels. The results show that 96.2% (2398/2494) and 96.3% (1910/1984) of the manually marked center points in the arteries overlapped with segmented vessels for the case without and with other lung diseases. For the manually marked center points in all vessels including arteries

  6. Diagnostic Performance of First-Pass Myocardial Perfusion Imaging without Stress with Computed Tomography (CT) Compared with Coronary CT Angiography Alone, with Fractional Flow Reserve as the Reference Standard

    PubMed Central

    Osawa, Kazuhiro; Miyoshi, Toru; Miki, Takashi; Koyama, Yasushi; Sato, Shuhei; Kanazawa, Susumu; Ito, Hiroshi

    2016-01-01

    Coronary computed tomography angiography (CCTA) in combination with first-pass CT myocardial perfusion imaging (MPI) has a better diagnostic performance than CCTA alone, compared with invasive coronary angiography as the reference standard. The aim of this study was to investigate the additional diagnostic value of first-pass CT-MPI without stress for detecting hemodynamic significance of coronary stenosis, compared with invasive fractional flow reserve (FFR). We recruited 53 patients with suspected coronary artery disease undergoing both CCTA and first-pass CT-MPI without stress and invasive FFR, and 75 vessels were analyzed. We used the same raw data for CCTA and CT-MPI. First-pass CT-MPI was reconstructed by examining the diastolic signal densities as a bull’s eye map. Invasive FFR <0.8 was considered as positive. On per-vessel analysis, the area under the receiver operating characteristic curve for CCTA plus first-pass CT-MPI and CCTA alone was 0.81 (0.73–0.90) and 0.70 (0.61–0.81), respectively (P = 0.036). CCTA plus first-pass CT-MPI without stress showed 0.73 sensitivity, 0.74 specificity, 0.53 positive predictive value, and 0.87 negative predictive value for detecting hemodynamically significant coronary stenosis. First-pass CT-MPI without stress correctly reclassified 38% of CCTA false-positive vessels as true negative. First-pass CT-MPI without stress combined with CCTA demonstrated excellent diagnostic accuracy, compared with invasive FFR as the reference standard. This technique could complement CCTA for diagnosis of coronary artery disease. PMID:26894686

  7. Diagnostic Performance of First-Pass Myocardial Perfusion Imaging without Stress with Computed Tomography (CT) Compared with Coronary CT Angiography Alone, with Fractional Flow Reserve as the Reference Standard.

    PubMed

    Osawa, Kazuhiro; Miyoshi, Toru; Miki, Takashi; Koyama, Yasushi; Sato, Shuhei; Kanazawa, Susumu; Ito, Hiroshi

    2016-01-01

    Coronary computed tomography angiography (CCTA) in combination with first-pass CT myocardial perfusion imaging (MPI) has a better diagnostic performance than CCTA alone, compared with invasive coronary angiography as the reference standard. The aim of this study was to investigate the additional diagnostic value of first-pass CT-MPI without stress for detecting hemodynamic significance of coronary stenosis, compared with invasive fractional flow reserve (FFR). We recruited 53 patients with suspected coronary artery disease undergoing both CCTA and first-pass CT-MPI without stress and invasive FFR, and 75 vessels were analyzed. We used the same raw data for CCTA and CT-MPI. First-pass CT-MPI was reconstructed by examining the diastolic signal densities as a bull's eye map. Invasive FFR <0.8 was considered as positive. On per-vessel analysis, the area under the receiver operating characteristic curve for CCTA plus first-pass CT-MPI and CCTA alone was 0.81 (0.73-0.90) and 0.70 (0.61-0.81), respectively (P = 0.036). CCTA plus first-pass CT-MPI without stress showed 0.73 sensitivity, 0.74 specificity, 0.53 positive predictive value, and 0.87 negative predictive value for detecting hemodynamically significant coronary stenosis. First-pass CT-MPI without stress correctly reclassified 38% of CCTA false-positive vessels as true negative. First-pass CT-MPI without stress combined with CCTA demonstrated excellent diagnostic accuracy, compared with invasive FFR as the reference standard. This technique could complement CCTA for diagnosis of coronary artery disease. PMID:26894686

  8. Image quality in low-dose coronary computed tomography angiography with a new high-definition CT scanner.

    PubMed

    Kazakauskaite, Egle; Husmann, Lars; Stehli, Julia; Fuchs, Tobias; Fiechter, Michael; Klaeser, Bernd; Ghadri, Jelena R; Gebhard, Catherine; Gaemperli, Oliver; Kaufmann, Philipp A

    2013-02-01

    A new generation of high definition computed tomography (HDCT) 64-slice devices complemented by a new iterative image reconstruction algorithm-adaptive statistical iterative reconstruction, offer substantially higher resolution compared to standard definition CT (SDCT) scanners. As high resolution confers higher noise we have compared image quality and radiation dose of coronary computed tomography angiography (CCTA) from HDCT versus SDCT. Consecutive patients (n = 93) underwent HDCT, and were compared to 93 patients who had previously undergone CCTA with SDCT matched for heart rate (HR), HR variability and body mass index (BMI). Tube voltage and current were adapted to the patient's BMI, using identical protocols in both groups. The image quality of all CCTA scans was evaluated by two independent readers in all coronary segments using a 4-point scale (1, excellent image quality; 2, blurring of the vessel wall; 3, image with artefacts but evaluative; 4, non-evaluative). Effective radiation dose was calculated from DLP multiplied by a conversion factor (0.014 mSv/mGy × cm). The mean image quality score from HDCT versus SDCT was comparable (2.02 ± 0.68 vs. 2.00 ± 0.76). Mean effective radiation dose did not significantly differ between HDCT (1.7 ± 0.6 mSv, range 1.0-3.7 mSv) and SDCT (1.9 ± 0.8 mSv, range 0.8-5.5 mSv; P = n.s.). HDCT scanners allow low-dose 64-slice CCTA scanning with higher resolution than SDCT but maintained image quality and equally low radiation dose. Whether this will translate into higher accuracy of HDCT for CAD detection remains to be evaluated. PMID:22825255

  9. Grade-response relationship between blood pressure and severity of coronary atherosclerosis in asymptomatic adults: assessment with coronary CT angiography.

    PubMed

    Im, Tae Seong; Chun, Eun Ju; Lee, Min Su; Adla, Theodor; Kim, Jeong A; Choi, Sang Il

    2014-12-01

    Hypertension is known to be a strong risk factor for coronary atherosclerosis. We aimed to investigate the prevalence, severity, and plaque characteristics of coronary atherosclerosis according to grade of blood pressure (BP) using coronary CT angiography (CCTA) in asymptomatic adults. We enrolled 8,238 asymptomatic subjects who underwent coronary artery calcium scoring (CACS) and CCTA for health screening purposes. Subjects were classified according to JNC 7 guidelines (normal, systolic BP/diastolic BP < 120/80; pre-hypertension [PH], 120-139/80-89; hypertension stage 1 [H1], 140-159/90-99; hypertension stage 2 [H2], >160/100). Isolated systolic hypertension (ISH; systolic BP > 140, diastolic BP < 80) was additionally categorized. With CCTA, the presence of plaques, severity of stenosis, and plaque types were assessed. Using multiple logistic regression analysis, the adjusted odds ratios (AORs) for plaque, obstructive coronary artery disease (CAD) (luminal stenosis ≥50 %), non-calcified plaque (NCP), and CACS > 100 were assessed according to BP grade. After adjustment for clinical risk factors, the risk of subclinical atherosclerosis, NCP, and CACS > 100 gradually increased from PH stage (all P values for trend <0.05), while the risk of obstructive CAD increased from the H1 stage (AORs of H1 and H2: 1.70 and 2.33, respectively). In the ISH group, the AOR of subclinical atherosclerosis (1.64) was higher than in the H1 group (1.55), while the AOR of obstructive CAD (2.58) was higher than in the H2 group (2.33). Therefore, our study strongly suggests that coronary atherosclerosis in asymptomatic adults shows a grade-response relationship according to hypertension grade. PMID:25178841

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

    PubMed

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

    2010-03-01

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

  11. A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation

    SciTech Connect

    Rupcich, Franco; Badal, Andreu; Kyprianou, Iacovos; Schmidt, Taly Gilat

    2012-09-15

    Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360 Degree-Sign through anthropomorphic voxelized female chest and head (0 Degree-Sign and 30 Degree-Sign tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tables of normalized dose deposition for several radiosensitive organs quantifying the organ dose per emitted photon for each incident photon energy and projection angle for coronary angiography and brain perfusion acquisitions. The values in a table can be multiplied by an incident spectrum and number of photons at each projection angle and then summed across all energies and angles to estimate total organ dose. Scanner-specific organ dose may be approximated by normalizing the database-estimated organ dose by the database-estimated CTDI{sub vol} and multiplying by a physical CTDI{sub vol} measurement. Two examples are provided demonstrating how to use the tables to estimate relative organ dose. In the first, the change in breast and lung dose during coronary angiography CT scans is calculated for reduced kVp, angular tube current modulation, and partial angle scanning protocols relative to a reference protocol. In the second example, the change in dose to the eye lens is calculated for a brain perfusion CT acquisition in which the gantry is tilted 30 Degree-Sign relative to a nontilted scan. Results: Our database provides tables of normalized dose deposition for several radiosensitive organs irradiated during coronary angiography and brain perfusion CT scans. Validation results indicate

  12. Automated bone removal in CT angiography: Comparison of methods based on single energy and dual energy scans

    SciTech Connect

    Straten, Marcel van; Schaap, Michiel; Dijkshoorn, Marcel L.; Greuter, Marcel J.; Lugt, Aad van der; Krestin, Gabriel P.; Niessen, Wiro J.

    2011-11-15

    Purpose: To evaluate dual energy based methods for bone removal in computed tomography angiography (CTA) images and compare these with single energy based methods that use an additional, nonenhanced, CT scan. Methods: Four different bone removal methods were applied to CT scans of an anthropomorphic thorax phantom, acquired with a second generation dual source CT scanner. The methods differed by the way information on the presence of bone was obtained (either by using an additional, nonenhanced scan or by scanning with two tube voltages at the same time) and by the way the bone was removed from the CTA images (either by masking or subtracting the bone). The phantom contained parts which mimic vessels of various diameters in direct contact with bone. Both a quantitative and qualitative analysis of image quality after bone removal was performed. Image quality was quantified by the contrast-to-noise ratio (CNR) normalized to the square root of the dose (CNRD). At locations where vessels touch bone, the quality of the bone removal and the vessel preservation were visually assessed. The dual energy based methods were assessed with and without the addition of a 0.4 mm tin filter to the high voltage x-ray tube filtration. For each bone removal method, the dose required to obtain a certain CNR after bone removal was compared with the dose of a reference scan with the same CNR but without automated bone removal. The CNRD value of the reference scan was maximized by choosing the lowest tube voltage available. Results: All methods removed the bone completely. CNRD values were higher for the masking based methods than for the subtraction based methods. Single energy based methods had a higher CNRD value than the corresponding dual energy based methods. For the subtraction based dual energy method, tin filtration improved the CNRD value with approximately 50%. For the masking based dual energy method, it was easier to differentiate between iodine and bone when tin filtration

  13. Computerized detection of noncalcified plaques in coronary CT angiography: Evaluation of topological soft gradient prescreening method and luminal analysis

    SciTech Connect

    Wei, Jun Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2014-08-15

    Purpose: The buildup of noncalcified plaques (NCPs) that are vulnerable to rupture in coronary arteries is a risk for myocardial infarction. Interpretation of coronary CT angiography (cCTA) to search for NCP is a challenging task for radiologists due to the low CT number of NCP, the large number of coronary arteries, and multiple phase CT acquisition. The authors conducted a preliminary study to develop machine learning method for automated detection of NCPs in cCTA. Methods: With IRB approval, a data set of 83 ECG-gated contrast enhanced cCTA scans with 120 NCPs was collected retrospectively from patient files. A multiscale coronary artery response and rolling balloon region growing (MSCAR-RBG) method was applied to each cCTA volume to extract the coronary arterial 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 NCP candidates by analyzing the 2D topological features of the radial gradient field surface along the vessel wall. The NCP candidates were then characterized by a luminal analysis that used 3D geometric features to quantify the shape information and gray-level features to evaluate the density of the NCP candidates. With machine learning techniques, useful features were identified and combined into an NCP score to differentiate true NCPs from false positives (FPs). To evaluate the effectiveness of the image analysis methods, the authors performed tenfold cross-validation with the available data set. Receiver operating characteristic (ROC) analysis was used to assess the classification performance of individual features and the NCP score. The overall detection performance was estimated by free response ROC (FROC) analysis. Results: With our TSG prescreening method, a prescreening sensitivity of 92.5% (111/120) was achieved with a total of 1181 FPs (14.2 FPs/scan). On average, six features

  14. Individually optimized uniform contrast enhancement in CT angiography for the diagnosis of pulmonary thromboembolic disease—A simulation study

    SciTech Connect

    Xue, Ming; Zhang, Hao; D’Souza, Warren; Lu, Wei; Kligerman, Seth; Klahr, Paul

    2013-12-15

    Purpose: To improve the diagnostic quality of CT pulmonary angiography (CTPA) by individually optimizing a biphasic contrast injection function to achieve targeted uniform contrast enhancement. To compare the results against a previously reported discrete Fourier transform (DFT) approach. Methods: This simulation study used the CTPA datasets of 27 consecutive patients with pulmonary thromboembolic disease (PE). An optimization approach was developed consisting of (1) computation of the impulse enhancement function (IEF) based on a test bolus scan, and (2) optimization of a biphasic contrast injection function using the IEF in order to achieve targeted uniform enhancement. The injection rates and durations of a biphasic contrast injection function are optimized by minimizing the difference between the resulting contrast enhancement curve and the targeted uniform enhancement curve, while conforming to the clinical constraints of injection rate and total contrast volume. The total contrast volume was limited first to the clinical standard of 65 ml, and then to the same amount used in the DFT approach for comparison. The optimization approach and the DFT approach were compared in terms of the root mean square error (RMSE) and total contrast volume used. Results: When the total contrast volume was limited to 65 ml, the optimization approach produced significantly better contrast enhancement (closer to the targeted uniform contrast enhancement) than the DFT approach (RMSE 17 HU vs 56 HU,p < 0.00001). On average, the optimization approach used 63 ml contrast, while the DFT approach used 50 ml with four patients exceeding 65 ml. When equivalent total contrast volume was used for individual patient, the optimization approach still generated significantly better contrast enhancement (RMSE 44 HU vs 56 HU, p < 0.01). Constraints for the injection function could be easily accommodated into the optimization process when searching for the optimal biphasic injection function

  15. Coronary artery disease in patients with atypical chest pain with and without diabetes mellitus assessed with coronary CT angiography

    PubMed Central

    Krul, Marije M G; Bogaard, Kjell; Knol, Remco J J; van Rossum, Albert C; Knaapen, Paul; Cornel, Jan H; van der Zant, Friso M

    2014-01-01

    Introduction Coronary artery disease (CAD) in diabetes mellitus (DM) is often widespread when diagnosed. Non-invasive coronary calcium scoring and coronary CT angiography (CAC-score/CCTA) are accurate in the detection of CAD. This study compared CAD characteristics as identified by CCTA between patients with and without DM with atypical chest pain. Methods CAD was defined as CAC-score >0 and/or presence of coronary plaque. Several CAD characteristics (number of affected segments, obstructive (>50% stenosis) CAD and CAD distribution) were compared on a per patient and segment basis. Subanalysis of duration of DM (<5 or >5 years) and gender was performed. Results A total of 1148 patients (63.3% men, mean age 57.7±10.7), of whom 99 (8.6%) suffered from DM, were referred for CCTA. There was no difference in the prevalence of CAD between patients with and without DM (53.5% vs 50.9%, p=0.674). However patients with DM showed more affected coronary segments compared with patients without DM (2.5±3.4 vs 1.7±2.4, p=0.003). Multivariate analysis indicated that DM was an independent predictor of obstructive CAD (OR 2.16, 95% CI 1.23 to 3.78), as were age, women, and Diamond-Forrester score. In our study, obstructive CAD was more prevalent in women than in men (DM 40.0% vs 14.1%, p=0.003; non-DM 16.8% vs 8.4%, p<0.001). Patients suffering from DM >5 years showed more distal plaques (11.2% vs 7.7%, p=0.030). Conclusions Patients with atypical chest pain and DM showed more extensive CAD, as well as more obstructive CAD, particularly in women. Diabetes duration (>5 years) was not associated with more obstructive coronary disease or different plaque morphology, although more distal disease was present. PMID:25452855

  16. Catheter Angiography

    MedlinePlus

    ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ...

  17. Optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter.

    PubMed

    Dhungel, Abinashi; Qian, Zhen; Vazquez, Gustavo; Rinehart, Sarah; Weeks, Michael; Voros, Szilard

    2012-01-01

    3D Computed Tomography (CT) provides noninvasive, low-radiation method of coronary artery calcium (CAC) measurement. Conventional CAC images are acquired on multidetector-row CT scanners without contrast, and reconstructed with 3 mm slice thickness. The calcium volume is quantified by registering voxels with attenuation values greater than or equal to 130 Hounsfield Unit (HU). In isotropic CAC images with 0.5 mm slice thickness obtained from 320-detector row CT, the optimal value of attenuation cutoff threshold is unknown. In this paper we find the optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter (IVUS/VH). From the statistical analysis of calcium data obtained from the images of 9 patients we found a range of optimal thresholds and the conventional threshold of 130 HU was in the range. Further, the optimal values were different for individual patients. PMID:23367046

  18. Metal artifact reduction for flat panel detector intravenous CT angiography in patients with intracranial metallic implants after endovascular and surgical treatment

    PubMed Central

    Pjontek, Rastislav; Önenköprülü, Belgin; Scholz, Bernhard; Kyriakou, Yiannis; Schubert, Gerrit A; Othman, Ahmed; Wiesmann, Martin; Brockmann, Marc A

    2016-01-01

    Background Flat panel detector CT angiography with intravenous contrast agent injection (IV CTA) allows high-resolution imaging of cerebrovascular structures. Artifacts caused by metallic implants like platinum coils or clips lead to degradation of image quality and are a significant problem. Objective To evaluate the influence of a prototype metal artifact reduction (MAR) algorithm on image quality in patients with intracranial metallic implants. Methods Flat panel detector CT after intravenous application of 80 mL contrast agent was performed with an angiography system (Artis zee; Siemens, Forchheim, Germany) using a 20 s rotation protocol (200° rotation angle, 20 s acquisition time, 496 projections). The data before and after MAR of 26 patients with a total of 34 implants (coils, clips, stents) were independently evaluated by two blinded neuroradiologists. Results MAR improved the assessability of the brain parenchyma and small vessels (diameter <1 mm) in the neighborhood of metallic implants and at a distance of 6 cm (p<0.001 each, Wilcoxon test). Furthermore, MAR significantly improved the assessability of parent vessel patency and potential aneurysm remnants (p<0.005 each, McNemar test). MAR, however, did not improve assessability of stented vessels. Conclusions When an intravenous contrast protocol is used, MAR significantly ameliorates the assessability of brain parenchyma, vessels, and treated aneurysms in patients with intracranial coils or clips. PMID:26346458

  19. Photogrammetric measurement and visualization of blood vessel branching casting: a tool for quantitative accuracy tests of MR, CT, and DS angiography

    NASA Astrophysics Data System (ADS)

    D'Apuzzo, Nicola

    2000-12-01

    Currently three different angiographic techniques are used to measure and visualize major blood vessels in the human body: magnetic resonance (MR), computer tomography (CT) and digital subtraction (DS) angiography. Although these imaging systems have been already qualitatively compared, a quantitative assessment is still missing. The goal of this work is to provide a tool enabling a quantitative comparison of the three imaging techniques to an unbiased reference. MR-, CT- and DS-angiographies are first performed on a corpse. Then, a casting of the abdominal aorta and its main branches is prepared, removed from the body and measured with photogrammetric methods. The elongated and thin cast is fixed in a 3D frame with 16 signalized small spheres used for calibration and orientation purposes. Three fixed CCD cameras acquire triplets of images of the casting, which is turned in 8 positions. In order to perform multi-image matching, an artificial random texture is projected onto the object. For each triplet of images, a semi-automated matching process based on least squares matching determines a dense set of corresponding points. Their 3D coordinates are then computed by forward intersection, with a mean standard deviation of about 0.2 mm. The result from the 8 positions are merged together into a 3D point cloud and an adequate filter is applied to remove the noise and the redundancy in the overlapping regions. The paper depicts the basic design of the system and the measurement methods. Furthermore some preliminary results are presented.

  20. Non-contrast 3D time-of-flight magnetic resonance angiography for visualization of intracranial aneurysms in patients with absolute contraindications to CT or MRI contrast

    PubMed Central

    Yanamadala, Vijay; Sheth, Sameer A.; Walcott, Brian P.; Buchbinder, Bradley R.; Buckley, Deidre; Ogilvy, Christopher S.

    2013-01-01

    The preoperative evaluation in patients with intracranial aneurysms typically includes a contrast-enhanced vascular study, such as computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography. However, there are numerous absolute and relative contraindications to the administration of imaging contrast agents, including pregnancy, severe contrast allergy, and renal insufficiency. Evaluation of patients with contrast contraindications thus presents a unique challenge. We identified three patients with absolute contrast contraindications who presented with intracranial aneurysms. One patient was pregnant, while the other two had previous severe anaphylactic reactions to iodinated contrast. Because of these contraindications to intravenous contrast, we performed non-contrast time-of-flight MRA with 3D reconstruction (TOF MRA with 3DR) with maximum intensity projections and volume renderings as part of the preoperative evaluation prior to successful open surgical clipping of the aneurysms. In the case of one paraclinoid aneurysm, a high-resolution non-contrast CT scan was also performed to assess the relationship of the aneurysm to the anterior clinoid process. TOF MRA with 3DR successfully identified the intracranial aneurysms and adequately depicted the surrounding microanatomy. Intraoperative findings were as predicted by the preoperative imaging studies. The aneurysms were successfully clip-obliterated, and the patients had uneventful post-operative courses. These cases demonstrate that non-contrast imaging is a viable modality to assess intracranial aneurysms as part of the surgical planning process in patients with contrast contraindications. TOF MRA with 3DR, in conjunction with high-resolution non-contrast CT when indicated, provides adequate visualization of the microanatomy of the aneurysm and surrounding structures. PMID:23685107

  1. Comparison of diagnostic accuracy of dual-source CT and conventional angiography in detecting congenital heart diseases

    PubMed Central

    Sedaghat, Fariborz; Pouraliakbar, Hamidreza; Motevalli, Marzieh; Karimi, Mohammad Ali; Armand, Sandbad

    2014-01-01

    Summary Background Cardiac dual-source computed tomography (DSCT) is primarily used for coronary arteries. There are limited studies about the application of DSCT for congenital heart diseases. The aim of this study was to determine the diagnostic value of DSCT in the cardiac anomalies. Material/Methods The images of DSCTs and conventional angiographies of 36 patients (21 male; mean age: 8.5 month) with congenital heart diseases were reviewed and the parameters of diagnostic value of these methods were compared. Cardiac surgery was the gold standard. Results A total of 105 cardiac anomalies were diagnosed at surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of DSCT were 98.25%, 97.9%, 98.1%, 99.07%, and 98.2%, respectively. The corresponding values of angiography were 95.04%, 98.7%, 97.8%, 98.1%, and 98%, respectively. Only one atrial septal defect (ASD) and two patent ductus arteriosus (PDA) were missed by DSCT. Angiography missed two ASD and two PDA. DSCT also provided important additional findings (n=35) about the intrathoracic or intraabdominal organs. Conclusions DSCT is a highly accurate diagnostic modality for congenital heart diseases, obviating the need for invasive modalities. Beside its noninvasive nature, the advantage of DSCT over the angiography is its ability to provide detailed anatomical information about the heart, vessels, lungs and intraabdominal organs. PMID:24987488

  2. Efficiency and safety of coronary CT angiography compared to standard care in the evaluation of patients with acute chest pain: a Canadian study.

    PubMed

    Peña, Elena; Rubens, Fraser; Stiell, Ian; Peterson, Rebecca; Inacio, Joao; Dennie, Carole

    2016-08-01

    The optimal assessment of patients with chest pain and possible acute coronary syndrome (ACS) remains a diagnostic dilemma for emergency physicians. Cardiac computed tomographic angiography (CCTA) may identify patients who can be safely discharged home from the emergency department (ED). The objective of the study was to compare the efficiency and safety of CCTA to standard care in patients presenting to the ED with low- to intermediate-risk chest pain. This was a single-center before-after study enrolling ED patients with chest pain and low to intermediate risk of ACS, before and after implementing a cardiac CT-based management protocol. The primary outcome was efficiency (time to diagnosis). Secondary outcomes included safety (30-day incidence of major adverse cardiovascular events (MACE)) and length of stay in the ED. We enrolled 258 patients: 130 in the standard care group and 128 in the cardiac CT-based management group. The cardiac CT group had a shorter time to diagnosis of 7.1 h (IQR 5.8-14.0) compared to 532.9 h (IQR 312.8-960.5) for the standard care group (p < 0.0001) but had a longer length of stay in the ED of 7.9 h (IQR 6.5-10.8) versus 5.5 h (IQR 3.9-7.7) (p < 0.0001). The MACE rate was 1.6 % in the standard care group and 0 % in the cardiac CT group. In conclusion, a cardiac CT-based management strategy to rule out ACS in ED patients with low- to intermediate-risk chest pain was safe and led to a shorter time to diagnosis but increased length of stay in the ED. PMID:27220653

  3. Enhanced diagnostic value for coronary CT angiography of calcified coronary arteries using dual energy and a novel high-Z contrast material: a phantom study

    NASA Astrophysics Data System (ADS)

    Lambert, Jack W.; Ordovas, Karen G.; Sun, Yuxin; Yeh, Benjamin M.

    2016-03-01

    Dual-energy CT is emerging as a dose-saving tool for coronary CT angiography that allows calcium-scoring without the need for a separate unenhanced scan acquisition. Unfortunately the similar attenuation coefficient profiles of iodine and calcium limits the accuracy of their decomposition in the material basis images. We evaluate a tungsten-based contrast material with a more distinct attenuation profile from calcium, and compare its performance to a conventional iodinated agent. We constructed a custom thorax phantom containing simulated sets of vessels 3, 6 and 9 mm in diameter. The vessel sets were walled with concentric and eccentric calcifications ("plaque") with concentrations of 0, 20, 30 and 40% weight calcium hydroxyapatite (HAP). The phantom was filled sequentially with iodine and tungsten contrast material, and scanned helically using a fast-kV-switching DECT scanner. At material decomposition, both iodine and tungsten vessel lumens were separable from the HAP vessel walls, but separation was superior with tungsten which showed minimal false positive signal in the HAP image. Assessing their relative performance using line profiles, the HAP signal was greater in the tungsten separation in 6/9 of the vessel sets, and within 15% of the iodine separation for the remaining 3/9 sets. The robust phantom design enabled systematic evaluation of dual-energy material separation for calcium and a candidate non-iodinated vascular contrast element. This approach can be used to screen further agents and also refine dual energy CT material decomposition approaches.

  4. Determining the haemodynamic significance of arterial stenosis: the relationship between CT angiography, computational fluid dynamics, and non-invasive fractional flow reserve.

    PubMed

    Pang, C L; Alcock, R; Pilkington, N; Reis, T; Roobottom, C

    2016-08-01

    Coronary artery disease causes significant morbidity and mortality worldwide. Invasive coronary angiography (ICA) is currently the reference standard investigation. Fractional flow reserve (FFR) complements traditional ICA by providing extra information on blood flow, which has convincingly led to better patient management and improved cost-effectiveness. Computed tomography coronary angiography (CTCA) is suitable for the investigation of chest pain, especially in the low- and intermediate-risk groups. FFR generated using CT data (producing FFRCT) may improve the positive predictive value of CTCA. The basic science of FFRCT is like a "black box" to most imaging professionals. A fundamental principle is that good quality CTCA is likely to make any post-processing easier and more reliable. Both diagnostic and observational studies have suggested that the accuracy and the short-term outcome of using FFRCT are both comparable with FFR in ICA. More multidisciplinary research with further refined diagnostic and longer-term observational studies will hopefully pinpoint the role of FFRCT in existing clinical pathways. PMID:27061041

  5. Extremity angiography

    MedlinePlus

    ... angiography. Angiography uses x-rays and a special dye to see inside the arteries. Arteries are blood ... like monitor, and uses them as a guide. Dye flows through the catheter and into the arteries. ...

  6. Normalized CT Dose Index of the CT Scanners Used in the National Lung Screening Trial

    PubMed Central

    Cody, Dianna D.; Kim, Hyun-Jung; Cagnon, Christopher H.; Larke, Frederick J.; McNitt-Gray, Michael M.; Kruger, Randell L.; Flynn, Michael J.; Seibert, J. Anthony; Judy, Philip F.; Wu, Xizeng

    2010-01-01

    The National Lung Screening Trial (NLST) includes 33 participating institutions, which performed 75, 133 lung cancer screening CT exams from 26,724 subjects during 2002–2007. For trial quality assurance reasons, CT radiation dose measurement data were collected from all multidetector-row CT scanners used in the NLST. A total of 247 measurements on 96 multi-row detector scanners were collected using a standard CT dose index (CTDI) measurement protocol. The scan parameters employed in the measurements (tube voltage, mAs and detector-channel configuration) were set according to trial-protocol for average size subjects. The normalized CTDIw (computed as CTDIw /mAs) obtained from each trial-participating scanner was tabulated. This study demonstrated a statistically significant difference in normalized CT dose index among CT scanner manufacturers, likely due to design differences such as filtration, bow-tie design and geometry. Our findings also indicated a statistically significant difference in normalized CT dose index among CT scanner models within GE, Siemens, and Philips. We also demonstrated a statistically significant difference in normalized CT dose index among all models and all manufacturers. And, we demonstrated a statistically significant difference in normalized CT dose index from CT scanners among manufacturers when grouped by 4 or 8 data channels vs 16, 32, or 64 channels, suggesting improved dose efficiency in more complex scanners. Average normalized CT dose index values varied by almost a factor of two across all scanners from all manufacturers. This study was focused on machine specific normalized CT dose index; patient dose and image quality were not addressed. PMID:20489094

  7. Low-dose coronary-CT angiography using step and shoot at any heart rate: comparison of image quality at systole for high heart rate and diastole for low heart rate with a 128-slice dual-source machine.

    PubMed

    Paul, Jean-François; Amato, Aude; Rohnean, Adela

    2013-03-01

    To compare image quality of coronary CT angiography in step-and-shoot mode at the diastolic phase at low heart rates (<70 bpm) and systolic phase at high heart rates (≥70 bpm). We prospectively included 96 consecutive patients then excluded 5 patients with arrhythmia. Coronary CT-angiography was performed using a dual-source 128-slice CT machine, at the diastolic phase in the 55 patients with heart rates <70 bpm (group D) and at the systolic phase in the 36 patients with heart rates ≥70 (group S). Image quality was scored on a 5 point-scale (1, not interpretable; 2, insufficient for diagnosis; 3, fair, sufficient for diagnosis; 4, good; 5, excellent). In addition, we compared the number of stair-step artifacts in the two groups. Mean image quality score was 4 (0.78) in group D and 4.1 (0.34) in group S (NS), with an unequal distribution (p = 0.01). Step artifacts were seen in 44 % of group D and 18 % of group S patients (p = 0.02). In 3 group D patients and no group S patients, the image score was <3 due to artifacts, requiring repeat CT-angiography. When performing dual-source 128-slice CT-angiography, step-and-shoot acquisition provides comparable mean image quality in systole, with less variability and fewer stair-step artifacts, compared to diastole. This method may be feasible at any heart rate in most patients in sinus rhythm, allowing low-dose prospective acquisition without beta-blocker premedication. PMID:22918571

  8. Regional Mapping of Aortic Wall Stress by Using Deformable, Motion-coherent Modeling based on Electrocardiography-gated Multidetector CT Angiography: Feasibility Study.

    PubMed

    Mileto, Achille; Heye, Tobias J; Makar, Ryan A; Hurwitz, Lynne M; Marin, Daniele; Boll, Daniel T

    2016-07-01

    Purpose To investigate the feasibility of deformable, motion-coherent modeling based on electrocardiography-gated multidetector computed tomographic (CT) angiography of the thoracic aorta and to evaluate whether quantifiable information on aortic wall stress as a function of patient-specific cardiovascular parameters can be gained. Materials and Methods For this institutional review board-approved, HIPAA-compliant study, thoracic electrocardiography-gated dual-source multidetector CT angiographic images were used from 250 prospectively enrolled patients (150 men, 100 women; mean age, 79 years). On reconstructed 50-phase CT angiographic images, aortic strain and deformation were determined at seven cardiac and aortic locations. One-way analysis of variance was used by assessing the magnitude for longitudinal and axial strain and axial deformation, as well as time-resolved peak and maxima count for longitudinal strain and axial deformation. Interdependencies between aortic strain and deformation with extracted hemodynamic parameters were evaluated. Results With increasing heart rates, there was a significant decrease in longitudinal strain (P = .009, R(2) = 0.95) and a decrease in the number of longitudinal strain peaks (P < .001, R(2) = 0.79); however, a significant increase in axial deformation (P < .001, R(2) = 0.31) and axial strain (P = .009, R(2) = 0.61) was observed. Increasing aortic blood velocity led to increased longitudinal strain (P = .018, R(2) = 0.42) and longitudinal strain peak counts (P = .011, R(2) = 0.48). Pronounced motion in the longitudinal direction limited motion in the axial plane (P < .019, R(2) = 0.29-0.31). Conclusion The results of this study render a clinical basis and provide proof of principle for the use of deformable, motion-coherent modeling to provide quantitative information on physiological motion of the aorta under various hemodynamic circumstances. (©) RSNA, 2016 Online supplemental material is available for this article

  9. Comparison Between Prospectively Electrocardiogram-Gated High-Pitch Mode and Retrospectively Electrocardiogram-Gated Mode for Dual-Source CT Coronary Angiography

    PubMed Central

    Koplay, Mustafa; Celik, Mahmut; Avcı, Ahmet; Erdogan, Hasan; Demir, Kenan; Sivri, Mesut; Nayman, Alaaddin

    2015-01-01

    Summary Background We aimed to report the image quality, relationship between heart rate and image quality, amount of contrast agent given to the patients and radiation doses in coronary CT angiography (CTA) obtained by using high-pitch prospectively ECG-gated “Flash Spiral” technique (method A) or retrospectively ECG-gated technique (method B) using 128×2-slice dual-source CT. Material/Methods A total of 110 patients who were evaluated with method A and method B technique with a 128×2-detector dual-source CT device were included in the study. Patients were divided into three groups based on their heart rates during the procedure, and a relationship between heart rate and image quality were evaluated. The relationship between heart rate, gender and radiation dose received by the patients was compared. Results A total of 1760 segments were evaluated in terms of image quality. Comparison of the relationship between heart rate and image quality revealed a significant difference between heart rate <60 beats/min group and >75 beats/min group whereas <60 beats/min and 60–75 beats/min groups did not differ significantly. The average effective dose for coronary CTA was calculated as 1.11 mSv (0.47–2.01 mSv) for method A and 8.22 mSv (2.19–12.88 mSv) for method B. Conclusions Method A provided high quality images with doses as low as <1 mSv in selected patients who have low heart rates with a high negative predictive value to rule out coronary artery disease. Although method B increases the amount of effective dose, it provides high diagnostic quality images for patients who have a high heart rate and arrhythmia which makes it is difficult to obtain images. PMID:26767072

  10. The feasibility of sub-millisievert coronary CT angiography with low tube voltage, prospective ECG gating, and a knowledge-based iterative model reconstruction algorithm.

    PubMed

    Park, Chul Hwan; Lee, Joohee; Oh, Chisuk; Han, Kyung Hwa; Kim, Tae Hoon

    2015-12-01

    We evaluated the feasibility of sub-millisievert (mSv) coronary CT angiography (CCTA) using low tube voltage, prospective ECG gating, and a knowledge-based iterative model reconstruction algorithm. Twenty-four non-obese healthy subjects (M:F 13:11; mean age 50.2 ± 7.8 years) were enrolled. Three sets of CT images were reconstructed using three different reconstruction methods: filtered back projection (FBP), iterative reconstruction (IR), and knowledge-based iterative model reconstruction (IMR). The scanning parameters were as follows: step-and-shoot axial scanning, 80 kVp, and 200 mAs. On the three sets of CT images, the attenuation and image noise values were measured at the aortic root. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated at the proximal right coronary artery and the left main coronary artery. The qualitative image quality of the CCTA with IMR was assessed using a 4-point grading scale (grade 1, poor; grade 4, excellent). The mean radiation dose of the CCTA was 0.89 ± 0.09 mSv. The attenuation values with IMR were not different from those of other reconstruction methods. The image noise with IMR was significantly lower than with IR and FBP. Compared to FBP, the noise reduction rate of IMR was 69 %. The SNR and CNR of CCTA with IMR were significantly higher than with FBP or IR. On the qualitative analysis with IMR, all included segments were diagnostic (grades 2, 3, and 4), and the mean image quality score was 3.6 ± 0.6. In conclusion, CCTA with low tube voltage, prospective ECG gating, and an IMR algorithm might be a feasible method that allows for sub-millisievert radiation doses and good image quality when used with non-obese subjects. PMID:26521066

  11. Post-Pancreaticoduodenectomy Hemorrhage of Unusual Origin: Treatment with Endovascular Embolization and the value of preoperative CT Angiography

    PubMed Central

    Robinson, Kortney; Rajebi, Mohammad Reza; Zimmerman, Nicole; Zeinati, Chadi

    2013-01-01

    Post-pancreaticoduodenectomy hemorrhage is a life threatening complication reported to occur in 2–7% of patients. Historically, treatment required an exploratory laparotomy. Introduction of endovascular embolization has broadened the available treatment options. The most common location for a post-pancreaticoduodenectomy hemorrhage is the gastroduodenal artery stump. Nonetheless, unusual sources of hemorrhage exist and are hard to localize, thus they are often treated with open surgery. Here we report two cases of CTA proven hemorrhage from the dorsal pancreatic arcade and transverse pancreatic artery, which were successfully located with conventional angiography and treated with endovascular arterial coil embolization. Both patients were status post-pancreaticoduodenectomy (Whipple procedure) and presented with a sentinel bleed and a drop in hematocrit levels. PMID:23705050

  12. Preoperative CT angiography versus Doppler ultrasound mapping of abdominal perforator in DIEP breast reconstructions: A randomized prospective study.

    PubMed

    Klasson, S; Svensson, H; Malm, K; Wassélius, J; Velander, P

    2015-06-01

    Is there a difference in surgery time and complication rate when Doppler ultrasound (US) is used for the preoperative mapping of perforators in comparison with computer tomography angiography (CTA)? Women who were candidates for breast reconstruction using the deep inferior epigastric perforator (DIEP) free flap were enrolled in a prospective randomized study. The operating time was 249 ± 62 min (mean ± SD) in the CTA group (n = 32) and 255 min ± 75 in the US group (n = 31)--hence a difference of 6 min on average. No flaps were lost. Sixteen complications occurred in 15 patients: seven in the CTA group and nine in the US group. Complications were remedied without delay and all patients came through with a favorable reconstruction. Preoperative mapping of perforators with US is satisfactory enough provided the microsurgery team has proper experience in breast reconstruction with the DIEP flap. PMID:25824193

  13. Accuracy of dual-source CT coronary angiography: first experience in a high pre-test probability population without heart rate control

    PubMed Central

    Scheffel, Hans; Plass, André; Vachenauer, Robert; Desbiolles, Lotus; Gaemperli, Oliver; Schepis, Tiziano; Frauenfelder, Thomas; Schertler, Thomas; Husmann, Lars; Grunenfelder, Jürg; Genoni, Michele; Kaufmann, Philipp A.; Marincek, Borut; Leschka, Sebastian

    2006-01-01

    The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control. Thirty patients (24 male, 6 female, mean age 63.1±11.3 years) with a high pre-test probability of CAD underwent DSCT coronary angiography and invasive coronary angiography (ICA) within 14±9 days. No beta-blockers were administered prior to the scan. Two readers independently assessed image quality of all coronary segments with a diameter ≥1.5 mm using a four-point score (1: excellent to 4: not assessable) and qualitatively assessed significant stenoses as narrowing of the luminal diameter >50%. Causes of false-positive (FP) and false-negative (FN) ratings were assigned to calcifications or motion artifacts. ICA was considered the standard of reference. Mean body mass index was 28.3±3.9 kg/m2 (range 22.4–36.3 kg/m2), mean heart rate during CT was 70.3±14.2 bpm (range 47–102 bpm), and mean Agatston score was 821±904 (range 0–3,110). Image quality was diagnostic (scores 1–3) in 98.6% (414/420) of segments (mean image quality score 1.68±0.75); six segments in three patients were considered not assessable (1.4%). DSCT correctly identified 54 of 56 significant coronary stenoses. Severe calcifications accounted for false ratings in nine segments (eight FP/one FN) and motion artifacts in two segments (one FP/one FN). Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively. First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control. PMID:17031451

  14. SU-E-I-25: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Simulation Study

    SciTech Connect

    Johnson, T; Ding, H; Lipinski, J; Molloi, S

    2015-06-15

    Purpose: To develop a physics-based model for accurate quantification of the cross-sectional area (CSA) of coronary arteries in CT angiography by measuring the integrated density to account for the partial volume effect. Methods: In this technique the integrated density of the object as compared with its local background is measured to account for the partial volume effect. Normal vessels were simulated as circles with diameters in the range of 0.1–3mm. Diseased vessels were simulated as 2, 3, and 4mm diameter vessels with 10–90% area stenosis, created by inserting circular plaques. A simplified two material model was used with the lumen as 8mg/ml Iodine and background as lipid. The contrast-to-noise ratio between lumen and background was approximately 26. Linear fits to the known CSA were calculated. The precision and accuracy of the measurement were quantified using the root-mean-square fit deviations (RMSD) and errors to the known CSA (RMSE). Results compared to manual segmentation of the vessel lumen. To assess the impact of random variations, coefficients of variation (CV) from 10 simulations for each vessel were computed to determine reliability. Measurements with CVs less than 10% were considered reliable. Results: For normal vessels, the precision and accuracy of the integrated density technique were 0.12mm{sup 2} and 0.28mm{sup 2}, respectively. The corresponding results for manual segmentation were 0.27mm{sup 2} and 0.43mm{sup 2}. For diseased vessels, the precision and accuracy of the integrated density technique were 0.14mm{sup 2} and 0.19mm{sup 2}. Corresponding results for manual segmentation were 0.42mm{sup 2} and 0.71mm{sup 2}. Reliable CSAs were obtained for normal vessels with diameters larger than 1 mm and for diseased vessels with area as low as 1.26mm2. Conclusion: The CSA based on integrated density showed improved precision and accuracy as compared with manual segmentation in simulation. These results indicate the potential of using

  15. Quantitative analysis of myocardial perfusion SPECT anatomically guided by co-registered 64-slice coronary CT angiography

    PubMed Central

    Slomka, Piotr J.; Cheng, Victor Y.; Dey, Damini; Woo, Jonghye; Ramesh, Amit; Kriekinge, Serge Van; Suzuki, Yasuzuki; Elad, Yaron; Karlsberg, Ronald; Berman, Daniel S.; Germano, Guido

    2012-01-01

    Aim Sequential testing by coronary computed tomography angiography (CTA) and myocardial perfusion SPECT (MPS) obtained on standalone scanners may be needed to diagnose coronary artery disease (CAD) in equivocal cases. We have developed an automated technique for MPS-CTA registration and demonstrate its utility for improved MPS quantification by guiding the co-registered physiological (MPS) with anatomical CTA information. Methods Automated registration of MPS left ventricular (LV) surfaces with CTA coronary trees was accomplished by iterative minimization of voxel differences between pre-segmented CTA volumes and “motion-frozen” MPS data. Studies of 35 sequential patients (26 males), mean age 67±12 years with 64-slice coronary CTA, MPS and with available results of the invasive coronary angiography performed within 3 months were retrospectively analyzed. 3D coronary vessels and CTA slices were extracted and fused with quantitative MPS results mapped on LV surfaces and MPS coronary regions. Automatically co-registered CTA images and extracted trees were used to correct the MPS contours and to adjust the standard vascular region definitions for MPS quantification. Results Automated co-registration of MPS and coronary CTA had the success rate of 96% as assessed visually; the average errors were 4.3±3.3 mm in translation and 1.5±2.6 deg in rotation on stress and 4.2±3.1 mm in translation and 1.7±3.2 deg in rotation on rest. MPS vascular region definition was adjusted in 17 studies and LV contours were adjusted in 11 studies using co-registered CTA images as a guide. CTA-guided MP analysis resulted in improved area under the receiver operator characteristics (ROC) curves for the detection of RCA and LCX lesions as compared to standard MPS analysis 0.84±0.08 vs. 0.70±0.11 for LCX (p = 0.03) and 0.92±0.05 vs. 0.75±0.09 (p=0.02) for RCA. Conclusions Software image co-registration of standalone coronary CTA and MPS obtained on separate scanners can be performed

  16. Evaluation of a Chest Circumference-Adapted Protocol for Low-Dose 128-Slice Coronary CT Angiography with Prospective Electrocardiogram Triggering

    PubMed Central

    Lu, Chenying; Wang, Zufei; Wang, Hailin; Hu, Xianghua; Chen, Chunmiao

    2015-01-01

    Objective To assess the effect of chest circumference-adapted scanning protocol on radiation exposure and image quality in patients undergoing prospective electrocardiogram (ECG)-triggered coronary CT angiography (CCTA). Materials and Methods One hundred-eighty-five consecutive patients, who had undergone prospective ECG triggering CCTA with a 128-slice CT, were included in the present study. Nipple-level chest circumference, body weight and height were measured before CT examinations. Patients were divided into four groups based on kV/ref·mAs = 100/200, 100/250, 120/200, and 120/250, when patient's chest circumference was ≤ 85.0 (n = 56), 85.0-90.0 (n = 53), 90.0-95.0 (n = 44), and > 95.0 (n = 32), respectively. Image quality per-segment was independently assessed by two experienced observers. Image noise and attenuation were also measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The effective radiation dose was calculated using CT dose volume index and the dose-length product. Results A significant correlation was observed between patients' chest circumference and body mass index (r = 0.762, p < 0.001). Chest circumference ranged from 74 to 105 cm, and the mean effective radiation dose was 1.9-3.8 mSv. Diagnostic image quality was obtained in 98.5% (2440/2478) of all evaluated coronary segments without any significant differences among the four groups (p = 0.650). No significant difference in image noise was observed among the four groups (p = 0.439), thus supporting the validity of the chest circumference-adapted scanning protocol. However, vessel attenuation, SNR and CNR were significantly higher in the 100 kV groups than in the 120 kV groups (p < 0.05). Conclusion A measure of chest circumference can be used to adapt tube voltage and current for individualized radiation dose control, with resultant similar image noise and sustained diagnostic image quality. PMID:25598671

  17. Free deep circumflex iliac artery vascularised bone flap for reconstruction of the distal radius: planning with CT angiography.

    PubMed

    Ting, Jeannette W C; Rozen, Warren M; Leong, James; Crock, John

    2010-01-01

    Distal radius fractures in the younger population are often comminuted and intra-articular, which can increase the complexity of their management. In addition, these patients tend to place high demands on their wrists, and the prevention of functional arthritis necessitates excellent anatomical reduction. Complicated cases such as these are often limited in their management options. We present a complex case of distal radius fracture and bone loss in which initial therapy with nonvascularized bone graft failed, and osteomyelitis was a further complicating factor. With the aid of preoperative planning with computed tomographic angiography (CTA), a deep circumflex iliac artery (DCIA) bone flap was able to be assessed as a reconstructive option. The use of preoperative CTA, the first description of such imaging in this role, was able to delineate the bone to be harvested, confirm its vascular supply, and plan flap harvest. The use of a vascularized bone flap in this setting was thus undertaken and was able to provide an autologous anatomical support for the wrist while reducing the risk of recurrent infection and still preserving internal fixation. This unique application of the free DCIA bone flap was potentiated by CTA, achieving complete healing and good functional outcomes. PMID:20017201

  18. CT Angiography and Presentation NIH stroke Scale in Predicting TIA in Patients Presenting with Acute Stroke Symptoms.

    PubMed

    Karaman, Bedriye; Selph, James; Burdine, Joselyn; Graham, Cole Blease; Sen, Souvik

    2013-11-01

    Patient candidacy for acute stroke intervention, is currently assessed using brain computed tomography angiography (CTA) evidence of significant stenosis/occlusion (SSO) with a high National Institutes of Health Stroke Scale (NIHSS) (>6). This study examined the association between CTA without significant stenosis/occlusion (NSSO) and lower NIHSS (≤ 6) with transient ischemic attack (TIA) and other good clinical outcomes at discharge. Patients presenting <8 hours from stroke symptom onset, had an NIHSS assessment and brain CTA performed at presentation. Good clinical outcomes were defined as: discharge diagnosis of TIA, modified Rankin Score [mRS] ≤ 1, and home as the discharge disposition. Eighty-five patients received both an NIHSS at presentation and a CTA at 4.2 ± 2.2 hours from stroke symptom onset. Patients with NSSO on CTA as well as those with NIHSS≤6 had better outcomes at discharge (p<0.001). NIHSS ≤ 6 were more likely than NSSO (p=0.01) to have a discharge diagnosis of TIA (p<0.001). NSSO on CTA and NIHSS ≤ 6 also correlated with fewer deaths (p<0.001). Multivariable analyses showed NSSO on CTA (Adjusted OR: 5.8 95% CI: 1.2-27.0, p=0.03) independently predicted the discharge diagnosis of TIA. Addition of NIHSS ≤ 6 to NSSO on CTA proved to be a stronger independent predictor of TIA (Adjusted OR 18.7 95% CI: 3.5-98.9, p=0.001). PMID:24851234

  19. CT Angiography and Presentation NIH stroke Scale in Predicting TIA in Patients Presenting with Acute Stroke Symptoms

    PubMed Central

    Karaman, Bedriye; Selph, James; Burdine, Joselyn; Graham, Cole Blease; Sen, Souvik

    2014-01-01

    Patient candidacy for acute stroke intervention, is currently assessed using brain computed tomography angiography (CTA) evidence of significant stenosis/occlusion (SSO) with a high National Institutes of Health Stroke Scale (NIHSS) (>6). This study examined the association between CTA without significant stenosis/occlusion (NSSO) and lower NIHSS (≤ 6) with transient ischemic attack (TIA) and other good clinical outcomes at discharge. Patients presenting <8 hours from stroke symptom onset, had an NIHSS assessment and brain CTA performed at presentation. Good clinical outcomes were defined as: discharge diagnosis of TIA, modified Rankin Score [mRS] ≤ 1, and home as the discharge disposition. Eighty-five patients received both an NIHSS at presentation and a CTA at 4.2 ± 2.2 hours from stroke symptom onset. Patients with NSSO on CTA as well as those with NIHSS≤6 had better outcomes at discharge (p<0.001). NIHSS ≤ 6 were more likely than NSSO (p=0.01) to have a discharge diagnosis of TIA (p<0.001). NSSO on CTA and NIHSS ≤ 6 also correlated with fewer deaths (p<0.001). Multivariable analyses showed NSSO on CTA (Adjusted OR: 5.8 95% CI: 1.2-27.0, p=0.03) independently predicted the discharge diagnosis of TIA. Addition of NIHSS ≤ 6 to NSSO on CTA proved to be a stronger independent predictor of TIA (Adjusted OR 18.7 95% CI: 3.5-98.9, p=0.001). PMID:24851234

  20. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography.

    PubMed

    van Velsen, Evert F S; Niessen, Wiro J; de Weert, Thomas T; de Monyé, Cécile; van der Lugt, Aad; Meijering, Erik; Stokking, Rik

    2007-07-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results. PMID:17077978

  1. Mid-Term Patency in Radial Artery and Saphenous Vein After Coronary Artery Bypass Grafting in Asymptomatic Patients Using 128-Slice CT Coronary Angiography

    PubMed Central

    Sadeghpour, Ali; Pouraliakbar, Hamidreza; Azarfarin, Rasoul; Alizadeh Ghavidel, Alireza; Zavareian, Somayeh; Amirahmadi, Ali

    2015-01-01

    Background: Patency of the revascularization conduit is an essential predictor of long-standing survival after coronary artery bypass grafting. Objectives: We have conducted this study to compare the mid-term patency rates of radial artery (RA), left internal thoracic artery (LITA) and also saphenous vein (SV) grafts in asymptomatic patients following coronary artery bypass graft surgery (CABG) undergoing total IV anesthesia. Patients and Methods: In this study, 30 three-vessel disease patients with 104 RA, LITA, and SV grafts used concomitantly for primary isolated non-emergent CABG surgery were assessed. The primary end point was CT angiographic graft patency rate. After 53.5 (24-97) months’ follow-up, graft patency was assessed using 128-slice CT coronary angiography. Logistic regression analysis was used to detect the independent predictors of graft failure. Results: A total of 104 grafts, including 30 LITA, 44 SV, and 30 RA grafts, were studied. Cumulative graft patency rates were 93.3% in LITA, 83.3% in RA, and 70.5% in SV grafts. Statistically significant difference was found between the LITA and the SV graft patency rates (P = 0.019), whereas the difference between the RA conduit patency and the LITA or SV graft patency rates did not have any statistical significance (P = 0.424 and P = 0.273, respectively). Independent predictors of RA grafts occlusion were native coronary stenosis < 70% and female gender. Conclusions: In our patients, the RA grafts had an acceptable patency rate in 2 to 5 years’ follow-up. Although the SV grafts had a relatively higher patency rate than RA grafts in our asymptomatic patients, the patency rates in RA and SV grafts were close to each other. The RA graft function was poor in the patients with a higher number of risk factors and in the females. PMID:25789243

  2. The Prognostic Value of a Four-Dimensional CT Angiography-Based Collateral Grading Scale for Reperfusion Therapy in Acute Ischemic Stroke Patients

    PubMed Central

    Zhang, Sheng; Chen, Weili; Tang, Huan; Han, Quan; Yan, Shenqiang; Zhang, Xiaocheng; Chen, Qingmeng; Parsons, Mark; Wang, Shaoshi; Lou, Min

    2016-01-01

    Objective Leptomeningeal collaterals, which affects tissue fate, are still challenging to assess. Four-dimensional CT angiography (4D CTA) originated from CT perfusion (CTP) provides the possibility of non-invasive and time-resolved assessment of leptomeningeal collateral flow. We sought to develop a comprehensive rating system to integrate the speed and extent of collateral flow on 4D CTA, and investigate its prognostic value for reperfusion therapy in acute ischemic stroke (AIS) patients. Methods We retrospectively studied 80 patients with M1 ± internal carotid artery (ICA) occlusion who had baseline CTP before intravenous thrombolysis. The velocity and extent of collaterals were evaluated by regional leptomeningeal collateral score on peak phase (rLMC-P) and temporally fused intensity projections (tMIP) (rLMC-M) on 4D CTA, respectively. The cutoffs of rLMC-P and rLMC-M score for predicting good outcome (mRS score ≤ 2) were integrated to develop the collateral grading scale (CGS) (rating from 0–2). Results The CGS score was correlated with 3-months mRS score (non-recanalizers: ρ = -0.495, p = 0.01; recanalizers: ρ = -0.671, p < 0.001). Patients with intermediate or good collaterals (CGS score of 1 and 2) who recanalized were more likely to have good outcome than those without recanalization (p = 0.038, p = 0.018), while there was no significant difference in outcome in patients with poor collaterals (CGS score of 0) stratified by recanalization (p = 0.227). Conclusions Identification of collaterals based on CGS may help to select good responders to reperfusion therapy in patients with large artery occlusion. PMID:27505435

  3. Diagnostic Confidence of Run-Off CT-Angiography as the Primary Diagnostic Imaging Modality in Patients Presenting with Acute or Chronic Peripheral Arterial Disease

    PubMed Central

    Werncke, Thomas; Ringe, Kristina Imeen; von Falck, Christian; Kruschewski, Martin; Wacker, Frank; Meyer, Bernhard Christian

    2015-01-01

    Objectives To investigate the reliability of CT-angiography of the lower extremities (run-off CTA) to derive a treatment decision in patients with acute and chronic peripheral artery disease (PAD). Materials and Methods 314 patients referred for run-off CTA were includ-ed in this retrospective study. First, diagnostic confidence of run-off CTA to derive a treat-ment decision was assessed in an interdisciplinary vascular conference using a 2 point scale (sufficient or not sufficient diagnostic confidence) and compared with the image quality eval-uated by two readers in consensus in four different levels (abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment decision was verified in all patients undergoing re-vascularization therapy. Results Diagnostic confidence of run-off CTA to derive a treatment deci-sion was sufficient in all patients with acute and in 97% of patients (215/221) with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image quality was considerably higher in the calf and foot level (acute vs. chronic; calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was superior for patients with chronic (123/133 = 92%) than for patients with acute PAD (64/78 = 82%, P = 0.02). Conclusion Run-off CTA is a reliable imaging modality for primary diag-nostic work-up of patients with acute and chronic PAD. PMID:25835948

  4. Multislice CT Angiography of Fenestrated Endovascular Stent Grafting for Treating Abdominal Aortic Aneurysms: a Pictorial Review of the 2D/3D Visualizations

    PubMed Central

    Mwipatayi, Bibombe P; Allen, Yvonne B; Hartley, David E; Lawrence-Brown, Michael M

    2009-01-01

    Fenestrated endovascular repair of an abdominal aortic aneurysm has been developed to treat patients with a short or complicated aneurysm neck. Fenestration involves creating an opening in the graft fabric to accommodate the orifice of the vessel that is targeted for preservation. Fixation of the fenestration to the renal arteries and the other visceral arteries can be done by implanting bare or covered stents across the graft-artery ostia interfaces so that a portion of the stent protrudes into the aortic lumen. Accurate alignment of the targeted vessels in a longitudinal aspect is hard to achieve during stent deployment because rotation of the stent graft may take place during delivery from the sheath. Understanding the 3D relationship of the aortic branches and the fenestrated vessel stents following fenestration will aid endovascular specialists to evaluate how the stent graft is situated within the aorta after placement of fenestrations. The aim of this article is to provide the 2D and 3D imaging appearances of the fenestrated endovascular grafts that were implanted in a group of patients with abdominal aortic aneurysms, based on the multislice CT angiography. The potential applications of each visualization technique were explored and compared with the 2D axial images. PMID:19412517

  5. The Impact of Different Levels of Adaptive Iterative Dose Reduction 3D on Image Quality of 320-Row Coronary CT Angiography: A Clinical Trial

    PubMed Central

    Feger, Sarah; Rief, Matthias; Zimmermann, Elke; Martus, Peter; Schuijf, Joanne Désirée; Blobel, Jörg; Richter, Felicitas; Dewey, Marc

    2015-01-01

    Purpose The aim of this study was the systematic image quality evaluation of coronary CT angiography (CTA), reconstructed with the 3 different levels of adaptive iterative dose reduction (AIDR 3D) and compared to filtered back projection (FBP) with quantum denoising software (QDS). Methods Standard-dose CTA raw data of 30 patients with mean radiation dose of 3.2 ± 2.6 mSv were reconstructed using AIDR 3D mild, standard, strong and compared to FBP/QDS. Objective image quality comparison (signal, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contour sharpness) was performed using 21 measurement points per patient, including measurements in each coronary artery from proximal to distal. Results Objective image quality parameters improved with increasing levels of AIDR 3D. Noise was lowest in AIDR 3D strong (p≤0.001 at 20/21 measurement points; compared with FBP/QDS). Signal and contour sharpness analysis showed no significant difference between the reconstruction algorithms for most measurement points. Best coronary SNR and CNR were achieved with AIDR 3D strong. No loss of SNR or CNR in distal segments was seen with AIDR 3D as compared to FBP. Conclusions On standard-dose coronary CTA images, AIDR 3D strong showed higher objective image quality than FBP/QDS without reducing contour sharpness. Trial Registration Clinicaltrials.gov NCT00967876 PMID:25945924

  6. Evaluation of organ doses in CT examinations with an infant anthropomorphic phantom.

    PubMed

    Fujii, K; Akahane, K; Miyazaki, O; Horiuchi, T; Shimada, A; Nagmatsu, H; Yamauchi, M; Yamauchi-Kawaura, C; Kawasaki, T

    2011-09-01

    The aim of this study is to evaluate organ doses in infant CT examinations with multi-detector row CT scanners. Radiation doses were measured with radiophotoluminescence glass dosemeters set in various organ positions within a 1-y-old child anthropomorphic phantom and organ doses were evaluated from the measurement values. Doses for tissues or organs within the scan range were 28-36 mGy in an infant head CT, 3-11 mGy in a chest CT, 5-11 mGy in an abdominal-pelvic CT and 2-14 mGy in a cardiac CT. The doses varied by the differences in the types of CT scanners and scan parameters used at each medical facility. Compared with those for children of various ages, the doses in an infant CT protocol were found to be similar to or slightly smaller than those in a paediatric CT for 5- or 6-y-old children. PMID:21743079

  7. Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies.

    PubMed

    Hoffman, Heidi; Torres, William E; Ernst, Randy D

    2002-01-01

    Axial thin-collimation state-of-the-art spiral computed tomography (CT) was combined with sagittal and coronal reformatting, three-dimensional (3D) reconstruction, and virtual "fly-through" techniques to nondestructively study nine Egyptian mummies. These techniques provided important paleopathologic and historical information about mummification techniques, depicted anatomy in the most informative imaging plane, illustrated the soft-tissue preservation and physical appearance of mummies in superb detail, and generated an intriguing virtual tour through hollow mummified remains without harming the specimens themselves. Images generated with these methods can help archaeologists and Egyptologists understand these fascinating members of mankind and can serve as adjunct visual aids for laypersons who are interested in mummies. CT has emerged as the imaging modality of choice for the examination of Egyptian mummies due to its noninvasive cross-sectional nature and inherently superior contrast and spatial resolution. As multi-detector row CT and postprocessing tools evolve, the capabilities and applications of CT will continue to proliferate, attesting to the expanded versatility and utility of CT as a noninvasive research tool in the multidisciplinary study of Egyptian mummies. PMID:11896227

  8. Image Quality and Radiation Dose of Lower Extremity CT Angiography Using 70 kVp, High Pitch Acquisition and Sinogram-Affirmed Iterative Reconstruction

    PubMed Central

    Qi, Li; Meinel, Felix G.; Zhou, Chang Sheng; Zhao, Yan E.; Schoepf, U. Joseph; Zhang, Long Jiang; Lu, Guang Ming

    2014-01-01

    Objectives The purpose of this study was to assess image quality and radiation dose of lower extremity CT angiography (CTA) with 70 kVp, high pitch acquisition and sinogram-affirmed iterative reconstruction (SAFIRE). Methods Lower extremity CTAs were performed on 44 patients: 22 patients were examined using protocol A (120 kVp, pitch of 0.85 and 120 ml of contrast agent on a first-generation dual-source CT) (120 kVp group) and 22 patients were evaluated with protocol B (70 kVp, pitch of 2.2 and 80 ml of contrast agent on a second-generation dual-source CT) (70 kVp group). Images from the 120 kVp group were reconstructed with filtered back projection (FBP) and images from the 70 kVp group with SAFIRE. The attenuation, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Two radiologists subjectively assessed image quality of lower extremity arteries, plantar arterial enhancement and venous contamination of all patients. Radiation dose was compared between the two groups. Results Higher mean intravascular attenuation was obtained in the 70 kVp group (70 vs. 120 kVp group, 555.4±83.4 HU vs. 300.9±81.4 HU, P<0.001), as well as image noise (20.0±2.8 HU vs. 17.5±3.2 HU, P = 0.010), SNR (32.0±7.0 vs. 19.1±6.9, P<0.001) and CNR (28.1±6.6 vs 15.9±6.3, P<0.001). No difference in subjective image quality and plantar arterial enhancement was found between 120 kVp group and 70 kVp group (all P>0.05). The venous contamination score was 1.5±0.8 for 120 kVp group while no venous contamination was found in 70 kVp group. The inter-observer agreement was moderate to good for both groups (0.515∼1, P<0.001). The effective dose was lower in 70 kVp group (0.3±0.1 mSv) than in 120 kVp group (1.6±0.7 mSv)(P<0.001). Conclusions Lower extremity CTA using 70 kVp, high pitch acquisition and SAFIRE, except increasing imaging noise, allows for lower radiation dose and contrast material volume without compromising image quality. PMID

  9. High-Pitch, Low-Voltage and Low-Iodine-Concentration CT Angiography of Aorta: Assessment of Image Quality and Radiation Dose with Iterative Reconstruction

    PubMed Central

    Shen, Yanguang; Sun, Zhonghua; Xu, Lei; Li, Yu; Zhang, Nan; Yan, Zixu; Fan, Zhanming

    2015-01-01

    Objective To assess the image quality of aorta obtained by dual-source computed tomography angiography (DSCTA), performed with high pitch, low tube voltage, and low iodine concentration contrast medium (CM) with images reconstructed using iterative reconstruction (IR). Methods One hundred patients randomly allocated to receive one of two types of CM underwent DSCTA with the electrocardiogram-triggered Flash protocol. In the low-iodine group, 50 patients received CM containing 270 mg I/mL and were scanned at low tube voltage (100 kVp). In the high-iodine CM group, 50 patients received CM containing 370 mg I/mL and were scanned at the tube voltage (120 kVp). The filtered back projection (FBP) algorithm was used for reconstruction in both groups. In addition, the IR algorithm was used in the low-iodine group. Image quality of the aorta was analyzed subjectively by a 3-point grading scale and objectively by measuring the CT attenuation in terms of the signal- and contrast-to-noise ratios (SNR and CNR, respectively). Radiation and CM doses were compared. Results The CT attenuation, subjective image quality assessment, SNR, and CNR of various aortic regions of interest did not differ significantly between two groups. In the low-iodine group, images reconstructed by FBP and IR demonstrated significant differences in image noise, SNR, and CNR (p<0.05). The low-iodine group resulted in 34.3% less radiation (4.4 ± 0.5 mSv) than the high-iodine group (6.7 ± 0.6 mSv), and 27.3% less iodine weight (20.36 ± 2.65 g) than the high-iodine group (28 ± 1.98 g). Observers exhibited excellent agreement on the aortic image quality scores (κ = 0.904). Conclusions CT images of aorta could be obtained within 2 s by using a DSCT Flash protocol with low tube voltage, IR, and low-iodine-concentration CM. Appropriate contrast enhancement was achieved while maintaining good image quality and decreasing the radiation and iodine doses. PMID:25643353

  10. Comparison of the effectiveness of using the optic strut and tuberculum sellae as radiological landmarks in diagnosing paraclinoid aneurysms with CT angiography.

    PubMed

    Liao, Chih-Hsiang; Lin, Chung-Jung; Lin, Chun-Fu; Huang, Hsin-Yi; Chen, Min-Hsiung; Hsu, Sanford P C; Shih, Yang-Hsin

    2016-08-01

    OBJECTIVE The treatment of paraclinoid aneurysms remains challenging. It is important to determine the exact location of the paraclinoid aneurysm when considering treatment options. The authors herein evaluated the effectiveness of using the optic strut (OS) and tuberculum sellae (TS) as radiographic landmarks for distinguishing between intradural and extradural paraclinoid aneurysms on source images from CT angiography (CTA). METHODS Between January 2010 and September 2013, a total of 49 surgical patients with the preoperative diagnoses of paraclinoid aneurysm and 1 symptomatic cavernous-clinoid aneurysm were retrospectively identified. With the source images from CTA, the OS and the TS were used as landmarks to predict the location of the paraclinoid aneurysm and its relation to the distal dural ring (DDR). The operative findings were examined to confirm the definitive location of the paraclinoid aneurysm. Statistical analysis was performed to determine the diagnostic effectiveness of the landmarks. RESULTS Nineteen patients without preoperative CTA were excluded. The remaining 30 patients comprised the current study. The intraoperative findings confirmed 12 intradural, 12 transitional, and 6 extradural paraclinoid aneurysms, the diagnoses of which were significantly related to the type of aneurysm (p < 0.05) but not factors like sex, age, laterality of aneurysm, or relation of the aneurysm to the ophthalmic artery on digital subtraction angiography. To measure agreement with the correct diagnosis, the OS as a reference point was far superior to the TS (Cohen's kappa coefficients 0.462 and 0.138 for the OS and the TS, respectively). For paraclinoid aneurysms of the medial or posterior type, using the base of the OS as a reference point tended to overestimate intradural paraclinoid aneurysms. The receiver operating characteristic curve indicated that if the aneurysmal neck traverses the axial plane 2 mm above the base of the OS, the aneurysm is most likely to grow

  11. Planning Evaluation of C-Arm Cone Beam CT Angiography for Target Delineation in Stereotactic Radiation Surgery of Brain Arteriovenous Malformations

    SciTech Connect

    Kang, Jun; Huang, Judy; Gailloud, Philippe; Rigamonti, Daniele; Lim, Michael; Bernard, Vincent; Ehtiati, Tina; Ford, Eric C.

    2014-10-01

    Purpose: Stereotactic radiation surgery (SRS) is one of the therapeutic modalities currently available to treat cerebral arteriovenous malformations (AVM). Conventionally, magnetic resonance imaging (MRI) and MR angiography (MRA) and digital subtraction angiography (DSA) are used in combination to identify the target volume for SRS treatment. The purpose of this study was to evaluate the use of C-arm cone beam computed tomography (CBCT) in the treatment planning of SRS for cerebral AVMs. Methods and Materials: Sixteen consecutive patients treated for brain AVMs at our institution were included in this retrospective study. Prior to treatment, all patients underwent MRA, DSA, and C-arm CBCT. All images were coregistered using the GammaPlan planning system. AVM regions were delineated independently by 2 physicians using either C-arm CBCT or MRA, resulting in 2 volumes: a CBCT volume (VCBCT) and an MRA volume (V{sub MRA}). SRS plans were generated based on the delineated regions. Results: The average volume of treatment targets delineated using C-arm CBCT and MRA were similar, 6.40 cm{sup 3} and 6.98 cm{sup 3}, respectively (P=.82). However, significant regions of nonoverlap existed. On average, the overlap of the MRA with the C-arm CBCT was only 52.8% of the total volume. In most cases, radiation plans based on V{sub MRA} did not provide adequate dose to the region identified on C-arm CBCT; the mean minimum dose to V{sub CBCT} was 29.5%, whereas the intended goal was 45% (P<.001). The mean volume of normal brain receiving 12 Gy or more in C-arm CBCT-based plans was not greater than in the MRA-based plans. Conclusions: Use of C-arm CBCT images significantly alters the delineated regions of AVMs for SRS planning, compared to that of MRA/MRI images. CT-based planning can be accomplished without increasing the dose to normal brain and may represent a more accurate definition of the nidus, increasing the chances for successful obliteration.

  12. Optimal image reconstruction phase at low and high heart rates in dual-source CT coronary angiography.

    PubMed

    Araoz, Philip A; Kirsch, Jacobo; Primak, Andrew N; Braun, Natalie N; Saba, Osama; Williamson, Eric E; Harmsen, W Scott; Mandrekar, Jayawant N; McCollough, Cynthia H

    2009-12-01

    The purpose of this study was to determine the cardiac phase having the highest coronary sharpness for low and high heart rate patients scanned with dual source CT (DSCT) and to compare coronary image sharpness over different cardiac phases. DSCT coronary CT scans for 30 low heart rate (< or =70 beats per minute- bpm) and 30 high heart rate (>70 bpm) patients were reconstructed into different cardiac phases, starting at 30% and increasing at 5% increments until 70%. A blinded observer graded image sharpness per coronary segment, from which sharpness scores were produced for the right (RCA), left main (LM), left anterior descending (LAD), and circumflex (Cx) coronary arteries. For each coronary artery, the phase with maximal image sharpness was identified with repeated measures analysis of variance. Comparison of coronary sharpness between low and high heart rate patients was made using generalized estimating equations. For low heart rates the highest sharpness scores for all four vessels (RCA, LM, LAD, and Cx) were at the 65 or 70% phase, which are end-diastolic cardiac phases. For high heart rates the highest sharpness scores were between the 35 and 45% phases, which are end-systolic phases. Low heart rate patients had higher coronary sharpness at most cardiac phases; however, patients with high heart rates had higher coronary sharpness in the 45% phase for all four vessels (P < 0.0001). Using DSCT scanning, optimal image sharpness is obtained in end-diastole at low heart rates and in end-systole in high heart rates. PMID:19669664

  13. Optimal image reconstruction phase at low and high heart rates in dual-source CT coronary angiography

    PubMed Central

    Kirsch, Jacobo; Primak, Andrew N.; Braun, Natalie N.; Saba, Osama; Williamson, Eric E.; Harmsen, W. Scott; Mandrekar, Jayawant N.; McCollough, Cynthia H.

    2009-01-01

    The purpose of this study was to determine the cardiac phase having the highest coronary sharpness for low and high heart rate patients scanned with dual source CT (DSCT) and to compare coronary image sharpness over different cardiac phases. DSCT coronary CT scans for 30 low heart rate (≤ 70 beats per minute- bpm) and 30 high heart rate (>70 bpm) patients were reconstructed into different cardiac phases, starting at 30% and increasing at 5% increments until 70%. A blinded observer graded image sharpness per coronary segment, from which sharpness scores were produced for the right (RCA), left main (LM), left anterior descending (LAD), and circumflex (Cx) coronary arteries. For each coronary artery, the phase with maximal image sharpness was identified with repeated measures analysis of variance. Comparison of coronary sharpness between low and high heart rate patients was made using generalized estimating equations. For low heart rates the highest sharpness scores for all four vessels (RCA, LM, LAD, and Cx) were at the 65 or 70% phase, which are end-diastolic cardiac phases. For high heart rates the highest sharpness scores were between the 35 and 45% phases, which are end-systolic phases. Low heart rate patients had higher coronary sharpness at most cardiac phases; however, patients with high heart rates had higher coronary sharpness in the 45% phase for all four vessels (P < 0.0001). Using DSCT scanning, optimal image sharpness is obtained in end-diastole at low heart rates and in end-systole in high heart rates. PMID:19669664

  14. Computational geometry for patient-specific reconstruction and meshing of blood vessels from MR and CT angiography.

    PubMed

    Antiga, Luca; Ene-Iordache, Bogdan; Remuzzi, Andrea

    2003-05-01

    Investigation of three-dimensional (3-D) geometry and fluid-dynamics in human arteries is an important issue in vascular disease characterization and assessment. Thanks to recent advances in magnetic resonance (MR) and computed tomography (CT), it is now possible to address the problem of patient-specific modeling of blood vessels, in order to take into account interindividual anatomic variability of vasculature. Generation of models suitable for computational fluid dynamics is still commonly performed by semiautomatic procedures, in general based on operator-dependent tasks, which cannot be easily extended to a significant number of clinical cases. In this paper, we overcome these limitations making use of computational geometry techniques. In particular, 3-D modeling was carried out by means of 3-D level sets approach. Model editing was also implemented ensuring harmonic mean curvature vectors distribution on the surface, and model geometric analysis was performed with a novel approach, based on solving Eikonal equation on Voronoi diagram. This approach provides calculation of central paths, maximum inscribed sphere estimation and geometric characterization of the surface. Generation of adaptive-thickness boundary layer finite elements is finally presented. The use of the techniques presented here makes it possible to introduce patient-specific modeling of blood vessels at clinical level. PMID:12846436

  15. Use of Cardiac CT Angiography Imaging in an Epidemiology Study – the Methodology of the Multicenter AIDS Cohort Study Cardiovascular Disease Substudy

    PubMed Central

    Hacıoğlu, Yalçın; Gupta, Mohit; Choi, Tae-Young; George, Richard T.; Deible, Christopher R.; Jacobson, Lisa P.; Witt, Mallory D.; Palella, Frank J.; Post, Wendy S.; Budoff, Matthew J.

    2013-01-01

    Objective The methodology for use of cardiac CT angiography (CTA) in low risk populations is not well defined. In order to present a reference for future studies, we present CTA methodology that is being used in an epidemiology study- the Multicenter AIDS Cohort Study (MACS). Methods The Multicenter AIDS Cohort Study (MACS) is an on-going multicenter prospective, observational cohort study. The MACS Cardiovascular Disease substudy plans to enroll 800 men (n= 575 HIV seropositive and n= 225 HIV seronegative) age 40-75 years for coronary atherosclerosis imaging using cardiac CTA. The protocol includes heart rate (HR) optimization with beta blockers; use of proper field of view; scan length limitation; prospective ECG-gating using the lowest beam voltage possible. All scans are evaluated for presence, extent, and composition of coronary atherosclerosis, left atrial volumes, left ventricular volume and mass and non-coronary cardiac pathology. Results The first 498 participants had an average radiation dose of 2.5±1.6 milliSieverts (mSv) for the cardiac CTA study. Overall quality of scans was fair to excellent in 98.6% of studies. There were three significant adverse events- two allergic reactions to contrast and one subcutaneous contrast extravasation. Conclusion Cardiac CTA was safe and afforded a low effective radiation exposure to these asymptomatic research participants and provides valuable cardiovascular endpoints for scientific analysis. The cardiac CTA methodology described here may serve as a reference for use in future epidemiology studies aiming to assess coronary atherosclerosis and cardiac anatomy in low risk populations while minimizing radiation exposure. PMID:23376648

  16. Type 2 Endoleaks: The Diagnostic Performance of Non-Specialized Readers on Arterial and Venous Phase Multi-Slice CT Angiography

    PubMed Central

    2016-01-01

    Purpose To define the diagnostic precision of non-specialized readers in the detection of type 2 endoleaks (T2EL) in arterial versus venous phase acquisitions, and to evaluate an approach for radiation dose reduction. Methods The pre-discharge and final follow-up multi-slice CT angiographies of 167 patients were retrospectively analyzed. Image data were separated into an arterial and a venous phase reading set. Two radiology residents assessed the reading sets for the presence of a T2EL, feeding vessels, and aneurysm sac size. Findings were compared with a standard of reference established by two experts in interventional radiology. The effective dose was calculated. Results Overall, experts detected 131 T2ELs, and 331 feeding vessels in 334 examinations. Persistent T2ELs causing aneurysm sac growth > 5 mm were detected in 20 patients. Radiation in arterial and venous phases contributed to a mean of 58.6% and 39.0% of the total effective dose. Findings of reader 1 and 2 showed comparable sensitivities in arterial sets of 80.9 versus 85.5 (p = 0.09), and in venous sets of 73.3 versus 79.4 (p = 0.15), respectively. Reader 1 and 2 achieved a significant higher detection rate of feeding vessels with arterial compared to venous set (p = 0.04, p < 0.01). Both readers correctly identified T2ELs with growing aneurysm sac in all cases, independent of the acquisition phase. Conclusion Arterial acquisitions enable non-specialized readers an accurate detection of T2ELs, and a significant better identification of feeding vessels. Based on our results, it seems reasonable to eliminate venous phase acquisitions. PMID:26930490

  17. Utility of Coronary Artery Calcium Scanning Beyond Coronary CT Angiography in the Emergency Department Evaluation for Acute Chest Pain: The ROMICAT II Trial

    PubMed Central

    Pursnani, Amit; Chou, Eric; Zakroysky, Pearl; Deaño, Roderick C.; Mamuya, Wilfred S.; Woodard, Pamela K.; Nagurney, John T.; Fleg, Jerome L.; Lee, Hang; Schoenfeld, David; Udelson, James E.; Hoffmann, Udo; Truong, Quynh A.

    2015-01-01

    Background Whether a coronary artery calcium (CAC) scan provides added value to coronary CT angiography (CCTA) in emergency department (ED) patients with acute chest pain (ACP) remains unsettled. We sought to determine the value of CAC scan in ACP patients undergoing CCTA. Methods and Results In the multicenter ROMICAT II trial, we enrolled low-intermediate risk ED patients with symptoms suggesting acute coronary syndrome (ACS). In this pre-specified sub-analysis of 473 patients (54±8years, 53%male) who underwent both CAC scanning and CCTA, the ACS rate was 8%. Overall, 53% of patients had CAC=0 of whom 2 (0.8%) developed ACS, while 7% had CAC>400 with 49% whom developed ACS. C-statistic of CAC>0 was 0.76, while that using the optimal cutpoint of CAC≥22 was 0.81. Continuous CAC score had lower discriminatory capacity than CCTA (c-statistic 0.86 vs. 0.92, p=0.03). Compared to CCTA alone, there was no benefit combining CAC score with CCTA (c-statistic 0.93, p=0.88) or with selective CCTA strategies after initial CAC>0 or optimal cutpoint CAC≥22 (p≥0.09). Mean radiation dose from CAC acquisition was 1.4±0.7mSv. Higher CAC scores resulted in more non-diagnostic CCTA studies though the majority remained interpretable. Conclusions In ED patients with ACP, CAC score does not provide incremental value beyond CCTA for ACS diagnosis. CAC=0 does not exclude ACS, nor a high CAC score preclude interpretation of CCTA in most patients. Thus, CAC results should not influence the decision to proceed with CCTA, and the decision to perform a CAC scan should be balanced with the additional radiation exposure required. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01084239. PMID:25710925

  18. CT angiography of neonates and infants: comparison of radiation dose and image quality of target mode prospectively ECG-gated 320-MDCT and ungated helical 64-MDCT.

    PubMed

    Jadhav, Siddharth P; Golriz, Farahnaz; Atweh, Lamya A; Zhang, Wei; Krishnamurthy, Rajesh

    2015-02-01

    OBJECTIVE. The purpose of this study was to evaluate the radiation dose and image quality of target mode prospectively ECG-gated volumetric CT angiography (CTA) performed with a 320-MDCT scanner compared with the radiation dose and image quality of ungated helical CTA performed with a 64-MDCT scanner. MATERIALS AND METHODS. An experience with CTA for cardiovascular indications in neonates and infants 0-6 months old was retrospectively assessed. Radiation doses and quantitative and qualitative image quality scores of 28 CTA examinations performed with a 320-MDCT scanner and volumetric target mode prospective ECG gating plus iterative reconstruction (target mode) were compared with the doses and scores of 28 CTA examinations performed with a 64-MDCT scanner and ungated helical scanning plus filtered back projection reconstruction (ungated mode). All target mode studies were performed during free breathing. Seven ungated CTA examinations (25%) were performed with general endotracheal anesthesia. The findings of 17 preoperative CTA examinations performed in target mode were also compared with surgical reports for evaluation of diagnostic accuracy. RESULTS. All studies performed with target mode technique were diagnostic for the main clinical indication. Effective doses were significantly lower in the target mode group (0.51 ± 0.19 mSv) compared with the ungated mode group (4.8 ± 1.4 mSv) (p < 0.0001). Quantitative analysis revealed no statistically significant difference between the two groups with respect to signal-to-noise ratio (of pulmonary artery and aorta) and contrast-to-noise ratio. Subjective image quality was significantly better with target mode than with ungated mode (p < 0.0001). CONCLUSION. Target mode prospectively ECG-gated volumetric scanning with iterative reconstruction performed with a 320-MDCT scanner has several benefits in cardiovascular imaging of neonates and infants, including low radiation dose, improved image quality, high diagnostic

  19. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  20. Evaluation of exposure dose reduction in multislice CT coronary angiography (MS-CTA) with prospective ECG-gated helical scan

    NASA Astrophysics Data System (ADS)

    Ota, Takamasa; Tsuyuki, Masaharu; Okumura, Miwa; Sano, Tomonari; Kondo, Takeshi; Takase, Shinichi

    2008-03-01

    A novel low-dose ECG-gated helical scan method to investigate coronary artery diseases was developed. This method uses a high pitch for scanning (based on the patient's heart rate) and X-rays are generated only during the optimal cardiac phases. The dose reduction was obtained using a two-level approach: 1) To use a 64-slice CT scanner (Aquilion, Toshiba, Otawara, Tochigi, Japan) with a scan speed of 0.35 s/rot. to helically scan the heart at a high pitch based on the patient's heart rate. By changing the pitch from the conventional 0.175 to 0.271 for a heart rate of 60 bpm, the exposure dose was reduced to 65%. 2) To employ tube current gating that predicts the timing of optimal cardiac phases from the previous cardiac cycle and generates X-rays only during the required cardiac phases. The combination of high speed scanning with a high pitch and appropriate X-ray generation only in the cardiac phases from 60% to 90% allows the exposure dose to be reduced to 5.6 mSv for patients with a heart rate lower than 65 bpm. This is a dose reduction of approximately 70% compared to the conventional scanning method recommended by the manufacturer when segmental reconstruction is considered. This low-dose protocol seamlessly allows for wide scan ranges (e.g., aortic dissection) with the benefits of ECG-gated helical scanning: smooth continuity for longitudinal direction and utilization of data from all cardiac cycles.

  1. SU-C-207-07: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Phantom Study

    SciTech Connect

    Johnson, T; Ding, H; Torabzadeh, M; Molloi, S

    2015-06-15

    Purpose: To investigate the feasibility of quantifying the cross-sectional area (CSA) of coronary arteries using integrated density in a physics-based model with a phantom study. Methods: In this technique the total integrated density of the object as compared with its local background is measured so it is possible to account for the partial volume effect. The proposed method was compared to manual segmentation using CT scans of a 10 cm diameter Lucite cylinder placed inside a chest phantom. Holes with cross-sectional areas from 1.4 to 12.3 mm{sup 2} were drilled into the Lucite and filled with iodine solution, producing a contrast-to-noise ratio of approximately 26. Lucite rods 1.6 mm in diameter were used to simulate plaques. The phantom was imaged with and without the Lucite rods placed in the holes to simulate diseased and normal arteries, respectively. Linear regression analysis was used, and the root-mean-square deviations (RMSD) and errors (RMSE) were computed to assess the precision and accuracy of the measurements. In the case of manual segmentation, two readers independently delineated the lumen in order to quantify the inter-reader variability. Results: The precision and accuracy for the normal vessels using the integrated density technique were 0.32 mm{sup 2} and 0.32 mm{sup 2}, respectively. The corresponding results for the manual segmentation were 0.51 mm{sup 2} and 0.56 mm{sup 2}. In the case of diseased vessels, the precision and accuracy of the integrated density technique were 0.46 mm{sup 2} and 0.55 mm{sup 2}, respectively. The corresponding results for the manual segmentation were 0.75 mm{sup 2} and 0.98 mm{sup 2}. The mean percent difference for the two readers was found to be 8.4%. Conclusion: The CSA based on integrated density had improved precision and accuracy as compared with manual segmentation in a Lucite phantom. The results indicate the potential for using integrated density to improve CSA measurements in CT angiography.

  2. High-pitch coronary CT angiography at 70 kVp with low contrast medium volume: comparison of 80 and 100 kVp high-pitch protocols.

    PubMed

    Zhang, Long Jiang; Qi, Li; De Cecco, Carlo N; Zhou, Chang Sheng; Spearman, James V; Schoepf, U Joseph; Lu, Guang Ming

    2014-11-01

    The purpose of this article is to evaluate image quality and radiation dose of prospectively electrocardiogram (ECG)-triggered high-pitch coronary computed tomography angiography (CCTA) at 70 kVp and 30 mL contrast medium.One hundred fifty patients with a heart rate ≤70 beats per minute (bpm) underwent CCTA using a second-generation dual-source computed tomography (CT) scanner and were randomized into 3 groups according to tube voltage and contrast medium volume (370 mg/mL iodine concentration) (100 kVp group, 100 kVp/60 mL, n = 55; 80 kVp group, 80 kVp/60 mL, n = 44; 70 kVp group, 70 kVp/30 mL, n = 51). Objective and subjective image quality along with the effect of heart rate (HR) and body mass index (BMI) was evaluated and compared between the groups. Radiation dose was estimated for each patient.CT attenuation and image noise were higher in the 80 and 70 kVp groups than in the 100 kVp group (all P < 0.001). Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were lower in the 70 kVp group than in the 80 and 100 kVp groups (all P < 0.05). There was no difference for subjective image quality between the groups (P > 0.05). HR did not affect subjective image quality (all P > 0.05), while patients with BMI <23 kg/m had higher image quality than patients with BMI ≥23 kg/m (P < 0.05). Compared with the 100 kVp group, the radiation dose of the 70 kVp group was reduced by 75%.In conclusion, prospectively ECG-triggered high-pitch 70 kVp/30 mL CCTA can obtain diagnostic image quality with lower radiation dose in selected patients with BMI <23 kg/m compared with 80/100 kVp/60 mL CCTA. PMID:25396334

  3. The Role of CT Angiography of Coronaries in Early Diagnosis of Coronary Artery Plaques in Albanian People with No History of Cardiovascular Disease in Correlation with Traditional Risk Factors

    PubMed Central

    Allajbeu, Iris; Hajro, Edjon; Temali, Indrit; Cekrezi, Bledi; Preza, Krenar

    2014-01-01

    Objective: To evaluate the role of CT angiography of coronaries (CTAC) in the diagnosis of subclinical atherosclerosis by detection of coronary artery plaques (CAP) in a group of consecutive albanian individuals with no history of coronary artery disease (CAD) or acute coronary syndrome and to investigate the relation between the prevalence of CAP, traditional risk factors and the expected 10-year risk of fatal cardiovascular event (CVE) based on our own experience. Method and Technique: This is a prospective study including 456 patients with no history of CAD who underwent CTAC in our hospital from September 2009 to March 2013. Risk estimation of fatal CVE was assessed using Systematic Coronary Risk Evaluation (SCORE) and then CT scan was performed with a 64 detector CT, including Ca Score and angiography of coronaries with iv contrast. Results: From 456 patients 61.4% were low risk and 32.9% were at intermediate risk according to SCORE. The prevalence of CAP diagnosed by CTAC was calculated as 55.7 % overall. Though the presence and severity of CAP increased significantly with the increase of SCORE, it was found to be 44.1% in the low risk patients and 80% in the intermediate risk group, with a presence of 17% and 25% of stenotic plaques (>50%) respectively. Significant correlation was found between all traditional risk factors and CAP. Conclusion: Although a direct relation between the prevalence of CAP, risk factors and the related 10-year risk of fatal CVE was found, there was a significant prevalence of CAP in low –intermediate risk group with a considerable presence of stenotic lesions. Also 8.3% of patients with no risk factors and 18% of the patients with Ca score 0 had CAP in CT angiography, one resulting with severe stenosis. Our results suggest once more that CT angiography is a reliable, very accurate noninvasive technique for the diagnosis of early CAD, especially in the low-intermediate risk patients compared to the traditional evaluation schemes

  4. Cerebral angiography

    MedlinePlus

    ... computer removes the bones and tissues on the images being viewed, so that only the blood vessels filled with the dye are seen. This is called digital subtraction angiography (DSA). After the x-rays are ...

  5. Coronary angiography

    MedlinePlus

    ... angiography is a procedure that uses a special dye (contrast material) and x-rays to see how ... the catheter. Once the catheter is in place, dye (contrast material) is injected into the catheter. X- ...

  6. Coronary angiography

    MedlinePlus

    Coronary angiography is often done along with cardiac catheterization . This is a procedure which measures pressures in ... Cardiac catheterization carries a slightly increased risk when compared with other heart tests. However, the test is very safe ...

  7. Cerebral angiography

    MedlinePlus

    ... Cerebral angiography is done in the hospital or radiology center. You lie on an x-ray table. ... be done in preparation for medical treatment (interventional radiology procedures) by way of certain blood vessels. What ...

  8. Low-Dose Prospectively Electrocardiogram-Gated Axial Dual-Source CT Angiography in Patients with Pulsatile Bilateral Bidirectional Glenn Shunt: An Alternative Noninvasive Method for Postoperative Morphological Estimation

    PubMed Central

    Ji, Xiaopeng; Zhao, Bin; Cheng, Zhaoping; Si, Biao; Wang, Zhiheng; Duan, Yanhua; Nie, Pei; Li, Haiou; Yang, Shifeng; Jiao, Hui; Wang, Ximing

    2014-01-01

    Objective To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA) in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG) as an alternative noninvasive method for postoperative morphological estimation. Methods Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years) underwent both low-dose PGA scanning and conventional cardiac angiography (CCA) for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC) and pulmonary artery (PA), the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland–Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated. Results The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P<0.001) was observed between the measurements on CTA images and on CCA images. Bland–Altman analysis demonstrated a systematic overestimation of the measurements by CTA (the mean value of bias>0).The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively. Conclusion CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG. PMID:24736546

  9. Absorbed Radiation Dose in Radiosensitive Organs During Coronary CT Angiography Using 320-MDCT: Effect of Maximum Tube Voltage and Heart Rate Variations

    PubMed Central

    Nikolic, Boris; Khosa, Faisal; Lin, Pei-Jan Paul; Khan, Atif N.; Sarwar, Sheryar; Yam, Chun-Shan; Court, Laurence E.; Raptopoulos, Vassilios; Clouse, Melvin E.

    2012-01-01

    OBJECTIVE The purpose of this article is to estimate the absorbed radiation dose in radiosensitive organs during coronary MDCT angiography using 320-MDCT and to determine the effects of tube voltage variation and heart rate (HR) control on absorbed radiation dose. MATERIALS AND METHODS Semiconductor field effect transistor detectors were used to measure absorbed radiation doses for the thyroid, midbreast, breast, and midlung in an anthropomorphic phantom at 100, 120, and 135 kVp at two different HRs of 60 and 75 beats per minute (bpm) with a scan field of view of 320 mm, 400 mA, 320 × 0.5 mm detectors, and 160 mm collimator width (160 mm range). The paired Student’s t test was used for data evaluation. RESULTS At 60 bpm, absorbed radiation doses for 100, 120, and 135 kVp were 13.41 ± 3.59, 21.7 ± 4.12, and 29.28 ± 5.17 mGy, respectively, for midbreast; 11.76 ± 0.58, 18.86 ± 1.06, and 24.82 ± 1.45 mGy, respectively, for breast; 12.19 ± 2.59, 19.09 ± 3.12, and 26.48 ± 5.0 mGy, respectively, for lung; and 0.37 ± 0.14, 0.69 ± 0.14, and 0.92 ± 0.2 mGy, respectively, for thyroid. Corresponding absorbed radiation doses for 75 bpm were 38.34 ± 2.02, 59.72 ± 3.13, and 77.8 ± 3.67 mGy for midbreast; 26.2 ± 1.74, 44 ± 1.11, and 52.84 ± 4.07 mGy for breast; 38.02 ± 1.58, 58.89 ± 1.68, and 78 ± 2.93 mGy for lung; and 0.79 ± 0.233, 1.04 ± 0.18, and 2.24 ± 0.52 mGy for thyroid. Absorbed radiation dose changes were significant for all organs for both tube voltage reductions as well as for HR control from 75 to 60 bpm at all tube voltage settings (p < 0.05). The absorbed radiation doses for the calcium score protocol were 11.2 ± 1.4 mGy for midbreast, 9.12 ± 0.48 mGy for breast, 10.36 ± 1.3 mGy for lung, and 0.4 ± 0.05 mGy for thyroid. CONCLUSION CT angiography with 320-MDCT scanners results in absorbed radiation doses in radiosensitive organs that compare favorably to those previously reported. Significant dose reductions can be achieved by tube

  10. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    PubMed Central

    Yi, Ji Sook; Han, Jong Kyu; Kim, Hyun-Joo

    2015-01-01

    Objective To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. Results The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Conclusion Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI. PMID:26175589

  11. Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography

    PubMed Central

    Yang, Shifeng; Li, Xia; Chao, Baoting; Wu, Lebin; Cheng, Zhaoping; Duan, Yanhua; Wu, Dawei; Zhan, Yiqiang; Chen, Jiuhong; Liu, Bo; Ji, Xiaopeng; Nie, Pei; Wang, Ximing

    2014-01-01

    Objectives To evaluate the feasibility of dose-modulated retrospective ECG-gated thoracoabdominal aorta CT angiography (CTA) assessing abdominal aortic intimal flap motion and investigate the motion characteristics of intimal flap in acute aortic dissection (AAD). Materials and Methods 49 patients who had thoracoabdominal aorta retrospective ECG-gated CTA scan were enrolled. 20 datasets were reconstructed in 5% steps between 0 and 95% of the R-R interval in each case. The aortic intimal flap motion was assessed by measuring the short axis diameters of the true lumen and false lumen 2 cm above of celiac trunk ostium in different R-R intervals. Intimal flap motion and configuration was assessed by two independent observers. Results In these 49 patients, 37 had AAD, 7 had intramural hematoma, and 5 had negative result for acute aortic disorder. 620 datasets of 31 patients who showed double lumens in abdominal aorta were enrolled in evaluating intimal flap motion. The maximum and minimum true lumen diameter were 12.2±4.1 mm (range 2.6∼17.4) and 6.7±4.1 mm (range 0∼15.3) respectively. The range of intimal flap motion in all patients was 5.5±2.6 mm (range 1.8∼10.2). The extent of maximum true lumen diameter decreased during a cardiac cycle was 49.5%±23.5% (range 12%∼100%). The maximum motion phase of true lumen diameter was in systolic phase (5%∼40% of R-R interval). Maximum and minimum intimal flap motion was at 15% and 75% of the R-R interval respectively. Intimal flap configuration had correlation with the phase of cardiac cycle. Conclusions Abdominal intimal flap position and configuration varied greatly during a cardiac cycle. Retrospective ECG-gated thoracoabdominal aorta CTA can reflect the actual status of the true lumen and provide more information about true lumen collapse. This information may be helpful to diagnosis and differential diagnosis of dynamic abstraction. PMID:24503676

  12. Dependence of Coronary 3-Dimensional Dose Maps on Coronary Topologies and Beam Set in Breast Radiation Therapy: A Study Based on CT Angiographies

    SciTech Connect

    Moignier, Alexandra; Girinsky, Théodore; Paul, Jean-François; and others

    2014-05-01

    Purpose: In left-side breast radiation therapy (RT), doses to the left main (LM) and left anterior descending (LAD) coronary arteries are usually assessed after delineation by prior anatomic knowledge on the treatment planning computed tomography (CT) scan. In this study, dose sensitivity due to interindividual coronary topology variation was assessed, and hot spots were located. Methods and Materials: Twenty-two detailed heart models, created from heart computed tomography angiographies, were fitted into a single representative female thorax. Two breast RT protocols were then simulated into a treatment planning system: the first protocol comprised tangential and tumoral bed beams (TGs{sub T}B) at 50 + 16 Gy, the second protocol added internal mammary chain beams at 50 Gy to TGs{sub T}B (TGs{sub T}B{sub I}MC). For the heart, the LAD, and the LM, several dose indicators were calculated: dose-volume histograms, mean dose (D{sub mean}), minimal dose received by the most irradiated 2% of the volume (D{sub 2%}), and 3-dimensional (3D) dose maps. Variations of these indicators with anatomies were studied. Results: For the LM, the intermodel dispersion of D{sub mean} and D{sub 2%} was 10% and 11%, respectively, with TGs{sub T}B and 40% and 80%, respectively, with TGs{sub T}B{sub I}MC. For the LAD, these dispersions were 19% (D{sub mean}) and 49% (D{sub 2%}) with TGs{sub T}B and 35% (D{sub mean}) and 76% (D{sub 2%}) with TGs{sub T}B{sub I}MC. The 3D dose maps revealed that the internal mammary chain beams induced hot spots between 20 and 30 Gy on the LM and the proximal LAD for some coronary topologies. Without IMC beams, hot spots between 5 and 26 Gy are located on the middle and distal LAD. Conclusions: Coronary dose distributions with hot spot location and dose level can change significantly depending on coronary topology, as highlighted by 3D coronary dose maps. In clinical practice, coronary imaging may be required for a relevant coronary dose assessment

  13. Improvement of Image Quality and Diagnostic Performance by an Innovative Motion-Correction Algorithm for Prospectively ECG Triggered Coronary CT Angiography

    PubMed Central

    Lu, Bin; Yan, Hong-Bing; Mu, Chao-Wei; Gao, Yang; Hou, Zhi-Hui; Wang, Zhi-Qiang; Liu, Kun; Parinella, Ashley H.; Leipsic, Jonathon A.

    2015-01-01

    Objective To investigate the effect of a novel motion-correction algorithm (Snap-short Freeze, SSF) on image quality and diagnostic accuracy in patients undergoing prospectively ECG-triggered CCTA without administering rate-lowering medications. Materials and Methods Forty-six consecutive patients suspected of CAD prospectively underwent CCTA using prospective ECG-triggering without rate control and invasive coronary angiography (ICA). Image quality, interpretability, and diagnostic performance of SSF were compared with conventional multisegment reconstruction without SSF, using ICA as the reference standard. Results All subjects (35 men, 57.6 ± 8.9 years) successfully underwent ICA and CCTA. Mean heart rate was 68.8±8.4 (range: 50–88 beats/min) beats/min without rate controlling medications during CT scanning. Overall median image quality score (graded 1–4) was significantly increased from 3.0 to 4.0 by the new algorithm in comparison to conventional reconstruction. Overall interpretability was significantly improved, with a significant reduction in the number of non-diagnostic segments (690 of 694, 99.4% vs 659 of 694, 94.9%; P<0.001). However, only the right coronary artery (RCA) showed a statistically significant difference (45 of 46, 97.8% vs 35 of 46, 76.1%; P = 0.004) on a per-vessel basis in this regard. Diagnostic accuracy for detecting ≥50% stenosis was improved using the motion-correction algorithm on per-vessel [96.2% (177/184) vs 87.0% (160/184); P = 0.002] and per-segment [96.1% (667/694) vs 86.6% (601/694); P <0.001] levels, but there was not a statistically significant improvement on a per-patient level [97.8 (45/46) vs 89.1 (41/46); P = 0.203]. By artery analysis, diagnostic accuracy was improved only for the RCA [97.8% (45/46) vs 78.3% (36/46); P = 0.007]. Conclusion The intracycle motion correction algorithm significantly improved image quality and diagnostic interpretability in patients undergoing CCTA with prospective ECG triggering and

  14. Image Quality and Radiation Dose of CT Coronary Angiography with Automatic Tube Current Modulation and Strong Adaptive Iterative Dose Reduction Three-Dimensional (AIDR3D)

    PubMed Central

    Shen, Hesong; Dai, Guochao; Luo, Mingyue; Duan, Chaijie; Cai, Wenli; Liang, Dan; Wang, Xinhua; Zhu, Dongyun; Li, Wenru; Qiu, Jianping

    2015-01-01

    Purpose To investigate image quality and radiation dose of CT coronary angiography (CTCA) scanned using automatic tube current modulation (ATCM) and reconstructed by strong adaptive iterative dose reduction three-dimensional (AIDR3D). Methods Eighty-four consecutive CTCA patients were collected for the study. All patients were scanned using ATCM and reconstructed with strong AIDR3D, standard AIDR3D and filtered back-projection (FBP) respectively. Two radiologists who were blinded to the patients' clinical data and reconstruction methods evaluated image quality. Quantitative image quality evaluation included image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). To evaluate image quality qualitatively, coronary artery is classified into 15 segments based on the modified guidelines of the American Heart Association. Qualitative image quality was evaluated using a 4-point scale. Radiation dose was calculated based on dose-length product. Results Compared with standard AIDR3D, strong AIDR3D had lower image noise, higher SNR and CNR, their differences were all statistically significant (P<0.05); compared with FBP, strong AIDR3D decreased image noise by 46.1%, increased SNR by 84.7%, and improved CNR by 82.2%, their differences were all statistically significant (P<0.05 or 0.001). Segments with diagnostic image quality for strong AIDR3D were 336 (100.0%), 486 (96.4%), and 394 (93.8%) in proximal, middle, and distal part respectively; whereas those for standard AIDR3D were 332 (98.8%), 472 (93.7%), 378 (90.0%), respectively; those for FBP were 217 (64.6%), 173 (34.3%), 114 (27.1%), respectively; total segments with diagnostic image quality in strong AIDR3D (1216, 96.5%) were higher than those of standard AIDR3D (1182, 93.8%) and FBP (504, 40.0%); the differences between strong AIDR3D and standard AIDR3D, strong AIDR3D and FBP were all statistically significant (P<0.05 or 0.001). The mean effective radiation dose was (2.55±1.21) mSv. Conclusion

  15. Image quality of CT angiography with model-based iterative reconstruction in young children with congenital heart disease: comparison with filtered back projection and adaptive statistical iterative reconstruction.

    PubMed

    Son, Sung Sil; Choo, Ki Seok; Jeon, Ung Bae; Jeon, Gye Rok; Nam, Kyung Jin; Kim, Tae Un; Yeom, Jeong A; Hwang, Jae Yeon; Jeong, Dong Wook; Lim, Soo Jin

    2015-06-01

    To retrospectively evaluate the image quality of CT angiography (CTA) reconstructed by model-based iterative reconstruction (MBIR) and to compare this with images obtained by filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR) in newborns and infants with congenital heart disease (CHD). Thirty-seven children (age 4.8 ± 3.7 months; weight 4.79 ± 0.47 kg) with suspected CHD underwent CTA on a 64detector MDCT without ECG gating (80 kVp, 40 mA using tube current modulation). Total dose length product was recorded in all patients. Images were reconstructed using FBP, ASIR, and MBIR. Objective image qualities (density, noise) were measured in the great vessels and heart chambers. The contrast-to-noise ratio (CNR) was calculated by measuring the density and noise of myocardial walls. Two radiologists evaluated images for subjective noise, diagnostic confidence, and sharpness at the level prior to the first branch of the main pulmonary artery. Images were compared with respect to reconstruction method, and reconstruction times were measured. Images from all patients were diagnostic, and the effective dose was 0.22 mSv. The objective image noise of MBIR was significantly lower than those of FBP and ASIR in the great vessels and heart chambers (P < 0.05); however, with respect to attenuations in the four chambers, ascending aorta, descending aorta, and pulmonary trunk, no statistically significant difference was observed among the three methods (P > 0.05). Mean CNR values were 8.73 for FBP, 14.54 for ASIR, and 22.95 for MBIR. In addition, the subjective image noise of MBIR was significantly lower than those of the others (P < 0.01). Furthermore, while FBP had the highest score for image sharpness, ASIR had the highest score for diagnostic confidence (P < 0.05), and mean reconstruction times were 5.1 ± 2.3 s for FBP and ASIR and 15.1 ± 2.4 min for MBIR. While CTA with MBIR in newborns and infants with CHD can reduce image noise and

  16. Ultra-low-dose dual-source CT coronary angiography with high pitch: diagnostic yield of a volumetric planning scan and effects on dose reduction and imaging strategy

    PubMed Central

    Hamm, B; Huppertz, A; Lembcke, A

    2015-01-01

    Objective: To evaluate the role of an ultra-low-dose dual-source CT coronary angiography (CTCA) scan with high pitch for delimiting the range of the subsequent standard CTCA scan. Methods: 30 patients with an indication for CTCA were prospectively examined using a two-scan dual-source CTCA protocol (2.0 × 64.0 × 0.6 mm; pitch, 3.4; rotation time of 280 ms; 100 kV): Scan 1 was acquired with one-fifth of the tube current suggested by the automatic exposure control software [CareDose 4D™ (Siemens Healthcare, Erlangen, Germany) using 100 kV and 370 mAs as a reference] with the scan length from the tracheal bifurcation to the diaphragmatic border. Scan 2 was acquired with standard tube current extending with reduced scan length based on Scan 1. Nine central coronary artery segments were analysed qualitatively on both scans. Results: Scan 2 (105.1 ± 10.1 mm) was significantly shorter than Scan 1 (127.0 ± 8.7 mm). Image quality scores were significantly better for Scan 2. However, in 5 of 6 (83%) patients with stenotic coronary artery disease, a stenosis was already detected in Scan 1 and in 13 of 24 (54%) patients with non-stenotic coronary arteries, a stenosis was already excluded by Scan 1. Using Scan 2 as reference, the positive- and negative-predictive value of Scan 1 was 83% (5 of 6 patients) and 100% (13 of 13 patients), respectively. Conclusion: An ultra-low-dose CTCA planning scan enables a reliable scan length reduction of the following standard CTCA scan and allows for correct diagnosis in a substantial proportion of patients. Advances in knowledge: Further dose reductions are possible owing to a change in the individual patient's imaging strategy as a prior ultra-low-dose CTCA scan may already rule out the presence of a stenosis or may lead to a direct transferal to an invasive catheter procedure. PMID:25710210

  17. Imaging strategies in the evaluation of soft-tissue hemangiomas of the extremities: correlation of the findings of plain radiography, angiography, CT, MRI, and ultrasonography in 12 histologically proven cases.

    PubMed

    Greenspan, A; McGahan, J P; Vogelsang, P; Szabo, R M

    1992-01-01

    Twelve patients with the histologic diagnosis of soft-tissue hemangioma of the extremities (nine intramuscular, two subcutaneous, and one synovial) were evaluated in a retrospective study using plain film radiography (n = 12), angiography (n = 8), computed tomography (CT; n = 4), magnetic resonance imaging (MRI; n = 3), and ultrasonography (US; n = 2). In eight of nine intramuscular lesions, the plain film demonstration of phleboliths suggested the diagnosis, while the plain radiographs were normal in three. Angiograms showed the pathognomonic features of soft-tissue hemangioma in six patients. MRI was characteristic in all three patients: The lesion demonstrated intermediate signal intensity on T1-weighted spin echo images and extremely bright signal on T2-weighting. US showed a hypoechoic soft-tissue mass in one case and a mixed echo pattern in the other. In one case, a central echogenic focus with acoustic shadowing consistent with a calcified phlebolith was identified, and one lesion exhibited increased color flow and low resistance arterial Doppler signal. CT showed a nonspecific mass in one of four cases and a mass with phleboliths in three. If a deep hemangioma is suspected, we recommend initial imaging with plain radiography followed by MRI. US may be useful in confirming the presence of a mass in doubtful cases or if MRI is unavailable. CT offers no distinct advantage over the combined use of plain radiography and MRI. Although angiography demonstrated the pathognomonic features in all six deeply situated lesions, because of its invasiveness it should be reserved chiefly for those patients undergoing surgical resection. PMID:1546331

  18. The feasibility of a 64-slice MDCT for detection of the Adamkiewicz artery: comparison of the detection rate of intravenous injection CT angiography using a 64-slice MDCT versus intra-arterial and intravenous injection CT angiography using a 16-slice MDCT.

    PubMed

    Nishii, Tatsuya; Kono, Atsushi K; Negi, Noriyuki; Hashimura, Hiromi; Uotani, Kensuke; Okita, Yutaka; Sugimura, Kazuro

    2013-12-01

    Identification of the Adamkiewicz artery (AKA) using CT angiography (CTA) is crucial in patients with thoracic aortic aneurysm (TAA) or aortic dissection (AD). The purpose of this study was to compare the AKA detection rate of intravenous injection with a 64-slice MDCT (IV64) versus a 16-slice MDCT (IV16) as well as by CTA using intra-arterial injection with a 16-slice MDCT (IA16). A retrospective review of 160 consecutive patients who underwent CTA was performed. There were 108 TAA and 52 AD cases, 105 of whom were examined with IV64, 15 with IV16, and 40 with IA16. The AKA detectability for each imaging method was assessed, and the factors influencing the detectability were analyzed by multivariate analysis. The detection rates for IV64, IV16, and IA16 were 85.7, 60.0, and 80.0 %, respectively, with IV64 being more sensitive than IV16 (P = 0.025). The detection rate for AD patients was 66.7 % with IV64, which was similar to IV16 (57.1 %) and IA16 (66.8 %). On the other hand, the detection rate for TAA patients was 93.3 % with IV64, which was higher than IV16 (62.5 %, P = 0.021) and similar to IA16 (88.0 %). Multivariate analysis demonstrated the independent factors for AKA detectability were TAA versus AD (P = 0.005, Odds ratio = 3.98) and IV64 versus IV16 (P = 0.037, Odds ratio = 4.03). The detection rate was higher for IV64 than for IV16, especially for TAA patients, while the rate was similar between IV64 and invasive IA16. A 64-slice MDCT thus provides a less invasive visualization of the AKA. PMID:24081485

  19. Spiral CT: vascular applications.

    PubMed

    Rankin, S C

    1998-08-01

    Recent technical advances in CT have renewed interest in the development of CT angiography (CTA). CT angiography is a minimally invasive method of visualising the vascular system and is becoming an alternative to conventional arteriography in some situations. Spiral technology allows a volume of data to be obtained on a single breath-hold with no respiratory misregistration. Fast machines with second or subsecond acquisition times mean the images are obtained while there are high circulating levels of contrast medium giving peak vascular opacification from a peripheral intravenous injection. Accurate timing will ensure either the arterial or venous phase is imaged. Multiple overlapping axial images can be obtained from the data set with no increase in radiation dose to the patient and from these scans computer generated multiplanar and 3D images are obtained which can be viewed from numerous angles. CT angiography can be performed more quickly, less invasively and at reduced cost compared to conventional angiography. PMID:9717621

  20. Coronary dominance and prognosis in patients undergoing coronary computed tomographic angiography: results from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry

    PubMed Central

    Gebhard, Catherine; Fuchs, Tobias A.; Stehli, Julia; Gransar, Heidi; Berman, Daniel S.; Budoff, Matthew J.; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Chinnaiyan, Kavitha M.; Chow, Benjamin J. W.; Cury, Ricardo C.; Delago, Augustin; Gomez, Millie J.; Hadamitzky, Martin; Hausleiter, Joerg; Hindoyan, Niree; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison M.; Min, James K.; Kaufmann, Philipp A.

    2015-01-01

    Aims Coronary computed tomographic angiography (CCTA) has become an important tool for non-invasive diagnosis of coronary artery disease (CAD). Coronary dominance can be assessed by CCTA; however, the predictive value of coronary dominance is controversially discussed. The aim of this study was to evaluate the prevalence and prognosis of coronary dominance in a large prospective, international multicentre cohort of patients undergoing CCTA. Methods and results The study population consisted of 6382 patients with or without CAD (47% females, 53% males, mean age 56.9 ± 12.3 years) who underwent CCTA and were followed over a period of 60 months. Right or left coronary dominance was determined. Right dominance was present in 91% (n = 5817) and left in 9% (n = 565) of the study population. At the end of follow-up, outcome in patients with obstructive CAD (>50% luminal stenosis) and right dominance was similar compared with patients with left dominance [hazard ratio (HR) 0.46, 95% CI 0.16–1.32, P = 0.15]. Furthermore, no differences were observed for the type of coronary dominance in patients with non-obstructive CAD (HR 0.95, 95% CI 0.41–2.21, P = 0.8962) or normal coronary arteries (HR 1.04, 95% CI 0.68–1.59, P = 0.9). Subgroup analysis in patients with left main disease revealed an elevated hazard of the combined endpoint for left dominance (HR 6.45, 95% CI 1.66–25.0, P = 0.007), but not for right dominance. Conclusion In our study population, survival after 5 years of follow-up did not differ significantly between patients with left or right coronary dominance. Thus, assessment of coronary vessel dominance by CCTA may not enhance risk stratification in patients with normal coronary arteries or obstructive CAD, but may add prognostic information for specific subpopulations. PMID:25744341

  1. Comparison of Quantity of Coronary Atherosclerotic Plaques Detected by Computed Tomography Versus Angiography.

    PubMed

    Kolossváry, Márton; Szilveszter, Bálint; Édes, István Ferenc; Nardai, Sándor; Voros, Viktor; Hartyánszky, István; Merkely, Béla; Voros, Szilard; Maurovich-Horvat, Pál

    2016-06-15

    Numerous clinical studies using coronary computed tomography angiography (CTA) and conventional invasive coronary angiography (ICA) confirmed the strong relation between atherosclerotic disease burden and risk of adverse events. Few studies have compared coronary CTA and ICA regarding semiquantitative plaque burden measurements, reproducibility, and cardiovascular risk assessment. We enrolled 71 consecutive patients (mean age 62 ± 9 years, 37% women) from the Genetic Loci and the Burden of Atherosclerotic Lesions study (NCT01738828), who underwent 256-slice multidetector row coronary CTA and ICA at a single site. On average, 42 ± 32 days passed between the 2 examinations. A total of 1,016 coronary segments were imaged by both CTA and ICA according the 18-segment Society of Cardiovascular Computed Tomography classification. We excluded 16 segments treated with coronary stents. Overall, 1,000 segments were evaluated for the presence of stenosis severity (<25%: minimal, 25% to 49%: mild, 50% to 70%: moderate, 70% to 99%: severe, 100%: occlusion). We calculated the segment involvement score (SIS) and segment stenosis score. Patients were classified into 4 groups: extensive obstructive (SIS >4 and ≥50% stenosis), extensive nonobstructive (SIS >4 and <50% stenosis), nonextensive obstructive (SIS ≤4 and ≥50% stenosis), or nonextensive nonobstructive (SIS ≤4 and <50% stenosis). CTA detected coronary artery plaques in 49%, whereas ICA showed coronary plaques in 24% of the analyzed 1,000 segments (p <0.001). CTA detected atherosclerotic plaque in 35% of coronary segments where ICA was negative, whereas ICA detected plaque only in 3% of segments where CTA was negative. CTA-based segment scores were significantly greater, SIS: 6.9 ± 3.0 versus 3.3 ± 2.0, segment stenosis score: 16.4 ± 8.8 versus 9.4 ± 6.8 (p <0.001 for both). In conclusion, coronary CTA detected approximately twice as many coronary segments with plaque compared to ICA, which resulted in 52% of

  2. Image quality and attenuation values of multi detector CT coronary angiography using high iodine-concentration contrast material: A comparison of the use of iopromide 370 and iomeprol 400

    PubMed Central

    Kim, Eun Young; Yeh, Dae Wook; Choe, Yeon Hyeon; Lee, Won Jae; Lim, Hyo Keun

    2010-01-01

    Background: Effects of high iodine-concentration contrast material on the image quality of coronary CT angiography (CCTA) have not been well evaluated. Purpose: To compare the image quality and attenuation values of CCTA between patients administered iopromide 370 and iomeprol 400 with the use of 64-slice multidetector CT. Material and Methods: Patients were prospectively enrolled and were randomized into two groups (group A, 151 patients received iopromide 370, iodine flux = 1.48 g I/s; group B, 146 patients received iomeprol 400, iodine flux = 1.60 g I/s). CT attenuation was measured in the coronary arteries and great arteries and measurements were standardized based on an iodine flux of 1.5 0 g I/s. The image quality of 15 coronary artery segments was graded by two radiologists in consensus with the use of a four-point scale (1 = excellent to 4 = poor enhancement). Non-parametric statistical approaches were used to compare the two groups. Results: The median attenuation values in the coronary arteries were 454 HU and 464 HU for iopromide 370 and iomeprol 400, respectively, and they did not differ (P = 0.26). When standardizing for an iodine flux, significantly higher attenuation values were found for iopromide 370 (median = 460 HU, range = 216-791 HU) compared with iomeprol 400 (median = 435 HU, range = 195—758 HU) (P = 0.006). The median image quality score of coronary arterial segments was 1 (range 1—2) for both groups (P = 0.84). Conclusion: The attenuation values in the coronary arteries after injection of the same amount of two high iodine-concentration contrast materials at the same flow rate with different iodine fluxes are similar with no difference in image quality. With standardization for an iodine flux, the attenuation is significantly higher when using iopromide 370. PMID:20849317

  3. Sex Differences in the Effectiveness of Early Coronary CT Angiography Compared to Standard Emergency Department Evaluation for Acute Chest Pain: The ROMICAT II Trial

    PubMed Central

    Truong, Quynh A.; Hayden, Douglas; Woodard, Pamela K.; Kirby, Ruth; Chou, Eric T.; Nagurney, John T.; Wiviott, Stephen D.; Fleg, Jerome L.; Schoenfeld, David A.; Udelson, James E.; Hoffmann, Udo

    2013-01-01

    Background We evaluate sex-based differences in the effectiveness of early cardiac computed tomographic angiography (CCTA) versus standard emergency department (ED) evaluation in patients with acute chest pain. Methods and Results In the ROMICAT II multicenter controlled trial, we randomized 1000 patients (47% women) 40-74 years old with symptoms suggestive of acute coronary syndrome (ACS) to an early CCTA or standard ED evaluation. In this pre-specified analysis, women in the CCTA arm had greater reduction in length of stay (LOS), lower hospital admission rates, and lesser increased cumulative radiation dose than men when comparing ED strategies (p-interactions≤0.02). While women had lower ACS rates than men (3% vs 12%, p<0.0001), sex differences in LOS persisted after adjustment for baseline differences including ACS rate (p-interaction<0.03). LOS was similar between sexes with normal CCTA findings (p=0.11). There was no missed ACS for either sex. No difference was observed in major adverse cardiac events between sex and ED strategies (p-interaction=0.39). Women had more normal CCTA examinations than men (58% vs 37%, p<0.0001), less obstructive coronary disease by CCTA (5% vs 17%, p=0.0001), but similar normalcy rates for functional testing (p=1.0). Men in the CCTA arm had the highest rate of invasive coronary angiography (18%), while women had comparable low 5% rates irrespective of ED strategies. Conclusions This trial provides data supporting an early CCTA strategy as an attractive option in women presenting to the ED with symptoms suggestive of ACS. The findings may be explained by lower CAD prevalence and severity in women than men. PMID:23685743

  4. Calcified coronary artery plaque measurement with cardiac CT in population-based studies: standardized protocol of Multi-Ethnic Study of Atherosclerosis (MESA) and Coronary Artery Risk Development in Young Adults (CARDIA) study.

    PubMed

    Carr, J Jeffrey; Nelson, Jennifer Clark; Wong, Nathan D; McNitt-Gray, Michael; Arad, Yadon; Jacobs, David R; Sidney, Stephan; Bild, Diane E; Williams, O Dale; Detrano, Robert C

    2005-01-01

    Calcified coronary artery plaque, measured at cardiac computed tomography (CT), is a predictor of cardiovascular disease and may play an increasing role in cardiovascular disease risk assessment. The Multi-Ethnic Study of Atherosclerosis (MESA) and the Coronary Artery Risk Development in Young Adults (CARDIA) study of the National Heart, Lung, and Blood Institute are population-based studies in which calcified coronary artery plaque was measured with electron-beam and multi-detector row CT and a standardized protocol in 6814 (MESA) and 3044 (CARDIA study) participants. The studies were approved by the appropriate institutional review board from the study site or agency, and written informed consent was obtained from each participant. Participation in the CT examination was high, image quality was good, and agreement for the presence of calcified plaque was high (kappa = 0.92, MESA; kappa = 0.77, CARDIA study). Extremely high agreement was observed between and within CT image analysts for the presence (kappa > 0.90, all) and amount (intraclass correlation coefficients, >0.99) of calcified plaque. Measurement of calcified coronary artery plaque with cardiac CT is well accepted by participants and can be implemented with consistently high-quality results with a standardized protocol and trained personnel. If predictive value of calcified coronary artery plaque for cardiovascular events proves sufficient to justify screening a segment of the population, then a standardized cardiac CT protocol is feasible and will provide reproducible results for health care providers and the public. PMID:15618373

  5. Rational diagnosis of pulmonary embolism (RADIA PE) in symptomatic outpatients with suspected PE: an improved strategy to exclude or diagnose venous thromboembolism by the sequential use of a clinical model, rapid ELISA D-dimer test, perfusion lung scan, ultrasonography, spiral CT, and pulmonary angiography.

    PubMed

    Michiels, J J

    1998-01-01

    A prospective management decision analysis for the exclusion and diagnosis of pulmonary embolism (PE) based on pre-test clinical probability (PCP) estimation for PE, a rapid ELISA D-dimer test, perfusion lungscan (P-scan), CUS, spiral CT, and pulmonary angiography is proposed. The modified PCP model for PE of Wells et al. allows reasonably accurate classification of patients with no, low, moderate, and high probability for PE. The combined rational use of the evidence-based noninvasive imaging techniques P-scan, CUS, and spiral CT with the rapid ELISA D-dimer test and PCP will reduce the need for invasive pulmonary angiography to perhaps 10 to 15% of patients, who initially presented with suspected PE. A Rational Diagnosis of Pulmonary Embolism (RADIA PE) model is proposed for testing in a large multicenter study of patients with suspected PE. PMID:9763360

  6. Effect of Heart Rate and Coronary Calcification on the Diagnostic Accuracy of the Dual-Source CT Coronary Angiography in Patients with Suspected Coronary Artery Disease

    PubMed Central

    Meng, Lingdong; Cheng, Yuntao; Wu, Xiaoyan; Tang, Yuansheng; Wang, Yong; Xu, Fayun

    2009-01-01

    Objective To evaluate the diagnostic accuracy of a dual-source computed tomography (DSCT) coronary angiography, with a particular focus on the effect of heart rate and calcifications. Materials and Methods One hundred and nine patients with suspected coronary disease were divided into 2 groups according to a mean heart rate (< 70 bpm and ≥ 70 bpm) and into 3 groups according to the mean Agatston calcium scores (≤ 100, 101-400, and > 400). Next, the effect of heart rate and calcification on the accuracy of coronary artery stenosis detection was analyzed by using an invasive coronary angiography as a reference standard. Coronary segments of less than 1.5 mm in diameter in an American Heart Association (AHA) 15-segment model were independently assessed. Results The mean heart rate during the scan was 71.8 bpm, whereas the mean Agatston score was 226.5. Of the 1,588 segments examined, 1,533 (97%) were assessable. A total of 17 patients had calcium scores above 400 Agatston U, whereas 50 had heart rates ≥ 70 bpm. Overall the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) for significant stenoses were: 95%, 91%, 65%, and 99% (by segment), respectively and 97%, 90%, 81%, and 91% (by artery), respectively (n = 475). Heart rate showed no significant impact on lesion detection; however, vessel calcification did show a significant impact on accuracy of assessment for coronary segments. The specificity, PPV and accuracy were 96%, 80%, and 96% (by segment), respectively for an Agatston score less than 100% and 99%, 96% and 98% (by artery). For an Agatston score of greater to or equal to 400 the specificity, PPV and accuracy were reduced to 79%, 55%, and 83% (by segment), respectively and to 79%, 69%, and 85% (by artery), respectively. Conclusion The DSCT provides a high rate of accuracy for the detection of significant coronary artery disease, even in patients with high heart rates and evidence of coronary calcification

  7. Magnetic resonance angiography

    MedlinePlus

    ... angiography is an MRI exam of the blood vessels. Unlike traditional angiography that involves placing a tube ( ... MRA is used to look at the blood vessels in all parts of the body, including the ...

  8. Evaluation for Basic Image Qualities Dependence on the Position in XYZ Directions and Acquisition Parameters of the Cone Beam CT for Angiography System with Flat Panel Detector.

    PubMed

    Tsuda, Norisato; Mitsui, Kota; Oda, Shinichiro

    2016-08-01

    The purpose of this study was to investigate the effect of the position in XYZ directions and acquisition parameters on the basic image qualities of for cone beam computed tomography (CBCT) in an angiography system with flat panel detector. The resolution property (modulation transfer function: MTF) and the noise property (Wiener spectrum: WS) of CBCT images in X-Y plane were measured with different acquisition parameters (scan matrix number and projection number) and the effect of the position in XYZ directions. The MTFs with 1024×1024 matrix were higher than those of 512×512 matrix and decreased in the peripheral areas due to the reduction of projection number. The highest and the lowest MTFs were measured at the X-ray tube side and on the detector side of the position in X-Y plane, respectively. The WS-doubled projection number showed about 50% lesser noise level. There were differences in the Wiener spectra (WS) at the position in XYZ directions. We conclude that the resolution and the noise property of CBCT image in X-Y plane showed dependences on the position in XYZ directions and acquisition parameters of the CBCT. PMID:27546079

  9. Qualitative indices and enhancement rate of CT pulmonary angiography in patients with suspected pulmonary embolism: Comparison between test bolus and bolus-tracking methods

    PubMed Central

    Moradi, Maryam; Khalili, Babak

    2016-01-01

    Background: The aim of the present study was to assess the qualitative indices and enhancement rate of computed tomographic pulmonary angiography (CTPA) in patients with suspected pulmonary embolism using Test bolus and Bolus-tracking techniques. Materials and Methods: Fifty-two patients with suspected pulmonary embolism that passed informed consent were randomly divided in the two groups. In each group, demographic characteristics, qualitative indices, and enhancement rate of CTPA were recorded. Results: The diagnostic result obtained in majority of the participants in the two groups (88.5 % in Test bolus group vs. 73.1% in the Bolus tracking group). In the case of quantitative variables, no statistically significant differences were found between the groups (P > 0.05). The only statistically significant difference between the two groups is average of “X-ray dose”. Conclusion: The results of our study show that there is no statistically significant difference between the Bolus Tracking and Test Bolus techniques for producing more homogeneous enhancement. PMID:27403408

  10. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S. P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

    2011-08-01

    The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm.MaterialsAll reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique.ResultsNo statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients.ConclusionThis study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  11. Complex aortic arch anomaly: Right aortic arch with aberrant left subclavian artery, fenestrated proximal right and duplicated proximal left vertebral arteries—CT angiography findings and review of the literature

    PubMed Central

    Tong, Elizabeth; Hagspiel, Klaus D

    2015-01-01

    Congenital aortic arch and vertebral artery anomalies are a relatively rare finding discovered on imaging either incidentally or for evaluation of entities like dysphagia or subclavian steal. Right aortic arch is an uncommon anatomical anomaly that occurs in less than 0.1% of the population, and in half of these cases the left subclavian artery is also aberrant.1 Unilateral vertebral artery (VA) duplication is rare with an observed prevalence of 0.72% in cadavers.2 Fenestration of the VA is more common than duplication, with a prevalence of approximately 0.23%–1.95%.3,4 We describe the case of a 25-year-old female who was found to have a right aortic arch with aberrant left subclavian artery, duplicated left vertebral artery and a fenestrated right vertebral artery on CT angiography performed for evaluation of dysphagia. This combination of findings has not been reported before, to the best of our knowledge. We review the embryologic mechanism for the development of the normal aortic arch, right aortic arch, vertebral artery duplication and vertebral artery fenestration. The incidence of these entities, resultant symptoms and clinical implications are also reviewed. The increased associated incidence of aneurysm formation, dissection, arteriovenous malformations and thromboembolic events with fenestration is also discussed. PMID:26306929

  12. Diagnostic Phase of Calcium Scoring Scan Applied as the Center of Acquisition Window of Coronary Computed Tomography Angiography Improves Image Quality in Minimal Acquisition Window Scan (Target CTA Mode) Using the Second Generation 320-Row CT

    PubMed Central

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

    2016-01-01

    Objective. To compare the image quality of coronary computed tomography angiography (CCTA) acquired under two conditions: 75% fixed as the acquisition window center (Group 75%) and the diagnostic phase for calcium scoring scan as the center (CS; Group CS). Methods. 320-row cardiac CT with a minimal acquisition window (scanned using “Target CTA” mode) was performed on 81 patients. In Group 75% (n = 40), CS was obtained and reconstructed at 75% and the center of the CCTA acquisition window was set at 75%. In Group CS (n = 41), CS was obtained at 75% and the diagnostic phase showing minimal artifacts was applied as the center of the CCTA acquisition window. Image quality was evaluated using a four-point scale (4-excellent) and the mean scores were compared between groups. Results. The CCTA scan diagnostic phase occurred significantly earlier in CS (75.7 ± 3.2% vs. 73.6 ± 4.5% for Groups 75% and CS, resp., p = 0.013). The mean Group CS image quality score (3.58 ± 0.63) was also higher than that for Group 75% (3.19 ± 0.66, p < 0.0001). Conclusions. The image quality of CCTA in Target CTA mode was significantly better when the center of acquisition window is adjusted using CS. PMID:26977449

  13. Accessible or Inaccessible? Diagnostic Efficacy of CT-Guided Core Biopsies of Head and Neck Masses

    SciTech Connect

    Cunningham, Jane D. McCusker, Mark W.; Power, Sarah; PearlyTi, Joanna; Thornton, John; Brennan, Paul; Lee, Michael J.; O’Hare, Alan; Looby, Seamus

    2015-04-15

    PurposeTissue sampling of lesions in the head and neck is challenging due to complex regional anatomy and sometimes necessitates open surgical biopsy. However, many patients are poor surgical candidates due to comorbidity. Thus, we evaluated the use of CT guidance for establishing histopathological diagnosis of head and neck masses.MethodsAll consecutive patients (n = 22) who underwent CT-guided core biopsy of head or neck masses between April 2009 and August 2012 were retrospectively reviewed using the departmental CT interventional procedures database. The indication for each biopsy performed was to establish or exclude a diagnosis of neoplasia in patients with suspicious head or neck lesions found on clinical examination or imaging studies. Patients received conscious sedation and 18 G, semiautomated core needle biopsies were performed by experienced neuroradiologists using 16-slice multidetector row CT imaging guidance (Somatom Definition Siemens Medical Solutions, Germany). Histopathology results of each biopsy were analysed.ResultsSixteen of 22 biopsies that were performed (73 %) yielded a pathological diagnosis. Anatomic locations biopsied included: masticator (n = 7), parapharyngeal (n = 3), parotid (n = 3), carotid (n = 3), perivertebral (n = 3), pharyngeal (n = 2), and retropharyngeal (n = 1) spaces. Six biopsies (27 %) were nondiagnostic due to inadequate tissue sampling, particularly small biopsy sample size and failure to biopsy the true sampling site due to extensive necrosis. No major complications were encountered.ConclusionsThe use of CT guidance to perform core biopsies of head and neck masses is an effective means of establishing histopathological diagnosis and reduces the need for diagnostic open surgical biopsy and general anaesthesia.

  14. Role of (68)Ga-DOTATATE PET/CT in patients with multiple endocrine neoplasia type 1 (MEN1).

    PubMed

    Lastoria, Secondo; Marciello, Francesca; Faggiano, Antongiulio; Aloj, Luigi; Caracò, Corradina; Aurilio, Michela; D'Ambrosio, Laura; Di Gennaro, Francesca; Ramundo, Valeria; Camera, Luigi; De Luca, Leonardo; Fonti, Rosa; Napolitano, Vincenzo; Colao, Annamaria

    2016-06-01

    Multiple endocrine neoplasia type 1 (MEN1) is a hereditary syndrome predisposing to many endocrine and neuroendocrine tumors (NET). Conventional imaging (CI) cannot provide satisfactory results for all the different types of MEN1-related tumors. Objective of this prospective observational study was to evaluate the role of (68)Ga-DOTATATE PET/CT in MEN1 compared to CI. Diagnostic performance of (68)Ga-DOTATATE PET/CT for the detection of NET was evaluated as well as the prognostic role of SUVmax. Eighteen patients with genetically confirmed MEN1 were evaluated by (68)Ga-DOTATATE PET/CT, endoscopic ultrasounds, multidetector-row computed tomography, magnetic resonance imaging, and hormone/markers serum measurements. Four MEN1-related tumor sites (pancreas, pituitary, parathyroids, adrenals) were considered. Sensitivity and specificity of (68)Ga-DOTATATE PET/CT for the detection of NET were calculated. There was (68)Ga-DOTATATE PET/CT uptake in 11/11 patients with pancreatic lesions, in 9/12 with pituitary adenoma, in 5/15 with parathyroid enlargements, and in 5/7 with adrenal lesions. (68)Ga-DOTATATE PET/CT showed sensitivity and specificity of 100 and 100 % in pancreas, 75 and 83 % in pituitary, 28 and 100 % in parathyroids, and 62.5 and 100 % in adrenals, respectively. Compared with CI, no significant difference in sensitivity for pancreas, pituitary, and adrenals was found, while CI had a better sensitivity for parathyroids (p = 0.002). On the ROC analysis, progression of pancreatic lesions was significantly associated to SUVmax <12.3 (p < 0.05). (68)Ga-DOTATATE PET/CT is greatly helpful in the work-up of MEN1 providing a panoramic view of MEN1-related lesions. There is also a prognostic role of (68)Ga-PET in patients with MEN1-pancreatic lesions. PMID:26242621

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

    PubMed Central

    2005-01-01

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

  16. Coronary Plaque Characteristics Assessed by 256-Slice Coronary CT Angiography and Association with High-Sensitivity C-Reactive Protein in Symptomatic Patients with Type 2 Diabetes.

    PubMed

    Zhang, Jinling; Lv, Zhehao; Zhao, Deli; Liu, Lili; Wan, Yong; Fan, Tingting; Li, Huimin; Guan, Ying; Liu, Bailu; Yang, Qi

    2016-01-01

    Little is known regarding plaque distribution, composition, and the association with inflammation in type 2 diabetes mellitus (DM2). This study aimed to assess the relationship between coronary plaque subtypes and high-sensitivity C-reactive protein levels. Coronary CTA were performed in 98 symptomatic DM2 patients and 107 non-DM2 patients using a 256-slice CT. The extent and types of plaque as well as luminal narrowing were evaluated. Patients with DM2 were more likely to have significant stenosis (>50%) with calcified plaques in at least one coronary segment (p < 0.01); the prevalence rates of diffuse calcified plaques in the DM2 and non-DM2 groups were 31.6% and 4.7%, respectively (p < 0.01). Plasma hs-CRP levels in DM2 with calcified plaques were higher compared with values obtained for the non-DM2 group (p < 0.01). In conclusion, combination of coronary CTA and hs-CRP might improve risk stratification in symptomatic DM2 patients. PMID:27579325

  17. Coronary Plaque Characteristics Assessed by 256-Slice Coronary CT Angiography and Association with High-Sensitivity C-Reactive Protein in Symptomatic Patients with Type 2 Diabetes

    PubMed Central

    Zhang, Jinling; Lv, Zhehao; Zhao, Deli; Liu, Lili; Wan, Yong; Fan, Tingting; Li, Huimin; Guan, Ying; Liu, Bailu

    2016-01-01

    Little is known regarding plaque distribution, composition, and the association with inflammation in type 2 diabetes mellitus (DM2). This study aimed to assess the relationship between coronary plaque subtypes and high-sensitivity C-reactive protein levels. Coronary CTA were performed in 98 symptomatic DM2 patients and 107 non-DM2 patients using a 256-slice CT. The extent and types of plaque as well as luminal narrowing were evaluated. Patients with DM2 were more likely to have significant stenosis (>50%) with calcified plaques in at least one coronary segment (p < 0.01); the prevalence rates of diffuse calcified plaques in the DM2 and non-DM2 groups were 31.6% and 4.7%, respectively (p < 0.01). Plasma hs-CRP levels in DM2 with calcified plaques were higher compared with values obtained for the non-DM2 group (p < 0.01). In conclusion, combination of coronary CTA and hs-CRP might improve risk stratification in symptomatic DM2 patients. PMID:27579325

  18. Automatic identification of origins of left and right coronary arteries in CT angiography for coronary arterial tree tracking and plaque detection

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Chightai, Aamer; Wei, Jun; Hadjiiski, Lubomir M.; Agarwal, Prachi; Kuriakose, Jean W.; Kazerooni, Ella A.

    2013-03-01

    Automatic tracking and segmentation of the coronary arterial tree is the basic step for computer-aided analysis of coronary disease. The goal of this study is to develop an automated method to identify the origins of the left coronary artery (LCA) and right coronary artery (RCA) as the seed points for the tracking of the coronary arterial trees. The heart region and the contrast-filled structures in the heart region are first extracted using morphological operations and EM estimation. To identify the ascending aorta, we developed a new multiscale aorta search method (MAS) method in which the aorta is identified based on a-priori knowledge of its circular shape. Because the shape of the ascending aorta in the cCTA axial view is roughly a circle but its size can vary over a wide range for different patients, multiscale circularshape priors are used to search for the best matching circular object in each CT slice, guided by the Hausdorff distance (HD) as the matching indicator. The location of the aorta is identified by finding the minimum HD in the heart region over the set of multiscale circular priors. An adaptive region growing method is then used to extend the above initially identified aorta down to the aortic valves. The origins at the aortic sinus are finally identified by a morphological gray level top-hat operation applied to the region-grown aorta with morphological structuring element designed for coronary arteries. For the 40 test cases, the aorta was correctly identified in 38 cases (95%). The aorta can be grown to the aortic root in 36 cases, and 36 LCA origins and 34 RCA origins can be identified within 10 mm of the locations marked by radiologists.

  19. Marketing cardiac CT programs.

    PubMed

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing. PMID:22276376

  20. Diagnosing pulmonary embolism: time to rewrite the textbooks.

    PubMed

    Schoepf, U Joseph

    2005-02-01

    Computed tomography (CT) is rapidly becoming the first line modality for imaging pulmonary embolism (PE). However, limitations for the accurate diagnosis of small peripheral emboli have prevented the unanimous acceptance of CT as the new standard of reference for imaging PE although the actual significance of the detection and treatment of isolated peripheral emboli is uncertain. At the same time the high negative predictive value of CT pulmonary angiography for excluding clinically significant PE has been established in retrospective and prospective studies. The introduction of multidetector-row spiral CT has greatly improved visualization of peripheral pulmonary arteries and detection of small emboli. Previous concerns regarding the accuracy of spiral CT for the accurate diagnosis of peripheral pulmonary emboli should thus be overcome. Multidetector-row spiral CT has become a widely available and cost-effective modality, which has surpassed other imaging modalities for PE diagnosis to a point where over-utilization may become of concern. Our most immediate goal must be to educate our referring colleagues about these important transitions so that the diagnostic algorithm in patients with suspected acute PE is updated to accurately reflect our current diagnostic prowess in medical imaging. PMID:15915948

  1. Transient Cortical Blindness Following Vertebral Angiography: A Case Report

    PubMed Central

    Chan, Ho Fung; Ma, Ka Fai; Cheng, Lik Fai; Chan, Tony KT

    2015-01-01

    Transient cortical blindness (TCB) is a rare but well-known complication of cerebral angiography. Its pathophysiology remains uncertain. We would like to report a case of TCB in a patient during a follow up vertebral angiogram for post-coil embolization of left posterior inferior cerebellar artery aneurysm. Patient's vision was resumed spontaneously within 24 hours after angiography, with no residual neurological deficit in subsequent clinical follow up. Multi-modality imaging evaluation including vertebral angiography, brain CT and MRI performed on same day are presented. PMID:25763297

  2. Computed Tomography Angiography of the Lower Extremities.

    PubMed

    Cook, Tessa Sundaram

    2016-01-01

    CT angiography (CTA) of the lower extremities is an important and versatile, noninvasive tool for diagnosis as well as surgical or endovascular interventional planning. Although lower extremity CTA is most commonly performed in patients with peripheral artery disease or trauma affecting the lower extremities, it also plays a role in the workup of nonischemic etiologies such as vasculitis, aneurysms, and congenital vascular malformations. CT scan protocols should adjust bolus timing and multiphasic imaging to account for the clinical question of interest, and 3-dimensional postprocessing plays an important role in the visualization and interpretation of these high-resolution imaging examinations. PMID:26654395

  3. Reducing radiation dose to the female breast during CT coronary angiography: A simulation study comparing breast shielding, angular tube current modulation, reduced kV, and partial angle protocols using an unknown-location signal-detectability metric

    SciTech Connect

    Rupcich, Franco; Gilat Schmidt, Taly; Badal, Andreu; Popescu, Lucretiu M.; Kyprianou, Iacovos

    2013-08-15

    Purpose: The authors compared the performance of five protocols intended to reduce dose to the breast during computed tomography (CT) coronary angiography scans using a model observer unknown-location signal-detectability metric.Methods: The authors simulated CT images of an anthropomorphic female thorax phantom for a 120 kV reference protocol and five “dose reduction” protocols intended to reduce dose to the breast: 120 kV partial angle (posteriorly centered), 120 kV tube-current modulated (TCM), 120 kV with shielded breasts, 80 kV, and 80 kV partial angle (posteriorly centered). Two image quality tasks were investigated: the detection and localization of 4-mm, 3.25 mg/ml and 1-mm, 6.0 mg/ml iodine contrast signals randomly located in the heart region. For each protocol, the authors plotted the signal detectability, as quantified by the area under the exponentially transformed free response characteristic curve estimator (A-caret{sub FE}), as well as noise and contrast-to-noise ratio (CNR) versus breast and lung dose. In addition, the authors quantified each protocol's dose performance as the percent difference in dose relative to the reference protocol achieved while maintaining equivalent A-caret{sub FE}.Results: For the 4-mm signal-size task, the 80 kV full scan and 80 kV partial angle protocols decreased dose to the breast (80.5% and 85.3%, respectively) and lung (80.5% and 76.7%, respectively) with A-caret{sub FE} = 0.96, but also resulted in an approximate three-fold increase in image noise. The 120 kV partial protocol reduced dose to the breast (17.6%) at the expense of increased lung dose (25.3%). The TCM algorithm decreased dose to the breast (6.0%) and lung (10.4%). Breast shielding increased breast dose (67.8%) and lung dose (103.4%). The 80 kV and 80 kV partial protocols demonstrated greater dose reductions for the 4-mm task than for the 1-mm task, and the shielded protocol showed a larger increase in dose for the 4-mm task than for the 1-mm task

  4. Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

    PubMed Central

    2013-01-01

    Background Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780). Methods/Design The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest

  5. What Is Coronary Angiography?

    MedlinePlus

    ... OG-rah-fee) is a test that uses dye and special x rays to show the insides ... the coronary arteries. Overview During coronary angiography, special dye is released into the bloodstream. The dye makes ...

  6. Diagnosis of a Cerebral Arteriovenous Malformation Using Isolated Brain Computed Tomography Angiography: Case Report.

    PubMed

    Qian, Hui; Shao, Yu; Li, Zhengdong; Huang, Ping; Zou, Donghua; Liu, Ningguo; Chen, Yijiu; Wan, Lei

    2016-09-01

    This report presents a case of a 40-year-old woman who was found dead in her house. The examination of the body revealed no external injuries. The whole body was scanned by multi-detector-row computed tomography (CT) before autopsy, revealing massive hemorrhage in the right frontal extending into the ventricular system. At autopsy, the brain parenchyma was removed. Then CT angiography was carried on the isolated brain. Computed tomography angiography suggested a mass of irregular, tortuous vessels in areas of hemorrhage in the right frontal lobe of the brain. Finally, histological examination confirmed the result of CT angiography due to an arteriovenous malformation. Hence, postmortem CT angiography played an important role in diagnosis of the cerebral arteriovenous malformation that was responsible for a massive hemorrhage in the skull. PMID:27367577

  7. Assessment of regional ventilation and deformation using 4D-CT imaging for healthy human lungs during tidal breathing.

    PubMed

    Jahani, Nariman; Choi, Sanghun; Choi, Jiwoong; Iyer, Krishna; Hoffman, Eric A; Lin, Ching-Long

    2015-11-15

    This study aims to assess regional ventilation, nonlinearity, and hysteresis of human lungs during dynamic breathing via image registration of four-dimensional computed tomography (4D-CT) scans. Six healthy adult humans were studied by spiral multidetector-row CT during controlled tidal breathing as well as during total lung capacity and functional residual capacity breath holds. Static images were utilized to contrast static vs. dynamic (deep vs. tidal) breathing. A rolling-seal piston system was employed to maintain consistent tidal breathing during 4D-CT spiral image acquisition, providing required between-breath consistency for physiologically meaningful reconstructed respiratory motion. Registration-derived variables including local air volume and anisotropic deformation index (ADI, an indicator of preferential deformation in response to local force) were employed to assess regional ventilation and lung deformation. Lobar distributions of air volume change during tidal breathing were correlated with those of deep breathing (R(2) ≈ 0.84). Small discrepancies between tidal and deep breathing were shown to be likely due to different distributions of air volume change in the left and the right lungs. We also demonstrated an asymmetric characteristic of flow rate between inhalation and exhalation. With ADI, we were able to quantify nonlinearity and hysteresis of lung deformation that can only be captured in dynamic images. Nonlinearity quantified by ADI is greater during inhalation, and it is stronger in the lower lobes (P < 0.05). Lung hysteresis estimated by the difference of ADI between inhalation and exhalation is more significant in the right lungs than that in the left lungs. PMID:26316512

  8. Multidetector computed tomographic angiography of the cardiovascular system

    PubMed Central

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

    2007-01-01

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

  9. Radiation dose reduction with application of non-linear adaptive filters for abdominal CT

    PubMed Central

    Singh, Sarabjeet; Kalra, Mannudeep K; Sung, Mi Kim; Back, Anni; Blake, Michael A

    2012-01-01

    AIM: To evaluate the effect of non-linear adaptive filters (NLAF) on abdominal computed tomography (CT) images acquired at different radiation dose levels. METHODS: Nineteen patients (mean age 61.6 ± 7.9 years, M:F = 8:11) gave informed consent for an Institutional Review Board approved prospective study involving acquisition of 4 additional image series (200, 150, 100, 50 mAs and 120 kVp) on a 64 slice multidetector row CT scanner over an identical 10 cm length in the abdomen. The CT images acquired at 150, 100 and 50 mAs were processed with the NLAF. Two radiologists reviewed unprocessed and processed images for image quality in a blinded randomized manner. CT dose index volume, dose length product, patient weight, transverse diameters, objective noise and CT numbers were recorded. Data were analyzed using Analysis of Variance and Wilcoxon signed rank test. RESULTS: Of the 31 lesions detected in abdominal CT images, 28 lesions were less than 1 cm in size. Subjective image noise was graded as unacceptable in unprocessed images at 50 and 100 mAs, and in NLAF processed images at 50 mAs only. In NLAF processed images, objective image noise was decreased by 21% (14.4 ± 4/18.2 ± 4.9) at 150 mAs, 28.3% (15.7 ± 5.6/21.9 ± 4) at 100 mAs and by 39.4% (18.8 ± 9/30.4 ± 9.2) at 50 mAs compared to unprocessed images acquired at respective radiation dose levels. At 100 mAs the visibility of smaller structures improved from suboptimal in unprocessed images to excellent in NLAF processed images, whereas diagnostic confidence was respectively improved from probably confident to fully confident. CONCLUSION: NLAF lowers image noise, improves the visibility of small structures and maintains lesion conspicuity at down to 100 mAs for abdominal CT. PMID:22328968

  10. Rotational angiography of left ventricle to guide ventricular tachycardia ablation.

    PubMed

    Wolf, Jiri; Starek, Zdenek; Jez, Jiri; Lehar, Frantisek; Lukasova, Marketa; Kulik, Tomas; Novak, Miroslav

    2015-06-01

    Three-dimensional rotational angiography (3 DRA) is a novel imaging method introduced to guide complex catheter ablations of the left atrium. Our aim was to investigate the feasibility of the method in visualization of left ventricular anatomy and to develop a corresponding protocol for guidance of ventricular tachycardia ablation. We performed 3D rotational angiography in 13 patients using a direct left atrial protocol for data acquisition and the 3D reconstruction of the left ventricle was achieved in all patients. Clinical data comparison has proved lower use of radiation and contrast medium during 3 DRA-guided ablations as compared to CT-guided procedures. PMID:25761532

  11. Computed tomography, angiography, and endoscopic retrograde cholangiopancreatography in the nonoperative management of hepatic and splenic trauma.

    PubMed

    Delgado Millán, M A; Deballon, P O

    2001-11-01

    There is a marked trend toward nonoperative management of abdominal trauma. This has been possible thanks to the advances in imaging and interventional techniques. In this work we review in which way computed tomography (CT) abdominal scans, angiography, and endoscopic retrograde cholangiopancreatography (ERCP) can guide the nonoperative management of hepatic and splenic trauma. The CT abdominal scan with intravenous contrast is the "departure imaging" of choice for the nonoperative management of hepatic and splenic trauma in the hemodynamically stable patient. It is the most accurate test for detecting, defining, and characterizing these injuries, the associated hemoperitoneum, and other abdominal abnormalities (the hollow viscus injuries missed on the CT scan were detected by clinical parameters and had no negative consequences in the outcome). It has an accuracy of more than 95% for these injuries, but CT grading alone cannot decide which patient can be treated conservatively and which patient requires surgery. Its usefulness for follow-up seems challenging. Angiography can be therapeutic, thereby avoiding surgery (some report that angiography can be performed even in patients with active bleeding as damage control); if vessel injury, active bleeding or hemobilia are suspected on the basis of a CT scan in a stable patient, angiography should be carried out. ERCP should be performed in patients with suspected injury to the biliary tree, even with normal iminodiacetic acid radionuclide scanning (HIDA) if symptoms persist. A biliary stent can be placed. Indications for angiography and ERCP remain unclear. PMID:11760741

  12. Image quality and radiation reduction of 320-row area detector CT coronary angiography with optimal tube voltage selection and an automatic exposure control system: comparison with body mass index-adapted protocol.

    PubMed

    Lim, Jiyeon; Park, Eun-Ah; Lee, Whal; Shim, Hackjoon; Chung, Jin Wook

    2015-06-01

    To assess the image quality and radiation exposure of 320-row area detector computed tomography (320-ADCT) coronary angiography with optimal tube voltage selection with the guidance of an automatic exposure control system in comparison with a body mass index (BMI)-adapted protocol. Twenty-two patients (study group) underwent 320-ADCT coronary angiography using an automatic exposure control system with the target standard deviation value of 33 as the image quality index and the lowest possible tube voltage. For comparison, a sex- and BMI-matched group (control group, n = 22) using a BMI-adapted protocol was established. Images of both groups were reconstructed by an iterative reconstruction algorithm. For objective evaluation of the image quality, image noise, vessel density, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were measured. Two blinded readers then subjectively graded the image quality using a four-point scale (1: nondiagnostic to 4: excellent). Radiation exposure was also measured. Although the study group tended to show higher image noise (14.1 ± 3.6 vs. 9.3 ± 2.2 HU, P = 0.111) and higher vessel density (665.5 ± 161 vs. 498 ± 143 HU, P = 0.430) than the control group, the differences were not significant. There was no significant difference between the two groups for SNR (52.5 ± 19.2 vs. 60.6 ± 21.8, P = 0.729), CNR (57.0 ± 19.8 vs. 67.8 ± 23.3, P = 0.531), or subjective image quality scores (3.47 ± 0.55 vs. 3.59 ± 0.56, P = 0.960). However, radiation exposure was significantly reduced by 42 % in the study group (1.9 ± 0.8 vs. 3.6 ± 0.4 mSv, P = 0.003). Optimal tube voltage selection with the guidance of an automatic exposure control system in 320-ADCT coronary angiography allows substantial radiation reduction without significant impairment of image quality, compared to the results obtained using a BMI-based protocol. PMID:25604967

  13. Pediatric digital subtraction angiography

    SciTech Connect

    Amundson, G.M.; Wesenberg, R.L.; Mueller, D.L.; Reid, R.H.

    1984-12-01

    Experience with intravenous digital subtraction angiography (DSA) in infants and children is limited, although its relative rate of performance, low complication rate, and diagnostic accuracy indicate great potential. The authors performed 87 DSA examinations (74 patients) and obtained sufficient detail to facilitate diagnosis in most cases. The major problems of patient movement and overlapping vessels can be minimized by judicious use of sedation and strict attention to technique. Exposure of patients to radiation has not been a limiting factor since our system uses low exposure factors. Our results demonstrate that DSA has wide applicability to many organ systems and is especially useful in intracranial disease and for preoperative evaluation of neoplasms.

  14. Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

    SciTech Connect

    Koike, Yuya Nishimura, Jun-ichi Hase, Soichiro Yamasaki, Motoshige

    2015-04-15

    PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.

  15. Fluorescent blood cell angiography

    NASA Astrophysics Data System (ADS)

    Ben-nun, Joshua; Constable, Ian J.

    1994-06-01

    Fluorescein angiography is currently the main method for evaluation of the retinal vascular patency. Ashton noted that capillary patency to the small fluorescein molecule may differ from that of the larger red blood cells. He concluded that fluorescein angiography is not able to demonstrate a developing stenosis, that might be the precipitating cause of a later capillary closure in various microvasculopathies. Sarelius et al have shown, in hamster cheek pouch and cremaster muscle, that fluorescently labeled erythrocytes in known concentrations can be used for the direct measurement of capillary flow parameters. The only assumption that this method relies on, is that the labeled cells are rheologically normal and therefore reflect the behavior of the total cell population. We have developed a new method for an in-vivo, real-time demonstration of the blood cell flow in the retinal capillary net. Based on the assumption presented by Sarelius et al, measurement and analysis of the retinal capillary blood cell flow is also possible from the results achieved by the new method.

  16. Performance evaluation of a 64-slice CT system with z-flying focal spot.

    PubMed

    Flohr, T; Stierstorfer, K; Raupach, R; Ulzheimer, S; Bruder, H

    2004-12-01

    The meanwhile established generation of 16-slice CT systems enables routine sub-millimeter imaging at short breath-hold times. Clinical progress in the development of multidetector row CT (MDCT) technology beyond 16 slices can more likely be expected from further improvement in spatial and temporal resolution rather than from a mere increase in the speed of volume coverage. We present an evaluation of a recently introduced 64-slice CT system (SOMATOM Sensation 64, Siemens AG, Forchheim, Germany), which uses a periodic motion of the focal spot in longitudinal direction (z-flying focal spot) to double the number of simultaneously acquired slices. This technique acquires 64 overlapping 0.6 mm slices per rotation. The sampling scheme corresponds to that of a 64 x 0.3 mm detector, with the goal of improved longitudinal resolution and reduced spiral artifacts. After an introduction to the detector design, we discuss the basics of z-flying focal spot technology (z-Sharp). We present phantom and specimen scans for performance evaluation. The measured full width at half maximum (FWHM) of the thinnest spiral slice is 0.65 mm. All spiral slice widths are almost independent of the pitch, with deviations of less than 0.1 mm from the nominal value. Using a high-resolution bar pattern phantom (CATPHAN, Phantom Laboratories, Salem, NY), the longitudinal resolution can be demonstrated to be up to 15 lp/cm at the isocenter independent of the pitch, corresponding to a bar diameter of 0.33 mm. Longitudinal resolution is only slightly degraded for off-center locations. At a distance of 100 mm from the isocenter, 14 lp/cm can be resolved in the z-direction, corresponding to a bar diameter of 0.36 mm. Spiral "windmill" artifacts presenting as hyper- and hypodense structures around osseous edges are effectively reduced by the z-flying focal spot technique. Cardiac scanning benefits from the short gantry rotation time of 0.33 s, providing up to 83 ms temporal resolution with 2-segment ECG

  17. Implications of Discordant Findings Between Hepatic Angiography and Cross-Sectional Imaging in Transplant Candidates With Hepatocellular Carcinoma

    PubMed Central

    Young, Kellie; Fidelman, Nicholas; Yao, Francis Y.; Hills, Nancy K.; Kohi, Maureen P.; Kolli, K. Pallav; Taylor, Andrew G.; Kerlan, Robert K.

    2016-01-01

    The goal of this study was to determine whether the detection of discordant numbers of hypervascular foci at hepatic angiography versus contrast-enhanced (CE) cross-sectional imaging [computed tomography (CT) or magnetic resonance imaging (MRI)] is associated with adverse clinical outcomes in patients with hepatocellular carcinoma (HCC) who are listed for liver transplantation. We retrospectively reviewed the records of 218 consecutive patients with HCC who were listed for a liver transplant and who underwent transarterial chemoembolization at our institution between January 1, 2006 and December 31, 2010. Patients were grouped into 3 categories: (1) the number of nodules at CT/MRI was concordant with the number of hypervascular foci detected at angiography (n = 136), (2) the number of nodules at CT/MRI was greater than the number of hypervascular foci at angiography (n = 45), and (3) the number of nodules at CT/MRI was fewer than the number of hypervascular foci at angiography (n = 37). The study outcomes were liver transplantation and tumor recurrence after transplantation. The detection of at least 3 more hypervascular foci at angiography versus the number of HCC nodules on CT/MRI was associated with a significantly lower rate of transplantation [multivariate subhazard ratio (SHR), 0.39; 95% confidence interval (CI), 0.17–0.92]. The detection of fewer hypervascular foci at angiography versus the number of HCC nodules on CT/MRI was associated with a significantly higher rate of tumor recurrence after transplantation (multivariate SHR, 3.49; 95% CI, 1.27–9.56). In conclusion, liver transplant candidates with HCC who demonstrate discordant findings between angiography and CE CT or MRI may be at a higher risk for dropout from the transplant list and for tumor recurrence after transplantation. PMID:25678220

  18. Long term prognostic utility of coronary CT angiography in patients with no modifiable coronary artery disease risk factors: Results from the 5 year follow-up of the CONFIRM International Multicenter Registry

    PubMed Central

    Cheruvu, Chaitu; Precious, Bruce; Naoum, Christopher; Blanke, Philipp; Ahmadi, Amir; Soon, Jeanette; Arepalli, Chesnaldey; Gransar, Heidi; Achenbach, Stephan; Berman, Daniel S.; Budoff, Matthew J.; Callister, Tracy Q.; Al-Mallah, Mouaz H.; Cademartiri, Filippo; Chinnaiyan, Kavitha; Rubinshtein, Ronen; Marquez, Hugo; DeLago, Augustin; Villines, Todd C.; Hadamitzky, Martin; Hausleiter, Joerg; Shaw, Leslee J.; Kaufmann, Philipp A.; Cury, Ricardo C.; Feuchtner, Gudrun; Kim, Yong-Jin; Maffei, Erica; Raff, Gilbert; Pontone, Gianluca; Andreini, Daniele; Chang, Hyuk-Jae; Min, James K.; Leipsic, Jonathon

    2016-01-01

    Background Coronary computed tomography angiography (coronary CTA) can prognosticate outcomes in patients without modifiable risk factors over medium term follow-up. This ability was driven by major adverse cardiovascular events (MACE). Objective Determine if coronary CTA could discriminate risk of mortality with longer term follow-up. In addition we sought to determine the long-term relationship to MACE. Methods From 12 centers, 1884 patients undergoing coronary CTA without prior coronary artery disease (CAD) or any modifiable CAD risk factors were identified. The presence of CAD was classified as none (0% stenosis), mild (1% to 49% stenosis) and obstructive (≥50% stenosis severity). The primary endpoint was all-cause mortality and the secondary endpoint was MACE. MACE was defined as the combination of death, nonfatal myocardial infarction, unstable angina, and late target vessel revascularization (>90 days). Results Mean age was 55.6 ± 14.5 years. At mean 5.6 ± 1.3 years follow-up, 145(7.7%) deaths occurred. All-cause mortality demonstrated a dose-response relationship to the severity and number of coronary vessels exhibiting CAD. Increased mortality was observed for >1 segment non-obstructive CAD (hazard ratio [HR]:1.73; 95% confidence interval [CI]: 1.07–2.79; p = 0.025), obstructive 1&2 vessel CAD (HR: 1.70; 95% CI: 1.08–2.71; p = 0.023) and 3-vessel or left main CAD (HR: 2.87; 95% CI: 1.57–5.23; p = 0.001). Both obstructive CAD (HR: 6.63; 95% CI: 3.91–11.26; p < 0.001) and non-obstructive CAD (HR: 2.20; 95% CI: 1.31–3.67; p = 0.003) predicted MACE with increased hazard associated with increasing CAD severity; 5.60% in no CAD, 13.24% in non-obstructive and 36.28% in obstructive CAD, p < 0.001 for trend. Conclusions In individuals being assessed for CAD with no modifiable risk factors, all-cause mortality in the long term (>5 years) was predicted by the presence of more than 1 segment of non-obstructive plaque, obstructive 1- or 2-vessel CAD and 3

  19. Society for Cardiovascular Angiography and Interventions

    MedlinePlus

    ... jointly produced, collaborated with, or endorsed by the Society of Cardiovascular Angiography and Interventions. Press & News » Review ... SCAI Member? Create an Account Advertisement Advertisement The Society for Cardiovascular Angiography and Interventions Foundation, 1100 17th ...

  20. CT Angiography Analysis of Axillary Artery Diameter versus Common Femoral Artery Diameter: Implications for Axillary Approach for Transcatheter Aortic Valve Replacement in Patients with Hostile Aortoiliac Segment and Advanced Lung Disease

    PubMed Central

    Tayal, Rajiv; Iftikhar, Humayun; LeSar, Benjamin; Patel, Rahul; Tyagi, Naveen; Cohen, Marc; Wasty, Najam

    2016-01-01

    Objective. The use of the axillary artery as an access site has lost favor in percutaneous intervention due to the success of these procedures from a radial or brachial alternative. However, these distal access points are unable to safely accommodate anything larger than a 7-French sheath. To date no studies exist describing the size of the axillary artery in relation to the common femoral artery in a patient population. We hypothesized that the axillary artery is of comparable size to the CFA in most patients and less frequently diseased. Methods. We retrospectively reviewed 110 CT scans of the thoracic and abdominal aorta done at our institution to rule out aortic dissection in which the right axillary artery, right CFA, left axillary artery, and left CFA were visualized. Images were then reconstructed using commercially available TeraRecon software and comparative measurements made of the axillary and femoral arteries. Results. In 96 patients with complete data, the mean sizes of the right and left axillary artery were slightly smaller than the left and right CFA. A direct comparison of the sizes of the axillary artery and CFA in the same patient yielded a mean difference of 1.69 mm ± 1.74. In all patients combined, the mean difference between the axillary artery and CFA was 1.88 mm on the right and 1.68 mm on the left. In 19 patients (19.8%), the axillary artery was of the same caliber as the associated CFA. In 8 of 96 patients (8.3%), the axillary artery was larger compared to the CFA. Conclusions. Although typically smaller, the axillary artery is often of comparable size to the CFA, significantly less frequently calcified or diseased, and in almost all observed cases large enough to accommodate a sheath with up to 18 French. PMID:27110403

  1. CT Angiography Analysis of Axillary Artery Diameter versus Common Femoral Artery Diameter: Implications for Axillary Approach for Transcatheter Aortic Valve Replacement in Patients with Hostile Aortoiliac Segment and Advanced Lung Disease.

    PubMed

    Tayal, Rajiv; Iftikhar, Humayun; LeSar, Benjamin; Patel, Rahul; Tyagi, Naveen; Cohen, Marc; Wasty, Najam

    2016-01-01

    Objective. The use of the axillary artery as an access site has lost favor in percutaneous intervention due to the success of these procedures from a radial or brachial alternative. However, these distal access points are unable to safely accommodate anything larger than a 7-French sheath. To date no studies exist describing the size of the axillary artery in relation to the common femoral artery in a patient population. We hypothesized that the axillary artery is of comparable size to the CFA in most patients and less frequently diseased. Methods. We retrospectively reviewed 110 CT scans of the thoracic and abdominal aorta done at our institution to rule out aortic dissection in which the right axillary artery, right CFA, left axillary artery, and left CFA were visualized. Images were then reconstructed using commercially available TeraRecon software and comparative measurements made of the axillary and femoral arteries. Results. In 96 patients with complete data, the mean sizes of the right and left axillary artery were slightly smaller than the left and right CFA. A direct comparison of the sizes of the axillary artery and CFA in the same patient yielded a mean difference of 1.69 mm ± 1.74. In all patients combined, the mean difference between the axillary artery and CFA was 1.88 mm on the right and 1.68 mm on the left. In 19 patients (19.8%), the axillary artery was of the same caliber as the associated CFA. In 8 of 96 patients (8.3%), the axillary artery was larger compared to the CFA. Conclusions. Although typically smaller, the axillary artery is often of comparable size to the CFA, significantly less frequently calcified or diseased, and in almost all observed cases large enough to accommodate a sheath with up to 18 French. PMID:27110403

  2. Adrenal pseudomasses due to varices: angiographic-CT-MRI-pathologic correlations

    SciTech Connect

    Brady, T.M.; Gross, B.H.; Glazer, G.M. Williams, D.M.

    1985-08-01

    Periadrenal and adrenal portosystemic collaterals are a recently reported cause of adrenal pseudotumor on computed tomography (CT). Nine patients with this left adrenal pseudotumor illustrate its typical position and appearance on CT, angiography, CT-angiography, and magnetic resonance imaging (MRI). The anatomic basis for variceal adrenal pseudotumors is the left inferior phrenic vein, which passes immediately anterior to the left adrenal gland and which serves as a collateral pathway from splenic to left renal vein in portal hypertension. Thus, unlike previously described adrenal pseudotumors, these venous collaterals are not anatomically distinguishable from the adrenal gland on CT. Bolus dynamic CT is usually diagnostic, but in equivocal cases, MRI may prove useful.

  3. Computed Tomography Angiography of the Hepatic, Pancreatic, and Splenic Circulation.

    PubMed

    Price, Melissa; Patino, Manuel; Sahani, Dushyant

    2016-01-01

    Multidetector computed tomography angiography (MDCTA) has become a routine imaging tool to assess visceral vascular anatomy and abdominal parenchymal pathology. Enhanced temporal resolution and rapid acquisition allow for precise delineation of arterial and venous anatomy. The excellent spatial resolution permits assessment of small parenchyma lesions and vasculature. The ability of CT to rapidly acquire data and reconstruct with thinner slices allows robust 3D mapping using maximum intensity projection before definitive surgical or interventional therapy. Emerging novel techniques of image acquisition offer sensitive methods for detecting enhancement and allow for virtual imaging subtraction, all while limiting the total radiation burden. PMID:26654391

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

    PubMed

    Bootsveld, A; Puetz, J; Grube, E

    2004-06-01

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

  5. Acoustic angiography: a new imaging modality for assessing microvasculature architecture.

    PubMed

    Gessner, Ryan C; Frederick, C Brandon; Foster, F Stuart; Dayton, Paul A

    2013-01-01

    The purpose of this paper is to provide the biomedical imaging community with details of a new high resolution contrast imaging approach referred to as "acoustic angiography." Through the use of dual-frequency ultrasound transducer technology, images acquired with this approach possess both high resolution and a high contrast-to-tissue ratio, which enables the visualization of microvascular architecture without significant contribution from background tissues. Additionally, volumetric vessel-tissue integration can be visualized by using b-mode overlays acquired with the same probe. We present a brief technical overview of how the images are acquired, followed by several examples of images of both healthy and diseased tissue volumes. 3D images from alternate modalities often used in preclinical imaging, contrast-enhanced micro-CT and photoacoustics, are also included to provide a perspective on how acoustic angiography has qualitatively similar capabilities to these other techniques. These preliminary images provide visually compelling evidence to suggest that acoustic angiography may serve as a powerful new tool in preclinical and future clinical imaging. PMID:23997762

  6. Comparison of computed tomography pulmonary angiography and point-of-care tests for pulmonary thromboembolism diagnosis in dogs

    PubMed Central

    Goggs, R; Chan, D L; Benigni, L; Hirst, C; Kellett-Gregory, L; Fuentes, V L

    2014-01-01

    Objectives To evaluate the feasibility of CT pulmonary angiography for identification of naturally occurring pulmonary thromboembolism in dogs using predefined diagnostic criteria and to assess the ability of echocardiography, cardiac troponins, D-dimers and kaolin-activated thromboelastography to predict the presence of pulmonary thromboembolism in dogs. Methods Twelve dogs with immune-mediated haemolytic anaemia and evidence of respiratory distress were prospectively evaluated. Dogs were sedated immediately before CT pulmonary angiography using intravenous butorphanol. Spiral CT pulmonary angiography was performed with a 16 detector-row CT scanner using a pressure injector to infuse contrast media through peripheral intravenous catheters. Pulmonary thromboembolism was diagnosed using predefined criteria. Contemporaneous tests included echocardiography, arterial blood gas analysis, kaolin-activated thromboelastography, D-dimers and cardiac troponins. Results Based on predefined criteria, four dogs were classified as pulmonary thromboembolism positive, three dogs were suspected to have pulmonary thromboembolism and the remaining five dogs had negative scans. The four dogs identified with pulmonary thromboembolism all had discrete filling defects in main or lobar pulmonary arteries. None of the contemporaneous tests was discriminant for pulmonary thromboembolism diagnosis, although the small sample size was limiting. Clinical Significance CT pulmonary angiography can be successfully performed in dogs under sedation, even in at-risk patients with respiratory distress and can both confirm and rule out pulmonary thromboembolism in dogs. PMID:24521253

  7. Undersampled projection reconstruction applied to MR angiography.

    PubMed

    Peters, D C; Korosec, F R; Grist, T M; Block, W F; Holden, J E; Vigen, K K; Mistretta, C A

    2000-01-01

    Undersampled projection reconstruction (PR) is investigated as an alternative method for MRA (MR angiography). In conventional 3D Fourier transform (FT) MRA, resolution in the phase-encoding direction is proportional to acquisition time. Since the PR resolution in all directions is determined by the readout resolution, independent of the number of projections (Np), high resolution can be generated rapidly. However, artifacts increase for reduced Np. In X-ray CT, undersampling artifacts from bright objects like bone can dominate other tissue. In MRA, where bright, contrast-filled vessels dominate, artifacts are often acceptable and the greater resolution per unit time provided by undersampled PR can be realized. The resolution increase is limited by SNR reduction associated with reduced voxel size. The hybrid 3D sequence acquires fractional echo projections in the k(x)-k(y) plane and phase encodings in k(z). PR resolution and artifact characteristics are demonstrated in a phantom and in contrast-enhanced volunteer studies. PMID:10642735

  8. 99mTc-Macroaggregated Albumin SPECT/CT Perfusion Imaging of Omental Extrahepatic Vascularization.

    PubMed

    Nguyen, Ba D; Yang, Ming; Roarke, Michael C

    2016-01-01

    The authors present a case of omental perfusion by an extrahepatic branch of the right hepatic artery depicted during pre-embolization planning with 99mTc-macroaggregated albumin SPECT/CT imaging. This omental scintigraphic finding corresponds to an extrahepatic branch of the right hepatic artery demonstrated by selective angiography and related CT angiography. The authors would like to add the omentum to the previously reported sites of extrahepatic vascularization encountered during the hepatic pre-embolization imaging. PMID:26650883

  9. Pulmonary Bone Cement Embolism: CT Angiographic Evaluation with Material Decomposition Using Gemstone Spectral Imaging

    PubMed Central

    Huh, Sun

    2014-01-01

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition. PMID:25053903

  10. Pulmonary bone cement embolism: CT angiographic evaluation with material decomposition using gemstone spectral imaging.

    PubMed

    Huh, Sun; Lee, Heon

    2014-01-01

    We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition. PMID:25053903

  11. Intracranial vascular malformations: MR and CT imaging

    SciTech Connect

    Kucharczyk, W.; Lemme-Pleghos, L.; Uske, A.; Brant-Zawadzki, M.; Dooms, G.; Norman, D.

    1985-08-01

    Twenty-four patients with 29 cerebrovascular malformations were evaluated with a combination of computed tomography (CT), angiography, and magnetic resonance (MR) imaging. Characteristics of the malformations on MR images were reviewed retrospectively, and a comparative evaluation of MR and CT images was made. Of 14 angiographically evident malformations, 13 intra-axial lesions were detected on both CT and MR images, and one dural malformation gave false-negative results on both modalities. The appearance of parenchymal lesions on MR images closely mirrored characteristic CT findings. Angiographically evident malformations have a highly characteristic appearance on MR images. MR may be more sensitive than CT in the detection of small hemorrhagic foci associated with cryptic arteriovenous malformations and may add specificity in the diagnosis of occult malformations in some cases, but MR is less sensitive than CT for the detection of small calcified malformations.

  12. [Multislice computerized tomography coronary angiography: general principles, technique and clinical applications].

    PubMed

    Karabulut, Nevzat

    2008-07-01

    Electrocardiogram-gated coronary multislice computerized tomography (CT) angiography is a rapidly improving technology allowing noninvasive imaging of coronary arteries. After the initial promising results obtained with four-section CT scanners, progressively higher temporal and spatial resolutions have been achieved by increasing gantry rotation speed and the number of detector rows and by reducing individual detector size. This review presents an overview of the general principles, technique and emerging applications and artifacts of coronary multislice CT angiography. The diagnostic performance of this new technology allows it to be used to evaluate the presence of coronary plaques and stenosis, coronary bypass graft patency, and the origin and course of congenital coronary anomalies. As it visualizes coronary artery wall in addition to lumen and provides volumetric data of heart and great vessels, it readily demonstrates plaque remodeling, ostial lesions and other cardiac and extracardiac abnormalities. The high negative predictive value of coronary CT angiography makes it a valuable tool in the evaluation of patients with low or intermediate pretest probability for coronary artery disease. However, improvements in spatial and temporal resolution are still needed in the imaging of small coronary stents, in the detection and characterization of noncalcified plaques, and to overcome image degradation by arrhythmias, higher heart rates, and calcium-related artifacts. PMID:18611837

  13. Physiologic evaluation of ischemia using cardiac CT: current status of CT myocardial perfusion and CT fractional flow reserve.

    PubMed

    Choi, Andrew D; Joly, Joanna M; Chen, Marcus Y; Weigold, Wm Guy

    2014-01-01

    Cardiac CT, specifically coronary CT angiography (CTA), is an established technology which detects anatomically significant coronary artery disease with a high sensitivity and negative predictive value compared with invasive coronary angiography. However, the limited ability of CTA to determine the physiologic significance of intermediate coronary stenoses remains a shortcoming compared with other noninvasive methods such as single-photon emission CT, stress echocardiography, and stress cardiac magnetic resonance. Two methods have been investigated recently: (1) myocardial CT perfusion and (2) fractional flow reserve (FFR) computed from CT (FFRCT). Improving diagnostic accuracy by combining the anatomic aspects of coronary CTA with a physiologic assessment via CT perfusion or FFRCT may reduce the need for additional testing to evaluate for ischemia, reduce downstream costs and risks associated with an invasive procedure, and lead to improved patient outcomes. Given a rapidly expanding body of research in this field, this comparative review summarizes the present literature while contrasting the benefits, limitations, and future directions in myocardial CT perfusion and FFRCT imaging. PMID:25151919

  14. CT and angiography of primary extradural juxtasellar tumors

    SciTech Connect

    Moore, T.; Ganti, S.R.; Mawad, M.E.; Hilal, S.K.

    1985-09-01

    The computed tomographic and angiographic features of 15 histologically proven primary extradural juxtasellar tumors were retrospectively reviewed. Five chordomas were characterized by prominent bone erosion and a significant posterior fossa component. Four trigeminal nerve neuromas each demonstrated bone erosion centered about Meckel's cave and moderate to marked contrast enhancement. Two cavernous sinus meningiomas revealed moderate contrast enhancement, expansion of the cavernous sinus, and moderate angiographic stain. Two cavernous hemangiomas of the cavernous sinus were intensely enhancing and demonstrated angiographic stain. Opacification of the sphenoid sinus with prominent bone destruction and lack of contrast enhancement was characteristic of a sphenoid sinus mucocele. The dural reflection could be directly visualized or indirectly inferred in each case.

  15. Image reconstruction and image quality evaluation for a 64-slice CT scanner with z-flying focal spot.

    PubMed

    Flohr, T G; Stierstorfer, K; Ulzheimer, S; Bruder, H; Primak, A N; McCollough, C H

    2005-08-01

    We present a theoretical overview and a performance evaluation of a novel z-sampling technique for multidetector row CT (MDCT), relying on a periodic motion of the focal spot in the longitudinal direction (z-flying focal spot) to double the number of simultaneously acquired slices. The z-flying focal spot technique has been implemented in a recently introduced MDCT scanner. Using 32 x 0.6 mm collimation, this scanner acquires 64 overlapping 0.6 mm slices per rotation in its spiral (helical) mode of operation, with the goal of improved longitudinal resolution and reduction of spiral artifacts. The longitudinal sampling distance at isocenter is 0.3 mm. We discuss in detail the impact of the z-flying focal spot technique on image reconstruction. We present measurements of spiral slice sensitivity profiles (SSPs) and of longitudinal resolution, both in the isocenter and off-center. We evaluate the pitch dependence of the image noise measured in a centered 20 cm water phantom. To investigate spiral image quality we present images of an anthropomorphic thorax phantom and patient scans. The full width at half maximum (FWHM) of the spiral SSPs shows only minor variations as a function of the pitch, measured values differ by less than 0.15 mm from the nominal values 0.6, 0.75, 1, 1.5, and 2 mm. The measured FWHM of the smallest slice ranges between 0.66 and 0.68 mm at isocenter, except for pitch 0.55 (0.72 mm). In a centered z-resolution phantom, bar patterns up to 15 lp/cm can be visualized independent of the pitch, corresponding to 0.33 mm longitudinal resolution. 100 mm off-center, bar patterns up to 14 lp/cm are visible, corresponding to an object size of 0.36 mm that can be resolved in the z direction. Image noise for constant effective mAs is almost independent of the pitch. Measured values show a variation of less than 7% as a function of the pitch, which demonstrates correct utilization of the applied radiation dose at any pitch. The product of image noise and

  16. Image reconstruction and image quality evaluation for a 64-slice CT scanner with z-flying focal spot

    SciTech Connect

    Flohr, T.G.; Stierstorfer, K.; Ulzheimer, S.; Bruder, H.; Primak, A.N.; McCollough, C.H.

    2005-08-15

    We present a theoretical overview and a performance evaluation of a novel z-sampling technique for multidetector row CT (MDCT), relying on a periodic motion of the focal spot in the longitudinal direction (z-flying focal spot) to double the number of simultaneously acquired slices. The z-flying focal spot technique has been implemented in a recently introduced MDCT scanner. Using 32x0.6 mm collimation, this scanner acquires 64 overlapping 0.6 mm slices per rotation in its spiral (helical) mode of operation, with the goal of improved longitudinal resolution and reduction of spiral artifacts. The longitudinal sampling distance at isocenter is 0.3 mm. We discuss in detail the impact of the z-flying focal spot technique on image reconstruction. We present measurements of spiral slice sensitivity profiles (SSPs) and of longitudinal resolution, both in the isocenter and off-center. We evaluate the pitch dependence of the image noise measured in a centered 20 cm water phantom. To investigate spiral image quality we present images of an anthropomorphic thorax phantom and patient scans. The full width at half maximum (FWHM) of the spiral SSPs shows only minor variations as a function of the pitch, measured values differ by less than 0.15 mm from the nominal values 0.6, 0.75, 1, 1.5, and 2 mm. The measured FWHM of the smallest slice ranges between 0.66 and 0.68 mm at isocenter, except for pitch 0.55 (0.72 mm). In a centered z-resolution phantom, bar patterns up to 15 lp/cm can be visualized independent of the pitch, corresponding to 0.33 mm longitudinal resolution. 100 mm off-center, bar patterns up to 14 lp/cm are visible, corresponding to an object size of 0.36 mm that can be resolved in the z direction. Image noise for constant effective mAs is almost independent of the pitch. Measured values show a variation of less than 7% as a function of the pitch, which demonstrates correct utilization of the applied radiation dose at any pitch. The product of image noise and square

  17. CT -- Body

    MedlinePlus

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

  18. Transient Global Amnesia After Cerebral Angiography With Iomeprol

    PubMed Central

    Tiu, Cristina; Terecoasă, Elena Oana; Grecu, Nicolae; Dorobăţ, Bogdan; Marinescu, Andreea Nicoleta; Băjenaru, Ovidiu Alexandru

    2016-01-01

    Abstract Transient global amnesia is now considered a very rare complication of cerebral angiography. Various etiological mechanisms have been suggested to account for this complication, but no consensus has been reached yet. This case report documents one of the few reported cases of cerebral angiography-related transient global amnesia associated with magnetic resonance imaging (MRI) evidence of unilateral hippocampal ischemia, most probably as a consequence of a transient reduction in regional hippocampal blood flow. However, the possibility of a direct neurotoxic effect of the nonionic contrast media Iomeprol on the Cornu ammonis – field 1 neurons cannot be firmly ruled out. We describe the case of a 54-year-old woman admitted to our department for left upper limb weakness with acute onset 8 days before. The brain computed tomography (CT) scan performed at admission revealed subacute ischemic lesions in the right watershed superficial territories and a right thalamic lacunar infarct. Diagnostic digital subtraction cerebral angiography was performed 4 days after admission with the nonionic contrast media Iomeprol. A few minutes after completion of the procedure, the patient developed symptoms suggestive for transient global amnesia. The brain MRI performed 22 hours after the onset of symptoms demonstrated increased signal within the lateral part of the right hippocampus on the diffusion-weighted imaging (DWI) sequences, associated with a corresponding reduction in the apparent diffusion coefficient (ADC) and increased signal on the fluid-attenuated inversion recovery (FLAIR) sequences, consistent with acute hippocampal ischemia and several T2/FLAIR hyperintensities in the right watershed superficial territories and in the right thalamus, corresponding to the lesions already identified on the CT scan performed at admission. A follow-up MRI, performed 2 months later, demonstrated the disappearance of the increased signal within the right hippocampus on the DWI

  19. Computed tomography angiography in acute stroke (revisiting the 4Ps of imaging).

    PubMed

    Varadharajan, Shriram; Saini, Jitender; Acharya, Ullas V; Gupta, Arun Kumar

    2016-02-01

    Imaging in acute stroke has traditionally focussed on the 4Ps-parenchyma, pipes, perfusion, and penumbra-and has increasingly relied upon advanced techniques including magnetic resonance imaging to evaluate such patients. However, as per European Magnetic Resonance Forum estimates, the availability of magnetic resonance imaging scanners for the general population in India (0.5 per million inhabitants) is quite low as compared to Europe (11 per million) and United States (35 per million), with most of them only present in urban cities. On the other hand, computed tomography (CT) is more widely available and has reduced scanning duration. Computed tomography angiography of cervical and intracranial vessels is relatively simpler to perform with extended coverage and can provide all pertinent information required in such patients. This imaging review will discuss relevant imaging findings on CT angiography in patients with acute ischemic stroke through illustrated cases. PMID:26614583

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

    PubMed

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

    2016-07-01

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

  1. Cognitive function in patients undergoing coronary angiography

    PubMed Central

    Devapalasundarum, A N; Silbert, B S; Evered, L A; Scott, D A; MacIsaac, A I; Maruff, P T

    2010-01-01

    Objective To measure cognition in patients before and after coronary angiography. Design Prospective observational cohort study. Setting University teaching hospital. Patients 56 patients presenting for elective coronary angiography. Main outcome measures Computerised cognitive test battery administered before coronary angiography, before discharge from hospital and 7 days after discharge. A matched healthy control group was used as a comparator. Results When analysed by group, coronary angiography patients performed worse than matched controls at each time point. When the cognitive change was examined for each individual, of the 48 patients tested at discharge, 19 (39.6%) were classified as having a new cognitive dysfunction, and of 49 patients tested at day 7, six (12.2%) were classified as having a new cognitive dysfunction. Conclusions The results confirm that cognitive function is decreased in patients who have cardiovascular disease. Furthermore, coronary angiography may exacerbate this impaired cognition in some patients.

  2. Impact of Cardiac Service Availability on Case-Selection for Angiography and Survival Associated with Angiography

    PubMed Central

    Dendukuri, Nandini; Normand, Sharon-Lise T; McNeil, Barbara J

    2003-01-01

    Objective To examine whether availability of cardiac services at the admitting hospital affects case-selection for angiography and one-year survival following angiography, within groups of patients who have similar clinical need for angiography according to published criteria. Study Setting Elderly Medicare beneficiaries (37,788) discharged with a diagnosis of acute myocardial infarction (AMI) from hospitals in seven U.S. states between February 1994 and July 1995. We focused on patients who were eligible to receive angiography 12 or more hours after symptom onset. Data Collection Data were abstracted from patient's medical records, Medicare National Claims Standard Analytic Files, Health Care Financing Administration (HCFA) Provider of Service File and Health Insurance Master File. Methods Admitting hospitals were classified as offering no cardiac services, angiography only, or revascularization. Case-selection differences across these three types of hospitals were examined by comparing relative risk of receiving angiography for various patient and hospital characteristics. Relative differences in one-year survival rate, comparing patients who received angiography to those who did not, were estimated within each hospital type and clinical need category (necessary, appropriate, or uncertain) after matching on propensity to receive angiography. Principal Findings Compared to patients for whom angiography was deemed necessary, the relative risk of receiving angiography among those for whom it was deemed of uncertain benefit was 0.58, 0.79, and 0.92 (p-value of homogeneity test < 0.001) at hospitals offering no cardiac services, angiography only, and revascularization, respectively. There was no significant difference in survival following angiography across hospital types, overall as well as within clinical need categories. Conclusions Despite increased case selection at hospitals with on-site cardiac services, there was no evidence of increase in the survival rate

  3. Advanced digital subtraction angiography and MR fusion imaging protocol applied to accurate placement of flow diverter device.

    PubMed

    Faragò, Giuseppe; Caldiera, Valentina; Tempra, Giovanni; Ciceri, Elisa

    2016-02-01

    In recent years there has been a progressive increase in interventional neuroradiology procedures, partially due to improvements in devices, but also to the simultaneous development of technologies and radiological images. Cone beam CT (Dyna-CT; Siemens) is a method recently used to obtain pseudo CT images from digital subtraction angiography (DSA) with a flat panel detector. Using dedicated software, it is then possible to merge Dyna-CT images with images from a different source. We report here the usefulness of advanced DSA techniques (Syngo-Dyna CT, three-dimensional DSA iPilot) for the treatment of an intracranial aneurysm with a flow diverter device. Merging MR and Dyna-CT images at the end of the procedure proved to be a simple and rapid additional method of verifying the success of the intervention. PMID:25589548

  4. Digital subtraction angiography of the heart and lungs

    SciTech Connect

    Moodie, D.S.; Yiannikas, J.

    1986-01-01

    This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions.

  5. CT Scans

    MedlinePlus

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  6. [Nursing care in fluorescein angiography].

    PubMed

    Santos-Blanco, Feliciano

    2008-01-01

    Fluoresceinic angiography of the ocular fundus is a diagnostic technique to study retinal and choroidal circulation. This technique consists of parenteral administration of 500 mg of sodium fluorescein 10% and photographing the fluorescence in the eye vessels. Although this substance is fairly safe, it may also produce mild, moderate or severe local and/or general adverse reactions. The nursing process is routinely used in hospital units but not always in outpatient clinics, even through the use of invasive procedures with intravenous medication administration is common. Therefore, nurses, as those reponsible for intravenous administration, should use the nursing process to guarantee the quality of care required by the patient. To do this, we describe an individualized care plan based on evaluation by Marjorie Gordon's functional health patterns, NANDA's nursing diagnoses Taxonomy II, Nursing Outcomes Classification (NOC), Nursing Interventions Classifications (NIC) and potential complications of the procedure. PMID:18579067

  7. "Geyser" leakage on fluorescein angiography.

    PubMed

    Levy, Jaime; Fagan, Xavier J; Lifshitz, Tova; Schneck, Marina

    2013-01-01

    An 82-year-old patient with diabetes was followed up due to moderate nonproliferative diabetic retinopathy with macular edema in the right eye. Visual acuity was 6/36. Focal macular laser was conducted (A). Three years later, the patient presented with blurry vision in the right eye. Visual acuity was 3/60. Vitreous hemorrhage was observed (B), and neovascularization of the disc was suspected (C). Fluorescein angiography (D, mid venous phase; E-F, recirculation phase) confirmed neovascularization of the disc and depicted a striking vertical leakage. Panretinal photocoagulation was started. Possible explanations for the "geyser" leakage may be either a partial posterior vitreous detachment allowing the fluorescein to track upwards but not elsewhere or a pocket of syneretic vitreous allowing the fluorescein passage in which to diffuse, much like the passage the blood would have taken. PMID:24548789

  8. Ultra-low dose comprehensive cardiac CT imaging in a patient with acute myocarditis.

    PubMed

    Tröbs, Monique; Brand, Michael; Achenbach, Stephan; Marwan, Mohamed

    2014-01-01

    The ability of contrast-enhanced CT to detect "late enhancement" in a fashion similar to magnetic resonance imaging has been previously reported. We report a case of acute myocarditis with coronary CT angiography as well as "late enhancement" imaging with ultra-low effective radiation dose. PMID:25439792

  9. In vitro dose measurements in a human cadaver with abdomen/pelvis CT scans

    PubMed Central

    Zhang, Da; Padole, Atul; Li, Xinhua; Singh, Sarabjeet; Khawaja, Ranish Deedar Ali; Lira, Diego; Liu, Tianyu; Shi, Jim Q.; Otrakji, Alexi; Kalra, Mannudeep K.; Xu, X. George; Liu, Bob

    2014-01-01

    Purpose: To present a study of radiation dose measurements with a human cadaver scanned on a clinical CT scanner. Methods: Multiple point dose measurements were obtained with high-accuracy Thimble ionization chambers placed inside the stomach, liver, paravertebral gutter, ascending colon, left kidney, and urinary bladder of a human cadaver (183 cm in height and 67.5 kg in weight) whose abdomen/pelvis region was scanned repeatedly with a multidetector row CT. The flat energy response and precision of the dosimeters were verified, and the slight differences in each dosimeter's response were evaluated and corrected to attain high accuracy. In addition, skin doses were measured for radiosensitive organs outside the scanned region with OSL dosimeters: the right eye, thyroid, both nipples, and the right testicle. Three scan protocols were used, which shared most scan parameters but had different kVp and mA settings: 120-kVp automA, 120-kVp 300 mA, and 100-kVp 300 mA. For each protocol three repeated scans were performed. Results: The tube starting angle (TSA) was found to randomly vary around two major conditions, which caused large fluctuations in the repeated point dose measurements: for the 120-kVp 300 mA protocol this angle changed from approximately 110° to 290°, and caused 8% − 25% difference in the point dose measured at the stomach, liver, colon, and urinary bladder. When the fluctuations of the TSA were small (within 5°), the maximum coefficient of variance was approximately 3.3%. The soft tissue absorbed doses averaged from four locations near the center of the scanned region were 27.2 ± 3.3 and 16.5 ± 2.7 mGy for the 120 and 100-kVp fixed-mA scans, respectively. These values were consistent with the corresponding size specific dose estimates within 4%. The comparison of the per-100-mAs tissue doses from the three protocols revealed that: (1) dose levels at nonsuperficial locations in the TCM scans could not be accurately deduced by simply scaling the

  10. In vitro dose measurements in a human cadaver with abdomen/pelvis CT scans

    SciTech Connect

    Zhang, Da; Padole, Atul; Li, Xinhua; Singh, Sarabjeet; Khawaja, Ranish Deedar Ali; Lira, Diego; Shi, Jim Q.; Otrakji, Alexi; Kalra, Mannudeep K.; Liu, Bob; Liu, Tianyu; Xu, X. George

    2014-09-15

    Purpose: To present a study of radiation dose measurements with a human cadaver scanned on a clinical CT scanner. Methods: Multiple point dose measurements were obtained with high-accuracy Thimble ionization chambers placed inside the stomach, liver, paravertebral gutter, ascending colon, left kidney, and urinary bladder of a human cadaver (183 cm in height and 67.5 kg in weight) whose abdomen/pelvis region was scanned repeatedly with a multidetector row CT. The flat energy response and precision of the dosimeters were verified, and the slight differences in each dosimeter's response were evaluated and corrected to attain high accuracy. In addition, skin doses were measured for radiosensitive organs outside the scanned region with OSL dosimeters: the right eye, thyroid, both nipples, and the right testicle. Three scan protocols were used, which shared most scan parameters but had different kVp and mA settings: 120-kVp automA, 120-kVp 300 mA, and 100-kVp 300 mA. For each protocol three repeated scans were performed. Results: The tube starting angle (TSA) was found to randomly vary around two major conditions, which caused large fluctuations in the repeated point dose measurements: for the 120-kVp 300 mA protocol this angle changed from approximately 110° to 290°, and caused 8% − 25% difference in the point dose measured at the stomach, liver, colon, and urinary bladder. When the fluctuations of the TSA were small (within 5°), the maximum coefficient of variance was approximately 3.3%. The soft tissue absorbed doses averaged from four locations near the center of the scanned region were 27.2 ± 3.3 and 16.5 ± 2.7 mGy for the 120 and 100-kVp fixed-mA scans, respectively. These values were consistent with the corresponding size specific dose estimates within 4%. The comparison of the per-100-mAs tissue doses from the three protocols revealed that: (1) dose levels at nonsuperficial locations in the TCM scans could not be accurately deduced by simply scaling the

  11. SPECT/CT and pulmonary embolism.

    PubMed

    Mortensen, Jann; Gutte, Henrik

    2014-05-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE. PMID:24213621

  12. New horizons in cardiac CT.

    PubMed

    den Harder, A M; Willemink, M J; de Jong, P A; Schilham, A M R; Rajiah, P; Takx, R A P; Leiner, T

    2016-08-01

    Until recently, cardiovascular computed tomography angiography (CCTA) was associated with considerable radiation doses. The introduction of tube current modulation and automatic tube potential selection as well as high-pitch prospective ECG-triggering and iterative reconstruction offer the ability to decrease dose with approximately one order of magnitude, often to sub-millisievert dose levels. In parallel, advancements in computational technology have enabled the measurement of fractional flow reserve (FFR) from CCTA data (FFRCT). This technique shows potential to replace invasively measured FFR to select patients in need of coronary intervention. Furthermore, developments in scanner hardware have led to the introduction of dual-energy and photon-counting CT, which offer the possibility of material decomposition imaging. Dual-energy CT reduces beam hardening, which enables CCTA in patients with a high calcium burden and more robust myocardial CT perfusion imaging. Future-generation CT systems will be capable of counting individual X-ray photons. Photon-counting CT is promising and may result in a substantial further radiation dose reduction, vastly increased spatial resolution, and the introduction of a whole new class of contrast agents. PMID:26932775

  13. CT of acute abdominal aortic disorders.

    PubMed

    Bhalla, Sanjeev; Menias, Christine O; Heiken, Jay P

    2003-11-01

    Aortic aneurysm rupture, aortic dissection, PAU, acute aortic occlusion, traumatic aortic injury, and aortic fistula represent acute abdominal aortic conditions. Because of its speed and proximity to the emergency department, helical CT is the imaging test of choice for these conditions. MR imaging also plays an important role in the imaging of aortic dissection and PAU, particularly when the patient is unable to receive intravenous contrast material. In this era of MDCT, conventional angiography is used as a secondary diagnostic tool to clarify equivocal findings on cross-sectional imaging. Ultrasound is helpful when CT is not readily available and the patient is unable or too unstable to undergo MR imaging. PMID:14661663

  14. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    MedlinePlus Videos and Cool Tools

    ... talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is a noninvasive ... possibility that you’re pregnant tell your doctor as well. On the day of your exam, it’s ...

  15. CT of thrombosed arteriovenous malformations in children

    SciTech Connect

    Mitnick, J.S.; Pinto, R.S.; Lin, J.P.; Rose, H.; Lieberman, A.

    1984-02-01

    Thrombosed arteriovenous malformations (AVMs) in children are rare lesions that may present with headaches or a seizure disorder. Thirteen patients (4 months to 21 years of age) with this lesion were examined with computed tomography (CT). In 11 patients surgical confirmation was obtained, and the other two patients were examined with follow-up CT scans. Angiography either showed an avascular mass (7/13) or was negative (6/13). CT showed a lobulated lesion (8/13), peripheral location (11/13), and minimal surrounding edema (8/13). All of the lesions were hyperdense prior to the administration of contrast material and all enhanced either slightly or not at all following contrast material administration. It is concluded that these characteristic CT features aid in making the diagnosis of thrombosed AVM. The major differential diagnosis is small intracerebral neoplasm.

  16. Giant coronary aneurysm caused by Kawasaki disease: consistency between catheter angiography and electrocardiogram gated dual-source computed tomography angiography.

    PubMed

    Hwang, Eun-Ha; Ju, Jung-Ki; Cho, Min-Jung; Lee, Ji-Won; Lee, Hyoung-Doo

    2015-12-01

    We present the case of a 5-year-old child with coronary complications due to Kawasaki disease; this patient unintentionally underwent both dual-source computed tomography (DSCT) coronary angiography and invasive coronary angiographic examination in 2 months. This case highlights the strong consistency of the results between DSCT coronary angiography and invasive coronary angiography. Compared to conventional invasive coronary angiography, DSCT coronary angiography offered additional advantages such as minimal invasiveness and less radiation exposure. PMID:26770226

  17. Coronary angiography in rats using synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Matsushita, S.; Hyodo, K.; Akishima, S.; Sato, F.; Imazuru, T.; Noma, M.; Hiramatsu, Y.; Shigeta, O.; Sakakibara, Y.

    2005-08-01

    Monochromatic X-rays obtained from synchrotron radiation (SR), provide a high-quality tool for medical imaging including, coronary angiography. To pursue higher resolution in experimental coronary angiography, a smaller visual field had seemed to be inevitable. However, there are cases in which whole coronary angiography is preferable in order to investigate such vasomotor activities as coronary vasospasm. To meet these requirements, we are trying to develop a new type of SR coronary angiography using Langendorff excised rat hearts. Experiments were performed at Photon Factory Accelerator Ring (PF-AR), High Energy Accelerator Research Organization (KEK), Japan. SR was obtained from a 6.5 GeV electron beam. The energy of the monochromatic X-rays was 33.3 keV, which is just above the K-edge energy of iodine. Iodine (35%) was infused as a contrast material to the aorta at the rate of 1 ml/min for 1 s. In the image obtained from coronary angiography, the resolution was 13 μm and the width of the visual field 26 mm×26 mm. Whole heart coronary vasculature identifying small arteries down to those 100 μm in diameter was obtained in beating hearts. Arteries as small as 50 μm were identified in arrested hearts. This method of SR coronary angiography is useful for the investigation of whole coronary configurations simultaneously in one visual field to the level of microvasculature.

  18. Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children

    PubMed Central

    Chakravarthy, Murali; Sunilkumar, Gubbihalli; Pargaonkar, Sumant; Hosur, Rajathadri; Harivelam, Chidananda; Kavaraganahalli, Deepak; Srinivasan, Pradeep

    2015-01-01

    Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the “apnea group” were compared with those in “nonapnea group.” After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored. Results: We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann–Whitney U, Fischer's exact test and Pearson's Chi-square test). In the induced apnea group, overall image quality was considered excellent in 89% (n = 33) of the studies, while in the “no apnea group,” only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%). In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in

  19. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial ... or other growth (mass) Cerebral atrophy (loss of brain tissue) ... with the hearing nerve Stroke or transient ischemic attack (TIA)

  20. Preoperative Identification of a Perforator Using Computed Tomography Angiography and Metal Clip Marking in Perforator Flap Reconstruction

    PubMed Central

    Lee, Jung Woo; Kim, Han Kyeol; Kim, Sin Rak; Han, Yea Sik

    2015-01-01

    In perforator flap reconstruction, vascular mapping using preoperative computed tomography (CT) angiography is widely used to confirm the existence and location of an appropriate perforator. This study proposes a rapid, accurate, and convenient method for marking the perforator location on the skin surface. For 12 patients who underwent perforator flap reconstruction between November 2011 and November 2013, metal clips were fixed on the skin surface at the anticipated perforator locations, which were decided using a handheld Doppler. CT angiography was used to compare the location between the metal clip and the actual perforator. The metal clip was moved and repositioned, if needed, on the basis of the CT images. The locations of the appropriate perforator and the metal clip, which were observed during the surgery, were then compared. In CT angiography, the mean distance between the metal clip and the perforator was 3±3.9 mm, and the mean distance that was measured during surgery was 0.8±0.8 mm. In conclusion, we report a simple, rapid, and precise technique to indicate the accurate location of the appropriate perforator on the skin surface. PMID:25606494

  1. Modern Perforator Flap Imaging with High-Resolution Blood Pool MR Angiography.

    PubMed

    Kagen, Alexander C; Hossain, Rydhwana; Dayan, Erez; Maddula, Soumya; Samson, William; Dayan, Joseph; Smith, Mark L

    2015-01-01

    Advances in microsurgical techniques have improved autologous reconstructions by providing new donor site options while decreasing donor site morbidity. Various preoperative imaging modalities have been studied to assess the relevant vascular anatomic structures, with magnetic resonance (MR) angiography traditionally lagging behind computed tomography (CT) with respect to spatial resolution. Blood pool MR angiography with gadofosveset trisodium, a gadolinium-based contrast agent with extended intravascular retention, has allowed longer multiplanar acquisitions with resultant voxel sizes similar to or smaller than those of CT and with improved signal-to-noise ratio and soft-tissue contrast while maintaining the ability to depict flow with time-resolved imaging. The resultant vascular detail enables precise evaluation of the relevant vascular anatomic structures, including the vessel course, size, and branching pattern, as well as the venous arborization pattern. In addition, any architectural distortion, vessel alteration, or injury from prior surgery can be depicted. The reporting radiologist should be aware of pertinent and incidental findings relevant to the planned surgery and the patient's disease so that he or she can assist the microsurgeon in flap design as a member of the multidisciplinary team. Given the lack of ionizing radiation exposure in patients who often have an elevated body mass index, high-spatial-resolution blood pool MR angiography has become the imaging reference standard for the preoperative assessment of perforator flap vascular and soft-tissue morphology in our practice. PMID:25884098

  2. Three-dimensional coronary angiography

    NASA Astrophysics Data System (ADS)

    Suurmond, Rolf; Wink, Onno; Chen, James; Carroll, John

    2005-04-01

    Three-Dimensional Coronary Angiography (3D-CA) is a novel tool that allows clinicians to view and analyze coronary arteries in three-dimensional format. This will help to find accurate length estimates and to find the optimal viewing angles of a lesion based on the three-dimensional vessel orientation. Various advanced algorithms are incorporated in this 3D processing utility including 3D-RA calibration, ECG phase selection, 2D vessel extraction, and 3D vessel modeling into a utility with optimized workflow and ease-of-use features, which is fully integrated in the environment of the x-ray catheterization lab. After the 3D processing, the 3D vessels can be viewed and manipulated interactively inside the operating room. The TrueView map provides a quick overview of gantry angles with optimal visualization of a single or bifurcation lesion. Vessel length measurements can be performed without risk of underestimating a vessel segment due to foreshortening. Vessel cross sectional diameters can also be measured. Unlike traditional, projection-based quantitative coronary analysis, the additional process of catheter calibration is not needed for diameter measurements. Validation studies show a high reproducibility of the measurements, with little user dependency.

  3. Clinical value of coronary bypass graft evaluation with CT

    SciTech Connect

    Godwin, J.D.; Califf, R.M.; Korobkin, M.; Moore, A.V.; Breiman, R.S.; Kong, Y.

    1983-04-01

    Computed tomography (CT) has a reported accuracy of 45%-97% in assessment of patency of coronary artery bypass grafts. Dynamic CT was done in 26 patients (47 grafts) with recurrent cardiac symptoms after graft surgery. Although CT was 79% accurate (with selective angiography as the standard), the authors do not believe that it provides sufficient information for the assessment of symptomatic patients. Four patients had high-grade stenoses in their grafts, and 50% of patients had significant progression of atherosclerosis in their native coronary arteries. Neither of these conditions could be detected by CT. The clinical contribution of CT will probably be greatest for routine screening of asymptomatic patients soon after operation. Technical problems with CT scanning for graft patency are discussed.

  4. Korean Guidelines for the Appropriate Use of Cardiac CT

    PubMed Central

    Kim, Young Jin; Kim, Sung Mok; Kim, Jeong A; Yang, Dong Hyun; Hong, Yoo Jin

    2015-01-01

    The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease. PMID:25741189

  5. Visualization of the Spinal Artery by CT During Embolization for Pulmonary Artery Pseudoaneurysm

    PubMed Central

    Maki, Hiroyuki; Shimohira, Masashi; Hashizume, Takuya; Kawai, Tatsuya; Nakagawa, Motoo; Ozawa, Yoshiyuki; Sakurai, Keita; Shibamoto, Yuta

    2016-01-01

    Summary Background Spinal artery ischemia is a rare but serious complication of embolization for treatment of hemoptysis. When the spinal artery is visualized at angiography, embolization should not be performed. However, it has been reported that spinal artery feeders are not visible on angiography in patients with developing spinal infarction. Case Report A 70-year-old man with a history of pulmonary aspergillosis had hemoptysis and underwent contrast-enhanced CT, revealing a pulmonary artery pseudoaneurysm (PAP) in the left upper lobe. Systemic angiography from the fifth left intercostal artery showed the PAP at the distal site, but the access route to the PAP was very tortuous and long. Although the spinal branch could not be observed with that angiography, CT during angiography was performed, and it visualized the posterior spinal artery obviously. Thus, the artery distal and proximal to the PAP was then successfully coil-embolized from the pulmonary artery. Conclusions CT during angiography may be useful to confirm the presence of the spinal artery for treatment of hemoptysis by embolization.

  6. Could contrast-enhanced CT detect STEMI prior to electrocardiogram?

    PubMed

    Sabbagh, Chadi; Rahi, Mayda; Baz, Maria; Haddad, Fadi; Helwe, Omar; Aoun, Noel; Ibrahim, Tony; Abdo, Lynn

    2015-01-01

    We present here a case in which contrast-enhanced computed tomography (CT) was the first diagnostic tool to detect myocardial hypoperfusion in a patient with atypical symptoms and normal electrocardiogram (ECG) on admission. An ST-segment elevation was detected thereafter on a second ECG realized several minutes after CT with raised troponin levels. Percutaneous coronary intervention was performed after failure of thrombolysis and confirmed occlusion of the left anterior descending artery. Further studies are needed to evaluate the role of high-resolution contrast-enhanced CT with or without coronary angiography in the workup of suspected myocardial infarction in the setting of a normal ECG. PMID:25085282

  7. CT angiographic evaluation of perforators in the lower limb and their reconstructive implication

    PubMed Central

    Bhattacharya, Visweswar; Agrawal, Neeraj K.; Chaudhary, Gurab R.; Arvind, Srivastava; Bhattacharya, Siddharth

    2012-01-01

    Background: The perforator flaps evolved on the knowledge of the vascular tree from the main vascular trunk up to the subdermal plexus. Therefore, we thought that it's necessary to map the whole vascular arcade by CT angiography. The aim of this study is to evaluate the perforators and the whole vascular tree of the lower limb by peripheral CT angiography with 3D reconstruction and intraoperative evaluation. This study helps in designing flaps of different constituents based on the selected perforators. Materials and Methods: Twenty patients having lower limb defects were selected. CT angiography was done using a non-ionic iodinated contrast media injected through the antecubital vein. The lower limbs were imaged using volume rendering CT scan machine. Three dimensional reconstructions were made. The whole arterial tree, along with the perforators, were mapped. Findings of the audio-Doppler were correlated with the CT angiographic observations. Further these evaluations were confirmed by intraoperative findings. Results: The three dimensional CT angiographic reconstruction with bone and soft tissue provided advanced knowledge of this vascular network. It delineated the main vessel, the perforators, their caliber, distance from fixed bony landmarks and course up to the subdermal plexus. These findings were confirmed during dissection of the proposed flap. The perforators were mainly musculocutaneous in the proximal leg and septocutaneous distally. Conclusions: The vascular details visualized by this technique made advancement over the existing methods namely color Doppler, audio Doppler, two dimensional angiography etc. It improved the understanding of perforator flaps and their successful clinical application. PMID:23450763

  8. Full-field optical micro-angiography

    NASA Astrophysics Data System (ADS)

    Wang, Mingyi; Zeng, Yaguang; Liang, Xianjun; Lu, Xuanlong; Feng, Guanping; Han, Dingan; Yang, Guojian

    2014-02-01

    We present a detailed description of full-field optical micro-angiography on the basis of frequency-domain laser speckle imaging with intensity fluctuation modulation (LSI-IFM). The imaging approach works based on the instantaneous local intensity fluctuation realized via the combination of short exposure and low sampling rate of a camera and appropriate magnification of a microscope. In vivo experiments on mouse ear verify the theoretical description we made for the imaging mechanism and demonstrate the ability of LSI-IFM as optical micro-angiography. By introducing a fundus camera into LSI-IFM system, our approach has a potential application in label-free retina optical micro-angiography.

  9. Attenuation-based size metric for estimating organ dose to patients undergoing tube current modulated CT exams

    SciTech Connect

    Bostani, Maryam McMillan, Kyle; Lu, Peiyun; Kim, Hyun J.; Cagnon, Chris H.; McNitt-Gray, Michael F.; DeMarco, John J.

    2015-02-15

    Purpose: Task Group 204 introduced effective diameter (ED) as the patient size metric used to correlate size-specific-dose-estimates. However, this size metric fails to account for patient attenuation properties and has been suggested to be replaced by an attenuation-based size metric, water equivalent diameter (D{sub W}). The purpose of this study is to investigate different size metrics, effective diameter, and water equivalent diameter, in combination with regional descriptions of scanner output to establish the most appropriate size metric to be used as a predictor for organ dose in tube current modulated CT exams. Methods: 101 thoracic and 82 abdomen/pelvis scans from clinically indicated CT exams were collected retrospectively from a multidetector row CT (Sensation 64, Siemens Healthcare) with Institutional Review Board approval to generate voxelized patient models. Fully irradiated organs (lung and breasts in thoracic scans and liver, kidneys, and spleen in abdominal scans) were segmented and used as tally regions in Monte Carlo simulations for reporting organ dose. Along with image data, raw projection data were collected to obtain tube current information for simulating tube current modulation scans using Monte Carlo methods. Additionally, previously described patient size metrics [ED, D{sub W}, and approximated water equivalent diameter (D{sub Wa})] were calculated for each patient and reported in three different ways: a single value averaged over the entire scan, a single value averaged over the region of interest, and a single value from a location in the middle of the scan volume. Organ doses were normalized by an appropriate mAs weighted CTDI{sub vol} to reflect regional variation of tube current. Linear regression analysis was used to evaluate the correlations between normalized organ doses and each size metric. Results: For the abdominal organs, the correlations between normalized organ dose and size metric were overall slightly higher for all three

  10. Fluorescein and Indocyanine Green Angiography for Uveitis

    PubMed Central

    Herbort, Carl P

    2009-01-01

    In recent years enormous progress has been achieved in investigational procedures for uveitis. Imaging is one such example with the advent of new methods such as indocyanine green angiography, ultrasound biomicroscopy and optical coherence tomography to cite only the most important. This tremendous increase in precision and accuracy in the assessment of the level and degree of inflammation and its monitoring comes in parallel with the development of extremely potent and efficacious therapies. In view of these developments, our whole attitude in the appraisal and investigation of the uveitis patient has to be adapted and correctly reoriented integrating the recent developments and this is no different for ocular angiography. PMID:20404985

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

    PubMed Central

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

    2015-01-01

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

  12. Renal Artery Stenting Using CO2 Gas Angiography in Combination with Iodinated Contrast Angiography.

    PubMed

    Adachi, Yuya; Endo, Akihiro; Nakashima, Ryuma; Sugamori, Takashi; Takahashi, Nobuyuki; Kinoshita, Yoshihisa; Tanabe, Kazuaki

    2016-01-01

    A 76-year-old woman was hospitalized repeatedly due to unexplained heart failure. On admission, she had hypertensive acute heart failure. Her symptoms disappeared promptly after the initial treatment; however, her systolic blood pressure remained at over 160 mmHg despite her taking three antihypertensive drugs. Closer examination revealed hemodynamically significant right renal artery stenosis and a lack of left kidney function. We performed percutaneous transluminal renal angioplasty using CO2 angiography in combination with iodinated contrast agents. The patient's renal function and blood pressure improved, however, CO2 gas-induced mild ischemic colitis occurred. We discuss the possibility of the use of combined iodinated contrast angiography and CO2 angiography to avoid contrast-induced nephropathy and the complications peculiar to CO2 angiography. PMID:27580543

  13. CT scan

    MedlinePlus

    ... that slides into the center of the CT scanner. Once you are inside the scanner, the machine's x-ray beam rotates around you. Modern spiral scanners can perform the exam without stopping. A computer ...

  14. Computed Tomography Angiography of the Neurovascular Circulation.

    PubMed

    Mohan, Suyash; Agarwal, Mohit; Pukenas, Bryan

    2016-01-01

    Computed tomography angiography of the head and neck is a powerful tool for imaging and diagnosis of a plethora of disorders of the cervicocerebral vasculature. This article reviews the technique, indications, and interpretation of many of these disorders. A standard report checklist is also presented. PMID:26654397

  15. Optical Coherence Tomography Angiography in Healthy Subjects.

    PubMed

    Coscas, Gabriel; Lupidi, Marco; Coscas, Florence

    2016-01-01

    Fluorescein angiography and indocyanine green angiography provide information about normal retinal and choroidal anatomy that is nearly comparable to histological findings. These results are absolutely fundamental for the evaluation of retinal and choroidal vascular diseases and allow the clinician to define and diagnose several pathological conditions. Fluorescein angiography has become the 'gold standard' in retinal imaging due to its capacity to allow visualization of the retinal capillary bed and its changes, particularly in the macular area. Although the fluorescence of the injected dye enables improved visualization of retinal capillaries, not all of the different layers of the retinal capillary network can be visualized using this bi-dimensional examination technique, possibly because of a light scattering phenomenon. Optical coherence tomography angiography allows depth-resolved visualization of the retinal and choroidal microvasculature by calculating the difference between static and nonstatic tissue. Given that the main moving elements in the eye fundus are contained within vessels, determining a vascular decorrelation signal enables three-dimensional visualization of the retinal and choroidal vascular network without the administration of intravenous dye and therefore reduces the risk of potential adverse events. PMID:27023473

  16. Angiography contrast injector safety. Visualizing the marketplace.

    PubMed

    2010-06-01

    The most common risk associated with angiography contrast injectors is air embolism. Injector manufacturers have attempted to address this concern by adding air detection systems and other safety features. Find out which injectors do the best job of protecting patients. PMID:21309283

  17. An unusual complication of transradial coronary angiography.

    PubMed

    McEntegart, Margaret B; Dalzell, Jonathan R; Lindsay, M Mitchell

    2009-05-01

    We report the first case of extensive cellulitis and staphylococcal bacteremia with the subsequent development of a remote mycotic pseudoaneurysm in the ipsilateral brachial artery following right transradial coronary angiography in a diabetic patient with previous right axillary node clearance. The potential for serious complication should be borne in mind when deciding on the site of vascular access in such patients. PMID:19411734

  18. A case of acute subdural hematoma due to ruptured aneurysm detected by postmortem angiography.

    PubMed

    Inokuchi, Go; Makino, Yohsuke; Yajima, Daisuke; Motomura, Ayumi; Chiba, Fumiko; Torimitsu, Suguru; Hoshioka, Yumi; Iwase, Hirotaro

    2016-03-01

    Acute subdural hematoma (ASDH) is mostly caused by head trauma, but intrinsic causes also exist such as aneurysm rupture. We describe here a case involving a man in his 70s who was found lying on the bedroom floor by his family. CT performed at the hospital showed ASDH and a forensic autopsy was requested. Postmortem cerebral angiography showed dilatation of the bifurcation of the middle cerebral artery, which coincided with the dilated part of the Sylvian fissure. Extravasation of contrast medium into the subdural hematoma from this site was suggestive of a ruptured aneurysm. Autopsy revealed a fleshy hematoma (total weight 110 g) in the right subdural space and findings of brain herniation. As indicated on angiography, a ruptured saccular aneurysm was confirmed at the bifurcation of the middle cerebral artery. Obvious injuries to the head or face could not be detected on either external or internal examination, and intrinsic ASDH due to a ruptured middle cerebral artery aneurysm was determined as the cause of death. One of the key points of forensic diagnosis is the strict differentiation between intrinsic and extrinsic onset for conditions leading to death. Although most subdural hematomas (SDH) are caused by extrinsic factors, forensic pathologists should consider the possibility of intrinsic SDH. In addition, postmortem angiography can be useful for identifying vascular lesions in such cases. PMID:26362305

  19. Fatal right coronary artery rupture following blunt chest trauma: detection by postmortem selective coronary angiography.

    PubMed

    Inokuchi, Go; Makino, Yohsuke; Motomura, Ayumi; Chiba, Fumiko; Torimitsu, Suguru; Hoshioka, Yumi; Iwase, Hirotaro

    2016-05-01

    Coronary artery injury is a rare complication following blunt chest trauma (BCT), and can be fatal. Here we report findings on postmortem selective coronary angiography of right coronary artery rupture after an assault involving blunt trauma to the chest. A woman in her 60s died after her son stomped on her chest. There were no appreciable signs of injury on external examination, and cause of death could not be determined by postmortem computed tomography (PMCT). Internal findings indicated that an external force had been applied to the anterior chest, as evidenced by subcutaneous hemorrhage and pericardial and cardiac contusions. Postmortem coronary angiography revealed irregularity of the intima and of the fat tissue surrounding the proximal part of the right coronary artery associated with a local filling defect. Histopathological examination suggested coronary rupture with dissection of the tunica media and compression of the lumen cavity. The key points in the present case are that no fatal injuries could be determined on external examination, and the heart and coronary artery injuries were not evident on PMCT. Criminality might be overlooked in such cases, as external investigation at the crime scene would be inadequate and could result in a facile diagnosis of cause of death. This is the first report of coronary artery rupture with dissection that was detected by CT coronary angiography, and provides helpful findings for reaching an appropriate decision both forensically and clinically. PMID:26126482

  20. Usefulness of magnetic resonance angiography for the evaluation of varices at hepaticojejunostomy after liver transplantation

    PubMed Central

    Suzuki, Mitsuyoshi; Fujii, Tohru; Ohtsuka, Yoshikazu; Sugo, Hiroyuki; Kawasaki, Seiji; Shimizu, Toshiaki

    2015-01-01

    A 7-year-old Japanese girl who had undergone living-donor liver transplantation (LT) at the age of 10 months for decompensated liver cirrhosis caused by biliary atresia presented with recurrent episodes of obscure gastrointestinal bleeding (GIB) with anemia. Over the following 6 years, she experienced five episodes of GIB requiring hospitalization. Subsequent evaluations including repeat esophagogastroduodenoscopy (EGD), colonoscopy (CS), contrast-enhanced computed tomography (CT), and Meckel’s scan all failed to reveal a bleeding source. However, varices at the site of hepaticojejunostomy were detected on abdominal ultrasonography and magnetic resonance angiography (MRA) at the age of 7 years. MRA might be more helpful than contrast-enhanced CT for identifying such bleeding. PMID:26034644

  1. Normal Proximal Coronary Artery Diameters in Adults from India as Assessed by Computed Tomography Angiography

    PubMed Central

    Mahadevappa, Manjappa; Math, Ravi

    2016-01-01

    Introduction The normative data of coronary artery size among Indians are sparse. It is often essential to know the coronary dimensions especially during interventions such as stenting to choose the appropriate size of the stent and to decide the very need for stenting. In current practice it is the luminal angiography which is most widely employed to assess the coronary artery size. However, luminal angiography is not very accurate in estimating the epicardial coronary artery size as it does not take into account the mural thickness of the arterial wall. Hence it is prudent to assess coronary artery size by other methods such as Computed Tomography (CT) coronary angiography, quantitative coronary angiogram, Magnetic Resonanace (MR) angiogram, etc. In this study we chose computed tomography as it demonstrates mural thickness along with lumen of the vessels and hence measures the diameter more accurately. Aim To establish normative data for diameters of the proximal coronary artery segments during life by using MDCT in a cohort of individuals without any structural heart disease. Materials and Methods Between October 2012 and April 2013, 168 consecutive patients who did not have any structural heart disease underwent CT coronary angiography for evaluation of Coronary Artery Disease (CAD) with atypical symptoms with low pretest probability. Patients who were found to have no coronary artery disease on CT-CAG were recruited in this study. The baseline clinical status and demographic data were obtained from the hospital records. Results In our study we found that the mean indexed diameter to BSA among females for LMCA 2.32±0.12mm, LAD 1.95±0.15mm, LCX 1.73±0.20mm and RCA 1.84±0.22mm. For males the values were LMCA 2.33±0.13mm, LAD 1.94±0.16mm, LCX 1.74±0.21mm, and RCA 1.79±0.20mm. These values are comparable to other studies. Conclusion We attempted to establish normative data for normal proximal coronary artery dimensions among South Indian population

  2. Coronary angiography in Lebanon: Use and overuse.

    PubMed

    Sibai, Abla-Mehio; Tohme, Rania A; Saade, Georges A

    2008-04-25

    Coronary angiography remains the gold standard for coronary artery disease diagnosis. In Lebanon, the density of cardiac catheterization centers is almost three times that of France (9.32 vs. 2.92 per 1,000,000 individuals) and recently collated national data indicate notably a high utilization rate of 53 per 10,000 individuals, placing Lebanon third after the United States and Germany. PMID:17399809

  3. Tomosynthesis applied to digital subtraction angiography

    SciTech Connect

    Kruger, R.A.; Sedaghati, M.; Roy, D.G.; Liu, P.; Nelson, J.A.; Kubal, W.; Del Rio, P.

    1984-09-01

    This extension of the author's previous work on tomographic digital subtraction angiography (DSA) describes the theory of tomosynthetic DSA image reconstruction techniques. In addition to developing the resolution limits resulting from x-ray exposure length and image intensifier field curvature, the authors describe one method of image formation and show tomosynthetic DSA images of animal and human anatomy. Methods for improving the present technique are discussed.

  4. Principles of CT and CT technology.

    PubMed

    Goldman, Lee W

    2007-09-01

    This article provides a review of the basic principles of CT within the context of the evolution of CT. Modern CT technology can be understood as a natural progression of improvements and innovations in response to both engineering problems and clinical requirements. Detailed discussions of multislice CT, CT image quality evaluation, and radiation doses in CT will be presented in upcoming articles in this series. PMID:17823453

  5. Sources of error in quantitative coronary angiography.

    PubMed

    Herrington, D M; Siebes, M; Walford, G D

    1993-08-01

    Many studies have reported the accuracy of quantitative coronary angiography (QCA) based on experiments using moderated-size phantoms imaged under unrealistic radiographic conditions. However, these observations may not be generalizable to the setting of clinical angiography. To determine QCA accuracy in a realistic radiographic setting and evaluate the impact of the x-ray system line spread function, plexiglass phantoms were imaged inside and out of a human thorax. A realistic radiographic background was associated with a 38% increase in variability of results (p < 0.05). Low concentrations of contrast and large image intensifier input screens were associated with significantly larger errors and variability in results (p < 0.05). There was a systematic overestimation of diameter in the smallest phantom. A mathematical model of the x-ray line spread function was developed that explains the observed overestimation of the smallest phantom and provide a rational approach for correction of the line spread function for QCA. Many factors encountered in clinical coronary angiography such as nonuniform radiographic background, low concentrations of contrast, and small vessel diameters have a significant adverse impact on the accuracy and/or variability of gradient-based edge detection QCA systems. PMID:8221856

  6. Optical Coherence Tomography Angiography in Retinal Diseases

    PubMed Central

    Chalam, K. V.; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases. PMID:27195091

  7. Optical Coherence Tomography Angiography in Retinal Diseases.

    PubMed

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases. PMID:27195091

  8. Lumbosacral spine CT

    MedlinePlus

    Spinal CT; CT - lumbosacral spine ... In other cases, a CT of the lumbosacral spine may be done after injecting contrast dye into ... of the body. A CT of the lumbosacral spine can evaluate fractures and changes of the spine, ...

  9. Thoracic CT

    MedlinePlus

    ... table that slides into the center of the scanner. Once you are inside the scanner, the machine's x-ray beam rotates around you. ... than 300 pounds, have your doctor contact the scanner operator before the exam. CT scanners have a ...

  10. Chest pain: coronary CT in the ER.

    PubMed

    Maffei, Erica; Seitun, Sara; Guaricci, Andrea I; Cademartiri, Filippo

    2016-01-01

    Cardiac CT has developed into a robust clinical tool during the past 15 years. Of the fields in which the potential of cardiac CT has raised more interest is chest pain in acute settings. In fact, the possibility to exclude with high reliability obstructive coronary artery disease (CAD) in patients at low-to-intermediate risk is of great interest both from the clinical standpoint and from the management standpoint. Several other modalities, with or without imaging, have been used during the past decades in the settings of new onset chest pain or in acute chest pain for both diagnostic and prognostic assessment of CAD. Each one has advantages and disadvantages. Most imaging modalities also focus on inducible ischaemia to guide referral to invasive coronary angiography. The advent of cardiac CT has introduced a new practice diagnostic paradigm, being the most accurate non-invasive method for identification and exclusion of CAD. Furthermore, the detection of subclinical CAD and plaque imaging offer the opportunity to improve risk stratification. Moreover, recent advances of the latest generation CT scanners allow combining both anatomical and functional imaging by stress myocardial perfusion. The role of cardiac CT in acute settings is already important and will become progressively more important in the coming years. PMID:26866681

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

    SciTech Connect

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

    2011-02-15

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

  12. Noninvasive Physiologic Assessment of Coronary Stenoses Using Cardiac CT

    PubMed Central

    Fan, Zhanming

    2015-01-01

    Coronary CT angiography (CCTA) has become an important noninvasive imaging modality in the diagnosis of coronary artery disease (CAD). CCTA enables accurate evaluation of coronary artery stenosis. However, CCTA provides limited information on the physiological significance of stenotic lesions. A noninvasive “one-stop-shop” diagnostic test that can provide both anatomical significance and functional significance of stenotic lesions would be beneficial in the diagnosis and management of CAD. Recently, with the introduction of novel techniques, such as myocardial CT perfusion, CT-derived fractional flow reserve (FFRCT), and transluminal attenuation gradient (TAG), CCTA has emerged as a noninvasive method for the assessment of both anatomy of coronary lesions and its physiological consequences during a single study. This review provides an overview of the current status of new CT techniques for the physiologic assessments of CAD. PMID:25685790

  13. [CT fluoroscopy].

    PubMed

    Rogalla, P; Juran, R

    2004-07-01

    Percutaneous biopsy of pulmonary nodules requires precise needle placement, with the goal of attaining a secure position of the needle for therapeutic or diagnostic purposes as quickly as possible and with minimal tissue damage along the access route. The requirements from the image guidance system during the intervention are, in addition to universal applicability, a quick reaction time and a user-friendly interface. CT fluoroscopy fulfils these requirements, although radiation protection for the patient and radiologist becomes an important issue. PMID:15232690

  14. Comparison of coronary angiography-assisted and computed coronary tomography angiography-assisted recanalisation of coronary chronic total occlusion

    PubMed Central

    Zhang, Shuoyang; Gai, Luyue; Jin, Qinhua; Gai, Jingjing; He, Bin; Chen, Yundai

    2013-01-01

    Background Computed coronary tomography angiography (CCTA) provides an alternative to coronary angiography (CAG) and a complementary way of imaging. Objective To determine whether CT assistance might help increase the recanalisation rate of coronary chronic total occlusion (CTO). Method Two experienced physicians took part in the study—one specialised in both CCTA and percutaneous coronary intervention (PCI), and the other had PCI experience only and no knowledge of CCTA. Consecutive patients were enrolled if CTO was diagnosed by CAG or by CCTA. The images were analysed on a dedicated work station which examined the length and characteristics of the occlusion, the calibre of the artery, the best projection for precision guidewire penetration, the use of a side branch and calcification for landmarking and selection of most suitable guidewires. Patients underwent CAG-guided PCI or CCTA-assisted PCI. The main end point was the recanalisation rate. Secondary end points included the time for successful passage of the guidewire, fluoroscopy time, and contrast, guidewire and stent consumption. Results Thirty-six patients underwent CAG and 44 CCTA. The clinical characteristics and laboratory data of the two groups were similar (p>0.05). The patients in the CCTA group had more complex disease than those in the CAG group as shown by the J-CTO score (Multicenter CTO Registry of Japan) (p<0.05). Recanalisation was possible in 75.8% of the CAG group and 72.1% of the CCTA group. However, no statistical significance was found, p>0.05. In five of seven patients who had undergone unsuccessful PCI previously the procedure was successful at the second attempt when CCTA-assisted PCI was used. The patients were divided into those for whom the procedure was a failure or a success. The J-CTO score was an independent predictor of failure (OR=0.290, 95% CI 0.158 to 0.533). Conclusion CTO with favourable characteristics does not need CCTA guidance, but CCTA can be used to recanalise CTO

  15. Coronary Computed Tomography Angiography of Spontaneous Coronary Artery Dissection: A Case Report and Review of the Literature

    PubMed Central

    Torres-Ayala, Stephanie C.; Maldonado, Jose; Scott Bolton, J.; Bhalla, Sanjeev

    2015-01-01

    Patient: Male, 23 Final Diagnosis: Spontaneous coronary artery dissection Symptoms: Chest discomfort • chest pain Medication: — Clinical Procedure: Coronary computed tomography angiography Specialty: Radiology Objective: Rare disease Background: Multidetector computed tomography (MDCT) has gained wide acceptance in the evaluation of the cardiovascular system. Of particular clinical interest is its ability to non-invasively evaluate coronary arteries in patients presenting to the emergency room. In acute coronary syndromes, myocardial ischemia is most often caused by atherosclerosis. We present a case of a rare cause of acute coronary syndrome, spontaneous coronary artery dissection (SCAD), which was initially evaluated with MDCT and followed by intravascular ultrasound (IVUS) and invasive coronary angiography (ICA). We discuss the findings and role of each modality with particular attention to coronary computed tomographic angiography (CCTA) in the diagnosis and management of SCAD. As the use of CCTA in the emergency department continues to rise, radiologists must become familiar with CT appearance of SCAD. Case Report: We report the multidetector computed tomography (MDCT), intravascular ultrasound (IVUS), and invasive coronary angiography (ICA) findings in a case of spontaneous coronary artery dissection of the left anterior descending artery in a previously healthy 23-year-old man. The role of coronary computed tomographic angiography (CCTA) in diagnosis and management of this potentially life-threatening condition is discussed. Conclusions: In the clinical setting of acute coronary syndrome, SCAD must be a consideration, particularly in young patients without clear risk factors for coronary artery disease and in women in the peripartum period. CCTA is a very helpful diagnostic tool to diagnose the condition in a non-invasive manner and to follow up after treatment. PMID:25738889

  16. Transient Global Amnesia After Cerebral Angiography With Iomeprol: A Case Report.

    PubMed

    Tiu, Cristina; Terecoasă, Elena Oana; Grecu, Nicolae; Dorobăţ, Bogdan; Marinescu, Andreea Nicoleta; Băjenaru, Ovidiu Alexandru

    2016-05-01

    Transient global amnesia is now considered a very rare complication of cerebral angiography. Various etiological mechanisms have been suggested to account for this complication, but no consensus has been reached yet. This case report documents one of the few reported cases of cerebral angiography-related transient global amnesia associated with magnetic resonance imaging (MRI) evidence of unilateral hippocampal ischemia, most probably as a consequence of a transient reduction in regional hippocampal blood flow. However, the possibility of a direct neurotoxic effect of the nonionic contrast media Iomeprol on the Cornu ammonis - field 1 neurons cannot be firmly ruled out.We describe the case of a 54-year-old woman admitted to our department for left upper limb weakness with acute onset 8 days before. The brain computed tomography (CT) scan performed at admission revealed subacute ischemic lesions in the right watershed superficial territories and a right thalamic lacunar infarct. Diagnostic digital subtraction cerebral angiography was performed 4 days after admission with the nonionic contrast media Iomeprol. A few minutes after completion of the procedure, the patient developed symptoms suggestive for transient global amnesia. The brain MRI performed 22 hours after the onset of symptoms demonstrated increased signal within the lateral part of the right hippocampus on the diffusion-weighted imaging (DWI) sequences, associated with a corresponding reduction in the apparent diffusion coefficient (ADC) and increased signal on the fluid-attenuated inversion recovery (FLAIR) sequences, consistent with acute hippocampal ischemia and several T2/FLAIR hyperintensities in the right watershed superficial territories and in the right thalamus, corresponding to the lesions already identified on the CT scan performed at admission. A follow-up MRI, performed 2 months later, demonstrated the disappearance of the increased signal within the right hippocampus on the DWI, T2/FLAIR

  17. Diagnostic angiography of the cerebrospinal vasculature.

    PubMed

    Rabinov, James D; Leslie-Mazwi, Thabele M; Hirsch, Joshua A

    2016-01-01

    Diagnostic catheter angiography remains the gold standard for evaluation of vascular lesions of the brain, head and neck, and spine. It is often combined with cross-sectional and functional imaging to provide a complete anatomic and physiologic workup of patients. Such data are combined with clinical information to help make treatment decisions. This chapter describes the specific techniques for arterial access and catheter navigation of the cerebrospinal vasculature. Discussion of patient positioning, injection rates, and basic anatomy of arterial and venous systems is included. Finally, important safety issues related to contrast allergy, renal failure, and complications are considered. PMID:27432664

  18. Prostaglandin E1 in hand angiography

    SciTech Connect

    Levy, J.M.; Joseph, R.B.; Bodell, L.S.; Nykamp, P.W.; Hessel, S.J.

    1983-11-01

    Prostaglandin E1 (PG1) is a rapid, potent vasodilator which, when infused into the arterial system in low doses by bolus injection, has no significant systemic effects and has a relatively long duration of action. Sixty-three hand angiograms were done on 55 patients, comparing PGE1 to tolazoline and to angiograms done with no vasodilation. There was no significant difference between PGE1 and tolazoline in digital artery opacification; however, venous opacification was very significantly better with PGE1. PGE1 should be a drug of choice in hand angiography.

  19. Lateral rectus palsy following coronary angiography and percutaneous coronary intervention

    PubMed Central

    Nicholson, Luke; Jones, Ruth; Hughes, David S

    2014-01-01

    We present a rare case of unilateral lateral rectus palsy following an elective coronary angiography and percutaneous coronary intervention in a 78-year-oldwoman. Ophthalmoplegia following coronary angiography is extremely rare and this is the first case of a unilateral lateral rectus palsy following the procedure. PMID:24536054

  20. Radiation dose and physical image quality in 128-section dual-source computed tomographic coronary angiography: a phantom study.

    PubMed

    Matsubara, Kosuke; Koshida, Haruka; Sakuta, Keita; Takata, Tadanori; Horii, Junsei; Iida, Hiroji; Koshida, Kichiro; Ichikawa, Katsuhiro; Matsui, Osamu

    2012-01-01

    One-hundred-and-twenty-eight-section dual X-ray source computed tomography (CT) systems have been introduced into clinical practice and have been shown to increase temporal resolution. Higher temporal resolution allows low-dose spiral mode at a high pitch factor during CT coronary angiography. We evaluated radiation dose and physical image qualities in CT coronary angiography by applying high-pitch spiral, step-and-shoot, and low-pitch spiral modes to determine the optimal acquisition mode for clinical situations. An anthropomorphic phantom, small dosimeters, a calibration phantom, and a microdisc phantom were used to evaluate the radiation doses absorbed by thoracic organs, noise power spectrums, in-plane and z-axis modulation transfer functions, slice sensitivity profiles, and number of artifacts for the three acquisition modes. The high-pitch spiral mode had the advantage of a small absorbed radiation dose, but provided low image quality. The low-pitch spiral mode resulted in a high absorbed radiation dose of approximately 200 mGy for the heart. Although the absorbed radiation dose was lower in the step-and-shoot mode than in the low-pitch spiral mode, the noise power spectrum was inferior. The quality of the in-plane modulation transfer function differed, depending on spatial frequency. Therefore, the step-and-shoot mode should be applied initially because of its low absorbed radiation dose and superior image quality. PMID:22955662

  1. Motion analysis and removal in intensity variation based OCT angiography.

    PubMed

    Liu, Xuan; Kirby, Mitchell; Zhao, Feng

    2014-11-01

    In this work, we investigated how bulk motion degraded the quality of optical coherence tomography (OCT) angiography that was obtained through calculating interframe signal variation, i.e., interframe signal variation based optical coherence angiography (isvOCA). We demonstrated theoretically and experimentally that the spatial average of isvOCA signal had an explicit functional dependency on bulk motion. Our result suggested that the bulk motion could lead to an increased background in angiography image. Based on our motion analysis, we proposed to reduce image artifact induced by transient bulk motion in isvOCA through adaptive thresholding. The motion artifact reduced angiography was demonstrated in a 1.3μm spectral domain OCT system. We implemented signal processing using graphic processing unit for real-time imaging and conducted in vivo microvasculature imaging on human skin. Our results clearly showed that the adaptive thresholding method was highly effective in the motion artifact removal for OCT angiography. PMID:25426314

  2. Perfusion Angiography in Acute Ischemic Stroke.

    PubMed

    Scalzo, Fabien; Liebeskind, David S

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and T max, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  3. Carbon Dioxide Angiography: Scientific Principles and Practice

    PubMed Central

    Cho, Kyung Jae

    2015-01-01

    Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention. PMID:26509137

  4. Angiography with a multifunctional line scanning ophthalmoscope

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Ferguson, R. Daniel; Patel, Ankit H.; Vazquez, Vanessa; Husain, Deeba

    2012-02-01

    A multifunctional line scanning ophthalmoscope (mLSO) was designed, constructed, and tested on human subjects. The mLSO could sequentially acquire wide-field, confocal, near-infrared reflectance, fluorescein angiography (FA), and indocyanine green angiography (ICGA) retinal images. The system also included a retinal tracker (RT) and a photodynamic therapy laser treatment port. The mLSO was tested in a pilot clinical study on human subjects with and without retinal disease. The instrument exhibited robust retinal tracking and high-contrast line scanning imaging. The FA and ICGA angiograms showed a similar appearance of hyper- and hypo-pigmented disease features and a nearly equivalent resolution of fine capillaries compared to a commercial flood-illumination fundus imager. An mLSO-based platform will enable researchers and clinicians to image human and animal eyes with a variety of modalities and deliver therapeutic beams from a single automated interface. This approach has the potential to improve patient comfort and reduce imaging session times, allowing clinicians to better diagnose, plan, and conduct patient procedures with improved outcomes.

  5. Intraoperative fluorescence vascular angiography: during tibial bypass.

    PubMed

    Perry, Diana; Bharara, Manish; Armstrong, David G; Mills, Joseph

    2012-01-01

    Preventing amputations in persons with lower extremity complications of diabetes is a complex endeavor, particularly in those with concomitant ischemia and tissue loss. Fluorescence angiography (Novadaq SPY system) may provide a tool for objective evaluations of tissue viability in the diabetic foot, which is an important indicator of the ability of the diabetic ulcer to heal adequately. The SPY system uses a low-power laser coupled with a charge-coupled device camera and indocyanine green (ICG) to sequence perfusion at the surface of the skin. We present an illustrated example of the potential utility of ICG fluorescence angiography (ICGFA) before and after vascular intervention in a high-risk limb. ICGFA appeared to reveal demarcation between viable and nonviable tissue and real-time perfusion, specifically capillary fill. ICGFA clarified the extent of necessary debridement and provided an immediate indication of improvement in regional perfusion status following revascularization. Future studies involving ICGFA may include pre- and postdebridement and closure perfusion, comparison of tissue perfusion pre- and post-endovascular therapy, and lower extremity flap viability. Future works will also address the consistency of results with ICGFA by analyzing a larger cohort of patients being treated by our unit. PMID:22401340

  6. Indocyanine green angiography in posterior uveitis

    PubMed Central

    Agrawal, Rupesh V; Biswas, Jyotirmay; Gunasekaran, Dinesh

    2013-01-01

    Literature review for indocyanine green angiography and evaluate the role of indocyanine green angiogram (ICGA) in patients with posterior uveitis seen at a tertiary referral eye care centre. Detailed review of the literature on ICGA was performed. Retrospective review of medical records of patients with posterior uveitis and dual fundus and ICGA was done after institutional board approval. Eighteen patients (26 eyes) had serpiginous choroiditis out of which 12 patients had active choroiditis and six patients had healed choroiditis, six patients (12 eyes) had ampiginous choroiditis, six patients (12 eyes) had acute multifocal posterior placoid pigment epitheliopathy, eight patients (10 eyes) had multifocal choroiditis, four patients (eight eyes) had presumed ocular histoplasmosis syndrome, four patients (eight eyes) had presumed tuberculous choroiditis, two patients (four eyes) had multiple evanescent white dot syndrome and two patients (four eyes) had Vogt Koyanagi Harada (VKH) syndrome. The most characteristic feature noted on ICGA was the presence of different patterns of hypofluorescent dark spots, which were present at different stages of the angiogram. ICGA provides the clinician with a powerful adjunctive tool in choroidal inflammatory disorders. It is not meant to replace already proven modalities such as the fluorescein angiography, but it can provide additional information that is useful in establishing a more definitive diagnosis in inflammatory chorioretinal diseases associated with multiple spots. It still needs to be determined if ICGA can prove to be a follow up parameter to evaluate disease progression. PMID:23685486

  7. Magnetic Resonance Angiography of the Aorta

    PubMed Central

    Takehara, Yasuo; Yamashita, Shuhei; Sakahara, Harumi; Masui, Takayuki; Isoda, Haruo

    2011-01-01

    Magnetic resonance angiography (MRA) is capable of imaging arteries in the half to whole body by a single acquisition without a nephrotoxic contrast medium, and acquired images can be reconstructed into a specific cross-sectional view in an arbitrary directions. MRA is applicable for vessels non-reachable by a catheter approach, and collateral vessels can be fully visualized. Since MRA is minimally-invasive with no exposure to ionized radiation, it can be repeatedly applied for follow-up. However, there are also disadvantages: the temporal and spatial resolutions are inferior to those of X-ray angiography, and, at present, it cannot be used as a guide for intervention. Moreover, gadolinium administrations may cause NSF in patients who have lost renal function, as a new risk. Accordingly, strict consideration is required for an indication of its application. Development of non-contrast MRA and evaluation of the wall itself may draw more attention in the future. Plaque imaging is being routinely performed nowadays, and the measurement of vascular wall shear stress, which has a close association with arteriosclerosis, may become possible by utilizing the time-resolved phase-contrast method capable of measuring the time-resolved velocity vectors of blood flow throughout the body. (*English Translation of J Jpn Coll Angiol, 2009, 49: 503-516.) PMID:23555465

  8. Carbon Dioxide Angiography: Scientific Principles and Practice.

    PubMed

    Cho, Kyung Jae

    2015-09-01

    Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention. PMID:26509137

  9. Angiography with a multifunctional line scanning ophthalmoscope

    PubMed Central

    Ferguson, R. Daniel; Patel, Ankit H.; Vazquez, Vanessa; Husain, Deeba

    2012-01-01

    Abstract. A multifunctional line scanning ophthalmoscope (mLSO) was designed, constructed, and tested on human subjects. The mLSO could sequentially acquire wide-field, confocal, near-infrared reflectance, fluorescein angiography (FA), and indocyanine green angiography (ICGA) retinal images. The system also included a retinal tracker (RT) and a photodynamic therapy laser treatment port. The mLSO was tested in a pilot clinical study on human subjects with and without retinal disease. The instrument exhibited robust retinal tracking and high-contrast line scanning imaging. The FA and ICGA angiograms showed a similar appearance of hyper- and hypo-pigmented disease features and a nearly equivalent resolution of fine capillaries compared to a commercial flood-illumination fundus imager. An mLSO-based platform will enable researchers and clinicians to image human and animal eyes with a variety of modalities and deliver therapeutic beams from a single automated interface. This approach has the potential to improve patient comfort and reduce imaging session times, allowing clinicians to better diagnose, plan, and conduct patient procedures with improved outcomes. PMID:22463040

  10. Perfusion Angiography in Acute Ischemic Stroke

    PubMed Central

    Liebeskind, David S.

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and Tmax, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  11. Contrast agent choice for intravenous coronary angiography

    SciTech Connect

    Zeman, H.D.; Siddons, D.P.

    1989-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation x-rays and an iodine containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic x-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the x-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation x-rays is visualizing a coronary artery through the left ventricle or aorta which also contains a contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth.

  12. Prospective Coronary Heart Disease Screening in Asymptomatic Hodgkin Lymphoma Patients Using Coronary Computed Tomography Angiography: Results and Risk Factor Analysis

    SciTech Connect

    Girinsky, Theodore; M’Kacher, Radhia; Koscielny, Serge; Elfassy, Eric; Raoux, François; Carde, Patrice; Santos, Marcos Dos; Margainaud, Jean-Pierre; Sabatier, Laure; Paul, Jean-François

    2014-05-01

    Purpose: To prospectively investigate the coronary artery status using coronary CT angiography (CCTA) in patients with Hodgkin lymphoma treated with combined modalities and mediastinal irradiation. Methods and Materials: All consecutive asymptomatic patients with Hodgkin lymphoma entered the study during follow-up, from August 2007 to May 2012. Coronary CT angiography was performed, and risk factors were recorded along with leukocyte telomere length (LTL) measurements. Results: One hundred seventy-nine patients entered the 5-year study. The median follow-up was 11.6 years (range, 2.1-40.2 years), and the median interval between treatment and the CCTA was 9.5 years (range, 0.5-40 years). Coronary artery abnormalities were demonstrated in 46 patients (26%). Coronary CT angiography abnormalities were detected in nearly 15% of the patients within the first 5 years after treatment. A significant increase (34%) occurred 10 years after treatment (P=.05). Stenoses were mostly nonostial. Severe stenoses were observed in 12 (6.7%) of the patients, entailing surgery with either angioplasty with stent placement or bypass grafting in 10 of them (5.5%). A multivariate analysis demonstrated that age at treatment, hypertension, and hypercholesterolemia, as well as radiation dose to the coronary artery origins, were prognostic factors. In the group of patients with LTL measurements, hypertension and LTL were the only independent risk factors. Conclusions: The findings suggest that CCTA can identify asymptomatic individuals at risk of acute coronary artery disease who might require either preventive or curative measures. Conventional risk factors and the radiation dose to coronary artery origins were independent prognostic factors. The prognostic value of LTL needs further investigation.

  13. Optimal Contrast of Cerebral Dual-Energy Computed Tomography Angiography in Patients With Spontaneous Subarachnoid Hemorrhage

    PubMed Central

    Wang, Dan; Zhang, Qiaowei; Hu, Hongjie; Zhang, Wenming; Chen, Renbiao; Zee, Chi S.; Yu, Risheng

    2016-01-01

    Objective The aim of this study was to investigate the image quality of cerebral dual-energy computed tomography (CT) angiography using a nonlinear image blending technique as compared with the conventional linear blending method in patients with spontaneous subarachnoid hemorrhage (SAH). Methods A retrospective review of 30 consecutive spontaneous SAH patients who underwent a dual-source, dual-energy (80 kV and Sn140 kV mode) cerebral CT angiography was performed with permission from hospital ethical committee. Optimized images using nonlinear blending method were generated and compared with the 0.6 linear blending images by evaluating cerebral artery enhancement, attenuation of SAH, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR), respectively. Two neuroradiologists independently assessed subjective vessel visualization per segment using a 5-point scale. Results The nonlinear blending images showed higher cerebral artery enhancement (307.24 ± 58.04 Hounsfield unit [HU]), lower attenuation of SAH (67.07 ± 6.79 HU), and image noise (7.18 ± 1.20 HU), thus achieving better SNR (43.92 ± 11.14) and CNR (34.34 ± 10.25), compared with those of linear blending images (235.47 ± 46.45 HU for cerebral artery enhancement, 70.00 ± 6.41 HU for attenuation of SAH, 8.39 ± 1.25 HU for image noise, 28.86 ± 8.43 for SNR, and 20.37 ± 7.74 for CNR) (all P < 0.01). The segmental scorings of the nonlinear blending image (31.6% segments with a score of 5, 57.4% segments with a score of 4, 11% segments with a score of 3) ranged significantly higher than those of linear blending images (11.5% segments with a score of 5, 77.5% segments with a score of 4, 11% segments with a score of 3) (P < 0.01). The interobserver agreement was good (κ = 0.762), and intraobserver agreement was excellent for both observers (κ = 0.844 and 0.858, respectively). Conclusions The nonlinear image blending technique improved vessel visualization of cerebral dual-energy CT

  14. Aortic ostia of the bronchial arteries and tracheal bifurcation: MDCT analysis

    PubMed Central

    Ziyawudong, Julaiti; Kawai, Nobuyuki; Sato, Morio; Ikoma, Akira; Sanda, Hiroki; Takeuchi, Taizo; Minamiguchi, Hiroki; Nakai, Motoki; Tanaka, Takami; Sonomura, Tetsuo

    2012-01-01

    AIM: To explore the anatomical relationships between bronchial artery and tracheal bifurcation using computed tomography angiography (CTA). METHODS: One hundred consecutive patients (84 men, 16 women; aged 46-85 years) who underwent CTA using multi-detector row CT (MDCT) were investigated retrospectively. The distance between sites of bronchial artery ostia and tracheal bifurcation, and dividing directions were explored. The directions of division from the descending aorta were described as on a clock face. RESULTS: We identified ostia of 198 bronchial arteries: 95 right bronchial arteries, 67 left bronchial arteries, 36 common trunk arteries. Of these, 172 (87%) divided from the descending aorta, 25 (13%) from the aortic arch, and 1 (0.5%) from the left subclavian artery. The right, left, and common trunk bronchial arteries divided at -1 to 2 cm from tracheal bifurcation with frequencies of 77% (73/95), 82% (54/66), and 70% (25/36), respectively. The dividing direction of right bronchial arteries from the descending aorta was 9 to 10 o’clock with a frequency of 81% (64/79); that of left and common tract bronchial arteries was 11 to 1 o’clock with frequencies of 70% (43/62) and 77% (24/31), respectively. CONCLUSION: CTA using MDCT provides details of the relation between bronchial artery ostia and tracheal bifurcation. PMID:22328969

  15. Selecting a CT scanner for cardiac imaging: the heart of the matter.

    PubMed

    Lewis, Maria A; Pascoal, Ana; Keevil, Stephen F; Lewis, Cornelius A

    2016-09-01

    Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA. PMID:27302494

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

    PubMed Central

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

    2016-01-01

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

  17. Use of CT Angiogram in Interventions Involving Coronary Artery Anomalies: A Case Series

    PubMed Central

    Ramesh, Dwarakanath; Setty Natraj Setty, Huliyurdurga S.; Patil, Veeresh; Swamy, Kumar; Kumar, Sunil; Guruprasad, Guruprasad; Manjunath, Cholenahalli Nanjappa

    2015-01-01

    Case series Patient: — Final Diagnosis: Coronary anamolies Symptoms: Chest pain Medication: None Clinical Procedure: PTCA with stent/CABG Specialty: Cardiology Objective: Challenging differential diagnosis Background: Coronary artery anomalies are rare, accounting for about 0.3–1.3% of patients undergoing diagnostic coronary angiography. Interventions in these cases are still rare, and therefore pose technical challenges during intervention. CT Angiography provides a non-invasive means of assessment of coronary artery disease and also shows the anatomy of the coronary tree. This helps in knowing the origin of the coronaries and also to plan selection of hardware. There are no specific guidelines for use of guiding catheters and guide wires in anomalous coronary artery intervention. Case Report: We report a series of 5 patients presenting with effort angina who had anomalous coronary arteries with coronary stenosis diagnosed by CT angiography. Three patients received percutaneous intervention, 1 patient underwent CABG, and 1 patient received medical management. Conclusions: CT Angiography provides a useful tool for showing the coronary anatomy and for selecting the guiding catheter and the guide wire that remain the mainstay of interventions in coronary artery anomalies. PMID:26637639

  18. Calibration free beam hardening correction for cardiac CT perfusion imaging

    NASA Astrophysics Data System (ADS)

    Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

  19. Automatic detection and quantification of the Agatston coronary artery calcium score on contrast computed tomography angiography.

    PubMed

    Ahmed, Wehab; de Graaf, Michiel A; Broersen, Alexander; Kitslaar, Pieter H; Oost, Elco; Dijkstra, Jouke; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2015-01-01

    Potentially, Agatston coronary artery calcium (CAC) score could be calculated on contrast computed tomography coronary angiography (CTA). This will make a separate non-contrast CT scan superfluous. This study aims to assess the performance of a novel fully automatic algorithm to detect and quantify the Agatston CAC score in contrast CTA images. From a clinical registry, 20 patients were randomly selected for each CAC category (i.e. 0, 1-99, 100-399, 400-999, ≥1,000). The Agatston CAC score on non-contrast CT was calculated manually, while the novel algorithm was used to automatically detect and quantify Agatston CAC score in contrast CTA images. The resulting Agatston CAC scores were validated against the non-contrast images. A total of 100 patients (60 ± 11 years, 63 men) were included. The median CAC score on non-contrast CT was 145 (IQR 5-760), whereas the contrast CTA CAC score was 170 (IQR 23-594) (P = 0.004). The automatically computed CAC score showed a high correlation (R = 0.949; P < 0.001) and intra-class correlation (R = 0.863; P < 0.001) with non-contrast CT CAC score. Moreover, agreement within CAC categories was good (κ 0.588). Fully automatic detection of Agatston CAC score on contrast CTA is feasible and showed high correlation with non-contrast CT CAC score. This could imply a radiation dose reduction and time saving by omitting the non-contrast scan. PMID:25159031

  20. Optical Coherence Tomography Angiography Features of Diabetic Retinopathy

    PubMed Central

    Hwang, Thomas S.; Jia, Yali; Gao, Simon S.; Bailey, Steven T.; Lauer, Andreas K.; Flaxel, Christina J.; Wilson, David J.; Huang, David

    2015-01-01

    Purpose To describe the optical coherence tomography (OCT) angiography features of diabetic retinopathy Methods Using a 70kHz OCT and the split-spectrum amplitude decorrelation angiography (SSADA) algorithm, 6 × 6 mm 3-dimensional angiograms of the macula of 4 patients with diabetic retinopathy were obtained and compared with fluorescein angiography (FA) for features catalogued by the Early Treatment of Diabetic Retinopathy Study. Results OCT angiography detected enlargement and distortion of the foveal avascular zone, retinal capillary dropout, and pruning of arteriolar branches. Areas of capillary loss obscured by fluorescein leakage on FA were more clearly defined on OCT angiography. Some areas of focal leakage on FA that were thought to be microaneurysms were found to be small tufts of neovascularization that extended above the inner limiting membrane. Conclusion OCT angiography does not show leakage, but can better delineate areas of capillary dropout and detect early retinal neovascularization. This new noninvasive angiography technology may be useful for routine surveillance of proliferative and ischemic changes in diabetic retinopathy. PMID:26308529

  1. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-03-01

    Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.

  2. Patient radiation dose from computed tomography angiography and digital subtraction angiography of the brain

    NASA Astrophysics Data System (ADS)

    Netwong, Y.; Krisanachinda, A.

    2016-03-01

    The 64-row multidetector computed tomography angiography (64-MDCTA) provides vascular image quality of the brain similar to digital subtraction angiography (DSA), but the effective dose of CTA is lower than DSA studied in phantom. The purpose of this study is to evaluate the effective dose from 64-MDCTA and DSA. Effective dose (according to ICRP 103) from 64-MDCTA and DSA flat panel detector for cerebral vessels examination of the brain using standard protocols as recommended by the manufacturer was calculated for 30 cases of MDCTA (15 male and 15 female).The mean patient age was 49.5 (23-89) yrs. 30 cases of DSA (14 male and 16 female), the mean patient age was 46.8 (21-81) yrs. For CTA, the mean effective dose was 3.7 (2.82- 5.19) mSv. For DSA, the mean effective dose was 5.78 (3.3-10.06) mSv. The effective dose of CTA depends on the scanning protocol and scan length. Low tube current can reduce patient dose whereas the number of exposures and number of series in 3D rotational angiography (3D RA) resulted in increasing effective dose in DSA patients.

  3. Projection-resolved optical coherence tomographic angiography

    PubMed Central

    Zhang, Miao; Hwang, Thomas S.; Campbell, J. Peter; Bailey, Steven T.; Wilson, David J.; Huang, David; Jia, Yali

    2016-01-01

    Shadowgraphic projection artifacts from superficial vasculature interfere with the visualization of deeper vascular networks in optical coherence tomography angiography (OCT-A). We developed a novel algorithm to remove this artifact by resolving the ambiguity between in situ and projected flow signals. The algorithm identifies voxels with in situ flow as those where intensity-normalized decorrelation values are higher than all shallower voxels in the same axial scan line. This “projection-resolved” (PR) algorithm effectively suppressed the projection artifact on both en face and cross-sectional angiograms and enhanced depth resolution of vascular networks. In the human macula, the enhanced angiograms show three distinct vascular plexuses in the inner retina and no vessels in the outer retina. We demonstrate that PR OCT-A cleanly removes flow projection from the normally avascular outer retinal slab while preserving the density and continuity of the intermediate and deep retinal capillary plexuses. PMID:27231591

  4. Magnetic resonance angiography: physical principles and applications.

    PubMed

    Kiruluta, Andrew J M; González, R Gilberto

    2016-01-01

    Magnetic resonance angiography (MRA) is the visualization of hemodynamic flow using imaging techniques that discriminate flowing spins in blood from those in stationary tissue. There are two classes of MRA methods based on whether the magnetic resonance imaging signal in flowing blood is derived from the amplitude of the moving spins, the time-of-flight methods, or is based on the phase accumulated by these flowing spins, as in phase contrast methods. Each method has particular advantages and limitations as an angiographic imaging technique, as evidenced in their application space. Here we discuss the physics of MRA for both classes of imaging techniques, including contrast-enhanced approaches and the recent rapid expansion of the techniques to fast acquisition and processing techniques using parallel imaging coils as well as their application in high-field MR systems such as 3T and 7T. PMID:27432663

  5. Digital subtraction angiography: overview of technical principles.

    PubMed

    Harrington, D P; Boxt, L M; Murray, P D

    1982-10-01

    The rapid development of equipment for digital subtraction angiography (DSA) has created a new diagnostic imaging method, the limits of which have not been scientifically determined. Yet through aggressive marketing, the technique is already beginning to permeate radiologic practice. The radiologist requires technical understanding of the instrumentation for informed judgment on clinical applications. DSA depends on the mating of high-resolution image-intensifier and television technology with computerized information manipulation and storage. In this overview, the individual components of the system are analyzed, from the generator to the image intensifier to the television system to the associated computer. By examining the role of each component, the current limitations and the areas of possible future development of DSA can be understood. This provides a basis for dealing with current technology and for evaluating the rapid technological changes that will occur over the next few years. PMID:6751053

  6. Digital subtraction angiography in extremity trauma

    SciTech Connect

    Goodman, P.C.; Jeffrey, R.B. Jr.; Brant-Zawadzki, M.

    1984-10-01

    Digital subtraction angiography (DSA) may have considerable impact on the work-up of patients who have suffered trauma. The angiographic evaluation of vascular injuries can be accomplished rapidly and with minimal catheter use and manipulation, which is particularly important for those critically ill patients who have significant immobility because of multiple fractures. The authors retrospectively reviewed the digital subtraction angiograms in 50 consecutive cases of extremity trauma. The quality of the images in 44 of these permitted a confident diagnosis, the accuracy of which was confirmed by surgical or clinical follow-up. DSA reduces the time required to perform the procedure, the amount of contrast material injected, patient discomfort, and film cost. Its major disadvantage is the limited field size of the image intensifier.

  7. Angiography and embolisation for solid abdominal organ injury in adults - a current perspective

    PubMed Central

    2010-01-01

    Over the past twenty years there has been a shift towards non-operative management (NOM) for haemodynamically stable patients with abdominal trauma. Embolisation can achieve haemostasis and salvage organs without the morbidity of surgery, and the development and refinement of embolisation techniques has widened the indications for NOM in the management of solid organ injury. Advances in computed tomography (CT) technology allow faster scanning times with improved image quality. These improvements mean that whilst surgery is still usually recommended for patients with penetrating injuries, multiple bleeding sites or haemodynamic instability, the indications for NOM are expanding. We present a current perspective on angiography and embolisation in adults with blunt and penetrating abdominal trauma with illustrative examples from our practice including technical advice. PMID:20584325

  8. Interrupted Aortic Arch Associated with Absence of Left Common Carotid Artery: Imaging with MDCT

    SciTech Connect

    Onbas, Omer Olgun, Hasim; Ceviz, Naci; Ors, Rahmi; Okur, Adnan

    2006-06-15

    Interrupted aortic arch (IAA) is a rare severe congenital heart defect defined as complete luminal and anatomic discontinuity between ascending and descending aorta. Although its association with various congenital heart defects has been reported, absence of left common carotid artery (CCA) in patients with IAA has not been reported previously. We report a case of IAA associated with the absence of left CCA which was clearly shown on multidetector-row spiral CT.

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

    PubMed Central

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

    2009-01-01

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

  10. Computed Tomography (CT) - Spine

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Spine Computed tomography (CT) of the spine is a diagnostic imaging ... Spine? What is CT Scanning of the Spine? Computed tomography, more commonly known as a CT or CAT ...

  11. Nuclide angiography in Paget's disease of the skull: Case report.

    PubMed

    Fitzer, P M

    1975-07-01

    Early-appearing and persistent uptake on nuclear angiography in a patient with early Paget's disease of the skull is described. The diagnosis of subdural hematoma may be ruled out at the time of brain scanning. PMID:1167280

  12. Digital subtraction angiography in pediatric cerebrovascular occlusive disease

    SciTech Connect

    Faerber, E.N.; Griska, L.A.B.; Swartz, J.D.; Capitanio, M.A.; Popky, G.L.

    1984-08-01

    While conventional angiography has been used to demonstrate cerebrovascular occlusive disease in the past, digital subtraction angiography (DSA) is capable of showing progressive vascular involvement with ease, simplicity, and extremely low morbidity, making it particularly well suited for children and outpatients either alone or coordinated with computed tomography. The authors discuss the usefulness and advantages of DSA as demonstrated in 7 infants and children with hemiplegia, 4 of whom had sickle-cell disease.

  13. A novel method for non-invasive plaque morphology analysis by coronary computed tomography angiography.

    PubMed

    Fujimoto, Shinichiro; Kondo, Takeshi; Kodama, Takahide; Fujisawa, Yasuko; Groarke, John; Kumamaru, Kanako K; Takamura, Kazuhisa; Matsunaga, Eriko; Miyauchi, Katsumi; Daida, Hiroyuki; Rybicki, Frank J

    2014-10-01

    Coronary computed tomography angiography (CCTA) plaque morphology based on conventional Hounsfield units relies on absolute CT numbers is influenced by imaging and anatomical variables. The project describes and tests a novel alternative method, termed the "labeling method", which uses relative CT numbers and 3-dimensional plaque structure. Using virtual histology intravascular ultrasound (VH-IVUS) as the reference standard, this study compares the labeling method to a conventional CT-number based method to determine coronary plaque morphology. Thirty-seven high-risk, non-calcified atherosclerotic coronary lesions were prospectively evaluated in 33 consecutive patients who underwent CCTA followed by VH-IVUS (mean interval 8.6 ± 13.3 days). CCTA-derived vessel and minimum lumen areas were compared to VH-IVUS measures. Fibrotic and necrotic core areas were calculated by both the labeling method to the CT-number based method; both were tested for agreement with reference standard VH-IVUS. Inter- and intra-observer correlations were assessed. CCTA significantly underestimated minimum lumen area when compared to VH-IVUS (mean difference -1.4 ± 0.9 mm(2), p < 0.0001). Necrotic core and fibrous areas quantified using the labeling method demonstrated superior correlation with VH-IVUS compared to those quantified using the CT-number based method, Pearson's r = 0.75 versus 0.42 and r = 0.80 and 0.59, respectively. Compared to VH-IVUS, limits of agreement for the labeling method-derived necrotic core (-2.0 to 2.5 mm(2)) and fibrous areas (0.6-8.0 mm(2)) were more narrow than those determined using the CT-number based method (-3.7 to 7.3 and -4.0 to 8.9 mm(2), respectively). Inter- and intraobserver correlations were excellent for all CCTA derived measures (r = 0.85-0.98). A novel CCTA-based labeling method offers an alternative to conventional CT-number based analyses for plaque morphology. The labeling method demonstrates superior correlation to VH-IVUS for measures of

  14. Postmortem angiography using femoral cannulation and postmortem microbiology.

    PubMed

    Palmiere, Cristian; Egger, Coraline; Grabherr, Silke; Jaton-Ogay, Katia; Greub, Gilbert

    2015-07-01

    Despite the undeniable advantages of postmortem angiography, numerous questions have arisen concerning the influence that the injected contrast media may exercise on biological fluids and tissues collected for toxicological and biochemical investigations. Moreover, cardiac blood for microbiological investigations cannot be obtained post-angiography. In this study, we examined whether the peripheral blood collected prior to postmortem angiography, using percutaneous access to femoral vessels after skin surface disinfection, could be suitable for microbiological investigations when postmortem angiography with femoral vessel cannulation is also performed. A total of 66 cases were included in the study and were divided into two subgroups (angiography and bacteriology group, 33 cases and control group, 33 cases). Autopsies, histology, toxicology, bacteriology, and biochemical investigations (procalcitonin, C-reactive protein, interleukin-6, and soluble triggering receptors expressed on myeloid cells type 1) were performed in all cases. No statistically significant differences between the two groups were noted, and identified category distribution (death unrelated to infection, true infection, false positive, and undetermined) was rather similar in both studied populations. These preliminary results suggest that postmortem angiography using a femoral approach does not constitute an impediment to the collection of peripheral blood for microbiology and vice versa. Moreover, the use of femoral blood for microbiology does not lead to an increased risk of doubtful results. PMID:25381195

  15. Iterative CT shading correction with no prior information

    NASA Astrophysics Data System (ADS)

    Wu, Pengwei; Sun, Xiaonan; Hu, Hongjie; Mao, Tingyu; Zhao, Wei; Sheng, Ke; Cheung, Alice A.; Niu, Tianye

    2015-11-01

    Shading artifacts in CT images are caused by scatter contamination, beam-hardening effect and other non-ideal imaging conditions. The purpose of this study is to propose a novel and general correction framework to eliminate low-frequency shading artifacts in CT images (e.g. cone-beam CT, low-kVp CT) without relying on prior information. The method is based on the general knowledge of the relatively uniform CT number distribution in one tissue component. The CT image is first segmented to construct a template image where each structure is filled with the same CT number of a specific tissue type. Then, by subtracting the ideal template from the CT image, the residual image from various error sources are generated. Since forward projection is an integration process, non-continuous shading artifacts in the image become continuous signals in a line integral. Thus, the residual image is forward projected and its line integral is low-pass filtered in order to estimate the error that causes shading artifacts. A compensation map is reconstructed from the filtered line integral error using a standard FDK algorithm and added back to the original image for shading correction. As the segmented image does not accurately depict a shaded CT image, the proposed scheme is iterated until the variation of the residual image is minimized. The proposed method is evaluated using cone-beam CT images of a Catphan©600 phantom and a pelvis patient, and low-kVp CT angiography images for carotid artery assessment. Compared with the CT image without correction, the proposed method reduces the overall CT number error from over 200 HU to be less than 30 HU and increases the spatial uniformity by a factor of 1.5. Low-contrast object is faithfully retained after the proposed correction. An effective iterative algorithm for shading correction in CT imaging is proposed that is only assisted by general anatomical information without relying on prior knowledge. The proposed method is thus practical

  16. Application of intelligent optimal kV scanning technology (CARE kV) in dual-source computed tomography (DSCT) coronary angiography

    PubMed Central

    Zhang, Jun; Kang, Shaolei; Han, Dan; Xie, Xiaojie; Deng, Yaming

    2015-01-01

    This study aims to evaluate the applications and values of dual-source computed tomography (DSCT) intelligent optimal kV scanning technology (CARE kV) in coronary CT angiography (CCTA). 150 patients with normal body mass index were performed DSCT coronary angiography, then randomly divided into the “Semi”, 120,100 and 80 kV Group, and the 2 “on” groups, with 30 patients in each group. The first 5 groups used the reference voltage as 120 kV, and the reference current as 400 mAs, while the other group used the reference voltage as 100 kV, and the reference current as 400 mAs. The image quality, average CT value, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and radiation dose were comparatively analyzed among the 5 groups. The image quality scores of the five groups showed no significant difference (P > 0.05); the average CT values and image noises had significance (P < 0.05), while SNR and CNR showed no significant difference (P > 0.05). The 80 kV group showed the biggest noise, with the CT value as 700 HU, while the radiation dose was the lowest, followed by the on group. As for the patients with normal body mass index (BMI), CARE kV-“on” could obtain high-quality images and lower radiation dose for CCTA, while the operation was simple and convenient. PMID:26770354

  17. Contrast agent choice for intravenous coronary angiography

    NASA Astrophysics Data System (ADS)

    Zeman, H. D.; Siddons, D. P.

    1990-05-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. Gd-DTPA is already approved for use as a contrast agent for

  18. Optical Coherence Tomography Angiography in Choroideremia

    PubMed Central

    Jain, Nieraj; Jia, Yali; Gao, Simon S.; Zhang, Xinbo; Weleber, Richard G.; Huang, David; Pennesi, Mark E.

    2016-01-01

    Importance Novel therapies for choroideremia, an X-linked recessive chorioretinal degeneration, demand a better understanding of the primary site(s) of cellular degeneration. Optical coherence tomography angiography allows for choriocapillaris (CC) imaging. We compared the extent of structural alterations of the CC, retinal pigment epithelium, and photoreceptors with multimodal imaging. Observations In a clinical case series conducted from September 15,2014, through February 5,2015,14 eyes of 7 male patients with choroideremia (median age, 34 years [interquartile range, 15-46 years]; age range, 13-48 years), 4 eyes of 2 women with choroideremia carrier state (both in mid-50s), and 6 eyes of 6 controls (median age, 42.5 years [interquartile range, 33-55 years]; age range, 24-55 years) underwent multimodal imaging with optical coherence tomography angiography and electroretinography. The mean (SD) macular CC density was 82.9% (13.4%) in patients with choroideremia, 93.0% (3.8%) in female carriers, and 98.2% (1.3%) in controls. The mean (SD) CC density in affected eyes was higher in regions with preserved (92.6% [5.8%]) vs absent (75.9% [12.6%]) ellipsoid zone (mean difference. 16.7%; 95% CI, 12.1% to 21.3%; P < .001). Seventeen of 18 eyes of the patients and carriers had outer retinal tubulations forming pseudopod-like extensions from islands of preserved ellipsoid zone. Outer retinal tubulations were associated with absence of underlying retinal pigment epithelium and were longer (r = −0.62; 95% CI, −0.84 to −0.19; P < .001) and more numerous (r = −0.71; 95% CI, −0.91 to −0.27; P < .001) in more severely affected eyes. Conclusions and Relevance These findings suggest that regional changes in CC density correlate with photoreceptor structural alterations in choroideremia. Although closely coupled, the results suggest that retinal pigment epithelium loss is more extensive than photoreceptor loss. PMID:27149258

  19. Mechanical thrombectomy using a combined CT/C-arm X-ray system

    PubMed Central

    Herweh, Christian; Pham, Mirko; Schönenberger, Silvia; Bösel, Julian; Ringleb, Peter A; Heiland, Sabine; Bendszus, Martin; Möhlenbruch, Markus

    2016-01-01

    Background Mechanical thrombectomy (MT) using stent-retrievers has been proven to be a safe and effective treatment in acute ischemic stroke (AIS), particularly in large vessel occlusion. Other than patient characteristics, time to recanalization is the most important factor linked to outcome. MT is usually performed in a dedicated angiography suite using a floor- and/or ceiling-mounted biplane angiographic system. Here we report our first experience of MT with a new combined CT and mobile C-arm X-ray device setup. Methods Patients with AIS underwent stroke imaging (non-contrast enhanced CT, CT perfusion, and CT angiography) using a commercially available 64-slice CT scanner which was modified for combined use with a C-arm system. In patients with large vessel occlusion, MT was conducted without further patient transfer within the CT imaging suite using a mobile C-arm X-ray device equipped with a 30×30 cm (12×12 inch), 1.5×1.5 k full-view flat detector which was positioned between the gantry and patient table. The safety and feasibility of this new system was assessed in preliminary patients. Results Angiographic imaging quality of the mobile C-arm was feasible and satisfactory for diagnostic angiography and MT. Using this setup, time between stroke imaging and groin puncture (picture-to-puncture time) was reduced by up to 35 min (including time for preparation of the patient such as intubation). Conclusions MT using a combined CT/C-arm system is safe and feasible. The potential advantages, particularly time saving and ensuing improvement in patient outcome, need to be assessed in a larger study. PMID:25935925

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

    PubMed

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

    2013-03-15

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

  1. 4D motion animation of coronary arteries from rotational angiography

    NASA Astrophysics Data System (ADS)

    Holub, Wolfgang; Rohkohl, Christopher; Schuldhaus, Dominik; Prümmer, Marcus; Lauritsch, Günter; Hornegger, Joachim

    2011-03-01

    Time-resolved 3-D imaging of the heart is a major research topic in the medical imaging community. Recent advances in the interventional cardiac 3-D imaging from rotational angiography (C-arm CT) are now also making 4-D imaging feasible during procedures in the catheter laboratory. State-of-the-art reconstruction algorithms try to estimate the cardiac motion and utilize the motion field to enhance the reconstruction of a stable cardiac phase (diastole). The available data offers a handful of opportunities during interventional procedures, e.g. the ECG-synchronized dynamic roadmapping or the computation and analysis of functional parameters. In this paper we will demonstrate that the motion vector field (MVF) that is output by motion compensated image reconstruction algorithms is in general not directly usable for animation and motion analysis. Dependent on the algorithm different defects are investigated. A primary issue is that the MVF needs to be inverted, i.e. the wrong direction of motion is provided. A second major issue is the non-periodicity of cardiac motion. In algorithms which compute a non-periodic motion field from a single rotation the in depth motion information along viewing direction is missing, since this cannot be measured in the projections. As a result, while the MVF improves reconstruction quality, it is insufficient for motion animation and analysis. We propose an algorithm to solve both problems, i.e. inversion and missing in-depth information in a unified framework. A periodic version of the MVF is approximated. The task is formulated as a linear optimization problem where a parametric smooth motion model based on B-splines is estimated from the MVF. It is shown that the problem can be solved using a sparse QR factorization within a clinical feasible time of less than one minute. In a phantom experiment using the publicly available CAVAREV platform, the average quality of a non-periodic animation could be increased by 39% by applying the

  2. Using DynaCT for the assessment of ilio-femoral arterial calibre, calcification and tortuosity index in patients selected for trans-catheter aortic valve replacement.

    PubMed

    Crowhurst, James A; Campbell, Douglas; Raffel, Owen C; Whitby, Mark; Pathmanathan, Pavthrun; Redmond, Stanley; Incani, Alexander; Poon, Karl; James, Christopher; Aroney, Constantine; Clarke, Andrew; Walters, Darren L

    2013-10-01

    Adequate vascular access for femoral trans-catheter aortic valve replacement is fundamental to the success of the procedure. Assessment of vascular calibre, tortuosity and calcification is performed by angiography and multi-slice computed tomography (MSCT). Can DynaCT provide the same information as MSCT? 15 Patients underwent MSCT, angiography and DynaCT. Vessel diameter measurements were taken in three positions of the left and right ilio-femoral arteries. Tortuosity was assessed using an index of the direct distance and the distance taken by the artery between two points. Calcification was assessed in MSCT and DynaCT using a simple scoring system. Concordance correlation coefficient of arterial calibre between angiography and MSCT was 0.96 (95 % CI 0.94-0.97). DynaCT and angiography was 0.94 (95 % CI 0.91-0.96) and Dyna CT and MSCT, 0.95 (95 % CI 0.92-0.97). Bland-Altman tests demonstrate a mean difference between the angiogram and the MSCT of 0.06 mm (+0.97, -1.42), angiogram and DynaCT, 0.13 mm, (+1.00, -0.87), DynaCT and MSCT, 0.2 mm, (+1.15, -0.76). Tortuosity comparisons gave a median tortuosity index for MSCT 1.29 and DynaCT 1.23 (p = 0.472). Calcification comparisons of MSCT and DynaCT using correlation coefficients demonstrate a correlation of 0.245 (p = 0.378). Effective radiation doses were: DynaCT; 3.63 ± 0.65 mSv and angiography; 0.57 ± 0.72 mSv, MSCT; 7.15 ± 2.58 mSv. DynaCT is equal to MSCT and angiography in assessing femoral artery calibre. Like MSCT, it can assess tortuosity and can produce 3D images but is inferior in the assessment of calcification. PMID:23925712

  3. Imaging and angiography in male factor infertility.

    PubMed

    Jurewicz, Michael; Gilbert, Bruce R

    2016-06-01

    Ultrasound imaging and angiography play a crucial role in the diagnosis and treatment of men with subfertility. The most commonly used imaging modality is ultrasound (US), which can be used for diagnostic purposes or to aid in treatment. Scrotal US can be used to document varicoceles in subfertile men in the context of difficult examination or for confirmation before treatment. Spectral Doppler, sonoelastography, and power Doppler have aided in the evaluation and treatment of azoospermia and oligospermia. They have proven useful in the detection of spermatogenesis and sperm retrieval. In the population with congenital Wolffian duct abnormalities, renal US can evaluate renal anomalies. In subfertile men with low ejaculate volume and oligospermia or azoospermia transrectal US can be used to evaluate and assist in treatment of ejaculatory duct obstruction. Non-US-based modalities are also commonly used in evaluating and treating men with subfertility. Magnetic resonance imaging (MRI) can be used for evaluation of pituitary adenomas in hypogonadism. More invasive imaging modalities used during treatment of subfertile men include vasography for vasal obstruction, venography and angioembolization for varicocele, and US-guided needle placement for testis-sparing surgery. Male subfertility is a complex problem and the use of imaging techniques is often essential in providing accurate diagnosis and appropriate treatment. PMID:27125229

  4. [Magnetic resonance angiography of the renal arteries].

    PubMed

    Matos, C; Metens, T; Nicaise, N; Golzarian, J; Dussaussois, L; Struyven, J

    1999-09-01

    Initially, the clinical use of magnetic resonance angiography (MRA) in the abdomen has been restricted because of motion and flow related artifacts. The advent of high performance gradient systems made possible the development of 3D gadolinium-enhanced MRA techniques and expanded the clinical applications of MRA into the abdominal area, particularly for the investigation of renal arteries. This technique is safe, because the administered contrast agent (gadolinium) is free of clinically detectable nephrotoxicity and has a low incidence of allergic reactions. Moreover, contrast MRA also eliminates the risks of ionizing radiation which allows repeating the examination without the accumulation of radiation exposure. The main disadvantages of the technique are its low availability and the fact that the use of contrast agents for this procedure is still not reimbursed by the social security. Many studies demonstrated that contrast MRA allows for the reliable assessment of renal artery morphology and pathologic states. Furthermore, within a single MR examination a comprehensive approach including renal artery morphology, hemodynamic significance of any stenosis and kidney perfusion is available. In this paper, we provide a review of the literature concerning the clinical performance of contrast MRA for the renal arteries and suggest its rationale for the investigation of patients suspected of renovascular disease in our specific environment. PMID:10523920

  5. Three-dimensional power Doppler angiography

    NASA Astrophysics Data System (ADS)

    Guo, Zhenyu; Durand, Louis-Gilles; Holdsworth, David W.; Fenster, Aaron

    1997-05-01

    The purpose of the present study is to improve the quantification of peripheral arterial stenosis using 3D power Doppler angiography and investigate the potential of this technique for generating the arterial tree of the lower limb for surgery planning. Stenotic wall-less agar arteries were created to simulate the femoral and carotid arteries. 3D power Doppler angiograms of those arteries were generated under different hemodynamic conditions using a 3D ultrasound imaging system developed by the Life Imaging System Inc. The effect of multiple stenoses on the 3D power Doppler angiograms was investigated using the femoral arterial phantoms. Using the carotid arterial phantoms, 3D power Doppler angiograms of the carotid arteries were generated and compared with the known geometry. To image a whole lower limb arterial tree for lower limb salvage surgery planning, multiple scans are required to cover the entire field-of- view interested by using a water-coupled scanner. Preliminary in vivo test was performed using water-coupled scanning.

  6. Image quality metrics for optical coherence angiography.

    PubMed

    Lozzi, Andrea; Agrawal, Anant; Boretsky, Adam; Welle, Cristin G; Hammer, Daniel X

    2015-07-01

    We characterized image quality in optical coherence angiography (OCA) en face planes of mouse cortical capillary network in terms of signal-to-noise ratio (SNR) and Weber contrast (Wc) through a novel mask-based segmentation method. The method was used to compare two adjacent B-scan processing algorithms, (1) average absolute difference (AAD) and (2) standard deviation (SD), while varying the number of lateral cross-sections acquired (also known as the gate length, N). AAD and SD are identical at N = 2 and exhibited similar image quality for N<10. However, AAD is relatively less susceptible to bulk tissue motion artifact than SD. SNR and Wc were 15% and 35% higher for AAD from N = 25 to 100. In addition data sets were acquired with two objective lenses with different magnifications to quantify the effect of lateral resolution on fine capillary detection. The lower power objective yielded a significant mean broadening of 17% in Full Width Half Maximum (FWHM) diameter. These results may guide study and device designs for OCA capillary and blood flow quantification. PMID:26203372

  7. An anatomical review of spinal cord blood supply.

    PubMed

    Melissano, G; Bertoglio, L; Rinaldi, E; Leopardi, M; Chiesa, R

    2015-10-01

    Knowledge of the spinal cord (SC) vascular supply is important in patients undergoing procedures that involve the thoracic and thoracoabdominal aorta. However, the SC vasculature has a complex anatomy, and teaching is often based only on anatomical sketches with highly variable accuracy; historically, this has required a "leap of faith" on the part of aortic surgeons. Fortunately, this "leap of faith" is no longer necessary given recent breakthroughs in imaging technologies and postprocessing software. Imaging methods have expanded the non-invasive diagnostic ability to determine a patient's SC vascular pattern, particularly in detecting the presence and location of the artery of Adamkiewicz. CT is the imaging modality of choice for most patients with thoracic and thoracoabdominal aortic disease, proving especially useful in the determination of feasibility and planning of endovascular treatment. Thus the data set required for analysis of SC vascular anatomy is usually already available. We have concentrated our efforts on CT angiography, which offers particularly good imaging capabilities with state-of-the-art multidetector scanners. Multidetector row helical CT provides examinations of an extensive range in the craniocaudal direction with thin collimation in a short time interval, giving excellent temporal and spatial resolution. This paper provides examples of the SC vasculature imaging quality that can be obtained with 64 row scanners and appropriate postprocessing. Knowledge of the principal anatomical features of the SC blood supply of individual patients undergoing open or endovascular thoracoabdominal procedures has several potential benefits. For open surgery, analysis of the SC vasculature could tell us the aortic region that feeds the Adamkiewicz artery and thus needs to be reimplanted. For endovascular procedures, we can determine whether the stent-graft will cover the Adamkiewicz artery, thus avoiding unnecessary coverage. CT data can also be used to

  8. Spontaneous vertebral dissection: Clinical, conventional angiographic, CT, and MR findings

    SciTech Connect

    Provenzale, J.M.; Morgenlander, J.C.; Gress, D.

    1996-03-01

    The purpose of this study was to determine if typical clinical and neuroradiologic patterns exist in patients with spontaneous vertebral artery (VA) dissection. The medical records and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to exclude patients with a history of trauma and to record evidence of a nontratimatic precipitating event ({open_quotes}trivial trauma{close_quotes}) and presence of possible risk factors such as hypertension. All patients under-went conventional angiography, 13 either CT or MRI (II both CT and MRI), and 3 MRA. Conventional arteriograrris were evaluated for dissection site, evidence of fibromuscular dysplasia, luminal stenosis or occlusion, and pseudoaneurysm formation, CT examinations for the presence of infarction or subarachnoid hemorrhage, MR examinations for the presence of infarction or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column. Seven patients had precipitating events within 24 h of onset of symptoms that may have been causative of dissection and five had hypertension. At catheter angiography, two patients had dissections in two arteries (both VAs in one patient, VA and internal carotid artery in one patient), giving a total of 15 VAs with dissection. Dissection sites included V1 in four patients, V2 in one patient, V3 in three patients, V4 in six patients, and both V3 and V4 in one patient. Luminal stenosis was present in 13 VAs, occlusion in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia in 1. Posterior circulation infarcts were found on CT or MR in five patients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination in one.

  9. Interventricular membranous septal aneurysm: CT and MR manifestations.

    PubMed

    Carcano, Carolina; Kanne, Jeffrey P; Kirsch, Jacobo

    2016-02-01

    Advanced cardiac imaging is a valuable method to investigate cardiac malformations. The detection of the interventricular membranous septum has clinical significance due to thrombogenic and arrythmogenic predisposition, as well as a role in obstructing the pulmonary flow. This review describes six clinical presentations in which advanced cardiac imaging has been the tool for evaluation, with special emphasis in CT angiography and cardiac MRI sequences. Teaching Points • The interventricular membranous septum can predispose patients to thrombogenic and arrythmogenic events. • Subpulmonic stenosis relates to the protrusion of the aneurysm into the right ventricle • During surgery, ventricular pressures of the opened heart become balanced, making the aneurysm less evident. PMID:26687514

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

    PubMed

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

    2016-06-01

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

  11. Emerging role of cardiovascular CT and MRI in the evaluation of stroke.

    PubMed

    Pagán, Ricardo J; Parikh, Pragnesh P; Mergo, Patricia J; Gerber, Thomas C; Mankad, Rekha; Freeman, William D; Shapiro, Brian P

    2015-02-01

    OBJECTIVE. The purposes of this article are to explore the potential for use of CT angiography and MRI and to highlight data suggestive of their usefulness in specific cardiovascular abnormalities. CONCLUSION. The evaluation of stroke requires comprehensive assessment of potential stroke mechanisms, including cardiac sources. Despite an exhaustive search for secondary causes, the precise cause of many strokes remains unknown (cryptogenic). It is well recognized, however, that some of these potential causes occur as a result of embolism from the heart or great vessels. Thus, echocardiography, in particular transesophageal echocardiography, is instrumental in a careful assessment of cardiac causes in selected individuals. Unfortunately, transesophageal echocardiography is invasive, and some patients may have relative or absolute contraindications. Cardiovascular CT angiography and MRI have growing potential compared with conventional cardiovascular echography. PMID:25615749

  12. Contrast Extravasation on Computed Tomography Angiography Imitating a Basilar Artery Trunk Aneurysm in Subsequent Conventional Angiogram-Negative Subarachnoid Hemorrhage: Report of Two Cases with Different Clinical Courses

    PubMed Central

    Cho, Won Ho; Choi, Hyuk Jin; Nam, Kyoung Hyup

    2015-01-01

    Contrast extravasation on computed tomography angiography (CTA) is rare but becoming more common, with increasing use of CTA for various cerebral vascular diseases. We report on two cases of spontaneous subarachnoid hemorrhage (SAH) in which the CTA showed an upper basilar trunk saccular lesion suggesting ruptured aneurysm. However, immediate subsequent digital subtraction angiography (DSA) failed to show a vascular lesion. In one case, repeated follow up DSA was also negative. The patient was treated conservatively and discharged without any neurologic deficit. In the other case, the patient showed sudden mental deterioration on the third hospital day and her brain CT showed rebleeding. The immediate follow up DSA showed contrast stagnation in the vicinity of the upper basilar artery, suggestive of pseudoaneurysm. Double stents deployment at the disease segment was performed. Due to the frequent use of CTA, contrast extravasation is an increasingly common observation. Physicians should be aware that basilar artery extravasation can mimic the appearance of an aneurysm. PMID:27066442

  13. Stent sizing strategies in renal artery stenting: the comparison of conventional invasive renal angiography with renal computed tomographic angiography

    PubMed Central

    Michalowska, Ilona; Pregowski, Jerzy; Janaszek-Sitkowska, Hanna; Lech, Katarzyna; Kabat, Marek; Staruch, Adam; Januszewicz, Andrzej; Witkowski, Adam

    2016-01-01

    Introduction Randomized trials comparing invasive treatment of renal artery stenosis with standard pharmacotherapy did not show substantial benefit from revascularization. One of the potential reasons for that may be suboptimal procedure technique. Aim To compare renal stent sizing using two modalities: three-dimensional renal computed tomography angiography (CTA) versus conventional angiography. Material and methods Forty patients (41 renal arteries), aged 65.1 ±8.5 years, who underwent renal artery stenting with preprocedural CTA performed within 6 months, were retrospectively analyzed. In CTA analysis, reference diameter (CTA-D) and lesion length (CTA_LL) were measured and proposed stent diameter and length were recorded. Similarly, angiographic reference diameter (ANGIO_D) and lesion length (ANGIO_LL) as well as proposed stent dimensions were obtained by visual estimation. Results The median CTA_D was 0.5 mm larger than the median ANGIO_D (p < 0.001). Also, the proposed stent diameter in CTA evaluation was 0.5 mm larger than that in angiography (p < 0.0001). The median CTA_LL was 1 mm longer than the ANGIO_LL (p = NS), with significant correlation of these variables (r = 0.66, p < 0.0001). The median proposed stent length with CTA was equal to that proposed with angiography. The median diameter of the implanted stent was 0.5 mm smaller than that proposed in CTA (p < 0.0005) and identical to that proposed in angiography. The median length of the actual stent was longer than that proposed in angiography (p = 0.0001). Conclusions Renal CTA has potential advantages as a tool adjunctive to angiography in appropriate stent sizing. Careful evaluation of the available CTA scans may be beneficial and should be considered prior to the planned procedure. PMID:27279870

  14. Head CT (image)

    MedlinePlus

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

  15. CT scan (image)

    MedlinePlus

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

  16. CT appearance of splenosis

    SciTech Connect

    Mendelson, D.S.; Cohen, B.A.; Armas, R.R.

    1982-12-01

    Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT.

  17. NETL CT Imaging Facility

    ScienceCinema

    None

    2014-05-21

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  18. NETL CT Imaging Facility

    SciTech Connect

    2013-09-04

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  19. Orbit CT scan

    MedlinePlus

    ... results may mean: Bleeding Broken eye socket bone Graves disease Infection Tumor Risks CT scans and other x- ... Livingstone; 2014:chap 66. Read More CT scan Graves disease Tumor Update Date 1/18/2015 Updated by: ...

  20. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia.

    PubMed

    Duan, Hongzhou; Li, Liang; Zhang, Yang; Zhang, Jiayong; Chen, Ming; Bao, Shengde

    2016-01-01

    Introduction. Transient global amnesia (TGA) following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360) or cardiac angiography (4 in 8817) and no case with TGA following peripheral angiography (0 in 7659). Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p = 0.022). Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p = 0.82) and different contrast agents (p = 0.619). Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography. PMID:27419129

  1. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    PubMed Central

    Zhang, Yang; Chen, Ming; Bao, Shengde

    2016-01-01

    Introduction. Transient global amnesia (TGA) following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360) or cardiac angiography (4 in 8817) and no case with TGA following peripheral angiography (0 in 7659). Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p = 0.022). Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p = 0.82) and different contrast agents (p = 0.619). Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography. PMID:27419129

  2. Hepatic Artery Angiography and Embolization for Hemobilia Following Laparoscopic Cholecystectomy

    SciTech Connect

    Nicholson, Tony; Travis, Simon; Ettles, Duncan; Dyet, John; Sedman, Peter; Wedgewood, Kevin; Royston, Christopher

    1999-01-15

    Purpose: The effectiveness of angiography and embolization in diagnosis and treatment were assessed in a cohort of patients presenting with upper gastrointestinal hemorrhage secondary to hepatic artery pseudoaneurysm following laparoscopic cholecystectomy. Methods: Over a 6-year period 1513 laparoscopic cholecystectomies were carried out in our region. Nine of these patients (0.6%) developed significant upper gastrointestinal bleeding, 5-43 days after surgery. All underwent emergency celiac and selective right hepatic artery angiography. All were treated by coil embolization of the right hepatic artery proximal and distal to the bleeding point. Results: Pseudoaneurysms of the hepatic artery adjacent to cholecystectomy clips were demonstrated in all nine patients at selective right hepatic angiography. In three patients celiac axis angiography alone failed to demonstrate the pseudoaneurysm. Embolization controlled hemorrhage in all patients with no further bleeding and no further intervention. One patient developed a candidal liver abscess in the post-procedure period. All patients are alive and well at follow-up. Conclusion: Selective right hepatic angiography is vital in the diagnosis of upper gastrointestinal hemorrhage following laparoscopic cholecystectomy. Embolization offers the advantage of minimally invasive treatment in unstable patients, does not disrupt recent biliary reconstruction, allows distal as well as proximal control of the hepatic artery, and is an effective treatment for this potentially life-threatening complication.

  3. Overuse of Computed Tomography Pulmonary Angiography in the Evaluation of Patients with Suspected Pulmonary Embolism in the Emergency Department

    PubMed Central

    Crichlow, Amanda; Cuker, Adam; Mills, Angela M.

    2012-01-01

    Background Clinical decision rules have been developed and validated for the evaluation of patients presenting with suspected pulmonary embolism (PE) to the emergency department (ED). Objectives To assess the percentage of computed tomographic pulmonary angiography (CT-PA) which could have been avoided by use of the Wells score coupled with D-dimer testing (Wells/D-dimer) or Pulmonary Embolism Rule-Out Criteria (PERC) in ED patients with suspected PE. Methods The authors conducted a prospective cohort study of adult ED patients undergoing CT-PA for suspected PE. Wells score and PERC were calculated. A research blood sample was obtained for D-dimer testing for subjects who did not undergo testing as part of their ED evaluation. The primary outcome was PE by CT-PA or 90-day follow-up. Secondary outcomes were ED length of stay (LOS) and CT-PA time as defined by time from order to initial radiologist interpretation. Results Of 152 suspected PE subjects available for analysis (mean age 46.3±15.6 years, 74% female, 59% black or African American, 11.8% diagnosed with PE), 14 (9.2%) met PERC, none of whom were diagnosed with PE. A low-risk Wells score (≤4) was assigned to 110 (72%) subjects, of whom only 38 (35%) underwent clinical D-dimer testing (elevated in 33/38). Of the 72 subjects with low-risk Wells scores who did not have D-dimers performed in the ED, archived research samples were negative in 16 (22%). All 21 subjects with low-risk Wells scores and negative D-dimers were PE-negative. CT-PA time (median 160 minutes) accounted for more than half of total ED LOS (median 295 minutes). Conclusions In total, 9.2% and 13.8% of CT-PA could have been avoided by use of PERC and Wells/D-dimer, respectively. PMID:23167851

  4. Coronary Events and Anatomy After Arterial Switch Operation for Transposition of the Great Arteries: Detection by 16-Row Multislice Computed Tomography Angiography in Pediatric Patients

    SciTech Connect

    Oztunc, Funda Baris, Safa; Adaletli, Ibrahim Onol, Nurper Onder Olgun, Deniz Cebi; Guezeltas, Alper Ozyilmaz, Isa Ozdil, Mine; Kurugoglu, Sebuh; Eroglu, Ayse Gueler

    2009-03-15

    The purpose of this study was to evaluate the feasibility of multislice computed tomographic (MSCT) angiography as a noninvasive method for detecting ostial, proximal, and middle segment coronary stenosis or occlusion and anatomy in patients with transposition of the great arteries who had undergone arterial switch operation (ASO). Sixteen-detector-row MSCT angiography was performed in 16 patients treated with ASO for transposition of the great arteries. The median age was 10.3 years (range, 6.2-16.3 years). Sixteen-detector-row MSCT angiography was performed in 16 patients who had undergone ASO. CT imaging was performed in the craniocaudal direction from 2 cm above the carina up to the heart basis. Noninvasive assessment of coronary artery stenosis and anatomy were investigated by MSCT angiography. Two patients were excluded from the study because of artifacts. Of 14 evaluated patients, 1 patient had ostial stenosis (7.1%). A coronary artery anatomy variant was present in six patients: left main artery (LMA) and right coronary artery (RCA) originating from the right sinus as a single orifice (n = 2); left circumflex artery (LCX) originating from the RCA (n = 1); LMA and RCA, after branching to the LCX, originating separately from the right sinus (n = 1); and LMA (n = 1) and left anterior descending artery (LADA; n = 1) originating directly from the right sinus. Intramural bridging in the LAD (n = 2) was detected. Five patients were normal. In conclusion, MSCT angiography, as a noninvasive, feasible technique for assessing coronary stenosis or occlusion and anatomy, can be used in the follow-up of patients who have undergone ASO.

  5. Intraoperative DynaCT Detection and Immediate Correction of a Type 1a Endoleak Following Endovascular Repair of Abdominal Aortic Aneurysm

    SciTech Connect

    Biasi, Lukla; Ali, Tahir; Hinchliffe, Robert; Morgan, Rob; Loftus, Ian; Thompson, Matt

    2009-05-15

    Reintervention following endovascular aneurysm repair (EVAR) is required in up to 10% of patients at 30 days and is associated with a demonstrable risk of increased mortality. Completion angiography cannot detect all graft-related anomalies and computed tomographic angiography is therefore mandatory to ensure clinical success. Intraoperative angiographic computed tomography (DynaCT; Siemens, Germany) utilizes cone beam reconstruction software and flat-panel detectors to generate CT-like images from rotational angiographic acquisitions. We report the intraoperative use of this novel technology in detecting and immediately treating a proximal anterior type Ia endoleak, following an endovascular abdominal aortic repair, which was not seen on completion angiography. Immediate evaluation of cross-sectional imaging following endograft deployment may allow for on-table correction of clinically significant stent-related complications. This should both improve technical success and minimize the need for early secondary intervention following EVAR.

  6. Glucagon-Induced Vasospasm of Hepatic Artery Branches During Visceral Angiography

    SciTech Connect

    Dziedzic, T. Scott; Smith, Tony P.

    2008-07-15

    Glucagon is often used in radiology to decrease bowel motility for enhanced imaging, including visceral digital subtraction angiography. We present a case in which branch hepatic artery vasospasm followed the intravenous administration of glucagon during visceral angiography.

  7. [3D-MR-angiography using Gd-DTPA].

    PubMed

    Seiderer, M; Bauer, W M; Villringer, A; Einhäupl, K

    1990-03-01

    Projection angiograms similar to DSA can be obtained via 3D-gradient echo techniques by subtraction of data sets acquired before and after the intravenous administration of Gd-DTPA (0.1-0.2 mmol/kg body weight). As Gd-DTPA does not penetrate the blood-brain barrier, image subtraction results in complete cancellation of non vascular tissue. In organs without blood-brain barrier Gd-DTPA induced signal enhancement results in modest background superposition of vascular anatomy. With Gd-DTPA angiography vessels are imaged favouring the venous system because of the more constant flow velocity and the lack of ECG synchronization. Gd-DTPA angiography results in high signal-to-noise angiograms and can even be performed with MR imagers which do not meet the hardware requirements for angiography based on flow compensated gradients. PMID:2157258

  8. Quantitative OCT angiography of optic nerve head blood flow

    PubMed Central

    Jia, Yali; Morrison, John C.; Tokayer, Jason; Tan, Ou; Lombardi, Lorinna; Baumann, Bernhard; Lu, Chen D.; Choi, WooJhon; Fujimoto, James G.; Huang, David

    2012-01-01

    Optic nerve head (ONH) blood flow may be associated with glaucoma development. A reliable method to quantify ONH blood flow could provide insight into the vascular component of glaucoma pathophysiology. Using ultrahigh-speed optical coherence tomography (OCT), we developed a new 3D angiography algorithm called split-spectrum amplitude-decorrelation angiography (SSADA) for imaging ONH microcirculation. In this study, a method to quantify SSADA results was developed and used to detect ONH perfusion changes in early glaucoma. En face maximum projection was used to obtain 2D disc angiograms, from which the average decorrelation values (flow index) and the percentage area occupied by vessels (vessel density) were computed from the optic disc and a selected region within it. Preperimetric glaucoma patients had significant reductions of ONH perfusion compared to normals. This pilot study indicates OCT angiography can detect the abnormalities of ONH perfusion and has the potential to reveal the ONH blood flow mechanism related to glaucoma. PMID:23243564

  9. Split-spectrum phase-gradient optical coherence tomography angiography

    PubMed Central

    Liu, Gangjun; Jia, Yali; Pechauer, Alex D.; Chandwani, Rahul; Huang, David

    2016-01-01

    A phase gradient angiography (PGA) method is proposed for optical coherence tomography (OCT). This method allows the use of phase information to map the microvasculature in tissue without the correction of bulk motion and laser trigger jitter induced phase artifacts. PGA can also be combined with the amplitude/intensity to improve the performance. Split-spectrum technique can further increase the signal to noise ratio by more than two times. In-vivo imaging of human retinal circulation is shown with a 70 kHz, 840 nm spectral domain OCT system and a 200 kHz, 1050 nm swept source OCT system. Four different OCT angiography methods are compared. The best performance was achieved with split-spectrum amplitude and phase-gradient angiography. PMID:27570689

  10. Split-spectrum phase-gradient optical coherence tomography angiography.

    PubMed

    Liu, Gangjun; Jia, Yali; Pechauer, Alex D; Chandwani, Rahul; Huang, David

    2016-08-01

    A phase gradient angiography (PGA) method is proposed for optical coherence tomography (OCT). This method allows the use of phase information to map the microvasculature in tissue without the correction of bulk motion and laser trigger jitter induced phase artifacts. PGA can also be combined with the amplitude/intensity to improve the performance. Split-spectrum technique can further increase the signal to noise ratio by more than two times. In-vivo imaging of human retinal circulation is shown with a 70 kHz, 840 nm spectral domain OCT system and a 200 kHz, 1050 nm swept source OCT system. Four different OCT angiography methods are compared. The best performance was achieved with split-spectrum amplitude and phase-gradient angiography. PMID:27570689

  11. CT Imaging of Coronary Stents: Past, Present, and Future

    PubMed Central

    Mahnken, Andreas H.

    2012-01-01

    Coronary stenting became a mainstay in coronary revascularization therapy. Despite tremendous advances in therapy, in-stent restenosis (ISR) remains a key problem after coronary stenting. Coronary CT angiography evolved as a valuable tool in the diagnostic workup of patients after coronary revascularization therapy. It has a negative predictive value in the range of 98% for ruling out significant ISR. As CT imaging of coronary stents depends on patient and stent characteristics, patient selection is crucial for success. Ideal candidates have stents with a diameter of 3 mm and more. Nevertheless, even with most recent CT scanners, about 8% of stents are not accessible mostly due to blooming or motion artifacts. While the diagnosis of ISR is currently based on the visual assessment of the stent lumen, functional information on the hemodynamic significance of in-stent stenosis became available with the most recent generation of dual source CT scanners. This paper provides a comprehensive overview on previous developments, current techniques, and clinical evidence for cardiac CT in patients with coronary artery stents. PMID:22997590

  12. Optical Coherence Tomography Angiography of Optic Disc Perfusion in Glaucoma

    PubMed Central

    Jia, Yali; Wei, Eric; Wang, Xiaogang; Zhang, Xinbo; Morrison, John C.; Parikh, Mansi; Lombardi, Lori H.; Gattey, Devin M.; Armour, Rebecca L.; Edmunds, Beth; Kraus, Martin F.; Fujimoto, James G.; Huang, David

    2014-01-01

    Purpose To compare optic disc perfusion between normal and glaucoma subjects using optical coherence tomography (OCT) angiography and detect optic disc perfusion changes in glaucoma. Design Observational, cross-sectional study. Participants Twenty-four normal subjects and 11 glaucoma patients were included. Methods One eye of each subject was scanned by a high-speed 1050 nm wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography algorithm (SSADA) was used to compute three-dimensional optic disc angiography. A disc flow index was computed from four registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc ratios. Wide field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. Main Outcome Measurements Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations between disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. Results In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in glaucoma subjects. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV respectively. The disc flow index was reduced by 25% in the glaucoma group (p = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R2 = 0.752, p = 0.001). These correlations were significant even after accounting for age, cup/disc area ratio, NFL, and rim area. Conclusions OCT angiography, generated by the new SSADA algorithm, repeatably measures optic disc perfusion. OCT

  13. When is rotational angiography superior to conventional single‐plane angiography for planning coronary angioplasty?

    PubMed Central

    Taylor, Jane; Boutong, Sara; Brett, Sarah; Louis, Amal; Heppenstall, James; Morton, Allison C.; Gunn, Julian P.

    2015-01-01

    Objectives To investigate the value of rotational coronary angiography (RoCA) in the context of percutaneous coronary intervention (PCI) planning. Background As a diagnostic tool, RoCA is associated with decreased patient irradiation and contrast use compared with conventional coronary angiography (CA) and provides superior appreciation of three‐dimensional anatomy. However, its value in PCI remains unknown. Methods We studied stable coronary artery disease assessment and PCI planning by interventional cardiologists. Patients underwent either RoCA or conventional CA pre‐PCI for planning. These were compared with the referral CA (all conventional) in terms of quantitative lesion assessment and operator confidence. An independent panel reanalyzed all parameters. Results Six operators performed 127 procedures (60 RoCA, 60 conventional CA, and 7 crossed‐over) and assessed 212 lesions. RoCA was associated with a reduction in the number of lesions judged to involve a bifurcation (23 vs. 30 lesions, P < 0.05) and a reduction in the assessment of vessel caliber (2.8 vs. 3.0 mm, P < 0.05). RoCA improved confidence assessing lesion length (P = 0.01), percentage stenosis (P = 0.02), tortuosity (P < 0.04), and proximity to a bifurcation (P = 0.03), particularly in left coronary artery cases. X‐ray dose, contrast agent volume, and procedure duration were not significantly different. Conclusions Compared with conventional CA, RoCA augments quantitative lesion assessment, enhances confidence in the assessment of coronary artery disease and the precise details of the proposed procedure, but does not affect X‐ray dose, contrast agent volume, or procedure duration. © 2015 Wiley Periodicals, Inc. PMID:26012725

  14. Optical Coherence Tomography Angiography in Mice: Comparison with Confocal Scanning Laser Microscopy and Fluorescein Angiography

    PubMed Central

    Giannakaki-Zimmermann, Helena; Kokona, Despina; Wolf, Sebastian; Ebneter, Andreas; Zinkernagel, Martin S.

    2016-01-01

    Purpose Optical coherence tomography angiography (OCT-A) allows noninvasive visualization of retinal vessels in vivo. OCT-A was used to characterize the vascular network of the mouse retina and was compared with fluorescein angiography (FA) and histology. Methods In the present study, OCT-A based on a Heidelberg Engineering Spectralis system was used to investigate the vascular network in mice. Data was compared with FA and confocal microscopy of flat-mount histology stained with isolectin IB4. For quantitative analysis the National Cancer Institute's AngioTool software was used. Vessel density, the number of vessel junctions, and endpoints were measured and compared between the imaging modalities. Results The configuration of the superficial capillary network was comparable with OCT-A and flat-mount histology in BALBc mice. However, vessel density and the number of vessel junctions per region of interest (P = 0.0161 and P = 0.0015, respectively) in the deep vascular network of BALBc mice measured by OCT-A was significantly higher than with flat-mount histology. In C3A.Cg-Pde6b+Prph2Rd2/J mice, where the deep capillary plexus is absent, analysis of the superficial network provided similar results for all three imaging modalities. Conclusion OCT-A is a helpful imaging tool for noninvasive, in vivo imaging of the vascular plexus in mice. It may offer advantages over FA and confocal microscopy especially for imaging the deep vascular plexus. Translational Relevance The present study shows that OCT-A can be employed for small animal imaging to assess the vascular network and offers advantages over flat-mount histology and FA. PMID:27570710

  15. Use of Computed Tomography – Digital Subtraction Angiography in differentiating pulmonary thrombosis and pulmonary artery dissection in a large pulmonary artery aneurysm

    PubMed Central

    Rashid, Hashrul N.Z.; Lim, Andy K.; Lau, Kenneth K.

    2016-01-01

    70 year-old female with chronic obstructive pulmonary disease (COPD) presented with typical symptoms of an exacerbation of COPD. Management of COPD resolved her wheezing, but ongoing hypoxia and retrospective history of atypical chest pain prompted exclusion of a pulmonary embolus. A CT Pulmonary Angiogram (CTPA) with standard 64-slice CT revealed an extensive non-occlusive defect in a grossly dilated right pulmonary artery. Presence of circumferential cuff of soft tissue within sub-segmental pulmonary artery branch raised the possibility of pulmonary artery dissection (PAD). Exclusion of PAD was important as it precluded full anticoagulation. A dynamic CT-digital subtraction angiography (CT-DSA) with the 320-slice multidetector CT (Aquilion-one Vision, Toshiba) did not reveal any intimal flap or contrast extension into the pulmonary arterial wall, suggesting it is unlikely to be PAD. The patient was started on full anticoagulation and reported improvement of symptoms with reduction in pulmonary thrombus burden on repeat CTPA at 4 weeks. To our knowledge, this is the first reported use of dynamic CT-DSA in ruling out PAD. PMID:27144113

  16. Use of Computed Tomography - Digital Subtraction Angiography in differentiating pulmonary thrombosis and pulmonary artery dissection in a large pulmonary artery aneurysm.

    PubMed

    Rashid, Hashrul N Z; Lim, Andy K; Lau, Kenneth K

    2016-01-01

    70 year-old female with chronic obstructive pulmonary disease (COPD) presented with typical symptoms of an exacerbation of COPD. Management of COPD resolved her wheezing, but ongoing hypoxia and retrospective history of atypical chest pain prompted exclusion of a pulmonary embolus. A CT Pulmonary Angiogram (CTPA) with standard 64-slice CT revealed an extensive non-occlusive defect in a grossly dilated right pulmonary artery. Presence of circumferential cuff of soft tissue within sub-segmental pulmonary artery branch raised the possibility of pulmonary artery dissection (PAD). Exclusion of PAD was important as it precluded full anticoagulation. A dynamic CT-digital subtraction angiography (CT-DSA) with the 320-slice multidetector CT (Aquilion-one Vision, Toshiba) did not reveal any intimal flap or contrast extension into the pulmonary arterial wall, suggesting it is unlikely to be PAD. The patient was started on full anticoagulation and reported improvement of symptoms with reduction in pulmonary thrombus burden on repeat CTPA at 4 weeks. To our knowledge, this is the first reported use of dynamic CT-DSA in ruling out PAD. PMID:27144113

  17. Dual-energy CT revisited with multidetector CT: review of principles and clinical applications.

    PubMed

    Karçaaltıncaba, Muşturay; Aktaş, Aykut

    2011-09-01

    Although dual-energy CT (DECT) was first conceived in the 1970s, it was not widely used for CT indications. Recently, the simultaneous acquisition of volumetric dual-energy data has been introduced using multidetector CT (MDCT) with two X-ray tubes and rapid kVp switching (gemstone spectral imaging). Two major advantages of DECT are material decomposition by acquiring two image series with different kVp and the elimination of misregistration artifacts. Hounsfield unit measurements by DECT are not absolute and can change depending on the kVp used for an acquisition. Typically, a combination of 80/140 kVp is used for DECT, but for some applications, 100/140 kVp is preferred. In this study, we summarized the clinical applications of DECT and included images that were acquired using the dual-source CT and rapid kVp switching. In general, unenhanced images can be avoided by using DECT for body and neurological applications; iodine can be removed from the image, and a virtual, non-contrast (water) image can be obtained. Neuroradiological applications allow for the removal of bone and calcium from the carotid and brain CT angiography. Thorax applications include perfusion imaging in patients with pulmonary thromboemboli and other chest diseases, xenon ventilation-perfusion imaging and solitary nodule characterization. Cardiac applications include dual-energy cardiac perfusion, viability and cardiac iron detection. The removal of calcific plaques from arteries, bone removal and aortic stent graft evaluation may be achieved in the vascular system. Abdominal applications include the detection and characterization of liver and pancreas masses, the diagnosis of steatosis and iron overload, DECT colonoscopy and CT cholangiography. Urinary system applications are urinary calculi characterization (uric acid vs. non-uric acid), renal cyst characterization and mass characterization. Musculoskeletal applications permit the differentiation of gout from pseudogout and a reduction of

  18. Multi-modal CT scanning in the evaluation of cerebrovascular disease patients

    PubMed Central

    Anzidei, Michele; Piga, Mario; Ciolina, Federica; Mannelli, Lorenzo; Catalano, Carlo; Suri, Jasjit S.; Raz, Eytan

    2014-01-01

    Ischemic stroke currently represents one of the leading causes of severe disability and mortality in the Western World. Until now, angiography was the most used imaging technique for the detection of the extra-cranial and intracranial vessel pathology. Currently, however, non-invasive imaging tool like ultrasound (US), magnetic resonance (MR) and computed tomography (CT) have proven capable of offering a detailed analysis of the vascular system. CT in particular represents an advanced system to explore the pathology of carotid arteries and intracranial vessels and also offers tools like CT perfusion (CTP) that provides valuable information of the brain’s vascular physiology by increasing the stroke diagnostic. In this review, our purpose is to discuss stroke risk prediction and detection using CT. PMID:25009794

  19. Comparison of stroke infarction between CT perfusion and diffusion weighted imaging: preliminary results

    NASA Astrophysics Data System (ADS)

    Abd. Rahni, Ashrani Aizzuddin; Arka, Israna Hossain; Chellappan, Kalaivani; Mukari, Shahizon Azura; Law, Zhe Kang; Sahathevan, Ramesh

    2016-03-01

    In this paper we present preliminary results of comparison of automatic segmentations of the infarct core, between that obtained from CT perfusion (based on time to peak parameter) and diffusion weighted imaging (DWI). For each patient, the two imaging volumes were automatically co-registered to a common frame of reference based on an acquired CT angiography image. The accuracy of image registration is measured by the overlap of the segmented brain from both images (CT perfusion and DWI), measured within their common field of view. Due to the limitations of the study, DWI was acquired as a follow up scan up to a week after initial CT based imaging. However, we found significant overlap of the segmented brain (Jaccard indices of approximately 0.8) and the percentage of infarcted brain tissue from the two modalities were still fairly highly correlated (correlation coefficient of approximately 0.9). The results are promising with more data needed in future for clinical inference.

  20. Single incision laparoscopic surgery approach for obscure small intestine bleeding localized by CT guided percutaneous injection of methylene blue

    PubMed Central

    Martinez, Juan Carlos; Thomas, Jamie L.; Lukaszczyk, John J.

    2014-01-01

    INTRODUCTION Traditionally, localization of small intestine sources of obscure gastrointestinal bleeding has been a challenge. Advances in the field of endoscopy with the introduction of capsule endoscopy and radiographic imaging with computed tomography angiography and visceral angiography have facilitated more accurate visualization of the small intestine. If a bleeding lesion is identified on angiography and surgery is indicated, the use of methylene blue for enteric mapping is very effective to aid intraoperative localization of the culprit. However, when this is not an option, more invasive surgical techniques are required. PRESENTATION OF CASE We present a new technique used in a patient with angiodysplasia of the small intestine, in where preoperative localization was done using percutaneous computed tomography (CT) guided injection of methylene blue dye. This allowed us to perform a single incision laparoscopic small intestine resection of the culprit. PMID:25460480

  1. Cardiac magnetic resonance and computed tomography angiography for clinical imaging of stable coronary artery disease. Diagnostic classification and risk stratification

    PubMed Central

    Korosoglou, Grigorios; Giusca, Sorin; Gitsioudis, Gitsios; Erbel, Christian; Katus, Hugo A.

    2014-01-01

    Despite advances in the pharmacologic and interventional treatment of coronary artery disease (CAD), atherosclerosis remains the leading cause of death in Western societies. X-ray coronary angiography has been the modality of choice for diagnosing the presence and extent of CAD. However, this technique is invasive and provides limited information on the composition of atherosclerotic plaque. Coronary computed tomography angiography (CCTA) and cardiac magnetic resonance (CMR) have emerged as promising non-invasive techniques for the clinical imaging of CAD. Hereby, CCTA allows for visualization of coronary calcification, lumen narrowing and atherosclerotic plaque composition. In this regard, data from the CONFIRM Registry recently demonstrated that both atherosclerotic plaque burden and lumen narrowing exhibit incremental value for the prediction of future cardiac events. However, due to technical limitations with CCTA, resulting in false positive or negative results in the presence of severe calcification or motion artifacts, this technique cannot entirely replace invasive angiography at the present time. CMR on the other hand, provides accurate assessment of the myocardial function due to its high spatial and temporal resolution and intrinsic blood-to-tissue contrast. Hereby, regional wall motion and perfusion abnormalities, during dobutamine or vasodilator stress, precede the development of ST-segment depression and anginal symptoms enabling the detection of functionally significant CAD. While CT generally offers better spatial resolution, the versatility of CMR can provide information on myocardial function, perfusion, and viability, all without ionizing radiation for the patients. Technical developments with these 2 non-invasive imaging tools and their current implementation in the clinical imaging of CAD will be presented and discussed herein. PMID:25147526

  2. Dual-Energy Spectral CT: Various Clinical Vascular Applications.

    PubMed

    Machida, Haruhiko; Tanaka, Isao; Fukui, Rika; Shen, Yun; Ishikawa, Takuya; Tate, Etsuko; Ueno, Eiko

    2016-01-01

    Single-source dual-energy (DE) computed tomography (CT) with fast switching of tube voltage allows projection-based image reconstruction, substantial reduction of beam-hardening effects, reconstruction of accurate monochromatic images and material decomposition images (MDIs), and detailing of material composition by using x-ray spectral information. In vascular applications, DE CT is expected to overcome limitations of standard single-energy CT angiography, including patient exposure to nephrotoxic contrast medium and carcinogenic radiation, insufficient contrast vascular enhancement, interference from metallic and beam-hardening artifacts and severe vessel calcification, and limited tissue characterization and perfusion assessment. Acquisition of low-energy monochromatic images and iodine/water MDIs can reasonably reduce contrast agent dose and improve vessel enhancement. Acquisition of virtual noncontrast images, such as water/iodine MDIs, can reduce overall radiation exposure by replacing true noncontrast CT in each examination. Acquisition of monochromatic images by using metal artifact reduction software or acquisition of iodine/water MDIs can reduce metal artifacts with preserved or increased vessel contrast, and subtraction of monochromatic images between two energy levels can subtract coils composed of dense metallic materials. Acquisition of iodine/calcium (ie, hydroxyapatite) MDIs permits subtraction of vessel calcification and improves vessel lumen delineation. Sensitive detection of lipid-rich plaque can be achieved by using fat/water MDIs, the spectral Hounsfield unit curve (energy level vs CT attenuation), and a histogram of effective atomic numbers included in an image. Various MDIs are useful for accurate differentiation among materials with high attenuation values, including contrast medium, calcification, and fresh hematoma. Iodine/water MDIs are used to assess organ perfusion, such as in the lungs and myocardium. Understanding these DE CT

  3. Neurologic complications of cerebral angiography in childhood moyamoya syndrome.

    PubMed

    Robertson, R L; Chavali, R V; Robson, C D; Barnes, P D; Eldredge, E A; Burrows, P E; Scott, R M

    1998-11-01

    Purpose. To determine the incidence of neurologic complications of cerebral angiography in children with moyamoya syndrome (MMS) as compared to children without MMS. Materials and methods. One-hundred-ninety consecutive cerebral angiograms obtained in 152 children were evaluated. Sixty of these angiograms were obtained in 40 children with MMS. Patients underwent neurologic evaluation prior to and after the procedure. For this study, a neurologic complication was defined as any new focal neurologic deficit or alteration in mental status occurring during the procedure or within the ensuing 24 hours. Results. There were 2 neurologic complications within 24 hours of angiography, one in the MMS group and one in the non-MMS group. One patient with MMS became mute following angiography. The symptom resolved within 12 hours. One patient without MMS being examined postoperatively for residual arteriovenous malformation developed intracranial hemorrhage requiring reexploration 12 hours after the angiogram. Using a two-tail Fisher's exact test, there was no significant statistical difference in the ischemic (P = 0.3) or hemorrhagic (P = 1.0) complication rates between the group of patients with MMS and the non-MMS groups. Conclusion. The risk of a neurologic complication from cerebral angiography in children with MMS is low and not statistically different from the risk in children with other cerebrovascular disorders. PMID:9799310

  4. Bilateral persistent trigeminal artery variants diagnosed by MR angiography.

    PubMed

    Uchino, Akira

    2011-12-01

    A persistent trigeminal artery (PTA) is the most common anastomosis between the carotid and vertebrobasilar system. A PTA variant (PTAV) is a rare anomaly in which the cerebellar artery arises from the internal carotid artery (ICA) without connection with the basilar artery (BA). I present what I believe is the first report of bilateral PTAVs diagnosed using magnetic resonance (MR) angiography and briefly discuss the embryology of this rare anomaly. An 81-year-old woman with small infarctions underwent cerebral MR imaging and MR angiography with a 1.5-tesla imager for the evaluation of brain lesions. An MR angiography was obtained using the standard noncontrast three-dimensional time-of-flight technique. The MR angiographic demonstration of bilateral anterior inferior cerebellar arteries arising from the precavernous segment of the ICA without anastomosis to the BA indicated bilateral PTAVs. This is the first report of bilateral PTAVs diagnosed by MR angiography. The literature review indicates that an estimated prevalence of bilateral PTAVs is about 0.0012%. PMID:21544587

  5. High-speed lossless compression for angiography image sequences

    NASA Astrophysics Data System (ADS)

    Kennedy, Jonathon M.; Simms, Michael; Kearney, Emma; Dowling, Anita; Fagan, Andrew; O'Hare, Neil J.

    2001-05-01

    High speed processing of large amounts of data is a requirement for many diagnostic quality medical imaging applications. A demanding example is the acquisition, storage and display of image sequences in angiography. The functional performance requirements for handling angiography data were identified. A new lossless image compression algorithm was developed, implemented in C++ for the Intel Pentium/MS-Windows environment and optimized for speed of operation. Speeds of up to 6M pixels per second for compression and 12M pixels per second for decompression were measured. This represents an improvement of up to 400% over the next best high-performance algorithm (LOCO-I) without significant reduction in compression ratio. Performance tests were carried out at St. James's Hospital using actual angiography data. Results were compared with the lossless JPEG standard and other leading methods such as JPEG-LS (LOCO-I) and the lossless wavelet approach proposed for JPEG 2000. Our new algorithm represents a significant improvement in the performance of lossless image compression technology without using specialized hardware. It has been applied successfully to image sequence decompression at video rate for angiography, one of the most challenging application areas in medical imaging.

  6. [OCT Angiography - Is this the Future for Macular Diagnosis?].

    PubMed

    Pauleikhoff, D; Heimes, B; Spital, G; Gutfleisch, M; Ziegler, M; Book, B; Farecki, M-L; Lommatzsch, A P

    2015-09-01

    Recent developements in OCT technology using high speed acquisition and calculation of consecutive scans (SSADA = split spectrum amplitude decorrelation algorithm) have resulted in the possibility to demonstrate retinal and choroidal vessels in the macula. This new technology of "OCT angiography" thus allows the non-invasive and rapid (within seconds) reconstruction of the three-dimensional structure of the retinal and choroidal vascularisation. There are still limitations caused by movement artefacts, superposition of superficial retinal vessels at the RPE level or insufficient three-dimensional imaging, but the first experience with this new method and especially the correlations with the current standard diagnostic procedure fluorescein angiography shows that especially for vascular changes which are predominantly in one retinal layer (e.g., the inner retina) like in diabetic retinopathy or retinal vein occlusions, a very good correlation can be seen. Also in MacTel type 2 patients the proposed vascular changes in the deeper capillary network of the retina can be visualised very well with OCT angiography. In contrast, more three-dimensional vascular changes like the neovascular complex in exsudative AMD need a more sophisticated diagnostic analysis strategy, which has still to be developed. However, the first experience also demonstrates that fluorescein angiographic differentiation can also be seen in OCT angiography. In addition, the new technology gives additional information about the choroidal and outer retinal changes in these pathologies, which may result in a better understanding of the underlying pathologies. PMID:26241062

  7. Clinical Assessment of a New Stereoscopic Digital Angiography System

    SciTech Connect

    Moll, Thierry; Douek, Philippe; Finet, Gerard; Turjman, Francis; Picard, Catherine; Revel, Didier; Amiel, Michel

    1998-01-15

    Purpose: To assess the clinical feasibility of an experimental modified angiographic system capable of real-time digital stereofluoroscopy and stereography in X-ray angiography, using a twin-focus tube and a stereoscopic monitor. Methods: We report the experience obtained in 37 patients with a well-documented examination. The patients were examined for coronary angiography (11 cases), aortography (7 cases), pulmonary angiography (6 cases), inferior vena cava filter placement (2 cases), and cerebral angiography (11 cases). Six radiologists were asked to use stereoscopic features for fluoroscopy and angiography. A questionnaire was designed to record their subjective evaluation of stereoscopic image quality, ergonomics of the system, and its medical interest. Results: Stereofluoroscopy was successfully used in 25 of 37 cases; diplopia and/or ghost images were reported in 6 cases. It was helpful for aortic catheterization in 10 cases and for selective catheterization in 5 cases. In stereoangiography, depth was easily and accurately perceived in 27 of 37 cases; diplopia and/or ghost images were reported in 4 cases. A certain gain in the three-dimensional evaluation of the anatomy and relation between vessels and lesions was noted. As regards ergonomic considerations, polarized spectacles were not considered cumbersome. Visual fatigue and additional work were variously reported. Stereoshift tuning before X-ray acquisition was not judged to be a limiting factor. Conclusion: A twin-focus X-ray tube and a polarized shutter for stereoscopic display allowed effective real-time three-dimensional perception of angiographic images. Our clinical study suggests no clear medical interest for diagnostic examinations, but the field of interventional radiology needs to be investigated.

  8. Practical CT dosimetry

    SciTech Connect

    Yoshizumi, T.T.; Suneja, S.K.; Teal, J.S. )

    1989-07-01

    The dose from computed tomography (CT) examinations is not negligible from a radiation safety standpoint. Occasionally, one encounters a case in which an unsuspected pregnant woman undergoes a CT pelvic scan, and the radiologist is required to estimate the dose to the fetus. This article addresses practical methods of CT dosimetry with a specific discussion on fetal dose estimate. Three methods are described: (1) the use of a dose chart, (2) the pencil ionization chamber method, and (3) the thermoluminescence dosimetry (TLD) method.

  9. CT findings in leukemia

    SciTech Connect

    Heiberg, E.; Wolverson, M.K.; Sundaram, M.; Shields, J.B.

    1984-12-01

    Review of 84 computed tomographic (CT) scans in leukemic patients demonstrate a wide spectrum of abnormalities. Findings caused by leukemia were lymphadenopathy, visceral enlargement, focal defects, and tissue infiltration. Hemorrhage was by far the most common complication and could usually be characterized on the noncontrast CT scan. The distinction between old hematomas, foci of infection, and leukemia infiltration could not be made with certainty without CT-guided aspiration. Unusual instances of sepsis, such as microabscesses of the liver and typhlitis, were seen.

  10. PET/CT Artifacts

    PubMed Central

    Blodgett, Todd M.; Mehta, Ajeet S.; Mehta, Amar S.; Laymon, Charles M.; Carney, Jonathan; Townsend, David W.

    2014-01-01

    There are several artifacts encountered in PET/CT imaging, including attenuation correction (AC) artifacts associated with using CT for attenuation correction. Several artifacts can mimic a 2-deoxy-2-[18F] fluoro-D-glucose (FDG) avid malignant lesions and therefore recognition of these artifacts is clinically relevant. Our goal was to identify and characterize these artifacts and also discuss some protocol variables that may affect image quality in PET/CT. PMID:21237418

  11. Pulmonary 64-MDCT angiography with 50 mL of iodinated contrast material in an unselected patient population: a feasible protocol*

    PubMed Central

    Trad, Henrique Simão; Boasquevisque, Gustavo Santos; Giacometti, Tiago Rangon; Trad, Catherine Yang; Zoghbi Neto, Orlando Salomão; Trad, Clovis Simão

    2016-01-01

    Objective To propose a protocol for pulmonary angiography using 64-slice multidetector computed tomography (64-MDCT) with 50 mL of iodinated contrast material, in an unselected patient population, as well as to evaluate vascular enhancement and image quality. Materials and Methods We evaluated 29 patients (22-86 years of age). The body mass index ranged from 19.0 kg/m2 to 41.8 kg/m2. Patients underwent pulmonary CT angiography in a 64-MDCT scanner, receiving 50 mL of iodinated contrast material via venous access at a rate of 4.5 mL/s. Bolus tracking was applied in the superior vena cava. Two experienced radiologists assessed image quality and vascular enhancement. Results The mean density was 382 Hounsfield units (HU) for the pulmonary trunk; 379 and 377 HU for the right and left main pulmonary arteries, respectively; and 346 and 364 HU for the right and left inferior pulmonary arteries, respectively. In all patients, subsegmental arteries were analyzed. There were streak artifacts from contrast material in the superior vena cava in all patients. However, those artifacts did not impair the image analysis. Conclusion Our findings suggest that pulmonary angiography using 64-MDCT with 50 mL of iodinated contrast can produce high quality images in unselected patient populations. PMID:27141128

  12. CT of Gastric Emergencies.

    PubMed

    Guniganti, Preethi; Bradenham, Courtney H; Raptis, Constantine; Menias, Christine O; Mellnick, Vincent M

    2015-01-01

    Abdominal pain, nausea, and vomiting are common presenting symptoms among adult patients seeking care in the emergency department, and, with the increased use of computed tomography (CT) to image patients with these complaints, radiologists will more frequently encounter a variety of emergent gastric pathologic conditions on CT studies. Familiarity with the CT appearance of emergent gastric conditions is important, as the clinical presentation is often nonspecific and the radiologist may be the first to recognize gastric disease as the cause of a patient's symptoms. Although endoscopy and barium fluoroscopy remain important tools for evaluating patients with suspected gastric disease in the outpatient setting, compared with CT these modalities enable less comprehensive evaluation of patients with nonspecific complaints and are less readily available in the acute setting. Endoscopy is also more invasive than CT and has greater potential risks. Although the mucosal detail of CT is relatively poor compared with barium fluoroscopy or endoscopy, CT can be used with the appropriate imaging protocols to identify inflammatory conditions of the stomach ranging from gastritis to peptic ulcer disease. In addition, CT can readily demonstrate the various complications of gastric disease, including perforation, obstruction, and hemorrhage, which may direct further clinical, endoscopic, or surgical management. We will review the normal anatomy of the stomach and discuss emergent gastric disease with a focus on the usual clinical presentation, typical imaging appearance, and differentiating features, as well as potential imaging pitfalls. PMID:26562229

  13. Measurement of cardiac output from dynamic pulmonary circulation time CT

    SciTech Connect

    Yee, Seonghwan; Scalzetti, Ernest M.

    2014-06-15

    Purpose: To introduce a method of estimating cardiac output from the dynamic pulmonary circulation time CT that is primarily used to determine the optimal time window of CT pulmonary angiography (CTPA). Methods: Dynamic pulmonary circulation time CT series, acquired for eight patients, were retrospectively analyzed. The dynamic CT series was acquired, prior to the main CTPA, in cine mode (1 frame/s) for a single slice at the level of the main pulmonary artery covering the cross sections of ascending aorta (AA) and descending aorta (DA) during the infusion of iodinated contrast. The time series of contrast changes obtained for DA, which is the downstream of AA, was assumed to be related to the time series for AA by the convolution with a delay function. The delay time constant in the delay function, representing the average time interval between the cross sections of AA and DA, was determined by least square error fitting between the convoluted AA time series and the DA time series. The cardiac output was then calculated by dividing the volume of the aortic arch between the cross sections of AA and DA (estimated from the single slice CT image) by the average time interval, and multiplying the result by a correction factor. Results: The mean cardiac output value for the six patients was 5.11 (l/min) (with a standard deviation of 1.57 l/min), which is in good agreement with the literature value; the data for the other two patients were too noisy for processing. Conclusions: The dynamic single-slice pulmonary circulation time CT series also can be used to estimate cardiac output.

  14. Computed Tomography Angiography of Carotid Arteries and Vertebrobasilar System: A Simulation Study for Radiation Dose Reduction.

    PubMed

    Kramer, Manuel; Ellmann, Stephan; Allmendinger, Thomas; Eller, Achim; Kammerer, Ferdinand; May, Matthias S; Baigger, João F; Uder, Michael; Lell, Michael M

    2015-07-01

    Computed tomography angiography (CTA) of carotid arteries and vertebrobasilar system is a standardized procedure with excellent image quality, but radiation exposure remains a matter of concern. The aim of this study is to examine to what extent radiation dose can be lowered in relation to a standard protocol by simulating examinations with lower tube currents applying a dedicated software.Lower tube current was simulated by a dedicated noise insertion and reconstruction software (ReconCT). In a phantom study, true scans were performed with different dose protocols and compared to the results of simulated dose reductions of the same degree, respectively. In a patient study, 30 CTAs of supra-aortic vessels were reconstructed at a level of 100%, 75%, 50%, and 25% of the initial dose. Objective and subjective image analyses were performed.No significant noise differences between true scans and simulated scans of mimicked contrasted vessels were found. In the patient study, the quality scores of the 4 dose groups differed statistically significant; this difference vanished for the comparison of the 100% and 75% datasets after dichotomization into the categories of diagnostic and nondiagnostic image quality (P = .50).This study suggests an easy-to-implement method of simulating CTAs of carotid arteries and vertebrobasilar system with lower tube current for dose reduction by artificially adding noise to the original raw data. Lowering the radiation dose in a moderate extent to 75% of the original dose levels does not significantly alter the diagnostic image quality. PMID:26131822

  15. Multi-Detector Coronary CT Imaging for the Identification of Coronary Artery Stenoses in a “Real-World” Population

    PubMed Central

    Makaryus, Amgad N; Henry, Sonia; Loewinger, Lee; Makaryus, John N; Boxt, Lawrence

    2014-01-01

    BACKGROUND Multi-detector computed tomography (CT) has emerged as a modality for the non-invasive assessment of coronary artery disease (CAD). Prior studies have selected patients for evaluation and have excluded many of the “real-world” patients commonly encountered in daily practice. We compared 64-detector-CT (64-CT) to conventional coronary angiography (CA) to investigate the accuracy of 64-CT in determining significant coronary stenoses in a “real-world” clinical population. METHODS A total of 1,818 consecutive patients referred for 64-CT were evaluated. CT angiography was performed using the GE LightSpeed VCT (GE® Healthcare). Forty-one patients in whom 64-CT results prompted CA investigation were further evaluated, and results of the two diagnostic modalities were compared. RESULTS A total of 164 coronary arteries and 410 coronary segments were evaluated in 41 patients (30 men, 11 women, age 39–85 years) who were identified by 64-CT to have significant coronary stenoses and who thereafter underwent CA. The overall per-vessel sensitivity, specificity, positive predictive value, negative predictive value, and accuracy at the 50% stenosis level were 86%, 84%, 65%, 95%, and 85%, respectively, and 77%, 93%, 61%, 97%, and 91%, respectively, in the per-segment analysis at the 50% stenosis level. CONCLUSION 64-CT is an accurate imaging tool that allows a non-invasive assessment of significant CAD with a high diagnostic accuracy in a “real-world” population of patients. The sensitivity and specificity that we noted are not as high as those in prior reports, but we evaluated a population of patients that is typically encountered in clinical practice and therefore see more “real-world” results. PMID:25628513

  16. Ultrahigh-speed non-invasive widefield angiography

    NASA Astrophysics Data System (ADS)

    Blatter, Cedric; Klein, Thomas; Grajciar, Branislav; Schmoll, Tilman; Wieser, Wolfgang; Andre, Raphael; Huber, Robert; Leitgeb, Rainer A.

    2012-07-01

    Retinal and choroidal vascular imaging is an important diagnostic benefit for ocular diseases such as age-related macular degeneration. The current gold standard for vessel visualization is fluorescence angiography. We present a potential non-invasive alternative to image blood vessels based on functional Fourier domain optical coherence tomography (OCT). For OCT to compete with the field of view and resolution of angiography while maintaining motion artifacts to a minimum, ultrahigh-speed imaging has to be introduced. We employ Fourier domain mode locking swept source technology that offers high quality imaging at an A-scan rate of up to 1.68 MHz. We present retinal angiogram over ˜48 deg acquired in a few seconds in a single recording without the need of image stitching. OCT at 1060 nm allows for high penetration in the choroid and efficient separate characterization of the retinal and choroidal vascularization.

  17. Towards the use of OCT angiography in clinical dermatology

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Choi, Woo June; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography (OCT) is a popular imaging technique used in ophthalmology, and on the way to become clinically viable alternative in dermatology due to its capability of acquiring histopathology level images of in vivo tissue, noninvasively. In this study, we demonstrate the capabilities of OCT-based angiography (OMAG) in detecting high-resolution, volumetric structural and microvascular features of in vivo human skin with various conditions using a swept source OCT system that operates on a central wavelength of 1310 nm with an A-line rate of 100 kHz. OMAG images provide detailed in vivo visualization of microvasculature of abnormal human skin conditions from face, chest and belly. Moreover, the progress of wound healing on human skin from arm is monitored during longitudinal wound healing process. The presented results promise the clinical use of OCT angiography in treatment of prevalent cutaneous diseases within human skin, in vivo.

  18. The Artery of Percheron Infarction after Coronary Angiography

    PubMed Central

    Mazek, Haitham; Sherif, Khaled; Suarez, Jose; Wischmeyer, Jason

    2016-01-01

    Coronary angiography is the golden choice for coronary artery disease evaluation and management. However, as with any invasive procedures, there is a risk of complications. We are reporting a case of 69-year-old male with past medical history of cardiac bypass surgery, CHF, hypertension, and hyperlipidemia who was admitted to the hospital to evaluate his chest pain. He had treadmill stress test that showed ischemic induced exercise. Patient underwent coronary angiography that showed proximal complete occlusion of the RCA with a patent graft. At the end of the procedure, the patient did not wake up and remained minimally responsive. An urgent brain MRI was ordered and showed infarctions consistent with an artery of Percheron infarction. Later, patient has improved slowly and was discharged home. We briefly here discuss this rare complication including the risk factor, clinical presentation, and the management. PMID:27213059

  19. Diagnosis of jugular paraganglioma by radionuclide angiography: concise communication

    SciTech Connect

    Zwas, S.T.; Kronenberg, J.; Tadmor, R.; Leventon, G.

    1983-11-01

    Jugular paraganglioma is a highly vascular tumor, slowly growing, extending into the surrounding stuctures and causing otologic and /or neurologic symptoms according to its location in the jugular bulb region or the middle-ear. In our study, modified vertex and posterior head scintiangiography was used in seven cases. Scintiangiography was positive in all seven, whereas concomitant radiographic studies were limited: four of the seven gave positive findings by transmission computerized tomography (TCT). Only four patients underwent angiography, with positive results in two. Hypocycloidal tomography was positive in three cases. However, some radiographic studies, particularly TCT, may be useful in detecting local extension, bone destruction, and soft-tissue infiltration. Radionuclide angiography proved highly reliable and should be used initially whenever a jugular paraganglioma is suspected.

  20. Quantification of Microvascular Tortuosity during Tumor Evolution Using Acoustic Angiography.

    PubMed

    Shelton, Sarah E; Lee, Yueh Z; Lee, Mike; Cherin, Emmanuel; Foster, F Stuart; Aylward, Stephen R; Dayton, Paul A

    2015-07-01

    The recent design of ultra-broadband, multifrequency ultrasound transducers has enabled high-sensitivity, high-resolution contrast imaging, with very efficient suppression of tissue background using a technique called acoustic angiography. Here we perform the first application of acoustic angiography to evolving tumors in mice predisposed to develop mammary carcinoma, with the intent of visualizing and quantifying angiogenesis progression associated with tumor growth. Metrics compared include vascular density and two measures of vessel tortuosity quantified from segmentations of vessels traversing and surrounding 24 tumors and abdominal vessels from control mice. Quantitative morphologic analysis of tumor vessels revealed significantly increased vascular tortuosity abnormalities associated with tumor growth, with the distance metric elevated approximately 14% and the sum of angles metric increased 60% in tumor vessels versus controls. Future applications of this imaging approach may provide clinicians with a new tool in tumor detection, differentiation or evaluation, though with limited depth of penetration using the current configuration. PMID:25858001

  1. National Synchrotron Light Source angiography personnel protection interlock

    SciTech Connect

    Gmuer, N.; Larson, R.; Thomlinson, W.

    1992-06-01

    This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

  2. Digital subtraction angiography of a persistent trigeminal artery variant.

    PubMed

    Temizöz, Osman; Genchellac, Hakan; Unlü, Ercüment; Cağli, Bekir; Ozdemir, Hüseyin; Demir, M Kemal

    2010-09-01

    Persistent trigeminal artery variants are described as cerebellar arteries that directly originate from the precavernous segment of the internal carotid artery. This has been observed in 0.18% of cerebral catheter angiograms. On the other hand, a persistent trigeminal artery variant feeding both the anterior inferior cerebellar artery and the posterior inferior cerebellar artery territory is very rare. We present this uncommon anomalous artery along with digital subtraction angiography findings and discuss its clinical significance in light of the literature. PMID:19821254

  3. Evaluation of vascular rings with digital subtraction angiography.

    PubMed

    Tonkin, I L; Gold, R E; Moser, D; Laster, R E

    1984-06-01

    Seven patients with vascular rings were evaluated over a 2-year period with intravenous digital subtraction angiography (DSA), which was compared with screen-film aortography or cineangiography. The seven patients were also evaluated with barium esophagography. Six of the seven DSA images were totally diagnostic and one study was only partly diagnostic. Six of the seven vascular anomalies were confirmed surgically. DSA is suggested as an alternative to arteriography in evaluating patients with suspected vascular rings. PMID:6372419

  4. Risks and Complications of Coronary Angiography: A Comprehensive Review

    PubMed Central

    Tavakol, Morteza; Ashraf, Salman; Brener, Sorin J.

    2012-01-01

    Coronary angiography and heart catheterization are invaluable tests for the detection and quantification of coronary artery disease, identification of valvular and other structural abnormalities, and measurement of hemodynamic parameters. The risks and complications associated with these procedures relate to the patient’s concomitant conditions and to the skill and judgment of the operator. In this review, we examine in detail the major complications associated with invasive cardiac procedures and provide the reader with a comprehensive bibliography for advanced reading. PMID:22980117