WorldWideScience

Sample records for angiography visual estimation

  1. Angiography

    International Nuclear Information System (INIS)

    The history of angiography is short, with its centennial approaching. A very brief review of milestones begins with the discovery of x-rays in 1895. Only a few months later contrast agents too toxic for human use were being injected into cadavers, severed limbs, and animals. The next major developments came in the late 1970s when percutaneous translumbar aortography and cerebral angiography were described. Contrast agents were now less toxic, and clinically useful angiography was a reality. In 1953 a technique for percutaneous vascular catheterization which formed the basis of many catheterization techniques to follow was described. In the 1970s the development of less invasive diagnostic methods such as computed tomography and diagnostic ultrasound decreased the indications for angiography, but newer interventional techniques such as embolization therapy and angioplasty have taken up the slack. Angiography remains the most important way to demonstrate vascular diseases graphically. Specific techniques such as angioplasty and digital subtraction angiography will be dealt with in other chapters. The authors hope to provide an overview of major areas of angiographic utilization. The basic techniques of arterial puncture and catheterization have been well described elsewhere

  2. Generalised brain edema and brain infarct in ergotamine abuse: Visualization by CT, MR and angiography

    International Nuclear Information System (INIS)

    Abuse of ergotamine can release a generalised brain edema and brain infarctions. This can be visualized by CT, MR and angiography. The reason, however, can only be found in the patients history. (orig.)

  3. Multislice computed tomography angiography in the diagnosis of cardiovascular disease: 3D visualizations

    Institute of Scientific and Technical Information of China (English)

    Zhonghua Sun

    2011-01-01

    Multislice computed tomography (CT) has been widely used in clinical practice for the diagnosis of cardiovascular disease due to its reduced invasiveness and high spatial and temporal resolution.As a reliable alternative to conventional angiography,multislice CT angiography has been recognized as the method of choice for detecting and diagnosing head and neck vascular disease,abdominal aortic aneurysm,aortic dissection,and pulmonary embolism.In patients with suspected coronary artery disease,although invasive coronary angiography still remains as the gold standard technique,multislice CT angiography demonstrates high diagnostic accuracy; in selected patients,it is considered as the first-line technique.The imaging diagnosis of cardiovascular disease is based on a combination of two-dimensional (2D) and three-dimensional (3D) visualization tools to enhance the diagnostic value.This is facilitated by reconstructed visualizations which provide additional information about the extent of the disease,an accurate assessment of the spatial relationship between normal structures and pathological changes,and pre-operative planning and post-procedure follow-up.The aim of the present article is to present an overview of the diagnostic performance of various 2D and 3D CT visualizations in cardiovascular disease,including multiplanar reformation,maximum intensity projection,volume rendering,and virtual intravascular endoscopy.The recognition of the potential value of these visualizations will assist clinicians in efficiently using the muitislice CT imaging modality for the diagnostic management of patients with cardiovascular disease.

  4. Comparison of intra-aortic computed tomography angiography to conventional angiography in the presurgical visualization of the Adamkiewicz artery: first results in patients with thoracoabdominal aortic aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Clarencon, Frederic [Paris VI University, Department of Interventional Neuroradiology, Pitie-Salpetriere Hospital, Paris (France); Pitie-Salpetriere Hospital, Department of Neuroradiology, Paris (France); Maria, Federico di; Cormier, Evelyne; Sourour, Nader; Gabrieli, Joseph; Iosif, Christina; Chiras, Jacques [Paris VI University, Department of Interventional Neuroradiology, Pitie-Salpetriere Hospital, Paris (France); Gaudric, Julien; Koskas, Fabien [Paris VI University, Department of Vascular Surgery, Pitie-Salpetriere Hospital, Paris (France); Jenny, Catherine [Paris VI University, Department of Radiophysics, Pitie-Salpetriere Hospital, Paris (France)

    2013-11-15

    The aim of this study was to compare the sensitivity of intra-aortic computed tomography angiography (IA-CTA) to that of regular spinal digital subtraction angiography for the presurgical location of the Adamkiewicz artery (AKA). Thirty patients (21 males, 9 females; mean age 64 years) had an IA-CTA for the location of the AKA before surgery of aneurysm (n = 24) or dissection (n = 6) of the thoracoabdominal aorta. After femoral artery puncture, a pigtail catheter was positioned at the origin of the descending aorta. CT acquisition was performed with an intra-aortic iodinated contrast media injection (15 mL/s, 120 mL). The visualization of the AKA and the location of the feeder(s) to the AKA were independently evaluated by two observers. Interrater agreement was calculated using a kappa test. Spinal angiogram by selective catheterization was systematically performed to confirm the results of the IA-CTA. The AKA was visualized by the IA-CTA in 27/30 cases (90 %); in 26/31 (84 %) cases, the continuity with the aorta was satisfactorily seen. Interrater agreement was good for the visualization of the AKA and its feeder(s): 0.625 and 0.87, respectively. In 75 % of the cases for which the AKA was visualized, the selective catheterization confirmed the results of the IA-CTA. In the remaining 25 % of the cases, the selective catheterization could not be performed due to marked vessels' tortuosity or ostium stenosis. IA-CTA is a feasible technique in a daily practice that presents a good sensitivity for the location of the AKA. (orig.)

  5. Radiation dose estimates in dual-source computed tomography coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Stolzmann, Paul; Scheffel, Hans; Schertler, Thomas; Frauenfelder, Thomas; Leschka, Sebastian; Husmann, Lars; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Flohr, Thomas G. [Siemens Medical Solutions, Forchheim (Germany); Kaufmann, Philipp A. [Cardiovascular Center, Forchheim (Germany)

    2008-03-15

    The purpose of this study was to quantify radiation dose parameters of dual-source CT coronary angiography. Eighty patients underwent contrast-enhanced, retrospectively ECG-gated dual-source CT coronary angiography with heart rate-adapted ECG pulsing using two algorithms: In 40 patients, the tube current was reduced to 20% (A{sub min1}) of the normal tube current (A{sub max}) outside the pulsing window; in 40 patients tube current was reduced to 4% (A{sub min2}) of A{sub max}. Mean CTDI{sub vol} in the A{sub min1} group was 45.1 {+-} 3.6 mGy; the mean CTDI{sub vol} in the A{sub min2} group was 39.1 {+-} 3.2 mGy, with CTDI{sub vol} in the A{sub min2} group being significantly reduced when compared to the A{sub min1} group (P < 0.001). A significant negative correlation was found between CTDI{sub vol} and heart rate in group A{sub min1} (r = -0.82, P < 0.001), whereas no correlation was found between CTDI{sub vol} and heart rate in group A{sub min2} (r = -0.066). Using the conversion coefficient for the chest, dual-source CT coronary angiography resulted in an estimated mean effective dose of 8.8 mSv in the A{sub min1} group and 7.8 mSv in the A{sub min2}. Radiation exposure of dual-source CT coronary angiography using an ECG-pulsing protocol reducing the tube current to 20% significantly decreases with increasing heart rates, despite using wider pulsing windows at higher heart rates. When using a protocol with reduced tube current of 4%, the radiation dose is significantly lower, irrespective of the heart rate. (orig.)

  6. Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization.

    Science.gov (United States)

    Cui, Dongmei; Lynch, James C; Smith, Andrew D; Wilson, Timothy D; Lehman, Michael N

    2016-01-01

    Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin. PMID:25929248

  7. In vivo validation of a blood vector velocity estimator with MR angiography

    DEFF Research Database (Denmark)

    Hansen, K.L.; Udesen, J.; Thomsen, C.;

    2009-01-01

    contrast angiography (MRA) by comparing in vivo measurements of stroke volume. Eleven healthy volunteers were included in this prospective study. From the obtained data sets recorded with the 2 modalities, vector velocity sequences were constructed and stroke volume calculated. Angle of insonation...... method transverse oscillation (TO), which combines estimates of the axial and the transverse velocity components in the scan plane, makes it possible to estimate the vector velocity of the blood regardless of the Doppler angle. The present study evaluates the TO method with magnetic resonance phase.......4 ml and 1.9 ml. The results indicate that reliable vector velocity estimates can be obtained in vivo using the presented angle-independent 2-D vector velocity method. The TO method can be a useful alternative to conventional Doppler systems by avoiding the angle artifact, thus giving quantitative...

  8. Diagnostic Accuracy of Early Computed Tomographic Angiography for Visualizing Medium Sized Inferior and Posterior Projecting Carotid System Aneurysms

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2011-11-01

    Full Text Available Background:Conventional angiography, generally referred to as intra-arterial digital subtraction angiography, still remains the gold standard reference method for the diagnosis of intracranial aneurysms,helical computed tomography angiography (CTA is a new non-invasive volumetric imaging method.Objectives:This study was conducted to screen patients presenting with subarachnoidhemorrhage by CTA before conventional digital subtraction angiography (DSA and subsequently comparing the results for various aneurysm projections.Patients and Methods: In a prospective study, 99 consecutive patients with an initial diagnosis of subarachnoid hemorrhage were screened for aneurysms with CTA followed by conventional DSA. There were 17 cases with negative angiograms in whom repeat angiograms, three months later were negative for 15 cases, while two cases were found to bear aneurysm on the repeat examination. Eighty two patients had at least one proven aneurysm on initial DSA and two on the repeat angiogram.Out of 84 patients, five underwent endovascular treatment and 79 patients who underwent surgical clipping were considered for projection evaluation.Results: Sensitivity of CTA was 98.78% (95% confidence interval [CI], 93.4-99.7%, while the specificity was 100% (95% CI, 81.57-100% and the kappa coefficient of agreement between CTA and DSA was 96.5%. The most significant discrepancies with DSA findings were for visualizing the projection of inferior and posterior projecting proximal anterior circulation aneurysms.Conclusions:Helical CTA was in good concordance with DSA for screening of cerebral aneurysms; however, for exact visualization of the aneurysm neck and its projection, especially if it is inferior or posterior, DSA remains the gold standard.

  9. Use of performance curves in estimating number of procedures required to achieve proficiency in coronary angiography

    DEFF Research Database (Denmark)

    Räder, Sune B E W; Jørgensen, Erik; Bech, Bo;

    2011-01-01

    Background: Current guidelines in cardiology training programs recommend 100-300 coronary angiography procedures for certification. We aimed to assess the number of procedures needed to reach sufficient proficiency. Methods: Procedure time, fluoroscopy time, dose area product (DAP), and contrast...... needed for trainees to reach recommended reference levels was estimated as 226 and 353, for DAP and use of contrast media, respectively. After 300 procedures, trainees' procedure time, fluoroscopy time, DAP, and contrast media volume were significantly higher compared with experts' performance, P ....001 for all parameters. To approach the experts' level of DAP and contrast media use, trainees need 394 and 588 procedures, respectively. Performance curves showed large individual differences in the development of competence. Conclusion: On average, trainees needed 300 procedures to reach sufficient level...

  10. Webcam-based visual gaze estimation

    NARCIS (Netherlands)

    R. Valenti; J. Staiano; N. Sebe; T. Gevers

    2009-01-01

    In this paper we combine a state of the art eye center locator and a new eye corner locator into a system which estimates the visual gaze of a user in a controlled environment (e.g. sitting in front of a screen). In order to reduce to a minimum the computational costs, the eye corner locator is buil

  11. Exploiting magnetic resonance angiography imaging improves model estimation of BOLD signal.

    Directory of Open Access Journals (Sweden)

    Zhenghui Hu

    Full Text Available The change of BOLD signal relies heavily upon the resting blood volume fraction ([Formula: see text] associated with regional vasculature. However, existing hemodynamic data assimilation studies pretermit such concern. They simply assign the value in a physiologically plausible range to get over ill-conditioning of the assimilation problem and fail to explore actual [Formula: see text]. Such performance might lead to unreliable model estimation. In this work, we present the first exploration of the influence of [Formula: see text] on fMRI data assimilation, where actual [Formula: see text] within a given cortical area was calibrated by an MR angiography experiment and then was augmented into the assimilation scheme. We have investigated the impact of [Formula: see text] on single-region data assimilation and multi-region data assimilation (dynamic cause modeling, DCM in a classical flashing checkerboard experiment. Results show that the employment of an assumed [Formula: see text] in fMRI data assimilation is only suitable for fMRI signal reconstruction and activation detection grounded on this signal, and not suitable for estimation of unobserved states and effective connectivity study. We thereby argue that introducing physically realistic [Formula: see text] in the assimilation process may provide more reliable estimation of physiological information, which contributes to a better understanding of the underlying hemodynamic processes. Such an effort is valuable and should be well appreciated.

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

    Directory of Open Access Journals (Sweden)

    Murali Chakravarthy

    2015-01-01

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

  13. COMMUNICATING ARTERY NOT VISUALIZED BY CEREBRAL ANGIOGRAPHY-REPORT OF FOUR CASES

    Institute of Scientific and Technical Information of China (English)

    张俊延; 王忠诚; 石祥恩

    1994-01-01

    Four cases of anterior communicating aneurysms are reported with clinical presentations of recurrent intracranial hemorrhage undisclosed in their cerbral angiography.Operative exploration revealed anterior communicating aneurysms in these patients.It is thought possible that these patients harbored aneurysms which failed to exhibit on angiograms due to temporary thrombosis or development of abnormal cerebral vessels.CT scanning was important for tdiagnosis of these patients.

  14. Human Posture Estimation using Visual Information

    Institute of Scientific and Technical Information of China (English)

    Jiayu XU

    2014-01-01

    Human-robot cooperation is one of the central research issues in robotics.Al kinds of sensors wil be used since the robot should understand human’s intention.This article wil focus on the human posture estimation by using Microsoft Kinect.The visual Information from Kinect can be acquired and used to extract the human skeletal information and further,calcu-late the human posture.The experiment results have been compared with a Qualisys system,which has been proved quite precisely.

  15. Multivariate density estimation theory, practice, and visualization

    CERN Document Server

    Scott, David W

    2015-01-01

    David W. Scott, PhD, is Noah Harding Professor in the Department of Statistics at Rice University. The author of over 100 published articles, papers, and book chapters, Dr. Scott is also Fellow of the American Statistical Association (ASA) and the Institute of Mathematical Statistics. He is recipient of the ASA Founder's Award and the Army Wilks Award. His research interests include computational statistics, data visualization, and density estimation. Dr. Scott is also Coeditor of Wiley Interdisciplinary Reviews: Computational Statistics and previous Editor of the Journal of Computational and

  16. Visual acuity estimation from simulated images

    Science.gov (United States)

    Duncan, William J.

    Simulated images can provide insight into the performance of optical systems, especially those with complicated features. Many modern solutions for presbyopia and cataracts feature sophisticated power geometries or diffractive elements. Some intraocular lenses (IOLs) arrive at multifocality through the use of a diffractive surface and multifocal contact lenses have a radially varying power profile. These type of elements induce simultaneous vision as well as affecting vision much differently than a monofocal ophthalmic appliance. With myriad multifocal ophthalmics available on the market it is difficult to compare or assess performance in ways that effect wearers of such appliances. Here we present software and algorithmic metrics that can be used to qualitatively and quantitatively compare ophthalmic element performance, with specific examples of bifocal intraocular lenses (IOLs) and multifocal contact lenses. We anticipate this study, methods, and results to serve as a starting point for more complex models of vision and visual acuity in a setting where modeling is advantageous. Generating simulated images of real- scene scenarios is useful for patients in assessing vision quality with a certain appliance. Visual acuity estimation can serve as an important tool for manufacturing and design of ophthalmic appliances.

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

    OpenAIRE

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

    2015-01-01

    Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in pati...

  18. Reliability of the interpretation of coronary angiography by the simple visual method

    Directory of Open Access Journals (Sweden)

    Guimarães Jorge Augusto Nunes

    2000-01-01

    Full Text Available OBJECTIVE: Evaluation of inter and intraobserver reproducibility of by the visual method interpretation of cineangiogram in a clinically based context. METHODS: Five interventional cardiologists analyzed 11 segments of 8 coronary cineangiograms at a two month apart sessions. The percent luminal reduction by the lesions were analyzed by two different classifications: in one (A the lesions were graded in 0% = absent, 1-50% = mild, 51 - 69 = moderate, and > or = 70% = severe; the other classification (B was a dichotomic one : or = 70%=significant lesions. The agreement were measured by the kappa (k index. RESULTS: Interobserver agreement was moderate for classification A (1st measurement, k = 0.36 -- 0.63, k m = 0.49; 2nd measurement, k = 0.39-0.68, k m = 0.52 and good for classification B (1st measurement, k = 0.55-0.73, k m = 0.63; 2nd measurement, k = 0.37-0.82, k m = 0.61. Intraobserver levels of agreement were k = 0.57-0.95 for classification A and 0.62-1.0 for classification B. CONCLUSION: The higher level of reproducibility obtained by adopting the dichotomous criteria usually considered for ischemic limits demonstrates that in the present clinical context, the reliability of the simple visual method is adequate for the identification of patients with clinically significant lesions and candidates for myocardial revascularization procedures.

  19. The role of visual information in numerosity estimation.

    Directory of Open Access Journals (Sweden)

    Titia Gebuis

    Full Text Available Mainstream theory suggests that the approximate number system supports our non-symbolic number abilities (e.g. estimating or comparing different sets of items. It is argued that this system can extract number independently of the visual cues present in the stimulus (diameter, aggregate surface, etc.. However, in a recent report we argue that this might not be the case. We showed that participants combined information from different visual cues to derive their answers. While numerosity comparison requires a rough comparison of two sets of items (smaller versus larger, numerosity estimation requires a more precise mechanism. It could therefore be that numerosity estimation, in contrast to numerosity comparison, might rely on the approximate number system. To test this hypothesis, we conducted a numerosity estimation experiment. We controlled for the visual cues according to current standards: each single visual property was not informative about numerosity. Nevertheless, the results reveal that participants were influenced by the visual properties of the dot arrays. They gave a larger estimate when the dot arrays consisted of dots with, on average, a smaller diameter, aggregate surface or density but a larger convex hull. The reliance on visual cues to estimate numerosity suggests that the existence of an approximate number system that can extract numerosity independently of the visual cues is unlikely. Instead, we propose that humans estimate numerosity by weighing the different visual cues present in the stimuli.

  20. Comparison of Clinical Interpretation with Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice: The Assessing Angiography (A2) Project

    Science.gov (United States)

    Nallamothu, Brahmajee K.; Spertus, John A.; Lansky, Alexandra J.; Cohen, David J.; Jones, Philip G.; Kureshi, Faraz; Dehmer, Gregory J.; Drozda, Joseph P.; Walsh, Mary Norine; Brush, John E.; Koenig, Gerald C.; Waites, Thad F.; Gantt, D. Scott; Kichura, George; Chazal, Richard A.; O’Brien, Peter K.; Valentine, C. Michael; Rumsfeld, John S.; Reiber, Johan H.C.; Elmore, Joann G.; Krumholz, Richard A.; Weaver, W. Douglas; Krumholz, Harlan M.

    2013-01-01

    Background Studies conducted decades ago described substantial disagreement and errors in physicians’ angiographic interpretation of coronary stenosis severity. Despite the potential implications of such findings, no large-scale efforts to measure or improve clinical interpretation were subsequently made. Methods & Results We compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective percutaneous coronary intervention (PCI) at 7 U.S. hospitals in 2011. To assess agreement, we calculated mean difference in percent diameter stenosis between clinical interpretation and QCA and a Cohen’s weighted kappa statistic. Of 216 treated lesions, median percent diameter stenosis was 80.0% (Q1 and Q3, 80.0 and 90.0%) with 213 (98.6%) assessed as ≥70%. Mean difference in percent diameter stenosis between clinical interpretation and QCA was +8.2 ± 8.4%, reflecting an average higher percent diameter stenosis by clinical interpretation (P<0.001). A weighted kappa of 0.27 (95% CI, 0.18 to 0.36) was found between the 2 measurements. Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA though none was <50%. Differences between the 2 measurements were largest for intermediate lesions by QCA (50 to <70%) with variation existing across sites. Conclusions Physicians tended to assess coronary lesions treated with PCI as more severe than measurements by QCA. Almost all treated lesions were ≥70% by clinical interpretation, while approximately a quarter were <70% by QCA. These findings suggest opportunities to improve clinical interpretation of coronary angiography. PMID:23470859

  1. Predictive visual tracking based on least absolute deviation estimation

    Institute of Scientific and Technical Information of China (English)

    Rongtai Cai; Yanjie Wang

    2008-01-01

    To cope with the occlusion and intersection between targets and the environment, location prediction is employed in the visual tracking system. Target trace is fitted by sliding subsection polynomials based on least absolute deviation (LAD) estimation, and the future location of target is predicted with the fitted trace. Experiment results show that the proposed location prediction algorithm based on LAD estimation has significant robustness advantages over least square (LS) estimation, and it is more effective than LS-based methods in visual tracking.

  2. Interstudy repeatability of left and right ventricular volume estimations by serial-gated tomographic radionuclide angiographies using a cadmium-zinc-telluride detector gamma camera

    DEFF Research Database (Denmark)

    Jensen, Maria M; Haase, Christine; Zerahn, Bo

    2015-01-01

    PURPOSE: Estimation of left ventricular ejection fraction (LVEF) with 99MTc-HSA equilibrium radionuclide angiography (RA) is frequently used for assessing cardiac function. The purpose of this study was to investigate the interstudy repeatability of left (LV) and right (RV) ventricular volume...

  3. Fused methods for visual saliency estimation

    Science.gov (United States)

    Danko, Amanda S.; Lyu, Siwei

    2015-02-01

    In this work, we present a new model of visual saliency by combing results from existing methods, improving upon their performance and accuracy. By fusing pre-attentive and context-aware methods, we highlight the abilities of state-of-the-art models while compensating for their deficiencies. We put this theory to the test in a series of experiments, comparatively evaluating the visual saliency maps and employing them for content-based image retrieval and thumbnail generation. We find that on average our model yields definitive improvements upon recall and f-measure metrics with comparable precisions. In addition, we find that all image searches using our fused method return more correct images and additionally rank them higher than the searches using the original methods alone.

  4. High-resolution coronary MR angiography for evaluation of patients with anomalous coronary arteries: visualization of the intramural segment

    Energy Technology Data Exchange (ETDEWEB)

    Biko, David M. [UCSF Benioff Children' s Hospital Oakland, Department of Diagnostic Imaging, Oakland, CA (United States); The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Chung, Claudia; Chung, Taylor [UCSF Benioff Children' s Hospital Oakland, Department of Diagnostic Imaging, Oakland, CA (United States); Hitt, David M. [Philips Healthcare, Cleveland, OH (United States); Kurio, Gregory [UCSF Benioff Children' s Hospital Oakland, Department of Cardiology, Oakland, CA (United States); Reinhartz, Olaf [UCSF Benioff Children' s Hospital Oakland, Department of Cardiac Surgery, Oakland, CA (United States)

    2015-08-15

    Anomalous origin of the coronary artery from the contralateral coronary sinus is a rare coronary anomaly associated with sudden death. The inter-arterial course is most closely associated with sudden death, but it has been suggested that the presence of an intramural segment of a right anomalous coronary is associated with more symptoms and therefore may be an important criterion for intervention in these patients. To demonstrate that MR angiography can accurately determine the presence or absence of an intramural segment in an anomalous coronary artery. All studies of children who underwent MR angiography for the evaluation of an anomalous coronary artery were retrospectively reviewed by two pediatric radiologists in consensus. Criteria for an intramural anomalous coronary artery were the presence of a small or slit-like ostium and the relative smaller size of the proximal intramural portion of the coronary artery in relation to the more distal epicardial coronary artery. The anomalous coronary artery was classified as not intramural if these two findings were absent. These findings were correlated with operative reports confirming the presence or absence of an intramural segment. Twelve patients (86%) met MR angiography criteria for the presence of an intramural course. Only 2 patients (14%) met MR angiography criteria for a non-intramural course. When correlating with intraoperative findings, MR angiography was successful in distinguishing between intramural and non-intramural anomalous coronary arteries in all cases (P = 0.01). MR angiography may be able to reliably identify the intramural segment of an anomalous coronary artery in older children using the imaging criteria of a small or slit-like ostium and relative decrease in size of the proximal portion of the anomalous coronary artery compared to the distal portion of the anomalous coronary artery. Determining the presence of the intramural segment may help with surgical planning and may be an important

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

    Science.gov (United States)

    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.

    Science.gov (United States)

    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. In Vivo Validation of a Blood Vector Velocity Estimator with MR Angiography

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Udesen, Jesper; Thomsen, Carsten;

    2009-01-01

    Conventional Doppler methods for blood velocity estimation only estimate the velocity component along the ultrasound beam direction. This implies that a Doppler angle under examination close to 90° results in unreliable information about the true blood direction and blood velocity. The novel meth...

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

    Science.gov (United States)

    D'Apuzzo, Nicola

    2000-12-01

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

  9. Distributed Estimation, Coding, and Scheduling in Wireless Visual Sensor Networks

    Science.gov (United States)

    Yu, Chao

    2013-01-01

    In this thesis, we consider estimation, coding, and sensor scheduling for energy efficient operation of wireless visual sensor networks (VSN), which consist of battery-powered wireless sensors with sensing (imaging), computation, and communication capabilities. The competing requirements for applications of these wireless sensor networks (WSN)…

  10. Estimating and Correcting Bias in Stereo Visual Odometry

    Science.gov (United States)

    Farboud-Sheshdeh, Sara

    Stereo visual odometry (VO) is a common technique for estimating a camera's motion; features are tracked across frames and the pose change is subsequently inferred. This method can play a particularly important role in environments where the global positioning system (GPS) is not available (e.g., Mars rovers). Recently, some authors have noticed a bias in VO position estimates that grows with distance travelled; this can cause the resulting estimate to become highly inaccurate. In this thesis, two effects are identified at play in stereo VO bias: first, the inherent bias in the maximum-likelihood estimation framework, and second, the disparity threshold used to discard far-away and erroneous observations. To estimate the bias, the sigma-point method (with modification) combined with the concept of bootstrap bias estimation is proposed. This novel method achieves similar accuracy to Monte Carlo experiments, but at a fraction of the computational cost. The approach is validated through simulations.

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

    International Nuclear Information System (INIS)

    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° through anthropomorphic voxelized female chest and head (0° and 30° 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 CTDIvol and multiplying by a physical CTDIvol 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° 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 total organ doses calculated using our database are

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

    Energy Technology Data Exchange (ETDEWEB)

    Rupcich, Franco; Badal, Andreu; Kyprianou, Iacovos; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Division of Imaging and Applied Mathematics (OSEL/CDRH), US Food and Drug Administration, Silver Spring, Maryland 20905 (United States); Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States)

    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

  13. Fluorescein angiography

    Science.gov (United States)

    ... with cataracts. Alternative Names Retinal photography; Eye angiography Images Retinal dye injection References Maguire JI, Federman JL. Intravenous ... Topics Diabetic Eye Problems Eye ... audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among ...

  14. Using Visual Odometry to Estimate Position and Attitude

    Science.gov (United States)

    Maimone, Mark; Cheng, Yang; Matthies, Larry; Schoppers, Marcel; Olson, Clark

    2007-01-01

    A computer program in the guidance system of a mobile robot generates estimates of the position and attitude of the robot, using features of the terrain on which the robot is moving, by processing digitized images acquired by a stereoscopic pair of electronic cameras mounted rigidly on the robot. Developed for use in localizing the Mars Exploration Rover (MER) vehicles on Martian terrain, the program can also be used for similar purposes on terrestrial robots moving in sufficiently visually textured environments: examples include low-flying robotic aircraft and wheeled robots moving on rocky terrain or inside buildings. In simplified terms, the program automatically detects visual features and tracks them across stereoscopic pairs of images acquired by the cameras. The 3D locations of the tracked features are then robustly processed into an estimate of overall vehicle motion. Testing has shown that by use of this software, the error in the estimate of the position of the robot can be limited to no more than 2 percent of the distance traveled, provided that the terrain is sufficiently rich in features. This software has proven extremely useful on the MER vehicles during driving on sandy and highly sloped terrains on Mars.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhonghua [Curtin University, Perth (Australia); Mwipatayi, Bibombe P [Royal Perth Hospital, Perth (Australia); Allen, Yvonne B; Hartley, David E [Cook R and D, Perth (Australia); Lawrence-Brown, Michael M [Curtin University of Technology, Perth (Australia)

    2009-06-15

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

  16. Visualization and quality assessment of the contrast transfer function estimation.

    Science.gov (United States)

    Sheth, Lisa K; Piotrowski, Angela L; Voss, Neil R

    2015-11-01

    The contrast transfer function (CTF) describes an undesirable distortion of image data from a transmission electron microscope. Many users of full-featured processing packages are often new to electron microscopy and are unfamiliar with the CTF concept. Here we present a common graphical output to clearly demonstrate the CTF fit quality independent of estimation software. Separately, many software programs exist to estimate the four CTF parameters, but their results are difficult to compare across multiple runs and it is all but impossible to select the best parameters to use for further processing. A new measurement is presented based on the correlation falloff of the calculated CTF oscillations against the normalized oscillating signal of the data, called the CTF resolution. It was devised to provide a robust numerical quality metric of every CTF estimation for high-throughput screening of micrographs and to select the best parameters for each micrograph. These new CTF visualizations and quantitative measures will help users better assess the quality of their CTF parameters and provide a mechanism to choose the best CTF tool for their data. PMID:26080023

  17. Digital angiography

    International Nuclear Information System (INIS)

    The basic principles of digital angiography and the clinical applications of the method are discussed. The authors review the experience at the Hotel-Dieu de Montreal covering more than 1000 digital examinations. The indications, results and contra-indications are exposed: numerous advantages (decreased invasiveness, diminished examination times, reduced radiation and improved cost efficiency) far outweigh the disadvantages (slight loss in resolution and small field of examination). A prospective appraisal of the potential and of future developments in digital radiography is also presented

  18. Perfusion Angiography in Acute Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Fabien Scalzo

    2016-01-01

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

  19. Perfusion Angiography in Acute Ischemic Stroke.

    Science.gov (United States)

    Scalzo, Fabien; Liebeskind, David S

    2016-01-01

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

  20. MR angiography

    International Nuclear Information System (INIS)

    As the result of the application of the recently developed MR techniques, the diagnosis of the morphology and the function has been possible. MR angiography (MRA) is one of these new techniques, and provides vascular anatomy and hemodynamics. At present, there is the limitation in the indication of MRA for pediatric cerebral vascular diseases. However, the frequency of clinical application of MRA is expected to increase by rapidly progressed MR techniques. Of these MRA, time-of flight (TOF) MRA, and phase contrast (PC) MRA are now being examined clinically as main MRA methods for evaluating cerebrovascular diseases, such as Moyamoya disease, arteriovenous malformation, and cerebral aneurysm. During our study, 2D and 3D TOF MRA, and 2D PC and 3D PC MRA were performed for evaluating cerebrovascular diseases. The purpose of this paper is to explain the methods of these MRA, and clinical indications of MRA by showing representative clinical cases of cerebrovascular diseases. We consider that MRA ia a useful method for detecting and following-up pediatric cerebrovascular diseases at present time. It is necessary for radiologists to know the basis and clinical indications of MRA. (author)

  1. The VESPA: A method for the rapid estimation of a visual evoked potential

    OpenAIRE

    Lalor, Edmund C.; Pearlmutter, Barak A.; Richard B. Reilly; McDarby, Gary; Foxe, John J.

    2006-01-01

    Faster and less obtrusive means for measuring a Visual Evoked Potential would be valuable in clinical testing and basic neuroscience research. This study presents a method for accomplishing this by smoothly modulating the luminance of a visual stimulus using a stochastic process. Despite its visually unobtrusive nature, the rich statistical structure of the stimulus enables rapid estimation of the visual system's impulse response. The profile of these responses, which we ...

  2. Three-dimensional coronary angiography

    Science.gov (United States)

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

    2005-04-01

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

  3. Merging Psychophysical and Psychometric Theory to Estimate Global Visual State Measures from Forced-Choices

    Science.gov (United States)

    Massof, Robert W.; Schmidt, Karen M.; Laby, Daniel M.; Kirschen, David; Meadows, David

    2013-09-01

    Visual acuity, a forced-choice psychophysical measure of visual spatial resolution, is the sine qua non of clinical visual impairment testing in ophthalmology and optometry patients with visual system disorders ranging from refractive error to retinal, optic nerve, or central visual system pathology. Visual acuity measures are standardized against a norm, but it is well known that visual acuity depends on a variety of stimulus parameters, including contrast and exposure duration. This paper asks if it is possible to estimate a single global visual state measure from visual acuity measures as a function of stimulus parameters that can represent the patient's overall visual health state with a single variable. Psychophysical theory (at the sensory level) and psychometric theory (at the decision level) are merged to identify the conditions that must be satisfied to derive a global visual state measure from parameterised visual acuity measures. A global visual state measurement model is developed and tested with forced-choice visual acuity measures from 116 subjects with no visual impairments and 560 subjects with uncorrected refractive error. The results are in agreement with the expectations of the model.

  4. Tensor completion for estimating missing values in visual data

    KAUST Repository

    Liu, Ji

    2013-01-01

    In this paper, we propose an algorithm to estimate missing values in tensors of visual data. The values can be missing due to problems in the acquisition process or because the user manually identified unwanted outliers. Our algorithm works even with a small amount of samples and it can propagate structure to fill larger missing regions. Our methodology is built on recent studies about matrix completion using the matrix trace norm. The contribution of our paper is to extend the matrix case to the tensor case by proposing the first definition of the trace norm for tensors and then by building a working algorithm. First, we propose a definition for the tensor trace norm that generalizes the established definition of the matrix trace norm. Second, similarly to matrix completion, the tensor completion is formulated as a convex optimization problem. Unfortunately, the straightforward problem extension is significantly harder to solve than the matrix case because of the dependency among multiple constraints. To tackle this problem, we developed three algorithms: simple low rank tensor completion (SiLRTC), fast low rank tensor completion (FaLRTC), and high accuracy low rank tensor completion (HaLRTC). The SiLRTC algorithm is simple to implement and employs a relaxation technique to separate the dependant relationships and uses the block coordinate descent (BCD) method to achieve a globally optimal solution; the FaLRTC algorithm utilizes a smoothing scheme to transform the original nonsmooth problem into a smooth one and can be used to solve a general tensor trace norm minimization problem; the HaLRTC algorithm applies the alternating direction method of multipliers (ADMMs) to our problem. Our experiments show potential applications of our algorithms and the quantitative evaluation indicates that our methods are more accurate and robust than heuristic approaches. The efficiency comparison indicates that FaLTRC and HaLRTC are more efficient than SiLRTC and between Fa

  5. A framework for organ dose estimation in x-ray angiography and interventional radiology based on dose-related data in DICOM structured reports

    Science.gov (United States)

    Omar, Artur; Bujila, Robert; Fransson, Annette; Andreo, Pedro; Poludniowski, Gavin

    2016-04-01

    Although interventional x-ray angiography (XA) procedures involve relatively high radiation doses that can lead to deterministic tissue reactions in addition to stochastic effects, convenient and accurate estimation of absorbed organ doses has traditionally been out of reach. This has mainly been due to the absence of practical means to access dose-related data that describe the physical context of the numerous exposures during an XA procedure. The present work provides a comprehensive and general framework for the determination of absorbed organ dose, based on non-proprietary access to dose-related data by utilizing widely available DICOM radiation dose structured reports. The framework comprises a straightforward calculation workflow to determine the incident kerma and reconstruction of the geometrical relation between the projected x-ray beam and the patient’s anatomy. The latter is difficult in practice, as the position of the patient on the table top is unknown. A novel patient-specific approach for reconstruction of the patient position on the table is presented. The proposed approach was evaluated for 150 patients by comparing the estimated position of the primary irradiated organs (the target organs) with their position in clinical DICOM images. The approach is shown to locate the target organ position with a mean (max) deviation of 1.3 (4.3), 1.8 (3.6) and 1.4 (2.9) cm for neurovascular, adult and paediatric cardiovascular procedures, respectively. To illustrate the utility of the framework for systematic and automated organ dose estimation in routine clinical practice, a prototype implementation of the framework with Monte Carlo simulations is included.

  6. Carotid angiography

    Directory of Open Access Journals (Sweden)

    Arne Torkildsen

    1950-03-01

    Full Text Available After a brief review of the history of cerebral angiography, some of the most important points concerning the percutaneous angiographic technique have been described. The value of the angiographic examination in cases of cerebral gliomas has been studied, based upon a consecutive series of 127 verified cases of hemispherical gliomas. Of 31 cases of frontal glioma, 28 could be diagnosed by the angiographic method; of 33 cases of parietal glioma, the angiograms revealed the neoplasm in 27 instances; of 39 cases of temporal glioma, the tumor could be localized in 38 cases; of 13 cases of occipital glioma, the angiographic localization of the tumor was successfull in 9 instances; of 11. cases of glioma infiltrating the corpus callosum and (or the basal ganglia, the angiographic examination was successful in only 3 cases. The angiographic examination in cases of cerebral glioma, in my experience, yields a more satisfactory result as to the localization than does the pneumography. The only exception concerns the gliomas growing in the thalamus or in the basal ganglia. These are more easily localized by means of ventriculography. As to the differential diagnosis of the gliomas, tumor vessels could, be seen both in astrocytomas and in glioblastomas. Most cases of astrocytomas were however devoid of specific tumor vessels. When present they could not be definitely distinguished from those seen in glioblastomas, but the abnormal findings were far less numerous and definitely less pronounced in astrocytomas than in glioblastomas. In most cases the astrocytomas were characterized only by displacement of blood vessels of normal appearance, while the glioblastomas frequently-presented both displacement of normal appearing blood vessels and new formed blood vessels within the neoplasm itself. The pathological blood vessels in the tumor were frequently abnormal both regarding their topographical appearance and their type. Frequent findings were arterio

  7. Estimation of radiation dose and image quality of coronary 320-row area detector CT angiography by optimal prospective ECG-gated protocols for different heart rate

    International Nuclear Information System (INIS)

    The purpose of this study is to estimate radiation dose and image quality of electrocardiogram (ECG)-gated coronary 320-area detector CT (ADCT) angiography which was acquired using the protocols that were considered as optimal methods for different heart rates (HR) in 1031 consecutive patients (M/F =580/451, 65±12 yr) without arrhythmias. We set up 5 protocols for 320-ADCT based on the relationship among heart rates, temporal resolution, gantry rotation speed, optimal reconstruction phase and slow filling phase on 64-multidetector-row computed tomography (MDCT), id est (ie), 1) mid-diastolic (75% of risk ratio (RR)) 1 beat scan (moderate disability (MD) 1 beat, N=761 (73.8%)) for HR ≤60, 2) mid-diastolic (75% of RR) 2 beat scan (MD 2 beat, N=135) for 61≤ HR ≤65, 3) end-systolic and mid-diastolic (37-80% of RR) 2 beat scan (embryonic stem (ES)-MD 2 beat, N=92) for 66≤ HR ≤75, 4) end-systolic (R +280-430 ms) 2 beat scan (ES 2 beat, N=21) for 76≤ HR ≤80, and 5) end-systolic (R +250-400 ms) 3 beat scan (ES 3 beat, N=22) for 81≤ HR ≤105. Image quality was classified into 3 categories (excellent (3 points), acceptable (2 points), and unacceptable (1 point)). Scanning time, DLP.e and image quality score were 1.4±0.1 s, 220±59 mGy·cm, 3.0±0.2 points in MD 1 beat, 2.2±0.2 s, 434±118 mGy·cm, 2.9±0.3 points in MD 2 beat, 2.1±0.2 s, 729±229 mGy·cm, 2.7±0.5 points in ES-MD 2 beat, 1.9±0.1 s, 432±148 mGy·cm, 2.2±0.6 points in ES 2 beat, and 2.4±0.2 s, 669±152 mGy·cm, 2.3±0.6 points in ES 3 beat respectively. In conclusion, the prospective ECG-gated scan protocol for coronary 320-ADCT angiography in any HR group was considered reasonable and proper for image quality and radiation dose. (author)

  8. Super-resolution spectral estimation of optical micro-angiography for quantifying blood flow within microcirculatory tissue beds in vivo

    OpenAIRE

    Yousefi, Siavash; Qin, Jia; Wang, Ruikang K.

    2013-01-01

    In this paper, we propose a super-resolution spectral estimation technique to quantify microvascular hemodynamics using optical microangiography (OMAG) based on optical coherence tomography (OCT). The proposed OMAG technique uses both amplitude and phase information of the OCT signals which makes it sensitive to the axial and transverse flows. The scanning protocol for the proposed method is identical to three-dimensional ultrahigh sensitive OMAG, and is applicable for in vivo measurements. I...

  9. Reliability of visual assessment of non-contrast CT, CT angiography source images and CT perfusion in patients with suspected ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Tom van Seeters

    Full Text Available BACKGROUND AND PURPOSE: Good reliability of methods to assess the extent of ischemia in acute stroke is important for implementation in clinical practice, especially between observers with varying experience. Our aim was to determine inter- and intra-observer reliability of the 1/3 middle cerebral artery (MCA rule and the Alberta Stroke Program Early CT Score (ASPECTS for different CT modalities in patients suspected of acute ischemic stroke. METHODS: We prospectively included 105 patients with acute neurological deficit due to suspected acute ischemic stroke within 9 hours after symptom onset. All patients underwent non-contrast CT, CT perfusion and CT angiography on admission. All images were evaluated twice for presence of ischemia, ischemia with >1/3 MCA involvement, and ASPECTS. Four observers evaluated twenty scans twice for intra-observer agreement. We used kappa statistics and intraclass correlation coefficient to calculate agreement. RESULTS: Inter-observer agreement for the 1/3 MCA rule and ASPECTS was fair to good for non-contrast CT, poor to good for CT angiography source images, but excellent for all CT perfusion maps (cerebral blood volume, mean transit time, and predicted penumbra and infarct maps. Intra-observer agreement for the 1/3 MCA rule and ASPECTS was poor to good for non-contrast CT, fair to moderate for CT angiography source images, and good to excellent for all CT perfusion maps. CONCLUSION: Between observers with a different level of experience, agreement on the radiological diagnosis of cerebral ischemia is much better for CT perfusion than for non-contrast CT and CT angiography source images, and therefore CT perfusion is a very reliable addition to standard stroke imaging.

  10. Optical Coherence Tomography Angiography in Fovea Plana.

    Science.gov (United States)

    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.].

  11. Visual Estimation and Control of Robot Manipulating Systems

    OpenAIRE

    Robuffo Giordano, Paolo

    2008-01-01

    With this sentence from his Metaphysica, Aristotle perfectly introduces us to the importance of eyesight for humans, as well as for any advanced living being. Since, to a large extent, robotics is concerned with the emulation of human skills in an artificial context, a natural requirement is to cope with vision for a full interaction with the world. In this respect, this Thesis explores the problem of exploiting visual information to control the motion of robotic systems equipp...

  12. Effect of calcified plaques on estimation of arterial stenosis of lower extremity in diabetic foot patients using multislice computed tomography angiography

    International Nuclear Information System (INIS)

    Objective: To investigate the impacts of calcified plaques on estimation of arterial stenosis of lower extremity in diabetic foot patients using 16 -slice computed tomography angiography (MSCTA). Materials and Methods: Thirty-five patients (representing 38 cases)underwent both MSCTA and digital subtraction angiography (DSA) examinations. The arteries of lower extremity were divided into 15 anatomic segments, and the degree of artery stenosis in each segment was classified as normal, mildly, moderately. severely or occluded. The extent of calcification in each segment was also assessed on cross -sectional image of MDCTA and was classified as absent, mildly, moderately, or severely. Using DSA as the standard reference, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were calculated. Agreement between MSCTA and DSA was assessed by Cohen's kappa statistics. Results: In the noncalcified, mildly and moderately calcified segments of the artery above the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy. Youden index, positive predictive value and negative predictive value of MSCTA were 97.1%, 98.7%, 98.2%, 95.8%, 97.0% and 98.7%, respectively. In the severely calcified segments of the artery above the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were 96.3%, 93.8%, 94.7%, 90.1%, 89.7% and 97.8%, respectively. In the noncalcified, mildly and moderately calcified segments of the artery below the knee, for the detection of segments that had more than mild stenosis, the sensitivity, specificity, accuracy, Youden index, positive predictive value and negative predictive value of MSCTA were 95.1%, 93.2%, 94.1%, 88.3%, 93.4% and 94.9%, respectively. In the severely calcified segments of the artery below the

  13. Estimation of organ-absorbed radiation doses during 64-detector CT coronary angiography using different acquisition techniques and heart rates: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, Kosuke; Koshida, Kichiro; Kawashima, Hiroko (Dept. of Quantum Medical Technology, Faculty of Health Sciences, Kanazawa Univ., Kanazawa (Japan)), email: matsuk@mhs.mp.kanazawa-u.ac.jp; Noto, Kimiya; Takata, Tadanori; Yamamoto, Tomoyuki (Dept. of Radiological Technology, Kanazawa Univ. Hospital, Kanazawa (Japan)); Shimono, Tetsunori (Dept. of Radiology, Hoshigaoka Koseinenkin Hospital, Hirakata (Japan)); Matsui, Osamu (Dept. of Radiology, Faculty of Medicine, Kanazawa Univ., Kanazawa (Japan))

    2011-07-15

    Background: Though appropriate image acquisition parameters allow an effective dose below 1 mSv for CT coronary angiography (CTCA) performed with the latest dual-source CT scanners, a single-source 64-detector CT procedure results in a significant radiation dose due to its technical limitations. Therefore, estimating the radiation doses absorbed by an organ during 64-detector CTCA is important. Purpose: To estimate the radiation doses absorbed by organs located in the chest region during 64-detector CTCA using different acquisition techniques and heart rates. Material and Methods: Absorbed doses for breast, heart, lung, red bone marrow, thymus, and skin were evaluated using an anthropomorphic phantom and radiophotoluminescence glass dosimeters (RPLDs). Electrocardiogram (ECG)-gated helical and ECG-triggered non-helical acquisitions were performed by applying a simulated heart rate of 60 beats per minute (bpm) and ECG-gated helical acquisitions using ECG modulation (ECGM) of the tube current were performed by applying simulated heart rates of 40, 60, and 90 bpm after placing RPLDs on the anatomic location of each organ. The absorbed dose for each organ was calculated by multiplying the calibrated mean dose values of RPLDs with the mass energy coefficient ratio. Results: For all acquisitions, the highest absorbed dose was observed for the heart. When the helical and non-helical acquisitions were performed by applying a simulated heart rate of 60 bpm, the absorbed doses for heart were 215.5, 202.2, and 66.8 mGy for helical, helical with ECGM, and non-helical acquisitions, respectively. When the helical acquisitions using ECGM were performed by applying simulated heart rates of 40, 60, and 90 bpm, the absorbed doses for heart were 178.6, 139.1, and 159.3 mGy, respectively. Conclusion: ECG-triggered non-helical acquisition is recommended to reduce the radiation dose. Also, controlling the patients' heart rate appropriately during ECG-gated helical acquisition with

  14. Magnetic resonance angiography

    Science.gov (United States)

    MRA; Angiography - magnetic resonance ... Kwong RY. Cardiovascular Magnetic Resonance Imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . ...

  15. 3D-MR cholangio-angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ohkawa, Shinichi [Isehara Kyohdoh Hospital, Kanagawa (Japan); Hiramatsu, Kyoichi

    1995-04-01

    This report introduces a new 3D-MR cholangio-angiography technique using 3D Fast SE MR cholangiography and 3D phase contrast MR angiography for obstructive jaundice. In all eight cases, dilated biliary tracts as well as portal veins were clearly visualized in the same image. This new technique helped to determine the operability and surgical strategy for cases with obstructive jaundice. It also provided anatomical guidance for surgical procedures. This study suggests that this technique may replace the currently used modalities for obstructive jaundice. (author).

  16. Abnormal course of the vertebral artery at the craniovertebral junction in patients with Down syndrome visualized by three-dimensional CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Masashi; Okawa, Akihiko; Hashimoto, Mitsuhiro; Aiba, Atsuomi; Someya, Yukio; Koda, Masao [Chiba University Graduate School of Medicine, Spine Section, Department of Orthopaedic Surgery, Chiba (Japan)

    2008-06-15

    We determined the incidence of vertebral artery (VA) anomalies at the craniovertebral junction (CVJ) in patients with Down syndrome, and characterized the VA anomalies. The course of the VA in 46 consecutive patients who were due to undergo posterior arthrodesis surgery at the CVJ were evaluated by three-dimensional CT angiography (3DCTA). Included were five patients with Down syndrome who suffered from myelopathy due to atlantoaxial subluxation. All five patients with Down syndrome also had a simultaneous congenital skeletal anomaly, either os odontoideum or ossiculum terminale. Of the five patients with Down syndrome, three had VA anomalies at the CVJ, two had fenestration and one had a persistent first intersegmental artery. Of the other 41 patients without Down syndrome, five had VA anomalies at the CVJ. The incidence of VA anomalies at the CVJ was much higher in patients with Down syndrome than in those without Down syndrome. In planning surgery in patients with Down syndrome with symptomatic atlantoaxial subluxation and a congenital skeletal anomaly at the CVJ, we should consider the possible presence of VA anomalies. Preoperative 3DCTA allows us to precisely identify an anomalous VA and evaluate the possible risk of intraoperative VA injury in advance. (orig.)

  17. Mortality estimates from repeated visual censuses of a parrotfish (Sparisoma viride) population : Demographic implications

    NARCIS (Netherlands)

    vanRooij, JM; Videler, JJ

    1997-01-01

    Repeated visual censuses of different categories (juveniles, females, territorial and group males) of the stoplight parrotfish (Sparisoma viride, a protogynous hermaphrodite) over a 3-year period indicated a relatively stable size and structure of the adult population. This allowed estimates of size

  18. Visual feedback about time estimation is related to a right hemisphere activation measured by PET

    NARCIS (Netherlands)

    Brunia, CHM; de Jong, BM; van den Berg-Lenssen, MMC; Paans, AMJ

    2000-01-01

    In previous EEG experiments we have presented a time estimation task to our subjects, who bad to press a button with either the left or right index finger 3 s after an auditory warning stimulus (WS). Two seconds later a visual Knowledge of Results (KR) stimulus was presented on a screen in front, in

  19. A Probabilistic Model of Visual Working Memory: Incorporating Higher Order Regularities into Working Memory Capacity Estimates

    Science.gov (United States)

    Brady, Timothy F.; Tenenbaum, Joshua B.

    2013-01-01

    When remembering a real-world scene, people encode both detailed information about specific objects and higher order information like the overall gist of the scene. However, formal models of change detection, like those used to estimate visual working memory capacity, assume observers encode only a simple memory representation that includes no…

  20. High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues

    Directory of Open Access Journals (Sweden)

    Boel Lene WT

    2010-03-01

    Full Text Available Abstract Background In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR method for ex vivo angiography and to compare the findings with computed tomography (CT. To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. Results The optimal solution for ex vivo MR angiography (MRA was a compound containing gelatine (0.05 g/mL, the CT contrast agent barium sulphate (0.43 mol/L and the MR contrast agent gadoteric acid (2.5 mmol/L. It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. Conclusions Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.

  1. Estimation of frequency and pretest probability of CAD in patients presenting with recent onset chest pain by multi-detector CT angiography

    Directory of Open Access Journals (Sweden)

    Omar Muayad Sultan

    2016-03-01

    Conclusion: CAD was seen in 77.5% in those with recent onset chest pain. Higher incidence of significant CAD was seen in hypertensive and diabetic patients. Family history is still not a reliable factor in our society. Male patient <60 years old has higher incidence of CAD than female in same age group. Pretest probability for CAD is a simple and important test as all patients in higher probability have CAD and most of them have significant disease so it is better to direct referral of them to conventional angiography to gain a benefit from direct intervention, radiation and cost benefit.

  2. Low-dose prospectively electrocardiogram-gated axial dual-source CT angiography in patients with pulsatile bilateral bidirectional Glenn Shunt: an alternative noninvasive method for postoperative morphological estimation.

    Directory of Open Access Journals (Sweden)

    Xiaopeng Ji

    Full Text Available OBJECTIVE: To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG as an alternative noninvasive method for postoperative morphological estimation. METHODS: Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years underwent both low-dose PGA scanning and conventional cardiac angiography (CCA for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC and pulmonary artery (PA, the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland-Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated. RESULTS: The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P0.The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively. CONCLUSION: CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG.

  3. Visual and skill effects on soccer passing performance, kinematics, and outcome estimations.

    Science.gov (United States)

    Basevitch, Itay; Tenenbaum, Gershon; Land, William M; Ward, Paul

    2015-01-01

    The role of visual information and action representations in executing a motor task was examined from a mental representations approach. High-skill (n = 20) and low-skill (n = 20) soccer players performed a passing task to two targets at distances of 9.14 and 18.29 m, under three visual conditions: normal, occluded, and distorted vision (i.e., +4.0 corrective lenses, a visual acuity of approximately 6/75) without knowledge of results. Following each pass, participants estimated the relative horizontal distance from the target as the ball crossed the target plane. Kinematic data during each pass were also recorded for the shorter distance. Results revealed that performance on the motor task decreased as a function of visual information and task complexity (i.e., distance from target) regardless of skill level. High-skill players performed significantly better than low-skill players on both the actual passing and estimation tasks, at each target distance and visual condition. In addition, kinematic data indicated that high-skill participants were more consistent and had different kinematic movement patterns than low-skill participants. Findings contribute to the understanding of the underlying mechanisms required for successful performance in a self-paced, discrete and closed motor task. PMID:25784886

  4. Visual and Skill Effects on Soccer Passing Performance, Kinematics and Outcome Estimations

    Directory of Open Access Journals (Sweden)

    Itay eBasevitch

    2015-03-01

    Full Text Available The role of visual information and action representations in executing a motor task was examined from a mental representations approach. High-skill (n = 20 and low-skill (n = 20 soccer players performed a passing task to two targets at distances of 9.14m and 18.29m, under three visual conditions: normal, occluded, and distorted vision (i.e., +4.0 corrective lenses, a visual acuity of approximately 6/75 without knowledge of results. Following each pass, participants estimated the relative horizontal distance from the target as the ball crossed the target plane. Kinematic data during each pass were also recorded for the shorter distance. Results revealed that performance on the motor task decreased as a function of visual information and task complexity (i.e., distance from target regardless of skill level. High-skill players performed significantly better than low-skill players on both the actual passing and estimation tasks, at each target distance and visual condition. In addition, kinematic data indicated that high skill participants were more consistent and had different kinematic movement patterns than low skill participants. Findings contribute to the understanding of the underlying mechanisms required for successful performance in a self-paced, discrete and closed motor task.

  5. Genetic parameter estimates for carcass traits and visual scores including or not genomic information.

    Science.gov (United States)

    Gordo, D G M; Espigolan, R; Tonussi, R L; Júnior, G A F; Bresolin, T; Magalhães, A F Braga; Feitosa, F L; Baldi, F; Carvalheiro, R; Tonhati, H; de Oliveira, H N; Chardulo, L A L; de Albuquerque, L G

    2016-05-01

    The objective of this study was to determine whether visual scores used as selection criteria in Nellore breeding programs are effective indicators of carcass traits measured after slaughter. Additionally, this study evaluated the effect of different structures of the relationship matrix ( and ) on the estimation of genetic parameters and on the prediction accuracy of breeding values. There were 13,524 animals for visual scores of conformation (CS), finishing precocity (FP), and muscling (MS) and 1,753, 1,747, and 1,564 for LM area (LMA), backfat thickness (BF), and HCW, respectively. Of these, 1,566 animals were genotyped using a high-density panel containing 777,962 SNP. Six analyses were performed using multitrait animal models, each including the 3 visual scores and 1 carcass trait. For the visual scores, the model included direct additive genetic and residual random effects and the fixed effects of contemporary group (defined by year of birth, management group at yearling, and farm) and the linear effect of age of animal at yearling. The same model was used for the carcass traits, replacing the effect of age of animal at yearling with the linear effect of age of animal at slaughter. The variance and covariance components were estimated by the REML method in analyses using the numerator relationship matrix () or combining the genomic and the numerator relationship matrices (). The heritability estimates for the visual scores obtained with the 2 methods were similar and of moderate magnitude (0.23-0.34), indicating that these traits should response to direct selection. The heritabilities for LMA, BF, and HCW were 0.13, 0.07, and 0.17, respectively, using matrix and 0.29, 0.16, and 0.23, respectively, using matrix . The genetic correlations between the visual scores and carcass traits were positive, and higher correlations were generally obtained when matrix was used. Considering the difficulties and cost of measuring carcass traits postmortem, visual scores of

  6. Digital subtraction angiography of the cerebral vessels by intraarterial injection

    International Nuclear Information System (INIS)

    Three hundred and fifty-seven digital subtraction angiography (DSA) were performed in 184 neurosurgical patients by intraarterial injection. Examinations consisted of 192 carotid angiography, 110 vertebral angiography, 23 aortography, 11 spinal angiography and 21 other angiography. In all examinations, visualization of the vessels was excellent and the complications were never experienced. High contrast sensitivity of DSA resulted in better visualization of tumor stains, phlebogram, and arteries in cerebral arteriovenous malformations with large shunt blood flow than conventional angiography. Selective catheterization into each cerebral arteries was not necessarily demanded for good opacification of the vessels because of high sensitivity. High contrast sensitivity also permitted low concentration of contrast material, small dose of contrast material, and slow injection rate. Low concentration of contrast material reduced pain and heat during injection especially in the external carotid and vertebral angiography. Using slow injection, recoiling of catheter into the aorta was reduced, so that injection from the innominate and subclavian arteries for visualization of origin of the cerebral arteries were always successful. Full study of cerebral arteries by Seldinger's method, if necessary, was easily achieved using DSA even in patient with high age or with severe atherosclerosis. Bolus injection of small dose of contrast material as well as serial imaging was helpful in evaluating hemodynamics in the lesion. Real time display of DSA reduced the time required for angiography and was very convenient for artificial embolization. Besides these advantages, DSA became comparable to conventional angiography in spacial resolution by use of intraarterial injection and could be a preoperative genuine examination as well as a screening method. (author)

  7. Early diagnosis of retinopathy in juvenile diabetes by fluorescence angiography

    International Nuclear Information System (INIS)

    The authors defined the usefulness of the fluorescein angiography of the retina and choroid in the early stage diagnosis of diabetic retinopathy in children comparing its results to the traditional ophthalmoscopy. Examination involved 50 children from 4 to 18 (30 boys and 20 girls) on insulin treatment. The duration of the disease was 1 to 14 years (average 7.36 years). Ophthalmoscopy showed pathological changes in 24% of the children. The fluorescein angiography visualized more microaneurysms compared to ophthalmoscopy and showed them sometimes in the eyes where they had not been found in eye fundus studies. By means of angiography the early and advanced stages of vascular complications were found in 64% of patients. Comparing to ophthalmoscopy a 40% increase was noted. Fluorescein angiography can lead to the decrease in the number of patients with markedly impaired visual acuity and cases of blindness in the diabetic population. (author)

  8. Depth estimation and camera calibration of a focused plenoptic camera for visual odometry

    Science.gov (United States)

    Zeller, Niclas; Quint, Franz; Stilla, Uwe

    2016-08-01

    This paper presents new and improved methods of depth estimation and camera calibration for visual odometry with a focused plenoptic camera. For depth estimation we adapt an algorithm previously used in structure-from-motion approaches to work with images of a focused plenoptic camera. In the raw image of a plenoptic camera, scene patches are recorded in several micro-images under slightly different angles. This leads to a multi-view stereo-problem. To reduce the complexity, we divide this into multiple binocular stereo problems. For each pixel with sufficient gradient we estimate a virtual (uncalibrated) depth based on local intensity error minimization. The estimated depth is characterized by the variance of the estimate and is subsequently updated with the estimates from other micro-images. Updating is performed in a Kalman-like fashion. The result of depth estimation in a single image of the plenoptic camera is a probabilistic depth map, where each depth pixel consists of an estimated virtual depth and a corresponding variance. Since the resulting image of the plenoptic camera contains two plains: the optical image and the depth map, camera calibration is divided into two separate sub-problems. The optical path is calibrated based on a traditional calibration method. For calibrating the depth map we introduce two novel model based methods, which define the relation of the virtual depth, which has been estimated based on the light-field image, and the metric object distance. These two methods are compared to a well known curve fitting approach. Both model based methods show significant advantages compared to the curve fitting method. For visual odometry we fuse the probabilistic depth map gained from one shot of the plenoptic camera with the depth data gained by finding stereo correspondences between subsequent synthesized intensity images of the plenoptic camera. These images can be synthesized totally focused and thus finding stereo correspondences is enhanced

  9. MR angiography in abdominal neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Squillaci, E. [Dept. of Radiology, Rome-2 Univ., Hospital S. Eugenio, Rome (Italy); Crecco, M. [Dept. of Radiology, Cancer Research Inst. (Regina Elena), Rome (Italy); Grandinetti, M.L. [Dept. of Radiology, Cancer Research Inst. (Regina Elena), Rome (Italy); Maspes, F. [Dept. of Radiology, Rome-2 Univ., Hospital S. Eugenio, Rome (Italy); Lo Presti, G. [Dept. of Radiology, Rome-2 Univ., Hospital S. Eugenio, Rome (Italy); Squillaci, S. [Dept. of Radiology, Cancer Research Inst. (Regina Elena), Rome (Italy); Simonetti, G. [Dept. of Radiology, Rome-2 Univ., Hospital S. Eugenio, Rome (Italy)

    1994-10-01

    The role of magnetic resonance angiography (MRA) in the evaluation of vascular involvement was studied in 55 patients with abdominal neoplasms. A 2-D time-of-flight (TOF) technique was used in all patients. All patients underwent CT and MR examinations before MRA. Also, MR angiograms were compared with digital subtraction angiography in 22 cases, with Doppler US in 13 cases, and with surgical findings in 20 cases. In all patients with liver neoplasms (n=29) MRA demonstrated the absence of flow in the infiltrated segments. Pericapsular neovascularization was observed in 12 patients. Portal vein involvement was correctly detected in 27 patients. In all cases MRA demonstrated in relationship between the tumor and venous structures. Portosystemic shunts were visualized in 20 of 21 patients with portal hypertension. Vena cava thrombosis (3 cases), compression (5 cases), and displacement (2 cases) were correctly demonstrated. In renal (n=6) and adrenal gland (n=3) tumors renal vein compression was correctly detected in 2 cases, displacement in 1 case, and thrombosis in 3 cases, with only 1 false-positive finding. In 7 patients with pancreatic tumors MRA demonstrated splenic vein thrombosis in 2 cases and compression in 2 cases, with one false-positive finding. Our results indicate that MRA provides precise information regarding venous vascular involvement in abdominal neoplasms, but preoperative arterial mapping is still problematic. (orig.)

  10. Evaluation of vascular pathologies with MR angiography

    International Nuclear Information System (INIS)

    The flow sensitivity of MR imaging methods can be used to visualize vascular structures (MR angiography). In this paper the method of flow-enhanced three-dimensional MR angiography will be presented. This technique makes use of the signal enhancement due to inflow of unsaturated spins into the imaging volume in combination with flow-compensated three-dimensional Fourier transform gradient-echo sequences. Projective images are calculated from the measured data by means of a maximum-intensity algorithm. The procedure was optimized for the visualization of the intra-and extracranial vasculature. The purpose of this study was to demonstrate the potential of this MR angiographic procedure to evaluate vascular disease in a clinical situation. Prospective studies in patients with vascular disease including aneurysms, arteriovenous malformations, arterial occlusion, and stenosis are shown in correlation with conventional procedures

  11. Estimation of visual maps with a robot network equipped with vision sensors.

    Science.gov (United States)

    Gil, Arturo; Reinoso, Óscar; Ballesta, Mónica; Juliá, Miguel; Payá, Luis

    2010-01-01

    In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM) problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment. PMID:22399930

  12. Estimation of Visual Maps with a Robot Network Equipped with Vision Sensors

    Directory of Open Access Journals (Sweden)

    Arturo Gil

    2010-05-01

    Full Text Available In this paper we present an approach to the Simultaneous Localization and Mapping (SLAM problem using a team of autonomous vehicles equipped with vision sensors. The SLAM problem considers the case in which a mobile robot is equipped with a particular sensor, moves along the environment, obtains measurements with its sensors and uses them to construct a model of the space where it evolves. In this paper we focus on the case where several robots, each equipped with its own sensor, are distributed in a network and view the space from different vantage points. In particular, each robot is equipped with a stereo camera that allow the robots to extract visual landmarks and obtain relative measurements to them. We propose an algorithm that uses the measurements obtained by the robots to build a single accurate map of the environment. The map is represented by the three-dimensional position of the visual landmarks. In addition, we consider that each landmark is accompanied by a visual descriptor that encodes its visual appearance. The solution is based on a Rao-Blackwellized particle filter that estimates the paths of the robots and the position of the visual landmarks. The validity of our proposal is demonstrated by means of experiments with a team of real robots in a office-like indoor environment.

  13. Vein visualization using a smart phone with multispectral Wiener estimation for point-of-care applications.

    Science.gov (United States)

    Song, Jae Hee; Kim, Choye; Yoo, Yangmo

    2015-03-01

    Effective vein visualization is clinically important for various point-of-care applications, such as needle insertion. It can be achieved by utilizing ultrasound imaging or by applying infrared laser excitation and monitoring its absorption. However, while these approaches can be used for vein visualization, they are not suitable for point-of-care applications because of their cost, time, and accessibility. In this paper, a new vein visualization method based on multispectral Wiener estimation is proposed and its real-time implementation on a smart phone is presented. In the proposed method, a conventional RGB camera on a commercial smart phone (i.e., Galaxy Note 2, Samsung Electronics Inc., Suwon, Korea) is used to acquire reflectance information from veins. Wiener estimation is then applied to extract the multispectral information from the veins. To evaluate the performance of the proposed method, an experiment was conducted using a color calibration chart (ColorChecker Classic, X-rite, Grand Rapids, MI, USA) and an average root-mean-square error of 12.0% was obtained. In addition, an in vivo subcutaneous vein imaging experiment was performed to explore the clinical performance of the smart phone-based Wiener estimation. From the in vivo experiment, the veins at various sites were successfully localized using the reconstructed multispectral images and these results were confirmed by ultrasound B-mode and color Doppler images. These results indicate that the presented multispectral Wiener estimation method can be used for visualizing veins using a commercial smart phone for point-of-care applications (e.g., vein puncture guidance). PMID:24691170

  14. Estimation of metallurgical parameters of flotation process from froth visual features

    Directory of Open Access Journals (Sweden)

    Mohammad Massinaei

    2015-06-01

    Full Text Available The estimation of metallurgical parameters of flotation process from froth visual features is the ultimate goal of a machine vision based control system. In this study, a batch flotation system was operated under different process conditions and metallurgical parameters and froth image data were determined simultaneously. Algorithms have been developed for measuring textural and physical froth features from the captured images. The correlation between the froth features and metallurgical parameters was successfully modeled, using artificial neural networks. It has been shown that the performance parameters of flotation process can be accurately estimated from the extracted image features, which is of great importance for developing automatic control systems.

  15. Estimates of genetic parameters for visual scores and daily weight gain in Brangus animals.

    Science.gov (United States)

    Queiroz, S A; Oliveira, J A; Costa, G Z; Fries, L A

    2011-05-01

    (Co)variance components were estimated for visual scores of conformation (CY), early finishing (PY) and muscling (MY) at 550 days of age (yearling), average daily gain from weaning to yearling (GWY), conformation (CW), early finishing (PW) and muscling (MW) scores at weaning, and average daily gain from birth to weaning (GBW) in animals forming the Brazilian Brangus breed born between 1986 and 2002 from the livestock files of GenSys Consultants Associados S/C Ltda. The data set contained 53 683; 45 136; 52 937; 56 471; 24 531; 21 166; 24 006 and 25 419 records for CW, PW, MW, GBW, CY, PY, MY and GWY, respectively. Data were analyzed by the restricted maximum likelihood method using single- and two-trait animal models. Direct heritability estimates obtained by single-trait analysis were 0.12, 0.14, 0.13 and 0.14 for CY, PY and MY scores and GWY, respectively. A positive association was observed between the same visual scores at weaning and yearling, with correlations ranging from 0.64 to 0.94. Estimated correlations between GBW and weaning and yearling scores ranged from 0.60 to 0.77. The genetic correlation between GBW and GWY was low (0.10), whereas correlations of 0.55, 0.37 and 0.47 were observed between GWY and CY, PY and MY, respectively. Moreover, GWY showed a weak correlation with CW (0.10), PW (-0.08) and MW (-0.03) scores. These results indicate that selection of the traits that was studied would result in a small response. In addition, selection based on average daily gain may have an indirect effect on visual scores as the correlations between GWY and visual scores were generally strong. PMID:22440022

  16. Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

    Directory of Open Access Journals (Sweden)

    Francisco Amorós

    2014-01-01

    Full Text Available In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map. After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions.

  17. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    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.

  18. The Exact Estimation of Visual Acuity by VEP Technology:A Report of 726 Cases of Eye Injury

    Institute of Scientific and Technical Information of China (English)

    饶广勋; 吴炳为; 张玲莉

    2010-01-01

    This study explored the accuracy of using visual evoked potentials(VEP)technology for visual acuity estimation.The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group,and the healthy eyes as the control group.The least signal visual angle(LSVA),and amplitude and latency of P100 were chosen as test indexes.The results under different experimental conditions were recorded by PRVEP technology.All data collected were processed...

  19. Bottom-Up Visual Saliency Estimation With Deep Autoencoder-Based Sparse Reconstruction.

    Science.gov (United States)

    Xia, Chen; Qi, Fei; Shi, Guangming

    2016-06-01

    Research on visual perception indicates that the human visual system is sensitive to center-surround (C-S) contrast in the bottom-up saliency-driven attention process. Different from the traditional contrast computation of feature difference, models based on reconstruction have emerged to estimate saliency by starting from original images themselves instead of seeking for certain ad hoc features. However, in the existing reconstruction-based methods, the reconstruction parameters of each area are calculated independently without taking their global correlation into account. In this paper, inspired by the powerful feature learning and data reconstruction ability of deep autoencoders, we construct a deep C-S inference network and train it with the data sampled randomly from the entire image to obtain a unified reconstruction pattern for the current image. In this way, global competition in sampling and learning processes can be integrated into the nonlocal reconstruction and saliency estimation of each pixel, which can achieve better detection results than the models with separate consideration on local and global rarity. Moreover, by learning from the current scene, the proposed model can achieve the feature extraction and interaction simultaneously in an adaptive way, which can form a better generalization ability to handle more types of stimuli. Experimental results show that in accordance with different inputs, the network can learn distinct basic features for saliency modeling in its code layer. Furthermore, in a comprehensive evaluation on several benchmark data sets, the proposed method can outperform the existing state-of-the-art algorithms. PMID:26800552

  20. Visual and instrumental correlation of sparkle by the magnitude estimation method.

    Science.gov (United States)

    Gómez, Omar; Perales, Esther; Chorro, Elísabet; Viqueira, Valentín; Martínez-Verdú, Francisco M

    2016-08-10

    Most real surfaces and objects show variations in appearance with viewing and illumination directions. Besides angular dependency, they also show spatial variation in color, i.e., they exhibit some sort of texture. Of the surfaces we see, surfaces colored by special-effect pigments produce several complex visual effects, like change in color and lightness with viewing and illumination angles, and effects like sparkle and gloss on other textures. In the last two decades, different commercial devices have appeared to help ensure the proper characterization of materials with special-effect pigments. However, the instrumental characterization of sparkle is currently available only by a commercial device integrated into a multi-angle spectrophotometer. As it is difficult to find complete open original studies about the sparkle effect for designing and calibrating this commercial instrument, the main objective of this work was to check whether a good visual and instrumental correlation exists between the sparkle that the observer perceives and the sparkle value provided by the device using some subsets of goniochromatic samples with different types of special-effect pigments and colors. Visual assessments were made by a conventional magnitude estimation method in a directional lighting booth, which belonged to the same company owner of the sparkle instrument, in different geometries and at distinct illuminance levels. The results revealed that there was a good visual correlation of the sparkle grade value. By separately analyzing the factors used in its instrument algorithm, such as sparkle intensity and sparkle area values, it was clearly shown that the correlation was not good or simply did not exist. Consequently, and perhaps in regards to the choice of new special-effect pigments, such as synthetic mica and other future ones, we generated herein even more questions about current mathematical algorithms, and only recognized calculating this texture effect at the

  1. Superselective pseudo-continuous arterial spin labeling angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, Ulf [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Lindner, Thomas, E-mail: thomas.lindner@uksh.de [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Osch, Matthias J.P. van [C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden (Netherlands); Rohr, Axel; Jansen, Olav [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Helle, Michael [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Now with Philips GmbH Innovative Technologies, Research Laboratories, Hamburg (Germany)

    2015-09-15

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  2. Influences of extinction coefficient profile on the estimation of Slant Visual Range

    Science.gov (United States)

    Sun, Xuejin; Zhou, Yongbo; Zhang, Riwei; Zhou, Junhao; Li, Haoran

    2015-12-01

    Slant Visual Range (SVR) is defined as the distance at which the contrast of a given object with respect to its background is just equal to the contrast threshold of an observer in slant direction. In this study, estimation methods and errors of SVR are explored in lidar-free circumstances where Extinction Coefficient Profile (ECP), vertical distribution of Single Scattering Albedo (SSA) and asymmetry parameter (ASY) cannot be acquired. Statistical characteristics of aerosol optical properties in the Taklimakan Basin for sand-dust weather are derived from the CALIPSO daytime aerosol product from 2011 to 2014. SSA and ASY are approximated as 0.92 and 0.7 because aerosol types are mainly dust and polluted dust throughout layers. Besides, ECP can be categorized into exponential, Gaussian and other patterns. Based on whether the determination of real ECP into one of the three patterns is feasible, two SVR estimation methods are introduced and termed the accurate estimation method (AEM) and the blind estimation method (BEM), both methods are performed using SBDART radiative transfer model. For the AEM, analysis of estimated SVR and real SVR reveals a minimum linear correlation coefficient of 0.98 and a maximum root mean square error of 0.07, and the hit rate (R) of SVR estimation increases from 86% to nearly 100% when the maximum allowable relative error (MARE) increases from 10% to 25%. Validation of the BEM shows that R varies from 78% to 100% for MARE of 25% and falls drastically with the decrease of MARE, with the highest R value in spring and summer for the Gaussian pattern and the lowest values in fall and winter for exponential and other patterns. This study is among the first to explore the feasibility and methodology of deriving SVR in lidar-free circumstances.

  3. Evaluation of the pedal artery: comparison of three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Min; Kang, Sung Gwon; Byun, Joo Nam; Kim, Young Cheol; Choi, Jeong Yeol; Kim, Dong Hyun [College of Medicine, Chosun Univ., Kwangju (Korea, Republic of)

    2002-07-01

    To compare the three-dimensional gadolinium-enhanced MR angiography with digital subtraction angiography (DSA) for evaluation of the pedal artery. In 12 extremities of 11 patients, both digital subtraction angiography (DSA) and contrast-enhanced MR angiography (CE-MR angiography) were performed during the same week. Among ten of the 11 patients, the following conditions were present: atherosclerosis (n=4), diabetic foot (n=3), Buerger's disease (n=1), calciphylactic arteriopathy (n=1) and arteriovenous malformation of the foot (n=1). The remaining patient underwent angiography prior to flap surgery. For MR angiography, a 1.5T system using an extremity or head coil was used. A three-dimensional FISP (fast imaging with steady state precession) sequence was obtained before enhancement, followed by four sequential acquisitions (scan time, 20 secs, scan interval time, 10 secs) 10 seconds after intravenous bolus injection of normal saline (total 10 cc), following intravenous administration of gadolinium (0.02 mmol/kg, 3 ml/sec). Arterial segments of the ankle and foot were classified as the anterior or posterior tibial artery, the distal peroneal artery, the medial or lateral plantar artery, the pedal arch, and the dorsalis pedis artery. Two radiologists independently analysed visualization of each arteraial segment and the mean of visible arterial segments in one extreminty using CE-MR angiography and DSA. Among 84 arterial segments, 16 were invisible at both CE-MR angiography and DSA, while 39 were demonstrated by both modalities. Twenty-six segments were visible only at CE-MR angiography and three only at DSA. CE-MR angiography displayed a higher number of arterial segments than DSA (mean, 5.42 vs. mean 3.50, respectively), a difference which was statistically significant (p<0.000). The difference between each arterial segment was not statistically significant, except for the dorsalis pedis artery (t test, p<0.000). In that it provides additional information for

  4. Distance estimation in a dynamic simulated environment: a visual field dependence problem?

    Science.gov (United States)

    Vianin, Pascal; Baumberger, Bernard; Flückiger, Michelangelo

    2004-01-01

    Egocentric distance estimation implies that the subject perceives his own location in the environment. In a simulated environment, subjects have to transpose perceptively their own observation point in order to assume their virtual body position. As only visual information specifies this position, their ability to perceive the camera viewpoint should be linked to the field dependence independence factor (FDI). Field-independent subjects underestimated the mid-distance between their own virtual body position and a far-located target; their bisection was located between the projective (2-D) and the simulated (3-D) mid-distance which indicates their difficulty in considering the in-depth simulated spatial references. High correlations between the vertical estimation in the rod-and-frame test and the egocentric-distance-estimation task (with shifted camera) suggest a similar perceptive process in both tasks. This result is confirmed by the better performances of the field-dependent subjects in this condition. In conclusion, we discuss the relationship between FDI and the sense of presence in virtual environments.

  5. Variability in abundance of temperate reef fishes estimated by visual census.

    Directory of Open Access Journals (Sweden)

    Alejo J Irigoyen

    Full Text Available Identifying sources of sampling variation and quantifying their magnitude is critical to the interpretation of ecological field data. Yet, most monitoring programs of reef fish populations based on underwater visual censuses (UVC consider only a few of the factors that may influence fish counts, such as the diver or census methodology. Recent studies, however, have drawn attention to a broader range of processes that introduce variability at different temporal scales. This study analyzes the magnitude of different sources of variation in UVCs of temperate reef fishes off Patagonia (Argentina. The variability associated with time-of-day, tidal state, and time elapsed between censuses (minutes, days, weeks and months was quantified for censuses conducted on the five most conspicuous and common species: Pinguipes brasilianus, Pseudopercis semifasciata, Sebastes oculatus, Acanthistius patachonicus and Nemadactylus bergi. Variance components corresponding to spatial heterogeneity and to the different temporal scales were estimated using nested random models. The levels of variability estimated for the different species were related to their life history attributes and behavior. Neither time-of-day nor tidal state had a significant effect on counts, except for the influence of tide on P. brasilianus. Spatial heterogeneity was the dominant source of variance in all but one species. Among the temporal scales, the intra-annual variation was the highest component for most species due to marked seasonal fluctuations in abundance, followed by the weekly and the instantaneous variation; the daily component was not significant. The variability between censuses conducted at different tidal levels and time-of-day was similar in magnitude to the instantaneous variation, reinforcing the conclusion that stochastic variation at very short time scales is non-negligible and should be taken into account in the design of monitoring programs and experiments. The present

  6. Variability in abundance of temperate reef fishes estimated by visual census.

    Science.gov (United States)

    Irigoyen, Alejo J; Galván, David E; Venerus, Leonardo A; Parma, Ana M

    2013-01-01

    Identifying sources of sampling variation and quantifying their magnitude is critical to the interpretation of ecological field data. Yet, most monitoring programs of reef fish populations based on underwater visual censuses (UVC) consider only a few of the factors that may influence fish counts, such as the diver or census methodology. Recent studies, however, have drawn attention to a broader range of processes that introduce variability at different temporal scales. This study analyzes the magnitude of different sources of variation in UVCs of temperate reef fishes off Patagonia (Argentina). The variability associated with time-of-day, tidal state, and time elapsed between censuses (minutes, days, weeks and months) was quantified for censuses conducted on the five most conspicuous and common species: Pinguipes brasilianus, Pseudopercis semifasciata, Sebastes oculatus, Acanthistius patachonicus and Nemadactylus bergi. Variance components corresponding to spatial heterogeneity and to the different temporal scales were estimated using nested random models. The levels of variability estimated for the different species were related to their life history attributes and behavior. Neither time-of-day nor tidal state had a significant effect on counts, except for the influence of tide on P. brasilianus. Spatial heterogeneity was the dominant source of variance in all but one species. Among the temporal scales, the intra-annual variation was the highest component for most species due to marked seasonal fluctuations in abundance, followed by the weekly and the instantaneous variation; the daily component was not significant. The variability between censuses conducted at different tidal levels and time-of-day was similar in magnitude to the instantaneous variation, reinforcing the conclusion that stochastic variation at very short time scales is non-negligible and should be taken into account in the design of monitoring programs and experiments. The present study provides

  7. CT coronary angiography vs. invasive coronary angiography in CHD

    Directory of Open Access Journals (Sweden)

    Anja Hagen

    2012-04-01

    Full Text Available Scientific background: Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT coronary angiography are used in the diagnosis of coronary heart disease (CHD. Research questions: The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD. Methods: A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc. in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications. The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI. Additionally, data on radiation doses from current non-systematic reviews were taken into account. A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources. Data on special indications (bypass or in-stent-restenosis were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered. Results: No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD. Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive

  8. Three-dimensional gadolinium-enhanced MR angiography of the intracranial venous system

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) angiography for evaluation of the intracranial venous system. Thirty-three patients underwent 3D dynamic gadolinium-enhanced MR angiography as well as two-dimensional (2D) time-of-flight (TOF) MR venography in transverse and coronal planes and conventional catheter cerebral angiography with digital subtraction. MR venography was displayed using a maximum-intensity-projection (MIP) algorithm. The acquisition time of 3D gadolinium-enhanced MR angiography was 102 seconds, and that of 2D TOF MR venography was about 7 minutes in the transverse plane and about 9 minutes in the coronal plane. Degree of visualization of the intracranial venous system on each MR sequence was compared with that on conventional catheter cerebral angiography as a standard. Superficial cortical veins and the dural sinus were better visualized on 3D gadolinium-enhanced MR angiography than on 2D TOF MR venography. Three-dimensional gadolinium-enhanced MR angiography is noninvasive and very useful for imaging of the intracranial venous system. It can replace 2D TOF MR venography not only because of its short examination time but because it better demonstrates intracranial venous structures. For evaluation of the SSS, lateral sinus, sigmoid sinus and straight sinus in particular, conventional catheter angiography seems to be unnecessary. (author)

  9. Three-dimensional gadolinium-enhanced MR angiography of the intracranial venous system

    Energy Technology Data Exchange (ETDEWEB)

    Daikokuya, Hideo; Inoue, Yuichi; Yamada, Ryusaku [Osaka City Univ. (Japan). Medical School

    2001-12-01

    The purpose of this study was to assess the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) angiography for evaluation of the intracranial venous system. Thirty-three patients underwent 3D dynamic gadolinium-enhanced MR angiography as well as two-dimensional (2D) time-of-flight (TOF) MR venography in transverse and coronal planes and conventional catheter cerebral angiography with digital subtraction. MR venography was displayed using a maximum-intensity-projection (MIP) algorithm. The acquisition time of 3D gadolinium-enhanced MR angiography was 102 seconds, and that of 2D TOF MR venography was about 7 minutes in the transverse plane and about 9 minutes in the coronal plane. Degree of visualization of the intracranial venous system on each MR sequence was compared with that on conventional catheter cerebral angiography as a standard. Superficial cortical veins and the dural sinus were better visualized on 3D gadolinium-enhanced MR angiography than on 2D TOF MR venography. Three-dimensional gadolinium-enhanced MR angiography is noninvasive and very useful for imaging of the intracranial venous system. It can replace 2D TOF MR venography not only because of its short examination time but because it better demonstrates intracranial venous structures. For evaluation of the SSS, lateral sinus, sigmoid sinus and straight sinus in particular, conventional catheter angiography seems to be unnecessary. (author)

  10. Coronary CT angiography and MR angiography of Kawasaki disease

    International Nuclear Information System (INIS)

    Although the incidence of coronary artery aneurysms has diminished in patients with Kawasaki disease, coronary artery involvement is still regarded as a major complication of the disease, significantly affecting morbidity and mortality. Recent technical advances in coronary CT angiography (CTA) and MR angiography (MRA) have led to the possibility of using these two imaging methods as minimally invasive alternatives to the more invasive diagnostic catheter angiography in evaluating coronary artery abnormalities, such as aneurysm, stenosis, and occlusion. In this article, we describe imaging techniques and findings of coronary CTA and MRA in Kawasaki disease. (orig.)

  11. Misleading Population Estimates: Biases and Consistency of Visual Surveys and Matrix Modelling in the Endangered Bearded Vulture

    OpenAIRE

    Antoni Margalida; Daniel Oro; Ainara Cortés-Avizanda; Rafael Heredia; Donázar, José A.

    2011-01-01

    Conservation strategies for long-lived vertebrates require accurate estimates of parameters relative to the populations' size, numbers of non-breeding individuals (the "cryptic" fraction of the population) and the age structure. Frequently, visual survey techniques are used to make these estimates but the accuracy of these approaches is questionable, mainly because of the existence of numerous potential biases. Here we compare data on population trends and age structure in a bearded vulture (...

  12. Determination of left ventricular heart volume by fast MRI in breath-hold technique: how different are quantitative ventricular angiography, quantitative MRI, and visual echocardiography?; Linksventrikulaere Herzvoluminabestimmung mittels schneller MRT in Atemanhaltetechnik: Wie unterschiedlich sind quantitativer Herzkatheter, quantitativer MRT und visuelle Echokardiographie?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F. [Giessen Univ. (Germany). Diagnostische Radiologie; Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Pabst, W. [Giessen Univ. (Germany). Inst. fuer Medizinische Informatik; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Dinkel, H.P.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie

    2000-01-01

    Goal: Comparison of fast MRI, echocardiography (Echo), and ventricular angiography (Cath) in the assessment of left ventricular global function. Methods: Fast MRI in short axis plane, biplane Cath, and 2D Echo were performed in 62 patients [35 coronary artery diseases, 16 acquired valvular diseases (VD), 9 dilated cardiomyopathies (DCM), 1 congenital heart disease and 1 heart transplantation]. Enddiastolic (EDV), endsystolic (ESV), stroke volumes (SV), cardiac output (CO), and ejection fraction (EF) were compared in MRI and Cath. EF was visually estimated in 2D Echo by an experienced observer. Results: In comparison to MRI, Cath overestimated EF by 8.4%, and Echo underestimated EF by 5.6%. The limits of agreement between MRI and Cath in EF were {+-}23.8%, between MRI and Echo {+-}18%, and between Echo and Cath {+-}19.4%. Significant differences were found between Cath and MRI in EDV, SV, and CO, but not for ESV. The best agreement in EF was found in the group with DCM, the worst in the group with VD. Conclusion: Important systemic and random errors were found in the comparison of MRI, Echo, and Cath. For therapy decision and follow-up, the methods should not be exchanged unscrupulously. (orig.) [German] Ziel: Methodenvergleich von schneller Magnetresonanztomographie (MRT), Echokardiographie (Echo) und Herzkatheter (HK) in der Bestimmung linksventrikulaerer globaler Funktionsparameter. Material und Methoden: Bei 62 Patienten (35 koronare Herzerkrankungen, 16 Herzklappenvitien (KV), 9 idiopathische dilatative Kardiomyopathien (DCM), 1 kongenitale Herzerkrankung und 1 Herzktransplantation) wurde ein Methodenvergleich zwischen schneller Cine MRT im Kurzachsenschnitt, biplanarem HK und 2D Echo durchgefuehrt. Verglichen wurden in MRT und HK linksventrikulaeres enddiastolisches (EDV) und endsystolisches Volumen (ESV), Schlagvolumen (SV), Herzzeitvolumen (HZV) und Ejektionsfraktion (EF). In der Echo wurde die EF visuell durch einen erfahrenen Untersucher bestimmt

  13. Quantitative Simulations of MST Visual Receptive Field Properties Using a Template Model of Heading Estimation

    Science.gov (United States)

    Stone, Leland S.; Perrone, J. A.

    1997-01-01

    We previously developed a template model of primate visual self-motion processing that proposes a specific set of projections from MT-like local motion sensors onto output units to estimate heading and relative depth from optic flow. At the time, we showed that that the model output units have emergent properties similar to those of MSTd neurons, although there was little physiological evidence to test the model more directly. We have now systematically examined the properties of the model using stimulus paradigms used by others in recent single-unit studies of MST: 1) 2-D bell-shaped heading tuning. Most MSTd neurons and model output units show bell-shaped heading tuning. Furthermore, we found that most model output units and the finely-sampled example neuron in the Duffy-Wurtz study are well fit by a 2D gaussian (sigma approx. 35deg, r approx. 0.9). The bandwidth of model and real units can explain why Lappe et al. found apparent sigmoidal tuning using a restricted range of stimuli (+/-40deg). 2) Spiral Tuning and Invariance. Graziano et al. found that many MST neurons appear tuned to a specific combination of rotation and expansion (spiral flow) and that this tuning changes little for approx. 10deg shifts in stimulus placement. Simulations of model output units under the same conditions quantitatively replicate this result. We conclude that a template architecture may underlie MT inputs to MST.

  14. Accuracy of using visual identification of white sharks to estimate residency patterns.

    Directory of Open Access Journals (Sweden)

    David G Delaney

    Full Text Available Determining the residency of an aquatic species is important but challenging and it remains unclear what is the best sampling methodology. Photo-identification has been used extensively to estimate patterns of animals' residency and is arguably the most common approach, but it may not be the most effective approach in marine environments. To examine this, in 2005, we deployed acoustic transmitters on 22 white sharks (Carcharodon carcharias in Mossel Bay, South Africa to quantify the probability of detecting these tagged sharks by photo-identification and different deployment strategies of acoustic telemetry equipment. Using the data collected by the different sampling approaches (detections from an acoustic listening station deployed under a chumming vessel versus those from visual sightings and photo-identification, we quantified the methodologies' probability of detection and determined if the sampling approaches, also including an acoustic telemetry array, produce comparable results for patterns of residency. Photo-identification had the lowest probability of detection and underestimated residency. The underestimation is driven by various factors primarily that acoustic telemetry monitors a large area and this reduces the occurrence of false negatives. Therefore, we propose that researchers need to use acoustic telemetry and also continue to develop new sampling approaches as photo-identification techniques are inadequate to determine residency. Using the methods presented in this paper will allow researchers to further refine sampling approaches that enable them to collect more accurate data that will result in better research and more informed management efforts and policy decisions.

  15. Time-to-Collision estimation from motion based on primate visual processing.

    Science.gov (United States)

    Galbraith, John M; Kenyon, Garrett T; Ziolkowski, Richard W

    2005-08-01

    A population coded algorithm, built on established models of motion processing in the primate visual system, computes the time-to-collision of a mobile robot to real-world environmental objects from video imagery. A set of four transformations starts with motion energy, a spatiotemporal frequency based computation of motion features. The following processing stages extract image velocity features similar to, but distinct from, optic flow; "translation" features, which account for velocity errors including those resulting from the aperture problem; and finally, estimate the time-to-collision. Biologically motivated population coding distinguishes this approach from previous methods based on optic flow. A comparison of the population coded approach with the popular optic flow algorithm of Lucas and Kanade against three types of approaching objects shows that the proposed method produces more robust time-to-collision information from a real world input stimulus in the presence of the aperture problem and other noise sources. The improved performance comes with increased computational cost, which would ideally be mitigated by special purpose hardware architectures.

  16. Misleading population estimates: biases and consistency of visual surveys and matrix modelling in the endangered bearded vulture.

    Directory of Open Access Journals (Sweden)

    Antoni Margalida

    Full Text Available Conservation strategies for long-lived vertebrates require accurate estimates of parameters relative to the populations' size, numbers of non-breeding individuals (the "cryptic" fraction of the population and the age structure. Frequently, visual survey techniques are used to make these estimates but the accuracy of these approaches is questionable, mainly because of the existence of numerous potential biases. Here we compare data on population trends and age structure in a bearded vulture (Gypaetus barbatus population from visual surveys performed at supplementary feeding stations with data derived from population matrix-modelling approximations. Our results suggest that visual surveys overestimate the number of immature (6 y.o. were underestimated in comparison with the predictions of a population model using a stable-age distribution. In addition, we found that visual surveys did not provide conclusive information on true variations in the size of the focal population. Our results suggest that although long-term studies (i.e. population matrix modelling based on capture-recapture procedures are a more time-consuming method, they provide more reliable and robust estimates of population parameters needed in designing and applying conservation strategies. The findings shown here are likely transferable to the management and conservation of other long-lived vertebrate populations that share similar life-history traits and ecological requirements.

  17. Dissociating position and heading estimations: rotated visual orientation cues perceived after walking reset headings but not positions.

    Science.gov (United States)

    Mou, Weimin; Zhang, Lei

    2014-12-01

    This project examined the roles of idiothetic cues due to individuals' movement and allothetic cues independent of individuals' movement in individuals' estimations of their position and heading during locomotion. In an immersive virtual environment, participants learned the locations of five objects and then moved along two legs of a path before positioning the origin and the objects. Participants' estimations of their test position and their test heading were calculated based on the responded objects' locations, using a method of dissociating position estimation and heading estimation developed in this project. Results showed that when a conflicting visual orientation cue was presented after walking, participants relied on the allothetic cues (i.e., the visual orientation cue) for their heading estimation, but on idiothetic cues for their position estimation. These results indicate that after participants updated their position in terms the origin of the path (homing vector) via path integration, they estimated their heading. These results are inconsistent with the theoretical models stipulating that homing vectors are specified in terms of participants' body coordinate systems, but are consistent with the models stipulating that both homing vectors and participants' heading are specified in terms of a fixed reference direction in the environment. PMID:25215931

  18. Carbon dioxide digital subtraction angiography manifestations of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Yan-hao; HE Xiao-feng; CHEN Yong; ZENG Qing-le; XU Xiao-li

    2002-01-01

    Objective: To investigate the imaging features and clinical significance of carbon dioxide digital subtraction angiography (CO2-DSA) in the diagnosis and treatment of hepatocellular carcinoma (HCC).Methods: Both CO2-DSA and conventional DSA were performed in all 47 patients with HCC, and the angiographic manifestations of CO2-DSA were compared with those of conventional DSA in the same patients.Results: Peripheral arterial and capillary imaging by CO2-DSA was inferior to that by conventional DSA, although blood pools were well visualized with CO2. Improved visualization of arterioportal shunting (APS)was obtained with CO2-DSA compared with that by conventional angiography. APS was observed in 33 cases by CO2-DSA and in 12 cases by conventional angiography (P<0. 001). Retrograde visualization of the portal vein (PV) trunk and its large branches was demonstrated in 16 cases by CO2-DSA and in 1 case by conventional DSA (P<0. 001). The manifestation of lipiodol retention in the tumors was consistent with CO2-DSA images after TAE in 38 cases, and with those of conventional DSA in 23 cases (P<0. 01). Conclusion: CO2-DSA was superior to conventional DSA in the detection of APS and retrograde visualization of PV system,and the former can provide usefulness information for the treatment planning (chemoembolization) and patient prognosis. Demonstration of APS by CO2-DSA may suggest the presence of intrahepatic metastases.

  19. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates.

    Science.gov (United States)

    Fraser, Lindsey E; Makooie, Bobbak; Harris, Laurence R

    2015-01-01

    The subjective visual vertical (SVV) and the subjective haptic vertical (SHV) both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert) and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-effect). We compared the two methods in a series of five experiments and provide evidence that the two measures access two different but related estimates of gravitational vertical. Experiment 1 compared SVV and SHV across three levels of whole-body tilt and found that SVV showed an A-effect at larger tilts while SHV was accurate. Experiment 2 found that tilting either the head or the trunk independently produced an A-effect in SVV while SHV remained accurate when the head was tilted on an upright body but showed an A-effect when the body was tilted below an upright head. Experiment 3 repeated these head/body configurations in the presence of vestibular noise induced by using disruptive galvanic vestibular stimulation (dGVS). dGVS abolished both SVV and SHV A-effects while evoking a massive E-effect in the SHV head tilt condition. Experiments 4 and 5 show that SVV and SHV do not combine in an optimally statistical fashion, but when vibration is applied to the dorsal neck muscles, integration becomes optimal. Overall our results suggest that SVV and SHV access distinct underlying gravity percepts based primarily on head and body position information respectively, consistent with a model proposed by Clemens and colleagues. PMID:26716835

  20. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates.

    Directory of Open Access Journals (Sweden)

    Lindsey E Fraser

    Full Text Available The subjective visual vertical (SVV and the subjective haptic vertical (SHV both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-effect. We compared the two methods in a series of five experiments and provide evidence that the two measures access two different but related estimates of gravitational vertical. Experiment 1 compared SVV and SHV across three levels of whole-body tilt and found that SVV showed an A-effect at larger tilts while SHV was accurate. Experiment 2 found that tilting either the head or the trunk independently produced an A-effect in SVV while SHV remained accurate when the head was tilted on an upright body but showed an A-effect when the body was tilted below an upright head. Experiment 3 repeated these head/body configurations in the presence of vestibular noise induced by using disruptive galvanic vestibular stimulation (dGVS. dGVS abolished both SVV and SHV A-effects while evoking a massive E-effect in the SHV head tilt condition. Experiments 4 and 5 show that SVV and SHV do not combine in an optimally statistical fashion, but when vibration is applied to the dorsal neck muscles, integration becomes optimal. Overall our results suggest that SVV and SHV access distinct underlying gravity percepts based primarily on head and body position information respectively, consistent with a model proposed by Clemens and colleagues.

  1. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    Directory of Open Access Journals (Sweden)

    Oddershede L

    2014-01-01

    Full Text Available Lars Oddershede,1,2 Jan Jesper Andreasen,1 Lars Ehlers2 1Department of Cardiothoracic Surgery, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark; 2Danish Center for Healthcare Improvements, Faculty of Social Sciences and Faculty of Health Sciences, Aalborg University, Aalborg East, Denmark Introduction: In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease. Methods: Patients undergoing coronary artery bypass grafting at Aalborg University Hospital in Denmark were asked to score their health using the five VAS items (mobility, self-care, ability to perform usual activities, pain, and presence of anxiety or depression and the EuroQol 5 Dimensions questionnaire. Regression analysis was used to estimate four mapping models from patients' age, sex, and the self-reported VAS scores. Prediction errors were compared between mapping models and on subsets of the observed utility scores. Agreement between predicted and observed values was assessed using Bland–Altman plots. Results: Random effects generalized least squares (GLS regression yielded the best results when quadratic terms of VAS scores were included. Mapping models fitted using the Tobit model and censored least absolute deviation regression did not appear superior to GLS regression. The mapping models were able to explain approximately 63%–65% of the variation in the observed utility scores. The mean absolute error of predictions increased as the observed utility values decreased. Conclusion: We concluded that it was possible to predict utility scores from VAS scores of the five

  2. Validation of a Mexican food photograph album as a tool to visually estimate food amounts in adolescents.

    Science.gov (United States)

    Bernal-Orozco, M Fernanda; Vizmanos-Lamotte, Barbara; Rodríguez-Rocha, Norma P; Macedo-Ojeda, Gabriela; Orozco-Valerio, María; Rovillé-Sausse, Françoise; León-Estrada, Sandra; Márquez-Sandoval, Fabiola; Fernández-Ballart, Joan D

    2013-03-14

    The aim of the present study was to validate a food photograph album (FPA) as a tool to visually estimate food amounts, and to compare this estimation with that attained through the use of measuring cups (MC) and food models (FM). We tested 163 foods over fifteen sessions (thirty subjects/session; 10-12 foods presented in two portion sizes, 20-24 plates/session). In each session, subjects estimated food amounts with the assistance of FPA, MC and FM. We compared (by portion and method) the mean estimated weight and the mean real weight. We also compared the percentage error estimation for each portion, and the mean food percentage error estimation between methods. In addition, we determined the percentage error estimation of each method. We included 463 adolescents from three public high schools (mean age 17·1 (sd 1·2) years, 61·8 % females). All foods were assessed using FPA, 53·4 % of foods were assessed using MC, and FM was used for 18·4 % of foods. The mean estimated weight with all methods was statistically different compared with the mean real weight for almost all foods. However, a lower percentage error estimation was observed using FPA (2·3 v. 56·9 % for MC and 325 % for FM, Pfoods, comparisons between methods showed FPA to be the most accurate tool for estimating food amounts.

  3. Preoperative evaluation of the artery of adamkiewicz by MR angiography and CT angiography in patients with a thoracic aortic aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Niinuma, Hiroyuki; Ohira, Atsushi; Makita, Shinji; Moriai, Yoshiteru; Hiramori, Katsuhiko [Iwate Medical Univ., Morioka (Japan). School of Medicine; Yoshioka, Kunihiro; Nakajima, Takayuki; Kawazoe, Kohei [Iwate Medical Univ., Morioka (Japan). Memorial Heart Center

    2002-08-01

    Paraplegia is known as an extremely serious and important complication of surgical repair in patients with a thoraco-abdominal aortic aneurysm. It is important to evaluate the artery of Adamkiewicz (AdA) before surgical repair to prevent paraplegia. But the AdA is difficult to visualize by the invasive and hazardous, conventional selective angiography. The aim of this study was to visualize AdA by MR angiography (MRA) and CT angiography (CTA). Twenty-one consecutive patients with a thoracic aortic aneurysm underwent both gadolinium-enhanced, three-dimensional MRA and CTA using multislice helical CT. The AdA was successfully visualized in 15 of the 21 patients (71.4%) by MRA, and in 17 of those 21 patients (80.9%) by CTA. Its continuity was depicted in 12 of 15 patients (80%) by MRA, and in 9 of 17 patients (47%) by CTA. AdA was visualized at 85.7% by MRA or CTA, respectively. This study shows that CTA is a much more sensitive method to detect AdA than MRA. On the other hand, MRA is better to evaluate the continuity of AdA from the descending aorta to the anterior spinal artery, than CTA. Therefore, MRA and CTA are both useful for a preoperative evaluation of AdA and its detailed vascular anatomy from the aorta to the anterior spinal artery. (author)

  4. Carbon Dioxide Angiography: Scientific Principles and Practice.

    Science.gov (United States)

    Cho, Kyung Jae

    2015-09-01

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

  5. Estimates of genetic parameters for visual scores and their correlation with production and reproductive traits in Brahman cattle

    OpenAIRE

    Tássia Souza Bertipaglia; Luis Orlando Duitama Carreño; Carlos Henrique Cavallini Machado; Cristiana Andrighetto; Ricardo da Fonseca

    2012-01-01

    The objective of this study was to evaluate the association of visual scores of body structure, precocity and muscularity with production (body weight at 18 months and average daily gain) and reproductive (scrotal circumference) traits in Brahman cattle in order to determine the possible use of these scores as selection criteria to improve carcass quality. Covariance components were estimated by the restricted maximum likelihood method using an animal model that included contemporary group as...

  6. Contributions of visual and proprioceptive information to travelled distance estimation during changing sensory congruencies.

    Science.gov (United States)

    Campos, Jennifer L; Butler, John S; Bülthoff, Heinrich H

    2014-10-01

    Recent research has provided evidence that visual and body-based cues (vestibular, proprioceptive and efference copy) are integrated using a weighted linear sum during walking and passive transport. However, little is known about the specific weighting of visual information when combined with proprioceptive inputs alone, in the absence of vestibular information about forward self-motion. Therefore, in this study, participants walked in place on a stationary treadmill while dynamic visual information was updated in real time via a head-mounted display. The task required participants to travel a predefined distance and subsequently match this distance by adjusting an egocentric, in-depth target using a game controller. Travelled distance information was provided either through visual cues alone, proprioceptive cues alone or both cues combined. In the combined cue condition, the relationship between the two cues was manipulated by either changing the visual gain across trials (0.7×, 1.0×, 1.4×; Exp. 1) or the proprioceptive gain across trials (0.7×, 1.0×, 1.4×; Exp. 2). Results demonstrated an overall higher weighting of proprioception over vision. These weights were scaled, however, as a function of which sensory input provided more stable information across trials. Specifically, when visual gain was constantly manipulated, proprioceptive weights were higher than when proprioceptive gain was constantly manipulated. These results therefore reveal interesting characteristics of cue-weighting within the context of unfolding spatio-temporal cue dynamics.

  7. Adaptive thresholding of digital subtraction angiography images

    Science.gov (United States)

    Sang, Nong; Li, Heng; Peng, Weixue; Zhang, Tianxu

    2005-10-01

    In clinical practice, digital subtraction angiography (DSA) is a powerful technique for the visualization of blood vessels in the human body. Blood vessel segmentation is a main problem for 3D vascular reconstruction. In this paper, we propose a new adaptive thresholding method for the segmentation of DSA images. Each pixel of the DSA images is declared to be a vessel/background point with regard to a threshold and a few local characteristic limits depending on some information contained in the pixel neighborhood window. The size of the neighborhood window is set according to a priori knowledge of the diameter of vessels to make sure that each window contains the background definitely. Some experiments on cerebral DSA images are given, which show that our proposed method yields better results than global thresholding methods and some other local thresholding methods do.

  8. Acoustic Angiography: A New Imaging Modality for Assessing Microvasculature Architecture

    Directory of Open Access Journals (Sweden)

    Ryan C. Gessner

    2013-01-01

    Full Text Available 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.

  9. 64. The prevalence of coronary artery anomalies in Qassim province detected by cardiac computed tomography angiography

    Directory of Open Access Journals (Sweden)

    O. smettei

    2016-07-01

    Full Text Available Coronary artery anomalies (CAAs affect about 1% of the general population based on invasive coronary angiography (ICA data, computed tomography angiography (CTA enables better visualization of the origin, course, relation to the adjacent structures, and termination of CAAs compared to ICA. The aim of our work is to estimate the frequency of CAAs in Qassim province among patients underwent cardiac CTA at PSCCQ. Retrospective analysis of the CTA data of 2235 patients between 2009 and 2015. The prevalence of CAAs in our study was 1.029%. Among the 2235 patients, 241 (10.78% had CAAs or coronary variants, 198 (8.85% had myocardial bridging, 34 (1.52% had a variable location of the Coronary Ostia, Twenty two (0.98% had a separate origin of left anterior descending (LAD and left circumflex coronary (LCX arteries, ten (0.447% had a separate origin of the RCA and the Conus artery. Seventeen (0.76% had an anomalous origin of the coronaries. Six (0.268% had a coronary artery fistula, which is connected mainly to the right heart chambers, one of these fistulas was complicated by acute myocardial infarction. The incidence of CAAs in our patient population was similar to the former studies, CTA is an excellent tool for diagnosis and guiding the management of the CAAs.

  10. Changes of Indocyanine Green and Fluorescein Angiography in Multiple Evanescent White-dot Syndrome: A Case Report

    Institute of Scientific and Technical Information of China (English)

    Changxian Yi; Guilin Zhao; Jiexiong Ou; Hong Yan

    2003-01-01

    Purpose: To study the clinicopathological change on "Multiple Evanescent White-dot Syndrome (MEWDS)"through fundus angiogrphy analyses.Methods:Examing the case with fluorescein angiography (FFA) and indocyanine green angiography(ICGA), visual field and following up for 15 months.Results :There exist multiple white dots in the fundus photo and angiography. The changes on ICGA maintain longer than fundus photo and FFA. Papille may be edematous and macula could present with special hypofluorescent flecks.Conclusions:MEWDS has specific angiographic features. Its pathological changes involve deep retinal pigment epithelium(RPE) as well as choroidal capillaries. The prognosis of the visual acuity for MEWDS is very good.

  11. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Science.gov (United States)

    ... produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  12. Estimating the body portion of CT volumes by matching histograms of visual words

    Science.gov (United States)

    Feulner, Johannes; Zhou, S. Kevin; Seifert, Sascha; Cavallaro, Alexander; Hornegger, Joachim; Comaniciu, Dorin

    2009-02-01

    Being able to automatically determine which portion of the human body is shown by a CT volume image offers various possibilities like automatic labeling of images or initializing subsequent image analysis algorithms. This paper presents a method that takes a CT volume as input and outputs the vertical body coordinates of its top and bottom slice in a normalized coordinate system whose origin and unit length are determined by anatomical landmarks. Each slice of a volume is described by a histogram of visual words: Feature vectors consisting of an intensity histogram and a SURF descriptor are first computed on a regular grid and then classified into the closest visual words to form a histogram. The vocabulary of visual words is a quantization of the feature space by offline clustering a large number of feature vectors from prototype volumes into visual words (or cluster centers) via the K-Means algorithm. For a set of prototype volumes whose body coordinates are known the slice descriptions are computed in advance. The body coordinates of a test volume are computed by a 1D rigid registration of the test volume with the prototype volumes in axial direction. The similarity of two slices is measured by comparing their histograms of visual words. Cross validation on a dataset of 44 volumes proved the robustness of the results. Even for test volumes of ca. 20cm height, the average error was 15.8mm.

  13. Assessment of anemia during CT pulmonary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Caroline, E-mail: cjung@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Groth, Michael; Bley, Thorsten A.; Henes, Frank O. [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Treszl, András [Department of Medical Biometry and Epidemiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany); Adam, Gerhard; Bannas, Peter [Department of Diagnostic and Interventional Radiology, University Hospital Eppendorf, Martinistrasse 52, 20246 Hamburg (Germany)

    2012-12-15

    Objectives: Anemia is associated with increased mortality in patients with acute symptomatic pulmonary embolism (PE). The purpose of this study was to evaluate the feasibility of Hounsfield unit (HU) measurements on the single unenhanced trigger slice of pulmonary CT angiography scans for diagnosis of anemia. Material and Methods: 150 consecutive patients (median age 64 ± 16 years) with suspected PE underwent pulmonary CT angiography. Two radiologists, blinded to laboratory results, performed HU measurements in the single unenhanced trigger scan independently by region-based analysis (ROI). HU values from ascending and descending aorta and the calculated mean of both were correlated with serum hemoglobin levels. Inter- and intraobserver variability was determined for HU measurements, and ROC analysis was performed for diagnosis of anemia. Calculated linear models were used to assess formulas for estimation of hemoglobin levels from HU measurements. Results: HU measurements revealed high intra- and interrater reliability (ICC > 0.981 and ICC > 0.965, respectively). Calculated mean HU values showed a strong correlation with serum hemoglobin levels (r = 0.734), which allowed generation of different formulas for calculation of hemoglobin levels from HU measurements. ROC analyses confirmed a high sensitivity (80.4 for men; 91.3 for women) and specificity (84.0 for men; 84.9 for women) for diagnosing anemia. Conclusion: Diagnosis of anemia and quantification of hemoglobin levels upon a single unenhanced trigger scan of pulmonary CT angiography is feasible. We suggest disclosing the anemic state in the radiological report, independent of the presence of PE, since anemia carries increased risks of morbidity and mortality.

  14. Comparison of intra-arterial digital subtraction angiography with conventional angiography after transcatheter arterial embolization for hepatic malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Minakuchi, Kazuo; Takada, Keiji; Manabe, Takao; Kobayashi, Nobuyuki; Nakamura, Kenji; Onoyama, Yasuto (Osaka City Univ. (Japan). Faculty of Medicine)

    Twenty patients with hepatic malignancy were treated with transcatheter arterial embolization (TAE) under examination by intra-arterial digital subtraction angiography (IA-DSA) and conventional angiography (CA). Comparison of these two angiographies revealed that the time required for confirmation of the embolized portion of the artery was about four-and-a-half times shorter with IA-DSA than CA. Moreover, IA-DSA revealed the obstructed portion more readily and accurately than CA. In particular, confirmation could not be made by CA in 35% of cases because of residual Gelform sponge containing contrast medium in the artery. The visualization of residual tumor stain after TAE was 40% better on IA-DSA than CA, because of residual Gelform sponge containing contrast medium and overlapping shadow with calcified costal cartilage, excretory pyelography, and original tumor stain. However, CA was better than IA-DSA in visualizing accidental obstruction of nonobjective arteries such as the cystic artery because of the poor spatial resolution and misregistration artifacts of IA-DSA. CA was better than IA-DSA in visualizing surrounding nonembolized hepatic parenchyma because of the misregistration artifacts of IA-DSA. For effective TAE without severe complication, we concluded that TAE for HCC should be performed under a combination of IA-DSA and CA. (author).

  15. Estimates of genetic parameters for visual scores and their correlation with production and reproductive traits in Brahman cattle

    Directory of Open Access Journals (Sweden)

    Tássia Souza Bertipaglia

    2012-06-01

    Full Text Available The objective of this study was to evaluate the association of visual scores of body structure, precocity and muscularity with production (body weight at 18 months and average daily gain and reproductive (scrotal circumference traits in Brahman cattle in order to determine the possible use of these scores as selection criteria to improve carcass quality. Covariance components were estimated by the restricted maximum likelihood method using an animal model that included contemporary group as fixed effect. A total of 1,116 observations of body structure, precocity and muscularity were used. Heritability was 0.39, 043 and 0.40 for body structure, precocity and muscularity, respectively. The genetic correlations were 0.79 between body structure and precocity, 0.87 between body structure and muscularity, and 0.91 between precocity and muscularity. The genetic correlations between visual scores and body weight at 18 months were positive (0.77, 0.57 and 0.59 for body structure, precocity and muscularity, respectively. Similar genetic correlations were observed between average daily gain and visual scores (0.60, 0.57 and 0.48, respectively, whereas the genetic correlations between scrotal circumference and these scores were low (0.13, 0.02, and 0.13. The results indicate that visual scores can be used as selection criteria in Brahman breeding programs. Favorable correlated responses should be seen in average daily gain and body weight at 18 months. However, no correlated response is expected for scrotal circumference.

  16. Estimating Occupancy of Rare Fishes Using Visual Surveys, with a Comparison to Backpack Electrofishing

    NARCIS (Netherlands)

    Albanese, Brett; Owers, Katharine A.; Weiler, Deborah A.; Pruitt, William

    2011-01-01

    There is an ongoing need to monitor the status of imperiled fishes in the southeastern United States using effective methods. Visual surveys minimize harm to target species, but few studies have specifically examined their effectiveness compared to other methods or accounted for imperfect species de

  17. New abdominal CT angiography protocol on a 16 detector-row CT scanner - first results

    International Nuclear Information System (INIS)

    Purpose. Purpose of this study was the implementation of a new abdominal CT angiography protocol on a 16 detector-row CT scanner and the comparison to selective catheter angiography.Methods. 76 patients with various vascular disorders underwent abdominal CT angiography on a recently developed 16 detector-row CT scanner using submillimeter slice collimation (16 x 0.75 mm). Results were compared with mesenteric and/or hepatic angiography in 17 patients performed during tumor embolization. Opacification was provided using individually tailored contrast application with a test bolus setting. To evaluate the contrast injection protocol density measurements within the vessel lumen were performed.Results. Diagnostic image quality was achieved in all patients with angiographic comparison (n = 17). Within the hepatic and mesenteric vasculature up to 4th generation vessels could be identified. Compared to selctive angiography CT angiography provided equivalent morphologic information up to the detectable vessel generation. With the applied contrast application regimen there were no significant differences in vessel enhancement along the abdominal aorta and iliac arteries.Conclusion. 16 detector-row CT enables whole abdominal angiographic studies with submillimeter resolution in a single breath-hold. The improved spatial resolution enables for high quality 3D visualization. Compared to invasive angiography, 16 detector-row CT reveals equivalent morphologic information. (orig.)

  18. Role of 3-D Conventional Angiography In Evaluation of Intra Carnial Aneurysms

    Directory of Open Access Journals (Sweden)

    Ahmed M Bassiouny*, Maher M Arafa*, Sameh M Abdelwahab*,

    2013-04-01

    Full Text Available Introduction: intracranial aneurysms are pathological enlargement of the brain arteries that are most commonly located in the circle of Willis. Intracranial aneurysms are relatively common with a prevalence of approximately 4%. The real danger of aneurysms is subarachnoid hemorrhage. 3D digital subtraction angiography has become a critical imaging tool in neuroradiology allowing for the visualization of detailed cerebral vasculature prior to any intervention. Aim of the work: The aim of this work is to evaluate the diagnostic performance of 3D conventional angiography in the evaluation of intracranial aneurysms compared with the conventional cerebral angiography. Methods: The studied group included 20 patients (5 men and 15 women with subarachnoid hemorrhage or known to have cerebral aneurysms. All patients were subjected to conventional cerebral angiography and 3D cerebral angiography, using C-arm (Toshiba rotational technique.Results: 3D digital subtraction angiography is superior to conventional digital subtraction angiography in 100% of the cases 3D imaging revealed the proper aneurysmal shape, size, precise assessment of its neck and relation to the surrounding vessels. Conclusion: Three-dimensional DSA improves the detection and delineation of intracranial aneurysms

  19. In vivo tear film thickness measurement and tear film dynamics visualization using spectral domain OCT and an efficient delay estimator

    Science.gov (United States)

    Aranha dos Santos, Valentin; Schmetterer, Leopold; Gröschl, Martin; Garhofer, Gerhard; Werkmeister, René M.

    2016-03-01

    Dry eye syndrome is a highly prevalent disease of the ocular surface characterized by an instability of the tear film. Traditional methods used for the evaluation of tear film stability are invasive or show limited repeatability. Here we propose a new noninvasive approach to measure tear film thickness using an efficient delay estimator and ultrahigh resolution spectral domain OCT. Silicon wafer phantoms with layers of known thickness and group index were used to validate the estimator-based thickness measurement. A theoretical analysis of the fundamental limit of the precision of the estimator is presented and the analytical expression of the Cramér-Rao lower bound (CRLB), which is the minimum variance that may be achieved by any unbiased estimator, is derived. The performance of the estimator against noise was investigated using simulations. We found that the proposed estimator reaches the CRLB associated with the OCT amplitude signal. The technique was applied in vivo in healthy subjects and dry eye patients. Series of tear film thickness maps were generated, allowing for the visualization of tear film dynamics. Our results show that the central tear film thickness precisely measured in vivo with a coefficient of variation of about 0.65% and that repeatable tear film dynamics can be observed. The presented method has the potential of being an alternative to breakup time measurements (BUT) and could be used in clinical setting to study patients with dry eye disease and monitor their treatments.

  20. The Subjective Visual Vertical and the Subjective Haptic Vertical Access Different Gravity Estimates

    OpenAIRE

    Fraser, Lindsey E.; Bobbak Makooie; Harris, Laurence R.

    2015-01-01

    The subjective visual vertical (SVV) and the subjective haptic vertical (SHV) both claim to probe the underlying perception of gravity. However, when the body is roll tilted these two measures evoke different patterns of errors with SVV generally becoming biased towards the body (A-effect, named for its discoverer, Hermann Rudolph Aubert) and SHV remaining accurate or becoming biased away from the body (E-effect, short for Entgegengesetzt-effect, meaning "opposite", i.e., opposite to the A-ef...

  1. Hepatic angiography: Portal hypertension

    International Nuclear Information System (INIS)

    Portal hypertension is usually a manifestation of underlying hepatic parenchymal disease, although it may be secondary to portal or hepatic venous thrombosis and rarely to hyperdynamic portal states. Portal hypertension may present as encephalopathy, ascites, jaundice, hepatic failure, or catastrophic upper gastrointestinal hemorrhage. Radiologic investigation should include indirect or direct measurements of portal pressure, assessment of portal venous perfusion, visualization of collaterals, and demonstration of arterial and venous anatomy for potential shunt procedure. Following survival of initial variceal bleeding, the most effective procedure to prevent recurrent hemorrhage is a shunt to decompress the varices. The decision whether to intervene medically or surgically during the acute hemorrhagic episode as well as the type of shunt used to prevent future hemorrhage is the subject of continuing controversy

  2. Delayed clopidogrel transit during myocardial infarction evident on angiography.

    Science.gov (United States)

    Ghobrial, Joanna; Gibson, C Michael; Pinto, Duane S

    2015-05-01

    We describe the case of a patient with non-ST segment elevation myocardial infarction (NSTEMI) where a limitation of oral clopidogrel loading prior to percutaneous coronary intervention (PCI) was directly visualized on angiography. Clopidogrel is a thienopyridine antiplatelet agent used in acute coronary syndromes. It reduces platelet aggregation via inhibition of the P2Y12 receptor. Clopidogrel is an inactive metabolite that is metabolized into the active metabolite by the cytochrome P450 isoenzymes located mostly in the liver and partly in the gastrointestinal system. As such, it requires at least 2 hours to reach maximal effect. A 63-year-old female went to an outside facility where she was diagnosed with NSTEMI and underwent angiography. She was administered 324 mg of aspirin and 600 mg of clopidogrel, and was transferred to our facility. Upon arrival, approximately 1.5 hours after the oral loading dose, the clopidogrel tablets were visualized intact in the stomach during angiography, implying a very low likelihood of adequate absorption or antiplatelet effect. This observation raises the concern that delayed gastrointestinal transit, apart from other metabolic derangements, may be a factor in achieving optimal platelet inhibition using oral agents. PMID:25929306

  3. Towards the use of OCT angiography in clinical dermatology

    Science.gov (United States)

    Baran, Utku; Choi, Woo June; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography (OCT) is a popular imaging technique used in ophthalmology, and on the way to become clinically viable alternative in dermatology due to its capability of acquiring histopathology level images of in vivo tissue, noninvasively. In this study, we demonstrate the capabilities of OCT-based angiography (OMAG) in detecting high-resolution, volumetric structural and microvascular features of in vivo human skin with various conditions using a swept source OCT system that operates on a central wavelength of 1310 nm with an A-line rate of 100 kHz. OMAG images provide detailed in vivo visualization of microvasculature of abnormal human skin conditions from face, chest and belly. Moreover, the progress of wound healing on human skin from arm is monitored during longitudinal wound healing process. The presented results promise the clinical use of OCT angiography in treatment of prevalent cutaneous diseases within human skin, in vivo.

  4. Ultrahigh-speed non-invasive widefield angiography

    Science.gov (United States)

    Blatter, Cedric; Klein, Thomas; Grajciar, Branislav; Schmoll, Tilman; Wieser, Wolfgang; Andre, Raphael; Huber, Robert; Leitgeb, Rainer A.

    2012-07-01

    Retinal and choroidal vascular imaging is an important diagnostic benefit for ocular diseases such as age-related macular degeneration. The current gold standard for vessel visualization is fluorescence angiography. We present a potential non-invasive alternative to image blood vessels based on functional Fourier domain optical coherence tomography (OCT). For OCT to compete with the field of view and resolution of angiography while maintaining motion artifacts to a minimum, ultrahigh-speed imaging has to be introduced. We employ Fourier domain mode locking swept source technology that offers high quality imaging at an A-scan rate of up to 1.68 MHz. We present retinal angiogram over ˜48 deg acquired in a few seconds in a single recording without the need of image stitching. OCT at 1060 nm allows for high penetration in the choroid and efficient separate characterization of the retinal and choroidal vascularization.

  5. The Visualization and Analysis of POI Features under Network Space Supported by Kernel Density Estimation

    Directory of Open Access Journals (Sweden)

    YU Wenhao

    2015-01-01

    Full Text Available The distribution pattern and the distribution density of urban facility POIs are of great significance in the fields of infrastructure planning and urban spatial analysis. The kernel density estimation, which has been usually utilized for expressing these spatial characteristics, is superior to other density estimation methods (such as Quadrat analysis, Voronoi-based method, for that the Kernel density estimation considers the regional impact based on the first law of geography. However, the traditional kernel density estimation is mainly based on the Euclidean space, ignoring the fact that the service function and interrelation of urban feasibilities is carried out on the network path distance, neither than conventional Euclidean distance. Hence, this research proposed a computational model of network kernel density estimation, and the extension type of model in the case of adding constraints. This work also discussed the impacts of distance attenuation threshold and height extreme to the representation of kernel density. The large-scale actual data experiment for analyzing the different POIs' distribution patterns (random type, sparse type, regional-intensive type, linear-intensive type discusses the POI infrastructure in the city on the spatial distribution of characteristics, influence factors, and service functions.

  6. Pulmonary angiography with lopamidol 370

    International Nuclear Information System (INIS)

    Fifty-one consecutive patients who underwent pulmonary angiography with iopamidol, 370 mg/ml, were studied prospectively. Patients were asked to grade any heat or pain felt on injection, and were observed for coughing. Right atrial and pulmonary artery pressures were obtained before the first and after the final contrast agent injection. Pressure changes were compared with those in a consecutive group of 25 patients who underwent examinations performed with Na-meglumine diatrizoate, 370 mg/ml. Film quality was evaluated for patient motion. Iopamidol generated marked discomfort in only three patients. Pressure changes were largely unremarkable. In no case was there any significant motion artifact secondary to coughing. Iopamidol is a safe, well-tolerated contrast agent for pulmonary angiography. It improves image quality by nearly eliminating coughing

  7. Bilateral persistent trigeminal artery variants diagnosed by MR angiography.

    Science.gov (United States)

    Uchino, Akira

    2011-12-01

    A persistent trigeminal artery (PTA) is the most common anastomosis between the carotid and vertebrobasilar system. A PTA variant (PTAV) is a rare anomaly in which the cerebellar artery arises from the internal carotid artery (ICA) without connection with the basilar artery (BA). I present what I believe is the first report of bilateral PTAVs diagnosed using magnetic resonance (MR) angiography and briefly discuss the embryology of this rare anomaly. An 81-year-old woman with small infarctions underwent cerebral MR imaging and MR angiography with a 1.5-tesla imager for the evaluation of brain lesions. An MR angiography was obtained using the standard noncontrast three-dimensional time-of-flight technique. The MR angiographic demonstration of bilateral anterior inferior cerebellar arteries arising from the precavernous segment of the ICA without anastomosis to the BA indicated bilateral PTAVs. This is the first report of bilateral PTAVs diagnosed by MR angiography. The literature review indicates that an estimated prevalence of bilateral PTAVs is about 0.0012%. PMID:21544587

  8. Estimating the critical thermal maximum (CTmax) of bed bugs, Cimex lectularius: Comparing thermolimit respirometry with traditional visual methods.

    Science.gov (United States)

    DeVries, Zachary C; Kells, Stephen A; Appel, Arthur G

    2016-07-01

    Evaluating the critical thermal maximum (CTmax) in insects has provided a number of challenges. Visual observations of endpoints (onset of spasms, loss of righting response, etc.) can be difficult to measure consistently, especially with smaller insects. To resolve this problem, Lighton and Turner (2004) developed a new technique: thermolimit respirometry (TLR). TLR combines real time measurements of both metabolism (V·CO2) and activity to provide two independent, objective measures of CTmax. However, several questions still remain regarding the precision of TLR and how accurate it is in relation to traditional methods. Therefore, we evaluated CTmax of bed bugs using both traditional (visual) methods and TLR at three important metabolic periods following feeding (1d, 9d, and 21d). Both methods provided similar estimates of CTmax, although traditional methods produced consistently lower values (0.7-1°C lower than TLR). Despite similar levels of precision, TLR provided a more complete profile of thermal tolerance, describing changes in metabolism and activity leading up to the CTmax, not available through traditional methods. In addition, feeding status had a significant effect on bed bug CTmax, with bed bugs starved 9d (45.19[±0.20]°C) having the greatest thermal tolerance, followed by bed bugs starved 1d (44.64[±0.28]°C), and finally bed bugs starved 21d (44.12[±0.28]°C). Accuracy of traditional visual methods in relation to TLR is highly dependent on the selected endpoint; however, when performed correctly, both methods provide precise, accurate, and reliable estimations of CTmax. PMID:26970580

  9. Angiography of the upper extremity

    International Nuclear Information System (INIS)

    This thesis provides a description of the technical and medical aspects of arteriography of the upper extremity and an extensive analysis of the angiographic anatomy and pathology of 750 selective studies performed in more than 500 patients. A short historical review is provided of angiography as a whole and of arteriography of the hand in particular. The method of percutaneous transfemoral catheterization of the arteries of the upper extremity and particularly the arteries of the hand is considered, discussing the problems the angiographer encounters frequently, describing the angiographic complications which may occur and emphasizing the measures to keep them to a minimum. The use of vasodilators in hand angiography is discussed. A short description of the embryological patterns persisting in the arteries of the arm is included in order to understand the congenital variations of the arteries of the upper extremity. The angiographic patterns and clinical aspects of the most common pathological processes involving the arteries of the upper extremities are presented. Special attention is paid to the correlation between angiography and pathology. (Auth.)

  10. Estimating cohesion in small groups using audio-visual nonverbal behavior

    NARCIS (Netherlands)

    H. Hung; D. Gatica-Perez

    2010-01-01

    Cohesiveness in teams is an essential part of ensuring the smooth running of task-oriented groups. Research in social psychology and management has shown that good cohesion in groups can be correlated with team effectiveness or productivity, so automatically estimating group cohesion for team traini

  11. Estimation of mental effort in learning visual search by measuring pupil response.

    Directory of Open Access Journals (Sweden)

    Tatsuto Takeuchi

    Full Text Available Perceptual learning refers to the improvement of perceptual sensitivity and performance with training. In this study, we examined whether learning is accompanied by a release from mental effort on the task, leading to automatization of the learned task. For this purpose, we had subjects conduct a visual search for a target, defined by a combination of orientation and spatial frequency, while we monitored their pupil size. It is well known that pupil size reflects the strength of mental effort invested in a task. We found that pupil size increased rapidly as the learning proceeded in the early phase of training and decreased at the later phase to a level half of its maximum value. This result does not support the simple automatization hypothesis. Instead, it suggests that the mental effort and behavioral performance reflect different aspects of perceptual learning. Further, mental effort would be continued to be invested to maintain good performance at a later stage of training.

  12. Computed Tomographic Angiography (CTA) in Vascular Trauma

    OpenAIRE

    M. Tehrai

    2007-01-01

    In the evaluation of trauma patients, computed tomo-graphy and CT angiography (CTA) are powerful non-invasive tools that provide a large amount of informa-tion in so little time that they have virtually replaced plain film radiography and catheter angiography. In our hospital, CTA has replaced catheter angiogra-phy for diagnosing most vascular injuries, resulting from penetrating and blunt trauma to head, neck, thorax, abdomen and extremities. This lecture will cover current imaging protocols...

  13. Patent ductus venosus: diagnosis by MR angiography

    International Nuclear Information System (INIS)

    We report a 15-year-old boy with patent ductus venosus in whom the diagnosis was made by MR angiography. A patent ductus venosus Arantii is a rare form of portosystemic shunt. Only a few cases have been reported in adults and children. The diagnosis is usually made by US and digital subtraction angiography. In our patient, the diagnosis was first made by MR angiography. This demonstrates the excellent diagnostic potential of the method in paediatric patients. (orig.)

  14. Spinal angiography. Anatomy, technique and indications

    International Nuclear Information System (INIS)

    Spinal angiography is a diagnostic modality requiring detailed knowledge of spinal vascular anatomy. The cervical spinal cord is supplied by the vertebral arteries while segmental arteries which are preserved from fetal anatomy, supply the thoracic and lumbar regions. As spinal angiography carries the risk of paraplegia the indications have to be considered very carefully. Nevertheless, spinal angiography should be performed if there is reason to suspect a spinal vascular malformation from magnetic resonance imaging (MRI). (orig.)

  15. Clinical experience of ioxaglate in femoral angiography

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S.; Mine, H.; Iwai, T. (Tokyo Medical and Dental Univ. (Japan). School of Medicine)

    1982-01-01

    Painless femoral angiography could be performed in patients under slight analgesic premedication by using ioxaglate (320 mg I/ml). Slower flow of ioxaglate resulted in longer segments of the arteries being filled by the contrast column than by using iothalamate, which was confirmed by serial whole-limb angiography. The dynamic characteristics of ioxaglate, in addition to marked reduction of pain, fulfilled the requirements for its use as a contrast medium in femoral or peripheral angiography.

  16. Initialisation and Estimation Methods for Batch Optimisation of Inertial/Visual SLAM

    OpenAIRE

    Skoglund, Martin; Sjanic, Zoran; Gustafsson, Fredrik

    2013-01-01

    Simultaneous Localisation and Mapping (SLAM) denotes the problem of jointly localizing a moving platform and mapping the environment. This work studies the SLAM problem using a combination of inertial sensors, measuring the platform's accelerations and angular velocities, and a monocular camera observing the environment. We formulate the SLAM problem on a nonlinear least squares (NLS) batch form, whose solution provides a smoothed estimate of the motion and map. The NLS problem is highly nonc...

  17. Contrast agent choice for intravenous coronary angiography

    Science.gov (United States)

    Zeman, H. D.; Siddons, D. P.

    1990-05-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. Gd-DTPA is already approved for use as a contrast agent for

  18. Improved quantitative visualization of hypervelocity flow through wavefront estimation based on shadow casting of sinusoidal gratings.

    Science.gov (United States)

    Medhi, Biswajit; Hegde, Gopalakrishna M; Gorthi, Sai Siva; Reddy, Kalidevapura Jagannath; Roy, Debasish; Vasu, Ram Mohan

    2016-08-01

    A simple noninterferometric optical probe is developed to estimate wavefront distortion suffered by a plane wave in its passage through density variations in a hypersonic flow obstructed by a test model in a typical shock tunnel. The probe has a plane light wave trans-illuminating the flow and casting a shadow of a continuous-tone sinusoidal grating. Through a geometrical optics, eikonal approximation to the distorted wavefront, a bilinear approximation to it is related to the location-dependent shift (distortion) suffered by the grating, which can be read out space-continuously from the projected grating image. The processing of the grating shadow is done through an efficient Fourier fringe analysis scheme, either with a windowed or global Fourier transform (WFT and FT). For comparison, wavefront slopes are also estimated from shadows of random-dot patterns, processed through cross correlation. The measured slopes are suitably unwrapped by using a discrete cosine transform (DCT)-based phase unwrapping procedure, and also through iterative procedures. The unwrapped phase information is used in an iterative scheme, for a full quantitative recovery of density distribution in the shock around the model, through refraction tomographic inversion. Hypersonic flow field parameters around a missile-shaped body at a free-stream Mach number of ∼8 measured using this technique are compared with the numerically estimated values. It is shown that, while processing a wavefront with small space-bandwidth product (SBP) the FT inversion gave accurate results with computational efficiency; computation-intensive WFT was needed for similar results when dealing with larger SBP wavefronts. PMID:27505389

  19. 3D global estimation and augmented reality visualization of intra-operative X-ray dose.

    Science.gov (United States)

    Rodas, Nicolas Loy; Padoy, Nicolas

    2014-01-01

    The growing use of image-guided minimally-invasive surgical procedures is confronting clinicians and surgical staff with new radiation exposure risks from X-ray imaging devices. The accurate estimation of intra-operative radiation exposure can increase staff awareness of radiation exposure risks and enable the implementation of well-adapted safety measures. The current surgical practice of wearing a single dosimeter at chest level to measure radiation exposure does not provide a sufficiently accurate estimation of radiation absorption throughout the body. In this paper, we propose an approach that combines data from wireless dosimeters with the simulation of radiation propagation in order to provide a global radiation risk map in the area near the X-ray device. We use a multi-camera RGBD system to obtain a 3D point cloud reconstruction of the room. The positions of the table, C-arm and clinician are then used 1) to simulate the propagation of radiation in a real-world setup and 2) to overlay the resulting 3D risk-map onto the scene in an augmented reality manner. By using real-time wireless dosimeters in our system, we can both calibrate the simulation and validate its accuracy at specific locations in real-time. We demonstrate our system in an operating room equipped with a robotised X-ray imaging device and validate the radiation simulation on several X-ray acquisition setups. PMID:25333145

  20. Early Swept-Source Optical Coherence Tomography Angiography Findings in Unilateral Acute Idiopathic Maculopathy.

    Science.gov (United States)

    Nicolo, Massimo; Rosa, Raffaella; Musetti, Donatella; Musolino, Maria; Traverso, Carlo Enrico

    2016-02-01

    Unilateral acute idiopathic maculopathy (UAIM) is a rare disorder presenting in young people with an acute onset of unilateral central visual loss often associated with a prodromal flu-like illness. The authors present the early anatomical findings of a 35-year-old man clinically diagnosed with UAIM using swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography.

  1. Impact of Scoring Single or Multiple Occlusal Lesions on Estimates of Diagnostic Accuracy of the Visual ICDAS-II System

    Directory of Open Access Journals (Sweden)

    Anahita Jablonski-Momeni

    2009-01-01

    differ in appearance and severity. This study aimed to evaluate how estimates of reproducibility and accuracy of ICDAS-II were affected when all lesions on occlusal surfaces, or only a representative lesion, were scored. 100 permanent teeth with 1–4 investigation sites on the occlusal surface were examined visually by four examiners. Serial sections of the teeth were assessed for lesion depth. Intra- and interexaminer reproducibility (weighted kappa values, sensitivity, and specificity were calculated for all investigation sites and for a randomly selected site per tooth. Comparing the kappa values for the whole sample and the independent sites, no effect or only a small effect was found. Comparing the areas under the ROC-curves no effect could be shown. Examining multiple sites on teeth leads to results comparable to when a single independent site is chosen per tooth.

  2. Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice.

    Science.gov (United States)

    McLenachan, Samuel; Magno, Aaron Len; Ramos, David; Catita, Joana; McMenamin, Paul G; Chen, Fred Kuanfu; Rakoczy, Elizabeth Piroska; Ruberte, Jesus

    2015-09-01

    The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2(Akita) and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2(Akita) mice. Blood vessel density was increased in the DVP of 6 month old Ins2(Akita) mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2(Akita) mouse model of diabetes. PMID:26122048

  3. ECG changes during cerebral angiography

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, K.; Nishimura, Y.; Yoshida, M.; Itoh, K.; Hayashi, N.; Aoki, J.; Nakamura, K.; Imai, M.; Ono, T.; Morikawa, S.

    1984-09-01

    We have analyzed HR changes greater than 20% among 334 patients and 942 cerebral angiographies. A tachycardial effect was seen in 14.9% of patients, while a bradycardial effect was seen in 7.1% including two patients having cardiac standstill (0.5%). These two patients were examined without atropine premedication after subarachnoid hemorrhage. Patients under 19 years of age, unpremedicated with atropine sulfate and suffering from subarachnoid hemorrhage secondary to ruptured aneurysm or arteriovenous malformation showed a significantly high incidence of bradycardia. On the other hand, patients with the neoplastic disease and having an initial sinus bradycardia showed a significantly high incidence of a tachycardial effect.

  4. Hyperpolarized 13C MR angiography

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Magnusson, Peter; Ardenkjær-Larsen, Jan Henrik

    2016-01-01

    Magnetic resonance angiography (MRA) is a non-invasive technology that can be used for diagnosis and monitoring of cardiovascular disease; the number one cause of mortality worldwide. Hyperpolarized imaging agents provide signal enhancement of more than 10, 000 times, which implies large reduction......SSFP sequence, where the signal destruction of the GRE sequence is avoided. However, for intra-arterial injections, the bSSFP sequence results in strong artefacts, and the GRE sequence is preferred. Hyperpolarized MRA presents many challenges and cannot currently compete with conventional contrast enhanced MRA...

  5. Posterior Chamber Hemorrhage during Fluorescein Angiography

    Directory of Open Access Journals (Sweden)

    Manuel A. P. Vilela

    2015-01-01

    Full Text Available This paper provides the first reported case of acute posterior chamber hemorrhage during fluorescein angiography (FA. This is a case review with serial color photographs of the anterior segment. A 76-year-old male was referred for angiographic control of age-related macular degeneration. He was pseudophakic OU, BCVA 20/40 OU. He had mild hypertension, but not diabetes. He had had two previous angiograms without adverse effects. Difficulty was experienced in obtaining the images owing to a progressive reduction in the transparency of the media. A dense hemorrhage in the posterior chamber of the right eye was found, involving the visual axis. Thorough biomicroscopy, gonioscopy, and ultrasonic biomicroscopy showed that part of one of the haptics of the right intraocular lens (IOL was touching and tearing the posterior face of the iris, without any visible synechiae, iris, or angle neovascularization. Anterior segment FA and posterior ultrasonography were normal. No similar case has been described in the literature involving dense progressive bleeding located in the capsular bag and posterior chamber, without any detectable triggering ocular event other than mydriasis and fluorescein injection. Contact of the iris or sulcus with part of the intraocular lens, aggravated by the intense use of mydriatics during the FA procedure, probably caused bleeding to happen.

  6. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  7. Detection of malignant right coronary artery anomaly by multi-slice CT coronary angiography

    International Nuclear Information System (INIS)

    Coronary artery anomalies occur in 0.3-0.8% of the population and infer a high risk for sudden cardiac death in young adults. Diagnosis is usually established during coronary angiography, which is hampered by poor spatial visualization. Magnetic resonance imaging is an alternative, but it is not feasible in the presence of metal objects or claustrophobia. In this report, a 15-year-old boy experienced ventricular fibrillation and was successfully resuscitated. Cardiac catheterization was inconclusive, and pacemaker implantation prohibited the use of MR imaging. Multi-slice CT coronary angiography revealed a malignant anomalous right coronary artery. (orig.)

  8. Optical Coherence Tomography Angiography in Mice: Comparison with Confocal Scanning Laser Microscopy and Fluorescein Angiography

    Science.gov (United States)

    Giannakaki-Zimmermann, Helena; Kokona, Despina; Wolf, Sebastian; Ebneter, Andreas; Zinkernagel, Martin S.

    2016-01-01

    Purpose Optical coherence tomography angiography (OCT-A) allows noninvasive visualization of retinal vessels in vivo. OCT-A was used to characterize the vascular network of the mouse retina and was compared with fluorescein angiography (FA) and histology. Methods In the present study, OCT-A based on a Heidelberg Engineering Spectralis system was used to investigate the vascular network in mice. Data was compared with FA and confocal microscopy of flat-mount histology stained with isolectin IB4. For quantitative analysis the National Cancer Institute's AngioTool software was used. Vessel density, the number of vessel junctions, and endpoints were measured and compared between the imaging modalities. Results The configuration of the superficial capillary network was comparable with OCT-A and flat-mount histology in BALBc mice. However, vessel density and the number of vessel junctions per region of interest (P = 0.0161 and P = 0.0015, respectively) in the deep vascular network of BALBc mice measured by OCT-A was significantly higher than with flat-mount histology. In C3A.Cg-Pde6b+Prph2Rd2/J mice, where the deep capillary plexus is absent, analysis of the superficial network provided similar results for all three imaging modalities. Conclusion OCT-A is a helpful imaging tool for noninvasive, in vivo imaging of the vascular plexus in mice. It may offer advantages over FA and confocal microscopy especially for imaging the deep vascular plexus. Translational Relevance The present study shows that OCT-A can be employed for small animal imaging to assess the vascular network and offers advantages over flat-mount histology and FA.

  9. Indocyanine green angiography in chronic central serous chorioretinopathy

    Science.gov (United States)

    Gajdzik-Gajdecka, Urszula; Dorecka, Mariola; Nita, Ewa; Michalska, Anna; Miniewicz-Kurkowska, Joanna; Romaniuk, Wanda

    2012-01-01

    Summary Background Central serous chorioretinopathy (CSC) is a condition that originates from alterations of the choroidal circulation. The aim of this paper was to evaluate the use of indocyanine green angiography (ICGA) in patients with chronic CSC. Material/Methods The analysis included 17 patients (34 eyes) with chronic CSC in at least 1 eye. The eye examination included: distance and near visual acuity, biomicroscopy, applanation tonometry, fundus examination, colored and red-free fundus photography, evaluation of autofluorescence, optical coherence tomography, and fluorescein and indocyanine green angiography. Results In 34 eyes (100%) involved in the ICGA study the results revealed zones of transient increased choroidal vessels permeability. In 18 eyes (52.9%) choroidal changes were accompanied by a focal serous pigment epithelial detachment. In 4 eyes (11.8%) of 3 patients’ the ICGA examination confirmed the presence of occult choroidal neovascularization (CNV). In the patient with bilateral diffuse retinal pigment epitheliopathy, CNV was present in 1 eye, in the patient with unilateral chronic CSC it was also present in 1 eye, and in the third patient with bilateral chronic CSC it was detected in both eyes. Conclusions ICGA is a very useful examination that enables ophthalmologists to visualize choroidal changes due to chronic CSC, as well as to diagnose occult CNV in chronic CSC. PMID:22293877

  10. Digital subtraction angiography for breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tsurumi, Kiyohiko; Okuyama, Nobuo

    1987-07-01

    We performed digital subtraction angiography (DSA) on 42 patients with breast diseases to investigate its efficiency. As a result we came to the following conclusions: 1. The sensitivity was well evaluated in intraarterial digital subtraction angiography (IA-DSA) of breast. 2. IA-DSA could diagnose difficult cases like cancer which had undergone augmentation mammoplasty, or like Paget's disease and others. 3. DSA was a safe examination method. 4. The sensitivity of IA-DSA of breast cancer is superior to intravenous digital subtraction angiography (IV-DSA).

  11. Parathyroid gland angiography with indocyanine green fluorescence to predict parathyroid function after thyroid surgery

    Science.gov (United States)

    Vidal Fortuny, J.; Belfontali, V.; Sadowski, S. M.; Karenovics, W.; Guigard, S.

    2016-01-01

    Background Postoperative hypoparathyroidism remains the most common complication following thyroidectomy. The aim of this pilot study was to evaluate the use of intraoperative parathyroid gland angiography in predicting normal parathyroid gland function after thyroid surgery. Methods Angiography with the fluorescent dye indocyanine green (ICG) was performed in patients undergoing total thyroidectomy, to visualize vascularization of identified parathyroid glands. Results Some 36 patients underwent ICG angiography during thyroidectomy. All patients received standard calcium and vitamin D supplementation. At least one well vascularized parathyroid gland was demonstrated by ICG angiography in 30 patients. All 30 patients had parathyroid hormone (PTH) levels in the normal range on postoperative day (POD) 1 and 10, and only one patient exhibited asymptomatic hypocalcaemia on POD 1. Mean(s.d.) PTH and calcium levels in these patients were 3·3(1·4) pmol/l and 2·27(0·10) mmol/l respectively on POD 1, and 4·0(1.6) pmol/l and 2·32(0·08) mmol/l on POD 10. Two of the six patients in whom no well vascularized parathyroid gland could be demonstrated developed transient hypoparathyroidism. None of the 36 patients presented symptomatic hypocalcaemia, and none received treatment for hypoparathyroidism. Conclusion PTH levels on POD 1 were normal in all patients who had at least one well vascularized parathyroid gland demonstrated during surgery by ICG angiography, and none required treatment for hypoparathyroidism. PMID:26864909

  12. Comparison of effective doses between computed tomography cardiac angiography and conventional angiography at Pantai Hospital, Kuala Lumpur

    Science.gov (United States)

    Mohamed, Faizal; Moin, F. H. A.

    2013-05-01

    This research studies two types of cardiac angiography procedures, namely Computed Tomography Cardiac Angiography (CTCA) and Conventional Angiography (CA). The following research was executed to estimate the difference of mean effective doses that the patients received through both procedures. The mean dose-length-product (DLP) from CTCA and mean dose-area-product (DAP) from CA were utilized in calculating the effective doses. The result shows that the mean effective dose for CTCA and CA are 1.71±0.59 mSv and 53.25±14.22 mSv respectively. This proves that the mean effective dose received by patients undergoing CA is higher than patients undergoing CTCA. According to t-test, both procedures differ significantly, with a difference amounting to p<0.0001. The increases of the effective dose that the patients received through CA procedure were influenced by exposure time, the coronary anatomical condition, the operator's experience, and the operation methods.

  13. Multidetector-row CT angiography of hepatic artery: comparison with conventional angiography

    International Nuclear Information System (INIS)

    To determine the usefulness of three-dimensional CT angiography using multidetector-row CT (MD-CT) for delineating the arterial anatomy of the liver. Hepatic arterial three-dimensional CT angiography was performed using MDCT (lightspeed Qx/I; GE medical systems, milwaukee, Wis., U.S.A.) in 45 patients with HCC undergoing conventional angiography for transcatheter hepatic arterial chemoembolization. The scanning parameters during the early arterial phase were 2.5 mm slice thickness, 7.5 mm rotation of table speed, and a pitch of 3. Images were obtained by one radiologist using maximum intensity projection from axial CT images obtained during the early arterial phase. Two radiologists blinded to the findings of conventional angiography independently evaluated the hepatic arterial anatomy and the quality of the images obtained. Compared with conventional angiography, reader A correctly evaluated the hepatic arterial anatomy depicted at three-dimensional CT angiography. Reader B's evaluation was correct in 40 of 45 patients. Interobserver agreement was good (kappa value, 0.73), and both readers assessed the quality of three-dimensional CT angiography as excellent. Three-dimensional CT angiography using MDCT was accurate for delineating the arterial anatomy of the liver, and interobserver agreement was good. The modality may provide, prior to conventional angiography, valuable information regrading a patient's hepatic arterial anatomy

  14. Perceptual enhancement of arteriovenous malformation in MRI angiography displays

    Science.gov (United States)

    Abhari, Kamyar; Baxter, John S. H.; Eagleson, Roy; Peters, Terry; de Ribaupierre, Sandrine

    2012-02-01

    The importance of presenting medical images in an intuitive and usable manner during a procedure is essential. However, most medical visualization interfaces, particularly those designed for minimally-invasive surgery, suffer from a number of issues as a consequence of disregarding the human perceptual, cognitive, and motor system's limitations. This matter is even more prominent when human visual system is overlooked during the design cycle. One example is the visualization of the neuro-vascular structures in MR angiography (MRA) images. This study investigates perceptual performance in the usability of a display to visualize blood vessels in MRA volumes using a contour enhancement technique. Our results show that when contours are enhanced, our participants, in general, can perform faster with higher level of accuracy when judging the connectivity of different vessels. One clinical outcome of such perceptual enhancement is improvement of spatial reasoning needed for planning complex neuro-vascular operations such as treating Arteriovenous Malformations (AVMs). The success of an AVM intervention greatly depends on fully understanding the anatomy of vascular structures. However, poor visualization of pre-operative MRA images makes the planning of such a treatment quite challenging.

  15. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  16. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  17. CT coronary angiography versus conventional invasive coronary angiography. The view of the referring physician

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Martin H. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Universitaetsspital Bern (Switzerland). Dept. fuer Diagnostische, Interventionelle und Paediatrische Radiologie; Zimmermann, E.; Hamm, B. [Charite - Universitaetsmedizin Berlin (Germany). Dept. of Radiology; Dewey, M.

    2014-12-15

    Assessment of experience gained by local referring physicians with the procedure of coronary computed tomographic angiography (CCTA) in the everyday clinical routine. A 25-item questionnaire was sent to 179 physicians, who together had referred a total of 1986 patients for CCTA. They were asked about their experience to date with CCTA, the indications for coronary imaging, and their practice in referring patients for noninvasive CCTA or invasive catheter angiography. 53 questionnaires (30%) were assessable, corresponding to more than 72% of the patients referred. Of the referring physicians who responded, 94% saw a concrete advantage of CCTA in the treatment of patients, whereby 87% were 'satisfied' or 'very satisfied' with the reporting. For excluding coronary heart disease (CHD) where there was a low pre-test probability of disease, the physicians considered CCTA to be superior to conventional coronary diagnosis (4.2 on a scale of 1-5) and vice versa for acute coronary syndrome (1.6 of 5). The main reasons for unsuitability of CCTA for CT diagnosis were claustrophobia and the absence of a sinus rhythm. The level of exposure to radiation in CCTA was estimated correctly by only 42% of the referring physicians. 90% of the physicians reported that their patients evaluated their coronary CT overall as 'positive' or 'neutral', while 87% of the physicians whose patients had undergone both procedures reported that the patients had experienced CCTA as the less disagreeable of the two. CCTA is accepted by the referring physicians as an alternative imaging procedure for the exclusion of CHD and received a predominantly positive assessment from both the referring physicians and the patients.

  18. CT coronary angiography versus conventional invasive coronary angiography. The view of the referring physician

    International Nuclear Information System (INIS)

    Assessment of experience gained by local referring physicians with the procedure of coronary computed tomographic angiography (CCTA) in the everyday clinical routine. A 25-item questionnaire was sent to 179 physicians, who together had referred a total of 1986 patients for CCTA. They were asked about their experience to date with CCTA, the indications for coronary imaging, and their practice in referring patients for noninvasive CCTA or invasive catheter angiography. 53 questionnaires (30%) were assessable, corresponding to more than 72% of the patients referred. Of the referring physicians who responded, 94% saw a concrete advantage of CCTA in the treatment of patients, whereby 87% were 'satisfied' or 'very satisfied' with the reporting. For excluding coronary heart disease (CHD) where there was a low pre-test probability of disease, the physicians considered CCTA to be superior to conventional coronary diagnosis (4.2 on a scale of 1-5) and vice versa for acute coronary syndrome (1.6 of 5). The main reasons for unsuitability of CCTA for CT diagnosis were claustrophobia and the absence of a sinus rhythm. The level of exposure to radiation in CCTA was estimated correctly by only 42% of the referring physicians. 90% of the physicians reported that their patients evaluated their coronary CT overall as 'positive' or 'neutral', while 87% of the physicians whose patients had undergone both procedures reported that the patients had experienced CCTA as the less disagreeable of the two. CCTA is accepted by the referring physicians as an alternative imaging procedure for the exclusion of CHD and received a predominantly positive assessment from both the referring physicians and the patients.

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

    OpenAIRE

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

    2015-01-01

    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 advantage...

  20. MRI and MR-angiography of persistent trigeminal artery and its variant; La persistance de l`artere trigeminee et savariante. Apport de l`IRM et de l`angio-RM

    Energy Technology Data Exchange (ETDEWEB)

    Boukobza, M.; Houdart, E.; Chapot, R.; Guichard, J.P.; Merland, J.J. [Hopital Lariboisiere, 75 - Paris (France)

    1997-11-01

    We describe the magnetic resonance imaging and magnetic resonance angiography findings in 5 cases of persistent trigeminal artery, and in two cases of variant trigeminal artery. Six patients underwent complete four-vessel angiography, performed to depict other pathology. Magnetic resonance imaging and magnetic resonance angiography allowed in each case to visualize this artery and to precise its latero- or intra-sellar situation. The variant is not defined on conventional magnetic resonance imaging, but may be individualized on magnetic resonance angiography. In each case, identification of these persistent artery is crucial if surgery of sellar or gasserian region is planned. (authors)

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

    Science.gov (United States)

    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

  2. Digital angiography of camel foot

    International Nuclear Information System (INIS)

    In this study, angiography of normal digits of camel has been accomplished, and the vessels of digits and its distribution have been evaluated to be compared with abnormal digits in the future studies. The thoracic and pelvic limb of 16 camels were collected immediately following slaughter. The palmar and plantar arteries were isolated and catheterised by 18-gauge angiocatheter needle; perfused by 40Ð’–50 ml of iodinated compound injected into each vessel. Angiograms were obtained using dorsopalmer, dorsoplanter and latero-medial projections. In the pelvic limb, above the fetlock joint, the deep palmar arch communicates with the median artery via the anastomotic branch, forming the superfcial palmar arch, from which two branches were clear, 1-palmar common digital artery IV that divides into palmar proper digital arteries IV and V, close to the lateral accessory (ffth) digit. 2-Palmar common digital artery III, produces the first branch and continues distally near the middle of the proximal phalanx, it gives off two palmar branches of the proximal phalanx. Vascular distribution of the pelvic limb was similar to thoracic limb, carrying the name of plantar instead of palmar

  3. A High-Speed, Real-Time Visualization and State Estimation Platform for Monitoring and Control of Electric Distribution Systems: Implementation and Field Results

    Energy Technology Data Exchange (ETDEWEB)

    Lundstrom, Blake; Gotseff, Peter; Giraldez, Julieta; Coddington, Michael

    2015-10-05

    Continued deployment of renewable and distributed energy resources is fundamentally changing the way that electric distribution systems are controlled and operated; more sophisticated active system control and greater situational awareness are needed. Real-time measurements and distribution system state estimation (DSSE) techniques enable more sophisticated system control and, when combined with visualization applications, greater situational awareness. This paper presents a novel demonstration of a high-speed, real-time DSSE platform and related control and visualization functionalities, implemented using existing open-source software and distribution system monitoring hardware. Live scrolling strip charts of meter data and intuitive annotated map visualizations of the entire state (obtained via DSSE) of a real-world distribution circuit are shown. The DSSE implementation is validated to demonstrate provision of accurate voltage data. This platform allows for enhanced control and situational awareness using only a minimum quantity of distribution system measurement units and modest data and software infrastructure.

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

    Science.gov (United States)

    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.

  5. Study of spatial resolution in three-dimensional rotational angiography

    International Nuclear Information System (INIS)

    In interventional radiology (IVR) of cerebral aneurysms, it is important to understand the form and physical relationships between the cerebral aneurysm and the surrounding vessels. However, because the vessels in the head area are highly complex, it can be difficult to comprehend the structure using conventional angiography. Therefore, three-dimensional rotational angiography (3D-RA) has been used in recent years. This article discusses studies of the spatial resolution of 3D-RA. We reconstructed 3D-RA of an acrylic slit phantom (slit widths: 0.5, 0.75, 1.0, 1.5 mm) and examined spatial resolution by visual evaluation and profile curves. When the slit phantom was arranged to avoid the effect of beam hardening, the spatial resolution of 3D-RA was found to be as high as 0.75 mm. When the slit phantom was placed orthogonal to the rotational axis of the C-arm, the spatial resolution of 3D-RA was decreased because of the cone angle effect of X-rays. However, it was considered within the allowable range for clinical study. Consequently, 3D-RA is valuable in IVR. (author)

  6. MR angiography in tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Kalita, Jayantee; Prasad, Sreeram; Maurya, Pradeep K.; Misra, Usha K. (Dept. of Neurology, Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India)), Email: drukmisra@rediffmail.com; Kumar, Sunil (Dept. of Radiodiagnosis, Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India))

    2012-04-15

    Background: Infarctions in tuberculous meningitis (TBM) are common but there is a paucity of studies on MR angiography (MRA). Purpose: To evaluate the pattern and predictors of MRA abnormality in patients with TBM. Material and Methods: Sixty-seven patients with TBM were subjected to clinical, laboratory, magnetic resonance imaging (MRI), and MRA evaluation. The severity of meningitis, focal deficit, CSF findings, and stroke co-morbidities were recorded. Presence of exudates, infarction, hydrocephalous, and tuberculoma on MRI were noted. On intracranial MRA, occlusion or more than 50% narrowing of proximal middle cerebral artery (MCA), anterior cerebral artery (ACA) and posterior cerebral artery (PCA), and basilar artery were considered abnormal. The MRA abnormality was correlated with clinical, laboratory, and MRI findings. Results: Sixty-seven patients, aged 3-75 years (median 34 years) were included. MRI was abnormal in 61 (91%) patients; basal exudates in 24, hydrocephalous in 23, tuberculoma in 33, and infarction in 40. MRA was abnormal in 34 (50.7%); MCA was most commonly involved (n = 21), followed by PCA (n = 14), ICA (n = 8), ACA (n 5), basilar artery (n = 5), and vertebral and superior cerebellar artery (1 each). One-fourth of the patients had abnormality in both anterior and posterior circulations. MRA abnormality was related to hydrocephalous and infarction; corresponding infarct was present in 61.8% patients; 41.7% patients with abnormal MRA developed infarct at 3 months but none with normal MRA. Conclusion: Half the patients with TBM had MRA abnormality involving both anterior and posterior circulations and 61.8% of them had corresponding infarcts

  7. Differential diagnosis of choroidal melanomas and nervi using scanning laser ophthalmoscopical indocyanine green angiography

    DEFF Research Database (Denmark)

    Andersen, Mads V. Nis; Scherfig, Erik; Prause, J.U.

    1995-01-01

    Ophthalmology, choroidal melanoma, choroidal nevus, fluorescein angiography, indocyanine green (ICG), scanning laser ophthalmoscope (SLO), angiography......Ophthalmology, choroidal melanoma, choroidal nevus, fluorescein angiography, indocyanine green (ICG), scanning laser ophthalmoscope (SLO), angiography...

  8. Cerebral blood flow imaged with ultrahigh-resolution optical coherence angiography and Doppler tomography

    OpenAIRE

    Ren, Hugang; Du, Congwu; Pan, Yingtian

    2012-01-01

    Speckle contrast based optical coherence angiography (OCA) and optical coherence Doppler tomography (ODT) have been applied to image cerebral blood flow previously. However, the contrast mechanisms of these two methods are not fully studied. Here, we present both flow phantom and in vivo animal experiments using ultrahigh-resolution OCA (μOCA) and ODT (μODT) to investigate the flow sensitivity differences between these two methods. Our results show that the high sensitivity of μOCA for visual...

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

    Science.gov (United States)

    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.

  10. Occupational Exposure in Angiography (Prague Workplaces)

    International Nuclear Information System (INIS)

    The results of measurements, which were performed at angiography departments, are presented. The aim of this work was not only to assess patient exposure but also to perform a survey of the occupational exposures of physicians during common angiography examinations of the skull, chest, abdomen and limbs. Patient data, type of examination, fluoroscopy time, the whole number of film frames, dose-area product (Diameter E) and physician dose (Stephen 6000) were also recorded. There are many factors influencing the level of measured exposures. They include input parameters of X ray performance (kV, mA, projection, diaphragms, ZOOM, type of record etc) and individual approach of the physicians. This paper contributes to the discussion about the increasing exposures of the physicians specialising in diagnostic and interventional angiography. (author)

  11. MR angiography: clinical applications in thoracic surgery

    International Nuclear Information System (INIS)

    MR angiography (MRA) is a promising completion of MR imaging in the preoperative assessment of pulmonary and mediastinal tumours. Scan acquisition was done by sequential FLASH 2D angiograms (TR = 30 ms, TE = 10 ms, FA = 30 ), one section per breathhold, section thickness 5 mm with 1 mm overlap between sequential sections. An automated control procedure allowed individual continuation of the examination. Postprocessing by a maximum-intensity-projection algorithm using angiograms of interest (AOI) resulted in 3D reconstructions illustrating vascular anatomy and avoiding superimposition. This technique was evaluated in a prospective study of 15 patients with malignant intrathoracic tumours. The results were validated by conventional angiographic procedures such as pulmonary angiography, digital subtraction angiography or cavography. Complementing spin-echo (SE) imaging, MRA provided diagnostic information about vessel displacement, stenosis and perfusion defects due to space-occupying lesions. Thus, MRA was helpful in planning thoracic surgery. (orig.)

  12. Digital subtraction angiography of the thoracic aorta

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

    1984-02-01

    Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.

  13. Digital subtraction angiography of the thoracic aorta

    International Nuclear Information System (INIS)

    Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram

  14. Fluorescein and Indocyanine Green Angiography for Uveitis

    Science.gov (United States)

    Herbort, Carl P

    2009-01-01

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

  15. Fluorescein and indocyanine green angiography for uveitis

    Directory of Open Access Journals (Sweden)

    Herbort Carl

    2009-01-01

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

  16. User manual of Visual Balan V. 1.0 Interactive code for water balances and refueling estimation

    International Nuclear Information System (INIS)

    This document contains the Users Manual of Visual Balan V1.0, an updated version of Visual Balan V0.0 (Samper et al., 1997). Visual Balan V1.0 performs daily water balances in the soil, the unsaturated zone and the aquifer in a user-friendly environment which facilitates both the input data process and the postprocessing of results. The main inputs of the balance are rainfall and irrigation while the outputs are surface runoff, evapotranspiration, interception, inter flow and groundwater flow. The code evaluates all these components in a sequential manner by starting with rainfall and irrigation, which must be provided by the user, and continuing with interception, surface runoff, evapotranspiration, and potential recharge (water flux crossing the bottom of the soil). This potential recharge is the input to the unsaturated zone where water can flow horizontally as subsurface flow (inter flow) or vertically as percolation into the aquifer. (Author)

  17. Value of computed angiography in children with osteosarcomas

    International Nuclear Information System (INIS)

    The authors analyse the results of 50 computed angiographies made for osteosarcoma and Ewing's sarcoma. Better tolerated than conventional angiography, computed angiography is also more sensitive in preoperative evaluation of effectiveness of neoadjuvant chemotherapy. Automatic substraction, direct measuring of tumor size and vascularization density give to angiographic changes after chemotherapy the most predictive value. After conservative surgery or radiotherapy digital angiography provides most reliable local follow up

  18. Patient acceptance of noninvasive and invasive coronary angiography.

    Directory of Open Access Journals (Sweden)

    Eva Schönenberger

    Full Text Available BACKGROUND: Noninvasive angiography using multislice computed tomography (MSCT is superior to magnetic resonance imaging (MRI for detection of coronary stenoses. We compared patient acceptance of these two noninvasive diagnostic tests and invasive conventional coronary angiography (Angio. METHODS AND FINDINGS: A total of 111 consecutive patients with suspected coronary artery disease underwent MSCT, MRI, and Angio. Subsequently, patient acceptance of the three tests was evaluated with questionnaires in all patients. The main acceptance variables were preparation and information prior to the test, degree of concern, comfort, degree of helplessness, pain (on visual analog scales, willingness to undergo the test again, and overall satisfaction. Preparation for each test was not rated significantly differently, whereas patients were significantly more concerned about Angio than the two noninvasive tests (p<0.001. No pain during MSCT, MRI, and Angio as assessed on visual analog scales (0 to 100 was reported by 99, 93, and 31 patients, respectively. Among the 82 patients who felt pain during at least one procedure, both CT (0.9+/-4.5 and MRI (5.2+/-16.6 were significantly less painful than Angio (24.6+/-23.4, both p<0.001. MSCT was considered significantly more comfortable (1.49+/-0.64 than MRI (1.75+/-0.81, p<0.001. In both the no-revascularization (55 patients and the revascularization group (56 patients, the majority of the patients (73 and 71% would prefer MSCT to MRI and Angio for future imaging of the coronary arteries. None of the patients indicated to be unwilling to undergo MSCT again. The major advantages patients attributed to MSCT were its fast, uncomplicated, noninvasive, and painless nature. CONCLUSIONS: Noninvasive coronary angiography with MSCT is considered more comfortable than MRI and both MSCT and MRI are less painful than Angio. Patient preference for MSCT might tip the scales in favor of this test provided that the diagnostic

  19. CT angiography and CT perfusion in acute ischemic stroke

    NARCIS (Netherlands)

    Seeters, T. van

    2016-01-01

    CT angiography and CT perfusion are used in patients with acute ischemic stroke for diagnostic purposes and to select patients for treatment. In this thesis, the reproducibility of CT angiography and CT perfusion is examined, the additional value of CT angiography and CT perfusion for stroke outcome

  20. Non-enhanced MR angiography of renal arteries - Comparison with contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Angeretti, M. G.; Lumia, D.; Cani, A.; Barresi, M.; Cardim, L Nocchi; Piacentino, F.; Genovese, E. A.; Fugazzola, C. [Dept. of Radiology, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy)], e-mail: laranocchi@gmail.com; Maresca, A. M. [Dept. of Internal Medicine, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy); Novario, R. [Dept. of Medical Physics, Insubria Univ., Ospedale di Circolo e Fondazione Macchi, Varese (Italy)

    2013-09-15

    Background: The main causes of renal artery stenosis (RAS) are atherosclerosis and fibromuscular dysplasia. Despite contrast-enhanced magnetic resonance angiography (CE-MRA) being a safe and reliable method for diagnosis of RAS especially in young individuals, recently it has been possible to adopt innovative technologies that do not require paramagnetic contrast agents. Purpose: To assess the accuracy of steady-state free-precession (SSFP) non-contrast-enhanced magnetic resonance angiography (NC-MRA) by using a 1.5 T MR scanner for the detection of renal artery stenosis, in comparison with breath-hold CE-MRA as the reference standard. Material and Methods: Sixty-three patients (33 men, 30 women) with suspected renovascular hypertension (RVHT) were examined by a 1.5T MR scanner; NC-MRA with an electrocardiography (ECG)-gated SSFP sequence was performed in 58.7% (37/63) of patients; in 41.3% (26/63) of patients a respiratory trigger was used in addition to cardiac gating. CE-MRA, with a three-dimensional gradient echo (3D-GRE) T1-weighted sequence, was performed in all patients within the same session. Maximum intensity projection (MIP) image quality, number of renal arteries, and the presence of stenosis were assessed by two observers (independently for NC-MRA and together for CE-MRA). The agreement between NC-MRA and CE-MRA as well as the inter-observer reproducibility were calculated with Bland-Altman plots. Results: MIP image quality was considered better for NC-MRA. NC-MRA identified 143 of 144 (99.3%) arteries detected by CE-MRA (an accessory artery was not identified). Fourteen stenoses were detected by CE-MRA (11 atherosclerotic, 3 dysplastic) with four of 14 (28.5%) significant stenosis. Bland-Altman plot demonstrated an excellent concordance between NC-MRA and CE-MRA; particularly, the reader A evaluated correctly all investigated arteries, while over-estimation of two stenoses occurred for reader B. Regarding NC-MRA, inter-observer agreement was excellent

  1. Magnetic resonance angiography of intracranial aneurysms: comparison with intra-arterial digital subtraction angiography

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) with flow rephased gradient-echo sequences is a new non-invasive method for vascular imaging. We compared MRA and intra-arterial digital subtraction angiography in 18 patients with intracranial aneurysms to test whether MRA presently provides an alternative to cerebral angiography for the diagnosis of these anomalies. MRA showed 19 of the 22 aneurysms detected (86.4%). However, problems, especially with turbulent or slow flow, resulted in 6 studies (27.3%) with limited and 2 with questionable demonstration of an aneurysm, and 1 false negative study. At present, MRA is definitely inferior to angiography for the demonstration of intracranial aneurysms, due to its lower resolution and other limitations. (orig.)

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

    Science.gov (United States)

    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

  3. Computed tomographic angiography in tetralogy of Fallot.

    Science.gov (United States)

    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.

  4. Digital subtraction angiography: patient preparation and care.

    Science.gov (United States)

    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

  5. Angiography and angiotherapy of gastrointestinal tract bleeding

    International Nuclear Information System (INIS)

    In selected patients with upper and lower gastrointestinal hemorrhage there is an indication for angiography. Vasoconstrictive drugs or embolization materials can be submitted through the catheter to stop the hermorrhage (angiotherapy). 81 patients were diagnosed by this method. Treatment through the angiographic catheter followed the diagnostic procedure in 41 cases. The hemorrhage was controlled in 36 patients. (orig.)

  6. Unexpected Angiography Findings and Effects on Management.

    Science.gov (United States)

    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

  7. Interventional angiography in the diagnosis of acute lower gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Interventional angiography with the use of indwelling arterial catheters, anticoagulants, vasodilators and fibrinolytic agents, complements conventional angiography in the diagnosis of acute lower gastrointestinal bleeding. These interventional techniques prolong, augment or reactive bleeding and, by enabling better timing of examinations, they increase the diagnostic efficacy of angiography. In the reported series of 63 patients with acute lower gastrointestinal hemorrhage, interventions increased the diagnostic yield of angiography for demonstration of extravasation from 32% to 65% and decreased the percentage of negative angiograms from 27% to 16%. Indications, techniques and risks of interventional angiography in the diagnosis of acute lower gastrointestinal bleeding are discussed. (orig.)

  8. Coronary CT angiography in coronary artery disease: Opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Zhonghua Sun

    2016-06-01

    Full Text Available Coronary CT angiography is widely recognised as a reliable imaging modality for the diagnosis of coronary artery disease. Coronary CT angiography not only provides excellent visualisation of anatomical changes in the coronary artery with high diagnostic value in the detection of lumen stenosis or occlusion, but also offers quantitative characterisation of coronary plaque components. Furthermore, coronary CT angiography allows myocardial perfusion imaging with diagnostic value comparable to the reference standard method. Coronary CT angiography-derived haemodynamic analysis has the potential to evaluate functional significance of coronary lesions. This review article aims to provide an overview of clinical applications of coronary CT angiography in coronary artery disease.

  9. Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

    Directory of Open Access Journals (Sweden)

    Manouras Aristomenis

    2009-08-01

    Full Text Available Abstract Background Visual assessment of left ventricular ejection fraction (LVEF is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE and triplane echocardiography (TPE using quantitative real-time three-dimensional echocardiography (RT3DE as the reference method. Methods Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE. Results There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively. Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP. Conclusion Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

  10. Utility estimation of the application of auditory-visual-tactile sense feedback in respiratory gated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Jung Hun; KIm, Byeong Jin; Roh, Shi Won; Lee, Hyeon Chan; Jang, Hyeong Jun; Kim, Hoi Nam [Dept. of Radiation Oncology, Biomedical Engineering, Seoul St. Mary' s Hospital, Seoul (Korea, Republic of); Song, Jae Hoon [Dept. of Biomedical Engineering, Seoul St. Mary' s Hospital, Seoul (Korea, Republic of); Kim, Young Jae [Dept. of Radiological Technology, Gwang Yang Health Collage, Gwangyang (Korea, Republic of)

    2013-03-15

    The purpose of this study was to evaluate the possibility to optimize the gated treatment delivery time and maintenance of stable respiratory by the introduction of breath with the assistance of auditory-visual-tactile sense. The experimenter's respiration were measured by ANZAI 4D system. We obtained natural breathing signal, monitor-induced breathing signal, monitor and ventilator-induced breathing signal, and breath-hold signal using real time monitor during 10 minutes beam-on-time. In order to check the stability of respiratory signals distributed in each group were compared with means, standard deviation, variation value, beam{sub t}ime of the respiratory signal. The stability of each respiratory was measured in consideration of deviation change studied in each respiratory time lapse. As a result of an analysis of respiratory signal, all experimenters has showed that breathing signal used both Real time monitor and Ventilator was the most stable and shortest time. In this study, it was evaluated that respiratory gated radiation therapy with auditory-visual-tactual sense and without auditory-visual-tactual sense feedback. The study showed that respiratory gated radiation therapy delivery time could significantly be improved by the application of video feedback when this is combined with audio-tactual sense assistance. This delivery technique did prove its feasibility to limit the tumor motion during treatment delivery for all patients to a defined value while maintaining the accuracy and proved the applicability of the technique in a conventional clinical schedule.

  11. Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children

    International Nuclear Information System (INIS)

    Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand

  12. Quality of abdominal computed tomography angiography: hand versus mechanical intravenous contrast administration in children

    Energy Technology Data Exchange (ETDEWEB)

    Ayyala, Rama S.; Lee, Edward Y. [Boston Children' s Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Zurakowski, David [Boston Children' s Hospital and Harvard Medical School, Departments of Anesthesiology and Surgery, Boston, MA (United States)

    2015-11-15

    Abdominal CT angiography has been increasingly used for evaluation of various conditions related to abdominal vasculature in the pediatric population. However, no direct comparison has evaluated the quality of abdominal CT angiography in children using hand versus mechanical administration of intravenous (IV) contrast agent. To compare hand versus mechanical administration of IV contrast agent in the quality of abdominal CT angiography in the pediatric population. We retrospectively reviewed the electronic medical record to identify pediatric patients (≤18 years) who had abdominal CT angiography between August 2012 and August 2013. The information obtained includes: (1) type of administration of IV contrast agent (hand [group 1] versus mechanical [group 2]), (2) size (gauge) of IV catheter, (3) amount of contrast agent administered and (4) rate of contrast agent administration (ml/s). Two reviewers independently performed qualitative and quantitative evaluation of abdominal CT angiography image quality. Qualitative evaluation of abdominal CT angiography image quality was performed by visual assessment of the degree of contrast enhancement in the region of interest (ROI) based on a 4-point scale. Quantitative evaluation of each CT angiography examination was performed by measuring the Hounsfield unit (HU) using an ROI within the abdominal aorta at two levels (celiac axis and the inferior mesenteric artery) for each child. Analysis of variance (ANOVA) using the F-test was applied to compare contrast enhancement within the abdominal aorta at two levels (celiac axis and inferior mesenteric artery) between hand administration and mechanical administration of IV contrast methods with adjustment for age. We identified 46 pediatric patients (24 male, 22 female; mean age 7.3 ± 5.5 years; range 5 weeks to 18 years) with abdominal CT angiography performed during the study period. Of these patients, 16 (35%; 1.7 ± 2.2 years; range 5 weeks to 5 years) had hand

  13. [Intraoperative verification of a perforator flap vascularization by indocyanine green angiography].

    Science.gov (United States)

    Royer, E; Rausky, J; Binder, J-P; May, P; Virzi, D; Revol, M

    2014-02-01

    After Koshima and Soeda first described perforator flaps in 1988, Wei has improved the technique by describing the "free style perforator flap". These flaps have the advantage of being performed on all skin perforators and in reducing donor site morbidity. The disadvantage, however is that the size of their angiosome is not defined and the evaluation of their relay on the experience of the surgeon. An evaluation of the size of an angiosome by conducting intraoperative angiography is proposed. Intraoperative angiography is performed after injection of indocyanine green. Stimulation of the indocyanine green by infrared causes the emission of fluorescent radiation. This fluorescence is then detected by a specific camera that displays real-time visualization of the skin's perfusion. We present the case of a 39-year-old patient who had an open tibial pilon fracture, for which we performed a pedicled propeller flap based on a posterior tibial perforator. Angiography was used to determine accurately the optimal skin perfusion of the propeller flap, which was based on a perforator from the posterior tibial artery. Angiography identified several levels of skin perfusion with a high fluorescence, intermediate and absent. The non-vascularized part of the skin paddle was resected. Given the unreliability of this technique, hypoperfused area was retained. Debridment of this area, however was necessary at day 5 postoperative with repositionning of the flap. Indocyanine green angiography may be a useful decision-making tool for intraoperative surgeon. It allows to adjust the size of the propeller flap's skin paddle to it angiosome. However, this evaluation method needs to be improved with the introduction of a quantitative threshold.

  14. Three-dimensional CT angiography with volume rendering for the dignosis of multiple intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    FANG Bing; LI Tie-lin; ZHANG Jian-min; DUAN Chuan-zhi; WANG Qiu-jing; ZAO Qing-ping

    2004-01-01

    Objective:To evaluate the importance of 3D-CTA with volume rendering for the diagnosis of multiple intracranial aneurysms. Methods: Axial source images were obtained by helical CT scanning and reconstruction of 3D-CTA images was done by volume rendering technique in conjunction with multiplanar reformation. Results: In the past one year,there were 10 patients diagnosed as having multiple intracranial aneurysms by 3D-CTA and altogether 24 aneurysms were visualized,including 10 small aneurysms(≤5mm.Three dimensional CT angiography with volume rendering demonstrated aneurysms very well and provided useful information concerning the site,shape,size and spatial relationship with the surrounding vessels and bone anatomy. Conclusion: Three-dimensional CT angiography with volume rendering is a quick,reliable,and relatively noninvasive method for diagnosing multiple intracranial aneurysms.It delineates detailed aneurysmal morphology,and provides useful information for planning microsurgical approaches.

  15. Optoacoustic angiography of peripheral vasculature

    Science.gov (United States)

    Ermilov, Sergey; Su, Richard; Zamora, Mario; Hernandez, Travis; Nadvoretsky, Vyacheslav; Oraevsky, Alexander

    2012-02-01

    We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vascular imaging of a human finger. The system employs an arc-shaped acoustic array that is rotated 360 degrees around the finger providing optoacoustic data necessary for tomographic reconstruction of the three-dimensional images of a finger. A near-infrared Q-switched laser is used to generate optoacoustic signals with increased contrast of blood vessels. The laser is coupled through two randomized fiberoptic bundles oriented in orthogonal optoacoustic mode. To demonstrate OmAS capabilities, we present a time-series of optoacoustic images of a human finger taken after the hypothermia stress test. The images show a detailed vascular anatomy of a finger down to the capillary level. A series of quick 30s scans allowed us to visualize the thermoregulatory response within the studied finger as it was manifested via vasomotor activity during the hypothermia recovery. We propose that the developed system can be used for diagnostics of various medical conditions that are manifested in change of the peripheral (finger) blood flow. Examples of the medical conditions that could be diagnosed and staged using the OmAS include the peripheral arterial disease (PAD), thrombosis, frostbite, and traumas.

  16. Estimating Synaphobranchus kaupii densities: Contribution of fish behaviour to differences between bait experiments and visual strip transects

    Science.gov (United States)

    Trenkel, Verena M.; Lorance, Pascal

    2011-01-01

    Kaup's arrowtooth eel Synaphobranchus kaupii is a small-bodied fish and an abundant inhabitant of the European continental slope. To estimate its local density video information using the remotely operated vehicle (ROV) Victor 6000 were collected at three locations in the Bay of Biscay slope. Two methods for estimating local densities were tested: strip transect counts and bait experiments. For bait experiments three behaviour types were observed in about equal proportions for individuals arriving near the seafloor: moving up the current towards the ROV, moving across the current and drifting with the current. Visible attraction towards the bait was the highest for individuals swimming against the current (80%) and about equally low for the other two types (around 30%); it did not depend on current speed nor temperature. Three main innovations were introduced for estimating population densities from bait experiments: (i) inclusion of an additional behaviour category—that of passively drifting individuals, (ii) inclusion of reaction behaviour for actively swimming individuals and (iii) a hierarchical Bayesian estimation framework. The results indicated that about half of individuals were foraging actively of which less than one third reacted on encountering the bait plume and the other half were drifting with the current. Taking account of drifting individuals and the reaction probability made density estimates from bait experiments and strip transects more similar.

  17. Types of diaphragmatic motion during hepatic angiography.

    Science.gov (United States)

    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.

  18. Invasive or non invasive angiography? The role of conventional catheder angiography

    International Nuclear Information System (INIS)

    Within the last decade, diagnostic and interventional angiography have been developed to a high degree of performance, due to the widespread use of DSA, the miniaturisation of the puncture trauma and the introduction sets (catheters, sheaths), the development of high-tech materials (e.g., Nitinol guidewires) and the application of non-ionic, low osmolal contrast media. The specific risks of the procedure, thereby, have been significantly reduced, but could not be totally eliminated. To evaluate vascular diseases non-invasively, special attention was attributed to the progress of colour coded duplex, (spiral) CT-angiography and (CE)MR-angiography, based on the estbalished imaging with US, CT and MRT. The matter in question is whether or not they can substitute the role of conventional angiography as the 'gold standard' of vessel imaging. Clinical validity and economic efficiency both determine the indication for the use of invasive or non-invasive methods. In diagnostic procedures, there is a growing tendency for the use of non-invasive techniques, like in imaging of the abdominal and thoracic aorta, the renal, pulmonary and extra- and intra-cranial arteries. Conventional angiography is still reserved for the evaluation of small vessels of the upper and lower extremities, and vessel status in preoperative conditions (carotid, celiac trunk, mesenteric and renal arteries and aneurysms of the cerebral vasculature). Fluoroscopic guiding of catheters and contrast enhancement in interventional procedures, however, cannot be substituted by alternative techniques in the foreseeable future. (orig.)

  19. Cerebral angiography in leptomeningitis and cerebritis

    International Nuclear Information System (INIS)

    This is a report of the cerebral angiographic findings in cases of meningitis and cerebritis. Fifty-nine patients, 38 of whom were under 1 year of age, underwent cerebral angiography by means of femoral catheterization. All the patients had signs of increased intracranial pressure, seizures, focal cerebral signs, positive transillumination of the head, and or abnormal brain scan findings. A few patients who did not respond to systemic antibiotics as was expected were also evaluated by means of cerebral angiography. The following characteristic angiographic findings were observed in 18 cases of active meningitis: (1) A hasy appearance around the arteries (halo formation) between the late arterial and capillary phases. (2) Narrowing of the arteries in the basal cistern. This sometimes extended to the peripheral arteries. (3) Irregular caliber following the narrowing of arteries (in few cases). (4) Circulation time so slow that veins could be seen in the late arterial phase. (5) Halo formation around the anterior chroidal artery and the clear appearance of the choroid plexus in the venous phase (when the infectious process reached the choroid plexus). Cerebritis could be identified on the angiograms by two signs: (1) local swelling of the brain (mainly the temporal lobe) and (2) staining around the veins without any abnormal signs in the arterial phase (laminar staining). In conclusion, angiography is a meaningful test by which to determine the phase of meningitis and cerebritis. These two conditions should be treated based on valid information obtained by means of CSF examinations and neuroradiological tests, especially CT scan and cerebral angiography. (author)

  20. Fluorescein and Indocyanine Green Angiography for Uveitis

    OpenAIRE

    Herbort Carl

    2009-01-01

    In recent years enormous progress has been achieved in investigational procedures for uveitis. Imaging is one such example with the advent of new methods such as indocyanine green angiography, ultrasound biomicroscopy and optical coherence tomography to cite only the most important. This tremendous increase in precision and accuracy in the assessment of the level and degree of inflammation and its monitoring comes in parallel with the development of extremely potent and efficacious therapies....

  1. 一种改进的视觉罗盘姿态测量方法%AModified Visual Compass Attitude Estimation Method

    Institute of Scientific and Technical Information of China (English)

    徐伟杰; 李平; 韩波

    2011-01-01

    The visual compass proposed by Montiel et al. Is an attitude estimation method based on EKF-SLAM that using camera as the only sensor. When camera rotation is unsmooth, a priori system noise covariance in motion model should be set to a large value,but it results in high computational cost for matching and high rate of matching error occurrence. Focusing on those problems, a modified visual compass attitude estimation method is presented. First, a multi-resolution landmark selection strategy is used for new landmark initialization. Then,an active search/match layer by layer algorithm is used to reduce both the computational cost and the rate of error occurrence. Finally, a RANSAC algorithm sampling 2 matched points is used to remove the outliers in matching result. The modified visual compass attitude estimation method is applied to the outdoor video, and the experimental results shows that the modified method has advantage of less computational cost and improved accuracy of attitude estimation.%Montiel等人提出的“视觉罗盘”是一种以摄像机为唯一传感器,基于EKF-SLAM的姿态测量方法.在摄像机旋转不平滑时需要提高运动模型中系统噪声的先验方差设定值,但是会导致匹配计算量增大和匹配错误发生率升高.针对上述问题,本文给出一种改进的视觉罗盘姿态测量方法.该方法首先使用多分辨率路标选取策略初始化新路标,然后使用逐层主动搜索匹配算法以减少匹配计算量和降低匹配错误发生率,最后使用最小抽样集为2个匹配点的RANSAC算法去除匹配野点.将改进的视觉罗盘姿态测量方法用于处理室外采集的视频,实验结果表明其具有计算量更小和测量姿态精确的优点.

  2. A method for estimating the minimum visual stimulus that evokes a behavioural response in the drone, Apis mellifera male.

    Science.gov (United States)

    Vallet, A M; Coles, J A

    1991-01-01

    Drones, attracted to an observation site by a scented lure, left the lure to fly directly towards a small object suspended nearby. An object the size of a queen bee was detected at distances up to 2 m. It is estimated that at this maximum distance the object will have decreased the light incident on a single rhabdom by 6%. PMID:1891832

  3. Multidetector computed tomography pulmonary angiography in childhood acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chun Xiang; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Department of Pediatrics, Charleston, SC (United States); Chowdhury, Shahryar M. [Medical University of South Carolina, Department of Pediatrics, Charleston, SC (United States); Fox, Mary A. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2015-09-15

    Pulmonary embolism is a life-threatening condition affecting people of all ages. Multidetector row CT pulmonary angiography has improved the imaging of pulmonary embolism in both adults and children and is now regarded as the routine modality for detection of pulmonary embolism. Advanced CT pulmonary angiography techniques developed in recent years, such as dual-energy CT, have been applied as a one-stop modality for pulmonary embolism diagnosis in children, as they can simultaneously provide anatomical and functional information. We discuss CT pulmonary angiography techniques, common and uncommon findings of pulmonary embolism in both conventional and dual-energy CT pulmonary angiography, and radiation dose considerations. (orig.)

  4. Efficacy of Patient Selection for Diagnostic Coronary Angiography in Suspected Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Francisco Flávio Costa Filho

    2015-11-01

    Full Text Available AbstractBackground:Guidelines recommend that in suspected stable coronary artery disease (CAD, a clinical (non-invasive evaluation should be performed before coronary angiography.Objective:We assessed the efficacy of patient selection for coronary angiography in suspected stable CAD.Methods:We prospectively selected consecutive patients without known CAD, referred to a high-volume tertiary center. Demographic characteristics, risk factors, symptoms and non-invasive test results were correlated to the presence of obstructive CAD. We estimated the CAD probability based on available clinical data and the incremental diagnostic value of previous non-invasive tests.Results:A total of 830 patients were included; median age was 61 years, 49.3% were males, 81% had hypertension and 35.5% were diabetics. Non-invasive tests were performed in 64.8% of the patients. At coronary angiography, 23.8% of the patients had obstructive CAD. The independent predictors for obstructive CAD were: male gender (odds ratio [OR], 3.95; confidence interval [CI] 95%, 2.70 - 5.77, age (OR for 5 years increment, 1.15; CI 95%, 1.06 - 1.26, diabetes (OR, 2.01; CI 95%, 1.40 - 2.90, dyslipidemia (OR, 2.02; CI 95%, 1.32 - 3.07, typical angina (OR, 2.92; CI 95%, 1.77 - 4.83 and previous non-invasive test (OR 1.54; CI 95% 1.05 - 2.27.Conclusions:In this study, less than a quarter of the patients referred for coronary angiography with suspected CAD had the diagnosis confirmed. A better clinical and non-invasive assessment is necessary, to improve the efficacy of patient selection for coronary angiography.

  5. Gated tomographic radionuclide angiography using cadmium-zinc-telluride detector gamma camera; comparison to traditional gamma cameras

    DEFF Research Database (Denmark)

    Jensen, Maria Maj; Schmidt, Ulla; Huang, Chenxi;

    2014-01-01

    PURPOSE: Estimation of left ventricular ejection fraction (LVEF) with equilibrium 99MTc-HSA equilibrium radionuclide angiography (MUGA) is frequently used for assessing cardiac function. The purpose of this study was to compare intra- and interobserver variation between three different gamma...

  6. Cardiovascular CT angiography in neonates and children : Image quality and potential for radiation dose reduction with iterative image reconstruction techniques

    NARCIS (Netherlands)

    Tricarico, Francesco; Hlavacek, Anthony M.; Schoepf, U. Joseph; Ebersberger, Ullrich; Nance, John W.; Vliegenthart, Rozemarijn; Cho, Young Jun; Spears, J. Reid; Secchi, Francesco; Savino, Giancarlo; Marano, Riccardo; Schoenberg, Stefan O.; Bonomo, Lorenzo; Apfaltrer, Paul

    2013-01-01

    To evaluate image quality (IQ) of low-radiation-dose paediatric cardiovascular CT angiography (CTA), comparing iterative reconstruction in image space (IRIS) and sinogram-affirmed iterative reconstruction (SAFIRE) with filtered back-projection (FBP) and estimate the potential for further dose reduct

  7. Preoperative evaluation of neurovascular relationship by using contrast-enhanced and unenhanced 3D time-of-flight MR angiography in patients with trigeminal neuralgia

    International Nuclear Information System (INIS)

    Background Microvascular decompression is an etiological strategy for the therapy of trigeminal neuralgia (TN). Preoperative identification of neurovascular compression, therefore, could have an impact on the determination of appropriate treatment for TN. Purpose To evaluate the value of contrast-enhanced and unenhanced three-dimensional (3D) time-of-flight (TOF) MR angiography in the visualization of neurovascular relationship in patients with TN. Material and Methods Thirty-seven patients with unilateral TN underwent unenhanced and contrast-enhanced 3D TOF MR angiography with a 3.0-T MR system. Images were reviewed by a radiologist blinded to clinical details. Vascular contact with the trigeminal nerve was identified, and the nature of the involved vessels (artery or vein) was determined. All patients underwent microvascular decompression. Results In 37 patients with TN, contrast-enhanced 3D TOF MR angiography identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves, and there was no false-positive. Based on surgical findings, the sensitivity of MR imaging was 97.2% and specificity 100%. The nature of the offending vessel was correctly identified in 94.4% of the patients by using the combination of contrast-enhanced and unenhanced MR angiography. Conclusion Contrast-enhanced 3D TOF MR angiography is useful in the detection of vascular contact with the trigeminal nerve in patients with TN, and this MR imaging in combination with unenhanced MR angiography could help in the identification of the nature of the responsible vessels

  8. Preoperative evaluation of neurovascular relationship by using contrast-enhanced and unenhanced 3D time-of-flight MR angiography in patients with trigeminal neuralgia

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhou; Zhiling, Liu; Chuanfu, Li; Qingshi Zeng (Dept. of Radiology, Qilu Hospital of Shandong Univ., Jinan (China)), email: zengqingshi@yahoo.cn; Chuncheng, Qu (Dept. of Neurosurgery, the Second Hospital of Shandong Univ., Jinan (China)); Shilei, Ni (Dept. of Neurosurgery, Qilu Hospital of Shandong Univ., Jinan (China))

    2011-10-15

    Background Microvascular decompression is an etiological strategy for the therapy of trigeminal neuralgia (TN). Preoperative identification of neurovascular compression, therefore, could have an impact on the determination of appropriate treatment for TN. Purpose To evaluate the value of contrast-enhanced and unenhanced three-dimensional (3D) time-of-flight (TOF) MR angiography in the visualization of neurovascular relationship in patients with TN. Material and Methods Thirty-seven patients with unilateral TN underwent unenhanced and contrast-enhanced 3D TOF MR angiography with a 3.0-T MR system. Images were reviewed by a radiologist blinded to clinical details. Vascular contact with the trigeminal nerve was identified, and the nature of the involved vessels (artery or vein) was determined. All patients underwent microvascular decompression. Results In 37 patients with TN, contrast-enhanced 3D TOF MR angiography identified surgically verified neurovascular contact in 35 of 36 symptomatic nerves, and there was no false-positive. Based on surgical findings, the sensitivity of MR imaging was 97.2% and specificity 100%. The nature of the offending vessel was correctly identified in 94.4% of the patients by using the combination of contrast-enhanced and unenhanced MR angiography. Conclusion Contrast-enhanced 3D TOF MR angiography is useful in the detection of vascular contact with the trigeminal nerve in patients with TN, and this MR imaging in combination with unenhanced MR angiography could help in the identification of the nature of the responsible vessels

  9. The ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography

    OpenAIRE

    Liu, Ying; Xu, Jian; Jian LI; Ren, Jing; LIU, HONGTAO; Xu, Junqing; Wei, Mengqi; Hao, Yuewen; Zheng, Minwen

    2013-01-01

    Background Aortic dissection is a lift-threatening medical emergency associated with high rates of morbidity and mortality. The incidence rate of aortic dissection is estimated at 5 to 30 per 1 million people per year. The prompt and correct diagnosis of aortic dissection is critical. This study was to compare the ascending aortic image quality and the whole aortic radiation dose of high-pitch dual-source CT angiography and conventional dual-source CT angiography. Methods A total of 110 conse...

  10. Digital subtraction angiography: Its use in the diagnosis and management of vascular disease

    International Nuclear Information System (INIS)

    Recent developments in the area of computerized image enhancement have made it possible to visualize the arterial circulation by the intravenous injection of a contrast agent. This technique has been referred to by a variety of terms including digital video angiography (DVA), digital video imaging (DVI), or digital subtraction angiography (DSA). These terms are interchangeably used to describe a process of arterial imaging made possible by computerized fluoroscopy. DSA has generated interest among physicians because of its ability to combine many of the safety features of noninvasive testing with the anatomic information provided by standard angiography. Intravenous DSA significantly reduces the risk of hemorrhage and thrombosis by avoiding arterial catheterization and lowers the potential costs by reducing the need for hospitalization. The patient acceptance is better because there is less discomfort and because the time required to perform the procedure is significantly shorter. However, in order to determine the appropriate clinical applications of DSA, one must look critically not only at its strengths, but at its weaknesses as well

  11. Non-contrast-enhanced renal and abdominal MR angiography using velocity-selective inversion preparation.

    Science.gov (United States)

    Shin, Taehoon; Worters, Pauline W; Hu, Bob S; Nishimura, Dwight G

    2013-05-01

    Non-contrast-enhanced MR angiography is a promising alternative to the established contrast-enhanced approach as it reduces patient discomfort and examination costs and avoids the risk of nephrogenic systemic fibrosis. Inflow-sensitive slab-selective inversion recovery imaging has been used with great promise, particularly for abdominal applications, but has limited craniocaudal coverage due to inflow time constraints. In this work, a new non-contrast-enhanced MR angiography method using velocity-selective inversion preparation is developed and applied to renal and abdominal angiography. Based on the excitation k-space formalism and Shinnar-Le-Roux transform, a velocity-selective excitation pulse is designed that inverts stationary tissues and venous blood while preserving inferiorly flowing arterial blood. As the magnetization of the arterial blood in the abdominal aorta and iliac arteries is well preserved during the magnetization preparation, artery visualization over a large abdominal field of view is achievable with an inversion delay time that is chosen for optimal background suppression. Healthy volunteer tests demonstrate that the proposed method significantly increases the extent of visible arteries compared with the slab-selective approach, covering renal arteries through iliac arteries over a craniocaudal field of view of 340 mm. PMID:22711643

  12. Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography.

    Science.gov (United States)

    Zhang, Anqi; Zhang, Qinqin; Wang, Ruikang K

    2015-10-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers. PMID:26504660

  13. Vertebral angiography of cerebellar astrocytoma. Tumor stain, tumor circulation, CT and angiography in diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Kitaoka, K.; Ito, T.; Tashiro, K.; Abe, H.; Tsuru, M.; Miyasaka, K. (Hokkaido Univ., Sapporo (Japan). School of Medicine)

    1982-05-01

    Thirteen cases of cerebellar astrocytoma were examined primarily for tumor stain and pathological tumor circulation by angiography and CT. Tumor stain was observed in only one case by cerebral angiogram. A tumor was demonstrated as an avascular mass in the remaining 12 cases. It is suggested that mural nodules of cystic lesions should have certain weight and sizes so that they could be demonstrated as tumor stain. In the supratentorial region, five of the 12 low-grade astrocytoma exhibited abnormal tumor stain and tumor circulation by cerebral angiogram. It is considered that supratentorial and posterior fossa astrocytoma must usually exhibit different pathological tumor circulation by cerebral angiogram, since each group has distinctive clinical and biological characteristics. CT was performed in 7 of 13 cases. It appeared to be more useful than cerebral angiography in the morphological diagnosis. Especially in cystic tumors, CT produced minute information concerning peritumoral edema, enhancement of margin of cystic astrocytoma after intravenous contrast medium, and marginal enhancement with layering in the dependent part of the cyst. Neuroradiological differential diagnosis of cerebellar astrocytoma and cerebellar hemagioblastoma by CT was difficult in the cases of tumors. However, both tumors were differentiated from each other with ease by tumor stain and tumor circulation in cerebral angiography. Thus, it is concluded that cerebral angiography is superior to CT in differential diagnosis between cerebellar astrocytoma and cerebellar hemangioblastoma.

  14. Agreement between optical coherence tomography and fundus fluorescein angiography in post-cataract surgery cystoid macular edema

    OpenAIRE

    Mitne Somaia; Paranhos Júnior Augusto; Rodrigues Ana Paula Silvério; Guia Tércio; Bordon Arnaldo; Moraes Nilva Simeren Bueno de; Farah Michel Eid; Bonomo Pedro Paulo

    2003-01-01

    PURPOSE: To evaluate the agreement between optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) regarding the detection of cystoid macular edema (CME) following cataract surgery. METHODS: Retrospective comparative observational series of 25 eyes with suspected CME. Patients with low visual acuity and alterations in fundus biomicroscopy after cataract surgery underwent OCT scanning followed by FFA on the same visit. The diagnosis of CME was established considering fluore...

  15. Usefulness of CT angiography for demonstrating cerebral aneurysm

    International Nuclear Information System (INIS)

    We report the usefulness of computed cerebral angiotomography (CT angiography) for demonstrating cerebral aneurysm and the clinical significance of CT angiography for ruptured cerebral aneurysm. Our modified method of CT angiography was easy and less time-consuming. Fifteen seconds after starting a single bolus injection, 1 ml/kg/25 seconds via cubital vein, of contrast medium (60 % urograffin), 5 serial 5 mm thick-CT slices were scanned in every 6.5 seconds including 2 seconds of interval, beginning from an axial level 20 mm above the orbitomeatal line and ending at a level 40 mm. A total of 103 patients were examined in this report, consisting of 70 unruptured asymptomatic, 8 unruptured symptomatic (oculomotor nerve palsy) and 25 subarachnoid hemorrhage (SAH). Seven unruptured aneurysms in 4 asymptomatic cases, 2 unruptured aneurysms in 2 symptomatic cases 27 aneurysms in 24 SAH cases were suspected by CT angiography. Of these 36 aneurysms suspected by CT angiography 32 aneurysms were confirmed by cerebral angiography. The detection rate of CT angiography in this report was 89 %, higher than those of previous reports. Thirteen aneurysms were located at internal carotidposterior communicating artery (ICPC) junction. 11 at anterior communicating artery (Acom), 7 at middle cerebral artery (MCA). CT angiography showed a false positive findings in 4 cases, which were all located at Acom. Four aneurysms were not detected in CT angiography, which were all located at MCA and were very small (2 - 3 mm) in diameter. There were no deteriorated cases during and after CT angiography. We suggest that CT angiography is a useful and safe method for predicting the location of not only unruptured but ruptured aneurysms. (author)

  16. The multidetector computed tomography angiography (MDCTA) in the diagnosis of splenic artery aneurysm and pseudoaneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Mallarini, Giorgio (Dept. of Radiology, Azienda Ospedaliero Universitaria (AOU), Cagliari (Italy)), email: lucasaba@tiscali.it; Anzidei, Michele; Lucatelli, Pierleone (Dept. of Radiological Sciences, Univ. of Rome La Sapienza, Rome (Italy))

    2011-06-15

    Splenic artery aneurysm is the most frequent visceral artery aneurysm and rupture of the aneurysm is associated with a high mortality rate. It is important to discriminate between a true aneurysm and a pseudoaneurysm that may be caused by pancreatitis, iatrogenic and postoperative causes, trauma and peptic ulcer disease. Multidetector-row CT angiography (MDCTA) allows detailed visualization of the vascular anatomy and may allow identification of aneurysms and pseudoaneurysms that affect the splenic artery. The objective of this article is to provide a review of the general characteristics of splenic artery aneurysms and pseudoaneurysms and to describe the findings of MDCTA

  17. Quantification of choroidal neovascularization vessel length using optical coherence tomography angiography

    Science.gov (United States)

    Gao, Simon S.; Liu, Li; Bailey, Steven T.; Flaxel, Christina J.; Huang, David; Li, Dengwang; Jia, Yali

    2016-07-01

    Quantification of choroidal neovascularization (CNV) as visualized by optical coherence tomography angiography (OCTA) may have importance clinically when diagnosing or tracking disease. Here, we present an automated algorithm to quantify the vessel skeleton of CNV as vessel length. Initial segmentation of the CNV on en face angiograms was achieved using saliency-based detection and thresholding. A level set method was then used to refine vessel edges. Finally, a skeleton algorithm was applied to identify vessel centerlines. The algorithm was tested on nine OCTA scans from participants with CNV and comparisons of the algorithm's output to manual delineation showed good agreement.

  18. Diagnostic angiography of the cerebrospinal vasculature.

    Science.gov (United States)

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

    2016-01-01

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

  19. Effects of Video Instruction on Fatigue and Back Pain in Patients Undergoing Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Nahid Jamshidi

    2010-01-01

    Full Text Available Introduction: : In order to prevent from the complications of the coronary angiography, patients who undergo this procedure need to have absolute rest on bed at least for 6 hours. This restriction to bed leads to patient's fatigue and back pain. The objective of this study is to assess the effect of patients' instruction by video on the levels of fatigue and back pain after angiography.Methods: In a quasi-experimental, pretest-posttest design, 128 patients were randomly assigned to either control or experimental group. Control group received verbal routine education by nurses, and experimental group received an informative video about the required measures before, during and after the coronary angiography procedure. Using visual analogue Scale (VAS, levels of fatigue and back pain were assessed immediately after and at 2, 4 and 6 hours after the procedure. The data were analyzed by descriptive and interpretive statistics such as t-test and ANOVA via SPSS 15.Results: Analysis of data showed that the average score of fatigue and back pain in the first stage of assessment was not statistically significant between the two groups (P>0.05. The study finding also showed that the control group at 2, 4 and 6 hours had significantly higher fatigue and back pain score than the experimental group(P<0.001.Conclusion: The results of this study recommend the use of instructional video as a useful method for decreasing fatigue and back pain in patients undergoing coronary angiography procedure. To increase satisfaction and reduce fatigue and back pain, it is suggested that this method be used as a part of the preparatory program for patients who are to undergo invasive procedures.

  20. A screen for constituents of motor control and decision making in Drosophila reveals visual distance-estimation neurons.

    Science.gov (United States)

    Triphan, Tilman; Nern, Aljoscha; Roberts, Sonia F; Korff, Wyatt; Naiman, Daniel Q; Strauss, Roland

    2016-01-01

    Climbing over chasms larger than step size is vital to fruit flies, since foraging and mating are achieved while walking. Flies avoid futile climbing attempts by processing parallax-motion vision to estimate gap width. To identify neuronal substrates of climbing control, we screened a large collection of fly lines with temporarily inactivated neuronal populations in a novel high-throughput assay described here. The observed climbing phenotypes were classified; lines in each group are reported. Selected lines were further analysed by high-resolution video cinematography. One striking class of flies attempts to climb chasms of unsurmountable width; expression analysis guided us to C2 optic-lobe interneurons. Inactivation of C2 or the closely related C3 neurons with highly specific intersectional driver lines consistently reproduced hyperactive climbing whereas strong or weak artificial depolarization of C2/C3 neurons strongly or mildly decreased climbing frequency. Contrast-manipulation experiments support our conclusion that C2/C3 neurons are part of the distance-evaluation system. PMID:27255169

  1. A screen for constituents of motor control and decision making in Drosophila reveals visual distance-estimation neurons

    Science.gov (United States)

    Triphan, Tilman; Nern, Aljoscha; Roberts, Sonia F.; Korff, Wyatt; Naiman, Daniel Q.; Strauss, Roland

    2016-01-01

    Climbing over chasms larger than step size is vital to fruit flies, since foraging and mating are achieved while walking. Flies avoid futile climbing attempts by processing parallax-motion vision to estimate gap width. To identify neuronal substrates of climbing control, we screened a large collection of fly lines with temporarily inactivated neuronal populations in a novel high-throughput assay described here. The observed climbing phenotypes were classified; lines in each group are reported. Selected lines were further analysed by high-resolution video cinematography. One striking class of flies attempts to climb chasms of unsurmountable width; expression analysis guided us to C2 optic-lobe interneurons. Inactivation of C2 or the closely related C3 neurons with highly specific intersectional driver lines consistently reproduced hyperactive climbing whereas strong or weak artificial depolarization of C2/C3 neurons strongly or mildly decreased climbing frequency. Contrast-manipulation experiments support our conclusion that C2/C3 neurons are part of the distance-evaluation system. PMID:27255169

  2. Acquisition-related motion compensation for digital subtraction angiography.

    Science.gov (United States)

    Ionasec, Razvan Ioan; Heigl, Benno; Hornegger, Joachim

    2009-06-01

    Subtraction methods in angiography are generally applied in order to enhance the visualization of blood vessels by eliminating bones and surrounding tissues from X-ray images. The main limitation of these methods is the sensitivity to patient movement, which leads to artifacts and reduces the clinical value of the subtraction images. In this paper we present a novel method for rigid motion compensation with primary application to road mapping, frequently used in image-guided interventions. Using the general concept of image-based registration, we optimize the physical position and orientation of the C-arm X-ray device, thought of as the rigid 3D transformation accounting for the patient movement. The registration is carried out using a hierarchical optimization strategy and a similarity measure based on the variance of intensity differences, which has been shown to be most suitable for fluoroscopic images. Performance evaluation demonstrated the capabilities of the proposed approach to compensate for potential intra-operative patient motion, being more resilient to the fundamental problems of pure image-based registration.

  3. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease

    Energy Technology Data Exchange (ETDEWEB)

    Hyare, Harpreet [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)]. E-mail: hhyare@doctors.org.uk; Desigan, Sharmini [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Nicholl, Helen [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Guiney, Michael J. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Brookes, Jocelyn A. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom); Lees, William R. [Department of Imaging, University College London Hospitals NHS Foundation Trust, University College Hospital, 235 Euston Road, London NW1 2BU (United Kingdom)

    2006-08-15

    Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients.

  4. Multi-section CT angiography compared with digital subtraction angiography in diagnosing major arterial hemorrhage in inflammatory pancreatic disease

    International Nuclear Information System (INIS)

    Purpose: Major arterial hemorrhage is an uncommon but serious complication of pancreatitis with high morbidity and mortality. Digital subtraction angiography (DSA) has long been the gold standard for the detection of a visceral artery pseudoaneurysm or for the site of active bleeding in patients with pancreatitis. Multi-section CT angiography is a minimally invasive technique which can provide high-resolution and high-contrast images of the arterial lumen and wall, with a much lower risk of complication and morbidity compared to DSA. The aim of this study was to determine the accuracy of multi-section CT angiography for the diagnosis of arterial complications of inflammatory pancreatitic disease. Materials and methods: A retrospective analysis of all patients undergoing visceral angiography for major bleeding as a complication of pancreatitis between 1998 and 2004 was performed. Twenty-nine studies in 25 patients (20 males, 5 females) with a mean age of 50.9 years (range 11-67 years) were identified where multi-section CT angiography was performed in the 24 h preceding the digital subtraction angiogram. Results: Digital subtraction angiography detected a pseudoaneurysm or contrast extravasation in 19 studies and no bleeding was demonstrated in 9 studies. CT angiography correctly identified the site and type of bleeding in 18 of the 19 positive studies. CT angiography detected extravasation of contrast in one study that was not demonstrated on digital subtraction angiography. The sensitivity and specificity for multi-section CT angiography for the detection of major arterial bleeding on a background of pancreatitis were 0.947 and 0.900, respectively. Conclusion: Multi-section CT angiography is a sensitive and accurate technique for the detection of major arterial hemorrhage in inflammatory pancreatic disease and should be considered as the first investigation in the management of these patients

  5. Coronary computed tomography angiography indicates complexity of percutaneous coronary interventions

    OpenAIRE

    Stähli, B E; Bonassin, F; Goetti, R; Küest, S M; Frank, M.; Altwegg, L A; Gebhard, C; Levis, A; Wischnewsky, M. B.; Lüscher, T F; Alkadhi, H.; Kaufmann, P A; Maier, W.

    2012-01-01

    BACKGROUND: Coronary computed tomography angiography (CCTA) provides information regarding lesion morphology and three-dimensional coronary anatomy incremental to coronary angiography. We addressed the question whether preprocedural CCTA bears potential for guiding percutaneous coronary interventions (PCI). METHODS AND RESULTS: Sixty-six coronary lesions attempted with PCI within 6 months of preprocedural CCTA were retrospectively assessed. Lesion parameters from unenhanced computed tomogr...

  6. On the ultimate x-ray detector for angiography

    NARCIS (Netherlands)

    Slump, C.H.; Kauffman, J.A.; Flynn, M.J.

    2005-01-01

    The purpose of our research is to describe the ultimate X-ray detector for angiography. Angiography is a well established X-ray imaging technique for the examination of blood vessels. Contrast agent is injected followed by X-ray exposures and possible obstructions in the blood vessels can be visuali

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

    Science.gov (United States)

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

    2014-01-01

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

  8. Computerized tomography and angiography - competing processes in liver diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Wunschik, F.; Luetgemeier, J.; Hoerst, M.

    1981-02-01

    In the diagnostics of liver diseases, computerized tomography is a valuable method. It is particularly superior to angiography in detecting cysts, parasitosis and abscesses. Angiography however is better for known solid tumours regarding differencial diagnosis. Both methods supplement each other in the tumour and bile ducts diagnostics.

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

    Science.gov (United States)

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

    2016-02-01

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

  10. Choriocapillaris and choroidal microvasculature imaging with ultrahigh speed OCT angiography.

    Directory of Open Access Journals (Sweden)

    WooJhon Choi

    Full Text Available We demonstrate in vivo choriocapillaris and choroidal microvasculature imaging in normal human subjects using optical coherence tomography (OCT. An ultrahigh speed swept source OCT prototype at 1060 nm wavelengths with a 400 kHz A-scan rate is developed for three-dimensional ultrahigh speed imaging of the posterior eye. OCT angiography is used to image three-dimensional vascular structure without the need for exogenous fluorophores by detecting erythrocyte motion contrast between OCT intensity cross-sectional images acquired rapidly and repeatedly from the same location on the retina. En face OCT angiograms of the choriocapillaris and choroidal vasculature are visualized by acquiring cross-sectional OCT angiograms volumetrically via raster scanning and segmenting the three-dimensional angiographic data at multiple depths below the retinal pigment epithelium (RPE. Fine microvasculature of the choriocapillaris, as well as tightly packed networks of feeding arterioles and draining venules, can be visualized at different en face depths. Panoramic ultra-wide field stitched OCT angiograms of the choriocapillaris spanning ∼32 mm on the retina show distinct vascular structures at different fundus locations. Isolated smaller fields at the central fovea and ∼6 mm nasal to the fovea at the depths of the choriocapillaris and Sattler's layer show vasculature structures consistent with established architectural morphology from histological and electron micrograph corrosion casting studies. Choriocapillaris imaging was performed in eight healthy volunteers with OCT angiograms successfully acquired from all subjects. These results demonstrate the feasibility of ultrahigh speed OCT for in vivo dye-free choriocapillaris and choroidal vasculature imaging, in addition to conventional structural imaging.

  11. Computed tomography imaging and angiography - principles.

    Science.gov (United States)

    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

  12. Bolus characteristics based on Magnetic Resonance Angiography

    Directory of Open Access Journals (Sweden)

    Bi Xiaoming

    2006-10-01

    Full Text Available Abstract Background A detailed contrast bolus propagation model is essential for optimizing bolus-chasing Computed Tomography Angiography (CTA. Bolus characteristics were studied using bolus-timing datasets from Magnetic Resonance Angiography (MRA for adaptive controller design and validation. Methods MRA bolus-timing datasets of the aorta in thirty patients were analyzed by a program developed with MATLAB. Bolus characteristics, such as peak position, dispersion and bolus velocity, were studied. The bolus profile was fit to a convolution function, which would serve as a mathematical model of bolus propagation in future controller design. Results The maximum speed of the bolus in the aorta ranged from 5–13 cm/s and the dwell time ranged from 7–13 seconds. Bolus characteristics were well described by the proposed propagation model, which included the exact functional relationships between the parameters and aortic location. Conclusion The convolution function describes bolus dynamics reasonably well and could be used to implement the adaptive controller design.

  13. Angiography with a multifunctional line scanning ophthalmoscope

    Science.gov (United States)

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

    2012-02-01

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

  14. Breath-holding gadolinium-enhanced three-dimensional MR angiography in the evaluation of patients with vascular reconstruction

    International Nuclear Information System (INIS)

    Breath-bolding gadolinium-enhanced three-dimensional MR angiography (MRA) was performed in 20 patients with vascular reconstruction (arterial reconstruction in 18 and venous reconstruction in 2) after administration of 0.1 mmol/kg gadopentetate dimeglumine. A 3D fast gradient echo sequence was employed for MRA. Comparison was made with angiography in 10 patients and with CT in 12 patients. In all patients, the patency of artificial grafts could be assessed on MRA. On the other hand, angiography failed to visualization of an artificial grafts in one of ten cases, the case with venous reconstruction. Postprocessing images of maximum intensity projection allowed evaluation of the anastomotic region from any direction. There were two limitations in MRA; it overestimated the stenosis compared with the results of angiography, and it did not clearly show fluid collection around the artificial grafts. However, MRA has another advantage in that it is applicable to the patients with renal failure or iodine allergy. We concluded MRA has great possibilities in evaluation of artificial grafts if the examiner pays attention to these minor limitations. (author)

  15. Coronary CT Angiography versus Conventional Cardiac Angiography for Therapeutic Decision Making in Patients with High Likelihood of Coronary Artery Disease

    NARCIS (Netherlands)

    Moscariello, Antonio; Vliegenthart, Rozemarijn; Schoepf, U. Joseph; Nance, John W.; Zwerner, Peter L.; Meyer, Mathias; Townsend, Jacob C.; Fernandes, Valerian; Steinberg, Daniel H.; Fink, Christian; Oudkerk, Matthijs; Bonomo, Lorenzo; O'Brien, Terrence X.; Henzler, Thomas

    2012-01-01

    Purpose: To assess the efficacy of coronary computed tomographic (CT) angiography for therapeutic decision making in patients with high likelihood of coronary artery disease (CAD)-specifically the ability of coronary CT angiography to help differentiate patients without and patients with a need for

  16. Evaluation of Intracranial Vasculatures in Healthy Subjects with Arterial-Spin-Labeling-Based 4D-MR Angiography at 3T.

    Science.gov (United States)

    Iryo, Yasuhiko; Hirai, Toshinori; Nakamura, Masanobu; Tateishi, Machiko; Hayashida, Eri; Azuma, Minako; Nishimura, Shinichiro; Kitajima, Mika; Yamashita, Yasuyuki

    2016-07-11

    Contrast inherent inflow-enhanced multi-phase angiography combining multiple-phase flow-alternating inversion-recovery (CINEMA-FAIR) is an arterial-spin-labeling-based four-dimensional magnetic resonance angiography (4D-MRA) technique. Two neuroradiologists independently evaluated the depiction of the intracranial vasculatures in healthy subjects with 3T 4D-MRA using CINEMA-FAIR. Our results indicated that this technique can provide good visualization of the cerebral arteries with a high spatial and temporal resolution. It appears to have sufficient resolution for identifying flow difference in the anterior and posterior circulation in healthy subjects. PMID:26701696

  17. Comparison of digital subtraction angiography, CT angiography, and ultrasonic doppler examination in the evaluation of penile arterial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Kawanisi, Yasuo; Kimura, Kazunori; Lee, Kyong Soo; Koizumi, Takahiro; Nakatsuji, Hiroyoshi; Kojima, Keiji; Yamamoto, Akira; Numata, Akira [Takamatsu Red Cross Hospital (Japan)

    2001-11-01

    CT angiography reconstructed by a multidetector-row helical CT scanner is a newly developed form of imaging. We compared CT angiography and ultrasonic Doppler examination with digital subtraction angiography (DSA) in the diagnosis of arterial lesion. Eighteen patients with arteriogenic erectile dysfunction (ED) underwent color Doppler study DSA, and CT angiography after providing informed consent. The CT angiography images were obtained by a multidetector-row helical CT scanner, Asteion TSX021A (TOSHIBA). We injected prostaglandin E{sub 1} into the penile cavernous body, and then rapidly infused nonionic contrast medium into the antecubital vein. DSA and CT angiography images of the bilateral internal pudendal arteries and cavernous arteries were examined for stenotic lesions or occlusion. We also compared the peak systolic blood flow velocity in the cavernous artery measured by color Doppler ultrasound with CT angiography and DSA. The CT anigography and color Doppler studies were performed on an outpatient basis, but DSA required hospitalization. In the 36 internal pudendal arteries, DSA represented 22 normal arteries and 14 stenosis or occlusions. CT angiography showed 15 normal arteries and 21 occlusions. For the diagnosis of stenosis or occlusion in the internal pudendal artery, the CT angiography image had a good agreement, with a sensitivity of 1.00, specificity of 0.68, and accuracy of 0.81. For diagnosis in the cavernous artery, CT angiography image also showed a good agreement with DSA; however, the quality of the images of fine arteries was better in the DSA images. The inferior view and internal view of the pelvis in CT angiography were helpful for visulaizing the internal pudendal artery, especially at the pubic bone. There was insufficient correlation between peak systolic blood flow velocity and DSA findings. There were no serious complications involved in either examination. CT angiography has not yet reached the same level as DSA in the evaluation

  18. [A case of pituitary adenoma progressing to pituitary apoplexy on the occasion of cerebral angiography].

    Science.gov (United States)

    Suga, T; Kagawa, S; Goto, H; Yoshioka, K; Hosoya, T

    1996-05-01

    A case of pituitary adenoma which had progressed from subclinical pituitary apoplexy to subacute pituitary apoplexy on the occasion of cerebral angiography is reported. A 29-year-old man, complaining of bitemporal hemianopsia, was admitted to our department. Plain skull X-p revealed enlargement and double floor of the sella turcica. No abnormal calcification was revealed. CT demonstrated an isodensity mass with a diameter of 4 x 4 cm, and with ring enhancement in the suprasellar region. The mass extended from the intrasellar region to the suprasellar region and had a signal of high intensity on T1-weighted images. Endocrinological examination revealed hyperprolactinemia with a serum level of 422 ng/ml and normal reaction of anterior pituitary hormones. On 3rd March, digital subtraction angiography with 5F catheter was performed with the patient under sedation. The contrast medium was ioxaglic acid (Hexabrix 320). A volume of 6 ml with a speed of 4 ml per second was injected for the internal carotid angiogram. A total volume of 60 ml was used. Serum saline with 10 unit per ml of heparin sodium was also used for flushing. During angiography, the patient's blood pressure was 125/60-115/60mm Hg. DSA revealed upward displacement of the proximal portion of the anterior cerebral artery, pocket formation, and staining of the tumor capsule. Six hours later, he complained of retroorbital headache. Next morning, he noticed complete lack of left visual acuity. On 7th March, right visual acuity degenerated to blindness. CT revealed that the mass had increased its density. With bifrontal osteoplastic craniotomy, the tumor with marked intratumoral hemorrhage was resected. Its histology was chromophobe adenoma. The patient's right visual acuity improved rapidly. On the occasion of cerebral angiography, we could observe that subclinical pituitary apoplexy deteriorated to subacute pituitary apoplexy. Rosenbaum postulated that injection of contrast media increased intravascular

  19. Assessment of coronary artery aneurysms in paediatric patients with Kawasaki disease by multidetector row CT angiography: feasibility and comparison with 2D echocardiography

    International Nuclear Information System (INIS)

    Transthoracic ECHO is the locally accepted method for coronary surveillance of patients with Kawasaki disease but it may have limited visualization in the older child. To assess the feasibility of multidetector CT (MDCT) angiography in the follow-up of coronary artery aneurysms in children with previous Kawasaki disease. Six children (5 boys, 1 girl; mean age 11.5 years) with known Kawasaki disease and coronary artery involvement underwent CT coronary angiography using 16-detector MDCT. The visualized lengths and diameter of all coronary segments were measured. The number, size and location of coronary artery aneurysms were recorded and compared with recent ECHO. Twelve coronary artery aneurysms (seven saccular, five fusiform) were identified by MDCT angiography. One saccular aneurysm at the junction of the distal right coronary artery and posterior descending artery was not detected by ECHO while the remaining six in proximal segments were detected by both modalities. Two of five fusiform aneurysms were not detected by ECHO due to their small sizes. Excellent agreement was found between CT and ECHO for maximal diameter and length of the visualized aneurysms. MDCT angiography accurately defines coronary artery aneurysms. It is more sensitive for detecting aneurysms at distal coronary segments and fusiform aneurysms of small size

  20. Comparison of magnetic resonance angiography and conventional angiography in sickle cell disease: clinical significance and realibility

    Energy Technology Data Exchange (ETDEWEB)

    Kandeel, A.Y. [Dept. of Radiology, Mansoura Univ. Hospital (Egypt); Zimmerman, R.A. [Dept. of Radiology, The Children`s Hospital of Philadelphia, PA (United States); Ohene-Frempong, K. [Div. of Hematology, The Children`s Hospital of Philadelphia, PA (United States)

    1996-07-01

    We retrospectively reviewed the medical records and conventional angiograms of 21 patients with known sickle cell disease, who underwent a total of 50 magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies. MRA and conventional angiography were assessed separately for evidence of stenosis or occulusion. Follow up MRI/MRA studies were also assessed for evidence of progression, regression or stability of the disease in these patients. In the carotid circulation, MRA made the correct diagnosis in 85% of the vessels evaluated with a sensitivity of 80.5% and a specificity of 94%. MRA was also found to show evidence of disease progression, more often than did MRI or the clinical condition of the patients. (orig.)

  1. Efficacy and safety of dual-axis rotational coronary angiography versus conventional angiography

    International Nuclear Information System (INIS)

    Background:Conventional coronary angiography (CA) is the gold standard for the diagnosis of coronary artery disease. However, this technique requires several orthogonal projections to determine the severity of the disease. Dual-axis rotational coronary angiography (DARCA) is a new technique which acquires the image of each coronary artery using a single contrast injection, potentially reducing both radiation and contrast exposure. Objective: The aim of this study was to determine the amount of contrast used, radiation exposure and diagnostic accuracy of DARCA compared to conventional CA. Methods: We conducted a prospective, self-controlled study of consecutive patients undergoing elective coronary angiography to compare DARCA versus the conventional technique. All the angiographies were reviewed by two independent interventional cardiologists (observer 1 and observer 2) who evaluated agreement between both types of images. The observers evaluated firstly DARCA and three weeks later conventional CA images to prevent bias in their interpretation. Results: The contrast volume used in the diagnostic procedure was significantly lower with DARCA (33.29 ± 11.2 ml vs. 17±5.4 ml; p < 0.01). Radiation exposure in the patient (235.6 ± 76.8 mGy vs. 82.7 ± 46.6 mGy; p <0.01) and operator was also significantly lower (5.7 ± 3.26 μSv vs. 2.48 ± 1.47 μSv; p <0.04). A slight difference and a strong correlation were seen in the number of lesions, vessel diameter and percentage of stenosis between both observers and both methods. Categorical assessment of percentage of stenosis also showed adequate agreement. Conclusion: DARCA reduces the use of contrast agents and radiation exposure compared to the conventional technique without modifying the diagnostic accuracy of the method. (authors)

  2. Multiple detector-row CT angiography of the renal and mesenteric vessels

    International Nuclear Information System (INIS)

    Computed tomography angiography (CTA) of the abdomen with multiple detector-row computed tomography (MD-CT) is an effective technique for minimally invasive imaging of the renal arteries and the visceral vasculature. This article reviews the clinical and technical aspects of MD-CT angiography in terms of image acquisition and reconstruction parameters, contrast medium application, and three-dimensional visualization with special attention to renal and mesenteric vascular imaging. Because of its high sensitivity to detect renal artery stenosis on the one hand, and because a normal renal CTA virtually excludes the presence of a significant renal artery stenosis on the other hand, renal CTA plays a useful role in the management of patients with suspected renovascular hypertension. Mesenteric CTA is a useful tool for visualizing normal vascular anatomy and its variants--particularly in the setting of organ transplantation. Vascular pathology, e.g. atherosclerotic disease (abdominal angina), or aneurysms of the visceral arteries are reliably assessed with CTA. Mesenteric CTA is an invaluable adjunct to abdominal CT in the setting of abdominal emergencies, because of its ability to detect the causes of acute intestinal ischemia (superior mesenteric artery embolism or thrombosis, superior mesenteric vein thrombosis). Accurate timing of the CTA acquisition and the subsequent parenchymal phase acquisition relative to the contrast medium transit time is critical to obtain excellent image quality in double-pass abdominal CT acquisitions

  3. The importance of peripheral angiography in elderly patients undergoing coronary angiography

    Institute of Scientific and Technical Information of China (English)

    Gianluca Rigatelli; Giorgio Rigatelli

    2005-01-01

    Objectives Early and accurate diagnosis of peripheral atherosclerosis is of paramount importance for global managerment of patients with known coronary artery disease (CAD), especially in the elderly. We sought to evaluate the prevalence and clinical relevance of significant abdominal vessel stenosis or aneurysm (AVA) in patients undergoing coronary angiography. Methods Medical records of consecutive > 75-year old patients who underwent coronary angiography at two public institutions over a 12-month period were evaluated. Angiographic results of patients who underwent coincident diagnostic abdominal aorta angiography to evaluate abdominal vessels on the basis of clinical and angiographic criteria were analyzed. Results During the study period, AVA was found in 90 (35.7% ) of 252 consecutive patients (185 males, mean age 79±5.8 years), renal artery stenosis in 13.1% of cases (33 patients), aortoiliac artery disease in 13.7 % (35 patients), and aortic aneurismal disease in 8.9% (22 patients). Logistic regression analyses revealed > 3-vessel CAD (odds ratio [OR] :9.917, P = 0.002), and > 3 risk factors (OR: 2.8, P =0. 048) as independent predictors of AVA. Conclusions Aged patients with multivessel CAD frequently have a high risk profile and multiple vascular atherosclerotic distributions, suggesting the usefulness of a mere global and comprehensive cardiovascular approach in aged patients.

  4. Patient radiation dose from computed tomography angiography and digital subtraction angiography of the brain

    Science.gov (United States)

    Netwong, Y.; Krisanachinda, A.

    2016-03-01

    The 64-row multidetector computed tomography angiography (64-MDCTA) provides vascular image quality of the brain similar to digital subtraction angiography (DSA), but the effective dose of CTA is lower than DSA studied in phantom. The purpose of this study is to evaluate the effective dose from 64-MDCTA and DSA. Effective dose (according to ICRP 103) from 64-MDCTA and DSA flat panel detector for cerebral vessels examination of the brain using standard protocols as recommended by the manufacturer was calculated for 30 cases of MDCTA (15 male and 15 female).The mean patient age was 49.5 (23-89) yrs. 30 cases of DSA (14 male and 16 female), the mean patient age was 46.8 (21-81) yrs. For CTA, the mean effective dose was 3.7 (2.82- 5.19) mSv. For DSA, the mean effective dose was 5.78 (3.3-10.06) mSv. The effective dose of CTA depends on the scanning protocol and scan length. Low tube current can reduce patient dose whereas the number of exposures and number of series in 3D rotational angiography (3D RA) resulted in increasing effective dose in DSA patients.

  5. E-learn Computed Tomographic Angiography

    DEFF Research Database (Denmark)

    Havsteen, Inger; Christensen, Anders; Nielsen, Jens K;

    2012-01-01

    BACKGROUND: Computed tomographic angiography (CTA) is widely available in emergency rooms to assess acute stroke patients. To standardize readings and educate new readers, we developed a 3-step e-learning tool based on the test-teach-retest methodology in 2 acute stroke scenarios: vascular...... occlusion and "spot sign" in acute intracerebral hemorrhage. We hypothesized that an e-learning program enhances reading skills in physicians of varying experience. METHODS: We developed an HTML-based program with a teaching segment and 2 matching test segments. Tests were taken before and after...... sign correctly 69% before versus 92% after teaching (P = .009) and reported a median self-perceived diagnostic certainty of 50% versus 75% (P = .030). Self-perceived diagnostic certainty revealed no significant increase for vascular occlusion. CONCLUSIONS: The e-learning program is a useful educational...

  6. Radial pseudoaneurysm following diagnostic coronary angiography

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2015-06-01

    Full Text Available The radial artery access has gained popularity as a method of diagnostic coronary catheterization compared to femoral artery puncture in terms of vascular complications and early ambulation. However, very rare complication like radial artery pseudoaneurysm may occur following cardiac catheterization which may give rise to serious consequences. Here, we report a patient with radial pseudoaneurysm following diagnostic coronary angiography. Adequate and correct methodology of compression of radial artery following puncture for maintaining hemostasis is the key to prevention.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12776 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 48-50

  7. Multidetector CT angiography in Takayasu arteritis

    Energy Technology Data Exchange (ETDEWEB)

    Khandelwal, Niranjan; Kalra, Naveen [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Chandigarh 160012 (India); Garg, Mandeep Kumar, E-mail: gargmandeep@hotmail.com [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Chandigarh 160012 (India); Kang, Mandeep; Lal, Anupam [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Chandigarh 160012 (India); Jain, Sanjay [Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh 160012 (India); Suri, Sudha [Department of Radiodiagnosis and Imaging, Post Graduate Institute of Medical Education and Research, Chandigarh 160012 (India)

    2011-02-15

    Objective: To analyse the spectrum of Takayasu's arteritis (TA) on multidetector CT angiography (MDCTA). Materials and methods: A retrospective analysis of the MDCTA findings was performed on 15 patients clinically diagnosed as Takayasu's arteritis. The spectrum and incidence of imaging findings on CTA were compared to studies in literature on catheter angiography in Takayasu's arteritis. Laboratory parameters were available in nine patients. The disease was considered active if erythrocyte sedimentation rate (ESR) levels were elevated and 'C' reactive protein (CRP) was positive. An attempt was made to correlate disease activity with the imaging findings. Results: Ascending aorta, arch of aorta and descending thoracic aorta were involved in 14 out of 15 (93%) patients. The wall thickness varied between 1 and 10 mm with maximal involvement in arch and descending thoracic aorta. Major neck vessels were involved in 11 (73%) patients with most pronounced changes seen in the brachiocephalic trunk, left common carotid artery (CCA) and left subclavian artery (SCA). Abdominal aorta and its branches were involved in all the 11 (100%) patients in whom abdominal CTA was performed. Celiac axis and SMA were involved in 10 (91%) and seven (64%) patients, respectively while renal artery stenosis was present in five (45%) patients. In six patients, ESR was elevated and CRP was positive indicating active disease. All patients in whom the laboratory parameters were available showed mural thickening in the aorta and at least one of the neck vessels except for one patient with inactive disease who had aortic mural thickening only. Conclusion: MDCTA provides information about both the vessel wall and lumen in patients with Takayasu's disease.

  8. Analysis and dynamic 3D visualization of cerebral blood flow combining 3D and 4D MR image sequences

    Science.gov (United States)

    Forkert, Nils Daniel; Säring, Dennis; Fiehler, Jens; Illies, Till; Möller, Dietmar; Handels, Heinz

    2009-02-01

    In this paper we present a method for the dynamic visualization of cerebral blood flow. Spatio-temporal 4D magnetic resonance angiography (MRA) image datasets and 3D MRA datasets with high spatial resolution were acquired for the analysis of arteriovenous malformations (AVMs). One of the main tasks is the combination of the information of the 3D and 4D MRA image sequences. Initially, in the 3D MRA dataset the vessel system is segmented and a 3D surface model is generated. Then, temporal intensity curves are analyzed voxelwise in the 4D MRA image sequences. A curve fitting of the temporal intensity curves to a patient individual reference curve is used to extract the bolus arrival times in the 4D MRA sequences. After non-linear registration of both MRA datasets the extracted hemodynamic information is transferred to the surface model where the time points of inflow can be visualized color coded dynamically over time. The dynamic visualizations computed using the curve fitting method for the estimation of the bolus arrival times were rated superior compared to those computed using conventional approaches for bolus arrival time estimation. In summary the procedure suggested allows a dynamic visualization of the individual hemodynamic situation and better understanding during the visual evaluation of cerebral vascular diseases.

  9. [Chronic subdural hematoma presenting visual disturbance: a case report].

    Science.gov (United States)

    Hasegawa, S; Manabe, H; Shimizu, T; Itoh, C; Suzuki, S

    2001-03-01

    The authors reported a rare case of chronic subdural hematoma presenting bilateral visual impairment caused by papilledema. A 49-year-old man was admitted to our department due to left blurred vision. On admission, ophthalmological examination revealed visual acuity disturbance on the left eye, bilateral nasal visual field defect and papilledema. CT scan and MRI demonstrated bilateral subdural hematoma. No remarkable findings were detected on cerebral angiography. After evacuation of bilateral subdural hematomas, his visual symptoms recovered. In this report, we discuss the mechanism of visual impairment caused by chronic subdural hematoma. PMID:11296405

  10. Detection and assessment of circle of Willis aneurysms in acute subarachnoid hemorrhage with three-dimensional computed tomographic angiography: correlation with digital substraction angiography findings.

    Science.gov (United States)

    Lai, P H; Yang, C F; Pan, H B; Chen, C; Ho, J T; Hsu, S S

    1999-10-01

    In this retrospective study, we examined the usefulness of computed tomographic angiography (CTA) for the detection and assessment of circle of Willis aneurysms in patients with acute nontraumatic subarachnoid hemorrhage (SAH), using selective digital substraction angiography (DSA) as the gold standard. Thirty-five patients who presented with acute, nontraumatic SAH, diagnosed on the basis of unenhanced computed tomography or lumbar puncture findings or both, underwent both CTA and DSA. The CTA images were interpreted for the presence, location, size, and shape of the aneurysm, presence of a neck, and relationship of the aneurysm to adjacent arterial branches. The CTA and DSA images were then compared, with the latter images serving as the gold standard. DSA revealed 37 aneurysms in 32 patients and ruled out intracranial aneurysms in the remaining three. The sensitivity and specificity of CTA for aneurysm detection were 97% and 100%, respectively. The size of the smallest aneurysm shown was 4 mm, and the largest aneurysm was 21 mm. The size and lobularity of the aneurysms estimated from CTA images corresponded well with those estimated from DSA images. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. Our results confirm the accuracy of CTA in comparison with DSA. Because of its reliability, minimal invasiveness, and rapidity, CTA may become the technique of choice for neuroradiologic work-up of SAH patients. DSA then would be used to diagnose intracranial aneurysms only in selected, questionable cases. PMID:10575836

  11. Evaluation of occupational and patient dose in cerebral angiography procedures

    Directory of Open Access Journals (Sweden)

    Neuri Antonio Lunelli

    2013-12-01

    Full Text Available Objective The present study was aimed at estimating the doses received by physicians and patients during cerebral angiography procedures in a public hospital of Recife, PE, Brazil. Materials and Methods The study sample included 158 adult patients, and during the procedures the following parameters were evaluated: exposure parameters (kV, mAs, number of acquired images, reference air kerma value (Ka,r and air kerma-area product (PKA. Additionally, the physicians involved in the procedures were evaluated as for absorbed dose in the eyes, thyroid, chest, hands and feet. Results The results demonstrated that the doses to the patients' eyes region were relatively close to the threshold for cataract occurrence. As regards the physicians, the average effective dose was 2.6 µSv, and the highest effective dose recorded was 16 µSv. Conclusion Depending on the number of procedures, the doses received by the physicians may exceed the annual dose limit for the crystalline lenses (20 mSv established by national and international standards. It is important to note that the high doses received by the physicians are due to the lack of radiation protection equipment and accessories, such as leaded curtains, screens and protective goggles.

  12. Cerebral computed tomographic angiography scan delay in subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Lukosevicius Saulius

    2005-01-01

    Full Text Available CONTEXT: Computed tomographic angiography (CTA is widely applied in the evaluation of cerebral vessels. Contrast enhancement in cerebral CTA without care or test bolus is not always sufficient for high-quality images. AIMS: Evaluation of the possibilities of calculation of scan delay for cerebral CTA in case of subarachnoid hemorrhage (SAH, based on clinical data of a patient and to find out prognostic error of the model. SETTINGS AND DESIGN: Prospective study in Neurosurgery and Radiology departments. MATERIALS AND METHODS: Scan delay in 53 patients suffering an acute SAH was measured employing test bolus technique. Cerebral CTA was performed afterwards. STATISTICAL ANALYSIS USED: SPSS for Windows v.10.1 software package was applied for dispersion analysis, including one-sample Kolmogorov-Smirnov′s test and Levene′s Test of Equality of Error Variances. RESULTS: A statistical model for the prediction of scan delay in SAH was developed. Cerebral CTA scan delay was dependent upon age, neurological status and impact of the latter factors together (P<0.05. The determined mean square error of prognosis of scan delay of the developed model equals 3.3 sec. CONCLUSION: Using our proposed model it is possible to estimate an optimal delay time for CTA in most patients with SAH with a determined error.

  13. High-Resolution Magnetic Resonance Angiography of the Mouse Brain: Application to Murine Focal Cerebral Ischemia Models

    Science.gov (United States)

    Beckmann, Nicolau; Stirnimann, Roger; Bochelen, Damien

    1999-10-01

    Three-dimensional time-of-flight high-resolution magnetic resonance angiography was applied to visualize the cerebral vasculature of the mouse brain. In normal mice, angiograms of good quality, showing the essential details of the arterial cerebrovascular anatomy, could be obtained in only 2.5 min without the use of contrast agents. Signals from slowly flowing blood, e.g., in veins, could also be detected after administration of a blood pool contrast agent. The technique was applied to mouse models of permanent and transient brain ischemia, involving the occlusion of the middle cerebral artery. High-resolution magnetic resonance angiography proved to be a very useful tool for verifying the success of the occlusion in these models.

  14. CT coronary angiography in patients with atrial fibrillation

    International Nuclear Information System (INIS)

    Purpose: Reliable visualization of the coronary arteries with multislice spiral CT angiography (MSCTA) in patients with atrial fibrillation (AF) remains a challenge despite retrospective ECG gating. A recently developed new algorithm automatically compensates dynamic changes in the heart rate during the scan, thus reducing misregistration and motion artifacts. The HeartBeat-RT algorithm combines a fixed percent delay determined from the first R wave and the fixed offset delay based on the second R wave in the ECG cycle. The purpose of this study was to find out the optimal reconstruction window in MSCTA in patients with AF for each of the three major coronary arteries during the cardiac cycle. Materials and methods: 20 patients with permanent AF were imaged on a 16-slice scanner (slice collimation: 16 x 0.75 mm; rotation time 0.42 s; 140 kV; 380 mAs; 120 ml Ultravist 370 registered i.v.). The patients had not received any previous drugs for heart frequency regulation. Acquisition was started after bolus tracking of a biphasic bolus of 120 ml Ultravist 370 injected intravenously. Each coronary segment was reconstructed at 0%-90% of the cardiac cycle in increments of 10%. For image analysis we used coronary segments as defined by the American Heart Association. Two blinded independent readers assessed the image quality in terms of visibility and artifacts (five-point rating scale 1=very poor, 2=poor, 3=fair, 4=good and 5=excellent) and the degree of stenosis (five-point rating scale 1=0%, 2=1%-49%, 3=50%-74%, 4=75%-99%, 5=100%) on axial slices, multiplanar reconstructions and three-dimensional volume-rendered images. (orig.)

  15. Manifestations of hepatic cavernous hemangioma in carbon dioxidedigital subtraction angiography

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Yan-ha0; HE Xiao-feng; CHEN Yong; ZENG Qing-le

    2002-01-01

    Objective: To describe the characteristic appearance of cavernous hemangioma of the liver (CHL)presented in carbon dioxide digital subtraction angiography (CO2-DSA) and to evaluate the significance of CO2-DSA in the diagnosis of CHL. Methods: Both CO2-DSA and iodinated contrast DSA (IC-DSA) were performed in all 16 patients with CHL, and the angiographic manifestations in the same patients were compared. The image quality was rated by three experienced angiographers, and the complications were also assessed. Results; There was good correlation between angiographers on image quality (R=0. 73). Diagnostic images were obtained with both CO2-DSA and IC-DSA in all CHL patients. No difference was noted between IC-DSA and CO2-DSA in visualizing the proper hepatic arteries and its branches (P>0. 05). CO2-DSA produced better images that clearly described the tumor size, shape and margination than those by IC-DSA (P<0. 05), but both demonstrated characteristic appearances of early opacification and persistent contrast enhancement of the tumors. The portal vein branches near the tumors were constantly demonstrated by CO2-DSA in 15 cases (15/16) but only in 2 cases (2/16) by IC-DSA. Conclusion: CO2-DSA is sensitive in CHL diagnosis, and in patients with contraindications to IC or with unsatisfactory imaging results by IC-DSA,CO2-DSA is a good alternative. As show in most cases by CO2-DSA, the portal veins might act as the main drainage vein of CHLs.

  16. Magnetic resonance angiography in the diagnosis of thoracic venous obstruction.

    Science.gov (United States)

    Chang, Y C; Su, C T; Yang, P C; Wang, T C; Chiu, L C; Hsu, J C

    1998-01-01

    The aims of this study were to evaluate the diagnostic value of orthogonal magnetic resonance angiography (MRA) and to compare the results of MRA with those of digital subtraction venography (DSV) in thoracic venous diseases. Ten normal volunteers were evaluated using two-dimensional time-of-flight MRA in three orthogonal planes to determine the image quality of each venous segment. Twelve consecutive patients suspected of having thoracic venous disease were studied with both MRA and DSV. In the normal subjects, the plane perpendicular to the target vein provided the most consistent visualization. Using three orthogonal MRA images, a diagnostic-quality image was obtained in 175 (83%) of 210 venous segments in normal volunteers. In patients with thoracic venous obstructive disease, MRA was more effective than DSV in detecting total (84 vs 54), patent (56 vs 36), stenotic (13 vs 10), and obstructive (15 vs 8) venous segments, poststenotic or postobstructive veins (15 vs 10), thrombosis of the internal jugular vein (7 vs 2), intraluminal thrombus (5 vs 3), and azygos veins (12 vs 2). Using venous segments visible on DVS (n = 54) as the standard, the sensitivity and specificity of MRA were 94% and 100%, respectively, in detecting venous patency, and 100% and 98% in detecting complete venous obstruction. In the shoulder region, the sensitivity and specificity of MRA were 93% and 100%, respectively, in detecting venous patency, and 100% and 97% in detecting venous obstruction. We conclude that MRA with three orthogonal planes can provide relatively complete and reliable venous mapping, without the need for contrast medium. PMID:9481063

  17. Fatal Deep Inguinal Infection after Diagnostic Coronary Angiography

    OpenAIRE

    Akkoyun, Dursun Çayan; Alpsoy, Şeref; Akyüz, Aydın; Güneş, Hayati

    2015-01-01

    Herein we would like to share our case complicated with inguinal infection secondary to femoral haematoma after coronary angiography. A-79 years-old female underwent diagnostic coronary angiography suffered from a large haematoma in the right inguinal region where femoral artery puncture was performed at another hospital. She was treated at same hospital 16 days and discharged. She presented to our department with a deep ulcerative and ruptured wound in the femoral artery puncture site. The w...

  18. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Zhi-wei [Department of Health Statistics, School of Public Health, Fourth Military Medical University, No. 169, Changle West Road, Xi’an, Shaanxi 710032 (China); Xu, Lin [Department of Medical Cardiology, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui; Ding, Juan; Li, Li [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jin, Zhi-tao [Department of Cardiology, General Hospital of the Second Artillery, Beijing 100088 (China)

    2013-10-01

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels.

  19. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    International Nuclear Information System (INIS)

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels

  20. CT Angiography in the Diagnosis of Brain Death

    International Nuclear Information System (INIS)

    Summary Brain death is defined as the irreversible cessation of functioning of the entire brain, including the brainstem. Brain death is principally established using clinical criteria including coma, absence of brainstem reflexes and loss of central drive to breathe assessed with apnea test. In situations in which clinical testing cannot be performed or when uncertainty exists about the reliability of its parts due to confounding conditions ancillary tests (i.a. imaging studies) may be useful. The objective of ancillary tests in the diagnosis of brain death is to demonstrate the absence of cerebral electrical activity (EEG and evoked potentials) or cerebral circulatory arrest. In clinical practice catheter cerebral angiography, perfusion scintigraphy, transcranial Doppler sonography, CT angiography and MR angiography are used. Other methods, like perfusion CT, xenon CT, MR spectroscopy, diffusion weighted MRI and functional MRI are being studied as potentially useful in the diagnosis of brain death. CT angiography has recently attracted attention as a promising alternative to catheter angiography – a reference test in the diagnosis of brain death. Since 1998 several major studies were published and national guidelines were introduced in several countries (e.g. in France, Austria, Switzerland, the Netherlands and Canada). This paper reviews technique, characteristic findings and criteria for the diagnosis of cerebral circulatory arrest in CT angiography

  1. The feasibility of left radial artery approach for coronary angiography

    Institute of Scientific and Technical Information of China (English)

    Liangbo Chen; Can Chen; Shian Huang

    2008-01-01

    Objective:To study the feasibility of the left radial approach for coronary angiography. Methods:195 patients diagnosed with coronary atherosclerotic heart disease were randomly divided for coronary angiography(CAG) into a left radial artery approach group(98 cases) and a fight radial artery approach group(97 cases) from Jan 2006 to Dec 2006. Selective coronary angiographies were performed with 5F TIG catheters. The time of puncturing, duration under X-ray fluoroscopy and of the operation, successful rates of puncturing and coronary angiography were recorded. Results:There was no difference in the time of puncturing(2.25 -F 1.58 min vs 2.19±1.62 min), duration under X-ray fluoroscopy(3.12±1.53 min vs 3.21±1.49 min) and the duration of the operation(12.87±2.52 rain vs 12.98±2.85 min), nor in the success rates of puncturing(95.91% vs 95.87%) and coronary angiography(94.90% vs 94.85%). Conclusion: Coronary angiography can be accomplished via the left radial artery approach, indicating that this is a worthwhile clinical approach.

  2. Contrast-enhanced MR angiography in patients after kidney transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Huber, A.; Heuck, A.; Scheidler, J.; Holzknecht, N.; Baur, A.; Reiser, M. [Klinikum Grosshadern, Muenchen (Germany). Radiologische Klinik und Poliklinik; Stangl, M.; Theodorakis, J.; Illner, W.-D.; Land, W. [Dept. of Transplant Surgery, Klinikum Grosshadern, Muenchen (Germany)

    2001-12-01

    The aim of this study was to investigate the value of a contrast-enhanced 3D MR angiography in detecting postoperative vascular complications after kidney transplantation in comparison with digital subtraction angiography (DSA). Forty-one patients who underwent a kidney transplantation were examined with MR angiography and DSA. Contrast-enhanced MR angiography was performed as a dynamic measurement with one precontrast and three postcontrast measurements. Maximum intensity projection reconstructions were performed for all postcontrast data sets after DSA. The results were evaluated by two independent observers who were unaware of the DSA results. Twenty-three hemodynamically significant arterial stenoses were identified with DSA in the iliac arteries (n=7), the renal allograft arteries (n=12), and in their first branches (n=4). For a patient-based analysis the sensitivity and specificity, respectively, for observer 1 were 100 and 97%, and for observer 2, 100 and 93%. Respective data were 100 and 100% after a consensus evaluation by two observers. Complications involving the renal veins were detected in 2 cases and perfusion defects of the kidney parenchyma were detected in 4 cases. Contrast-enhanced MR angiography is a reliable method in identifying postoperative arterial stenoses after kidney transplantation. In addition, dynamic MR angiography can be helpful in detecting venous complications and perfusion defects in kidney allografts. (orig.)

  3. In vivo comparison of three ultrasound vector velocity techniques to MR phase contrast angiography

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Udesen, Jesper; Oddershede, Niels;

    2009-01-01

    The objective of this paper is to validate angle independent vector velocity methods for blood velocity estimation. Conventional Doppler ultrasound (US) only estimates the blood velocity along the US beam direction where the estimate is angle corrected assuming laminar flow parallel to vessel...... boundaries. This results in incorrect blood velocity estimates, when angle of insonation approaches 90° or when blood flow is non-laminar. Three angle independent vector velocity methods are evaluated in this paper: directional beamforming (DB), synthetic aperture flow imaging (STA) and transverse...... oscillation (TO). The performances of the three methods were investigated by measuring the stroke volume in the right common carotid artery of 11 healthy volunteers with magnetic resonance phase contrast angiography (MRA) as reference. The correlation with confidence intervals (CI) between the three vector...

  4. The comparative study on diagnostic validity of cerebral aneurysm by computed tomography angiography versus digital subtraction angiography after subarachnoid hemorrhage

    Directory of Open Access Journals (Sweden)

    Masih Saboori

    2011-01-01

    Full Text Available Background: In order to declare the preoperative diagnostic value of brain aneurysms, two radiological modalities, computed tomographic angiography and digital subtraction angiography were compared. Methods: In this descriptive analytic study, diagnostic value of computed tomographic angiography (CTA was com-pared with digital subtraction angiography (DSA. Sensitivity, specificity, positive and negative predictive values were calculated and compared between the two modalities. All data were analyzed with SPSS software, version 16. Results: Mean age of patients was 49.5 ± 9.13 years. 57.9 % of subjects were female. CTA showed 89% sensitivity and 100% specificity whereas DSA demonstrated 74% sensitivity and 100% specificity. Positive predictive value of both methods was 100%, but negative predictive value of CTA and DSA was 85% and 69%, respectively. Conclusions: Based on our data, CTA is a valuable diagnostic modality for detection of brain aneurysm and su-barachnoid hemorrhage.

  5. CT angiography versus 3D rotational angiography in patients with subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    CT angiography (CTA) is increasingly used as primary diagnostic tool to replace digital subtraction angiography (DSA) in patients with subarachnoid hemorrhage (SAH). However, 3D rotational angiography (3DRA) has substituted DSA as a reference standard. In this prospective observational study, we compare CTA with 3DRA of all cerebral vessels in a large cohort of patients with SAH. Of 179 consecutive patients with SAH admitted between March 2013 and July 2014, 139 underwent 64- to 256-detector row CTA followed by complete cerebral 3DRA within 24 h. In 86 patients (62 %), 3DRA was performed under general anesthesia. Two observers from outside hospitals reviewed CTA data. In 118 of 139 patients (85 %), 3DRA diagnosed the cause of hemorrhage: 113 ruptured aneurysms, three arterial dissections, one micro-arteriovenous malformation (AVM), and one reversible vasoconstriction syndrome. On CTA, both observers missed all five non-aneurysmal causes of SAH. Sensitivity of CTA in depicting ruptured aneurysms was 0.88-0.91, and accuracy was 0.88-0.92. Of 113 ruptured aneurysms, 28 were ≤3 mm (25 %) and of 95 additional aneurysms, 71 were ≤3 mm (75 %). Sensitivity of depicting aneurysms ≤3 mm was 0.28-0.43. Of 95 additional aneurysms, the two raters missed 65 (68 %) and 58 (61 %). Sensitivity in detection was lower in aneurysms of the internal carotid artery than in other locations. CTA had some limitations as primary diagnostic tool in patients with SAH. All non-aneurysmal causes for SAH and one in ten ruptured aneurysms were missed. Performance of CTA was poor in aneurysms ≤3 mm. The majority of additional aneurysms were not depicted on CTA. (orig.)

  6. CT angiography versus 3D rotational angiography in patients with subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Bechan, R.S.; Peluso, J.P.; Sluzewski, M.; Rooij, W.J. van [Sint Elisabeth Ziekenhuis Tilburg, Department of Radiology, Tilburg (Netherlands); Rooij, S.B. van [Medisch Centrum Alkmaar, Department of Radiology, Alkmaar (Netherlands); Sprengers, M.E.; Majoie, C.B. [Academisch Medisch Centrum, Department of Radiology, Amsterdam (Netherlands)

    2015-12-15

    CT angiography (CTA) is increasingly used as primary diagnostic tool to replace digital subtraction angiography (DSA) in patients with subarachnoid hemorrhage (SAH). However, 3D rotational angiography (3DRA) has substituted DSA as a reference standard. In this prospective observational study, we compare CTA with 3DRA of all cerebral vessels in a large cohort of patients with SAH. Of 179 consecutive patients with SAH admitted between March 2013 and July 2014, 139 underwent 64- to 256-detector row CTA followed by complete cerebral 3DRA within 24 h. In 86 patients (62 %), 3DRA was performed under general anesthesia. Two observers from outside hospitals reviewed CTA data. In 118 of 139 patients (85 %), 3DRA diagnosed the cause of hemorrhage: 113 ruptured aneurysms, three arterial dissections, one micro-arteriovenous malformation (AVM), and one reversible vasoconstriction syndrome. On CTA, both observers missed all five non-aneurysmal causes of SAH. Sensitivity of CTA in depicting ruptured aneurysms was 0.88-0.91, and accuracy was 0.88-0.92. Of 113 ruptured aneurysms, 28 were ≤3 mm (25 %) and of 95 additional aneurysms, 71 were ≤3 mm (75 %). Sensitivity of depicting aneurysms ≤3 mm was 0.28-0.43. Of 95 additional aneurysms, the two raters missed 65 (68 %) and 58 (61 %). Sensitivity in detection was lower in aneurysms of the internal carotid artery than in other locations. CTA had some limitations as primary diagnostic tool in patients with SAH. All non-aneurysmal causes for SAH and one in ten ruptured aneurysms were missed. Performance of CTA was poor in aneurysms ≤3 mm. The majority of additional aneurysms were not depicted on CTA. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Randolf Klingebiel

    2008-08-01

    Full Text Available Randolf Klingebiel1, Max Kentenich3, Hans-Christian Bauknecht3, Florian Masuhr2, Eberhard Siebert1, Markus Busch2, Georg Bohner11Department of Neuroradiology, 2Department of Neurology, 3Department of Radiology, Charité Universitary Medicine Berlin, GermanyBackground: Noninvasive 64-slice computed tomography angiography (64-MSCTA closely approximates conventional catheter angiography (DSA in terms of detail resolution. Objective: Retrospective evaluation of cervicocranial (cc 64-MSCTA in comparison with DSA in patients with presumptive cc vascular disorders.Material and methods: Twenty-four 64-MSCTA studies (32 mm detector width, slice thickness 0.5 mm, 120 kv, 150 mAs, pitch 0.75 of patients with presumptive cc vascular pathology (13 men, 11 women, mean age 38.3 ± 11.3 yrs, range 19–54 yrs were assessed in comparison with DSA studies without abnormal findings in age-matched patients (11 men, 13 women, mean age 39.7 ± 11.9 yrs, range 18–54 yrs. Study readings were performed in a blinded manner by two neuroradiologists with respect to image quality and assessibility of various cc vascular segments by using a five-point scale. Radiation exposure was calculated for 64-MSCTA.Results: Each reader assessed 384/528 different vessel segments (64-MSCTA/DSA. Superior image quality was attributed to DSA with respect to the C1 ICA–C6 ICA, A3 ACA, and P3 PCA segments as well the AICA and SCA. 64-MSCTA was scored superior for C7 ICA and V4 VA segments. A significantly increased number of nonassessable V2- and V3 VA segments in DSA studies was noted. The effective dose for 64-MSCTA amounted to 2.2 mSv.Conclusions: 64-MSCTA provides near-equivalent diagnostic information of the cc vasculature as compared with DSA. According to our results, DSA should be considered primarily when peripheral vessels (A3/P3 or ICA segments close to the skull base (C2-5 are of interest, such as in primary angiitis or stenoocclusive ICA disease, respectively.Keywords: CT-angiography

  8. Medical personnel and patient dosimetry during coronary angiography and intervention

    Science.gov (United States)

    Efstathopoulos, Efstathios P.; Makrygiannis, Stamatis S.; Kottou, Sofia; Karvouni, Evangelia; Giazitzoglou, Eleftherios; Korovesis, Socrates; Tzanalaridou, Efthalia; Raptou, Panagiota D.; Katritsis, Demosthenes G.

    2003-09-01

    Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 +/- 9 Gy cm2. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 +/- 30 Gy cm2, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y-1 for the primary operator, and 0.03-0.04 mSv y-1 for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

  9. Medical personnel and patient dosimetry during coronary angiography and intervention

    Energy Technology Data Exchange (ETDEWEB)

    Efstathopoulos, Efstathios P [2nd Department of Radiology, University of Athens, 20 Papadiamantopoulou Str., 11828, Athens (Greece); Makrygiannis, Stamatis S [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece); Kottou, Sofia [Department of Medical Physics, University of Athens, 3 Mikras Asias Str., Athens (Greece); Karvouni, Evangelia [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece); Giazitzoglou, Eleftherios [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece); Korovesis, Socrates [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece); Tzanalaridou, Efthalia [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece); Raptou, Panagiota D [Department of Medical Physics, KAT Hospital, Kifissia, Athens (Greece); Katritsis, Demosthenes G [Department of Cardiology, Athens Euroclinic, 9 Athanasiadou Str., 115 21 Athens (Greece)

    2003-09-21

    Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 {+-} 9 Gy cm{sup 2}. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 {+-} 30 Gy cm{sup 2}, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y{sup -1} for the primary operator, and 0.03-0.04 mSv y{sup -1} for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

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

    International Nuclear Information System (INIS)

    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

  11. Microfocal angiography of the pulmonary vasculature

    Science.gov (United States)

    Clough, Anne V.; Haworth, Steven T.; Roerig, David T.; Linehan, John H.; Dawson, Christopher A.

    1998-07-01

    X-ray microfocal angiography provides a means of assessing regional microvascular perfusion parameters using residue detection of vascular indicators. As an application of this methodology, we studied the effects of alveolar hypoxia, a pulmonary vasoconstrictor, on the pulmonary microcirculation to determine changes in regional blood mean transit time, volume and flow between control and hypoxic conditions. Video x-ray images of a dog lung were acquired as a bolus of radiopaque contrast medium passed through the lobar vasculature. X-ray time-absorbance curves were acquired from arterial and microvascular regions-of-interest during both control and hypoxic alveolar gas conditions. A mathematical model based on indicator-dilution theory applied to image residue curves was applied to the data to determine changes in microvascular perfusion parameters. Sensitivity of the model parameters to the model assumptions was analyzed. Generally, the model parameter describing regional microvascular volume, corresponding to area under the microvascular absorbance curve, was the most robust. The results of the model analysis applied to the experimental data suggest a significant decrease in microvascular volume with hypoxia. However, additional model assumptions concerning the flow kinematics within the capillary bed may be required for assessing changes in regional microvascular flow and mean transit time from image residue data.

  12. Coherent bremsstrahlung used for digital subtraction angiography

    Science.gov (United States)

    Überall, Herbert

    2007-05-01

    Digital subtraction angiography (DSA), also known as Dichromography, using synchrotron radiation beams has been developed at Stanford University (R. Hofstadter) and was subsequently taken over at the Brookhaven Synchrotron and later at Hamburg (HASYLAB) [see, e.g., W.R. Dix, Physik in unserer Zeit. 30 (1999) 160]. The imaging of coronary arteries is carried out with an iodine-based contrast agent which need not be injected into the heart. The radiation must be monochromatized and is applied above and below the K-edge of iodine (33.16 keV), with a subsequent digital subtraction of the two images. Monochromatization of the synchrotron radiation causes a loss of intensity of 10 -3. We propose instead the use of coherent bremsstrahlung [see, e.g., A.W. Saenz and H. Uberall, Phys. Rev. B25 (1982) 448] which is inherently monochromatic, furnishing a flux of 10 12 photon/sec. This requires a 10-20 MeV electron linac which can be obtained by many larger hospitals, eliminating the scheduling problems present at synchrotrons. The large, broad incoherent bremsstrahlung background underlying the monochromatic spike would lead to inadmissible overexposure of the patient. This problem can be solved with the use of Kumakhov's capillary optics [see e.g., S.B.Dabagov, Physics-Uspekhi 46 (2003) 1053]: the low-energy spiked radiation can be deflected towards the patient, while the higher energy incoherent background continues forward, avoiding the patient who is placed several meters from the source.

  13. CT Angiography of the Coronary Arteries

    Directory of Open Access Journals (Sweden)

    H.Ghanaati

    2005-08-01

    Full Text Available Introduction & Background: Cardiac imaging is currently one the most rapidly advancing fields in clinical cardiology. Continuing technical innovations are expanding the applicability and usefulness of non-invasive imaging modalities such as ultrasound, nuclear imaging, positron emis-sion tomography Magnetic Resonance Imaging and most recently computed tomography (CT. In 1998, the 4-slice spiral CT scanners were introduced with a rotation time of 500ms a collimated detector width varying from 0.5 to 1.25mm. In 2002, the 16-slice spiral CT scanners were first used for coronary imag-ing. The rotation time and some of these scanners is now less than 400ms, the slice thickness varies be-tween 0.5 and 0.75mm, and a complete cardiac scan can be performed in less than 20s. In 2004, 64-slice spiral CT released into the market. Imaging of the heart requires acquisition or image reconstruction that is synchronized to the motion of the heart. Nie-man et al, irrespectively of the image quality, evalu-ated all branches with a minimal luminal diameter of 2.0mm and sensitivity and specificity of 95% and 86% respectively in comparison to angiography.

  14. Visualizing statistical models and concepts

    CERN Document Server

    Farebrother, RW

    2002-01-01

    Examines classic algorithms, geometric diagrams, and mechanical principles for enhancing visualization of statistical estimation procedures and mathematical concepts in physics, engineering, and computer programming.

  15. When is rotational angiography superior to conventional single‐plane angiography for planning coronary angioplasty?

    Science.gov (United States)

    Taylor, Jane; Boutong, Sara; Brett, Sarah; Louis, Amal; Heppenstall, James; Morton, Allison C.; Gunn, Julian P.

    2015-01-01

    Objectives To investigate the value of rotational coronary angiography (RoCA) in the context of percutaneous coronary intervention (PCI) planning. Background As a diagnostic tool, RoCA is associated with decreased patient irradiation and contrast use compared with conventional coronary angiography (CA) and provides superior appreciation of three‐dimensional anatomy. However, its value in PCI remains unknown. Methods We studied stable coronary artery disease assessment and PCI planning by interventional cardiologists. Patients underwent either RoCA or conventional CA pre‐PCI for planning. These were compared with the referral CA (all conventional) in terms of quantitative lesion assessment and operator confidence. An independent panel reanalyzed all parameters. Results Six operators performed 127 procedures (60 RoCA, 60 conventional CA, and 7 crossed‐over) and assessed 212 lesions. RoCA was associated with a reduction in the number of lesions judged to involve a bifurcation (23 vs. 30 lesions, P RoCA improved confidence assessing lesion length (P = 0.01), percentage stenosis (P = 0.02), tortuosity (P RoCA augments quantitative lesion assessment, enhances confidence in the assessment of coronary artery disease and the precise details of the proposed procedure, but does not affect X‐ray dose, contrast agent volume, or procedure duration. © 2015 Wiley Periodicals, Inc. PMID:26012725

  16. Pre-chemotherapy values for left and right ventricular volumes and ejection fraction by gated tomographic radionuclide angiography using a cadmium-zinc-telluride detector gamma camera

    DEFF Research Database (Denmark)

    Haarmark, Christian; Haase, Christine; Jensen, Maria Maj;

    2016-01-01

    BACKGROUND: Estimation of left ventricular ejection fraction (LVEF) using equilibrium radionuclide angiography is an established method for assessment of left ventricular function. The purpose of this study was to establish normative data on left and right ventricular volumes and ejection fraction...... age and both left and right ventricular volumes in women (r = -0.4, P cancer patients without other known cardiopulmonary...

  17. Role of multi-slice CT coronary angiography in evaluating the different patterns of coronary artery disease in patients with unstable angina

    Directory of Open Access Journals (Sweden)

    Gamal Eldine M. Niazi

    2015-09-01

    Conclusion: Non-invasive multi-slice CT coronary angiography is a reliable technique of high ability to detect coronary artery disease and estimate the degree of obstruction, number of affected arteries and the pattern of their affection and can be used in workup in patients with unstable angina.

  18. Characterization of rat model of acute anterior uveitis using optical coherence tomography angiography

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-03-01

    Uveitis, or ocular inflammation, is a cause of severe visual impairment. Rodent models of uveitis are powerful tools used to investigate the pathological mechanisms of ocular inflammation and to study the efficacy of new therapies prior to human testing. In this paper, we report the utility of spectral-domain optical coherence tomography (SD-OCT) angiography in characterizing the inflammatory changes induced in the anterior segment of a rat model of uveitis. Acute anterior uveitis (AAU) was induced in two rats by intravitreal injection of a killed mycobacterial extract. One of them received a concurrent periocular injection of steroids to model a treatment effect. OCT imaging was performed prior to inflammation induction on day 0 (baseline), and 2 days post-injection (peak inflammation). Baseline and inflamed images were compared. OCT angiography identified swelling of the cornea, inflammatory cells in the anterior and posterior chambers, a fibrinous papillary membrane, and dilation of iris vessels in the inflamed eyes when compared to baseline images. Steroid treatment was shown to prevent the changes associated with inflammation. This is a novel application of anterior OCT imaging in animal models of uveitis, and provides a high resolution, in vivo assay for detecting and quantifying ocular inflammation and the response to new therapies.

  19. Intravenous coronary angiography utilizing K-emission and bremsstrahlung X-rays produced by electron bombardment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with synchrotron radiation at SSRL and NSLS have shown that such an intravenous angiography procedure would be possible with an intense source of monochromatic X-rays. Because of the high cost of an electron synchrotron, theoretical analysis and experiments using inanimate phantoms has been undertaken to demonstrate the feasibility of using the spectrum produced by two appropriately chosen anode materials when bombarded with electrons in the 100--500 keV energy range for angiography. By using the X-rays emitted at 120{degree} to the incident electron direction, about 20--30% of the X-ray intensity would be due to K-emission lines. Calculations using the TIGERP Monte Carlo Code, have shown that high quality angiograms of human coronary arteries should be possible with a contrast agent containing ytterbium, if an electron beam pulses of 16 kJ were used for each anode target. The experimental program supported in part by the DOE has consisted of these theoretical calculations and experiments at the Dynamitron Electron Accelerator Facility at BNL.

  20. Coexistent coronary artery disease or myocardial bridging in patients with hypertrophic cardiomyopathy using coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hwan; Chun, Eun Ju; Kim, Yeo Koon; Yoo, Jin Young; Choi, Sang Il; Choi, Dong Ju [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-07-15

    To evaluate the prevalence of coexistent coronary artery disease (CAD) or myocardial bridging (MB) in patients with hypertrophic cardiomyopathy (HCM) using coronary CT angiography (CCTA) and assess the role of CCTA. The prevalence of obstructive CAD (> 50% luminal reduction) and MB (partial and full encasement) were assessed in 150 patients with HCM diagnosed by clinical findings, electrocardiography, and echocardiography of 19588 consecutive patients who underwent CCTA for suspected CAD. The overall feasibility of coronary artery visualization was 98.9% with CCTA. In patients with HCM, the prevalence of obstructive CAD and MB (14.7% partial and 28.0% full encasement) were 23.3% and 42.7%, respectively. Age, hypertension, family history of premature CAD, Framingham risk score and severe chest pain were associated with CAD, whereas male gender and septal type were associated with MB (all p < 0.05). In comparison to invasive coronary angiography (n = 37), the diagnostic accuracy of CCTA for the detection of CAD and full encasement MB was 89.2% and 86.5%, respectively. One-quarter of patients with HCM had coexistent obstructive CAD or full encasement MB. CCTA can be a feasible and accurate noninvasive imaging modality for the detection of CAD and MB in patients with HCM.

  1. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration

    Science.gov (United States)

    Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-03-01

    Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.

  2. A feasibility study for compressed sensing combined phase contrast MR angiography reconstruction

    Science.gov (United States)

    Lee, Dong-Hoon; Hong, Cheol-Pyo; Lee, Man-Woo; Han, Bong-Soo

    2012-02-01

    Phase contrast magnetic resonance angiography (PC MRA) is a technique for flow velocity measurement and vessels visualization, simultaneously. The PC MRA takes long scan time because each flow encoding gradients which are composed bipolar gradient type need to reconstruct the angiography image. Moreover, it takes more image acquisition time when we use the PC MRA at the low-tesla MRI system. In this study, we studied and evaluation of feasibility for CS MRI reconstruction combined PC MRA which data acquired by low-tesla MRI system. We used non-linear reconstruction algorithm which named Bregman iteration for CS image reconstruction and validate the usefulness of CS combined PC MRA reconstruction technique. The results of CS reconstructed PC MRA images provide similar level of image quality between fully sampled reconstruction data and sparse sampled reconstruction using CS technique. Although our results used half of sampling ratio and do not used specification hardware device or performance which are improving the temporal resolution of MR image acquisition such as parallel imaging reconstruction using phased array coil or non-cartesian trajectory, we think that CS combined PC MRA technique will be helpful to increase the temporal resolution and at low-tesla MRI system.

  3. Retinal angiography with real-time speckle variance optical coherence tomography.

    Science.gov (United States)

    Xu, Jing; Han, Sherry; Balaratnasingam, Chandrakumar; Mammo, Zaid; Wong, Kevin S K; Lee, Sieun; Cua, Michelle; Young, Mei; Kirker, Andrew; Albiani, David; Forooghian, Farzin; Mackenzie, Paul; Merkur, Andrew; Yu, Dao-Yi; Sarunic, Marinko V

    2015-10-01

    This report describes a novel, non-invasive and label-free optical imaging technique, speckle variance optical coherence tomography (svOCT), for visualising blood flow within human retinal capillary networks. This imaging system uses a custom-built swept source OCT system operating at a line rate of 100 kHz. Real-time processing and visualisation is implemented on a consumer grade graphics processing unit. To investigate the quality of microvascular detail acquired with this device we compared images of human capillary networks acquired with svOCT and fluorescein angiography. We found that the density of capillary microvasculature acquired with this svOCT device was visibly greater than fluorescein angiography. We also found that this svOCT device had the capacity to generate en face images of distinct capillary networks that are morphologically comparable with previously published histological studies. Finally, we found that this svOCT device has the ability to non-invasively illustrate the common manifestations of diabetic retinopathy and retinal vascular occlusion. The results of this study suggest that graphics processing unit accelerated svOCT has the potential to non-invasively provide useful quantitative information about human retinal capillary networks. Therefore svOCT may have clinical and research applications for the management of retinal microvascular diseases, which are a major cause of visual morbidity worldwide. PMID:25733527

  4. Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography

    Science.gov (United States)

    Miwa, Yuko; Murakami, Tomoaki; Suzuma, Kiyoshi; Uji, Akihito; Yoshitake, Shin; Fujimoto, Masahiro; Yoshitake, Tatsuya; Tamura, Yukino; Yoshimura, Nagahisa

    2016-01-01

    The decorrelation signals in optical coherence tomography angiography (OCTA) are derived from the flow of erythrocytes and concomitantly delineate the retinal vasculature. We compared the structural and functional characteristics of vascular lesions visualized in fluorescein angiography (FA), OCTA, and en-face OCT images in 53 eyes (28 patients) with diabetic retinopathy (DR). The foveal avascular zone (FAZ) areas in OCTA images in the superficial layer almost corresponded to those in FA images. The FAZ areas in the en-face OCT images in the superficial layer were smaller than those in the FA images and correlated with each other, which agreed with the finding that en-face OCT images often delineated the vascular structure in the nonperfused areas in FA images. Microaneurysms appeared as fusiform, saccular, or coiled capillaries in OCTA images and ringed, round, or oval hyperreflective lesions in en-face OCT images. OCTA and en-face OCT images detected 41.0 ± 16.1% and 40.1 ± 18.6%, respectively, of microaneurysms in FA images, although both depicted only 13.9 ± 16.4%. The number of microaneurysms in FA images was correlated with that in OCTA and en-face OCT images. Comparisons of these modalities showed the associations and dissociations between blood flow and vascular structures, which improves the understanding of the pathogenesis of DR. PMID:27350562

  5. Characteristics of Indocyanine Green Angiography in Exudative Age—related Macular Degeneration

    Institute of Scientific and Technical Information of China (English)

    WuDZ; WenF

    1999-01-01

    Objective:To observe the characteristics of indocyanine green angiography(ICGA)in exudative age-related macular degeneration(AMD).Methods:Thirty-one cases(39 eyes)were diagnosed as exudative AMD by ocular examination,fundus color photography,fundus fluorescein angiography(FFA)and ICGA.Their ages ranged from 50 to 82 years and visual acuities from FC/30cm to 0.7.We analyzed and compared the characteristics of ICGA and FFA in these patients.Results:of 26 eyes with ccult choroidal neovascularization (CNV)by FFA,15(57.7%)had classic CNV by ICGA.Of 4 eyes with serous retinal pigment epithelial detachment(PED)without CNV by FFA,1 had serous PED with classic CNV by ICGA.The hyperfluorescence of the scar staining was detecfed by ICGA.Conclusion:ICGA adds clinically useful information and is an important adjunct in the evaluation,classification,and laser treatment of patients with occult CNV in AMD.

  6. Multidetector-Row CT Angiography of Cerebral Vasospasm after Aneurysmal Subarachnoid Hemorrhage: Comparison of Bone Subtraction and Standard CT Angiography with Digital Subtraction Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Hee; You, Jin Jong; Choi, Ho Cheol; Kim, Ji Eun [Dept. of Radiology, Gyeongsang National University Hospital, Jinju (Korea, Republic of); Choi, Dae Seob [Gyeongsang Institue of Health Science, Gyeongsang National University School of Medicine, Jinju (Korea, Republic of); Ryoo, Jae Wook [Dept. of Radiology, Samsung Seoul Hospital, Seoul (Korea, Republic of)

    2011-10-15

    To evaluate the usefulness of multidetector-row CT angiography (MDCTA) for the diagnosis of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) by comparison of digital subtraction angiography (DSA) and to compare the bone subtraction CT angiography (BS-CTA) and standard CT angiography (S-CTA). Thirty-three patients who were treated with intraarterial nimodipine infusion for the cerebral vasospasm after aneurysmal SAH were evaluated with MDCTA and DSA. BS-CTA images were reconstructed from the S-CTA and unenhanced CT source images. A total of 207 vascular segments were evaluated. A four-step scale for the degree of stenosis was applied for each segment. With DSA as the standard images, BS-CTA and S-CTA images were comparied. On DSA, 56 segments (27%) presented vasospasm. Concordance between the DSA and S-CTA and between DSA and BS-CTA were 94.7% and 82.1%, respectively. Overestimation for the degree of stenosis was shown in 37 segments on BS-CTA and in 8 segments on S-CTA, but underestimated segments were only shown on S-CTA (n = 4). MDCTA with standard technique seems to be a useful imaging tool for the evaluation of the cerebral vasospasm after aneurysmal SAH. However, BS-CTA is not needed because of additional radiation and overestimation of the degree of stenosis.

  7. Gadolinium-enhanced magnetic resonance angiography of the abdominal vessels

    International Nuclear Information System (INIS)

    Contrast enhanced (CE) magnetic resonance angiography (MRA) provides high resolution angiograms within 20-40 sec. The technique is based on the acquisition of heavily T1-weighted threedimensional (3D) gradient-echo data sets (FISP) with ultrashort echo-(<2 ms) and repetition times (<5 ms) during the arterial phase of an intravenously injected bolus of a T1-shortening agent such as Gd-DTPA. For MR-angiography of abdominal vessels CE-MRA is better suited than 'time-of-flight' (TOF) and phase-contrast (PC) MRA because motional artifacts can be obviated with breath-held acquisitions. We have optimised the technique and evaluated its potential for angiography of the abdominal aorta and its branches as well as the portal vein and its tributaries. Whilst CE-MRA provides reliable diagnostic accuracy in the aorta and the proximal sections of its branches, small peripheral arteries cannot be assessed accurately. The portal vein and its tributaries can often be depicted better with CE-MRA than with conventional angiography but, like conventional angiography, CE-MRA is hampered by slow and reversed flow, conditions under which TOF or 'true FISP' MRA may perform bst. We have also investigated FLASH-echo-planar imaging (EPI) hybrid techniques, a further technical development which due to shorter acquisition times of 12-15 sec. allows semi-dynamic imaging of the arterial and venous phase and provide better vessel contrast due to the use of fat-suppression. (orig.)

  8. Patient radiation exposure during coronary angiography and intervention

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, S.G.; Persliden, J. [Univ. Hospital, Linkoeping (Sweden). Dept. of Thoracic Radiology

    2000-03-01

    Purpose: To prospectively register fluoroscopic and cine times in a random fashion, and to measure patient radiation exposure from routine coronary angiography and coronary balloon angioplasty. We also evaluated an optional dose reduction system used during interventions. Material and methods: The incident radiation to the patient was measured as kerma area product (KAP) in Gycm{sup 2}, obtained from an ionisation chamber mounted on the undercouch tube during 65 coronary angiography procedures and another 53 percutaneous transluminal coronary angioplasties, mostly directly following complete coronary angiography. Results and conclusion: The values from coronary angiography were comparable to other reports with a mean fluoroscopic time of 4.4 min and a mean KAP value of 62.6 Gy/cm{sup 2}. The corresponding figures from coronary balloon angioplasty without stenting were lower than otherwise reported, with 8.2 min and 47.9 Gycm{sup 2}, respectively. The use of coronary stents did prolong the mean fluoroscopic time (10.5 min) but did not significantlyenhance the patient mean radiation dose (51.4 Gycm{sup 2}). The dose reduction technique resulted in a significant KAP value reduction of 57%. In conclusion, with regard to radiation exposure, coronary angiography and balloon angioplasty are considered safe procedures.

  9. Radiolucent retractor for operative coronary angiography.

    Science.gov (United States)

    Collins, J J

    1977-05-01

    A new retractor has been designed for sternal separation during cardiac operations. This retractor has the advantage of radiolucent blades that allow visualization of the entire heart by roentgenographic techniques without compromise of surgical exposure during the course of operation. The retractor also has swivel blades that provide excellent conformity to the sternal edges without pressure points, which tend to produce fractures.

  10. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    Directory of Open Access Journals (Sweden)

    Hongzhou Duan

    2016-01-01

    Full Text Available Introduction. Transient global amnesia (TGA following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360 or cardiac angiography (4 in 8817 and no case with TGA following peripheral angiography (0 in 7659. Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p=0.022. Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p=0.82 and different contrast agents (p=0.619. Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography.

  11. Dream recall and visual memory.

    Science.gov (United States)

    Schredl, M; Frauscher, S; Shendi, A

    1995-08-01

    The present study estimated correlations for 50 subjects among frequency of dream recall, length of dream report, and visual memory. Whereas the results confirmed the previously found relationship between frequency of dream recall and visual memory, influence of visual memory on length of dream report was not found. PMID:8532466

  12. 4D phase contrast flow imaging for in-stent flow visualization and assessment of stent patency in peripheral vascular stents – A phantom study

    International Nuclear Information System (INIS)

    Purpose: 4D phase contrast flow imaging is increasingly used to study the hemodynamics in various vascular territories and pathologies. The aim of this study was to assess the feasibility and validity of MRI based 4D phase contrast flow imaging for the evaluation of in-stent blood flow in 17 commonly used peripheral stents. Materials and methods: 17 different peripheral stents were implanted into a MR compatible flow phantom. In-stent visibility, maximal velocity and flow visualization were assessed and estimates of in-stent patency obtained from 4D phase contrast flow data sets were compared to a conventional 3D contrast-enhanced magnetic resonance angiography (CE-MRA) as well as 2D PC flow measurements. Results: In all but 3 of the tested stents time-resolved 3D particle traces could be visualized inside the stent lumen. Quality of 4D flow visualization and CE-MRA images depended on stent type and stent orientation relative to the magnetic field. Compared to the visible lumen area determined by 3D CE-MRA, estimates of lumen patency derived from 4D flow measurements were significantly higher and less dependent on stent type. A higher number of stents could be assessed for in-stent patency by 4D phase contrast flow imaging (n = 14) than by 2D phase contrast flow imaging (n = 10). Conclusions: 4D phase contrast flow imaging in peripheral vascular stents is feasible and appears advantageous over conventional 3D contrast-enhanced MR angiography and 2D phase contrast flow imaging. It allows for in-stent flow visualization and flow quantification with varying quality depending on stent type

  13. MR imaging, US, and angiography examinations in the NZW rabbit with high-cholesterol diet and mechanical injury

    International Nuclear Information System (INIS)

    This paper presents a study to determine the comparative accuracy of visualization of atherosclerotic plaque between MR imaging, US, angiography, and histopathologic examinations. Experiments were conducted with New Zealand white rabbits and concentrated on the abdominal aorta, bifurcation, and iliac arteries.Following baseline MR imaging, US, and angiographic examinations, the animals were entered into protocols to produce atherosclerosis, with a combination of mechanical injury and Purina high-cholesterol diet. The diet, which includes corn oil, molasses, cholesterol, and Purina rabbit show, raised the cholesterol level to 700 mg/mL within 5 weeks

  14. CT angiography versus intraarterial DSA in abdominal aortic aneurysms; CT-Angiographie versus intraarterielle DSA bei Bauchaortenaneurysmen

    Energy Technology Data Exchange (ETDEWEB)

    Rieker, O. [Klinik fuer Radiologie, Johannes-Gutenberg-Universitaet, Mainz (Germany); Dueber, C. [Klinik fuer Radiologie, Johannes-Gutenberg-Universitaet, Mainz (Germany); Schmiedt, W. [Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Johannes-Gutenberg-Universitaet, Mainz (Germany); Neufang, A. [Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Johannes-Gutenberg-Universitaet, Mainz (Germany); Pittow, M. [Klinik fuer Radiologie, Johannes-Gutenberg-Universitaet, Mainz (Germany); Schweden, F. [Klinik fuer Radiologie, Johannes-Gutenberg-Universitaet, Mainz (Germany)

    1996-07-01

    To evaluate if CT angiography is able to image all features necessary for the preoperative planning of abdominal aortic aneurysms (accessory renal arteries, stenoses or occlusions of renal and iliac arteries, patency of inferior mesentric artery). CT angiography and DSA were performed on 27 patients with abdominal aortic aneurysms. CT angiography was performed using a protocol that covered the abdominal aorta and the pelvic arteries with a single spiral acquisition (contrast dose: 150 ml, collimation: 5 mm, table feed: 7.5 mm/s, increment of reconstruction: 2 mm). Maximum intensity projections (MIP) and axial scans were compared with the results of intraarterial DSA. Using axial scans and subvolume MIP, CTA accurately defined 7/8 accessory renal arteries, 13/13 occlusions and 9/12 high grade stenoses of renal and pelvic arteries. High-grade stenoses of the iliac arteries were underestimated in two cases and overlooked in one case. CT angiography was superior to DSA in imaging the inferior mesenteric artery. CT angiography precisely diagnosed 33 aneurysms of the iliac, renal and coeliac arteries. CT angiography using a single administration of intravenous contrast may replace preoperative DSA in most cases of abdominal aortic aneurysm. (orig.) [Deutsch] Ziel dieser Studie war es zu pruefen, ob mit der CT-Angiographie die fuer die praeoperative Planung von Bauchaortenaneurysmen relevanten Gefaessveraenderungen darstelbar sind (Akzessorische Nierenarterien, Nierenarterienstenosen, A. mesenterica inferior, Beckenarterien). Die CT-Angiographien wurden mit einem Protokoll durchgefuehrt, das die Bauchaorta und die Beckenarterien bis zur Leiste mit einer einzigen Spiralakquisition erfasst (150 ml Kontrastmittel, Kollimation: 5 mm, Tischvorschub: 7,5 mm/s, Rekonstruktionsintervall: 2 mm). Die Befunde aus Maximum-Intensitaets-Projektionen (MIP) und den axialen Schnittbildern wurden mit den Befunden der intraarteriellen DSA bei 27 Patienten verglichen. Bei Hinzuziehung von

  15. MR angiography of the central nervous system in pediatric patients

    International Nuclear Information System (INIS)

    This paper defines the role of both time-of-flight (TOF) and phase-contrast MR angiography in pediatric neuroimaging. MR angiographic techniques included two- and three-dimensional TOF and two- and three-dimensional phase contrast MR angiography in 30 patients. Reprojections were done with a maximum-intensity-pixel algorithm. MR angiograms were reviewed retrospectively with spin-echo images (10 cases) and/or conventional angiograms (20 cases). MR angiography provided additional information compared with spin-echo imaging in cases of sinus thrombosis (n = 5), arterial thrombosis (n = 2), arterial stenosis (n = 5), aneurysm evaluation (n = 3), vascular pathology exclusion (n = 5) and preoperative cortical venous mapping (n = 7). Stationary tissue signal suppression was better achieved with two-dimensional than with three-dimensional TOF images. Signal shine through in two cases of hemorrhage created pitfalls in interpreting the flow on TOF images

  16. Multidetector CT angiography of renal vasculature: normal anatomy and variants

    Energy Technology Data Exchange (ETDEWEB)

    Tuerkvatan, Aysel; Oezdemir, Mustafa; Cumhur, Turhan; Oelcer, Tuelay [Tuerkiye Yueksek ihtisas Hospital, Department of Radiology, Sihhiye, Ankara (Turkey)

    2009-01-15

    Knowledge of the variations in renal vascular anatomy is important before laparoscopic donor or partial nephrectomy and vascular reconstruction for renal artery stenosis or abdominal aortic aneurysm. Recently, multidetector computed tomographic (MDCT) angiography has become a principal imaging investigation for assessment of the renal vasculature and has challenged the role of conventional angiography. It is an excellent imaging technique because it is a fast and non-invasive tool that provides highly accurate and detailed evaluation of normal renal vascular anatomy and variants. The number, size and course of the renal arteries and veins are easily identified by MDCT angiography. The purpose of this pictorial essay is to illustrate MDCT angiographic appearance of normal anatomy and common variants of the renal vasculature. (orig.)

  17. Fractional flow reserve versus angiography for guiding percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Tonino, Pim A L; De Bruyne, Bernard; Pijls, Nico H J;

    2009-01-01

    BACKGROUND: In patients with multivessel coronary artery disease who are undergoing percutaneous coronary intervention (PCI), coronary angiography is the standard method for guiding the placement of the stent. It is unclear whether routine measurement of fractional flow reserve (FFR; the ratio...... of maximal blood flow in a stenotic artery to normal maximal flow), in addition to angiography, improves outcomes. METHODS: In 20 medical centers in the United States and Europe, we randomly assigned 1005 patients with multivessel coronary artery disease to undergo PCI with implantation of drug...... in the angiography group were free from angina at 1 year, as compared with 81% of patients in the FFR group (P=0.20). CONCLUSIONS: Routine measurement of FFR in patients with multivessel coronary artery disease who are undergoing PCI with drug-eluting stents significantly reduces the rate of the composite end point...

  18. Pseudoaneurysm after pancreatoduodenectomy: diagnosis and embolization on angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jun Yong [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of); Lee, Sang Hyun; Kim, Sam Soo; Han, Heon; Chung, Hye Won [Seoul City Boramae Hospital, Seoul (Korea, Republic of); Youn, Byung Jae; Han, Joon Koo; Choi, Byung Ihn; Chung, Jin Wook; Park, Jae Hyung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-08-01

    To evaluate the efficacy of angiography in the diagnosis and treatment of pseudoaneurysm manifesting arterial hemorrhage as a significant complication following pancreatoduodenectomy. For 51 months, of a total of 298 patients who had undergone pancreatoduodenectomy, 19 patients (6.4%) developed clinically significant hemorrhage and nine patients proved to have a pseudoaneurysm of angiography. These nine patients (3.0%) were managed by transcatheter arterial embolization. We analyzed clinical feature, angiography findings and hemostatic effect of embolization retrospectively. In nine patients (3.0%), pseudoaneurysm was diagnosed on angiography (common hepatic artery in four, gastroduodenal artery in three, proper hepatic artery in one, and left gastroepoploic artery in on patient). The size ranged from 0.3 cm to 6.5 cm (mean 1.9 cm). And extravasation was noted in five patients (55.6%). The remained ten patients showed no evidence of bleeding on angiography. Those who manifested as early bleeding (within two weeks) or delayed bleeding ( later than two weeks) were five and four patients respectively. Before the onset of major bleeding, among the nine pseudoaneurysm patients, seven patients (77.8%) had experienced percutaneous drainage due to intra-abdominal fluid collection with or without abscess resulting from anastomotic leak, and all nine patients had preliminary minor bleeding. The angiogram demonstrated an exact site of bleeding as a pseucoaneurysm followed by transcatheter arterial embolization (microcoil in eight patients, gelfoam in one) and achieved complete hemostasis yielding a success rate of 100%. Overall, no patients experienced complications related directly to the transcatheter arterial embolization technique. During the follow-up period (72-1, 336days, mean 640), no recurrence of bleeding was note. Although pseudoaneurysm is a rare complication, it is important as a cause of hemorrhage after pancreatoduodenectomy. Angiography followed by

  19. Wounded penetrating to neck: Angiotomography helical vs conventional Angiography

    International Nuclear Information System (INIS)

    Purpose: to determine the diagnostic potential of helical CT angiography (HCTA) in the assessment of arterial injuries resulting from penetrating neck trauma. Materials and methods: forty-seven adult patients with penetrating neck trauma who were referred for angiographic evaluation of suspected arterial injuries were included in the study. All patients underwent both conventional angiography and HCTA within 1 hour, our protocol included a 100 cc nonionic contrast bolus automatically injected at 4.5 cc/sec, with 11 sec scan delay. Scan parameters were: 120 kV, 200 mAs, slice thickness 3 mm and table speed 4 mm/sec. the volumetric data set was reconstructed retrospectively at 1 mm intervals. Three-dimensional and two-dimensional reconstructions were performed at a separate workstation. Two radiologists who were blinded to clinical and angiographic data interpreted the images. HCTA findings were compared with those of conventional angiography and surgery. Results: eight patients (17%) had carotid artery injuries: internal carotid artery occlusion (n=2), arteriovenous fistula with associated carotid pseudoaneurysm (n=1), arteriovenous fistula with vertebral artery pseudoanurysm (n=2) and common carotid pseudoaneurysm (n=2). seven of these arterial injuries were demonstrated by both HCTA and angiography, there was one false negative case. in the remaining 39 patients, HCTA and conventional angiography showed normal carotid arteries; therefore sensitivity was 87.5%, specificity and positive predictive value 100% and negative predictive value 97.5%. Conclusion: our initial experience indicates that helical CT angiography is an adequate non-invasive diagnostic method for the evaluation of patients with suspected arterial injuries resulting from penetrating trauma to the neck

  20. Optimization of Ecg Gating in Quantitative Femoral Angiography

    International Nuclear Information System (INIS)

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

  1. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  2. Evaluation of magnetic resonance angiography in detection of gastric varices

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Takahiro; Yamazaki, Katsu; Toyota, Jouji; Karino, Yoshiyasu; Ohmura, Takumi; Suga, Toshihiro [Sapporo Kosei General Hospital (Japan)

    1999-06-01

    We evaluated the detection of gastric varices, inflowing blood vessels to gastric varices, and outflowing blood vessels from gastric varices via magnetic resonance (MR) angiography in 31 patients with gastric varices. Twenty-four patients had F{sub 2} type varices and 7 had F{sub 3} type, classified according to the Japanese Research Society for Portal Hypertension. Seventeen patients had cardiofornical varices, and 14 had fundal varices. All patients were examined with an MR system operating at 1.5 T. MR angiography was performed using the two-dimensional time-of-flight method. With MR angiography, the imaging of gastric varices was clearly delineated in 28 of the 31 patients (90.3%). From the images of MR angiography, flow direction itself cannot be determined. The outflowing blood vessels of gastric varices were reported to be the gastro-renal shunt and the subphrenic vein, and angiographic findings have shown the inflowing blood vessels to be the left gastric vein (LGV), the short gastric vein (SGV), and the posterior gastric vein (PGV). In 25 of the 31 patients (80.7%), the outflowing blood vessels from gastric varices were detected (gastro-renal shunt in 24; subphrenic vein in 1). MR angiography provided clear images of the inflowing blood vessels to gastric varices in 18 of the 31 patients (58.1%). These inflowing vessels were categorized as SGV in 7 patients, LGV in 5, LGV and SGV in 4, and LGV and PGV in 2. We suggest that MR angiography be used as a routine method for detecting and diagnosing collateral veins in patients with gastric varices. (author)

  3. Multi-detector Computed Tomography Angiography of the Hepatic Artery in Liver Transplant Recipients

    Energy Technology Data Exchange (ETDEWEB)

    Boraschi, P.; Donati, F.; Cossu, M.C.; Gigoni, R.; Vignali, C.; Filipponi, F.; Bartolozzi, C.; Falaschi, F. [Pisa Univ. Hospital (Italy). 2nd Dept. of Radiology

    2005-08-01

    PURPOSE: To evaluate the ability of multi-detector row computed tomography angiography (CTA) in detecting hepatic artery complications in the follow-up of liver transplant patients, performing volume-rendering as reconstruction technique. MATERIAL AND METHODS: The anatomy of hepatic artery was studied in 27 liver transplant recipients with a four-row CT scanner using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 6-8 mm/s; spiral reconstruction time, 0.5 s; reconstruction interval, 0.5 mm; mAs, 160; kVp, 120. Before the study, the patients received 1000 ml of water as oral contrast agent to produce negative contrast in the stomach and the small bowel. A non-ionic contrast medium was infused intravenously at a rate of 5 ml/s with a bolus tracking system. Volume-rendering of hepatic artery was performed with the 3D Virtuoso software. RESULTS: The celiac trunk, the hepatic artery, and the right and left hepatic arteries were successfully displayed in high detail in all patients. Side branches, including small collaterals, and hepatic artery anastomosis could also be readily visualized. Volume-rendered CTA detected six hepatic artery stenoses, two hepatic artery thromboses, and two intrahepatic pseudoaneurysms. In two cases, CT detected hepatic artery stenosis with a diameter reduction of less than 50%, while digital subtraction angiography showed a normal artery. CONCLUSION: Volume-rendered multi-detector CTA is a promising non-invasive technique, since it allows images of high quality to be generated with excellent anatomical visualization of the hepatic artery and its complications in liver transplant recipients.

  4. Detection of viable myocardium using coronary angiography and ventriculography.

    Science.gov (United States)

    Conti, C Richard

    2002-08-01

    In 2002, coronary angiography is the only way to assess precisely the combination of proximal stenoses, distal target vessels, collaterals, microcirculation, and TIMI antegrade flow. At the time of coronary angiography, global LV function is best determined using biplane ventriculography in order to correlate wall motion with coronary stenoses, distal target vessels, microcirculation, collaterals, and antegrade TIMI flow. This can be done under resting conditions after nitrates or after postextrasystolic potentiation. The absolute diagnosis of viability can only be made retrospectively. Large areas of ischemic viable myocardium should improve contraction after revascularization, decrease symptoms, and prolong survival.

  5. A comparison of iopamidol and iohexol in cerebral angiography.

    Science.gov (United States)

    Pelz, D M; Fox, A J; Viñuela, F; Lylyk, P

    1988-01-01

    Iopamidol and iohexol, the new nonionic low-osmolality contrast agents, have both been shown to be safe, effective, and better tolerated than conventional ionic agents for cerebral angiography. In this randomized, double-blind study involving 40 patients, these two agents were compared for adverse effects, radiographic quality, and patient tolerance. No significant differences were observed in 220 injections. Because we found iopamidol and iohexol to be equally safe and effective for cerebral angiography, the choice of which contrast agent to use should be based on other considerations.

  6. Digital subtraction angiography in head and neck radiology

    Energy Technology Data Exchange (ETDEWEB)

    Carmody, R.F.; Seeger, J.F.; Smith, R.L.; Horsley, W.W.; Miller, R.W.

    1984-07-01

    Intravenous digital subtraction angiography (IVDSA) was used to evaluate 44 patients with suspected otolaryngologic abnormalities. Sixteen had IVDSA for pulsatile tinnitus or suspected glomus tumor of the petrous bone. Nine patients were evaluated because of pulsatile neck masses, and 12 others had suspected tumors of the neck, face, and paranasal sinuses. Seven had IVDSA following head and neck trauma. The technique of examination is described. The current indications of IVDSA in head and neck radiology are discussed. It is concluded that IVDSA is a suitable substitute for conventional angiography for many otolaryngologic conditions and, because of its safety, can be used more liberally.

  7. The Impact of Aromatherapy on the Anxiety of Patients Experiencing Coronary Angiography

    OpenAIRE

    Homeyra Tahmasbi; Ghahraman Mahmoodi; Vahid Mokhberi; Soghra Hassani; Homeyra Akbarzadeh; Niloofar Rahnamai

    2012-01-01

    Background: Anxiety among patients experiencing coronary angiography increases within invasive studies including angiography. Anxiety as an intensifier at cardiovascular reactions can endanger patients in angiography clinics. Studies indicate that lavendula spica L. inhalation can decrease anxiety. The purpose of this study is to determine the impact of aromatherapy on the anxiety level of patients experiencing coronary angiography. Materials and Methods: This research is a clinical trial st...

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

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To analyze the accuracy of computed tomography (CT) angiography in the diagnosis of acute gastrointestinal (GI) bleeding. METHODS: The MEDLINE, EMBASE, Cancerlit, Cochrane Library database, Sciencedirect, Springerlink and Scopus, from January 1995 to December 2009, were searched for studies evaluating the accuracy of CT angiography in diagnosing acute GI bleeding. Studies were included if the ycompared CT angiography to a reference standard of upper GI endoscopy, colonoscopy, angiography or surgery in ...

  9. CT angiography with three-dimensional techniques for the early diagnosis of intracranial aneurysms. Comparison with intra-arterial DSA and the surgical findings

    Energy Technology Data Exchange (ETDEWEB)

    Karamessini, Maria T.; Kagadis, George C.; Petsas, Theodore; Karnabatidis, Dimitrios; Konstantinou, Dimitrios; Sakellaropoulos, George C.; Nikiforidis, George C.; Siablis, Dimitrios E-mail: siablis@med.upatras.gr

    2004-03-01

    aneurysms, remain problematic. The delineating features of each aneurysm are better depicted with CTA due to 3D visualization. The use of digital subtraction angiography as a diagnostic tool can be limited in equivocal cases.

  10. Clinical application of magnetic resonance angiography for coronary arteries. Correlation with conventional angiography and evaluation of imaging time

    Energy Technology Data Exchange (ETDEWEB)

    Nitatori, Toshiaki; Hanaoka, Hideto; Yoshino, Ayako [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine] [and others

    1995-08-01

    Magnetic resonance angiography (MRA) of the coronary arteries is a particularly difficult task because of the small size of the vessels and cardio-respiratory motion. The authors describe a method of performing of ultrafast MRA of the coronary arteries with a standard MR system and body coil. Each image was obtained within a single breath hold by `segmented Turbo FLASH` sequences using an electro-cardiography gate. Clinical application was performed in 20 patients with ischemic heart disease, and a comparison was made with conventional coronary angiography. The imaging time was shortened significantly by our methods. The diagnosis was made by at least two different images to avoid false positives. The results indicated a good correlation between MRA and conventional angiography. (author).

  11. Optimal iodine dose for 3-dimensional multidetector-row CT angiography of the liver

    International Nuclear Information System (INIS)

    Purpose: To clarify the optimal iodine dose of contrast material for 3-dimensional multidetector-row CT angiography (3D-MDCTA) of the venous vasculature of the liver using volume rendering technique. Materials and methods: This study included 103 patients who were randomly assigned to 5 contrast-enhanced MDCT protocol groups with different body-weight-tailored doses of contrast material: 500, 600, 630, 650, and 700 mgI/kg body weight. The arterial, portal, and hepatic parenchymal phases were obtained to evaluate enhancement values of the aorta, portal vein, and hepatic vein. Visualization of the portal and hepatic veins on the volume-rendering images of 3D-MDCTA was evaluated using a 5-point grade. Dunnett's test was used to compare the mean enhancement value and mean grades of image quality (700 mgI/kg dose group was control). Results: The mean enhancement values of portal and hepatic vein in the group with 500 and 600 mgI/kg were significantly lower than those of the control group. During visual assessment, a significantly lower mean grades were observed in 500 mgI/kg groups for the portal vein, and 500 and 600 mgI/kg groups for hepatic vein. There were no significant intergroup differences in mean enhancement values and visual assessment among the groups using 630 mgI/kg or more. Conclusion: Iodine doses of 630 mgI/kg was recommended for 3D-MDCTA

  12. Coronary CT angiography: automatic cardiac-phase selection for image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Ruzsics, Balazs; Brothers, Robin L.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Gebregziabher, Mulugeta [Medical University of South Carolina, Department of Biostatistics, Bioinformatics, and Epidemiology, Charleston, SC (United States); Lee, Heon [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Seoul Medical Center, Department of Radiology, Seoul (Korea); Allmendinger, Thomas; Vogt, Sebastian [Siemens Medical Solutions, Division CT, Forchheim (Germany); Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Charleston, SC (United States)

    2009-08-15

    We evaluated an algorithm for automatic selection of the cardiac phase with the least motion for image reconstruction at coronary computed tomography (CT) angiography (CCTA). We analyzed data of 100 patients (49 female, mean age 59 years) who had undergone retrospectively ECG-gated CCTA. Two experienced observers visually identified the most suitable end-systolic and end-diastolic phases using a series of image reconstructions in 5% increments across the RR cycle. The same data were then reconstructed using an automatic phase finding algorithm based on a 4D weighting function of cardiac motion. On average, the algorithm determined the most suitable systolic reconstruction phase at 40.11{+-}6.29% RR compared with 40.07{+-}5.58% RR by the human observers (p=NS). The most suitable diastolic phase was found at 72.71{+-}7.37% RR by the automatic algorithm, compared with 76.43{+-}6.35% RR by the observers (p<0.05). No statistically significant difference was found between automatically and visually determined reconstruction phases regarding motion and stair-step artifacts in either systole or diastole (p>0.05). Thus, there appears to be no relevant difference between an automatic phase finding algorithm and visual selection by experienced observers for determining the phase with the least cardiac motion for CCTA image reconstruction. The use of automatic phase finding may therefore facilitate the performance of cardiac CT and reduce human error. (orig.)

  13. Visual agnosia.

    Science.gov (United States)

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  14. Comparison of visual scoring and quantitative planimetry methods for estimation of global infarct size on delayed enhanced cardiac MRI and validation with myocardial enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Mewton, Nathan, E-mail: nmewton@gmail.com [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France); Revel, Didier [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France); Bonnefoy, Eric [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); Ovize, Michel [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); INSERM Unite 886 (France); Croisille, Pierre [Hopital Cardiovasculaire Louis Pradel, 28, Avenue Doyen Lepine, 69677 Bron cedex, Hospices Civils de Lyon (France); CREATIS-LRMN (Centre de Recherche et d' Applications en Traitement de l' Image et du Signal), Universite Claude Bernard Lyon 1, UMR CNRS 5220, U 630 INSERM (France)

    2011-04-15

    Purpose: Although delayed enhanced CMR has become a reference method for infarct size quantification, there is no ideal method to quantify total infarct size in a routine clinical practice. In a prospective study we compared the performance and post-processing time of a global visual scoring method to standard quantitative planimetry and we compared both methods to the peak values of myocardial biomarkers. Materials and methods: This study had local ethics committee approval; all patients gave written informed consent. One hundred and three patients admitted with reperfused AMI to our intensive care unit had a complete CMR study with gadolinium-contrast injection 4 {+-} 2 days after admission. A global visual score was defined on a 17-segment model and compared with the quantitative planimetric evaluation of hyperenhancement. The peak values of serum Troponin I (TnI) and creatine kinase (CK) release were measured in each patient. Results: The mean percentage of total left ventricular myocardium with hyperenhancement determined by the quantitative planimetry method was (20.1 {+-} 14.6) with a range of 1-68%. There was an excellent correlation between quantitative planimetry and visual global scoring for the hyperenhancement extent's measurement (r = 0.94; y = 1.093x + 0.87; SEE = 1.2; P < 0.001) The Bland-Altman plot showed a good concordance between the two approaches (mean of the differences = 1.9% with a standard deviation of 4.7). Mean post-processing time for quantitative planimetry was significantly longer than visual scoring post-processing time (23.7 {+-} 5.7 min vs 5.0 {+-} 1.1 min respectively, P < 0.001). Correlation between peak CK and quantitative planimetry was r = 0.82 (P < 0.001) and r = 0.83 (P < 0.001) with visual global scoring. Correlation between peak Troponin I and quantitative planimetry was r = 0.86 (P < 0.001) and r = 0.85 (P < 0.001) with visual global scoring. Conclusion: A visual approach based on a 17-segment model allows a rapid

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

    Science.gov (United States)

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

    2014-01-01

    Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed. PMID:23746119

  16. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  17. The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy: technical note.

    Science.gov (United States)

    Kim, Kyongsong; Isu, Toyohiko; Chiba, Yasuhiro; Morimoto, Daijiro; Ohtsubo, Seiji; Kusano, Mitsuo; Kobayashi, Shiro; Morita, Akio

    2013-11-01

    Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery. Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment.

  18. The usefulness of ICG video angiography in the surgical treatment of superior cluneal nerve entrapment neuropathy: technical note.

    Science.gov (United States)

    Kim, Kyongsong; Isu, Toyohiko; Chiba, Yasuhiro; Morimoto, Daijiro; Ohtsubo, Seiji; Kusano, Mitsuo; Kobayashi, Shiro; Morita, Akio

    2013-11-01

    Superior cluneal nerve (SCN) entrapment neuropathy is a known cause of low back pain. Although surgical release at the entrapment point of the osteofibrous orifice is effective, intraoperative identification of the thin SCN in thick fat tissue and confirmation of sufficient decompression are difficult. Intraoperative indocyanine green video angiography (ICG-VA) is simple, clearly demonstrates the vascular flow dynamics, and provides real-time information on vascular patency and flow. The peripheral nerve is supplied from epineurial vessels around the nerve (vasa nervorum), and the authors now present the first ICG-VA documentation of the technique and usefulness of peripheral nerve neurolysis surgery to treat SCN entrapment neuropathy in 16 locally anesthetized patients. Clinical outcomes were assessed with the Roland-Morris Disability Questionnaire before surgery and at the latest follow-up after surgery. Indocyanine green video angiography was useful for identifying the SCN in fat tissue. It showed that the SCN penetrated and was entrapped by the thoracolumbar fascia through the orifice just before crossing over the iliac crest in all patients. The SCN was decompressed by dissection of the fascia from the orifice. Indocyanine green video angiography visualized the SCN and its termination at the entrapment point. After sufficient decompression, the SCN was clearly visualized on ICG-VA images. Low back pain improved significantly, from a preoperative Roland-Morris Questionnaire score of 13.8 to a postoperative score of 1.3 at the last follow-up visit (p < 0.05). The authors suggest that ICG-VA is useful for the inspection of peripheral nerves such as the SCN and helps to identify the SCN and to confirm sufficient decompression at surgery for SCN entrapment. PMID:24053371

  19. Value of abdominal angiography in Turner's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, A.; Castaneda-Zuniga, W.R.; Velasquez, G.; Zollikofer, C.; Amplatz, K.

    1981-01-01

    In patients with Turner's syndrome, there is a relatively high incidence of gastrointestinal bleeding due to telangiectasias of the intestine. Despite the importance of preoperative diagnosis of the lesion in planning surgical treatment. The related angiographic findings have never been reported. We have studied one patient in whom the diagnosis was established by preoperative angiography.

  20. Evaluation of angiography performed by radiographers and nurses

    International Nuclear Information System (INIS)

    AIM: To evaluate out-patient angiography performed by nurses and radiographers. MATERIALS AND METHODS: A protocol for out-patient angiography performed by nurses and radiographers was drawn up and approved by the Trust's Risk Management Committee. Following training, two experienced radiographers and one nurse undertook elective peripheral or renal angiography according to the protocol on 187 patients. Angiograms were performed using a 3F catheter introduced into the abdominal aorta from a femoral approach. Patients were discharged after 2 hours and contacted by telephone the following morning. RESULTS: No patient refused consent for the procedure. One hundred and seventy-two patients underwent successful catheterization without assistance from a radiologist. Radiologist assistance was required with femoral puncture or catheter/guidewire manipulation in 15 cases (8%). Images were considered diagnostic by the reporting radiologist in all but one case. This patient was recalled for further aortogram and pressure measurements. There was a single puncture site complication due to transient stenosis of the common femoral artery at the puncture site. This is thought to have been the result of subintimal injection of local anaesthetic, and it resolved spontaneously over 30 minutes. There were no delayed complications. CONCLUSION: Experienced nurses and radiographers can rapidly acquire the skills to perform diagnostic angiography safely and efficiently. Chalmers, N. et al. (2002)

  1. Preoperative CT angiography reduces surgery time in perforator flap reconstruction

    NARCIS (Netherlands)

    Smit, Jeroen M.; Dimopoulou, Angeliki; Liss, Anders G.; Zeebregts, Clark J.; Kildal, Morten; Whitaker, Iain S.; Magnusson, Anders; Acosta, Rafael

    2009-01-01

    The use of perforator flaps in breast reconstructions has increased considerably in the past decade. A disadvantage of the perforator flap is difficult dissection, which results in a longer procedure. During spring 2006, we introduced CT angiography (CTA) as part of the diagnostic work-up in perfora

  2. The value of abdominal angiography in Turner's syndrome

    International Nuclear Information System (INIS)

    In patients with Turner's syndrome, there is a relatively high incidence of gastrointestinal bleeding due to telangiectasias of the intestine. Despite the importance of preoperative diagnosis of the lesion in planning surgical treatment. The related angiographic findings have never been reported. We have studied one patient in whom the diagnosis was established by preoperative angiography. (orig.)

  3. Carotid stenosis degree in CT angiography: assessment based on luminal area versus luminal diameter measurements

    International Nuclear Information System (INIS)

    The aim of this study was to investigate CT angiography (CTA) luminal area measurements in the assessment of carotid artery stenosis compared with the current clinically used criteria based on lumen diameter measurements. Seventy-two vessels in 36 patients were evaluated by CTA and digital subtraction angiography (DSA). Two observers measured area and diameter stenosis degrees using automated 3D CTA analysis software. The ratio of the largest/smallest luminal diameter at the level of maximal stenosis (L/S ratio) was used to describe lumen morphology. Diagnostic agreement between CTA and DSA was calculated. For the assessment of area stenosis, interobserver and intraobserver correlation coefficients were 0.898 and 0.906 (p<0.001). The correlation coefficient between the diameter stenosis and area stenosis was lower in stenoses with extremely noncircular lumen (L/S ratio ≥1.5) (r=0.797, p<0.001) compared with stenoses with circular lumen (LS ratio <1.2) (r=0.978, p<0.001). Only satisfactory agreement (κ 0.54-0.77, p<0.001) was obtained between area stenosis on CTA and diameter stenosis on DSA. Assessment of stenosis degree with area measurements on 3D CTA proved to be reproducible. Area stenosis provides a less-severe estimate of the degree of carotid stenosis but might theoretically express the real hemodynamic significance of the lesion better than diameter stenosis, especially in stenoses with noncircular lumen. (orig.)

  4. Detection, grading and classification of coronary stenoses in computed tomography angiography.

    Science.gov (United States)

    Kelm, B Michael; Mittal, Sushil; Zheng, Yefeng; Tsymbal, Alexey; Bernhardt, Dominik; Vega-Higuera, Fernando; Zhou, S Kevin; Meer, Peter; Comaniciu, Dorin

    2011-01-01

    Recently conducted clinical studies prove the utility of Coronary Computed Tomography Angiography (CCTA) as a viable alternative to invasive angiography for the detection of Coronary Artery Disease (CAD). This has lead to the development of several algorithms for automatic detection and grading of coronary stenoses. However, most of these methods focus on detecting calcified plaques only. A few methods that can also detect and grade non-calcified plaques require substantial user involvement. In this paper, we propose a fast and fully automatic system that is capable of detecting, grading and classifying coronary stenoses in CCTA caused by all types of plaques. We propose a four-step approach including a learning-based centerline verification step and a lumen cross-section estimation step using random regression forests. We show state-of-the-art performance of our method in experiments conducted on a set of 229 CCTA volumes. With an average processing time of 1.8 seconds per case after centerline extraction, our method is significantly faster than competing approaches. PMID:22003680

  5. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  6. Case Report of Bullous Pemphigoid following Fundus Fluorescein Angiography

    Directory of Open Access Journals (Sweden)

    Goktug Demirci

    2010-05-01

    Full Text Available Purpose: To report a first case of bullous pemphigoid (BP following intravenous fluorescein for fundus angiography. Clinical Features: A 70-year-old male patient was admitted to the intensive care unit with BP and sepsis. He reported a history of fundus fluorescein angiography with a pre-diagnosis of senile macular degeneration 2 months prior to presentation. At that time, fluorescein extravasated at the antecubital region. Following the procedure, pruritus and erythema began at the wrists bilaterally, and quickly spread to the entire body. The patient also reported a history of allergy to human albumin solution (Plamasteril®; Abbott 15 years before, during bypass surgery. On dermatologic examination, erythematous patches were present on the scalp, chest and anogenital region. Vesicles and bullous lesions were present on upper and lower extremities. On day 2 of hospitalization, tense bullae appeared on the upper and lower extremities. The patient was treated with oral methylprednisolone 48 mg (Prednol®; Mustafa Nevzat, topical clobetasol dipropionate 0.05% cream (Dermovate®; Glaxo SmithKline, and topical 4% urea lotion (Excipial Lipo®; Orva for presumptive bullous pemphigoid. Skin punch biopsy provided tissue for histopathology, direct immunofluorescence examination, and salt extraction, which were all consistent with BP. After 1 month, the patient was transferred to the intensive care unit with sepsis secondary to urinary tract infection; he died 2 weeks later from sepsis and cardiac failure. Conclusions: To our knowledge, this is the first reported case of BP following fundus fluorescein angiography in a patient with known human albumin solution allergy. Consideration should be made to avoid fluorescein angiography, change administration route, or premedicate with antihistamines in patients with known human albumin solution allergy. The association between fundus fluorescein angiography and BP should be further investigated.

  7. Three-Dimensional Respiratory-Gated Coronary Mr Angiography with Reference to X-Ray Coronary Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ikonen, A. E. J.; Manninen, H. I.; Vainio, P.; Vanninen, R. L.; Matsi, P. J.; Soimakallio, S. [Kuopio Univ. Hospital (Finland). Dept. of Clinical Radiology; Hirvonen, T.P.J.; Hartikainen, J.E.K. [Kuopio Univ. Hospital (Finland). Dept. of Medicine

    2003-11-01

    Purpose: To assess the clinical value of three-dimensional coronary MR angiography (CMRA) in the detection of significant coronary artery stenosis using conventional X-ray angiography as the standard reference. Material and Methods: Sixty-nine patients underwent X-ray coronary angiography and CMRA because of suspected or previously diagnosed coronary artery disease. MRI was performed with a 1.5-T whole body imaging system using ECG-triggered 3D gradient echo sequence with retrospective navigator echo respiratory gating and fat suppression. Results: A total of 276 coronary artery segments were analyzed. The X-ray coronary angiography was normal in 22 patients. Significant proximal stenoses (exceeding 50%) or occlusions were present in 102 coronary artery segments. In all, 120 stenoses or occlusions were identified in CMRA. Sixteen percent of the coronary artery segments had to be excluded because of poor image quality. The overall sensitivity and specificity for MRA for identification of significant stenosis were 75% and 62%, respectively. CMRA correctly detected 89% of patients with at least one vessel disease, but 6 patients with coronary artery disease would have been missed. Conclusions: Because of the high data exclusion and false-negative case rate, CMRA with retrospective navigator echo triggering is at present not suitable as a clinical screening method in coronary artery disease.

  8. The Prognosis of Patients With Nonobstructive Coronary Artery Disease Versus Normal Arteries Determined by Invasive Coronary Angiography or Computed Tomography Coronary Angiography: A Systematic Review.

    Science.gov (United States)

    Huang, Fang-Yang; Huang, Bao-Tao; Lv, Wen-Yu; Liu, Wei; Peng, Yong; Xia, Tian-Li; Wang, Peng-Ju; Zuo, Zhi-Liang; Liu, Rui-Shuang; Zhang, Chen; Gui, Yi-Yue; Liao, Yan-Biao; Chen, Mao; Zhu, Ye

    2016-03-01

    Limited data exist regarding the outcomes of patients with nonobstructive coronary artery disease (CAD) detected by computed tomography coronary angiography (CTCA) or invasive coronary angiography (ICA). Our aim was to compare the prognosis of patients with nonobstructive coronary artery plaques with that of patients with entirely normal arteries. The MEDLINE, Cochrane Library, and Embase databases were searched. Studies comparing the prognosis of individuals with nonobstructive CAD versus normal coronary arteries detected by CTCA or ICA were included. The primary outcome was major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization due to unstable angina or revascularization. A fixed effects model was chosen to pool the estimates of odds ratios (ORs). Forty-eight studies with 64,905 individuals met the inclusion criteria. Patients in the nonobstructive CAD arm had a significantly higher risk of MACE compared to their counterparts in the normal artery arm (pooled OR, 3.17, 95% confidence interval, 2.77-3.63). When excluding revascularization as an endpoint, hard cardiac composite outcomes were also more frequent among patients with nonobstructive CAD (pooled OR, 2.10; 95%CI, 1.79-2.45). All subgroups (age, sex, follow-up duration, different outcomes, diagnostic modality, and CAD risk factor) consistently showed a poorer prognosis with nonobstructive CAD than with normal arteries. When dividing the studies into a CTCA and ICA group for further analysis based on the indications for diagnostic tests, we also found nonobstructive CAD to be associated with a higher risk of MACE in both stable and acute chest pain. Patients with nonobstructive CAD had a poorer prognosis compared with their counterparts with normal arteries.

  9. Effect of change in patient′s bed angles on pain after coronary angiography according to vital signals

    Directory of Open Access Journals (Sweden)

    Mohamad Amin Younessi Heravi

    2015-01-01

    Full Text Available Background: One of the most common and important diagnostic methods for the detection of heart diseases is coronary angiography. The aim of this study was to determine the optimum angle of the bed by using vital signals to optimize the patient′s position after the angiography. Materials and Methods: This study was a randomized clinical trial (RCT on participants after angiography who were divided into five groups. The first group was placed routinely in a supine position. In the other groups, all of the patients were placed in bed by angle 15°, 30°, 45°, and 60° upward. In each group, vital signals were measured that included blood pressure, percent of blood oxygen saturation, heart rate, respiratory rate, and temperature. All of measured data compared with the pain score has been achieved from numerical pain scale. The data were analyzed by descriptive statistics method, variance analysis, and post hoc tests in the Statistical Package for the Social Sciences (SPSS software, version 16. Estimation of the relationship was done by MATLAB version 2011. The level of significance was considered to be 0.05. Results: In various groups, there was no significance difference in demographic variables such as gender, age, height, and weight. The mean of pain score, heart rate, systolic blood pressure, and respiratory rate changed significantly (P 0.05. It showed linear changes between pain and systolic blood pressure, respiratory rate, and heart rate changes. A dramatic reduction was also seen in systolic blood pressure, respiratory rate, heart rate, and also pain at an angle of 45 ° . Conclusion: This study showed that, 45 ° was the best angle of the bed to optimize the patient′s position after the procedure, based on his/her vital signs and pain score. Thus, in order to relive pain, this change in bed angle is advised to be planned by postangiography nurses in patients after coronary angiography.

  10. Traffic Visualization

    DEFF Research Database (Denmark)

    Picozzi, Matteo; Verdezoto, Nervo; Pouke, Matti;

    2013-01-01

    In this paper, we present a space-time visualization to provide city's decision-makers the ability to analyse and uncover important "city events" in an understandable manner for city planning activities. An interactive Web mashup visualization is presented that integrates several visualization te...

  11. Clinical values of intraoperative indocyanine green fluorescence video angiography with Flow 800 software in cerebrovascular surgery

    Institute of Scientific and Technical Information of China (English)

    YE Xun; LIU Xing-ju; MA Li; LIU Ling-tong; WANG Wen-lei; WANG Shuo; CAO Yong

    2013-01-01

    Background Microscope-integrated near-infrared indocyanine green video angiography (ICG-VA) has been used in neurosurgery for a decade.This study aimed to assess the value of intraoperative indocyanine green (ICG) video angiography with Flow 800 software in cerebrovascular surgery and to discover its hemodynamic features and changes of cerebrovascular diseases during surgery.Methods A total of 87 patients who received ICG-VA during various surgical procedures were enrolled in this study.Among them,45 cases were cerebral aneurysms,25 were cerebral arteriovenous malformations (AVMs),and 17 were moyamoya disease (MMD).A surgical microscope integrating an infrared fluorescence module was used to confirm the residual aneurysms and blocking of perforating arteries in aneurysms.Feeder arteries,draining veins,and normal cortical vessels were identified by the time delay color mode of Flow 800 software.Hemodynamic parameters were recorded.All data were analyzed by SPSS version 18.0 (SPSS Inc.,USA).T-test was used to analyze the hemodynamic features of AVMs and MMDs,the influence on peripheral cortex after resection in AVMs,and superficial temporal artery to middle cerebral artery (STA-MCA) bypass in MMDs.Results The visual delay map obtained by Flow 800 software had more advantages than the traditional playback mode in identifying the feeder arteries,draining veins,and their relations to normal cortex vessels.The maximum fluorescence intensity (MFI) and the slope of ICG fluorescence curve of feeder arteries and draining veins were higher than normal peripheral vessels (MFI:584.24±85.86 vs.382.94±91.50,slope:144.95±38.08 vs.69.20±13.08,P <0.05).The artefiovenous transit time in AVM was significantly shorter than in normal cortical vessels ((0.60±0.27) vs.(2.08±1.42) seconds,P <0.05).After resection of AVM,the slope of artery in the cortex increased,which reflected the increased cerebral flow.In patients with MMD,after STA-MCA bypass,cortex perfusion of

  12. An Effect of Spatial Filtering in Visualization of Coronary Arteries Imaging

    CERN Document Server

    Kodge, B G

    2011-01-01

    At present, coronary angiography is the well known standard for the diagnosis of coronary artery disease. Conventional coronary angiography is an invasive procedure with a small, yet inherent risk of myocardial infarction, stroke, potential arrhythmias, and death. Other noninvasive diagnostic tools, such as electrocardiography, echocardiography, and nuclear imaging are now widely available but are limited by their inability to directly visualize and quantify coronary artery stenoses and predict the stability of plaques. Coronary magnetic resonance angiography (MRA) is a technique that allows visualization of the coronary arteries by noninvasive means; however, it has not yet reached a stage where it can be used in routine clinical practice. Although coronary MRA is a potentially useful diagnostic tool, it has limitations. Further research should focus on improving the diagnostic resolution and accuracy of coronary MRA. This paper will helps to cardiologists to take the clear look of spatial filtered imaging o...

  13. A free-breathing non-contrast-enhanced pulmonary magnetic resonance angiography at 3 Tesla

    Institute of Scientific and Technical Information of China (English)

    YANG Jian; WANG Wei; WANG Ya-rong; NIU Gang; JIN Chen-wang; WU Ed Xuekui

    2009-01-01

    Background The breathhold contrast-enhanced three-dimensional magnetic resonance angiography (MRA) using T1-weighted gradient-echo imaging sequence is the standard technique for MRA of the thorax. However, this technique is not desirable for certain patients with respiratory insufficiency, serious renal impairment, or allergy to contrast agents. The objective of this study was to optimize and evaluate a non-contrast-enhanced free-breathing pulmonary MRA protocol at 3 Tesla.Methods The time-of-flight protocol was based on a two-dimensional T1-weighted turbo field echo sequence with slice-selective inversion recovery and magnetization transfer preparation together with respiratory navigator gating, cardiac gating, and parallel imaging. Optimal values for time of inversion delay, flip angle and slice thickness were experimentally determined and used for all subjects.Results Excellent pulmonary MRA images, in which the 7th order branches of pulmonary arteries could be reliably identified, were obtained in the 12 free-breathing healthy volunteers. TI of ~300 ms provides the best suppression of background thoracic and cardiac muscles and effective inflow enhancement. With increasing flip angle, the pulmonary vessels gradually brightened and exhibited optimal contrast at 20°-30°. The 2 mm slice thickness and 0.5 mm slice overlap is suitable for visualization of the peripheral pulmonary vessel.Conclusions The MRA protocol at 3 Tesla may have clinical significance for pulmonary vascular imaging in patients who are not available for contrast-enhanced 3D MRA and CT angiography examination or are unable to sustain a long breath-hold.

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

    International Nuclear Information System (INIS)

    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.

  15. Data visualization

    CERN Document Server

    Azzam, Tarek

    2013-01-01

    Do you communicate data and information to stakeholders? In Part 1, we introduce recent developments in the quantitative and qualitative data visualization field and provide a historical perspective on data visualization, its potential role in evaluation practice, and future directions. Part 2 delivers concrete suggestions for optimally using data visualization in evaluation, as well as suggestions for best practices in data visualization design. It focuses on specific quantitative and qualitative data visualization approaches that include data dashboards, graphic recording, and geographic information systems (GIS). Readers will get a step-by-step process for designing an effective data dashboard system for programs and organizations, and various suggestions to improve their utility.

  16. Three-dimensional MDCT angiography of splanchnic arteries: pearls and pitfalls.

    Science.gov (United States)

    Dohan, A; Dautry, R; Guerrache, Y; Fargeaudou, Y; Boudiaf, M; Le Dref, O; Sirol, M; Soyer, P

    2015-02-01

    Fast scanning along with high resolution of multidetector computed tomography (MDCT) have expanded the role of non-invasive imaging of splanchnic arteries. Advancements in both MDCT scanner technology and three-dimensional (3D) imaging software provide a unique opportunity for non-invasive investigation of splanchnic arteries. Although standard axial computed tomography (CT) images allow identification of splanchnic arteries, visualization of small or distal branches is often limited. Similarly, a comprehensive assessment of the complex anatomy of splanchnic arteries is often beyond the reach of axial images. However, the submillimeter collimation that can be achieved with MDCT scanners now allows the acquisition of true isotropic data so that a high spatial resolution is now maintained in any imaging plane and in 3D mode. This ability to visualize the complex network of splanchnic arteries using 3D rendering and multiplanar reconstruction is of major importance for an optimal analysis in many situations. The purpose of this review is to discuss and illustrate the role of 3D MDCT angiography in the detection and assessment of abnormalities of splanchnic arteries as well as the limitations of the different reconstruction techniques. PMID:24994585

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

    Science.gov (United States)

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

    2010-01-01

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

  18. Visual Language in Visual Communication

    OpenAIRE

    Jia Wang

    2009-01-01

    In visual communication the design information is mainly communicated by visual language, the correct use of which is the standard of evaluation of a graphic design composition. Therefore it is necessary to understand and percept visual language properly. It will be helpful for viewers to percept the desired information from the designer as well as the significance within the work.

  19. Contrast-enhanced MR angiography of abdominal vessels: Is there still a role for angiography?

    Energy Technology Data Exchange (ETDEWEB)

    Vosshenrich, R.; Fischer, U. [Department of Radiology, Georg-August-Universitaet Goettingen (Germany)

    2002-01-01

    The purpose of this review article is to describe recent advantages in contrast-enhanced (CE) three-dimensional (3D) magnetic resonance angiography (MRA) in comparison with other vascular imaging techniques, and to discuss their current clinical applications for the imaging of abdominal vessels. Principles and technical considerations are presented and clinical applications are reviewed for different vascular diseases. In ruptured aortic aneurysms and acute dissections CT is the method of first choice. Contrast-enhanced 3D MRA can be well used for therapeutic planning and follow-up in patients with stable disease. A comprehensive MR examination including CE 3D MRA, MR urography and MR nephrogram has the potential to replace the conventional studies for the evaluation of renal vascular disease. It is an accurate method for imaging the origins of coeliac and superior mesenteric arteries, although the image resolution is too low for reliable assessment of the inferior mesenteric artery. Contrast-enhanced 3D MRA has emerged as the method of choice for studying the portal venous system in liver transplant recipients, in patients with portal hypertension and in cases with abdominal tumours for preoperative evaluation. Additional non-invasive flow measurements are useful in monitoring portal hypertension. The abdominal veins can be well imaged using unenhanced MR techniques. Imaging may be facilitated with intravascular contrast media. Contrast-enhanced 3D MRA can replace intra-arterial DSA for diagnosis, therapy planning and follow-up in patients with abdominal vascular disease. Catheter-based arteriography will still be used for interventional procedures such as percutaneous transluminal angioplasty, stent placement and embolisation. (orig.)

  20. Numerical reconstruction of pulsatile blood flow from 4D computer tomography angiography data

    CERN Document Server

    Lovas, Attila; Csobo, Elek; Szilágyi, Brigitta; Sótonyi, Péter

    2015-01-01

    We present a novel numerical algorithm developed to reconstuct pulsatile blood flow from ECG-gated CT angiography data. A block-based optimization method was constructed to solve the inverse problem corresponding to the Riccati-type ordinary differential equation that can be deduced from conservation principles and Hooke's law. Local flow rate for 5 patients was computed in 10cm long aorta segments that are located 1cm below the heart. The wave form of the local flow rate curves seems to be realistic. Our approach is suitable for estimating characteristics of pulsatile blood flow in aorta based on ECG gated CT scan thereby contributing to more accurate description of several cardiovascular lesions.

  1. [Affine transformation-based automatic registration for peripheral digital subtraction angiography (DSA)].

    Science.gov (United States)

    Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min

    2008-07-01

    In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.

  2. Current principles in the use of diagnostic coronary angiography

    International Nuclear Information System (INIS)

    Current principles in designing diagnostic coronary angiography by taken into account of fundamental achievements in endovascular medicine in diagnosing and treating various heart diseases are presented. Basic qualitative and quantitative requirements for X-ray contrast study of cardiac vessels to enhance the information value of coronary angiography are given. Necessary diagnostic criteria to be achieved during the study to choose a surgical or endovascular treatment are considered. The present-day accumulated data on X-ray anatomic features of coronary vessels in coronary heart disease are classified. Current classifications of coronary circulation, principles in the development of collateral blood supply, main sources of collaterals, and the specific features of the coronary bed in patients with coronary heart disease are also given

  3. The need for repeat angiography in subarachnoid haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Urbach, H.; Solymosi, L. [Department of Neuroradiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany); Zentner, J. [Department of Neurosurgery, University of Bonn, Sigmund-Freud-Strasse 25, D-53127 Bonn (Germany)

    1998-01-01

    This study was designed to assess the necessity for a second angiogram study in patients in whom initial angiography after primary subarachnoid haemorrhage (SAH) was negative. During a 12-year period, 122 of 694 patients (17.5 %) had negative initial angiograms. CT, available for 98 patients, showed a preponderance of subarachnoid blood in the perimesencephalic cisterns in 50 of 73 patients (68.5 %) in whom blood was visible on CT. Angiography, repeated in 67 patients, revealed an aneurysm in 4 (6 %): 2 had an aneurysm of the anterior communicating artery, 1 of the posterior inferior cerebellar artery, and 1 of the P2 segment of the posterior cerebral artery. CT showed subarachnoid blood in the interpeduncular and ambient cisterns in this last case, and a preponderance of subarachnoid blood outside the perimesencephalic cisterns in the remaining 3 patients. (orig.) With 2 figs., 1 tab., 32 refs.

  4. Magnetic resonance tomographic angiography: diagnostic value in trigeminal neuralgia

    International Nuclear Information System (INIS)

    A combination of MRI, MR angiography and MR tomographic angiography (MRTA) was used to study the relationship of the root exit zone of the trigeminal nerve to surrounding vascular structures in seven patients with trigeminal neuralgia (TN) and ten patients with no evidence at a lesion in this region. MRTA is the technique for showing the relationship between vessels, cranial nerves and brain stem. MRTA clearly demonstrated the presence of a vessel at the root exit zone of the trigeminal nerve in all patients with TN. In the ten other patients, examination of 20 trigeminal nerves revealed that only one nerve (5%) was in contact with a vessel at the root exit zone. This study supports vascular compression of trigeminal nerves as a cause of TN, and demonstrates the value of MRTA as noninvasive technique for demonstrating compression. (orig.)

  5. Magnetic resonance tomographic angiography: diagnostic value in trigeminal neuralgia

    Energy Technology Data Exchange (ETDEWEB)

    Umehara, F. [Third Dept. of Internal Medicine, Faculty of Medicine, Kagoshima Univ. (Japan); Kamishima, K. [Div. of Diagnostic Neuroradiology, Kagoshima Univ. (Japan); Kashio, N. [Third Dept. of Internal Medicine, Faculty of Medicine, Kagoshima Univ. (Japan); Yamaguchi, K. [Div. of Diagnostic Neuroradiology, Kagoshima Univ. (Japan); Sakimoto, T.; Osame, M. [Third Dept. of Internal Medicine, Faculty of Medicine, Kagoshima Univ. (Japan)

    1995-07-01

    A combination of MRI, MR angiography and MR tomographic angiography (MRTA) was used to study the relationship of the root exit zone of the trigeminal nerve to surrounding vascular structures in seven patients with trigeminal neuralgia (TN) and ten patients with no evidence at a lesion in this region. MRTA is the technique for showing the relationship between vessels, cranial nerves and brain stem. MRTA clearly demonstrated the presence of a vessel at the root exit zone of the trigeminal nerve in all patients with TN. In the ten other patients, examination of 20 trigeminal nerves revealed that only one nerve (5%) was in contact with a vessel at the root exit zone. This study supports vascular compression of trigeminal nerves as a cause of TN, and demonstrates the value of MRTA as noninvasive technique for demonstrating compression. (orig.)

  6. Comparison of amplitude-decorrelation, speckle-variance and phase-variance OCT angiography methods for imaging the human retina and choroid.

    Science.gov (United States)

    Gorczynska, Iwona; Migacz, Justin V; Zawadzki, Robert J; Capps, Arlie G; Werner, John S

    2016-03-01

    We compared the performance of three OCT angiography (OCTA) methods: speckle variance, amplitude decorrelation and phase variance for imaging of the human retina and choroid. Two averaging methods, split spectrum and volume averaging, were compared to assess the quality of the OCTA vascular images. All data were acquired using a swept-source OCT system at 1040 nm central wavelength, operating at 100,000 A-scans/s. We performed a quantitative comparison using a contrast-to-noise (CNR) metric to assess the capability of the three methods to visualize the choriocapillaris layer. For evaluation of the static tissue noise suppression in OCTA images we proposed to calculate CNR between the photoreceptor/RPE complex and the choriocapillaris layer. Finally, we demonstrated that implementation of intensity-based OCT imaging and OCT angiography methods allows for visualization of retinal and choroidal vascular layers known from anatomic studies in retinal preparations. OCT projection imaging of data flattened to selected retinal layers was implemented to visualize retinal and choroidal vasculature. User guided vessel tracing was applied to segment the retinal vasculature. The results were visualized in a form of a skeletonized 3D model. PMID:27231598

  7. Time-resolved CT angiography in aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, Felix G., E-mail: felix.meinel@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Nikolaou, Konstantin, E-mail: konstantin.nikolaou@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Weidenhagen, Rolf, E-mail: rolf.weidenhagen@med.uni-muenchen.de [Department of Surgery, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Hellbach, Katharina, E-mail: katharina.hellbach@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Helck, Andreas, E-mail: andreas.helck@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Bamberg, Fabian, E-mail: fabian.bamberg@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Reiser, Maximilian F., E-mail: maximilian.reiser@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Sommer, Wieland H., E-mail: wieland.sommer@med.uni-muenchen.de [Department of Clinical Radiology, Ludwig Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany)

    2012-11-15

    Objectives: We performed this study to assess feasibility and additional diagnostic value of time-resolved CT angiography of the entire aorta in patients with aortic dissection. Materials and methods: 14 consecutive patients with known or suspected aortic dissection (aged 60 {+-} 9 years) referred for aortic CT angiography were scanned on a dual-source CT scanner (Somatom Definition Flash; Siemens, Forchheim, Germany) using a shuttle mode for multiphasic image acquisition (range 48 cm, time resolution 6 s, 6 phases, 100 kV, 110 mAs/rot). Effective radiation doses were calculated from recorded dose length products. For all phases, CT densities were measured in the aortic lumen and renal parenchyma. From the multiphasic data, 3 phases corresponding to a triphasic standard CT protocol, served as a reference and were compared against findings from the time-resolved datasets. Results: Mean effective radiation dose was 27.7 {+-} 3.5 mSv. CT density of the true lumen peaked at 355 {+-} 53 HU. Compared to the simulated triphasic protocol, time-resolved CT angiography added diagnostic information regarding a number of important findings: the enhancement delay between true and false lumen (n = 14); the degree of membrane oscillation (n = 14); the perfusion delay in arteries originating from the false lumen (n = 9). Other additional information included true lumen collapse (n = 4), quantitative assessment of renal perfusion asymmetry (n = 2), and dynamic occlusion of aortic branches (n = 2). In 3/14 patients (21%), these additional findings of the multiphasic protocol altered patient management. Conclusions: Multiphasic, time-resolved CT angiography covering the entire aorta is feasible at a reasonable effective radiation dose and adds significant diagnostic information with therapeutic consequences in patients with aortic dissection.

  8. Ischemic enterocolitis examined by colonoscopy and selective angiography

    Institute of Scientific and Technical Information of China (English)

    Lei He; He-Sheng Luo

    2005-01-01

    AIM: To study the value of colonoscopy and selective angiography in diagnosing ischemic enterocolitis.METHODS: Among the 16 cases under study, 10 cases had hypertension and a history of coronary artery disease (one was hospitalized for sub-ventricular-wall infarction). The blood pressure of 10 of the 16 cases ranged from 13.9-23.8 to 13.3-14.6 kPa (170-180/100-110 mmHg). Two cases had chronic auricular fibrillation, and in four cases, a cardiogram showed left-front branch conduction block. Sixteen patients were examined by colonoscopy. Among them, 14 cases had a long course of angiocardiac disease, and were further examined by selective mesenteric inferior angiography.RESULTS: The colonoscopy revealed local mucous hyperemia edema and blood on contact. Lesions were found in the sigmoid colon in four cases, in the descending colon in eight cases and in splenic flexure in four cases, which suggests that the lesion always appeared in the left part of colon. There were different degrees of inflammatory cell infiltration, submucous bleeding, edema, fibro-embolism and hemosiderosis by biopsy in the 16 patients whose membranes affect part of the enteral wall. Of the 14 patients examined by mesenteric inferior angiography, 3 cases showed mesenteric amphraxis inferior and formation of collateral circulation. There were different degrees of stenosis in the other 11 subjects' mesenteric inferior cavities which grew slim and their branches were stenotic, so the radiographic image was not complete and the ends of some branches even cannot be seen. CONCLUSION: The colonoscopy and the selective mesenteric inferior angiography are both helpful in the diagnosis of ischemic enterocolitis.

  9. Waiting for coronary angiography: is there a clinically ordered queue?

    Science.gov (United States)

    Hemingway, H; Crook, A M; Feder, G; Dawson, J R; Timmis, A

    2000-03-18

    Among over 3000 patients undergoing coronary angiography in the absence of a formal queue-management system, we found that a-priori urgency scores were strongly associated with waiting times, prevalence of coronary-artery disease, rate of revascularisation, and mortality. These data challenge the widely held assumption that such waiting lists are not clinically ordered; however, the wide variation in waiting times within urgency categories suggests the need for further improvements in clinical queueing.

  10. Indications for secondary cerebral angiography after primary negative imaging

    OpenAIRE

    Vassilev, Vladislav

    2015-01-01

    The following study evaluates digital subtraction angiography (DSA) as follow-up diabnostic the detection of vascular lesions in patients with perimesencephalic and non perimesencephalic subarachnoid hemorrhage (SAH) after initially negative primary noninvasive and invasive neurovascular imaging. In our Neurovascular Center we analyzed 372 patients with non traumatic SAH over a 14-years period. We used CT or CTA followed by DSA to confirm the diagnosis. Secondary examinations, either secon...

  11. Evaluation of vascular rings with digital subtraction angiography.

    Science.gov (United States)

    Tonkin, I L; Gold, R E; Moser, D; Laster, R E

    1984-06-01

    Seven patients with vascular rings were evaluated over a 2-year period with intravenous digital subtraction angiography (DSA), which was compared with screen-film aortography or cineangiography. The seven patients were also evaluated with barium esophagography. Six of the seven DSA images were totally diagnostic and one study was only partly diagnostic. Six of the seven vascular anomalies were confirmed surgically. DSA is suggested as an alternative to arteriography in evaluating patients with suspected vascular rings. PMID:6372419

  12. Digital subtraction angiography of a persistent trigeminal artery variant.

    Science.gov (United States)

    Temizöz, Osman; Genchellac, Hakan; Unlü, Ercüment; Cağli, Bekir; Ozdemir, Hüseyin; Demir, M Kemal

    2010-09-01

    Persistent trigeminal artery variants are described as cerebellar arteries that directly originate from the precavernous segment of the internal carotid artery. This has been observed in 0.18% of cerebral catheter angiograms. On the other hand, a persistent trigeminal artery variant feeding both the anterior inferior cerebellar artery and the posterior inferior cerebellar artery territory is very rare. We present this uncommon anomalous artery along with digital subtraction angiography findings and discuss its clinical significance in light of the literature. PMID:19821254

  13. Magnetic resonance angiography: current status and future directions

    OpenAIRE

    François Christopher J; Grist Thomas M; Hartung Michael P

    2011-01-01

    Abstract With recent improvement in hardware and software techniques, magnetic resonance angiography (MRA) has undergone significant changes in technique and approach. The advent of 3.0 T magnets has allowed reduction in exogenous contrast dose without compromising overall image quality. The use of novel intravascular contrast agents substantially increases the image windows and decreases contrast dose. Additionally, the lower risk and cost in non-contrast enhanced (NCE) MRA has sparked renew...

  14. Assessment of the kidneys: magnetic resonance angiography, perfusion and diffusion

    OpenAIRE

    Attenberger Ulrike I; Morelli John N; Schoenberg Stefan O; Michaely Henrik J

    2011-01-01

    Abstract Renal magnetic resonance (MR) imaging has undergone major improvements in the past several years. This review focuses on the technical basics and clinical applications of MR angiography (MRA) with the goal of enabling readers to acquire high-resolution, high quality renal artery MRA. The current role of contrast agents and their safe use in patients with renal impairment is discussed. In addition, an overview of promising techniques on the horizon for renal MR is provided. The clinic...

  15. Angiography suite concept for an interdisciplinary centre for cardiovascular interventions

    OpenAIRE

    Teichgräber, Ulf K. M.; Wintzer, Christian; Hamm, Bernd

    2010-01-01

    A permanently mounted angiography suite in an operating room (OR) is considered to be a hybrid OR. However, regular use for angiographic interventions is restricted with this setup. We introduce an alternative use of space for the efficient utilisation of an angiographic suite outside the surgical unit. This concept includes three scenarios that describe a modification of the catheter suite according to the specific clinical demands by adapting the workflow.

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

    Science.gov (United States)

    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. Intracranial aneurysms: evaluation in 200 patients with spiral CT angiography

    International Nuclear Information System (INIS)

    The goal of this study was to assess the usefulness of spiral CT angiography (CTA) with three- dimensional reconstructions in defining intracranial aneurysms, particularly around the Circle of Willis. Two hundred consecutive patients with angiographic and/or surgical correlation were studied between 1993 and 1998, with CTA performed on a GE HiSpeed unit and Windows workstation. The following clinical situations were evaluated: conventional CT suspicion of an aneurysm; follow-up of treated aneurysm remnants or of untreated aneurysms; subarachnoid haemorrhage (SAH) and negative angiography; family or past aneurysm history; and for improved definition of aneurysm anatomy. Spiral CTA detected 140 of 144 aneurysms, and an overall sensitivity of 97%, including 30 of 32 aneurysms 3 mm or less in size. In 38 patients with SAH and negative angiography, CTA found six of the seven aneurysms finally diagnosed. There was no significant artefact in 17 of 23 patients (74%) with clips. The specificity of CTA was 86% with 8 false-positive cases. Spiral CTA is very useful in demonstrating intracranial aneurysms. (orig.)

  18. Ectopic Origin of Coronary Arteries Diagnozed by Coronary Angiography

    Science.gov (United States)

    Krasniqi, Xhevdet; Gorani, Daut; Sejdiu, Basri; Citaku, Hajdin

    2016-01-01

    Introduction: Anomalous origin of coronary arteries from opposite sinus of Valsalva is rare finding. The incidence of anomalous origination of the left coronary artery from right sinus is 0.15% and the right coronary artery from the left sinus is 0.92%. The ectopic origin of left coronary artery or right coronary artery from opposite sinus depending on pathways and considering atherosclerotic changes are manifested with different clinical significance. Case report: We report two cases, the first case the coronary angiography showed the left coronary artery arising from the right coronary sinus, presenting with proximally and distally stenosed left anterior descending artery (LAD), associated with medial and distal stenosed right coronary artery (RCA). The second case the coronary angiography revealed the right coronary artery arising from the left coronary sinus, associated with tortuous medial and distal segments of left anterior descending artery (LAD), without atherosclerotic changes. The first case successfully underwent treatment procedures based on guidelines for revascularization. Conclusion: The coronary angiography of patients with coronary ischemia determines atherosclerotic disease with possibility of the presence of coronary artery anomalies that in cases with ectopic origin from opposite sinus continues to exist as a challenge during treatment in interventional cardiology. PMID:27482140

  19. Computed tomography angiography in patients with active gastrointestinal bleeding

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Fatima Regina Silva; D' Ippolito, Giuseppe, E-mail: fatima.rsreis@gmail.com [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina; Cardia, P.P. [Hospital Vera Cruz, Campinas, SP (Brazil)

    2015-11-15

    Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding. (author)

  20. Body MR angiography in children: how we do it.

    Science.gov (United States)

    Krishnamurthy, Rajesh; Malone, LaDonna; Lyons, Karen; Ketwaroo, Pamela; Dodd, Nicholas; Ashton, Daniel

    2016-05-01

    Vascular pathology is ubiquitous in children. Common indications for angiographic imaging in the body include congenital anomalies, portal hypertension, assessing resectability of neoplasms, renovascular hypertension, vascular malformations, vasculitis, systemic vein thrombosis, and trauma. MR angiography, with or without the use of intravenous contrast agents, is therefore a mainstay in the repertoire of MR imaging in children. Pediatric contrast-enhanced MR angiography has benefited from several innovations in recent years, including improved hardware options like high-field-strength scanners and integrated high-density coil arrays, new sequences that combine parallel imaging, innovative k-space sampling and Dixon fat suppression with time-resolved imaging, new contrast agents with longer blood-pool residence time, and advanced post-processing solutions like image fusion. This article focuses on the principles of contrast-enhanced MR angiography of the body as it pertains to the physiologies and pathologies encountered in children. It also discusses tools to adapt the MR angiographic technique to the clinical indication, as well as pitfalls of post-processing and interpretation in commonly encountered vascular imaging scenarios in the pediatric body. PMID:27229494

  1. Penile angiography and superselective embolization therapy in arterial priapism

    International Nuclear Information System (INIS)

    Purpose: To report feasibility, benefit and complications of penile angiography and superselective penile embolization in arterial priapism. Materials and Methods: Four consecutive patients (aged 28, 29, 40 and 49 years), who underwent penile angiography for arterial priapism (high-flow priapism) within a four-year period, were identified by a keyword search of our radiology information system. One patient had sustained a direct penile trauma (severe blow to the erected penis) and three patients suffered from recurrent spontaneous priapism. All patients had previously undergone corporeal aspiration and noradrenaline injection to achieve detumescence. Two patients had one or several unsuccessful spongiocavernous shunt procedures. Results: In three of the four patients, superselective pudendal and penile angiography demonstrated pathologic arteriocavernous shunting. In two of the three patients, superselective embolization using a coaxial micro-catheter was attempted. In one of the two patients, the cavernous artery became spastic before embolization material was actually injected, inducing immediate and lasting detumescence. In the other patient, unilateral Gelfoam embolization led to immediate detumescence but the priapism recurred 12 hours after the procedure. A subsequent contralateral Gelfoam embolization was successful. Erectile function was preserved in all cases. No procedure-related complications occurred. Conclusion: Our experience supports the prevailing opinion found in the current literature that superselective coaxial embolization constitutes the treatment of choice in patients with high-flow priapism. Prognosis is good with high probability of preserving the erectile function. (orig.)

  2. Computed tomography angiography in patients with active gastrointestinal bleeding

    Directory of Open Access Journals (Sweden)

    Fatima Regina Silva Reis

    2015-12-01

    Full Text Available Abstract Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding.

  3. CT Pulmonary Angiography and Suspected Acute Pulmonary Embolism

    Energy Technology Data Exchange (ETDEWEB)

    Enden, T.; Kloew, N.E. [Ullevaal Univ. Hospital, Oslo (Norway). Dept. of Cardiovascular Radiology

    2003-05-01

    Purpose: To evaluate the use and quality of CT pulmonary angiography in our department, and to relate the findings to clinical parameters and diagnoses. Material and Methods: A retrospective study of 324 consecutive patients referred to CT pulmonary angiography with clinically suspected pulmonary embolism (PE). From the medical records we registered clinical parameters, blood gases, D-dimer, risk factors and the results of other relevant imaging studies. Results: 55 patients (17%) had PE detected on CT. 39 had bilateral PE, and 8 patients had isolated peripheral PE. 87% of the examinations showing PE had satisfactory filling of contrast material including the segmental pulmonary arteries, and 60% of the subsegmental arteries. D-dimer test was performed in 209 patients, 85% were positive. A negative D-dimer ruled out PE detected at CT. Dyspnea and concurrent symptoms or detection of deep vein thrombosis (DVT), contraceptive pills and former venous thromboembolism (VTE) were associated with PE. The presence of only one clinical parameter indicated a negative PE diagnosis (p < 0.017), whereas two or more suggested a positive PE diagnosis (p < 0.002). CT also detected various ancillary findings such as consolidation, pleural effusion, nodule or tumor in nearly half of the patients; however, there was no association with the PE diagnosis. Conclusion: The quality of CT pulmonary angiography was satisfactory as a first-line imaging of PE. CT also showed additional pathology of importance in the chest. Our study confirmed that a negative D-dimer ruled out clinically suspected VTE.

  4. Data analysis on patient exposures in cardiac angiography

    Energy Technology Data Exchange (ETDEWEB)

    Huyskens, C.J.; Hummel, W.A. [Eindhoven University of Technology (Netherlands). Radiation Protection Dept.

    1995-12-31

    In cardiac interventional radiology the fluoroscopy time and the film length are dominating factors for the resulting exposure of patients. From experiments in laboratory conditions and from measurements in actual practice an empirical formula has been derived to calculate the kerma-exposure product as a function of fluoroscopy time and film length. to simulate actual medical practice as closely as possible during the experiments, reference procedures were composed for fluoroscopy and cine-angiography. Over a period of two years, data on fluoroscopy time and cine film length were collected in the clinical practice of a large cardiology department in a major hospital in the Netherlands. The data refer to nearly 3000 cardiac intervention procedures, 50/50 divided between cardio-angiography (CAG) and percutaneous transluminal coronary angiography (PTCA). The mean value for the kerma-area product over all cardiac procedures is approx. 40 Gy cm{sup 2}. The relative standard deviation is 60%. From the distribution measured, it follows that about 20 % of all cardiac procedures account for approximately half the collective dose for patients. The empirically derived fit-function to calculate the kerma-area product provides a useful method to analyse patient exposures in interventional radiology as an aid in the context of quality assurance of medical practice and ALARA programmes in radiological protection. (Author).

  5. Automatic quantification and characterization of coronary atherosclerosis with computed tomography coronary angiography: cross-correlation with intravascular ultrasound virtual histology.

    Science.gov (United States)

    de Graaf, Michiel A; Broersen, Alexander; Kitslaar, Pieter H; Roos, Cornelis J; Dijkstra, Jouke; Lelieveldt, Boudewijn P F; Jukema, J Wouter; Schalij, Martin J; Delgado, Victoria; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2013-06-01

    Plaque constitution on computed tomography coronary angiography (CTA) is associated with prognosis. At present only visual assessment of plaque constitution is possible. An accurate automatic, quantitative approach for CTA plaque constitution assessment would improve reproducibility and allows higher accuracy. The present study assessed the feasibility of a fully automatic and quantitative analysis of atherosclerosis on CTA. Clinically derived CTA and intravascular ultrasound virtual histology (IVUS VH) datasets were used to investigate the correlation between quantitatively automatically derived CTA parameters and IVUS VH. A total of 57 patients underwent CTA prior to IVUS VH. First, quantitative CTA quantitative computed tomography (QCT) was performed. Per lesion stenosis parameters and plaque volumes were assessed. Using predefined HU thresholds, CTA plaque volume was differentiated in 4 different plaque types necrotic core (NC), dense calcium (DC), fibrotic (FI) and fibro-fatty tissue (FF). At the identical level of the coronary, the same parameters were derived from IVUS VH. Bland-Altman analyses were performed to assess the agreement between QCT and IVUS VH. Assessment of plaque volume using QCT in 108 lesions showed excellent correlation with IVUS VH (r = 0.928, p algorithm (Panel I). Using a unique registration a complete pullback series of IVUS images was mapped on the CTA volume using true anatomical markers (Panel II). Fully automatic lumen and vessel wall contour detection was performed for both imaging modalities (Panel III). Finally, fusion-based quantification of atherosclerotic lesions was based on the lumen and vessel wall contours as well as the corresponding reference lines (estimate of normal tapering of the coronary artery), as shown in panel IV. At the level of the minimal lumen area (MLA) (yellow lines), stenosis parameters, could be calculated for both imaging techniques. Additionally, plaque volumes and plaque types were derived for the

  6. VALIDEZ DE LA ESTIMACIÓN VISUAL COMO MÉTODO DIAGNÓSTICO DE LA HEMORRAGIA POSTPARTO SEVERA EN UN HOSPITAL UNIVERSITARIO. BOGOTÁ. 2007 Validity of visual estimation of blood loss as diagnostic tool in severe post partum hemorrhage in an university hospital. Bogotá. 2007

    Directory of Open Access Journals (Sweden)

    Jorge Andrés Rubio-Romero

    2010-07-01

    Full Text Available Antecedentes. La dificultad para diagnosticar una hemorragia anormal postparto radica en la necesidad de esperar la presencia de signos clínicos de hipovolemia para confirmarla. Objetivo. Evaluar la exactitud diagnóstica de la estimación visual para el diagnóstico de hemorragia postparto severa inmediata (HPPI luego de parto vaginal. Material y métodos. Se realizó un estudio de exactitud diagnóstica, aprobado por los comités de ética e investigaciones de las instituciones participantes, en una cohorte de embarazadas atendidas por parto vaginal en un hospital universitario. El gold estándar de referencia fue definido como un complejo de signos clínicos y de laboratorio: necesidad de maniobras terapéuticas para el control de la hemorragia, caída de más de 10% del hematocrito o necesidad de transfusión. Resultados. La incidencia de HPPI fue de 10,7% en 168 pacientes incluidas. La mediana de volumen estimado de sangrado fue de 375 mL mientras que la mediana del volumen real observado fue de 475 mL. Para el diagnóstico y manejo clínico de HPPI, el volumen estimado mayor de 500 mL tuvo una sensibilidad y especificidad de 77,8 y 73,3% respectivamente. Cuando el sangrado estimado superó los 800 mL, la sensibilidad y especificidad fueron 44,4 y 94% siendo este punto el que mejor clasificó las pacientes con necesidad de tratamiento para la hemorragia postparto severa inmediata. Conclusiones. La estimación visual del sangrado intraparto como prueba diagnóstica aislada es poco sensible y específica para diagnosticar hemorragia postparto severa inmediata por la tendencia a subestimar la magnitud real del sangrado.Background. The difficulty to diagnose an abnormal hemorrhage of the post partum period is related to the need to wait until the presence of clinical signs of hypovolemia to confirm it. Objetive. To evaluate the diagnostic accuracy of visual estimation of blood quantity for the diagnosis of severe postpartum hemorrhage (SPPH

  7. Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Juan; Sun, Gang; Yu, Bling Bing; Li, Min; Li, Guo Ying; Peng, Zhao Hui; Zhang, Xu Ping [Dept. of Medical Imaging, Jinan Military General Hospital, Jinan (China); Lu, Yang [Dept. of Radiology, University of Illinois College of Medicine, Illinois (United States)

    2012-11-15

    To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 {+-} 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 {+-} 0.01 mSv) (p < 0.001). 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.

  8. Visual Hallucinations in a Patient with Horner's Syndrome Secondary to Internal Carotid Dissection

    DEFF Research Database (Denmark)

    Singh, Amardeep; Mortzos, Panteleimon; Sørensen, Torben Lykke

    2014-01-01

    A 67-year-old female presented with post-ganglionic Horner's syndrome. In addition to the classical symptoms of Horner's syndrome, the patient reported experiencing frightening complex visual and auditory hallucinations on two different occasions. Magnetic resonance angiography of the cerebrum...

  9. Quantification of tumor vessels in glioblastoma patients using time-of-flight angiography at 7 Tesla: a feasibility study.

    Directory of Open Access Journals (Sweden)

    Alexander Radbruch

    Full Text Available PURPOSE: To analyze if tumor vessels can be visualized, segmented and quantified in glioblastoma patients with time of flight (ToF angiography at 7 Tesla and multiscale vessel enhancement filtering. MATERIALS AND METHODS: Twelve patients with newly diagnosed glioblastoma were examined with ToF angiography (TR = 15 ms, TE = 4.8 ms, flip angle = 15°, FOV = 160 × 210 mm(2, voxel size: 0.31 × 0.31 × 0.40 mm(3 on a whole-body 7 T MR system. A volume of interest (VOI was placed within the border of the contrast enhancing part on T1-weighted images of the glioblastoma and a reference VOI was placed in the non-affected contralateral white matter. Automated segmentation and quantification of vessels within the two VOIs was achieved using multiscale vessel enhancement filtering in ImageJ. RESULTS: Tumor vessels were clearly visible in all patients. When comparing tumor and the reference VOI, total vessel surface (45.3 ± 13.9 mm(2 vs. 29.0 ± 21.0 mm(2 (p<0.035 and number of branches (3.5 ± 1.8 vs. 1.0 ± 0.6 (p<0.001 per cubic centimeter were significantly higher, while mean vessel branch length was significantly lower (3.8 ± 1.5 mm vs 7.2 ± 2.8 mm (p<0.001 in the tumor. DISCUSSION: ToF angiography at 7-Tesla MRI enables characterization and quantification of the internal vascular morphology of glioblastoma and may be used for the evaluation of therapy response within future studies.

  10. Quantitative myocardial perfusion PET combined with coronary anatomy derived from CT angiography. Validation of a new fusion and visualisation software

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Harald; Weise, Reiner; Burchert, Wolfgang; Fricke, Eva [Inst. of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Centre North Rhine-Westphalia, Ruhr-Univ. Bochum, Bad Oeynhausen (Germany); Elsner, Andreas; Bolte, Matthias; Domik, Gitta [Research Group Computergraphics, Visualization and Image Processing, Univ. of Paderborn (Germany); Hoff, Joerg van den [PET Center, Inst. of Radiopharmacy, Research Center Rossendorf, Dresden (Germany)

    2009-07-01

    Aim: Dynamic perfusion PET offers a clinical relevant advantage over myocardial perfusion scintigraphy due to its ability to measure myocardial blood flow quantitatively. This leads to an improved detection of multivessel disease and the possibility to assess not only the culprit lesion but lower grade stenoses as well. For appropriate revascularization, perfusion defects must be matched to coronary lesions. It has been shown that image fusion of morphological and functional images is superior to side-by-side analysis. Still, software for quantitative perfusion PET combined with CT angiography is rare. In this paper we present a new software tool for image fusion and visualization of quantitative perfusion PET and coronary morphology derived from CT angiography. Methods: In our software, a PET uptake image is used for manual co-registration. Co-registration results are then applied to the functional data derived from compartment modelling. To evaluate the reproducibility of the manual co-registration, we calculated the deviation between a series of manual co-registrations performed on nine pairs of unregistered PET and CT datasets by five trained participants. Two dimensional transfer functions were used to highlight the coronary arteries from the CT study in the combined data sets. Results: The average Euclidian distances for three references points were between 3.7 and 4.1 mm. The maximum distance was 10.6 mm. By the use of the two dimensional transfer functions, coronary anatomy could be easily visualised either by user-interaction or automatically by use of neuronal networks. Conclusions: With this approach it is possible to combine quantitative perfusion PET with coronary anatomy derived from CT angiography. Our first experiences indicate that manual image fusion with our tool is reproducible and that visualisation of the combined datasets is achieved within short time. (orig.)

  11. Evaluation of preoperative computed tomography angiography in association with conventional angiography versus computed tomography angiography only, in the endovascular treatment of aortic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Metzger, Patrick Bastos; Novero, Eduardo Rafael; Rossi, Fabio Henrique; Moreira, Samuel Martins; Linhares, Frederico Augusto; Almeida, Bruno Lorencao de; Barbato, Heraldo Antonio; Izukawa, Nilo Mitsuru; Kambara, Antonio Massamitsu, E-mail: patrickvascular@gmail.com [Instituto Dante Pazzanese de Cardiologia, Sao Paulo, SP (Brazil)

    2013-09-15

    Objective: to evaluate the association of conventional angiography (AG) with computed tomography angiography (CTA) as compared with CTA only, preoperatively, in the treatment of aortic diseases. Materials and methods: retrospective study involving patients submitted to endovascular treatment of aortic diseases, in the period from January 2009 to July 2010, with use of preoperative CTA + conventional AG or CTA only. The patients were divided into two groups, namely: G1 - thoracic aortic diseases; and G2 - abdominal aortic diseases. G1 was subdivided into 1A (preoperative AG + CTA) and 1B (preoperative CTA). G2 was subdivided into 2C (CTA + AG) and 2D (CTA only). Results: the authors evaluated 156 patients. In subgroups 1A and 1B, the rate of technical success was, respectively, 100% and 94.7% (p = 1.0); and the rate of therapeutic success was, respectively, 81% and 58% (p = 0.13). A higher number of complications were observed in subgroup 1B (p = 0.057). The accuracy in the calculation of the prosthesis was higher in subgroup 1A (p = 0.065). In their turn, the rate of technical success in subgroups 2C and 2D was, respectively, 92.3% and 98.6% (p = 0.17). The rate of therapeutic success was 73% and 98.6% (p = 0.79). Conclusion: preoperative conventional AG should be reserved for cases where CTA cannot provide all the information in the planning of a therapeutic intervention. (author)

  12. 3D Multislice CT Angiography in Post-Aortic Stent Grafting: A Pictorial Essay

    International Nuclear Information System (INIS)

    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

  13. Visualization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  14. Persistent Trigeminal Artery Variant Detected by Conventional Angiography and Magnetic Resonance Angiography-Incidence and Clinical Significance-

    Science.gov (United States)

    Rhee, Sun Joo; Lee, Chae Heuck; Lee, Ghi Jai

    2007-01-01

    Objective Persistent trigeminal artery variant (PTAV) is an anastomosis between the internal carotid artery (ICA) and the cerebellar artery without any interposing basilar artery segment. We discuss its probable embryological origin and emphasize clinical implications. Methods Retrospectively 1250 conventional cerebral angiograms and 2947 cranial magnetic resonance angiographies (MRAs) were evaluated for the patients with PTAV. Results Five patients (four men and one woman, 23 to 76 years of age, median age 65 years) had a PTAV. Three patients who underwent MRA had a PTAV (3/2947=0.1%). Four of the patients who underwent cerebral angiography had a PTAV (4/1250=0.32%). Two of 143 patients who underwent both conventional angiography and cranial MRA showed PTAV. The PTAV was an incidental finding in all five patients. The PTAV originated from the cavernous segment of the left ICA in four patients and from the cavernous segment of the right ICA in one patient. The terminal branch of the PTAV was the anterior inferior cerebellar artery (AICA) and superior cerebellar artery (SCA) in two patients and the AICA only in the other three patients. Conclusion Neurosurgeons should be aware of possible presence of PTAV. Manipulation of this vessel during a surgical approach to the parasellar region and percutaneous gasserian ganglion procedure may result in hemorrhage or ischemia. PMID:19096587

  15. Development and Application of Software to Estimate Ecological Baseflow Based on Visual Basic 6.0%基于VB 6.0的生态基流计算软件开发与应用

    Institute of Scientific and Technical Information of China (English)

    李磊; 徐宗学

    2012-01-01

    In order to solve the problem that there is no suitable platform to estimate ecological baseflow by using different methods,a software to estimate ecological baseflow with friendly interface,simplicity of operation,and integrated 12 hydrological and hydraulics methods is developed by using Visual Basic 6.0.It not only simplifies the estimation for ecological baseflow,but also easily makes comparison among different methods.A case study in the Weihe River basin was carried out by using this software.Results show that ecological baseflows estimated by using different methods are significantly different.Therefore,the average of various methods,13.7 m3/s,is selected as the ecological baseflow and the result of Texas method is regarded as the monthly ecological baseflow in the Weihe River.This software provides a great support for the development of the dynamic estimation of ecological baseflow in the future.%针对目前河流生态基流量尚无统一的计算平台,各种方法的计算和对比研究较为繁琐等问题,使用Visual Basic 6.0作为开发工具,开发出界面友好,操作简单,交互性强,包含12种水文学、水力学计算方法的河流生态基流量计算软件。该软件不仅简化了生态基流量计算步骤,而且便于不同方法之间的相互比较。使用该软件对渭河关中段进行了实例研究,结果发现不同方法的计算结果差别较大。选择8种单流量计算方法的平均值13.7m3/s作为渭河关中段的生态基流量,选择与研究区流量实际变化情况较为吻合的Texas法计算结果作为渭河关中段月生态基流量序列。该软件的开发与应用为今后河流生态基流量动态计算奠定了基础。

  16. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)

    2009-11-15

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  17. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    International Nuclear Information System (INIS)

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 μm2). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0±5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCODSA=COFick. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  18. In vitro comparison of different carotid artery stents: a pixel-by-pixel analysis using CT angiography and contrast-enhanced MR angiography at 1.5 and 3 T

    International Nuclear Information System (INIS)

    CT angiography (CTA) and MR angiography (MRA) are increasingly used methods for evaluation of stented vessel segments. The purpose of this study was to compare CTA, contrast-enhanced MRA (CEMRA) at 1.5 T, and CEMRA at 3 T for the visualization of carotid artery stents and to define the best noninvasive imaging technique for each stent. CTA and CEMRA appearances of 18 carotid artery stents of different designs and sizes (4.0 to 10.0 mm) were investigated in vitro. The profile of the contrast-to-noise ratio (CNR) of the lumen of each stent was calculated semiautomatically by a pixel-by-pixel analysis using the medical imaging software OSIRIS registered. For each stent, artificial lumen narrowing (ALN) was calculated. In all but one stents, ALN was lower on CEMRA at 3 T than at 1.5 T. With CEMRA at 3 T and at 1.5 T, ALN in most nitinol stents was lower than in the groups of stainless steel and cobalt alloy stents. In most nitinol stents, ALN on CEMRA at 3 T was lower than on CTA. In all stainless steel stents and cobalt alloy stents, ALN was lower on CTA than on CEMRA. With CTA and CEMRA, in most stents ALN decreased with increasing stent diameter. CTA and CEMRA evaluation of vessel patency after stent placement is possible, but considerably impaired by ALN. Investigators should be informed about the method of choice for every stent. (orig.)

  19. Spontaneous occlusion of traumatic carotid-cavernous fistula - the effect of angiography

    Energy Technology Data Exchange (ETDEWEB)

    Stampfel, G.

    1984-08-01

    In two patients with a traumatic carotid-cavernous fistula, permanent occlusion of the lesion was observed following cerebral angiography and confirmed by further angiography. A delay is therefore recommended between performing angiography and carrying out further treatment, which may carry some risk. Possibly the use of ionic contrast media, which irritate the vessels, compression of the carotid artery, which reduces flow through the fistula, and general anaesthesia, which may drop the blood pressure, initiate thrombosis in the cavernous sinus. 3 figs.

  20. Validation of a Novel Clinical Prediction Score for Severe Coronary Artery Diseases before Elective Coronary Angiography

    OpenAIRE

    Zhang-Wei Chen; Ying-Hua Chen; Ju-Ying Qian; Jian-Ying Ma; Jun-Bo Ge

    2014-01-01

    OBJECTIVES: Coronary artery disease (CAD) severity is associated with patient prognosis. However, few efficient scoring systems have been developed to screen severe CAD in patients with stable angina and suspected CAD before coronary angiography. Here, we present a novel scoring system for CAD severity before elective coronary angiography. METHODS: Five hundred fifty-one patients with stable angina who were admitted for coronary angiography were enrolled in this study. Patients were divided i...

  1. Effectiveness of embolization for management of hemoptysis pulmonary tuberculosis: comparison of chest radiographic study and angiography

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Chul; Kim, Yong Ju; Park, Joong Wha; Lee Myeong Sub; Kim Dong Jin; Hong In Soo [Yonsei Univ. College of Medicine, Wonju (Korea, Republic of)

    2001-01-01

    To compare the effectiveness of embolization of the bronchial artery embolization for the management of hemoptysis in pulmonary tuberculosis cases with the severity of lung parenchymal injury and pleural infiltration, as seen on plain chest radiographs, and with the findings of angiography of the branchial artery. Among 265 patients with hemoptysis due to pulmonary tuberculosis, the findings of plain chest radiography and angiography of the bronchial artery were comparatively analyzed in the 206 for whom the results of follow up were available. The chest radiographin findings were classified as follows: Type I refers to simple pulmonary tuberculosis; Type II includes cases in which pulmonary tuberculosis is complicated by bronchiectasis, aspergillosis, or cavitation; Type III si either Types I or II acompainted by pleural in filtrates limited to the lung apex, and Type IV includes cases in which pleural infiltrates have extended beyond the apex in the whole the lung. Bronchial angiographic findings were divided into four groups: Group I consists of cases which show abnormalities of only the bronchial artery; Group II includes those in which abnormalities are seen in the bronchial artery and either the internal mammary or an intercostal artery; Group III comprises cases which belong to Group I or II and which a bronch of the subclavian artery is abnormal, and Group IV includes those in which abnormalities occur in at least two branches of the subclavian artery, or there is direct visualization of hypervascularity of this vessel. The initial post-embolic hemostatic effect and the results of follow up were studied over a six-month period. As compared with simple pulmonary tuberculosis (Type I), we found that as the severity of pleural infiltration and complications revealed by plain chest radiographs increased (Type II, III, IV), so did the severity of the manifestation of systemic collateral arteries other than the bronchial artery, as depicted by increased on

  2. Effectiveness of embolization for management of hemoptysis pulmonary tuberculosis: comparison of chest radiographic study and angiography

    International Nuclear Information System (INIS)

    To compare the effectiveness of embolization of the bronchial artery embolization for the management of hemoptysis in pulmonary tuberculosis cases with the severity of lung parenchymal injury and pleural infiltration, as seen on plain chest radiographs, and with the findings of angiography of the branchial artery. Among 265 patients with hemoptysis due to pulmonary tuberculosis, the findings of plain chest radiography and angiography of the bronchial artery were comparatively analyzed in the 206 for whom the results of follow up were available. The chest radiographin findings were classified as follows: Type I refers to simple pulmonary tuberculosis; Type II includes cases in which pulmonary tuberculosis is complicated by bronchiectasis, aspergillosis, or cavitation; Type III si either Types I or II acompainted by pleural in filtrates limited to the lung apex, and Type IV includes cases in which pleural infiltrates have extended beyond the apex in the whole the lung. Bronchial angiographic findings were divided into four groups: Group I consists of cases which show abnormalities of only the bronchial artery; Group II includes those in which abnormalities are seen in the bronchial artery and either the internal mammary or an intercostal artery; Group III comprises cases which belong to Group I or II and which a bronch of the subclavian artery is abnormal, and Group IV includes those in which abnormalities occur in at least two branches of the subclavian artery, or there is direct visualization of hypervascularity of this vessel. The initial post-embolic hemostatic effect and the results of follow up were studied over a six-month period. As compared with simple pulmonary tuberculosis (Type I), we found that as the severity of pleural infiltration and complications revealed by plain chest radiographs increased (Type II, III, IV), so did the severity of the manifestation of systemic collateral arteries other than the bronchial artery, as depicted by increased on

  3. MR angiography for follow-up after percutaneous vessel recanalization and surgery

    International Nuclear Information System (INIS)

    This paper compares MR angiography with conventional and digital subtraction angiography (DSA) in arteriosclerosis and to find out whether arteriosclerotic vessel pathology is delineated correctly by MR angiography. MR angiographic findings in 103 cases were correlated with DSA and conventional angiographic findings. The angiograms were obtained in patients with arteriosclerosis before and after percutaneous recanalization or vascular surgery in the femoropopliteal region. For MR angiography, a flow-sensitive, three-dimensional, fast imaging with steady precision sequence with rephased and dephased subtracted images were used on a 1.5-T Magnetom imager. The scan time is 4-5 minutes

  4. Digital subtraction angiography (DSA). Work load and financial implications for a neuroradiology department.

    Science.gov (United States)

    Kingsley, D P; Butler, P; Rowe, G M; Travis, R C; Wylie, I G

    1989-01-01

    A four year study has been undertaken into the effects on the workload and cost implications of the introduction of digital subtraction angiography (DSA) in a large United Kingdom teaching hospital. The increase in workload has been entirely due to the ability to perform intravenous angiography. DSA is cheaper than conventional angiography if more than 210 cases are undertaken each year. This difference is accounted for by the reduced use of X-ray film. However, intravenous angiography is more expensive because of the use of large volumes of nonionic medium. PMID:2674769

  5. Radiation Dose and Image Quality from Coronary Angiography in 320-Detecor Row CT

    International Nuclear Information System (INIS)

    Introduction: Coronary Computed Tomography Angiography examinations are increasing rapidly. New Computed Tomography has been developed to improve image quality with the patient dose reduction. The purpose of this study is to evaluate radiation dose and image quality of Coronary Computed Tomography Angiography in patients using 320-detector row CT. Methods: Forty-one patients referred for cardiac CT examinations at King Chulalongkorn Memorial Hospital were included in this study. All coronary computed tomographic angiography (CCTA) examinations were performed on the 320-detector row CT, Toshiba Aquilion One. Scanning protocol was investigated on dose estimates and image quality. Patients were scanned base on heart rate (HR) by HR75 bpm use retrospective with dose modulation. Scanning parameters, kVp, mAs, HR, BMI, CTDIvol(mGy) and DLP(mGy.cm), were recorded to study the factors affecting the image quality and patient dose. And mA and kVp setting depend on BMI of the patient. Effective dose is calculated from DLP using specific conversion factor. The image quality was evaluated in 4 vessels by two radiologists. Noise assessment was also studied quantitatively. Results: The patient effective dose in prospective gating 70-80% was 3.6 ± 0.9 mSv, prospective gating 30-80% (1R-R) was 6.3 ± 1.9 mSv, and 30-80% (2R-R) was 10.8 ± 1.8 mSv and in retrospective with tube current modulation was 12.1± 7.7 mSv. Image noise was highest in PGT 70-80% 1R-R and decreased in RGT with tube current modulation, PGT 30-80% 1R-R and lowest in PGT 30-80% 2 R-R. And overall qualitative image quality was mostly good to excellent score. Discussion: The heart rate, heart rate variability and disease of the patient are affecting in the radiation dose and image quality so the suitable acquisition protocol used could be necessary. the effective dose and the image noise for the image quality. (author)

  6. Stent assisted angioplasty in intracranial atherosclerotic severe stenoses. Efficacy of CT angiography in evaluation of the stented vessels

    International Nuclear Information System (INIS)

    Our aim was to determine whether CT angiography (CTA) is suitable for the evaluation of patency and in-stent restenoses in small vessel stents for intracranial angioplasty. From June, 2000 to February, 2006, 26 patients received stent-assisted angioplasty for intracranial atherosclerotic lesions. The procedure was successfully performed in all patients. Multi plannar reconstruction (MPR) was evaluated for image quality on three groups with I-E (Internal-External diameter) ratios, as follows: Group A=I-E ratio>0.5 (Possible to evaluate stent lumen, high certainty), Group B=0.31≤I-E ratio≤0.5 (Possible to evaluate stent lumen, low certainty), Group C=I-E ratio≤0.31 (Uninterpretable). We examined the possibility of evaluating the stent lumen, maching the identity with the angiographical findings, and finding a predictor of favorable CTA findings. CTA was performed in 19 patients. It was possible to evaluate the visible stent lumen in 14 patients (73.7%); 10 patients comprised group A, 4 patients group B, 5 patients group C. Nine patients were evaluated with both CTA and angiography after the stenting. CTA findings were identical with angiographical findings in 8 of 9 patients. Stent diameter was associated with CTA findings, all of the patients who received 4.0 mm stents were in group A. The stent lumen may be visualized and evaluated in most stents using CTA, but tend to only be interpretable in the small vessels. (author)

  7. Visual art and visual perception

    OpenAIRE

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their weight in gold”. I perceive a metabletic (van den Berg, 1956) parallel to philosophy transforming itself into speculative logic games, and psychology going cognitive by freeing itself from phenomen...

  8. Visual Education

    DEFF Research Database (Denmark)

    Buhl, Mie; Flensborg, Ingelise

    2010-01-01

    The intrinsic breadth of various types of images creates new possibilities and challenges for visual education. The digital media have moved the boundaries between images and other kinds of modalities (e.g. writing, speech and sound) and have augmented the possibilities for integrating the functi......The intrinsic breadth of various types of images creates new possibilities and challenges for visual education. The digital media have moved the boundaries between images and other kinds of modalities (e.g. writing, speech and sound) and have augmented the possibilities for integrating...... to emerge in the interlocutory space of a global visual repertoire and diverse local interpretations. The two perspectives represent challenges for future visual education which require visual competences, not only within the arts but also within the subjects of natural sciences, social sciences, languages...

  9. Extended Renal Outcomes with Use of Iodixanol versus Iohexol after Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Horng-Ruey Chua

    2014-01-01

    Full Text Available The impact of isoosmolar versus low-osmolar contrast media (CM administration on contrast-induced acute kidney injury (CI-AKI and extended renal dysfunction (ERD is unclear. We retrospectively examined incidences of CI-AKI and ERD in patients who received iodixanol (isoosmolar versus iohexol (low-osmolar during angiography for cardiac indications. Of 713 patients, 560 (cohort A, 190 (cohort B, and 172 (cohort C had serum creatinine monitored at 3 days, 30 days, and 6 months after angiography, respectively. 18% of cohort A developed CI-AKI, which was more common with iodixanol than iohexol (22% versus 13%, P=0.006. However, patients given iodixanol were older with lower baseline estimated glomerular filtration rates (eGFR. On multivariate analysis, independent associations with higher CI-AKI risk include age >65 years, female gender, cardiac failure, ST-elevation myocardial infarction, intra-aortic balloon pump, and critical illness, but not CM type, higher CM load, or eGFR<45 mL/min/1.73 m2. 32% of cohort B and 34% of cohort C had ERD at 30 days and 6 months, while 44% and 41% of subcohorts had ERD at 90 days and 1 year, respectively. CI-AKI, but not CM type, was associated with medium- and longer-term ERD, with 3-fold higher risk. Advanced age, emergent cardiac conditions, and critical illness are stronger predictors of CI-AKI, compared with CM-related factors. CI-AKI predicts longer-term ERD.

  10. Diagnostic performance of computed tomography coronary angiography (from the Prospective National Multicenter Multivendor EVASCAN Study).

    Science.gov (United States)

    Gueret, Pascal; Deux, Jean-François; Bonello, Laurent; Sarran, Anthony; Tron, Christophe; Christiaens, Luc; Dacher, Jean-Nicolas; Bertrand, David; Leborgne, Laurent; Renard, Cedric; Caussin, Christophe; Cluzel, Philippe; Helft, Gerard; Crochet, Dominique; Vernhet-Kovacsik, Hélène; Chabbert, Valérie; Ferrari, Emile; Gilard, Martine; Willoteaux, Serge; Furber, Alain; Barone-Rochette, Gilles; Jankowski, Adrien; Douek, Philippe; Mousseaux, Elie; Sirol, Marc; Niarra, Ralph; Chatellier, Gilles; Laissy, Jean-Pierre

    2013-02-15

    Computed tomographic coronary angiography (CTCA) has been proposed as a noninvasive test for significant coronary artery disease (CAD), but only limited data are available from prospective multicenter trials. The goal of this study was to establish the diagnostic accuracy of CTCA compared to coronary angiography (CA) in a large population of symptomatic patients with clinical indications for coronary imaging. This national, multicenter study was designed to prospectively evaluate stable patients able to undergo CTCA followed by conventional CA. Data from CTCA and CA were analyzed in a blinded fashion at central core laboratories. The main outcome was the evaluation of patient-, vessel-, and segment-based diagnostic performance of CTCA to detect or rule out significant CAD (≥50% luminal diameter reduction). Of 757 patients enrolled, 746 (mean age 61 ± 12 years, 71% men) were analyzed. They underwent CTCA followed by CA 1.7 ± 0.8 days later using a 64-detector scanner. The prevalence of significant CAD in native coronary vessels by CA was 54%. The rate of nonassessable segments by CTCA was 6%. In a patient-based analysis, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of CTCA were 91%, 50%, 68%, 83%, 1.82, and 0.18, respectively. The strongest predictors of false-negative results on CTCA were high estimated pretest probability of CAD (odds ratio [OR] 1.97, p <0.001), male gender (OR 1.5, p <0.002), diabetes (OR 1.5, p <0.0001), and age (OR 1.2, p <0.0001). In conclusion, in this large multicenter study, CTCA identified significant CAD with high sensitivity. However, in routine clinical practice, each patient should be individually evaluated, and the pretest probability of obstructive CAD should be taken into account when deciding which method, CTCA or CA, to use to diagnose its presence and severity.

  11. Importance of oral fluid intake after coronary computed tomography angiography: An observational study

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Daiji [Department of Cardiology, Nagoya University Graduate School of Medicine (Japan); Department of Cardiology, Kami-iida Daiichi General Hospital, Nagoya (Japan); Isobe, Satoshi, E-mail: sisobe@med.nagoya-u.ac.jp [Department of Cardiology, Nagoya University Graduate School of Medicine (Japan); Department of Cardiology, Kami-iida Daiichi General Hospital, Nagoya (Japan); Sato, Kimihide; Ohashi, Toshio [Division of Radiology, Kami-iida Daiichi General Hospital, Nagoya (Japan); Fujiwara, Yuka; Ohyama, Hisato [Division of Nursing, Kami-iida Daiichi General Hospital, Nagoya (Japan); Ishii, Hideki; Murohara, Toyoaki [Department of Cardiology, Nagoya University Graduate School of Medicine (Japan)

    2011-01-15

    Background: The prevention of contrast-induced acute kidney injury (AKI) after coronary computed tomography angiography (CCTA) is important because patients referred for CCTA often need further contrast exposure such as an invasive coronary angiography. We aimed to examine the effects of oral volume intake on renal function in patients with preserved renal function referred for CCTA. Methods: We enrolled 180 patients who were referred for CCTA. The serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) levels were measured before, 24 h, and a mean of 4.8 days after CCTA. The amount of unrestricted oral fluid intake for 24 h was checked. The patients were divided into two groups: 106 subjects with a rise in SCr after CCTA (group A); and 74 without (group B). Results: Significant correlations were observed between the amount of oral fluid intake and the percentage changes in SCr (%SCr) (r = -0.66, p < 0.0001) as well as the absolute changes in eGFR ({Delta}eGFR) (r = 0.65, p < 0.0001). The percentage of patients showing hemoglobin-A1c (HbA1c) {>=} 6.5% was greater in group A than in group B (29% vs. 18%, p < 0.001). Patients with HbA1c {>=} 6.5% showed higher %SCr and lower {Delta}eGFR compared to those without it. Multiple regression analysis revealed that the amount of oral fluid intake was the only independent predictor for a rise in SCr ({beta} = -0.731, p < 0.0001). Conclusion: Oral volume intake after CCTA is a very simple but important prophylactic procedure for contrast-induced AKI especially in diabetic patients.

  12. Contrast-enhanced MR angiography for differentiation between perigastric and submucosal gastric fundal varices; Kontrastmittelverstaerkte MR-Angiographie zur Differenzierung zwischen perigastrischen und submukoesen Fundusvarizen des Magens

    Energy Technology Data Exchange (ETDEWEB)

    Willmann, J.K.; Boehm, T.; Lutz, A.M.; Goepfert, K.; Marincek, B.; Weishaupt, D. [Inst. fuer Diagnostische Radiologie, Universitaetsspital Zuerich (Switzerland); Bauerfeind, P. [Abt. fuer Gastroenterologie, Universitaetsspital Zuerich (Switzerland)

    2003-04-01

    Purpose: To evaluate contrast-enhanced MR angiography for the distinction between perigastric and submucosal fundal varices. Materials and Methods: Nineteen consecutive patients with clinically suspected fundal varices underwent contrast-enhanced MR angiography and endoscopic ultrasound (EUS) within one week. Diagnostic confidence for the detection of perigastric and submucosal fundal varices was compared between MR angiography (two radiologists) and EUS (one gastroenterologist), and the agreement of size and location was evaluated. Results: Both MR angiography and EUS detected perigastric varices in all 19 patients and submucosal fundal varices in 14 of the 19 patients. The interobserver reliability of MR angiography was good for measuring the variceal diameter ({kappa} = 0.76) and excellent for localizing the varices ({kappa} = 1.0). EUS and MR angiography agreed in 12 of 14 patients (86%) in determining variceal diameter and location. Conclusions: Contrast-enhanced MR angiography is comparable to endoscopic ultrasound in the detection and characterization of gastric fundal varices. (orig.) [German] Fragestellung: Das Ziel dieser Studie war es, die kontrastmittelverstaerkte MR-Angiographie bei der Diagnose von Fundusvarizen des Magens, insbesondere bei der Differenzierung von perigastrischen und submukoesen Fundusvarizen mit dem endoskopischen Ultraschall (EUS) zu vergleichen. Methoden: Neunzehn Patienten mit klinischem Verdacht auf Fundusvarizen wurden prospektiv in die Studie eingeschlossen und innerhalb einer Woche mittels kontrastmittelverstaerkter MR-Angiographie und EUS untersucht. Die Uebereinstimmungen zwischen MR-Angiographie (Radiologe 1 und 2) und EUS (1 Gastroenterologe) bei der diagnostischen Sicherheit bezueglich der Diagnose perigastrischer und submukoeser Fundusvarizen sowie bei der Groessen- und Lokalisationsbestimmung submukoeser Fundusvarizen wurden untersucht. Ergebnisse: Sowohl bezueglich der Diagnose perigastrischer (19/19 Patienten) als

  13. Stereoscopic Vascular Models of the Head and Neck: A Computed Tomography Angiography Visualization

    Science.gov (United States)

    Cui, Dongmei; Lynch, James C.; Smith, Andrew D.; Wilson, Timothy D.; Lehman, Michael N.

    2016-01-01

    Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching…

  14. Reliability of myocardial perfusion quantification in angiography using a digital flat panel cardiac system

    Science.gov (United States)

    Perrin, Muriel; Vaillant, Regis; Gavit-Houdant, Laurence; Lienard, Jean; Benali, Karim

    2002-04-01

    Discordance between lesion severity from angiocardiography and physiological effects has been reported elsewhere. Quantification of myocardial perfusion during the angiography procedure may supply additional information about short- and long-term outcomes and may be helpful for clinical decision making. In previous works, myocardial perfusion has been assessed using time density curves (TDC), which represent the contrast medium dilution over time in the myocardium. The mean transit time (MTT), derived from the TDC, has been reported as a good indicator of the regional myocardial perfusion. Our objective is to estimate the accuracy and reproducibility of MTT estimation on digital flat panel (DFP) images. We have simulated typical myocardium TDC obtained with a DFP cardiac system (Innova 2000, GE), taking into account scatter and noise. Logarithmic or linear subtractions have been applied to derive a contrast medium concentration proportional quantity from image intensity. A non-linear minimisation realises the model curve fitting. MTT estimates are more stable with linear subtraction in presence of scatter. However logarithmic subtraction presents smaller bias when scatter level is small. Both approaches are equally sensible to image noise. Linear subtraction should be preferred. Image noise has a high influence on MTT accuracy and we may reduce.

  15. Atorvastatin and prevention of contrast induced nephropathy following coronary angiography

    Directory of Open Access Journals (Sweden)

    Peyman Bidram

    2015-01-01

    Full Text Available Background: Contrast induced nephropathy (CIN is one of the most common complications after radiographic procedures using intravascular radiocontrast media. The aim of the current study was to assess the effect of atorvastatin on prevention of CIN in patients undergoing coronary angiography. Materials and Methods: In a clinical trial study, 200 patients referred for angiography were randomly divided into two groups of using 80 mg atorvastatin and placebo before the procedure. Furthermore, 100 patients who were under chronic treatment of statins were included as the third group. Serum creatinine (Scr levels before and after the procedure were evaluated and incidence of CIN (post-procedural Scr of >0.5 mg/dl or >25% from baseline was assessed. Results: Mean age of the participants was 60.06 ± 0.69 years and 276 (92% were male. There were no significant differences between group with respect to age and gender. In pre-operation atorvastatin, placebo and long term statin groups, the incidence of CIN was 1%, 2% and 1%, and mean changes of Glomerular filtration rate (GFR was 3.68 ± 1.32, −0.77 ± 1.21 and 1.37 ± 0.86; and mean changes of creatinine (Cr was −0.05 ± 0.02, 0.02 ± 0.02 and −0.01 ± 0.01 respectively. (P = 0.776, 0.026 and 0.041 respectively. In pre-operation atorvastatin group, Cr decreased, and GFR increased significantly (P = 0.019 and 0.007 respectively. Conclusion: pre-operation short term high dose atorvastatin use was associated with a significant decrease in serum Cr level and increase in GFR after angiography.

  16. CE-MR Angiography at 3.0 T Magnetic Field in the Study of Spinal Dural Arteriovenous Fistula: Preliminary Results

    OpenAIRE

    Albini Riccioli, L.; Marliani, A. F.; Ghedin, P.; Agati, R.; M. Leonardi

    2007-01-01

    We report technical data and results in eight patients studied with spinal contrast-enhanced MR angiography (CE-MRA). We used a 3.0 Tesla device, dedicated phased array coil and time resolved imaging of contrast kinetics (TRICKS) sequences to visualize the feeder vessels in patients with vascular malformations. TRICKS is a method of 3D CE-MRA providing temporal information. Thanks to its high temporal and spatial resolution and high signal/noise ratio the TRICKS optimized sequence at 3.0 T yi...

  17. MR-Angiography in young adults with cerebral infarction

    International Nuclear Information System (INIS)

    Out of 111 patient with cerebral infarction of uncertain etiology, who underwent a magnetic resonance angiography (MRA) study, a group of seven patents younger than 40 years is described. In four patients MRA showed patterns typical for cerebral artery with concomitant infarction. Only in one patient MRA was inconspicuous. Especially in young stroke patients, where magnetic resonance tomography (MRT) is indicated, MRT should be completed with a MRA of the circle of Willis. Depending on negative or questionable MRA findings and clinical considerations an additional angio-graphical investigation is required. (authors)

  18. Digital subtraction angiography in the evaluation of chemodectomas

    Energy Technology Data Exchange (ETDEWEB)

    Vlahos, L.; Papathanasiou, M.; Gouliamos, A.; Dimakakos, P.; Papavassiliou, C.

    1988-05-01

    During the last 2 years eleven patients with surgically confirmed chemodectomas have been investigated by means of digital subtraction angiography (DSA). Seven patients underwent i.v. DSA, which revealed eight carotid body tumours, and in the remaining four with jugulotympanic chemodectomas intra-arterial (i.a.) DSA was performed. We found i.v. DSA an easy and satisfactory method for the investigation of carotid body tumours but when glomus intravagale, tympanicum or jugulare is suspected an i.a. selective injection is required.

  19. Radionuclide angiography: Role of the stroke-volume ratio

    International Nuclear Information System (INIS)

    Intracardiac shunts and valvular regurgitation impose an abnormal flow pattern and a ventricular volume overload condition that can be readily assessed by radionuclide angiography. Recent advances in the radionuclide angiographic measurement of ventricular volumes (diastolic, systolic, forward ejected, regurgitant, right, or left) have made it a practical technique for the detection, quantitation, and functional assessment of valvular regurgitation and shunts. The role of these new parameters in determining the prognosis and management of patients with ventricular overload requires further evaluation. In this review, the authors describe the proposed methods for comparison of total to systemic ventricular output and their use in the evaluation of patients with valvular regurgitation and shunts

  20. Stress reduction through music in patients undergoing cerebral angiography

    International Nuclear Information System (INIS)

    We studied the influence of music on stress reaction of patients during cerebral angiography. We randomised 30 patients to a music or a control group. We measured stress hormones, blood pressure, heart rate and psychological parameters. Patients examined without music showed rising levels of cortisol in plasma, indicating high stress levels, while cortisol in patients examined with music remained stable. Systolic blood pressure was significantly lower listening to music. Patients with a high level of fear did appear to benefit particularly from the music. (orig.)

  1. Transient Global Amnesia After Cerebral Angiography With Iomeprol

    Science.gov (United States)

    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

  2. Stress reduction through music in patients undergoing cerebral angiography

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, N.; Becker, H. [Dept. of Neuroradiology, Hannover Medical School (Germany); Schedlowski, M. [Dept. of Clinical Psychiatry and Psychotherapy, Hannover Medical School (Germany); Schuermeyer, T.H. [Dept. of Endocrinology, Hannover Medical School (Germany)

    2001-06-01

    We studied the influence of music on stress reaction of patients during cerebral angiography. We randomised 30 patients to a music or a control group. We measured stress hormones, blood pressure, heart rate and psychological parameters. Patients examined without music showed rising levels of cortisol in plasma, indicating high stress levels, while cortisol in patients examined with music remained stable. Systolic blood pressure was significantly lower listening to music. Patients with a high level of fear did appear to benefit particularly from the music. (orig.)

  3. Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Eric H. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); Amigenics, Inc, Las Vegas, NV (United States); Roach, Cayce J. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); University of Nevada Las Vegas, School of Life Sciences, Las Vegas, NV (United States); Ringdahl, Erik N. [University of Nevada Las Vegas, Department of Psychology, Las Vegas, NV (United States); Wynn, Brad L. [Family Medicine Spokane, Spokane, WA (United States); DeChancie, Sean M.; Mann, Nathan D. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); Diamond, Alan S. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); Orrison, William W. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); University of Nevada School of Medicine, Department of Medical Education, Reno, NV (United States)

    2011-05-15

    Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

  4. Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

    International Nuclear Information System (INIS)

    Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

  5. Angiography of the corpus cavernosum penis in the pony stallion during erection and quiescence.

    Science.gov (United States)

    Bartels, J E; Beckett, S D; Brown, B G

    1984-07-01

    Serial arteriography was used to determine the vascular pattern and blood flow in the penis of the pony stallion. Ponies were anesthetized with pentobarbital sodium, and catheters were surgically introduced into the internal pudendal and obturator arteries. The vascular anatomy was visualized by angiography via image-intensified fluoroscopy and was recorded on 70-mm film at 3 frames/s or by direct radiography. Blood flow into the corpus cavernosum penis (CCP) was limited during quiescence because the blood was immediately shunted into the venous system. After vasodilation with mild stimulation from an electroejaculator, there was increased filling of the CCP and corpus spongiosum penis. Contrast medium injected into the internal pudendal artery entered the bulb of the penis during peak erection, but medium injected into the obturator artery could not enter the crus penis during peak erection. The contrast medium stopped in the obturator artery at the edge of the ischiocavernous muscles due to the occlusion of the deep arteries of the penis by contraction of these muscles. When contrast medium was injected directly into the CCP near the glans to outline the body of the penis, there was no evidence of venous outlets along the body.

  6. Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter.

    Science.gov (United States)

    Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Liang, Kaicheng; Wang, Zhao; Cleveland, Cody; Booth, Lucas; Potsaid, Benjamin; Jayaraman, Vijaysekhar; Cable, Alex E; Mashimo, Hiroshi; Langer, Robert; Traverso, Giovanni; Fujimoto, James G

    2016-08-01

    We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec. Volumetric data consisting of 4200 circumferential images of 5,000 A-scans each over a 2.6 cm length, covering a ~13 cm(2) area is acquired in <18 seconds. A non-rigid image registration algorithm is used to suppress motion artifacts from non-uniform rotational distortion (NURD), cardiac motion or respiration. En face OCT images at various depths can be generated. OCT angiography (OCTA) is computed using intensity decorrelation between sequential pairs of circumferential scans and enables three-dimensional visualization of vasculature. Wide area volumetric OCT and OCTA imaging of the swine esophagus in vivo is demonstrated.

  7. THREE-DIMENSIONAL COLOR POWER ANGIOGRAPHY FOR HEPATOCELLULAR CARCINOMA: CORRELATION WITH CLINICOPATHOLOGY

    Institute of Scientific and Technical Information of China (English)

    赵玉珍; 李胜棉; 姚树坤

    2001-01-01

    Objective To evaluate characteristics of three-dimensional color power angiography (3D-CPA) imaging for hepatocellular carcinoma(HCC) and its clinicopathological significance.Methods ATL HDI-3000 ultrasonic system with C4-2 superwide frequency transducer was available. 58 cases were examined and classified by 3D-CPA in order to predict the prognosis of HCC. Comparative study of 3D-CPA with pathological outcome in 30 HCC was performed, pathological characteristics including size, microvessel density (MVD), and vascular pattern and distribution in tumor.Results Blood flows in tumor margin and branch-like intratumoral vessels were considered as the characteristics of 3D-CPA of HCC. There were more blood flow in tumor margin than in inner part as well as in large tumor than in small one. Vascular classification according to 3D-CPA visualization was related to MVD(P>0.1). The 3D-CPA appearance for HCC corresponded to pathological findings. One-year survival rate was different in different tumor stage of HCC(P<0.05).Conclusion 3D-CPA can reflect microvascular conditions of HCC and has clinicopathological significance in defining the TNM stage and predicting the prognosis.

  8. Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings

    Directory of Open Access Journals (Sweden)

    Tuğba Aydoğan

    2015-01-01

    Full Text Available A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes’ best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF was slightly increased. Spectral domain optical coherence tomography (SD-OCT showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL. One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease.

  9. Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography

    Science.gov (United States)

    Chen, Chieh-Li; Bojikian, Karine D.; Xin, Chen; Wen, Joanne C.; Gupta, Divakar; Zhang, Qinqin; Mudumbai, Raghu C.; Johnstone, Murray A.; Chen, Philip P.; Wang, Ruikang K.

    2016-06-01

    Optical coherence tomography angiography (OCTA) has increasingly become a clinically useful technique in ophthalmic imaging. We evaluate the repeatability and reproducibility of blood perfusion in the optic nerve head (ONH) measured using optical microangiography (OMAG)-based OCTA. Ten eyes from 10 healthy volunteers are recruited and scanned three times with a 68-kHz Cirrus HD-OCT 5000-based OMAG prototype system (Carl Zeiss Meditec Inc., Dublin, California) centered at the ONH involving two separate visits within six weeks. Vascular images are generated with OMAG processing by detecting the differences in OCT signals between consecutive B-scans acquired at the same retina location. ONH perfusion is quantified as flux, vessel area density, and normalized flux within the ONH for the prelaminar, lamina cribrosa, and the full ONH. Coefficient of variation (CV) and intraclass correlation coefficient (ICC) are used to evaluate intravisit and intervisit repeatability, and interobserver reproducibility. ONH perfusion measurements show high repeatability [CV≤3.7% (intravisit) and ≤5.2% (intervisit)] and interobserver reproducibility (ICC≤0.966) in all three layers by three metrics. OCTA provides a noninvasive method to visualize and quantify ONH perfusion in human eyes with excellent repeatability and reproducibility, which may add additional insight into ONH perfusion in clinical practice.

  10. Paramagnetic Gd(3+) labeled red blood cells for magnetic resonance angiography.

    Science.gov (United States)

    Aryal, Santosh; Stigliano, Cinzia; Key, Jaehong; Ramirez, Maricela; Anderson, Jeff; Karmonik, Christof; Fung, Steve; Decuzzi, Paolo

    2016-08-01

    Despite significant advances in contrast enhanced-magnetic resonance angiography, the lack of truly blood-pool agents with long circulating property is limiting the clinical impact of this imaging technique. The terminal half-life for blood elimination of most small molecular weight gadolinium (Gd) based extracellular fluid agents is about 1.5 h when administered intravenously to subjects with normal renal function. The small size of these extracellular fluid agents does not prevent them from extravasating, especially from damaged vessels which are generally hyperpermeable. Therefore, the development of novel, clinically relevant blood pool contrast agents is critically needed to improve outcomes in the prevention, detection, and treatment of vascular diseases. We have demonstrated the fusion strategies in which the Gd-liposome without any stealth property radically fuses with red blood cells (RBCs) forming MR glowing Gd-RBC with the order of magnitude enhancements in circulation half-life (t1/2 = 50 h) and r1 relaxivity (r1 = 19.0 mM(-1) s(-1)) of Gd. The in vivo contrast enhancement of Gd-RBC was studied by using 3T clinical MR scanner for extended period of time, which clearly visualized the abdominal aorta. In summary, the vascular delivery of blood pool agents may benefit from carriage by RBCs because it naturally stays within the vascular lumen. PMID:27192419

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

    Science.gov (United States)

    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.

  12. Visual cognition

    Energy Technology Data Exchange (ETDEWEB)

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

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

    International Nuclear Information System (INIS)

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

  14. Multislice computed tomography angiography in the diagnosis of coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    Zhong-Hua Sun; Yan Cao; Hua-Feng Li

    2011-01-01

    Multislice Cr angiography represents one of the most exciting technological revolutions in cardiac imaging and it has been increasingly used in the diagnosis of coronary artery disease.Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a potentially effective alternative to invasive coronary angiography in patients with suspected coronary artery disease.High diagnostic value has been achieved with multisfice CT angiography with use of 64-and more slice CT scanners.In addition,multislice CT angiography shows accurate detection and analysis of coronary calcium,characterization of coronary plaques,as well as prediction of the disease progression and major cardiac events.Thus,patients can benefit from multislice CT angiography that provides a rapid and accurate diagnosis while avoiding unnecessary invasive coronary angiography procedures.The aim of this article is present an overview of the clinical applications of multislice CT angiography in coronary artery disease with a focus on the diagnostic accuracy of coronary artery disease;prognostic value of coronary artery disease with regard to the prediction of major cardiac events; detection and quantification of coronary calcium and characterization of coronary plaques.Limitations of multislice Cr angiography in coronary artery disease are also briefly discussed,and future directions are highlighted.

  15. Assessment of feasibility of endovascular treatment of ruptured intracranial aneurysms with 16-detector row CT angiography

    NARCIS (Netherlands)

    M. van der Jagt (Mathieu); H.Z. Flach (Zwenneke); H.L.J. Tanghe (Hervé); S.L.M. Bakker (Stef); M.G.M. Hunink (Myriam); P.J. Koudstaal (Peter Jan); A. van der Lugt (Aad)

    2008-01-01

    textabstractBackground: It is unclear whether 16-detector row CT angiography (CTA) can replace digital subtraction angiography (DSA) to assess the feasibility of endovascular treatment (EVT) in the acute phase after aneurysmal subarachnoid hemorrhage. Methods: We studied 80 consecutive patients with

  16. Stereo Visual Localization Based on Motion Estimation in Disparity Space%基于视差空间运动估计的高精度立体视觉定位

    Institute of Scientific and Technical Information of China (English)

    许允喜; 陈方

    2012-01-01

    The motion estimation in stereo visual localization is usually carried out in 3D Euclidean space. 3D points are corrupted with heteroscedastic and anisotropic noise, and the depth direction of 3D reconstruction is less accurate than the two other direction. And therefore, the accuracy of motion estimation in 3D Euclidean space is low. We propose a new high-precision stereo visual localization algorithm based on motion estimation in disparity space. Initial robust motion parameters and matching inliers are obtained by four points closed-form linear motion estimation in disparity space combined with RANSAC algorithm. Then, we propose nonlinear motion optimization method based on L-M algorithm in the new disparity space re-projection error function. The mothod is appied to optimise the initial motion parameters. The noise in disparity space is homogeneous and isotropic, and our initial linear motion estimation and nonlinear optimization method all are carried out in disparity space and can achive globally minimum. Simulated and real experimental result show that our method can achive higher localization accuracy than traditional motion estimation method in 3D Euclidean space.%立体视觉定位算法的运动估计通常在3D欧式空间中进行,但由于特征点3D坐标的噪声各向异性且分布不均匀,3D重建在深度方向上比另两个方向上的准确性差,从而导致3D欧式空间运动估计精确不高.本文提出了一种新的基于视差空间运动估计的高精度立体视觉定位算法.算法首先采用视差空间4点闭环线性解法和RANSAC算法得到初始鲁棒运动估计和匹配内点.接着,利用新的视差空间再投影误差函数提出了基于LM算法的视差空间运动参数非线性优化方法,对初始运动参数进一步优化.视差空间噪声分布均匀且各向同性,本文的初始运动参数线性估计和非线性优化都在视差空间中进行且能达到全局最小.仿真实验和真实实验结

  17. “Real-world” comparison of non-invasive imaging to conventional catheter angiography in the diagnosis of cerebral aneurysms

    OpenAIRE

    Tomycz, Luke; Bansal, Neil K.; Hawley, Catherine R.; Goddard, Tracy L.; Ayad, Michael J; Mericle, Robert A.

    2011-01-01

    Background: Based on numerous reports citing high sensitivity and specificity of non-invasive imaging [e.g. computed tomography angiography (CTA) or magnetic resonance angiography (MRA)] in the detection of intracranial aneurysms, it has become increasingly difficult to justify the role of conventional angiography [digital subtraction angiography (DSA)] for diagnostic purposes. The current literature, however, largely fails to demonstrate the practical application of these technologies within...

  18. Indocyanine Green Angiography Guided Management of Vogt-Koyanagi-Harada Disease

    Directory of Open Access Journals (Sweden)

    Nadia Bouchenaki

    2011-01-01

    Full Text Available Purpose: To report the management of Vogt-Koyanagi-Harada (VKH disease based on indocyanine green angiography (ICGA. Methods: VKH patients with acute episodes of inflammation (inaugural or recurrent who had received standard ICGA-guided care were studied retrospectively. Standard of care included high dose systemic corticosteroids at presentation and close ICGA follow-up with addition of immunosuppressive agents and/or intensification of ongoing therapy when recurrent choroidal lesions were detected by ICGA. Visual acuity, number of subclinical recurrences, type and duration of therapy, proportion of quiescent patients after therapy, and ICGA findings were recorded. Results: Nine patients including 8 female and one male subject were studied. Five patients had inaugural disease and 4 presented with recurrent acute episodes. Visual acuity increased from 0.86±0.36 to 1.14±0.34 in the right eyes, and from 0.77±0.34 to 1.05±0.33 in the left eyes. The number of ICGA-detected occult choroidal recurrences amounted to 13. Mean duration of treatment was 30.1±34.6 months leading to recurrence-free status after discontinuation of therapy in 6 cases with mean duration of 29.5 months. Conclusion: Continuous monitoring and aggressive therapy guided by ICGA in VKH disease prolongs treatment as compared to textbook guidelines but offers the prospect of reaching inflammation-free status after discontinuation of therapy. Zero tolerance to subclinical choroidal inflammation avoids irremediable evolution towards sunset glow fundus in patients treated early after the initial acute inflammatory attack.

  19. Assessment of vessel diameters for MR brain angiography processed images

    Science.gov (United States)

    Moraru, Luminita; Obreja, Cristian-Dragos; Moldovanu, Simona

    2015-12-01

    The motivation was to develop an assessment method to measure (in)visible differences between the original and the processed images in MR brain angiography as a method of evaluation of the status of the vessel segments (i.e. the existence of the occlusion or intracerebral vessels damaged as aneurysms). Generally, the image quality is limited, so we improve the performance of the evaluation through digital image processing. The goal is to determine the best processing method that allows an accurate assessment of patients with cerebrovascular diseases. A total of 10 MR brain angiography images were processed by the following techniques: histogram equalization, Wiener filter, linear contrast adjustment, contrastlimited adaptive histogram equalization, bias correction and Marr-Hildreth filter. Each original image and their processed images were analyzed into the stacking procedure so that the same vessel and its corresponding diameter have been measured. Original and processed images were evaluated by measuring the vessel diameter (in pixels) on an established direction and for the precise anatomic location. The vessel diameter is calculated using the plugin ImageJ. Mean diameter measurements differ significantly across the same segment and for different processing techniques. The best results are provided by the Wiener filter and linear contrast adjustment methods and the worst by Marr-Hildreth filter.

  20. MR-angiography with intravenous administration of Gd-DTPA

    International Nuclear Information System (INIS)

    We carried out phase contrast MR-angiography of the lower extremities with intravenous administration of Gd-DTPA. Five healthy male volunteers, 25 to 40 years of age, were examined with a 0.5T MRI unit. We used fast scan (gradient echo) technique and it took about 8 minutes for whole procedure. Images were obtained before and after intravenous injection of Gd-DTPA. Injection dose was 0.1 mmol/kg. In two cases, we got images with variable flip angles. However angles of 30 or 40 degrees were thought to be best on the scan with Gd-DTPA. In three cases, we repeated short time procedures for about 4 minutes each time and continued to check the signal intensities of vessels for as long as one hour. The signal intensities greatly increased soon after administration of Gd-DTPA, and then they gradually decreased, but for as long as 60 minutes after administration they remained much higher than those before administration of Gd-DTPA. MR-angiography with Gd-DTPA was found very useful to demonstrate the peripheral femoral vessels clearly. No significant side effect was noticed in any case. Therefore, this method was thought to be very useful clinically. (author)

  1. 64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents

    Energy Technology Data Exchange (ETDEWEB)

    Maintz, David; Seifarth, Harald; Rink, Michael; Oezguen, Murat; Heindel, Walter; Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Raupach, Rainer; Flohr, Thomas [Siemens Medical Solutions, Forchheim (Germany); Sommer, Torsten [University of Bonn, Department of Radiology, Bonn (Germany)

    2006-04-15

    The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32x0.6 collimation, pitch 0.24, 680 mAs, 120 kV, rotation time 0.37 s. Four different image reconstructions were obtained with varying convolution kernels and section thicknesses: (1) soft, 0.6 mm, (2) soft, 0.75, (3) medium soft, 0.6, and (4) stent-optimized sharp, 0.6. To evaluate visualization characteristics of of the stent, the lumen diameter, intraluminal density and noise were measured. The high-resolution kernel offered significantly better average lumen visualization (57% {+-}10%) and more realistic lumen attenuation (222 HU {+-}66 HU) at the expense of increased noise (15.3 HU {+-}3.7 HU) compared with the soft and medium-soft CT angiography (CTA) protocol (p<0.001 for all). Stents with a lumen visibility of more than 66% were: Arthos pico, Driver, Flex, Nexus2, S7, Tenax complete, Vision (all 67%), Symbiot, Teneo (70%), and Radius (73%). Only ten stents showed a lumen visibility of less than 50%. Stent lumen visibility largely varies depending on the stent type. Even with the improved spatial resolution of 64-slice CT, a stent-optimized kernel remains beneficial for stent visualization when compared with the standard medium-soft CTA protocol. Using 64-slice CT and high-resolution kernel, the majority of stent products show a lumen visibility of more than 50% of the stent

  2. Monocular visual ranging

    Science.gov (United States)

    Witus, Gary; Hunt, Shawn

    2008-04-01

    The vision system of a mobile robot for checkpoint and perimeter security inspection performs multiple functions: providing surveillance video, providing high resolution still images, and providing video for semi-autonomous visual navigation. Mid-priced commercial digital cameras support the primary inspection functions. Semi-autonomous visual navigation is a tertiary function whose purpose is to reduce the burden of teleoperation and free the security personnel for their primary functions. Approaches to robot visual navigation require some form of depth perception for speed control to prevent the robot from colliding with objects. In this paper present the initial results of an exploration of the capabilities and limitations of using a single monocular commercial digital camera for depth perception. Our approach combines complementary methods in alternating stationary and moving behaviors. When the platform is stationary, it computes a range image from differential blur in the image stack collected at multiple focus settings. When the robot is moving, it extracts an estimate of range from the camera auto-focus function, and combines this with an estimate derived from angular expansion of a constellation of visual tracking points.

  3. Visual Working Memory Capacity and Proactive Interference

    OpenAIRE

    Hartshorne, Joshua K.

    2008-01-01

    BACKGROUND: Visual working memory capacity is extremely limited and appears to be relatively immune to practice effects or the use of explicit strategies. The recent discovery that visual working memory tasks, like verbal working memory tasks, are subject to proactive interference, coupled with the fact that typical visual working memory tasks are particularly conducive to proactive interference, suggests that visual working memory capacity may be systematically under-estimated. METHODOLOGY/P...

  4. Visual comparison for information visualization

    KAUST Repository

    Gleicher, M.

    2011-09-07

    Data analysis often involves the comparison of complex objects. With the ever increasing amounts and complexity of data, the demand for systems to help with these comparisons is also growing. Increasingly, information visualization tools support such comparisons explicitly, beyond simply allowing a viewer to examine each object individually. In this paper, we argue that the design of information visualizations of complex objects can, and should, be studied in general, that is independently of what those objects are. As a first step in developing this general understanding of comparison, we propose a general taxonomy of visual designs for comparison that groups designs into three basic categories, which can be combined. To clarify the taxonomy and validate its completeness, we provide a survey of work in information visualization related to comparison. Although we find a great diversity of systems and approaches, we see that all designs are assembled from the building blocks of juxtaposition, superposition and explicit encodings. This initial exploration shows the power of our model, and suggests future challenges in developing a general understanding of comparative visualization and facilitating the development of more comparative visualization tools. © The Author(s) 2011.

  5. 基于2D-3D双目运动估计的立体视觉定位算法%Stereo Visual Localization Algorithm Based on 2D-3D Binocular Motion Estimation

    Institute of Scientific and Technical Information of China (English)

    许允喜; 蒋云良; 陈方

    2011-01-01

    Motion estimation algorithm of stereo vision is one of the important factors which affect the accuracy of stereo visual localization. The traditional 3D-3D motion estimation is greatly affected by noise, so the accuracy of algorithm is not high. We propose a new stereo visual localization algorithm based on 2D-3D binocular motion estimation. In our method, 2D image projection coordinates is directly used instead of 3D coordinates of feature after motion. Firstly, EPnP motion estimation is applied to determine matching inliers and initial motion parameters. We propose 2 x 2D-3D motion parameters optimization method based on Levenberg-Marquardt algorithm and geometric constraints between the 2D projection of binocular cameras. Optimal 2D-3D motion estimation is achieved by minimizing the error between the observed 2×2D image points and the re-projected 2×2D image points of stereo cameras from the reconstructed 3D features. Simulated experiment and outdoor real experiment show that our method performs well in accuracy and robustness, and are better than traditional 3D-3D methods.%运动估计算法是影响立体视觉定位精度的重要因素,传统的3D-3D运动估计算法受噪声影响很大,计算精度不高.本文提出了一种基于2D-3D双目运动估计的立体视觉定位算法.算法不使用运动后的特征点3D坐标,而直接利用其2D图像投影坐标.首先,利用EPnP运动估计算法确定匹配内点和初始运动参数.接着,利用双目相机之间的2D投影几何约束,提出了基于Levenberg-Marquardt算法的2×2D-3D运动参数优化算法,利用确定的匹配内点和初始运动参数,使特征点在立体相机左右图像上的再投影误差最小,从而达到最优的立体相机2D-3D运动估计.仿真实验和户外真实实验表明:本文算法获得了很高的计算精度、鲁棒性,大大优于传统的基于3D-3D运动估计的立体视觉定位算法.

  6. Accuracy of CT angiography in the assessment of the circle of Willis: comparison of volume-rendered images and digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Han, Ari; Yoon, Dae Young; Chang, Suk Ki (Dept. of Radiology, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)), email: evee0914@chollian.net; Lim, Kyoung Ja (Dept. of Radiology, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of); Dept. of Radiology, Kangwon National Univ. College of Medicine, Chuncheon, Kangwon-do (Korea, Republic of)); Cho, Byung-Moon (Dept. of Neurosurgery, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)); Shin, Yoon Cheol (Dept. of Thoracic Surgery, Kangdong Seong-Sim Hospital, Hallym Univ. College of Medicine, Seoul (Korea, Republic of)); Kim, Sam Soo (Dept. of Radiology, Kangwon National Univ. College of Medicine, Chuncheon, Kangwon-do (Korea, Republic of)); Kim, Keon Ha (Dept. of Radiology, Samsung Medical Center, Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of))

    2011-10-15

    Background Computed tomography angiography (CTA) is increasingly used for non-invasive imaging of the cerebrovascular diseases. Purpose To evaluate the accuracy of CTA in the assessment of the variation of the segment calibers of the circle of Willis. Material and Methods One hundred and 17 patients with acute SAH (51 men and 66 women, mean age 50.9 years) who underwent CTA using a 16 detector-row CT scanner and DSA were evaluated retrospectively. The CTA and DSA studies were performed within 24 h after the onset of symptoms and within 24 h of each other. A total of 819 arterial segments (A-comA, right and left A1 segment, right and left P-com A, and right and left P1 segment) of the circle of Willis were determined to be aplastic (grade 1), hypoplastic (grade 2), or normal-sized (grade 3) by blinded observers evaluating CTA volume-rendered images. The CTA results were then compared with findings on the corresponding DSA images (reference standard). Results The overall agreement between CTA and DSA was 92.4%. We had 62 (7.6%) cases of disagreement (58 cases of under-estimation and four cases of over-estimation by CTA) between tow modalities. The sensitivity and specificity of CTA in the detection of aplastic and normal-sized segments were more than 90%. In contrast, subgroup analysis of the hypoplastic segments showed a sensitivity of 52.6% and a specificity of 98.2%. Conclusion CTA is highly accurate in the assessment of anatomical variations of the circle of Willis; however, its sensitivity is limited in depicting hypoplastic segments

  7. Towards Dense Visual SLAM

    OpenAIRE

    Pietzsch, Tobias

    2011-01-01

    Visual Simultaneous Localisation and Mapping (SLAM) is concerned with simultaneously estimating the pose of a camera and a map of the environment from a sequence of images. Traditionally, sparse maps comprising isolated point features have been employed, which facilitate robust localisation but are not well suited to advanced applications. In this thesis, we present map representations that allow a more dense description of the environment. In one approach, planar features are used to repr...

  8. Magnetic resonance angiography and CT angiography of persistent primitive olfactory artery: Incidence and association rate with aneurysm in Korea

    International Nuclear Information System (INIS)

    Japanese data indicates an incidence of persistent primitive olfactory artery (PPOA) of 0.14%. We studied the incidence of PPOA and associated cerebral vascular variation or anomalies in Korea. We retrospectively reviewed cranial magnetic resonance angiography (MRA) and computed tomography angiography (CTA) images of a total of 9841 patients of our institution. The diagnostic criterion of PPOA is extreme anterioinferior course of the proximal anterior cerebral artery, with a hairpin turn of the lateral projection. We found 29 cases (0.29%) with PPOA. The PPOA location was on the left in 19 cases, bilateral in 3 cases, and on the right in 7 cases. An aneurysm was found at the hairpin turn in 2 patients. There were aneurysms in other sites in 3 cases. There were hypoplasia of anterior cerebral artery in 3 cases, and fenestration of intracranial artery in 1 case. In Korean populations, the incidence of PPOA found in MRA and CTA was twice as high as that shown in the previous Japanese data. Within Korea, left side laterality is more common than right side or bilalterality. Aneurysmal dilatations at the hairpin turning point and aneurysms at other sites were found, and other vascular variations were observed in several cases

  9. Peripheral Arterial Disease. Contrast-Enhanced 3D MR Angiography of the Lower Leg and Foot Compared with Conventional Angiography

    International Nuclear Information System (INIS)

    Purpose: To determine whether contrast-enhanced 3D MR angiography (CE MRA) could replace digital subtraction angiography (DSA) for the evaluation of atherosclerotic peripheral vascular disease of the lower leg and foot. Material and Methods: Thirty-five patients with symptoms of atherosclerotic disease of the leg were examined prospectively with CE MRA of the foot and the lower legs as well as with DSA from the aorta to the pedal arches. The MRA technique was focused on optimal imaging of the arteries of the foot. Results: The agreement between CE MRA and DSA for grading of stenosis was moderate to good (weighted -values 0.48-0.80). The sensitivity of CE MRA for detection of significant stenosis (50%) was 92% and the specificity was 64% with DSA as gold standard. Conclusion: CE MRA is a fairly accurate method for the demonstration of atherosclerotic disease below the knee including the pedal arches. It can replace DSA for the assessment of distal arteries in patients with impaired renal function. However, image quality and resolution still needs to be improved before CE MRA can become the method of choice in all patients

  10. Comparison of 16-row multislice CT angiography with conventional angiography for detection and evaluation of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Donmez, Halil; Serifov, Elman; Kahriman, Guven [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Mavili, Ertugrul, E-mail: ertmavili@yahoo.com [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Durak, Ahmet Candan [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Menkue, Ahmet [University of Erciyes, School of Medicine, Department of Neurosurgery, Kayseri (Turkey)

    2011-11-15

    Purpose: The aim of this study is to compare the diagnostic performance of 16-row computed tomographic angiography (MDCTA) with digital subtraction angiography (DSA) for the detection and characterization of intracranial aneurysms in patients with nontraumatic subarachnoid hemorrhages (SAH). Materials and methods: One-hundred and twelve consecutive patients with suspected intracranial aneurysm underwent both 16-row MDCTA and DSA. The MDCT angiograms were interpreted in a blinded fashion by using combination with VRI, MIP and MPR techniques. Sensitivity specificity and accuracy were calculated for the CTA and DSA. The results were compared with each other. The DSA reader's interpretation was accepted as the reference standard. Results: A total of 164 aneurysms were detected at DSA in 112 patients, no aneurysms were detected by DSA and MDCTA in 16 patients. Eight aneurysms were missed by MDCTA. The overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 95.1%, 94.1%, and 95%, respectively. According to the size of the aneurysm less than 3 mm; sensitivity, specificity and diagnostic accuracy of MDCTA were 86.1%, 94.1%, 88.6%, respectively. Conclusion: This study suggests that MDCTA is equally as sensitive as DSA in the detection of intracranial aneurysms of greater than 3 mm, and it also reveals 100% detection rate for ruptured aneurysms.

  11. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  12. Visualization of congenital thoracic vascular anomalies using multi-detector row computed tomography and two- and three-dimensional post-processing

    Energy Technology Data Exchange (ETDEWEB)

    Schertler, Thomas [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Wildermuth, Simon [Institute of Diagnostic Radiology, Kantonsspital St.Gallen (Switzerland)]. E-mail: Simon.Wildermuth@kssg.ch; Teodorovic, Ninoslav [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Mayer, Dieter [Division of Cardiovascular Surgery, University Hospital Zurich (Switzerland); Marincek, Borut [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Boehm, Thomas [Department of Medical Radiology, Institute of Diagnostic Radiology, University Hospital Zurich (Switzerland); Department of Medical Radiology, Institute of Diagnostic Radiology, Kantonsspital Chur (Switzerland)

    2007-01-15

    Anomalies of the vascular system are caused by false embryogenesis and are therefore present from birth. Single-detector row spiral computed tomography angiography (CTA) and multi-detector row computed tomography angiography (MDCTA) have gained increasing importance in the non-invasive assessment of vascular pathologies and replace conventional angiography in many cases. High-resolution volumetric datasets that are acquired during a single breath-hold give the possibility of two- (2D) and three-dimensional (3D)-post-processing. Due to post-processing, even complex vascular malformations are visualized in an understandable way. Furthermore, CTA, in contrast to conventional angiography, depicts not only the vascular structures but also allows assessment of the surrounding anatomical structures. We present cases of rare congenital anomalies of the thoracic vessels using MDCT with special respect to 2D- and 3D-post-processing.

  13. A comparison between magnetic resonance angiography at 3 teslas (time-of-flight and contrast-enhanced and flat-panel digital subtraction angiography in the assessment of embolized brain aneurysms

    Directory of Open Access Journals (Sweden)

    Guilherme S. Nakiri

    2011-01-01

    Full Text Available PURPOSE: To compare the time-of-flight and contrast-enhanced- magnetic resonance angiography techniques in a 3 Tesla magnetic resonance unit with digital subtraction angiography with the latest flat-panel technology and 3D reconstruction in the evaluation of embolized cerebral aneurysms. INTRODUCTION: Many embolized aneurysms are subject to a recurrence of intra-aneurismal filling. Traditionally, imaging surveillance of coiled aneurysms has consisted of repeated digital subtraction angiography. However, this method has a small but significant risk of neurological complications, and many authors have advocated the use of noninvasive imaging methods for the surveillance of embolized aneurysms. METHODS: Forty-three aneurysms in 30 patients were studied consecutively between November 2009 and May 2010. Two interventional neuroradiologists rated the time-of-flight-magnetic resonance angiography, the contrast-enhanced-magnetic resonance angiography, and finally the digital subtraction angiography, first independently and then in consensus. The status of aneurysm occlusion was assessed according to the Raymond scale, which indicates the level of recanalization according to degrees: Class 1: excluded aneurysm; Class 2: persistence of a residual neck; Class 3: persistence of a residual aneurysm. The agreement among the analyses was assessed by applying the Kappa statistic. RESULTS: Inter-observer agreement was excellent for both methods (K = 0.93; 95 % CI: 0.84-1. Inter-technical agreement was almost perfect between time-of-flight-magnetic resonance angiography and digital subtraction angiography (K = 0.98; 95 % CI: 0.93-1 and between time-of-flight-magnetic resonance angiography and contrast-enhanced-magnetic resonance angiography (K = 0.98; 95% CI: 0.93-1. Disagreement occurred in only one case (2.3%, which was classified as Class I by time-of-flight-magnetic resonance angiography and Class II by digital subtraction angiography. The agreement between

  14. Visual cognition

    Energy Technology Data Exchange (ETDEWEB)

    Pinker, S.

    1985-01-01

    This collection of research papers on visual cognition first appeared as a special issue of Cognition: International Journal of Cognitive Science. The study of visual cognition has seen enormous progress in the past decade, bringing important advances in our understanding of shape perception, visual imagery, and mental maps. Many of these discoveries are the result of converging investigations in different areas, such as cognitive and perceptual psychology, artificial intelligence, and neuropsychology. This volume is intended to highlight a sample of work at the cutting edge of this research area for the benefit of students and researchers in a variety of disciplines. The tutorial introduction that begins the volume is designed to help the nonspecialist reader bridge the gap between the contemporary research reported here and earlier textbook introductions or literature reviews.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jabbarli, Ramazan; Shah, Mukesch; Hippchen, Beate; Velthoven, Vera van [University Hospital of Freiburg, Department of Neurosurgery, Freiburg/Breisgau (Germany); Taschner, Christian [University Hospital of Freiburg, Department of Neuroradiology, Freiburg (Germany); Kaier, Klaus [University Hospital of Freiburg, Institute for Medical Biometry and Medical Informatics, Freiburg (Germany)

    2014-10-15

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

  16. Correlation of myocardial perfusion scintigraphy and coronary angiography; Korrelation der Myokardszintigraphie mit der Koronarangiographie

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T. [Freiburg Univ. (Germany). Abt. Klinische Nuklearmedizin

    1999-06-01

    Discrepancy in findings of coronary angiography and myocardial perfusion-SPECT mostly reflect the hemodynamic effect of the pathological coronary morphology rather than misinterpretation by welltrained nuclear medicine physicians. Thus, perfusion scintigraphy gives a valuable completion of the angiographic findings. Consequently, forecast of coronary stenoses loses importance. The intention of cardiovascular medicine focuses more and more on functional statements. The detection of ischemia is not enough for correlated evaluation of SPECT/PET and coronary angiography. At least, assignment of perfusion defects and vascular territories is necessary. Quantitative evaluation and display of bull's eye are helpful and superior to visual interpretation. Due to the variability of the coronary vascular tree, assignment of angiographic and scintigraphic findings may sometimes remain ambiguous. Moreover, in patients with multivessel disease the detection of less stenosed vessels can be hidden if the stress tolerance is limited by the most severe stenosis. Other factors like morphology, length, and location of a stenosis, collaterals and endothelial dysfunction may also modify myocardial perfusion. Thus 'sensitivity' and 'specificity' of assignment of ischemia to a vascular territory ranges between 62% and 86%. With respect to a high-quality standard of the examinations and to the methodical limitations, head to head comparison of scintigraphic and angiographic images enable evaluation of the hemodynamic consequences of stenoses of a distinct coronary artery. The discrepancy of scintigraphic and angiographic findings in particular can lead to more reliable conclusions than the single examination does with direct impact on decision-making regarding medical or invasive therapy, complete or partial revascularization, and the selection of the vessel which has to be revascularized. Correlation of scintigraphy and angiography enables an individual planning of

  17. Utility of CT angiography in cervical spine trauma: analysis of radiation and cost

    Directory of Open Access Journals (Sweden)

    Waqas Shuaib

    2014-12-01

    Full Text Available Purpose: Vertebral artery injuries (VAIs can be seen in cervical injuries. This investigation was conducted to assess the impact of head and neck computed tomography (CT angiography (CTA on planning treatment of vertebral artery injuries, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast material. Methods: This retrospective review included all patients who underwent CT of the cervical spine and CTA of the head and neck from March 2011 to October 2012 at a single institution. Patients were divided into two groups, those with and those without cervical spine fracture appreciated on CT of the cervical spine. The frequency of vascular injury on CTA in those with a cervical fracture was assessed. The frequency of vascular injury treatment and modifications owed to a positive CTA of head and neck were also assessed. A study was considered appropriate if it was ordered in accordance with the modified Denver Screening criteria. Effective radiation dose (mSv was calculated by multiplying dose length product (DLP from the scanner with the standard conversion coefficient (k (k = 0.0021 mSv/mGy x cm.Results: In the 387 CTAs of head and neck, a cervical injury was recorded in 128 patients. Twenty CTA scans were correctly ordered for non-spinal indications, and 19 were ordered off protocol. CTA was found positive in 1 patient for whom the imaging was off protocol and 1 for whom the clinical indication was non-cervical. There were 19 positive CTA cases of head and neck, none of which underwent surgical intervention. CTA was positive in 13 of 48 patients who had suffered a C2 fracture; this accounted for 13 of the 19 positive CTA studies (p < 0.01. Estimated fee for CTA was $3783, and radiation exposure was 4 mSv with a standard deviation (±1.3. Conclusion: CTA of head and neck ordered off an institutional imaging protocol has a low probability of being positive. Adherence to protocols for CTA of

  18. Computed tomography coronary angiography accuracy in women and men at low to intermediate risk of coronary artery disease

    International Nuclear Information System (INIS)

    To investigate the diagnostic accuracy of CT coronary angiography (CTCA) in women at low to intermediate pre-test probability of coronary artery disease (CAD) compared with men. In this retrospective study we included symptomatic patients with low to intermediate risk who underwent both invasive coronary angiography and CTCA. Exclusion criteria were previous revascularisation or myocardial infarction. The pre-test probability of CAD was estimated using the Duke risk score. Thresholds of less than 30 % and 30-90 % were used for determining low and intermediate risk, respectively. The diagnostic accuracy of CTCA in detecting obstructive CAD (≥50 % lumen diameter narrowing) was calculated on patient level. P < 0.05 was considered significant. A total of 570 patients (46 % women [262/570]) were included and stratified as low (women 73 % [80/109]) and intermediate risk (women 39 % [182/461]). Sensitivity, specificity, PPV and NPV were not significantly different in and between women and men at low and intermediate risk. For women vs. men at low risk they were 97 % vs. 100 %, 79 % vs. 90 %, 80 % vs. 80 % and 97 % vs. 100 %, respectively. For intermediate risk they were 99 % vs. 99 %, 72 % vs. 83 %, 88 % vs. 93 % and 98 % vs. 99 %, respectively. CTCA has similar diagnostic accuracy in women and men at low and intermediate risk. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Yuya, E-mail: r06118@hotmail.co.jp; Nishimura, Jun-ichi, E-mail: jun-ichi-n@nifty.com; Hase, Soichiro, E-mail: haseman@hotmail.co.jp; Yamasaki, Motoshige, E-mail: genyamasaki@gmail.com [Kawasaki Saiwai Hospital, Department of Interventional Radiology (Japan)

    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.

  20. Didactics and training in cardiovascular computed tomography angiography.

    Science.gov (United States)

    Bhojraj, Sanjay D; Al-Mallah, Mouaz H

    2009-01-01

    As the role of cardiovascular computed tomography angiography (CCTA) is further expanded through research, the use of this technology will expand as a result of demand both from medical professionals and the public. To ensure a standardized quality of interpretation of these scans in the face of an increased demand for physicians qualified to interpret these studies, the Society of Cardiovascular Computed Tomography, along with several other professional societies, has proposed a didactic curriculum for the study of CCTA. This review highlights the currently proposed didactic curriculum for the study of CCTA, examines current trends in training for both medical trainees and physicians in practice, and proposes future directions for the study of CCTA. PMID:19203747

  1. K-Edge Subtraction Angiography with Synchrotron X-Rays

    CERN Document Server

    Giacomini, J C

    1996-01-01

    The purpose of this project was to utilize dual energy, monochromatic X-rays produced from synchrotrons radiation in order to obtain noninvasive medical imaging. The application of synchrotrons radiation to medical imaging is based on the principle of iodine dichromography, first described by Bertil Jacobson of the Karolinska Institute in 1953. Medical imaging using synchrotrons radiation and K-edge dichromography was pioneered at Stanford University under the leadership of Dr. Ed Rubenstein, and the late Nobel Laureate in Physics, Dr. Robert Hofstadter. With progressive refinements in hardware, clinical-quality images were obtained of human coronary arteries utilizing peripheral injections of iodinated contrast agent. These images even now are far superior to those being presented by investigators using MRI as an imaging tool for coronary arteries. However, new supplies and instruments in the cardiac catheterization laboratory have served to transform coronary angiography into an outpatient procedure, with r...

  2. Evaluation of measurement parameters in clinical cerebral MR angiography

    International Nuclear Information System (INIS)

    A three-dimensional MR angiography technique was developed in patients and volunteers that can produce clinically useful studies of the cerebral vasculature with multiple views possible from a single data set acquisition. A low-flip angle, three-dimensional fast imaging with steady precessing sequence was found to provide the optimal vessel/soft-tissue contrast related to the tissues' relaxation parameters and inflow. The inflowing unsaturated spins and vessel orientation made an axial acquisition most effective. The flow-related phase dispersion could be largelly corrected with the appropriate orientation, strength, order, and combination of refocusing gradients with the shortest possible echo times. Reduced voxel size also affected the phase dispersion due to motion and field inhomogeneities. Postprocessing yielded projection images of vessels throughout the three-dimensional volume

  3. MR-angiography of the carotid and vertebral artery

    International Nuclear Information System (INIS)

    Magnetic Resonance Angiography (MRA) is a new, noninvasive modality for evaluation of carotid and vertebral artery disease. At a field strength of 1.5 T subtraction of flowrephased and dephased images, to eliminate signal from stationary tissue, offers no significant advantage over computerized postprocessing of rephased images. In a protocol of 3D-gradient-echo-sequenzes, using gradient motion refocussing (GMR), 27 patients with evidence of carotid or vertebral artery disease have been examined by MRA in comparison to ultrasound. MRA displays the carotid and vertebral arteries up to the cricle of Willis. Within short examination times, the method is sensitive in the detection of disturbed hemodynamics, secondary to vessel disease. The specific, at that time is limited. MRA has great potential in the diagnoses of cerebrovascular disease. (orig.)

  4. MR angiography of the abdominal aorta: Preliminary results

    International Nuclear Information System (INIS)

    Flowing blood can be demonstrated as bright signal in MR-imaging resulting in MR-angiography (MRA). This study presents the results of MRA using the 'time of flight'-effect in which projection angiograms along the longitudinal axis were established by a row of 2D-gradient echo (GE) images (FLASH) in breathhold technique. The method was proven in 5 normal volunteers and evaluated against DSA in 21 patients with aortic diseases. The preliminary results demonstrate a satisfactory flow signal in the normally perfused aorta; thus occlusions, stenoses, and aneurysms could be defined clearly. In smaller vessels the signal was still insufficient. Diagnostic problems of vascular overlapping can be solved in most cases by rotating the angiograms, and by additional analysis of individual 2D-GE images. In the present form the quality of MRA is still inferior to that of DSA. (orig.)

  5. Optimizing MR angiography of popliteal-tibial arteries

    International Nuclear Information System (INIS)

    Conventional time-of-flight MR angiography techniques have suffered from low signal-to-noise ratio (SNR), cardiac gating requirements, higher-order motion effects at stenoses and branch points, and limited area imaged, yielding poor vascular delineation for lower-extremity studies. The authors of this paper combined a rephase-dephase gradient-refocused-echo (GRE) pulse sequence with bolus injection of Gd-DTPA to improve peripheral MR angiographic image quality. Imaging was performed with a Siemens 1.5-T (Magnetom) imager and a specially constructed, 40-cm-long cylindrical coil. A three-dimensional steady-state free precession pulse sequence was used (flip angle = 25 degrees, 60-mm slab select, TR = 36 msec, TE = 18 msec). Signal from moving spins was alternatively focused and then dephased for each phase-encoding step followed by postprocessing subtraction of stationary components. Maximum-intensity projection algorithms were used to obtain projection MR angiograms

  6. Transvenous coronary angiography in humans with synchrotron radiation

    International Nuclear Information System (INIS)

    The transvenous coronary angiography project at the National Synchrotron Light Source (NSLS) is presently undergoing a significant upgrade to the hardware and software in the synchrotron medical facility. When completed, the project will have reached a level of maturity in the imaging technology which will allow the research team to begin to concentrate on medical research programs. This paper will review the status of the project and imaging technology and will discuss the current upgrades and future advanced technology initiatives. The advantages of using the radiation from a synchrotron, over that from a standard x-ray source, were the motivation for the project. A total of 23 human imaging sessions have been carried out with in the project. The primary goals have been to establish the imaging parameters and protocol necessary to obtain clinically useful images

  7. Statistical analysis of motion contrast in optical coherence tomography angiography

    CERN Document Server

    Cheng, Yuxuan; Pan, Cong; Lu, Tongtong; Hong, Tianyu; Ding, Zhihua; Li, Peng

    2015-01-01

    Optical coherence tomography angiography (Angio-OCT), mainly based on the temporal dynamics of OCT scattering signals, has found a range of potential applications in clinical and scientific researches. In this work, based on the model of random phasor sums, temporal statistics of the complex-valued OCT signals are mathematically described. Statistical distributions of the amplitude differential (AD) and complex differential (CD) Angio-OCT signals are derived. The theories are validated through the flow phantom and live animal experiments. Using the model developed in this work, the origin of the motion contrast in Angio-OCT is mathematically explained, and the implications in the improvement of motion contrast are further discussed, including threshold determination and its residual classification error, averaging method, and scanning protocol. The proposed mathematical model of Angio-OCT signals can aid in the optimal design of the system and associated algorithms.

  8. Statistical analysis of motion contrast in optical coherence tomography angiography

    Science.gov (United States)

    Cheng, Yuxuan; Guo, Li; Pan, Cong; Lu, Tongtong; Hong, Tianyu; Ding, Zhihua; Li, Peng

    2015-11-01

    Optical coherence tomography angiography (Angio-OCT), mainly based on the temporal dynamics of OCT scattering signals, has found a range of potential applications in clinical and scientific research. Based on the model of random phasor sums, temporal statistics of the complex-valued OCT signals are mathematically described. Statistical distributions of the amplitude differential and complex differential Angio-OCT signals are derived. The theories are validated through the flow phantom and live animal experiments. Using the model developed, the origin of the motion contrast in Angio-OCT is mathematically explained, and the implications in the improvement of motion contrast are further discussed, including threshold determination and its residual classification error, averaging method, and scanning protocol. The proposed mathematical model of Angio-OCT signals can aid in the optimal design of the system and associated algorithms.

  9. Cardiac CT angiography in children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Siripornpitak, Suvipaporn, E-mail: ssiripornpitak@yahoo.com [Division of Diagnostic Radiology, Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok (Thailand); Pornkul, Ratanaporn [Division of Diagnostic Radiology, Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok (Thailand); Khowsathit, Pongsak [Pediatric Cardiac Unit, Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok (Thailand); Layangool, Thanarat; Promphan, Worakan [Pediatric Cardiology Unit, Queen Sirikit National Institute of Child Health, Bangkok (Thailand); Pongpanich, Boonchob [Pediatric Cardiac Unit, Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok (Thailand)

    2013-07-15

    Cardiac imaging plays an important role in both congenital and acquired heart diseases. Cardiac computed tomography (angiography) cCT(A) is a non-invasive, increasingly popular, complementary modality to echocardiography in evaluation of congenital heart diseases (CHD) in children. Despite radiation exposure, cCT(A) is now commonly used for evaluation of the complex CHD, giving information of both intra-cardiac and extra-cardiac anatomy, coronary arteries, and vascular structures. This review article will focus on the fundamentals and essentials for performing cCT(A) in children, including radiation dose awareness, basic techniques, and strengths and weaknesses of cCT(A) compared with cardiac magnetic resonance imaging (cMRI), and applications. The limitations of this modality will also be discussed, including the CHD for which cMRI may be substituted.

  10. 320-detector row CT coronary angiography in patients with arrhythmia

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility of CT coronary angiography (CTCA) in patients with arrhythmia using 320-detector row CT. Methods: Thirty-one patients with persistent atrial fibrillation and 8 patients with premature ventricular contraction were enrolled in this study. All patients underwent 320- detector row CTCA. CT image quality was evaluated with 4-point grading scale by two radiologists. Inter- observer agreement was evaluated by Kappa statistics. The radiation dose was calculated. Results: In total 510 coronary segments, 496 (97.2%) segments met diagnostic standard. The mean effective dose was (12.7±4.8) mSv in this study. There was a good agreement in image quality scoring between the two reviewers (Kappa = 0.72). Conclusion: 320-detector row CTCA is feasible in patients with atrial fibrillation and premature ventricular contraction. Arrhythmia may not be considered as a contraindication to CTCA. (authors)

  11. MR angiography in portal hypertension: state of the art

    International Nuclear Information System (INIS)

    When imaging the portal vascular system colour-coded sonography and CT angiography are used as an alternative to intraarterial DSA. Today fast CE 3D- MRA is the imaging modality of choice in the diagnostic of patients with portal hypertension. It enables a clear picture of the portalvenous vascular system and portalsystemic shunts. Statements regarding velocity and direction of blood flow can be made with additional use of TOF and PC techniques. CE-3D MRA can be used preoperatively before liver transplantation or shunt surgery. In the follow-up of interventional or surgical procedures exact statements concerning haemodynamically significant pathologies e.g. vascular thromboses, stenoses and occlusions can be made. Patient consent is symplify and the numbers of complications can be reduced as well as duration of surgery minimized applying this technique (orig.)

  12. Radiation doses in angiography in the University Hospital of Caracas

    International Nuclear Information System (INIS)

    In the present work is evaluated, in angiography procedures carried out in the Radiology Department of the University Hospital of Caracas, the radiation dose received by the exposed professional when they carry out these explorations invasive and the followed norms of radiological protection during the exploration. The measurement was carried out on the exposed professional conformed by a medical interventionist, a medical assistant (resident), a nurse and a technical radiologist. Dosimeters TL was placed in the inter-orbital line at level of the crystalline lens, on thyroid, on the hands, thorax, breast, and on the gonads. The maximum values of dose (in mGy) that were measured: 1,84 at level of the crystalline lens; 1,24 on thyroid; 9,04 on the right hand; 65,04 on hand left; 0,07 on thorax; 0,07 on Breast; 0,07 for ovaries; and smaller than 0,04 for testicle. (author)

  13. Didactics and training in cardiovascular computed tomography angiography.

    Science.gov (United States)

    Bhojraj, Sanjay D; Al-Mallah, Mouaz H

    2009-01-01

    As the role of cardiovascular computed tomography angiography (CCTA) is further expanded through research, the use of this technology will expand as a result of demand both from medical professionals and the public. To ensure a standardized quality of interpretation of these scans in the face of an increased demand for physicians qualified to interpret these studies, the Society of Cardiovascular Computed Tomography, along with several other professional societies, has proposed a didactic curriculum for the study of CCTA. This review highlights the currently proposed didactic curriculum for the study of CCTA, examines current trends in training for both medical trainees and physicians in practice, and proposes future directions for the study of CCTA.

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

    Science.gov (United States)

    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.

  15. MRI and MR angiography of persistent trigeminal artery

    Energy Technology Data Exchange (ETDEWEB)

    Piotin, M. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France); Miralbes, S. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France); Cattin, F. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France); Marchal, H. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France); Amor-Sahli, M. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France); Moulin, T. [Department of Neurology, University Hospital, Besancon (France); Bonneville, J.F. [Departments of Neuroradiology, Jean Minjoz University Hospital, Besancon (France)

    1996-11-01

    We describe the MRA and MR angiography (MRA) features of persistent trigeminal artery (PTA) found incidentally in eight patients, with special attention to its origin, site and course. The different patterns of posterior communicating arteries were also noted. The PTA were shown on sagittal, coronal and axial MRI and on MRA. In four cases, the PTA arose from the lateral aspect of the intracavernous internal carotid artery, ran caudally, passing round the bottom of the dorsum sellae to join the basilar artery. In the other four cases, it arose from the medial aspect, ran caudally through the sella turcica and pierced the dorsum sellae to join the basilar artery. The posterior communicating arteries were present unilaterally in five cases and bilaterally in one, and absent bilaterally in two. Identification of a PTA with a trans-sellar course is crucial if a trans-sphenoidal surgery is planned. (orig.). With 3 figs.

  16. Gadolinium-enhanced magnetic resonance angiography in brain death

    Science.gov (United States)

    Luchtmann, M.; Beuing, O.; Skalej, M.; Kohl, J.; Serowy, S.; Bernarding, J.; Firsching, R.

    2014-01-01

    Confirmatory tests for the diagnosis of brain death in addition to clinical findings may shorten observation time required in some countries and may add certainty to the diagnosis under specific circumstances. The practicability of Gadolinium-enhanced magnetic resonance angiography to confirm cerebral circulatory arrest was assessed after the diagnosis of brain death in 15 patients using a 1.5 Tesla MRI scanner. In all 15 patients extracranial blood flow distal to the external carotid arteries was undisturbed. In 14 patients no contrast medium was noted within intracerebral vessels above the proximal level of the intracerebral arteries. In one patient more distal segments of the anterior and middle cerebral arteries (A3 and M3) were filled with contrast medium. Gadolinium-enhanced MRA may be considered conclusive evidence of cerebral circulatory arrest, when major intracranial vessels fail to fill with contrast medium while extracranial vessels show normal blood flow.

  17. Does Fundus Fluorescein Angiography Procedure Affect Ocular Pulse Amplitude?

    Directory of Open Access Journals (Sweden)

    Gökhan Pekel

    2013-01-01

    Full Text Available Purpose. This study examines the effects of fundus fluorescein angiography (FFA procedure on ocular pulse amplitude (OPA and intraocular pressure (IOP. Materials and Methods. Sixty eyes of 30 nonproliferative diabetic retinopathy patients (15 males, 15 females were included in this cross-sectional case series. IOP and OPA were measured with the Pascal dynamic contour tonometer before and after 5 minutes of intravenous fluorescein dye injection. Results. Pre-FFA mean OPA value was  mmHg and post-FFA mean OPA value was  mmHg (. Pre-FFA mean IOP value was  mmHg and post-FFA mean IOP value was  mmHg (. Conclusion. Although both mean OPA and IOP values were decreased after FFA procedure, the difference was not statistically significant. This clinical trial is registered with Australian New Zealand Clinical Trials Registry number ACTRN12613000433707.

  18. Visualizing inequality

    Science.gov (United States)

    Eliazar, Iddo

    2016-07-01

    The study of socioeconomic inequality is of substantial importance, scientific and general alike. The graphic visualization of inequality is commonly conveyed by Lorenz curves. While Lorenz curves are a highly effective statistical tool for quantifying the distribution of wealth in human societies, they are less effective a tool for the visual depiction of socioeconomic inequality. This paper introduces an alternative to Lorenz curves-the hill curves. On the one hand, the hill curves are a potent scientific tool: they provide detailed scans of the rich-poor gaps in human societies under consideration, and are capable of accommodating infinitely many degrees of freedom. On the other hand, the hill curves are a powerful infographic tool: they visualize inequality in a most vivid and tangible way, with no quantitative skills that are required in order to grasp the visualization. The application of hill curves extends far beyond socioeconomic inequality. Indeed, the hill curves are highly effective 'hyperspectral' measures of statistical variability that are applicable in the context of size distributions at large. This paper establishes the notion of hill curves, analyzes them, and describes their application in the context of general size distributions.

  19. CORONARY ANGIOGRAPHY WITH DUAL SOURCE COMPUTED TOMOGRAPHY: INITIAL EXPERIENCE

    Institute of Scientific and Technical Information of China (English)

    Zhu-hua Zhang; Wen-min Zhao; Wen-bin Mou; Li-ren Zhang; Wen-ling Zhu; Qi Miao; Qi Fang; Zheng-yu Jin; Shu-yang Zhang; Song-bai Lin; Dong-jing Li; Ling-yan Kong; Yi-ning Wang; Lan Song; Yun Wang

    2007-01-01

    To explore the scan technique and image quality of coronary angiography with dual source computed tomography (CT) without oral metoprolol preparation.Methods Plain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients. Calcium scoring with plain scan images as well as multi-planar reconstruction( MPR ), maximum intensity projection (MIP), and volume rendering technique (VRT) reconstruction with enhanced scan images were performed in all cases. The scan technique and post-reconstruction experience was summarized. The image quality was classified as 1 to 4 points, and coronary segments classified according to the American Heart Association standards were evaluated.Results The average calcium score of the 600 cases was 213.6 ± 298.7 (0-3 216. 5). The average heart rate of the enhanced scan was 82.1 ± 16.2 (47-139) bpm. The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method, two or more phases supplemented method, and electrocardiogram editing method. Altogether 8 457 coronary segments were evaluated, among which 97.2% were evaluated as point 1, 1.7% point 2, 0.5% point 3, and0.6% point 4. The coronary segments in 261 cases were completely normal, while 360 segments were diagnosed with < 50% stenosis and 625 segments with ≥50%stenosis.Conclusions Excellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation. Heart rate is not a major source of the artifact, coronary segments can be well shown with single or multiple-phase reconstruction method.

  20. Automated myocardial perfusion from coronary x-ray angiography

    Science.gov (United States)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2010-03-01

    The purpose of our study is the evaluation of an algorithm to determine the physiological relevance of a coronary lesion as seen in a coronary angiogram. The aim is to extract as much as possible information from a standard coronary angiogram to decide if an abnormality, percentage of stenosis, as seen in the angiogram, results in physiological impairment of the blood supply of the region nourished by the coronary artery. Coronary angiography, still the golden standard, is used to determine the cause of angina pectoris based on the demonstration of an important stenose in a coronary artery. Dimensions of a lesion such as length and percentage of narrowing can at present easily be calculated by using an automatic computer algorithm such as Quantitative Coronary Angiography (QCA) techniques resulting in just anatomical information ignoring the physiological relevance of the lesion. In our study we analyze myocardial perfusion images in standard coronary angiograms in rest and in artificial hyperemic phases, using a drug e.g. papaverine intracoronary. Setting a Region of Interest (ROI) in the angiogram without overlying major vessels makes it possible to calculate contrast differences as a function of time, so called time-density curves, in the basal and hyperemic phases. In minimizing motion artifacts, end diastolic images are selected ECG based in basal and hyperemic phase in an identical ROI in the same angiographic projection. The development of new algorithms for calculating differences in blood supply in the region as set are presented together with the results of a small clinical case study using the standard angiographic procedure.

  1. Inhalation RI-angiography with 11CO gas, 2

    International Nuclear Information System (INIS)

    15 mCi 11CO was injected with one litre of air into a gas box connected to respiratory circuit. Five volunteers inhaled the gas mixture through the respiratory circuit by single method breathing. After 20-30 seconds breath holding, the alveolar 11CO gas mixture was washed out. During these time, remaining radioactivity of 11CO in the lung was counted with the positron camera and recorded into an on-line computer. This records were fitted to an exponential equation of Y=A.esup(-lambda t) by least square method. Then we calculated the lung clearance values by the equation of Y'=100 (1-esup(-lambda)). The mean value of lambda was 0.0314 (sec-1). The uptake into blood flow from alveoli at t=1 sec. was 3.1% and at t=20 sec. was 45.7%. Simultaneously, 11CO radioactivities at each site of the left thigh and the expiring site of respiratory-circuit were counted using two ratemeters. These dynamic curves gave us a conclusion that the 11CO uptake rate into human blood flow in this method is fast enough for labelling erythrocytes. The erythrocyte labelling rate with 11CO after inhalation was calculated from radioactivities in the plasma and the venous blood. The rates of five volunteers are all over 97.9%. After the inhalation studies, RI-angiography with positron camera were taken. These scintigrams showed good resolution. We could distinguish main sinuses of the head and two arteries of the forearm. We could found a rapid and easy labelling method for RI-angiography using 11CO gas inhalation and we could get RI-angiograms with good resolution using a positron camera. This combination method is safe and comfortable for patients because of the low radiation absorbed dose and an entirely noninvasive method. We concluded this RI-angiogram is a good method for clinical use. (auth.)

  2. The Hunter Pulmonary Angiography Catheter for a Brachiocephalic Vein Approach

    International Nuclear Information System (INIS)

    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a 'C-shaped' curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk

  3. Visual SLAM using straight lines

    OpenAIRE

    Mees Martínez, Oier

    2013-01-01

    The present thesis is focuses on the problem of Simultaneous Localisation and Mapping (SLAM) using only visual data (VSLAM). This means to concurrently estimate the position of a moving camera and to create a consistent map of the environment. Since implementing a whole VSLAM system is out of the scope of a degree thesis, the main aim is to improve an existing visual SLAM system by complementing the commonly used point features with straight line primitives. This enables more accurate...

  4. Estimation of visual motion in image sequences

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1994-01-01

    with a priori knowledge. We have surveyed a series of attempts to extract motion invariants. Specifically we have illustrate the use of local Fourier phase. The Fourier phase is shown to define the local shape of the signal, thus accurately localizing an event. Different strategies for local measurement...

  5. Patient Selection for Diagnostic Coronary Angiography and Hospital-Level PCI Appropriateness: Insights from the NCDR®

    Science.gov (United States)

    Bradley, Steven M.; Spertus, John A.; Kennedy, Kevin F.; Nallamothu, Brahmajee K.; Chan, Paul S.; Patel, Manesh R.; Bryson, Chris L.; Malenka, David J.; Rumsfeld, John S.

    2014-01-01

    Importance Diagnostic coronary angiography in asymptomatic patients may lead to inappropriate percutaneous coronary intervention (PCI) due to a diagnostic to therapeutic cascade. Understanding the relationship between patient selection for coronary angiography and PCI appropriateness may inform strategies to minimize inappropriate procedures. Objective To determine if hospitals that frequently perform coronary angiography in asymptomatic patients, a clinical scenario wherein the benefit of angiography is less clear, are more likely to perform inappropriate PCI. Design, Setting and Participants Multicenter observational study of 544 hospitals participating in the CathPCI Registry® between July 2009 and September 2013. Measures Hospital proportion of asymptomatic patients at diagnostic coronary angiography and a hospital's rate of inappropriate PCI, as defined by 2012 Appropriate Use Criteria for coronary revascularization. Results Of 1,225,562 patients who underwent elective coronary angiography, 308,083 (25.1%) were asymptomatic. The hospital proportion of angiograms in asymptomatic patients ranged from 1.0% to 73.6% (median 24.7%, interquartile range 15.9% to 35.9%). By hospital quartiles of asymptomatic patients at angiography, hospitals with higher rates of asymptomatic patients at angiography had higher median rates of inappropriate PCI (14.8% vs. 20.2% vs. 24.0 vs. 29.4% from lowest to highest quartile, P<.001 for trend). This was attributable to more frequent use of PCI in asymptomatic patients at hospitals with higher rates of angiography in asymptomatic patients (inappropriate and asymptomatic PCI; 5.4% vs. 9.9% vs. 14.7% vs. 21.6% from lowest to highest quartile, P<.001 for trend). Hospitals with higher rates of asymptomatic patients at angiography also had lower rates of appropriate PCI (38.6% vs. 33.0% vs. 32.3% vs. 32.9%% from lowest to highest quartile, P<.001 for trend). Conclusions and Relevance In a national sample of hospitals, performing coronary

  6. Radiation dose in cerebral angiography and flat detector CT applications in neuroradiology; Strahlendosis bei zerebraler Angiographie und Flachdetektor-CT-Applikationen in der Neuroradiologie

    Energy Technology Data Exchange (ETDEWEB)

    Struffert, T.; Lang, S.; Doerfler, A. [Universitaetsklinikum Erlangen, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Abteilung fuer Neuroradiologie, Erlangen (Germany); Scholz, R. [Siemens Healthcare GmbH, Forchheim (Germany); Hauer, M. [Klinikum Nuernberg Sued, Institut fuer Radiologie und Neuroradiologie, Nuernberg (Germany)

    2015-08-15

    Flat detectors (FD) have completely replaced image intensifiers in angiography. Due to this development not only the image quality of 2D digital subtraction angiography series (2-D-DSA) could be improved but also the acquisition of computed tomography (CT)-like cross-sectional images (FD-CT) within the angio suite became feasible. These techniques are now being used in daily clinical routine. Only little information about effective doses of these applications to patients has been published in the literature. We describe the effective patient dose of current applications in the field of angiography and demonstrate strategies to minimize the dose to the patient. In addition, we compare FD-CT applications to standard multislice CT applications. (orig.) [German] Flachdetektoren haben Bildverstaerker in der Angiographie vollstaendig abgeloest. Mit dieser Entwicklung verbesserte sich nicht nur die Bildqualitaet subtrahierter 2-D-Angiographieserien (2-D-DSA), sondern auch die Akquisition CT-aehnlicher Schnittbilder (FD-CT) mit unterschiedlichen Indikationen wurde moeglich. Diese Techniken werden nun in der taeglichen klinischen Routine eingesetzt. Angaben zur effektiven Patientendosis dieser Applikationen sind bis jetzt in der Literatur nur wenige publiziert worden. Wir beschreiben die effektive Patientendosis aktueller Anwendungen im Bereich der Angiographie und zeigen Strategien zur Minimierung der Dosis fuer den Patienten auf. Zudem vergleichen wir FD-CT-Applikationen mit Standard-Multislice-CT-Anwendungen. (orig.)

  7. Contrast enhanced magnetic resonance angiography for determining patency of coronary bypass grafts. A comparison with coronary angiography

    International Nuclear Information System (INIS)

    Aim: Assessment of graft patency with current non-invasive MRA techniques is particularly difficult for evaluating internal mammary artery grafts. Our aim is to determine the accuracy of a contrast enhanced MRA technique in assessing graft patency. Methods: We examined 19 patients with a total of 53 grafts (32 venous/21 arterial), using an ultrafast contrast enhanced 3D gradient-echo technique and compared this with the results of selective angiography. Results: Sensitivity of the contrast enhanced method was 95.2% for venous grafts, 94.4% for IMA grafts and 94.8% overall. Specificity was 85.7% overall, 90.9% for venous and 66.7% for IMA grafts. Positive predictive value was 94.4%. Conclusion: Compared with previous studies, visualisation of IMA grafts was improved by using contrast enhanced MRA. In this preliminary study, contrast enhanced MRA proved promising for the assessment of graft patency. (orig.)

  8. Comparison of MR angiography and conventional angiography in the investigation of intracranial arteriovenous malformations and aneurysms in children

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) is an attractive alternative to conventional catheter angiography (CCA) in children, especially for the detection of intracranial arteriovenous malformations (AVMs) or aneurysms in the out-of-hours setting, because it has fewer risks and complications. To compare MRA with CCA for the detection of intracranial AVMs, aneurysms and arterial anatomy in children. Retrospective blinded review of MRAs and CCAs by two independent paediatric radiologists, in a group of 19 children already diagnosed with AVMs, aneurysms and subarachnoid haemorrhage (SAH) and who had undergone both imaging techniques. Abnormalities were identified on MRA in 15 of 19 patients and by CCA in 11 of 19 patients. MRA showed one aneurysm, nine AVMs, three haemorrhages and two indeterminate lesions. CCA showed nine AVMs and two indeterminate lesions. The two modalities showed excellent correlation in the detection of AVMs in nine patients. Vascular supply to the AVMs correlated well in four cases. There was complete disagreement in the determination of vessel supply in one case, and in two cases CCA showed additional vessel supply compared to MRA, while in two further cases MRA showed an additional vessel supply compared to CCA. CCA was superior to MRA in demonstrating arterial anatomy, except with regard to the anterior and posterior communicating arteries where MRA was superior. The high sensitivity of MRA in the detection of AVMs when compared to CCA and the low incidence of aneurysms support the use of MRA as the initial imaging modality when intracranial haemorrhage is diagnosed on CT, especially in the out-of-hours setting. (orig.)

  9. Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience

    International Nuclear Information System (INIS)

    Coronary computed tomography angiography (coronary CTA) is a powerful non-invasive imaging method to evaluate coronary artery disease. Nowadays, coronary CTA estimated effective radiation dose can be dramatically reduced using state-of-the-art scanners, such as 320-row detector CT (320-CT), without changing coronary CTA diagnostic accuracy. To optimize and further reduce the radiation dose, new iterative reconstruction algorithms were released recently by several CT manufacturers, and now they are used routinely in coronary CTA. This paper presents our first experience using coronary CTA with 320-CT and the Adaptive Iterative Dose Reduction 3D (AIDR-3D). In addition, we describe the current indications for coronary CTA in our practice as well as the acquisition standard protocols and protocols related to CT application for radiation dose reduction. In conclusion, coronary CTA radiation dose can be dramatically reduced following the 'as low as reasonable achievable' principle by combination of exam indication and well-documented technics for radiation dose reduction, such as beta blockers, low-kV, and also the newest iterative dose reduction software as AIDR-3D. (author)

  10. Automatic segmentation of blood vessels from MR angiography volume data by using fuzzy logic technique

    Science.gov (United States)

    Kobashi, Syoji; Hata, Yutaka; Tokimoto, Yasuhiro; Ishikawa, Makato

    1999-05-01

    This paper shows a novel medical image segmentation method applied to blood vessel segmentation from magnetic resonance angiography volume data. The principle idea of the method is fuzzy information granulation concept. The method consists of 2 parts: (1) quantization and feature extraction, (2) iterative fuzzy synthesis. In the first part, volume quantization is performed with watershed segmentation technique. Each quantum is represented by three features, vascularity, narrowness and histogram consistency. Using these features, we estimate the fuzzy degrees of each quantum for knowledge models about MRA volume data. In the second part, the method increases the fuzzy degrees by selectively synthesizing neighboring quantums. As a result, we obtain some synthesized quantums. We regard them as fuzzy granules and classify them into blood vessel or fat by evaluating the fuzzy degrees. In the experimental result, three dimensional images are generated using target maximum intensity projection (MIP) and surface shaded display. The comparison with conventional MIP images shows that the unclarity region in conventional images are clearly depict in our images. The qualitative evaluation done by a physician shows that our method can extract blood vessel region and that the results are useful to diagnose the cerebral diseases.

  11. The value of low kilovoltage of dual-source CT coronary angiography in overweight patients

    International Nuclear Information System (INIS)

    Objective: To investigate the image quality and the radiation dose of dual-source computed tomography coronary angiography by using low kilovoltage combination with low tube current in overweight patients. Methods: Sixty-six patients with body mass index (BMI) 25.0-30.0 kg/m2 and a body weight 0.05). Estimated ED in group B was significantly lower than that in group A [CTDIvol = (42.2±13.8) mGy, ED = (9.5±3.6) mSv in group A vs. CTDIvol = (20.2±6.5) mGy, ED = (4.8±1.7) mSv in group B; each P0.05). A total of 383 coronary artery segments were evaluated in group A and 490 segments in group B. The difference of grading quantity of coronary artery segment was no statistical significant between two groups. Conclusions: 100 kVp combination with ECG-pulsing and CARE Dose 4D of dual-source CTCA was valuable for patients with BMI ranging from 25 to 30 kg/m2 which have a better image quality and low radiation dose. (authors)

  12. Kendall-Theil Robust Line (KTRLine--version 1.0)-A Visual Basic Program for Calculating and Graphing Robust Nonparametric Estimates of Linear-Regression Coefficients Between Two Continuous Variables

    Science.gov (United States)

    Granato, Gregory E.

    2006-01-01

    The Kendall-Theil Robust Line software (KTRLine-version 1.0) is a Visual Basic program that may be used with the Microsoft Windows operating system to calculate parameters for robust, nonparametric estimates of linear-regression coefficients between two continuous variables. The KTRLine software was developed by the U.S. Geological Survey, in cooperation with the Federal Highway Administration, for use in stochastic data modeling with local, regional, and national hydrologic data sets to develop planning-level estimates of potential effects of highway runoff on the quality of receiving waters. The Kendall-Theil robust line was selected because this robust nonparametric method is resistant to the effects of outliers and nonnormality in residuals that commonly characterize hydrologic data sets. The slope of the line is calculated as the median of all possible pairwise slopes between points. The intercept is calculated so that the line will run through the median of input data. A single-line model or a multisegment model may be specified. The program was developed to provide regression equations with an error component for stochastic data generation because nonparametric multisegment regression tools are not available with the software that is commonly used to develop regression models. The Kendall-Theil robust line is a median line and, therefore, may underestimate total mass, volume, or loads unless the error component or a bias correction factor is incorporated into the estimate. Regression statistics such as the median error, the median absolute deviation, the prediction error sum of squares, the root mean square error, the confidence interval for the slope, and the bias correction factor for median estimates are calculated by use of nonparametric methods. These statistics, however, may be used to formulate estimates of mass, volume, or total loads. The program is used to read a two- or three-column tab-delimited input file with variable names in the first row and

  13. Three-Dimensional Rotational Angiography of the Foot in Critical Limb Ischemia: A New Dimension in Revascularization Strategy

    International Nuclear Information System (INIS)

    Purpose. To evaluate the additional value of three-dimensional rotational angiography (3DRA) of the foot compared with digital subtraction angiography (DSA) in patients with critical limb ischemia (CLI). Technique. For 3DRA, the C-arm was placed in the propeller position with the foot in an isocentric position. The patient’s unaffected foot was positioned in a footrest outside the field of view. For correct timing of 3DRA, the delay from contrast injection in the popliteal artery at the level of knee joint to complete pedal arterial enhancement was assessed using DSA. With this delay, 3DRA was started after injection of 15 ml contrast. Imaging of the 3DRA could directly be reconstructed and visualized.Materials and MethodsPatients undergoing 3DRA of the foot were prospectively registered. DSA and 3DRA images were scored separately for arterial patency and presence of collaterals. Treatment strategies were proposed based on DSA with and without the availability of 3DRA. Results. Eleven patients underwent 3DRA of the foot. One 3DRA was not included because the acquisition was focused on the heel instead of the entire foot. Diagnostic quality of 3DRA was good in all ten patients. 3DRA compared with DSA showed additional patent arteries in six patients, patent plantar arch in three patients, and collaterals between the pedal arteries in five patients. Additional information from 3DRA resulted in a change of treatment strategy in six patients. Conclusion, 3DRA of the foot contains valuable additional real-time information to better guide peripheral vascular interventions in patients with CLI and nonhealing tissue lesions.

  14. Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging. (orig.)

  15. Magnetic resonance angiography virtual endoscopy in the assessment of pulmonary veins before radiofrequency ablation procedures for atrial fibrillation

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, S.; Tosetti, Irene; Giuseppe, M.De; Longo, M.; Regge, D. [Institute for Cancer Research and Treatment (IRCC), Unit of Radiology, Candiolo (Torino) (Italy); Bonamini, R. [University of Torino, Department of Cardiology, Torino (Italy); Gaita, F.; Bianchi, F.; Vivalda, L. [Ospedale Mauriziano Umberto I, Department of Cardiology, Torino (Italy)

    2004-11-01

    Magnetic resonance angiography (MRA) is a safe and non-invasive imaging method that can readily depict the pulmonary veins (PV), whose imaging has acquired momentum with the advent of new techniques for radiofrequency ablation of atrial fibrillation (AF). We evaluated whether virtual endoscopy from 3D MRA images (MRA-VE) is feasible in studying the morphology of PV. Fifty patients with AF underwent pre-ablative MRA (1.5 T). Images were acquired with axial T-2 weighted and 3D-SPGR sequences after intravenous administration of Gd-DTPA and automatic triggering. Postprocessing was performed by an experienced radiologist with maximum intensity projection (MIP) and virtual endoscopy software (Navigator, GEMS). The venoatrial junction was visualized with MRA-VE in 49 of 50 patients (98.0%). Twenty-seven patients (55.1%) had two ostia on both sides, 13 patients (26.5%) had two ostia on the right and a single common ostium on the left, 5 patients (10.2%) had accessory PV and 4 patients (8.2%) had both an accessory right PV and a single common ostium on the left. Flythrough navigation showed the number and spatial disposition of second-order PV branches in 48 out of 49 patients (98.0%). MRA-VE is an excellent tool for at-a-glance visualization of ostia morphology, navigation of second-generation PV branches and easy endoluminal assessment of left atrial structures in pre-ablative imaging. (orig.)

  16. 256-Slice coronary computed tomographic angiography in patients with atrial fibrillation: optimal reconstruction phase and image quality

    International Nuclear Information System (INIS)

    To assess the optimal reconstruction phase and the image quality of coronary computed tomographic angiography (CCTA) in patients with atrial fibrillation (AF). We performed CCTA in 60 patients with AF and 60 controls with sinus rhythm. The images were reconstructed in multiple phases in all parts of the cardiac cycle, and the optimal reconstruction phase with the fewest motion artefacts was identified. The coronary artery segments were visually evaluated to investigate their assessability. In 46 (76.7 %) patients, the optimal reconstruction phase was end-diastole, whereas in 6 (10.0 %) patients it was end-systole or mid-diastole, and in 2 (3.3 %) patients it was another cardiac phase. In 53 (88.3 %) of the controls, the optimal reconstruction phase was mid-diastole, whereas it was end-systole in 4 (6.7 %), and in 3 (5.0 %) it was another cardiac phase. There was a significant difference between patients with AF and the controls in the optimal phase (p < 0.01) but not in the visual image quality score (p = 0.06). The optimal reconstruction phase in most patients with AF was the end-diastolic phase. The end-systolic phase tended to be optimal in AF patients with higher average heart rates. (orig.)

  17. 256-Slice coronary computed tomographic angiography in patients with atrial fibrillation: optimal reconstruction phase and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Seitaro; Yuki, Hideaki; Kidoh, Masafumi; Utsunomiya, Daisuke; Nakaura, Takeshi; Namimoto, Tomohiro; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Faculty of Life Sciences, Chuou-ku, Kumamoto (Japan); Honda, Keiichi; Yoshimura, Akira; Katahira, Kazuhiro [Kumamoto Chuo Hospital, Department of Diagnostic Radiology, Minami-ku, Kumamoto (Japan); Noda, Katsuo; Oshima, Shuichi [Kumamoto Chuo Hospital, Department of Cardiology, Minami-ku, Kumamoto (Japan)

    2016-01-15

    To assess the optimal reconstruction phase and the image quality of coronary computed tomographic angiography (CCTA) in patients with atrial fibrillation (AF). We performed CCTA in 60 patients with AF and 60 controls with sinus rhythm. The images were reconstructed in multiple phases in all parts of the cardiac cycle, and the optimal reconstruction phase with the fewest motion artefacts was identified. The coronary artery segments were visually evaluated to investigate their assessability. In 46 (76.7 %) patients, the optimal reconstruction phase was end-diastole, whereas in 6 (10.0 %) patients it was end-systole or mid-diastole, and in 2 (3.3 %) patients it was another cardiac phase. In 53 (88.3 %) of the controls, the optimal reconstruction phase was mid-diastole, whereas it was end-systole in 4 (6.7 %), and in 3 (5.0 %) it was another cardiac phase. There was a significant difference between patients with AF and the controls in the optimal phase (p < 0.01) but not in the visual image quality score (p = 0.06). The optimal reconstruction phase in most patients with AF was the end-diastolic phase. The end-systolic phase tended to be optimal in AF patients with higher average heart rates. (orig.)

  18. Relative safety of intravenous digital subtraction angiography over other methods of carotid angiography and impact on clinical management of cerebrovascular disease.

    Science.gov (United States)

    Stevens, J M; Barter, S; Kerslake, R; Schneidau, A; Barber, C; Thomas, D J

    1989-09-01

    Data from a multicentre survey based on three London teaching hospitals on the relative safety and clinical utility of intravenous carotid digital subtraction angiography (DSA) over intra-arterial DSA and conventional carotid angiography are presented. The incidence of stroke during intra-arterial DSA was 0.7% (n = 538) and during conventional angiography was 0.8% (n = 780). The incidence of stroke during intravenous DSA was zero (n = 3710). When it constituted the initial investigation, intravenous DSA achieved a 93.8% replacement value over intra-arterial studies as a whole (n = 474) and 89% replacement value for patients having carotid endarterectomy (n = 99). It was also noted that the installation of DSA equipment at one unit coincided with a sixfold increase in the number of carotid angiographic examinations and an almost threefold increase in carotid endarterectomies. PMID:2790421

  19. Contrast-enhanced MR Angiography of the Abdomen with Highly Accelerated Acquisition Techniques

    OpenAIRE

    Mostardi, Petrice M.; Glockner, James F; Young, Phillip M.; Riederer, Stephen J.

    2011-01-01

    A three-dimensional time-resolved acquisition can provide accurate timing information for subsequent renal MR angiography, as well as a diagnostic overview of the vasculature; a highly accelerated acquisition can provide high-quality renal angiograms.

  20. Outcome after emergency surgery without angiography in patients with intracerebral haemorrhage after aneurysm rupture

    DEFF Research Database (Denmark)

    Bergdal, Ove; Springborg, Jacob; Hauerberg, John;

    2009-01-01

    and aneurysm occlusion without preoperative angiography. METHODS: We retrospectively identified 13 consecutive patients. We recorded clinical data and evaluated mortality and morbidity with the Glasgow Outcome Score (GOS) and Telephone Interview of Cognitive Status (TICS). FINDINGS: At follow up seven...

  1. Low-dose CT coronary angiography using iterative reconstruction with a 256-slice CT scanner

    OpenAIRE

    Carrascosa, Patricia; Rodriguez-Granillo, Gastón A; Capuñay, Carlos; Deviggiano, Alejandro

    2013-01-01

    AIM: To explore whether computer tomography coronary angiography (CTCA) using iterative reconstruction (IR) leads to significant radiation dose reduction without a significant loss in image interpretability compared to conventional filtered back projection (FBP).

  2. The value of RI scintigraphy and angiography in small intestinal bleeding; Report of eight cases

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Susumu; Kuwata, Hajime; Kushibiki, Kyoko; Akimoto, Kimihiko; Hashimoto, Toshiyuki; Kojima, Toshiya (Showa General Hospital, Kodaira, Tokyo (Japan))

    1991-07-01

    We retrospectively reviewed eight cases of small intestinal bleeding and assessed the value of RI scintigraphy and angiography in diagnosing the bleeding site. The patients' average age was 56.2 years. Chief complaint was melena of variable degree. In most cases neither upper endoscopy nor colonoscopy was diagnostic. RI scientigraphy (Tc-99 labeled human serum albumin) showed 75% of positive rate whereas angiography showed 66.7% (4/6) of positive rate. All four cases of leiomyosarcoma and leiomyoma demonstrated hypervascular stain and/or extra-vasation in angiography whereas RI scintigraphy failed to detect active gastrointestinal bleeding in 2 of the 4 cases. Therefore angiography was considered useful for the detection of bleeding from leiomyoma and leiomyosarcoma which are often hypervascular. Scintigraphy is thought of most value in the demonstration of small amount of bleeding with minimum vascular abnormality. (author).

  3. Coronary Computed Tomography Angiography Derived Fractional Flow Reserve and Plaque Stress

    DEFF Research Database (Denmark)

    Nørgaard, Bjarne Linde; Leipsic, Jonathon; Koo, Bon-Kwon;

    2016-01-01

    Fractional flow reserve (FFR) measured during invasive coronary angiography is an independent prognosticator in patients with coronary artery disease and the gold standard for decision making in coronary revascularization. The integration of computational fluid dynamics and quantitative anatomic...

  4. CLINICAL ASPECTS OF PATIENT SELECTION FOR CORONARY ANGIOGRAPHY IN NON-ST ELEVATION ACUTE CORONARY SYNDROME

    Directory of Open Access Journals (Sweden)

    K. A. Kireev

    2015-01-01

    Full Text Available Own clinical experience in the selection of patients with non-ST elevation acute coronary syndrome for coronary angiography based on clinical guidelines of the European Society of Cardiology (2011 is presented.

  5. Co-registration of optical coherence tomography and X-ray angiography in percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Hebsgaard, Lasse; Nielsen, Troels Munck; Tu, Shengxian;

    2014-01-01

    Background Intracoronary imaging provides accurate lesion delineation and precise measurements for sizing and positioning of coronary stents. During percutaneous coronary intervention (PCI), it may be challenging to identify corresponding segments between intracoronary imaging and angiography...

  6. Dual-energy CT angiography of the lung in patients with suspected pulmonary embolism. Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C.; Michaely, H.J. [Inst. fuer Klinische Radiologie und Nuklearmedizin, Universitaetsklinikum Mannheim, Univ. Heidelberg (Germany); Inst. fuer Klinische Radiologie, Campus Grosshadern, Klinikum der Univ. Muenchen (Germany); Johnson, T.R.; Morhard, D.; Becker, C.; Reiser, M.; Nikolaou, K. [Inst. fuer Klinische Radiologie, Campus Grosshadern, Klinikum der Univ. Muenchen (Germany)

    2008-10-15

    To evaluate the feasibility of dual-energy CT angiography (CTA) of the lung in patients with suspected pulmonary embolism (PE). 24 patients with suspected PE were examined with a single-acquisition, dual-energy CTA protocol (A-system: 140 kV/65 mAsref, B-system: 80 kV/190 mAsref) on a dual-source CT system. Lung perfusion was visualized by color-coding voxels containing iodine and air using dedicated dual-energy post-processing software. Perfusion defects were classified by two blinded radiologists as being consistent or non-consistent with PE. Subjective image quality of perfusion maps and CTA was rated using a 5-point scale (1: excellent, 5: poor). The reading of a third independent radiologist served as the standard of reference for the diagnosis of PE. In all patients with PE (n = 4), perfusion defects classified as being consistent with PE were identified in lung areas affected by PE. Both readers did not record perfusion defects classified as being consistent with PE in any of the patients without PE. Thus, on a per patient basis the sensitivity and specificity for the assessment of PE was 100% for both readers. On a per segment basis the sensitivity and specificity ranged between 60 - 66.7% and 99.5 - 99.8%. The interobserver agreement was good (k = 0.81). Perfusion defects rated as non-consistent with PE were most frequently caused by streak artifacts from dense contrast material in the great thoracic vessels. The median score of the image quality of both the perfusion maps and CTA was 2. In conclusion, dual-energy CTA of pulmonary embolism is feasible and allows the assessment of perfusion defects caused by pulmonary embolism. Further optimization of the injection protocol is required to reduce artifacts from dense contrast material. (orig.)

  7. CT coronary angiography in patients with atrial fibrillation; CT-Koronarangiographie bei Patienten mit Vorhofflimmern

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, A.; Sommer, T.; Leiss, A.; Naehle, P.; Schild, H.; Flacke, S. [Universitaetsklinikum Bonn, Radiologische Klinik (Germany); Probst, C.; Welz, A. [Universitaetsklinikum Bonn, Klinik fuer Herzchirurgie (Germany)

    2005-12-15

    Purpose: Reliable visualization of the coronary arteries with multislice spiral CT angiography (MSCTA) in patients with atrial fibrillation (AF) remains a challenge despite retrospective ECG gating. A recently developed new algorithm automatically compensates dynamic changes in the heart rate during the scan, thus reducing misregistration and motion artifacts. The HeartBeat-RT algorithm combines a fixed percent delay determined from the first R wave and the fixed offset delay based on the second R wave in the ECG cycle. The purpose of this study was to find out the optimal reconstruction window in MSCTA in patients with AF for each of the three major coronary arteries during the cardiac cycle. Materials and methods: 20 patients with permanent AF were imaged on a 16-slice scanner (slice collimation: 16 x 0.75 mm; rotation time 0.42 s; 140 kV; 380 mAs; 120 ml Ultravist 370 {sup registered} i.v.). The patients had not received any previous drugs for heart frequency regulation. Acquisition was started after bolus tracking of a biphasic bolus of 120 ml Ultravist 370 injected intravenously. Each coronary segment was reconstructed at 0%-90% of the cardiac cycle in increments of 10%. For image analysis we used coronary segments as defined by the American Heart Association. Two blinded independent readers assessed the image quality in terms of visibility and artifacts (five-point rating scale 1=very poor, 2=poor, 3=fair, 4=good and 5=excellent) and the degree of stenosis (five-point rating scale 1=0%, 2=1%-49%, 3=50%-74%, 4=75%-99%, 5=100%) on axial slices, multiplanar reconstructions and three-dimensional volume-rendered images. (orig.)

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

    Science.gov (United States)

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

    2012-04-01

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

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

    OpenAIRE

    Doris, Mhairi; Newby, David, E

    2016-01-01

    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-HEA...

  10. Effect of Benson Relaxation Techniques on Hemodynamic Variables of Patient Undergoing Coronary Angiography

    OpenAIRE

    M khani; R Memarian; Ahmadi, F.; N Hanifi

    2005-01-01

    Introduction: Invasive diagnostic procedures such as coronary angiography, in most cases, are accompanied by stress and anxiety for patients,which may effect on hemodynamic signs. Materials and Methods:This research, as a quasi experimental study, has the objective to determine the influence of applying methods of relaxation on hemodynamic signs in hospitalized 40 patients, experienciny coronary angiography (CA),, has been studied, in regard to existing conditions and methods of sampling and ...

  11. Usefulness of Y-shaped sheaths in CT angiography for examination of liver tumors

    Institute of Scientific and Technical Information of China (English)

    Toru; Ishikawa; Kazuo; Higuchi; Tomoyuki; Kubota; Kei-ichi; Seki; Terasu; Honma; Toshiaki; Yoshida; Takeo; Nemoto; Keiko; Takeda; Tomoteru; Kamimura

    2010-01-01

    AIM: To conduct a single-stage, combined computed tomography (CT) arterial portography (CTAP) and CT arteriography (CTA) imaging operation, we used Y-shaped sheaths with 2 valves, which allowed the insertion of 2 catheters simultaneously. METHODS: Of 1254 patients who underwent abdominal angiography for transarterial embolization and/or intraarterial chemotherapy in our department from May 2002 to November 2009, 664 patients in whom Y-shaped sheaths with 2 valves were used underwent CT angiography using a c...

  12. Ventilation-perfusion imaging and pulmonary angiography: changing pattern of use

    International Nuclear Information System (INIS)

    The hospital and departmental records of the University of Virginia Medical Center from 1976 to 1980 show an increasing frequency of ventilation studies relative to perfusion studies and a decrease in frequency of ventilation-perfusion diagnosis of pulmonary embolus. Pulmonary angiograms have increased from one per 68 nuclear studies to one per 14. A review of 70 patients with correlating angiography or autopsy shows that 89% of nuclear studies were accurate. We have revised our interpretation criteria and indications for pulmonary angiography

  13. Patient’s Radiation Exposure in Coronary Angiography and Angioplasty: The Impact of Different Projections

    OpenAIRE

    Farajollahi Alireza; Rahimi Atena; Khayati Shal Ebrahim; Ghaffari Samad; Ghojazadeh Morteza; Tajlil Arezou; Aslanabadi Nasser

    2014-01-01

    Introduction: We aimed to determine angiography projections with lower Dose Area Product (DAP) rate by measuring the mean DAP and fluoroscopy times in coronary angiography (CAG) and percutaneous coronary intervention (PCI) and calculating DAP rate in different projections. Methods: DAP and fluoroscopy times were measured in all employed projections in real-time in 75 patients who underwent CAG or PCI by a single cardiologist in Madani Cardiovascular University Hospital (45 in CAG group and 30...

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

    OpenAIRE

    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 an...

  15. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography

    Science.gov (United States)

    Makita, Shuichi; Kurokawa, Kazuhiro; Hong, Young-Joo; Miura, Masahiro; Yasuno, Yoshiaki

    2016-01-01

    This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients’ eyes can be obtained. PMID:27446673

  16. Coronary computed tomography angiography - Tolerability of β-blockers and contrast media, and temporal changes in radiation dose

    DEFF Research Database (Denmark)

    Pedersen, Charlotte; Thomsen, Camilla F; Hosbond, Susanne Elisabeth;

    2014-01-01

    Abstract Objective: To determine the risk of administration of β-blockers, contrast induced nephropathy (CIN) and trend in x-rays use, during coronary computed tomography angiography (CCTA). Methods: A total of 416 patients were referred for elective CCTA. To achieve a resting heart rate below 60...... beats per minute oral and / or intravenously β-blockers were administered. Information was collected from patients on the adverse effects of β-blockers in the form of questionnaires. S-creatinine and estimated GFR (eGFR) were measured before and after contrast enhanced CCTA. Radiation exposure was....../L, p=0.09), while eGFR increased non-significantly (78 versus 79 mL/min, p=0.17). Also subgroups of patients with hypertension, hypercholesterolemia, diabetes or pre-excisting slightly impaired renal function did not develop CIN. Mean radiation exposure decreased from 17.5 to 6.7 mSv, p<0...

  17. Transthoracic echocardiography as an alternative major guidance to angiography during transcatheter closure of patent ductus arteriosus: technical feasibility and clinical relevance.

    Science.gov (United States)

    Chen, Wanhua; Yan, Xiaoping; Huang, Yu; Sun, Xudong; Zhong, Ling; Li, Jinguo; Chen, Hua; Zhong, Huiying; Chen, Lianglong

    2015-01-01

    The conventional transcatheter closure of patent ductus arteriosus (PDA) requires femoral artery puncture and angiography for duct anatomic and shunting estimation. If such estimation can be replaced by transthoracic echocardiography (TTE), the procedure will be further simplified, with fewer invasions. This study aimed to examine whether TTE can serve as an alternative to aorta angiography and as a major guidance for transcatheter duct closure. The study enrolled 298 consecutive patients (71 males and 227 females) with PDA. In the study, TTE with combined two-dimensional echocardiography (2DE) imaging and color-coded flow imaging (CDFI) was performed to measure the minimal shunting width (MSW) as the estimated minimal duct size for selection of an Amplatzer duct occluder (ADO) and to monitor the transcatheter duct closure intraprocedurally. The MSW was validated against the duct-stretched diameter (SDD), against the minimal waist diameter of the conical part of a released occluder measured by X-ray spot picture after successful duct closure (SDC), and against the size of the finally used ADO (SADO). Good correlation was found between MSW and SDD [SDD (mm) = 1.31 MSW; r = 0.89; p MSW and SADO [SADO (mm) = 1.71 MSW; r = 0.88; p MSW as the reference for selection of the occluder, SDC was attained in 288 (97.3%), 5 (1.7%), and 2 (0.7%) patients, respectively, at the first, second (1 ADO replacement), and third (2 ADO replacements) occluding attempt. Acute occluder dislodgement occurred in one patient (0.3%). At the 12-month follow-up assessment, no major complications were found, and the total immediate or 12-month SDC was 99.7%. Echocardiography as an alternative major guidance to angiography for transcatheter duct closure is technically feasible, and TTE guidance can further simplify the procedure, with fewer invasions and potential complications. PMID:25070385

  18. Coronary Computed Tomography Angiography in the Assessment of Acute Chest Pain in the Emergency Room

    Energy Technology Data Exchange (ETDEWEB)

    Prazeres, Carlos Eduardo Elias dos; Cury, Roberto Caldeira; Carneiro, Adriano Camargo de Castro [Hospital do Coração - HCor, Associação do Sanatório Sírio, São Paulo, SP (Brazil); Rochitte, Carlos Eduardo, E-mail: rochitte@cardiol.br [Hospital do Coração - HCor, Associação do Sanatório Sírio, São Paulo, SP (Brazil); Instituto do Coração - InCor - HCFMUSP, São Paulo, SP (Brazil)

    2013-12-15

    The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies.

  19. Effects of video information on anxiety, stress and depression of patients undergoing coronary angiography

    International Nuclear Information System (INIS)

    Objective: Anxiety and stress are common in patients undergoing invasive procedures. Coronary angiography is a definitive diagnostic evaluation for coronary artery disease and valvular disease. It is necessary to give information to the patients in order to minimize levels of anxiety and stress to this invasive procedure. The aim of this study was to evaluate the effect of patients education by video on levels of anxiety, stress and depression of patients undergoing coronary angiography. Methodology: In a quasi-experimental, pretest-posttest design, 128 patients were randomly assigned to either control or experimental group. Control group received verbal routine education by nurses and experimental group received an informative video about coronary angiography procedure as well as pre and post angiography interventions. Using Depression, Anxiety, Stress Scale (DASS-21) levels of these variables were measured before and after education. Results: Seventy eight (60.9%) males and fifty (39.1%) females participated in the study. There was a statistically significant reduction in the Anxiety, stress and depression levels of experimental group after video information (P = .000). There was a statistically significant correlation between sex with anxiety (P = .000) and stress (P = .04). Conclusions: The use of patients education by informative video is a useful method for decreasing psychological parameters of patients undergoing coronary angiography procedure. Results of the study confirm the usefulness of video information prior to an Invasive angiography procedure. (author)

  20. K-Edge Subtraction Angiography with Synchrotron X-Rays

    International Nuclear Information System (INIS)

    The purpose of this project was to utilize dual energy, monochromatic X-rays produced from synchrotrons radiation in order to obtain noninvasive medical imaging. The application of synchrotrons radiation to medical imaging is based on the principle of iodine dichromography, first described by Bertil Jacobson of the Karolinska Institute in 1953. Medical imaging using synchrotrons radiation and K-edge dichromography was pioneered at Stanford University under the leadership of Dr. Ed Rubenstein, and the late Nobel Laureate in Physics, Dr. Robert Hofstadter. With progressive refinements in hardware, clinical-quality images were obtained of human coronary arteries utilizing peripheral injections of iodinated contrast agent. These images even now are far superior to those being presented by investigators using MRI as an imaging tool for coronary arteries. However, new supplies and instruments in the cardiac catheterization laboratory have served to transform coronary angiography into an outpatient procedure, with relatively little morbidity. We extended the principles learned with coronary angiography to noninvasive imaging of the human bronchial tree. For these images, we utilized xenon as the contrast agent, as it has a K-edge very similar to that of iodine. In this case, there is no true competing diagnostic test, and pulmonary neoplasm is an enormous public health concern. In early experiments, we demonstrated remarkably clear images of the human bronchial tree. These images have been shown internationally; however, funding difficulties primarily with the Department of Energy have not allowed for progression of this promising avenue of research. One potential criticism of the project is that in order to obtain these images, we utilized national laboratories. Some have questioned whether this would lead to a practical imaging modality. However, we have shown that the technology exists to allow for construction of a miniature storage ring, with a superconducting