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Sample records for abdominal ct angiography

  1. 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.

  2. 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 ...

  3. CT angiography - chest

    MedlinePlus

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

  4. 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.

  5. Computer-assisted diagnosis in CT angiography of abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Fiebich, Martin; Tomiak, Myrosia M.; Engelmann, Roger M.; McGill, James; Hoffmann, Kenneth R.

    1997-04-01

    The purpose of this study was to develop methods for automatic 3D-segmentation and automatic quantification of vascular structures in CT angiographic studies, e.g., abdominal aortic aneurysms. Methods for segmentation were developed based on thresholding, maximum gradient, and second derivative techniques. All parameters for the segmentation are generated automatically, i.e. no user interaction is necessary for this process. Median filtering of all images is initially performed to reduce the image noise. The algorithm then automatically identifies the starting point inside the aorta for the volume growing. The segmentation of the vascular tree is achieved in two steps. First, only the aorta and small parts of branch vessels are segmented by using strong restrictions in the parameters for threshold and gradient. A description of the aorta is generated by fitting the detected outer border of the aorta with an ellipse. This description includes centerline, direction, contour, eccentricity, and area. In the second step, segmentation parameters are changed automatically for segmentation of branch vessels. A shaded surface display of the segmented structures is then generated. The segmentation of the aorta appears accurate, is fast, and the 3D display can be manipulated in real time. The quantitative description of the aorta is reliable giving reproducible information. Total CPU time for the segmentation and description is less than five minutes on a standard workstation. Time-consuming manual segmentation and parameterization of vascular structures are obviated, with 3D visualization and quantitative results available in minutes instead of hours. This technique for segmentation and description of the aorta and renal arteries shows the feasibility of computer assisted diagnosis in CT angiographic studies without user interaction. Besides the description, a rapid 3D view of the vessels is generated, often needed by the physician and normally only achievable by time

  6. 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

  7. 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

  8. An hybrid CPU-GPU framework for quantitative follow-up of abdominal aortic aneurysm volume by CT angiography

    NASA Astrophysics Data System (ADS)

    Kauffmann, Claude; Tang, An; Therasse, Eric; Soulez, Gilles

    2010-03-01

    We developed a hybrid CPU-GPU framework enabling semi-automated segmentation of abdominal aortic aneurysm (AAA) on Computed Tomography Angiography (CTA) examinations. AAA maximal diameter (D-max) and volume measurements and their progression between 2 examinations can be generated by this software improving patient followup. In order to improve the workflow efficiency some segmentation tasks were implemented and executed on the graphics processing unit (GPU). A GPU based algorithm is used to automatically segment the lumen of the aneurysm within short computing time. In a second step, the user interacted with the software to validate the boundaries of the intra-luminal thrombus (ILT) on GPU-based curved image reformation. Automatic computation of D-max and volume were performed on the 3D AAA model. Clinical validation was conducted on 34 patients having 2 consecutive MDCT examinations within a minimum interval of 6 months. The AAA segmentation was performed twice by a experienced radiologist (reference standard) and once by 3 unsupervised technologists on all 68 MDCT. The ICC for intra-observer reproducibility was 0.992 (>=0.987) for D-max and 0.998 (>=0.994) for volume measurement. The ICC for inter-observer reproducibility was 0.985 (0.977-0.90) for D-max and 0.998 (0.996- 0.999) for volume measurement. Semi-automated AAA segmentation for volume follow-up was more than twice as sensitive than D-max follow-up, while providing an equivalent reproducibility.

  9. Radiation dose measurements in coronary CT angiography

    PubMed Central

    Sabarudin, Akmal; Sun, Zhonghua

    2013-01-01

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

  10. Abdominal and Pelvic CT

    MedlinePlus

    ... Professions Site Index A-Z Computed Tomography (CT) - Abdomen and Pelvis Computed tomography (CT) of the abdomen ... and Pelvis? What is CT Scanning of the Abdomen/Pelvis? Computed tomography, more commonly known as a ...

  11. Abdominal CT scan

    MedlinePlus

    Computed tomography scan - abdomen; CT scan - abdomen; CT abdomen and pelvis ... 2016:chap 133. Radiologyinfo.org. Computed tomography (CT) - abdomen and pelvis. Updated June 16, 2016. www.radiologyinfo. ...

  12. Computed Tomographic Angiography of the Abdominal Aorta.

    PubMed

    Hansen, Neil J

    2016-01-01

    Computed tomographic (CT) angiography (CTA) has become the preferred imaging test of choice for various aortic conditions because of its excellent spatial resolution, rapid image acquisition, and its wide availability. CTA provides a robust tool for planning aortic interventions and diagnosing acute and chronic vascular diseases in the abdomen. CTA is the standard for imaging aneurysms before intervention and evaluating the aorta in the acute setting to assess traumatic injury, dissection, and aneurysm rupture. Knowledge of the imaging features of these disease processes, inflammatory vasculitides, and occlusive atherosclerotic disease is essential for guiding surgical and medical management of patients. PMID:26654390

  13. CT angiography - head and neck

    MedlinePlus

    Computed tomography angiography - brain; CTA - skull; CTA - cranial; TIA-CTA head; Stroke-CTA head; Computed tomography angiography - neck; CTA - neck; Vertebral artery - CTA; Carotid artery stenosis - CTA; ...

  14. CT angiography - abdomen and pelvis

    MedlinePlus

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

  15. 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.

  16. Coronary CT angiography: Beyond morphological stenosis analysis.

    PubMed

    Sun, Zhonghua

    2013-12-26

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

  17. Progress in Fully Automated Abdominal CT Interpretation

    PubMed Central

    Summers, Ronald M.

    2016-01-01

    OBJECTIVE Automated analysis of abdominal CT has advanced markedly over just the last few years. Fully automated assessment of organs, lymph nodes, adipose tissue, muscle, bowel, spine, and tumors are some examples where tremendous progress has been made. Computer-aided detection of lesions has also improved dramatically. CONCLUSION This article reviews the progress and provides insights into what is in store in the near future for automated analysis for abdominal CT, ultimately leading to fully automated interpretation. PMID:27101207

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

    PubMed

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

    2014-09-01

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

  19. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study*

    PubMed Central

    Cantador, Alex Aparecido; Siqueira, Daniel Emílio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fábio Hüsemann; Guillaumon, Ana Terezinha

    2016-01-01

    Objective To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. PMID:27777476

  20. 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.

  1. 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

  2. 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

  3. Newer cardiac imaging techniques: multidetector CT angiography.

    PubMed

    Davidoff, Ravin; Ruberg, Frederick L

    2006-01-01

    An update of new developments with multidetector computed tomography (MDCT) coronary angiography is presented. Similar to what has occurred with the introduction of other new technologies such as electron beam computed tomography (EBCT), life insurance medical directors are expected to evaluate a technology before there are sufficient data from large clinical trials. Well-performed studies of the performance of MDCT coronary angiography have only recently appeared. MDCT appears to perform well for excluding significant coronary disease, and will perhaps be useful in emergency room "rule-out" situations. Other applications may be for the diagnosis of significant coronary obstruction (> 75% stenosis), as well as for the evaluation of bypass grafts. Limitations include the requirement for radiologic contrast administration and significant radiation exposure. MDCT does not provide information on atheroma morphology. Given these limitations, MDCT coronary angiography utilization will grow, and it will prove to be a useful tool in specific situations. PMID:16845845

  4. 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

  5. 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

  6. 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

  7. Pleuropulmonary and abdominal paragonimiasis: CT and ultrasound findings

    PubMed Central

    Shim, S S; Kim, Y; Lee, J K; Lee, J H; Song, D E

    2012-01-01

    Objectives The purpose of this study was to review radiological images of patients with Paragonimus westermani (PW) that simultaneously involved the chest and abdomen. Methods Our study included four patients with serologically and histopathologically confirmed paragonimiasis. Abdomen CT (n=3) and chest CT (n=3) scans were available, and abdominal wall ultrasonography was performed in all patients. We retrospectively reviewed the clinical, radiological and histopathological findings of these patients. Results The most common abdominal CT findings were ascites and intraperitoneal or abdominal wall nodules. Low-attenuated serpentine lesions of the liver were another common and relatively specific feature. Conclusion Radiologists should consider the possibility of PW when these abdominal CT findings are noted, especially with pleural effusion or subpleural nodules in patients with initial abdominal symptoms. PMID:22457403

  8. 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

  9. 3D multislice CT angiography in post-aortic stent grafting: a pictorial essay.

    PubMed

    Sun, Zhonghua

    2006-01-01

    Helical CT angiography has been widely used in both pre- and post-aortic stent grafting and it has been confirmed to be the preferred modality when compared to conventional angiography. The recent development of multislice CT (MSCT) has further enhanced the applications of CT angiography for aortic stent grafting. One of the advantages of MSCT angiography over conventional angiography is that the 3D reconstructions, based on the volumetric CT data, provide additional information during follow-up of aortic stent grafting. While endovascular repair has been increasingly used in clinical practice, the use of 3D MSCT imaging in endovascular repair continues to play an important role. In this pictorial essay, we aimed to discuss the diagnostic performance of 3D MSCT angiography in post aortic stent grafting, including the most commonly used surface shaded display, curvilinear reformation, the maximum intensity projection, volume rendering and virtual endoscopy. The advantages and disadvantages of each 3D reconstruction are also explored.

  10. Feasibility of Three-Dimensional MR Angiography Image Fusion Guidance for Endovascular Abdominal Aortic Aneurysm Repair.

    PubMed

    Tacher, Vania; Desgranges, Pascal; You, Ketsakin; Ridouani, Fourat; Marzelle, Jean; Kobeiter, Hicham

    2016-02-01

    Magnetic resonance (MR) angiography image fusion (IF) with live fluoroscopy guidance was used while performing endovascular repair of abdominal aortic aneurysm (EVAR) in five patients with a history of chronic renal disease or severe contrast allergy. Intraprocedural technical success was 100%. Median procedure time was 120 minutes (range, 60-180 min), fluoroscopy time was 40 minutes (range, 17-65 min), dose-area product was 245,867 mGy × cm(2) (range, 68,435-690,053 mGy × cm(2)), and iodinated contrast volume injected was 15 mL (range, 0-40 mL). Technical success was achieved in four of five patients (80%); one case was complicated by a type 1 endoleak on follow-up MR angiography, which was successfully treated. EVAR with MR angiography IF guidance was technically feasible and safe in five patients and reduced or eliminated the use of iodinated contrast media. PMID:26830935

  11. Coronary CT angiography: how should physicians use it wisely and when do physicians request it appropriately?

    PubMed

    Sun, Zhonghua; Aziz, Yang Faridah Abdul; Ng, Kwan-Hoong

    2012-04-01

    Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease due to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with 64- and more slice CT scanners and in selected patients, coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. Although the tremendous contributions of coronary CT angiography to cardiac imaging are acknowledged, appropriate use of cardiac CT as the first line technique by physicians has not been well established. Optimal selection of cardiac CT is essential to ensure acquisition of valuable diagnostic information and avoid unnecessary invasive procedures. This is of paramount importance since cardiac CT not only involves patient risk assessment, prediction of major cardiac events, but also impacts physician decision-making on patient management. Applications of CT in cardiac imaging include coronary artery calcium scoring for predicting the patient risk of developing major cardiac events, followed by coronary CT angiography which is commonly used to determine the diagnostic and prognostic accuracy in the coronary artery disease. This review presents an overview of the applications of CT in cardiac imaging in terms of coronary calcium scoring and coronary CT angiography. Judicious use of both cardiac CT tools will be discussed with regard to their value in different patient risk groups with the aim of identifying the appropriate criteria for choosing a cardiac CT modality. An effective diagnostic pathway is finally recommended to physicians for appropriate selection of cardiac CT in clinical practice.

  12. Cardiovascular manifestations of heterotaxy and related situs abnormalities assessed with CT angiography

    PubMed Central

    Wolla, Christopher D.; Hlavacek, Anthony M.; Schoepf, U. Joseph; Bucher, Andreas M.; Chowdhury, Shahryar

    2014-01-01

    Heterotaxy and situs abnormalities describe an abnormal arrangement of visceral organs in the thoracoabdominal cavity across the normal left–right axis of the body. It is associated with a high occurrence of congenital heart and abdominal defects, including anomalous pulmonary venous connections, systemic venous abnormalities, asplenia, and intestinal malrotation. Without proper diagnosis and surgical intervention, the prognosis of patients with heterotaxy syndrome and associated congenital defects is extremely poor. Complex intracardiac and extracardiac lesions are common in heterotaxy and can be difficult to assess by echocardiography. CT angiography (CTA) is a useful tool in this setting to accurately assess intracardiac and extracardiac abnormalities in this population for medical or surgical management. The intention of this pictorial essay is to review the most common cardiovascular defects involved with heterotaxy syndrome in addition to emphasizing the utility of CTA in the identification and classification of anomalies seen in these patients. This review briefly defines most common terminology used in situs abnormalities as well as presents CT images and 3-dimensional reconstructions of common anomalies associated with situs abnormalities. In summary, this review should prepare radiologists and pediatric cardiologists to describe heterotaxy and situs abnormalities in addition to recognizing the utility of CTA in these patients. PMID:24331937

  13. Variations in Branching Pattern of Renal Artery in Kidney Donors Using CT Angiography

    PubMed Central

    Munnusamy, Kumaresan; Gurusamy, Karthikeyan; Raghunath, Gunapriya; Bolshetty, Shilpakala Leshappa; Chakrabarti, Sudakshina; Annadurai, Priyadarshini; Miyajan, Zareena Begum

    2016-01-01

    Introduction Each kidney is supplied by a single renal artery originating from abdominal aorta. Since there are lots of renal surgeries happening now-a-days, it becomes mandatory for the surgeons to understand the abnormality and variations in the renal vasculature. Aim To study the variations in the branching pattern of renal artery for the presence of early division and accessory renal artery in Indian kidney donors using CT angiography. Materials and Methods The CT angiogram images of 100 normal individuals willing for kidney donation were analysed for early divisions and occurrence of accessory renal artery. Results A 51% of kidney donors showed variation in the renal artery. Out of 51% variations 38 individuals had accessory renal artery and 13 individuals had early division of renal artery. The distribution of accessory renal artery was equal on both sides (13% on right and left) and 12% of individuals had accessory renal artery on both sides. Out of 13% earlier divisions, 5% was on right side, 7% was on left side and 1% was on both sides. Conclusion This study concludes that 51% of kidney donors had renal artery variations. Hence, awareness of variations by evaluating the donors is a must before renal transplantation, urological procedures and angiographic interventions. PMID:27134847

  14. Ultra Low Dose CT Pulmonary Angiography with Iterative Reconstruction

    PubMed Central

    Koehler, Thomas; Fingerle, Alexander A.; Brendel, Bernhard; Richter, Vivien; Rasper, Michael; Rummeny, Ernst J.; Noël, Peter B.; Münzel, Daniela

    2016-01-01

    Objective Evaluation of a new iterative reconstruction algorithm (IMR) for detection/rule-out of pulmonary embolism (PE) in ultra-low dose computed tomography pulmonary angiography (CTPA). Methods Lower dose CT data sets were simulated based on CTPA examinations of 16 patients with pulmonary embolism (PE) with dose levels (DL) of 50%, 25%, 12.5%, 6.3% or 3.1% of the original tube current setting. Original CT data sets and simulated low-dose data sets were reconstructed with three reconstruction algorithms: the standard reconstruction algorithm “filtered back projection” (FBP), the first generation iterative reconstruction algorithm iDose and the next generation iterative reconstruction algorithm “Iterative Model Reconstruction” (IMR). In total, 288 CTPA data sets (16 patients, 6 tube current levels, 3 different algorithms) were evaluated by two blinded radiologists regarding image quality, diagnostic confidence, detectability of PE and contrast-to-noise ratio (CNR). Results iDose and IMR showed better detectability of PE than FBP. With IMR, sensitivity for detection of PE was 100% down to a dose level of 12.5%. iDose and IMR showed superiority to FBP regarding all characteristics of subjective (diagnostic confidence in detection of PE, image quality, image noise, artefacts) and objective image quality. The minimum DL providing acceptable diagnostic performance was 12.5% (= 0.45 mSv) for IMR, 25% (= 0.89 mSv) for iDose and 100% (= 3.57 mSv) for FBP. CNR was significantly (p < 0.001) improved by IMR compared to FBP and iDose at all dose levels. Conclusion By using IMR for detection of PE, dose reduction for CTPA of up to 75% is possible while maintaining full diagnostic confidence. This would result in a mean effective dose of approximately 0.9 mSv for CTPA. PMID:27611830

  15. 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.

  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. Fully automated adipose tissue measurement on abdominal CT

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Sussman, Daniel L.; Summers, Ronald M.

    2011-03-01

    Obesity has become widespread in America and has been associated as a risk factor for many illnesses. Adipose tissue (AT) content, especially visceral AT (VAT), is an important indicator for risks of many disorders, including heart disease and diabetes. Measuring adipose tissue (AT) with traditional means is often unreliable and inaccurate. CT provides a means to measure AT accurately and consistently. We present a fully automated method to segment and measure abdominal AT in CT. Our method integrates image preprocessing which attempts to correct for image artifacts and inhomogeneities. We use fuzzy cmeans to cluster AT regions and active contour models to separate subcutaneous and visceral AT. We tested our method on 50 abdominal CT scans and evaluated the correlations between several measurements.

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

    PubMed

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-04-05

    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.

  19. Diagnosis of pulmonary embolism with CT pulmonary angiography: a systematic review

    PubMed Central

    Hogg, K; Brown, G; Dunning, J; Wright, J; Carley, S; Foex, B; Mackway‐Jones, K

    2006-01-01

    Objective To appraise the evidence on the diagnostic accuracy of CT pulmonary angiography and the prognostic value of a negative CT pulmonary angiogram in the diagnosis of pulmonary embolism. Methods Medline, EMBASE, and grey literature were systematically searched by two researchers. Any study which compared CT pulmonary angiography to an acceptable reference standard or prospectively followed up a cohort of patients with a normal CT pulmonary angiogram was included. Study methods were appraised independently by two researchers, and data were extracted independently by three researchers. Results Thirteen diagnostic and 11 follow up studies were identified. Studies varied in prevalence of pulmonary embolism (19–79%), patient groups, and method quality. Few studies recruited unselected emergency department patients. There was heterogeneity in the analysis of sensitivity (53 to 100%), specificity (79 to 100%), and false negative rate (1.0 to 10.7%). The pooled false negative rate of combined negative CT pulmonary angiography and negative deep vein thrombosis testing was 1.5% (95% CI 1.0 to 1.9%). Conclusion Diagnostic studies give conflicting results for the diagnostic accuracy of CT pulmonary angiography. Follow up studies show that CT pulmonary angiography can be used in combination with investigation for deep vein thrombosis to exclude pulmonary embolism. PMID:16498151

  20. 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.

  1. 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.

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

    PubMed

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

    2014-01-01

    Whole-body postmortem computed tomographic (CT) angiography is a promising new development in forensic radiology that has the potential to improve vascular and soft-tissue imaging beyond levels currently achievable with unenhanced postmortem CT. Postmortem access to the vascular system and injection of contrast medium are different from those steps in clinical (antemortem) radiology. Because there is no circulation in a corpse that could transport or dilute a contrast medium, the injection must be performed by using a roller pump to fill the vasculature (arterial and venous) with a mixture of a water-soluble iodized contrast medium and polyethylene glycol. In contrast to a classic autopsy, postmortem CT angiography is a minimally invasive procedure. It allows the diagnosis of vascular lesions without the disruption or destruction of anatomic structures, which could result in a loss of evidence in a criminal investigation. Furthermore, postmortem CT angiography facilitates the display of vascular pathologic conditions in areas that are not typically covered with autopsy alone, such as the craniocervical junction and the small pelvis. Therefore, postmortem CT angiography adds substantial value to the classic forensic autopsy; cross-sectional data can be reevaluated objectively at any time and are fully reproducible as counterexpertise, which is as useful in the fields of forensic medicine and pathology as in clinical research. Familiarity with the capabilities of postmortem CT angiography may help radiologists working with forensic cases improve their diagnostic performance. PMID:24819799

  3. 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

  4. 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.

  5. Cerebral CT angiography and CT perfusion in acute stroke detection: a systematic review of diagnostic value

    PubMed Central

    Subramaniam, Cantiriga; Sun, Zhonghua

    2014-01-01

    The purpose of this study was to analyse the diagnostic value of cerebral CT angiography (CTA) and CT perfusion (CTP) examinations in the detection of acute stroke based on a systematic review of the current literature. The review was conducted based on searching of seven databases for articles published between 1993 and 2013. Diagnostic value in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was analysed from 21 articles which were found to meet selection criteria. The mean sensitivity, specificity, PPV, NPV and accuracy for CTA were significantly higher than those for CTP with 83.2% (95% CI: 57.9-100.0%), 95.0% (95% CI: 74.4-100%), 84.1% (95% CI: 50.0-100%), 97.1 (95% CI: 94.0-100%) and 94.0% (95% CI: 83.0-99.0) versus 69.9% (95% CI: 20.0-97.0%), 87.4 (95% CI: 61.0-100.0%), 76.4% (95% CI: 48.0-95.4%), 78.2% (95% CI: 55.8-93.9%) and 89.8% (95% CI: 75.7-97.1%), respectively. This analysis shows that CTA has high diagnostic value in detecting high degree of cerebral arterial stenosis (>70%) whereas CTP provides high specificity in the detection of ischemia and infarct tissue of brain. PMID:25202664

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

    PubMed

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

    2016-10-01

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

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

    PubMed

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

    2015-07-01

    The surgical treatment of distal anterior cerebral artery (DACA) aneurysms still presents a challenge for neurosurgeons because of their small size and their location in the depth of the narrow frontal interhemispheric fissure. This study aimed to investigate feasibility, safety, accuracy, and usefulness of electromagnetic (EM) navigation to aid clipping of DACA aneurysms. Eight patients (age between 2 and 68 years, mean age 49.8 years) with a DACA aneurysm underwent EM-guided neuronavigated microsurgery for clipping of the aneurysm. All patients underwent craniocervical 3D-CT angiography preoperatively. After planning the optimal approach and surgical trajectory avoiding opening of the frontal sinus, the head was fixed. Intraoperative screenshots were correlated with the microscopical view of the DACA aneurysms before clipping. EM-guided neuronavigation using CT angiography for DACA aneurysms enabled fast and accurate referencing of the patient and planning of a tailored craniotomy without opening of the frontal sinus. Intraoperative accuracy was highly reliable except in one instance due to dislocation of the dynamic reference frame (DRF). There was a good correlation between the 3D-CT angiography-based navigation data sets and the intraoperative vascular anatomy. In all patients, bridging veins were spared. The aid of EM neuronavigation was considered useful in all instances. EM-guided neuronavigation using CT angiography for surgery of DACA aneurysms is a useful tool optimizing the surgical approach directly to the aneurysm minimizing additional damage to the surrounding tissue during preparation of the aneurysm and the parent vessel. PMID:25666391

  8. Contrast-Enhanced Abdominal Angiographic CT for Intra-abdominal Tumor Embolization: A New Tool for Vessel and Soft Tissue Visualization

    SciTech Connect

    Meyer, Bernhard Christian Frericks, Bernd Benedikt; Albrecht, Thomas; Wolf, Karl-Juergen; Wacker, Frank Klaus

    2007-07-15

    C-Arm cone-beam computed tomography (CACT), is a relatively new technique that uses data acquired with a flat-panel detector C-arm angiography system during an interventional procedure to reconstruct CT-like images. The purpose of this Technical Note is to present the technique, feasibility, and added value of CACT in five patients who underwent abdominal transarterial chemoembolization procedures. Target organs for the chemoembolizations were kidney, liver, and pancreas and a liposarcoma infiltrating the duodenum. The time for patient positioning, C-arm and system preparation, CACT raw data acquisition, and data reconstruction for a single CACT study ranged from 6 to 12 min. The volume data set produced by the workstation was interactively reformatted using maximum intensity projections and multiplanar reconstructions. As part of an angiography system CACT provided essential information on vascular anatomy, therapy endpoints, and immediate follow-up during and immediately after the abdominal interventions without patient transfer. The quality of CACT images was sufficient to influence the course of treatment. This technology has the potential to expedite any interventional procedure that requires three-dimensional information and navigation.

  9. Spleen volume on CT and the effect of abdominal trauma.

    PubMed

    Cruz-Romero, Cinthia; Agarwal, Sheela; Abujudeh, Hani H; Thrall, James; Hahn, Peter F

    2016-08-01

    The aim of this study is to determine the magnitude of change in spleen volume on CT in subjects sustaining blunt abdominal trauma without hemorrhage relative to patients without disease and how the spleen volumes are distributed. Sixty-seven subjects with blunt abdominal trauma and 101 control subjects were included in this retrospective single-center, IRB-approved, and HIPAA-compliant study. Patients with an injured spleen were excluded. Using a semiautomatic segmentation program, two readers computed spleen volumes from CT. Spleen volume distribution in male and female trauma and control cohorts were compared nonparametrically. Spleen volume plotted against height, weight, and age were analyzed by linear regression. The number of females and males are, respectively, 35 and 32 in trauma subjects and 69 and 32 among controls. Female trauma patients (49.6 years) were older than males (39.8 years) (p = 0.02). Distributions of spleen volume were not normal, skewed above their means, requiring a nonparametric comparison. Spleen volumes in trauma patients were smaller than those in controls with medians of 230 vs 294 mL in males(p < 0.006) and 163 vs 191 mL in females(p < 0.04). Spleen volume correlated positively with weight in females and with height in male controls, and negatively with age in male controls (p < 0.01). Variation in reproducibility and repeatability was acceptable at 1.5 and 4.9 %, respectively. Reader variation was 1.7 and 4.6 % for readers 1 and 2, respectively. The mean spleen volume in controls was 245 mL, the largest ever reported. Spleen volume decreases in response to blunt abdominal trauma. Spleen volumes are not normally distributed. Our population has the largest spleen volume reported in the literature, perhaps a consequence of the obesity epidemic. PMID:27166964

  10. Spleen volume on CT and the effect of abdominal trauma.

    PubMed

    Cruz-Romero, Cinthia; Agarwal, Sheela; Abujudeh, Hani H; Thrall, James; Hahn, Peter F

    2016-08-01

    The aim of this study is to determine the magnitude of change in spleen volume on CT in subjects sustaining blunt abdominal trauma without hemorrhage relative to patients without disease and how the spleen volumes are distributed. Sixty-seven subjects with blunt abdominal trauma and 101 control subjects were included in this retrospective single-center, IRB-approved, and HIPAA-compliant study. Patients with an injured spleen were excluded. Using a semiautomatic segmentation program, two readers computed spleen volumes from CT. Spleen volume distribution in male and female trauma and control cohorts were compared nonparametrically. Spleen volume plotted against height, weight, and age were analyzed by linear regression. The number of females and males are, respectively, 35 and 32 in trauma subjects and 69 and 32 among controls. Female trauma patients (49.6 years) were older than males (39.8 years) (p = 0.02). Distributions of spleen volume were not normal, skewed above their means, requiring a nonparametric comparison. Spleen volumes in trauma patients were smaller than those in controls with medians of 230 vs 294 mL in males(p < 0.006) and 163 vs 191 mL in females(p < 0.04). Spleen volume correlated positively with weight in females and with height in male controls, and negatively with age in male controls (p < 0.01). Variation in reproducibility and repeatability was acceptable at 1.5 and 4.9 %, respectively. Reader variation was 1.7 and 4.6 % for readers 1 and 2, respectively. The mean spleen volume in controls was 245 mL, the largest ever reported. Spleen volume decreases in response to blunt abdominal trauma. Spleen volumes are not normally distributed. Our population has the largest spleen volume reported in the literature, perhaps a consequence of the obesity epidemic.

  11. 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

  12. 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

  13. Functional Evaluation of Coronary Disease by CT Angiography.

    PubMed

    Gonçalves, Pedro de Araújo; Rodríguez-Granillo, Gastón A; Spitzer, Ernest; Suwannasom, Pannipa; Loewe, Christian; Nieman, Koen; Garcia-Garcia, Hector M

    2015-11-01

    In recent years, several technical developments in the field of cardiac computed tomography (CT) have made possible the extraction of functional information from an anatomy-based examination. Several different lines have been explored and will be reviewed in the present paper, namely: 1) myocardial perfusion imaging; 2) transluminal attenuation gradients and corrected coronary opacification indexes; 3) fractional flow reserve computed from CT; and 4) extrapolation from atherosclerotic plaque characteristics. In view of these developments, cardiac CT has the potential to become in the near future a truly 2-in-1 noninvasive evaluation for coronary artery disease. PMID:26563862

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

    SciTech Connect

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

    2009-07-15

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

  15. 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

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

    PubMed

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

    1995-03-01

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

  17. Contrast Enhancement of the Right Ventricle during Coronary CT Angiography – Is It Necessary?

    PubMed Central

    Kok, Madeleine; Kietselaer, Bas L. J. H.; Mihl, Casper; Altintas, Sibel; Nijssen, Estelle C.; Wildberger, Joachim E.; Das, Marco

    2015-01-01

    Purpose It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. Materials and Methods 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Results Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Conclusion Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography. PMID:26029905

  18. 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.

  19. Imaging of the aortic valve with MRI and CT angiography.

    PubMed

    Harvey, J J; Hoey, E T D; Ganeshan, A

    2013-12-01

    The aortic valve may be affected by a wide range of congenital and acquired diseases. Echocardiography is the main non-invasive imaging technique for assessing patho-anatomical alterations of the aortic valve and adjacent structures and in many cases is sufficient to establish a diagnosis and/or guide treatment decisions. Recent technological advances in magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) have enabled these techniques to play a complimentary role in certain clinical scenarios and as such can be useful problem-solving tools. Radiologists should be familiar with the indications, advantages, and limitations of MRI and MDCT in order to advise and direct an appropriate imaging strategy depending upon the clinical scenario. This article reviews the role of MRI and MDCT angiography for assessment of the aortic valve including relevant anatomy, scan acquisition protocols, and post-processing methods. An approach to interpretation and the key imaging features of commonly encountered aortic valvular diseases are discussed.

  20. Can CT angiography replace conventional bi-planar angiography in the management of severe scapulothoracic dissociation injuries?

    PubMed

    Merchant, Nishant; Scalea, Thomas; Stein, Deborah

    2012-08-01

    Severe scapulothoracic dissociation (SSTD) (Type III or IV; Zelle classification) is often life-threatening and is commonly associated with other devastating injuries. Rapid evaluation, including of the vascular system, is critical to limit the time to definitive therapy. CT angiography (CTA) has evolved as a diagnostic tool, replacing angiography (angio) as it can simultaneously evaluate bony, soft tissue, and vascular injuries. We hypothesized that CTA would be useful in evaluating patients with SSTD. We retrospectively reviewed the trauma registry between June 2002 and June 2010 to identify patients over 18 years of age who sustained SSTD. Patients that were transferred or died before diagnostic imaging were excluded. Comparisons were made between the group that underwent angio before surgery compared with CTA with regards to outcome and length of hospital and intensive care unit stay. Fourteen patients were identified with Type III or IV SSTD over the study period. In the CTA group, mean Injury Severity Score was higher, but time to definitive operative intervention was significantly shorter. There was no difference in amputation rates or mortality. Replacing arteriography with CTA in the preoperative workup of patients with SSTD reduces time to surgery. Despite a greater injury severity in the group in which CTA was used as the primary imaging modality, length of stay, amputation rates, and mortality were no different. CTA can be safely used to evaluate patients with suspected SSTD.

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

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

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

  2. 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

  3. 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.

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

    PubMed

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

    2002-01-01

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

  5. 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

  6. 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.

  7. 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.

  8. Intracranial arterial variations: A comprehensive evaluation using CT angiography

    PubMed Central

    Kovač, Jelena Djokić; Stanković, Ana; Stanković, Danilo; Kovač, Bojan; Šaranović, Djordjije

    2014-01-01

    Background Intracranial arterial variations are a frequent finding in the general population. Knowledge of these vascular variations has significant clinical impact because some of them predispose patients to development of an aneurysm or cerebrovascular ischemic disease. The purpose of this study was to evaluate the frequency of intracranial vascular variations and associated vascular lesions on computed tomography angiography (CTA) examinations. Material/Methods CTA examinations performed by 16-detector computed tomography were prospectively reviewed in 455 patients for the presence of fenestrations, duplications, hypoplasia, aplasia, aneurysms, and other vascular lesions. Results Arterial fenestrations were found in 2.4% of patients, with the vertebrobasilar system as the most common location. The remaining fenestrations were located on the middle cerebral artery M1 segment (0.2%), anterior communicating artery (0.4%), and anterior cerebral artery A1 segment (0.6%). No associated aneurysms were noted in these patients. The prevalence of an azygos anterior cerebral artery was 1.5%. Bihemispheric anterior cerebral artery was found in 0.9%, hypoplastic A1 segment in 17.6%, and congenital absence of A1 segment in 0.4% of patients. Fetal origin of the posterior cerebral artery was found in 37% of cases. Hypoplastic vertebral artery terminating as posterior inferior cerebellar artery was observed in 9 patients, while transversal anastomosis between vertebral arteries was seen in only 1 patient. Conclusions CTA precisely demonstrates the diversity of intracranial arterial variations, whose overall frequency in this study is similar to previous radiological reports. Furthermore, our results do not show significant association between the frequency of aneurysms and cerebral arterial anomalies. PMID:24625840

  9. CT Pulmonary Angiography: Increasingly Diagnosing Less Severe Pulmonary Emboli

    PubMed Central

    Schissler, Andrew J.; Rozenshtein, Anna; Kulon, Michal E.; Pearson, Gregory D. N.; Green, Robert A.; Stetson, Peter D.; Brenner, David J.; D'Souza, Belinda; Tsai, Wei-Yann; Schluger, Neil W.; Einstein, Andrew J.

    2013-01-01

    Background It is unknown whether the observed increase in computed tomography pulmonary angiography (CTPA) utilization has resulted in increased detection of pulmonary emboli (PEs) with a less severe disease spectrum. Methods Trends in utilization, diagnostic yield, and disease severity were evaluated for 4,048 consecutive initial CTPAs performed in adult patients in the emergency department of a large urban academic medical center between 1/1/2004 and 10/31/2009. Transthoracic echocardiography (TTE) findings and peak serum troponin levels were evaluated to assess for the presence of PE-associated right ventricular (RV) abnormalities (dysfunction or dilatation) and myocardial injury, respectively. Statistical analyses were performed using multivariate logistic regression. Results 268 CTPAs (6.6%) were positive for acute PE, and 3,780 (93.4%) demonstrated either no PE or chronic PE. There was a significant increase in the likelihood of undergoing CTPA per year during the study period (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.04–1.07, P<0.01). There was no significant change in the likelihood of having a CTPA diagnostic of an acute PE per year (OR 1.03, 95% CI 0.95–1.11, P = 0.49). The likelihood of diagnosing a less severe PE on CTPA with no associated RV abnormalities or myocardial injury increased per year during the study period (OR 1.39, 95% CI 1.10–1.75, P = 0.01). Conclusions CTPA utilization has risen with no corresponding change in diagnostic yield, resulting in an increase in PE detection. There is a concurrent rise in the likelihood of diagnosing a less clinically severe spectrum of PEs. PMID:23776522

  10. An Effort to Develop an Algorithm to Target Abdominal CT Scans for Patients After Gastric Bypass.

    PubMed

    Pernar, Luise I M; Lockridge, Ryan; McCormack, Colleen; Chen, Judy; Shikora, Scott A; Spector, David; Tavakkoli, Ali; Vernon, Ashley H; Robinson, Malcolm K

    2016-10-01

    Abdominal CT (abdCT) scans are frequently ordered for Roux-en-Y gastric bypass (RYGB) patients presenting to the emergency department (ED) with abdominal pain, but often do not reveal intra-abdominal pathology. We aimed to develop an algorithm for rational ordering of abdCTs. We retrospectively reviewed our institution's RYGB patients presenting acutely with abdominal pain, documenting clinical and laboratory data, and scan results. Associations of clinical parameters to abdCT results were examined for outcome predictors. Of 1643 RYGB patients who had surgery between 2005 and 2015, 355 underwent 387 abdCT scans. Based on abdCT, 48 (12 %) patients required surgery and 86 (22 %) another intervention. No clinical or laboratory parameter predicted imaging results. Imaging decisions for RYGB patients do not appear to be amenable to a simple algorithm, and patient work-up should be based on astute clinical judgment.

  11. Immersive virtual reality for visualization of abdominal CT

    NASA Astrophysics Data System (ADS)

    Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A.; Bodenheimer, Robert E.

    2013-03-01

    Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

  12. Value of Single-Dose Contrast-Enhanced Magnetic Resonance Angiography Versus Intraarterial Digital Subtraction Angiography in Therapy Indications in Abdominal and Iliac Arteries

    SciTech Connect

    Schaefer, Philipp J. Schaefer, Fritz K. W.; Mueller-Huelsbeck, Stefan; Both, Markus; Heller, Martin; Jahnke, Thomas

    2007-06-15

    The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committee was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30{sup o}, field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses {>=}50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.

  13. Coronary CT Angiography versus Standard Evaluation in Acute Chest Pain

    PubMed Central

    Hoffmann, Udo; Truong, Quynh A.; Schoenfeld, David A.; Chou, Eric T.; Woodard, Pamela K.; Nagurney, John T.; Pope, J. Hector; Hauser, Thomas H.; White, Charles S.; Weiner, Scott G.; Kalanjian, Shant; Mullins, Michael E.; Mikati, Issam; Peacock, W. Frank; Zakroysky, Pearl; Hayden, Douglas; Goehler, Alexander; Lee, Hang; Gazelle, G. Scott; Wiviott, Stephen D.; Fleg, Jerome L.; Udelson, James E.

    2013-01-01

    Background It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes. Methods In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes. Results The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65). Conclusions In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National

  14. [ECG-gated bypass CT angiography--application in imaging arterial bypasses].

    PubMed

    Wintersperger, B J; Bastarrika, G; Nikolaou, K; Rist, C; Huber, A; Knez, A; Reiser, M F; Becker, C R; Vicol, C

    2004-02-01

    Nowadays coronary artery bypass grafting is increasingly performed using arterial grafts. Purpose of the study was the evaluation of a appropriate 16 detector-row CT angiography protocol in patients after predominantly arterial bypass grafting. Fourteen patients after bypass grafting were including into the study and CT angiography carried out in the early postoperative period using a 16 detector-row CT system. To reduce cardiac pulsation artifacts data acquisition was implemented using ECG-gating algorithms. Overall 43 grafts (37 arterial, 6 venous) were examined. In 13 patients surgery had been performed using composite grafts with T or TY configuration. The mean heart rate was 74.1 bpm and showed a negative correlation to the image quality (r=-0.65; p=0.01). However, all data sets were diagnostic. Contrast injection protocol allowed for a homogeneous opacification throughout the vessels of interest. All non-delineationable grafts (5) showed a close proximity to the heart (T or Y grafts). Cardiac surgery is increasingly focusing on arterial revascularisation in bypass grafting and therefore leading to new demands for non-invasive bypass graft imaging. 16 detector-row CT allows a reliable visualization of even composite arterial grafts. However, for detection of grafts in the proximity of the heart a reduction of the heart rate (<65-70) still seems to be necessary. PMID:14991132

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

    PubMed Central

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

    2015-01-01

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

  16. CT-based myocardial ischemia evaluation: quantitative angiography, transluminal attenuation gradient, myocardial perfusion, and CT-derived fractional flow reserve.

    PubMed

    Koo, Hyun Jung; Yang, Dong Hyun; Kim, Young-Hak; Kang, Joon-Won; Kang, Soo-Jin; Kweon, Jihoon; Kim, Hyun Jung; Lim, Tae-Hwan

    2016-06-01

    The detection of hemodynamically significant stenosis is important because ischemia-guided revascularization improves overall patient outcomes. Fractional flow reserve (FFR), which is measured during invasive coronary angiography, is regarded as the gold standard for determining hemodynamically significant coronary stenosis. Although coronary computed tomography angiography (CCTA) has been widely used to exclude significant coronary artery disease in patients with low to intermediate pretest probability, anatomic assessment by CCTA using diameter stenosis ≥50 % does not correlate well with the functional assessment of FFR. To overcome the weaknesses of conventional CCTA, such as its low specificity and positive predictive value, especially in patients with a small-diameter artery, poor image quality, or high calcium score, more sophisticated CCTA analysis methods have been developed to detect hemodynamically significant coronary stenosis. Studies that use the quantification of coronary plaque, transluminal attenuation gradient (TAG), CT myocardial perfusion (CTP), and CT-derived FFR have been conducted to validate their diagnostic performances, though each method has its pros and cons. This review provides details on the quantification of coronary plaque, TAG, CTP, and CT-derived FFR, including a definition of each, how to gather and interpret data, and the strengths and limitations of each. Further, we provide an overview of recent clinical studies.

  17. 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%.

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

    SciTech Connect

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

    2012-01-15

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

  19. 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

  20. High-pitch coronary CT angiography with third generation dual-source CT: limits of heart rate.

    PubMed

    Gordic, Sonja; Husarik, Daniela B; Desbiolles, Lotus; Leschka, Sebastian; Frauenfelder, Thomas; Alkadhi, Hatem

    2014-08-01

    To determine the average heart rate (HR) and heart rate variability (HRV) required for diagnostic imaging of the coronary arteries in patients undergoing high-pitch CT-angiography (CTA) with third-generation dual-source CT. Fifty consecutive patients underwent CTA of the thoracic (n = 8) and thoracoabdominal (n = 42) aorta with third-generation dual-source 192-slice CT with prospective electrocardiography (ECG)-gating at a pitch of 3.2. No β-blockers were administered. Motion artifacts of coronary arteries were graded on a 4-point scale. Average HR and HRV were noted. The average HR was 66 ± 11 beats per minute (bpm) (range 45-96 bpm); the HRV was 7.3 ± 4.4 bpm (range 3-20 bpm). Interobserver agreement on grade of image quality for the 642 coronary segments evaluated by both observers was good (κ = 0.71). Diagnostic image quality was found for 608 of the 642 segments (95%) in 43 of 50 patients (86%). In 14% of the patients, image quality was nondiagnostic for at least one segment. HR (p = 0.001) was significantly higher in patients with at least one non-diagnostic segment compared to those without. There was no significant difference (p > 0.05) in HRV between patients with nondiagnostic segments and those with diagnostic images of all segments. All patients with a HR < 70 bpm had diagnostic image quality in all coronary segments. The effective radiation dose and scan time for the heart were 0.4 ± 0.1 mSv and 0.17 ± 0.02 s, respectively. Third-generation dual-source 192-slice CT allows for coronary angiography in the prospectively ECG-gated high-pitch mode with diagnostic image quality at HR up to 70 bpm. HRV is not significantly related to image quality of coronary CTA.

  1. 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

  2. CT coronary angiography: new risks for low-risk chest pain.

    PubMed

    Radecki, Ryan Patrick

    2013-10-01

    Widespread conservative management of low-risk chest pain has motivated the development of a rapid triage strategy based on CT coronary angiography (CTCA) in the Emergency Department (ED). Recently, three prominent trials using this technology in the ED setting have presented results in support of its routine use. However, these studies fail to show the incremental prognostic value of CTCA over clinical and biomarker-based risk-stratification strategies, demonstrate additional downstream costs and interventions, and result in multiple harms associated with radio-contrast and radiation exposure. Observing the widespread overdiagnosis of pulmonary embolism following availability of CT pulmonary angiogram as a practice pattern parallel, CTCA use for low-risk chest pain in the ED should be advanced only with caution.

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

    PubMed

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

    2015-12-01

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

  4. 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).

  5. 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.

  6. Construction of Abdominal Probabilistic Atlases and Their Value in Segmentation of Normal Organs in Abdominal CT Scans

    NASA Astrophysics Data System (ADS)

    Park, Hyunjin; Hero, Alfred; Bland, Peyton; Kessler, Marc; Seo, Jongbum; Meyer, Charles

    A good abdominal probabilistic atlas can provide important information to guide segmentation and registration applications in the abdomen. Here we build and test probabilistic atlases using 24 abdominal CT scans with available expert manual segmentations. Atlases are built by picking a target and mapping other training scans onto that target and then summing the results into one probabilistic atlas. We improve our previous abdominal atlas by 1) choosing a least biased target as determined by a statistical tool, i.e. multidimensional scaling operating on bending energy, 2) using a better set of control points to model the deformation, and 3) using higher information content CT scans with visible internal liver structures. One atlas is built in the least biased target space and two atlases are built in other target spaces for performance comparisons. The value of an atlas is assessed based on the resulting segmentations; whichever atlas yields the best segmentation performance is considered the better atlas. We consider two segmentation methods of abdominal volumes after registration with the probabilistic atlas: 1) simple segmentation by atlas thresholding and 2) application of a Bayesian maximum a posteriori method. Using jackknifing we measure the atlas-augmented segmentation performance with respect to manual expert segmentation and show that the atlas built in the least biased target space yields better segmentation performance than atlases built in other target spaces.

  7. Percutaneous Transhepatic Drainage of Inaccessible Abdominal Abscesses Following Abdominal Surgery Under Real-Time CT-Fluoroscopic Guidance

    SciTech Connect

    Yamakado, Koichiro Takaki, Haruyuki; Nakatsuka, Atsuhiro; Kashima, Masataka; Uraki, Junji; Yamanaka, Takashi; Takeda, Kan

    2010-02-15

    This study evaluated the safety, feasibility, and clinical utility of transhepatic drainage of inaccessible abdominal abscesses retrospectively under real-time computed tomographic (CT) guidance. For abdominal abscesses, 12 consecutive patients received percutaneous transhepatic drainage. Abscesses were considered inaccessible using the usual access route because they were surrounded by the liver and other organs. The maximum diameters of abscesses were 4.6-9.5 cm (mean, 6.7 {+-} 1.4 cm). An 8-Fr catheter was advanced into the abscess cavity through the liver parenchyma using real-time CT fluoroscopic guidance. Safety, feasibility, procedure time, and clinical utility were evaluated. Drainage catheters were placed with no complications in abscess cavities through the liver parenchyma in all patients. The mean procedure time was 18.8 {+-} 9.2 min (range, 12-41 min). All abscesses were drained. They shrank immediately after catheter placement. In conclusions, this transhepatic approach under real-time CT fluoroscopic guidance is a safe, feasible, and useful technique for use of drainage of inaccessible abdominal abscesses.

  8. Multidetector CT in emergency radiology: acute and generalized non-traumatic abdominal pain.

    PubMed

    Paolantonio, Pasquale; Rengo, Marco; Ferrari, Riccardo; Laghi, Andrea

    2016-01-01

    Multidetector CT (MDCT) is an imaging technique that provides otherwise unobtainable information in the diagnostic work-up of patients presenting with acute abdominal pain. A correct working diagnosis depends essentially on understanding the individual patient's clinical data and laboratory findings. In haemodynamically stable patients with acute severe and generalized abdominal pain, MDCT is now the preferred imaging test and gives invaluable diagnostic information, also in unstable patients after stabilization. In this descriptive review, we focus our attention on acute, severe and generalized or undifferentiated non-traumatic abdominal pain. The main differential diagnoses are acute pancreatitis, gastrointestinal perforation, ruptured abdominal aneurysm and acute mesenteric ischaemia. We will provide radiologist readers with a technical guide to optimize MDCT imaging protocols and list the major CT signs essential to reach a correct diagnosis and guide the best treatment. PMID:26689097

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

    PubMed Central

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

    2015-01-01

    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

  10. New technique for treating abdominal surgical site infection using CT woundgraphy and NPWT: A case report

    PubMed Central

    Ito, Eisaku; Yoshida, Masashi; Nakashima, Keigo; Suzuki, Norihiko; Imakita, Tomonori; Tsutsui, Nobuhiro; Ohdaira, Hironori; Kitajima, Masaki; Suzuki, Yutaka

    2016-01-01

    Introduction Negative pressure wound therapy (NPWT) for abdominal surgical site infection (SSI) is becoming increasingly common, although enterocutaneous fistula (ECF) has been reported as a complication. To avoid ECF, we used computed tomography (CT) woundgraphy to evaluate the relationship between the wound and the intestine, and then safely treated the abdominal SSI with NPWT. Case presentation Following a laparoscopic intersphincteric resection for low rectal neuroendocrine tumor and covering ileostomy, a 59-year-old woman underwent stoma closure. Six days after surgery, we diagnosed SSI. We suspected ECF, because the wound was deep and the pus resembled enteric fluid. However, CT woundgraphy showed that the wound was separated from the abdominal cavity and the intestine by the abdominal rectus muscle. Accordingly, we performed NPWT. SSI was cured and the wound was well granulated. Twenty-three days after surgery, the patient was discharged. Eventually, the wound was completely epithelialized. Discussion Although successful NPWT has been reported for open abdominal wounds, ECF is a common complication. ECF can be prevented by separating the wound from the intestine by the omentum or muscle fascia, protecting the intestinal serosa during surgery, and applying low vacuum pressure. The relationships among the wound, the fascia, and the intestine must be evaluated before abdominal SSI treatment. One good method is CT woundgraphy, which evaluates wound extent and depth, closure of muscle fascia, and the relationship between the wound and the intestine. Conclusion We report a case of CT woundgraphy before NPWT for abdominal SSI. CT woundgraphy is a good candidate for evaluating wound condition. PMID:27002290

  11. Computer-aided CT coronary artery stenosis detection: comparison with human reading and quantitative coronary angiography.

    PubMed

    Rief, Matthias; Kranz, Anisha; Hartmann, Lisa; Roehle, Robert; Laule, Michael; Dewey, Marc

    2014-12-01

    To evaluate computer-aided stenosis detection for computed tomography coronary angiography (CTA) in comparison with human reading and conventional coronary angiography (CCA) as the reference standard. 50 patients underwent CTA and CCA and out of these 44 were evaluable for computer-aided stenosis detection. The diagnostic performance of the software and of human reading were compared and quantitative coronary angiography (QCA) served as the reference standard for the detection of significant stenosis (>50 %). Overall, three readers with high (reader 1), intermediate (reader 2) and low (reader 3) experience in cardiac CT imaging performed the manual CTA evaluation on a commercially available workstation, whereas the automated software processed the datasets without any human interaction. The prevalence of coronary artery disease was 41 % (18/44) and QCA indicated significant stenosis (>50 %) in 33 coronary vessels. The automated software accurately diagnosed 18 individuals with significant coronary artery disease (CAD), and correctly ruled out CAD in 10 patients. In summary the sensitivity of computer-aided detection was 100 %/94 % (per-patient/per-vessel) and the specificity was 38 %/70 %, the positive predictive value (PPV) was 53 %/42 % and the negative predictive value (NPV) was 100 %/98 %. In comparison, reader 1-3 showed per-patient sensitivities of 100/94/89 %, specificities of 73/69/50 %, PPVs of 72/68/55 % and NPVs of 100/95/87 %. Computer-aided detection yields a high NPV that is comparable to more experienced human readers. However, PPV is rather low and in the range of an unexperienced reader.

  12. Infected abdominal aortic aneurysm due to Morganella morganii: CT findings.

    PubMed

    Kwon, Oh Young; Lee, Jong Seok; Choi, Han Sung; Hong, Hoon Pyo; Ko, Young Gwan

    2011-02-01

    An infected aortic aneurysm, or mycotic aneurysm, is a rare arterial dilatation due to destruction of the infected vessel wall. Common pathogens resulting in an infected aortic aneurysm are Salmonella and Clostridium species, as well as Staphylococcus aureus; Morganella morganii, on the other hand, is very rare. An infected abdominal aortic aneurysm has tendencies to grow rapidly and to rupture. The mortality rate is high in patients undergoing emergent surgical intervention. We report the case of a 65-year-old man who presented with an infected abdominal aortic aneurysm caused by M. morganii. A high index of suspicion and imaging tests are necessary in order to diagnose an infected aortic aneurysm.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  14. Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnosis with CT Angiography

    PubMed Central

    Oncel, Guray; Oncel, Dilek

    2013-01-01

    Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly. It is associated with early infant mortality and sudden death in adults. Traditionally, ALCAPA has been diagnosed by angiography or autopsy; however, the development of cardiac computed tomography (CT) and magnetic resonance imaging (MRI) has allowed noninvasive evaluation of the coronary anatomy by direct visualization of the origin of the left coronary artery (LCA) from the pulmonary artery. We report a case of 10-year-old girl who has been on follow up for dilated cardiomyopathy for 4 years. The definitive diagnosis of ALCAPA is reached by multislice computed tomography (MSCT). The MSCT scan showed an anomalous origin of LCA from the pulmonary trunk, with a tortuous and dilated right coronary artery and right-to-left collateralization. Consequently, the patient was successfully treated with surgery. PMID:23607073

  15. 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.

  16. 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

  17. Study of Normal Branching Pattern of the Coeliac Trunk and its Variations Using CT Angiography

    PubMed Central

    Selvaraj, Lakshana

    2015-01-01

    Introduction Blood vessel anomalies are always interesting from embryological view and of considerable significance from a clinical or a surgical standpoint. Vascular anomalies are usually asymptomatic; they may cause problems in patients undergoing diagnostic angiography or any operative procedure. The length and course of the coeliac artery are variable and its branches frequently arise separately from the main trunk. Several other branches may additionally arise from the coeliac trunk, for example, inferior phrenic arteries, the dorsal pancreatic artery, and the middle colic artery. Aim The present study was undertaken to analyse the vertebral level of origin of coeliac artery, its branching pattern and the associated variations using computed tomographic angiography in 75 subjects. Results The results obtained were analysed and classified based on Adachi’s and Lipshutz’s classification method. The results were also compared with various other studies cited in the literature. The level of origin was found to be at the inter-vertebral disc between T12 and L1 in a majority of the cases (70.6%). It was also found that the coeliac trunk trifurcates in majority of the cases i.e. 90.6%. Trifurcation was of two types, classical and non-classical, the classical trunk being the commonest type. Variations included bifurcation of the trunk (8%) with Left gastric artery arising directly from the aorta, in a few cases (1.3%) Common hepatic artery arose as a separate trunk from the aorta. Conclusion A comprehensive knowledge of this arterial anatomy and variations will be very useful when planning abdominal surgeries and image-guided interventions. The success of procedures such as liver transplantation, intestinal anastomosis, intra-arterial chemotherapy, chemo-embolization, and radio-embolization requires a detailed knowledge of the coeliac artery and its anatomical variants, which are extremely common, to avoid iatrogenic injuries and to prevent complications. PMID

  18. Clinical performance of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast-enhanced pediatric abdominal MR angiography

    PubMed Central

    Yousaf, Ufra; Hsiao, Albert; Cheng, Joseph Y.; Alley, Marcus T.; Lustig, Michael; Pauly, John M.; Vasanawala, Shreyas S.

    2015-01-01

    Background Pediatric contrast-enhanced MR angiography is often limited by respiration, other patient motion and compromised spatiotemporal resolution. Objective To determine the reliability of a free-breathing spatiotemporally accelerated 3-D time-resolved contrast enhanced MR angiography method for depicting abdominal arterial anatomy in young children. Materials and methods With IRB approval and informed consent, we retrospectively identified 27 consecutive children (16 males and 11 females; mean age: 3.8 years, range: 14 days to 8.4 years) referred for contrast enhanced MR angiography at our institution, who had undergone free-breathing spatiotemporally accelerated time-resolved contrast enhanced MR angiography studies. An radio-frequency-spoiled gradient echo sequence with Cartesian variable density k-space sampling and radial view ordering, intrinsic motion navigation and intermittent fat suppression was developed. Images were reconstructed with soft-gated parallel imaging locally low-rank method to achieve both motion correction and high spatiotemporal resolution. Quality of delineation of 13 abdominal arteries in the reconstructed images was assessed independently by two radiologists on a five-point scale. Ninety-five percent confidence intervals of the proportion of diagnostically adequate cases were calculated. Interobserver agreements were also analyzed. Results Eleven out of 13 arteries achieved acceptable image quality (mean score range: 3.9–5.0) for both readers. Fair to substantial interobserver agreement was reached on nine arteries. Conclusion Free-breathing spatiotemporally accelerated 3-D time-resolved contrast enhanced MR angiography frequently yields diagnostic image quality for most abdominal arteries for pediatric contrast enhanced MR angiography. PMID:26040509

  19. 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.

  20. FDG PET/CT Findings in Abdominal Fat Necrosis After Treatment for Lymphoma.

    PubMed

    Dubreuil, Julien; Moreau, Aurélie; Sarkozy, Clémentine; Traverse-Glehen, Alexandra; Skanjeti, Andrea; Salles, Gilles; Giammarile, Francesco

    2016-05-01

    FDG PET/CT is now validated in non-Hodgkin lymphoma for response assessment in interim and posttreatment lymphoma. We report the case of a 62-year-old man followed by FDG PET/CT for a diffuse large B-cell lymphoma, with initial stage III. The interim FDG PET/CT examination concluded in complete metabolic and morphological response of subdiaphragmatic lymphadenopathy but a persistent abnormal subdiaphragmatic uptake (SUVmax at 9 and Deauville 5-point scale at 5). Therefore, an abdominal biopsy of the corresponding nodules was conducted with a final diagnosis of diffuse fat necrosis. PMID:26825213

  1. Coronary artery bypass graft flow: qualitative evaluation with cine single-detector row CT and comparison with findings at angiography.

    PubMed

    Tello, Richard; Hartnell, George G; Costello, Philip; Ecker, Christian P

    2002-09-01

    A four-point ordinal-scale qualitative flow index was used for assessment of patency of 75 coronary artery bypass grafts in 26 patients examined with spiral computed tomography (CT). CT findings were compared with selective graft angiographic findings. Of 54 open grafts, 52 were patent at initial selective graft angiography and 50 were patent at spiral CT; accuracy rates were 97% (73 of 75) and 95% (71 of 75), respectively. Spiral CT flow index agreed with angiographically determined flow in 85% (95% CI: 0.77, 0.93) of grafts. The kappa statistic demonstrated very good to excellent intermodality (0.75) and interobserver (0.89) agreement. Spiral CT may be a feasible means of assessing quality of flow in bypass grafts. PMID:12202732

  2. Colitis detection on abdominal CT scans by rich feature hierarchies

    NASA Astrophysics Data System (ADS)

    Liu, Jiamin; Lay, Nathan; Wei, Zhuoshi; Lu, Le; Kim, Lauren; Turkbey, Evrim; Summers, Ronald M.

    2016-03-01

    Colitis is inflammation of the colon due to neutropenia, inflammatory bowel disease (such as Crohn disease), infection and immune compromise. Colitis is often associated with thickening of the colon wall. The wall of a colon afflicted with colitis is much thicker than normal. For example, the mean wall thickness in Crohn disease is 11-13 mm compared to the wall of the normal colon that should measure less than 3 mm. Colitis can be debilitating or life threatening, and early detection is essential to initiate proper treatment. In this work, we apply high-capacity convolutional neural networks (CNNs) to bottom-up region proposals to detect potential colitis on CT scans. Our method first generates around 3000 category-independent region proposals for each slice of the input CT scan using selective search. Then, a fixed-length feature vector is extracted from each region proposal using a CNN. Finally, each region proposal is classified and assigned a confidence score with linear SVMs. We applied the detection method to 260 images from 26 CT scans of patients with colitis for evaluation. The detection system can achieve 0.85 sensitivity at 1 false positive per image.

  3. 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

  4. 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.

  5. Electrocardiogram-gated coronary CT angiography dose estimates using ImPACT.

    PubMed

    Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Koshida, Kichiro; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Toyama, Hiroshi; Kato, Ryouichi

    2016-07-08

    The primary study objective was to assess radiation doses using a modified form of the Imaging Performance Assessment of Computed Tomography (CT) scanner (ImPACT) patient dosimetry for cardiac applications on an Aquilion ONE ViSION Edition scanner, including the Ca score, target computed tomography angiography (CTA), prospective CTA, continuous CTA/cardiac function analysis (CFA), and CTA/CFA modulation. Accordingly, we clarified the CT dose index (CTDI) to determine the relationship between heart rate (HR) and X-ray exposure. As a secondary objective, we compared radiation doses using modified ImPACT, a whole-body dosimetry phantom study, and the k-factor method to verify the validity of the dose results obtained with modified ImPACT. The effective dose determined for the reference person (4.66 mSv at 60 beats per minute (bpm) and 33.43 mSv at 90bpm) were approximately 10% less than those determined for the phantom study (5.28 mSv and 36.68 mSv). The effective doses according to the k-factor (0.014 mSv•mGy-1•cm-1; 2.57 mSv and 17.10 mSv) were significantly lower than those obtained with the other two methods. In the present study, we have shown that ImPACT, when modified for cardiac applications, can assess both absorbed and effective doses. The results of our dose comparison indicate that modified ImPACT dose assessment is a promising and practical method for evaluating coronary CTA.

  6. Electrocardiogram-gated coronary CT angiography dose estimates using ImPACT.

    PubMed

    Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Koshida, Kichiro; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Toyama, Hiroshi; Kato, Ryouichi

    2016-01-01

    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

  7. Utilization of CT Pulmonary Angiography in Suspected Pulmonary Embolism in a Major Urban Emergency Department.

    PubMed

    Shujaat, Adil; Shapiro, Janet M; Eden, Edward

    2013-01-01

    Objectives. We conducted a study to answer 3 questions: (1) is CT pulmonary angiography (CTPA) overutilized in suspected pulmonary embolism (PE)? (2) What alternative diagnoses are provided by CTPA? (3) Can CTPA be used to evaluate right ventricular dilatation (RVD)? Methods. We retrospectively reviewed the clinical information of 231 consecutive emergency department patients who underwent CTPA for suspected PE over a one-year period. Results. The mean age of our patients was 53 years, and 58.4% were women. The prevalence of PE was 20.7%. Among the 136 patients with low clinical probability of PE, a d-dimer test was done in 54.4%, and it was normal in 24.3%; none of these patients had PE. The most common alternative findings on CTPA were emphysema (7.6%), pneumonia (7%), atelectasis (5.5%), bronchiectasis (3.8%), and congestive heart failure (3.3%). The sensitivity and negative predictive value of CTPA for (RVD) was 92% and 80%, respectively. Conclusions. PE could have been excluded without CTPA in ~1 out of 4 patients with low clinical probability of PE, if a formal assessment of probability and d-dimer test had been done. In patients without PE, CTPA did not provide an alternative diagnosis in 65%. In patients with PE, CTPA showed the potential to evaluate RVD.

  8. Best-Quality Vessel Identification Using Vessel Quality Measure in Multiple-Phase Coronary CT Angiography

    PubMed Central

    Liu, Jordan; Chan, Heang-Ping; Zhou, Chuan; Wei, Jun; Chughtai, Aamer; Kuriakose, Jean; Agarwal, Prachi; Kazerooni, Ella

    2016-01-01

    The detection of stenotic plaques strongly depends on the quality of the coronary arterial tree imaged with coronary CT angiography (cCTA). However, it is time consuming for the radiologist to select the best-quality vessels from the multiple-phase cCTA for interpretation in clinical practice. We are developing an automated method for selection of the best-quality vessels from coronary arterial trees in multiple-phase cCTA to facilitate radiologist's reading or computerized analysis. Our automated method consists of vessel segmentation, vessel registration, corresponding vessel branch matching, vessel quality measure (VQM) estimation, and automatic selection of best branches based on VQM. For every branch, the VQM was calculated as the average radial gradient. An observer preference study was conducted to visually compare the quality of the selected vessels. 167 corresponding branch pairs were evaluated by two radiologists. The agreement between the first radiologist and the automated selection was 76% with kappa of 0.49. The agreement between the second radiologist and the automated selection was also 76% with kappa of 0.45. The agreement between the two radiologists was 81% with kappa of 0.57. The observer preference study demonstrated the feasibility of the proposed automated method for the selection of the best-quality vessels from multiple cCTA phases. PMID:27721896

  9. 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.

  10. 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

  11. PET/CT imaging of abdominal aorta with intramural hematomas, penetrating ulcer, and saccular pseudoaneurysm.

    PubMed

    Nguyen, Vien X; Nguyen, Ba D

    2014-05-01

    Acute aortic syndromes, encompassing intramural hematoma, penetrating ulcer, and pseudoaneurysm, are best demonstrated by angiographic CT and magnetic resonance imaging. These imaging modalities provide an accurate evaluation and allow timely therapies of these frequently symptomatic lesions, thus reducing their morbidity and mortality. The inflammatory pathogenesis of these acute aortic syndromes may exhibit positive PET findings predictive of prognosis and outcomes of these vascular events. The authors present a case of PET/CT imaging showing asymptomatic intramural hematomas with penetrating ulcer and saccular pseudoaneurysm of the proximal abdominal aorta.

  12. Evaluation of five image registration tools for abdominal CT: pitfalls and opportunities with soft anatomy

    NASA Astrophysics Data System (ADS)

    Lee, Christopher P.; Xu, Zhoubing; Burke, Ryan P.; Baucom, Rebeccah; Poulose, Benjamin K.; Abramson, Richard G.; Landman, Bennett A.

    2015-03-01

    Image registration has become an essential image processing technique to compare data across time and individuals. With the successes in volumetric brain registration, general-purpose software tools are beginning to be applied to abdominal computed tomography (CT) scans. Herein, we evaluate five current tools for registering clinically acquired abdominal CT scans. Twelve abdominal organs were labeled on a set of 20 atlases to enable assessment of correspondence. The 20 atlases were pairwise registered based on only intensity information with five registration tools (affine IRTK, FNIRT, Non-Rigid IRTK, NiftyReg, and ANTs). Following the brain literature, the Dice similarity coefficient (DSC), mean surface distance, and Hausdorff distance were calculated on the registered organs individually. However, interpretation was confounded due to a significant proportion of outliers. Examining the retrospectively selected top 1 and 5 atlases for each target revealed that there was a substantive performance difference between methods. To further our understanding, we constructed majority vote segmentation with the top 5 DSC values for each organ and target. The results illustrated a median improvement of 85% in DSC between the raw results and majority vote. These experiments show that some images may be well registered to some targets using the available software tools, but there is significant room for improvement and reveals the need for innovation and research in the field of registration in abdominal CTs. If image registration is to be used for local interpretation of abdominal CT, great care must be taken to account for outliers (e.g., atlas selection in statistical fusion).

  13. Image Quality and Radiation Dose for Prospectively Triggered Coronary CT Angiography: 128-Slice Single-Source CT versus First-Generation 64-Slice Dual-Source CT

    PubMed Central

    Gu, Jin; Shi, He-shui; Han, Ping; Yu, Jie; Ma, Gui-na; Wu, Sheng

    2016-01-01

    This study sought to compare the image quality and radiation dose of coronary computed tomography angiography (CCTA) from prospectively triggered 128-slice CT (128-MSCT) versus dual-source 64-slice CT (DSCT). The study was approved by the Medical Ethics Committee at Tongji Medical College of Huazhong University of Science and Technology. Eighty consecutive patients with stable heart rates lower than 70 bpm were enrolled. Forty patients were scanned with 128-MSCT, and the other 40 patients were scanned with DSCT. Two radiologists independently assessed the image quality in segments (diameter >1 mm) according to a three-point scale (1: excellent; 2: moderate; 3: insufficient). The CCTA radiation dose was calculated. Eighty patients with 526 segments in the 128-MSCT group and 544 segments in the DSCT group were evaluated. The image quality 1, 2 and 3 scores were 91.6%, 6.9% and 1.5%, respectively, for the 128-MSCT group and 97.6%, 1.7% and 0.7%, respectively, for the DSCT group, and there was a statistically significant inter-group difference (P ≤ 0.001). The effective doses were 3.0 mSv in the 128-MSCT group and 4.5 mSv in the DSCT group (P ≤ 0.001). Compared with DSCT, CCTA with prospectively triggered 128-MSCT had adequate image quality and a 33.3% lower radiation dose. PMID:27752040

  14. 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.

  15. 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

  16. Computer-aided diagnosis of splenic enlargement using wave pattern of spleen in abdominal CT images

    NASA Astrophysics Data System (ADS)

    Seong, Won; Cho, June-Sik; Noh, Seung-Moo; Park, Jong Won

    2006-03-01

    It is known that the spleen accompanied by liver cirrhosis is hypertrophied or enlarged. We have examined a wave pattern at the left boundary of spleen on the abdominal CT images having liver cirrhosis, and found that they are different from those on the images having a normal liver. It is noticed that the abdominal CT images of patient with liver cirrhosis shows strong bending in the wave pattern. In the case of normal liver, the images may also have a wave pattern, but its bends are not strong. Therefore, the total waving area of the spleen with liver cirrhosis is found to be greater than that of the spleen with a normal liver. Moreover, we found that the waves of the spleen from the image with liver cirrhosis have the higher degree of circularity compared to the normal liver case. Based on the two observations above, we propose an automatic method to diagnose splenic enlargement by using the wave pattern of the spleen in abdominal CT images. The proposed automatic method improves the diagnostic performance compared with the conventional process based on the size of spleen.

  17. A Systematic Review of Protocols for the Three-Dimensional Morphologic Assessment of Abdominal Aortic Aneurysms Using Computed Tomographic Angiography

    SciTech Connect

    Ghatwary, Tamer M. H.; Patterson, Benjamin O.; Karthikesalingam, Alan; Hinchliffe, Robert J.; Loftus, Ian M.; Morgan, Robert; Thompson, Matt M.; Holt, Peter J. E.

    2013-02-15

    The morphology of infrarenal abdominal aortic aneurysms (AAAs) directly influences the perioperative outcome and long-term durability of endovascular aneurysm repair. A variety of methods have been proposed for the characterization of AAA morphology using reconstructed three-dimensional (3D) computed tomography (CT) images. At present, there is lack of consensus as to which of these methods is most applicable to clinical practice or research. The purpose of this review was to evaluate existing protocols that used 3D CT images in the assessment of various aspects of AAA morphology. An electronic search was performed, from January 1996 to the end of October 2010, using the Embase and Medline databases. The literature review conformed to PRISMA statement standards. The literature search identified 604 articles, of which 31 studies met inclusion criteria. Only 15 of 31 studies objectively assessed reproducibility. Existing published protocols were insufficient to define a single evidence-based methodology for preoperative assessment of AAA morphology. Further development and expert consensus are required to establish a standardized and validated protocol to determine precisely how morphology relates to outcomes after endovascular aneurysm repair.

  18. 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.

  19. 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

  20. Thromboembolic resolution assessed by CT pulmonary angiography after treatment for acute pulmonary embolism.

    PubMed

    den Exter, Paul L; van Es, Josien; Kroft, Lucia J M; Erkens, Petra M G; Douma, Renée A; Mos, Inge C M; Jonkers, Gé; Hovens, Marcel M C; Durian, Marc F; ten Cate, Hugo; Beenen, Ludo F M; Kamphuisen, Pieter Willem; Huisman, Menno V

    2015-07-01

    The systematic assessment of residual thromboembolic obstruction after treatment for acute pulmonary embolism (PE) has been understudied. This assessment is of potential clinical importance, should clinically suspected recurrent PE occur, or as tool for risk stratification of cardiopulmonary complications or recurrent venous thromboembolism (VTE). This study aimed to assess the rate of PE resolution and its implications for clinical outcome. In this prospective, multi-center cohort study, 157 patients with acute PE diagnosed by CT pulmonary angiography (CTPA) underwent follow-up CTPA-imaging after six months of anticoagulant treatment. Two expert thoracic radiologists independently assessed the presence of residual thromboembolic obstruction. The degree of obstruction at baseline and follow-up was calculated using the Qanadli obstruction index. All patients were followed-up for 2.5 years. At baseline, the median obstruction index was 27.5 %. After six months of treatment, complete PE resolution had occurred in 84.1 % of the patients (95 % confidence interval (CI): 77.4-89.4 %). The median obstruction index of the 25 patients with residual thrombotic obstruction was 5.0 %. During follow-up, 16 (10.2 %) patients experienced recurrent VTE. The presence of residual thromboembolic obstruction was not associated with recurrent VTE (adjusted hazard ratio: 0.92; 95 % CI: 0.2-4.1).This study indicates that the incidence of residual thrombotic obstruction following treatment for PE is considerably lower than currently anticipated. These findings, combined with the absence of a correlation between residual thrombotic obstruction and recurrent VTE, do not support the routine use of follow-up CTPA-imaging in patients treated for acute PE. PMID:26017397

  1. CT Hounsfield Numbers of Soft Tissues on Unenhanced Abdominal CT Scans: Variability Between Two Different Manufacturers’ MDCT Scanners

    PubMed Central

    Lamba, Ramit; McGahan, John P.; Corwin, Michael T.; Li, Chin-Shang; Tran, Tien; Seibert, J. Anthony; Boone, John M.

    2016-01-01

    OBJECTIVE The purpose of this study is to determine whether Hounsfield numbers of soft tissues on unenhanced abdominal CT of the same patient vary on repeat scans done on two different manufacturers’ MDCT scanners. MATERIALS AND METHODS A database search was performed to identify patients older than 18 years who underwent unenhanced CT of the abdomen and pelvis performed both on a Volume CT (GE Healthcare) and a Definition AS Plus (Siemens Healthcare) 64-MDCT scanner within 12 months of each other. After excluding those patients for whom Hounsfield unit measurements would be affected by mitigating factors, 48 patients (mean age, 58.8 years) were identified. Hounsfield unit measurements were obtained in nine different soft-tissue anatomic locations on each scan, and the location of these sites was kept identical on each scan pair. Data were analyzed to evaluate Hounsfield unit differences between these scanners. RESULTS In general, there was a low consistency in the Hounsfield unit measurements for each of these sites on scans obtained by the two scanners, with the subcutaneous fat in the left posterolateral flank showing the lowest correlation (intraclass correlation coefficient, 0.198). There were differences in the Hounsfield unit measurements obtained in all anatomic sites on scans obtained by both scanners. Mean Hounsfield unit measurements obtained on the Definition AS Plus scanner were lower than those obtained on the Volume CT scanner, with the intriguing exception of the anterior midline subcutaneous fat Hounsfield unit measurements, which were higher on the Definition AS Plus scanner. All differences were statistically significant (p < 0.05). CONCLUSION Hounsfield unit measurements for unenhanced abdominal soft tissues of the same patient vary between scanners of two common MDCT manufacturers. PMID:25341139

  2. Nonlinear registration of serial coronary CT angiography (CCTA) for assessment of changes in atherosclerotic plaque

    SciTech Connect

    Woo, Jonghye; Dey, Damini; Cheng, Victor Y.; Hong, Byung-Woo; Ramesh, Amit; Sundaramoorthi, Ganesh; Nakazato, Ryo; Berman, Daniel S.; Germano, Guido; Kuo, C.-C. Jay; Slomka, Piotr J.

    2010-02-15

    Purpose: Coronary CT angiography (CCTA) is a high-resolution three-dimensional imaging technique for the evaluation of coronary arteries in suspected or confirmed coronary artery disease (CAD). Coregistration of serial CCTA scans would allow precise superimposition of images obtained at two different points in time, which could aid in recognition of subtle changes and precise monitoring of coronary plaque progression or regression. To this end, the authors aimed at developing a fully automatic nonlinear volume coregistration for longitudinal CCTA scan pairs. Methods: The algorithm combines global displacement and local deformation using nonlinear volume coregistration with a volume-preserving constraint. Histogram matching of intensities between two serial scans is performed prior to nonlinear coregistration with dense nonparametric local deformation in which sum of squared differences is used as a similarity measure. The approximate segmentation of coronary arteries obtained from commercially available software provides initial anatomical landmarks for the coregistration algorithm that help localize and emphasize the structure of interest. To avoid possible bias caused by incorrect segmentation, the authors convolve the Gaussian kernel with the segmented binary coronary tree mask and define an extended weighted region of interest. A multiresolution approach is employed to represent coarse-to-fine details of both volumes and the energy function is optimized using a gradient descent method. The authors applied the algorithm in ten paired CCTA datasets (20 scans in total) obtained within 10.7{+-}5.7 months from each other on a dual source CT scanner to monitor progression of CAD. Results: Serial CCTA coregistration was successful in 9/10 cases as visually confirmed. The global displacement and local deformation of target registration error obtained from four anatomical landmarks were 2.22{+-}1.15 and 1.56{+-}0.74 mm, respectively, and the inverse consistency error of

  3. Rate of Contrast Extravasation on CT Angiography Predicts Hematoma Expansion and Mortality in Primary Intracerebral Hemorrhage

    PubMed Central

    Brouwers, H. Bart; Battey, Thomas W.K.; Musial, Hayley H.; Ciura, Viesha A.; Falcone, Guido J.; Ayres, Alison M.; Vashkevich, Anastasia; Schwab, Kristin; Viswanathan, Anand; Anderson, Christopher D.; Greenberg, Steven M.; Pomerantz, Stuart R.; Ortiz, Claudia J.; Goldstein, Joshua N.; Gonzalez, R. Gilberto; Rosand, Jonathan; Romero, Javier M.

    2015-01-01

    Background and Purpose In primary intracerebral hemorrhage (ICH), the presence of contrast extravasation following CT angiography (CTA), termed the ‘spot sign’, predicts hematoma expansion and mortality. Since the biological underpinnings of the spot sign are not fully understood, we investigated whether the rate of contrast extravasation - which may reflect the rate of bleeding - predicts expansion and mortality beyond the simple presence of the spot sign. Methods Consecutive ICH patients with first-pass CTA followed by a 90-second delayed post-contrast CT (delayed CTA) were included. CTAs were reviewed for spot sign presence by two blinded readers. Spot sign volumes on first-pass and delayed CTA and ICH volumes were measured using semi-automated software. Extravasation rates were calculated and tested for association with hematoma expansion and mortality using uni- and multivariable logistic regression. Results 162 patients were included, 48 (30%) of whom had ≥1 spot sign. Median spot sign volume was 0.04mL on first-pass CTA and 0.4mL on delayed CTA. Median extravasation rate was 0.23mL/min overall, and 0.30mL/min among expanders versus 0.07mL/min in non-expanders. Extravasation rates were also significantly higher in patients who died in hospital: 0.27mL/min versus 0.04mL/min. In multivariable analysis, the extravasation rate was independently associated with in-hospital mortality (OR1.09 [95%CI 1.04–1.18], p=0.004), 90-day mortality (OR1.15 [95%CI 1.08–1.27], p=0.0004), and hematoma expansion (OR1.03 [95%CI 1.01–1.08], p=0.047). Conclusions Contrast extravasation rate, or spot sign growth, further refines the ability to predict hematoma expansion and mortality. Our results support the hypothesis that the spot sign directly measures active bleeding in acute ICH. PMID:26243220

  4. Advantages of percutaneous abdominal biopsy under PET-CT/ultrasound fusion imaging guidance: a pictorial essay.

    PubMed

    Paparo, Francesco; Piccazzo, Riccardo; Cevasco, Luca; Piccardo, Arnoldo; Pinna, Francesco; Belli, Fiorenza; Bacigalupo, Lorenzo; Biscaldi, Ennio; De Caro, Giovanni; Rollandi, Gian Andrea

    2014-10-01

    Positron emission tomography (PET) is a functional imaging technique that can investigate the metabolic characteristics of tissues. Currently, PET images are acquired and co-registered with a computed tomography (CT) scan (PET-CT), which is employed for correction of attenuation and anatomical localization. In spite of the high negative predictive value of PET, false-positive results may occur; indeed, Fluorine 18 ((18)F)-fluorodeoxyglucose ((18)F-FDG) uptake is not specific to cancer. As (18)F-FDG uptake may also be seen in non-malignant infectious or inflammatory processes, FDG-avid lesions may necessitate biopsy to confirm or rule out malignancy. However, some PET-positive lesions may have little or no correlative ultrasound (US) and/or CT findings (i.e., low conspicuity on morphological imaging). Since it is not possible to perform biopsy under PET guidance alone, owing to intrinsic technical limitations, PET information has to be integrated into a CT- or US-guided biopsy procedure (multimodal US/PET-CT fusion imaging). The purpose of this pictorial essay is to describe the technique of multimodal imaging fusion between real-time US and PET/CT, and to provide an overview of the clinical settings in which this multimodal integration may be useful in guiding biopsy procedures in PET-positive abdominal lesions.

  5. [The Difference of CT Value Related to Monitor Position in the Head CT-angiography Bolus Tracking Method for Patients with Subarachnoid Hemorrhage].

    PubMed

    Mizui, Masato; Mizoguchi, Yuji; Tashiro, Takao

    2016-01-01

    The head computed tomography-angiography (head CT-A) examination is excellent for the detection and diagnosis of cerebral artery aneurysm. If we use bolus tracking method when implementing this examination, we must choose a monitoring point. We investigated the influence which the monitoring point (MCA or carotid-A) exerts on the CT value. As for the result, MCA monitoring point method was more excellent than the carotid artery monitoring point method. The CT value was higher about 50 HU in the MCA monitoring point than in the carotid artery monitoring point (average;carotid artery: 349.6±57.8 HU, MCA: 413.2±67.9 HU). So, we conclude that in the bolus tracking method of monitoring point of head CTA, MCA monitoring point should be used.

  6. Abdominal CT Does Not Improve Outcome for Children with Suspected Acute Appendicitis

    PubMed Central

    Miano, Danielle I.; Silvis, Renee M.; Popp, Jill M.; Culbertson, Marvin C.; Campbell, Brendan; Smith, Sharon R.

    2015-01-01

    Introduction Acute appendicitis in children is a clinical diagnosis, which often requires preoperative confirmation with either ultrasound (US) or computed tomography (CT) studies. CTs expose children to radiation, which may increase the lifetime risk of developing malignancy. US in the pediatric population with appropriate clinical follow up and serial exam may be an effective diagnostic modality for many children without incurring the risk of radiation. The objective of the study was to compare the rate of appendiceal rupture and negative appendectomies between children with and without abdominal CTs; and to evaluate the same outcomes for children with and without USs to determine if there were any associations between imaging modalities and outcomes. Methods We conducted a retrospective chart review including emergency department (ED) and inpatient records from 1/1/2009–2/31/2010 and included patients with suspected acute appendicitis. Results 1,493 children, aged less than one year to 20 years, were identified in the ED with suspected appendicitis. These patients presented with abdominal pain who had either a surgical consult or an abdominal imaging study to evaluate for appendicitis, or were transferred from an outside hospital or primary care physician office with the stated suspicion of acute appendicitis. Of these patients, 739 were sent home following evaluation in the ED and did not return within the subsequent two weeks and were therefore presumed not to have appendicitis. A total of 754 were admitted and form the study population, of which 20% received a CT, 53% US, and 8% received both. Of these 57%, 95% CI [53.5,60.5] had pathology-proven appendicitis. Appendicitis rates were similar for children with a CT (57%, 95% CI [49.6,64.4]) compared to those without (57%, 95% CI [52.9,61.0]). Children with perforation were similar between those with a CT (18%, 95% CI [12.3,23.7]) and those without (13%, 95% CI [10.3,15.7]). The proportion of children with a

  7. Patient-size-dependent radiation dose optimisation technique for abdominal CT examinations.

    PubMed

    Ngaile, J E; Msaki, P; Kazema, R

    2012-01-01

    Since patient doses from computed tomography (CT) are relatively high, risk-benefit analysis requires dose to patients and image quality be optimised. The aim of this study was to develop a patient-dependent optimisation technique that uses patient diameter to select a combination of CT scanning parameters that minimise dose delivered to patients undergoing abdominal CT examinations. The study was performed using cylindrical phantoms of diameters ranging from 16 to 40 cm in order to establish the relationship between image degradation, CT scanning techniques, patient dose and patient size from two CT scanners. These relationships were established by scanning the phantoms using standard scanning technique followed by selected combinations of scanning parameters. The image noises through phantom images were determined using region of interest software available in both scanners. The energy depositions to the X-ray detector through phantoms were determined from measurements of CT dose index in air corrected for attenuation of the phantom materials. The results demonstrate that exposure settings (milliampere seconds) could be reduced by up to 82 % for smaller phantom relative to standard milliampere seconds, while detector signal could be reduced by up to 93 % for smaller phantom relative to energy depositions required when scanned using standard scanning protocols. It was further revealed that the use of the object-specific scanning parameters on studies performed with phantom of different diameters could reduce the incident radiation to small size object by up to 86 % to obtain the same image quality required for standard adult object. In view of the earlier mentioned fact, substantial dose saving from small-sized adults and children patients undergoing abdomen CT examinations could be achieved through optimal adjustment of CT scanning technique based on the patient transverse diameter.

  8. CT-SPECT fusion to correlate radiolabeled monoclonal antibody uptake with abdominal CT findings

    SciTech Connect

    Kramer, E.L.; Noz, M.E.; Sanger, J.J.; Megibow, A.J.; Maguire, G.Q. )

    1989-09-01

    To enhance the information provided by computed tomography (CT) and single photon emission computed tomography (SPECT) performed with radiolabeled, anti-carcinoembryonic antigen monoclonal antibody (MoAb), the authors performed fusion of these types of images from eight subjects with suspected colorectal adenocarcinoma. Section thickness and pixel size of the two studies were matched, coordinates of corresponding points from each study were identified, and CT sections were translated, rotated, and reprojected to match the corresponding SPECT scans. The CT-SPECT fusion enabled identification of anatomic sites of tumor-specific MoAb accumulation in four cases, showed non-specific MoAb accumulation in two, and helped confirm information only suggested by the two studies separately in one.

  9. 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.

  10. Spleen Segmentation and Assessment in CT Images for Traumatic Abdominal Injuries.

    PubMed

    Reza Soroushmehr, S M; Davuluri, Pavani; Molaei, Somayeh; Hargraves, Rosalyn Hobson; Tang, Yang; Cockrell, Charles H; Ward, Kevin; Najarian, Kayvan

    2015-09-01

    Spleen segmentation is especially challenging as the majority of solid organs in the abdomen region have similar gray level range. Physician analysis of computed tomography (CT) images to assess abdominal trauma could be very time consuming and hence, automating this process can reduce time to treatment. The proposed method presented in this paper is a fully automated and knowledge based technique that employs anatomical information to accurately segment the spleen in CT images. The spleen detection procedure is proposed to locate the spleen in both healthy and injured cases. In the presence of hemorrhage and laceration, the edge merging technique is used. The accuracy of the method is measured by some criteria such as mis-segmented area, accuracy, specificity and sensitivity. The results show that the proposed spleen segmentation method performs well and outperforms other methods.

  11. 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.

  12. Pancreas segmentation from 3D abdominal CT images using patient-specific weighted subspatial probabilistic atlases

    NASA Astrophysics Data System (ADS)

    Karasawa, Kenichi; Oda, Masahiro; Hayashi, Yuichiro; Nimura, Yukitaka; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Rueckert, Daniel; Mori, Kensaku

    2015-03-01

    Abdominal organ segmentations from CT volumes are now widely used in the computer-aided diagnosis and surgery assistance systems. Among abdominal organs, the pancreas is especially difficult to segment because of its large individual differences of the shape and position. In this paper, we propose a new pancreas segmentation method from 3D abdominal CT volumes using patient-specific weighted-subspatial probabilistic atlases. First of all, we perform normalization of organ shapes in training volumes and an input volume. We extract the Volume Of Interest (VOI) of the pancreas from the training volumes and an input volume. We divide each training VOI and input VOI into some cubic regions. We use a nonrigid registration method to register these cubic regions of the training VOI to corresponding regions of the input VOI. Based on the registration results, we calculate similarities between each cubic region of the training VOI and corresponding region of the input VOI. We select cubic regions of training volumes having the top N similarities in each cubic region. We subspatially construct probabilistic atlases weighted by the similarities in each cubic region. After integrating these probabilistic atlases in cubic regions into one, we perform a rough-to-precise segmentation of the pancreas using the atlas. The results of the experiments showed that utilization of the training volumes having the top N similarities in each cubic region led good results of the pancreas segmentation. The Jaccard Index and the average surface distance of the result were 58.9% and 2.04mm on average, respectively.

  13. Computer-aided Assessment of Regional Abdominal Fat with Food Residue Removal in CT

    PubMed Central

    Makrogiannis, Sokratis; Caturegli, Giorgio; Davatzikos, Christos; Ferrucci, Luigi

    2014-01-01

    Rationale and Objectives Separate quantification of abdominal subcutaneous and visceral fat regions is essential to understand the role of regional adiposity as risk factor in epidemiological studies. Fat quantification is often based on computed tomography (CT) because fat density is distinct from other tissue densities in the abdomen. However, the presence of intestinal food residues with densities similar to fat may reduce fat quantification accuracy. We introduce an abdominal fat quantification method in CT with interest in food residue removal. Materials and Methods Total fat was identified in the feature space of Hounsfield units and divided into subcutaneous and visceral components using model-based segmentation. Regions of food residues were identified and removed from visceral fat using a machine learning method integrating intensity, texture, and spatial information. Cost-weighting and bagging techniques were investigated to address class imbalance. Results We validated our automated food residue removal technique against semimanual quantifications. Our feature selection experiments indicated that joint intensity and texture features produce the highest classification accuracy at 95%. We explored generalization capability using k-fold cross-validation and receiver operating characteristic (ROC) analysis with variable k. Losses in accuracy and area under ROC curve between maximum and minimum k were limited to 0.1% and 0.3%. We validated tissue segmentation against reference semimanual delineations. The Dice similarity scores were as high as 93.1 for subcutaneous fat and 85.6 for visceral fat. Conclusions Computer-aided regional abdominal fat quantification is a reliable computational tool for large-scale epidemiological studies. Our proposed intestinal food residue reduction scheme is an original contribution of this work. Validation experiments indicate very good accuracy and generalization capability. PMID:24119354

  14. Efficient multi-atlas abdominal segmentation on clinically acquired CT with SIMPLE context learning.

    PubMed

    Xu, Zhoubing; Burke, Ryan P; Lee, Christopher P; Baucom, Rebeccah B; Poulose, Benjamin K; Abramson, Richard G; Landman, Bennett A

    2015-08-01

    Abdominal segmentation on clinically acquired computed tomography (CT) has been a challenging problem given the inter-subject variance of human abdomens and complex 3-D relationships among organs. Multi-atlas segmentation (MAS) provides a potentially robust solution by leveraging label atlases via image registration and statistical fusion. We posit that the efficiency of atlas selection requires further exploration in the context of substantial registration errors. The selective and iterative method for performance level estimation (SIMPLE) method is a MAS technique integrating atlas selection and label fusion that has proven effective for prostate radiotherapy planning. Herein, we revisit atlas selection and fusion techniques for segmenting 12 abdominal structures using clinically acquired CT. Using a re-derived SIMPLE algorithm, we show that performance on multi-organ classification can be improved by accounting for exogenous information through Bayesian priors (so called context learning). These innovations are integrated with the joint label fusion (JLF) approach to reduce the impact of correlated errors among selected atlases for each organ, and a graph cut technique is used to regularize the combined segmentation. In a study of 100 subjects, the proposed method outperformed other comparable MAS approaches, including majority vote, SIMPLE, JLF, and the Wolz locally weighted vote technique. The proposed technique provides consistent improvement over state-of-the-art approaches (median improvement of 7.0% and 16.2% in DSC over JLF and Wolz, respectively) and moves toward efficient segmentation of large-scale clinically acquired CT data for biomarker screening, surgical navigation, and data mining. PMID:26046403

  15. Efficient multi-atlas abdominal segmentation on clinically acquired CT with SIMPLE context learning.

    PubMed

    Xu, Zhoubing; Burke, Ryan P; Lee, Christopher P; Baucom, Rebeccah B; Poulose, Benjamin K; Abramson, Richard G; Landman, Bennett A

    2015-08-01

    Abdominal segmentation on clinically acquired computed tomography (CT) has been a challenging problem given the inter-subject variance of human abdomens and complex 3-D relationships among organs. Multi-atlas segmentation (MAS) provides a potentially robust solution by leveraging label atlases via image registration and statistical fusion. We posit that the efficiency of atlas selection requires further exploration in the context of substantial registration errors. The selective and iterative method for performance level estimation (SIMPLE) method is a MAS technique integrating atlas selection and label fusion that has proven effective for prostate radiotherapy planning. Herein, we revisit atlas selection and fusion techniques for segmenting 12 abdominal structures using clinically acquired CT. Using a re-derived SIMPLE algorithm, we show that performance on multi-organ classification can be improved by accounting for exogenous information through Bayesian priors (so called context learning). These innovations are integrated with the joint label fusion (JLF) approach to reduce the impact of correlated errors among selected atlases for each organ, and a graph cut technique is used to regularize the combined segmentation. In a study of 100 subjects, the proposed method outperformed other comparable MAS approaches, including majority vote, SIMPLE, JLF, and the Wolz locally weighted vote technique. The proposed technique provides consistent improvement over state-of-the-art approaches (median improvement of 7.0% and 16.2% in DSC over JLF and Wolz, respectively) and moves toward efficient segmentation of large-scale clinically acquired CT data for biomarker screening, surgical navigation, and data mining.

  16. Texture-learning-based system for three-dimensional segmentation of renal parenchyma in abdominal CT images

    NASA Astrophysics Data System (ADS)

    Peng, Cong-Qi; Chang, Yuan-Hsiang; Wang, Li-Jen; Wong, Yon-Choeng; Chiang, Yang-Jen; Jiang, Yan-Yau

    2009-02-01

    Abdominal CT images are commonly used for the diagnosis of kidney diseases. With the advances of CT technology, processing of CT images has become a challenging task mainly because of the large number of CT images being studied. This paper presents a texture-learning based system for the three-dimensional (3D) segmentation of renal parenchyma in abdominal CT images. The system is designed to automatically delineate renal parenchyma and is based on the texturelearning and the region-homogeneity-based approaches. The first approach is achieved with the texture analysis using the gray-level co-occurrence matrix (GLCM) features and an artificial neural network (ANN) to determine if a pixel in the CT image is likely to fall within the renal parenchyma. The second approach incorporates a two-dimensional (2D) region growing to segment renal parenchyma in single CT image slice and a 3D region growing to propagate the segmentation results to neighboring CT image slices. The criterion for the region growing is a test of region-homogeneity which is defined by examining the ANN outputs. In system evaluation, 10 abdominal CT image sets were used. Automatic segmentation results were compared with manually segmentation results using the Dice similarity coefficient. Among the 10 CT image sets, our system has achieved an average Dice similarity coefficient of 0.87 that clearly shows a high correlation between the two segmentation results. Ultimately, our system could be incorporated in applications for the delineation of renal parenchyma or as a preprocessing in a CAD system of kidney diseases.

  17. 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

  18. 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

  19. 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.

  20. 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.

  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.

  2. Computerized left ventricular regional ejection fraction analysis for detection of ischemic coronary artery disease with multidetector CT angiography.

    PubMed

    Zeb, Irfan; Li, Dong; Nasir, Khurram; Gupta, Mohit; Kadakia, Jigar; Gao, Yanlin; Ma, Eva; Mao, Song Shou; Budoff, Matthew

    2013-03-01

    Regional ejection fraction (REF) provides important functional information of the left ventricular regional myocardium. We aimed to test the diagnostic accuracy of computerized REF analysis for detecting the ischemia and significant stenosis with multidetector CT angiography (MDCT). This is a retrospective study including 155 patients who underwent MDCT scans for evaluation of coronary artery disease. Among them, 83 patients also underwent SPECT imaging and invasive coronary angiography (ICA). Two groups of patients were defined: Control group with 0 coronary artery calcium and normal global and regional ventricular function, and comparison group. REF measurement was performed on all patients using computerized software. Control group REF measurements will be used as reference standard (mean-2SD REF/mean global ejection fraction) to define abnormal REF. The sensitivity, specificity, positive and negative predictive value of REF in detecting perfusion defects (fixed and reversible) was 73, 80, 75 and 79 % respectively, in a patient based analysis of comparison group. The diagnostic accuracy of REF in predicting significant stenosis (>50 %) on ICA compared with SPECT was 72 versus 61 % and 85 versus 79 % in patient and vessel based analysis of comparison group, respectively. ROC curve analysis showed REF to be a better predictor of perfusion defects on SPECT compared with significant stenosis (>50 %) alone or stenosis combined with REF (P < 0.05). The computerized assessment of REF analysis is comparable to SPECT in predicting ischemia and a better predictor of significant stenosis than SPECT. This study also provides reference standard to define abnormal values.

  3. Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing.

    PubMed

    Yu, Sheng; Kumamaru, Kanako K; George, Elizabeth; Dunne, Ruth M; Bedayat, Arash; Neykov, Matey; Hunsaker, Andetta R; Dill, Karin E; Cai, Tianxi; Rybicki, Frank J

    2014-12-01

    In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. The classification tasks include: PE present vs. absent, acute PE vs. others, central PE vs. others, and subsegmental PE vs. others. Statistical learning algorithms were trained with features extracted using the NLP tool and gold standard labels obtained via chart review from two radiologists. The areas under the receiver operating characteristic curves (AUC) for the four tasks were 0.998, 0.945, 0.987, and 0.986, respectively. We compared our classifiers with bag-of-words Naive Bayes classifiers, a standard text mining technology, which gave AUC 0.942, 0.765, 0.766, and 0.712, respectively. PMID:25117751

  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. Liver Segmentation Based on Snakes Model and Improved GrowCut Algorithm in Abdominal CT Image

    PubMed Central

    He, Baochun; Ma, Zhiyuan; Zong, Mao; Zhou, Xiangrong; Fujita, Hiroshi

    2013-01-01

    A novel method based on Snakes Model and GrowCut algorithm is proposed to segment liver region in abdominal CT images. First, according to the traditional GrowCut method, a pretreatment process using K-means algorithm is conducted to reduce the running time. Then, the segmentation result of our improved GrowCut approach is used as an initial contour for the future precise segmentation based on Snakes model. At last, several experiments are carried out to demonstrate the performance of our proposed approach and some comparisons are conducted between the traditional GrowCut algorithm. Experimental results show that the improved approach not only has a better robustness and precision but also is more efficient than the traditional GrowCut method. PMID:24066017

  6. 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

  7. Secondary aortoenteric fistula: active bleeding detected with multi-detector-row CT.

    PubMed

    Roos, Justus E; Willmann, Jürgen K; Hilfiker, Paul R

    2002-12-01

    We report a case of active bleeding of a secondary aortoenteric fistula (SAEF), in which CT angiography with multi-detector-row CT (MDCT) was finally diagnostic after negative catheter angiography and unsatisfactory endoscopy. The MDCT angiography clearly demonstrated the fistulous tract between the abdominal aortic graft and the duodenum. The dynamic process of bleeding was confirmed as a net increase of contrast agent accumulation in the duodenum through different phases. The MDCT angiography with its excellent 3D image quality is therefore a valuable method in the assessment of active SAEF bleeding. PMID:12522640

  8. Automatic vessel extraction and abdominal aortic stent planning in multislice CT

    NASA Astrophysics Data System (ADS)

    Subramanyan, Krishna; Smith, Dava; Varma, Jay; Chandra, Shalabh

    2002-05-01

    The abdominal aorta is the most common site for an aneurysm, which may lead to hemorrhage and death, to develop. The aim of this study was to develop a semi-automated method to de-lineate the vessels and detect the center-line of these vessels to make measurements necessary for stent design from multi-detector computed tomograms. We developed a robust method of tracking the aortic vessel tree with branches from a user selected seed point along the vessel path using scale space approaches, central transformation measures, vessel direction findings, iterative corrections and a priori information in determining the vessel branches. Fifteen patients were scanned with contrast on Mx8000 CT scanner (Philips Medical Systems), with a 3.2 mm thickness, 1.5 mm slice spacing, and a stack of 512x512x320 volume data sets were reconstructed. The algorithm required an initial user input to locate the vessel seen in axial CT slice. Next, the automated image processing took approximately two minutes to compute the centerline and borders of the aortic vessel tree. The results between the manually and automatically generated vessel diameters were compared and statistics were computed. We observed our algorithm was consistent (less than 0.01 S.D) and similar (less than 0.1 S.D) to manual results.

  9. Abdominal and pancreatic motion correlation using 4D CT, 4D transponders, and a gating belt.

    PubMed

    Betancourt, Ricardo; Zou, Wei; Plastaras, John P; Metz, James M; Teo, Boon-Keng; Kassaee, Alireza

    2013-01-01

    The correlation between the pancreatic and external abdominal motion due to respiration was investigated on two patients. These studies utilized four dimensional computer tomography (4D CT), a four dimensional (4D) electromagnetic transponder system, and a gating belt system. One 4D CT study was performed during simulation to quantify the pancreatic motion using computer tomography images at eight breathing phases. The motion under free breathing and breath-hold were analyzed for the 4D electromagnetic transponder system and the gating belt system during treatment. A linear curve was fitted for all data sets and correlation factors were evaluated between the 4D electromagnetic transponder system and the gating belt system data. The 4D CT study demonstrated a modest correlation between the external marker and the pancreatic motion with R-square values larger than 0.8 for the inferior-superior (inf-sup). Then, the relative pressure from the belt gating system correlated well with the 4D electromagnetic transponder system's motion in the anterior-posterior (ant-post) and the inf-post directions. These directions have a correlation value of -0.93 and 0.76, while the lateral only had a 0.03 correlation coefficient. Based on our limited study, external surrogates can be used as predictors of the pancreatic motion in the inf-sup and the ant-post directions. Although there is a low correlation on the lateral direction, its motion is significantly shorter. In conclusion, an appropriate treatment delivery can be used for pancreatic cancer when an internal tracking system, such as the 4D electromagnetic transponder system, is unavailable. PMID:23652242

  10. Hybrid point-and-intensity-based deformable registration for abdominal CT images

    NASA Astrophysics Data System (ADS)

    West, Jay B.; Maurer, Calvin R., Jr.; Dooley, John R.

    2005-04-01

    In this paper, we examine the problem of non-rigid, image-to-image registration for CT images of the abdomen. This problem has been previously addressed in many different contexts (e.g., visualization using different imaging modalities, modelling of organ deformation after surgical resection). The particular application in which we are interested is modelling of respiratory motion of abdominal organs, so that we may achieve a more accurate representation of the dose distribution in both targeted structures and non-targeted areas during radiosurgical treatment. Our goal is to register two CT images, each acquired at different positions in the respiratory cycle. We use a transformation model based on B-splines, and take advantage of B-splines' "locality" or "compact support" property to ensure computational efficiency and robust convergence to a satisfactory result. We demonstrate that, although a purely intensity-based registration metric performs well in matching the deformation of the lungs during the respiratory cycle, the movement of other organs (e.g., liver and kidney) is poorly represented due to the poor contrast within and between these organs in the CT images. We introduce a registration metric that is a weighted combination of intensity difference and distance between corresponding points that are manually identified in the two images being registered; we show how the influence of these points can be elegantly added to the metric so that it remains differentiable with respect to the spline control points. Visual inspection reveals that resulting registrations appear to be superior to the intensity-only ones in terms of representation of visceral organ deformation and movement.

  11. Abdominal and pancreatic motion correlation using 4D CT, 4D transponders, and a gating belt.

    PubMed

    Betancourt, Ricardo; Zou, Wei; Plastaras, John P; Metz, James M; Teo, Boon-Keng; Kassaee, Alireza

    2013-05-06

    The correlation between the pancreatic and external abdominal motion due to respiration was investigated on two patients. These studies utilized four dimensional computer tomography (4D CT), a four dimensional (4D) electromagnetic transponder system, and a gating belt system. One 4D CT study was performed during simulation to quantify the pancreatic motion using computer tomography images at eight breathing phases. The motion under free breathing and breath-hold were analyzed for the 4D electromagnetic transponder system and the gating belt system during treatment. A linear curve was fitted for all data sets and correlation factors were evaluated between the 4D electromagnetic transponder system and the gating belt system data. The 4D CT study demonstrated a modest correlation between the external marker and the pancreatic motion with R-square values larger than 0.8 for the inferior-superior (inf-sup). Then, the relative pressure from the belt gating system correlated well with the 4D electromagnetic transponder system's motion in the anterior-posterior (ant-post) and the inf-post directions. These directions have a correlation value of -0.93 and 0.76, while the lateral only had a 0.03 correlation coefficient. Based on our limited study, external surrogates can be used as predictors of the pancreatic motion in the inf-sup and the ant-post directions. Although there is a low correlation on the lateral direction, its motion is significantly shorter. In conclusion, an appropriate treatment delivery can be used for pancreatic cancer when an internal tracking system, such as the 4D electromagnetic transponder system, is unavailable.

  12. Coronary CT Angiography as a Diagnostic and Prognostic Tool: Perspectives from the SCOT-HEART Trial.

    PubMed

    Doris, Mhairi; Newby, David E

    2016-02-01

    Coronary artery disease is the leading cause of death worldwide. Many trials to date have investigated the diagnostic accuracy of coronary computed tomography angiography (CCTA) when compared to the gold standard diagnostic test, invasive coronary angiography. However, whether the use of a non-invasive anatomical test, such as CCTA, can translate into improved patient risk stratification, management and outcome has yet to be established. The Scottish COmputed Tomography of the HEART (SCOT-HEART) trial sought to address these questions and determined whether CCTA, when used in addition to standard care, could aid the diagnosis, further investigation and treatment of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. In this trial, CCTA clarified the diagnosis of angina due to coronary heart disease in a quarter of patients and this led to major alterations in treatment and management that appeared to reduce the risk of subsequent coronary heart disease death or non-fatal myocardial infarction. The SCOT-Heart trial has established that CCTA is a valuable diagnostic test in patients with suspected angina pectoris due to coronary heart disease and leads to greater clarity, more focused appropriate treatments and better coronary heart disease outcomes.

  13. 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.

  14. Characterization of indeterminate spleen lesions in primary CT after blunt abdominal trauma: potential role of MR imaging.

    PubMed

    Gordic, Sonja; Alkadhi, Hatem; Simmen, Hans-Peter; Wanner, Guido; Cadosch, Dieter

    2014-10-01

    The purpose of this study was to determine the value of magnetic resonance imaging (MRI) for characterization of indeterminate spleen lesions in primary computed tomography (CT) of patients with blunt abdominal trauma. Twenty-five consecutive patients (8 female, 17 male, mean age 51.6 ± 22.4 years) with an indeterminate spleen lesion diagnosed at CT after blunt abdominal trauma underwent MRI with T2- and T1-weighted images pre- and post-contrast material administration. MRI studies were reviewed by two radiologists. Age, gender, injury mechanism, injury severity score (ISS), management of patients, time interval between CT and MRI, and length of hospital stay were included into the analysis. Patient history, clinical history, imaging, and 2-month clinical outcome including review of medical records and telephone interviews served as reference standard. From the 25 indeterminate spleen lesions in CT, 11 (44 %) were traumatic; nine (36 %) were non-traumatic (pseudocysts, n=5; hemangioma, n=4) and five proven to represent artifacts in CT. The ISS (P<0.001) and the length of hospital stay (P=0.03) were significantly higher in patients with spleen lesions as compared with those without. All other parameters were similar among groups (all, P>0.05). The MRI features ill-defined lesion borders, variable signal intensity on T1- and T2-weighted images depending on the age of the hematoma, focal contrast enhancement indicating traumatic pseudoaneurysm, perilesional contrast enhancement, and edema were most indicative for traumatic spleen lesions. As compared with CT (2/25), MRI (5/25) better depicted thin subcapsular hematomas as indicator of traumatic spleen injury. In conclusion, MRI shows value for characterizing indeterminate spleen lesions in primary CT after blunt abdominal trauma.

  15. Retrospective Analysis of Artifacts in Four-Dimensional CT Images of 50 Abdominal and Thoracic Radiotherapy Patients

    SciTech Connect

    Yamamoto, Tokihiro Langner, Ulrich; Loo, Billy W.; Shen, John; Keall, Paul J.

    2008-11-15

    Purpose: To quantify the type, frequency, and magnitude of artifacts in four-dimensional (4D) CT images acquired using a multislice cine method. Methods and Materials: Fifty consecutive patients who underwent 4D-CT scanning and radiotherapy for thoracic or abdominal cancers were included in this study. All the 4D-CT scans were performed on the GE multislice PET/CT scanner with the Varian Real-time Position Management system in cine mode. The GE Advantage 4D software was used to create 4D-CT data sets. The artifacts were then visually and quantitatively analyzed. We performed statistical analyses to evaluate the relationships between patient- or breathing-pattern-related parameters and the occurrence as well as magnitude of artifacts. Results: It was found that 45 of 50 patients (90%) had at least one artifact (other than blurring) with a mean magnitude of 11.6 mm (range, 4.4-56.0 mm) in the diaphragm or heart. We also observed at least one artifact in 6 of 20 lung or mediastinal tumors (30%). Statistical analysis revealed that there were significant differences between several breathing-pattern-related parameters, including abdominal displacement (p < 0.01), for the subgroups of patients with and without artifacts. The magnitude of an artifact was found to be significantly but weakly correlated with the abdominal displacement difference between two adjacent couch positions (R = 0.34, p < 0.01). Conclusions: This study has identified that the frequency and magnitude of artifacts in 4D-CT is alarmingly high. Significant improvement is needed in 4D-CT imaging.

  16. CT features and common causes of arc of Riolan expansion: an analysis with 64-detector-row computed tomographic angiography

    PubMed Central

    Xie, Yuanliang; Jin, Chaolin; Zhang, Shutong; Wang, Xiang; Jiang, Yanping

    2015-01-01

    Objective: To study the manifestations of arc of Riolan expansion (ARE) using multi-detector computed tomography angiography (MDCTA). Materials and methods: The manifestations and clinical data of 626 consecutive mesentery CTA images were retrospectively analyzed. The 47 cases with ARE and 47 patients without expansion were involved. The average diameter of arc of Riolan was measured. Two radiologists after reaching consensus analyzed the shapes of mesenteric artery, CT findings and the occurrence and causes of ARE. Results: The mean diameter of arc of Riolan was 1.2 mm, 4.6 mm, 2.5 mm, 2.3 mm, 1.9 mm, 2.5 mm, and 2.0 mm at baseline and following obstruction of superior mesenteric artery (SMA), stenosis of SMA, obstruction of inferior mesenteric artery (IMA), stenosis of IMA, colon cancer, and active ulcerative colitis, respectively. The expansion of arc of Riolan was the most significant following obstruction of SMA. The diameters of arc of Riolan were significantly different between the upward flow group and the downward or the two-way flow groups, and between the colon tumor group and the active ulcerative colitis group. CT findings such as bowel wall thickening, contrast enhancement, intestinal obstruction, marginal artery expansion, lymph node enlargement varied and were help to identify the cause of ARE. Conclusions: ARE often suggests the occurrence of obstructed intestinal feeding artery or intestinal lesions. MDCTA can clearly display the situation of arc of Riolan and collateral circulation, and together with CT symptoms, can guide the selection of diagnosis and treatment schemes in clinic. PMID:26064208

  17. Interaction of expanding abdominal aortic aneurysm with surrounding tissue: Retrospective CT image studies

    PubMed Central

    Kwon, Sebastian T.; Burek, William; Dupay, Alexander C.; Farsad, Mehdi; Baek, Seungik; Park, Eun-Ah; Lee, Whal

    2015-01-01

    Objectives Abdominal aortic aneurysms (AAA) that rupture have a high mortality rate. Rupture occurs when local mechanical stress exceeds the local mechanical strength of an AAA, so stress profiles such as those from finite element analysis (FEA) are useful. The role and effect of surrounding tissues, like the vertebral column, which have not been extensively studied, are examined in this paper. Methods Longitudinal CT scans from ten patients with AAAs were studied to see the effect of surrounding tissues on AAAs. Segmentation was performed to distinguish the AAA from other tissues and we studied how these surrounding tissues affected the shape and curvature of the AAA. Previously established methods by Veldenz et al. were used to split the AAA into 8 sections and examine the specific effects of surrounding tissues on these sections [1]. Three-dimensional models were created to better examine these effects over time. Registration was done in order to compare AAAs longitudinally. Results The vertebral column and osteophytes were observed to have been affecting the shape and the curvature of the AAA. Interaction with the spine caused focal flattening in certain areas of the AAA. In 16 of the 41 CT scans, the right posterior dorsal section (section 5), had the highest radius of curvature, which was by far the section that had the maximum radius for a specified CT scan. Evolution of the growing AAA showed increased flattening in this section when comparing the last CT scan to the first scan. Conclusion Surrounding tissues have a clear influence on the geometry of an AAA, which may in turn affect the stress profile of AAA. Incorporating these structures in FEA and G&R models will provide a better estimate of stress. Clinical Relevance Currently, size is the only variable considered when deciding whether to undergo elective surgery to repair AAA since it is an easy enough measure for clinicians to utilize. However, this may not be the best indicator of rupture risk

  18. On the relationship of minimum detectable contrast to dose and lesion size in abdominal CT

    NASA Astrophysics Data System (ADS)

    Zhou, Yifang; Scott, Alexander, II; Allahverdian, Janet; Lee, Christina; Kightlinger, Blake; Azizyan, Avetis; Miller, Joseph

    2015-10-01

    CT dose optimization is typically guided by pixel noise or contrast-to-noise ratio that does not delineate low contrast details adequately. We utilized the statistically defined low contrast detectability to study its relationship to dose and lesion size in abdominal CT. A realistically shaped medium sized abdomen phantom was customized to contain a cylindrical void of 4 cm diameter. The void was filled with a low contrast (1% and 2%) insert containing six groups of cylindrical targets ranging from 1.2 mm to 7 mm in size. Helical CT scans were performed using a Siemens 64-slice mCT and a GE Discovery 750 HD at various doses. After the subtractions between adjacent slices, the uniform sections of the filtered backprojection reconstructed images were partitioned to matrices of square elements matching the sizes of the targets. It was verified that the mean values from all the elements in each matrix follow a Gaussian distribution. The minimum detectable contrast (MDC), quantified by the mean signal to background difference equal to the distribution’s standard deviation multiplied by 3.29, corresponding to 95% confidence level, was found to be related to the phantom specific dose and the element size by a power law (R^2  >  0.990). Independent readings on the 5 mm and 7 mm targets were compared to the measured contrast to the MDC ratios. The results showed that 93% of the cases were detectable when the measured contrast exceeds the MDC. The correlation of the MDC to the pixel noise and target size was also identified and the relationship was found to be the same for the scanners in the study. To quantify the impact of iterative reconstructions to the low contrast detectability, the noise structure was studied in a similar manner at different doses and with different ASIR blending fractions. The relationship of the dose to the blending fraction and low contrast detectability is presented.

  19. The diagnostic and prognostic value of coronary CT angiography in asymptomatic high-risk patients: a cohort study

    PubMed Central

    Plank, Fabian; Friedrich, Guy; Dichtl, Wolfgang; Klauser, Andrea; Jaschke, Werner; Franz, Wolfgang-Michael; Feuchtner, Gudrun

    2014-01-01

    Objective To prospectively assess the value of coronary CT angiography (CTA) in asymptomatic patients with high ‘a priori’ risk of coronary artery disease (CAD). Methods 711 consecutive asymptomatic patients (61.8 years; 40.1% female) with high ‘a priori’ risk of CAD were prospectively examined with a coronary calcium score (CCS) and CTA. Coronary arteries were evaluated for atherosclerotic plaque (non-calcified and calcified) and stenosis (mild <50%, intermediate 50–70% or high-grade >70%). Coronary Segment Involvement Score (SIS, total number of segments with plaque) and nc (non-calcified) SIS were calculated. Primary end points were major adverse cardiac events (ST-elevation MI, non-ST-elevation MI and cardiac death); secondary end points were coronary revascularisation and >50% stenosis by invasive angiography. Results Of 711 patients, 28.3% were negative for CAD and 71.7% positive (CAD+) by CTA (15.6% had plaques without stenosis, 23.9% mild, 10.7% intermediate and 21.5% high-grade stenosis). CCS zero prevalence was 306 (43%), out of those 100 (32.7%) had non-calcified plaque only. Mean follow-up period was 2.65 years. MACE rate was 0% in CAD negative and higher (1.2%) in CAD positive by CTA. Coronary revascularisation rate was 5.5%. Patients with SIS ≥5 had an HR of 6.5 (95% CI 1.6 to 25.8, p<0.013) for MACE, patients with ncSIS ≥1 had an HR of 2.4 (95% CI 1.2 to 4.6, p<0.01) for secondary end point. The sensitivity of CTA for stenosis >50% compared with invasive angiography was 92.9% (95% CI 83.0% to 98.1%). Negative predictive value of CTA was 99.4% (95% CI 98.3% to 99.8%) for combined end points. Conclusions CAD prevalence by CTA in asymptomatic high-risk patients is high. CCS zero does not exclude CAD. CTA is highly accurate to exclude CAD. Total coronary plaque burden and nc plaques, even if only one segment is involved, are associated with an increased risk of adverse outcome. PMID:25332810

  20. 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.

  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. 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

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

    NASA Astrophysics Data System (ADS)

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

    2007-11-01

    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.

  6. 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

  7. 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

  8. CT Angiography for Revascularization of CTO: Crossing the Borders of Diagnosis and Treatment.

    PubMed

    Opolski, Maksymilian P; Achenbach, Stephan

    2015-07-01

    Coronary computed tomography angiography (CTA) is increasingly used to diagnose and rule out coronary artery disease. Beyond stenosis detection, the ability of CTA to visualize and characterize coronary atherosclerotic plaque, as well as to obtain 3-dimensional coronary vessel trajectories, has generated considerable interest in the context of pre-procedural planning for revascularization of chronic total occlusions (CTOs). Coronary CTA can characterize features that influence the success rate of percutaneous coronary intervention (PCI) for CTOs such as the extent of calcification, vessel tortuosity, stump morphology, presence of multiple occlusions, and lesion length. Single features and combined scoring systems based on CTA may be used to grade the level of difficulty of the CTOs before PCI and have been shown to predict procedural success rates in several trials. In addition, the procedure itself may be facilitated by real-time integration of 3-dimensional CTA data and fluoroscopic images in the catheterization laboratory. Finally, the ability of coronary CTA to assess anatomy, perfusion, and viability in 1 single examination makes it a potential "one stop shop" that predicts not only the likelihood of successful PCI but also the clinical benefit of CTO revascularization. Further research is clearly needed, but many experienced sites have already integrated coronary CTA into the routine planning and guiding of CTO procedures.

  9. 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

  10. 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

  11. Technical note: Electrocardiogram electrode repositioning for 320-row coronary CT angiography in patients with regular and recurrent premature ventricular contractions.

    PubMed

    Kondo, Takeshi; Matsutani, Hideyuki; Groarke, John; Takamura, Kazuhisa; Fujimoto, Shinichiro; Rybicki, Frank J; Kumamaru, Kanako K

    2014-01-01

    Arrhythmias can compromise image quality and increase radiation exposure during coronary CT angiography (CTA). However, premature ventricular contractions (PVCs) can occur in a predictable recurrent and regular pattern (ie, bigeminy, trigeminy, quadrigeminy) with post-PVC compensatory pauses. Electrocardiographic (ECG) electrode repositioning can achieve relative amplification of the R waves of PVCs compared with R waves of sinus beats. This technical note describes how simple ECG electrode repositioning, combined with an absolute-delay strategy, facilitated selective R waves of PVC ECG triggering of image acquisition in 6 patients with PVC bigeminy or quadrigeminy at the time of 320-row coronary CTA. All 6 studies were single heartbeat acquisition scans with excellent image quality and a median effective radiation dose of 2.9 mSv (interquartile range, 2.1-3.8 mSv). Standard ECG electrode positions used for 2 patients with PVC bigeminy undergoing coronary CTA were associated with an acquisition over 2 heartbeats and effective radiation doses of 6.8 and 10.3 mSv, respectively. In conclusion, ECG electrode repositioning combined with an absolute-delay strategy for regularly recurring PVCs, such as ventricular bigeminy, facilitates high image quality and lower radiation dose during coronary CTA. This simple and straightforward technique can be considered for all patients with regular and recurrent PVCs undergoing coronary CTA.

  12. 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.

  13. 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

  14. Three dimensional CT angiography for patients with congenital heart disease: scanning protocol for pediatric patients.

    PubMed

    Jelnin, Vladimir; Co, Jennifer; Muneer, Basharat; Swaminathan, Balasubramanian; Toska, Suzanna; Ruiz, Carlos E

    2006-01-01

    The objective of our study was to determine the contrast attenuation level that yields high quality cardiac three-dimensional (3-D) images and to predict the contrast injection rate (IR), from body weight, to reach this attenuation level. Enhanced electron beam computerized tomography (EBCT) with 3-D reconstruction is useful in delineating cardiac anatomy in complex congenital heart disease (CHD). The current experience of using electron beam angiography (EBA) in pediatric CHD is limited. Well-defined contrast injection protocols, specifically the contrast IR, have not been standardized when compared to those for adults. Establishing the contrast IR is essential in obtaining high quality 3-D images. We retrospectively analyzed the studies of 115 pediatric patients with CHD. EBA images were divided into group 1 with good quality 3-D images and group 2 with poor quality. The mean of measured enhancement level, expressed in Hounsfield units (HU), and contrast IR were analyzed in both groups. Spearman correlation was used to examine the relationship between weight and IR. The IR was predicted from weight using simple linear regression analysis. The mean level of enhancement was 344 +/- 91 and 174 +/- 31 HU for group 1 and group 2, respectively. Group 1 consisted of 103 patients (90%) and the IR strongly correlated with weight (rho = 0.861, P < 0.01). The IR was estimated from the linear regression equation IR = 0.59 + 0.056 x weight. Necessary contrast enhancement level for quality 3-D reconstruction should be greater than 250 HU, and the IR can be estimated from patient's weight. PMID:16342271

  15. 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

  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. 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.

  18. [Acute and chronic progressive abdominal pain: what is the role of radiogical imaging?].

    PubMed

    Antes, G

    2005-06-01

    There are many causes for acute or chronic progressive abdominal pain. Although only about one percent of these patients suffer from acute mesenteric ischemia (MI), an efficient diagnostic work-up is mandatory to reduce the high mortality. An overview about the possibilities of conventional and modern imaging modalities is given. Plain films and ultrasonography are still important in the basic work-up, however, its sensitivity is limited. Angiography has a high sensitivity and specitivity. However, angiography is not always available. Modern spiral-CT is widely available and its sensitivity is already similar to angiography. An other advantage of CT is the possibility to detect the most other frequent causes of abdominal pain. Therefore CT should be performed as fast as possible.

  19. Single-centre cohort study of gender influence in coronary CT angiography in patients with a low to intermediate pretest probability of coronary heart disease

    PubMed Central

    Nørgaard, Kirsten Schou; Isaksen, Christin; Buhl, Jørgen Selmer; Kirk Johansen, Jane; Nielsen, Agnete Hedemann; Nørgaard, Aage; Urbonaviciene, Grazina; Lindholt, Jes S; Frost, Lars

    2015-01-01

    Background In ‘real-world’ patient populations undergoing coronary CT angiography (CCTA), it is unclear whether a correlation exists between gender, coronary artery calcium (CAC) score and subsequent referral for invasive coronary angiography and coronary revascularisation. We therefore investigated the relationship between gender, CAC and use of subsequent invasive coronary angiography and coronary revascularisation in a cohort of patients with chest discomfort and low to intermediate pretest probability of coronary artery disease who underwent a CCTA at our diagnostic centre. Methods This is a cohort study that included patients examined between 2010 and 2013. Data were obtained from the Western Denmark Heart Registry. The follow-up ended 11 March 2014. Results A total of 3541 people (1621 men and 1920 women) were examined by CCTA. The rate of invasive coronary angiography during follow-up was 28.5% in men versus 18.3% in women (p<0.001). The rate of coronary revascularisation during follow-up was 11.4% in men versus 5.1% in women (p<0.001). The CAC-adjusted HR in women versus men was 0.98 (95% CI 0.85 to 1.13) for invasive coronary angiography and 0.73 (95% CI 0.57 to 0.93) for coronary revascularisation. Further adjustment for age and other risk factors did not change these estimates. Conclusions Women had a lower CAC score than men and a corresponding lower rate of invasive coronary angiography. The risk of coronary revascularisation was modestly reduced in women, irrespective of CAC. This may reflect a gender-specific difference in coping with chest discomfort, gender-specific referral bias for CCTA, and/or a gender-specific difference in the balance between coronary calcification and obstructive coronary heart disease. PMID:26196016

  20. A Novel Multiinstance Learning Approach for Liver Cancer Recognition on Abdominal CT Images Based on CPSO-SVM and IO

    PubMed Central

    Yi, Dehui

    2013-01-01

    A novel multi-instance learning (MIL) method is proposed to recognize liver cancer with abdominal CT images based on instance optimization (IO) and support vector machine with parameters optimized by a combination algorithm of particle swarm optimization and local optimization (CPSO-SVM). Introducing MIL into liver cancer recognition can solve the problem of multiple regions of interest classification. The images we use in the experiments are liver CT images extracted from abdominal CT images. The proposed method consists of two main steps: (1) obtaining the key instances through IO by texture features and a classification threshold in classification of instances with CPSO-SVM and (2) predicting unknown samples with the key instances and the classification threshold. By extracting the instances equally based on the entire image, the proposed method can ignore the procedure of tumor region segmentation and lower the demand of segmentation accuracy of liver region. The normal SVM method and two MIL algorithms, Citation-kNN algorithm and WEMISVM algorithm, have been chosen as comparing algorithms. The experimental results show that the proposed method can effectively recognize liver cancer images from two kinds of cancer CT images and greatly improve the recognition accuracy. PMID:24368931

  1. A novel multiinstance learning approach for liver cancer recognition on abdominal CT images based on CPSO-SVM and IO.

    PubMed

    Jiang, Huiyan; Zheng, Ruiping; Yi, Dehui; Zhao, Di

    2013-01-01

    A novel multi-instance learning (MIL) method is proposed to recognize liver cancer with abdominal CT images based on instance optimization (IO) and support vector machine with parameters optimized by a combination algorithm of particle swarm optimization and local optimization (CPSO-SVM). Introducing MIL into liver cancer recognition can solve the problem of multiple regions of interest classification. The images we use in the experiments are liver CT images extracted from abdominal CT images. The proposed method consists of two main steps: (1) obtaining the key instances through IO by texture features and a classification threshold in classification of instances with CPSO-SVM and (2) predicting unknown samples with the key instances and the classification threshold. By extracting the instances equally based on the entire image, the proposed method can ignore the procedure of tumor region segmentation and lower the demand of segmentation accuracy of liver region. The normal SVM method and two MIL algorithms, Citation-kNN algorithm and WEMISVM algorithm, have been chosen as comparing algorithms. The experimental results show that the proposed method can effectively recognize liver cancer images from two kinds of cancer CT images and greatly improve the recognition accuracy.

  2. Correlation of coronary plaque characteristics and obstructive stenosis with chronic kidney disease by coronary CT angiography

    PubMed Central

    Wang, Chengming; Duanmu, Yibo; Zhu, Yi; Xu, Lu

    2015-01-01

    Background Chronic kidney disease (CKD) is an independent risk factor for cardiovascular events. We evaluated the correlation of coronary plaque characteristics and obstructive stenosis with CKD by coronary computed tomographic angiography (CCTA). Methods We enrolled 491 subjects who were suspected coronary artery disease (CAD) undergoing CCTA. Estimated glomerular filtration rate (eGFR) was calculated by the modification of diet in renal disease (MDRD) equation. Patients were subdivided into four groups based on their eGFR: normal GFR (n=213, eGFR ≥90 mL/min/1.73 m2), mild renal insufficiency (n=191, eGFR 60-89 mL/min/1.73 m2), moderate renal insufficiency(n=78, eGFR <60 mL/min/1.73 m2, ≥30 mL/min/1.73 m2), and severe renal insufficiency (n=9, eGFR <30 mL/min/1.73 m2, ≥15 mL/min/1.73 m2). Results Spearman correlation regression analysis showed that the prevalence of any plaque, calcified plaque (CP), mixed plaque (MP) were positively correlate with CKD (r=0.173, P<0.001; r=0.127, P=0.005; r=0.171, P<0.001), after adjustment for traditional risk factors the prevalence of any plaque and MP were still positively correlate with CKD (r=0.106, P=002; r=0.178, P<0.001). And the prevalence of any stenosis and severe stenosis were positively correlate with CKD (r=0.13, P<0.001; r=0.149, P<0.001), after adjustment for traditional risk factors were still positively correlate with CKD (r=0.134, P=0.003; r=0.174, P<0.001). Conclusions CKD is closely related with occurrence of CAD. CKD patients from mild renal insufficiency to severe renal insufficiency are the risk factors for CAD. More serious renal function impairment will indicates higher risk of coronary plaque, MP and obstructive stenosis. PMID:26676159

  3. Coronary centerline extraction from CT coronary angiography images using a minimum cost path approach

    SciTech Connect

    Metz, C. T.; Schaap, M.; Weustink, A. C.; Mollet, N. R.; Walsum, T. van; Niessen, W. J.

    2009-12-15

    Purpose: The application and large-scale evaluation of minimum cost path approaches for coronary centerline extraction from computed tomography coronary angiography (CTCA) data and the development and evaluation of a novel method to reduce the user-interaction time. Methods: A semiautomatic method based on a minimum cost path approach is evaluated for two different cost functions. The first cost function is based on a frequently used vesselness measure and intensity information, and the second is a recently proposed cost function based on region statistics. User interaction is minimized to one or two mouse clicks distally in the coronary artery. The starting point for the minimum cost path search is automatically determined using a newly developed method that finds a point in the center of the aorta in one of the axial slices. This step ensures that all computationally expensive parts of the algorithm can be precomputed. Results: The performance of the aorta localization procedure was demonstrated by a success rate of 100% in 75 images. The success rate and accuracy of centerline extraction was quantitatively evaluated on 48 coronary arteries in 12 images by comparing extracted centerlines with a manually annotated reference standard. The method was able to extract 88% and 47% of the vessel centerlines correctly using the vesselness/intensity and region statistics cost function, respectively. For only the proximal part of the vessels these values were 97% and 86%, respectively. Accuracy of centerline extraction, defined as the average distance from correctly automatically extracted parts of the centerline to the reference standard, was 0.64 mm for the vesselness/intensity and 0.51 mm for the region statistics cost function. The interobserver variability was 99% for the success rate measure and 0.42 mm for the accuracy measure. Qualitative evaluation using the best performing cost function resulted in successful centerline extraction for 233 out of the 252

  4. 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

  5. The Value of Restaging With Chest and Abdominal CT/MRI Scan After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

    PubMed Central

    Liu, Guo-Chen; Zhang, Xu; Xie, E.; An, Xin; Cai, Pei-Qiang; Zhu, Ying; Tang, Jing-Hua; Kong, Ling-Heng; Lin, Jun-Zhong; Pan, Zhi-Zhong; Ding, Pei-Rong

    2015-01-01

    Abstract Little was known with regard to the value of preoperative systemic restaging for patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT). This study was designed to evaluate the role of chest and abdominal computed tomography (CT) scan or magnetic resonance imaging (MRI) on preoperative restaging in LARC after neoadjuvant CRT and to assess the impact on treatment strategy. Between January 2007 and April 2013, 386 newly diagnosed consecutive patients with LARC who underwent neoadjuvant CRT and received restaging with chest and abdominal CT/MRI scan were included. Imaging results before and after CRT were analyzed. Twelve patients (3.1%) (6 liver lesions, 2 peritoneal lesions, 2 distant lymph node lesions, 1 lung lesions, 1 liver and lung lesions) were diagnosed as suspicious metastases on the restaging scan after radiotherapy. Seven patients (1.8%) were confirmed as metastases by pathology or long-term follow-up. The treatment strategy was changed in 5 of the 12 patients as a result of restaging CT/MRI findings. Another 10 patients (2.6%) who present with normal restaging imaging findings were diagnosed as metastases intra-operatively. The sensitivity, specificity accuracy, negative predictive value, and positive predictive values of restaging CT/MRI was 41.4%, 98.6%, 58.3%, and 97.3%, respectively. The low incidence of metastases and minimal consequences for the treatment plan question the clinical value of routine restaging of chest and abdomen after neoadjuvant CRT. Based on this study, a routine restaging CT/MRI of chest and abdomen in patients with rectal cancer after neoadjuvant CRT is not advocated, carcino-embryonic antigen (CEA) -guided CT/MRI restaging might be an alternative. PMID:26632714

  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. 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

  8. Evaluation of Effective Dose During Abdominal Three-Dimensional Imaging for Three Flat-Panel-Detector Angiography Systems

    SciTech Connect

    Suzuki, Shigeru; Yamaguchi, Ichiro; Kidouchi, Takashi; Yamamoto, Asako; Masumoto, Tomohiko; Ozaki, Yutaka

    2011-04-15

    The purpose of this study was to evaluate the effective dose during abdominal three-dimensional (3D) imaging on phantoms and estimate the dose-area product (DAP) for effective dose conversion factors for three types of angiographic units. Three-dimensional imaging was performed for three sizes (small, medium, large) of human-shaped phantoms using three types of angiographic units (Allura Xper FD20/10, INNOVA 4100, AXIOM Artis dTA). We calculated 25 organ doses and effective doses using Monte Carlo technique for the three phantoms with a program for a personal computer. As benchmark studies to back up the results by Monte Carlo technique, we measured the organ doses directly on the small phantom using radiophotoluminescent glass dosimeters. The DAP value increased as the phantom size increased. The organ doses and the effective doses during the 3D imaging increased as the phantom size increased. The effective doses for the small phantom by Monte Carlo technique were 1.9, 2.2, and 2.1 mSv for the Allura Xper FD20/10, INNOVA 4100, and AXIOM Artis dTA, respectively, while those by direct measurement were 1.6, 2.0, and 2.6 mSv. The effective doses to DAP ratios by Monte Carlo technique were 0.37-0.45, 0.26-0.32, and 0.13-0.15 (mSv Gy{sup -1}cm{sup -2}) for the Allura Xper FD20/10, INNOVA 4100, and AXIOM Artis dTA, respectively. In conclusion, the effective doses during 3D imaging and the dose-to-DAP ratios differ among angiographic units, and the effective dose can be estimated using a proper conversion factor for each angiographic unit.

  9. Evaluation of effective dose during abdominal three-dimensional imaging for three flat-panel-detector angiography systems.

    PubMed

    Suzuki, Shigeru; Yamaguchi, Ichiro; Kidouchi, Takashi; Yamamoto, Asako; Masumoto, Tomohiko; Ozaki, Yutaka

    2011-04-01

    The purpose of this study was to evaluate the effective dose during abdominal three-dimensional (3D) imaging on phantoms and estimate the dose-area product (DAP) for effective dose conversion factors for three types of angiographic units. Three-dimensional imaging was performed for three sizes (small, medium, large) of human-shaped phantoms using three types of angiographic units (Allura Xper FD20/10, INNOVA 4100, AXIOM Artis dTA). We calculated 25 organ doses and effective doses using Monte Carlo technique for the three phantoms with a program for a personal computer. As benchmark studies to back up the results by Monte Carlo technique, we measured the organ doses directly on the small phantom using radiophotoluminescent glass dosimeters. The DAP value increased as the phantom size increased. The organ doses and the effective doses during the 3D imaging increased as the phantom size increased. The effective doses for the small phantom by Monte Carlo technique were 1.9, 2.2, and 2.1 mSv for the Allura Xper FD20/10, INNOVA 4100, and AXIOM Artis dTA, respectively, while those by direct measurement were 1.6, 2.0, and 2.6 mSv. The effective doses to DAP ratios by Monte Carlo technique were 0.37-0.45, 0.26-0.32, and 0.13-0.15 (mSv Gy⁻¹ cm⁻²) for the Allura Xper FD20/10, INNOVA 4100, and AXIOM Artis dTA, respectively. In conclusion, the effective doses during 3D imaging and the dose-to-DAP ratios differ among angiographic units, and the effective dose can be estimated using a proper conversion factor for each angiographic unit.

  10. 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

  11. Computer-Aided Diagnosis of Splenic Enlargement Using Wave Pattern of Spleen in Abdominal CT Images: Initial Observations

    NASA Astrophysics Data System (ADS)

    Seong, Won; Cho, June-Sik; Noh, Seung-Moo; Park, Jong-Won

    In general, the spleen accompanied by abnormal abdomen is hypertrophied. However, if the spleen size is originally small, it is hard to detect the splenic enlargement due to abnormal abdomen by simply measure the size. On the contrary, the spleen size of a person having a normal abdomen may be large by nature. Therefore, measuring the size of spleen is not a reliable diagnostic measure of its enlargement or the abdomen abnormality. This paper proposes an automatic method to diagnose the splenic enlargement due to abnormality, by examining the boundary pattern of spleen in abdominal CT images.

  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. A knowledge-driven quasi-global registration of thoracic-abdominal CT and CBCT for image-guided interventions

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Chefd'hotel, Christophe; Ordy, Vincent; Zheng, Jie; Deng, Xiang; Odry, Benjamin

    2013-03-01

    In this work, we have developed a novel knowledge-driven quasi-global method for fast and robust registration of thoracic-abdominal CT and cone beam CT (CBCT) scans. While the use of CBCT in operating rooms has become a common practice, there is an increasing demand on the registration of CBCT with pre-operative scans, in many cases, CT scans. One of the major challenges of thoracic-abdominal CT/CBCT registration is from various fields of view (FOVs) of the two imaging modalities. The proposed approach utilizes a priori knowledge of anatomy to generate 2D anatomy targeted projection (ATP) images that surrogate the original volumes. The use of lower dimension surrogate images can significantly reduce the computation cost of similarity evaluation during optimization and make it practically feasible to perform global optimization based registration for image-guided interventional procedures. Another a priori knowledge about the local optima distribution on energy curves is further used to effectively select multi-starting points for registration optimization. 20 clinical data sets were used to validate the method and the target registration error (TRE) and maximum registration error (MRE) were calculated to compare the performance of the knowledge-driven quasi-global registration against a typical local-search based registration. The local search based registration failed on 60% cases, with an average TRE of 22.9mm and MRE of 28.1mm; the knowledge-driven quasi-global registration achieved satisfactory results for all the 20 data sets, with an average TRE of 3.5mm, and MRE of 2.6mm. The average computation time for the knowledge-driven quasi-global registration is 8.7 seconds.

  15. 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

  16. CT in ovarian cancer staging: how to review and report with emphasis on abdominal and pelvic disease for surgical planning.

    PubMed

    Sahdev, Anju

    2016-01-01

    CT of the abdomen and pelvis is the first line imaging modality for staging, selecting treatment options and assessing disease response in ovarian cancer. The staging CT provides disease distribution, disease burden and is the imaging surrogate for surgico-pathological FIGO staging. Optimal cyto-reductive surgery offers patients' the best chance for disease control or cure, but sub-optimal resection confers no advantage over chemotherapy and adversely increases the risk of post surgical complications. Although there is extensive literature comparing performance of CT against laparoscopy and surgery, for the staging abdominal and pelvic CT, there are currently no accepted guidelines for interpretation or routinely used minimum data set templates for reporting these complex CT scans often with extensive radiological findings. This review provides a systematic approach for identifying the important radiological findings and highlighting important sites of disease within the abdomen and pelvis, which may alter or preclude surgery at presentation or after adjuvant chemotherapy. The distribution of sites and volume of disease can be used to categorize patients as suitable, probably suitable or not suitable for optimal cyto-reductive surgery. This categorization can potentially assist oncological surgeons and oncologists as a semi objective assessment tool useful for selecting patient treatment, streamlining multi disciplinary discussion and improving the reproducibility and correlation of CT with surgical findings. The review also highlights sites of disease and complications of ovarian cancer which should be included as part of the radiological report as these may require additional surgical input from non gynaecological surgeons or influence treatment selection. PMID:27484100

  17. Automated segmentation of upper digestive tract from abdominal contrast-enhanced CT data using hierarchical statistical modeling of organ interrelations

    NASA Astrophysics Data System (ADS)

    Hirayama, S.; Otake, Y.; Okada, T.; Hori, M.; Tomiyama, N.; Sato, Y.

    2016-03-01

    We have been studying the automatic segmentation of multi-organ region from abdominal CT images. In previous work, we proposed an approach using a hierarchical statistical modeling using a relationship between organs. In this paper, we have proposed automatic segmentation of the upper digestive tract from abdominal contrast-enhanced CT using previously segmented multiple organs. We compared segmentation accuracy of the esophagus, stomach and duodenum between our proposed method using hierarchical statistical modeling and a conventional statistical atlas method. Additionally, preliminary experiment was performed which added the region representing gas to the candidate region at the segmentation step. The segmentation results were evaluated quantitatively by Dice coefficient, Jaccard index and the average symmetric surface distance of the segmented region and correct region data. Percentage of the average of Dice coefficient of esophagus, stomach and duodenum were 58.7, 68.3, and 38.6 with prediction-based method and 23.7, 51.1, and 24.4 with conventional atlas method.

  18. An Abdominal CT may be Safe in Selected Hypotensive Trauma Patients with Positive FAST Exam

    PubMed Central

    Cook, Mackenzie R.; Holcomb, John B.; Rahbar, Mohammad H.; Alarcon, Louis H.; Bulger, Eileen M.; Brasel, Karen J.; Schreiber, Martin A.

    2016-01-01

    Background Positive Focused Assessment with Sonography in Trauma (FAST) and hypotension often indicates urgent surgery. An abdomen/pelvis CT (apCT) may allow less invasive management but the delay may be associated with adverse outcomes. Methods Patients in the Prospective Observational Multicenter Major Trauma Transfusion study with hypotension and a positive FAST (HF+) who underwent a CT (apCT+) were compared to those who did not. Results Of the 92 HF+ identified, 32(35%) underwent apCT during initial evaluation and apCT was associated with decreased odds of an emergency operation, OR 0.11 95% CI (0.001–0.116) and increased odds of angiographic intervention, OR 14.3 95% CI (1.5–135). There was no significant difference in 30 day mortality or need for dialysis. Conclusion An apCt in HF+ patients is associated with reduced odds of emergency surgery, but not mortality. Select HF+ patients can safely undergo apCT to obtain clinically useful information. PMID:25805456

  19. Cerebral angiography

    MedlinePlus

    ... Carotid angiogram; Cervicocerebral catheter-based angiography; Intra-arterial digital subtraction angiography; IADSA ... with the dye are seen. This is called digital subtraction angiography (DSA). After the x-rays are ...

  20. Segmentation of Costal Cartilage in Abdominal CT Data using Watershed Markers

    NASA Astrophysics Data System (ADS)

    Holbrook, Andrew B.; Pauly, Kim Butts

    2007-05-01

    High Intensity Focused Ultrasound (HIFU) ablation is a promising non-invasive technique that heats a specific tumor region to fatal levels, while minimizing cell death in nearby healthy areas. For liver applications, the rib cage limits the transducer placement. A treatment plan based on CT images would segment the ribs and provide visualization of them and the tumor. A HIFU simulation of deposited heat would also require rib segmentation. Unfortunately, the ribs are difficult to segment on CT as they transition to cartilage, with CT units similar to that of the liver. The purpose of this work was to develop a rib segmentation algorithm based on CT images for HIFU treatment planning. After an initial threshold of the CT data, rib regions were characterized based on their size, and if a region were greater than a predetermined area parameter (i.e. it consisted of rib and liver), a marker based watershed transformation separated the two regions and continued to the next inferior slice. After false positives were removed by a predetermined volume parameter, the remaining objects were reassigned high CT values. Preliminary results from six human CT datasets indicated this segmentation method works well, successfully distinguishing the ribs from nearby organs. Of the fifty-five ribs counted in these datasets, only five contained small errors due to reconstruction shading irregularities, with four of these in one dataset. Once all cartilage was assigned high CT numbers, any commercially available 3D rendering software (e.g. OsiriX) can be used to visualize the ribs and tumor.

  1. Detection and visualization of endoleaks in CT data for monitoring of thoracic and abdominal aortic aneurysm stents

    NASA Astrophysics Data System (ADS)

    Lu, J.; Egger, J.; Wimmer, A.; Großkopf, S.; Freisleben, B.

    2008-03-01

    In this paper we present an efficient algorithm for the segmentation of the inner and outer boundary of thoratic and abdominal aortic aneurysms (TAA & AAA) in computed tomography angiography (CTA) acquisitions. The aneurysm segmentation includes two steps: first, the inner boundary is segmented based on a grey level model with two thresholds; then, an adapted active contour model approach is applied to the more complicated outer boundary segmentation, with its initialization based on the available inner boundary segmentation. An opacity image, which aims at enhancing important features while reducing spurious structures, is calculated from the CTA images and employed to guide the deformation of the model. In addition, the active contour model is extended by a constraint force that prevents intersections of the inner and outer boundary and keeps the outer boundary at a distance, given by the thrombus thickness, to the inner boundary. Based upon the segmentation results, we can measure the aneurysm size at each centerline point on the centerline orthogonal multiplanar reformatting (MPR) plane. Furthermore, a 3D TAA or AAA model is reconstructed from the set of segmented contours, and the presence of endoleaks is detected and highlighted. The implemented method has been evaluated on nine clinical CTA data sets with variations in anatomy and location of the pathology and has shown promising results.

  2. Congenital coronary anomalies in adults: comparison of anatomic course visualization by catheter angiography and electron beam CT.

    PubMed

    Memisoglu, Esat; Hobikoglu, Gultekin; Tepe, M Savas; Norgaz, Tugrul; Bilsel, Tuba

    2005-09-01

    The objective of this study was to compare the anatomic course of anomalous coronary arteries by axial and three-dimensional volume-rendered electron beam computed tomography (EBCT) angiography and X-ray catheter angiography (CAG). We performed a blinded study where patients who previously underwent CAG with (n = 14) and without (n = 14; age- and gender-matched controls) anomalous coronary anatomy were studied with EBCT coronary angiography. Forty to 50 EKG-triggered 3 mm overlapping axial slices were acquired with 2 mm table movement within one breath hold during the i.v. injection of 140 cc of nonionic iodinated contrast (4 ml/sec). The axial source images and volume-rendered three-dimensional reconstructions were evaluated for the presence, type, and course of coronary anomalies and the results were compared to those of CAG. All normal and anomalous coronary arteries were identified by both modalities in all subjects. Identified anomalies include single coronary artery (n = 3), left-sided right coronary artery (n = 3), right-sided left main coronary artery (n = 3), anterior descending coronary artery (n = 2), circumflex coronary artery (n = 2), and separate left-sided ostia for left anterior descending and circumflex coronary arteries (n = 1). In five cases, there was discrepancy in the course of the anomalous vessels between the two modalities. Consensus reading among cardiologist and radiologists favored the interpretation of EBCT over catheter angiography. Noninvasive EBCT coronary angiography compares well with CAG in identifying anomalous coronary arteries and may provide confirmatory evaluation of their precise anatomic relationships to the heart and great vessels. PMID:16097013

  3. Radiologist-initiated double reading of abdominal CT: retrospective analysis of the clinical importance of changes to radiology reports

    PubMed Central

    Andersen, Jack Gunnar; Stokke, Mali Victoria; Tennstrand, Anne Lise; Aamodt, Rolf; Heggelund, Thomas; Dahl, Fredrik A; Sandbæk, Gunnar; Hurlen, Petter

    2016-01-01

    Background Misinterpretation of radiological examinations is an important contributing factor to diagnostic errors. Consultant radiologists in Norwegian hospitals frequently request second reads by colleagues in real time. Our objective was to estimate the frequency of clinically important changes to radiology reports produced by these prospectively obtained double readings. Methods We retrospectively compared the preliminary and final reports from 1071 consecutive double-read abdominal CT examinations of surgical patients at five public hospitals in Norway. Experienced gastrointestinal surgeons rated the clinical importance of changes from the preliminary to final report. The severity of the radiological findings in clinically important changes was classified as increased, unchanged or decreased. Results Changes were classified as clinically important in 146 of 1071 reports (14%). Changes to 3 reports (0.3%) were critical (demanding immediate action), 35 (3%) were major (implying a change in treatment) and 108 (10%) were intermediate (requiring further investigations). The severity of the radiological findings was increased in 118 (81%) of the clinically important changes. Important changes were made less frequently when abdominal radiologists were first readers, more frequently when they were second readers, and more frequently to urgent examinations. Conclusion A 14% rate of clinically important changes made during double reading may justify quality assurance of radiological interpretation. Using expert second readers and a targeted selection of urgent cases and radiologists reading outside their specialty may increase the yield of discrepant cases. PMID:27013638

  4. Indirect Radionuclide Coronary Angiography to Evaluate Gradients of Myocardial Blood Flow and Flow Reserve Through Coronary Stenosis Using N-13 Ammonia PET/CT.

    PubMed

    Kim, Hyun-Sik; Cho, Sang-Geon; Kim, Ju Han; Bom, Hee-Seung

    2013-08-01

    Although quantitative evaluation of myocardial blood flow (MBF) and myocardial flow reserve (MFR) has been perceived as an attractive advantage of positron emission tomography (PET) over other cardiac imaging technologies, application of the information to specific coronary lesions is a difficult task for nuclear cardiologists. We hypothesized that changes in MBF and MFR over a coronary lesion could be identified by use of a hybrid technology of CT coronary angiography (CTCA) and N-13 ammonia PET. To evaluate this hypothesis, we measured the gradient of MBF and MFR through coronary stenosis in seven patients (M:F=3:4, median age 56 years) with coronary artery disease who underwent N-13 ammonia PET, CTCA, and interventional coronary angiography. Two patients had proximal left anterior descending (LAD) coronary artery disease and five patients had mid to distal LAD disease. Mean global stress and rest MBF were 2.62±0.58 and 1.03±0.19 ml/min/g, respectively. Mean global MFR was 2.6±0.73. Regional stress and rest MBF in the LAD territory were 2.36±0.75 and 0.96±0.21 ml/min/g, respectively. Regional MFR in the LAD territory was 2.55±0.83 ml/min/g. Stress MBF changed dramatically according to the location of coronary stenosis. It dropped acutely in proximal lesions, whereas it diminished gradually in mid to distal lesions. In conclusion, by use of a hybrid technology of CTCA and PET, it was feasible to make a direct correlation of coronary lesions with the gradient of MFR and CFR through coronary stenosis, which indicated the severity of the coronary lesion. We named this technique indirect radionuclide coronary angiography.

  5. 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.

  6. 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

  7. Patient-specific models of wall stress in abdominal aortic aneurysm: a comparison between MR and CT

    NASA Astrophysics Data System (ADS)

    de Putter, Sander; Breeuwer, Marcel; van de Vosse, Frans N.; Kose, Ursula; Gerritsen, Frans A.

    2006-03-01

    Finite element method based patient-specific wall stress in abdominal aortic aneurysm (AAA) may provide a more accurate rupture risk predictor than the currently used maximum transverse diameter. In this study, we have investigated the sensitivity of the wall stress in AAA with respect to geometrical variations. We have acquired MR and CT images for four patients with AAA. Three individual users have delineated the AAA vessel wall contours on the image slices. These contours were used to generate synthetic feature images for a deformable model based segmentation method. We investigated the reproducibility and the influence of the user variability on the wall stress. For sufficiently smooth models of the AAA wall, the peak wall stress is reproducible for three out of the four AAA geometries. The 0.99 percentiles of the wall stress show excellent reproducibility for all four AAAs. The variations induced by user variability are larger than the errors caused by the segmentation variability. The influence of the user variability appears to be similar for MR and CT. We conclude that the peak wall stress in AAA is sensitive to small geometrical variations. To increase reproducibility it appears to be best not to allow too much geometrical detail in the simulations. This could be achieved either by using a sufficiently smooth geometry representation or by using a more robust statistical parameter derived from the wall stress distribution.

  8. Cross-sectional area measurement of the coronary arteries using CT angiography at the level of the bifurcation: is there a relationship?

    PubMed Central

    Verim, Samet; Öztürk, Ersin; Küçük, Uğur; Kara, Kemal; Sağlam, Muzaffer; Kardeşoğlu, Ejder

    2015-01-01

    PURPOSE Our aim was to determine whether there is a correlation between cross-sectional areas of the left main coronary artery (LMCA), left anterior descending artery (LAD), and circumflex artery (CX) in normal cases using coronary CT angiography. METHOD Examinations of 180 patients (119 men and 61 women) were selected among 2248 consecutive coronary CT angiography studies. Cross-sectional areas of LMCA, LAD, and CX were measured at the level of bifurcation. Correlation between age, height, and body mass index and coronary artery cross-sectional areas was investigated and possibility of formulating a correlation between the cross-sectional areas of LMCA, LAD, and CX was explored. RESULTS Mean cross-sectional areas of LMCA, LAD, and CX were found as 17.4±3.9 mm2, 12.5±3.1 mm2, and 10.5±3.0 mm2, respectively. While cross-sectional areas of LMCA and LAD were significantly larger in men, no significant difference was found between the sectional areas of CX in men and women. A multiple regression analysis was conducted to elucidate the relationship between the cross-sectional areas of LMCA LAD, and CX. Our analysis showed that the relationship between LMCA, LAD, and CX cross-sectional areas can be formulated as follows: LMCA=3.870 + 0.718×LAD + 0.434×CX. CONCLUSION There is a correlation between the cross-sectional areas of LMCA, LAD, and CX at the level of bifurcation, and this correlation can be expressed with a formula. PMID:26359878

  9. SU-E-I-23: A General KV Constrained Optimization of CNR for CT Abdominal Imaging

    SciTech Connect

    Weir, V; Zhang, J

    2015-06-15

    Purpose: While Tube current modulation has been well accepted for CT dose reduction, kV adjusting in clinical settings is still at its early stage. This is mainly due to the limited kV options of most current CT scanners. kV adjusting can potentially reduce radiation dose and optimize image quality. This study is to optimize CT abdomen imaging acquisition based on the assumption of a continuous kV, with the goal to provide the best contrast to noise ratio (CNR). Methods: For a given dose (CTDIvol) level, the CNRs at different kV and pitches were measured with an ACR GAMMEX phantom. The phantom was scanned in a Siemens Sensation 64 scanner and a GE VCT 64 scanner. A constrained mathematical optimization was used to find the kV which led to the highest CNR for the anatomy and pitch setting. Parametric equations were obtained from polynomial fitting of plots of kVs vs CNRs. A suitable constraint region for optimization was chosen. Subsequent optimization yielded a peak CNR at a particular kV for different collimations and pitch setting. Results: The constrained mathematical optimization approach yields kV of 114.83 and 113.46, with CNRs of 1.27 and 1.11 at the pitch of 1.2 and 1.4, respectively, for the Siemens Sensation 64 scanner with the collimation of 32 x 0.625mm. An optimized kV of 134.25 and 1.51 CNR is obtained for a GE VCT 64 slice scanner with a collimation of 32 x 0.625mm and a pitch of 0.969. At 0.516 pitch and 32 x 0.625 mm an optimized kV of 133.75 and a CNR of 1.14 was found for the GE VCT 64 slice scanner. Conclusion: CNR in CT image acquisition can be further optimized with a continuous kV option instead of current discrete or fixed kV settings. A continuous kV option is a key for individualized CT protocols.

  10. Detection of necrosis of the gastric fundus after blunt abdominal trauma by PET-CT.

    PubMed

    Hofer, A; Kratochwill, H; Pentsch, A; Gabriel, M

    2015-02-01

    Positron emission tomography with [(18)F]-fluorodeoxyglucose provides functional and anatomic information by visualising the uptake of radiolabelled glucose in tumour and inflammatory cells. We report delayed diagnosis of necrosis of the gastric fundus after blunt abdominal trauma in a 73-year-old man. After a car accident with head-on collision, the patient was stabilised in our emergency room. His femur was treated by internal fixation, his ellbow was stabilised by a fixateur externe. During surgery his status deteriorated. The patient was in need of high dosage of inotrops during the following days. He had a biventricular pacemaker implanted because of ischemic myocardiopathy, and he suffered from renal insufficiency. Over the next days, his haemodynamics improved. A central venous line had to be removed because of ensuing septic fever. The patient complained of upper abdominal pain and nausea. A sonography and computer tomography without contrast medium were performed with negative result. Because of contamination of the central venous line with Staphylococcus epidermidis the pacemaker was evaluated for infection by transoesophageal echocardiography, again without any findings. Because of ongoing fever and positive inflammatory markers a positron emission tomography was indicated, as a contrast examination and a magnetic resonance examination were not feasible because of the renal insufficiency and the pacemaker, respectively. Prophylactic removal of the pacemaker would have been a substantial risk for the patient due to his underlying myocardiopathy. Positron emission tomography showed an increased tracer uptake in the gastric fundus, which turned out to be necrotic by endoscopy. A laparoscopic resection followed, and drainage of an abscess, which had evolved subsequently between stomach and spleen stopped the inflammatory process. This case report demonstrates that positron emission tomography may be an alternative to computer tomography with contrast medium

  11. ASSESSMENT OF CLINICAL IMAGE QUALITY IN PAEDIATRIC ABDOMINAL CT EXAMINATIONS: DEPENDENCY ON THE LEVEL OF ADAPTIVE STATISTICAL ITERATIVE RECONSTRUCTION (ASiR) AND THE TYPE OF CONVOLUTION KERNEL.

    PubMed

    Larsson, Joel; Båth, Magnus; Ledenius, Kerstin; Caisander, Håkan; Thilander-Klang, Anne

    2016-06-01

    The purpose of this study was to investigate the effect of different combinations of convolution kernel and the level of Adaptive Statistical iterative Reconstruction (ASiR™) on diagnostic image quality as well as visualisation of anatomical structures in paediatric abdominal computed tomography (CT) examinations. Thirty-five paediatric patients with abdominal pain with non-specified pathology undergoing abdominal CT were included in the study. Transaxial stacks of 5-mm-thick images were retrospectively reconstructed at various ASiR levels, in combination with three convolution kernels. Four paediatric radiologists rated the diagnostic image quality and the delineation of six anatomical structures in a blinded randomised visual grading study. Image quality at a given ASiR level was found to be dependent on the kernel, and a more edge-enhancing kernel benefitted from a higher ASiR level. An ASiR level of 70 % together with the Soft™ or Standard™ kernel was suggested to be the optimal combination for paediatric abdominal CT examinations.

  12. System and method for 3-D/3-D registration between non-contrast-enhanced CBCT and contrast-enhanced CT for abdominal aortic aneurysm stenting.

    PubMed

    Miao, Shun; Liao, Rui; Pfister, Marcus; Zhang, Li; Ordy, Vincent

    2013-01-01

    In this paper, we present an image guidance system for abdominal aortic aneurysm stenting, which brings pre-operative 3-D computed tomography (CT) into the operating room by registering it against intra-operative non-contrast-enhanced cone-beam CT (CBCT). Registration between CT and CBCT volumes is a challenging task due to two factors: the relatively low signal-to-noise ratio of the abdominal aorta in CBCT without contrast enhancement, and the drastically different field of view between the two image modalities. The proposed automatic registration method handles the first issue through a fast quasi-global search utilizing surrogate 2-D images, and solves the second problem by relying on neighboring dominant structures of the abdominal aorta (i.e. the spine) for initial coarse alignment, and using a confined and image-processed volume of interest around the abdominal aorta for fine registration. The proposed method is validated offline using 17 clinical datasets, and achieves 1.48 mm target registration error and 100% success rate in 2.83 s. The prototype system has been installed in hospitals for clinical trial and applied in around 30 clinical cases, with 100% success rate reported qualitatively. PMID:24505689

  13. SU-F-18C-12: On the Relationship of the Weighted Dose to the Surface Dose In Abdominal CT - Patient Size Dependency

    SciTech Connect

    Zhou, Y; Scott, A; Allahverdian, J

    2014-06-15

    Purpose: It is possible to measure the patient surface dose non-invasively using radiolucent dosimeters. However, the patient size specific weighted dose remains unknown. We attempted to study the weighted dose to surface dose relationship as the patient size varies in abdominal CT. Methods: Seven abdomen phantoms (CIRS TE series) simulating patients from an infant to a large adult were used. Size specific doses were measured with a 100 mm CT chamber under axial scans using a Siemens Sensation 64 (mCT) and a GE 750 HD. The scanner settings were 120 kVp, 200 mAs with fully opened collimations. Additional kVps (80, 100, 140) were added depending on the phantom sizes. The ratios (r) of the weighted CT dose (Dw) to the surface dose (Ds) were related to the phantom size (L) defined as the diameter resulting the equivalent cross-sectional area. Results: The Dw versus Ds ratio (r) was fitted to a linear relationship: r = 1.083 − 0.007L (R square = 0.995), and r = 1.064 − 0.007L (R square = 0.953), for Siemens Sensation 64 and GE 750 HD, respectively. The relationship appears to be independent of the scanner specifics. Conclusion: The surface dose to the weighted dose ratio decreases linearly as the patient size increases. The result is independent of the scanner specifics. The result can be used to obtain in vivo CT dosimetry in abdominal CT.

  14. Oral contrast for CT in patients with acute non-traumatic abdominal and pelvic pain: what should be its current role?

    PubMed

    Kielar, Ania Z; Patlas, Michael N; Katz, Douglas S

    2016-10-01

    Positive oral contrast agents, including barium suspensions and water-soluble iodinated solutions, have traditionally been used in conjunction with the CT evaluation of patients with abdominal and pelvic pain. Due to continued advancements in CT technology, and due to increasing obesity and correspondingly a general increase in the intra-abdominal and intra-pelvic fat separating bowel loops in North American patients and in patients in other parts of the world over the past few decades, the ability of radiologists to accurately evaluate the cause of acute symptoms has substantially improved. Recent research and evolving imaging society guidelines/systematic reviews increasingly support performing CT scans of the abdomen and pelvis without the need for positive oral contrast in these types of adult patient populations, in most clinical situations. Increased patient throughput, patient preference, patient safety, and most importantly, retention of high diagnostic accuracy, are reasons for this recent change in practice to routinely omit the use of enteric contrast agents for the majority of patients presenting with acute abdominal and pelvic pain whom are undergoing emergency CT. PMID:27166963

  15. Optimization of abdominal fat quantification on CT imaging through use of standardized anatomic space: A novel approach

    SciTech Connect

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.

    2014-06-15

    Purpose: The quantification of body fat plays an important role in the study of numerous diseases. It is common current practice to use the fat area at a single abdominal computed tomography (CT) slice as a marker of the body fat content in studying various disease processes. This paper sets out to answer three questions related to this issue which have not been addressed in the literature. At what single anatomic slice location do the areas of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) estimated from the slice correlate maximally with the corresponding fat volume measures? How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? Are there combinations of multiple slices (not necessarily contiguous) whose area sum correlates better with volume than does single slice area with volume? Methods: The authors propose a novel strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. The authors then study the volume-to-area correlations and determine where they become maximal. To address the third issue, the authors carry out similar correlation studies by utilizing two and three slices for calculating area sum. Results: Based on 50 abdominal CT data sets, the proposed mapping achieves significantly improved consistency of anatomic localization compared to current practice. Maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized currently for single slice area estimation as a marker. Conclusions: The maximum area-to-volume correlation achieved is quite high, suggesting that it may be reasonable to estimate body fat by measuring the area of fat from a single anatomic slice at the site of maximum correlation and use this as a marker. The site of maximum correlation is not at L4-L5 as commonly assumed

  16. 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

  17. Dual energy CT: preliminary observations and potential clinical applications in the abdomen.

    PubMed

    Graser, Anno; Johnson, Thorsten R C; Chandarana, Hersh; Macari, Michael

    2009-01-01

    Dual energy CT (DECT) is a new technique that allows differentiation of materials and tissues based on CT density values derived from two synchronous CT acquisitions at different tube potentials. With the introduction of a new dual source CT system, this technique can now be used routinely in abdominal imaging. Potential clinical applications include evaluation of renal masses, liver lesions, urinary calculi, small bowel, pancreas, and adrenal glands. In CT angiography of abdominal aortic aneurysms, dual energy CT techniques can be used to remove bones from the datasets, and virtual unenhanced images allow differentiation of contrast agent from calcifying thrombus in patients with endovascular stents. This review describes potential applications, practical guidelines, and limitations of dual energy CT in the abdomen.

  18. Prospective versus retrospective ECG-gated 64-detector coronary CT angiography for evaluation of coronary artery bypass graft patency: comparison of image quality, radiation dose and diagnostic accuracy.

    PubMed

    Lee, Jae Hwan; Chun, Eun Ju; Choi, Sang Il; Vembar, Mani; Lim, Cheong; Park, Kay-Hyun; Choi, Dong-Ju

    2011-06-01

    We aimed to evaluate image quality, radiation dose and diagnostic accuracy of coronary CT angiography (CCTA) with a prospectively gated transverse-axial scan (PGT) compared with a retrospectively gated helical scan (RGH), using a 64-slice scanner in patients who underwent coronary artery bypass graft (CABG). Of the 131 consecutive patients that underwent CABG using 64-slice multidetector row computed tomography during 2008, patients with heart rate (HR) of <75 beats/minute (bpm), and HR variation <10 bpm were included in the study. PGT was performed on 39 patients with 93 grafts, with RGH performed on 43 patients with 102 grafts. Image quality (1: excellent-4: poor) and estimated radiation dose were compared between the two groups. Of these, a total of 64 segments in 26 patients were subjected to invasive coronary angiography (ICA) for clinical reasons. Diagnostic accuracy of CCTA for evaluation of graft was performed between the two groups with ICA as a reference standard in terms of significant stenosis (≥ 50% of luminal stenosis). The image quality was not statistically different in the two groups. Mean effective radiation dose was 6.5 mSv in PGT-group, which was significantly lower than that in the RGH-group (21.2 mSv; P < 0.001). There was no statistically significant difference in diagnostic accuracy between the two groups (PGT-group versus RGH-group; 93.1% versus 91.4%). PGT can achieve dose reductions of up to 70% compared to RGH while maintaining image quality and high diagnostic accuracy in patients undergoing CABG. PMID:21678128

  19. Prospectively ECG-Triggered Sequential Dual-Source Coronary CT Angiography in Patients with Atrial Fibrillation: Influence of Heart Rate on Image Quality and Evaluation of Diagnostic Accuracy

    PubMed Central

    Yang, Lin; Xu, Lei; Schoepf, U. Joseph; Wichmann, Julian L.; Fox, Mary A.; Yan, Jing; Fan, Zhanming; Zhang, Zhaoqi

    2015-01-01

    Objectives To evaluate the effects of mean heart rate (HR) and heart rate variation (HRV) on image quality and diagnostic accuracy of prospectively ECG-triggered sequential dual-source coronary CT angiography (CCTA) in patients with atrial fibrillation (AF). Methods Eighty-five patients (49 women, 36 men; mean age 62.1±9.5 years) with persistent AF underwent prospectively ECG-triggered sequential second-generation dual-source CCTA. Tube current and voltage were adjusted according to body mass index (BMI) and iterative reconstruction was used. Image quality of coronary segments (four-point scale) and presence of significant stenosis (>50%) were evaluated. Diagnostic accuracy was analyzed in 30 of the 85 patients who underwent additional invasive coronary angiography (ICA). Results Only 8 of 1102 (0.7%) segments demonstrated poor image quality. No significant impact on image quality was found for mean HR (94.9±21.8 bpm; r=0.034, p=0.758; F=0.413, p=0.663) or HRV (67.5±22.8 bpm; r=0.097, p=0.377; F=0.111, p=0.895). On per-segment analysis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 89.7% (26/29), 99.4% (355/357), 92.9% (26/28), and 99.2% (355/358), respectively, with excellent correlation (kappa=0.91) with ICA. Mean effective dose was 3.3±1.0 mSv. Conclusions Prospectively ECG-triggered sequential dual-source CCTA provides diagnostic image quality and good diagnostic accuracy for detection of coronary stenosis in AF patients without significant influence by HR or HRV. PMID:26221952

  20. Can surgeons assess CT suitability for endovascular repair (EVAR) in ruptured abdominal aortic aneurysm? Implications for a ruptured EVAR trial.

    PubMed

    Rayt, Harjeet; Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-01-01

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; kappa = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  1. Can Surgeons Assess CT Suitability for Endovascular Repair (EVAR) in Ruptured Abdominal Aortic Aneurysm? Implications for a Ruptured EVAR Trial

    SciTech Connect

    Rayt, Harjeet Lambert, Kelly; Bown, Matthew; Fishwick, Guy; Morgan, Robert; McCarthy, Mark; London, Nick; Sayers, Robert

    2008-09-15

    The purpose of this study was to determine whether surgeons without formal radiological training are able to assess suitability of patients with ruptured abdominal aortic aneurysms (AAA) for EVAR. The CT scans of 20 patients with AAA were reviewed under timed conditions by six vascular surgeons. Twenty minutes was allocated per scan. They were asked to determine if each aneurysm would be treatable by EVAR in the emergency setting and, if so, to measure for device selection. The results were then compared with those of a vascular radiologist. Six surgeons agreed on the suitability of endovascular repair in 45% of cases (95% CI, 23.1-68.5%; 9/20 scans; {kappa} = 0.41 [p = 0.01]) and concurred with the radiologist in eight of these. Individually, agreement ranged from 13 to 16 of the 20 scans, 65-80% between surgeons. The kappa value for agreement between all the surgeons and the radiologist was 0.47 (p = 0.01, moderate agreement). For the individual surgeons, this ranged from 0.3 to 0.6 (p = 0.01). In conclusion, while overall agreement was moderate between the surgeons and the radiologist, it is clear that if surgeons are to assess patients for ruptured EVAR in the future, focused training of surgical trainees is required.

  2. Renal Tumor Quantification and Classification in Contrast-Enhanced Abdominal CT

    PubMed Central

    Linguraru, Marius George; Yao, Jianhua; Gautam, Rabindra; Peterson, James; Li, Zhixi; Linehan, W. Marston; Summers, Ronald M.

    2008-01-01

    Kidney cancer occurs in both a hereditary (inherited) and sporadic (non-inherited) form. It is estimated that almost a quarter of a million people in the USA are living with kidney cancer and their number increases with 51,000 diagnosed with the disease every year. In clinical practice, the response to treatment is monitored by manual measurements of tumor size, which are 2D, do not reflect the 3D geometry and enhancement of tumors, and show high intra- and inter-operator variability. We propose a computer-assisted radiology tool to assess renal tumors in contrast-enhanced CT for the management of tumor diagnoses and responses to new treatments. The algorithm employs anisotropic diffusion (for smoothing), a combination of fast-marching and geodesic level-sets (for segmentation), and a novel statistical refinement step to adapt to the shape of the lesions. It also quantifies the 3D size, volume and enhancement of the lesion and allows serial management over time. Tumors are robustly segmented and the comparison between manual and semi-automated quantifications shows disparity within the limits of inter-observer variability. The analysis of lesion enhancement for tumor classification shows great separation between cysts, von Hippel-Lindau syndrome lesions and hereditary papillary renal carcinomas (HPRC) with p-values inferior to 0.004. The results on temporal evaluation of tumors from serial scans illustrate the potential of the method to become an important tool for disease monitoring, drug trials and noninvasive clinical surveillance. PMID:19492069

  3. 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

  4. The adaptive statistical iterative reconstruction-V technique for radiation dose reduction in abdominal CT: comparison with the adaptive statistical iterative reconstruction technique

    PubMed Central

    Cho, Jinhan; Oh, Jongyeong; Kim, Dongwon; Cho, Junghyun; Kim, Sanghyun; Lee, Sangyun; Lee, Jihyun

    2015-01-01

    Objective: To investigate whether reduced radiation dose abdominal CT images reconstructed with adaptive statistical iterative reconstruction V (ASIR-V) compromise the depiction of clinically competent features when compared with the currently used routine radiation dose CT images reconstructed with ASIR. Methods: 27 consecutive patients (mean body mass index: 23.55 kg m−2 underwent CT of the abdomen at two time points. At the first time point, abdominal CT was scanned at 21.45 noise index levels of automatic current modulation at 120 kV. Images were reconstructed with 40% ASIR, the routine protocol of Dong-A University Hospital. At the second time point, follow-up scans were performed at 30 noise index levels. Images were reconstructed with filtered back projection (FBP), 40% ASIR, 30% ASIR-V, 50% ASIR-V and 70% ASIR-V for the reduced radiation dose. Both quantitative and qualitative analyses of image quality were conducted. The CT dose index was also recorded. Results: At the follow-up study, the mean dose reduction relative to the currently used common radiation dose was 35.37% (range: 19–49%). The overall subjective image quality and diagnostic acceptability of the 50% ASIR-V scores at the reduced radiation dose were nearly identical to those recorded when using the initial routine-dose CT with 40% ASIR. Subjective ratings of the qualitative analysis revealed that of all reduced radiation dose CT series reconstructed, 30% ASIR-V and 50% ASIR-V were associated with higher image quality with lower noise and artefacts as well as good sharpness when compared with 40% ASIR and FBP. However, the sharpness score at 70% ASIR-V was considered to be worse than that at 40% ASIR. Objective image noise for 50% ASIR-V was 34.24% and 46.34% which was lower than 40% ASIR and FBP. Conclusion: Abdominal CT images reconstructed with ASIR-V facilitate radiation dose reductions of to 35% when compared with the ASIR. Advances in knowledge: This study represents the first

  5. The utility of dual bioelectrical impedance analysis in detecting intra-abdominal fat area in obese patients during weight reduction therapy in comparison with waist circumference and abdominal CT.

    PubMed

    Yamakage, Hajime; Ito, Ryo; Tochiya, Mayu; Muranaka, Kazuya; Tanaka, Masashi; Matsuo, Yoshiyuki; Odori, Shinji; Kono, Shigeo; Shimatsu, Akira; Satoh-Asahara, Noriko

    2014-01-01

    An increase in intra-abdominal fat area (IAFA) is an essential component of metabolic syndrome (MetS). Waist circumference (WC) is not a precise measure of IAFA, and computed tomography (CT) is unsuitable for frequent monitoring. Here, we examined utility of a dual bioelectrical impedance analysis (Dual BIA) for measuring IAFA in obese patients during weight reduction. Fat distribution was measured by Dual BIA and CT in 100 obese outpatients. All fat areas including total, IAFA, and subcutaneous fat by Dual BIA were more closely correlated with those by CT than WC. Estimated IAFA by Dual BIA was significantly correlated with number of MetS components as well as CT, but WC was not. Furthermore, in 61 obese patients who received 6-month weight reduction therapy, estimated IAFA by Dual BIA showed an earlier and greater decrease as well as that by CT than WC and BMI. In addition, decrease in estimated IAFA by Dual BIA through weight reduction had a higher correlation with decrease in IAFA by CT, than WC. This study is the first to demonstrate that the change in estimated IAFA by Dual BIA was highly correlated with that in IAFA by CT during weight reduction therapy. Our findings also indicate that estimated IAFA by Dual BIA is, potentially, a better indicator of severity of MetS, cardiovascular risk factors, and effectiveness of weight reduction than WC, and equal to IAFA by CT. Estimated IAFA by Dual BIA may be useful for monitoring the effectiveness of weight reduction therapy in obese patients.

  6. Comparison of diagnostic performance of CT and MRI for abdominal staging of pediatric renal tumors: a report from the Children's Oncology Group

    PubMed Central

    Servaes, Sabah; Naranjo, Arlene; Geller, James I.; Ehrlich, Peter F.; Gow, Kenneth W.; Perlman, Elizabeth J.; Dome, Jeffrey S.; Gratias, Eric; Mullen, Elizabeth A.

    2015-01-01

    Background CT and MRI are both used for abdominal staging of pediatric renal tumors. The diagnostic performance of the two modalities for local and regional staging of renal tumors has not been systematically evaluated. Objective To compare the diagnostic performance of CT and MRI for local staging of pediatric renal tumors. Materials and methods The study population was derived from the AREN03B2 study of the Children's Oncology Group. Baseline abdominal imaging performed with both CT and MRI within 30 days of nephrectomy was available for retrospective review in 82 renal tumor cases. Each case was evaluated for capsular penetration, lymph node metastasis, tumor thrombus, preoperative tumor rupture, and synchronous contralateral lesions. The surgical and pathological findings at central review were the reference standard. Results The sensitivity of CT and MRI for detecting capsular penetration was 68.6% and 62.9%, respectively (P=0.73), while specificity was 86.5% and 83.8% (P=1.0). The sensitivity of CT and MRI for detecting lymph node metastasis was 76.5% and 52.9% (P=0.22), and specificity was 90.4% and 92.3% (P=1.0). Synchronous contralateral lesions were identified by CT in 4/9 cases and by MRI in 7/9 cases. Conclusion CT and MRI have similar diagnostic performance for detection of lymph node metastasis and capsular penetration. MR detected more contralateral synchronous lesions; however these were present in a very small number of cases. Either modality can be used for initial loco–regional staging of pediatric renal tumors. PMID:25135711

  7. 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

  8. 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

  9. Relationship between beat to beat coronary artery motion and image quality in prospectively ECG-gated two heart beat 320-detector row coronary CT angiography.

    PubMed

    Tomizawa, Nobuo; Komatsu, Shuhei; Akahane, Masaaki; Torigoe, Rumiko; Kiryu, Shigeru; Ohtomo, Kuni

    2012-01-01

    The objective was to investigate the influence of the beat-to-beat movement of the coronary arteries on image quality of multi-segment reconstruction (MSR) images. Although MSR improves temporal resolution, image quality would be degraded by beat-to-beat movement of the coronary arteries. In a retrospectively review, 18 patients (mean age, 67.0 years) who underwent coronary CT angiography using a 320-detector row CT were included. The displacement and diameter of coronary artery segments for each of the identified nine landmarks was recorded. The motion ratio was calculated as the division of displacement by diameter. Image quality (IQ) was graded by a four-point scale. The correlation between MSR IQ score and the motion ratio showed stronger negative correlation than that between MSR IQ score and the displacement (r = -0.54 vs. r = -0.36). The average motion ratio for segments in which half-scan reconstruction (HSR) IQ was better than MSR IQ (29.1%, group A) was higher than that for segments in which MSR IQ was better than HSR IQ (16.0%, group C). The motion ratio in group C was lower than 25%. Difference in IQ scores of the HSR images was more frequent in group A than in the remaining segments in which the motion ratio was lower than 25% (16.7% vs. 66.0%; P < 0.0002). The motion ratio could be a better index than the displacement to evaluate the influence of the motion of coronary arteries on image quality. MSR images would be impaired by a motion ratio larger than 25%. Image impairment of one of the HSR images might also impair MSR images.

  10. 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

  11. Transretroperitoneal CT-guided Embolization of Growing Internal Iliac Artery Aneurysm after Repair of Abdominal Aortic Aneurysm: A Transretroperitoneal Approach with Intramuscular Lidocaine Injection Technique

    SciTech Connect

    Park, Joon Young Kim, Shin Jung Kim, Hyoung Ook; Kim, Yong Tae; Lim, Nam Yeol Kim, Jae Kyu; Chung, Sang Young Choi, Soo Jin Na Lee, Ho Kyun

    2015-02-15

    This study was designed to evaluate the efficacy and safety of CT-guided embolization of internal iliac artery aneurysm (IIAA) after repair of abdominal aortic aneurysm by transretroperitoneal approach using the lidocaine injection technique to iliacus muscle, making window for safe needle path for three patients for whom CT-guided embolization of IIAA was performed by transretroperitoneal approach with intramuscular lidocaine injection technique. Transretroperitoneal access to the IIAA was successful in all three patients. In all three patients, the IIAA was first embolized using microcoils. The aneurysmal sac was then embolized with glue and coils without complication. With a mean follow-up of 7 months, the volume of the IIAAs remained stable without residual endoleaks. Transretroperitoneal CT-guided embolization of IIAA using intramuscular lidocaine injection technique is effective, safe, and results in good outcome.

  12. Assessment of myocardial infarction by CT angiography and cardiovascular MRI in patients with cocaine-associated chest pain: a pilot study

    PubMed Central

    Paraschin, K; Guerra De Andrade, A; Rodrigues Parga, J

    2012-01-01

    Objectives Cocaine is a commonly used illicit drug that leads to the most emergency department (ED) visits. Chest pain is the most common presentation, reported in 40% of patients. Our aim was to evaluate the incidence of previous myocardial infarction among young cocaine users (18–40 years) with cocaine-associated chest pain by the assessment of myocardial fibrosis by cardiovascular MRI. Second, we also intended to evaluate the coronary tree by CT angiography (CTA). Methods 24 cocaine users (22 males) who frequently complained about cocaine-associated chest pain underwent CTA and cardiovascular MRI. Mean age of patients was 29.7 years and most of them (79%) had frequently used inhalatory cocaine. Results The calcium score turned out to be positive in only one patient (Agatston=54). Among the coronary segments evaluated, only one patient had calcified plaques at the anterior descending coronary artery (proximal and medium segments). Assessment of regional ventricular function by the evaluation of 17 segments was normal in all patients. None of the patients showed myocardial delayed enhancement, indicative of myocardial fibrosis. CTA therefore confirmed the low cardiovascular risk of these patients, since most of them (96%) had no atherosclerosis detected by this examination. Only one patient (4%) had coronary atherosclerosis detected, without significant coronary stenosis. Conclusion Cardiovascular MR did not detect the presence of delayed enhancement indicative of myocardial fibrosis among young cocaine users with low cardiovascular risk who had complained of cocaine-associated chest pain. PMID:22167507

  13. CT Pulmonary Angiography at Reduced Radiation Exposure and Contrast Material Volume Using Iterative Model Reconstruction and iDose4 Technique in Comparison to FBP

    PubMed Central

    Laqmani, Azien; Kurfürst, Maximillian; Butscheidt, Sebastian; Sehner, Susanne; Schmidt-Holtz, Jakob; Behzadi, Cyrus; Nagel, Hans Dieter; Adam, Gerhard; Regier, Marc

    2016-01-01

    Purpose To assess image quality of CT pulmonary angiography (CTPA) at reduced radiation exposure (RD-CTPA) and contrast medium (CM) volume using two different iterative reconstruction (IR) algorithms (iDose4 and iterative model reconstruction (IMR)) in comparison to filtered back projection (FBP). Materials and Methods 52 patients (body weight < 100 kg, mean BMI: 23.9) with suspected pulmonary embolism (PE) underwent RD-CTPA (tube voltage: 80 kV; mean CTDIvol: 1.9 mGy) using 40 ml CM. Data were reconstructed using FBP and two different IR algorithms (iDose4 and IMR). Subjective and objective image quality and conspicuity of PE were assessed in central, segmental, and subsegmental arteries. Results Noise reduction of 55% was achieved with iDose4 and of 85% with IMR compared to FBP. Contrast-to-noise ratio significantly increased with iDose4 and IMR compared to FBP (p<0.05). Subjective image quality was rated significantly higher at IMR reconstructions in comparison to iDose4 and FBP. Conspicuity of central and segmental PE significantly improved with the use of IMR. In subsegmental arteries, iDose4 was superior to IMR. Conclusions CTPA at reduced radiation exposure and contrast medium volume is feasible with the use of IMR, which provides improved image quality and conspicuity of pulmonary embolism in central and segmental arteries. PMID:27611448

  14. 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

  15. Pineal gland calcification, lumbar intervertebral disc degeneration and abdominal aorta calcifying atherosclerosis correlate in low back pain subjects: A cross-sectional observational CT study.

    PubMed

    Turgut, Ahmet Tuncay; Sönmez, Iclal; Cakıt, Burcu Duyur; Koşar, Pınar; Koşar, Uğur

    2008-06-01

    The goal of this cross-sectional observational study was to assess the possible impact of pineal gland calcification upon the intervertebral disc degeneration and abdominal aorta atherosclerosis in subjects with low back pain, and to investigate the course of these processes with aging. The study was carried out on 81 (66 women and 15 men) subjects: younger than 45 years (group X, n=22), 45-65 years of age (group Y, n=45), and older than 65 years (group Z, n=14). In addition to clinical data, computed tomography (CT) scan of the brain as well as X-ray and CT examination of the lumbar spine were recorded in this study. The degree of disc degeneration and calcification rates of aortic wall and pineal gland were independently determined by two radiologists. Both ratio of calcified pineal gland and density of pineal calcification increased progressively with aging. Also, both the degree of aortic wall calcification and disc degeneration score increased with advancing age. On CT scan, a positive correlation between degree of aortic wall calcification and disc degeneration score was found (r=0.306, p<0.01). Importantly, there was a positive association between calcification of the pineal gland and degenerative disc disease in X-ray or CT study (r=0.378 and r=0.295, p<0.005 and p<0.01, respectively), as well as between abdominal aorta atherosclerosis and pineal calcification (r=0.634, p<0.001). Our findings suggest that there is a significant interaction between pineal gland calcification and lumbar intervertebral disc degeneration and also abdominal aorta atherosclerosis. However, further studies with a larger subject cohorts are needed. PMID:18215511

  16. 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

  17. Additional Value of Transluminal Attenuation Gradient in CT Angiography to Predict Hemodynamic Significance of Coronary Artery Stenosis

    PubMed Central

    Stuijfzand, Wynand J.; Danad, Ibrahim; Raijmakers, Pieter G.; Marcu, C. Bogdan; Heymans, Martijn W.; van Kuijk, Cornelis C.; van Rossum, Albert C.; Nieman, Koen; Min, James K.; Leipsic, Jonathon; van Royen, Niels; Knaapen, Paul

    2015-01-01

    OBJECTIVES The current study evaluates the incremental value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (CCO), and TAG with exclusion of calcified coronary segments (ExC) over coronary computed tomography angiogram (CTA) alone using fractional flow reserve (FFR) as the gold standard. BACKGROUND TAG is defined as the contrast opacification gradient along the length of a coronary artery on a coronary CTA. Preliminary data suggest that TAG provides additional functional information. Interpretation of TAG is hampered by multiple heartbeat acquisition algorithms and coronary calcifications. Two correction models have been proposed based on either dephasing of contrast delivery by relating coronary density to corresponding descending aortic opacification (TAG-CCO) or excluding calcified coronary segments (TAG-ExC). METHODS Eighty-five patients with intermediate probability of coronary artery disease were prospectively included. All patients underwent step-and-shoot 256-slice coronary CTA. TAG, TAG-CCO, and TAG-ExC analyses were performed followed by invasive coronary angiography in conjunction with FFR measurements of all major coronary branches. RESULTS Thirty-four patients (40%) were diagnosed with hemodynamically-significant coronary artery disease (i.e., FFR ≤0.80). On a per-vessel basis (n = 253), 59 lesions (23%) were graded as hemodynamically significant, and the diagnostic accuracy of coronary CTA (diameter stenosis ≥50%) was 95%, 75%, 98%, and 54% for sensitivity, specificity, negative predictive value, and positive predictive value, respectively. TAG and TAG-ExC did not discriminate between vessels with or without hemodynamically significant lesions (−13.5 ± 17.1 HU [Hounsfield units] × 10 mm−1 vs. −11.6 ± 13.3 HU × 10 mm−1, p = 0.36; and 13.1 ± 15.9 HU × 10 mm−1 vs. −11.4 ± 11.7 HU × 10 mm−1, p = 0.77, respectively). TAG-CCO was lower in vessels with a hemodynamically-significant lesion (−0

  18. 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.

  19. Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique.

    PubMed

    Sun, Kai; Liu, Guo-Rong; Li, Yue-Chun; Han, Rui-Juan; Cui, Li-Fang; Ma, Li-Jun; Li, Li-Gang; Li, Chang-Yong

    2013-01-01

    Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv, P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

  20. 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

  1. iPad-based primary 2D reading of CT angiography examinations of patients with suspected acute gastrointestinal bleeding: preliminary experience

    PubMed Central

    Neri, E; Bargellini, I; Scalise, P; Calcagni, F; Mantarro, A; D'Ippolito, G; Bartolozzi, C

    2015-01-01

    Objective: To evaluate the effectiveness of the iPad (Apple Inc., Cupertino, CA) for two-dimensional (2D) reading of CT angiography (CTA) studies performed for suspected acute non-variceal gastrointestinal bleeding. Methods: 24 CTA examinations of patients with suspected acute gastrointestinal bleeding confirmed (19/24, 79.2%) or ruled out (5/24, 20.8%) by digital subtraction angiography (DSA) were retrospectively reviewed by three independent readers on a commercial picture archiving communication system (PACS) workstation and on an iPad with Retina Display® 64 GB (Apple Inc.). The time needed to complete reading of every CTA examination was recorded, as well as the rate of detection of arterial bleeding and identification of suspected bleeding arteries on both devices. Results: Overall, the area under the receiver operating characteristic curve, sensitivity, specificity, positive- and negative-predictive values for bleeding detection were not significantly different while using the iPad and workstation (0.774 vs 0.847, 0.947 vs 0.895, 0.6 vs 0.8, 0.9 vs 0.944 and 0.750 vs 0.667, respectively; p > 0.05). In DSA-positive cases, the iPad and workstation allowed correct identification of the bleeding source in 17/19 cases (89.5%) and 15/19 cases (78.9%), respectively (p > 0.05). Finally, the time needed to complete reading of every CTA study was significantly shorter using the iPad (169 ± 74 vs 222 ± 70 s, respectively; p < 0.01). Conclusion: Compared with a conventional PACS workstation, iPad-based preliminary 2D reading of CTA studies has comparable diagnostic accuracy for detection of acute gastrointestinal bleeding and can be significantly faster. Advances in knowledge: The iPad could be used by on-call interventional radiologists for immediate decision on percutaneous embolization in patients with suspected acute gastrointestinal bleeding. PMID:25652643

  2. Coronary CT Angiography in Heavily Calcified Coronary Arteries: Improvement of Coronary Lumen Visualization and Coronary Stenosis Assessment With Image Postprocessing Methods.

    PubMed

    Sun, Zhonghua; Ng, Curtise K C; Xu, Lei; Fan, Zhanming; Lei, Jing

    2015-12-01

    To compare the diagnostic value of coronary CT angiography (CCTA) with use of 2 image postprocessing methods (CCTA_S) and (CCTA_OS) and original data (CCTA_O) for the assessment of heavily calcified plaques. Fifty patients (41 men, 9 women; mean age 61.9 years ± 9.1) with suspected coronary artery disease who underwent CCTA and invasive coronary angiography (ICA) examinations were included in the study. Image data were postprocessed with "sharpen" and smooth reconstruction algorithms in comparison with the original data without undergoing any image postprocessing to determine the effects on suppressing blooming artifacts due to heavy calcification in the coronary arteries. Minimal lumen diameter and degree of stenosis were measured and compared between CCTA_S, CCTA_OS, and CCTA_O with ICA as the reference method. The area under the curve (AUC) by receiver-operating characteristic curve analysis (ROC) was also compared among these 3 CCTA techniques. On a per-vessel assessment, the sensitivity, specificity, positive predictive value and negative predictive value, and 95% confidence interval (CI) were 100% (95% CI: 89%, 100%), 33% (95% CI: 22%, 45%), 41% (95% CI: 30%, 53%), 100% (95% CI: 85%, 100%) for CCTA_O, 94% (95% CI: 79%, 99%), 66% (95% CI: 54%, 77%), 57% (95% CI: 43%, 70%), and 95% (95% CI: 85%, 99%) for CCTA_S, 94% (95% CI: 79%, 99%), 44% (95% CI: 32%, 57%), 44% (95% CI: 32%, 57%), and 97% (95% CI: 79%, 99%) for CCTA_OS, respectively. The AUC by ROC curve analysis for CCTA_S showed significant improvement for detection of >50% coronary stenosis in left anterior descending coronary artery compared to that of CCTA_OS and CCTA_O methods (P < 0.05), with no significance differences for detection of coronary stenosis in the left circumflex and right coronary arteries (P > 0.05).CCTA with "sharpen" reconstruction reduces blooming artifacts from heavy calcification, thus, leading to significant improvement of specificity and positive predictive value of CCTA in

  3. Accuracy of four-dimensional CT angiography in detection and characterisation of arteriovenous malformations and dural arteriovenous fistulas

    PubMed Central

    Chandran, Arun; Radon, Mark; Puthuran, Mani; Bhojak, Maneesh; Nahser, Hans Christean; Das, Kumar

    2015-01-01

    A retrospective review was made to assess the accuracy of four dimensional CT angiogram (4D-CTA) in diagnosis of arteriovenous malformations (AVM) and dural arteriovenous fistulas (DAVF), with catheter-based digital-subtraction angiogram (DSA) being gold standard. 33 pairs of investigations (DSA and 4D-CTA) were performed primarily for suspicion of AVM/DAVF. Based on blinded reports, sensitivity and specificity for detection of AVM/DAVF were 77% (95% CI: 46 - 95%) and 100% (95% CI: 83 - 100%) respectively. Positive predictive value was 100% (95% CI: 69 - 100%) and negative predictive value 87% (95% CI: 66-97%). 4D-CTA is a practical minimally-invasive technique for evaluating cerebrovascular pathologies. There is good agreement between the findings of 4D-CTA and DSA despite the differences in temporal and spatial resolutions. 4D-CTA may obviate the need for DSA in a subgroup of patients who would otherwise have undergone this invasive investigation, which carries a risk of important complications. PMID:26427892

  4. Pulmonary Embolism with Abdominal Pain and ST Elevation: A Case Report.

    PubMed

    Fallahi, Mohammad Javad; Masoompour, Seyed Masoom; Mirzaee, Mehdi

    2014-07-01

    Pulmonary embolism is considered as a great masquerader due to its frequent nonspecific signs and symptoms. Typically pulmonary embolism is under-diagnosed or over-diagnosed. In this study a patient with pulmonary embolism is reported in which the patient exhibited two unusual manifestations namely; right upper quadrant abdominal pain and ST-T elevation in anterior precordial leads. Due to the fact that the patient did not display typical pulmonary embolism symptoms and its major risk factors, extensive workup to discern the cause was carried out. The examination included abdominal sonography, kidney ureter and bladder Computed Tomography scan (CT-scan) and coronary angiography. Eventually after a six-day delay, pulmonary embolism was diagnosed by spiral chest CT scan. This case and several other similar reports underlines the fact that while various other common causes may exist for right upper abdominal pain, one should always consider pulmonary embolism as a possible cause especially when backed up with ECG finding.

  5. Whole-body CT in polytrauma patients: The effect of arm position on abdominal image quality when using a human phantom

    NASA Astrophysics Data System (ADS)

    Jeon, Pil-Hyun; Kim, Hee-Joung; Lee, Chang-Lae; Kim, Dae-Hong; Lee, Won-Hyung; Jeon, Sung-Su

    2012-06-01

    For a considerable number of emergency computed tomography (CT) scans, patients are unable to position their arms above their head due to traumatic injuries. The arms-down position has been shown to reduce image quality with beam-hardening artifacts in the dorsal regions of the liver, spleen, and kidneys, rendering these images non-diagnostic. The purpose of this study was to evaluate the effect of arm position on the image quality in patients undergoing whole-body CT. We acquired CT scans with various acquisition parameters at voltages of 80, 120, and 140 kVp and an increasing tube current from 200 to 400 mAs in 50 mAs increments. The image noise and the contrast assessment were considered for quantitative analyses of the CT images. The image noise (IN), the contrast-to-noise ratio (CNR), the signal-to-noise ratio (SNR), and the coefficient of variation (COV) were evaluated. Quantitative analyses of the experiments were performed with CT scans representative of five different arm positions. Results of the CT scans acquired at 120 kVp and 250 mAs showed high image quality in patients with both arms raised above the head (SNR: 12.4, CNR: 10.9, and COV: 8.1) and both arms flexed at the elbows on the chest (SNR: 11.5, CNR: 10.2, and COV: 8.8) while the image quality significantly decreased with both arms in the down position (SNR: 9.1, CNR: 7.6, and COV: 11). Both arms raised, one arm raised, and both arms flexed improved the image quality compared to arms in the down position by reducing beam-hardening and streak artifacts caused by the arms being at the side of body. This study provides optimal methods for achieving higher image quality and lower noise in abdominal CT for trauma patients.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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

  14. Fluorescein angiography

    MedlinePlus

    ... abnormal vessels, and there are no blockages or leakages. ... If blockage or leakage is present, the pictures will map the location for possible treatment. An abnormal value on a fluorescein angiography may ...

  15. Staging of Primary Abdominal Lymphomas: Comparison of Whole-Body MRI with Diffusion-Weighted Imaging and 18F-FDG-PET/CT

    PubMed Central

    Stecco, Alessandro; Buemi, Francesco; Quagliozzi, Martina; Lombardi, Mariangela; Santagostino, Alberto; Sacchetti, Gian Mauro; Carriero, Alessandro

    2015-01-01

    Background. The purpose of this study was to compare the accuracy of whole-body MRI with diffusion-weighted sequences (WB-DW-MRI) with that of 18F-FDG-PET/CT in the staging of patients with primary gastrointestinal lymphoma. Methods. This retrospective study involved 17 untreated patients with primary abdominal gastrointestinal lymphoma. All patients underwent 18F-FDG-PET/CT and WB-DW-MRI. Histopathology findings or at least 6 months of clinical and radiological follow-up was the gold standard. The Musshoff-modified Ann Arbor system was used for staging, and diagnostic accuracy was evaluated on a per-node basis. Results. WB-DW-MRI exhibited 100% sensitivity, 96.3% specificity, and 96.1% and 100% positive and negative predictive values (PPV and NPV), respectively. The sensitivity, specificity, and PPV and NPV of PET/CT were 95.9%, 100%, and 100% and 96.4%, respectively. There were no statistically significant differences between the two techniques (p = 0.05). The weighted kappa agreement statistics with a 95% confidence interval were 0.97 (0.95–0.99) between the two MRI readers and 0.87 (0.82–0.92) between the two methods. Conclusions. WB-DW-MRI appears to have a comparable diagnostic value to 18F-FDG-PET/CT in staging patients with gastrointestinal lymphoma. PMID:26798331

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. The application of automatic tube current modulation (ATCM) on image quality and radiation dose at abdominal computed tomography (CT): A phantom study.

    PubMed

    Wang, Qian; Zhao, Xinming; Song, Junfeng; Guo, Ning; Zhu, Ying; Liu, Jianxin; Qi, Weiwei; Wu, Jing; Liang, Yuan; Feng, Shichao; Hu, Mancang; Zhou, Chunwu; Wang, Xiaoying; Hong, Nan

    2013-01-01

    Multi-phase spiral Computed tomography (CT) of abdomen has been widely used as an effective imaging modality to diagnose variety of diseases. As a result, the accumulated radiation exposure on the abdomen is substantially higher than other human organ regions. According to ALARA (as low as reasonably achievable) principle, how to control radiation dose without compromising imaging quality becomes a research topic of high interest. However, how to achieve dose optimization of the abdomen CT examinations in Chinese patients have not been fully investigated in previous studies. In this study, we develop an abdomen-equivalent tissue model made by well-known CTP579 auxiliary testing model and the real CT data acquired from 68 Chinese male subjects. Combining with catphan600, we simulated the visibility of low and high contrast objects at adult abdomen under variety of x-ray dose levels. Using the automatic tube current modulation (ATCM) technique, we reduced the total radiation dose and identified a proper noise index (NI) for Chinese patients to maintain low or high contrast detectability of abdominal CT image. Our numerical experiments showed that in the phantom study for Chinese patients, when a NI was set at 10, the radiation dose reduced by 34.3% with low contrast objects detectable, while setting NI at 14 the dose level decreased by 65.1% without change the detectability of high contrast targets. The subjective ratings from three radiologists also yielded high consistence with Kappa > 0.75. This study demonstrated the feasibility of performing the CT dose optimization studies through a unique phantom with the ATCM method.

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2014-01-01

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

  4. Association between Abdominal Fat (DXA) and Its Subcomponents (CT Scan) before and after Weight Loss in Obese Postmenopausal Women: A MONET Study.

    PubMed

    Doyon, Caroline Y; Brochu, Martin; Messier, Virginie; Lavoie, Marie-Ève; Faraj, May; Doucet, Eric; Rabasa-Lhoret, Rémi; Dionne, Isabelle J

    2011-01-01

    Introduction. Subcutaneous fat (ScF) and visceral fat (VF) measurements using CT scan are expensive and may imply significant radiation doses. Cross-sectional studies using CT scan showed that ScF and VF are significantly correlated with abdominal fat measured by DXA (AF-DXA). The association has not been studied after a weight loss. Objective. To determine (1) the associations between AF-DXA and ScF and VF before and after weight loss and (2) the associations between their changes. Methods. 137 overweight/obese postmenopausal women were divided in two groups (1-caloric restriction or 2-caloric restriction + resistance training). AF was assessed using DXA and CT scan. Results. Correlations between AF-DXA and ScF (before: r = 0.87, after; r = 0.87; P < .01) and, AF-DXA and VF (before: r = 0.61, after; r = 0.69; P < .01) are not different before and after the weight loss. Correlations between delta AF-DXA and delta ScF (r = 0.72; P < .01) or delta VF (r = 0.51; P < .01) were found. Conclusion. The use of AF-DXA as a surrogate for VF after weight loss is questionable, but may be interesting for ScF.

  5. CT angiography - arms and legs

    MedlinePlus

    ... are inside the scanner, the machine's x-ray beam rotates around you. Modern "spiral" scanners can perform ... Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 6th ed. ...

  6. Contrast enhanced ultrasonography versus MR angiography in aortocaval fistula: case report.

    PubMed

    Bhatia, Mona; Platon, Alexandra; Khabiri, Ebrahim; Becker, Christoph; Poletti, Pierre-Alexandre

    2010-06-01

    Aortocaval fistula (ACF) is a rare, life threatening complication of abdominal aortic aneurysms. Time to diagnosis is crucial as preoperative diagnosis and early surgical intervention significantly improve the outcome. The clinical spectrum being varied, the challenge of prompt and reliable diagnosis rests on emergency radiology. While the gold standard for detecting ACF today is CT angiography (CTA), frequently complicating renal insufficiency discourages the use of iodinated contrast making MR angiography (MRA) a useful alternative. Contrast enhanced ultrasound (CEUS) provides a promising new diagnostic option allowing rapid, non invasive and bedside diagnosis, especially in hemodynamically unstable patients. We present a case of prompt diagnosis of ACF by CEUS in comparison to modern MRA, thus establishing the new potential role of CEUS.

  7. Estimation of CT-Derived Abdominal Visceral and Subcutaneous Adipose Tissue Depots from Anthropometry in Europeans, South Asians and African Caribbeans

    PubMed Central

    Eastwood, Sophie V.; Tillin, Therese; Wright, Andrew; Heasman, John; Willis, Joseph; Godsland, Ian F.; Forouhi, Nita; Whincup, Peter; Hughes, Alun D.; Chaturvedi, Nishi

    2013-01-01

    Background South Asians and African Caribbeans experience more cardiometabolic disease than Europeans. Risk factors include visceral (VAT) and subcutaneous abdominal (SAT) adipose tissue, which vary with ethnicity and are difficult to quantify using anthropometry. Objective We developed and cross-validated ethnicity and gender-specific equations using anthropometrics to predict VAT and SAT. Design 669 Europeans, 514 South Asians and 227 African Caribbeans (70±7 years) underwent anthropometric measurement and abdominal CT scanning. South Asian and African Caribbean participants were first-generation migrants living in London. Prediction equations were derived for CT-measured VAT and SAT using stepwise regression, then cross-validated by comparing actual and predicted means. Results South Asians had more and African Caribbeans less VAT than Europeans. For basic VAT prediction equations (age and waist circumference), model fit was better in men (R2 range 0.59-0.71) than women (range 0.35-0.59). Expanded equations (+ weight, height, hip and thigh circumference) improved fit for South Asian and African Caribbean women (R2 0.35 to 0.55, and 0.43 to 0.56 respectively). For basic SAT equations, R2 was 0.69-0.77, and for expanded equations it was 0.72-0.86. Cross-validation showed differences between actual and estimated VAT of <7%, and SAT of <8% in all groups, apart from VAT in South Asian women which disagreed by 16%. Conclusion We provide ethnicity- and gender-specific VAT and SAT prediction equations, derived from a large tri-ethnic sample. Model fit was reasonable for SAT and VAT in men, while basic VAT models should be used cautiously in South Asian and African Caribbean women. These equations will aid studies of mechanisms of cardiometabolic disease in later life, where imaging data are not available. PMID:24069381

  8. 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.

  9. 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

  10. Automatic segmentation of the liver using multi-planar anatomy and deformable surface model in abdominal contrast-enhanced CT images

    NASA Astrophysics Data System (ADS)

    Jang, Yujin; Hong, Helen; Chung, Jin Wook; Yoon, Young Ho

    2012-02-01

    We propose an effective technique for the extraction of liver boundary based on multi-planar anatomy and deformable surface model in abdominal contrast-enhanced CT images. Our method is composed of four main steps. First, for extracting an optimal volume circumscribing a liver, lower and side boundaries are defined by positional information of pelvis and rib. An upper boundary is defined by separating the lungs and heart from CT images. Second, for extracting an initial liver volume, optimal liver volume is smoothed by anisotropic diffusion filtering and is segmented using adaptively selected threshold value. Third, for removing neighbor organs from initial liver volume, morphological opening and connected component labeling are applied to multiple planes. Finally, for refining the liver boundaries, deformable surface model is applied to a posterior liver surface and missing left robe in previous step. Then, probability summation map is generated by calculating regional information of the segmented liver in coronal plane, which is used for restoring the inaccurate liver boundaries. Experimental results show that our segmentation method can accurately extract liver boundaries without leakage to neighbor organs in spite of various liver shape and ambiguous boundary.

  11. Abdominal tap

    MedlinePlus

    Peritoneal tap; Paracentesis; Ascites - abdominal tap; Cirrhosis - abdominal tap; Malignant ascites - abdominal tap ... abdominal cavity ( most often cancer of the ovaries ) Cirrhosis of the liver Damaged bowel Heart disease Infection ...

  12. [Treatment of rupture of abdominal aortic aneurism in multi-field military hospital].

    PubMed

    Beliakin, S A; Obraztsov, A V; Pinchuk, O V; Kryzhov, S N; Iamenskov, B B; Bokachev, R A; Tikhonov, P A

    2013-09-01

    For the last 5 years in the center of vascular surgery of Vishnevskiy 3rd Central Military Clinical Hospital 218 patients with abdominal aortic aneurism were treated, 96 planned surgical operations for abdominal aortic aneurism (post-operative mortality 3.1%) were performed. 11 patients underwent urgent surgical operation because of rupture of abdominal aortic aneurism. 1 of 11 patients died at the stage of laparotomy, the second patient died after clipping of ruptured aneurysm. In other 9 cases surgical operation was performed successfully. But 2 of 9 patients died in a few hours after surgery. In summary, 4 of 11 patients underwent surgical operation for rupture of abdominal aortic aneurism survived. The postoperative mortality was 63.6%. Authors gave an example of successful treatment of patient with rupture of abdominal aortic aneurism. It was concluded that successful treatment of rupture of abdominal aortic aneurism is possible only in case of well-run integration of different treatment and diagnostic departments. CT angiography is crucial for instrumental diagnostics of rupture of abdominal aortic aneurism. Successful surgical operation is impossible without organized blood supply service, refusion and donor blood. Artificial lung ventilation, extracorporal detoxication and adequate pharmacological supply help to avoid severe complications during the postoperative period, even in patients with associated pathology. PMID:24341201

  13. The role of multidetector computed tomography versus digital subtraction angiography in triaging care and management in abdominopelvic trauma

    PubMed Central

    Hallinan, James Thomas Patrick Decourcy; Tan, Cher Heng; Pua, Uei

    2016-01-01

    INTRODUCTION This study aimed to assess the ability of contrast-enhanced computed tomography (CECT) to detect active abdominopelvic haemorrhage in patients with blunt trauma, as compared to digital subtraction angiography (DSA). METHODS In this retrospective study, patients who underwent DSA within 24 hours following CECT for blunt abdominal and/or pelvic trauma were identified. The computed tomography (CT) trauma protocol consisted of a portal venous phase scan without CT angiography; delayed phase study was performed if appropriate. All selected CECT studies were independently reviewed for the presence of active extravasation of contrast by two radiologists, who were blinded to the DSA results. Fisher’s exact test was used to correlate the presence of extravasation on CT with subsequent confirmed haemorrhage on DSA. RESULTS During the eight-year study period, 51 patients underwent CECT prior to emergent DSA for abdominal or pelvic trauma. Evidence of active extravasation of contrast on CECT was observed in 35 patients and active haemorrhage was confirmed on DSA in 31 of these patients; embolisation was performed in all 31 patients. Two patients who were negative for active extravasation of contrast on CECT but positive for active haemorrhage on DSA had extensive bilateral pelvic fractures and haematomas. The sensitivity, specificity, and positive and negative predictive values of CECT in detecting active abdominopelvic haemorrhage, as compared to DSA, were 93.9%, 77.8%, 88.6% and 87.5%, respectively. CONCLUSION When compared with DSA, dual-phase CECT without CT angiography shows high sensitivity and positive predictive value for the detection of active haemorrhage in patients with blunt abdominopelvic trauma. PMID:26778466

  14. Prospective Evaluation of Prior Image Constrained Compressed Sensing (PICCS) Algorithm in Abdominal CT: A comparison of reduced dose with standard dose imaging

    PubMed Central

    Lubner, Meghan G.; Pickhardt, Perry J.; Kim, David H.; Tang, Jie; Munoz del Rio, Alejandro; Chen, Guang-Hong

    2014-01-01

    Purpose To prospectively study CT dose reduction using the “prior image constrained compressed sensing” (PICCS) reconstruction technique. Methods Immediately following routine standard dose (SD) abdominal MDCT, 50 patients (mean age, 57.7 years; mean BMI, 28.8) underwent a second reduced-dose (RD) scan (targeted dose reduction, 70-90%). DLP, CTDIvol and SSDE were compared. Several reconstruction algorithms (FBP, ASIR, and PICCS) were applied to the RD series. SD images with FBP served as reference standard. Two blinded readers evaluated each series for subjective image quality and focal lesion detection. Results Mean DLP, CTDIvol, and SSDE for RD series was 140.3 mGy*cm (median 79.4), 3.7 mGy (median 1.8), and 4.2 mGy (median 2.3) compared with 493.7 mGy*cm (median 345.8), 12.9 mGy (median 7.9 mGy) and 14.6 mGy (median 10.1) for SD series, respectively. Mean effective patient diameter was 30.1 cm (median 30), which translates to a mean SSDE reduction of 72% (p<0.001). RD-PICCS image quality score was 2.8±0.5, improved over the RD-FBP (1.7±0.7) and RD-ASIR(1.9±0.8)(p<0.001), but lower than SD (3.5±0.5)(p<0.001). Readers detected 81% (184/228) of focal lesions on RD-PICCS series, versus 67% (153/228) and 65% (149/228) for RD-FBP and RD-ASIR, respectively. Mean image noise was significantly reduced on RD-PICCS series (13.9 HU) compared with RD-FBP (57.2) and RD-ASIR (44.1) (p<0.001). Conclusion PICCS allows for marked dose reduction at abdominal CT with improved image quality and diagnostic performance over reduced-dose FBP and ASIR. Further study is needed to determine indication-specific dose reduction levels that preserve acceptable diagnostic accuracy relative to higher-dose protocols. PMID:24943136

  15. Size-specific Dose Estimates for Chest, Abdominal, and Pelvic CT: Effect of Intrapatient Variability in Water-equivalent Diameter

    PubMed Central

    Shiung, Maria; Duan, Xinhui; Yu, Lifeng; Zhang, Yi; McCollough, Cynthia H.

    2015-01-01

    Purpose To develop software to automatically calculate size-specific dose estimates (SSDEs) and to assess the effect of variations in water-equivalent diameter (Dw) along the z-axis on SSDE for computed tomographic (CT) examinations of the torso. Materials and Methods In this institutional review board–approved, HIPAA-compliant, retrospective study, a software program was used to calculate Dw at each image position in 102 consecutive CT examinations of the combined chest, abdomen, and pelvis. SSDE was calculated by multiplying the size-dependent conversion factor and volume CT dose index (CTDIvol) at each image position. The variations in Dw along the z-axis were determined for six hypothetical scanning ranges: chest alone; abdomen alone; pelvis alone; chest and abdomen; abdomen and pelvis; and chest, abdomen, and pelvis. Mean SSDE was calculated in two ways: (a) from the SSDE at each position and (b) from the mean CTDIvol over each scan range and the conversion factor corresponding to Dw at the middle of the scan range. Linear regression analysis was performed to determine the correlation between SSDE values calculated in these two ways. Results Across patients, for scan ranges 1–6, the mean of the difference between maximal and minimal Dw within a given patient was 5.2, 4.9, 2.5, 6.0, 5.6, and 6.5 cm, respectively. The mean SSDE values calculated by using the two methods were in close agreement, with root mean square differences of 0.9, 0.5, 0.5, 1.4, 1.0, and 1.1 mGy or 6%, 3%, 2%, 9%, 4%, and 6%, for the scan ranges of chest; abdomen; pelvis; chest and abdomen; abdomen and pelvis; and chest, abdomen, and pelvis, respectively. Conclusion Using the mean CTDIvol from the whole scan range and Dw from the image at the center of the scan range provided an easily obtained estimate of SSDE for the whole scan range that agreed well with values from an image-by-image approach, with a root mean square difference less than 1.4 mGy (9%). © RSNA, 2015 Online

  16. Three-dimensional multi-detector row CT portal venography in the evaluation of portosystemic collateral vessels in liver cirrhosis.

    PubMed

    Kang, Heoung Keun; Jeong, Yong Yeon; Choi, Jun Ho; Choi, Song; Chung, Tae Woong; Seo, Jeong Jin; Kim, Jae Kyu; Yoon, Woong; Park, Jin Gyoon

    2002-01-01

    Multi-detector row computed tomography (CT) offers distinct advantages over traditional spiral CT. Multi-detector row CT scanners are faster and allow thinner collimation than single-detector row spiral CT scanners. The use of multi-detector row CT combined with postprocessing of the imaging data with a variety of three-dimensional reformatting techniques (eg, maximum intensity projection, shaded surface display, volume rendering) allows creation of vascular maps whose quality equals or exceeds that of maps created at classic angiography for many applications. Three-dimensional multi-detector row CT portal venography can help determine the extent and location of portosystemic collateral vessels (eg, left gastric vein, short gastric vein, esophageal and paraesophageal varices, splenorenal and gastrorenal shunts, paraumbilical and abdominal wall veins) in patients with liver cirrhosis and is probably the optimal imaging technique in this setting.

  17. The Acute Abdominal Aorta.

    PubMed

    Mellnick, Vincent M; Heiken, Jay P

    2015-11-01

    Acute disorders of the abdominal aorta are potentially lethal conditions that require prompt evaluation and treatment. Computed tomography (CT) is the primary imaging method for evaluating these conditions because of its availability and speed. Volumetric CT acquisition with multiplanar reconstruction and three-dimensional analysis is now the standard technique for evaluating the aorta. MR imaging may be useful for select applications in stable patients in whom rupture has been excluded. Imaging is indispensable for diagnosis and treatment planning, because management has shifted toward endoluminal repair. Acute abdominal aortic conditions most commonly are complications of aneurysms and atherosclerosis. PMID:26526434

  18. Computed Tomography (CT) -- Head

    MedlinePlus

    ... further information please consult the ACR Manual on Contrast Media and its references. The risk of serious allergic ... Angiography (CTA) Stroke Brain Tumors Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, ...

  19. Studies on the application of a low-voltage peak to the postsurgical follow-up CT scan in abdominal cancer patients in order to reduce the exposure of patients to radiation

    NASA Astrophysics Data System (ADS)

    Cho, J. H.; Lee, H. K.; Kim, H. J.; Dong, K. R.; Chung, W. K.

    2012-10-01

    This study examined the radiation dose, computed tomography (CT) number, contrast and image quality of patients requiring periodic follow-up abdominal CT examinations at various tube voltages. The subjects were divided into two groups. One group consisted of patients who underwent a clinical analysis and the other group was a phantom one. Somatom Sensation 16 (Siemens, Erlangen, Germany) was used. Twenty patients who underwent a periodic follow-up examination by CT were selected randomly. The tube current was fixed to 150 mA, and the tube voltage was adjusted according to the appropriate value of each examination. The computed tomography dose index (CTDI) values were measured. The CT number of each organ was measured by setting up a 1 cm diameter return on investment (ROI) in the abdominal organs at the same height of the first lumbar vertebra using images of the arterial phase. Two radiologists in consensus graded the quality of the abdominal images into three groups. An abdomen-shaped acrylic phantom was used in the phantom study. An ion chamber was inserted into the holes located at the center and periphery of the phantom, where the radiation dose was automatically displayed on the reader. Tube voltages of 80, 100, 120 and 140 kVp were applied to the phantom (diluted contrast medium with water at 1:10 ratio) and the phantom was scanned. The CT number was measured from a 1 cm diameter ROI at the center of the image. The CTDI value decreased by 36% at 100 kVp (7.50 mGy) compared with that at 120 kVp (11.70 mGy). According to the radiologists' evaluation, there were 17 equivalent, 3 acceptable and 0 unacceptable levels in the group of 20 subjects. The radiation dose in the phantom study decreased with increasing tube voltages from 80 to 140 kVp. The peripheral and central doses decreased by 38% and 41%, respectively. The CT numbers at 80, 100, 120 and 140 kVp were 1365.9±4.4, 1046.1±3.7, 862.8±3.2 and 737.5±3.0 HU, respectively. In conclusion, in a follow

  20. 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

  1. A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus

    SciTech Connect

    Allard, Louise; Chayer, Boris; Qin Zhao; Soulez, Gilles; Roy, David; Cloutier, Guy

    2013-06-15

    Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent-grafts. In vitro experimentations are very useful to improve stent-graft design and conformability or imaging guidance for stent-graft delivery or follow-up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2-weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo. X-ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in

  2. Stent fracture and longitudinal compression detected on coronary CT angiography in the first- and new-generation drug-eluting stents.

    PubMed

    Chung, Mi Sun; Yang, Dong Hyun; Kim, Young-Hak; Roh, Jae-Hyung; Song, Jihyun; Kang, Joon-Won; Ahn, Jung-Min; Park, Duk-Woo; Kang, Soo-Jin; Lee, Seung-Whan; Lee, Cheol Whan; Park, Seong-Wook; Park, Seung-Jung; Lim, Tae-Hwan

    2016-04-01

    To evaluated prevalence and clinical implication of stent fracture and longitudinal compression in first- and new-generation drug-eluting stents (DES) using coronary computed tomography angiography (CCTA). The incidence of stent fracture and longitudinal compression were compared between first- and new-generation DES in 374 patients who underwent coronary stenting using DES and follow-up CCTA due to recurrent angina. 235 and 139 patients received 322 first- and 213 new-generation DES, respectively. The crude per-stent incidence of longitudinal compression (6.1 vs. 0.3 %, p < 0.001) was higher after new- than first-generation DES implantation using CCTA and the incidence of stent fracture (11.3 vs. 8.1 %, p = 0.23) was comparable. On follow-up coronary angiography for 347 stents, stent fracture (3.2 %) and longitudinal compression (0.9 %) were less detected than those on CCTA. Ostial stenting was a risk factor of longitudinal compression (p < 0.001). Stent fracture was associated with younger patients (p = 0.03), longer stent (p = 0.010), and excessively tortuous lesions (p = 0.001). The presence of stent fracture or longitudinal compression was not associated with poor clinical outcomes. The longitudinal compression more frequently occurred after new-generation DES implantation. The stent fracture was comparable between two DES. However, the occurrence of such mechanical deformities did not translate into a poor clinical outcome.

  3. Low-dose Computed Tomography in a Pregnant Woman with a Ruptured Pseudoaneurysm of the Abdominal Aorta.

    PubMed

    Ramac, Jelena Popić; Vidjak, Vinko; Skegro, Dinko; Duić, Zeljko; Blasković, Darko; Erdelez, Lidija; Skopljanac-Macina, Andrija; Suknaić, Slaven; Slavica, Marko; Leder, Nikola Ivan

    2015-09-01

    Imaging the pregnant patient presents a unique challenge to radiologist due to the risk of radiation to the conceptus (embryo/fetus). A rare case of a successfully recognized and treated pseudoaneurysm (PA) of the abdominal aorta is to be presented. The pseudoaneurysm occurred in the third trimester and had a favorable outcome for the mother and the baby. Emergent abdominal ultrasound (US) is the first modality in diagnostic algorithm for the rupture of aortic aneurysm in a pregnant woman. It provides the most rapid diagnostic information, although intestinal gas and abdominal tenderness may limit its accuracy. To confirm the findings, magnetic resonance angiography (MRA) or CT angiography (CTA) can be used. In our case, the diagnosis was established using a color Doppler ultrasonography of the abdomen and was later confirmed by a low dose CT scan of the abdominal aorta. MRA in such cases have some disadvantages. At many health centers, the monitoring of patients with acute ruptures is more difficult in the MR suite than at the CT scanner. MRA angiographic images are also subject to degradation by multiple artifacts and the visualization of the distal vasculature is suboptimal and inferior to the one done by CTA. Due to fetal movements, a small quantity of fresh blood can be overlooked by MR. MRA is often not available on a 24-hours basis, and the time required for making a diagnosis can preclude the use of MRA in an unstable patient. For this reason, we used a low dose CTA protocol to confirm the diagnosis. Low dose scanning protocols in CT can obtain sufficient diagnostic information while reducing the risk of radiation. A particular focus is put on the outline of new concepts for dose management and optimization. We used new approaches based on tube current modulation. The birth was induced by an urgent Caesarean section followed by a resection of a pseudoaneurysm and a reconstruction of the aorta with an end-to-end vascular prosthesis. PMID:26898082

  4. Sixty-four-slice CT angiography to determine the three dimensional relationships of vascular and soft tissue wounds in lower extremity war time injuries.

    PubMed

    Smith, Jennifer M; Fox, Charles J; Brazaitis, Michael P; Via, Kathy; Garcia, Roman; Feuerstein, Irwin M

    2010-01-01

    This article analyzes the use and benefits of the 64-slice CT scanner in determining the 3D relationships of vascular and soft tissue wounds in lower extremity war time injuries. A brief overview of CT scanning is given as well as the techniques used to produce the images needed for diagnosis. The series follows two similar cases of war time injury patients at the Walter Reed Army Medical Center. The first case is a 30-year-old active duty male, who presented with multiple trauma from a motor vehicle accident because of an improvised explosive device (IED) blast, sustaining substantial lower extremity injuries. The second case is a 34-year-old active duty male, who presented with multiple trauma blast injuries. Both cases were of interest because the vasculature was found to be very close to the surface of the wound, which put the arteries at risk for rupture and for iatrogenic injury during repeated debridements.

  5. 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

  6. 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

  7. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Ziaja, K; Sedlak, L; Urbanek, T; Kostyra, J; Ludyga, T

    2000-01-01

    The reported incidence of inflammatory abdominal aortic aneurysm (IAAA) is from 2% to 14% of patients with abdominal aortic aneurysm and the etiology of this disease is still discussed--according to the literature several pathogenic theories have been proposed. From 1992 to 1997 32 patients with IAAA were operated on. The patients were mostly symptomatic--abdominal pain was present in 68.75% cases, back pain in 31.25%, fever in 12.5% and weight loss in 6.25% of the operated patients. In all the patients ultrasound examination was performed, in 4 patients CT and in 3 cases urography. All the patients were operated on and characteristic signs of inflammatory abdominal aortic aneurysm like: thickened aortic wall, perianeurysmal infiltration or retroperitoneal fibrosis with involvement of retroperitoneal structures were found. In all cases surgery was performed using transperitoneal approach; in three cases intraoperatively contiguous abdominal organs were injured, which was connected with their involvement into periaortic inflammation. In 4 cases clamping of the aorta was done at the level of the diaphragmatic hiatus. 3 patients (9.37%) died (one patient with ruptured abdominal aortic aneurysm). Authors present diagnostic procedures and the differences in the surgical tactic, emphasizing the necessity of the surgical therapy in patients with inflammatory abdominal aortic aneurysm.

  8. 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

  9. Coronary CT angiography findings based on smoking status: Do ex-smokers and never-smokers share a low probability of developing coronary atherosclerosis?

    PubMed

    Yi, Minkyung; Chun, Eun Ju; Lee, Min Su; Lee, Jaebong; Choi, Sang Il

    2015-12-01

    The relationship of coronary artery disease (CAD) in ex-smokers has not been elucidated, although smoking is considered to be one of the major risk factors of CAD. We investigate subclinical coronary atherosclerosis (SCA) in asymptomatic subjects with coronary computed tomography angiography (CCTA), according to smoking status, and determine whether ex-smokers share a low probability of developing CAD with never-smokers. We retrospectively enrolled 6930 self-referred asymptomatic adults who underwent both coronary artery calcium score (CACS) and CCTA. The prevalence and characteristics of SCA were assessed according to smoking status (never-, ex- and current smokers). After adjusting for variable risk factors, we used multivariate logistic regression for adjusted odds ratios (AOR) of high CACS (>100), SCA (any plaque), significant stenosis (>50 % in luminal stenosis) and each plaque type (non-calcified, mixed and calcified plaque) among the three groups. The prevalence of SCA was highest in the ex-smokers (35.4 %) and the prevalence of significant stenosis in ex-smokers (6.9 %) was as high as in current smokers (6.4 %). However, after adjusting for variable risk factors, SCA was significantly correlated with both ex-smokers (AOR; 1.21) and current smokers (AOR; 1.25), whereas significant stenosis was correlated only with current smokers (AOR; 1.91). The association between SCA and ex-smokers is as strong as with current smokers, although significant stenosis is only correlated with current smokers; thus, not only quitting smoking but also never initiating smoking would be helpful to reduce the progression of the SCA.

  10. Using clinical cardiovascular risk scores to predict coronary artery plaque severity and stenosis detected by CT coronary angiography in asymptomatic Chinese subjects.

    PubMed

    Lee, Bai-Chin; Lee, Wen-Jeng; Hsu, Hsiu-Ching; Chien, Kuo-Liong; Shih, Tiffany Ting-Fang; Chen, Ming-Fong

    2011-06-01

    We aimed to determine whether the Framingham risk score (FRS), systematic coronary risk evaluation (SCORE), and Chinese multi-provincial cohort study (CMCS) could predict anatomic severity of coronary plaques. From January 2007 to October 2010, we performed a contrast-enhanced 64-slice or 256-slice multidetector computed tomography coronary angiography as part of a health check-up protocol in 806 asymptomatic subjects (70.5% male, 56 ± 9 year-old). Risk scores significantly correlated with calcium volume score, plaque stenosis score and plaque distribution score (P < 0.001). Of the 3 risk scores, the SCORE system showed the best correlation. Overall, 180 (22%) and 37 (5%) subjects were found to have stenosis of 50-69% and more than 70% in at-least one coronary artery segment, respectively. In the prediction of the presence of obstructive CAD (≥ 50% diameter stenosis), all risk scores had similar discrimination. In the prediction of severe CAD (≥ 70% diameter stenosis), FRS and CMCS had similar area under curves but SCORE discriminated better than FRS (P < 0.05). The optimal cutoff point to predict obstructive CAD was 9.54% for FRS, 1.05% for CMCS, and 0.95% for SCORE, whereas to predict severe CAD was 9.63, 1.05, 1.15% for FRS, CMCS, SCORE, respectively, with a sensitivity of 0.61-0.70 and a specificity of 0.55-0.66. Cardiovascular risk scores are associated with the severity and extent of coronary artery plaque. The stronger association might translate into a better discrimination using SCORE. These findings will aid in the appropriate selection or recalibration of the risk assessment system for cardiovascular disease screening.

  11. Unusual congenital aortic anomaly with rare common celiamesenteric trunk variation: MR angiography and digital substraction angiography findings.

    PubMed

    Tosun, Ozgur; Sanlidilek, Umman; Cetin, Huseyin; Ozdemir, Ozcan; Kurt, Aydin; Sakarya, Mehmet Emin; Tas, Ismet

    2007-01-01

    Magnetic resonance angiography and digital substraction angiography (DSA) findings in a case with a rare congenital thoracoabdominal aortic hypoplasia and common celiamesenteric trunk variation with occlusion of infrarenal abdominal aorta are described here. To our knowledge, this aortic anomaly has not been previously described in the English literature. DSA is the optimum imaging modality for determination of aortic hypoplasia, associated vascular malformations, collateral vessels, and direction of flow within vessels. PMID:17468907

  12. Unusual Congenital Aortic Anomaly with Rare Common Celiamesenteric Trunk Variation: MR Angiography and Digital Substraction Angiography Findings

    SciTech Connect

    Tosun, Ozgur Sanlidilek, Umman; Cetin, Huseyin; Ozdemir, Ozcan; Kurt, Aydin; Sakarya, Mehmet Emin; Tas, Ismet

    2007-09-15

    Magnetic resonance angiography and digital substraction angiography (DSA) findings in a case with a rare congenital thoracoabdominal aortic hypoplasia and common celiamesenteric trunk variation with occlusion of infrarenal abdominal aorta are described here. To our knowledge, this aortic anomaly has not been previously described in the English literature. DSA is the optimum imaging modality for determination of aortic hypoplasia, associated vascular malformations, collateral vessels, and direction of flow within vessels.

  13. Trans-radial Carotid Artery Stenting in a Patient with Abdominal Aortic Occlusion

    PubMed Central

    Ha, Jin Heon; Kim, Hoon; Park, Ik Seong

    2016-01-01

    We report transradial access (TRA) for emergency carotid artery stenting (CAS) as a useful alternative when the femoral artery cannot be accessed. A 63-year-old man arrived at our emergency room 30 minutes after left hemiplegia and loss of consciousness. Brain computed tomography (CT) anigograpy showed occlusion of the right interntal carotid artery (ICA) and CT perfusion revealed delayed time-to-peak in the territory of the middle cerebral artery. For, endovascular treatment, trans-femoral access (TFA) was attempted but failed due to occlusion of the abdominal aorta. So, we changed access route via radial artery and confirmed proximal ICA dissection. CAS was attempted via TRA and it was successfully performed. Final angiography showed recanalization of ICA and patient was clinically improved. PMID:27790405

  14. Feasibility Study of Using Gemstone Spectral Imaging (GSI) and Adaptive Statistical Iterative Reconstruction (ASIR) for Reducing Radiation and Iodine Contrast Dose in Abdominal CT Patients with High BMI Values

    PubMed Central

    Zhu, Zheng; Zhao, Xin-ming; Zhao, Yan-feng; Wang, Xiao-yi; Zhou, Chun-wu

    2015-01-01

    Purpose To prospectively investigate the effect of using Gemstone Spectral Imaging (GSI) and adaptive statistical iterative reconstruction (ASIR) for reducing radiation and iodine contrast dose in abdominal CT patients with high BMI values. Materials and Methods 26 patients (weight > 65kg and BMI ≥ 22) underwent abdominal CT using GSI mode with 300mgI/kg contrast material as study group (group A). Another 21 patients (weight ≤ 65kg and BMI ≥ 22) were scanned with a conventional 120 kVp tube voltage for noise index (NI) of 11 with 450mgI/kg contrast material as control group (group B). GSI images were reconstructed at 60keV with 50%ASIR and the conventional 120kVp images were reconstructed with FBP reconstruction. The CT values, standard deviation (SD), signal-noise-ratio (SNR), contrast-noise-ratio (CNR) of 26 landmarks were quantitatively measured and image quality qualitatively assessed using statistical analysis. Results As for the quantitative analysis, the difference of CNR between groups A and B was all significant except for the mesenteric vein. The SNR in group A was higher than B except the mesenteric artery and splenic artery. As for the qualitative analysis, all images had diagnostic quality and the agreement for image quality assessment between the reviewers was substantial (kappa = 0.684). CT dose index (CTDI) values for non-enhanced, arterial phase and portal phase in group A were decreased by 49.04%, 40.51% and 40.54% compared with group B (P = 0.000), respectively. The total dose and the injection rate for the contrast material were reduced by 14.40% and 14.95% in A compared with B. Conclusion The use of GSI and ASIR provides similar enhancement in vessels and image quality with reduced radiation dose and contrast dose, compared with the use of conventional scan protocol. PMID:26079259

  15. 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

  16. Automated identification of best-quality coronary artery segments from multiple-phase coronary CT angiography (cCTA) for vessel analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Chughtai, Aamer; Wei, Jun; Kazerooni, Ella A.

    2016-03-01

    We are developing an automated method to identify the best quality segment among the corresponding segments in multiple-phase cCTA. The coronary artery trees are automatically extracted from different cCTA phases using our multi-scale vessel segmentation and tracking method. An automated registration method is then used to align the multiple-phase artery trees. The corresponding coronary artery segments are identified in the registered vessel trees and are straightened by curved planar reformation (CPR). Four features are extracted from each segment in each phase as quality indicators in the original CT volume and the straightened CPR volume. Each quality indicator is used as a voting classifier to vote the corresponding segments. A newly designed weighted voting ensemble (WVE) classifier is finally used to determine the best-quality coronary segment. An observer preference study is conducted with three readers to visually rate the quality of the vessels in 1 to 6 rankings. Six and 10 cCTA cases are used as training and test set in this preliminary study. For the 10 test cases, the agreement between automatically identified best-quality (AI-BQ) segments and radiologist's top 2 rankings is 79.7%, and between AI-BQ and the other two readers are 74.8% and 83.7%, respectively. The results demonstrated that the performance of our automated method was comparable to those of experienced readers for identification of the best-quality coronary segments.

  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. 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

  20. Pulmonary Embolism with Abdominal Pain and ST Elevation: A Case Report

    PubMed Central

    Fallahi, Mohammad Javad; Masoompour, Seyed Masoom; Mirzaee, Mehdi

    2014-01-01

    Pulmonary embolism is considered as a great masquerader due to its frequent nonspecific signs and symptoms. Typically pulmonary embolism is under-diagnosed or over-diagnosed. In this study a patient with pulmonary embolism is reported in which the patient exhibited two unusual manifestations namely; right upper quadrant abdominal pain and ST-T elevation in anterior precordial leads. Due to the fact that the patient did not display typical pulmonary embolism symptoms and its major risk factors, extensive workup to discern the cause was carried out. The examination included abdominal sonography, kidney ureter and bladder Computed Tomography scan (CT-scan) and coronary angiography. Eventually after a six-day delay, pulmonary embolism was diagnosed by spiral chest CT scan. This case and several other similar reports underlines the fact that while various other common causes may exist for right upper abdominal pain, one should always consider pulmonary embolism as a possible cause especially when backed up with ECG finding. PMID:25031494

  1. 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.

  2. Abdominal emergencies in pediatrics.

    PubMed

    Coca Robinot, D; Liébana de Rojas, C; Aguirre Pascual, E

    2016-05-01

    Abdominal symptoms are among the most common reasons for pediatric emergency department visits, and abdominal pain is the most frequently reported symptom. Thorough history taking and physical examination can often reach the correct diagnosis. Knowing the abdominal conditions that are most common in each age group can help radiologists narrow the differential diagnosis. When imaging tests are indicated, ultrasonography is usually the first-line technique, enabling the diagnosis or adding relevant information with the well-known advantages of this technique. Nowadays, plain-film X-ray studies are reserved for cases in which perforation, bowel obstruction, or foreign body ingestion is suspected. It is also important to remember that abdominal pain can also occur secondary to basal pneumonia. CT is reserved for specific indications and in individual cases, for example, in patients with high clinical suspicion of abdominal disease and inconclusive findings at ultrasonography. We review some of the most common conditions in pediatric emergencies, the different imaging tests indicated in each case, and the imaging signs in each condition.

  3. 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

  4. Computed tomography of the postoperative abdominal aorta

    SciTech Connect

    Hilton, S.; Megibow, A.J.; Naidich, D.P.; Bosniak, M.A.

    1982-11-01

    Computed tomography (CT) of the abdomen was performed on 46 patients who had undergone graft replacement of abdominal aortic aneurysms. Twelve post-operative complications were found in nine patients. They included hemorrhage, infection, anastomotic pseudoaneurysms, major vessel occlusion, postoperative pancreatitis, and others. The varied apperance of the normal postoperative graft is also presented. It is concluded that CT is a rapid, sensitive, and noninvasive method for detecting or excluding postoperative complications of abdominal aortic surgery.

  5. Reproducibility of aortic pulsatility measurements from ECG-gated abdominal CTA in patients with abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Manduca, Armando; Fletcher, Joel G.; Wentz, Robert J.; Shields, Raymond C.; Vrtiska, Terri J.; Siddiki, Hassan; Nielson, Theresa

    2009-02-01

    Purpose: ECG-gated abdominal CT angiography with reconstruction of multiple, temporally overlapping CT angiography datasets has been proposed for measuring aortic pulsatility. The purpose of this work is to develop algorithms to segment the aorta from surrounding structures from CTA datasets across cardiac phases, calculate registered centerlines and measurements of regional aortic pulsatility in patients with AAA, and to assess the reproducibility of these measurements. Methods: ECG-gated CTA was performed with a temporal resolution of 165 ms, reconstructed to 1 mm slices ranging at 14 cardiac phase points. Data sets were obtained from 17 patients on which two such scans were performed 6 to 12 months apart. Automated segmentation, centerline generation, and registration of centerlines between phases was performed, followed by calculation of cross-sectional areas and regional and local pulsatility. Results: Pulsatility calculations for the supraceliac region were very reproducible between earlier and later scans of the same patient, with average differences less than 1% for pulsatility values ranging from 2% to 13%. Local radial pulsatilities were also reproducible to within ~1%. Aneurysm volume changes between scans can also be quantified. Conclusion: Automated segmentation, centerline generation, and registration of temporally resolved CTA datasets permit measurements of regional changes in cross-sectional area over the course of the cardiac cycle (i.e., regional aortic pulsatility). These measurements are reproducible between scans 6-12 months apart, with differences in aortic areas reflecting both aneurysm remodeling and changes in blood pressure. Regional pulsatilities ranged from 2 to 13% but were reproducible at the 1% level.

  6. 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

  7. Technical innovation: Multidimensional computerized software enabled subtraction computed tomographic angiography.

    PubMed

    Bhatia, Mona; Rosset, Antoine; Platon, Alexandra; Didier, Dominique; Becker, Christoph D; Poletti, Pierre-Alexandre

    2010-01-01

    Computed tomographic angiography (CTA) is a frequent noninvasive alternative to digital subtraction angiography. We previously reported the development of a new subtraction software to overcome limitations of adjacent bone and calcification in CT angiographic subtraction. Our aim was to further develop and improve this fast and automated computerized software, universally available for free use and compatible with most CT scanners, thus enabling better delineation of vascular structures, artifact reduction, and shorter reading times with potential clinical benefits. This computer-based free software will be available as an open source in the next release of OsiriX at the Web site http://www.osirix-viewer.com.

  8. Abdominal Pain

    MedlinePlus

    ... can help the overall situation for the child. Teaching kids self-hypnosis [8] or guided imagery [8a] ... related topics? Functional Abdominal Pain (English, French or Spanish)—from The North American Society for Pediatric Gastroenterology, ...

  9. Abdominal pain

    MedlinePlus

    Stomach pain; Pain - abdomen; Belly ache; Abdominal cramps; Bellyache; Stomachache ... Almost everyone has pain in the abdomen at some point. Most of the time, it is not serious. How bad your pain is ...

  10. 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

  11. Management of a dislocated endovascular aneurysm repair in a challenging giant abdominal aortic aneurysm.

    PubMed

    Geers, Joachim; Daenen, Geert; Stabel, Patrick

    2016-02-01

    Introduction A case report of a contained rupture of an abdominal aneurysm, treated by endovascular technique (EVAR), but complicated by perioperative endoprosthesis limb dislocation. Case report An 81-year old male presented at the emergency department with a contained rupture of an infrarenal aortic aneurysm and bilateral extensive iliac aneurysmatic disease. Open repair was no option, due to the pulmonary condition. The patient was prepped for an emergency EVAR. After placing a bifurcated endoprosthesis, angiography revealed a type IIIa endoleak, due to a dislocation between two left iliac extensions. We converted to a right-sided aorto-uni-iliac endoprosthesis with a femorofemoral bypass. A postoperative CT-scan showed a complete exclusion of the aneurysm, a patent aorto-uni-iliac endoprosthesis and a femorofemoral bypass without an endoleak. Discussion EVAR is feasible with a hostile neck AAA, even in a ruptured AAA. In large AAA, one should consider an overlap larger than suggested in the instructions for use. PMID:27385140

  12. Abdominal Sepsis.

    PubMed

    De Waele, Jan J

    2016-08-01

    Abdominal infections are an important challenge for the intensive care physician. In an era of increasing antimicrobial resistance, selecting the appropriate regimen is important and, with new drugs coming to the market, correct use is important more than ever before and abdominal infections are an excellent target for antimicrobial stewardship programs. Biomarkers may be helpful, but their exact role in managing abdominal infections remains incompletely understood. Source control also remains an ongoing conundrum, and evidence is increasing that its importance supersedes the impact of antibiotic therapy. New strategies such as open abdomen management may offer added benefit in severely ill patients, but more data are needed to identify its exact role. The role of fungi and the need for antifungal coverage, on the other hand, have been investigated extensively in recent years, but at this point, it remains unclear who requires empirical as well as directed therapy. PMID:27363829

  13. Prognostic utility of coronary computed tomographic angiography

    PubMed Central

    Otaki, Yuka; Berman, Daniel S.; Min, James K.

    2013-01-01

    Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a noninvasive method that enables accurate detection and exclusion of anatomically obstructive coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. There are numerous potential advantages of CCTA beyond simply luminal stenosis assessment including quantification of atherosclerotic plaque volume as well as assessment of plaque composition, extent, location and distribution. In recent years, an array of studies has evaluated the prognostic utility of CCTA findings of CAD for the prediction of major adverse cardiac events, all-cause death and plaque instability. This prognostic information enhances risk stratification and, if properly acted upon, may improve medical therapy and/or behavioral changes that may enhance event-free survival. The goal of the present article is to summarize the current status of the prognostic utility of CCTA findings of CAD. PMID:23809386

  14. Abdominal thrusts

    MedlinePlus

    ... call 911 . If the person loses consciousness, start CPR . If you are not comfortable performing abdominal thrusts, ... American Red Cross. First Aid/CPR/AED Participant's Manual. 2nd ... Red Cross; 2014. Berg RA, Hemphill R, Abella BS, et al. Part 5: ...

  15. Fluorescein angiography printouts.

    PubMed

    Merin, L M

    1980-04-01

    Nineteen years after the pioneering efforts of Novotny and Alvis, fluorescein angiography has reached a level of acceptance and use which reflects its high value in ophthalmic diagnosis. Angiography laboratories are commonplace in hospitals, and many private physicians own fundus cameras and perform fluorescein angiograms routinely. As the use of this test has substantially increased, so has the number of methods used to present the film for analysis and interpretation. At this writing there are no fewer than 12 different ways of presenting fluorescein angiograms in common use (Table 1). Not all of these techniques are able to yield equal amounts of information, however, and as consultations between different laboratories occur, much difficulty results from the disparate styles. Evaluation of these varying techniques of fluorescein angiography presentation depends on the production complexity and the amount of useful information which each may yield. PMID:7235472

  16. Abdominal trauma by ostrich

    PubMed Central

    Usurelu, Sergiu; Bettencourt, Vanessa; Melo, Gina

    2015-01-01

    Introduction Ostriches typically avoid humans in the wild, since they correctly assess humans as potential predators, and, if approached, often run away. However, ostriches may turn aggressive rather than run when threatened, especially when cornered, and may also attack when they feel the need to defend their offspring or territories. Presentation of case A 71-year-old male patient presented with intra abdominal injury sustained from being kicked in the abdominal wall by an ostrich. During laparotomy, were found free peritoneal effusion and perforation of the small intestine. Discussion The clinical history and physical examination are extremely important for diagnostic and therapeutic decision making. CT-scan is the most accurate exam for making diagnosis. Surgery is the treatment of choice, and is always indicated when there is injury to the hollow viscera. In general it is possible to suture the defect. Conclusion In cases of blunt abdominal trauma by animals is necessary to have a low threshold of suspicion for acute abdomen. PMID:25685344

  17. Abdominal Aortic Aneurysms: Treatments

    MedlinePlus

    ... information Membership Directory (SIR login) Interventional Radiology Abdominal Aortic Aneurysms Interventional Radiologists Treat Abdominal Aneurysms Nonsurgically Interventional radiologists ...

  18. CT evaluation of intracholecystic bile

    SciTech Connect

    Rebner, M.; Ruggieri, P.M.; Gross, B.H.; Glazer, G.M.

    1985-08-01

    Computed tomography (CT) has been used to detect a variety of gallbladder abnormalities, but the accuracy of routine abdominal CT in evaluating intracholecystic bile has not been established. Forty-six patients were identified in whom abdominal CT and sonography were performed within 1 week of each other. Using sonographic results as the standard, sensitivity specificity, and accuracy of CT gallbladder evaluation were calculated; both initial CT interpretations and retrospective review of scans were used for this analysis. In the retrospective review, visual interpretation of gallbladder images and measurement of intracholecystic bile attenuation were analyzed. The most common cause of high-attenuation bile in the series was sludge, a cause not previously reported. It was concluded that intracholecystic bile is poorly evaluated on routine abdominal CT, particularly because of low sensitivity in disease detection.

  19. Emergency Endovascular Treatment of Abdominal Aortic Aneurysms: Feasibility and Results

    SciTech Connect

    Lagana, Domenico Carrafiello, Gianpaolo; Mangini, Monica; Fontana, Federico; Caronno, Roberto; Castelli, Patrizio; Cuffari, Salvatore; Fugazzola, Carlo

    2006-04-15

    Purpose. To assess the feasibility and effectiveness of emergency endovascular treatment of abdominal aortic aneurysms (AAAs). Methods. During 36 months we treated, on an emergency basis, 30 AAAs with endovascular exclusion. In 21 hemodynamically stable patients preoperative CT angiography (CTA) was performed to confirm the diagnosis and to plan the treatment; 9 patients with hemorrhagic shock were evaluated with angiography performed in the operating room. Twenty-two Excluder (Gore) and 8 Zenith (Cook) stent-grafts (25 bifurcated and 5 aorto-uni-iliac) were used. The follow-up was performed by CTA at 1, 3, 6, and 12 months. Results. Technical success was achieved in 100% of cases with a 10% mortality rate. The total complication rate was 23% (5 increases in serum creatinine level and 2 wound infections). During the follow-up, performed in 27 patients (1-36 months, mean 15.2 months), 4 secondary endoleaks (15%) (3 type II, 2 spontaneously thrombosed and 1 under observation, and 1 type III treated by iliac extender insertion) and 1 iliac leg occlusion (treated with femoro-femoral bypass) occurred. We observed a shrinkage of the aneurysmal sac in 8 of 27 cases and stability in 19 of 27 cases; we did not observe any endotension. Conclusions. Endovascular repair is a good option for emergency treatment of AAAs. The team's experience allows correct planning of the procedure in emergency situations also, with technical results comparable with elective repair. In our experience the bifurcated stent-graft is the device of choice in patients with suitable anatomy because the procedure is less time-consuming than aorto-uni-iliac stent-grafting with surgical crossover, allowing faster aneurysm exclusion. However, further studies are required to demonstrate the long-term efficacy of endovascular repair compared with surgical treatment.

  20. Subsecond magnetic resonance angiography and the evaluation of abnormal arteriovasuclar communications

    NASA Astrophysics Data System (ADS)

    Zachariah, Anish B.; Pereles, F. S.; Kaliney, Ryan; Carr, James C.; Collins, Jeremy D.; Wood, Cecil; Finn, John P.

    2003-05-01

    Magnetic resonance (MR) angiography is becoming widely accepted in the diagnosis of vascular diseases. When used for evaluation of arterial stenoses, aneurysm, thrombosis, or occlusion, MR angiography is a robust and accurate technique. Traditional techniques for contrast-enhanced magnetic resonance angiography (MRA) offer the benefit of high spatial resolution in characterizing vascular malformations, but have lacked the temporal resolution to describe dynamic flow events. The purpose of this project is to demonstrate the potential role of a novel technique, sub-second MRA, in the evaluation of abdominal arteriovenous malformation.

  1. Abdominal actinomycosis mimicking acute appendicitis.

    PubMed

    Conrad, Robert Joseph; Riela, Steven; Patel, Ravi; Misra, Subhasis

    2015-01-01

    A 52-year-old Hispanic woman presented to the emergency department, reporting worsening sharp lower right quadrant abdominal pain for 3 days. CT of the abdomen and pelvis showed evidence of inflammation in the peritoneal soft tissues adjacent to an enlarged and thick-walled appendix, an appendicolith, no abscess formation and a slightly thickened caecum consistent with acute appendicitis. During laparoscopic appendectomy, the caecum was noted to be firm, raising suspicion of malignancy. Surgical oncology team was consulted and open laparotomy with right hemicolectomy was performed. Pathology reported that the ileocaecal mass was not a malignancy but was, rather, actinomycosis. The patient was discharged after 10 days of intravenous antibiotics in the hospital, with the diagnosis of abdominal actinomycosis. Although the original clinical and radiological findings in this case were highly suggestive of acute appendicitis, abdominal actinomycosis should be in the differential for right lower quadrant pain as it may be treated non-operatively.

  2. Computed Tomography in the Diagnosis of Intra-abdominal Abscesses

    PubMed Central

    Daffner, Richard H.; Halber, Michael D.; Morgan, Carlisle L.; Trought, William S.; Thompson, William M.; Rice, Reed P.

    1979-01-01

    The diagnosis of intra-abdominal abscess by radiographic means often relies on combining the results of several different imaging modalities. Computed tomography (CT) has been shown to be a safe, accurate and rapid diagnostic method of diagnosing these abscesses. Five patients with a variety of intra-abdominal abscesses are presented in whom the CT scan alone provided the correct diagnosis. The various imaging modalities available for the radiologic diagnosis of intra-abdominal abscess are described and are compared to CT diagnosis regarding their pitfalls. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig.5.C. PMID:758860

  3. Renal trauma: radiological studies - comparison of urography, computed tomography, angiography, and radionuclide studies

    SciTech Connect

    Lang, E.K.; Sullivan, J.; Frentz, G.

    1985-01-01

    Excretory urography, computed radionuclide urography, angiography, and both conventional and dynamic computed tomography (CT) were compared with regard to accuracy, sensitivity, and specificity in 388 patients with renal trauma. Used as the triage examination, urography established the absence of significant renal injury with an accuracy of 87%, obviating further evaluation. Dynamic CT proved to be the best methods of assessing parenchymal injuries, establishing the correct diagnosis in 129 out of 130 cases compared to 116/130 for conventional CT. Angiography was the procedure of choice for diagnosis and categorization of renal artery injuries, which were diagnosed correctly in all 43 cases. The choice between dynamic CT and angiography as the second examination rests upon careful evaluation of clinical and urographic findings for signs of renal artery injury which would mandate angiographic assessment.

  4. 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

  5. Diagnostic accuracy and implementation of computed tomography angiography for gastrointestinal hemorrhage according to clinical severity

    PubMed Central

    Choi, Yoo Jin; Kim, Kyung Su; Suh, Gil Joon; Kwon, Woon Yong

    2016-01-01

    Objective This study compared the diagnostic accuracy of computed tomography (CT) angiography in patients with various severities of gastrointestinal hemorrhage (GIH). Methods We retrospectively enrolled adult patients (n=262) with GIH who had undergone CT angiography from January 2012 to December 2013. Age, sex, comorbidities, presenting symptoms, initial vital signs, laboratory results, transfusion volume, emergency department disposition, and hospital mortality were abstracted from patient records. CT angiography findings were reviewed and compared to reference standards consisting of endoscopy, conventional angiography, bleeding scan, capsule endoscopy, and surgery, either alone or in combination. Clinical severity was stratified according to the number of packed red blood cell units transfused during the first two days: the first quartile was categorized as mild severity, while the second and third quartiles were categorized as moderate severity. The fourth quartile was categorized as severe. Results Patients were categorized into the mild (n=75, 28.6%), moderate (n=139, 53.1%), and severe (n=48, 18.3%) groups. The mean number of transfused packed red blood cell units was 0, 3, and 9.6 in the mild, moderate, and severe groups, respectively. The overall sensitivity, specificity, positive predictive value, and negative predictive value of CT angiography were 73.8%, 94.0%, 97.3%, and 55.3%, respectively. The area under the receiver operating characteristics curve for the diagnostic performance of CT angiography was 0.780, 0.841, and 0.930 in the mild, moderate, and severe groups, respectively, which significantly differed among groups (P=0.006). Conclusion The diagnostic accuracy of CT angiography is better in patients with more severe GIH. PMID:27752620

  6. 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

  7. 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.

  8. Abdominal Aortic Aneurysm (AAA)

    MedlinePlus

    ... Resources Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis ... aortic aneurysm treated? What is an abdominal aortic aneurysm? The aorta, the largest artery in the body, ...

  9. Spine MR angiography.

    PubMed

    Bowen, B C; Pattany, P M

    1997-01-01

    The use of MR angiography to evaluate spinal vessels is in an early stage of development. Both time-of-flight (3D) and phase-contrast (2D and 3D) techniques have been applied, and for both types of techniques, the vessels are best visualized following intravenous gadolinium administration. The vessels of interest are the millimeter-sized intradural arteries and veins, which are located on the cord surface and travel from the cord to the epidural space. Only the post gadolinium 3D TOF technique has been shown to display normal intradural vessels (thoracolumbar region), principally veins. Both TOF and PC techniques provide better delineation of enlarged intradural vessels associated with spinal vascular malformations than standard MR imaging alone. PC techniques are much less sensitive in detecting the arterial supply to dural arteriovenous fistula than intramedullary arteriovenous malformation. The TOF technique can predict the foraminal level of a dural fistula when an enlarged medullary vein, resulting from retrograde drainage, is present. MR angiography, in conjunction with MR imaging, is now suggested for screening of suspected spinal vascular malformation. Other applications such as vascular tumors and arterial or venous occlusive disease are under investigation.

  10. Applications of dual energy computed tomography in abdominal imaging.

    PubMed

    Lestra, T; Mulé, S; Millet, I; Carsin-Vu, A; Taourel, P; Hoeffel, C

    2016-06-01

    Dual energy computed tomography (CT) is an imaging technique based on data acquisition at two different energy settings. Recent advances in CT have allowed data acquisition and almost simultaneously analysis of two spectra of X-rays at different energy levels resulting in novel developments in the field of abdominal imaging. This technique is widely used in cardiovascular imaging, especially for pulmonary embolism work-up but is now also increasingly developed in the field of abdominal imaging. With dual-energy CT it is possible to obtain virtual unenhanced images from monochromatic reconstructions as well as attenuation maps of different elements, thereby improving detection and characterization of a variety of renal, adrenal, hepatic and pancreatic abnormalities. Also, dual-energy CT can provide information regarding urinary calculi composition. This article reviews and illustrates the different applications of dual-energy CT in routine abdominal imaging.

  11. [Two cases of abdominal bronchogenic cyst].

    PubMed

    Takeshita, K; Watabe, N; Sato, A; Watanabe, I; Yamaguchi, M; Tezuka, H; Abe, H; Sakamoto, K

    1990-09-01

    Two cases of abdominal bronchogenic cyst were reported. In the first case, the cyst was communicated with gastric fundus and existed as gastric abscess. In the second case, the cyst showed high CT number and chemical analysis of the contents revealed high range of Ca, Fe and Amylase levels.

  12. Quantification of microvascular tortuosity during tumor evolution utilizing acoustic angiography

    PubMed Central

    Shelton, Sarah E.; Lee, Yueh Z.; Lee, Mike; Cherin, Emmanuel; Foster, F. Stuart; Aylward, Stephen R.; Dayton, Paul A.

    2016-01-01

    The recent design of ultra-broadband, multi-frequency 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 morphological analysis of tumor vessels demonstrated 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 a new tool in tumor detection, differentiation, or evaluation, though with limited depth of penetration using the current configuration. PMID:25858001

  13. Optical coherence angiography

    PubMed Central

    Wylęgała, Adam; Teper, Sławomir; Dobrowolski, Dariusz; Wylęgała, Edward

    2016-01-01

    Abstract Background: Retinal vascular diseases are one of the most common causes of blindness in the developed world. Optical Coherence Tomography Angiography (OCT-A) is a new noninvasive method that uses several algorithms to detect blood movement. This enables the creation of high-resolution vascular images with contrast depicting motionless tissue. Methods: This review presents the results of articles relevant to age-related macular degeneration (AMD), diabetic retinopathy (DR), and OCT-A. The OCT-A technique can successfully be used in the diagnosis of neovascularization, retinal vein occlusion (RVO) and retinal artery occlusion (RAO), vessel abnormalities and even anterior segment neovascularization. OCT-A can also be applied to compute data such as vessel density, and flow index in both superficial and deep plexuses. Results: Many studies have compared fluorescein angiography with OCT-A. Other studies have reported differences in vascular density in AMD patients and have compared them with people having healthy eyes. Although OCT-A offers rapid picture acquisition, high repeatability and resolution, it also has many drawbacks. The most common are: motion artifacts, projections from overlying vessels and limited field of view. An interesting new application is the possibility to assess changes during antivascular endothelial growth factor (anti-VEGF) therapy. Another function of OCT-A is the possible application in the study of choriocapillaries in many fields of ocular pathology. Conclusion: OCT-A is a new promising method that allows the visualization of the retinal vascular network and the counting of blood flow parameters. This technique provides reliable images useful in clinical routines. PMID:27741104

  14. Color Doppler ultrasonography of the abdominal aorta

    PubMed Central

    Battaglia, S.; Danesino, G.M.; Danesino, V.; Castellani, S.

    2010-01-01

    Alterations of the abdominal aorta are relatively common, particularly in older people. Technological advances in the fields of ultrasonography, computed tomography, angiography, and magnetic resonance imaging have greatly increased the imaging options for the assessment of these lesions. Because it can be done rapidly and is also non-invasive, ultrasonography plays a major role in the exploration of the abdominal aorta, from its emergence from the diaphragm to its bifurcation. It is indicated for the diagnosis and follow-up of various aortic diseases, especially aneurysms. It can be used to define the shape, size, and location of these lesions, the absence or presence of thrombi and their characteristics. It is also useful for monitoring the evolution of the lesion and for postoperative follow-up. However, its value is limited in surgical planning and in emergency situations. PMID:23396814

  15. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database

    SciTech Connect

    Petereit, D.; Mehta, M.; Turski, P.; Levin, A.; Strother, C.; Mistretta, C.; Mackie, R.; Gehring, M.; Kubsad, S.; Kinsella, T. )

    1993-01-15

    Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquanitfy flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60 and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none. Early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery an flow parameters should be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning. A single diagnostic test may therefore be used for diagnosis, radiosurgical treatment planning, follow-up, and treatment selection by identifying patients likely to respond early to radiosurgical management.

  16. Atrial myxomas and coronary angiography.

    PubMed

    Rafiq, Isma; Parthasarthy, H; Clark, C Grahame

    2010-07-01

    Coronary angiography is not an only important component of preoperative evaluation of the patient with underlying coronary artery disease but also diagnostic tool for delineating cardiac myxomas. This also serve as an important surgical anatomical marker. We present two cases which presented with repeated episode of chest pain, were found to have atrial blushing on coronary angiography subsequent confirmation of diagnosis of atrial myxoma on echocardiography. PMID:20578102

  17. A case of pancreatic arteriovenous malformation identified by investigating the cause of upper abdominal pain associated with acute pancreatitis.

    PubMed

    Sato, Kohei; Monden, Kazuteru; Ueki, Toru; Tatsukawa, Masashi; Sadamori, Hiroshi; Sakaguchi, Kousaku; Takakura, Norihisa

    2016-07-01

    A man in his 60s with epigastric pain was diagnosed with acute pancreatitis and subsequently recovered following conservative treatment. However, because of repeated upper abdominal pain and the formation of a pancreatic pseudocyst, he was transferred to our institution for evaluation. Dynamic computed tomography (CT) scanning confirmed abnormal vessels in the tail of the pancreas and early venous return to the splenic vein in the early arterial phase. Abdominal angiography revealed a racemose vascular network in the tail of the pancreas, confirming the presence of an arteriovenous malformation (AVM) in this region. This AVM was thought to be the cause of the acute pancreatitis, so a distal pancreatectomy was performed. The patient's postoperative course was uneventful, and there has been no recurrence at the 7-month postoperative follow-up. Surgical resection has a low recurrence rate and good outcome;thus, if a pancreatic AVM appears difficult to treat with conservative medical therapy, surgical resection appears to be the definitive treatment. PMID:27383106

  18. Coronary magnetic resonance angiography.

    PubMed

    Stuber, Matthias; Weiss, Robert G

    2007-08-01

    Coronary magnetic resonance angiography (MRA) is a powerful noninvasive technique with high soft-tissue contrast for the visualization of the coronary anatomy without X-ray exposure. Due to the small dimensions and tortuous nature of the coronary arteries, a high spatial resolution and sufficient volumetric coverage have to be obtained. However, this necessitates scanning times that are typically much longer than one cardiac cycle. By collecting image data during multiple RR intervals, one can successfully acquire coronary MR angiograms. However, constant cardiac contraction and relaxation, as well as respiratory motion, adversely affect image quality. Therefore, sophisticated motion-compensation strategies are needed. Furthermore, a high contrast between the coronary arteries and the surrounding tissue is mandatory. In the present article, challenges and solutions of coronary imaging are discussed, and results obtained in both healthy and diseased states are reviewed. This includes preliminary data obtained with state-of-the-art techniques such as steady-state free precession (SSFP), whole-heart imaging, intravascular contrast agents, coronary vessel wall imaging, and high-field imaging. Simultaneously, the utility of electron beam computed tomography (EBCT) and multidetector computed tomography (MDCT) for the visualization of the coronary arteries is discussed. PMID:17610288

  19. Association between abdominal aortic plaque and coronary artery disease

    PubMed Central

    Li, Wei; Luo, Songyuan; Luo, Jianfang; Liu, Yuan; Huang, Wenhui; Chen, Jiyan

    2016-01-01

    Objective Currently, the association between abdominal aortic plaques and coronary artery disease (CAD) has not yet been clarified clearly. The purpose of this study was to determine the prevalence of abdominal aortic plaques by ultrasound imaging and to explore its association with CAD in patients undergoing coronary angiography. Methods Between October 2014 and June 2015, a prospective study was conducted in the Department of Cardiology at Guangdong General Hospital, Guangzhou, People’s Republic of China. Ultrasound scanning of the abdominal aortas was performed in 1,667 consecutive patients undergoing coronary angiography. Clinical characteristics and coronary profile were collected from the patients. Results Of the 1,667 study patients (male, 68.9%; mean age, 63±11 years) undergoing coronary angiography, 1,268 had CAD. Compared with 399 patients without CAD, 1,268 patients with CAD had higher prevalence of abdominal aortic plaques (37.3% vs 17%, P<0.001). In multivariate analysis, abdominal aortic plaques served as independent factors associated with the presence of CAD (odds ratio =2.08; 95% confidence interval =1.50–2.90; P<0.001). Of the 1,268 patients with CAD, the prevalence of abdominal aortic plaques was 27.0% (98/363) in patients with one-vessel disease, 35.0% (107/306) in patients with two-vessel disease, and 44.7% (268/599) in patients with three-vessel disease. Stepwise increases in the prevalence of abdominal aortic plaque was found depending on the number of stenotic coronary vessels (P<0.001; P-value for trend <0.001). In an ordinal logistic regression model, abdominal aortic plaques served as independent factors associated with the severity of CAD according to the number of stenotic coronary vessels (P<0.001). Conclusion The prevalence of abdominal aortic plaques was higher in patients with CAD than in those without CAD. Abdominal aortic plaque was an independent factor associated with the presence and severity of CAD. PMID:27279740

  20. Noninvasive coronary artery angiography using electron beam computed tomography

    NASA Astrophysics Data System (ADS)

    Rumberger, John A.; Rensing, Benno J.; Reed, Judd E.; Ritman, Erik L.; Sheedy, Patrick F., II

    1996-04-01

    Electron beam computed tomography (EBCT), also known as ultrafast-CT or cine-CT, uses a unique scanning architecture which allows for multiple high spatial resolution electrocardiographic triggered images of the beating heart. A recent study has demonstrated the feasibility of qualitative comparisons between EBCT derived 3D coronary angiograms and invasive angiography. Stenoses of the proximal portions of the left anterior descending and right coronary arteries were readily identified, but description of atherosclerotic narrowing in the left circumflex artery (and distal epicardial disease) was not possible with any degree of confidence. Although these preliminary studies support the notion that this approach has potential, the images overall were suboptimal for clinical application as an adjunct to invasive angiography. Furthermore, these studies did not examine different methods of EBCT scan acquisition, tomographic slice thicknesses, extent of scan overlap, or other segmentation, thresholding, and interpolation algorithms. Our laboratory has initiated investigation of these aspects and limitations of EBCT coronary angiography. Specific areas of research include defining effects of cardiac orientation; defining the effects of tomographic slice thickness and intensity (gradient) versus positional (shaped based) interpolation; and defining applicability of imaging each of the major epicardial coronary arteries for quantitative definition of vessel size, cross-sectional area, taper, and discrete vessel narrowing.

  1. 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.

  2. Renal applications of dual-energy CT.

    PubMed

    Kaza, Ravi K; Platt, Joel F

    2016-06-01

    Dual-energy CT is being increasingly used for abdominal imaging due to its incremental benefit of material characterization without significant increase in radiation dose. Knowledge of the different dual-energy CT acquisition techniques and image processing algorithms is essential to optimize imaging protocols and understand potential limitations while using dual-energy CT renal imaging such as urinary calculi characterization, assessment of renal masses and in CT urography. This review article provides an overview of the current dual-energy CT techniques and use of dual-energy CT in renal imaging.

  3. A comparison study of radiation exposure to patients during EVAR and Dyna CT in an angiosuite vs. an operating theatre.

    PubMed

    Bruschi, Andrea; Michelagnoli, Stefano; Chisci, Emiliano; Mazzocchi, Silvia; Panci, Simone; Didona, Annamaria; Ghirelli, Alessandro; Zatelli, Giovanna

    2015-03-01

    The aim of this study was to assess the patient dosimetric impact of endovascular abdominal aortic aneurysm repair (EVAR), both in an operating theatre (OR) and in an angiosuite (AS), with the facility of Dynamic CT (Dyna CT, Siemens AG, Berlin, Germany). One hundred and forty-six consecutive EVAR procedures dating from May 2011 to March 2013 were analysed. These were performed either in an OR (n = 97) using a mobile C-arm or in an AS (n = 49) equipped with a ceiling-mounted angiography system. Air kerma area product (P(KA)) and total air kerma at reference point (K(a,r)) values were reported for all procedures and Dyna CT. Radiation exposure during EVAR was quite low in the majority of patients but nearly 50 % higher if performed in AS vs. OR. Median Dyna CT K(a,r) was the same as an entire EVAR procedure in OR. The higher patient's radiation exposure recorded in the AS should be balanced with the technical advantages given to the EVAR procedure.

  4. Abdominal cerebrospinal fluid pseudocysts.

    PubMed

    Erşahin, Y; Mutluer, S; Tekeli, G

    1996-12-01

    Abdominal cerebrospinal fluid pseudocyst in an infrequent complication of ventriculoperitoneal (VP) shunts. We reviewed ten patients with abdominal pseudocyst. There were five girls and five boys, aged between 4 months and 14 years. The number of shunt procedures prior to the presentation varied between one and five. Only one patient had had a previous shunt infection. No patients had undergone prior abdominal surgery other than VP shunting. The time from the last shunting procedure to the development of abdominal pseudocyst ranged from 3 weeks to 5 years. Presenting symptoms and signs were mainly related to abdominal complaints in all patients. Three patients also had signs of shunt malfunction. The diagnosis was made by ultrasound in all patients. Shunt infection was determined in six patients. Repositioning if the peritoneal catheter seemed to have a higher rate of recurrence. The diagnosis of abdominal pseudocyst should be considered in VP-shunted patients presenting with abdominal complaints.

  5. Abdominal Circulatory Interactions.

    PubMed

    Dagar, Gaurav; Taneja, Amit; Nanchal, Rahul S

    2016-04-01

    The abdominal compartment is separated from the thoracic compartment by the diaphragm. Under normal circumstances, a large portion of the venous return crosses the splanchnic and nonsplanchnic abdominal regions before entering the thorax and the right side of the heart. Mechanical ventilation may affect abdominal venous return independent of its interactions at the thoracic level. Changes in pressure in the intra-abdominal compartment may have important implications for organ function within the thorax, particularly if there is a sustained rise in intra-abdominal pressure. It is important to understand the consequences of abdominal pressure changes on respiratory and circulatory physiology. This article elucidates important abdominal-respiratory-circulatory interactions and their clinical effects. PMID:27016167

  6. Spiral CT Quantification of Aorto-Renal Calcification and Its Use in the Detection of Atheromatous Renal Artery Stenosis: A Study in 42 Patients

    SciTech Connect

    Gayard, Pierre; Garcier, Jean-Marc; Boire, Jean-Yves; Ravel, Anne; Perez, Nessim; Privat, Christian; Lucien, Pascal; Viallet, Jean-Francois; Boyer, Louis

    2000-01-15

    Purpose: To investigate whether a correlation exists between aortic and renal arterial calcifications detected with spiral CT and significant angiographic renal artery stenosis (RAS).Methods: Forty-two patients (mean age 67 years, range 37-84 years), of whom 24 were hypertensive, prospectively underwent abdominal helical CT and aortic and renal arteriography. The 3-mm thickness CT scans (pitch = 1) were reconstructed each millimeter. A manual outline of the renal artery including its ostial portion was produced. Calcific hyperdensities were defined as areas of density more than 130 HU. CT data were compared with the presence or absence of RAS on angiography (24 cases); hypertension and age were taken into account (Mann-Whitney U-test).Results: CT detection and quantification appeared to be reliable and reproductible. We did not find any correlation between aortic and renal arterial calcifications and RAS, even for the patients above 65 years, with or without hypertension. There was no correlation either between calcifications and hypertension in patients without RAS. Conclusion: In this population, aortic and renal arterial calcifications have no predictive value for RAS.

  7. [Indications for low-dose CT in the emergency setting].

    PubMed

    Poletti, Pierre-Alexandre; Andereggen, Elisabeth; Rutschmann, Olivier; de Perrot, Thomas; Caviezel, Alessandro; Platon, Alexandra

    2009-08-19

    CT delivers a large dose of radiation, especially in abdominal imaging. Recently, a low-dose abdominal CT protocol (low-dose CT) has been set-up in our institution. "Low-dose CT" is almost equivalent to a single standard abdominal radiograph in term of dose of radiation (about one sixth of those delivered by a standard CT). "Low-dose CT" is now used routinely in our emergency service in two main indications: patients with a suspicion of renal colic and those with right lower quadrant pain. It is obtained without intravenous contrast media. Oral contrast is given to patients with suspicion of appendicitis. "Low-dose CT" is used in the frame of well defined clinical algorithms, and does only replace standard CT when it can reach a comparable diagnostic quality.

  8. Surgical Repair of Abdominal Aortic and Renal Artery Aneurysms in Takayasu's Arteritis.

    PubMed

    Wetstein, Paul J; Clark, Margaret E; Cafasso, Danielle E; Golarz, Scott R; Ayubi, Farhan S; Kellicut, Dwight C

    2016-01-01

    Takayasu's arteritis is a large vessel vasculitis that can be a challenging diagnosis to make and has a varied clinical presentation. Management largely depends on affected vessel disease severity and individual patient considerations. The diagnosis must be considered in a young patient with large vessel aneurysms. We present a case of a 30 year-old woman of Pacific Islander descent who presented to the Tripler Army medical Center Vascular Surgery Department in Honolulu, Hawai'i seeking repair of her abdominal aortic and renal artery aneurysms prior to conception. A 30 year-old Pacific Islander woman with a history of a saccular abdominal aortic aneurysm and renal artery aneurysms presented to our clinic seeking vascular surgery consultation prior to a planned pregnancy. She had a renal artery stent placed at an outside institution for hypertension. She met the diagnosis of Takayasu's arteritis by Sharma's criteria. Physical exam was significant for a palpable, pulsatile, abdominal mass and CT angiography revealed a saccular irregular-appearing infra-renal abdominal aortic aneurysm, extending to the aortic bifurcation, with a maximum diameter of 3.3 cm. A right renal artery aneurysm was also identified proximally, contiguous with the aorta, with a maximal transverse diameter of 1.7 cm. The patient underwent a supraceliac bypass to the right renal artery with a 7 mm Dacron graft, as well as excision of the right renal artery aneurysm. The abdominal aortic aneurysm was replaced using a Hemashield Dacron bifurcated 14 mm x 7 mm bypass graft. Intraoperative measurements of the renal artery aneurysm were 1.5 x 1.5 cm and the saccular appearing distal abdominal aortic aneurysm measured 3.6 x 3.3 cm. The patient was discharged from the hospital 7 days post-operatively. At 1-year follow up, CT scan of the abdominal aorta revealed the repair was without any evidence of aneurysm formation, anastomotic pseudoaneurysm formation, or areas of stenosis. She has remained

  9. [Differential diagnosis of abdominal cysts in children].

    PubMed

    Józsa, Gergő; Mohay, Gabriella; Pintér, András; Vástyán, Attila

    2015-09-13

    19 children were diagnosed with abdominal cysts of different origin in the Surgical Unit of the Department of Pediatrics, Medical University of Pécs, Hungary between 2010 and 2013. The authors discuss the details of representative cases of a parovarial cyst, an intestinal duplication, and an omental cyst with emphasis on the clinical symptoms, diagnostic tools, and surgical interventions. The authors conclude that abdominal cysts often cause mild symptoms only, and they are discovered accidentally by ultrasound imaging performed for other reasons. In some cases, the cyst can cause severe complaints or even acute abdomen requiring emergency surgery. Laporoscopy may be a valuable method both in diagnosis and surgical therapy. Abdominal CT or MRI are not required in the majority of the patients.

  10. 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.

  11. Use of computerized tomography of the abdominal wall in the diagnosis of partial post-operative wound dehiscence.

    PubMed Central

    Smith-Behn, J.; Arnold, M.; Might, J.

    1986-01-01

    A patient had occult post-operative partial wound dehiscence which was accurately diagnosed by performing a CT scan of the abdomen. It is suggested that CT scan of the abdominal wall is useful for early diagnosis of occult abdominal wound dehiscence. Images Figure 1 Figure 2 PMID:2946035

  12. CT of schistosomal calcification of the intestine

    SciTech Connect

    Fataar, S.; Bassiony, H.; Satyanath, S.; Rudwan, M.; Hebbar, G.; Khalifa, A.; Cherian, M.J.

    1985-01-01

    The spectrum of schistosomal colonic calcification on abdominal radiographs has been described. The appearance on computed tomography (CT) is equally distinctive and occurs with varying degrees of genitourinary calcification. The authors have experience in three cases with the appearance on CT of intestinal calcification due to schistosomiasis.

  13. ECG gated tomographic reconstruction for 3-D rotational coronary angiography

    PubMed Central

    Hu, Yining; Xie, Lizhe; Nunes, Jean Claude; Bellanger, Jean Jacques; Bedossa, Marc; Toumoulin, Christine

    2010-01-01

    A method is proposed for 3-D reconstruction of coronary from a limited number of projections in rotational angiography. A Bayesian maximum a posteriori (MAP) estimation is applied with a Poisson distributed projection to reconstruct the 3D coronary tree at a given instant of the cardiac cycle. Several regularizers are investigated L0-norm, L1 and L2 -norm in order to take into account the sparsity of the data. Evaluations are reported on simulated data obtained from a 3D dynamic sequence acquired on a 64-slice GE LightSpeed CT scan. A performance study is conducted to evaluate the quality of the reconstruction of the structures. PMID:21096844

  14. Uncluttered single-image visualization of the abdominal aortic vessel tree: Method and evaluation

    SciTech Connect

    Won, Joong-Ho; Rosenberg, Jarrett; Rubin, Geoffrey D.; Napel, Sandy

    2009-11-15

    Purpose: The authors develop a method to visualize the abdominal aorta and its branches, obtained by CT or MR angiography, in a single 2D stylistic image without overlap among branches. Methods: The abdominal aortic vasculature is modeled as an articulated object whose underlying topology is a rooted tree. The inputs to the algorithm are the 3D centerlines of the abdominal aorta, its branches, and their associated diameter information. The visualization problem is formulated as an optimization problem that finds a spatial configuration of the bounding boxes of the centerlines most similar to the projection of the input into a given viewing direction (e.g., anteroposterior), while not introducing intersections among the boxes. The optimization algorithm minimizes a score function regarding the overlap of the bounding boxes and the deviation from the input. The output of the algorithm is used to produce a stylistic visualization, made of the 2D centerlines modulated by the associated diameter information, on a plane. The authors performed a preliminary evaluation by asking three radiologists to label 366 arterial branches from the 30 visualizations of five cases produced by the method. Each of the five patients was presented in six different variant images, selected from ten variants with the three lowest and three highest scores. For each label, they assigned confidence and distortion ratings (low/medium/high). They studied the association between the quantitative metrics measured from the visualization and the subjective ratings by the radiologists. Results: All resulting visualizations were free from branch overlaps. Labeling accuracies of the three readers were 93.4%, 94.5%, and 95.4%, respectively. For the total of 1098 samples, the distortion ratings were low: 77.39%, medium: 10.48%, and high: 12.12%. The confidence ratings were low: 5.56%, medium: 16.50%, and high: 77.94%. The association study shows that the proposed quantitative metrics can predict a reader

  15. Predictive parameters for angiography and embolization in the bleeding pelvic fracture

    PubMed Central

    Anandakumar, V.; Hussein, Fareed K.; Varuun, B.; Zhu, R.

    2013-01-01

    Aim In the bleeding pelvic fracture, decision needs to be made on definitive control of bleeding whilst resuscitation. The decision for angiography in unstable patients is difficult and this study hopes to identify the parameters that may aid in this decision. Methods 121 patients with traumatic pelvic fractures were identified from June 2005 till June 2010, from the National University Hospital, Singapore. Out of these 121 patients, 15 patients who underwent angiographic evaluation were identified. 11 out of the 15 had angiography and embolization done, while the remaining 4 only had angiography done. Another group of 29 patients who had not undergone angiography were identified from the main population via age-matched criteria. Clinical parameters were compared between the 15 angiography patients and the 29 non-angiography group of patients. Results Angiography group had a larger proportion (80%) with contrast blush noted on contrast-enhanced CT scan (CECT), a higher proportion with unstable pelvic fracture patterns as classified by Tile (80%), and Young and Burgess (92.4%) (p < 0.05). Embolized group had higher proportion (81.8%) with hematoma and with blush on CECT (100%), and higher proportion with unstable fracture patterns (UFPs) (72.7%) as classified by Tile (p < 0.05). Positive predictive value for embolization using hematoma alone is 39% while that of blush alone is 73% and unstable Tile fracture alone is 47%. Positive predictive value of combined hematoma, blush and unstable Tile fracture pattern is 75%. Conclusion Significant predictive factors for angiogram would be unstable pelvic fracture patterns, presence of hematoma and contrast blushing on CT. PMID:26403627

  16. Hydatidemesis: a bizarre presentation of abdominal hydatidosis.

    PubMed

    Thomas, S; Mishra, M C; Kriplani, A K; Kapur, B M

    1993-06-01

    A 31 year old male presented with high grade fever and abdominal pain of 20 days duration. At the age of 9 he had been operated on for a solitary retroperitoneal hydatid cyst and had been asymptomatic until the age of 21 when he sustained a blunt injury to the abdomen. An exploratory laparotomy for splenic rupture revealed multiple intra-abdominal hydatid cysts, which were removed. The patient remained well until the present episode. An ultrasound examination revealed multiple intra-abdominal hydatid cysts. Seven days after admission, the patient developed hydatidemesis (hydatid cysts and membranes in the vomitus) and hydatidenteria (passage of hydatid membranes in the stools), and his pain and fever subsided. A Gastrografin study and a computerized tomography (CT) scan revealed hydatid cysts communicating with the stomach and duodenum. In view of his disseminated recurrent abdominal hydatidosis, he was treated with high dose, long-term albendazole along with regular follow up. This is the first documented case of disseminated abdominal hydatidosis presenting with a cystogastric fistula and hydatidemesis.

  17. Acute intestinal anisakiasis: CT findings.

    PubMed

    Ozcan, H N; Avcu, S; Pauwels, W; Mortelé, K J; De Backer, A I

    2012-09-01

    Small bowel anisakiasis is a relatively uncommon disease that results from consumption of raw or insufficiently pickled, salted, smoked, or cooked wild marine fish infected with Anisakis larvae. We report a case of intestinal anisakiasis in a 63-year-old woman presenting with acute onset of abdominal complaints one day after ingestion of raw wild-caught herring from the Northsea. Computed tomography (CT) scanning demonstrated thickening of the distal small bowel wall, mucosa with hyperenhancement, mural stratification, fluid accumulation within dilated small-bowel loops and hyperemia of mesenteric vessels. In patients with a recent history of eating raw marine fish presenting with acute onset of abdominal complaints and CT features of acute small bowel inflammation the possibility of anisakiasis should be considered in the differential diagnosis of acute abdominal syndromes.

  18. Abdominal aortic aneurysm.

    PubMed

    Keisler, Brian; Carter, Chuck

    2015-04-15

    Abdominal aortic aneurysm refers to abdominal aortic dilation of 3.0 cm or greater. The main risk factors are age older than 65 years, male sex, and smoking history. Other risk factors include a family history of abdominal aortic aneurysm, coronary artery disease, hypertension, peripheral artery disease, and previous myocardial infarction. Diagnosis may be made by physical examination, an incidental finding on imaging, or ultrasonography. The U.S. Preventive Services Task Force released updated recommendations for abdominal aortic aneurysm screening in 2014. Men 65 to 75 years of age with a history of smoking should undergo one-time screening with ultrasonography based on evidence that screening will improve abdominal aortic aneurysm-related mortality in this population. Men in this age group without a history of smoking may benefit if they have other risk factors (e.g., family history of abdominal aortic aneurysm, other vascular aneurysms, coronary artery disease). There is inconclusive evidence to recommend screening for abdominal aortic aneurysm in women 65 to 75 years of age with a smoking history. Women without a smoking history should not undergo screening because the harms likely outweigh the benefits. Persons who have a stable abdominal aortic aneurysm should undergo regular surveillance or operative intervention depending on aneurysm size. Surgical intervention by open or endovascular repair is the primary option and is typically reserved for aneurysms 5.5 cm in diameter or greater. There are limited options for medical treatment beyond risk factor modification. Ruptured abdominal aortic aneurysm is a medical emergency presenting with hypotension, shooting abdominal or back pain, and a pulsatile abdominal mass. It is associated with high prehospitalization mortality. Emergent surgical intervention is indicated for a rupture but has a high operative mortality rate. PMID:25884861

  19. 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

  20. [Abdominal compartment syndrome].

    PubMed

    Pottecher, T; Segura, P; Launoy, A

    2001-04-01

    French physicians dealing with abdominal emergencies are not very familiar with the abdominal compartment syndrome (ACS). Increased abdominal pressure has deleterious consequences on local (intestine, liver, kidney) circulation, leading to death in the absence of correct treatment. Abdominal trauma and ruptured aortic aneurism are the main causes of ACS. Clinical presentation may be misleading: respiratory failure, oliguria or circulatory symptoms are often predominant. Abdominal palpation is inefficient for evaluating intra-abdominal pressure (IAP); only measurement of cystic pressure allows precise evaluation of IAP. Abdominal decompression is the treatment of choice. It must be performed as soon as IAP exceeds 25 mmHg. The procedure may be risky with a high incidence of severe complications when ischaemic territories are reperfused. Recent data underline the importance of compensation of hypovolemia before decompression. Abdominal closure may necessitate various techniques (aponevrotomy, Bogota bags, etc.). At any rate, IAP must remain low at the end of the procedure. In case of suspicion of ACS, early measurement of IAP is mandatory. If pressure is over 25 mmHg, a decompressive procedure must be initiated. PMID:11340703

  1. A 10-year restrospective evaluation of ultrasound in pregnant abdominal trauma patients.

    PubMed

    Meisinger, Quinn C; Brown, Michele A; Dehqanzada, Zia A; Doucet, Jay; Coimbra, Raul; Casola, Giovanna

    2016-04-01

    The pregnant abdominal trauma patient presents a unique diagnostic challenge. This study aimed to evaluate the accuracy of abdominal sonography for the detection of clinically important injuries in pregnant abdominal trauma patients. A retrospective review was performed of a trauma center database from 2001 to 2011. Medical records were reviewed to determine initial abdominal imaging test results and clinical course. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound for detection of traumatic injury were calculated. Of 19,128 patients with suspected abdominal trauma, 385 (2 %) were pregnant. Of these, 372 (97 %) received ultrasound as the initial abdominal imaging test. All 13 pregnant patients who did not receive ultrasound received abdominal CT. Seven pregnant patients underwent both ultrasound and CT. Seven ultrasound examinations were positive, leading to one therapeutic Cesarean section and one laparotomy. One ultrasound was considered false positive (no injury was seen on subsequent CT). There were 365 negative ultrasound examinations. Of these, 364 were true negative (no abdominal injury subsequently found). One ultrasound was considered false negative (a large fetal subchorionic hemorrhage seen on subsequent dedicated obstetrical ultrasound). Sensitivity and positive predictive value were 85.7 %. Specificity and negative predictive value were 99.7 %. Abdominal sonography is an effective and sufficient imaging examination in pregnant abdominal trauma patients. When performed as part of the initial assessment using an abbreviated trauma protocol with brief modifications for pregnancy, ultrasound minimizes diagnostic delay, obviates radiation risk, and provides high sensitivity for injury in the pregnant population.

  2. [Semeiotics of abdominal tuberculosis].

    PubMed

    Guseĭnov, G K; Ramazanova, A M; Guseĭnov, A G

    1984-01-01

    Examination of 119 patients with abdominal tuberculosis permitted the description of the characteristic semiotics of the illness. Today the patients with abdominal tuberculosis are mainly women of child-bearing age with a long-term tuberculosis catamnesis and intoxication, with a history of tuberculosis of different sites, those suffering from tuberculosis or its sequels at present (64%), those with pains (94%), discomfort or swelling of the abdomen (79%), malfunction of the gastrointestinal tract (65%), weight loss (86%), malnutrition (72%), anemia (63%), not infrequently with inflammatory induration (43%) or ascites in the abdominal cavity (39%). In addition to this characteristic semiotics, the patients with abdominal tuberculosis may demonstrate the most different and unexpected symptoms up to acute abdomen (23%). To make differential diagnosis of abdominal tuberculosis, one has often to resort to diagnostic laparotomy, laparoscopy, Koch's test and to trial therapy.

  3. 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

  4. 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.

  5. Coronary artery aneurysms and ectasia: role of coronary CT angiography.

    PubMed

    Díaz-Zamudio, Mariana; Bacilio-Pérez, Ulises; Herrera-Zarza, Mary C; Meave-González, Aloha; Alexanderson-Rosas, Erick; Zambrana-Balta, Greby F; Kimura-Hayama, Eric T

    2009-11-01

    Coronary artery dilatations-aneurysms and ectasia-are an uncommon and frequently unrecognized incidental finding in patients with coronary artery disease. Aneurysms and ectasia are associated with a vast group of disorders, and the evaluation and characterization of coronary aneurysms and ectasia represent a great diagnostic task with clinical and therapeutic implications. The underlying etiology is variable and includes degenerative, congenital, inflammatory, infectious, toxic, and traumatic causes. Unlike aneurysms, ectasia is more frequently seen in association with atherosclerosis or as a compensatory mechanism in those cases in which a proximal stenosis is noted in the opposite coronary artery; ectasia is also seen in some coronary artery anomalies, such as anomalous origin from the pulmonary artery, or as a result of a high-flow state, as seen in coronary artery fistulas. The diagnostic approach depends on the clinical scenario, and nowadays, noninvasive evaluation with multidetector computed tomography is possible. Imaging assessment should include evaluation of (a) the distribution, (b) maximal diameter, (c) presence or absence of intraluminal thrombi, (d) number, (e) extension, and (f) associated complications such as myocardial infarction. This article presents an overview of the definition, classification, etiology, clinical manifestations, and potential complications of coronary artery aneurysms and ectasia.

  6. 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.

  7. Pulmonary Thromboembolism: Evaluation By Intravenous Angiography

    NASA Astrophysics Data System (ADS)

    Pond, Gerald D.; Cook, Glenn C.; Woolfenden, James M.; Dodge, Russell R.

    1981-11-01

    Using perfusion lung scans as a guide, digital video subtraction angiography of the pulmonary arteries was performed in human subjects suspected of having pulmonary embolism. Dogs were employed as a pulmonary embolism model and both routine pulmonary angiography and intravenous pulmonary angiograms were obtained for comparison purposes. We have shown by our preliminary results that the technique is extremely promising as a safe and accurate alternative to routine pulmonary angiography in selected patients.

  8. Evaluation of computed tomography in patients with atypical angina or chest pain clinically referred for invasive coronary angiography: randomised controlled trial

    PubMed Central

    Rief, Matthias; Martus, Peter; Kendziora, Benjamin; Feger, Sarah; Dreger, Henryk; Priem, Sascha; Knebel, Fabian; Böhm, Marko; Schlattmann, Peter; Hamm, Bernd; Schönenberger, Eva; Laule, Michael; Zimmermann, Elke

    2016-01-01

    Objective To evaluate whether invasive coronary angiography or computed tomography (CT) should be performed in patients clinically referred for coronary angiography with an intermediate probability of coronary artery disease. Design Prospective randomised single centre trial. Setting University hospital in Germany. Participants 340 patients with suspected coronary artery disease and a clinical indication for coronary angiography on the basis of atypical angina or chest pain. Interventions 168 patients were randomised to CT and 172 to coronary angiography. After randomisation one patient declined CT and 10 patients declined coronary angiography, leaving 167 patients (88 women) and 162 patients (78 women) for analysis. Allocation could not be blinded, but blinded independent investigators assessed outcomes. Main outcome measure The primary outcome measure was major procedural complications within 48 hours of the last procedure related to CT or angiography. Results Cardiac CT reduced the need for coronary angiography from 100% to 14% (95% confidence interval 9% to 20%, P<0.001) and was associated with a significantly greater diagnostic yield from coronary angiography: 75% (53% to 90%) v 15% (10% to 22%), P<0.001. Major procedural complications were uncommon (0.3%) and similar across groups. Minor procedural complications were less common in the CT group than in the coronary angiography group: 3.6% (1% to 8%) v 10.5% (6% to 16%), P=0.014. CT shortened the median length of stay in the angiography group from 52.9 hours (interquartile range 49.5-76.4 hours) to 30.0 hours (3.5-77.3 hours, P<0.001). Overall median exposure to radiation was similar between the CT and angiography groups: 5.0 mSv (interquartile range 4.2-8.7 mSv) v 6.4 mSv (3.4-10.7 mSv), P=0.45. After a median follow-up of 3.3 years, major adverse cardiovascular events had occurred in seven of 167 patients in the CT group (4.2%) and six of 162 (3.7%) in the coronary angiography group (adjusted hazard

  9. [Echocardiographic gating in non-cardiac digital angiography].

    PubMed

    Gattoni, F; Baldini, U; Cairo, F; Nessi, R; Pozzato, C; Uslenghi, C

    1987-03-01

    This paper reports the results of the ECG-gating in non-cardiac digital subtraction angiography (DSA). One hundred and fifteen patients underwent DSA (126 examinations); ECG-gating was applied in 66/126 examinations: images recorded at 70% of R wave were subtracted. Artifacts produced by vascular movements were evaluated in all patients: only 40 examinations, carried out without ECG-gating, showed vascular artifacts. The major advantage of the ECG-gated DSA is the more efficient subtraction because of the better images superimposition: therefore, ECG-gating can be clinically helpful. On the contrary, it could be a problem in arrhythmic or bradycardic patients. ECG-gating is helpful in DSA imaging of the thoracic and abdominal aorta and of the cervical and renal arteries. In the examinations of peripheral vessels of the limbs it is not so efficient as in the trunk or in the neck.

  10. Abdominal ultrasound (image)

    MedlinePlus

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X-ray, MRI, ... it has its place as a diagnostic tool. Ultrasound scans use high frequency sound waves to produce ...

  11. 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 ...

  12. Abdominal Kaposiform Hemangioendothelioma Associated With Lymphangiomatosis Involving Mesentery and Ileum

    PubMed Central

    Dong, Aisheng; Zhang, Ling; Wang, Yang; He, Tianlin; Zuo, Changjing

    2016-01-01

    Abstract Kaposiform hemangioendothelioma (KH) is a rare vascular tumor of intermediate malignancy that occurs mainly in the childhood. Adult patients with KH are rare. Imaging findings of KH have rarely been reported before. We present magnetic resonance imaging (MRI), computed tomography (CT), and fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT findings in an adult patient with KH associated with lymphangiomatosis involving mesentery and ileum. A 22-year-old female complained of a 9-month history of intermittent melena, weakness, and palpitation. Laboratory tests revealed anemia and hypoproteinemia. Fecal occult blood test was positive. Abdominal enhanced MRI and CT showed a large abdominal mass involving mesentery and ileum. On enhanced MRI, there were many hypervascular nodules in the mass. On FDG PET/CT, the mass and the nodules showed slight FDG uptake. Small bowel capsule endoscopy showed numerous grape-shaped red nodules in the luminal wall of the involved ileum. The patient underwent resection of the abdominal mass and a segment of the ileum invaded by the abdominal mass. KH arising within lymphangiomatosis involving mesentery and ileum was confirmed by pathology. After surgery, the patient's symptoms improved. This is the first case of KH associated with lymphangiomatosis involving mesentery and ileum. In this case, the lymphangiomatosis overshadowed the small tumor nodules resulting in unusual imaging findings. Familiarity with these imaging findings is helpful for diagnosis and differential diagnosis of KH. PMID:26871848

  13. Myxoid Liposarcoma in the Abdominal Wall

    PubMed Central

    Fan, Zhe; Tian, Xiao Feng; Tang, Shun Xiong; Zhang, Ying Yi; Pan, Ji Yong; Wang, Shuang

    2014-01-01

    Abstract A liposarcoma is the most common type of soft tissue sarcoma, and most liposarcomas are malignant. The extremities are the most common site for liposarcomas. There are 5 histologic types of liposarcoma, as follows: well differentiated; myxoid; round cell; pleomorphic; and dedifferentiated. Myxoid liposarcomas (MLSs) represent a subgroup of liposarcomas. There has been no report of MLSs in the abdominal wall. We report a rare case of a MLS of a 43-year-old male who presented with tensile force on the abdominal wall. Computed tomography (CT) found a tumor in abdominal wall. There was no other abnormal symptom and the laboratory testing was also unusual. At last, the tumor was successfully excised, which was diagnosed MLSs in pathology. Following standard principles, after complete excision, the patient received radiotherapy. The patient was followed up for 8 month and no disease recurrence was identified. MLSs are rarely seen in the clinic, irrespective of the presenting signs, but also based on histologic features. The aim of this report was to present the differential diagnosis of an abdominal wall mass, and to remind us of MLSs. PMID:25526446

  14. Coronary artery WSS profiling using a geometry reconstruction based on biplane angiography.

    PubMed

    Goubergrits, Leonid; Wellnhofer, Ernst; Kertzscher, Ulrich; Affeld, Klaus; Petz, Christoph; Hege, Hans-Christian

    2009-04-01

    Computational fluid dynamics (CFD) methods based on three-dimensional (3D) vessel reconstructions have recently been shown to provide prognostically relevant hemodynamic data. However, the geometry reconstruction and the assessment of clinically relevant hemodynamic parameters may depend on the used imaging modality. In this study, the silicon model of the left coronary artery (LCA) was acquired with a biplane angiography. The geometry reconstruction was done using commercial CAAS 5.2 QCA 3D software and compared with an original geometry. The original model is an optically digitized post-mortem vessel cast. The biplane angiography reconstruction achieved a Hausdorff surface distance of 0.236 mm to the original geometry that is comparable with results obtained in our earlier study for computed tomography (CT) and magnetic resonance imaging (MRI) reconstructions. Steady flow simulations were performed with a commercial CFD program FLUENT. A comparison of the calculated wall shear stress (WSS) shows good correlation for histograms (r=0.97) and good agreement among the four modalities with a mean WSS of 0.65 Pa in the original model, of 0.68 Pa in the CT-based model, of 0.67 Pa in the MRI based model, and of 0.69 Pa in the biplane angiography-based model. We can conclude that the biplane angiography-based reconstructions can be used for the WSS profiling of the coronary arteries.

  15. 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

  16. 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.

  17. Acute renal infarction: an unusual cause of abdominal pain.

    PubMed

    Javaid, Muhammad M; Butt, Mohammed A; Syed, Yadullah; Carr, Patrick

    2009-01-01

    Acute renal infarction is an uncommon and under-diagnosed disease. Its clinical presentation is nonspecific and often mimics other more common disease entities. The diagnosis is usually missed or delayed, which frequently results in irreversible renal parenchyma damage. High index of suspicion is required for early diagnosis, as timely intervention may prevent loss of kidney function. We report a case of acute renal infarction following coronary angiography in a patient with paroxysmal atrial fibrillation who initially presented with acute abdominal pain mimicking appendicitis.

  18. Study on the anatomy of the lumbosacral anterior great vessels pertinent to L5/S1 anterior interbody surgery with computer tomography angiography.

    PubMed

    Liu, Liehua; Liang, Yong; Zhou, Qiang; Zhang, Hong; Wang, Haoming; Li, Songtao; Zhao, Chen; Hou, Tianyong; Liu, Ling

    2014-12-01

    We investigate the anatomy of the lumbosacral anterior great vessels using computer tomography (CT) angiography before L5/S1 anterior interbody surgery. Sixty-two adult patients were selected. The location of the abdominal aortic bifurcation and common iliac venous confluence in the lumbar vertebrae and the anatomic parameters of the iliac vascular space (e.g., distances from the included angle vertex of the iliac vascular space to the median sagittal plane and to the inferior boundary of L5 and distances between the left and right iliac vessels on the inferior boundary of L5 and on the superior boundary of S1) were analysed. Overall, 67.73% of the 62 cases had an abdominal aortic bifurcation located at L4 and L4/5 intervertebral disc; 61.29%, the common iliac venous confluence located at L5. The four distances mentioned above were 0.98 cm ± 0.38 cm, 2.01 cm ± 1.26 cm, 3.11 cm ± 1.35 cm and 4.34 cm ± 1.10 cm, respectively. A classification system of types A, B and C was developed. The calculated L5/S1 intervertebral space exposure percentages of types A, B and C were 32.21%, 82.58% and 54.68%, respectively. During L5/S1 anterior interbody surgery, type B intervertebral discs can be exposed conveniently, preventing injury of the iliac vessels, which was also observed in 54.68% and 32.21% of the type C and type A discs, respectively. Because the type A intervertebral disc has minimal exposure, the risk of iliac vascular injury is relatively high in these patients.

  19. Lymphangioleiomyomatosis: pulmonary and abdominal findings with pathologic correlation.

    PubMed

    Pallisa, Esther; Sanz, Pilar; Roman, Antonio; Majó, Joaquim; Andreu, Jordi; Cáceres, José

    2002-10-01

    Lymphangioleiomyomatosis (LAM) is a rare disease characterized by pulmonary cysts at computed tomography (CT) and proliferation of abnormal smooth muscle cells at lung biopsy. Almost all patients are female, and all have pulmonary cysts at high-resolution CT. Although the presence of cysts may be suggested at conventional CT or chest radiography, high-resolution CT is superior for cyst detection and is essential for diagnosis. The cysts are typically round; in most cases, the cyst wall is barely seen at thin-section CT. They are typically diffusely distributed throughout the central and peripheral lung parenchyma. The lung bases are affected in all patients. Some patients also have increased lung attenuation or a reticular pattern. Expiratory CT shows no air trapping between the cysts, and most of the cysts decrease in size. Pneumothorax, pleural effusion, and chylothorax are complications of LAM. Certain abdominal findings may provide additional corroborative evidence of the diagnosis. Renal angiomyolipomas, the most frequent abdominal lesions, usually manifest as asymptomatic, small, bilateral tumors of fat attenuation in the renal cortex. Lymphangiomas are cystic retroperitoneal masses that occur in up to 20% of patients. Other CT findings are hypo- or hyperattenuating lymph nodes, a dilated thoracic duct, and ascites.

  20. Combined transdiaphragmatic off-pump and minimally invasive coronary artery bypass with right gastroepiploic artery and abdominal aortic aneurysm repair

    PubMed Central

    Gürer, Onur; Haberal, Ismail; Ozsoy, Deniz

    2013-01-01

    Patient: Male, 74 Final Diagnosis: Abdominal aortic aneurysm (AAA) Symptoms: Palpable abdominal mass Medication: — Clinical Procedure: Abdominal aortic aneurysm repair Specialty: Surgery Objective: Rare disease Background: Coronary artery disease is common in elderly patients with abdominal aortic aneurysms. Here we report a case of the combination of surgical repair for abdominal aortic aneurysm and off-pump and minimally invasive coronary artery bypass surgery. Case Report: A 74-year-old man who presented at our clinic with chest pain was diagnosed with an abdominal aortic aneurysm. His medical history included right coronary artery stenting. Physical examination revealed a pulsatile abdominal mass on the left side and palpable peripheral pulses. Computed tomography scans showed an infrarenal abdominal aneurysm with a 61-mm enlargement. Coronary angiography revealed 80% stenosis in the stent within the right coronary artery and 20% stenosis in the left main coronary artery. The patient underwent elective coronary artery bypass grafting and abdominal aortic aneurysm repair. Abdominal aortic aneurysm repair and transdiaphragmatic off-pump and minimal invasive coronary artery bypass grafting with right gastroepiploic artery were performed simultaneously in a single surgery. Conclusions: We report this case to emphasize the safety and effectiveness of transdiaphragmatic off-pump and minimally invasive coronary artery bypass surgery with abdominal aortic aneurysm repair. This combined approach shortens hospital stay and decreases cost. PMID:23997852

  1. [Angiography of urotuberculosis (author's transl)].

    PubMed

    Klein, U; Eisenberger, F; Heinze, H G; Lissner, J; Pfeifer, K J; Runte, R; Thym, W

    1976-06-01

    119 kidneys demonstrating changes consistent with renal tuberculosis were studied in a total of 94 patients by means of selective, transfemoral renal antiography. In the first stage of the disease, this method detected parenchymal involvement which could not be visualized by excretory urography. In stage II the arcuate arteries and occasionally the intralobular arteries, showed typical changes. Cavitation, pathognomonic for the presence of renal tuberculosis were found in 39.3% of these cases. In 40% of the cases the angiographic findingd were more extensive than the apparent findings of excretory urography. Angiography, thus, can render valuable information pertaining to the course of the disease and the necessity of operative intervention. Stage III was usually characterized by extensive changes specific for parenchymal destruction. Typical vascular lesions were readily recognized. Cavitation was found in 86.5% of these cases. Tortuosity and dilatation of the renal pelvis- and/or ureter-arteries revealed evidence of ureteral involvement (stage III2). In the presence of a non-functioning kidney angiography is mandatory to rule out renal aplasia and to differentiate between a kidney destroyed by other disease processes and the complete cavitary destruction of end-stage renal tuberculosis (stage III3). PMID:959508

  2. [Pheochromocytoma with retroperitoneal hemorrhage after abdominal trauma].

    PubMed

    Hayashi, Takuji; Nin, Mikio; Yamamoto, Yoshiyuki; Kamoto, Akihito; Ujike, Takeshi; Nishimura, Kensaku; Miyoshi, Susumu

    2009-11-01

    A 35-year-old man was delivered to the emergency room complaining of right flank pain because of blunt abdominal trauma sustained while playing baseball. Enhanced computed tomography (CT) revealed a right adrenal mass and fluid collection around the mass. We diagnosed the mass as pheochromocytoma by endocrinological examination and radioisotopical imaging test. After absorption of the hematoma three months after the injury, laparoscopic right adrenalectomy was performed. He had an uncomplicated postoperative course without supplementation of catecholamine. Pathological findings were compatible with pheochromocytoma. Eight months after the operation, he had no evidence of recurrence.

  3. Large posterior abdominal masses: computed tomographic localization.

    PubMed

    Engel, I A; Auh, Y H; Rubenstein, W A; Whalen, J P; Kazam, E

    1983-10-01

    Large posterior abdominal masses, particularly those in the right upper abdomen, may be difficult to localize correctly into the peritoneal or retroperitoneal compartments. The following signs were found to be reliable CT indicators of retroperitoneal location: obliteration of the perinephric fat outlining the psoas muscle; lateral displacement of the fat outlining the posterior right lobe of the liver; rotation of the intrahepatic portal veins to the left; anterior displacement of the inferior vena cava and renal veins; and anterior displacement of the ascending colon, descending duodenum, or pancreatic head.

  4. Celiac Axis, Common Hepatic and Hepatic Artery Variants as Evidenced on MDCT Angiography in South Indian Population

    PubMed Central

    Parthasarathy, Ramesh

    2016-01-01

    Introduction With the increase in the hepatobiliary, pancreatic surgeries and liver transplantation, being aware of the anatomic variations of the celiac axis and the hepatic arteries is of paramount importance. Aim To illustrate the normal anatomy and variants of the celiac axis and the hepatic arteries with multidetector computed tomographic (MDCT) angiography in South Indian population and determine the potential variations in the celiac axis anatomy and the hepatic arteries, thus assisting the hepatobiliary surgeon and the interventional radiologist in avoiding iatrogenic injury to the arteries. Materials and Methods Two hundred patients undergoing abdominal CT angiography from July 2014 till July 2015 were retrospectively studied for hepatic arterial and celiac axis anatomical variation. The anatomic variations in our study were correlated with other studies. Results The celiac axis (CA) and the hepatic artery (HA) variations were analysed as per criteria laid by Song et al., and Michel. Out of 15 possible CA variations, 5 types of celiac artery variations were seen in 14 patients. A normal CA was seen in 179(89.5%) patients of the 200 patients. In the remaining 7 patients, the CA anatomy was classified as ambiguous since there was separate origin of the right and left hepatic arteries from the CA with absent common hepatic artery (CHA). The CHA originated normally from the celiac axis in 94% of the cases. Variation of CHA origin was seen in 5 patients. Normal HA anatomy was seen in 114 (57%) patients. Variation in HA anatomy was seen in 86 (43%) patients. Origin of the right hepatic artery (RHA) from the hepatic artery proper was seen in 182 (91%) patients and replaced origin of RHA from the superior mesenteric artery (SMA) was seen in 18 (9%) of the cases. Accessory RHA was seen in 7(3.5%) patients. The left hepatic artery (LHA) originated from the hepatic artery proper in 186 (93%) patients and replaced origin of LHA from the left gastric artery (LGA) was

  5. [The correlation between measurements performed by intravascular echography and quantitative digital angiography in large- and small-caliber arteries].

    PubMed

    Zamorano, J; Macaya, C; Alfonso, F; Goicolea, J; Iñíguez, A; Hernández-Antolín, R A; Ge, J; Zarco, P; Erbel, R; Meyer, J

    1992-04-01

    Intravascular ultrasound is a new promising technique that appears as a very useful complement to standard angiography in the study of atherosclerosis. Specifically, intravascular ultrasound provides by itself, information of great value concerning vessel wall characteristics. Nevertheless, before taking any decision with the results provided by this new technique, we must validate this information with that provided by other more conventional techniques like standard angiography. Accordingly, we have analyzed in 25 patients, 50 images of the abdominal aorta and 77 images of the coronary arteries taken from arterial segments free of atherosclerotic involvement. With the use of a calibrated small grid located over the patient's thorax, we have analyzed "in the same points" the images obtained with intravascular ultrasound and those provided by contrast angiography using a quantitative angiographic analysis. In the abdominal aorta the vessel diameter measured by intravascular ultrasound and angiography was 17.8 +/- 0.39 mm vs 18.6 +/- 0.42 mm (NS), whereas in the coronary arteries it was 2.76 +/- 0.39 mm vs 2.98 +/- 0.37 mm (NS), respectively. The correlation between both techniques was good for both types of arteries (r = 0.93 in the abdominal aorta and r = 0.87 in the coronary arteries). We conclude, that in our experience and with the methodology used, there is a good correlation between the measurements of the vessel diameters obtained by both intravascular ultrasound and digital angiography in arteries of different sizes, being the correlation even better in large arteries.

  6. 3D image analysis of abdominal aortic aneurysm

    NASA Astrophysics Data System (ADS)

    Subasic, Marko; Loncaric, Sven; Sorantin, Erich

    2002-05-01

    This paper presents a method for 3-D segmentation of abdominal aortic aneurysm from computed tomography angiography images. The proposed method is automatic and requires minimal user assistance. Segmentation is performed in two steps. First inner and then outer aortic border is segmented. Those two steps are different due to different image conditions on two aortic borders. Outputs of these two segmentations give a complete 3-D model of abdominal aorta. Such a 3-D model is used in measurements of aneurysm area. The deformable model is implemented using the level-set algorithm due to its ability to describe complex shapes in natural manner which frequently occur in pathology. In segmentation of outer aortic boundary we introduced some knowledge based preprocessing to enhance and reconstruct low contrast aortic boundary. The method has been implemented in IDL and C languages. Experiments have been performed using real patient CTA images and have shown good results.

  7. [Abdominal actinomycosis: four cases].

    PubMed

    Ghannouchi Jaafoura, N; Kaabia, N; Khalifa, M; Ben Jazia, I; Hachfi, W; Braham, A; Letaief, A; Bahri, F

    2008-12-01

    The abdominal actinomycosis (AA) is a rare and often unrecognised suppurative chronic illness. It is caused by an anaerobic Gram positive bacteria, Actinomyces israelii. Abdominal actinomycosis is responsible for pseudotumoral syndrome often leading, to a large and mutilating surgery whereas a prolonged treatment by antibiotics would have permitted to cure the disease. The diagnosis is obtained generally from anatomopathologic exam. We report four cases of abdominal actinomycosis being revealed by a pseudotumoral syndrome. The diagnosis was only made after surgery. In spite of an active treatment by antibiotics during several months, two of our patients had a relapse of the infectious process. These four observations confirm the diagnostic and therapeutic difficulties previously reported by other authors.

  8. Negative predictive value of preoperative computed tomography in determining pathologic local invasion, nodal disease, and abdominal metastases in gastric cancer

    PubMed Central

    Kagedan, D.J.; Frankul, F.; El-Sedfy, A.; McGregor, C.; Elmi, M.; Zagorski, B.; Dixon, M.E.; Mahar, A.L.; Vasilevska-Ristovska, J.; Helyer, L.; Rowsell, C.; Swallow, C.J.; Law, C.H.; Coburn, N.G.

    2016-01-01

    Background Before undergoing curative-intent resection of gastric adenocarcinoma (ga), most patients undergo abdominal computed tomography (ct) imaging to determine contraindications to resection (local invasion, distant metastases). However, the ability to detect contraindications is variable, and the literature is limited to single-institution studies. We sought to assess, on a population level, the clinical relevance of preoperative ct in evaluating the resectability of ga tumours in patients undergoing surgery. Methods In a provincial cancer registry, 2414 patients with ga diagnosed during 2005–2008 at 116 institutions were identified, and a primary chart review of radiology, operative, and pathology reports was performed for all patients. Preoperative abdominal ct reports were compared with intraoperative findings and final pathology reports (reference standard) to determine the negative predictive value (npv) of ct in assessing local invasion, nodal involvement, and intra-abdominal metastases. Results Among patients undergoing gastrectomy, the npv of ct imaging in detecting local invasion was 86.9% (n = 536). For nodal metastasis, the npv of ct was 43.3% (n = 450). Among patients undergoing surgical exploration, the npv of ct for intra-abdominal metastases was 52.3% (n = 407). Conclusions Preoperative abdominal ct imaging reported as negative is most accurate in determining local invasion and least accurate in nodal assessment. The poor npv of ct should be taken into account when selecting patients for staging laparoscopy. PMID:27536178

  9. Intra-Abdominal Hematoma Following Enoxaparin Injection.

    PubMed

    Chung, Kin Tong

    2016-01-01

    An elderly patient, who was being treated for therapeutic enoxaparin for a couple of days due to suspected deep vein thrombosis, was admitted to hospital following a collapse and severe abdominal pain. She was in hypovolemic shock and was fluid resuscitated. Ultrasound scan and computed tomography (CT) scan showed a large pelvic hematoma. Radiologists also suspected a possibility of bleeding from inferior epigastric artery following a CT angiogram. The patient was stabilized and transferred to intensive care unit (ICU) for further hemodynamic supports and close monitoring. The patient was then transferred back to the general ward when she was stable. She was managed conservatively as there were no more signs of active bleeding. Unfortunately, she died of recurrent bleeding three days after ICU discharge. PMID:27158226

  10. Intra-Abdominal Hematoma Following Enoxaparin Injection

    PubMed Central

    Chung, Kin Tong

    2016-01-01

    An elderly patient, who was being treated for therapeutic enoxaparin for a couple of days due to suspected deep vein thrombosis, was admitted to hospital following a collapse and severe abdominal pain. She was in hypovolemic shock and was fluid resuscitated. Ultrasound scan and computed tomography (CT) scan showed a large pelvic hematoma. Radiologists also suspected a possibility of bleeding from inferior epigastric artery following a CT angiogram. The patient was stabilized and transferred to intensive care unit (ICU) for further hemodynamic supports and close monitoring. The patient was then transferred back to the general ward when she was stable. She was managed conservatively as there were no more signs of active bleeding. Unfortunately, she died of recurrent bleeding three days after ICU discharge. PMID:27158226

  11. "Geyser" leakage on fluorescein angiography.

    PubMed

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

    2013-11-22

    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.

  12. "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

  13. 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.

  14. Cortical Blindness and Retrograde Amnesia Following Cerebral Angiography Studied by Early Diffusion Weighted MR imaging. A Case Report.

    PubMed

    Roccatagliata, L; Taveira-Lopes, L; Rossignol, M-D; Biondi, A

    2009-12-14

    Cortical blindness is a well described neuro-ophthalmologic complication of angiography due to neurotoxicity following contrast media exposure. A rarer association with retrograde amnesia has also been reported. Since ischemic stroke due to embolism remains the most common aetiology of neurological complications of diagnostic and therapeutic arterial catheterisation, prompt identification of the mechanism responsible for the clinical symptoms is essential for patient management. Although CT and conventional MRI findings have been reported in this condition, experience with diffusion weighted (DW) sequences is lacking especially in cases associated with memory impairment. A 65-year-old man with tinnitus underwent cerebral angiography for suspicion of a dural arteriovenous fistula. During the procedure the patient developed complete loss of vision and rapidly became confused. Brain CT showed bilateral cortical enhancement in the occipital lobes. MR with DWI was performed 3.5 hours after angiography. Early DWI showed no signal abnormalities thereby excluding an ischaemic complication. Gradual improvement of visual function occurred over the next 24 hours. After 48 hours the patient was alert and orientated but profound retrograde amnesia persisted with no memory for the events of the day of angiography. CT follow-up at one year was normal. DWI is invaluable in the evaluation of patients with cortical blindness with or without memory deficits precipitated by angiography and may advance understanding of the pathophysiology. Diffusion-weighted MRI is crucial in differentiating neuro-ophthalmologic complications precipitated by intracortical contrast leakage after angiography from an ischaemic stroke needing a prompt and often invasive treatment. PMID:24209406

  15. 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

  16. [A Case of Abdominal Wall Hernia Rupture during Bevacizumab Treatment].

    PubMed

    Sugimoto, Satoshi; Miyazaki, Yasuaki; Hirose, Sou; Michiura, Toshiya; Fujita, Shigeo; Yamabe, Kazuo; Miyazaki, Satoru; Nagaoka, Makio

    2015-11-01

    A 78 -year-old man with rectal cancer underwent abdominoperineal resection of the rectum. In the postoperative period, the patient experienced wound infection, leading to an abdominal wall hernia. Two years following surgery, a rise in the serum CEA level was seen. A metastatic tumor was detected in the right lung on chest CT. VATS right lung inferior lobe segmental resection was performed. After lobectomy, the serum CEA level continued to increase. Another metastatic tumor was detected in the right lung on chest CT. Chemotherapy with capecitabine, oxaliplatin, and bevacizumab was commenced. The erosive part of the abdominal wall scar hernia extended during the nine weeks of chemotherapy. The chemotherapy was then discontinued. In the follow-up CT scan, a right pleural recurrence, local recurrence in the pelvis, and a liver metastasis were detected. Chemotherapy was re-introduced 3 years after surgery. The erosive part of the abdominal wall hernia again began to spread with chemotherapy recommencement. Four months after restarting chemotherapy, the hernia ruptured, with a loop of the small intestine protruding out of it. The patient covered this with a sheet of vinyl and was taken by the ambulance to our hospital. The erosive part of the abdominal wall hernia had split by 10 cm, and a loop of the small intestine was protruding. As ischemia of the small intestine was not observed, we replaced it into the abdominal cavity, and performed a temporary suture repair of the hernia sac. Following this, bevacizumab was discontinued, and the erosive part reduced. We performed a radical operation for abdominal wall scar hernia repair 11 weeks after the discontinuation of bevacizumab. PMID:26805294

  17. Screening for Abdominal Aortic Aneurysm

    MedlinePlus

    Understanding Task Force Recommendations Screening for Abdominal Aortic Aneurysm The U.S. Preventive Services Task Force (Task Force) ... final recommendation statement on Screening for Abdominal Aortic Aneurysm. This final recommendation statement applies to adults ages ...

  18. Abdominal Pain, Long-Term

    MedlinePlus

    MENU Return to Web version Abdominal Pain, Long-term See complete list of charts. Ongoing or recurrent abdominal pain, also called chronic pain, may be difficult to diagnose, causing frustration for ...

  19. 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

  20. Cervical Castleman disease: CT study with angiographic correlation.

    PubMed

    Koslin, D B; Berland, L L; Sekar, B C

    1986-07-01

    The computed tomographic (CT) appearance, angiographic appearance, and clinical features of a patient with cervical Castleman disease, an uncommon disease of benign lymph node hyperplasia, are reported. CT scans showed a densely enhancing cervical mass. On external carotid angiography, the mass was seen as hypervascular with a capillary blush. Differential diagnosis included carotid body chemodectoma, vagal neuroma, tumor of the salivary gland, tuberculous adenitis and other granulomatous diseases, inflammatory lymph nodes, metastatic disease, and lymphoma.

  1. Mesh Sutured Repairs of Abdominal Wall Defects

    PubMed Central

    Lanier, Steven T.; Jordan, Sumanas W.; Miller, Kyle R.; Ali, Nada A.; Stock, Stuart R.

    2016-01-01

    Background: A new closure technique is introduced, which uses strips of macroporous polypropylene mesh as a suture for closure of abdominal wall defects due to failures of standard sutures and difficulties with planar meshes. Methods: Strips of macroporous polypropylene mesh of 2 cm width were passed through the abdominal wall and tied as simple interrupted sutures. The surgical technique and surgical outcomes are presented. Results: One hundred and seven patients underwent a mesh sutured abdominal wall closure. Seventy-six patients had preoperative hernias, and the mean hernia width by CT scan for those with scans was 9.1 cm. Forty-nine surgical fields were clean-contaminated, contaminated, or dirty. Five patients had infections within the first 30 days. Only one knot was removed as an office procedure. Mean follow-up at 234 days revealed 4 recurrent hernias. Conclusions: Mesh sutured repairs reliably appose tissue under tension using concepts of force distribution and resistance to suture pull-through. The technique reduces the amount of foreign material required in comparison to sheet meshes, and avoids the shortcomings of monofilament sutures. Mesh sutured closures seem to be tolerant of bacterial contamination with low hernia recurrence rates and have replaced our routine use of mesh sheets and bioprosthetic grafts. PMID:27757361

  2. The Benefits of Internal Thoracic Artery Catheterization in Patients With Chronic Abdominal Aortic Occlusion

    SciTech Connect

    Ilic, Nikola Davidovic, Lazar; Koncar, Igor; Dragas, Marko; Markovic, Miroslav; Colic, Momcilo; Cinara, Ilijas

    2011-04-15

    Occlusion of the abdominal aorta may be caused by an embolic lesion, but more commonly by thrombotic disease at the aortoiliac area, progressing retrograde. However, the visualization of the distal run-off via internal thoracic-epigastric inferior artery collateral channel may be a very important diagnostic tool, especially in countries with poor technical equipment. This study was designed to show the benefit of the selective internal thoracic angiography in cases with complete aortic occlusion. We present 30 patients with chronic aortic abdominal occlusion who were submitted to the transaxillary aortography and selective ITA angiography with purpose of distal run off evaluation. Angiographic evaluation was performed by two independent radiologists according to previously defined classification. Good angiographic score via internal thoracic angiography by first observer was achieved in 19 (63.3%) patients and in 18 (60%) by a second observer. Transaxillary aortography showed inferior results: good angiographic score by the first observer in six (20%) patients and by the second observer in three (3%) patients. Low extremity run-off is better visualized during internal thoracic angiography than during transaxillary aortography.

  3. Doctors Should Bone Up on CT Scan Cancer Risks

    MedlinePlus

    ... Medicine. For the study, the researchers surveyed doctors, radiologists and imaging technologists about radiation exposure from CT scans. They found the vast majority knew that one abdominal-pelvic CT increases patients' risk for cancer. But many didn't know how the dose ...

  4. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    MedlinePlus

    ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... time and for your attention! Spotlight Recently posted: Video: Ultrasound-guided Breast Biopsy Video: Breast MRI Video: ...

  5. 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

  6. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... conditions: Birth (congenital) defect of the head or brain Brain infection Brain tumor Buildup of fluid inside ...

  7. Multi-atlas segmentation for abdominal organs with Gaussian mixture models

    NASA Astrophysics Data System (ADS)

    Burke, Ryan P.; Xu, Zhoubing; Lee, Christopher P.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Abramson, Richard G.; Landman, Bennett A.

    2015-03-01

    Abdominal organ segmentation with clinically acquired computed tomography (CT) is drawing increasing interest in the medical imaging community. Gaussian mixture models (GMM) have been extensively used through medical segmentation, most notably in the brain for cerebrospinal fluid / gray matter / white matter differentiation. Because abdominal CT exhibit strong localized intensity characteristics, GMM have recently been incorporated in multi-stage abdominal segmentation algorithms. In the context of variable abdominal anatomy and rich algorithms, it is difficult to assess the marginal contribution of GMM. Herein, we characterize the efficacy of an a posteriori framework that integrates GMM of organ-wise intensity likelihood with spatial priors from multiple target-specific registered labels. In our study, we first manually labeled 100 CT images. Then, we assigned 40 images to use as training data for constructing target-specific spatial priors and intensity likelihoods. The remaining 60 images were evaluated as test targets for segmenting 12 abdominal organs. The overlap between the true and the automatic segmentations was measured by Dice similarity coefficient (DSC). A median improvement of 145% was achieved by integrating the GMM intensity likelihood against the specific spatial prior. The proposed framework opens the opportunities for abdominal organ segmentation by efficiently using both the spatial and appearance information from the atlases, and creates a benchmark for large-scale automatic abdominal segmentation.

  8. Lateral Abdominal Wall Reconstruction

    PubMed Central

    Baumann, Donald P.; Butler, Charles E.

    2012-01-01

    Lateral abdominal wall (LAW) defects can manifest as a flank hernias, myofascial laxity/bulges, or full-thickness defects. These defects are quite different from those in the anterior abdominal wall defects and the complexity and limited surgical options make repairing the LAW a challenge for the reconstructive surgeon. LAW reconstruction requires an understanding of the anatomy, physiologic forces, and the impact of deinnervation injury to design and perform successful reconstructions of hernia, bulge, and full-thickness defects. Reconstructive strategies must be tailored to address the inguinal ligament, retroperitoneum, chest wall, and diaphragm. Operative technique must focus on stabilization of the LAW to nonyielding points of fixation at the anatomic borders of the LAW far beyond the musculofascial borders of the defect itself. Thus, hernias, bulges, and full-thickness defects are approached in a similar fashion. Mesh reinforcement is uniformly required in lateral abdominal wall reconstruction. Inlay mesh placement with overlying myofascial coverage is preferred as a first-line option as is the case in anterior abdominal wall reconstruction. However, interposition bridging repairs are often performed as the surrounding myofascial tissue precludes a dual layered closure. The decision to place bioprosthetic or prosthetic mesh depends on surgeon preference, patient comorbidities, and clinical factors of the repair. Regardless of mesh type, the overlying soft tissue must provide stable cutaneous coverage and obliteration of dead space. In cases where the fasciocutaneous flaps surrounding the defect are inadequate for closure, regional pedicled flaps or free flaps are recruited to achieve stable soft tissue coverage. PMID:23372458

  9. Abdominal SPECT imaging

    SciTech Connect

    Van Heertum, R.L.; Brunetti, J.C.; Yudd, A.P.

    1987-07-01

    Over the past several years, abdominal single photon emission computed tomography (SPECT) imaging has evolved from a research tool to an important clinical imaging modality that is helpful in the diagnostic assessment of a wide variety of disorders involving the abdominal viscera. Although liver-spleen imaging is the most popular of the abdominal SPECT procedures, blood pool imaging is becoming much more widely utilized for the evaluation of cavernous hemangiomas of the liver as well as other vascular abnormalities in the abdomen. Adjunctive indium leukocyte and gallium SPECT studies are also proving to be of value in the assessment of a variety of infectious and neoplastic diseases. As more experience is acquired in this area, SPECT should become the primary imaging modality for both gallium and indium white blood cells in many institutions. Renal SPECT, on the other hand, has only recently been used as a clinical imaging modality for the assessment of such parameters as renal depth and volume. The exact role of renal SPECT as a clinical tool is, therefore, yet to be determined. 79 references.

  10. Abdominal emergencies during pregnancy.

    PubMed

    Bouyou, J; Gaujoux, S; Marcellin, L; Leconte, M; Goffinet, F; Chapron, C; Dousset, B

    2015-12-01

    Abdominal emergencies during pregnancy (excluding obstetrical emergencies) occur in one out of 500-700 pregnancies and may involve gastrointestinal, gynecologic, urologic, vascular and traumatic etiologies; surgery is necessary in 0.2-2% of cases. Since these emergencies are relatively rare, patients should be referred to specialized centers where surgical, obstetrical and neonatal cares are available, particularly because surgical intervention increases the risk of premature labor. Clinical presentations may be atypical and misleading because of pregnancy-associated anatomical and physiologic alterations, which often result in diagnostic uncertainty and therapeutic delay with increased risks of maternal and infant morbidity. The most common abdominal emergencies are acute appendicitis (best treated by laparoscopic appendectomy), acute calculous cholecystitis (best treated by laparoscopic cholecystectomy from the first trimester through the early part of the third trimester) and intestinal obstruction (where medical treatment is the first-line approach, just as in the non-pregnant patient). Acute pancreatitis is rare, usually resulting from trans-ampullary passage of gallstones; it usually resolves with medical treatment but an elevated risk of recurrent episodes justifies laparoscopic cholecystectomy in the 2nd trimester and endoscopic sphincterotomy in the 3rd trimester. The aim of the present work is to review pregnancy-induced anatomical and physiological modifications, to describe the main abdominal emergencies during pregnancy, their specific features and their diagnostic and therapeutic management.

  11. Bowel and mesenteric injuries from blunt abdominal trauma: a review.

    PubMed

    Iaselli, Francesco; Mazzei, Maria Antonietta; Firetto, Cristina; D'Elia, Domenico; Squitieri, Nevada Cioffi; Biondetti, Pietro Raimondo; Danza, Francesco Maria; Scaglione, Mariano

    2015-01-01

    The bowel and the mesentery represent the third most frequently involved structures in blunt abdominal trauma after the liver and the spleen. Clinical assessment alone in patients with suspected intestinal and/or mesenteric injury from blunt abdominal trauma is associated with unacceptable diagnostic delays. Multi-detector computed tomography, thanks to its high spatial, time and contrast resolutions, allows a prompt identification and proper classification of such conditions. The radiologist, in fact, is asked not only to identify the signs of trauma but also to provide an indication of their clinical significance, suggesting the chance of conservative treatment in the cases of mild and moderate, non-complicated or self-limiting injuries and focusing on life-threatening conditions which may benefit from immediate surgical or interventional procedures. Specific and non-specific CT signs of bowel and mesenteric injuries from blunt abdominal trauma are reviewed in this paper.

  12. Abdominal cystic lymphangiomas in children: presurgical evaluation with imaging.

    PubMed

    Chateil, J-F; Brun, M; Vergnes, P; Andrieu de Lewis, P; Pérel, Y; Diard, F

    2002-02-01

    Cystic lymphangiomas are benign vascular tumors which are most often seen in young children. They are considered to be congenital malformations stemming from sequestration of lymphatic tissue. The authors report 15 cases of abdominal location and detail the findings of imaging in the etiologic and topographic diagnosis of these lesions. The initial incidents were essentially the discovery of a palpable abdominal mass, and more rarely, an acute gastrointestinal complication. There was also one case of prenatal diagnosis. Plain films provide only indirect signs related to the displacement of neighboring organs. Ultrasonography permits the etiologic diagnosis by showing an often voluminous, septated cyst. The intra- or retroperitoneal location of the lesion is sometimes difficult to determine by sonography, in which case CT scanning is usually adequate. For abdominal locations, percutaneous sclerosis is not available, and surgical removal is the only treatment for this disorder. The topography of the lesion and the involvement of retroperitoneal structures is important to determine.

  13. Abdominal computed tomography for postoperative abscess: is it useful during the first week?

    PubMed

    Antevil, Jared L; Egan, John C; Woodbury, Robert O; Rivera, Louis; Oreilly, Eamon B; Brown, Carlos V R

    2006-06-01

    While classic teaching dictates computed tomography (CT) for postoperative abdominal or pelvic abscess in the first week is of low yield, little evidence supports intentional delays in imaging for suspected abscess. This retrospective review examined all CT scans obtained for clinical suspicion of abscess between 3 and 30 days after abdominal or pelvic operation over a 3-year period. Scans were grouped into those obtained between 3 and 7 days after surgery (EARLY) and those obtained after day 7 (LATE). Diagnostic yield was compared between EARLY and LATE groups. Of 262 CT examinations (EARLY, n = 106; LATE, n = 156), 71 studies (27%) demonstrated abscess. There was no significant difference in the diagnostic yield of CT for abscess between EARLY and LATE groups (23% [24 of 106] versus 30% [47 of 156], P = 0.18). Of patients with an abscess, 63% (45 of 71) underwent percutaneous or operative drainage (EARLY 75% [18 of 24], LATE 57% [27 of 47], P = 0.15). Abdominal CT for postoperative abscess can be expected to be diagnostic in a substantial proportion of cases in the first week, the majority of which lead to percutaneous or operative drainage. Postoperative CT for intra-abdominal abscess should be obtained as clinically indicated, regardless of interval from surgery.

  14. Use of abdominal computed tomography in blunt trauma: Do we scan too much?

    PubMed Central

    Garber, Bryan G.; Bigelow, Eric; Yelle, Jean-Denis; Pagliarello, Guiseppe

    2000-01-01

    Objectives To determine what proportion of abdominal computed tomography (CT) scans ordered after blunt trauma are positive and the applicability and accuracy of existing clinical prediction rules for obtaining a CT scan of the abdomen in this setting. Setting A leading trauma hospital, affiliated with the University of Ottawa. Design A retrospective cohort study. Patients and methods All patients with blunt trauma admitted to hospital over a 1-year period having an Injury Severity Score (ISS) greater than 12 who underwent CT of the abdomen during the initial assessment. Recorded data included age, sex, Glasgow Coma Scale (GCS) score, ISS, type of injuries, number of abdominal CT scans ordered, and scan results. Two clinical prediction rules were found in the literature that identify patients likely to have intra-abdominal injuries. These rules were applied retrospectively to the cohort. The predicted proportion of positive CT scans was compared with the observed proportion, and the sensitivity, specificity, and accuracy were estimated. Results Of the 297 patients entered in the study, 109 underwent abdominal CT. The median age was 32 years, 71% were male and the median ISS was 24. In only 36.7% (40 of 109) of scans were findings suggestive of intra-abdominal injuries. Application of one of the clinical prediction rules gave a sensitivity of 93.8% and specificity of 25.5% but excluded 23% of patients because of a GCS score less than 11. The second prediction rule tested could be applied to all patients and was highly sensitive (92.5%) and specific (100.0%). Conclusions The assessment of the abdomen in blunt trauma remains a challenge. Accuracy in predicting positive scans in equivocal cases is poor. Retrospective application of an existing clinical prediction rule was found to be highly accurate in identifying patients with positive CT findings. Prospective use of such a rule could reduce the number of CT scans ordered without missing significant injuries. PMID

  15. 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

  16. 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.

  17. Inflammatory abdominal aortic aneurysm presenting as bilateral hydroureteronephrosis: a case report and review of literature.

    PubMed

    Galosi, Andrea Benedetto; Grilli Cicilioni, Carlo; Sbrollini, Giulia; Angelini, Andrea; Maselli, Guevar; Carbonari, Luciano

    2014-12-01

    We report a case of Inflammatory Abdominal Aortic Aneurysm (IAAA) producing bilateral hydro-ureteronephrosis. A 74-year-old patient presented to urologist office for bilateral hydronephrosis detected by kidney and bladder ultrasound (US). Patient reported lower urinary tract symptoms and inconstant and slight low back pain irradiated to inguinal region dating 3 weeks. Renal function, urine analysis and abdominal examination were normal. However the repeated ultrasound in the urologist office revealed abdominal aortic aneurism extended to iliac vessels. The patient was sent directly to vascular surgery unit where contrast computerized tomography (CT) and successful surgical repair were done. Final diagnosis was IAAA. The post-operative course was uneventful. Renal function was regular and the hydronephrosis reduced spontaneously under monitoring by CT and US. We review diagnosis and management of hydronephrosis that is sometimes linked to IAAA rather than standard AAA. Abdominal ultrasound is mandatory in any bilateral hydronephrosis and it could save lives. PMID:25641477

  18. Complications with Outpatient Angiography and Interventional Procedures

    SciTech Connect

    Young, Noel; Chi, Ka-Kit; Ajaka, Joe; McKay, Lesa; O'Neill, Diane; Wong, Kai Ping

    2002-03-15

    Purpose: To prospectively identify the complications, and rates of complication, in outpatient angiography and interventional procedures. Methods: There were 1050 consecutive patients, 646 men and 404 women, aged 17-89 years, with a total of 1239 procedures studied in a 2-year period, 1997 to 1999. Results: There were 560 cases of aorto-femoral angiography,resulting in 124 complications (22%), with pain or hematoma in 110.There were 206 cases of neck and cerebral angiography, resulting in 51 complications (25%), with pain and hematoma in 34, transient ischemic attack in 2 and cerebrovascular accident in 1. There were 197 interfentional procedures, with 177 being balloon dilatations, resulting in 68 complications (35%), with 2 having hematomas and 1 having hematoma/abscess requiring active treatment. There were 276 cases having various 'other' procedures (e.g., renal angiography),resulting in 65 complications (24%), with pain and hematoma in 61. No procedure-related death occurred. Eighteen cases (1.5%) had significant complications, with contrast allergy in eight. Conclusion: Outpatient angiography and intervention are relatively safe, with low significant complication rates.

  19. Experience With Fenestrated Endovascular Repair of Juxtarenal Abdominal Aortic Aneurysms at a Single Center

    PubMed Central

    Hu, Zhongzhou; Li, Yue; Peng, Ran; Liu, Jie; Zhang, Tao; Guo, Wei

    2016-01-01

    Abstract To present the early and mid-term results of fenestrated endovascular aneurysm repair (FEVAR) using the Zenith fenestrated device for juxtarenal abdominal aortic aneurysms (JAAAs) at our center in China. Design: Retrospective study. The study included 15 male patients with JAAAs, who underwent FEVAR using the Zenith fenestrated device at our center between February 2011 and June 2015. All custom-made Zenith fenestrated devices were designed according to computed tomography angiography (CTA) images obtained preoperatively. The patients with renal insufficiency underwent duplex ultrasonography, while the patients with normal renal function underwent 3 CT data acquisitions including nonenhanced CT, arterial phase, and venous phase. These examinations and blood examinations were completed at 3, 6, and 12 months after discharge, and annually thereafter. The mean age of the patients was 73.13 ± 9.06 years (range, 57–86 years), and the median follow-up period was 30 months (8–52 months). Small fenestrations were used in 27 renal arteries, scallops were used in 7 superior mesenteric arteries (SMAs) and 2 renal arteries, and large fenestrations were used in 2 SMAs. Conversion to an open procedure was not required in any of the patients, and the technical success rate was 100%. The mean length of hospital stay was 11.33 ± 2.02 days (7–15 days). No patient died within the 1st 30 days after the operation. One patient had a type Ia endoleak, which disappeared at 6 months after the operation, 1 patient had a type Ib endoleak, which was detected at 17 months after the operation, and 2 patients had type II endoleaks. One patient died at 17 months and another patient died at 30 months after the operation. Therefore, the all-cause mortality rate was 13.33% (2/15). The target vessel patency rate was 100% without occlusion. The early and mid-term results of FEVAR using the Zenith fenestrated device were good, demonstrating that this procedure is effective for

  20. 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.

  1. 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. PMID:27617047

  2. Determination of dosimetric quantities in pediatric abdominal computed tomography scans*

    PubMed Central

    Jornada, Tiago da Silva; da Silva, Teógenes Augusto

    2014-01-01

    Objective Aiming at contributing to the knowledge on doses in computed tomography (CT), this study has the objective of determining dosimetric quantities associated with pediatric abdominal CT scans, comparing the data with diagnostic reference levels (DRL). Materials and methods The study was developed with a Toshiba Asteion single-slice CT scanner and a GE BrightSpeed multi-slice CT unit in two hospitals. Measurements were performed with a pencil-type ionization chamber and a 16 cm-diameter polymethylmethacrylate trunk phantom. Results No significant difference was observed in the values for weighted air kerma index (CW), but the differences were relevant in values for volumetric air kerma index (CVOL), air kerma-length product (PKL,CT) and effective dose. Conclusion Only the CW values were lower than the DRL, suggesting that dose optimization might not be necessary. However, PKL,CT and effective dose values stressed that there still is room for reducing pediatric radiation doses. The present study emphasizes the importance of determining all dosimetric quantities associated with CT scans. PMID:25741103

  3. Leaking mycotic abdominal aortic aneurysm.

    PubMed

    Sing, T M; Young, N; O'Rourke, I C; Tomlinson, P

    1994-11-01

    A case of leaking mycotic abdominal aortic aneurysm is reported, with a brief review of the literature. A 58 year old female presented with shoulder and abdominal pain associated with diarrhoea, vomiting and fever with leucocytosis. Computed tomography of the abdomen showed pooling of contrast in the retroperitoneum anterior to a non-dilated abdominal aorta. There was considerable retroperitoneal blood accumulating in a mass-like lesion in the right lower abdomen and pelvis obstructing the right renal collecting system. Laparotomy revealed a 4 cm diameter saccular aneurysm of the abdominal aorta, with a 1 cm diameter neck. Culture of the thrombus grew Streptococcus pyogenes. PMID:7993259

  4. Hypnosis for functional abdominal pain.

    PubMed

    Gottsegen, David

    2011-07-01

    Chronic abdominal pain is a common pediatric condition affecting 20% of the pediatric population worldwide. Most children with this disorder are found to have no specific organic etiology and are given the diagnosis of functional abdominal pain. Well-designed clinical trials have found hypnotherapy and guided imagery to be the most efficacious treatments for this condition. Hypnotic techniques used for other somatic symptoms are easily adaptable for use with functional abdominal pain. The author discusses 2 contrasting hypnotic approaches to functional abdominal pain and provides implications for further research. These approaches may provide new insights into this common and complex disorder. PMID:21922712

  5. Magnetic resonance angiography in neck masses.

    PubMed

    Colletti, P M; Terk, M R; Zee, C S

    1996-01-01

    Carotid MR angiography has primarily been used to evaluate for stenotic lesions. We performed 2D time of flight MR angiography in 25 patients with palpable neck masses. There were 23 masses confirmed histologically. Two of the masses represented abnormal carotid arteries. Carotid deviation was seen in 23 of 25 (92%) of patients. Widening of the carotid bifurcation was identified in seven patients, including four carotid body tumors, one inflammatory mass, one benign salivary gland tumor, and one schwannoma. Increased vascularity was identified in one carotid body tumor and in one metastatic papillary carcinoma of the thyroid. MR angiography may be useful to demonstrate flow within vessels and represents a familiar imaging display for surgical planning. Splaying of the carotid bifurcation is useful in demonstrating carotid space lesions.

  6. Time-resolved MR angiography with limited projections.

    PubMed

    Huang, Yuexi; Wright, Graham A

    2007-08-01

    A method for reconstruction of time-resolved MRI called highly-constrained backprojection (HYPR) has been developed. To evaluate the HYPR reconstruction in relation to data sparsity and temporal dynamics, computer simulations were performed, investigating signal modulations under different situations that reflect dynamic contrast-enhanced MR angiography (MRA). In vivo studies were also performed with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) for abdominal MRA in a canine model to demonstrate the application of HYPR for three-dimensional (3D) time-resolved MRA. When contrast dynamics vary over space, large vessels (e.g., veins) tend to introduce signal interference to small vessels (e.g., arteries) in HYPR, particularly when the vessels are in close proximity. The enhancement of background tissue signals may also alter the arterial and venous temporal profiles in HYPR. However, the artifacts are manifest as intensity modulation rather than structural interference, and therefore have little impact on structural diagnosis. Increasing the number of projections per time point increases temporal blur while reducing corruption of temporal behavior from adjacent tissues. Uniformly interleaved acquisition order, such as the bit-reversed order, is important to reduce artifacts. With high signal-to-noise ratio (SNR) and limited artifacts, HYPR reconstruction has potential to greatly improve time-resolved MRA in clinical practice.

  7. Optical Coherence Tomography Angiography in Fovea Plana.

    PubMed

    Dolz-Marco, Rosa; Phasukkijwatana, Nopasak; Sarraf, David; Freund, K Bailey

    2016-07-01

    Fovea plana is characterized by the anatomical absence of the foveal pit in eyes with normal visual function. The authors have analyzed three cases of idiopathic fovea plana with optical coherence tomography angiography (OCTA). As previously reported, the authors found the absence of a foveal avascular zone in all cases with OCTA; however, a preserved fusion of both the superficial and the deep capillary plexuses was found around the foveal center. This novel observation cannot be detected with conventional dye-based angiography, in which the deep capillary plexus is not visualized. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:670-673.].

  8. Intraarterial digital subtraction angiography of renal transplants

    SciTech Connect

    Picus, D.; Neeley, J.P.; McClennan, B.L.; Weyman, P.J.; Heiken, J.P.

    1985-07-01

    Twenty-four intraarterial digital subtraction angiography (IA-DSA) studies were performed in 23 renal transplant recipients for evaluation of possible postoperative complications. Ten patients had normal studies. Five patients had minimal (<50%) narrowing at the renal artery anastomosis and five had more severe stenoses. Three patients had vascular occlusions. IA-DSA results correlated well with findings at surgery and/or conventional angiography. The major advantage of IA-DSA is the small amount of contrast material needed to perform the study. IA-DSA is particularly well suited to the evaluation of vascular problems in renal transplant patients.

  9. [Abdominal approaches and drainages of the abdominal cavity].

    PubMed

    Hagel, C; Schilling, M

    2006-04-01

    Appropriate access to the abdominal cavity is the first and crucial step for successful abdominal surgical intervention. In planning the incision, several variables have to be considered, such as anatomy of the abdominal wall, localization of the target organ, and individual conditions (previous incisions, minimal access surgery, etc). Medial laparotomy is the preferred incision for emergency cases and ill-defined pathologies, allowing access and hence exploration to all quadrants. Transverse laparotomies give superior access to the dorsal and right aspects of the liver and cause less pain in patients unfit for regional anesthetic procedures. Draining of the abdominal cavity is used after various resective and reconstructive procedures, but there is little evidence for its use in a number of operations such as gastric, hepatic, and colorectal resections. Advantages and disadvantages of different abdominal wall incisions and drainages are discussed.

  10. [Radiofrequency ablation of an unresectable abdominal tumor].

    PubMed

    Sézeur, Alain; Fritsch, Sylvie; Louvet, Christophe; Kujas, Albert; Mosnier, Henri; Talbot, Jean-Noël; Grimberg, Sylvie

    2003-02-01

    Remnant malignant tissue is left behind after conventional surgery for an unresectable intraperitoneal malignant tumor. Standard radiotherapy or chemotherapy rarely enables good tumor control. We report the case of a 74-year-old man who developed a local recurrence of a sigmoid tumor located 5 to 6 cm from the anus. The tumor was fixed to the pelvic wall and could not be totally eradicated with conventional surgery. Preoperative peroperative assessment confirmed the absence of metastatic spread. Radiotherapy could not be performed due to risk of bowel injury. Peroperative radiofrequency ablation was followed by surgical colorectal resection without restoration of intestinal continuity, leaving only tumor tissue destroyed by radiofrequency. No adjuvant treatment was proposed because of intolerance to chemotherapy. Clinical assessment and thoracic and abdominal CT scan confirmed the absence of recurrence 26 months after radiofrequency ablation. Serum markers remained normal.

  11. Endovascular Repair of an Anastomotic Leak Following Open Repair of Abdominal Aortic Aneurysm

    SciTech Connect

    Mofidi, R. Flett, M.; Milne, A.; Chakraverty, S.

    2007-09-15

    This report describes the case of an early postoperative anastomotic leak following elective open repair of an infrarenal abdominal aortic aneurysm which was successfully treated by endovascular stent-grafting. A 71-year-old man underwent open tube graft repair of abdominal aortic aneurysm. Twelve days later he presented with a contained leak from the distal anastomosis, which was confirmed on CT scan. This was successfully treated with a bifurcated aortic stent-graft. This case illustrates the usefulness of the endovascular approach for resolving this rare surgical complication of open repair of abdominal aortic aneurysm and the challenges associated with the deployment of such a device within an aortic tube graft.

  12. [A case of polyarteritis nodosa with intra-abdominal bleeding due to rupture of the hepatic aneurysm].

    PubMed

    Teraoka, Hitoshi; Takeuchi, Kazuhiro; Sakurai, Katsunobu; Nitta, Atsunori

    2006-06-01

    A 39-year-old woman was admitted to our hospital because of abdominal pain. She was diagnosed as intra-abdominal bleeding and an emergency laparotomy was performed. On laparotomy, massive bleeding in the abdominal cavity due to a ruptured aneurysm of the intrahepatic artery was found. We also verified small aneurysm of the common hepatic artery, tinged with red, and was suspected systemic vasculitis. The post-operative course was uneventful, but the subsequent angiography revealed many other small aneurysm of hepatic, renal and lumbar aytery. Then it was diagnosed as polyarteritis nodosa. A case of polyarteritis nodosa presenting with intra-abdominal homorrhage like this case is rare, so we presented here together with a review of the literature.

  13. Standardized anatomic space for abdominal fat quantification

    NASA Astrophysics Data System (ADS)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.

    2014-03-01

    The ability to accurately measure subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from images is important for improved assessment and management of patients with various conditions such as obesity, diabetes mellitus, obstructive sleep apnea, cardiovascular disease, kidney disease, and degenerative disease. Although imaging and analysis methods to measure the volume of these tissue components have been developed [1, 2], in clinical practice, an estimate of the amount of fat is obtained from just one transverse abdominal CT slice typically acquired at the level of the L4-L5 vertebrae for various reasons including decreased radiation exposure and cost [3-5]. It is generally assumed that such an estimate reliably depicts the burden of fat in the body. This paper sets out to answer two questions related to this issue which have not been addressed in the literature. How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? At what anatomic location do the volumes of SAT and VAT correlate maximally with the corresponding single-slice area measures? To answer these questions, we propose two approaches for slice localization: linear mapping and non-linear mapping which is a novel learning based strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. We then study the volume-to-area correlations and determine where they become maximal. We demonstrate on 50 abdominal CT data sets that this mapping achieves significantly improved consistency of anatomic localization compared to current practice. Our results also indicate that maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized.

  14. How I Manage Abdominal Injuries.

    ERIC Educational Resources Information Center

    Haycock, Christine E.

    1986-01-01

    In sports, abdominal injuries occur most frequently in cycling, horseback riding, and skiing. Most involve children, not adults. Any athlete sustaining a severe blow to the abdomen should be examined. Guidelines are provided for recognizing and treating injuries to the abdominal muscles, kidneys, spleen, and liver. (Author/MT)

  15. [The abdominal drop flap].

    PubMed

    Bodin, F; Liverneaux, P; Seigle-Murandi, F; Facca, S; Bruant-Rodier, C; Dissaux, C; Chaput, B

    2015-08-01

    The skin between the mastectomy scar and the future infra-mammary fold may be managed in different ways in delayed breast reconstruction using a DIEP (deep inferior epigastric perforator). Conserving this skin and positioning the flap skin paddle in the middle of the breast usually highlights skin color disparity because of two visible transition zones. Resection of the entire skin under the scar may be more aesthetic but limits direct closure possibility in case of flap failure. In order to benefit from both aesthetic result and safe surgical method, we propose the abdominal drop flap. The inferior thoracic skin flap is detached from the thoracic wall beyond the future infra-mammary fold, preserved and pushed under the breast.

  16. 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

  17. Coronary computed tomographic angiography in clinical practice: state of the art.

    PubMed

    Meinel, Felix G; Bayer, Richard R; Zwerner, Peter L; De Cecco, Carlo Nicola; Schoepf, U Joseph; Bamberg, Fabian

    2015-03-01

    In patients with stable chest pain, coronary CT angiography (CCTA) has demonstrated high accuracy in excluding coronary artery disease and CCTA findings carry prognostic significance for the occurrence of future cardiovascular events. Increasingly, CCTA has been adopted as a triage tool in patients with acute chest pain. In specific clinical scenarios, CCTA further represents a useful tool to exclude an ischemic etiology in patients with cardiac arrhythmias or newly diagnosed heart failure. Several novel techniques are currently being investigated which may extend the ability of CCTA to characterize and quantify coronary artery plaque and assess the hemodynamic significance of stenosis. PMID:25726994

  18. Unexpected Angiography Findings and Effects on Management

    PubMed Central

    Neill, Matthew; Charles, Hearns W; Gross, Jonathan S; Farquharson, Sean; Deipolyi, Amy R

    2016-01-01

    Despite progress in noninvasive imaging with computed tomography and magnetic resonance imaging, conventional angiography still contributes to the diagnostic workup of oncologic and other diseases. Arteriography can reveal tumors not evident on cross-sectional imaging, in addition to defining aberrant or unexpected arterial supply to targeted lesions. This additional and potentially unanticipated information can alter management decisions during interventional procedures. PMID:27688932

  19. Unexpected Angiography Findings and Effects on Management.

    PubMed

    Neill, Matthew; Charles, Hearns W; Gross, Jonathan S; Farquharson, Sean; Deipolyi, Amy R

    2016-01-01

    Despite progress in noninvasive imaging with computed tomography and magnetic resonance imaging, conventional angiography still contributes to the diagnostic workup of oncologic and other diseases. Arteriography can reveal tumors not evident on cross-sectional imaging, in addition to defining aberrant or unexpected arterial supply to targeted lesions. This additional and potentially unanticipated information can alter management decisions during interventional procedures. PMID:27688932

  20. Digital subtraction angiography: patient preparation and care.

    PubMed

    Hunt, A H

    1987-08-01

    The use of digital subtraction angiography (DSA) is increasing. Nurses must be prepared to provide quality care to patients who have this relatively new method for radiographically studying the blood vessels. A description of DSA and its applications is provided. Patient preparation, assessment, teaching, and management are described. Complications of the procedure and their management are presented. PMID:2958568

  1. Computed tomographic angiography in tetralogy of Fallot.

    PubMed

    Kasar, Pankajkumar Ashok; Ravikumar, Radhakrishnan; Varghese, Roy; Kotecha, Monika; Vimala, Jesudian; Kumar, Raghavan Nair Suresh

    2011-10-01

    Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, -2; range, -11.1-0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range, -2.53-3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.

  2. Unexpected Angiography Findings and Effects on Management

    PubMed Central

    Neill, Matthew; Charles, Hearns W; Gross, Jonathan S; Farquharson, Sean; Deipolyi, Amy R

    2016-01-01

    Despite progress in noninvasive imaging with computed tomography and magnetic resonance imaging, conventional angiography still contributes to the diagnostic workup of oncologic and other diseases. Arteriography can reveal tumors not evident on cross-sectional imaging, in addition to defining aberrant or unexpected arterial supply to targeted lesions. This additional and potentially unanticipated information can alter management decisions during interventional procedures.

  3. Abdominal Aortic Disease Caused by Penetrating Atherosclerotic Ulcers

    PubMed Central

    Sato, Masataka; Imai, Akito; Sakamoto, Hiroaki; Sasaki, Akinobu; Watanabe, Yasunori; Jikuya,, Tomoaki

    2012-01-01

    Objective: Penetrating atherosclerotic ulcer (PAU) of the aorta is defined as an atherosclerotic lesion with ulceration of the aortic intima and media and rupture of the internal elastic lamina. PAU induced aortic dissection, aortic rupture, and secular aortic aneurysm and typically occurs in elderly hypertensive patients with severe atherosclerosis. Although it has been reported that atherosclerosis similarly occurs in the abdominal aorta, its natural history and treatment are still unclear. This study investigated the clinical features, natural history, and treatment of PAU of the abdominal aorta. Method:Between April 2006 and March 2009, 4 diagnoses of PAU in the abdominal aorta were made by computed tomography (CT) and magnetic resonance imaging (MRI). These 4 cases were analyzed along with 61 previously reported cases from the literature with diagnoses of PAU in the abdominal aorta, aortic rupture, and isolated abdominal aortic dissection over the past 15 years, giving a total of 65 cases. Results:The patients were men with an average age of 63.5 years. All 4 had hypertension, and 2 had concomitant coronary artery disease. Two patients were asymptomatic, and the other 2 were symptomatic and transmural rupture had occurred. All diagnoses were made by CT and MRI. All 4 patients underwent open surgery with a knitted Dacron graft, with no postoperative deaths. In the literature, 53% of cases were symptomatic, including pain (40%, n = 26), shock (4.6%, n = 3), and lower limb embolism (9.2%, n = 6). The remaining 40% of cases were asymptomatic (n = 26). Six patients were treated medically, while 58 patients underwent surgery, with 2 postoperative deaths. Conclusion:We suggest that surgical treatment (open surgery or endovascular stent grafting) should be performed to prevent an aortic catastrophe such as intramural hematoma, dissection, or rupture. (English translation of Jpn J Vasc Surg 2010; 19: 723-730.) PMID:23555480

  4. Abdominal Aortic Surgery in the Presence of a Horseshoe Kidney

    PubMed Central

    Lobe, Thom E.; Martin, Edward W.; Cooperman, Marc; Vasko, John; Evans, William E.

    1978-01-01

    Prior experience with the rare combination of horseshoe kidney and significant atherosclerotic vascular disease suggests difficulty in intraoperative management, often requiring division of the renal isthmus or sacrifice of some renal tissue. Seven patients have been managed successfully over the past ten years at The Ohio State University Hospital. There were six men and one woman, ranging in age from 39 to 66 years. Of the five patients with abdominal aortic aneurysm, four had a pulsatile abdominal mass, three had abdominal pain, and one had back pain. The other two patients had progressively symptomatic aortoiliac disease. All seven patients had hypertension, easily controlled by medication. Critical diagnostic procedures are preoperative intravenous pyelogram (IVP) and abdominal aortic arteriogram. The IVP detected the previously unsuspected diagnosis in 100% of the cases. The arteriogram accurately located the aneurysm in relation to the renal vascular supply, and disclosed aberrant blood supply in three of four patients with aberrant vessels. All seven horseshoe kidneys were fused at the lower pole. The operative approach involves meticulous dissection of the aberrant blood supply to the kidneys, and mobilization of the isthmus for adequate retrorenal aortic exposure. In six of the seven patients, the grafts were placed posterior to the isthmus. There were no deaths, and there were no complications related to the presence of the horseshoe kidney. In three of the seven patients, hypertension improved. Patients with horseshoe kidney and aortic disease may be safely operated upon without damage to the kidney. IVP and selective angiography are essential to provide preoperative information. ImagesFig. 11. PMID:666380

  5. Laparoscopic approach for the multiple abdominal vascular entrapment syndrome.

    PubMed

    Estraviz, Begoña; Arévalo, J Antonio; Eizaguirre, Enma; Jiménez, Eduardo; Corcostegui, Miguel; Goicoechea, Juan M; Maniega, Roberto; Ibáñez, F Javier

    2012-01-01

    We report an unusual case of a 25-year-old man affected by several vascular entrapment abdominal processes: celiac axis compression or Dunbar syndrome, superior mesenteric artery syndrome or Wilkie's disease and Nutcracker syndrome implying compression of the left renal vein. We discuss the diagnosis that was established by contrast-enhanced spiral computed tomography scan and magnetic resonance angiography. Once diagnosed the patient was treated conservatively by enteral high caloric diet in order to obtain a weight gain, however as it did not relieve the symptomatology of pain and vomit we opted for a surgical procedure. The therapeutic options were reviewed, highlighting the laparoscopic approach, which was the one we chose since it provides a less invasive procedure than open surgery but is an equally effective method of treatment.

  6. COMPARISON OF COMPUTED TOMOGRAPHY AND ABDOMINAL RADIOGRAPHY FOR DETECTION OF CANINE MECHANICAL INTESTINAL OBSTRUCTION.

    PubMed

    Drost, Wm Tod; Green, Eric M; Zekas, Lisa J; Aarnes, Turi K; Su, Lillian; Habing, Gregory G

    2016-07-01

    Vomiting, often caused by mechanical intestinal obstruction, is common in dogs. Equivocal radiographic signs often necessitate repeat radiographs or additional imaging procedures. For our prospective, case-controlled, accuracy study, we hypothesized the following: (1) using computed tomography (CT), radiologists will be more sensitive and specific for detecting mechanical intestinal obstruction and recommending surgery compared to using radiographs; and (2) using measurements, radiologists will be more sensitive and specific using radiographs or CT for detecting mechanical intestinal obstruction and recommending surgery. Twenty dogs had abdominal radiographs and abdominal CT. Seventeen dogs had abdominal surgery and three dogs were not obstructed based on clinical follow-up. Confidence levels (five-point scale) of three experienced radiologists for mechanical intestinal obstruction and recommending surgery were recorded before and after making selected measurements. Eight dogs had surgically confirmed mechanical intestinal obstruction, and 12 dogs did not have obstruction. For detecting mechanical intestinal obstruction, CT was more sensitive (95.8% vs. 79.2%) and specific (80.6% vs. 69.4%) compared to radiographs, but the difference was not statistically significant. For recommending surgery, radiography was more sensitive (91.7% vs. 83.3%) and specific (83.3% vs. 72.2%) than using CT, but differences were not statistically significant. We reported objective CT measurements for predicting small mechanical intestinal obstruction. By incorporating these objective data, the diagnosis of mechanical intestinal obstruction changed in five of 120 instances (radiographs and CT). In no instance (0/120), did the objective data change the recommendation for surgery. Using CT or abdominal radiographs for the detection of canine mechanical intestinal obstruction is sensitive and specific when evaluated by experienced veterinary radiologists.

  7. Contemporary Applications of Ultrasound in Abdominal Aortic Aneurysm Management

    PubMed Central

    Scaife, Mark; Giannakopoulos, Triantafillos; Al-Khoury, Georges E.; Chaer, Rabih A.; Avgerinos, Efthymios D.

    2016-01-01

    Ultrasound (US) is a well-established screening tool for detection of abdominal aortic aneurysms (AAAs) and is currently recommended not only for those with a relevant family history but also for all men and high-risk women older than 65 years of age. The advent of minimally invasive endovascular techniques in the treatment of AAAs [endovascular aneurysm repair (EVAR)] has increased the need for repeat imaging, especially in the postoperative period. Nevertheless, preoperative planning, intraoperative execution, and postoperative surveillance all mandate accurate imaging. While computed tomographic angiography and angiography have dominated the field, repeatedly exposing patients to the deleterious effects of cumulative radiation and intravenous nephrotoxic contrast, US technology has significantly evolved over the past decade. In addition to standard color duplex US, 2D, 3D, or 4D contrast-enhanced US modalities are revolutionizing AAA management and postoperative surveillance. This technology can accurately measure AAA diameter and volume, and most importantly, it can detect endoleaks post-EVAR with high sensitivity and specificity. 4D contrast-enhanced US can even provide hemodynamic information about the branch vessels following fenestrated EVARs. The need for experienced US operators and accredited vascular labs is mandatory to guarantee the reliability of the results. This review article presents a comprehensive overview of the literature on the state-of-art US imaging in AAA management, including post-EVAR follow-up, techniques, and diagnostic accuracy. PMID:27303669

  8. Contemporary Applications of Ultrasound in Abdominal Aortic Aneurysm Management.

    PubMed

    Scaife, Mark; Giannakopoulos, Triantafillos; Al-Khoury, Georges E; Chaer, Rabih A; Avgerinos, Efthymios D

    2016-01-01

    Ultrasound (US) is a well-established screening tool for detection of abdominal aortic aneurysms (AAAs) and is currently recommended not only for those with a relevant family history but also for all men and high-risk women older than 65 years of age. The advent of minimally invasive endovascular techniques in the treatment of AAAs [endovascular aneurysm repair (EVAR)] has increased the need for repeat imaging, especially in the postoperative period. Nevertheless, preoperative planning, intraoperative execution, and postoperative surveillance all mandate accurate imaging. While computed tomographic angiography and angiography have dominated the field, repeatedly exposing patients to the deleterious effects of cumulative radiation and intravenous nephrotoxic contrast, US technology has significantly evolved over the past decade. In addition to standard color duplex US, 2D, 3D, or 4D contrast-enhanced US modalities are revolutionizing AAA management and postoperative surveillance. This technology can accurately measure AAA diameter and volume, and most importantly, it can detect endoleaks post-EVAR with high sensitivity and specificity. 4D contrast-enhanced US can even provide hemodynamic information about the branch vessels following fenestrated EVARs. The need for experienced US operators and accredited vascular labs is mandatory to guarantee the reliability of the results. This review article presents a comprehensive overview of the literature on the state-of-art US imaging in AAA management, including post-EVAR follow-up, techniques, and diagnostic accuracy. PMID:27303669

  9. Penetrating abdominal trauma.

    PubMed

    Henneman, P L

    1989-08-01

    The management of patients with penetrating abdominal trauma is outlined in Figure 1. Patients with hemodynamic instability, evisceration, significant gastrointestinal bleeding, peritoneal signs, gunshot wounds with peritoneal violation, and type 2 and 3 shotgun wounds should undergo emergency laparotomy. The initial ED management of these patients includes airway management, monitoring of cardiac rhythm and vital signs, history, physical examination, and placement of intravenous lines. Blood should be obtained for initial hematocrit, type and cross-matching, electrolytes, and an alcohol level or drug screen as needed. Initial resuscitation should utilize crystalloid fluid replacement. If more than 2 liters of crystalloid are needed to stabilize an adult (less in a child), blood should be given. Group O Rh-negative packed red blood cells should be immediately available for a patient in impending arrest or massive hemorrhage. Type-specific blood should be available within 15 minutes. A patient with penetrating thoracic and high abdominal trauma should receive a portable chest x-ray, and a hemo- or pneumothorax should be treated with tube thoracostomy. An unstable patient with clinical signs consistent with a pneumothorax, however, should receive a tube thoracostomy prior to obtaining roentgenographic confirmation. If time permits, a nasogastric tube and Foley catheter should be placed, and the urine evaluated for blood (these procedures can be performed in the operating room). If kidney involvement is suspected because of hematuria or penetrating trauma in the area of a kidney or ureter in a patient requiring surgery, a single-shot IVP should be performed either in the ED or the operating room. An ECG is important in patients with possible cardiac involvement and in patients over the age of 40 going to the operating room. Tetanus status should be updated, and appropriate antibiotics covering bowel flora should be given. Operative management should rarely be delayed

  10. Acute incarcerated external abdominal hernia

    PubMed Central

    Yang, Xue-Fei

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surgery in some cases to achieve minimally invasive treatment. However, strict adherence to the indications and contraindications is still required. PMID:25489584

  11. Technological Development and Advances in SPECT/CT

    PubMed Central

    Seo, Youngho; Aparici, Carina Mari; Hasegawa, Bruce H

    2010-01-01

    SPECT/CT has emerged over the past decade as a means of correlating anatomical information from CT with functional information from SPECT. The integration of SPECT and CT in a single imaging device facilitates anatomical localization of the radiopharmaceutical to differentiate physiological uptake from that associated with disease and patient-specific attenuation correction to improve the visual quality and quantitative accuracy of the SPECT image. The first clinically available SPECT/CT systems performed emission-transmission imaging using a dual-headed SPECT camera and a low-power x-ray CT sub-system. Newer SPECT/CT systems are available with high-power CT sub-systems suitable for detailed anatomical diagnosis, including CT coronary angiography and coronary calcification that can be correlated with myocardial perfusion measurements. The high-performance CT capabilities also offer the potential to improve compensation of partial volume errors for more accurate quantitation of radionuclide measurement of myocardial blood flow and other physiological processes and for radiation dosimetry for radionuclide therapy. In addition, new SPECT technologies are being developed that significantly improve the detection efficiency and spatial resolution for radionuclide imaging of small organs including the heart, brain, and breast, and therefore may provide new capabilities for SPECT/CT imaging in these important clinical applications. PMID:18396178

  12. Endovascular Treatment of Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula

    SciTech Connect

    Guzzardi, Giuseppe Fossaceca, Rita; Divenuto, Ignazio; Musiani, Antonello; Brustia, Piero; Carriero, Alessandro

    2010-08-15

    Aortocaval fistula (ACF) is a rare complication of abdominal aortic aneurysm (AAA). We report the endovascular repair of an AAA rupture into the inferior vena cava. A 78-year-old woman was admitted to our hospital for acute hypotension. She presented with a pulsatile abdominal mass and became rapidly anuric. Abdominal computed tomography (CT) showed an AAA rupture into the inferior vena cava. The features of the AAA made it suitable for endovascular repair. To prevent pulmonary embolism caused by the presence of sac thrombosis near the vena cava lumen, a temporary vena cava filter was deployed before the procedure. A bifurcated stent-graft was placed with the patient under local anaesthesia, and the AAA was successfully treated. A transient type II endoleak was detected on CT 3 days after endograft placement. At routine follow-up 6 and 12 months after the procedure, the patient was in good clinical condition, and the type II endoleak had sealed completely. Endovascular treatment offers an attractive therapeutic alternative to open repair in case of ACF; however, only small numbers of patients have been treated, and long-term follow-up interval is lacking.

  13. Abdominal aortic feminism.

    PubMed

    Mortimer, Alice Emily

    2014-11-14

    A 79-year-old woman presented to a private medical practice 2 years previously for an elective ultrasound screening scan. This imaging provided the evidence for a diagnosis of an abdominal aortic aneurysm (AAA) to be made. Despite having a number of recognised risk factors for an AAA, her general practitioner at the time did not follow the guidance set out by the private medical professional, that is, to refer the patient to a vascular specialist to be entered into a surveillance programme and surgically evaluated. The patient became symptomatic with her AAA, was admitted to hospital and found to have a tender, symptomatic, 6 cm leaking AAA. She consented for an emergency open AAA repair within a few hours of being admitted to hospital, despite the 50% perioperative mortality risk. The patient spent 4 days in intensive care where she recovered well. She was discharged after a 12 day hospital stay but unfortunately passed away shortly after her discharge from a previously undiagnosed gastric cancer.

  14. Contrast-enhanced CT imaging in patients with chronic kidney disease.

    PubMed

    von Stillfried, Saskia; Apitzsch, Jonas C; Ehling, Josef; Penzkofer, Tobias; Mahnken, Andreas H; Knüchel, Ruth; Floege, Jürgen; Boor, Peter

    2016-10-01

    Renal microvascular rarefaction characterizes chronic kidney disease (CKD). In murine models of CKD, micro-CT imaging reflected capillary rarefaction using quantification of renal relative blood volume (rBV). In addition, micro-CT imaging revealed morphological alterations of the intrarenal vasculature including reduced vascular branching and lumen diameter. Here, we retrospectively quantified rBV in contrast-enhanced CT angiography in patients and found that, compared to non-CKD patients, those with CKD and renal fibrosis had significantly reduced rBV in the renal cortex. rBV values closely mirrored capillary rarefaction in the corresponding nephrectomy specimens. In patients with follow-up CT angiography, reduction of renal function was paralleled by a decline in rBV. Using virtual autopsy, i.e., postmortem CT angiography, morphometry of intrarenal arteries in 3D-rendered CT images revealed significantly reduced arterial diameter and branching in CKD compared to non-CKD cases. In conclusion, in CKD patients, contrast-enhanced CT imaging with quantification of rBV correlates with functional renal vasculature, whereas virtual autopsy allows morphometric analyses of macrovascular changes. Importantly, the observed vascular alterations in CKD patients mirror those in animals with progressive CKD, suggesting a high relevance of animal models for studying vascular alterations in CKD and renal fibrosis. PMID:27582011

  15. Added value of lung window in detecting drug mules on non-contrast abdominal computed tomography.

    PubMed

    Bahrami-Motlagh, Hooman; Vakilian, Fatemeh; Hassanian-Moghaddam, Hossein; Pourghorban, Ramin

    2016-06-01

    We evaluated the added value of lung window in non-contrast computed tomography (CT) of suspected body packers or stuffers. Forty suspected drug mules who were referred to our tertiary toxicology center were included. The final diagnosis of drug mule was based on the detection of packs in stool examination or surgery. Non-contrast CT scans were retrospectively interpreted by two blinded radiologists in consensus before and after reviewing the lung window images. The diagnostic performance of abdominal window scans alone and scans in both abdominal and lung windows were subsequently compared. Seven body packers and 21 body stuffers were identified. The sensitivity, negative predictive value (NPV), and diagnostic accuracy of scans in detection of drug mules (either drug packers or stuffers) raised from 60.7, 52.1, and 72.5 to 64.2, 54.5, and 75.0 %, respectively, with a more number of packs being detected (114 vs. 105 packs). In the body packers group, the diagnostic performance of both abdominal windows scans and combined abdominal and lung windows scans were 100 %. In the body stuffers group, the sensitivity, NPV, and diagnostic accuracy of scans increased from 47.6, 52.1, and 55.0 to 52.3, 54.5, and 57.5 %, respectively, after the addition of lung windows. Reviewing the lung window on non-contrast abdominal CT can be helpful in detection of drug mules.

  16. Outcome of Blunt Abdominal Traumas with Stable Hemodynamic and Positive FAST Findings

    PubMed Central

    Behboodi, Firooz; Mohtasham-Amiri, Zahra; Masjedi, Navid; Shojaie, Reza; Sadri, Peyman

    2016-01-01

    Introduction: Focused assessment with sonography for trauma (FAST) is a highly effective first screening tool for initial classification of abdominal trauma patients. The present study was designed to evaluate the outcome of patients with blunt abdominal trauma and positive FAST findings. Methods: The present prospective cross-sectional study was done on patients over 7 years old with normal abdominal examination, positive FAST findings, and available abdominopelvic computed tomography (CT) scan findings. The frequency of need for laparotomy as well as its probable risk factors were calculated. Results: 180 patients were enrolled (mean age: 28.0 ± 11.5 years; 76.7% male). FAST findings were confirmed by abdominopelvic CT scan in only 124 (68.9%) cases. Finally, 12 (6.6%) patients needed laparotomy. Mean age of those in need of laparotomy was significantly higher than others (36.75 ± 11.37 versus 27.34 ± 11.37, p = 0.006). Higher grading of spleen (p = 0.001) and hepatic (p = 0.038) ruptures increased the probability of need for laparotomy. Conclusion: 68.9% of the positive FAST findings in patients with blunt abdominal trauma and stable hemodynamics was confirmed by abdominopelvic CT scan and only 6.6% needed laparotomy. Simultaneous presence of free fluid and air in the abdominal area, old age, and higher grading o solid organ injuries were factors that had a significant correlation with need for laparotomy. PMID:27299142

  17. [ENDOVASCULAR ABDOMINAL AORTIC ANEURISM REPAIR].

    PubMed

    Maĭstrenko, D N; Generalov, M I; Tarazov, P G; Zherebtsov, F K; Osovskikh, V V; Ivanov, A S; Oleshchuk, A N; Granov, D A

    2015-01-01

    The authors analyzed the single-center experience of treatment of 72 patients with abdominal aortic aneurisms and severe accompanied pathology. The aneurisms were repaired by stent-grafts. All the patients had abdominal aortic aneurisms with the diameters from 41 to 84 mm against the background of severe somatic pathology. It was a contraindication to planned open surgery. An installation of stent-graft was successful in all 72 follow-ups. It wasn't necessary to use a conversion to open surgery. The follow-up period consisted of 44,6?2,1 months. Control ultrasound and computer tomography studies hadn't revealed an increase of aneurism sack sizes or "eakages". A reduction of abdominal aortic aneurism sizes was noted in 37 patients on 4-5% during first year after operation. The stent-graft implantation extends the possibilities of abdominal aortic aneurism treatment for patients from a high surgical risk group. PMID:26234059

  18. Functional Abdominal Pain in Children

    MedlinePlus

    ... At low doses, these medicines can be excellent pain relievers for some children. A fearful, anxious, or depressed child however should be fully assessed by a psychiatrist or psychologist. Some psychological treatments that help children cope with functional abdominal pain ...

  19. Abdominal ultrasonography, 2nd Ed

    SciTech Connect

    Goldberg, B.B.

    1984-01-01

    This volume is a new and updated edition of an extensively illustrated text and reference on the capabilities and imaging of gray scale ultrasonography for each major abdominal organ. Each major organ system is treated separately, including liver, gallbladder and bile ducts, pancreas, kidney, retroperitoneum, abdominal vasculature, and more. There are over 500 illustrations and ten pages of full color plates for cross sectional anatomy.

  20. To CT or not to CT? The influence of computed tomography on the diagnosis of appendicitis in obese pediatric patients

    PubMed Central

    Roy, Haven; Burbridge, Brent

    2015-01-01

    Background Appendicitis is a common pediatric query. However, obesity often results in nondiagnostic ultrasounds and increased likelihood of abdominal computed tomography (CT). Concern regarding radiation exposure led the Canadian Association of Radiologists to recommend foregoing CT when ultrasounds are nondiagnostic and clinical suspicion is high. We evaluated this recommendation by quantifying the influence of CT on the diagnosis of pediatric appendicitis. Methods We performed a 2-year retrospective case series of children presenting with suspected appendicitis. We stratified patients by weight (obese v. nonobese) and pediatric appendicitis score (PAS) and examined how often they received abdominal CT, why they received it, and its influence on diagnosis. Results Of 223 patients (84 obese, 139 nonobese), 54 received CT. Obese patients received CTs more frequently than nonobese patients (29% v. 22%). The most common reason for CT was a nondiagnostic ultrasound (75% in obese, 80% in nonobese patients). Sixty-five percent of CTs obtained after nondiagnostic ultrasounds confirmed the initial diagnosis, but the rates were 80% and 50%, respectively, when only obese and only nonobese patients were considered. Obese patients were 4 times more likely to have a CT confirming their initial appendicitis diagnosis. Conclusion Because obese patients are more likely than nonobese patients to have a CT that confirms appendicitis, when treating an obese pediatric patient with suspected appendicitis and a nondiagnostic ultrasound, surgeons with a high clinical suspicion should strongly consider foregoing CT and proceeding with treatment. PMID:26011850

  1. Types of diaphragmatic motion during hepatic angiography.

    PubMed

    Katsuda, T; Kuroda, C; Fujita, M

    1997-01-01

    To determine the types and causes of diaphragmatic motion during hepatic angiography, the authors used transarterial cut-film portography (TAP) to study movement of the diaphragm during breath-holding. Thirty-three TAP sequences were studied, and the patients' diaphragmatic motions were classified into four categories according to the distance their diaphragms moved. Results showed that the diaphragm was stationary in 33% of the TAP studies, while perpetual motion occurred in 15% of the studies, early-phase motion occurred in 12% and late-phase motion occurred in 40%. Ten sequences showed diaphragmatic motion of more than 10 mm, with eight sequences showing caudal motion and two showing cranial motion. This article discusses the cause of diaphragmatic motion during breath-holding for hepatic angiography and presents suggestions to reduce motion artifacts during the exam.

  2. Abdominal emergencies in the geriatric patient

    PubMed Central

    2014-01-01

    Abdominal pain is one of the most frequent reasons that elderly people visit the emergency department (ED). In this article, we review the deadliest causes of abdominal pain in this population, including mesenteric ischemia, abdominal aortic aneurysm, and appendicitis and potentially lethal non-abdominal causes. We also highlight the pitfalls in diagnosing, or rather misdiagnosing, these clinical entities. PMID:25635203

  3. 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

  4. Optical Coherence Tomography Angiography of Chorioretinal Diseases.

    PubMed

    Novais, Eduardo A; Roisman, Luiz; de Oliveira, Paulo Ricardo Chaves; Louzada, Ricardo N; Cole, Emily D; Lane, Mark; Filho, Marco Bonini; Romano, André; de Oliveira Dias, João Rafael; Regatieri, Caio V; Chow, David; Belfort, Rubens; Rosenfeld, Philip; Waheed, Nadia K; Ferrara, Daniela; Duker, Jay S

    2016-09-01

    Fluorescein angiography (FA) and indocyanine green angiography (ICGA) have been the gold standard for the evaluation of retinal and choroidal vasculature in the last three decades and have revolutionized the diagnosis of retinal and choroidal vascular diseases. The advantage of these imaging modalities lies in their ability to document retinal and choroidal vasculature through the dynamic assessment of contrast transit over time in the intravascular and extravascular spaces. However, disadvantages include the absence of depth resolution, blurring of details by contrast leakage, and the inability to selectively evaluate different levels of the retinal and choroidal microvasculature. In addition, these angiographic methods require intravenous dye, which may cause adverse reactions such as nausea, vomiting, and rarely, anaphylaxis. Optical coherence tomography angiography (OCTA) is a noninvasive imaging technique that, in contrast to dye-based angiography, is faster and depth-resolved, allowing in some cases for more precise evaluation of the vascular plexuses of the retina and choroid. The method has been demonstrated in the assessment of various vascular diseases such as venous occlusions, diabetic retinopathy, macular neovascularization, and others. Limitations of this imaging modality include a small registered field of view and the inability to visualize leakage and dye transit over time. It is also subject to a variety of artifacts, including those generated by blinking and eye movement during image acquisition. However, more than an alternative for FA and ICGA, OCTA is bringing new insights to our understanding of retinal and choroidal vascular structure and is changing fundamental paradigms in the clinical management of pathologic conditions. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:848-861.]. PMID:27631482

  5. 5-F catheter in cerebral angiography

    SciTech Connect

    O'Reilly, G.V.; Naheedy, M.H.; Colucci, V.M.; Hammerschlag, S.B.

    1981-11-01

    Although the 5-F catheter is reputed to cause less vascular trauma than larger catheters, subintimal injections of contrast material have occurred following intimal damage by the catheter tip. Microscopic studies of the tips of two widely used 5-F polyethylene catheters have revealed a difference in configuration resulting in one of the catheters becoming markedly damaged during angiography. The authors make recommendations for finishing and protecting the catheter tip.

  6. Comparison of spirometry and abdominal height as four-dimensional computed tomography metrics in lung

    SciTech Connect

    Lu Wei; Low, Daniel A.; Parikh, Parag J.; Nystrom, Michelle M.; El Naqa, Issam M.; Wahab, Sasha H.; Handoko, Maureen; Fooshee, David; Bradley, Jeffrey D.

    2005-07-15

    An important consideration in four-dimensional CT scanning is the selection of a breathing metric for sorting the CT data and modeling internal motion. This study compared two noninvasive breathing metrics, spirometry and abdominal height, against internal air content, used as a surrogate for internal motion. Both metrics were shown to be accurate, but the spirometry showed a stronger and more reproducible relationship than the abdominal height in the lung. The abdominal height was known to be affected by sensor placement and patient positioning while the spirometer exhibited signal drift. By combining these two, a normalization of the drift-free metric to tidal volume may be generated and the overall metric precision may be improved.

  7. 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

  8. 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.

  9. ENDOCOM : abdominal aortic aneurysm test bench for in vitro simulation.

    PubMed

    Mazeyrat, Johan; Romain, Olivier; Garda, Patrick; Lagrée, Pierre-Yves; Destrade, Michel; Karouia, Mourad; Leprince, Pascal

    2007-01-01

    An abdominal aortic aneurysm (AAA) is a dilatation of the aorta at the abdominal level, whose rupture is a life threatening complication. Recent treatment procedures of AAA consists in endovascular treatment with covered stent grafts. Despite improving design of these devices, this treatment is still associated with close to 25% of failure, due to persisting pressure into the excluded aneurysmal sac. The follow-up becomes thus crucial and demands frequent examinations (CT-scan, IRM) which are not so liable given the complications. In order to evaluate the post-operative period of an AAA treatment, we designed a communicative stent, comprising of an integrated pressure sensor. This paper presents the conception of a communicative sensor, the elaboration of a numerical model, and the development of an experimental testbench reproducing the aortic flux across an AAA and allowing the optimization and validation of the measurement principle. PMID:18002457

  10. Bubble gum simulating abdominal calcifications.

    PubMed

    Geller, E; Smergel, E M

    1992-01-01

    CT examination of the abdomens of two children demonstrated sites of high attenuation in the stomach, which were revealed to be bubble gum. Investigation of the CT appearance of samples of chewing gum showed that it consistently has high attenuation (178-345 HU). The attenuation of gum base, which contains calcium carbonate, was 476 HU. In addition, examination of a volunteer who had swallowed bubble gum confirmed the CT appearance. PMID:1523059

  11. 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

  12. Texture analysis improves level set segmentation of the anterior abdominal wall

    SciTech Connect

    Xu, Zhoubing; Allen, Wade M.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-12-15

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention.Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall.Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture.Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture

  13. Texture analysis improves level set segmentation of the anterior abdominal wall

    PubMed Central

    Xu, Zhoubing; Allen, Wade M.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-01-01

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention. Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall. Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture. Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture

  14. Conservative management of abdominal injuries

    PubMed Central

    Okuş, Ahmet; Sevinç, Barış; Ay, Serden; Arslan, Kemal; Karahan, Ömer; Eryılmaz, Mehmet Ali

    2013-01-01

    Objective: Non-operative management of abdominal injuries has recently become more common. Especially non-operative treatment of blunt abdominal trauma is gaining wide acceptance. In this study, the efficacy of non-operative treatment in abdominal trauma (blunt penetrating) is discussed. Material and Methods: All patients who received treatment due to abdominal trauma from November 2008 to January 2013 were retrospectively analyzed. The demographic characteristics, type of injury, injured organ, type of treatment (operative vs. nonoperative) and mortality data were evaluated. Results: The study includes 115 patients treated for abdominal trauma in our department. The mechanism of trauma was stab wounds in 60%, blunt abdominal trauma in 23.5% and gunshot wounds in 16.5%. Forty-two patients (36.5%) were operated for hemodynamic instability and/or peritonitis on admission. The remaining 63.5% of patients (n=73) were treated nonoperatively, 10 of whom required laparotomy during follow-up. The remaining 63 patients were treated with non-operative management. The success rate for non-operative treatment was 86.3% and there was no difference in terms of the types of injuries. The mortality rate was 4.3% (n= 5) in the whole series, but there were no deaths among the patients who had received non-operative treatment. In the whole patient group 54.2% (n=63) were treated nonoperatively. Conclusion: Nonoperative treatment in abdominal trauma is safe and effective. Patients with clinical stability and normal physical examination findings can be treated nonoperatively with close monitoring. PMID:25931868

  15. Adrenal Mass in Patients who Underwent Abdominal Computed Tomography Examination

    PubMed Central

    Al-Thani, Hassan; El-Menyar, Ayman; Al-Sulaiti, Marym; ElGohary, Hesham; Al-Malki, Ahmed; Asim, Mohammad; Tabeb, AbdelHakem

    2015-01-01

    Background: Adrenal masses are usually discovered incidentally (IAM) during abdominal computed tomography (CT). Aims: We aimed to describe the prevalence, management, and outcome of incidentally discovered adrenal mass on radiological investigation. Materials and Methods: A retrospective analysis was conducted to look for IAM identified by abdominal CT performed for other reasons between 2004 and 2008 and were followed for 4 years. IAM patients with known malignancy or clinically evident adrenal disease or overt disease originally missed due to insufficient clinical examination were excluded. Results: A total of 13,115 patients underwent abdominal CT, of which 136 were identified with adrenal mass (69 males and 67 females). Overall, 84 patients had benign IAM and six had primary adrenal carcinoma (all had tumor size ≥4 cm and five were males). Hormonal evaluation was performed in 80 cases, which revealed hypersecretion in 10 cases (six had Conn's syndrome and four had pheochromocytoma). Males had higher frequency of right-sided IAMs; whereas, left-sided IAM swere more common among females (P = 0.02). Seven patients underwent surgery and all were males (one Conn's syndrome, one pheochromocytoma, three primary adrenal adenocarcinoma, one benign nonfunctional adenoma, and one metastatic tumor). Only one patient died due to brain metastasis. Conclusion: The overall prevalence of adrenal incidentaloma is 1% in Qatar. Unfortunately, hormonal evaluation, surgical referral, and follow-up are not appropriate in this study. Moreover, screening of IAM warrants more attention to rule out malignancy. This work could be of value as a local auditing for the current management. PMID:26110133

  16. Volumetric analysis of abdominal aortic aneurysm

    NASA Astrophysics Data System (ADS)

    Baskin, Kevin M.; Kusnick, Catherine A.; Shamsolkottabi, Susanne; Lang, Elvira V.; Corson, J. D.; Stanford, William; Thompson, Brad H.; Hoffman, Eric A.

    1996-04-01

    The purpose of this study was to develop a valid, reliable and accurate system of measurement of abdominal aortic aneurysms, using volumetric analysis of x-ray computed tomographic data. This study evaluates illustrative cases, and compares measurements of AAA phantoms, using standard 2D versus volumetric methods. To validate the volumetric analysis, four phantom aneurysms were constructed in a range of diameters (4.5 - 7.0 cm) which presents the greatest management challenge to the clinician. These phantoms were imaged using a Toshiba Xpress SX helical CT. Separate scans were obtained at conventional (10 mm X 10 mm) and thin slice (5 mm X 5 mm) collimations. The thin slices were reconstructed at 2 mm intervals. Data from each of the 96 scans were interpreted using a standard 2D approach, then analyzed using task-oriented volumetric software. We evaluate patient assessments, and compare greatest outer diameters of phantoms, by standard versus volumetric methods. Qualitative differences between solutions based on standard versus volumetric analysis of illustrative patient cases are substantial. Expert radiologists' standard measurements of phantom aneurysms are highly reliable (r2 equals 0.901 - 0.958; p < 0.001), but biased toward significant overestimation of aneurysm diameters in the range of clinical interest. For the same phantoms, volumetric analysis was both more reliable (r2 equals 0.986 - 0.996; p < 0.001), and more accurate, with no significant bias in the range of interest. Volumetric analysis promotes selection of more valid management strategies, by providing vital information not otherwise available, and allowing more reliable and accurate assessment of abdominal aortic aneurysms. It is particularly valuable in the presence of aortic tortuosity, vessel eccentricity, and uncertain involvement of critical vessels.

  17. Strategies for reduction of radiation dose in cardiac multislice CT.

    PubMed

    Paul, Jean-François; Abada, Hicham T

    2007-08-01

    Because cardiac computed tomography (CT) (mainly coronary CT angiography) is a very promising technique, used more and more for coronary artery evaluation, the benefits and risks of this new low-invasive technique must be balanced. Radiation dose is a major concern for coronary CT angiography, especially in case of repeated examinations or in particular subgroups of patients (for example young female patients). Radiation dose to patient tends to increase from 16- to 64-slice CT. Radiation exposure in ECG-gated acquisitions may reach up to 40 mSv; considerable differences are attributable to the performance of CT machines, to technical dose-sparing tools, but also to radiological habits. Setting radiation dose at the lowest level possible should be a constant goal for the radiologist. Current technological tools are detailed in regard to their efficiency. Optimisation is necessary, by a judicious use of technological tools and also by individual adaptation of kV or mAs. This paper reviews the different current strategies for radiation dose reduction, keeping image quality constant. Data from the literature are discussed, and future technological developments are considered in regards to radiation dose reduction. The particular case of paediatric patients with congenital heart disease is also addressed.

  18. Intraoperative Sac Pressure Measurement During Endovascular Abdominal Aortic Aneurysm Repair

    SciTech Connect

    Ishibashi, Hiroyuki; Ishiguchi, Tsuneo; Ohta, Takashi; Sugimoto, Ikuo; Iwata, Hirohide; Yamada, Tetsuya; Tadakoshi, Masao; Hida, Noriyuki; Orimoto, Yuki; Kamei, Seiji

    2010-10-15

    PurposeIntraoperative sac pressure was measured during endovascular abdominal aortic aneurysm repair (EVAR) to evaluate the clinical significance of sac pressure measurement.MethodsA microcatheter was placed in an aneurysm sac from the contralateral femoral artery, and sac pressure was measured during EVAR procedures in 47 patients. Aortic blood pressure was measured as a control by a catheter from the left brachial artery.ResultsThe systolic sac pressure index (SPI) was 0.87 {+-} 0.10 after main-body deployment, 0.63 {+-} 0.12 after leg deployment (P < 0.01), and 0.56 {+-} 0.12 after completion of the procedure (P < 0.01). Pulse pressure was 55 {+-} 21 mmHg, 23 {+-} 15 mmHg (P < 0.01), and 16 {+-} 12 mmHg (P < 0.01), respectively. SPI showed no significant differences between the Zenith and Excluder stent grafts (0.56 {+-} 0.13 vs. 0.54 {+-} 0.10, NS). Type I endoleak was found in seven patients (15%), and the SPI decreased from 0.62 {+-} 0.10 to 0.55 {+-} 0.10 (P = 0.10) after fixing procedures. Type II endoleak was found in 12 patients (26%) by completion angiography. The SPI showed no difference between type II endoleak positive and negative (0.58 {+-} 0.12 vs. 0.55 {+-} 0.12, NS). There were no significant differences between the final SPI of abdominal aortic aneurysms in which the diameter decreased in the follow-up and that of abdominal aortic aneurysms in which the diameter did not change (0.53 {+-} 0.12 vs. 0.57 {+-} 0.12, NS).ConclusionsSac pressure measurement was useful for instant hemodynamic evaluation of the EVAR procedure, especially in type I endoleaks. However, on the basis of this small study, the SPI cannot be used to reliably predict sac growth or regression.

  19. Abdominal aortic grafting for spontaneous infrarenal abdominal aortic dissection.

    PubMed

    Iwasaki, Hiroto; Shibuya, Takashi; Shintani, Takashi; Uenaka, Hisazumi; Suehiro, Shigefumi; Satoh, Hisashi

    2010-02-01

    This case report concerns a 62-year-old woman with spontaneous infrarenal abdominal aortic dissection, which developed into claudication and rest pain in the lower extremity. Multi-row detector computed tomography showed the entry site of the abdominal aortic dissection at the second lumbar artery, while the reentry site was found intraoperatively at the median sacral artery, indicating that the false lumen had progressed and compressed the true lumen. A direct approach involving grafting appears to be an effective procedure for resolving mesenteric and lower extremity hypoperfusion due to aortic dissection with a dilated false channel, even during the acute period. PMID:19879731

  20. A Curious Case of Right Upper Quadrant Abdominal Pain.

    PubMed

    Grock, Andrew; Chan, Wendy; deSouza, Ian S

    2016-09-01

    An otherwise healthy 36-year-old man presented with sudden-onset right upper quadrant abdominal pain and vomiting. A bedside ultrasound, performed to evaluate hepatobiliary pathology, revealed a normal gallbladder but free intraperitoneal fluid. After an expedited CT and emergent explorative laparotomy, the patient was diagnosed with a small bowel obstruction with ischemia secondary to midgut volvulus. Though midgut volvulus is rare in adults, delays in definitive diagnosis and management can result in bowel necrosis. Importantly, an emergency physician must be able to recognize bedside ultrasound findings associated with acutely dangerous intrabdominal pathology. PMID:27625732

  1. A Curious Case of Right Upper Quadrant Abdominal Pain

    PubMed Central

    Grock, Andrew; Chan, Wendy; deSouza, Ian S.

    2016-01-01

    An otherwise healthy 36-year-old man presented with sudden-onset right upper quadrant abdominal pain and vomiting. A bedside ultrasound, performed to evaluate hepatobiliary pathology, revealed a normal gallbladder but free intraperitoneal fluid. After an expedited CT and emergent explorative laparotomy, the patient was diagnosed with a small bowel obstruction with ischemia secondary to midgut volvulus. Though midgut volvulus is rare in adults, delays in definitive diagnosis and management can result in bowel necrosis. Importantly, an emergency physician must be able to recognize bedside ultrasound findings associated with acutely dangerous intrabdominal pathology.

  2. A Curious Case of Right Upper Quadrant Abdominal Pain

    PubMed Central

    Grock, Andrew; Chan, Wendy; deSouza, Ian S.

    2016-01-01

    An otherwise healthy 36-year-old man presented with sudden-onset right upper quadrant abdominal pain and vomiting. A bedside ultrasound, performed to evaluate hepatobiliary pathology, revealed a normal gallbladder but free intraperitoneal fluid. After an expedited CT and emergent explorative laparotomy, the patient was diagnosed with a small bowel obstruction with ischemia secondary to midgut volvulus. Though midgut volvulus is rare in adults, delays in definitive diagnosis and management can result in bowel necrosis. Importantly, an emergency physician must be able to recognize bedside ultrasound findings associated with acutely dangerous intrabdominal pathology. PMID:27625732

  3. Contrast-enhanced MR angiography utilizing parallel acquisition techniques in renal artery stenosis detection.

    PubMed

    Slanina, Martin; Zizka, Jan; Klzo, Ludovít; Lojík, Miroslav

    2010-07-01

    Significant renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension and/or renal impairment. It is caused by either atherosclerosis or fibromuscular dysplasia. Correct and timely diagnosis remains a diagnostic challenge. MR angiography (MRA) as a minimally invasive method seems to be suitable for RAS detection, however, its diagnostic value widely differs in the literature (sensitivity 62-100% and specificity 75-100%). The aim of our prospective study was to compare the diagnostic value of contrast-enhanced MRA utilizing parallel acquisition techniques in the detection of significant RAS with digital subtraction angiography (DSA). A total of 78 hypertensive subjects with suspected renal artery stenosis were examined on a 1.5 Tesla MR system using a body array coil. Bolus tracking was used to monitor the arrival of contrast agent to the abdominal aorta. The MRA sequence parameters were as follows: TR 3.7 ms; TE 1.2 ms; flip angle 25 degrees; acquisition time 18s; voxel size 1.1 mm x1.0 mm x 1.1 mm; centric k-space sampling; parallel acquisition technique with acceleration factor of 2 (GRAPPA). Renal artery stenosis of 60% and more was considered hemodynamically significant. The results of MRA were compared to digital subtraction angiography serving as a standard of reference. Sensitivity and specificity of MRA in the detection of hemodynamically significant renal artery stenosis were 90% and 96%, respectively. Prevalence of RAS was 39% in our study population. Contrast-enhanced MRA with high spatial resolution offers sufficient sensitivity and specificity for screening of RAS. PMID:19671492

  4. Blunt Abdominal Wall Disruption by Seatbelt Injury; A Case Report and Review of the Literature

    PubMed Central

    Cornelissen, Maarten Philip; van Buijtenen, Jesse; van den Heuvel, Baukje; Bloemers, Frank; Geeraedts Jr., Leo

    2016-01-01

    With the introduction of the use of seatbelts in cars, mortality following motor vehicle crashes has decreased significantly. However, two patterns of injuries, the ‘seatbelt sign’ and ‘seatbelt syndrome’ have emerged. Injuries may consist of traumatic abdominal wall disruption. We present two cases of severe abdominal wall disruption caused by a seatbelt injury and treated with primary repair. A review of the literature is provided. Two patients were brought in after a high velocity Motor Vehicle Collision. Both presented with an acute abdomen and a seatbelt sign upon which the decision was made to perform emergency laparotomies. Both patients had an abdominal wall disruption along the seatbelt sign. These disruptions were primarily closed and during six months of follow-up no complications occurred. A disruption of the abdominal wall is a rare complication. However, it is a diagnosis that may not be missed as patients have a higher risk of morbidity and mortality. CT-scanning is an accurate method to detect disruptions. Closure of blunt traumatic abdominal wall disruption can be done primarily with sutures or addition of a mesh. In both cases of the severe abdominal wall disruption, primary repair without mesh in the acute phase was successful. When a laparotomy is not indicated, the abdominal wall must be assessed for disruption. If there is a disruption primary repair is a good option. PMID:27331068

  5. Abdominal radiation causes bacterial translocation

    SciTech Connect

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  6. Myocardial perfusion imaging with dual energy CT.

    PubMed

    Jin, Kwang Nam; De Cecco, Carlo N; Caruso, Damiano; Tesche, Christian; Spandorfer, Adam; Varga-Szemes, Akos; Schoepf, U Joseph

    2016-10-01

    Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  7. Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors

    PubMed Central

    Padole, Atul; Sainani, Nisha; Lira, Diego; Khawaja, Ranish Deedar Ali; Pourjabbar, Sarvenaz; Lo Gullo, Roberto; Otrakji, Alexi; Kalra, Mannudeep K

    2016-01-01

    AIM: To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (S