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Sample records for angiography current role

  1. 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

  2. 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.)

  3. 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

  4. Magnetic resonance angiography: current status and future directions

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    François Christopher J

    2011-03-01

    Full Text Available 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 renewed interest in these methods. This article discusses the current state of both contrast-enhanced (CE and NCE-MRA. New CE-MRA methods take advantage of dose reduction at 3.0 T, novel contrast agents, and parallel imaging methods. The risks of gadolinium-based contrast media, and the NCE-MRA methods of time-of-flight, steady-state free precession, and phase contrast are discussed.

  5. 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

  6. Magnetic resonance angiography: current status and future directions

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    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...

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

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    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.)

  8. Coronary CT Angiography: Current Applications in Clinical Practice Promise for the Future

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    S. Wann

    2007-05-01

    Full Text Available The use of computed tomography for cardiac diagno-sis has a long history. CT was first used experimentally to measure myocardial perfusion and to detect infarcation nearly 25 years ago, but poor temporal resolution and high radiation dosage pre-cluded its use in clinical medicine. Later electron beam computed tomography provided sufficiently high temporal resolution to precisely measure cal-cium depositions in the coronary arteries as a marker of coronary atherosclerosis. Large epidemiologic stud-ies have now shown that the coronary artery calcium score gives incremental predictive power to conven-tional risk factor analysis such as the Framinghan score. While its temporal resolution is unchallenged, electron beam CT lacks the spatial resolution to per-form clinically useful coronary angiography. The re-cent development of multi-detector computed tomo-graphy (MDCT has enabled non-invasive coronary angiography, capturing the excitement and enthusi-asm of clinicians around the world. This lecture will briefly review the technology underlying MDCT, dis-cussing limitations related to radiation dosimetry, calcium and gating, as well as other fundamental dif-ferences from conventional angiography. Current clinical indications and appropriate application of MDCT will be discussed, with an emphasis on evi-dence based practice. MDCT is a rapidly evolving field. Areas of research and technical development will be described.

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

    International Nuclear Information System (INIS)

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

  10. The role of cardiac CT angiography in the pre- and postoperative evaluation of tetralogy of Fallot

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    Ebrahim Banderker

    2015-10-01

    Full Text Available Tetralogy of Fallot (TOF is the first described and most common cyanotic congenital heart anomaly that generated the first successful surgical palliation procedure and definitive intracardiac repair. Classical TOF comprises the four typical features of right ventricular outflow tract obstruction (RVOTO, right ventricular hypertrophy (RVH, ventricular septal defect (VSD and aortic dextroposition. Complex forms of the condition include TOF associated with absent pulmonary valve and TOF with pulmonary atresia (TOF-PA with or without major aortopulmonary collateral arteries (MAPCAs. The pathophysiological understanding that the tetrad is basically the sequel of a singular abnormality of infundibular malformation, with anterior deviation of the infundibular septum, had major surgical consequences that improved survival. Diagnostic and functional imaging play a key role in the clinical and surgical management of patients with TOF. We revisit the role of traditionally employed imaging modalities (echocardiography and cardiac catheterisation only briefly as these remain within the domain of cardiology practice. The emphasis of the present review is to outline the role of cardiac computed tomographic angiography (CTA in the evaluation of TOF, with special reference to the technical considerations and best practice recommendations. Cardiovascular magnetic resonance imaging (CMR is addressed only in passing, as this service is not currently available at our institution.

  11. Diagnostic role of magnetic resonance angiography in Swyer James syndrome: Case series of two cases

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    Parashari Umesh

    2010-01-01

    Full Text Available Swyer James syndrome is a rare syndrome which occurs due to viral illness in early childhood. The post infective obliterative bronchiolitis results in arrest of lung growth and alveolarization with reduced vascularity resulting in classical radiological features. We describe two cases of patients fulfilling all the criteria of the syndrome - 1 Unilateral hyperlucent small lung in chest radiograph with air trapping on expiration, small ipsilateral hila and pulmonary artery. 2 Diffuse decrease in attenuation of lung parenchyma with bronchiectasis and reduction in vascularity. 3 Unilateral pruned tree appearance on angiography (MRA. The clinical presentation was recurrent chest infection in a child and infrequent bouts of hemoptysis in a middle aged female. The study demonstrates the role of magnetic resonance angiography in diagnosing the condition.

  12. Role of coronary CT angiography in asymptomatic patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Diabetic patients with coronary artery disease are often asymptomatic, making appropriate care of such patients difficult. The purpose of this study was to investigate the prevalence of coronary lesions in asymptomatic diabetic patients. Coronary computed tomography (CT) angiography was performed in 120 consecutive diabetic patients (90 of whom were men, mean age 65, mean HbA1c 7.2%). Images from patients whose coronary artery calcium scores (CAC scores) were less than 400 were subjected to stenosis and plaque analysis. Significant stenosis was defined as coronary artery stenosis >70%. High-risk plaque was defined as plaque having both a CT density <30 Hounsfield Units (HU) and showing positive remodeling. Significant stenoses were identified in 30.5% of the patients. High-risk plaques were identified in 17.1% of the patients. Less than half of the high-risk plaques were obstructive plaques. There was a statistically significant association between significant stenosis and high-risk plaque by chi-square test (P=0.022). We found significant stenosis even in patients whose CAC score =0 at a rate of 5.0%. Using univariate logistic-regression analysis, we found that coronary risk factors associated with significant stenosis and high-risk plaque were dyslipidemia (P=0.033) and current smoking (P=0.030), respectively. We report for the first time, the prevalence of high-risk plaques in the arteries of patients with asymptomatic diabetes, as assessed by coronary CT angiography. (author)

  13. Anomalous origin of coronary artery: the role of multislice CT Angiography: a case report and literature review

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    Rabelo, Daniel Rocha; Barros, Marcio Vinicius Lins; Nunes, Maria do Carmo Pereira; Siqueira, Maria Helena Albernaz, E-mail: marciovlbarros@uol.com.br [Hospital Mater Dei, Belo Horizonte, MG (Brazil)

    2012-07-15

    Anomalous origin of coronary arteries is a relatively rare entity and can present different clinical forms. Recently, CT angiography of the coronary arteries have demonstrated an important role in the diagnosis and management of these anomalies. We present the case of a young female without significant comorbidities who presented with cardiopulmonary arrest, being revived by a team of customer service mobile emergency. After completion of multislice CT angiography of the coronary arteries was observed anomalous origin of left main coronary artery in the right coronary artery, no signs of extrinsic compression. Patient received a defibrillator and had an uneventful follow-up performed. Multislice CT angiography is minimally invasive diagnostic methods to detect the origin and trajectory of the coronary arteries, allowing an alternative to cardiac catheterization for evaluation of patients with anomalous origin of coronary arteries. (author)

  14. Anomalous origin of coronary artery: the role of multislice CT Angiography: a case report and literature review

    International Nuclear Information System (INIS)

    Anomalous origin of coronary arteries is a relatively rare entity and can present different clinical forms. Recently, CT angiography of the coronary arteries have demonstrated an important role in the diagnosis and management of these anomalies. We present the case of a young female without significant comorbidities who presented with cardiopulmonary arrest, being revived by a team of customer service mobile emergency. After completion of multislice CT angiography of the coronary arteries was observed anomalous origin of left main coronary artery in the right coronary artery, no signs of extrinsic compression. Patient received a defibrillator and had an uneventful follow-up performed. Multislice CT angiography is minimally invasive diagnostic methods to detect the origin and trajectory of the coronary arteries, allowing an alternative to cardiac catheterization for evaluation of patients with anomalous origin of coronary arteries. (author)

  15. “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...

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

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    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

  17. The role of multidetector computed tomography coronary angiography in imaging complications post-cardiac surgery

    International Nuclear Information System (INIS)

    There have been numerous advances in the field of cardiac imaging. The advent of multidetector computed tomography coronary angiography (MDCT-CA) and in particular electrocardiographic (ECG)-gated acquisition has revolutionized the investigation of the complete spectrum of complications of common cardiothoracic surgical procedures. Generic complications, such as mediastinitis, pericardial effusion, sternal osteomyelitis, and mediastinal fibrosis, are discussed with illustrative examples of multiplanar and volume-rendered three-dimensional reconstructions. Graft-related complications of both coronary artery bypass grafts and aortic root grafts are reviewed. The role of MDCT-CA in the investigation of prosthetic valve endocarditis and root abscesses is outlined. We present a complete illustration of the detailed images that are obtained when investigating a full range of graft-related complications from both aortic and coronary surgery using ECG-gated MDCT-CA. MDCT-CA has the potential to become established as the optimal technique with which to image a multitude of complications post-cardiac surgery

  18. The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

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    Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

    2014-01-01

    Background: The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. Objectives: The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Patients and Methods: Sixty consecutive patients with clinically suspected non-traumatic...

  19. The role of angiography in the diagnosis and therapy of gastrointestinal hemorrhage

    International Nuclear Information System (INIS)

    Purpose: Evaluation of angiography in the diagnosis and treatment of acute and chronic gastrointestinal bleeding. Materials and Methods: Thirty-seven consecutive patients with clinically suspected gastrointestinal bleeding underwent selective angiography of the visceral arteries. If technically possible, patients with radiologically proven hemorrhage underwent selective embolization with microcoils. Not all angiographically detected bleeding vessels were embolized. Clinical outcome was determined from a review of the medical records. Results: 37 patients underwent 43 angiographies, which demonstrated 25 bleedings considered acute and 18 considered chronic. Seventeen patients had previous intestinal surgery. In 9 of the 37 patients, 12 of the 43 (sensitivity: 28%) hemorrhages were detected. A postoperative bleeding was found in 6 patients. With one exception, all angiographically positive cases were clinically considered to be acute. Transcatheter embolization of the bleeding vessels with microcoils was performed in 6 patients, with 3 patients having the bleeding stopped permanently and 3 patients requiring further surgical treatment. In 3 patients, embolization was not possible for technical reasons. No complications attributable to angiography were seen. Conclusion: Angiography should be performed in patients with spontaneous and postoperative gastrointestinal bleeding. Transcatheter embolization is an effective and safe therapeutical option in both clinical settings. (orig.)

  20. Role of multidetector CT angiography in the evaluation of suspected mesenteric ischemia

    International Nuclear Information System (INIS)

    Objective: To assess the role of multidetector CT angiography (MDCTA) in the diagnosis of acute mesenteric ischemia (AMI) and to compare the diagnostic utility of axial images with reconstructed images. Materials and methods: In this Institute Review Board approved prospective study, MDCTA was performed on 31 patients who presented with the clinical suspicion of AMI (25M; 6F, age range: 16–73 years). Axial and reconstructed images of each patient were evaluated independently by two radiologists for evidence of bowel wall thickening, abnormal mucosal enhancement, bowel dilatation or obstruction, mesenteric stranding, ascites, solid organ infarcts, pneumatosis intestinalis or porto-mesenteric gas, and mesenteric arterial or venous occlusion. MDCT findings were correlated with the surgical findings and clinical outcome. Patients were later divided into two groups: a study group of patients with proven AMI and a control group of patients with an alternate diagnosis, for the purpose of statistical analysis. Results: AMI was correctly diagnosed in all 16 patients on MDCTA (100% sensitivity and specificity) of whom nine patients underwent surgical exploration. Three patients expired before surgery and the remaining 5 patients were proven based on positive clinical and laboratory findings. Mesenteric arterial occlusion was seen in 7 patients while 5 patients had portomesenteric venous thrombosis. Reconstructed images using minimum intensity projection, volume rendering and multiplanar volume reconstruction were found to perform better for the detection of vascular abnormalities and improved the diagnostic confidence of both radiologists in the evaluation of bowel and mesenteric abnormalities. Conclusion: MDCTA is an effective non-invasive modality for the diagnosis of mesenteric ischemia.

  1. ROLE OF MDCT-CORONARY ANGIOGRAPHY IN THE EVALUATION OF CORONARY ARTERY ANOMALIES AND INCIDENCE OF CORONARY ARTERY ANOMALIES IN A SUBSET OF SOUTH INDIAN POPULATION

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    Senthil Kumar; Vadanika; Bulabai; Vinayagam; Saravanan

    2015-01-01

    AIM: To determine the role of MDCT-Coronary angiography in the evaluation of coronary artery anomalies and to calculate the prevalence of coronary artery anomalies in a subset of south Indian population. MATERIALS AND METHODS: This is a retrospective study. Data of 250 consecutive patients who underwent CT coronary angiography in our institution over a period of 2 years were collected and analysed. The studies are analysed for the presence of abnormal origin and course of the arteries. Pre...

  2. ROLE OF MDCT-CORONARY ANGIOGRAPHY IN THE EVALUATION OF CORONARY ARTERY ANOMALIES AND INCIDENCE OF CORONARY ARTERY ANOMALIES IN A SUBSET OF SOUTH INDIAN POPULATION

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    Senthil Kumar

    2015-11-01

    Full Text Available AIM: To determine the role of MDCT-Coronary angiography in the evaluation of coronary artery anomalies and to calculate the prevalence of coronary artery anomalies in a subset of south Indian population. MATERIALS AND METHODS: This is a retrospective study. Data of 250 consecutive patients who underwent CT coronary angiography in our institution over a period of 2 years were collected and analysed. The studies are analysed for the presence of abnormal origin and course of the arteries. Presence of anomalies of intrinsic coronary arterial anatomy like myocardial bridging were also evaluated. Few of these patients also underwent catheter coronary angiography and those findings were also included for analysis. RESULTS: Out of 250 patients, 7 patients had anomalies of origin and course of coronary arteries, 9 patients had myocardial bridging. Of these 16 patients, 10 patients underwent catheter coronary angiography which gave less information than CT-coronary angiography. CONCLUSION: The incidence of coronary artery anomalies in a subset of south Indian population was 6.4% and MDCT-Coronary angiography better evaluated these anomalies than catheter coronary angiography

  3. Noise-based tube current reduction method with iterative reconstruction for reduction of radiation exposure in coronary CT angiography

    International Nuclear Information System (INIS)

    Purpose: To investigate the potential of noise-based tube current reduction method with iterative reconstruction to reduce radiation exposure while achieving consistent image quality in coronary CT angiography (CCTA). Materials and methods: 294 patients underwent CCTA on a 64-detector row CT equipped with iterative reconstruction. 102 patients with fixed tube current were assigned to Group 1, which was used to establish noise-based tube current modulation formulas, where tube current was modulated by the noise of test bolus image. 192 patients with noise-based tube current were randomly assigned to Group 2 and Group 3. Filtered back projection was applied for Group 2 and iterative reconstruction for Group 3. Qualitative image quality was assessed with a 5 point score. Image noise, signal intensity, volume CT dose index, and dose-length product were measured. Results: The noise-based tube current modulation formulas were established through regression analysis using image noise measurements in Group 1. Image noise was precisely maintained at the target value of 35.00 HU with small interquartile ranges for Group 2 (34.17–35.08 HU) and Group 3 (34.34–35.03 HU), while it was from 28.41 to 36.49 HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 14% and 41% reduction in effective dose for Group 2 and Group 3 were observed compared with Group 1. Conclusion: Adequate image quality could be maintained at a desired and consistent noise level with overall 14% dose reduction using noise-based tube current reduction method. The use of iterative reconstruction further achieved approximately 40% reduction in effective dose

  4. Prospective electrocardiogram gated coronary 320-row area detector computed tomography angiography using low tube current scanning with full reconstruction

    International Nuclear Information System (INIS)

    It is possible to obtain equivalent image quality and a lower radiation dose using low tube current scanning with full reconstruction as compared to usual tube current scanning with half reconstruction in a 320-row area detector computed tomography (ADCT) angiography. Of 589 patient underwent coronary CT angiography (CCTA), 11 patients with (RR-PQ) ≥1069 ms were enrolled. In those patients, low tube current (50% mA) scanning with full or half reconstruction were performed. As a control, 11 patients with matched pairs of tube voltage, BMI and heart rate who underwent usual scanning with half reconstruction (100% mA with half reconstruction) were selected. Standard deviation of the CT value (SD) was measured in aorta (Ao), left atrium (LA) and left ventricle (LV), and extended dose-length products (DLP.e) were calculated. Significant motion artifact was not observed in any patients. SD of 50% mA with half reconstruction, 50% mA with full reconstruction, and 100% mA with half reconstruction were 28.1±2.6, 20.3±1.9, 20.7±2.5 Hounsfield unit (HU) in Ao, 34.4±4.4, 24.9±2.8, 24.9±3.1 HU in LA, and 29.7±2.3, 21.7±1.9, 22.1±2.3 HU in LV, respectively. There were not significant differences between 50% mA with full reconstruction and 100% mA with half reconstruction, but there were significant differences between 50% mA with half reconstruction and 50% mA with full reconstruction in all sites. The DLP.e of 50% mA scanning (74.1±21.8 mGy·cm) was significantly lower than 100% mA scanning (161.9±28.9 mGy·cm). CCTA with lower radiation dose and equivalent image quality can be obtained by ADCT using 50% mA scanning with full reconstruction in patients with (RR-PQ) ≥1069 ms. (author)

  5. The role of CT angiography in the evaluation of pediatric renovascular hypertension

    International Nuclear Information System (INIS)

    Historically, the evaluation of renovascular hypertension has been accomplished by US, renal scintigraphy and digital subtraction angiography. Based on its high accuracy reported in adults renal CT angiography (CTA) with pediatric-appropriate low radiation dose techniques has become an important tool in the workup of renovascular hypertension in children. Renal CTA has several advantages over more conventional imaging modalities, including rapid and non-invasive acquisition, high resolution and easy reproducibility. Additionally, in our experience high-quality renal CTA can be performed using low-dose radiation exposures and can be acquired without sedation in most instances. This article illustrates by examples the usefulness of renal CTA for diagnosis of childhood renovascular hypertension and provides an overview of renal CTA findings in the most common childhood renovascular diseases. (orig.)

  6. The role of simulator training for skills aquisition in coronary angiography

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    Jensen, Ulf

    2013-01-01

    Introduction Coronary angiography (CA) is one of our most common invasive techniques in medicine today and is used to investigate coronary anatomy and pathology. The method is crucial and lifesaving in diagnosing acute coronary syndromes and so far not interchangeable to any other modality. The skills of performing a CA are compulsory for the general cardiologist according to present international guidelines but the methods for achieving these skills are not well defined. CA i...

  7. Role of 320-slice multislice computed tomography coronary angiography in the assessment of coronary artery stenosis

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    Mohamed Ahmed Youssef

    2014-06-01

    Conclusion: In conclusion, MSCT coronary angiography is a very helpful and rapid non-invasive coronary imaging modality that was able to detect and grade coronary artery stenosis better than other noninvasive examinations used to detect CAD, such as exercise stress testing. Due to its very high negative predictive value, it may eliminate the need for invasive coronary procedures in the presence of normal coronary imaging.

  8. Acute chest pain: The role of MR imaging and MR angiography

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    Hunold, Peter, E-mail: peter.hunold@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Bischoff, Peter, E-mail: peter.bischoff@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Barkhausen, Jörg, E-mail: joerg.barkhausen@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany); Vogt, Florian M., E-mail: florian.vogt@uk-sh.de [Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany)

    2012-12-15

    MR imaging (MRI) and MR angiography (MRA) have gained a high level of diagnostic accuracy in cardiovascular disease. MRI in cardiac disease has been established as the non-invasive standard of reference in many pathologies. However, in acute chest pain the situation is somewhat special since many of the patients presenting in the emergency department suffer from potentially life-threatening disease including acute coronary syndrome, pulmonary embolism, and acute aortic syndrome. Those patients need a fast and definitive evaluation under continuous monitoring of vital parameters. Due to those requirements MRI seems to be less suitable compared to X-ray coronary angiography and multislice computed tomography angiography (CTA). However, MRI allows for a comprehensive assessment of all clinically stable patients providing unique information on the cardiovascular system including ischemia, inflammation and function. Furthermore, MRI and MRA are considered the method of choice in patients with contraindications to CTA and for regular follow-up in known aortic disease. This review addresses specific features of MRI and MRA for different cardiovascular conditions presenting with acute chest pain.

  9. Prospective ECG-triggered coronary CT angiography: clinical value of noise-based tube current reduction method with iterative reconstruction.

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    Junlin Shen

    Full Text Available OBJECTIVES: To evaluate the clinical value of noise-based tube current reduction method with iterative reconstruction for obtaining consistent image quality with dose optimization in prospective electrocardiogram (ECG-triggered coronary CT angiography (CCTA. MATERIALS AND METHODS: We performed a prospective randomized study evaluating 338 patients undergoing CCTA with prospective ECG-triggering. Patients were randomly assigned to fixed tube current with filtered back projection (Group 1, n = 113, noise-based tube current with filtered back projection (Group 2, n = 109 or with iterative reconstruction (Group 3, n = 116. Tube voltage was fixed at 120 kV. Qualitative image quality was rated on a 5-point scale (1 = impaired, to 5 = excellent, with 3-5 defined as diagnostic. Image noise and signal intensity were measured; signal-to-noise ratio was calculated; radiation dose parameters were recorded. Statistical analyses included one-way analysis of variance, chi-square test, Kruskal-Wallis test and multivariable linear regression. RESULTS: Image noise was maintained at the target value of 35HU with small interquartile range for Group 2 (35.00-35.03HU and Group 3 (34.99-35.02HU, while from 28.73 to 37.87HU for Group 1. All images in the three groups were acceptable for diagnosis. A relative 20% and 51% reduction in effective dose for Group 2 (2.9 mSv and Group 3 (1.8 mSv were achieved compared with Group 1 (3.7 mSv. After adjustment for scan characteristics, iterative reconstruction was associated with 26% reduction in effective dose. CONCLUSION: Noise-based tube current reduction method with iterative reconstruction maintains image noise precisely at the desired level and achieves consistent image quality. Meanwhile, effective dose can be reduced by more than 50%.

  10. MR angiography

    International Nuclear Information System (INIS)

    MR angiography allows the imaging of vessels comparable with the vessels imaged with digital angiography. MR angiograms were also generated by image subtraction. Basis are the different magnetic properties of moved and stationary spins. Contrast media are not required. In recent years the various techniques of image subtraction with the aim of well imaged vessels were developed. The most important are described. (author)

  11. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature

    OpenAIRE

    Lakshmi Sudha; Bhawna Dev; Ravindra Kamble; Santhosh Joseph

    2009-01-01

    Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulat...

  12. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature

    Directory of Open Access Journals (Sweden)

    Lakshmi Sudha

    2009-01-01

    Full Text Available Cranially conjoined twins (craniopagus are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.

  13. Critical role of pulmonary angiography in the diagnosis of pulmonary emboli following cardiac surgery.

    Science.gov (United States)

    Ramos, R S; Salem, B I; Haikal, M; Gowda, S; Coordes, C; Leidenfrost, R

    1995-10-01

    This study was conducted to identify patients at high risk of the development of Pulmonary Embolism (PE) after open heart surgery, to evaluate pertinent diagnostic methods, and to assess the mortality associated with this complication. We evaluated the records of 2,551 consecutive patients who underwent open heart surgery over a 10-year period to identify those patients in whom PE developed. All surgical reports, ventilation/perfusion scans, pulmonary angiograms, and autopsies from the same period were also reviewed. Preoperative and postoperative risk factors for pulmonary embolism were also analyzed, as well as the outcome of this complication in each type of surgical procedure. Pulmonary embolism was identified in 69 (2.7%) patients after open heart surgery, in 43 (62.3%) of whom the diagnosis was established within the first week of surgery. Factors associated with high incidence for PE were hyperlipidemia, congestive heart failure and heparin-induced thrombocytopenia (P mechanical ventilation (P ventilation/perfusion scan in 25 patients, by pulmonary angiography in 42 (29 of whom had prior V/Q scan read as intermediate or low probability for PE) and by autopsy in two patients. The mortality rate in patients who had PE was 7.2%, while in those without this complication it was 3.2%. These findings suggest that aggressive approach for the diagnosis of PE by pulmonary angiography whenever the V/Q scan is not read as high probability is crucial in patients with recent open heart surgery; such approach may identify patients with PE at an early stage and may have an impact in reducing mortality incurred by this complication. This diagnostic assessment should be emphasized in the perioperative period, especially in patients with multiple significant and identifiable risk factors for PE. PMID:8829830

  14. Cardiac catheterization and angiography. Third edition

    International Nuclear Information System (INIS)

    This book discusses the papers on cardiac catheterization and angiography. The topics covered are: historical perspective and present practice of cardiac catheterization; angiography principles and utilization of radiologic and cineangiographic equipment; complications, incidence and prevention of side effects of cardiac catheterization; techniques; blood flow measurement of heart; pressure measurement; diagnostic techniques of angiography; special catheter techniques; coronary angiography, temporary and permanent pacemakers, potential role of lasers in the cardiac catheterization and evaluation of cardiac function

  15. Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors

    Institute of Scientific and Technical Information of China (English)

    David; Bonekamp; Siva; P; Raman; Karen; M; Horton; Elliot; K; Fishman

    2015-01-01

    Small-bowel carcinoid tumors are the most common form(42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare(3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common(20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

  16. Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors.

    Science.gov (United States)

    Bonekamp, David; Raman, Siva P; Horton, Karen M; Fishman, Elliot K

    2015-09-28

    Small-bowel carcinoid tumors are the most common form (42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare (3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common (20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated. PMID:26435774

  17. Diagnostic performance of non-invasive fractional flow reserve derived from coronary computed tomography angiography: current perspectives

    OpenAIRE

    Kakouros, Nikolaos

    2016-01-01

    Mohamed Ahmed, Nikolaos Kakouros Department of Medicine, Division of Cardiology, University of Massachusetts Medical School, Worcester, MA, USAAbstract: Coronary computed tomography angiography (CTA) has been increasingly used to detect coronary artery disease. The diagnostic performance of coronary CTA is well established with a high sensitivity and negative predictive value. Nevertheless, the diagnostic value of coronary CTA is offset by a high false positive rate, partly due to the techniq...

  18. 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

  19. 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

  20. 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 ...

  1. 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

  2. Role of plain radiography and CT angiography in the evaluation of obstructed total anomalous pulmonary venous connection

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Quanli; Pa, Mier; Hu, Xihong; Wang, Junbo [Children' s Hospital, Fudan University, Department of Radiology, Shanghai (China)

    2013-07-15

    Obstructed total anomalous pulmonary venous connection (TAPVC) is frequently misdiagnosed as pulmonary disease and without operative correction early death is common. It is important to make a correct diagnosis before surgery. The purpose of this study was to describe the chest radiographic features of obstructed TAPVC and compare CT angiography with transthoracic echocardiography in the evaluation of obstructed TAPVC. Eighteen children with obstructed TAPVC were assessed. Their clinical and imaging data were retrospectively reviewed. The characteristic radiographic findings were analyzed and compared with surgical results, and the diagnostic accuracy of CT angiography and transthoracic echocardiography was evaluated in terms of pulmonary venous drainage and obstruction detection. The common radiographic features included pulmonary venous congestion or edema or both (16 of 18 cases, 89%), and absence of cardiomegaly (12 of 18 cases, 67%). CT angiography correctly diagnosed TAPVC and clearly revealed the draining sites in all children (five with supracardiac TAPVC, three with cardiac TAPVC, eight with infracardiac TAPVC and two with mixed TAPVC). The diagnostic agreement between CT angiography and surgery was 100%. Transthoracic echocardiography only correctly revealed the draining sites in 11 children (5 with supracardiac TAPVC, 2 with cardiac TAPVC and 4 with infracardiac TAPVC). The diagnostic agreement between transthoracic echocardiography and surgery was 61%. The diagnostic accuracy of CT angiography was higher than that of transthoracic echocardiography (P = 0.0156). Thirty-four sites of obstruction were correctly detected by CT angiography (11 in the mediastinum, 1 at the diaphragmatic level, 9 below the diaphragm and 13 stenotic individual pulmonary veins in the lung). The diagnostic agreement between CT angiography and surgery was 92%. Transthoracic echocardiography only correctly detected 15 sites of obstruction (11 in the mediastinum, 1 at the

  3. The role of vertebral angiography for the management of vertebrobasilar occlusive disease with special reference to recanalizing techniques

    International Nuclear Information System (INIS)

    Between 1980 and 1985 a total of 912 vertebral angiographies were performed in 793 patients, 198 of whom had ischemic symptoms attributable to the hindbrain circulation. The complication rate was 6%. With due consideration for the clinical findings and those recorded by Doppler ultrasound and computed tomography, vertebral angiography is indicated in vertebrobasilar occlusive disease if anticoagulation, percutaneous transluminal angioplasty (PTA) or local intraarterial fibrinolytic therapy (LIF) of the hindbrain circulation is intended, and also if there is a discrepancy between the clinical findings and the results of computed tomography or Doppler ultrasound examination. With today's sophisticated angiographic techniques (e.g. DSA) and the possibilities opened up by modern interventional neuroradiological techniques, the complication rate of vertebral angiography now seems to be lower than previously. (orig.)

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

    Science.gov (United States)

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

    2010-01-01

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

  5. 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

  6. 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...

  7. The role of a simulator-based course in coronary angiography on performance in real life cath lab

    OpenAIRE

    Jensen, Ulf J.; Jensen, Jens; Olivecrona, Göran; Ahlberg, Gunnar; Lagerquist, Bo; Tornvall, Per

    2014-01-01

    Background: The aim of this study was to explore if a course consisting of lectures combined with simulator training in coronary angiography (CA) could accelerate the early learning curve when performing CA on patients. Knowledge in performing CA is included in the curriculum for the general cardiologist. The method, according to American College of Cardiology and European Society of Cardiology guidelines, for this training is not well defined but simulator training is proposed to be an optio...

  8. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    Energy Technology Data Exchange (ETDEWEB)

    May, Matthias S.; Kuettner, Axel; Lell, Michael M.; Wuest, Wolfgang; Scharf, Michael; Uder, Michael [University of Erlangen, Department of Radiology, Erlangen (Germany); Deak, Paul; Kalender, Willi A. [University of Erlangen, Department of Medical Physics, Erlangen (Germany); Keller, Andrea K.; Haeberle, Lothar [University of Erlangen, Department of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Achenbach, Stephan; Seltmann, Martin [University of Erlangen, Department of Cardiology, Erlangen (Germany)

    2012-03-15

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 {+-} 2.1 mSv/100 mAs for TCM and 12.5 {+-} 5.3 mSv/100 mAs for CTC (P < 0.001). Relative dose reduction at low HR ({<=}60 bpm) was highest (49 {+-} 5%) compared to intermediate (60-70 bpm, 33 {+-} 12%) and high HR (>70 bpm, 29 {+-} 12%). However lowest ED is achieved at high HR (5.2 {+-} 1.5 mSv/100 mAs), compared with intermediate (6.7 {+-} 1.6 mSv/100 mAs) and low (8.3 {+-} 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  9. Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch

    International Nuclear Information System (INIS)

    To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine. Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment. Retrospective simulations with constant tube current (CTC) served as reference. Lung tissue was segmented and used for organ and effective dose (ED) calculation. Estimates for mean relative ED was 7.1 ± 2.1 mSv/100 mAs for TCM and 12.5 ± 5.3 mSv/100 mAs for CTC (P 70 bpm, 29 ± 12%). However lowest ED is achieved at high HR (5.2 ± 1.5 mSv/100 mAs), compared with intermediate (6.7 ± 1.6 mSv/100 mAs) and low (8.3 ± 2.1 mSv/100 mAs) HR when automated pitch adaptation is applied. Radiation dose savings up to 52% are achievable by TCM at low and regular HR. However lowest ED is attained at high HR by pitch adaptation despite inferior radiation dose reduction by TCM. circle Monte Carlo simulations allow for individual radiation dose calculations. (orig.)

  10. Coronary angiography

    International Nuclear Information System (INIS)

    Due to progressive improvements in catheter design, radiographic imaging, and contrast media, as well as the development of effective options for the treatment of coronary artery disease (bypass surgery and angioplasty), diagnostic coronary angiography has grown into a safe and widely practiced component of cardiac catheterization. It is estimated that more than 200,000 coronary angiographic procedures are performed each year in the United States, with a procedure-related mortality of 0.1%. In each procedure, the objective is to examine the entire coronary tree, recording details of coronary anatomy, including individual variations in arterial distribution, anatomic or functional pathology (atherosclerosis, thrombosis, congenital anomalies, or focal coronary spasm), and the presence of inter- and intracoronary collateral connections. With repeat intracoronary contrast injections in a series of angulated views, a high resolution image intensifier, and 35 mm cine-angiographic film or other recording media, it is possible to define all portions of the coronary arterial circulation down to vessels as small as 0.2 mm, and to eliminate artifacts due to vessel overlap or foreshortening

  11. 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)

  12. Iterative reconstruction and individualized automatic tube current selection reduce radiation dose while maintaining image quality in 320-multidetector computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Aim: To assess the effect of two iterative reconstruction algorithms (AIDR and AIDR3D) and individualized automatic tube current selection on radiation dose and image quality in computed tomography coronary angiography (CTCA). Materials and methods: In a single-centre cohort study, 942 patients underwent electrocardiogram-gated CTCA using a 320-multidetector CT system. Images from group 1 (n = 228) were reconstructed with a filtered back projection algorithm (Quantum Denoising Software, QDS+). Iterative reconstruction was used for group 2 (AIDR, n = 379) and group 3 (AIDR3D, n = 335). Tube current was selected based on body mass index (BMI) for groups 1 and 2, and selected automatically based on scout image attenuation for group 3. Subjective image quality was graded on a four-point scale (1 = excellent, 4 = non-diagnostic). Results: There were no differences in age (p = 0.975), body mass index (p = 0.435), or heart rate (p = 0.746) between the groups. Image quality improved with iterative reconstruction and automatic tube current selection [1.3 (95% confidence intervals (CI): 1.2–1.4), 1.2 (1.1–1.2) and 1.1 (1–1.2) respectively; p < 0.001] and radiation dose decreased [274 (260–290), 242 (230–253) and 168 (156–180) mGy cm, respectively; p < 0.001]. Conclusion: The application of the latest iterative reconstruction algorithm and individualized automatic tube current selection can substantially reduce radiation dose whilst improving image quality in CTCA

  13. Assessment of Left Ventricular Function and Volume in Patients Undergoing 128-Slice Coronary CT Angiography with ECG-Based Maximum Tube Current Modulation: a Comparison with Echocardiography

    International Nuclear Information System (INIS)

    To compare multi-detector CT (MDCT) using 128-slice coronary CT angiography (Definition AS+, Siemens Medical Solution, Forchheim, Germany) with ECG-based maximum tube current modulation with echocardiography for the determination of left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), end-systolic volume (ESV), as well as assessing coronary artery image quality and patient radiation dose. Thirty consecutive patients (M:F = 20:10: mean age, 57.9 ± 11.4 years) were referred for MDCT for evaluation of atypical chest pain. EF, EDV and ESV were determined for both MDCT and echocardiography, and the correlation coefficients were assessed. Coronary artery segment subjective image quality (1, excellent: 4, poor) and radiation dose were recorded. Left ventricular EF, EDV, and ESV were calculated by MDCT and echocardiography and the comparison showed a significant correlation with those estimated by echocardiography (p < 0.05). Consistently, the LVEFs calculated by MDCT and echocardiography were not statistically different. However, LV, EDV and ESV from MDCT were statistically higher than those from echocardiography (p < 0.05). The average image quality score of the coronary artery segment was 1.10 and the mean patient radiation dose was 3.99 ± 1.85 mSv. Although LV volume was overestimated by MDCT, MDCT provides comparable results to echocardiography for LVEF and LVV, with a low radiation dose

  14. CT angiography of the neck: Value of contrast medium dose reduction with low tube voltage and high tube current in a 64–detector row CT

    International Nuclear Information System (INIS)

    Aim: To evaluate the feasibility of a low-dose contrast medium protocol for 64-detector row computed tomography angiography (CTA) of the neck using a low-tube-voltage/high-tube-current setting. Materials and methods: A phantom study was performed using 64-detector row spiral CT at multiple tube voltage and current settings. Iodine contrast medium attenuation curves were acquired by processing and used to select the best contrast medium-to-noise ratio (CNR). A prospective clinical study was then performed on 84 patients requiring neck CTA. Patients were randomly divided into two groups of 42. Group A was examined using the conventional imaging protocol (120 kV, 400 mAs) and group B was examined at 80 kV and 600 mAs along with a 50% reduction in contrast medium dose. The CT dose index-volume (CTDIvol), background noise (BN), and CNR were measured and statistically analysed. Various image quality criteria were evaluated by two senior radiologists using a qualitative five-point scale. Results: Comparing group B with A, CTDIvol decreased by 54% (B: 27.48 mGy, A: 59.11 mGy), however, the CNR increased by 50%. The mean attenuation, which was caused by venous streak artefacts, was significantly lower in group B than A. Qualitative image analysis found that all criteria were significantly better for group B than A. Conclusion: At 64-detector row spiral CT, the low-tube-voltage/high-tube-current with low-dose contrast medium protocol was superior to the conventional protocol regarding radiation dose, venous streak artefacts, and image quality, and is feasible for CTA of the neck

  15. 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...

  16. 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

  17. Achieving consistent image quality and overall radiation dose reduction for coronary CT angiography with body mass index-dependent tube voltage and tube current selection

    International Nuclear Information System (INIS)

    Aim: To develop a quantitative body mass index (BMI)-dependent tube voltage and tube current selection method for obtaining consistent image quality and overall dose reduction in computed tomography coronary angiography (CTCA). Methods and materials: The images of 190 consecutive patients (group A) who underwent CTCA with fixed protocols (100 kV/193 mAs for 100 patients with a BMI of <27 and 120 kV/175 mAs for 90 patients with a BMI of >27) were retrospectively analysed and reconstructed with an adaptive statistical iterative reconstruction (ASIR) algorithm at 50% blending. Image noise was measured and the relationship to BMI was studied to establish BMI-dependent tube current for obtaining CTCA images with user-specified image noise. One hundred additional cardiac patients (group B) were examined using prospective triggering with the BMI-dependent tube voltage/current. CTCA image-quality score, image noise, and effective dose from groups B and C (subgroup of A of 100 patients examined with prospective triggering only) were obtained and compared. Results: There was a linear relationship between image noise and BMI in group A. Using a BMI-dependent tube current in group B, an average CTCA image noise of 27.7 HU (target 28 HU) and 31.7 HU (target 33 HU) was obtained for the subgroups of patients with BMIs of >27 and of <27, respectively, and was independent of patient BMI. There was no difference between image-quality scores between groups B and C (4.52 versus 4.60, p > 0.05). The average effective dose for group B (2.56 mSv) was 42% lower than group C (4.38 mSv; p < 0.01). Conclusion: BMI-dependent tube voltage/current selection in CTCA provides an individualized protocol that generates consistent image quality and helps to reduce overall patient radiation dose. - Highlights: • BMI-dependent kVp and mA selection method may be established in CCTA. • BMI-dependent kVp and mA enables consistent CCTA image quality. • Overall dose reduction of 40% can

  18. The role of cardiovascular magnetic resonance imaging and computed tomography angiography in suspected non-ST-elevation myocardial infarction patients : Design and rationale of the CARdiovascular Magnetic rEsoNance imaging and computed Tomography Angiography (CARMENTA) trial

    NARCIS (Netherlands)

    Smulders, Martijn W.; Kietselaer, Bastiaan L. J. H.; Das, Marco; Wildberger, Joachim E.; Crijns, Harry J. G. M.; Veenstra, Leo F.; Brunner-La Rocca, Hans-Peter; van Dieijen-Visser, Marja P.; Mingels, Alma M. A.; Dagnelie, Pieter C.; Post, Mark J.; Gorgels, Anton P. M.; van Asselt, Antoinette D. I.; Vogel, Gaston; Schalla, Simon; Kim, Raymond J.; Bekkers, Sebastiaan C. A. M.

    2013-01-01

    Background Although high-sensitivity cardiac troponin (hs-cTn) substantially improves the early detection of myocardial injury, it lacks specificity for acute myocardial infarction (MI). In suspected non-ST-elevation MI, invasive coronary angiography (ICA) remains necessary to distinguish between ac

  19. Current role of bloodless liver resection

    Institute of Scientific and Technical Information of China (English)

    Spiros G Delis; Juan Madariaga; A Bakoyiannis; Ch Dervenis

    2007-01-01

    Liver resections are demanding operations which can have life threatening complications although they are performed by experienced liver surgeons. Recently new technologies are applied in the field of liver surgery, having one goal: safer and easier liver operations. The aim of this article is to address the issue of bloodless liver resection using radiofrequency energy. Radionics, Cool-tipTM System and Tissue Link are some of the devices which are using radiofrequency energy. All information included in this article, refers to these devices in which we have personal experience in our unit of liver surgery. These devices take advantage of its unique combination of radiofrequency current and internal electrode cooling to perform sealing of the small vessels and biliary radicals. Dissection is also feasible with the cool-tip probe. For the purposes of this study patient sex, age, type of disease and type of surgical procedure in association with the duration of parenchymal transection, blood loss, length of hospital stay, morbidity and mortality were analyzed. Cool-tip RF device may provide a unique, simple and rather safe method of bloodless liver resections if used properly. It is indicated mostly in cirrhotic patients with challenging hepatectomies (segment W, central resections). The total operative time is eliminated and the average blood loss is significantly decreased. It is important to note that this technique should not be applied near the hilum or the vena cava to avoid damage of these structures.

  20. Peripheral MR angiography

    International Nuclear Information System (INIS)

    Atherosclerotic disease of the lower extremities is a common disorder in western society. Its debilitating nature calls for accurate diagnosis and treatment. The gold standard for diagnosing this disease by depiction of vessel morphology is X-ray angiography (either conventional or digital subtraction angiography). However, the invasive nature of this technique and the possible harmful effects of iodinated contrast agents have led to the idea that non-invasive MR angiography might be a good alternative for acquiring information about vessel morphology. Most extensively studied was time-of-flight MR angiography. Although first results with this technique were encouraging, it is now apparent that time-of-flight MR angiography is hampered by the virtue of which it exists, since blood flow not only generates vessel-to-background contrast, but is also the cause of disturbing artifacts. However, with the introduction of minimally invasive contrast-enhanced MR angiography, using gadolinium chelates to reduce the T1 of blood, image quality has improved dramatically. Moreover, using contrast-enhanced MR angiography, high-resolution three-dimensional data about the entire peripheral vascular tree can be obtained within several minutes, which might make MR angiography a true competitor of X-ray angiography as a diagnostic tool in the clinical work-up of a patient with complaints of peripheral atherosclerosis. The purpose of this article is to explain working mechanisms and usefulness of both time-of-flight and contrast-enhanced MR angiography. (orig.)

  1. Peripheral MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ho, K.Y.J.A.M.; Leiner, T.; Haan, M.W. de; Engelshoven, J.M.A. van [University Hospital Maastricht (AZM) (Netherlands). Dept. of Radiology

    1999-07-01

    Atherosclerotic disease of the lower extremities is a common disorder in western society. Its debilitating nature calls for accurate diagnosis and treatment. The gold standard for diagnosing this disease by depiction of vessel morphology is X-ray angiography (either conventional or digital subtraction angiography). However, the invasive nature of this technique and the possible harmful effects of iodinated contrast agents have led to the idea that non-invasive MR angiography might be a good alternative for acquiring information about vessel morphology. Most extensively studied was time-of-flight MR angiography. Although first results with this technique were encouraging, it is now apparent that time-of-flight MR angiography is hampered by the virtue of which it exists, since blood flow not only generates vessel-to-background contrast, but is also the cause of disturbing artifacts. However, with the introduction of minimally invasive contrast-enhanced MR angiography, using gadolinium chelates to reduce the T1 of blood, image quality has improved dramatically. Moreover, using contrast-enhanced MR angiography, high-resolution three-dimensional data about the entire peripheral vascular tree can be obtained within several minutes, which might make MR angiography a true competitor of X-ray angiography as a diagnostic tool in the clinical work-up of a patient with complaints of peripheral atherosclerosis. The purpose of this article is to explain working mechanisms and usefulness of both time-of-flight and contrast-enhanced MR angiography. (orig.)

  2. 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 . ...

  3. Current role of surgical therapy in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Ryan Swan; Thomas J Miner

    2006-01-01

    Surgery is currently the only potentially curative treatment for gastric cancer. Since the inception of the gastrectomy for cancer of the stomach, there has been debate over the bounds of surgical therapy, balancing potential long-term survival with perioperative morbidity and mortality. This review delineates the current role of surgery in preoperative staging, curative resection, and palliative treatment for gastric cancer.

  4. Pediatric digital substraction angiography

    International Nuclear Information System (INIS)

    The possibilities of intravenous and intraarterial digital substraction angiography (DSA) in childhood, involving various vascular territories, are analyzed and summed up. The characteristic features of the methods used in DSA are outlined - quantity of contrast medium, modes and routes of introduction, angiographic sequence and possibilities for processing. Various groups of diseases (volumetric processes, anomalies and variants, vascular lesions) are discussed, and the diagnostic implications of cerebral angiography, angiography of the cervical region, aortic arc, thoracic and abdominal aorta, abdominal angiography, angiopulmography, angiography of the upper and lower extremities are assayed. Advantages and shortcomings of the procedures in various anatomical regions are evaluated. In conclusion, proceeding from the specificity of examination in pediatrics, emphasis is laid on the necessity of individual approach to each single case with a special reference to the indications of including DSA in the general diagnostic scheme. 15 refs., 4 tabs., 6 figs. (orig.)

  5. The role of heating and current drive in ITER

    International Nuclear Information System (INIS)

    This report discusses and summarize the role of heating and non-inductive current drive in ITER as: (1) ITER must have heating power sufficient for ignition. (2) The heating system must be capable of current drive. (3) Steady-state operation is an ''ultimate goal.'' It is recognized that additional heating and current drive power (beyond what is initially installed on ITER) may be required. (4) The ''Ultimate goal of steady-state operation'' means steady-state with QCD ≥ 5. Unlike the ''Terms of Reference'' for the ITER CDA, the ''ITER Technical Objectives and Approaches'' for the EDA sets no goal for the neutron wall load during steady-state operation. (5) In addition to bulk current drive, the ITER heating and current drive system should be used for current profile control and for burn control

  6. Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose

    International Nuclear Information System (INIS)

    Background With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician. Purpose To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT). Material and Methods We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis. Results In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively. Conclusion The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates

  7. Two-dimensional thick-slice MR digital subtraction angiography for assessment of cerebrovascular occlusive diseases

    International Nuclear Information System (INIS)

    Although spatial resolution of current MR angiography is excellent, temporal resolution has remained unsatisfactory. We evaluated clinical applicability of 2D thick-slice, contrast-enhanced subtraction MR angiography (2D-MR digital subtraction angiography) with sub-second temporal resolution in cerebrovascular occlusive diseases. Twenty-five patients with cerebrovascular occlusive diseases (8 moyamoya diseases, 10 proximal internal carotid occlusions, and 2 sinus thromboses) were studied with a 1.5-T MR unit. The MR digital subtraction angiography (MRDSA) was performed per 0.97 s continuously just after a bolus injection of 15 ml of gadolinium chelates up to 40 s in sagittal (covering hemisphere) or coronal planes. Subtraction images were generated at a workstation. We evaluated imaging quality and hemodynamic information of MRDSA in comparison with those of routine MR imaging, non-contrast MR angiography, and X-ray intra-arterial DSA. Major cerebral arteries, all of the venous sinuses, and most tributaries were clearly visualized with 2D MRDSA. Also, pure arterial phases were obtained in all cases. The MRDSA technique demonstrated prolonged circulation in sinus thromboses, distal patent lumen of proximal occlusion, and some collateral circulation. Such hemodynamic information was comparable to that of intra-arterial DSA. Two-dimensional thick-slice MRDSA with high temporal resolution has a unique ability to demonstrate cerebral hemodynamics equivalent to that of intra-arterial DSA and may play an important role for evaluation of cerebrovascular occlusive diseases. (orig.)

  8. 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.

  9. Onset and role of the Antarctic Circumpolar Current

    OpenAIRE

    Barker, P. F.; Threshers Barn, Whitcott Keysett, Clun, Shropshire SY7 8QE, UK; Filippelli, G. M.; Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI), Indianapolis, IN 46202-5132, USA; Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Martin, E. E.; Department of Geological Sciences, University of Florida, Gainesville, FL 32611-2120, USA; Howard, D. S.; Department of Earth & Environmental Sciences, University of Rochester, Rochester, NY 14611, USA

    2007-01-01

    For some time, onset of the Antarctic Circumpolar Current (ACC) was considered to have caused or stabilised full Antarctic glaciation. Recently, however, the importance of the ACC in this role has been questioned. In order to understand the relationship between the ACC and Antarctic glaciation, and thence the importance of ocean circulation to palaeoclimate, we need to determine the development history of both processes. To this end, we summarise all published estimates of ACC ons...

  10. 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).

  11. Spinal angiography with iohexol

    International Nuclear Information System (INIS)

    Iohexol 300 was used for 55 selective spinal angiograms in 50 patients; all were of good quality. There was no significant change in vital signs during the angiographic procedure in any case. Two patients with spinal dural arteriovenous fistula draining into a coronal venous plexus developed transient subjective slight increase in their disability during the immediate post-angiographic period. Eight cases embolised at the time of angiography showed improvement in their neurological deficits within 24 h of the study. The other patients were unaffected by the procedure. Iohexol 300 is a very suitable contrast medium for spinal angiography. (orig.)

  12. MR angiography of the body. Technique and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Emanuele [Pisa Univ. Radiodiagnostica 1 Universitaria (Italy). Diagnostic and Interventional Radiology Dept. of Oncology, Transplants, and Advanced Technologies in Medicine; Cosottini, Mirco [Pisa Univ. (Italy). Unit of Neuroradiology Dept. of Neurosciences; Caramella, Davide (eds.) [Pisa Univ. (Italy). Diagnostic and Interventional Radiology Dept. of Oncology, Transplants, and Advanced Technologies in Medicine

    2010-07-01

    Magnetic resonance angiography (MRA) continues to undergo exciting technological advances that are rapidly being translated into clinical practice. It also has evident advantages over other imaging modalities, including better patient safety compared with CT angiography and superior accuracy and contrast resolution compared with ultrasonography. With the aid of numerous high-quality illustrations, this book reviews the current role of MRA of the body. It is divided into three sections. The first section is devoted to issues relating to image acquisition technique and sequences. Individual chapters focus on flow-based MRA, contrast media, contrast-enhanced MRA, artifacts, and image processing. The second and principal section of the book addresses the clinical applications of MRA in various parts of the body, including the neck vessels, the spine, the thoracic aorta and pulmonary vessels, the heart and coronary arteries, the abdominal aorta and renal arteries, and peripheral vessels. The role of the blood pool contrast agents for the diagnosis and characterization of vascular disease is fully explored. The final section considers the role of MRA in patients undergoing liver or pancreas and kidney transplantation. This book will be an invaluable aid to all radiologists who work with MRA. (orig.)

  13. The current role of imaging techniques in faecal incontinence

    Energy Technology Data Exchange (ETDEWEB)

    Terra, M.P.; Stoker, J. [University of Amsterdam, Department of Radiology, G1-229, Academic Medical Center, Amsterdam (Netherlands)

    2006-08-15

    Faecal incontinence is a common multifactorial disorder. Major causes of faecal incontinence are related to vaginal delivery and prior anorectal surgery. In addition to medical history and physical examination, several anorectal functional tests and imaging techniques can be used to assess the underlying pathophysiology and to guide treatment planning in faecal incontinent patients. Anorectal functional tests provide functional information, but the potential strength comes from combining test results. Imaging techniques, including defecography, endoanal sonography, and magnetic resonance (MR) imaging, provide structural information about the anorectal region with a direct clinical impact. The major role of imaging techniques in faecal incontinence is visualising the structural and functional integrity of the anal sphincter complex. Both two-dimensional endoanal sonography and endoanal MR imaging are accurate tools to depict anal sphincter defects. The major advantage of endoanal MR imaging is the accurate demonstration of external anal sphincter atrophy. Recent studies have suggested that external phased array MR imaging and three-dimensional endoanal sonography are also valuable tools in the diagnostic work up of faecal incontinence. Decisions about the preferred technique will mainly be determined by availability and local expertise. This article demonstrates the current role of tests, predominantly imaging tests, in the diagnostic work up of faecal incontinence. (orig.)

  14. The current role of thiazolidinediones in diabetes management.

    Science.gov (United States)

    Rizos, Christos V; Kei, Anastazia; Elisaf, Moses S

    2016-08-01

    Among the epidemics of modern time, type 2 diabetes mellitus (T2DM) is one of the main contributors to overall morbidity as well as mortality. A number of different treatment options are available for the management of diabetes. Among them thiazolidinediones (TZDs) is an interesting drug class since it does not target the result of T2DM, i.e., hyperglycemia but rather some of the core mechanisms of the disease. Indeed, glitazones increase insulin sensitivity by activating the peroxisome proliferator-activated receptor γ, which plays an important role in regulating various metabolic parameters. Although TZDs have an established efficacy in T2DM treatment, their usage during the past years was questioned following the emergence of some alarming data regarding their safety and especially the cardiovascular safety of rosiglitazone. As a result, there is often some skepticism about the current role of TZDs in T2DM management. This mainly affects rosiglitazone even leading to its withdrawal from several markets in contrast to pioglitazone, which has shown a beneficial cardiovascular profile. A comprehensive assessment of the benefit-to-risk ratio of TZDs is required in order to better understand the place of these drugs in T2DM management. PMID:27165418

  15. The Role of Curriculum Scholars in Current Curriculum Debates

    Directory of Open Access Journals (Sweden)

    Muhammad Mushtaq

    2012-09-01

    Full Text Available Curriculum is a set of planned tasks, learning experiences and behaviors proposed by an authority to achieve predetermined goals in form of behavioral change, academic achievements and learning outcomes within a particular time. The scholars are the people who have command and expertise in any of the curriculum components. The article focuses on the role of curriculum scholars in Pakistan and how and what type of changes they can initiate to bring harmony and tolerance, character and quality in development of curricula. The international issues, trends evolving globalization can be enhanced and incorporated to foster individual and social development. It is a qualitative study based on historical evidences and current researches highlighting the importance and role of curriculum scholars and meeting the world class education system. The issues and trends mentioned by developed countries curriculum experts paved way to synthesis them with local rising issues and trends.The study concluded that the curriculum developers have dynamic roles in curriculum debates because they have to work for bridging gaps of developing and developed nation, addressing local curriculum issues, Using pragmatic approach rather than ideological, reorganizing of recent curricula, solving language issue, facing controversies on curriculum change, making it unified and centralized, diverting curricula to research orientation, obtaining continuous feedback and developing harmony in society at the same time. It is imperative for scholars to have effective communication skills and dynamic personality to incorporate the future trends without creating conflicts and confusion in the society. They need to know the skill to motivate and mould high ups for future changes and bring changes without development of controversies.

  16. Digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    Besides the non-invasive techniques, angiography remains essential. The disadvantages of angiography are the complexity of the procedure and the possibility of complications. Digital subtraction angiography (DSA) is a considerable improvement in the examination of vessels. In DSA, subtraction combined with enhancement of the signals allows the use of intravenous injection to obtain good images of the arteries. However, when the contrast material is supplied intravenously, a rather large amount of contrast material is necessary to obtain images of good quality. Quantities of 30-40 cc of contrast material are required. The advantage of the intravenous injection of contrast material rather than the use of a catheter to deliver the contrast material in loco is that it is almost non-invasive thus circumventing the complications caused by catheter manipulation in the arterial system. This makes it possible to apply this method on an out-patient basis. DSA can also be applied with intra-arterial selective injection of the contrast material. In this case, the strong enhancement with DSA allows the use of a small quantity of contrast material while still obtaining images of the vessels with good contrast definition

  17. Role of high resolution contrast-enhanced magnetic resonance angiography (HR CeMRA) in management of arterial complications of the renal transplant

    International Nuclear Information System (INIS)

    Introduction: Transplant renal artery (RA) stenosis (TRAS) is the most frequent posttransplantation vascular complication. Contrast enhanced magnetic resonance (CeMRA) angiography has been established as the preferred imaging technique for the evaluation of TRAS because it does not require the use of iodinated contrast material and does not expose the patient to ionizing radiation. Digital subtraction angiography (DSA) is the gold standard in the evaluation of arterial tree of the renal allograft. Aim of the work: This study was carried out to assess the accuracy of CeMRA in the detection of arterial complications after renal transplantation. Patients and methods: Thirty renal transplant patients with suspected arterial complications in which both CeMRA and DSA were performed were included in the study. The HR CeMRA shows 93.7% sensitivity, 80% specificity, 88.2% positive predictive value, 88.9% negative predictive value and 88.5% accuracy. Conclusion: HR CeMRA is an accurate reliable tool in the assessment of arterial complications after renal transplantation. It may replace DSA as a diagnostic modality with reservation of interventional techniques for endovascular treatment of suitable cases.

  18. [Spiral CT angiography in practice].

    Science.gov (United States)

    Pavcec, Zlatko; Zokalj, Ivan; Rumboldt, Zoran; Pal, Andrej; Saghir, Hussein; Ozretić, David; Latin, Branko; Perhoć, Zeljka; Marotti, Miljenko

    2005-01-01

    Incidence of vascular diseases and development of new radiologic techniques in the last three decades has given strong impuls for introduction of non-invasive vascular diagnostic methods. Thanks to the introduction of Doppler ultrasound, new types of computed tomography (CT) and magnetic resonance (MR) scanners, non-invasive vascular diagnostic methods are replacing conventional invasive (catheter) angiographic methods. Computed tomographic angiography (CTA) is a noninvasive vascular diagnostic method based on continuous scanning with CT scanner during intravenous application of contrast material. Performing of CTA is possible after introduction of spiral CT technique whose characteristics are short imaging time and volumetric data acquisition. The main goal of this article, based on our experiences, is to review the role of CTA, performed on single-slice CT scanner, in managment of patients with vascular pathology. PMID:16145870

  19. 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

  20. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3±6.8) and retrospective CCTA with TCM (77, mean HR: 59.1±9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94±0.70 mSv) than for retrospective CCTA with TCM (4.51±1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI≥25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  1. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Dong Wook (Dept. of Family Medicine, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)); Choo, Ki Seok; Baik, Seung Kug; Kim, Yong Woo; Jeon, Ung Bae (Dept. of Radiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do, (Korea, Republic of)), email: kschoo0618@naver.com; Kim, Jeong Soo (Dept. of Cardiology, Medial Research Institute, Pusan National Univ. Yangsan Hospital, School of Medicine, Gyeongsangnam-do (Korea, Republic of)); Lim, Soo Jin (Dept. of Cardiology, Kim Hae Joongang Hospital, Gyeongsangnam-do (Korea, Republic of))

    2011-02-15

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3+-6.8) and retrospective CCTA with TCM (77, mean HR: 59.1+-9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94+-0.70 mSv) than for retrospective CCTA with TCM (4.51+-1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI>=25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  2. TRPV currents and their role in the nociception and neuroplasticity.

    Science.gov (United States)

    Satheesh, Noothan Jyothi; Uehara, Yoshio; Fedotova, Julia; Pohanka, Miroslav; Büsselberg, Dietrich; Kruzliak, Peter

    2016-06-01

    Transient receptor potential channels sensitive to vanilloids (TRPVs) are group of ion channels which are sensitive to various tissue damaging signals and their activation is generally perceived as pain. Therefore, they are generally named as nociceptors. Understanding their activation and function as well as their interaction with intracellular pathways is crucial for the development of pharmacological interference in order to reduce pain perception. The current review summarizes basic facts in regard to TRPV and discusses their relevance in the sensing of (pain-) signals and their intracellular processing, focussing on their modulation of the intracellular calcium ([Ca(2+)]i) signal. Furthermore we discuss the basic mechanisms how the modification of [Ca(2+)]i through TRPV might induce long-term-potentiation (LTP) or long-term- depression (LTD) and from "memories" of pain. Understanding of these mechanisms is needed to localize the best point of interference for pharmacological treatment. Therefore, high attention is given to highlight physiological and pathological processes and their interaction with significant modulators and their roles in neuroplasticity and pain modulation. PMID:26825374

  3. Current role of ultrasound for the management of hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Hitoshi Maruyama; Masaharu Yoshikawa; Osamu Yokosuka

    2008-01-01

    Hepatocellular carcinoma (HCC) has a decisive influence on the prognosis of cirrhotic patients. Although a-fetoprotein (AFP) is a known and specific tumor maker for HCC, it is not suitable for the screening and surveillance of HCC because of its poor predictive value and low sensitivity. The use of imaging modalities is essential for the screening, diagnosis and treatment of HCC. Ultrasound (US) plays a major role among them, because it provides real-time and non-invasive observation by a simple and easy technique. In addition, US-guided needle puncture methods are frequently required for the diagnosis and/or treatment process of HCC. The development of digital technology has led to the detection of blood flow by color Doppler US, and the sensitivity for detecting tumor vascularity has shown remarkable improvement with the introduction of microbubble contrast agents. Moreover, near realtime 3-dimensional US images are now available. As for the treatment of HCC, high intensity focused ultrasound (HIFU) was developed as a novel technology that provides transcutaneous ablation effect without needle puncture. These advancements in the US field have led to rapid progress in HCC management, and continuing advances are expected. This article reviews the current application of US for HCC in clinical practice.

  4. Persistent Sodium Current and Its Role in Epilepsy

    OpenAIRE

    Stafstrom, Carl E

    2007-01-01

    Sodium currents are essential for the initiation and propagation of neuronal firing. Alterations of sodium currents can lead to abnormal neuronal activity, such as occurs in epilepsy. The transient voltage-gated sodium current mediates the upstroke of the action potential. A small fraction of sodium current, termed the persistent sodium current (INaP), fails to inactivate significantly, even with prolonged depolarization. INaP is activated in the subthreshold voltage range and is capable of a...

  5. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    International Nuclear Information System (INIS)

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  6. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

    2014-08-28

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  7. Coronary computed tomography angiography for risk stratification before noncardiac surgery

    Science.gov (United States)

    Fathala, Ahmed

    2016-01-01

    Background: Currently, there are limited available data for coronary computed tomography angiography (CCTA) in the setting of the risk stratification before noncardiac surgery. The main purpose of this study is to investigate the role of CCTA in cardiac risk stratification before noncardiac surgery. Materials and Methods: Ninety-three patients underwent CCTA in the assessment of cardiac risk before noncardiac surgery. Patients with normal or mildly abnormal CCTA (<50% stenosis) underwent surgery without any further testing (Group 1). Patients with abnormal CCTA (17 patients) (more than 50% stenosis) and nondiagnostic CCTA (5%) underwent either stress myocardial perfusion scintigraphy or conventional coronary angiography, Group 2. Results: Group one consists of 71 patients who went for surgery without any further testing. 59 of 71 (83%) patients had no complications in the postoperative period, 9 patients had noncardiac complications, 1 had a cardiac complication (new onset atrial fibrillation), and 2 patients died in the postoperative period due to noncardiac complications. Group 2 comprises 22 (26%) patients, 16 patients had no postoperative complications, 5 patients had noncardiac complications, and one patient developed postoperative acute heart failure. Conclusions: CCTA is diagnostic in up to 95% in the preoperative setting, and it provides a comprehensive cardiac examination in the risk stratification before intermediate and high-risk noncardiac surgery. Therefore, CCTA may be considered as an alternative test for already established imaging techniques for preoperative cardiac risk stratification before noncardiac surgery. PMID:26750671

  8. Current Roles and Future Applications of Cardiac CT: Risk Stratification of Coronary Artery Disease

    International Nuclear Information System (INIS)

    Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future

  9. Pacific western boundary currents and their roles in climate.

    Science.gov (United States)

    Hu, Dunxin; Wu, Lixin; Cai, Wenju; Gupta, Alex Sen; Ganachaud, Alexandre; Qiu, Bo; Gordon, Arnold L; Lin, Xiaopei; Chen, Zhaohui; Hu, Shijian; Wang, Guojian; Wang, Qingye; Sprintall, Janet; Qu, Tangdong; Kashino, Yuji; Wang, Fan; Kessler, William S

    2015-06-18

    Pacific Ocean western boundary currents and the interlinked equatorial Pacific circulation system were among the first currents of these types to be explored by pioneering oceanographers. The widely accepted but poorly quantified importance of these currents-in processes such as the El Niño/Southern Oscillation, the Pacific Decadal Oscillation and the Indonesian Throughflow-has triggered renewed interest. Ongoing efforts are seeking to understand the heat and mass balances of the equatorial Pacific, and possible changes associated with greenhouse-gas-induced climate change. Only a concerted international effort will close the observational, theoretical and technical gaps currently limiting a robust answer to these elusive questions. PMID:26085269

  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. Pathophysiological role of omega pore current in channelopathies

    Directory of Open Access Journals (Sweden)

    Karin eJurkat-Rott

    2012-06-01

    Full Text Available In voltage-gated cation channels, a recurrent pattern for mutations is the neutralization of positively charged residues in the voltage-sensing S4 transmembrane segments. These mutations cause dominant ion channelopathies affecting many tissues such as brain, heart, and skeletal muscle. Recent studies suggest that the pathogenesis of associated phenotypes is not limited to alterations in the gating of the ion-conducting alpha pore. Instead, aberrant so-called omega currents facilitated by the movement of the S4 segments during activation and during recovery are thought to cause symptoms. Surprisingly, these omega currents display uni- or bi-directionality and conduct cations with varying ion selectivity. Additionally, the voltage-sensitivity enables the channels to conduct different omega currents in the various voltage ranges. This review gives an overview of voltage sensor channelopathies in general and focuses on pathogenesis of skeletal muscle S4 disorders for which current knowledge is most advanced.

  12. Magnetic resonance angiography

    International Nuclear Information System (INIS)

    MR angiography (MRA) proved to be promising combined to MR-Imaging (MRI) in the assessment of intrathoracic masses. Sequential FLASH 2D-angiograms were acquired in breathhold technique using the following parameters: TR=30 ms, TE=10 ms, FA=30deg. Section thickness was 5 mm with 1 mm overlap between sequential sections. Individual conditions of the examination were achieved by an automatised control procedure. Targeted MIP-postprocessing resulted in 3D-reconstructions illustrating vascular anatomy and avoiding superimposition. Presentation should be done by cine-mode for better spatial impression. This method was evaluated in a prospective study of 21 patients with malignant pulmonary and mediastinal masses in addition to spin-echo imaging. The diagnostic contribution concerning the relationship between the mass and the vasculature like displacement, stenosis, and poststenotic perfusion defect were assessed. (orig.)

  13. ROLE OF BHAGAVAD GITA IN CURRENT BUSINESS ENVIRONMENT

    OpenAIRE

    Ritu Yadav

    2015-01-01

    Today’s business environment is becoming very dynamic and organisations are facing the problems of fulfilling their responsibilities towards various stakeholders. In such situation, principles of Bhagavad Gita act as a guide to deal and survive in such environment.This study focuses on the growing importance of philosophy of Gita in solving current business problems and their relevance in current business environment. This is a conceptual study based on secondary sources of dat...

  14. 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

  15. 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...... angiography in the rat, and compare the performance of two standard angiographic pulse sequences, the gradient echo (GRE) sequence and the balanced steady-state free precession (bSSFP). 2D coronal cerebral angiographies using intra-arterial injections were acquired with a GRE sequence with in-plane resolution...

  16. Current Understanding of the Role of PPARγ in Gastrointestinal Cancers

    Directory of Open Access Journals (Sweden)

    Bing Zou

    2009-01-01

    Full Text Available Numerous studies have indicated that PPARγ plays multiple roles such as in inflammation, cell cycle control, cell proliferation, apoptosis, and carcinogenesis, thus PPARγ contributes to the homeostasis. Many in vitro studies have showed that ligand-induced activation of PPARγ possess antitumor effect in many cancers including CRC. However, the role of PPARγ in gastrointestinal cancers, especially in colorectal cancer, is rather controversial. Nevertheless, some recent studies with the positive results on the possible application of PPARγ ligands, such as Bezafibrate or Rosiglitazone in gastrointestinal cancers, have suggested a potential usefulness of PPARγ agonists in cancer prevention and therapy. In this review, the authors discuss the recent developments in the role of PPARγ in gastrointestinal cancers.

  17. Screening and detection of blunt vertebral artery injury in patients with upper cervical fractures: The role of cervical CT and CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Payabvash, Seyedmehdi, E-mail: spayab@gmail.com [Department of Radiology, University of Minnesota Medical Center, Minneapolis, MN (United States); McKinney, Alexander M., E-mail: mckinrad@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); McKinney, Zeke J., E-mail: zeke.mckinney@hcmed.org [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); Palmer, Christopher S., E-mail: palme018@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States); Truwit, Charles L., E-mail: truwit@umn.edu [Department of Radiology, Hennepin County Medical Center, 701 Park Avenue, Minneapolis, MN (United States)

    2014-03-15

    Objective: To evaluate the clinical utility of nonenhanced CT (NECT)-based screening criteria and CTA in detection of blunt vertebral artery injury (BVAI) in trauma patients with C1 and/or C2 fractures. Methods: We retrospectively reviewed the clinical records of all blunt trauma patients with C1 and/or C2 fractures between 8/2006 and 9/2011. Cervical CTA was prompted by cervical fractures involving/adjacent to a transverse foramen, and/or subluxation on NECT. Two neuroradiologists independently reviewed the CTA studies, and graded the BVAI. Results: 210 patients were included; of these, 124 underwent CTA (21/124 with digital subtraction angiography, DSA), and 2 underwent DSA only. Overall, 30/126 suffered BVAI. Among 21 patients who underwent both CTA and DSA, there was 1 false negative and 1 false positive (both grade 1). There was strong interobserver agreement regarding CTA-based BVAI detection (kappa = 0.93, p < 0.001) and grading (kappa = 0.90, p < 0001). Only 3/30 BVAI patients suffered a posterior circulation stroke; none of the patients who had a negative CTA or were not selected for CTA, based on NECT screening criteria, suffered symptomatic stroke. While C1/C2 comminuted fracture was more common in patients with high grade BVAI (p = 0.039), simultaneous C3–C7 comminuted fracture increased the overall BVAI risk (p = 0.011). Conclusion: CTA reliably detects symptomatic BVAI in patients with upper cervical fractures. Utilization of NECT-based screening criteria such as transverse foraminal involvement or subluxation may be adequate in deciding whether to perform CTA, as no patients who were not selected for CTA suffered a symptomatic stroke. However, CTA may miss lower grade, asymptomatic BVAI.

  18. Childhood Abuse and Current Interpersonal Conflict: The Role of Shame

    Science.gov (United States)

    Kim, Jungmeen; Talbot, Nancy L.; Cicchetti, Dante

    2009-01-01

    Objective: To examine whether shame-proneness mediates the relationship between women's histories of childhood sexual abuse and their current partner and family conflict and child maltreatment. Previous research has found that women with childhood sexual abuse histories experience heightened shame and interpersonal conflict. However, research…

  19. Pediatric hospitalists in medical education: current roles and future directions.

    Science.gov (United States)

    Heydarian, Cyrus; Maniscalco, Jennifer

    2012-05-01

    As the field of pediatric hospital medicine has evolved, pediatric hospitalists have become increasingly involved in medical student and resident education--providing direct education during clinical rotations, developing novel curricula to meet the demands of the new educational environment, occupying leadership roles in medical education, and more. The literature suggests that hospitalists possess the essential skills for teaching effectively, yet most hospitalists feel that additional training beyond residency is necessary to refine their knowledge and skills in education and in other essential domains. Several pediatric hospital medicine fellowships and continuing medical education activities have been developed in the last decade to meet this growing need. The recent publication of the Pediatric Hospital Medicine Core Competencies will help define the roles and expectations of practicing pediatric hospitalists, and will serve as a framework for future curriculum development in both graduate and continuing medical education. PMID:22483082

  20. Digital angiography in pulmonary embolism

    International Nuclear Information System (INIS)

    Pulmonary digital subtraction angiography was diagnostic in 98.3% of patients with possible acute pulmonary embolism. The procedure was well tolerated even in severely ill patients. A large image intensifier made simultaneous imaging of both lungs possible reducing the number of contrast injections necessary. Small volumes of low iso-osmolar concentration of modern contrast media were used. There was no need for catherization of the pulmonary artery. Theoretical considerations and our limited experience indicate that this will reduce the number of complications compared with conventional pulmonary angiography. The procedure is rapidly performed and the diagnostic accuracy high. This makes digital subtraction angiography cost effective. Digital pulmonary angiography can be recommended as the primary diagnostic method in most patients with possible pulmonary embolism. (orig.)

  1. The Role of Curriculum Scholars in Current Curriculum Debates

    OpenAIRE

    Muhammad Mushtaq

    2012-01-01

    Curriculum is a set of planned tasks, learning experiences and behaviors proposed by an authority to achieve predetermined goals in form of behavioral change, academic achievements and learning outcomes within a particular time. The scholars are the people who have command and expertise in any of the curriculum components. The article focuses on the role of curriculum scholars in Pakistan and how and what type of changes they can initiate to bring harmony and tolerance, character and quality ...

  2. Angiography: Indication-time-risk

    International Nuclear Information System (INIS)

    In diseases of the cerebral blood vessels, CT is indispensable only if surgical measures must be decided on. Unless early surgery within the first 2 to 6 hours is possible and intended, angiographies should not be carried out on the first day. Also, it should never be applied in case of a paralysis. General experience has shown that the incidence of complications in angiography is higher for vascular diseases than for other indications. (orig.)

  3. ROLE OF BHAGAVAD GITA IN CURRENT BUSINESS ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ritu Yadav

    2015-02-01

    Full Text Available Today’s business environment is becoming very dynamic and organisations are facing the problems of fulfilling their responsibilities towards various stakeholders. In such situation, principles of Bhagavad Gita act as a guide to deal and survive in such environment.This study focuses on the growing importance of philosophy of Gita in solving current business problems and their relevance in current business environment. This is a conceptual study based on secondary sources of data like journals, articles, books, web sites etc. This study highlighted the contribution of philosophy of Gita in modern business environment and its prospects in future.Decreasing ethical values among employees and depressed and frustrating work environment in the organisation act as a motivator for the study.

  4. Current role of ultrasound for the management of hepatocellular carcinoma

    OpenAIRE

    Maruyama, Hitoshi; Yoshikawa, Masaharu; Yokosuka, Osamu

    2008-01-01

    Hepatocellular carcinoma (HCC) has a decisive influence on the prognosis of cirrhotic patients. Although α-fetoprotein (AFP) is a known and specific tumor maker for HCC, it is not suitable for the screening and surveillance of HCC because of its poor predictive value and low sensitivity. The use of imaging modalities is essential for the screening, diagnosis and treatment of HCC. Ultrasound (US) plays a major role among them, because it provides real-time and non-invasive observation by a sim...

  5. What is the current role of endoscopy in primary sclerosingcholangitis?

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Endoscopy has important roles in the managementof primary sclerosing cholangitis (PSC), ranging fromnarrowing down the differential diagnoses, screeningfor complications, determining prognosis and therapy.While the need for a diagnostic endoscopic retrogradecholangiopancreatography (ERCP) may be obviated by apositive magnetic resonance cholangiopancreatography(MRCP), a negative MRCP does not exclude PSC andmay therefore necessitate an ERCP, which is traditionallyregarded as the gold standard. In this editorial we havenot covered the endoscopic management of inflammatorybowel disease in the context of PSC nor of endoscopicsurveillance and treatment of portal hypertension complicatingPSC.

  6. Current role of lung scintigraphy in pulmonary embolism

    International Nuclear Information System (INIS)

    The pivotal role of lung scintigraphy in the diagnosis of pulmonary embolism (PE) has been questioned in recent years due to the introduction of spiral computed tomography. However, the scintigraphic results used for comparisons are often those of the authoritative PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) study, carried out in the 1980s. Pulmonary scintigraphy has progressed from those years both in the methodological and interpretative fields, although perhaps too slowly. Results better than those of PIOPED's have been presented by study groups who used: 1) perfusion-only approach; 2) SPET imaging; 3) new interpretative criteria; 4) different prediction rules to integrate clinical and scintigraphic probabilities of PE. These advances are still insufficiently recognised by the nuclear medicine community, possibly due to a sort of PIOPED-based cultural globalisation. This paper reviews the actual advantages and limitations of nuclear medicine techniques, the diagnostic role of scintigraphy within the diagnostic algorithms proposed by international working groups and scientific societies and the results obtained from SPET imaging in the diagnosis of PE

  7. 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.)

  8. Current role of FDG PET/CT in lymphoma

    International Nuclear Information System (INIS)

    The management approach in Hodgkin's (HL) and high-grade non-Hodgkin's lymphomas (NHL) has shifted towards reducing the toxicity and long-term adverse effects associated with treatment while maintaining favorable outcomes in low-risk patients. The success of an individualized treatment strategy depends largely on accurate diagnostic tests both at staging and during therapy. In this regard, positron emission tomography (PET) using fluorodeoxyglucose (FDG) with computed tomography (CT) has proved effective as a metabolic imaging tool with compelling evidence supporting its superiority over conventional modalities, particularly in staging and early evaluation of response. Eventually, this modality was integrated into the routine staging and restaging algorithm of lymphomas. This review will summarize the data on the proven and potential utility of PET/CT imaging for staging, response assessment, and restaging, describing current limitations of this imaging modality. (orig.)

  9. Current role of FDG PET/CT in lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kostakoglu, Lale [Icahn School of Medicine at Mount Sinai, Department of Radiology, One Gustave Levy Place, Box 1141, New York, NY (United States); Cheson, Bruce D. [Georgetown University Hospital, Division of Hematology-Oncology, Lombardi Comprehensive Cancer Center, Washington, DC (United States)

    2014-05-15

    The management approach in Hodgkin's (HL) and high-grade non-Hodgkin's lymphomas (NHL) has shifted towards reducing the toxicity and long-term adverse effects associated with treatment while maintaining favorable outcomes in low-risk patients. The success of an individualized treatment strategy depends largely on accurate diagnostic tests both at staging and during therapy. In this regard, positron emission tomography (PET) using fluorodeoxyglucose (FDG) with computed tomography (CT) has proved effective as a metabolic imaging tool with compelling evidence supporting its superiority over conventional modalities, particularly in staging and early evaluation of response. Eventually, this modality was integrated into the routine staging and restaging algorithm of lymphomas. This review will summarize the data on the proven and potential utility of PET/CT imaging for staging, response assessment, and restaging, describing current limitations of this imaging modality. (orig.)

  10. Current Grid operation and future role of the Grid

    International Nuclear Information System (INIS)

    Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

  11. The role of simulation in teaching pediatric resuscitation: current perspectives

    Directory of Open Access Journals (Sweden)

    Lin Y

    2015-03-01

    Full Text Available Yiqun Lin,1 Adam Cheng2 1KidSIM-ASPIRE Simulation Research Program, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada; 2KidSIM-ASPIRE Research Program, Department of Pediatrics, Division of Emergency Medicine, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada Abstract: The use of simulation for teaching the knowledge, skills, and behaviors necessary for effective pediatric resuscitation has seen widespread growth and adoption across pediatric institutions. In this paper, we describe the application of simulation in pediatric resuscitation training and review the evidence for the use of simulation in neonatal resuscitation, pediatric advanced life support, procedural skills training, and crisis resource management training. We also highlight studies supporting several key instructional design elements that enhance learning, including the use of high-fidelity simulation, distributed practice, deliberate practice, feedback, and debriefing. Simulation-based training is an effective modality for teaching pediatric resuscitation concepts. Current literature has revealed some research gaps in simulation-based education, which could indicate the direction for the future of pediatric resuscitation research. Keywords: simulation, pediatric resuscitation, medical education, instructional design, crisis resource management, health care

  12. 双能量CT血管造影在自发性颅内出血中的诊断价值%Role of double energy CT angiography in diagnosis of spontaneous intracranial hemorrhage

    Institute of Scientific and Technical Information of China (English)

    费军; 张朝利; 刘军华; 郑冬; 闫如意; 程鹏

    2012-01-01

    Objective To study the role of double energy CT angiography(CTA) in diagnosis of spontaneous intracranial hemorrhage (SAH). Methods double energy CTA, digital subtraction angiography (DSA) and surgical data about 30 SAH patients were retrospectively analyzed. Results Twenty-one aneurysms were detected by DSA or in operation and 20 aneurysms were detected by double energy CTA in 30 SAH patients. Two aneurysms were missed and one aneurysm was misdiagnosed by double energy CTA. The sensitivity,specificity,positive and negative prediction rate of double energy CTA were 91. 3%,88. 9%,80. 0%,and 95. 5%,respectively. The average radiation dosage was 327. 63 ± 29. 89 mGy. The average scanning time was 4. 95±0. 42 seconds. Conclusion Double energy CTA can reduce the radiation dosage and scaning time of intracranial tumors with a high accuracy and is thus more suitable for its clinical application.%目的 探讨双能量CT血管造影(CTA)在自发性颅内出血诊治中的应用价值.方法 总结30例自发性颅内出血患者的双能量CTA影像学资料,结合数字减影血管造影术(DSA)和手术所见进行回顾性分析.结果 30例患者中DSA或手术共检出21个动脉瘤,CTA检出20个.与手术和DSA结果比较,双能量CTA漏诊2个,误诊1个,双能量CTA检出颅内动脉瘤的敏感性为91.3%,特异性为88.9%,阳性预测值为80.0%,阴性预测值为95.5%;平均辐射剂量(327.63±29.89) mGy;平均扫描时间(4.95±0.42)s.结论 双能量CTA检查在诊断颅内动脉瘤方面具有较高的准确性,同时可以降低辐射剂量和检查时间,更适合临床应用.

  13. Angiography. 2. tot. rev. and enl. ed.; Angiographie

    Energy Technology Data Exchange (ETDEWEB)

    Schild, H. (ed.); Born, M.; Eckert, B.; Hofer, U.; Kaltenborn, H.; Kersjes, W.; Malms, J.; Remig, J.; Schunk, K.; Strunk, H.; Urbach, H.; Wilhelm, K.

    2003-07-01

    New features of the second German edition of this standard textbook: a novel, attractive layout supporting the didactic concept, including highlighted important information and compact summaries. - Comparative evaluation with other methods, such as color Doppler sonography and MR angiography. - Comprehensive revision of images and addition of new pictures. (orig./CB) [German] Neu in der 2. Auflage: neues, ansprechendes Layout fuer noch mehr Didaktik und ''Spass am Lernen'' durch Merksaetze und Zusammenfassungen. - Vergleich mit anderen Verfahren wie Farbdoppler-Sonographie und MR-Angiographie. - Umfassende Ueberarbeitung und Erweiterung des Bildmaterials. (orig./AJ)

  14. Diagnostic accuracy of CT angiography in acute gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Full text: The aim of the study was to carry out a systematic review determining the accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding. A search of published work in Medline and manual searching of reference lists of articles was conducted. Studies were included if they compared CT angiography to a reference standard of upper gastrointestinal endoscopy, colonoscopy, angiography or surgery in the diagnosis of acute gastrointestinal bleeding. Eight published studies evaluating 129 patients were included. Data were used to form 2x2 tables. Computed tomography angiography showed pooled sensitivity of 86% (95% confidence interval 78-92%) and specificity of 95% (95% confidence interval 76-100%), without showing significant heterogeneity (x2 = 3.5, P=0.6) and (x2 - 5.4, P = 0.6), respectively. Summary receiver operating characteristic analysis showed an area under the curve of 0.93. Computed tomography angiography is accurate in the diagnosis of acute gastrointestinal bleeding and can show the precise location and aetiology of bleeding, thereby directing further management. Strong recommendations for use of CT cannot be made from this review because of the methodological limitations and further large prospective studies are needed to define the role of CT in acute gastrointestinal bleeding.

  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. Society for Cardiovascular Angiography and Interventions

    Science.gov (United States)

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

  17. 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 ...

  18. 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.

  19. 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

  20. Value of the CT angiography in the diagnosis of common carotid artery bifurcation disease: CT angiography versus digital subtraction angiography and color flow Doppler

    International Nuclear Information System (INIS)

    Objective: assessment of the degree of stenosis is the central point in the treatment of carotid stenosis. The purpose of our study was to assess whether invasive CT angiography (CTA) is a feasible alternative to the current invasive gold standard carotid digital subtraction angiography (DSA) and the current non-invasive gold standard color flow doppler. Subjects and methods: about 178 patients with cerebrovascular disease underwent digital subtraction angiography (DSA), CFD and CTA. CTA was performed on a Somatom plus 4 (Siemens, Erlangen Germany). CT was performed with 2/3/2 (collimation/table feed/reconstruction interval) or 2/3/1 mm, start delay 15-20 s, flow 2.5-3.0 ml/s, using 120 ml non-ionic contrast medium (300 mg J/ml). Quantification of degree of stenosis was based on the perfused area in the axial slices. Plaque morphology (soft and hard) and ulceration were evaluated. Results: CTA detected nine cases of significant stenosis, which had been underestimated by DSA. CTA failed in two cases of a membraneous stenosis, which were underestimated, and in two cases with teeth artifacts. Calcifications were more readily appreciated by CTA than in CFD. In this respect, both methods were superior to DSA. CFD, DSA and CTA had a sensitivity of 100% for occlusions, respectively. Conclusion: CT angiography is useful in case of inconclusive CFD in the pre- and postoperative phase, and as a third modality in case of disagreement between DSA and CFD

  1. Magnetic Resonance angiography. Pt 1

    International Nuclear Information System (INIS)

    The objective of this paper is to describe the basic physical principles important in magnetic resonance angiography (MRA). The data used were obtained from recent articles on MRA and direct experience working with prototype MRA sequence. The information is presented in a manner suitable for those unfamiliar with the principles of MRA and magnetic resonance imaging (MRI). Magnetic resonance angiography is an important method that can be used to obtain angiograms without the injection of intravascular contrast medium. It is already proving to be of clinical use in the assessment of vascular disease. 11 refs., 5 figs

  2. Digital subtraction angiography

    International Nuclear Information System (INIS)

    Digital subtraction angiography with selective coronary injections of contrast media has enabled us to obtain clear images, not only of the artery, but of the capillary and venous phases of the myocardial perfusion. In the present study, densitometry was used to estimate regional myocardial perfusion dynamics in 10 control cases and 11 anterior myocardial infarction cases. The time density curve showed that contrast material increased rapidly in the arterial phase and appeared to be washed out monoexponentially in the venous phase. The time from the onset of contrast medium injection to the maximal density of the contrast medium (Tp), and the time constant obtained from the washout curve (Tc) were analyzed. In the control group, Tp in the apical region was slightly prolonged as compared with Tp in the anterobasal region, but the difference was not significant (5.2 ± 0.5 vs 4.2 ± 0.4 sec: mean ± SEM). Tc did not definitely change in any portion of the myocardium (anterobasal 5.1 ± 0.5, anterior 4.8 ± 0.5, apex 4.6 ± 0.5 sec, respectively). In anterior myocardial infarction, Tp in the marginal region was significantly prolonged compared to Tp in the control region (6.0 ± 0.3 vs 4.7 ± 0.3 sec, p < 0.01). Tp was prolonged for more than 10 sec in the infarcted region. Tc in the marginal region was markedly prolonged compared to Tc in the control region (7.4 ± 0.9 vs 4.4 ± 0.5 sec, p < 0.025). Tc could not be determined in the infarcted regions because data acquisition time of our apparatus was inadequate. Two indices of Tp and Tc obtained from the time density curve were regarded capable of estimating regional myocardial perfusion dynamics. Analysis of the DSA image sequence is regarded a very useful method for revealing regional myocardial perfusion dynamics as well as for providing morphological information about the coronary artery. (author)

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

    International Nuclear Information System (INIS)

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

  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. Different Roles of Related Currents in Fast and Slow Spiking of Model Neurons From Two Phyla

    OpenAIRE

    Hong, En; Gurel Kazanci, Fatma; Prinz, Astrid A

    2008-01-01

    Neuronal activity arises from the interplay of membrane and synaptic currents. Although many channel proteins conducting these currents are phylogenetically conserved, channels of the same type in different animals can have different voltage dependencies and dynamics. What does this mean for our ability to derive rules about the role of different types of ion channels in neuronal activity? Can results about the role of a particular channel type in a particular type of neuron be generalized to...

  6. 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; Lönn, Lars; Ringsted, Charlotte V

    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...

  7. Physiological roles of the transient outward current Ito in normal and diseased hearts

    DEFF Research Database (Denmark)

    Cordeiro, Jonathan M; Calloe, Kirstine; Aschar-Sobbi, Roozbeh;

    2016-01-01

    constituents are consistently reduced in cardiac hypertrophy and heart failure. In this review, we discuss the physiological role of Ito as well as the molecular basis of this current in human and canine hearts, in which Ito has been thoroughly studied. In particular, we discuss the role of Ito; in the action...

  8. Carbon dioxide (CO2) angiography in children

    International Nuclear Information System (INIS)

    Background. When iodinated contrast material is contraindicated, carbon dioxide (CO2) gas can be injected intravascularly to produce high-quality digital subtraction angiograms. Objective. CO2 angiography, although previously described in adults, has never before been reported in children. Materials and methods. We present three children with renal transplants who required renal angiography. Because of elevated creatinine levels, iodinated contrast was not used to search for possible renal artery stenosis. Instead, CO2 angiography was used to evaluate the renal artery anastomosis. Results. In all three cases, the renal artery anastomosis was clearly visualized using CO2 angiography and showed no evidence of renal artery stenosis. Conclusion. Digital CO2 angiography is an effective method for pediatric renal angiography. The technique can easily be adapted for virtually any angiographic laboratory capable of digital subtraction imaging. Digital CO2 angiography also lacks the risks of a conventional iodinated contrast medium, namely nephrotoxicity, allergic reaction and volume overload. (orig.). With 1 fig

  9. Risk of renal allograft rejection following angiography

    International Nuclear Information System (INIS)

    In a retrospective study of 173 immediately functioning primary kidney transplants, correlation between angiography and renal allograft rejection was studied during the first 14 days. It was found that rejection was more frequent in kidneys undergoing angiography than in those not undergoing angiography. It was also found that in kidneys undergoing angiography an overwhelming number of the rejections started the day after angiography. These differences in rejection frequency could not be explained by differences in HLA matching or the origin of the kidneys. These findings suggest a possible connection indicating that the angiography might elicit an acute rejection episode. A possible mechanism for starting this reaction might be activation of the complement system which was found in 50 percent of the patients undergoing angiography in peripheral blood and in 100 percent when studied in vitro

  10. New measures for new roles: defining and measuring the current practices of health sciences librarians

    OpenAIRE

    Scherrer, Carol S.; Jacobson, Susan

    2002-01-01

    The roles of academic health sciences librarians are continually evolving as librarians initiate new programs and services in response to developments in computer technology and user demands. However, statistics currently collected by libraries do not accurately reflect or measure these new roles. It is essential for librarians to document, measure, and evaluate these new activities to continue to meet the needs of users and to ensure the viability of their professional role. To determine wha...

  11. The Current State of Controller Roles : Underlying Social Factors and Identity Control

    OpenAIRE

    Holm, Stefan; Thorstensson, Dag

    2013-01-01

    The aim of this thesis is to gather insights on the underlying social factors behind the current state of controller roles in a multinational enterprise. Additionally, the thesis explores the possibility of managing perceptions and expectations of controller roles, in accordance to corporate business objectives. In order to do this, theoretical concepts of Role Theory, Boundary Spanning and Identity Control were utilized. This paper has a qualitative research design and is based on an embedde...

  12. Psychology's Role in the Assessment of Erectile Dysfunction: Historical Precedents, Current Knowledge, and Methods.

    Science.gov (United States)

    Ackerman, Mark D.; Carey, Michael P.

    1995-01-01

    Describes the role of the psychologist in the evaluation of erectile dysfunction. Reviews current diagnostic criteria and provides a historical overview of the topic. Summarizes current epidemiologic knowledge, including data on prevalence and research on cognitive, affective, dydactic, and lifestyle etiologic risk factors. Discusses assessment…

  13. The role of current loop in harmonic generation from magnetic metamaterials in two polarizations

    CERN Document Server

    Sajedian, Iman; Zakery, Abdolnasser; Rho, Junsuk

    2016-01-01

    In this paper, we investigate the role of the current loop in the generation of second and third harmonic signals from magnetic metamaterials. We will show that the fact that the current loop in the magnetic resonance acts as a source for nonlinear effects and it consists of two orthogonal parts, leads to the generation of two harmonic signals in two orthogonal polarizations.

  14. The Managerial Roles of Sports Clubs CEOs in the Current and Desirable Conditions

    Directory of Open Access Journals (Sweden)

    Mahboobeh Surani

    2014-10-01

    Full Text Available Today, the proper playing of managerial roles is of special importance in effective and successful management of sports clubs. The present paper aimed to study the managerial roles of sports clubs CEOs in Isfahan Province in the current and desirable conditions. Statistical population included all managers and directors of Sepahan, Zobahan, Foolad Mahan, and Gitipasand sports clubs (N=83, which was considered as the sample as well. An author-made questionnaire with 31 items on a Likert’s 5-point scale was used for data collection. Validity of the questionnaire was confirmed by 15 experts and professors and its reliability was obtained α=0.94 by Cronbach’s alpha coefficient. 84 questionnaires were handed out among all managers and directors of the studied sports clubs, 76 of which (91.5% was returned. The results showed that priority of CEOs roles, respectively, include decisional role (4.16±0.61, informational role (4.09±0.56, and interpersonal role (4.03±0.67. The results of factor analysis also indicated that the roles of entrepreneurship, data collection, spokesman, and allocation of resources, respectively, are the most important roles of CEOs and negotiation, figurehead, and leadership roles are the least important ones in the desirable conditions. A significant difference was observed between the roles of managers in the current and desirable conditions (Sig.=0.001. The results suggested that the respondents’ expectations of sports clubs CEOs’ roles in desirable conditions is beyond their perceptions in the current situation. It can be generally concluded that sports clubs CEOs need to better perform all managerial roles, especially decisional role.

  15. The Role of Stock Markets in Current Account Dynamics: Evidence from the United States

    OpenAIRE

    Benoît Mercereau

    2003-01-01

    This paper tests a model of the role of stock markets in current account dynamics, developed in a companion paper. With U.S. data, the model performs better than the same model without stock markets. An insight given by the model is that the current account might help predict future stock market performance. This property receives some preliminary empirical confirmation. The results also suggest that stock markets matter to the current account dynamics.

  16. Tidal residual current and its role in the mean flow on the Changjiang Bank

    Energy Technology Data Exchange (ETDEWEB)

    Xuan, Jiliang; Yang, Zhaoqing; Huang, Daji; Wang, Taiping; Zhou, Feng

    2016-02-01

    Tidal residual current may play an important role in the mean flow in the Changjiang Bank region, in addition to other residual currents, such as the Taiwan Warm Current, the Yellow Sea Coastal Current, and the Yellow Sea Warm Current. In this paper, a detailed structure of the tidal residual current, in particular the meso-scale eddies, in the Changjiang Bank region is observed from model simulations, and its role in the mean flow is quantified using the well-validated Finite Volume Coastal Ocean Model). The tidal residual current in the Changjiang Bank region consists of two components: an anticyclonic regional-scale tidal residual circulation around the edge of the Changjiang Bank and some cyclonic meso-scale tidal residual eddies across the Changjiang Bank. The meso-scale tidal residual eddies occur across the Changjiang Bank and contribute to the regional-scale tidal residual circulation offshore at the northwest boundary and at the northeast edge of the Changjiang Bank, southeastward along the 50 m isobath. Tidal rectification is the major mechanism causing the tidal residual current to flow along the isobaths. Both components of the tidal residual current have significant effects on the mean flow. A comparison between the tidal residual current and the mean flow indicates that the contribution of the tidal residual current to the mean flow is greater than 50%.

  17. 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

  18. Angiography of the lower leg

    International Nuclear Information System (INIS)

    The authors have compared the validity of conventional angiography (CA) and intraarterial digital subtraction angiography (IA-DSA) of the lower leg in the staging of peripheral vascular disease. Such studies are important because of different therapeutic possibilities for limb salvage; small balloon and laser angioplasty, atherectomy, and surgically successful femorocrural and - pedal bypasses. A prospective comparative study was performed on 100 consecutive patients, who underwent CA via translumbar aortography. Seldinger catheterization or groin needle puncture, immediately followed by IA-DSA of the lower leg. Three months later, independent blinded observer analysis was performed by two vascular surgeons and two radiologists of both CA and IA-DSA, recording percentage stenosis of popliteal posterior, anterior tibial, and peroneal arteries. On the last 52 patients, the two surgeons also judged if the vessel was amenable for grafting. Statistical analysis was performed by calculating the kappa value, to measure agreement between observers

  19. Digital subtraction angiography: Preliminary report

    International Nuclear Information System (INIS)

    Recently, technical developments in digital electronics and image intensifier have improved the electronic recording and processing of images. Both department of radiology and of medical engineering of Seoul National University Hospital jointly developed digital subtraction angiography system (SRM-1) and performed DSA in patients. The system was composed of angiography equipment, computer, video image storage and logarithmic amplifier. Fluoroscopic images were taken before and after 40-60 ml of contrast media were intravenously injected with speed of 12-15 ml/sec. The images were recorded by V.T.R. with normal speed. The recorded images were processed with digitization, amplification, subtraction, enhancement, position manipulation and image smoothing. Arteriography of neck vessels, abdominal aorta and its branches and extremities were performed successfully by above mentioned methods in 20 cases and results were reviewed

  20. 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.)

  1. Roles of initial current carrier in the distribution of field-aligned current in 3-D Hall MHD simulations

    Institute of Scientific and Technical Information of China (English)

    ZHANG XianGuo; PU ZuYin; MA ZhiWei; ZHOU XuZhi

    2008-01-01

    A three-dimensional (3-D) Hall MHD simulation is carried out to study the roles of initial current carrier in the topology of magnetic field,the generation and distribuering the contribution of ions to the initial current,the topology of the obtained magnetic field turns to be more complex. In some cases,it is found that not only the traditional By quadrupole structure but also a reversal By quadrupole structure appears in the simulation box. This can explain the observational features near the diffusion region,which are inconsistent with the Hall MHD theory with the total initial current carried by electrons. Several other interesting features are also emerged. First,motions of electrons and ions are decoupled from each other in the small plasma region (Hall effect region) with a scale less than or comparable with the ion inertial length or ion skin depth di=c/ωp. In the non-Hall effect region,the global magnetic structure is shifted in +y direction under the influence of ions with initial y directional motion. However,in the Hall effect region,magnetic field lines are bent in -y direction,mainly controlled by the motion of electrons,then By is generated. Second,FACs emerge as a result of the appearance of By. Compared with the prior Hall MHD simulation results,the generated FACs shift in +y direction,

  2. 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.)

  3. 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.

  4. 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.)

  5. The role of currents distribution in general relativistic equilibria of magnetized neutron stars

    CERN Document Server

    Bucciantini, N; Del Zanna, L

    2014-01-01

    Magnetic fields play a critical role in the phenomenology of neutron stars. There is virtually no observable aspect which is not governed by them. Despite this, only recently efforts have been done to model magnetic fields in the correct general relativistic regime, characteristic of these compact objects. In this work we present, for the first time a comprehensive and detailed parameter study, in general relativity, of the role that the current distribution, and the related magnetic field structure, have in determining the precise structure of neutron stars. In particular, we show how the presence of localized currents can modify the field strength at the stellar surface, and we look for general trends, both in terms of energetic properties, and magnetic field configurations. Here we verify that, among other things, for a large class of different current distributions the resulting magnetic configurations are always dominated by the poloidal component of the current.

  6. Roles of initial current carrier in the distribution of field-aligned current in 3-D Hall MHD simulations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A three-dimensional (3-D) Hall MHD simulation is carried out to study the roles of initial current carrier in the topology of magnetic field, the generation and distribu- tion of field aligned currents (FACs), and the appearance of Alfvén waves. Consid- ering the contribution of ions to the initial current, the topology of the obtained magnetic field turns to be more complex. In some cases, it is found that not only the traditional By quadrupole structure but also a reversal By quadrupole structure appears in the simulation box. This can explain the observational features near the diffusion region, which are inconsistent with the Hall MHD theory with the total ini- tial current carried by electrons. Several other interesting features are also emerged. First, motions of electrons and ions are decoupled from each other in the small plasma region (Hall effect region) with a scale less than or comparable with the ion inertial length or ion skin depth di=c/ωp. In the non-Hall effect region, the global magnetic structure is shifted in +y direction under the influence of ions with initial y directional motion. However, in the Hall effect region, magnetic field lines are bent in ?y direction, mainly controlled by the motion of electrons, then By is generated. Second, FACs emerge as a result of the appearance of By. Compared with the prior Hall MHD simulation results, the generated FACs shift in +y direction, and hence the dawn-dusk symmetry is broken. Third, the Walén relation in our simulations is consistent with the Walén relation in Hall plasma, thus the presence of Alfvén wave is confirmed.

  7. Multislice CT angiography

    International Nuclear Information System (INIS)

    The introduction of multislice CT into clinical radiology constitutes a quantum leap that significantly widens the scope of vascular CT imaging. The advances over conventional spiral CT have been quantitative, mainly in terms of increased image acquisition speed which provides unprecedented volume coverage and spatial resolution. Moreover, significant technical innovations, such as cardiac scanning capabilities, have brought about a qualitative shift towards applications that were thought to be beyond the scope of CT imaging. This way multislice CT offers a wealth of new opportunities for quickly and accurately diagnosing suspected vascular disease in all organ systems; however, as we move towards faster and faster image acquisition techniques, we are also facing new challenges that require development of novel strategies in order to take full advantage of the increased capabilities of multislice CT in its current form and future generations of CT scanners. (orig.)

  8. Digital subtraction angiography in ischemic cerebrovascular accidents

    International Nuclear Information System (INIS)

    Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery

  9. Digital peripheral angiography with stepping and subtraction

    International Nuclear Information System (INIS)

    In a prospective randomised study including 60 patients digital peripheral angiography with stepping and subtraction (DPSA) was compared to DPA without subtraction (DPA), DSA without stepping and conventional angiography. Examination time could thus be shortened by about 20%. The amount of contrast medium could also be reduced by 15 to 20%. Both digital subtraction techniques supplied superior image quality especially in the lower limb in comparison with conventional and digital peripheral angiography without subtraction. X-ray exposure was similar for conventional angiography and DPSA. DSA without subtraction revealed a three times increased dose. (orig./GDG)

  10. CT Angiography and MR Angiography of Carotid Arteries

    Directory of Open Access Journals (Sweden)

    M Motevalli

    2009-01-01

    Full Text Available  CT angiography (CTA has revolutionized vascular imaging. Vessels smaller than 1mm in diameter can be visualized with single slice CTA and vessels 2 mm or more in diameter can be diagnostically evaluated. The acquisition of 3D data volumes makes it possible to generate "angiographic" views that facilitate anatomic orientation."nWith the advent of multi slice CTA, near isotropic resolution becomes available for most applications and allows evaluation of even smaller vessels."nMulti slice scanning makes CTA less technically challenging and more robust. It reduces scan time and the vulnerability to motion artifacts, and may be used to substantially decrease the required contrast material volume to as little as 50 ml in selected cases."nThe advantages of CTA over arterial angiography (DSA include substantially lower invasiveness, less cost, less radiation exposure, and better patient tolerance. Diagnostic advantages include simultaneous visualization of the vessel wall and lumen, and the ability to study vascular anatomy from arbitrary viewing angles using only one data acquisition."nCTA even allows projections (such as Caudocranial that cannot be obtained with conventional angiographic techniques."nAlthough CTA can replace diagnostic ultrasound with its various Doppler techniques, it may be preferred over CTA in regions that are easily accessible by sonography or when flow information is required. It also holds advantages whenever bedside imaging is to be preferred."nMagnetic resonance angiography (MRA has become the common place in the last few years. The improvements in pulse sequence design, hardware design, and post processing methods make it possible to acquire data in a short period with excellent vascular visualization in a variety of clinical applications."nContrast -enhanced magnetic resonance angiography (MRA offers competitive results to CTA, although spatial resolution is often lower than with multi slice CT scanning. The lack of

  11. THE ROLE OF STATE AIDS IN THE CURRENT FINANCIAL AND ECONOMIC CRISIS

    Directory of Open Access Journals (Sweden)

    Zugravu Bogdan-Gabriel

    2009-05-01

    Full Text Available This paper focuses on state aid’s role in the current financial and economic crisis, in order to help all the economic sectors to get back on their feet. The negative effects of the sub-prime mortgage lending affected not only the US, but also the Europea

  12. The Role of Education in Economic Growth: Theory, History and Current Returns

    Science.gov (United States)

    Breton, Theodore R.

    2013-01-01

    Background: This paper was prepared to address the issue of whether current levels of public expenditures on education are cost-effective in countries with widely differing average levels of education. Purpose: The paper examines the role of education in economic growth from a theoretical and historic perspective, addresses why education has been…

  13. Forget the Desk Job: Current Roles and Responsibilities in Entry-Level Reference Job Advertisements

    Science.gov (United States)

    Detmering, Robert; Sproles, Claudene

    2012-01-01

    This study examines the evolving roles and responsibilities of entry-level academic reference positions, as stated in recent job advertisements posted on the American Library Association's JobLIST Web site and other sources. Findings from a content analysis of these advertisements indicate that current entry-level reference positions in academic…

  14. The role and importance of UAV within the current theaters of operations

    Directory of Open Access Journals (Sweden)

    Niculae MARIN

    2010-06-01

    Full Text Available Current theaters of operations are not limited to battlefields, but they are much morediversified, including the fight against the international terrorism phenomenon, the social conflicts (ofreligious, political, economic and separatist nature within several countries, thus supplying somepolitical-military conflicts within different states and areas of the world. The armed interference mustbe done based on some highly accurate information that must be gathered without endangering thehuman lives. This is the role currently played by the unmanned air vehicles (UAVs; they can performseveral functions: surveillance, information gathering, data storage and their transmission to theground stations, including the function of interference, when needed. This paper presents, within theabove context, the status of the current theaters of operations and of the UAVs performing differentmissions within these theaters, together with their role and importance in warfare operations.

  15. Digital subtraction angiography in children

    International Nuclear Information System (INIS)

    Preliminary results with digital subtraction angiography in infants and children have shown this to be an excellent screening procedure and often diagnostic. The examination can be performed satisfactorily on outpatients. Sixty patients have undergone this examination for evaluation of suspected abnormalities of the aortic arch and its branches, intracranial arteries, pulmonary arteries, abdominal aorta and its branches, and peripheral vessels. Adequate sedation is mandatory to prevent motion artifacts. While the literature reports increasing use of central venous catheters for delivery of contrast material, the use of short catheters placed in an antecubital vein is satisfactory for the pediatric patient. Techniques of the procedures are described along with seven appropriate case examples

  16. 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.

  17. Ultravist in children's angiocardiography and angiography

    International Nuclear Information System (INIS)

    370 children, ranging from 1 day to 18 years of age, have underwent angiocardiography (285 children), cerebral angiography (36), abdominal (27) and peripheral angiography (22) with ultravist. The tolerance is excellent, there were no significant biological effects and allergic reactions. The quality of pictures is fairly good. Conclusively the use of ultravist is demanded for children. (author)

  18. 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 ...

  19. CT angiography in carotid stenosis

    International Nuclear Information System (INIS)

    Purpose: Prospective evaluation of the accuracy CT angiography (CTA) with different postprocessing for extracranial carotid artery in comparison with DSA. Method: one hundred patients were studied with standarized CTA. For postprocessing, MPR, MIP, and 3D reconstruction based on segmentation with upper and lower threshold were used. Intravascular density profiles were considered. All CTA studies were correlated with intra-arterial angiography. The degree and classification of stenoses was determined using the guidelines established by the NASCET collaborators. Results: Measurement of stenosis was possible by MPR in 82.5%, by MIP in 85%, and 3D in 100%. Correct classification was found in 65.5% for MPR, 66% for MIP and 88.5% for 3D. The sensitivity for severe stenoses was 74% for MPR, 82% for MIP, and 93% for 3D. The specificity of these methods was 98%, 96%, and 97%, respectively. All carotid occlusions were correctly identified, no carotid artery was wrongly classified as occluded. (orig./AJ)

  20. Current role of the USNRC safety research program in support of the regulatory process

    International Nuclear Information System (INIS)

    The current role of the USNRC's safety research program is shown. Some aspects of this role in the wake of the TMI accident are discused as well as some historical perspective on the development of USNRC's program, its relationship with the NRC mission, an overview of the program activities and some recent research results, and finally the impact of the TMI accident in clarifiying needs for expedited and new research activities, including the need for a greatly enhanced use of probabilistic analysis techniques to improve the coherence of its regulatory process. (author)

  1. CT angiography in carotid stenosis; CT-Angiographie bei Karotisstenosen

    Energy Technology Data Exchange (ETDEWEB)

    Mildenberger, P.; Kauczor, H.U.; Ehrhard, K.; Thelen, M. [Johannes Gutenberg-Universitaet Mainz (Germany). Klinik und Poliklinik fuer Radiologie; Schmiedt, W. [Johannes Gutenberg-Universitaet Mainz (Germany). Klinik fuer Herz-, Thorax- und Gefaesschirurgie

    1997-11-01

    Purpose: Prospective evaluation of the accuracy CT angiography (CTA) with different postprocessing for extracranial carotid artery in comparison with DSA. Method: one hundred patients were studied with standarized CTA. For postprocessing, MPR, MIP, and 3D reconstruction based on segmentation with upper and lower threshold were used. Intravascular density profiles were considered. All CTA studies were correlated with intra-arterial angiography. The degree and classification of stenoses was determined using the guidelines established by the NASCET collaborators. Results: Measurement of stenosis was possible by MPR in 82.5%, by MIP in 85%, and 3D in 100%. Correct classification was found in 65.5% for MPR, 66% for MIP and 88.5% for 3D. The sensitivity for severe stenoses was 74% for MPR, 82% for MIP, and 93% for 3D. The specificity of these methods was 98%, 96%, and 97%, respectively. All carotid occlusions were correctly identified, no carotid artery was wrongly classified as occluded. (orig./AJ) [Deutsch] In einer prospektiven Untersuchung sollte die Genauigkeit verschiedener Nachverarbeitungsmethoden der CT-Angiographie (CTA) der extrakraniellen Karotis im Vergleich zur DSA untersucht werden. 100 Patienten wurden mit einer standardisierten CTA untersucht. Zur Nachverarbeitung wurden MPR, MIP und 3D-Rekonstruktion nach Segmentation mit doppeltem Schwellenwert eingesetzt. Fuer die Durchmesserbestimmung wurden die intravasalen Dichteprofile beruecksichtigt. Alle CTA-Untersuchungen wurden mit intraarteriellen DSA-Untersuchungen korreliert. Die Bestimmung des Stenosegrades und die Klassifizierung erfolgte nach den NASCET-Kriterien. Die Auswertung der CTA war mit MPR in 82,5% mit MIP in 85% und mit der 3D in 100% moeglich. Die Uebereinstimmung zwischen DSA und CTA in der Klassifikation der Stenosegrade betrug fuer MPR 65,5%, fuer die MIP 66% und fuer die 3D-Rekonstruktion 88,5%. Die Sensitivitaet im Nachweis relevanter Karotisstenosen ist fuer die MPR 74%, fuer die MIP 82

  2. 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.

  3. Enhanced K-edge angiography utilizing cerium-target diode

    International Nuclear Information System (INIS)

    The cerium-target x-ray tube is useful in order to perform cone-beam K-edge angiography because Kα rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller, an x-ray tube unit with a high-voltage circuit and an insulation transformer, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were approximately 1 x 1 mm. Sharp cerium Kα lines were left using a barium sulfate filter, and the x-ray intensity was 16.8 μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.40 mA. Angiography was performed with an x-ray film (Fuji IX 100) using iodine-based microspheres 15 μm in diameter. In angiography of non-living animals, we observed fine blood vessels of 100 μm or less with high contrasts. (author)

  4. Physiological roles of the transient outward current Ito in normal and diseased hearts.

    Science.gov (United States)

    Cordeiro, Jonathan M; Calloe, Kirstine; Aschar-Sobbi, Roozbeh; Kim, Kyoung-Han; Korogyi, Adam; Occhipinti, Dona; Backx, Peter H; Panama, Brian K

    2016-01-01

    The Ca(2+)-independent transient outward K(+) current (I(to)) plays a critical role in underlying phase 1 of repolarization of the cardiac action potential and, as a result, is central to modulating excitation-contraction coupling and propensity for arrhythmia. Additionally, I(to) and its molecular constituents are consistently reduced in cardiac hypertrophy and heart failure. In this review, we discuss the physiological role of I(to) as well as the molecular basis of this current in human and canine hearts, in which I(to) has been thoroughly studied. In particular, we discuss the role of Ito; in the action potential and the mechanisms by which I(to) modulates excitation-contraction coupling. We also describe the effects of mutations in the subunits constituting the Ito channel as well as the role of I(to) in the failing myocardium. Finally, we review pharmacological modulation of I(to) and discuss the evidence supporting the hypothesis that restoration of I(to) in the setting of heart failure may be therapeutically beneficial by enhancing excitation-contraction coupling and cardiac function. PMID:26709904

  5. Manual Therapy: The Historical, Current, and Future Role in the Treatment of Pain

    Directory of Open Access Journals (Sweden)

    A. Russell Smith

    2007-01-01

    Full Text Available Manual therapy has been an approach in the management of patients with various disorders dating back to ancient times and continues to play a significant role in current health care. The future role of manual therapy in health care is an important area of research. This paper reviews the history of manual therapy, examines the current literature related to the use of manual techniques (including manipulation, massage, and nerve manipulation, and discusses future research topics. The literature related to manual therapy has historically been anecdotal and theoretical, and current research tends to have a generic approach with broad definitions of manual therapy and inconsistencies in the classification of specific disorders. Systematic reviews of various types of manual therapy have differed on their conclusions regarding the effectiveness of this treatment modality. The current demand in health care for evidence-based practice necessitates a movement towards more specificity in the research of the effectiveness of manual therapy, with emphasis on specific patient signs and symptoms and specific manual techniques that result in effective care.

  6. Role of tonic GABAergic currents during pre- and early postnatal rodent development

    Directory of Open Access Journals (Sweden)

    Werner eKilb

    2013-09-01

    Full Text Available In the last three decades it became evident that the GABAergic system plays an essential role for the development of the central nervous system, by influencing the proliferation of neuronal precursors, neuronal migration and differentiation, as well as by controlling early activity patterns and thus formation of neuronal networks. GABA controls neuronal development via depolarizing membrane responses upon activation of ionotropic GABA receptors. However, many of these effects occur before the onset of synaptic GABAergic activity and thus require the presence of extrasynaptic tonic currents in neuronal precursors and immature neurons. This review summarizes our current knowledge about the role of tonic GABAergic currents during early brain development. In this review we compare the temporal sequence of the expression and functional relevance of different GABA receptor subunits, GABA synthesizing enzymes and GABA transporters. We also refer to other possible endogenous agonists of GABAA receptors. In addition, we describe functional consequences mediated by the GABAergic system during early developmental periods and discuss current models about the origin of extrasynaptic GABA and/or other endogenous GABAergic agonists during early developmental states. Finally, we present evidence that tonic GABAergic activity is also critically involved in the generation of physiological as well as pathophysiological activity patterns before and after the establishment of functional GABAergic synaptic connections.

  7. Role of tonic GABAergic currents during pre- and early postnatal rodent development

    Science.gov (United States)

    Kilb, Werner; Kirischuk, Sergei; Luhmann, Heiko J.

    2013-01-01

    In the last three decades it became evident that the GABAergic system plays an essential role for the development of the central nervous system, by influencing the proliferation of neuronal precursors, neuronal migration and differentiation, as well as by controlling early activity patterns and thus formation of neuronal networks. GABA controls neuronal development via depolarizing membrane responses upon activation of ionotropic GABA receptors. However, many of these effects occur before the onset of synaptic GABAergic activity and thus require the presence of extrasynaptic tonic currents in neuronal precursors and immature neurons. This review summarizes our current knowledge about the role of tonic GABAergic currents during early brain development. In this review we compare the temporal sequence of the expression and functional relevance of different GABA receptor subunits, GABA synthesizing enzymes and GABA transporters. We also refer to other possible endogenous agonists of GABAA receptors. In addition, we describe functional consequences mediated by the GABAergic system during early developmental periods and discuss current models about the origin of extrasynaptic GABA and/or other endogenous GABAergic agonists during early developmental states. Finally, we present evidence that tonic GABAergic activity is also critically involved in the generation of physiological as well as pathophysiological activity patterns before and after the establishment of functional GABAergic synaptic connections. PMID:24027498

  8. Evaluation by digital subtraction angiography

    International Nuclear Information System (INIS)

    Digital subtraction angiography (DSA) is a form of digital radiography. In digital radiography, the X-ray signal is electronically detected, digitized, and proceeded before being displayed and stored. The technique allows detection of very low levels of iodinated contrast media such as those that occur in the arterial system following an intravenous injection of contrast. The X-ray imaging system used is a standard-image intensified fluoroscopy system with a wide dynamic-range TV camera. The video signal from the image intensifier is logarithmically enhanced and digitized on an image processor (computer). This signal, which is stored in one of two memories, serves as a mask. The mask is subtracted from digital images obtained after the injection of contrast media, and the subtraction images are stored on digital or analog disks or on magnetic tapes. Postprocedure reprocessing allows selection of different masks for subtraction, which is useful when patient motion has occurred. Hard copies can be obtained

  9. Digital subtraction angiography for breast cancer

    International Nuclear Information System (INIS)

    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). (author)

  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. Imaging of the digital arteries: Digital subtraction angiography versus conventional angiography

    International Nuclear Information System (INIS)

    The authors report their experience with the use of digital subtraction angiography (DSA) and conventional angiography of the hand. Of the 95 patients in the study group, 80 underwent conventional angiography and 15 underwent DSA. They analyzed the studies with regard to the type and amount of contrast agent used, the number of radiographs needed, and the diagnostic quality of the images. Conventional angiography often requires general anesthesia, magnification, and pharmaco-angiographic techniques to improve the image-based diagnosis. In comparison with conventional angiography, intraarterial DSA is characterized by improved contrast sensitivity and inferior spatial resolution. However, DSA provides images as acceptable as those of conventional angiography. Smaller catheters can be used, and the examination is performed under local anesthesia. The authors conclude that intraarterial DSA is now the technique of choice for examining patients with chronic ischemia of the hand

  12. Vitamin E in Sarcopenia: Current Evidences on Its Role in Prevention and Treatment

    Directory of Open Access Journals (Sweden)

    Shy Cian Khor

    2014-01-01

    Full Text Available Sarcopenia is a geriatric syndrome that is characterized by gradual loss of muscle mass and strength with increasing age. Although the underlying mechanism is still unknown, the contribution of increased oxidative stress in advanced age has been recognized as one of the risk factors of sarcopenia. Thus, eliminating reactive oxygen species (ROS can be a strategy to combat sarcopenia. In this review, we discuss the potential role of vitamin E in the prevention and treatment of sarcopenia. Vitamin E is a lipid soluble vitamin, with potent antioxidant properties and current evidence suggesting a role in the modulation of signaling pathways. Previous studies have shown its possible beneficial effects on aging and age-related diseases. Although there are evidences suggesting an association between vitamin E and muscle health, they are still inconclusive compared to other more extensively studied chronic diseases such as neurodegenerative diseases and cardiovascular diseases. Therefore, we reviewed the role of vitamin E and its potential protective mechanisms on muscle health based on previous and current in vitro and in vivo studies.

  13. Role of the current young generation within the space exploration sector

    Science.gov (United States)

    Calzada-Diaz, A.; Dayas-Codina, M.; MacArthur, J. L.; Bielicki, D. M.

    2014-08-01

    The space sector gathers together people from a variety of fields who work in the industry on different levels and with different expertise. What is often forgotten is the impact and role of the current young generation. Their engagement is of great importance as undeniably today's young 'space generation' will be defining the direction of future space exploration. Today's vision of future human and robotic space exploration has been set out in the Global Exploration Roadmap (GER). This focuses on sustainable, affordable and productive long-term goals. The strategy begins with the International Space Station (ISS) and then expands human presence into the solar system, including a human mission to Mars. This paper presents a general overview of the role of today's youth within the space exploration sector and the challenges to overcome. To complete this perspective, we present results from a survey made among students and young professionals about their levels of awareness of the GER. The respondents presented their opinion about current aspects of the GER and prioritised the GER's objectives. It is hoped that the paper will bring a new perspective into the GER and a contribution to the current GER strategy.

  14. 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

  15. 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.)

  16. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    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 ...

  17. Angiography in acute mesenteric arterial insufficiency

    International Nuclear Information System (INIS)

    The angiographic findings in 31 cases of acute mesenteric arterial insufficiency are presented. In 22 cases organic occlusions, in 9 vasoconstriction alone, were found. Angiography aids definitely in the diagnosis and planning of the treatment of this serious condition. (Auth.)

  18. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

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

  19. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    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 ...

  20. 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.)

  1. Current status and emerging role of glutathione in food grade lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Pophaly Sarang

    2012-08-01

    Full Text Available Abstract Lactic acid bacteria (LAB have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.

  2. Possible Role of Brain-Derived Neurotrophic Factor (BDNF) in Autism Spectrum Disorder: Current Status

    International Nuclear Information System (INIS)

    Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of survival-promoting molecules, plays a vital role in the growth, development, maintenance, and function of several neuronal systems. The purpose of this review is to document the support for the involvement of this molecule in the maintenance of normal cognitive, emotional functioning, and to outline recent developments in the content of Autism spectrum disorder (ASD). Current and future treatment development can be guided by developing understanding of this molecules actions in the brain and the ways the expression of BDNF can be planned. Over the years, research findings suggested a critical role played by BDNF in the development of autism including increased serum concentrations of BDNF in children with autism and identification of different forms of BDNF in families of autistic individuals. (author)

  3. Coronary computed tomography angiography: emerging technique for coronary artery imaging - pictorial essay

    International Nuclear Information System (INIS)

    Assessment of potential coronary artery disease is the single most common indication for cardiovascular imaging. Currently, definite anatomic diagnosis requires invasive cardiac catheterization. Recent developments in computed tomography (CT) technology have resulted in substantially improved noninvasive coronary artery imaging. We review an imaging protocol for coronary CT angiography (CTA), study interpretation, and current and future potential applications of this technology. (author)

  4. CT ANGIOGRAPHY EVALUATION OF PERIPHERAL VASCULAR DISEASE AND COMPARISON WITH COLOR DOPPLER ULTRASOUND

    Directory of Open Access Journals (Sweden)

    Sathyabhuwan Singh

    2015-10-01

    Full Text Available I NTRODUCTION: Peripheral vascular disease is narrowing or occlusion of arteries and comprises of atherosclerosis, burger,s disease, Renoud,s disease and aneurysm. DSA, CT angiography and color Doppler ultrasound are the radiological modalities used for these diseases. Here we compared role of the CT angiography and Color Doppler ultrasonography in detection of peripheral vascular disease. AIMS AND OBJECTIVE: To assess the role of CT angiography in peripheral vascular disease and comparison with color Doppler ultrasound. MATERIAL AND METHOD: we examined 50 patients by CT angiography and color Doppler ultrasound who were suspected for arterial disease. We divided the disease on the ground of severity as follows: No stenosis - grade - 0, 0 - 25% stenosis - grade - 1 , 25 - 50% stenosis - grade - 2, 50 - 75 % stenosis - grade - 3 and 75 - 100% stenosis - grade - 4. We compared the two modalities in terms of diagnosis and grading of peripheral vascular disease . RESULT: We found Color Doppler ultrasound detected more number of normal vessel segment, gra de - 1 and grade - 2 stenosis. In stenosis grade - 3 and grade - 4 CT angiography and Color Doppler ultrasound are equally sensitive. CONCLUSION: Doppler sonography is better than CT angiography in the diagnosis of early onset ( Grade I & II cases, with a better a ssessment of soft plaques, segmental flow and re - canalisation in peripheral arterial disease. CDUS is the initial modality of choice in any case of peripheral arterial disease. CT angiography is more accurate in assessing grade - 3 and grade - 4 stenosis. CT a ngiography exceeds the color Doppler in detecting vascular lesions in cases of gas gangrene and thick patients.

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

    Science.gov (United States)

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

    2015-12-01

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

  6. 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...

  7. Angiography with a multifunctional line scanning ophthalmoscope

    OpenAIRE

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

    2012-01-01

    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 exhi...

  8. Angiography in the diagnosis of erectile impotence

    International Nuclear Information System (INIS)

    The complex interactions of psychological, neurological, hormonal and vascular aspects of erectile dysfunctions require a standardised multidisciplinary diagnostic evaluation. The recent establishment of new noninvasive and invasive investigative procedures has led to a fundamental change in the assessment of erectile dysfunctions. Selective angiography of the internal pudendal artery and its branches represents the crucial diagnostic step before treatment can start. Indication, technique and results of 26 bilaterally performed pudendal angiographies on impotent patients are described. (orig.)

  9. The effect of transcranial direct current stimulation: a role for cortical excitation/inhibition balance?

    Directory of Open Access Journals (Sweden)

    Beatrix Krause

    2013-09-01

    Full Text Available Transcranial direct current stimulation (tDCS is a promising tool for cognitive enhancement and neurorehabilitation in clinical disorders in both cognitive and clinical domains (e.g., chronic pain, tinnitus. Here we suggest the potential role of tDCS in modulating cortical excitation/inhibition (E/I balance and thereby inducing improvements. We suggest that part of the mechanism of action of tDCS can be explained by non-invasive modulations of the E/I balance.

  10. Role of transverse-momentum currents in the optical Magnus effect in free space

    International Nuclear Information System (INIS)

    We establish a general vector field model to describe the role of transverse-momentum currents in the optical Magnus effect in free space. As an analogy of the mechanical Magnus effect, the circularly polarized wave packet in our model acts as the rotating ball, and its rotation direction depends on the polarization state. Based on this model, we demonstrate the existence of an optical polarization-dependent Magnus effect which is significantly different from the conventional optical Magnus effect in that light-matter interaction is not required. Further, we reveal the relation between transverse-momentum currents and the optical Magnus effect, and find that such a polarization-dependent rotation is unavoidable when the wave packet possesses transverse-momentum currents. The physics underlying this intriguing effect is the combined contributions of transverse spin and orbital currents. We predict that this effect may be observed experimentally even in the propagation direction. These findings provide further evidence for the optical Magnus effect in free space and can be extrapolated to other physical systems.

  11. Temporary oil production, current account deterioration and the role of monetary and fiscal policy

    International Nuclear Information System (INIS)

    This paper extends earlier work on the macroeconomic adjustment processes arising for an economy experiencing a temporary period of oil production. Emphasis is placed on developments in the current account, as reflected in foreign asset stock movements, after oil production ceases, as well as on the role that monetary, fiscal or fiscal/monetary policy can play in influencing current-account developments during this same period. The results presented suggest that, to improve the performance of the current account, irrespective of the wage adjustment mechanism operative, after oil production ceases, the major thrust of macroeconomic policy should operate through fiscal rather than monetary policy. However developments in non-oil output would be influenced by the wage adjustment mechanism. With wage indexation, a tight fiscal policy after oil production ceases leads to a higher level of non-oil output than in the no policy response case, or one where monetary policy alone is used. With no wage indexation, the use of monetary and/or fiscal policy leads to lower levels of non-oil output. The use of fiscal policy also has the added benefit of contributing to a lower consumer price level, again irrespective of the operative wage adjustment mechanism. If the emphasis of policy operates through monetary policy, irrespective of the wage adjustment mechanism, the current-account problem will be exacerbated since foreign assets stocks will be lower. In addition, non-oil output and consumer prices will be lower. (Author)

  12. Clinical application of intraarterial digital substraction angiography

    International Nuclear Information System (INIS)

    Though intravenous digital subtraction angiography (IV DSA) has several advantages over conventional angiography in diagnosis and follow up of various vascular disease, it also has several undesirable problems such as large volume of the contrast medium and inferior image quality compared to conventional angiography. So recently intraarterial digital subtraction angiography (IA DSA) was introduced for better image quality using small amount of contrast medium. The authors had good clinical results IA DSA which were made in 20 patients with our own system, SRM-II, developed by cooperation of Departments of Radiology and Medical engineering, Seoul National University Hospital. Intraarterial digital substraction angiography was found to have several advantages over conventional angiography: (a) small amount of contrast medium, (b) reduced need for selective arterial catheterization, (c) lower film cost, (d) shortened examination time, (e) ability to obtain a 'road map', and (f) easier detection of contrast medium. Also IA DSA has several advantages over IV DSA: (a) less dependency on cardiac output, (b) far less vessel overlapping, (c) reduction in patient motion through less procedure by reduced volume of contrast media and shorter imaging time

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

    OpenAIRE

    Maurer, Martin; Hamm, B; Huppertz, A; Lembcke, A.

    2015-01-01

    OBJECTIVE To evaluate the role of an ultra-low-dose dual-source CT coronary angiography (CTCA) scan with high pitch for delimiting the range of the subsequent standard CTCA scan. METHODS 30 patients with an indication for CTCA were prospectively examined using a two-scan dual-source CTCA protocol (2.0 × 64.0 × 0.6 mm; pitch, 3.4; rotation time of 280 ms; 100 kV): Scan 1 was acquired with one-fifth of the tube current suggested by the automatic exposure control software [CareDose 4...

  15. Current Role and Future Perspectives of Magnetic Resonance Spectroscopy in Radiation Oncology for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Aleksandra Zapotoczna

    2007-06-01

    Full Text Available Prostatic neoplasms are not uniformly distributed within the prostate volume. With recent developments in three-dimensional intensity-modulated and imageguided radiation therapy, it is possible to treat different volumes within the prostate to different thresholds of doses. This approach has the potential to adapt the dose to the biologic aggressiveness of various clusters of tumor cells within the gland. The definition of tumor burden volume in prostate cancer can be facilitated by the use of magnetic resonance spectroscopy (MRS. The increasing sensitivity and specificity of MRS to the prostate is causing new interest in its potential role in the definition of target subvolumes at higher risk of failure following radical radiotherapy. Prostate MRS might also play a role as a noninvasive predictive factor for tumor response and treatment outcome. We review the use of MRS in radiation therapy for prostate cancer by evaluating its accuracy in the classification of aggressive cancer regions and target definition; its current role in the radiotherapy planning process, with special interest in technical issues behind the successful inclusion of MRS in clinical use; and available early experiences as a prognostic tool.

  16. The role of community pharmacy-based vaccination in the USA: current practice and future directions

    Directory of Open Access Journals (Sweden)

    Bach AT

    2015-07-01

    Full Text Available Albert T Bach, Jeffery A Goad School of Pharmacy, Chapman University, Irvine, California, USA Abstract: Community pharmacy-based provision of immunizations in the USA has become commonplace in the last few decades, with success in increasing rates of immunizations. Community pharmacy-based vaccination services are provided by pharmacists educated in the practice of immunization delivery and provide a convenient and accessible option for receiving immunizations. The pharmacist's role in immunization practice has been described as serving in the roles of educator, facilitator, and immunizer. With a majority of pharmacist-provided vaccinations occurring in the community pharmacy setting, there are many examples of community pharmacists serving in these immunization roles with successful outcomes. Different community pharmacies employ a number of different models and workflow practices that usually consist of a year-round in-house service staffed by their own immunizing pharmacist. Challenges that currently exist in this setting are variability in scopes of immunization practice for pharmacists across states, inconsistent reimbursement mechanisms, and barriers in technology. Many of these challenges can be alleviated by continual education; working with legislators, state boards of pharmacy, stakeholders, and payers to standardize laws; and reimbursement design. Other challenges that may need to be addressed are improvements in communication and continuity of care between community pharmacists and the patient centered medical home. Keywords: immunization, pharmacy practice, pharmacists, continuity of care 

  17. 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.

  18. 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

  19. Stepped digital angiography with dynamic subtraction: a new diagnostic approach to peripheral angiography

    International Nuclear Information System (INIS)

    On the basis of our first experiences, a purchasable angiography system for peripheral angiography with dynamic subtraction and stepping (DPSA) has been developed. This study reports on the optimization of this technique and the first clinical results in comparison with conventional screen-film angiography and digital subtraction angiography (DSA) in single steps. For each method, 25 angiograms were interpreted to compare the image quality, the radiation exposure, the contrast medium and the film consumption as well as the examination time. Image quality proved to be comparable in DPSA and DSA in single steps. Both techniques showed better results than conventional angiography, especially in the region of the knee and lower leg. Using DPSA radiation exposure dropped by a factor of 2 compared with conventional angiography and by a factor of 6 compared with DSA in single steps. Consumption of contrast medium can also be reduced in comparison with the other two methods. Film consumption is incomparably higher in conventional screen-film angiography. With DPSA the examination time can be reduced by half on average compared with the other two methods. DPSA may come to be the standard in peripheral angiography. (orig.)

  20. Low radiation dose imaging of myocardial perfusion and coronary angiography with a hybrid PET/CT scanner

    OpenAIRE

    Kajander, S; Ukkonen, H; Sipilä, H.; Teräs, M.; Knuuti, J

    2009-01-01

    Objectives: To test the image quality and feasibility of a sequential low radiation dose protocol for hybrid cardiac PET/CT angiography (CTA). Background: Multidetector computed tomography (MDCT) is a non-invasive method for coronary angiography. The negative predictive value of MDCT is high but perfusion imaging has a role in detecting functional significance of coronary lesions. This has encouraged combining these techniques. However, radiation dose is of concern. We report our first experi...

  1. Slovenian experience from diagnostic angiography to interventional radiology

    International Nuclear Information System (INIS)

    The purpose of writing this article is to document the important events and people in the first 50 years of diagnostic angiography and interventional radiology in Slovenia. During this period not only did the name of the institutions and departments change, but also its governance. This depicted the important roles different people played at various times in the cardiovascular divisions inside and outside of the diagnostic and interventional radiology. Historical data show that Slovenian radiology has relatively immediately introduced the new methods of interventional radiology in clinical practice

  2. The Role of Current Sheets in Solar Eruptive Events: An ISSI International Team Project

    Science.gov (United States)

    Suess, Steven T.; Poletto, Giannina

    2006-01-01

    Current sheets (CSs) are a prerequisite for magnetic reconnection. An International Space Science Institute (ISSI, of Bern, Switzerland) research team will work to empirically define current sheet properties in the solar atmosphere and their signatures in the interplanetary medium, and to understand their role in the development of solar eruptive events. The project was inspired by recently acquired ground and space based observations that reveal CS signatures at the time of flares and Coronal Mass Ejections (CMEs), in the chromosphere, in the corona and in the interplanetary medium. At the same time, theoretical studies predict the formation of CSs in different models and configurations, but theories and observational results have not yet developed an interaction efficient enough to allow us to construct a unified scenario. The team will generate synergy between observers, data analysts, and theoreticians, so as to enable a significant advance in understanding of current sheet behavior and properties. A further motivation for studying CSs is related to the expected electric fields in CSs that may be the source of solar energetic particles (SEPs). The team has 14 members from Europe and the US. The first meeting is in October 2006 and the second is late in 2007.

  3. Current and future role of magnetically assisted gastric capsule endoscopy in the upper gastrointestinal tract.

    Science.gov (United States)

    Ching, Hey-Long; Hale, Melissa Fay; McAlindon, Mark Edward

    2016-05-01

    Capsule endoscopy first captivated the medical world when it provided a means to visualize the small bowel, which was previously out of endoscopic reach. In the subsequent decade and a half we continue to learn of the true potential that capsule endoscopy has to offer. Of particular current interest is whether capsule endoscopy has any reliable investigative role in the upper gastrointestinal tract. Much research has already been dedicated to enhancing the diagnostic and indeed therapeutic properties of capsule endoscopy. Specific modifications to tackle the challenges of the gut have already been described in the current literature. In the upper gastrointestinal tract, the capacious anatomy of the stomach represents one of many challenges that capsule endoscopy must overcome. One solution to improving diagnostic yield is to utilize external magnetic steering of a magnetically receptive capsule endoscope. Notionally this would provide a navigation system to direct the capsule to different areas of the stomach and allow complete gastric mucosal examination. To date, several studies have presented promising data to support the feasibility of this endeavour. However the jury is still out as to whether this system will surpass conventional gastroscopy, which remains the gold standard diagnostic tool in the foregut. Nevertheless, a minimally invasive and patient-friendly alternative to gastroscopy remains irresistibly appealing, warranting further studies to test the potential of magnetically assisted capsule endoscopy. In this article the authors would like to share the current state of magnetically assisted capsule endoscopy and anticipate what is yet to come. PMID:27134661

  4. Role of inductive electric fields and currents in dynamical ionospheric situations

    Directory of Open Access Journals (Sweden)

    H. Vanhamäki

    2007-03-01

    Full Text Available We study the role of ionospheric induction in different commonly observed ionospheric situations. These include an intensifying electrojet, westward travelling surge (WTS and Ω-band. We use data based, realistic models for these phenomena and calculate the inductive electric fields that are created due to the temporal variations of ionospheric currents. The ionospheric induction problem is solved using a new calculation technique that can handle non-uniform, time-dependent conductances and electric fields of any geometry. We find that in some situations inductive effects are not negligible and the ionospheric electric field is not a pure potential field, but has a significant induced rotational part. In the WTS and Ω-band models the induced electric field is concentrated in a small area, where the time derivatives are largest. In the electrojet model the induced field is significant over a large part of the jet area. In these examples the induced electric field has typical values of few mV/m, which amounts to several tens of percents of the potential electric field present at the same locations. The induced electric field is associated with ionospheric and field aligned currents (FAC, that modify the overall structure of the current systems. Especially the induced FAC are often comparable to the non-inductive FAC, and may thus modify the coupling between the ionosphere and magnetosphere in the most dynamical situations. We also present some examples with very simple ionospheric current systems, where the effect of different ionospheric parameters on the induction process is studied.

  5. 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...

  6. Role of current good manufacturing practices in establishment of quality assurance for in-house radiopharmaceuticals

    International Nuclear Information System (INIS)

    The ultimate goal in any facility involved in the preparation of radiopharmaceuticals should be the production of products that are as safe and effective as possible. Following Current Good Manufacturing Practices (CGMPs) is the best way to assure the final product quality, even for in-house preparation and for those facilities operating under Nuclear Pharmacy auspices. In some facilities this places the chemist in a unique role of not only being responsible for R ampersand D, but for designing quality into all levels of product planning, including targetry, synthesis, purification, and quality control. The incorporation of certain minimum standards into the establishment of QA is discussed in general and is illustrated using the preparation of cyclotron-produced products, particularly 2-[F-18]fluoro-2-deoxy-D-glucose(FDG) and high purity Indium-111 chloride

  7. MR angiography in tuberculous meningitis

    International Nuclear Information System (INIS)

    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

  8. 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

  9. Anaesthetic specialist registrars in Ireland: current teaching practices and perceptions of their role as undergraduate teachers.

    LENUS (Irish Health Repository)

    Walsh, K

    2012-02-03

    BACKGROUND AND OBJECTIVES: Teaching is an important responsibility of non-consultant hospital doctors. In Ireland, specialist registrars (SpRs) in anaesthesia are contractually obliged to teach medical students, other doctors and nurses. Both medical students and fellow non-consultant hospital doctors attribute between 30 and 40% of their knowledge gain to non-consultant hospital doctors. METHODS: We carried out a confidential telephone survey of anaesthetic SpRs in Ireland regarding their current teaching practices and the perceptions of their role as undergraduate teachers. All the SpRs currently working in clinical practice in Ireland were eligible. RESULTS: Fifty-five of the 79 (70%) SpRs responded to the questionnaire. Only 7 (12.7%) of the respondents said they had been well trained as a teacher. The majority of the respondents stated that they would attend a learning-to-teach course\\/workshop if one was available, and felt that such a course would improve their ability as a teacher. Only 8 (14.5%) agreed that adequate emphasis is placed on commitment to teaching in the assessment of SpRs, both by individual departments and by the College of Anaesthetists. Anaesthetic SpRs in Ireland spend a considerable amount of time each day teaching undergraduate medical students, the majority (68.9%) stated that they had inadequate time to prepare for teaching. CONCLUSION: The majority of the respondents stated that they enjoy teaching, feel that they play an important role in undergraduate teaching but have inadequate time to prepare for teaching. An adequate emphasis is not placed on their commitment to teaching.

  10. MR angiography of run-off vessels

    International Nuclear Information System (INIS)

    Magnetic resonance angiography has taken a huge step forward since the introduction of contrast-enhanced MR angiography using gadolinium chelates. The more conventional MR angiographic techniques, such as time-of-flight and phase-contrast MR angiography, have been ousted by contrast-enhanced MR angiography in most vascular areas. However, in imaging the lower extremities, the major obstacle is the length of the vascular tree. In order to cover the entire peripheral vasculature, at least two to three fields of view are required. Using contrast-enhanced MR angiography, the best results are obtained if the vessels of interest are imaged during passage of a bolus of contrast material. Vessel-to-background contrast in subsequent acquisitions using subsequent injections of contrast material is hampered by recirculation and leakage of previously injected gadolinium, enhancing both the venous system and surrounding tissue. To overcome this problem several research groups have come up with various solutions. The three main strategies employed can be classified as either bolus catch, bolus chase, or bolus track techniques. The purpose of this article is to explain working mechanisms of the three bolus imaging strategies for imaging both inflow and outflow vessels of the lower extremities, to show their advantages and disadvantages, and to review results described in the literature in imaging patients using these techniques. (orig.)

  11. Reconstruction of coronary arteries from X-ray angiography: A review.

    Science.gov (United States)

    Çimen, Serkan; Gooya, Ali; Grass, Michael; Frangi, Alejandro F

    2016-08-01

    Despite continuous progress in X-ray angiography systems, X-ray coronary angiography is fundamentally limited by its 2D representation of moving coronary arterial trees, which can negatively impact assessment of coronary artery disease and guidance of percutaneous coronary intervention. To provide clinicians with 3D/3D+time information of coronary arteries, methods computing reconstructions of coronary arteries from X-ray angiography are required. Because of several aspects (e.g. cardiac and respiratory motion, type of X-ray system), reconstruction from X-ray coronary angiography has led to vast amount of research and it still remains as a challenging and dynamic research area. In this paper, we review the state-of-the-art approaches on reconstruction of high-contrast coronary arteries from X-ray angiography. We mainly focus on the theoretical features in model-based (modelling) and tomographic reconstruction of coronary arteries, and discuss the evaluation strategies. We also discuss the potential role of reconstructions in clinical decision making and interventional guidance, and highlight areas for future research. PMID:27054277

  12. Current roles of specific bacteria in the pathogenesis of inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Lucy McMullen

    2015-12-01

    Full Text Available The relevance of alterations in gut microbiota in the pathogenesis of inflammatory bowel disease (IBD remains unclear. Currently there is conflicting evidence with regards to the roles of specific bacterial species. Escherichia coli (particularly the adherent invasive strain are more prevalent in those with IBD and are associated with higher risk of IBD. However, the organisms are also present in healthy individuals and colonisation does not correlate with the degree of inflammation in IBD. Campylobacter concisus is more prevalent in those with IBD and higher levels of C. concisus specific IgG antibodies are found in the serum of those with IBD compared to healthy controls. Further, C. concisus has immunogenic properties that stimulate an antibody response suggesting the bacteria might trigger or exacerbate disease. Conversely most mycobacteria are unlikely to be causative as they are not presentin microbial stool cultures early in disease. In various studies,Mycobacterium aviumparatuberculosishas been detected both more frequently and not at all in individuals with Crohn's disease. Similar conflict exists with respect to Yersinia enterocolitica,Bacteroidesvulgatus and Helicobacter hepaticus, which are also more prevalent in IBD. However, these organisms appear more likely to contribute to disease persistence than initial disease development. This review aims to summarise the current understanding of key bacterial species implicated in the pathogenesis of IBD.

  13. Simulation and Mechanistic Investigation of the Arrhythmogenic Role of the Late Sodium Current in Human Heart Failure

    OpenAIRE

    Trenor Gomis, Beatriz Ana; Cardona Urrego, Karen Eliana; Gómez García, Juan Francisco; Saiz Rodríguez, Francisco Javier; Ferrero De Loma-Osorio, José María; Rajamani, Sridharan; Belardinelli, Luiz

    2012-01-01

    Heart failure constitutes a major public health problem worldwide. The electrophysiological remodeling of failing hearts sets the stage for malignant arrhythmias, in which the role of the late Na + current (I NaL) is relevant and is currently under investigation. In this study we examined the role of I NaL in the electrophysiological phenotype of ventricular myocytes, and its proarrhythmic effects in the failing heart. A model for cellular heart failure was proposed using a modified version o...

  14. Evaluation of effective dose received by patients undergoing Cardiac Angiography Computed Tomography (CT) and Conventional Angiography

    International Nuclear Information System (INIS)

    Cardiac Angiography is a field of studies that utilizes the energy of radiation to study the coronary arteries of the heart. Patients undergoing this procedure has a probability of receiving an over dose of radiation that may further cause stochastic effect. The main objective of this research is to compare and clarify an approach for minimal effective dose receive by patients between procedures of Cardiac Angiography Computerized Tomography (CT) and Conventional Angiography. Based on this study, the patients recorded are based in Hospital University Sains Malaysia, Kubang Kerian, Kelantan. The Dose-Length-Product (DLP) was extracted from the Computed Tomography Dose Index (CTDI); meanwhile the Dose-Area-Product (DAP) was extracted from the modalities console screen. These relevant data are the means to clarify the effective dose receive by patients. The result shows that patients who undergo Conventional Angiography had a mean effective dose of 8.50 ± 6.41 mSv. Meanwhile, as for Cardiac Angiography Computerized Tomography, the patients had a mean effective dose of 7.08 ± 2.42 mSv. A significant difference in effective dose was seen between the two procedures. Cardiac Angiography CT provides high accurate diagnostic information with less radiation dose to patients compared to Conventional Angiography. (author)

  15. 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)

  16. 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.)

  17. The diagnosis of aortic rupture by digital subtraction angiography

    International Nuclear Information System (INIS)

    The typical signs of the rupture of the thoracic aorta in the chest radiographs of patients with this injury are shown. Because all these signs lack specifity only angiography was diagnostic till now. Digital subtraction angiography (dsa) as a new diagnostic procedure can replace invasive angiography. In four cases the rupture of the aorta was clearly diagnosed by means of digital subtraction angiography. In three additional cases it could be definitely exluded. (orig.)

  18. 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

  19. Intravenous digital subtraction angiography investigation of reversible cerebral ischemia

    International Nuclear Information System (INIS)

    The brachio-cephalic, carotid, vertebral and intra-cranial vessels of 497 patients presenting reversible ischemic attacks (R.I.A) were evaluated with venous digital subtraction angiography (V.D.S.A.). Alterations of the vascular wall were observed in 289/497 (58.2%) patients, of whom 60% presented multiple locations (539 lesions): obstruction (12%), stenosis >50% (29%), stenosis 50%. The incidence of vascular lesions was higher (p<0.01) in patients with multiple R.I.A. (66.6%) than in those with one isolated R.I.A. (55.6%). Among the patients (207/497) studied also with cerebral computed tomography (C.T.) no relationship could be defined between the extra-cranial vascular lesions demonstrated by V.D.S.A. and the cerebral alterations shown by C.T. Among the patients (64/497) studied also with high frequence ultrasonography (U.S.), the lesion shown by V.D.S.A. could be also demonstrated by U.S. in 84.8% of cases. The personal flow-chart in the study of R.I.A. is described emphasizing the primary role played by V.D.S.A. as well as the complementary role of the other techniques, both non invasive (U.S.,C.T.) and invasive (conventional or digital subtraction angiography)

  20. Ergotism of the lower limb complicating DHE-heparin thrombosis prophylaxis. Observation by serial angiography

    Energy Technology Data Exchange (ETDEWEB)

    Warmuth-Metz, M.

    1988-10-01

    Today ergotism is becoming more and more important as a complication in the treatment of migraine headache or thrombosis prophylaxis with DHE heparin. Although complete recovery is seldom reported in the current literature, in our case it was possible to resolve a spasm of the left lower limb completely by early diagnosis and adaequate pharmacological treatment. The case was well documented by serial angiography.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. CT angiography, MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

    International Nuclear Information System (INIS)

    The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms. (orig.)

  6. 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.

  7. 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.)

  8. 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

  9. The Current Role of Omega-3 Fatty Acids in the Management of Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Georgios A. Christou

    2015-09-01

    Full Text Available Background: The main dietary source of omega-3 polyunsaturated fatty acids (n-3 PUFA is fish, which contains eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. In the present manuscript, we aimed to review the current evidence regarding the clinical role of n-3 PUFA in the prevention of atrial fibrillation (AF and the possible underlying mechanisms. Methods: A literature search based on PubMed listings was performed using “Omega-3 fatty acids” and “atrial fibrilation” as key search terms. Results: n-3 PUFA have been shown to attenuate structural atrial remodeling, prolong atrial effective refractory period through the prevention of reentry and suppress ectopic firing from pulmonary veins. Dietary fish intake has been found to have no effect on the incidence of AF in the majority of studies. Circulating DHA has been consistently reported to be inversely associated with AF risk, whereas EPA has no such effect. The majority of studies investigating the impact of n-3 PUFA supplementation on the incidence of AF following cardiac surgery reported no benefit, though most of them did not use n-3 PUFA pretreatment for adequate duration. Studies using adequate four-week pretreatment with n-3 PUFA before cardioversion of AF showed a reduction of the AF incidence. Conclusions: Although n-3 PUFA have antiarrhythmogenic properties, their clinical efficacy on the prevention of AF is not consistently supported. Further well-designed studies are needed to overcome the limitations of the existing studies and provide robust conclusions.

  10. Current role of multiparametric magnetic resonance imaging in the management of prostate cancer

    Science.gov (United States)

    Katelaris, Nikolas Christopher; Bolton, Damien Michael; Weerakoon, Mahesha; Toner, Liam; Katelaris, Phillip Mark

    2015-01-01

    The purpose of this review was to evaluate the current role of multiparametric magnetic resonance imaging (mp-MRI) in the management of prostate cancer (PC). The diagnosis of PC remains controversial owing to overdetection of indolent disease, which leads to overtreatment and subsequent patient harm. mp-MRI has the potential to equilibrate the imbalance between detection and treatment. The limitation of the data for analysis with this new technology is problematic, however. This issue has been compounded by a paradigm shift in clinical practice aimed at utilizing this modality, which has been rolled out in an ad hoc fashion often with commercial motivation. Despite a growing body of literature, pertinent clinical questions remain. For example, can mp-MRI be calibrated to reliably detect biologically significant disease? As with any new technology, objective evaluation of the clinical applications of mp-MRI is essential. The focus of this review was on the evaluation of mp-MRI of the prostate with respect to clinical utility. PMID:25964833

  11. The role of monoamine oxidase A in aggression: Current translational developments and future challenges.

    Science.gov (United States)

    Godar, Sean C; Fite, Paula J; McFarlin, Kenneth M; Bortolato, Marco

    2016-08-01

    Drawing upon the recent resurgence of biological criminology, several studies have highlighted a critical role for genetic factors in the ontogeny of antisocial and violent conduct. In particular, converging lines of evidence have documented that these maladaptive manifestations of aggression are influenced by monoamine oxidase A (MAOA), the enzyme that catalyzes the degradation of brain serotonin, norepinephrine and dopamine. The interest on the link between MAOA and aggression was originally sparked by Han Brunner's discovery of a syndrome characterized by marked antisocial behaviors in male carriers of a nonsense mutation of this gene. Subsequent studies showed that MAOA allelic variants associated with low enzyme activity moderate the impact of early-life maltreatment on aggression propensity. In spite of overwhelming evidence pointing to the relationship between MAOA and aggression, the neurobiological substrates of this link remain surprisingly elusive; very little is also known about the interventions that may reduce the severity of pathological aggression in genetically predisposed subjects. Animal models offer a unique experimental tool to investigate these issues; in particular, several lines of transgenic mice harboring total or partial loss-of-function Maoa mutations have been shown to recapitulate numerous psychological and neurofunctional endophenotypes observed in humans. This review summarizes the current knowledge on the link between MAOA and aggression; in particular, we will emphasize how an integrated translational strategy coordinating clinical and preclinical research may prove critical to elucidate important aspects of the pathophysiology of aggression, and identify potential targets for its diagnosis, prevention and treatment. PMID:26776902

  12. Current role of surgery for the treatment of fulminant Clostridium difficile colitis

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-fei; DING Zhao; ZHAO Jian; JIANG Cong-qing; LIU Zhi-su; QIAN Qun

    2013-01-01

    Objective This review discusses the current status and progress in studies on fulminant Clostridium difficile colitis (FCDC),including the definition,risk factor,diagnostic role of CT,surgical treatment,postoperative mortality,and new therapeutic strategy.Data sources A literature search was conducted mainly in Medline and PubMed published in English between January 2000 and May 2011.The search terms were "fulminant Clostridium difficile colitis","treatment"","surgery" and "mortality".Resulta Recent studies show that the overall mortality rate for FCDC remains high despite early surgical intervention.It has been difficult to identify the real value for surgical intervention in patients with FCDC due to the absence of prospective,randomized studies.Early recognition of patients with FCDC will help a clinician decide the need for treatment in an intensive care setting,multi-disciplinary consultation,and appropriate therapeutic selection.Some studies emphasize the importance of early recognition and emergent surgery at a less severe stage.Monoclonal antibody therapy and intravenous immunoglobulin treatment may be useful for the treatment of FCDC.Conclusions Present studies do not provide strong evidence for guiding the surgical treatment of FCDC; hence,creation of collaborative research networks is crucial in order to undertake large prospective multi-center studies for improvement in overall survival.

  13. Magnetic resonance angiography: infrequent anatomic variants

    International Nuclear Information System (INIS)

    We studied through RM angiography (3D TOF) with high magnetic field equipment (1.5 T) different infrequent intracerebral vascular anatomic variants. For their detection we emphasise the value of post-processed images obtained after conventional angiographic sequences. These post-processed images should be included in routine protocols for evaluation of the intracerebral vascular structures. (author)

  14. Angiography of the testicular artery. IV

    International Nuclear Information System (INIS)

    Magnification angiography of the testis with selective injection into the testicular artery has been performed in patients with different lesions in the scrotum, either real or suggested. Characteristic angiographic appearances were found in epididymitis, testicular torsion, tumor, hematoma and hydrocele. (Auth.)

  15. Post-mortem CT-coronary angiography

    DEFF Research Database (Denmark)

    Pøhlsgaard, Camilla; Leth, Peter Mygind

    2007-01-01

    post-mortem coronary angiography and computerized tomography.  We describe how to prepare and inject the contrast medium, and how to establish a CT-protocol that optimizes spatial resolution, low contrast resolution and noise level. Testing of the method on 6 hearts, showed that the lumen of the...

  16. Digital subtraction angiography of carotid bifurcation

    International Nuclear Information System (INIS)

    This study demonstrates the reliability of digital subtraction angiography (DSA) by means of intra- and interobserver investigations as well as indicating the possibility of substituting catheterangiography by DSA in the diagnosis of carotid bifurcation. Whenever insufficient information is obtained from the combination of non-invasive investigation and DSA, a catheterangiogram will be necessary. (Auth.)

  17. 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.)

  18. Magnetic resonance angiography in meningovascular syphilis

    International Nuclear Information System (INIS)

    Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

  19. 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.)

  20. Prophylactic Effect of Theophylline in Renal Contrast Nephropathy after Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Asadollah Mohseni

    2006-07-01

    Full Text Available Background: Contrast nephropathy will increase mortality up to 30% following angiographic procedures. Adenosine is a crucial mediator of contrast-induced nephropathy. The purpose of this study was to investigate whether the adenosine antagonist Theophylline reduces the incidence of CN after coronary angiography.Methods: In this randomized, double-blind, placebo-controlled clinical trial study, carried out from February 2004 to September 2005 at the Fatemeh Zahra Hospital, 70 patients who were undergoing coronary angiography were divided into two groups. Case group (n=35 received oral Theophylline 200 mg bid. 24 h before and for 48 h after angiography. The control group (n=35 received placebo. Serum Na+, K+, blood urea nitrogen (BUN, creatinine, glomerular filtration rate (GFR were measured before and after angiography.Results: In the case group there were no significant change in serum creatinine (0.90± 0.7 vs. 0.92±0.3 mg/dl, BUN (17.76±7.8 vs. 19.35±9.6 mg/dl, GFR (83.01±26.7 vs. 81.36±24.9 ml/min Na+ (139.08±3.6 vs. 138.54±2.7 mEq/l and K+ (4.30±0.4 vs. 4.19±0.3 mEq/l. In the control group, there was a significant fall in GFR after angiography (86.10±34.8 vs. 80.7±30.4 ml/min, P=0.03. Following angiography, there were no significant difference in serum creatinine, BUN, GFR, Na+ and K+ level between the two groups. None of the patients in either group faced contrast induced nephropathy. Conclusion: Theophylline does not appear to add a protective role in preventing against contrast induced nephropathy in patients undergoing angiographic procedures.

  1. Current perspectives on the role of orbital fibroblasts in the pathogenesis of Graves' ophthalmopathy.

    Science.gov (United States)

    Dik, Willem A; Virakul, Sita; van Steensel, Leendert

    2016-01-01

    Graves' ophthalmopathy (GO) is an extra-thyroidal complication of Graves' disease (GD; Graves' hyperthyroidism) characterized by orbital tissue inflammation, expansion, remodeling and fibrosis. Although the initiating trigger of GO is still indistinct, excessive orbital fibroblast activity is at the heart of its pathogenesis. Orbital fibroblasts are activated by cellular interactions with immune cells and the soluble factors they secrete. Orbital fibroblasts, especially from GO patients, express the thyrotropin receptor (TSH-receptor; TSHR), and activation of the orbital fibroblast population by stimulatory autoantibodies directed against the TSHR may provide an important link between GD and GO. Furthermore, stimulatory autoantibodies directed against the insulin-like growth factor-1 receptor have been proposed to contribute to orbital fibroblast activation in GO. Activated orbital fibroblasts produce inflammatory mediators thereby contributing to the orbital inflammatory process in GO. Moreover, orbital fibroblasts exhibit robust proliferative activity and extracellular matrix (especially hyaluronan) synthesizing capacity and can differentiate into adipocytes and myofibroblasts with disease progression, thereby contributing to tissue expansion/remodeling and fibrosis in GO. Orbital fibroblasts, especially those from GO patients, exhibit a hyper-responsive phenotype when compared to fibroblasts from other anatomical regions, which may further contribute to GO pathogenesis. Fibrocytes have been identified as additional source of orbital fibroblasts in GO, where they may contribute to orbital tissue inflammation, adipogenesis and remodeling/fibrosis. This review addresses our current view on the role that orbital fibroblasts fulfill in GO pathogenesis and both established as well as less established not fully crystallized concepts that need future studies will be discussed. PMID:26675405

  2. The current and potential role of satellite remote sensing in the campaign against malaria

    Science.gov (United States)

    Kazansky, Yaniv; Wood, Danielle; Sutherlun, Jacob

    2016-04-01

    Malaria and other vector borne diseases claim lives and cause illness, especially in less developed countries. Although well understood methods, such as spraying and insecticidal nets, are identified as effective deterrents to malaria transmission by mosquitoes, the nations that have the greatest burden from the disease also struggle to deploy such measures sufficiently. More targeted and up to date information is needed to identify which regions of malaria-endemic countries are most likely to be at risk of malaria in the near future. This will allow national governments, local officials and public health workers to deploy protective equipment and personnel where they are most needed. This paper explores the role of environmental data generated via satellite remote sensing as an ingredient to a Malaria Early Warning System. Data from remote sensing satellites can cover broad geographical areas frequently and consistently. Much of the relevant data may be accessed by malaria-endemic countries at minimal cost via international data sharing polices. While previous research studies have demonstrated the potential to assign malaria risk to a geographic region based on indicators from satellites and other sources, there is still a need to deploy such tools in a broader and more operational manner to inform decision making on malaria management. This paper describes current research on the use of satellite-based environmental data to predict malaria risk and examines the barriers and opportunities for implementing Malaria Early Warning Systems enabled by satellite remote sensing. A Systems Architecture Framework analyses the components of a Malaria Early Warning System and highlights the need for effective coordination across public and private sector organizations.

  3. The glucose triad and its role in comprehensive glycaemic control: current status, future management.

    Science.gov (United States)

    Ceriello, A

    2010-11-01

    The prevalence of type 2 diabetes across the world has been described as a global pandemic. Despite significant efforts to limit both the increase in the number of cases and the long-term impact on morbidity and mortality, the total number of people with diabetes is projected to continue to rise and most patients still fail to achieve adequate glycaemic control. Optimal management of type 2 diabetes requires an understanding of the relationships between glycosylated haemoglobin (HbA(1c)), fasting plasma glucose and postprandial glucose (the glucose triad), and how these change during development and progression of the disease. Early and sustained control of glycaemia remains important in the management of type 2 diabetes. The contribution of postprandial glucose levels to overall glycaemic control and the role of postprandial glucose targets in disease management are currently debated. However, many patients do not reach HbA(1C) targets set according to published guidelines. As recent data suggest, if driving HbA(1C) down to lower target levels is not the answer, what other factors involved in glucose homeostasis can or should be targeted? Has the time come to change the treatment paradigm to include awareness of the components of the glucose triad, the existence of glucose variability and their potential influence on the choice of pharmacological treatment? It is becomingly increasingly clear that physicians are likely to have to consider plasma glucose levels both after the overnight fast and after meals as well as the variability of glucose levels, in order to achieve optimal glycaemic control for each patient. When antidiabetic therapy is initiated, physicians may need to consider selection of agents that target both fasting and postprandial hyperglycaemia. PMID:20860758

  4. Should computed tomography angiography supersede invasive coronary angiography for the evaluation of graft patency following coronary artery bypass graft surgery?

    Science.gov (United States)

    Gabriel, Joseph; Klimach, Stefan; Lang, Peter; Hildick-Smith, David

    2015-08-01

    Invasive coronary angiography (ICA) has long been the established gold standard in assessing graft patency following coronary artery bypass graft (CABG). Over the past decade or so however, improvements in computed tomography angiography (CTA) technology have allowed its emergence as a useful clinical tool in graft assessment. The recent introduction of 64-slice and now 128-slice scanners into widespread distribution, and the development of 320-detector row technology allowing volumetric imaging of the entire heart at single points in time within one cardiac cycle, has increased the potential of CTA to supersede ICA in this capacity. This study sought to examine the evidence surrounding this potential. A best evidence topic was constructed according to a structured protocol. The enquiry: In [patients who have undergone coronary artery bypass graft surgery] is [computed tomography angiography or invasive coronary angiography] superior in terms of [graft patency assessment, stenosis detection, radiation exposure and complication rate]? Four hundred and twenty-four articles were identified from the search strategy. Four additional articles were identified from references of key articles. Seventeen articles selected as best evidence were tabulated. The reliability of CTA as a tool in the detection of graft patency and stenosis has continued to improve with each successive generation of multislice technology. The latest 64- and 128-slice CTA techniques are able to detect graft patency and stenosis with very high sensitivities and specificities comparable with ICA, while remaining non-invasive procedures associated with fewer complications (ICA carries a 0.08% risk of myocardial infarction and 0.7% risk of minor complications in clinically stable patients). Present limitations of the technology include the accurate visualization of distal anastomoses and clip artefacts. In addition, the capacity of diagnostic ICA to be combined simultaneously with percutaneous coronary

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

    Science.gov (United States)

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

    2015-06-30

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

  6. Role of the thermoactivated and tunnel electron relaxations of radiation defects in initiation of isothermal exoemission current

    International Nuclear Information System (INIS)

    In this paper aimed at the determination of the role of thermoactivated and tunnel electron-hole recombinations of radiation defects in the appearance of the isothermal exoelectron emission (EEE) current, we carry out the calculation of a value of the isothermal EEE current and make its comparison with the experimental curves of the EEE decay, at various ses of the ultraviolet irradiation of the CsBr alkaline-halide crystals

  7. The role of computerized tomography in the evaluation of gastrointestinal bleeding following negative or failed endoscopy: A review of current status

    Directory of Open Access Journals (Sweden)

    Stunell H

    2008-01-01

    Full Text Available Gastrointestinal bleeding remains an important cause for emergency hospital admission with a significant related morbidity and mortality. Bleeding may relate to the upper or lower gastrointestinal tracts and clinical history and examination may guide investigations to the more likely source of bleeding. The now widespread availability of endoscopic equipment has made a huge impact on the rapid identification of the bleeding source. However, there remains a large group of patients with negative or failed endoscopy, in whom additional techniques are required to identify the source of bleeding. In the past, catheter angiography and radionuclide red cell labeling techniques were the preferred ′next step′ modalities used to aid in identifying a bleeding source within the gastrointestinal tract. However, these techniques are time-consuming and of limited sensitivity and specificity. In addition, catheter angiography is a relatively invasive procedure. In recent years, computerized tomography (CT has undergone major technological advances in its speed, resolution, multiplanar techniques and angiographic abilities. It has allowed excellent visualization of the both the small and large bowel allowing precise anatomical visualization of many causes of gastrointestinal tract (GIT bleeding. In addition, recent advances in multiphasic imaging now allow direct visualization of bleeding into the bowel. In many centers CT has therefore become the ′next step′ technique in identifying a bleeding source within the GIT following negative or failed endoscopy in the acute setting. In this review article, we review the current literature and discuss the current status of CT as a modality in investigating the patient with GIT bleeding.

  8. 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

  9. Angiography of histopathologic variants of synovial sarcoma

    International Nuclear Information System (INIS)

    Synovial sarcomas are rare soft tissue tumors which histopathologically can be divided into monophasic, biphasic and mixed variants. As part of a protocol for intra-arterial chemotherapy 12 patients with biopsy proven synovial sarcoma underwent angiography. The angiograms on these patients were reviewed to determine whether synovial sarcomas and their variants demonstrated a characteristic angiographic appearance. Synovial sarcomas appeared angiographically as soft tissue masses which showed a fine network of tumor vessels with an inhomogeneous capillary blush. Their degree of vascularity varied according to their histopathology. Monophasic synovial sarcomas demonstrated in general a higher degree of neovascularity than the biphasic form. This finding was also suggested by histopathologic analysis of the vessels in the tumor. Although angiography did not show a distinctive vascular pattern it may be useful to evaluate tumor size and vascularity. (orig.)

  10. Possibilities of conventional intravenous subtraction angiography (ISA)

    Energy Technology Data Exchange (ETDEWEB)

    Weigert, F.; Loessl, P.; Eggemann, F.

    1984-01-01

    Based on the experiences collected with 127 patients, the pros and cons as well as the indications for intravenous angiography with conventional photographic subtraction technique (ISA) are discussed in comparison with rival procedures. ISA can be performed in every angiography unit without any additional investment, and its possibilities of use are identical with those of the DSA. As a matter of fact, it is a simple and safe method for visualising the renal arteries in the course of intravenous urography in the diagnostic evaluation of hypertansion. For the first time, it has become possible to perform transvenous determination of the complete status of the arteries of the pelvis and legs, using a new technical system (simultaneous use of two film changers in the frontal plane - ISA aortoarteriography).

  11. Angiography in the region of the foot

    International Nuclear Information System (INIS)

    It is reported on technique, incidence and findings of angiography of the foot which provided magnifying angiography and non-ionic contrast media are used, is especially qualified for the differentiation of diabetic and non-diabetic angiopathies as well as for the identification of peripherical embolizations and digital arterial occlusions at thrombocytosis or polycythemia. The arteries of the foot represent the peripherical outflow at peripherical reconstructive performances at the lower leg and have to be studied prior to such reconstructive surgical interventions. The different localization of arterial obliterations and changes of the walls in diabetics of stage I-IV according to Fontaine shows the particularly large number of vascular-pathological findings in arteries of the lower leg and foot in diabetics with arterial occlusive diseases of stage III and IV. Therefore, the unfavourable prognoses of arterial occlusive diseases in diabetics have also to be made for peripherical arterial obliterations of the foot and lower leg. (orig.)

  12. Role of the electron temperature in the current decay during disruption in JT-60U

    International Nuclear Information System (INIS)

    The effect of the electron temperature Te on the plasma current decay after the mini-collapse was investigated for the disruption in JT-60U owing to a massive neon gas puff by using the disruption simulation code DINA. During the current quench in JT-60U, the fast electron temperature decrease is followed by a transient plasma current increase. This is called “mini-collapse”, typically occurring when the plasma current decreases to 80 - 90% of its value at the flattop phase. The plasma evolution after the mini-collapse was investigated using the DINA code for three assumed Te profiles: flat, broad, and peaked profiles. The time evolution of the plasma current, plasma center position, plasma cross section, and vacuum vessel current were not found to be sensitive to the Te profile after the mini-collapse. The plasma current after mini-collapse decreased owing to the plasma resistance, although it was previously found that the plasma current decrease during the initial phase of current quench was owing to the time derivative of the plasma inductance. (author)

  13. Angiography and interventional radiology of the kidneys

    International Nuclear Information System (INIS)

    For imaging of renal pathology a broad spectrum of radiologic diagnostic procedures are available which are, sometimes and particularly more recently, competing among each other in their diagnostic yield and relevance. For tumorous lesions ultrasound, computed tomography and magnetic resonance imaging are performed predominantly. Angiography is no longer required with the exception of highly selected cases and in some specific preoperative workup requirements. Until recently, catheter based digital subtraction angiography has been considered as gold standard. However, non-invasive techniques such as CT-angiography and MR-angiography are evolving parallel to their quantum leap of resolutions and readiness to use. Nevertheless, well accepted criteria for quality assessement of these new modalities are still lacking. More comparison studies are urgently warranted. Despite the availability of ultrashort pulse sequences applying the T1 relaxation reduction effect of gadolinium enhanced MR techniques overestimation of renal artery stenosis still poses a substantial problem. Renal intervention implies a variety of procedures such as plain angioplasty, stent placement, embolization of traumatic and both benign and malignant tumors. These methods have emerged over the last two decades from a more experimental nature to a fully accepted treatment option. When renal artery angioplasty is embedded in an aggressive approach including stenting as an adjunct for more complex cases, renal ostial lesions and a well organized follow-up regimen its therapeutic potential for treatment of renal insufficiency, malignant hypertension, for organ preservation bears a very high potential. Provided adequate periinterventional drug regimen restenosis rates may be as low as 10%. In highly selected cases capillary embolization might be used as an alternative to nephrectomy with a similar clinical outcome. Particularly the development of superselective small caliber embolization catheters

  14. The application of angiography in conjoined twins

    International Nuclear Information System (INIS)

    Objective: To report a case of conjoined twins with peripheral angiography together with cardioangiographic technique. Methods: Left ventriculogram, right ventriculogram, descending aortogram and selected celiac arteriogram were separately performed for both babies of the conjoined twin. Results: Angiocardiography showed the anatomy of cardiac and abdominal vessels of the thoraco-omphalopagus conjoined twin clearly and confirmed by the separation operation. Conclusions: The angiographic examination is difficult but very helpful for successful operation of the conjoined twin. (authors)

  15. Reuse of catheters for angiography. 2. Contribution

    International Nuclear Information System (INIS)

    The reuse of sterile medical devices designated for single use is a controversal practice, known to be performed in many countries. As far as catheters for angiography are concerned, various methods for cleaning and sterilisation are in use. However, interactions of detergents and ethylene oxide used in reprocessing with polyethylene materials of the catheters have not been investigated systematically. This paper presents a physico-chemical characterisation of common angiographic catheters. The interaction of polyethylene and ethylene oxide is examined. (orig.)

  16. 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....

  17. 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)

  18. Clinical application and diagnostic value of non-invasive spinal angiography in spinal vascular malformations

    International Nuclear Information System (INIS)

    Objective: To explore the value of CT spinal angiography with 256 MSCT and fast dynamic contrast-enhanced 3D MR angiography (CE-MRA) at 3.0 T in the diagnosis of spinal vascular malformations by comparing with results of DSA and operation. Methods: Seventeen patients suspected of spinal vascular diseases by initial MR and clinical manifestations all underwent CT spinal angiography. Of them, 10 patients underwent MRA, 15 patients underwent DSA within 3-5 days,and 8 patients finally underwent surgical treatment. Results: CTA examination clearly showed the abnormal vascular lesions in 16 of 17 cases, including 7 cases with the diagnosis of spinal dural arteriovenous fistula, 7 cases of perimedullary arteriovenous fistula, and 2 cases of spinal arteriovenous malformations. The results were consistent with the diagnosis of DSA or surgery. One case was poorly diagnosed. The feeding vessels were correctly determined in 12 cases, and the level of fistulas were correctly displayed in 12 cases. The level of fistulas and feeding vessels were accurately showed in 7 of 10 cases with MRA, while the other 3 cases exhibited normal with DSA. Conclusions: Spinal angiography with 256 MSCT and CE-MRA at 3.0 T can clearly show the extent of spinal vascular malformations, feeding arteries and fistula location. They are safe, noninvasive, convenient and can shorten the time of DSA diagnosis and treatment. They play an important role in diagnosis and treatment of spinal vascular malformations and postoperative follow-up. (authors)

  19. Integration of MR imaging with MR angiography

    International Nuclear Information System (INIS)

    Two potentially useful techniques for performing MR angiography include phase-contrast methods and sequences that take advantage of flow-related enhancement. The authors have investigated the ability of these methods to provide supplemental information when integrated with a routine proton MR imaging sequence. The authors have evaluated MR angiographic findings in 15 patients undergoing routine spin-echo MR imaging for various vascular abnormalities. Phase-contrast techniques provide projection images with high in-plane spatial resolution, but artifacts are created at sites of vessel crossings as well as in regions of complex flow. Flow-related enhancement sequences produce images with similar signal-to-noise ratio at slightly reduced spatial resolution compared with phase-contrast angiography. However, an important advantage of these sequences is reduced sensitivity to complex flow patterns. The disadvantage of this method is the longer acquisition time required compared with projection phase-contrast techniques. In summary, these angiography sequences appear to provide useful information in conjunction with conventional MR examinations

  20. Subtracted versus non-subtracted digital imaging in peripheral angiography

    International Nuclear Information System (INIS)

    Digital subtraction angiography (DSA) plays an important role in the management of vascular diseases of the lower extremities. A disadvantage is the lack of an automatically moving table top. We used a 1,024x1,024 matrix with a large-screen intensifier system and an automated 'stepping' facility. In 161 examinations of the arteries of the lower extremity digital peripheral arteriography was performed with and without the subtraction technique. We compared the influence of different iodine concentrations in DA and DSA. Peripheral DA proved to be equal to peripheral DSA in the region of the pelvis, thigh and knee, with no adequate contrasting being obtained merely in the region of the lower leg arteries in about 45%. It is necessary to use contrast medium at a concentration of 300 mg I/ml. The installation of an automated 'stepping' facility reduces the amount of contrast' medium needed and the exposure time. (orig.)

  1. 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.

  2. Cardiac CT angiography in children with congenital heart disease

    International Nuclear Information System (INIS)

    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

  3. A 2D finite element study on the role of material properties on eddy current losses in soft magnetic composites

    Science.gov (United States)

    Ren, Xiaotao; Corcolle, Romain; Daniel, Laurent

    2016-02-01

    The use of soft magnetic composites (SMCs) in electrical engineering applications is growing. SMCs provide an effective alternative to laminated steels because they exhibit a high permeability with low eddy current losses. Losses are a critical feature in the design of electrical machines, and it is necessary to evaluate the role of microstructure and constitutive properties of SMCs during the predesign stage. In this paper we propose a simplified finite element approach to compute eddy current losses in these materials. The computations allow to quantify the role of exciting source and material properties on eddy current losses. This analysis can later be used in the development of homogenization models for SMC. Contribution to the topical issue "Numelec 2015 - Elected submissions", edited by Adel Razek

  4. Current Research of the Roles of IL-35 in Tumor Progression

    Directory of Open Access Journals (Sweden)

    Chongbiao HUANG

    2016-04-01

    Full Text Available Interleukin(IL-35 is a new member of the interleukin-12 superfamily. Since its first report in 2007, IL-35 rapidly became a research highlight in the field of immunology. Like other IL-12 superfamily members, IL-35 was a heterodimer which was composed of an α chain P35 and a β chain Epstein-Barr virus induced gene 3 (EBI3. Recent research work revealed two distinct roles of IL-35. Firstly, IL-35 is highly expressed in some kinds of inflammatory diseases and autoimmune diseases and plays import roles in the pathogenesis. Secondly, IL-35 is positively expressed in some cancers and plays some roles in the process of tumor progression. Here we demonstrate the structure and the signalling of IL-35. We reviewed the the roles of IL-35 in promoting tumor progression.

  5. The Context of Current Content Analysis of Gender Roles: An Introduction to a Special Issue

    OpenAIRE

    Rudy, Rena M.; Popova, Lucy; Linz, Daniel G.

    2010-01-01

    The aim of this paper is to provide context for the quantitative content analyses of gender roles that are to be included in both parts of this special issue. First, a timeline of historical uses of the content analysis methodology is presented. Second, research objectives that frequently drive content analysis of gender roles are described; these include: to support feminist claims, to compare media with real life, to predict effects on audiences, and to detect effects of media producers on ...

  6. Preoperative cerebral aneurysm assessment by three-dimensional CT angiography. Feasibility of surgery without cerebral angiography

    International Nuclear Information System (INIS)

    The purpose of this study is to assess the capability of three-dimensional CT angiography (3D-CTA) to replace conventional catheter angiography as a preoperative examination for unruptured intracranial aneurysms. A prospective study was designed to evaluate 18 patients with 20 unruptured intracranial aneurysms (13 middle cerebral artery aneurysms, 6 anterior communicating artery aneurysms, and 1 internal carotid posterior communicating artery aneurysm) who underwent surgery. There were 12 women and 6 men with the average age of 63 years old. All patients were initially diagnosed as having intracranial aneurysms by MR angiography, followed by 3D-CTA and conventional catheter angiography for confirmation. Three experienced neurosurgeons were in charge of the operations. One of the neurosurgeons (surgeon 1) was provided with only 3D-CTA as the preoperative radiological evaluation, while the others (surgeon 2 and 3) were given through assessments with MRA, 3D-CTA, and conventional angiography. Surgeon 1 carried out the operations under careful observation by the surgeons 2 and 3. Problems encountered by the surgeon 1 during surgery were recorded. Neck clipping in 19 aneurysms and dome wrapping in 1 were successfully accomplished. All patients were discharged without complication. Surgeries went smoothly in 16 aneurysms with 3D-CTA alone. Discrepancies between the 3D-CTA findings and microsurgical anatomy were noted in 4 aneurysms: the size of the neck was overestimated in 3 aneurysms, the relationships to parent arteries were obscure in 2 aneurysms, and a perforating artery problematic to neck clipping was missed in 1 aneurysms by 3D-CTA. The results of this study support the notion that 3D-CTA can replace conventional catheter angiography as preoperative examination in the majority of regular-sized anterior circulation aneurysms. Nevertheless, surgeons should recognize and be prepared for the fact that 3D-CTA can give false impression about the aneurysm neck and

  7. Transvenous coronary angiography in humans with synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Thomlinson, W.

    1994-10-01

    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.

  8. 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

  9. On the possible role of stimulation duration for after-effects of transcranial alternating current stimulation

    OpenAIRE

    Stefan Rach; Toralf Neuling; Herrmann, Christoph S.

    2015-01-01

    Transcranial alternating current stimulation is a novel method that allows application of sinusoidal currents to modulate brain oscillations and cognitive processes. Studies in humans have demonstrated tACS after-effects following stimulation durations in the range of minutes. However, such after-effects are absent in animal studies using much shorter stimulation protocols in the range of seconds. Thus, stimulation duration might be a critical parameter for after-effects to occur. To test thi...

  10. On the Role of Global Magnetic Field Configuration in Affecting Ring Current Dynamics

    Science.gov (United States)

    Zheng, Y.; Zaharia, S. G.; Fok, M. H.

    2010-01-01

    Plasma and field interaction is one important aspect of inner magnetospheric physics. The magnetic field controls particle motion through gradient, curvature drifts and E cross B drift. In this presentation, we show how the global magnetic field affects dynamics of the ring current through simulations of two moderate geomagnetic storms (20 November 2007 and 8-9 March 2008). Preliminary results of coupling the Comprehensive Ring Current Model (CRCM) with a three-dimensional plasma force balance code (to achieve self-consistency in both E and B fields) indicate that inclusion of self-consistency in B tends to mitigate the intensification of the ring current as other similar coupling efforts have shown. In our approach, self-consistency in the electric field is already an existing capability of the CRCM. The magnetic self-consistency is achieved by computing the three-dimensional magnetic field in force balance with anisotropic ring current ion distributions. We discuss the coupling methodology and its further improvement. In addition, comparative studies by using various magnetic field models will be shown. Simulation results will be put into a global context by analyzing the morphology of the ring current, its anisotropy and characteristics ofthe interconnected region 2 field-aligned currents.

  11. Measurement of helicon wave coupling for current drive and anticipated role for high beta KSTAR plasmas

    Science.gov (United States)

    Wang, S. J.; Kim, H. J.; Joung, M.; Jeong, J. H.; Kim, J. H.; Bae, Y. S.; Kwak, J. G.; Wi, H. H.; Kim, H.-S.

    2015-11-01

    Helicon wave current drive has been suggested for efficient off-axis current drive in high electron beta tokamak plasmas. Fast wave drives centrally peaking current in the frequency range up to several ion cyclotron harmonics in the present tokamaks, such as KSTAR. Increasing fast wave frequency up to LH resonance frequency at the plasma edge, the spiral propagation of wave at the outer region of plasma lengthens the wave path to the plasma center. Also, optical thickness increases with frequency. It is expected that these effects produce efficient off-axis power deposition depending on the electron beta and magnetic field pitch. A low power TWA for helicon wave was installed and tested in KSTAR tokamak which is aiming for the steady-state high beta plasma requiring off-axis current drive. The power coupling properties of TWA at various plasma conditions will be presented. In addition to the coupling efficiency, issues such as load sensitivity and unwanted slow wave coupling will be addressed. Also, the simulation of plasma performance with the combination of helicon wave current drive and other conventional heating and current drive power in KSTAR will be discussed. This work was supported by the Korean Ministry of Science, ICT and Future Planning and by R&D Program through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

  12. Coronary computed tomography angiography and its increasing application in day to day cardiology practice.

    Science.gov (United States)

    Markham, R; Murdoch, D; Walters, D L; Hamilton-Craig, C

    2016-01-01

    Coronary artery disease (CAD) is the leading single cause of death in Australia affecting around 1.4 million people. Coronary computed tomography angiography has an established role in the assessment of patients with low to intermediate pretest probability for CAD who have chest pain and is typically used with the aim to rule out significant coronary artery stenosis. Use was initially limited because of concerns over radiation exposure, a Medicare rebate restricted to specialist referrals and an absence of data supporting its use as an alternative to functional testing in patients with chest pain. Recent advances in scanner technology and image sequencing, along with data from randomised control trials, have addressed these issues and indicate that coronary computed tomography angiography will play a greater role in the assessment of CAD in the coming years. PMID:26813899

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

    International Nuclear Information System (INIS)

    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.)

  14. 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.)

  15. Sausage instabilities in the electron current layer and its role in the concept of fast ignition

    International Nuclear Information System (INIS)

    The fast ignition concept of laser fusion utilizes hot electrons produced at the surface of the target by an incident intense laser pulse for the creation of the hot spot for ignition. As the hot electrons move inwards to the core of the precompressed target, the electrons from the background plasma provide a return shielding current. Three dimensional PIC simulations have shown that intense Weibel, tearing and coalescence instabilities take place which organize the current distribution into a few current filaments. In each of these filaments the central core region constitutes a current due to the fast electrons propagating inwards towards the pellet core, while the outer cylindrical shell region carries the return shielding current. The presence of instabilities and their subsequent nonlinear development can hinder the propagation of fast electrons towards the core influencing the location of the hot spot for ignition. Earlier studies showing the existence of sausage-like modes were carried out in the nonrelativistic limit and under the assumption of equal electron densities of the fast and the cold electrons. The fast electron density, in general, differs considerably from the background plasma density as it is dependent on the incident laser intensity. This paper incorporates relativistic effects and also studies the dependence of the growth rate on the fast electron density. Finally, nonlinear saturation of the instability and its impact on the stopping of the fast electron motion towards the core have also been investigated using numerical simulations. The simulations have, however, currently been carried out for non-relativistic dynamics. The results show that the sheared velocity profile of the channel gets flattened, causing an effective drop in the inward moving current. (author)

  16. Development of functional in vivo imaging of cerebral lenticulostriate artery using novel synchrotron radiation angiography

    International Nuclear Information System (INIS)

    The lenticulostriate artery plays a vital role in the onset and development of cerebral ischemia. However, current imaging techniques cannot assess the in vivo functioning of small arteries such as the lenticulostriate artery in the brain of rats. Here, we report a novel method to achieve a high resolution multi-functional imaging of the cerebrovascular system using synchrotron radiation angiography, which is based on spatio-temporal analysis of contrast density in the arterial cross section. This method provides a unique tool for studying the sub-cortical vascular elasticity after cerebral ischemia in rats. Using this technique, we demonstrated that the vascular elasticity of the lenticulostriate artery decreased from day 1 to day 7 after transient middle cerebral artery occlusion in rats and recovered from day 7 to day 28 compared to the controls (p < 0.001), which paralleled with brain edema formation and inversely correlated with blood flow velocity (p < 0.05). Our results demonstrated that the change of vascular elasticity was related to the levels of brain edema and the velocity of focal blood flow, suggesting that reducing brain edema is important for the improvement of the function of the lenticulostriate artery in the ischemic brain. (paper)

  17. 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.)

  18. Entanglement of two qubits coupled to an XY spin chain: Role of energy current

    International Nuclear Information System (INIS)

    We investigate the entanglement dynamics of a two-qubit system which interacts with a Heisenberg XY spin chain constrained to carry an energy current. We show an explicit connection between the decoherence factor and entanglement, and numerically and analytically study the dynamical process of entanglement in both weak- and strong-coupling cases for two initial states, the general pure state and the mixed Werner state. We provide results that the entanglement evolution depends not only on the energy current, the anisotropy parameter and the system-environment couplings but also on the size of degrees of freedom of environment. In particular, our results imply that entanglement will be strongly suppressed by the introduction of energy current on the environmental spin chain in the weak-coupling region while it is not sensitive to the energy current in the strong-coupling region. We also observe the sudden death of entanglement in the system and show how the energy current affects the phenomenon.

  19. On the role of collective interactions in asymmetric ring current formation

    Directory of Open Access Journals (Sweden)

    P. A. Bespalov

    Full Text Available The contribution of resonant wave-particle interactions to the formation and decay of the magnetospheric ring current is analysed in the framework of a self-consistent set of equations which take into account azimuthal plasmasphere asymmetry. It is shown that the cyclotron interaction of westward drifting energetic protons with Alfven waves in the evening-side plasmaspheric bulge region leads to the formation of a ring current asymmetry located near 18:00 MLT. The time-scale of this asymmetry is determined by the proton drift time through the plasmaspheric bulge and is about 1 - 3 h. A symmetrical ring current decays mainly due to charge exchange processes. The theory is compared with known experimental data on ions and waves in the ring current and on low-latitude magnetic disturbances. New low-latitude magnetometer data on the magnetic storm of 24 - 26 July 1986 are also discussed. The model presented explains the observed localization of an asymmetrical ring current loop in the evening sector and the difference in relaxation time-scales of the asymmetry and the Dst index. It also explains measured wave turbulence levels in the evening-side plasmasphere and wave observation statistics.

  20. 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.)

  1. Current Service Ideologies and Responses to Challenging Behaviour: Social Role Valorization or Vaporization?

    Science.gov (United States)

    Shaddock, A. J.; Zilber, D.

    1991-01-01

    This paper examines the principles underlying normalization and social role valorization with respect to the values and directions they offer service providers and the social structures they impose on individuals with disabilities who exhibit challenging behaviors. The paper argues that versions of normalization presented by Bengt Nirje and Wolf…

  2. Current role of anticholinergic drugs in the treatment of asthma : Key messages for clinical practice

    NARCIS (Netherlands)

    Pizzichini, Marcia M. M.; Kerstjens, Huib A. M.; Pizzichini, Emilio

    2015-01-01

    Anticholinergic bronchodilators such as tiotropium, a potent long-acting drug, are central to the symptomatic treatment of chronic obstructive pulmonary disease. Its role in asthma treatment has been recently investigated. This review critically evaluates documented evidence of clinical trials and a

  3. The Role of the Family in Genetic Testing: Theoretical Perspectives, Current Knowledge, and Future Directions

    Science.gov (United States)

    Peterson, Susan K.

    2005-01-01

    This article addresses conceptual challenges and theoretical approaches for examining the role of the family in responding and adapting to genetic testing for inherited conditions. Using a family systems perspective, family-based constructs that are relevant to genetic testing may be organized into three domains: family communication, organization…

  4. Recurrent massive bleeding due to dissecting intramural hematoma of the esophagus: Treatment with therapeutic angiography

    Institute of Scientific and Technical Information of China (English)

    Jaejun Shim; Jae Young Jang; Young Hwangbo; Seok Ho Dong; Joo Hyeong Oh; Hyo Jong Kim; Byung-Ho Kim; Young Woon Chang; Rin Chang

    2009-01-01

    Spontaneous or traumatic intramural bleeding of the esophagus, which is often associated with overlying mucosal dissection, constitutes a rare spectrum of esophageal injury called dissecting intramural hematoma of the esophagus (DIHE). Chest pain, swallowing difficulty, and minor hematemesis are common, which resolve spontaneously in most cases. This case report describes a patient with spontaneous DIHE with recurrent massive bleeding which required critical management and highlights a potential role for therapeutic angiography as an alternative to surgery.

  5. Role of Joule Heating on Current Saturation and Transient Behavior of Graphene Transistors

    Science.gov (United States)

    Islam, Sharnali; Li, Zuanyi; Dorgan, Vincent E.; Bae, Myung-Ho; Pop, Eric

    2013-02-01

    We use simulations to examine current saturation in sub-micron graphene transistors on SiO2/Si. We find self-heating is partly responsible for current saturation (lower output conductance), but degrades current densities >1 mA/um by up to 15%. Heating effects are reduced if the supporting insulator is thinned, or in shorter channel devices by partial heat sinking at the contacts. The transient behavior of such devices has thermal time constants of ~30-300 ns, dominated by the thickness of the supporting insulator and that of device capping layers (a behavior also expected in ultrathin body SOI transistors). The results shed important physical insight into the high-field and transient behavior of graphene transistors.

  6. Current-oriented swimming by jellyfish and its role in bloom maintenance.

    Science.gov (United States)

    Fossette, Sabrina; Gleiss, Adrian Christopher; Chalumeau, Julien; Bastian, Thomas; Armstrong, Claire Denise; Vandenabeele, Sylvie; Karpytchev, Mikhail; Hays, Graeme Clive

    2015-02-01

    Cross-flows (winds or currents) affect animal movements [1-3]. Animals can temporarily be carried off course or permanently carried away from their preferred habitat by drift depending on their own traveling speed in relation to that of the flow [1]. Animals able to only weakly fly or swim will be the most impacted (e.g., [4]). To circumvent this problem, animals must be able to detect the effects of flow on their movements and respond to it [1, 2]. Here, we show that a weakly swimming organism, the jellyfish Rhizostoma octopus, can orientate its movements with respect to currents and that this behavior is key to the maintenance of blooms and essential to reduce the probability of stranding. We combined in situ observations with first-time deployment of accelerometers on free-ranging jellyfish and simulated the behavior observed in wild jellyfish within a high-resolution hydrodynamic model. Our results show that jellyfish can actively swim countercurrent in response to current drift, leading to significant life-history benefits, i.e., increased chance of survival and facilitated bloom formation. Current-oriented swimming may be achieved by jellyfish either directly detecting current shear across their body surface [5] or indirectly assessing drift direction using other cues (e.g., magnetic, infrasound). Our coupled behavioral-hydrodynamic model provides new evidence that current-oriented swimming contributes to jellyfish being able to form aggregations of hundreds to millions of individuals for up to several months, which may have substantial ecosystem and socioeconomic consequences [6, 7]. It also contributes to improve predictions of jellyfish blooms' magnitude and movements in coastal waters. PMID:25619761

  7. Role of the rise rate of beam current in the microwave radiation of vircator

    Science.gov (United States)

    Li, Limin; Cheng, Guoxin; Zhang, Le; Ji, Xiang; Chang, Lei; Xu, Qifu; Liu, Lie; Wen, Jianchun; Li, Chuanlu; Wan, Hong

    2011-04-01

    In this paper, the effect of the rise rate of beam current on the microwave radiation of a virtual cathode oscillator (vircator) is presented. Interestingly, it was observed that the rise rate of the beam current increased as the pulse shot proceeded, which is accompanied by the decrease in microwave power. By comparing the experimental results of two cathode materials (carbon fiber and stainless steel), it was found that the above behavior is independent of the cathode materials. The ion flow, induced by the repetitive action of beam electrons with the anode grid, directly affects the development of beam current. A twice-increased process of ion flow was observed, and there are two factors involved in this process, namely, the reflection of electrons between the cathode and virtual cathode and the effect of one-time bombardment of electron beam. After the irradiation of pulsed electron beam, some microprotrusions toward the cathode appeared on the anode surface, with a quasiperiodic structure. The appearance of ion flow, as the anode plasma forms, increases the beam current and enhances the beam current density. The anode plasma is generated relatively easily as the shot test proceeds, due to the aging of anode grid, which allows the possibility of the decrease in the microwave power. As the pulse shot proceeds, the changes in the rise rate of beam current are closely related to the aging process of anode surface. Therefore, the further enhancement of vircator efficiency needs to lengthen the lifetime of anode, besides the optimization of explosive emission cathodes.

  8. The role of the sodium current complex in a nonreferred nationwide cohort of sudden infant death syndrome

    DEFF Research Database (Denmark)

    Winkel, Bo Gregers; Yuan, Lei; Olesen, Morten S.;

    2015-01-01

    of this study was to investigate the role of the sodium current complex in a nonreferred nationwide cohort of SIDS cases. METHODS: DNA was extracted from dried blood spot samples from the Danish Neonatal Screening Biobank. In total, 66 non-referred SIDS cases born in Denmark in the period of 2000...... significance. SCN5A R1193Q and GPD1L R220H (both considered variants of unknown significance) were present in the same infant. Functional analysis of variants not previously characterized (R458C, S1609L, and Q1909R in SCN5A) predominantly revealed increased transient and sustained sodium current. CONCLUSION...

  9. Wide-field optical coherence tomography angiography enabled by two repeated measurements of B-scans.

    Science.gov (United States)

    Wang, Ruikang K; Zhang, Anqi; Choi, Woo June; Zhang, Qinqin; Chen, Chieh-Li; Miller, Andrew; Gregori, Giovanni; Rosenfeld, Philip J

    2016-05-15

    Optical coherence tomography angiography (OCTA) has increasingly become clinically important, particularly in ophthalmology. However, the field of view (FOV) for current OCTA imaging is severely limited due to A-scan rates that can be afforded by current clinical systems and, more importantly, the requirement of a repeated scanning protocol. This Letter evaluates the possibility of using only two repeated B-scans for OCTA for the purpose of an increased FOV. The effect of repeated numbers on the OCTA result is discussed through experiments on an animal model in vivo and evaluated using quantitative metrics for image quality. Demonstrated through in vivo imaging of a pathological human eye, we show that optical microangiography-based OCTA with two repeated B-scans can provide wide-field angiography up to 12×12  mm with clinically acceptable image quality. PMID:27176995

  10. On the role of the current loss in radio pulsar evolution

    CERN Document Server

    Beskin, V S

    2006-01-01

    The aim of this article is to draw attention to the importance of the electric current loss in the energy output of radio pulsars. We remind that even the losses attributed to the magneto-dipole radiation of a pulsar in vacuum can be written as a result of an Ampere force action of the electric currens flowing over the neutron star surface (Michel, 1991, Beskin et al., 1993). It is this force that is responsible for the transfer of angular momentum of a neutron star to an outgoing magneto-dipole wave. If a pulsar is surrounded by plasma, and there is no longitudinal current in its magnetosphere, there is no energy loss (Beskin et al., 1993, Mestel et al., 1999). It is the longitudinal current closing within the pulsar polar cap that exerts the retardation torque acting on the neutron star. This torque can be determined if the structure of longitudinal current is known. Here we remind of the solution by Beskin, Gurevitch & Istomin (1993) and discuss the validity of such an assumption. The behavior of the r...

  11. The Roles of Artificial Intelligence in Education: Current Progress and Future Prospects

    Science.gov (United States)

    McArthur, David; Lewis, Matthew; Bishary, Miriam

    2005-01-01

    This report begins by summarizing current applications of ideas from artificial intelligence (Al) to education. It then uses that summary to project various future applications of Al--and advanced technology in general--to education, as well as highlighting problems that will confront the wide­ scale implementation of these technologies in the…

  12. Neutral beam heating and current drive system and its role in ITER-FEAT operation scenarios

    International Nuclear Information System (INIS)

    The NB H and CD system, providing 33 MW in deuterium beams at 1 MeV from two injectors, in addition to 40 MW RF power, contributes to heating a plasma to sub-ignition through the L-H mode transition followed by finite-Q driven-burn (Q≥10), and achievement of a hybrid operation with an extended-duration (∼1000 s) or steady-state operation with Q≤5. To achieve such operations, the NB provides non-inductive current drive by injecting the beams tangentially into the plasma with the capability of on- and off-axis current drive. The present engineering design is under the constraints of the beam envelope, vacuum confinement, neutron shielding, tolerances, and clearances required with the toroidal field coils. The on- and off-axis current drive is to be achieved by tilting the beam axis vertically. Each beam axis of the NB injectors can be tilted independently, providing flexibility in the control of heating and the driven current profile. (author)

  13. Current views on the role of Notch signaling and the pathogenesis of human leukemia

    Directory of Open Access Journals (Sweden)

    Pancewicz Joanna

    2011-11-01

    Full Text Available Abstract The Notch signaling pathway is highly conserved from Drosophila to humans and plays an important role in the regulation of cellular proliferation, differentiation and apoptosis. Constitutive activation of Notch signaling has been shown to result in excessive cellular proliferation and a wide range of malignancies, including leukemia, glioblastoma and lung and breast cancers. Notch can also act as a tumor suppressor, and its inactivation has been associated with an increased risk of spontaneous squamous cell carcinoma. This minireview focuses on recent advances related to the mechanisms and roles of activated Notch1, Notch2, Notch3 and Notch4 signaling in human lymphocytic leukemia, myeloid leukemia and B cell lymphoma, as well as their significance, and recent advances in Notch-targeted therapies.

  14. Current concepts in the pathophysiology of fibromyalgia: the potential role of oxidative stress and nitric oxide.

    Science.gov (United States)

    Ozgocmen, Salih; Ozyurt, Huseyin; Sogut, Sadik; Akyol, Omer

    2006-05-01

    Fibromyalgia (FM) is a common chronic pain syndrome with an unknown etiology. Recent years added new information to our understanding of FM pathophysiology. Researches on genetics, biogenic amines, neurotransmitters, hypothalamic-pituitary-adrenal axis hormones, oxidative stress, and mechanisms of pain modulation, central sensitization, and autonomic functions in FM revealed various abnormalities indicating that multiple factors and mechanisms are involved in the pathogenesis of FM. Oxidative stress and nitric oxide may play an important role in FM pathophysiology, however it is still not clear whether oxidative stress abnormalities documented in FM are the cause or the effect. This should encourage further researches evaluating the potential role of oxidative stress and nitric oxide in the pathophysiology of FM and the efficacy of antioxidant treatments (omega-3 and -6 fatty acids, vitamins and others) in double blind and placebo controlled trials. These future researches will enhance our understanding of the complex pathophysiology of this disorder. PMID:16328420

  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 Role of Education in Economic Development: Theory, History, and Current Returns

    OpenAIRE

    Theodore Breton

    2012-01-01

    Background This paper was prepared to contribute to a special issue on the value of education. Purpose The paper examines the role of education in economic development from both a theoretical and a historic perspective, addresses why education has been the limiting factor determining development historically, discusses why certain countries have provided education to the masses and others have not, provides estimates of the quantitative importance of the direct and indirect effects of educati...

  17. Current opinion on the role of testosterone in the development of prostate cancer: a dynamic model

    OpenAIRE

    Xu, Xiaohui; Chen, Xinguang (Jim); Hu, Hui; Dailey, Amy B.; Taylor, Brandie D.

    2015-01-01

    Background Since the landmark study conducted by Huggins and Hodges in 1941, a failure to distinguish between the role of testosterone in prostate cancer development and progression has led to the prevailing opinion that high levels of testosterone increase the risk of prostate cancer. To date, this claim remains unproven. Presentation of the hypothesis We present a novel dynamic mode of the relationship between testosterone and prostate cancer by hypothesizing that the magnitude of age-relat...

  18. Role of government in public health: Current scenario in India and future scope

    OpenAIRE

    Subitha Lakshminarayanan

    2011-01-01

    The new agenda for Public Health in India includes the epidemiological transition, demographical transition, environmental changes and social determinants of health. Based on the principles outlined at Alma-Ata in 1978, there is an urgent call for revitalizing primary health care in order to meet these challenges. The role of the government in influencing population health is not limited within the health sector but also by various sectors outside the health systems. This article is a literat...

  19. Book Review: Siroj Sorajjakool: Human Trafficking in Thailand: Current Issues, Trends and the Role of the Thai Government

    OpenAIRE

    Manassinee Moottatarn

    2014-01-01

    Book Review of the Monograph: Siroj Sorajjakool (2013), Human Trafficking in Thailand: Current Issues, Trends and the Role of the Thai Government. Chiang Mai, Thailand: Silkworm Books, ISBN: 978-616-215-060-9, 235 pages. Human trafficking is not widely reported in local Thai news, and news of it is often only picked up by international correspondents. The extent of this problem has only started to reveal itself as a widespread problem in the kingdom.

  20. Perception of community pharmacists toward their current professional role in the healthcare system of Dubai, United Arab Emirates

    OpenAIRE

    Rayes, Ibrahim Khalid; Hassali, Mohamed Azmi; Abduelkarem, Abduelmula R

    2014-01-01

    The new paradigm to pharmacy profession has changed the focus of pharmacists from product-centered to patient-oriented. This change has brought new set of beliefs and assumptions on the way services should be delivered to pharmacy clients. The main aim of this study was to explore the perception of community pharmacists on their current professional role in Dubai. Key findings show that community pharmacists are more directed toward business than patients. They almost dispense all categories ...

  1. Book Review: Siroj Sorajjakool: Human Trafficking in Thailand: Current Issues, Trends and the Role of the Thai Government

    Directory of Open Access Journals (Sweden)

    Manassinee Moottatarn

    2014-01-01

    Full Text Available Book Review of the Monograph: Siroj Sorajjakool (2013, Human Trafficking in Thailand: Current Issues, Trends and the Role of the Thai Government. Chiang Mai, Thailand: Silkworm Books, ISBN: 978-616-215-060-9, 235 pages. Human trafficking is not widely reported in local Thai news, and news of it is often only picked up by international correspondents. The extent of this problem has only started to reveal itself as a widespread problem in the kingdom.

  2. 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.

  3. Assessment of anemia during CT pulmonary angiography

    International Nuclear Information System (INIS)

    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.

  4. 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.

  5. Integral diagnosis of coronary atherosclerosis by coronary multidetector computed tomography and by invasive coronary angiography

    International Nuclear Information System (INIS)

    Coronary angiography by multidetector computed tomography (CMDCT) visualizes the wall and lumen of coronary arteries. Invasive coronary angiography (INVCA) only visualizes the arterial lumen but with better resolution

  6. Digital subtraction angiography in cardiac diseases

    International Nuclear Information System (INIS)

    DSA was done in 133 examinations of 128 patients during 2 years consist of 9 examination of IV DSA and 124 examination of selective cardiac DSA after cardiac catheterization. Open heart surgery was performed in 90 patients and 12 patients showed discrepancy between pre-and post operative diagnosis, showing a total 86.7% of diagnostic accuracy with DSA. We experienced the significant reduction in dose of contrast media, 30-40% of dose of conventional cardiac angiography. It is concluded that DSA is useful in the evaluation of septal defects, valvular disease and other congenital heart disease. DSA is an accurate simple and safe method in evaluating of cardiac diseases.

  7. 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

  8. Multidetector computed tomography angiography of the abdomen

    International Nuclear Information System (INIS)

    Multidetector computed tomography (MDCT) angiography has provided excellent opportunities for advancement of computed tomography (CT) technology and clinical applications. It has a wide range of applications in the abdomen including vascular pathologies either occlusive or aneurysmal; enables the radiologist to produce vascular mapping that clearly show tumor invasion of vasculature and the relationship of vessels to mass lesions. MDCTA can be used in preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation. MDCTA can also provide extremely valuable information in the evaluation of ischemic bowel disease, active Crohn disease, the extent and location of collateral vessels in cirrhosis

  9. High flow run-off angiography

    International Nuclear Information System (INIS)

    In this paper we investigated an improved technique for conventional run-off angiography. With this method only five (with the shortest KDT's) to ten 14-inch cut films are required for the entire abdominal and run-off study, which results in a reduction in film cost. Several authors report estimation of blood flow velocity by observing a hand injected test dose in the aorta or at the knee level on one or both sides, but they have not provided a quantitative analysis. In our study the knee delay time was determined using the power injector and DSA facilities for better accuracy. (orig./MG)

  10. Pain and hemodynamic effects in aortofemoral angiography

    International Nuclear Information System (INIS)

    Two new contrast media, iohexol (non-ionic monomer) and ioxaglate (monoacidic dimer), were compared with the non-ionic metrizamide during aortofemoral angiography in a single blind randomized trial in 2 groups of patients with 20 in each. The degree of heat and pain produced by iohexol and ioxaglate did not differ significantly from that produced by metrizamide, while subsequent injections of metrizoate caused significantly more heat and pain. The hemodynamic effects recorded in 10 patients in each group showed that iohexol and ioxaglate induced a decrease in vascular resistance, decrease in blood pressure and increase in heart rate not differing significantly from that induced by metrizamide. (Auth.)

  11. Current rectification in a single molecule diode: the role of electrode coupling

    OpenAIRE

    Sherif, Siya; Rubio-Bollinger, G.; Pinilla-Cienfuegos, E.; Coronado, E.; Cuevas, J. C.; Agrait, Nicolas

    2015-01-01

    We demonstrate large rectification ratios (> 100) in single-molecule junctions based on a metal-oxide cluster (polyoxometalate), using a scanning tunneling microscope (STM) both at ambient conditions and at low temperature. These rectification ratios are the largest ever observed in a single-molecule junction, and in addition these junctions sustain current densities larger than 10^5 A/cm^2. By following the variation of the I-V characteristics with tip-molecule separation we demonstrate unam...

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

    Science.gov (United States)

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

    2016-08-01

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

  13. Role of spin diffusion in current-induced domain wall motion for disordered ferromagnets

    KAUST Repository

    Akosa, Collins Ashu

    2015-03-12

    Current-induced spin transfer torque and magnetization dynamics in the presence of spin diffusion in disordered magnetic textures is studied theoretically. We demonstrate using tight-binding calculations that weak, spin-conserving impurity scattering dramatically enhances the nonadiabaticity. To further explore this mechanism, a phenomenological drift-diffusion model for incoherent spin transport is investigated. We show that incoherent spin diffusion indeed produces an additional spatially dependent torque of the form ∼∇2[m×(u⋅∇)m]+ξ∇2[(u⋅∇)m], where m is the local magnetization direction, u is the direction of injected current, and ξ is a parameter characterizing the spin dynamics (precession, dephasing, and spin-flip). This torque, which scales as the inverse square of the domain wall width, only weakly enhances the longitudinal velocity of a transverse domain wall but significantly enhances the transverse velocity of vortex walls. The spatial-dependent spin transfer torque uncovered in this study is expected to have significant impact on the current-driven motion of abrupt two-dimensional textures such as vortices, skyrmions, and merons.

  14. The Current and Evolving Role of PET in Personalized Management of Lung Cancer.

    Science.gov (United States)

    Mena, Esther; Yanamadala, Anusha; Cheng, Gang; Subramaniam, Rathan M

    2016-07-01

    Using tumor genomic profiling information has revolutionized the landscape of personalized treatment of lung cancer. The management of lung cancer and non-small cell lung cancer particularly is influenced by discoveries of activating mutations in epidermal growth factor receptor and targeted therapies with tyrosine kinase inhibitors, fusion genes involving anaplastic lymphoma kinase, and targeted therapies for Kristen-Rat-Sarcoma and MET protooncogenes. PET imaging plays an important role in assessing the biologic behavior of lung cancer and defining response to therapy. This review summarizes genomic discoveries in lung cancer and their implications for functional PET imaging. PMID:27321029

  15. The Current Role of Venous Sampling in the Localization of Endocrine Disease

    International Nuclear Information System (INIS)

    Endocrine venous sampling plays a specific role in the diagnosis of endocrine disorders. In this article, we cover inferior petrosal sinus sampling, selective parathyroid venous sampling, hepatic venous sampling with arterial stimulation, adrenal venous sampling, and ovarian venous sampling. We review their indications and the scientific evidence justifying these indications in the diagnosis and management of Cushing's syndrome, hyperparathyroidism, pancreatic endocrine tumors, Conn's syndrome, primary hyperaldosteronism, pheochromocytomas, and androgen-secreting ovarian tumors. For each sampling technique, we compare its diagnostic accuracy with that of other imaging techniques and, where possible, look at how it impacts patient management. Finally, we incorporate venous sampling into diagnostic algorithms used at our institution

  16. 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

  17. 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.

  18. Data acquisition for pediatric CT angiography: problems and solutions

    International Nuclear Information System (INIS)

    With appropriate attention to the technical aspects, excellent CT angiography can be obtained even in young infants. In this article, we will present the problems inherent with pediatric CT angiography and offer solutions that minimize or eliminate these difficulties. In addition, a literature review of specific pediatric applications is provided. (orig.)

  19. 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.

  20. 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...

  1. Pulmonary arteriovenous fistula: detection with magnetic resonance angiography

    International Nuclear Information System (INIS)

    Pulmonary arteriovenous fistula are an uncommon disorder, and are most frequently congenital, usually then associated with hereditary hemorrhagic telangectasia (Rendu-Osler-Weber disease). We present, to our knowledge, the first case of a pulmonary arteriovenous fistula detected by gadolinium-enhanced pulmonary magnetic resonance angiography and confirmed by digital subtraction pulmonary angiography in a patient where the CT scan was unremarkable. (orig.) (orig.)

  2. 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

  3. The role of epidemiology in MS research: Past successes, current challenges and future potential.

    Science.gov (United States)

    Simpson, Steve; Taylor, Bruce V; van der Mei, Ingrid

    2015-07-01

    Multiple sclerosis (MS) is a multifaceted condition, with a range of environmental, behavioural and genetic factors implicated in its aetiology and clinical course. Successes in advancing our appreciation of the roles of Epstein-Barr virus, vitamin D/UV and the HLA-DRB1 locus; and our greater understanding of these and related factors' modes of action in MS and other conditions, can be attributed in no small part to the work of generations of epidemiologists. Hardly content to rest on our laurels, however, there are yet a range of unsolved conundrums in MS, including some changes in epidemiological characteristics (e.g. increasing incidence and sex ratio), to say nothing of the unresolved parts regarding what underlies MS risk and its clinical course. There is evidence that epidemiology will continue to play a crucial role in unravelling the architecture of MS causation and clinical course. While classic epidemiological methods are ongoing, novel avenues for research include gene-environment interaction studies, the world of '-omic' research, and the utilisation of mobile and social media tools to both access and track study populations, which means that the epidemiological discoveries of the past century may be but a glimpse of our understanding in the next few decades. PMID:25767125

  4. Current role of capillary electrophoretic/electrokinetic techniques in forensic toxicology.

    Science.gov (United States)

    Tagliaro, Franco; Bortolotti, Federica; Pascali, Jennifer P

    2007-08-01

    The current application of capillary electrophoresis in forensic toxicology has been critically reviewed with special focus on the areas where this technique has shown real advantages over chromatographic methods. For example, capillary electrophoresis has been most successfully applied to the chiral analysis of some drugs of forensic interest, including amphetamines and their congeners. Another typical application field of capillary electrophoresis is represented by protein analysis. Recently, special interest has been paid to carbohydrate deficient transferrin (CDT), the most important biological marker of chronic alcohol abuse. Other specific applications of capillary electrophoresis of potential forensic toxicological concern are also discussed. The review includes 62 references. PMID:17572886

  5. The Current Role of Three-Dimensional Printing in Plastic Surgery.

    Science.gov (United States)

    Kamali, Parisa; Dean, David; Skoracki, Roman; Koolen, Pieter G L; Paul, Marek A; Ibrahim, Ahmed M S; Lin, Samuel J

    2016-03-01

    Since the advent of three-dimensional printing in the 1980s, it has become possible to produce physical objects from digital files and create three-dimensional objects by adding one layer at a time following a predetermined pattern. Because of the continued development of inexpensive and easy-to-use three-dimensional printers and bioprinting, this technique has gained more momentum over time, especially in the field of medicine. This article reviews the current and possible future application of three-dimensional printing technology within the field of plastic and reconstructive surgery. PMID:26910689

  6. The role of mesoscale eddies in the source regions of the Agulhas Current

    OpenAIRE

    Biastoch, Arne; Krauß, Wolfgang

    1999-01-01

    A primitive equation model to study the dynamics of the Agulhas system has been developed. The model domain covers the South Atlantic and the south Indian Ocean with a resolution of ⅓° in the Agulhas region while coarser outside. It is driven by a climatology of the European Centre for Medium-Range Weather Forecasts. It is shown that the model simulates the Agulhas Current, its retroflection, and the ring shedding successfully. The model results show baroclinic anticyclonic eddies in the Moza...

  7. Current role of non-anesthesiologist administered propofol sedation in advanced interventional endoscopy

    DEFF Research Database (Denmark)

    Burtea, Daniela Elena; Dimitriu, Anca; Maloş, Anca Elena;

    2015-01-01

    the patients and medical personnel. Current guidelines support the use of propofol sedation, which has the same rate of adverse effects as traditional sedation with benzodiazepines and/or opioids, but decreases the procedural and recovery time. Non-anesthesiologist administered propofol sedation has become...... an option in most of the countries, due to limited anesthesiology resources and the increasing evidence from prospective studies and meta-analyses that the procedure is safe with a similar rate of adverse events with traditional sedation. The advantages include a high quality of endoscopic examination...

  8. Two years of angiography without a film changer

    International Nuclear Information System (INIS)

    A prototype digital angiography system has been utilized exclusively for the past 2 years in more than 1,500 patients undergoing general vascular radiology at our 650-bed tertiary case hospital. The prototype system includes a 14-inch fiberoptic image intensifier, a high-resolution video camera, and a Trapix image processor. The authors acquire sixteen 1,024 x 1,024 nonsubtracted images at a rate as fast as three and three-quarters images per second. The stored images can undergo subtration and other postprocessing functions. A direct digital interface to a laser printer provides high-resolution hard copy. The authors have shown by a comparison study that digital angiography affords considerable savings in time and cost over conventional film angiography. Based on their experience, digital angiography can replace a film changer for general angiography

  9. On the possible role of stimulation duration for after-effects of transcranial alternating current stimulation

    Directory of Open Access Journals (Sweden)

    Stefan Rach

    2015-08-01

    Full Text Available Transcranial alternating current stimulation is a novel method that allows application of sinusoidal currents to modulate brain oscillations and cognitive processes. Studies in humans have demonstrated tACS after-effects following stimulation durations in the range of minutes. However, such after-effects are absent in animal studies using much shorter stimulation protocols in the range of seconds. Thus, stimulation duration might be a critical parameter for after-effects to occur. To test this hypothesis, we repeated a recent human tACS experiment with a short duration. We applied alpha tACS intermittently for one second duration while keeping other parameters identical. The results demonstrate that this very short intermittent protocol did not produce after-effects on amplitude or phase of the electroencephalogram. Since synaptic plasticity has been suggested as a possible mechanism for after-effects, our results indicate that a stimulation duration of one second is too short to induce synaptic plasticity. Future studies in animals are required that use extended stimulation durations to reveal the neuronal underpinnings. A better understanding of the mechanisms of tACS after-effects is crucial for potential clinical applications.

  10. The Role of Direct Current Electric Field-Guided Stem Cell Migration in Neural Regeneration.

    Science.gov (United States)

    Yao, Li; Li, Yongchao

    2016-06-01

    Effective directional axonal growth and neural cell migration are crucial in the neural regeneration of the central nervous system (CNS). Endogenous currents have been detected in many developing nervous systems. Experiments have demonstrated that applied direct current (DC) electric fields (EFs) can guide axonal growth in vitro, and attempts have been made to enhance the regrowth of damaged spinal cord axons using DC EFs in in vivo experiments. Recent work has revealed that the migration of stem cells and stem cell-derived neural cells can be guided by DC EFs. These studies have raised the possibility that endogenous and applied DC EFs can be used to direct neural tissue regeneration. Although the mechanism of EF-directed axonal growth and cell migration has not been fully understood, studies have shown that the polarization of cell membrane proteins and the activation of intracellular signaling molecules are involved in the process. The application of EFs is a promising biotechnology for regeneration of the CNS. PMID:27108005

  11. Status of High Latitude Precipitation Estimates: The Role of GPM in Advancing our Current Understanding

    Science.gov (United States)

    Behrangi, A.; Richardson, M.; Christensen, M.; Huffman, G. J.; Adler, R. F.; Stephens, G. L.; Lambrigtsen, B.

    2015-12-01

    This presentation reviews the current status of precipitation estimation from observation and reanalysis at high latitudes and discusses new insights gained by GPM. An intercomparison of high-latitude precipitation characteristics from observation-based and reanalysis products is performed. Precipitation products from GPM and the cloud profiling radar on the CloudSat satellite provide an independent assessment to other products which have already been widely used, these being the observationally-based GPCP, GPCC and CMAP and the reanalyses ERA-Interim, MERRA and NCEP-DOE. Seasonal and annual total precipitation in both hemispheres poleward of 55° latitude is considered in all products, and GPM and CloudSat products are used to assess frequency of precipitation occurrence by phase, defined as rain, snow or mixed phase. Estimates of snowfall over Antarctica and Greenland are compared from various products. A number of disagreements on regional or seasonal scales are identified which will be reported and discussed. These estimates from observations and reanalyses provide useful insights for diagnostic assessment of precipitation products in high latitudes, quantifying the current uncertainties among observations and reanalyses, and establishing a benchmark for assessment of climate models.

  12. The role of stents in the treatment of congenital heart disease: Current status and future perspectives

    International Nuclear Information System (INIS)

    Intravascular or intracardiac stenoses occur in many forms of congenital heart disease (CHD). Therefore, the implantation of stents has become an accepted interventional procedure for stenotic lesions in pediatric cardiology. Furthermore, stents are know to be used to exclude vessel aneurysm or to ensure patency of existing or newly created intracardiac communications. With the further refinement of the first generation of devices, a variety of “modern” stents with different design characteristics have evolved. Despite the tremendous technical improvement over the last 20 years, the “ideal stent” has not yet been developed. Therefore, the pediatric interventionalist has to decide which stent is suitable for each lesion. On this basis, currently available stents are discussed in regard to their advantages and disadvantages for common application in CHD. New concepts and designs developed to overcome some of the existing problems, like the failure of adaptation to somatic growth, are presented. Thus, in the future, biodegradable or growth stents might replace the currently used generation of stents. This might truly lead to widening indications for the use of stents in the treatment of CHD

  13. The emerging role of bexarotene in the treatment of Alzheimer’s disease: current evidence

    Directory of Open Access Journals (Sweden)

    Tousi B

    2015-02-01

    Full Text Available Babak Tousi Cleveland Clinic Lou Ruvo Center for Brian Health, Neurological Institute, Cleveland, OH, USA Abstract: In 2012, a novel approach to the treatment of Alzheimer’s disease was introduced, heralding a wave of excitement in the field of dementia. Bexarotene, a retinoid X receptor agonist, was shown to reverse neurodegeneration, improve cognition, and decrease levels of amyloid-ß in transgenic mice expressing familial Alzheimer disease mutations. Since then, there has been widespread discussion about bexarotene, as well as a number of follow-up studies. Bexarotene is a unique compound, as it is approved by the US Food and Drug Administration for other purposes and there are reasonable data to justify its mechanism of action in dementia. This review discusses these studies and the emerging role of bexarotene in the clinical field of Alzheimer’s dementia. Keywords: repurposing, ApoE-targeted mice, amyloid, therapy, dementia

  14. The food industry's current and future role in preventing microbial foodborne illness within the United States.

    Science.gov (United States)

    Doyle, Michael P; Erickson, Marilyn C; Alali, Walid; Cannon, Jennifer; Deng, Xiangyu; Ortega, Ynes; Smith, Mary Alice; Zhao, Tong

    2015-07-15

    During the past century, the microbiological safety of the US food supply has improved; however, many foodborne illnesses and outbreaks occur annually. Hence, opportunities for the food industry to improve the safety of both domestic and imported food exist through the adoption of risk-based preventive measures. Challenging food safety issues that are on the horizon include demographic changes to a population whose immune system is more susceptible to foodborne and opportunistic pathogens, climate changes that will shift where food is produced, and consumers' preferences for raw and minimally processed foods. Increased environmental and product testing and anonymous data sharing by the food industry with the public health community would aid in identifying system weaknesses and enabling more targeted corrective and preventive actions. Clinicians will continue to play a major role in reducing foodborne illnesses by diagnosing and reporting cases and in helping to educate the consumer about food safety practices. PMID:25824814

  15. SGLT 2 Inhibitors: A New Therapeutic Target And Its Role In Current Clinical Practice

    Directory of Open Access Journals (Sweden)

    PV Shiji

    2015-10-01

    Full Text Available Diabetes, one of the major life style diseases, is associated with high morbidity and mortality owing to its microvascular and macrovascular complications. The chance of development of various complications can be effectively prevented by tight glycemic control. We have various groups of drugs like Biguanides, Sulfonyl ureas, Glitazones, Alpha-glucosidase inhibitors, Incretin based therapy, Insulin and Insulin analogues in the armamentarium to treat diabetes. But still, the number of patients attaining glycemic targets are relatively low and various adverse effect limit the use of some of these drugs, especially in special groups. Hence there is ongoing research to develop newer and newer drugs which provide sustained blood glucose reduction with minimal adverse effects. SGLT-2 inhibitors are a new group of drugs recently approved by FDA to treat Diabetes. In this review we discuss about mechanism of action, various adverse effects and the clinical role of various SGLT-2 Inhibitors.

  16. The role of ultrasound elastographic techniques in chronic liver disease: Current status and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Piscaglia, Fabio, E-mail: fabio.piscaglia@unibo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Marinelli, Sara, E-mail: sara_marinelli@libero.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Bota, Simona, E-mail: bota_simona1982@yahoo.com [Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy “Victor Babeş”, Timişoara (Romania); Serra, Carla, E-mail: carla.serra@aosp.bo.it [Division of Medical Liver Transplant Care, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Venerandi, Laura, E-mail: laura.venerandi@gmail.com [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Leoni, Simona, E-mail: leonisimona@yahoo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Salvatore, Veronica, E-mail: veronica.salvatore@unibo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy)

    2014-03-15

    This review illustrates the state of the art clinical applications and the future perspectives of ultrasound elastographic methods for the evaluation of chronic liver diseases, including the most widely used and validated technique, transient elastography, followed by shear wave elastography and strain imaging elastography. Liver ultrasound elastography allows the non-invasive evaluation of liver stiffness, providing information regarding the stage of fibrosis, comparable to liver biopsy which is still considered the gold standard; in this way, it can help physicians in managing patients, including the decision as to when to start antiviral treatment. The characterization of focal liver lesions and the prognostic role of the elastographic technique in the prediction of complications of cirrhosis are still under investigation.

  17. The role of ultrasound elastographic techniques in chronic liver disease: Current status and future perspectives

    International Nuclear Information System (INIS)

    This review illustrates the state of the art clinical applications and the future perspectives of ultrasound elastographic methods for the evaluation of chronic liver diseases, including the most widely used and validated technique, transient elastography, followed by shear wave elastography and strain imaging elastography. Liver ultrasound elastography allows the non-invasive evaluation of liver stiffness, providing information regarding the stage of fibrosis, comparable to liver biopsy which is still considered the gold standard; in this way, it can help physicians in managing patients, including the decision as to when to start antiviral treatment. The characterization of focal liver lesions and the prognostic role of the elastographic technique in the prediction of complications of cirrhosis are still under investigation

  18. Role of Plants in a Constructed Wetland: Current and New Perspectives

    Directory of Open Access Journals (Sweden)

    Amit Gross

    2013-04-01

    Full Text Available The role of plants in the treatment of effluents by constructed wetland (CW systems is under debate. Here, we review ways in which plants can affect CW processes and suggest two novel functions for plants in CWs. The first is salt phytoremediation by halophytes. We have strong evidence that halophytic plants can reduce wastewater salinity by accumulating salts in their tissues. Our studies have shown that Bassia indica, a halophytic annual, is capable of salt phytoremediation, accumulating sodium to up to 10% of its dry weight. The second novel use of plants in CWs is as phytoindicators of water quality. We demonstrate that accumulation of H2O2, a marker for plant stress, is reduced in the in successive treatment stages, where water quality is improved. It is recommended that monitoring and management of CWs consider the potential of plants as phytoremediators and phytoindicators.

  19. On imaging exactness in digital subtraction angiography

    International Nuclear Information System (INIS)

    In digital subtraction angiography (DSA), the spatial resolution capacity is considerably influenced by the concentration of contrast medium. Studies in vascular models showed that in intravenous DSA (IV-DSA) the concentrations of contrast medium are not sufficient to depict minor lesions of the vascular walls. Under the conditions of intraarterial DSA (IA-DSA), the imaging exactness increases considerably. Minimal lesions may rather be detected in front or rear walls than in the marginal parts of the vessels. This is the field in which digital and conventional angiography differ considerably. In pulsating vessels, imaging quality requires the greatest possible difference between the video signal of the applied contrast medium and the noise of the motion artifact. Whereas in IV-DSA minor alterations of the vascular wall are masked by pulsatory movements, the increased concentrations of contrast medium used in IA-DSA are sufficient for detecting e.g. membrane stenoses of 1 mm breadth. Nonionic contrast media differ from conventional contrast media, among other things, by their increased viscosity. This causes flow artifacts which are less marked if the contrast medium is diluted to values usual in IA-DSA. (orig./HP)

  20. Radionuclide angiography in unilateral nonfocal renal disease

    Energy Technology Data Exchange (ETDEWEB)

    Aburano, Tamio; Takayama, Teruhiko; Nakajima, Kenichi; Tada, Akira; Michigishi, Takatoshi; Tonami, Norihisa; Hisada, Kinichi

    1984-12-01

    A total of 90 patients with unilateral nonfocal renal disease (58 patients with obstructive uropathy, 13 patients with renal artery stenosis, 13 patients with chronic pyelonephritis, 3 patients with renal tuberculosis and 3 patients with a- or hypogenesis) were examined with the method of serial dynamic imaging of Tc-99m DTPA including radionuclide angiography. And the diagnostic significance of renal perfusion abnormality on radionuclide angiogram was qualitatively evaluated compared to that of renoparenchymal uptake abnormality on the image from one min. to four min. after intravenous administration of Tc-99m DTPA. In fifty-nine out of 90 patients (65%) with unilateral nonfocal renal disease, both perfusion and parenchymal uptake abnormalities were found at the involved side. In two of 13 patients with renal artery stenosis, however, the unilateral hypoperfusion was only found as the evidence of unilateral disease on radionuclide angiogram although these did not show any parenchymal uptake abnormality. Moreover, four out of 58 patients with obstructive uropathy, did show the slight difference of renal perfusion between the involved and the univolved sides. and did not show any difference of parenchymal uptake between both sides. In the present study, the incidence of perfusion abnormality on radionuclide angiogram was slightly higher than that of parenchymal uptake abnormality on the image from one min. to four min. in unilateral renal disease. Therefore, it is suggested that the radionuclide angiography may be accepted as one of the routine nuclear medicine imagings for the evaluation of functional abnormalities in nonfocal renal disease. (author).

  1. Radionuclide angiography in unilateral nonfocal renal disease

    International Nuclear Information System (INIS)

    A total of 90 patients with unilateral nonfocal renal disease (58 patients with obstructive uropathy, 13 patients with renal artery stenosis, 13 patients with chronic pyelonephritis, 3 patients with renal tuberculosis and 3 patients with a- or hypogenesis) were examined with the method of serial dynamic imaging of Tc-99m DTPA including radionuclide angiography. And the diagnostic significance of renal perfusion abnormality on radionuclide angiogram was qualitatively evaluated compared to that of renoparenchymal uptake abnormality on the image from one min. to four min. after intravenous administration of Tc-99m DTPA. In fifty-nine out of 90 patients (65%) with unilateral nonfocal renal disease, both perfusion and parenchymal uptake abnormalities were found at the involved side. In two of 13 patients with renal artery stenosis, however, the unilateral hypoperfusion was only found as the evidence of unilateral disease on radionuclide angiogram although these did not show any parenchymal uptake abnormality. Moreover, four out of 58 patients with obstructive uropathy, did show the slight difference of renal perfusion between the involved and the univolved sides. and did not show any difference of parenchymal uptake between both sides. In the present study, the incidence of perfusion abnormality on radionuclide angiogram was slightly higher than that of parenchymal uptake abnormality on the image from one min. to four min. in unilateral renal disease. Therefore, it is suggested that the radionuclide angiography may be accepted as one of the routine nuclear medicine imagings for the evaluation of functional abnormalities in nonfocal renal disease. (author)

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Peripheral CT angiography for interventional treatment planning

    International Nuclear Information System (INIS)

    Lower extremity CT angiography (CTA) has evolved into a very effective, widely available and robust imaging modality for patients with peripheral arterial occlusive disease (PAOD). In this article we briefly review the acquisition and contrast administration techniques for 4- through 64-channel peripheral CTA. Visualization of atherosclerotic disease with CTA in general requires 'angiography-like' 3D images (such as volume rendered or maximum intensity projection images), but-notably in the presence of vessel wall calcifications and stents-cross-sectional views (such as curved planar reformations, CPR) are also required to accurately assess the flow lumen of the aorta down to the pedal arteries. Adequate visualization and mapping of atherosclerotic lesions in patients with PAOD is not only a prerequisite for generating a dictated report, but more importantly, standardized postprocessed images are the key to communicating the findings to the treating physician, and they also serve as a treatment planning tool. Treatment decisions (surgical versus transluminal revascularization, or conservative treatment), and percutaneous treatment planning (access site, antegrade versus retrograde puncture) can be made in the majority of patients with PAOD based on lower extremity CT angiograms. (orig.)

  8. The role of business in addressing the long-term implications of the current food crisis.

    Science.gov (United States)

    Yach, Derek

    2008-01-01

    Before the onset of the current food crisis, the evidence of a severely neglected nutrition crisis was starting to receive attention. Increased food prices are having severe impacts on the nutritional status of populations. Our current food system has evolved over decades in a largely unplanned manner and without consideration for the complexity and implications of linkages between health, nutrition, agricultural, economic, trade and security issues. The underlying causes for the nutrition crisis include the above, as well as decades of neglect with regard to nutrition, and agricultural science (especially in emerging markets); a failure of governance with respect to the major players involved in nutrition, a weak response by government donors and Foundations to invest in basic nutrition (in contrast to growing support for humanitarian aspects of food aid), and a reluctance to develop private-public partnerships. The emergence of new business models that tackle social problems while remaining profitable offers promise that the long term nutrition needs of people can be met. Businesses can have greater impact acting collectively than individually. Food, retail, food service, chemical and pharmaceutical companies have expertise, distribution systems and customers insights, if well harnessed, could leapfrog progress in addressing the food and nutrition crises. While business can do lots more, its combined impact will be minimal if a range of essential government actions and policies are not addressed. Governments need to create innovative and complementary opportunities that include incentives for businesses including: setting clear nutritional guidelines for fortification and for ready-to eat products; offering agreements to endorse approved products and support their distribution to clinics and schools; eliminating duties on imported vitamins and other micronutrients; and providing tax and other incentives for industry to invest with donors in essential nutrition

  9. The role of business in addressing the long-term implications of the current food crisis

    Directory of Open Access Journals (Sweden)

    Yach Derek

    2008-12-01

    Full Text Available Abstract Before the onset of the current food crisis, the evidence of a severely neglected nutrition crisis was starting to receive attention. Increased food prices are having severe impacts on the nutritional status of populations. Our current food system has evolved over decades in a largely unplanned manner and without consideration for the complexity and implications of linkages between health, nutrition, agricultural, economic, trade and security issues. The underlying causes for the nutrition crisis include the above, as well as decades of neglect with regard to nutrition, and agricultural science (especially in emerging markets; a failure of governance with respect to the major players involved in nutrition, a weak response by government donors and Foundations to invest in basic nutrition (in contrast to growing support for humanitarian aspects of food aid, and a reluctance to develop private-public partnerships. The emergence of new business models that tackle social problems while remaining profitable offers promise that the long term nutrition needs of people can be met. Businesses can have greater impact acting collectively than individually. Food, retail, food service, chemical and pharmaceutical companies have expertise, distribution systems and customers insights, if well harnessed, could leapfrog progress in addressing the food and nutrition crises. While business can do lots more, its combined impact will be minimal if a range of essential government actions and policies are not addressed. Governments need to create innovative and complementary opportunities that include incentives for businesses including: setting clear nutritional guidelines for fortification and for ready-to eat products; offering agreements to endorse approved products and support their distribution to clinics and schools; eliminating duties on imported vitamins and other micronutrients; and providing tax and other incentives for industry to invest with

  10. 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

  11. Current rectification in a single molecule diode: the role of electrode coupling

    Science.gov (United States)

    Sherif, Siya; Rubio-Bollinger, Gabino; Pinilla-Cienfuegos, Elena; Coronado, Eugenio; Cuevas, Juan Carlos; Agraït, Nicolás

    2015-07-01

    We demonstrate large rectification ratios (\\gt 100) in single-molecule junctions based on a metal-oxide cluster (polyoxometalate), using a scanning tunneling microscope (STM) both at ambient conditions and at low temperature. These rectification ratios are the largest ever observed in a single-molecule junction, and in addition these junctions sustain current densities larger than 105 A cm-2. By following the variation of the I-V characteristics with tip-molecule separation we demonstrate unambiguously that rectification is due to asymmetric coupling to the electrodes of a molecule with an asymmetric level structure. This mechanism can be implemented in other type of molecular junctions using both organic and inorganic molecules and provides a simple strategy for the rational design of molecular diodes.

  12. Current role of antibody therapy in patients with metastatic colorectal cancer

    DEFF Research Database (Denmark)

    Pfeiffer, P; Qvortrup, C; Eriksen, J G

    2007-01-01

    In less than 10 years, the number and importance of non-surgical treatment modalities in patients with colorectal cancer (CRC) have increased dramatically, both in the adjuvant and the advanced settings. However, despite the improvement of cytotoxic therapy in CRC, many patients still develop...... arsenal in CRC to a great extent, but they will also add to the complexity of treatment of CRC. In this review, we summarize the current status of antibody therapy in patients with CRC...... progressive disease and unfortunately in patients with disease resistant to 5-fluorouracil/folinic acid, irinotecan and oxaliplatin, no effective cytotoxic therapy is known. The rapidly expanding knowledge in tumor biology has encouraged optimism for the possibility to find and target tumor...

  13. Current rectification in a single molecule diode: the role of electrode coupling.

    Science.gov (United States)

    Sherif, Siya; Rubio-Bollinger, Gabino; Pinilla-Cienfuegos, Elena; Coronado, Eugenio; Cuevas, Juan Carlos; Agraït, Nicolás

    2015-07-24

    We demonstrate large rectification ratios (> 100) in single-molecule junctions based on a metal-oxide cluster (polyoxometalate), using a scanning tunneling microscope (STM) both at ambient conditions and at low temperature. These rectification ratios are the largest ever observed in a single-molecule junction, and in addition these junctions sustain current densities larger than 10(5) A cm(-2). By following the variation of the I-V characteristics with tip-molecule separation we demonstrate unambiguously that rectification is due to asymmetric coupling to the electrodes of a molecule with an asymmetric level structure. This mechanism can be implemented in other type of molecular junctions using both organic and inorganic molecules and provides a simple strategy for the rational design of molecular diodes. PMID:26133791

  14. Role of processing in improving the critical current of Ag/BPSCCO tapes

    International Nuclear Information System (INIS)

    Silver-clad tapes of high Tc Bi-Pb-Sr-Ca-Cu-O superconductors have been fabricated through the powder-in-tube method. The critical current density, Jc of a thick tape was 534 A cm-2 (77 K. OT). Subsequent rolling and sintering of the tapes led to a gradual decrease in Jc instead of the expected increase. This was caused by the microcracks developed in the core material by a rather drastic reduction during the rolling of the tapes. A modified and well controlled technique, on the other hand, resulted in much improved Jc values. Repeated rolling and sintering resulted in a good grain alignment and no microcracks were observed. In the present studies, maximum Jc of 1846 A cm-2 (77 K OT) and 2.43x104 A cm-2(4.2 K OT) have been obtained. Optimization of the processing and sintering parameters are expected to lead to still higher Jc values

  15. Pegylated liposomal doxorubicin: appraisal of its current role in the management of epithelial ovarian cancer

    Directory of Open Access Journals (Sweden)

    Markman M

    2011-06-01

    Full Text Available Maurie MarkmanCancer Treatment Centers of America, Eastern Regional Medical Center, Philadelphia, PA, USAAbstract: Pegylated liposomal doxorubicin (PLD has become a major component in the routine management of epithelial ovarian cancer. The drug is frequently employed as a single agent in the platinum-resistant setting, and recently reported data reveal the superiority of the combination of PLD plus carboplatin, compared with the platinum drug plus paclitaxel, in delaying the time to disease progression in women with recurrent (potentially platinum-sensitive disease. Current research efforts involving PLD in ovarian cancer are focusing on adding novel targeted drugs to this cytotoxic agent. The utility of such approaches in the platinum-resistant population, compared with the sequential administration of single agents active in this setting, remains to be determined.Keywords: PLD, carboplatin, paclitaxel, platinum-sensitive, platinum-resistant

  16. Current role of non-anesthesiologist administered propofolsedation in advanced interventional endoscopy

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Complex and lengthy endoscopic examinations likeendoscopic ultrasonography and/or endoscopic retrogradecholangiopancreatography benefit from deepsedation, due to an enhanced quality of examinations,reduced discomfort and anxiety of patients, as well asincreased satisfaction for both the patients and medicalpersonnel. Current guidelines support the use ofpropofol sedation, which has the same rate of adverseeffects as traditional sedation with benzodiazepines and/or opioids, but decreases the procedural and recoverytime. Non-anesthesiologist administered propofolsedation has become an option in most of the countries,due to limited anesthesiology resources and theincreasing evidence from prospective studies and metaanalysesthat the procedure is safe with a similar rate ofadverse events with traditional sedation. The advantagesinclude a high quality of endoscopic examination,improved satisfaction for patients and doctors, as wellas decreased recovery and discharge time. Despitethe advantages of non-anesthesiologist administeredpropofol, there is still a continuous debate related to thesuccessful generalization of the procedures.

  17. Sediment Dynamics in Shallow Tidal Landscapes: The Role of Wind Waves and Tidal Currents

    Science.gov (United States)

    Carniello, L.; D'Alpaos, A.

    2014-12-01

    A precise description of sediment dynamics (resuspension and re-distribution of sediments) is crucial when investigating the long term evolution of the different morphological entities characterizing tidal landscapes. It has been demonstrated that wind waves are the main responsible for sediment resuspension in shallow micro-tidal lagoons where tidal currents, which produce shear stresses large enough to carry sediments into suspension only within the main channels, are mainly responsible for sediment redistribution. A mathematical model has been developed to describe sediment entrainment, transport and deposition due to the combined effect of tidal currents and wind waves in shallow lagoons considering both cohesive and non-cohesive sediments. The model was calibrated and tested using both in situ point observations and turbidity maps obtained analyzing satellite images. Once calibrated the model can integrate the high temporal resolution of point observations with the high spatial resolution of remote sensing, overcoming the intrinsic limitation of these two types of observations. The model was applied to the specific test case of the Venice lagoon simulating an entire year (2005) which was shown to be a "representative" year for wind and tide characteristics. The time evolution of the computed total bottom shear stresses (BSS) and suspended sediment concentration (SSC) was analyzed on the basis of a "Peaks Over Threshold" method once a critical value for shear stress and turbidity were chosen. The analyses of the numerical results enabled us to demonstrate that resuspension events can be modeled as marked Poisson processes: interarrival time, intensity of peak excesses and duration being exponentially distributed random variable. The probability distributions of the interarrival time of overthreshold exceedances in both BSS and SSC as well as their intensity and duration can be used in long-term morphodynamic studies to generate synthetic series statistically

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

    International Nuclear Information System (INIS)

    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 E1 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 of fine

  19. 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

  20. Role of scintigraphy in the current diagnosis and management of thyroid diseases

    International Nuclear Information System (INIS)

    Recent developments have resulted in important changes in the diagnosis and management of thyroid diseases. Fine-needle aspiration biopsy has now supplanted imaging studies as the initial procedure for differentiating malignant from benign thyroid nodules. However, thyroid scintigraphy may be helpful in the management of patients without a definitive result of cytology and in Grave's disease with a nodule found in ultrasound scanning. On the other hand, scintigraphy remains critical for the determination of autonomously functioning tissue, and hyperthyroidism (over or subclinical) is an indisputable indication for scintigraphy in patients with a thyroid nodule. Besides, radionuclide scanning has retained its significance in the diagnosis of ectopic thyroid tissue, in the monitoring effects of radioiodine therapy, and in the evaluation of relapses in patients treated by surgery for benign thyroid diseases. The 131I scintigraphy is commonly used in the postoperative follow-up of patients with the differentiated thyroid carcinoma, although the role of this procedure in management of the disease may change in the near future. Nowadays, the 123I thyroid scintigraphy has been proposed as a safe and clinically important procedure for accurately counselling patients with congenital hypothyroidism. Moreover, the problem of underestimation of thyroid scintigraphy in diagnosis and management of benign diseases of gland in some regions of Poland has also been discussed. (author)

  1. Role of government in public health: Current scenario in India and future scope.

    Science.gov (United States)

    Lakshminarayanan, Subitha

    2011-01-01

    The new agenda for Public Health in India includes the epidemiological transition, demographical transition, environmental changes and social determinants of health. Based on the principles outlined at Alma-Ata in 1978, there is an urgent call for revitalizing primary health care in order to meet these challenges. The role of the government in influencing population health is not limited within the health sector but also by various sectors outside the health systems. This article is a literature review of the existing government machinery for public health needs in India, its success, limitations and future scope. Health system strengthening, human resource development and capacity building and regulation in public health are important areas within the health sector. Contribution to health of a population also derives from social determinants of health like living conditions, nutrition, safe drinking water, sanitation, education, early child development and social security measures. Population stabilization, gender mainstreaming and empowerment, reducing the impact of climate change and disasters on health, improving community participation and governance issues are other important areas for action. Making public health a shared value across the various sectors is a politically challenging strategy, but such collective action is crucial. PMID:21694957

  2. Role of government in public health: Current scenario in India and future scope

    Directory of Open Access Journals (Sweden)

    Subitha Lakshminarayanan

    2011-01-01

    Full Text Available The new agenda for Public Health in India includes the epidemiological transition, demographical transition, environmental changes and social determinants of health. Based on the principles outlined at Alma-Ata in 1978, there is an urgent call for revitalizing primary health care in order to meet these challenges. The role of the government in influencing population health is not limited within the health sector but also by various sectors outside the health systems. This article is a literature review of the existing government machinery for public health needs in India, its success, limitations and future scope. Health system strengthening, human resource development and capacity building and regulation in public health are important areas within the health sector. Contribution to health of a population also derives from social determinants of health like living conditions, nutrition, safe drinking water, sanitation, education, early child development and social security measures. Population stabilization, gender mainstreaming and empowerment, reducing the impact of climate change and disasters on health, improving community participation and governance issues are other important areas for action. Making public health a shared value across the various sectors is a politically challenging strategy, but such collective action is crucial.

  3. Doctors as managers of healthcare resources in Nigeria: Evolving roles and current challenges

    Directory of Open Access Journals (Sweden)

    Temitope Olumuyiwa Ojo

    2015-01-01

    Full Text Available Over the years, medical practice in Nigeria has evolved in scope and practice, in terms of changing disease patterns, patients' needs, and social expectations. In addition, there is a growing sentiment especially among the general public and some health workers that most doctors are bad managers. Besides drawing examples from some doctors in top management positions that have performed less creditably, critics also harp on the fact that more needs to be done to improve the training of doctors in health management. This article describes the role of doctors in this changing scene of practice and highlights the core areas where doctors' managerial competencies are required to improve the quality of healthcare delivery. Areas such as health care financing, essential drugs and supplies management, and human resource management are emphasized. Resources to be managed and various skills needed to function effectively at the different levels of management are also discussed. To ensure that doctors are well-skilled in managerial competencies, the article concludes by suggesting a curriculum review at undergraduate and postgraduate levels of medical training to include newer but relevant courses on health management in addition to the existing ones, whereas also advocating that doctors be incentivized to go for professional training in health management and not only in the core clinical specialties.

  4. How stakeholders frame dam removal: The role of current and anticipated future ecosystem service use

    Science.gov (United States)

    Reilly, Kate; Adamowski, Jan

    2016-04-01

    Many river restoration projects, including dam removal, are controversial and can trigger conflicts between stakeholders who are for and against the proposed project. The study of environmental conflicts suggests that differences in how stakeholders 'frame', or make sense of a situation based on their prior knowledge and experiences, can perpetuate conflicts. Understanding different stakeholders' frames, particularly how they converge, can form the basis of successful conflict resolution. In the case of dam removals, it is often assumed that emphasising increased provision of ecosystem services can be a point of convergence between those advocating for ecological restoration and those opposed to removal because of negative human impacts. However, how exactly stakeholders frame a contentious proposed dam removal and how those frames relate to ecosystem services has been little studied. Here we used the case of a potential dam removal in New Brunswick to investigate how people frame the issue and how that relates to their current and anticipated future use of ecosystem services. Based on in-depth interviews with 30 stakeholders in the area, including both people for and against dam removal, we found that both groups currently used ecosystem services and were in favour of ecosystem protection. However, they differed in how they framed the issue of the potential dam removal. The group against dam removal framed the issue as one of loss and risk - they thought that any potential benefits to the ecosystem would be outweighed by the high risk of negative social impacts caused by a loss of access to ecosystem services, such as recreation and aesthetic enjoyment. By contrast, the group in favour of the dam framed the issue as one of opportunity and justice. They thought that following a short transition period, all stakeholders would benefit from the restored river, particularly from a restored salmon fishery, improved aesthetic appeal and the long-term sustainability of an

  5. Demonstration of enhanced K-edge angiography using a cerium target x-ray generator

    International Nuclear Information System (INIS)

    The cerium target x-ray generator is useful in order to perform enhanced K-edge angiography using a cone beam because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller, a unit with a Cockcroft-Walton circuit and a fixed anode x-ray tube, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.0x1.3 mm. Cerium Kα lines were left using a barium sulfate filter, and the x-ray intensity was 0.48 μC/kg at 1.0 m from the source with a tube voltage of 60 kV, a current of 0.40 mA, and an exposure time of 1.0 s. Angiography was performed with a computed radiography system using iodine-based microspheres. In coronary angiography of nonliving animals, we observed fine blood vessels of approximately 100 μm with high contrasts

  6. 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

  7. 64-MSCT coronary angiography with prospective ECG gating at intermediate heart rate

    International Nuclear Information System (INIS)

    Objective: To evaluate robustness of coronary artery computed tomographic (CT) angiography with prospectively gated axial (PGA) CT technique at intermediate heart rate (65-75 beats per minute) using retrospectively gated helical (RGH) CT technique in 64-slice spiral CT. Methods: 63 consecutive patients with heart rates (HR) of 65 to 75 bpm, heart rate variability of below 5 bpm underwent CT angiography with RGH technique (tube voltage was 120 kV and tube current tailored to BMI). The 5% acquired data during each intermediate temporal window in the R-R interval were used to reconstruct images. The intermediate temporal window was 400 ms in the R-R interval at current mean HR, and the centre of the temporal window was 60%. All coronary artery segments were evaluated for image quality with 5-point scale. The mean image quality score and the percentage of assessable coronary artery segments were used to evaluate diagnostic value on the selected temporal window. Results: 822 coronary artery segments were depicted and were evaluated. The mean image quality score was 4.15±0.72. The percentage of assessable coronary artery segments was 97.76%. Conclusion: PCA coronary CT angiography with proper revise image acquisition phase and padding time could offer assessable image quality at intermediate HR. (authors)

  8. Current & Heat Transport in Graphene Nanoribbons: Role of Non-Equilibrium Phonons

    Science.gov (United States)

    Pennington, Gary; Finkenstadt, Daniel

    2010-03-01

    The conducting channel of a graphitic nanoscale device is expected to experience a larger degree of thermal isolation when compared to traditional inversion channels of electronic devices. This leads to enhanced non-equilibrium phonon populations which are likely to adversely affect the mobility of graphene-based nanoribbons due to enhanced phonon scattering. Recent reports indicating the importance of carrier scattering with substrate surface polar optical phonons in carbon nanotubes^1 and graphene^2,3 show that this mechanism may allow enhanced heat removal from the nanoribbon channel. To investigate the effects of hot phonon populations on current and heat conduction, we solve the graphene nanoribbon multiband Boltzmann transport equation. Monte Carlo transport techniques are used since phonon populations may be tracked and updated temporally.^4 The electronic structure is solved using the NRL Tight-Binding method,^5 where carriers are scattered by confined acoustic, optical, edge and substrate polar optical phonons. [1] S. V. Rotkin et al., Nano Lett. 9, 1850 (2009). [2] J. H. Chen, C. Jang, S. Xiao, M. Ishigami and M. S. Fuhrer, Nature Nanotech. 3, 206 (2008). [3] V. Perebeinos and P. Avouris, arXiv:0910.4665v1 [cond-mat.mes-hall] (2009). [4] P. Lugli et al., Appl. Phys. Lett. 50, 1251 (1987). [5] D. Finkenstadt, G. Pennington & M.J. Mehl, Phys. Rev. B 76, 121405(R) (2007).

  9. The current role of simulators for performance evaluations and licensing (case of Mexico)

    International Nuclear Information System (INIS)

    The main purpose of this paper is to share the experience acquired by the National Commission of Nuclear Safety and Safeguards (CNSNS) during the administration of both certification and licensing operational exams applied to Senior Reactor Operators (SRO) and Reactor OPerators (RO) by using a full-scope simulator. The licensing operational exams are administered to examinate candidates for a SRO or RO license while the certification operational exams are administered to all personnel that possess a SRO or RO license in order to renew their licenses within a six years period. A general description with the most important simulator antecedents from the initial authorization for its usage to provide the ''Initial Simulator Training Course'' until currently in which it has been started the installation and testing performance of a new computer equipment that will improve and increase the simulation capacity of the Laguna Verde Nuclear Power Plant (LVNPP) simulator. In other hand, it is showed the process that the CNSNS will apply during the next verification of the simulator certification which should be performed due to the old computer equipment is being replaced with a more modern computer equipment so that the simulation capability will be improved. The verification process was discussed with the utility personnel and as result of this an agreement has been established to carry into effect this hard task. Finally, the conclusions and recommendations from regulators point of view are presented regarding to the importance of perform a well both evaluation and verification of simulators performance. (author)

  10. Current perspectives on natural killer cell education and tolerance: emerging roles for inhibitory receptors

    Directory of Open Access Journals (Sweden)

    Thomas LM

    2015-03-01

    Full Text Available L Michael Thomas Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA Abstract: Natural killer (NK cells are regulated through the coordinated functions of activating and inhibitory receptors. These receptors can act during the initial engagement of an NK cell with a target cell, or in subsequent NK cell engagements to maintain tolerance. Notably, each individual possesses a sizable minority-population of NK cells that are devoid of inhibitory receptors that recognize the surrounding MHC class I (ie, self-MHC. Since these NK cells cannot perform conventional inhibition, they are rendered less responsive through the process of NK cell education (also known as licensing in order to reduce the likelihood of auto-reactivity. This review will delineate current views on NK cell education, clarify various misconceptions about NK cell education, and, lastly, discuss the relevance of NK cell education in anti-cancer therapies. Keywords: natural killer cell education, natural killer cell inhibitory receptors, immunotherapy, cancer

  11. The current role of sublingual immunotherapy in the treatment of allergic rhinitis in adults and children

    Directory of Open Access Journals (Sweden)

    Simonetta Masieri

    2011-02-01

    Full Text Available Cristoforo Incorvaia1, Simonetta Masieri2, Silvia Scurati3, Silvia Soffia3, Paola Puccinelli3, Franco Frati31Allergy/Pulmonary rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy; 2ENT Clinic, University La Sapienza, Rome, Italy; 3Medical and Scientific Department, Stallergenes, Milan, ItalyAbstract: Allergic rhinitis is a very common disease affecting about 20% of people. It may be treated by allergen avoidance when possible, by antiallergic drugs such as antihistamines and topical corticosteroids, and by allergen-specific immunotherapy. The latter is the only treatment able to act on the causes and not only on the symptoms of respiratory allergy and is able to maintain its efficacy even after stopping, provided an adequate duration of treatment of 3–5 years is ensured. Sublingual immunotherapy (SLIT was introduced in the 1990s as a possible solution to the problem of adverse systemic reactions to subcutaneous immunotherapy and has been demonstrated by more than 50 trials and globally evaluated thus far by five meta-analyses as an effective and safe treatment for allergic rhinitis. Life-threatening reactions are extremely rare. However, it is important to note that clinical efficacy occurs only if SLIT meets its needs, ie, sufficiently high doses are regularly administered for at least 3 consecutive years. This is often overlooked in the current practice and may prevent the same success reported by trials from being achieved.Keywords: allergic rhinitis, sublingual immunotherapy, efficacy, safety, compliance, meta-analysis 

  12. Adult leukaemia: what is the role of currently known risk factors?

    International Nuclear Information System (INIS)

    Leukaemias are a heterogeneous group of tumours including acute and chronic forms. Considerable efforts have been made to identify risk factors for these diseases, but only a minority of leukaemia cases can currently be attributed to identified or hypothesized factors. This review highlights recent epidemiological literature concerning adult leukaemia, discussing in detail the hereditary, environmental and medical risks. Chromosomal syndromes and genetically based diseases carry a high risk of leukaemia, but rarely occur in the population. Environmental and occupational exposures to chemicals including pesticides have been widely studied, although the results are not consistent, with the exception of benzene. Smoking seems to be a weak causal risk factor. The risk of ionizing radiation has further been quantified in recent studies, although the effects of low doses have not yet been clarified. The results for non-ionizing radiation continue to be inconsistent, but a large effect of electromagnetic fields on the risk of leukaemia appears to be unlikely. Medically applied radio- and chemotherapy are clearly associated with subsequent leukaemia development, and there are links between leukaemia and viral infections. Future research should emphasize the shortcomings in exposure assessment that pervade many studies, and interactions between different risk factors need to be taken into consideration. (orig.)

  13. Adult leukaemia: what is the role of currently known risk factors?

    Energy Technology Data Exchange (ETDEWEB)

    Zeeb, H. [Deutsches Krebsforschungszentrum, Abt. Epidemiologie, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Blettner, M. [International Agency for Research on Cancer (IARC), Unit of Carcinogen Identification and Evaluation, 150 Cours Albert Thomas, F-69372 Lyon (France)

    1998-02-01

    Leukaemias are a heterogeneous group of tumours including acute and chronic forms. Considerable efforts have been made to identify risk factors for these diseases, but only a minority of leukaemia cases can currently be attributed to identified or hypothesized factors. This review highlights recent epidemiological literature concerning adult leukaemia, discussing in detail the hereditary, environmental and medical risks. Chromosomal syndromes and genetically based diseases carry a high risk of leukaemia, but rarely occur in the population. Environmental and occupational exposures to chemicals including pesticides have been widely studied, although the results are not consistent, with the exception of benzene. Smoking seems to be a weak causal risk factor. The risk of ionizing radiation has further been quantified in recent studies, although the effects of low doses have not yet been clarified. The results for non-ionizing radiation continue to be inconsistent, but a large effect of electromagnetic fields on the risk of leukaemia appears to be unlikely. Medically applied radio- and chemotherapy are clearly associated with subsequent leukaemia development, and there are links between leukaemia and viral infections. Future research should emphasize the shortcomings in exposure assessment that pervade many studies, and interactions between different risk factors need to be taken into consideration. (orig.) With 1 fig., 5 tabs., 114 refs.

  14. Psychosocial factors and their role in chronic pain: A brief review of development and current status

    Directory of Open Access Journals (Sweden)

    Innes Stanley I

    2005-04-01

    Full Text Available Abstract The belief that pain is a direct result of tissue damage has dominated medical thinking since the mid 20th Century. Several schools of psychological thought proffered linear causal models to explain non-physical pain observations such as phantom limb pain and the effects of placebo interventions. Psychological research has focused on identifying those people with acute pain who are at risk of transitioning into chronic and disabling pain, in the hope of producing better outcomes. Several multicausal Cognitive Behavioural models dominate the research landscape in this area. They are gaining wider acceptance and some aspects are being integrated and implemented into a number of health care systems. The most notable of these is the concept of Yellow Flags. The research to validate the veracity of such programs has not yet been established. In this paper I seek to briefly summarize the development of psychological thought, both past and present, then review current cognitive-behavioural models and the available supporting evidence. I conclude by discussing these factors and identifying those that have been shown to be reliable predictors of chronicity and those that may hold promise for the future.

  15. Current status of nuclear-energy development and role of university research and education in US

    International Nuclear Information System (INIS)

    It is widely shared that utilization of nuclear power is an effective measure for slowing down global warming and relaxing tight demand-supply situation for energy, as China, India, Brazil, and Russia are emerging as new economies. Challenges have also been recognized. Those are proliferation of nuclear materials, increase in environmental impacts, higher levels of nuclear safety, and uranium resources availability. To solve these hopefully simultaneously with minimum economic penalty, recycling of nuclear materials, or nuclear fuel cycle, has once again been considered to be essential feature of future nuclear utilization. While the United States currently apply the once-through policy for commercial nuclear-power utilization, the Bush Administration announced the Global Nuclear Energy Partnership (GNEP), and strongly supports development of advanced nuclear technology. Various different technological options for reactors, separation processes, repository concepts, etc, have already been proposed, but human and capital resources that can be used for such developments are limited. Because deployment of technologies will take as long as a century or longer, careful planning and decision making are crucial. Concurrently, we need to address the human resources issue, especially in the US. Many nuclear engineering departments in universities changed its name or merged with other departments. For more than three decades, few now textbooks have been published in major nuclear-engineering areas. We need a good plan to restore educational programs, this time, worldwide to share common culture for nuclear utilization. (author)

  16. Gadolinium-enhanced MR angiography of arterial occlusive disease in lower extremity : comparison with conventional digital subtraction angiography

    International Nuclear Information System (INIS)

    To compare the diagnostic value of gadolinium-enhanced MR angiography with that of conventional digital subtraction angiography for the evaluation of lower extremity arterial occlusive diseases. In 26 patients with symptomatic lower extremity arterial occlusive disease, both conventional digital subtraction angiography (DSA) and gadolinium-enhanced MR angiography (CE-MRA) were performed during the same week. MR angiography was performed using three-dimensional gradient-echo acquisition before, and two sequential acquisitions after, the administration of gadolinium (0.2 mmol/kg). In 23 patients, two separate, contiguous areas were scanned using additional doses. In three patients, only one field with a suspicious lesion was scanned. Three radiologists independently analyzed the CE-MRA and DSA findings of each vascular segment (20 segments per arterial tree) for the presence of obstructive lesions; the grade assigned was either mild or none (less than 50%), stenotic (50%-99%), or occlusion (100%). From among a total of 462 segments, DSA detected 99 which were significantly narrowed (stenosis, 33; occlusion, 66). Using MR angiography, 102 segments (stenosis 39; occlusion, 63) were identified, and 94 lesions (stenosis, 32; occlusion, 62) were graded correctly. Seven lesions were overestimated and four were underestimated. For the detection of hemodynamically significant stenosis or occlusions using MR angiography, sensitivity, specificity, and diagnostic accuracy were 95%, 98%, and 98% (G=3D0.995, P less than 0.001), respectively. To prove the absence of lesions, we repeated DSA in two patients with arterial spasm due to puncture. Three occluded segments seen on DSA, which revealed intact segments on MR angiography, suggested slow distal flow after reconstitution. For the evaluation of lower extremity arterial occlusive disease, the diagnostic value of gadolinium-enhanced MR angiography is comparable with that of digital subtraction angiography. The advantages of the

  17. The potential role for ocrelizumab in the treatment of multiple sclerosis: current evidence and future prospects.

    Science.gov (United States)

    Sorensen, Per Soelberg; Blinkenberg, Morten

    2016-01-01

    B cells play a central role in the pathogenesis in multiple sclerosis (MS), being involved in the activation of proinflammatory T cells, secretion of proinflammatory cytokines, and production of autoantibodies directed against myelin. Hence, the usage of B-cell-depleting monoclonal antibodies as therapy for autoimmune diseases including MS lay near at hand. Rituximab was the first therapeutic B-cell-depleting chimeric monoclonal antibody to be used successfully in MS. Ocrelizumab, a second-generation humanized anti-CD20 antibody, was explored in a large phase II, randomized, placebo-controlled multicentre trial in patients with relapsing-remitting disease. Compared with placebo, two doses of ocrelizumab (600 and 2000 mg on days 1 and 15) showed a pronounced effect on disease activity seen in magnetic resonance imaging (MRI) as gadolinium-enhanced lesions (89% and 96% relative reduction, both p ocrelizumab had better effect on gadolinium-enhanced lesions than interferon beta-1a intramuscularly that was used as a reference arm. Adverse effects were mainly infusion-related reactions, in particular during the first infusion. Serious infections occurred at similar rates in ocrelizumab and placebo-treated patients, and no opportunistic infections were reported. However, progressive multifocal leukoencephalopathy (PML) has been reported in patients treated with anti-CD20 monoclonal antibodies for other indications. Other anti-CD20 monoclonal antibodies have been tested as treatments for MS, including ofatumumab that has shown beneficial results in placebo-controlled phase II trials in patients with relapsing-remitting MS. Ocrelizumab is now in phase III development for the treatment of relapsing-remitting MS, as well as primary progressive MS, and the results of ongoing clinical trials are eagerly awaited and will determine the place of ocrelizumab in the armamentarium of MS therapies. PMID:26788130

  18. Current procedural terminology; a primer.

    Science.gov (United States)

    Hirsch, Joshua A; Leslie-Mazwi, Thabele M; Nicola, Gregory N; Barr, Robert M; Bello, Jacqueline A; Donovan, William D; Tu, Raymond; Alson, Mark D; Manchikanti, Laxmaiah

    2015-04-01

    In 1966, The American Medical Association (AMA) working with multiple major medical specialty societies developed an iterative coding system for describing medical procedures and services using uniform language, the Current Procedural Terminology (CPT) system. The current code set, CPT IV, forms the basis of reporting most of the services performed by healthcare providers, physicians and non-physicians as well as facilities allowing effective, reliable communication among physician and other providers, third parties and patients. This coding system and its maintenance has evolved significantly since its inception, and now goes well beyond its readily perceived role in reimbursement. Additional roles include administrative management, tracking new and investigational procedures, and evolving aspects of 'pay for performance'. The system also allows for local, regional and national utilization comparisons for medical education and research. Neurointerventional specialists use CPT category I codes regularly--for example, 36,215 for first-order cerebrovascular angiography, 36,216 for second-order vessels, and 37,184 for acute stroke treatment by mechanical means. Additionally, physicians add relevant modifiers to the CPT codes, such as '-26' to indicate 'professional charge only,' or '-59' to indicate a distinct procedural service performed on the same day. PMID:24589819

  19. The Current and Future Role of Nigerian Indigenous Oil Companies in the Mature Niger Delta

    International Nuclear Information System (INIS)

    Over the last 10 years, there has been a steady increase in the number of successful Indigenous Oil Companies exploring for hydrocarbons in the Niger Delta. A number of these companies have already entered into partnership agreements with overseas based oil companies, however, many more are still seeking technical and financial partnership agreements with overseas based oil companies, however, many more are still seeking technical and financial partners to fulfil their licence commitments. The first exploration licence to an Indigenous Company was awarded in the mid eighties. However, it wasn't until the early nineties that the Nigerian Government's intention to privatise the oil industry gathered momentum. Between 1991 and 1993 a number of discretionary awards of acreage from various sedimentary basins in Nigeria were made to Nigerian Indigenous Companies. Many of these companies had little or no previous experience of hydrocarbon exploration.Sixteen of the Indigenous Companies have already reported discoveries in various parts of the delta, either in partnerships with foreign companies or independently. Eight of the Indigenous Companies are producing hydrocarbons. With very little production in the early 90's, the Indigenous Companies now account for over 4.5% of Nigeria's daily production. The government is intent on increasing this percentage through initiatives such as the Marginal Fields re-allocation programme, and the continued award of acreage in traditional license rounds. This paper takes a closer look at the operations and discoveries of two Indigenous Companies Solgas and Summit with the aim of providing an insight into the structure and mode of operation of typical Nigerian Indigenous Oil Companies.The more recent licensing activity in Nigeria includes the current Marginal Fields re-allocation programme and also possible participation of Nigerian companies in the join Development Zone between Nigeria and Sao Tome and Principe. The paper concludes with

  20. Phylogeography of Ophioblennius: the role of ocean currents and geography in reef fish evolution.

    Science.gov (United States)

    Muss, A; Robertson, D R; Stepien, C A; Wirtz, P; Bowen, B W

    2001-03-01

    Many tropical reef fishes are divided into Atlantic and East Pacific taxa, placing similar species in two very different biogeographic regimes. The tropical Atlantic is a closed ocean basin with relatively stable currents, whereas the East Pacific is an open basin with unstable oceanic circulation. To assess how evolutionary processes are influenced by these differences in oceanography and geography, we analyze a 630-bp region of mitochondrial cytochrome b from 171 individuals in the blenniid genus Ophioblennius. Our results demonstrate deep genetic structuring in the Atlantic species, O. atlanticus, corresponding to recognized biogeographic provinces, with divergences of d = 5.2-12.7% among the Caribbean, Brazilian, St. Helena/Ascension Island, Gulf of Guinea, and Azores/Cape Verde regions. The Atlantic phylogeny is consistent with Pliocene dispersal from the western to eastern Atlantic, and the depth of these separations (along with prior morphological comparisons) may indicate previously unrecognized species. The eastern Pacific species, O. steindachneri, is characterized by markedly less structure than O. atlanticus, with shallow mitochondrial DNA lineages (dmax = 2.7%) and haplotype frequency shifts between locations in the Sea of Cortez, Pacific Panama, Clipperton Island, and the Galapagos Islands. No concordance between genetic structure and biogeographic provinces was found for O. steincdachneri. We attribute the phylogeographic pattern in O. atlanticus to dispersal during the reorganization of Atlantic circulation patterns that accompanied the shoaling of the Isthmus of Panama. The low degree of structure in the eastern Pacific is probably due to unstable circulation and linkage to the larger Pacific Ocean basin. The contrast in genetic signatures between Atlantic and eastern Pacific blennies demonstrates how differences in geology and oceanography have influenced evolutionary radiations within each region. PMID:11327163

  1. Nipple discharge disorders: current diagnostic management and the role of fiber-ductoscopy

    International Nuclear Information System (INIS)

    Nipple discharge disorders is a field in which there has been both increasing awareness on the part of patients and advances in management. Today secretion from nipples can be classified according to its color, cellularity and biology. To be significant a discharge should be true, spontaneous, persistent and non-lactational. Moreover there are methods to differentiate patients who require surgical intervention from those who do not. Surgically significant nipple discharges are watery, serous (yellow), serosanguineous and bloody. Cytology smears of discharge material have helped to classify the cellular material, providing information about normality, atypia and malignancy and also about papillary formation of the exfoliated cells. Tests such as Hemoccult help to discover occult blood in the secreted fluid. Modern immunological tests can be performed on cytology smears where occurrence of high levels of carcinoembryonic antigen could indicate a latent malignancy. Galactography investigation is today the state-of-the-art approach to investigate patients with nipple discharge disorders and this examination can demonstrate the size, location and extent of an intraductal abnormality. Modern high-resolution ultrasound techniques are helpful in visualizing intraductal disorders and are becoming a good complementary approach if not an alternative to traditional radiology techniques. Recently even MR galactography has been shown to be of diagnostic value, but not as informative as regular galactography. The most sophisticated investigation method, which can also be used therapeutically, is fiber-ductoscopy of the concerned duct in a breast. This technique, although expensive and in its infancy, is a fascinating and promising approach for inspecting the intraductal lumina. In this article the background, current investigation methods and possibilities of the technique are described, as well as the most sophisticated ways to deal with nipple discharge disorders in human

  2. Current role of NAA in biological and health-related environmental studies as exemplified by programs of the IAEA

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) has many projects and activities supporting the utilization of nuclear research reactors for neutron activation analysis (NAA). Globally the number of operating nuclear research reactors has been in decline since about 1975. This contrasts with the situation in developing countries where the numbers show a modest increase over the same period. This paper reviews the current status of NAA as seen from the particular perspective of IAEA programs involving studies of biological and environmental specimens. Some of the areas in which NAA is maintaining its role as a competitive technique are briefly reviewed. (author)

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

    International Nuclear Information System (INIS)

    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.)

  4. 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.)

  5. Habituation-Like Decrease of Acetylcholine-Induced Inward Current in Helix Command Neurons: Role of Microtubule Motor Proteins.

    Science.gov (United States)

    Vasil'yeva, Natal'ya A; Murzina, Galina B; Pivovarov, Arkady S

    2015-07-01

    The role of kinesin and dynein microtubule-associated molecular motors in the cellular mechanism of depression of acetylcholine-induced inward chloride current (ACh-current) was examined in command neurons of land snails (Helix lucorum) in response to repeated applications of ACh to neuronal soma. This pharmacological stimulation imitated the protocol of tactile stimulation evoking behavioural habituation of the defensive reaction. In this system, a dynein inhibitor (erythro-9-(2-hydroxy-3-nonyl)adenine, 50 µM) decreased the ACh-current depression rate. Kinesin Eg5 inhibitors (Eg5 inhibitor III, 10 µM and Eg5 inhibitor V, trans-24, 15 µM) reduced the degree of current depression, and Eg5 inhibitor V also reduced the initial rate of depression. The results of electrophysiological experiments in combination with mathematical modelling provided evidence of the participation of dyneins and kinesin Eg5 proteins in the radial transport of acetylcholine receptors in command neurons of H. lucorum in the cellular analogue of habituation. Furthermore, these results suggest that the reciprocal interaction between dynein and kinesin proteins located on the same vesicle can lead to reverse their usual direction of transport (dyneins-in exocytosis and kinesin Eg5-in endocytosis). PMID:25687906

  6. Current Evidence for a Role of the Kynurenine Pathway of Tryptophan Metabolism in Multiple Sclerosis

    Science.gov (United States)

    Lovelace, Michael D.; Varney, Bianca; Sundaram, Gayathri; Franco, Nunzio F.; Ng, Mei Li; Pai, Saparna; Lim, Chai K.; Guillemin, Gilles J.; Brew, Bruce J.

    2016-01-01

    KP inhibitors are currently in clinical trials for other neurological diseases, and hence may make suitable candidates for MS patients. Underpinning these drug discovery endeavors, in recent years, several advances have been made in how KP metabolites are assayed in various biological fluids, and tremendous advancements have been made in how specimens are imaged to determine disease progression and involvement of various cell types and molecules in MS.

  7. Renoprotective effect of alprostadil in combination with statins in patients with mild to moderate renal failure undergoing coronary angiography

    Institute of Scientific and Technical Information of China (English)

    LIU Wei-jing; ZHANG Bu-chun; GUO Rong; WEI Yi-dong; LI Wei-ming; XU Ya-wei

    2013-01-01

    Background The role of alprostadil and statins in contrast-induced acute kidney injury (CI-AKI) is controversial.The purpose of this study was to explore the efficacy of combined therapy with alprostadil and statins in protecting renal function and preventing contrast-induced nephropathy (CIN) in patients undergoing coronary angiography.Methods A total of 156 consecutive patients with mild to moderate renal failure who underwent coronary angiography were enrolled in our study,and randomly categorized into two groups.In the statins group,80 patients were treated with statins before and after coronary angiography.in the alprostadil plus statins group,76 patients were treated with statins and alprostadil before and after coronary angiography.Serum creatinine (SCr),serum cystatin (CysC) and neutrophil gelatinase-associated lipocalin (NGAL) were detected after administration of contrast media,and adverse events were evaluated within six months.Results In both groups,the SCr,CysC and NGAL significantly increased after coronary angiography and peaked at 48,24 and 6 hours,respectively.SCr,CysC and NGAL were significantly lower in the alprostadil plus statins group than in the statins group (P<0.05).The incidence of CIN in the alprostadil plus statins group was slightly lower than in the statins group.The incidence of adverse events within six months in the alprostadil plus statins group was significantly lower than in the statins group (P=0.034).Conclusions Intravenous alprostadil in combination with oral statins is superior to statins alone for protecting renal function in patients with mild to moderate renal dysfunction who undergo coronary angiography,and can reduce the incidence of adverse events seen within six months.

  8. 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)

  9. Quantification of extracranial stenoses of the cartoid artery - MR angiography and Doppler sonography vs intraarterial angiography

    International Nuclear Information System (INIS)

    To assess various non-invasive techniques for quantifying internal carotid artery CA stenosis, per cent luminal diameter reduction on intraarterial angiograms (IAA) was measured in 63 patients with ICA stenosis or occulsion. These data were compared with independent measurements based on MR-angiography, continuous-wave (cw) Doppler ultrasonography, systolic peak flow velocity and colour Doppler assisted duplex imaging. Correlations with IAA were equally strong for MR angiography, cw Doppler and colour Doppler analysis (0.95, 0.92; 0.92). Positive predictive values for ≥70% ICA stenosis were lower and negative predictive values were higher for cw Doppler (0.85; 0.92) and colour duplex analysis (0.81; 0.94) than for MR angiography (0.86; 0.88). Statistical analysis showed non-linear correlations between percentage of lumen diameter narrowing and the length of the zone of signal intensity loss (0.72) and maximum systolic peak flow velocity (0.77). Conclusion: Several non-invasive methods do compare with IAA in identifying and quantifying highgrade ICA stenosis and may suffice for decisions on treatment. (orig.)

  10. 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.

  11. 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)

  12. Radiation dose in digital subtraction angiography

    International Nuclear Information System (INIS)

    A phantom study using thermoluminescence dosimeter was undertaken to compare radiation doses from five different imaging systems used in digital subtraction angiography (DSA). Red bone marrow and maximum skin doses were generally high. Depending upon the system, the maximum skin dose ranged from 202 to 53 mGy. Based on these results, the maximum skin dose was obtained in the clinical setting. The average dose in patients was 175 mGy for arterial DSA and 250 mGy for intravenous DSA. For radiologists, radiation doses to the lens, fingers of the right hand, and thyroid gland were 0.34, 0.27, and 0.4 mGy, respectively, in the case of mannual injection of contrast media; and undetectable, 0.029, and 0.0143 mGy, respectively, in the case of automatic injection. (Namekawa, K.)

  13. 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 the...... 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...

  14. Digital subtraction angiography in extremity trauma

    International Nuclear Information System (INIS)

    Digital subtraction angiography (DSA) may have considerable impact on the work-up of patients who have suffered trauma. The angiographic evaluation of vascular injuries can be accomplished rapidly and with minimal catheter use and manipulation, which is particularly important for those critically ill patients who have significant immobility because of multiple fractures. The authors retrospectively reviewed the digital subtraction angiograms in 50 consecutive cases of extremity trauma. The quality of the images in 44 of these permitted a confident diagnosis, the accuracy of which was confirmed by surgical or clinical follow-up. DSA reduces the time required to perform the procedure, the amount of contrast material injected, patient discomfort, and film cost. Its major disadvantage is the limited field size of the image intensifier

  15. Intraarterial digital subtraction angiography of aortofemoral bypasses

    International Nuclear Information System (INIS)

    In a retrospective study, 214 digital subtraction angiography (DSA) examinations of aortofemoral and femorocrural bypasses were reviewed. In 90% of cases intravenous DSA was diagnostic for aortofemoral bypasses, and in 95% of cases intrarterial DSA angiograms of excellent image quality were obtained. In 82% arterial stenoses proximal to the bypass, in 62% stenoses distal to the bypass, and in only 15% stenoses involving the bypass itself could be detected. In 54% the bypass was regularly perfused. In 26% a complete occlusion could be seen. All angiograms were obtained after infusion of the low-osmolar nonionic contrast medium Iopromide, 150mg/ml. All examinations were painless, and no heat-induced motion artifacts were registered. No disturbances of vital signs were observed. DSA with a nonionic low-osmolarity contrast medium (Iopromide) is a safe and reliable technique for the examination of all surgical aortofemoral bypasses

  16. [Leopard-spot pattern in fluorescein angiography].

    Science.gov (United States)

    Friedel, S; Polak, A

    2013-04-01

    The uveal effusion syndrome is a rare disease characterized by serous choroidal detachment. The pathogenesis of idiopathic uveal effusion syndrome has not yet been conclusively established. One hypothesis is an abnormality of diffusion of extravascular proteins in the choroid leading to decompensation of the pigment epithelium pumping capacity. Fluid then accumulates in the subretinal space leading to retinal detachment which results in loss of visual acuity. It typically affects males and hypermetropia is another risk factor. When looking at the fundus a circular serous detachment of the choroid and choroidal puckering is typical. The fluorescein angiography shows hyperfluorescence in the form of a leopard-spot pattern. Space-occupying lesions have to be excluded with the help of ultrasound or magnetic resonance tomography. The uveal effusion syndrome is a diagnosis by exclusion. Treatment varies because of the different hypotheses for the pathogenesis. An intraocular tamponade in combination with laser coagulation may for example be an effective treatment. PMID:23338531

  17. Contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Magnetic resonance angiography (MRA) protocols are based on standard sequence protocols like time of flight MRA, which evaluates inflowing spins. This technique is limited by a variety of artifacts like the saturation artifact via turbulent blood flow. Contrast media diminish these artifacts like extracellular agents and blood-pool contrast media. The clinical value of the contrast-enhanced MRA for cerebral pathologies is based on the use of the paramagnetic contrast agent Gd-DTPA. For extracerebral diseases this technique is restricted because of the simultaneous visualization of both arterial and venous vascular territorities. Occult venous sinus thrombosis or AV malformations are clinical essential indications for the use of C-MRA. Experimental data prove the excellent contrast abilities of blood-pool agents like Gd-DTPA-polylysin or Gd-DTPA-albumin, which demonstrate long intravascular persistence and retarded excretion. (orig.)

  18. MR angiography of the iliofemoral artery system

    International Nuclear Information System (INIS)

    During the last years, magnetic resonance angiography (MRA) has become a widely used modality for intracerebral and carotid artery imaging. Due to technical limitations, the clinical impact of MRA in the iliofemoral arteries has been rather poor. New developments in MRA like ECG-triggered sequences and the occurrence of contrast-enhanced MRA has overcome most of these limitations. Therefore, a major advance in clinical use of these diagnostic tools can be predicted. This paper discussed the advantages of ECG-gated 2D-Phase contrast, ECG-gated 2D-Time-of-Flight and contrast enhanced FLASH 3D angiography sequences from a clinical point of view. 2D-PC-MRA is a robust technique, which provides an overview of the iliofemoral artery system in less than 5 minutes. Limitations are the true 2D impression of the sequence and the partial venous overlay. 2D-TOF-MRA on the other hand is time consuming, however it enables 3D reconstruction and effective venous suppression can be applied. Contrast enhanced MRA as the third sequence discussed provides high resolution images in less than 30 sec. However contrast bolus timing might be a problem. In conclusion the authors suggest a combination of 2D-PC-MRA and additional 2D-TOF sequences at questionable vacular areas as the modality of choice, due to the fact, that MRA of the iliofemoral arteries is mostly only one step of a complete lower limb examination. Contrast MRA might become the method of choice in the future however problems with multiple contrast injections and upper limits of contrast dose have to be solved. (orig.)

  19. 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.

  20. Multidetector CT angiography in Takayasu arteritis

    International Nuclear Information System (INIS)

    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.

  1. Assessment of moyamoya disease with 3.0-T magnetic resonance angiography and magnetic resonance imaging versus conventional angiography

    International Nuclear Information System (INIS)

    3.0-T magnetic resonance (MR) angiography and MR imaging were compared with conventional angiography for the evaluation of moyamoya disease in 13 preoperative patients (26 hemispheres) with moyamoya disease (4 males and 9 females aged 21-54 years). The correlation between MR angiography scores determined by modified Houkin's grading system (MRA score) and conventional angiography stages determined by Suzuki's grading system (CA stage) was analyzed. Other MR findings such as moyamoya vessel scores, ''ivy sign'' scores, and the presence of small, medium, and large cerebrovascular attack (CVA) lesions were compared with CA stages. MRA scores were significantly correlated with CA stages (p<0.01). Moyamoya vessel scores correlated well with CA stages (p<0.01). There was no significant correlation between ''ivy sign'' scores and CA stages, and no significant differences in CA stages with the presence and absence of CVA lesions of any size. 3.0-T MR angiography can be used as a vascular assessment in moyamoya disease with its priority of noninvasive nature and visual clarity compared with conventional angiography. The findings of 3.0-T MR angiography may reflect the steno-occlusive changes in moyamoya disease. (author)

  2. Mediation and moderation of the effects of watching the angiography screen on patients.

    Science.gov (United States)

    Shiloh, Shoshana; Drori, Erga; Peleg, Shira; Banai, Shmuel; Finkelstein, Ariel

    2016-10-01

    It has been reported that allowing patients to watch the coronary angiography screen during the procedure results in psychological benefits. This study aimed to investigate the roles of illness perceptions as mediators of this outcome and to examine whether individual differences in monitoring coping style moderated these effects. The experiment compared patients who were instructed to watch the monitor screen (n = 57) with those who were not (n = 51). Questionnaires were used to measure the research variables at one day and one month after the procedure. Results showed that watching the angiography screen increased patients' personal and treatment control perceptions that mediated changes in self-assessed health, risk perceptions, negative affect, general and diet outcome expectancies, and diet and physical activity intentions. The behavior-related outcomes were moderated by monitoring coping style. These findings illustrate the significance of illness perceptions, perceived control and monitoring coping style in achieving desirable outcomes among patients undergoing coronary angiography, and reveal opportunities for interventions using medical imaging technologies. PMID:26740003

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

    Science.gov (United States)

    Alkadhi, Hatem; Schindera, Sebastian T

    2011-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistr. 100, 8091 Zurich (Switzerland); Schindera, Sebastian T. [Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital Berne, University of Berne, Berne (Switzerland)

    2011-10-15

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

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

    International Nuclear Information System (INIS)

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

  6. Role of Pulmonary Angiography in Congenital Heart Diseases among Children

    Directory of Open Access Journals (Sweden)

    Kavita U Vaishnav

    2013-08-01

    Full Text Available CT is a useful imaging modality for the morphologic evaluation of CHD. CT is useful in identifying different types of congenital anomalies of the cardiovascular system in children. It is essentially useful in the evaluation of vascular anomalies located outside the heart and in the assessment of complications that occur post operatively. [Natl J Med Res 2013; 3(4.000: 332-337

  7. 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

  8. Prevalence and Characteristics of Myocardial Bridging in Multidetector-Row Computed Tomography Coronary Angiography

    International Nuclear Information System (INIS)

    Background: Myocardial bridging (MB) are congenital defects of the coronary arteries in which a segment of an epicardial artery lies in the myocardium for part of its course. The current gold standard for diagnosing MB is coronary angiography; however other invasive techniques are also useful. Myocardial bridging can also be visualized with the use of novel non-invasive imaging techniques such as multidetector-row computed tomography coronary angiography (MDCT-CA). Objectives: To assess the prevalence and characteristics of myocardial bridging in patients undergoing multidetector-row computed tomography coronary angiography (MDCT-CA). Material and Methods: A total of 452 consecutive patients were evaluated with 16-row and 64-row MDCT-CA due to the presence of abnormal findings in myocardial perfusion image tests, symptoms suggestive of coronary artery disease, and in asymptomatic patients with a family history of coronary artery disease. The presence of MB, their location and characteristics were analyzed. Myocardial bridging were classified as complete and incomplete bridges with respect to continuity of the myocardium over the tunneled segment of the artery involved. Quantitative measurements of vessel diameter during systole and diastole were evaluated. Results: The prevalence of MB was 35.18%; 88 were complete and 71 incomplete. Among complete MB, 6 affected both systole and diastole, 27 presented only systolic compression and 55 showed no compression. Incomplete MB showed absence of arterial compression. Conclusions: Multidetector-row computed tomography coronary angiography detected a higher prevalence of MB in the study population and allowed to classify them and to assess their functional aspects throughout the cardiac cycle. (authors)

  9. Digital angiography and surgery in the same room

    International Nuclear Information System (INIS)

    Albany Medical Center and private industries (XRE and United X-ray corporations) have collaborated to develop a room within the operating suite that allows high-speed and high-resolution digital angiography and surgery to be performed simultaneously. Patients who have sustained massive trauma can be transferred directly from the ambulance to this new facility. While the patient is undergoing exploratory laparotomy, other vital areas of the body can be evaluated by angiography. This combined approach of surgery and angiography has also led to improved management of patients with massive or occult intestinal hemorrhage and patients with peripheral vascular disease. Other patients undergoing difficult emergency or elective surgery, as in the biliary tract, can now have available the benefits of an operating room facility that also allows high-resolution fluoroscopy and complete angiography to be undertaken

  10. 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)

  11. Superselective pseudo-continuous arterial spin labeling angiography

    International Nuclear Information System (INIS)

    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

  12. 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

  13. Computed tomography angiography in the investigation of carotid stenosis

    International Nuclear Information System (INIS)

    The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. Goddard, A.J. P.et al. (2001)

  14. Computed tomography angiography in the investigation of carotid stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, A.J.P.; Mendelow, A.D.; Birchall, D

    2001-07-01

    The assessment of carotid atherosclerotic disease is an essential pre-requisite for determining a patients suitability for carotid endarterectomy to prevent ischaemic stroke. Catheter angiography is regarded as the most accurate investigative tool for this purpose. However, with its finite morbidity and invasiveness, there is an increasing reliance upon non-invasive methods to accurately assess carotid disease. We present a review of the technique and applications of computed tomography angiography. Goddard, A.J. P.et al. (2001)

  15. 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...

  16. Diagnostic and therapeutic results of angiography of blunt abdominal trauma

    International Nuclear Information System (INIS)

    Angiographic findings in blunt abdominal trauma are reviewed. 693 posttraumatic angiograms were performed at the University of Freiburg from 1972-1980. 24% of these patients suffered from blunt abdominal trauma. It could be shown that recently ultrasongraphy and computerized tomography have replaced angiography as screening method. Remaining indications for angiography are primary vascular lesions, uncertain findings of US- and/or C Texamination and documentation of hemorrhage with the possibility of therapeutic intervention. (orig.)

  17. Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sijie; Gillin, W. P., E-mail: w.gillin@qmul.ac.uk [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Willis, M. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Gotto, R.; Roy, K. A.; Kreouzis, T. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Rolfe, N. J. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); University of Surrey, Guildford, Surrey GU2 5XH (United Kingdom)

    2014-01-27

    The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminium tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. The diagnosis value of pulmonary perfusion/ventilation imaging for pulmonary embolism: in comparison with pulmonary artery angiography

    International Nuclear Information System (INIS)

    Objective: To evaluate the value of the pulmonary perfusion/ventilation imaging in diagnosis of pulmonary embolism (PE). Methods: Forty-five patients undergone pulmonary radionuclide imaging and pulmonary artery angiography in Fuwai Hospital were analyzed retrospectively. Results: Twenty-six patients were diagnosed as with PE by pulmonary angiography. For the pulmonary segments with complete filling defect on pulmonary artery angiography, the coincidence rate was 92.7% between the angiography and radionuclide pulmonary imaging, while the pulmonary segments with partial filling defect, the coincidence rate was 73.2% (P<0.01). The sensitivity and specificity were 92.3% and 84.2%, respectively. Both the positive predictive value and negative predictive value were 88.9%. Out of 26 patients with PE, 23 patients had also pulmonary ventilation imaging. The results showed mismatch between pulmonary perfusion and ventilation imaging in all of the 23 patients. Conclusion: The pulmonary perfusion plus pulmonary ventilation imaging plays an important role in diagnosing PE

  3. Relative roles of local disturbance, current climate and palaeoclimate in determining phylogenetic and functional diversity in Chinese forests

    Directory of Open Access Journals (Sweden)

    G. Feng

    2013-09-01

    Full Text Available The main processes underlying the generation and maintenance of biodiversity include both local factors such as competition and abiotic filtering and regional forces such as palaeoclimate, speciation and dispersal. While the effects of regional and local drivers on species diversity are increasingly studied, their relative importance for other aspects of diversity, notably phylogenetic and functional diversity is so far little studied. Here, we link data from large Chinese forest plots to data on current and Last Glacial Maximum (LGM climate as well as local disturbance regimes to study their relative roles in determining woody plant phylogenetic and functional diversity in this important hotspot for woody plant diversity. Local disturbance was the best predictor of functional diversity as represented by maximum canopy height (Hmax, probably reflecting the dominant role of competition for light in determining the forest Hmax structure. In contrast, the LGM-present anomaly in temperature was the factor with the strongest explanatory power for phylogenetic diversity, with modern climate also important. Hence, local contemporary and regional historical factors have highly contrasting importance for the geographic patterns of the functional and phylogenetic aspects of Chinese forest woody plant diversity. Importantly, contemporary factors are of overriding importance for functional diversity, while palaeoclimate has left a strong signature in the phylogenetic diversity patterns.

  4. Current Understanding on the Role of Standard and Immunoproteasomes in Inflammatory/Immunological Pathways of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Elena Bellavista

    2014-01-01

    Full Text Available The ubiquitin-proteasome system is the major intracellular molecular machinery for protein degradation and maintenance of protein homeostasis in most human cells. As ubiquitin-proteasome system plays a critical role in the regulation of the immune system, it might also influence the development and progression of multiple sclerosis (MS. Both ex vivo analyses and animal models suggest that activity and composition of ubiquitin-proteasome system are altered in MS. Proteasome isoforms endowed of immunosubunits may affect the functionality of different cell types such as CD8+ and CD4+ T cells and B cells as well as neurons during MS development. Furthermore, the study of proteasome-related biomarkers, such as proteasome antibodies and circulating proteasomes, may represent a field of interest in MS. Proteasome inhibitors are already used as treatment for cancer and the recent development of inhibitors selective for immunoproteasome subunits may soon represent novel therapeutic approaches to the different forms of MS. In this review we describe the current knowledge on the potential role of proteasomes in MS and discuss the pro et contra of possible therapies for MS targeting proteasome isoforms.

  5. Toward Understanding the Role of Aryl Hydrocarbon Receptor in the Immune System: Current Progress and Future Trends

    Directory of Open Access Journals (Sweden)

    Hamza Hanieh

    2014-01-01

    Full Text Available The immune system is regulated by distinct signaling pathways that control the development and function of the immune cells. Accumulating evidence suggest that ligation of aryl hydrocarbon receptor (Ahr, an environmentally responsive transcription factor, results in multiple cross talks that are capable of modulating these pathways and their downstream responsive genes. Most of the immune cells respond to such modulation, and many inflammatory response-related genes contain multiple xenobiotic-responsive elements (XREs boxes upstream. Active research efforts have investigated the physiological role of Ahr in inflammation and autoimmunity using different animal models. Recently formed paradigm has shown that activation of Ahr by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or 3,3′-diindolylmethane (DIM prompts the differentiation of CD4+Foxp3+ regulatory T cells (Tregs and inhibits T helper (Th-17 suggesting that Ahr is an innovative therapeutic strategy for autoimmune inflammation. These promising findings generate a basis for future clinical practices in humans. This review addresses the current knowledge on the role of Ahr in different immune cell compartments, with a particular focus on inflammation and autoimmunity.

  6. Feedback-Controlled Transcranial Alternating Current Stimulation Reveals a Functional Role of Sleep Spindles in Motor Memory Consolidation.

    Science.gov (United States)

    Lustenberger, Caroline; Boyle, Michael R; Alagapan, Sankaraleengam; Mellin, Juliann M; Vaughn, Bradley V; Fröhlich, Flavio

    2016-08-22

    Transient episodes of brain oscillations are a common feature of both the waking and the sleeping brain. Sleep spindles represent a prominent example of a poorly understood transient brain oscillation that is impaired in disorders such as Alzheimer's disease and schizophrenia. However, the causal role of these bouts of thalamo-cortical oscillations remains unknown. Demonstrating a functional role of sleep spindles in cognitive processes has, so far, been hindered by the lack of a tool to target transient brain oscillations in real time. Here, we show, for the first time, selective enhancement of sleep spindles with non-invasive brain stimulation in humans. We developed a system that detects sleep spindles in real time and applies oscillatory stimulation. Our stimulation selectively enhanced spindle activity as determined by increased sigma activity after transcranial alternating current stimulation (tACS) application. This targeted modulation caused significant enhancement of motor memory consolidation that correlated with the stimulation-induced change in fast spindle activity. Strikingly, we found a similar correlation between motor memory and spindle characteristics during the sham night for the same spindle frequencies and electrode locations. Therefore, our results directly demonstrate a functional relationship between oscillatory spindle activity and cognition. PMID:27476602

  7. Current role of radial and curved-linear arrayed EUS scopes for diagnosis of pancreatic abnormalities in Japan.

    Science.gov (United States)

    Irisawa, Atsushi

    2011-05-01

    To elucidate the current status of radial and curved-linear arrayed endoscopic ultrasonography (EUS), the author conducted a survey using a questionnaire at different institutions to assess the following. 1. Number of EUS procedures conducted annually for pancreatic malignancies. 2. Role of radial arrayed EUS for pancreatic abnormalities. 3. Role of curved-linear arrayed EUS for pancreatic abnormalities. 4. Indication of EUS-guided fine-needle aspiration biopsy (EUS-FNA) for pancreatic abnormalities. 5. Percentage of EUS-FNA among the cases carried out with EUS for pancreatic abnormalities. 6. Experience of EUS with contrast harmonic echo for pancreatic malignancies and its indications. 7. Experience of elastography on EUS for pancreatic abnormalities. In Japan, although usage of curved-linear arrayed EUS has become popular for both EUS-FNA and for screening, radial EUS is widely used for diagnosing pancreatic abnormalities. Endosonographers must understand the respective advantages and disadvantages of EUS devices and carry out EUS procedures appropriately. PMID:21535192

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

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    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.)

  9. 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.)

  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. Physical principles of cardiac digital subtraction angiography

    International Nuclear Information System (INIS)

    Advances in the applications of computers with standard radiologic equipment have resulted in the development of electronic, or so-called ''film-less'' imaging. This technique, discussed by the authors, has become of particular value in the visualization of the central vascular system and has become known as digital subtraction angiography (DSA). Commercial products have become increasingly available and are capable of converting T.V. signals, obtained by conventional fluorography, to a computed array of digital values. Addition, subtraction, and averaging of this data, result in images with adequate signal-to-noise ratios that achieve detection of low concentrations of contrast media not possible with conventional screen film techniques. Computer subtraction of unnecessary background information improves the conspicuity of the opacified vessels to permit detection of vascular structures containing a concentration of no more than 1-3 percent of contrast media. This improved visualization is possible even with intravenous peripheral injections or reduced amounts of contrast media given intraarterially. With either method of contrast media administration, DSDA has become an excellent means of anatomic demonstration of the heart and great vessels with decreased morbidity and at lower cost

  12. Localization strategy for magnetic resonance coronary angiography

    International Nuclear Information System (INIS)

    Objective: To develop a localization strategy for magnetic resonance coronary angiography (MRCA). Methods: In 89 subjects, the standard 4-chamber view and long-axis view of left and right ventricle were acquired using Fast-Imaging-Employing-Steady-State-Acquisition (FIESTA) sequence in CINE mode, and the trigger-delay time for mid-diastolic phase was determined. Coronary vessels including right coronary artery (RCA), left main (LM), left anterior descending (LAD), and left circumflex (LCX) were localized and imaged using 3- dimensional fat-suppressed FIESTA sequence during end-expiration. The reproducibility of the localization strategy was evaluated by taking the standard of coronary segmentation system recommended by American Heart Association. Results: Eighty-six subjects completed the examination with full respiratory co-operation and the indication ratio was 96.63%. Nine planes were optimized as the standard to target the main branches of coronary arteries, and a comprehensive reproducibility reached 100% in demonstrating the proximal and middle segment of RCA (AHA-18, 19), LM (AHA-1, 2), proximal and middle segment of LAD (AHA-3, 5, 7), and proximal LCX (AHA-10). The reproducibility for the demonstration of distal segments of LAD, LCX, and RCA (AHA-9, 14, 21) was 94.19%, 72.09%, and 96.51%, respectively. Conclusion: This is a simple and practical localization strategy for MRCA. It could image the proximal and middle segments of the coronary arteries with good reproducibility, which indicates the potential for clinical application

  13. Indocyanine green angiography findings in patients with long-standing Vogt-Koyanagi-Harada disease: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    da Silva Felipe T

    2012-08-01

    Full Text Available Abstract Background To investigate indocyanine green angiography (ICGA findings in patients with long-standing Vogt-Koyanagi-Harada (VKH disease and their correlation with disease activity on clinical examination as well as with systemic corticosteroid therapy. Methods Twenty-eight patients (51 eyes with long-standing (≥6 months from disease onset VKH disease whose treatment was tapered based only in clinical features were prospectively included at a single center in Brazil. All patients underwent standardized clinical evaluation, which included fundus photography, fluorescein angiography and ICGA. Clinical disease activity was determined based in the Standardization in Uveitis Nomenclature Working Group. Fisher exact test and logistic regression models were used for statistical analysis. Results Disease-related choroidal inflammation on ICGA was observed in 72.5% (31 of 51 eyes. Angiographic findings suggestive of (choroidal and/or retinal disease activity were not observed on FA. Clinically active disease based on clinical evaluation was observed in 41.2% (21 of 51 eyes. In these 21 eyes, disease-related choroidal inflammation on ICGA was observed in 76.2% (16 of 21 eyes; in the remaining eyes (without clinical active disease disease-related choroidal inflammation on ICGA was observed in 70.0% (21 of 30 eyes. In respect to systemic corticosteroid therapy, 10 patients (18 of 51 eyes were under treatment with prednisone. In these 10 (18 of 51 eyes patients, disease-related choroidal inflammation on ICGA was observed in 83.3% (15 of 18 eyes; in the remaining patients (33 of 51 eyes disease-related choroidal inflammation on ICGA was observed in 66.7% (22 of 33 eyes. Conclusion ICGA findings suggestive of disease-related choroidal inflammation were observed in a considerable proportion of patients with long-standing VKH disease, independent of the inflammatory status of the disease on clinical examination or current use of systemic

  14. MDCT angiography of the major congenital anomalies of the extracranial arteries: pictorial review

    International Nuclear Information System (INIS)

    Multidetector computed tomographic angiography is becoming the modality of choice for evaluation of the supra-aortic circulation in acute stroke imaging. Variations of the supra-aortic circulation, in particular of the extracranial arteries, are common. This article aims to provide a pictorial description of the variant anatomy of the aortic arch and extracranial arteries. Knowledge of the presence and clinical relevance of normal variants such as anomalies, duplications and embryological persistence plays a clinically relevant role in the diagnosis and management of neurological and surgical conditions, particularly as we enter an era of increasing extracranial intervention.

  15. Assessment of coronary artery disease using coronary computed tomography angiography and biochemical markers

    Institute of Scientific and Technical Information of China (English)

    Gitsios; Gitsioudis; Hugo; A; Katus; Grigorios; Korosoglou

    2014-01-01

    Chronic inflammatory mechanisms in the arterial wall lead to atherosclerosis,and include endothelial cell damage,inflammation,apoptosis,lipoprotein deposition,calcification and fibrosis.Cardiac computed tomography angiography(CCTA)has been shown to be a promising tool for non-invasive assessment of theses specific compositional and structural changes in coronary arteries.This review focuses on the technical background of CCTA-based quantitative plaque characterization.Furthermore,we discuss the available evidence for CCTA-based plaque characterization and the potential role of CCTA for risk stratification of patients with coronary artery disease.

  16. Choroid plexus papilloma of the third ventricle: angiography, preoperative embolization, and histology

    Energy Technology Data Exchange (ETDEWEB)

    Do, H.M. [Interventional Neuroradiology, S-047, Department of Radiology, Stanford University Medical Center (United States); Dept. of Radiology, University of Virginia Health Sciences Center, Charlottesville, VA (United States); Marx, W.F. [Dept. of Radiology, University of Virginia Health Sciences Center, Charlottesville, VA (United States); Khanam, H. [Dept. of Pathology, University of Virginia Health Sciences Center, Charlottesville, VA (United States); Jensen, M.E. [Dept. of Radiology, University of Virginia Health Sciences Center, Charlottesville, VA (United States); Dept. of Neurosurgery, University of Virginia Health Sciences Center, Charlottesville, VA (United States)

    2001-06-01

    We report a unique case of choroid plexus papilloma of the third ventricle in an 8-month-old girl in which preoperative embolization played a salient role in management. Initial surgery was aborted due to excessive bleeding. Cerebral angiography demonstrated enlarged posterior choroidal arteries feeding the tumor, and intense, persistent tumor staining. These vessels were effectively embolized to stasis with polyvinyl alcohol particles. The patient underwent a second craniotomy and complete resection of the tumor with minimal blood loss. Postsurgical histology showed postembolization iatrogenic intratumoral necrosis. (orig.)

  17. Detection and characterization of intracranial aneurysms: magnetic resonance angiography versus digital subtraction angiography

    International Nuclear Information System (INIS)

    Objective: To compare magnetic resonance angiography (MRA) with Intra-arterial digital subtraction angiography (IA-DSA) in detection and characterization of intracranial aneurysms. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Diagnostic Imaging, Lahore General Hospital, Lahore, from January to June 2007. Methodology: Thirty patients presented with aneurysmal subarachnoid haemorrhage (SAH) and focal neurological signs were selected by convenience sampling. Three dimensional time of flight (3D TOF) MRA using maximum intensity projection (MIP) was performed on all patients along with DSA. Results of 3D TOF MRA were compared with those of IA-DSA taking IA-DSA as Gold standard. Results: Out of 30 patients 14 (46.7%) were males and 16 (53.3%) were females with mean age of 41+-14.1 years. MRA detected 29 out of 30 aneurysmal lesions with sensitivity of 96.7%. Regarding characterization of aneurysms results of MRA were comparable to those of IA-DSA. Conclusion: 3D TOF MRA technique showed a high sensitivity in this study. This technique can be used as a non-invasive screening test for intracranial aneurysms and as a suitable alternative primary examination to IA-DSA prior to aneurysmal surgery. (author)

  18. 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

  19. Indocyanine green-based fluorescent angiography in breast reconstruction

    Science.gov (United States)

    Chae, Michael P.; Rozen, Warren Matthew

    2016-01-01

    Background Fluorescent angiography (FA) has been useful for assessing blood flow and assessing tissue perfusion in ophthalmology and other surgical disciplines for decades. In plastic surgery, indocyanine green (ICG) dye-based FA is a relatively novel imaging technology with high potential in various applications. We review the various FA detector systems currently available and critically appraise its utility in breast reconstruction. Methods A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE was undertaken. Results In comparison to the old fluorescein dye, ICG has a superior side effect profile and can be accurately detected by various commercial devices, such as SPY Elite (Novadaq, Canada), FLARE (Curadel LLC, USA), PDE-Neo (Hamamatsu Photonics, Japan), Fluobeam 800 (Fluoptics, France), and IC-View (Pulsion Medical Systems AG, Germany). In breast reconstruction, ICG has established as a safer, more accurate tracer agent, in lieu of the traditional blue dyes, for detection of sentinel lymph nodes with radioactive isotopes (99m-Technetium). In prosthesis-based breast reconstruction, intraoperative assessment of the mastectomy skin flap to guide excision of hypoperfused areas translates to improved clinical outcomes. Similarly, in autologous breast reconstructions, FA can be utilized to detect poorly perfused areas of the free flap, evaluate microvascular anastomosis for patency, and assess SIEA vascular territory for use as an alternative free flap with minimal donor site morbidity. Conclusions ICG-based FA is a novel, useful tool for various applications in breast reconstruction. More studies with higher level of evidence are currently lacking to validate this technology. PMID:27047782

  20. Inferior vena cava leiomyosarcoma confirmed by catheter suction biopsy during digital subtraction angiography.

    Science.gov (United States)

    Wei, Ning; Xu, Xiang-Dong; Xu, Hao; Zu, Mao-Heng

    2014-01-01

    Leiomyosarcoma of vascular origin is a rare disease and most cases arise in the inferior vena cava. Inferior vena cava leiomyosarcoma (IVCLMS) usually presents in females in their sixth decade of life. The clinical symptoms are often non-specific and the diagnosis is often delayed. Current imaging techniques can accurately differentiate inferior vena cava neoplasms from other non-neoplastic lesions. However, definitive diagnosis of IVCLMS needs histologic evidence. We report a case of IVCLMS in a 61-year old Chinese woman. This is the first IVCLMS case confirmed by catheter suction biopsy during digital subtraction angiography. PMID:25232438

  1. 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.

  2. Consensus report: the current role of self-monitoring of blood glucose in non-insulin-treated type 2 diabetes.

    Science.gov (United States)

    Klonoff, David C; Blonde, Lawrence; Cembrowski, George; Chacra, Antonio Roberto; Charpentier, Guillaume; Colagiuri, Stephen; Dailey, George; Gabbay, Robert A; Heinemann, Lutz; Kerr, David; Nicolucci, Antonio; Polonsky, William; Schnell, Oliver; Vigersky, Robert; Yale, Jean-François

    2011-11-01

    The Coalition for Clinical Research--Self-Monitoring of Blood Glucose Scientific Board convened a meeting in San Francisco, CA, July 20-21, 2011, to discuss the current practice of self-monitoring of blood glucose (SMBG) in non-insulin-treated (NIT) type 2 diabetes mellitus (T2DM). Twelve physician panel members from academia, practice, and government attended this meeting. These experts came from the United States, Brazil, Canada, France, Germany, Italy, and the United Kingdom. In addition, three consultants from Australia, Germany, and the United States contributed to the group's final report. This coalition was organized by Diabetes Technology Society. Self-monitoring of blood glucose was studied from eight perspectives related to patients with NIT T2DM: (1) epidemiological studies; (2) randomized controlled trials (RCT)s and meta-analyses; (3) targets, timing, and frequency of SMBG use; (4) incidence and role of SMBG in preventing hypoglycemia with single-drug regimens and combination regimens consisting of antihyperglycemic agents other than secretagogues and insulin; (5) comparison of SMBG with continuous glucose monitoring; (6) technological capabilities and limitations of SMBG; (7) barriers to appropriate use of SMBG; and (8) methods and end points for appropriate future clinical trials. The panel emphasized recent studies, which reflect the current approach for applying this intervention. Among the participants there was consensus that: SMBG is an established practice for patients with NIT T2DM, and to be most effective, it should be performed in a structured format where information obtained from this measurement is used to guide treatment; New, high-quality efficacy data from RCTs have demonstrated efficacy of SMBG in NIT T2DM in trials reported since 2008; Both patients and health care professionals require education on how to respond to the data for SMBG to be effective; and Additional well-defined studies are needed to assess the benefits and costs of

  3. Current and emerging techniques in gastrointestinal imaging

    Directory of Open Access Journals (Sweden)

    McSweeney S

    2010-01-01

    Full Text Available This review is devoted to current and emerging techniques in gastrointestinal (GI imaging. It is divided into three sections focusing on areas that are both interesting and challenging: imaging of the small bowel and appendix, imaging of the colon and rectum and finally liver and pancreas in the upper abdomen. The first section covers cross-sectional imaging of the small bowel using the techniques of multidetector computed tomography (MDCT (including CT enterography and magnetic resonance imaging (MRI. The evaluation of mesenteric ischemia and GI tract bleeding using MDCT angiography is also reviewed. Current imaging practice in the evaluation of appendix is also reviewed and illustrated. The second section reviews CT and MR colonography and imaging of the rectum. It describes CT virtual colonoscopy (CTVC with emphasis on the advantages and disadvantages of the technique with discussion of the role of CTVC in screening. The intriguing topic of MR colonography (MRC is also reviewed. Imaging of the rectum with emphasis on imaging of rectal cancer is described with the roles of CT, MR, endoluminal ultrasound and positron emission tomography scanning discussed. The final section reviews current and emerging techniques in liver imaging with the role of ultrasound including contrast ultrasound, MDCT and MR (including contrast agents discussed. The new developments and applications of imaging of pancreatic disease are discussed with emphasis on the role of MDCT and MRI with gadolinium. This review highlights the current role and advancement of imaging techniques with new diagnostic and prognostic information pertinent to gastrointestinal disease continuing to emerge.

  4. Comparison of CO2 DSA and conventional angiography using non-ionic contrast media in lower extremity angiography

    International Nuclear Information System (INIS)

    The purpose of this study is to compare CO2 DSA and nonionic contrast media angiography in respect to the quality of the opacification of collaterals and incidence of side-effects in peripheral occlusive arterial disease. Sixteen patients who were suspected to have peripheral occlusive arterial disease were performed angiography with nonionic contrast media and CO2 at the same location with the same catheter. The causes of the lesions were atherosclerosis(n=7) and Buerger's disease(n=9). CO2 DSA was compared with nonionic contrast media angiography in respect to the quality of image in the diagnosis of the lesions, opacifications of collaterals and side-effects. In atherosclerosis; quality of the images of CO2 DSA was same as that of nonionic contrast media angiography in 6 patients and was poor in 1 patient; opacifications of collaterals of CO2 DSA were same as that of nonionic contrast media angiography in 5 patients and was poor in 2 patients. In Buerger's disease; quality of the images of CO2 DSA was same as that of nonionic contrast media angiography in 2 patients and was poor in 7 patients; opacifications of collaterals of CO2 DSA were same as that of nonionic contrast media angiography in 1 patient and was poor in 8 patients. Leg pain was the only side-effect after CO2 injection occurring in 4 out of 16 patients. CO2 could be used as safe contrast media in patient with risk factors for nonionic contrast media and for diagnosis of the atherosclerosis in lower extremity. For the procedures such as vascular intervention requiring large amount of contrast media CO2 could effectively replace nonionic contrast media

  5. Digital subtraction angiography in cerebral infarction

    International Nuclear Information System (INIS)

    The usefulness and radiographic findings of the angiography in cerebral infarction are well known. We attempted to evaluate the angiographic causes, findings, and the usefulness of DSA in cerebral infarction. The authors reviewed retrospectively DSA images of 51 patients who were diagnosed as having cerebral infarction by brain CT and/or MRI and clinical settings. DSA was performed in all 51 patients, and in 3 patients, conventional angiogram was also done. Both carotid DSA images were obtained in AP, lateral, oblique projections, and one or both vertebral DSA images in AP and lateral. The authors reviewed the patient's charts for symptoms, operative findings and final diagnosis, and analysed DSA findings of cerebral atherosclerosis with focus on 6 major cerebral arteries. Among the 51 patients of cerebral infarction 43 patients (84.3%) had cerebral atherosclerosis, 1 dissecting aneurysm, 1 moyamoya disease and 6 negative in angiogram. DSA findings of cerebral atherosclerosis were multiple narrowing in 42 patients (97.7%), tortuosity in 22 (51.2%), dilatation in 14, occlusion in 12, avascular region in 8, collaterals in 7, ulcer in 6, and delayed washout of contrast media in 3. In cerebral atherosclerosis, internal carotid artery was involved in 37 patients (86.0%), middle cerebral artery in 29 (67.4%) posterior cerebral artery in 28, anterior cerebral artery in 26, vertebral artery in 22, and basilar artery in 15. Intracranial involvement of cerebral atherosclerosis (64.9%) was more common than extracranial involvement (16.2%). In cerebral infarction MRA may be the screening test, but for more precise evaluation of vascular abnormality and its extent, DSA should be considered

  6. Cerebral angiography in patients with complicated migraine

    International Nuclear Information System (INIS)

    38 patients (mean age: 29 years) were investigated by means of complete 4-vessel angiography: all of them were suffering from complicated migraine without detectable vascular malformation. Stenoses of the great craniocervical vessels were found in 11 patients (28.9%), but there was not a single case of vascular occlusion. A correlation between the localization of the stenosis, the localization of the headache and the presumed region of the transient cerebral function disturbance was found only in a few patients. Concerning the morphological changes of the small intracranial arterial branches, there was hardly an difference between clinically affected and non-affected territories of the middle cerebral artery. The angiograms of the 38 cases of complicated migraine were compared with the angiograms of 40 patients suffering from strokes in the young and those of 49 patients with transient ischaemic attacks. There were remarkably fewer stenoses or occlusions in the great craniocervical arteries of patients suffering from complicated migraine (28.9%) than in the vessels of cases of stroke in the young (52.5%). However, the incidence was comparable with the results in patients with transient ischaemic attacks (34.7%). The degree of morphological changes in the small intracranial arterial branches is likely to depend primarily on the patient's age and less on the diagnosis. The results suggest that in almost 30% of patients with complicated migraine - even at juvenile age-stenoses of the great craniocervical vessels might be found. However, considering the fact that most of the stenoses are without haemodynamic significance and their localization is not in agreement with the clinical data, the pathogenetic value of these vessel wall changes is highly questionable. (Author)

  7. Fluorescein angiography of the canine retina

    International Nuclear Information System (INIS)

    The retinal vascular bed was examined in 37 canine eyes by studying 50 retinal fluorangiograms. All angiographic phases could distinctly be visualized by the use of a small intravenous bolus of 10 mg/kg fluorescein. The choroidal phase is characterized by spot-like and lobular filling of the choriocapillaris. By coalescence of the choroidal lobules, this uneven filling progressively disappears in the subsequent phases. The retinal arterial phase is characterized by a hyperfluorescence of the retinal arterioles at the level of the optic disc border. The time interval between the start of the choroidal phase and the retinal arterial phase is very short due to the common origin of the choroidal and retinal arteries from the choroidoretinal arteries. The retinal arterio-venous phase is characterized by a complete filling of the smaller arterioles, capillaries, and venules. During this phase the branching pattern of the retinal blood vessels at the area centralis region can be most easily studied. This also applies to the periarteriolar capillary-free zones and the radial peripapillary capillaries. The retinal early venous phase is characterized by the onset of laminar flow in the larger retinal venules. A homogeneous and complete filling of the larger venules is characteristic for the onset of the late venous phase. During the retinal venous phase the border venule can be observed just posterior to the ora ciliaris retinae. Fluorescein angiography of the canine retinal microvasculature shows that the dog is less suitable as an experimental animal model in ophthalmology, due to the presence of the choroidal tapetum which reflects fluorescent light and thus diminishes the contrast between the retinal blood vessels and the background

  8. 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.

  9. 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.)

  10. 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.

  11. Conventional and CT angiography in children: dosimetry and dose comparisons

    International Nuclear Information System (INIS)

    Tremendous advances have been made in imaging in children with both congenital and acquired heart disease. These include technical advances in cardiac catheterization and conventional angiography, especially with advancements in interventional procedures, as well as noninvasive imaging with MR and CT angiography. With rapid advances in multidetector CT (MDCT) technology, most recently 64-detector array systems (64-slice MDCT), have come a number of advantages over MR. However, both conventional and CT angiography impart radiation dose to children. Although the presence of radiation exposure to children has long been recognized, it is apparent that our ability to assess this dose, particularly in light of the rapid advancements, has been limited. Traditional methods of dosimetry for both conventional and CT angiography are somewhat cumbersome or involve a potential for substantial uncertainty. Recent developments in dosimetry, including metal oxide semiconductor field effect transistors (MOSFET) and the availability of anthropomorphic, tissue-equivalent phantoms have provided new opportunities for dosimetric assessments. Recent work with this technology in state-of-the-art cardiac angiography suites as well as with MDCT have offered direct comparisons of doses in infants and children undergoing diagnostic cardiac evaluation. It is with these dose data that assessment of risks, and ultimately the assessment of risk-benefit, can be better achieved. (orig.)

  12. Analysis of the role of the low threshold currents IT and Ih in intrinsic delta oscillations of thalamocortical neurons

    Directory of Open Access Journals (Sweden)

    Yimy eAmarillo

    2015-05-01

    Full Text Available Thalamocortical neurons are involved in the generation and maintenance of brain rhythms associated with global functional states. The repetitive burst firing of TC neurons at delta frequencies (1-4 Hz has been linked to the oscillations recorded during deep sleep and during episodes of absence seizures. To get insight into the biophysical properties that are the basis for intrinsic delta oscillations in these neurons, we performed a bifurcation analysis of a minimal conductance-based thalamocortical neuron model including only the IT channel and the sodium and potassium leak channels. This analysis unveils the dynamics of repetitive burst firing of TC neurons, and describes how the interplay between the amplifying variable mT and the recovering variable hT of the calcium channel IT is sufficient to generate low threshold oscillations in the delta band. We also explored the role of the hyperpolarization activated cationic current Ih in this reduced model and determine that, albeit not required, Ih amplifies and stabilizes the oscillation.

  13. Proceedings of the DOE workshop on the role of a high-current accelerator in the future of nuclear medicine

    International Nuclear Information System (INIS)

    The meeting was prompted by recent problems with isotope availability from DOE accelerator facilities; these difficulties have resulted from conflicting priorities between physics experiments and isotope production activities. The workshop was a forum in which the nuclear medicine community, isotope producers, industry, and other interested groups could discuss issues associated with isotope availability (including continuous supply options), the role of DOE and industry in isotope production, and the importance of research isotopes to the future of nuclear medicine. The workshop participants endorsed DOE's presence in supplying radioisotopes for research purposes and recommended that DOE should immediately provide additional support for radionuclide production in the form of personnel and supplies, DOE should establish a policy that would allow income from sales of future ''routine'' radionuclide production to be used to support technicians, DOE should obtain a 70-MeV, 500-/mu/A variable-energy proton accelerator as soon as possible, and DOE should also immediately solicit proposals to evaluate the usefulness of a new or upgraded high-energy, high-current machine for production of research radionuclides. This proceedings volume is a summary of workshop sessions that explored the future radionuclide needs of the nuclear medicine community and discussed the DOE production capabilities that would be required to meet these needs

  14. Assessment of the roles of various inactivation agents in an argon-based direct current atmospheric pressure cold plasma jet

    International Nuclear Information System (INIS)

    Three types of gases, pure argon (99.999%), argon with 2% oxygen, and argon with 2% oxygen and 10% nitrogen were used as operating gases of a direct current atmospheric pressure cold plasma jet to inactivate Staphylococcus aureus (S. aureus) suspended in a liquid. The inactivation efficacies for the plasma jets operating in the three gases decrease from Ar/O2(2%) to Ar/O2(2%)/N2(10%) to pure Ar. Optical emission spectroscopy, electron spin resonance spectroscopy, high performance liquid chromatography, and atomic absorption spectrophotometry were employed to identify and monitor the reactive species in the plasma-liquid system for the three operating gases and revealed the presence of O, 1O2, OH, NO, H2O2, O3, and NO3-/NO2- as well as Cu+/Cu2+. The S. aureus inactivation results indicate that atomic oxygen (O) is the key inactivation agent, while other species play a lesser role in the inactivation progress studied here.

  15. The importance of antioxidants which play the role in cellular response against oxidative/nitrosative stress: current state.

    Science.gov (United States)

    Kurutas, Ergul Belge

    2016-01-01

    Remarkable interest has risen in the idea that oxidative/nitrosative stress is mediated in the etiology of numerous human diseases. Oxidative/Nitrosative stress is the result of an disequilibrium in oxidant/antioxidant which reveals from continuous increase of Reactive Oxygen and Reactive Nitrogen Species production. The aim of this review is to emphasize with current information the importance of antioxidants which play the role in cellular responce against oxidative/nitrosative stress, which would be helpful in enhancing the knowledge of any biochemist, pathophysiologist, or medical personnel regarding this important issue. Products of lipid peroxidation have commonly been used as biomarkers of oxidative/nitrosative stress damage. Lipid peroxidation generates a variety of relatively stable decomposition end products, mainly α, β-unsaturated reactive aldehydes, such as malondialdehyde, 4-hydroxy-2-nonenal, 2-propenal (acrolein) and isoprostanes, which can be measured in plasma and urine as an indirect index of oxidative/nitrosative stress. Antioxidants are exogenous or endogenous molecules that mitigate any form of oxidative/nitrosative stress or its consequences. They may act from directly scavenging free radicals to increasing antioxidative defences. Antioxidant deficiencies can develop as a result of decreased antioxidant intake, synthesis of endogenous enzymes or increased antioxidant utilization. Antioxidant supplementation has become an increasingly popular practice to maintain optimal body function. However, antoxidants exhibit pro-oxidant activity depending on the specific set of conditions. Of particular importance are their dosage and redox conditions in the cell. PMID:27456681

  16. Enhanced Magnification Angiography Using 20-μm-Focus Tungsten Tube

    Science.gov (United States)

    Enomoto, Toshiyuki; Sato, Eiichi; Sumiyama, Yoshinobu; Aizawa, Katsuo; Watanabe, Manabu; Tanaka, Etsuro; Mori, Hidezo; Kawakami, Hiroki; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Sato, Shigehiro

    2006-10-01

    A microfocus X-ray tube is useful for performing magnification radiography, and its X-ray generator (L9631, Hamamatsu Photonics) consists of a personal computer for controlling the tube voltage and current, and a main unit with a high-voltage circuit and a fixed-anode X-ray tube. The maximum tube voltage, current, and electric power were 110 kV, 800 μA, and 50 W, respectively. The focal-spot size was proportional to the electric power of the tube, and the size was approximately 20 μm with a power of 20 W. Using a 3-mm-thick aluminum filter, the X-ray intensity was 7.75 μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 100 μA. Because the peak photon energy was approximately 38 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung X-rays were absorbed effectively by iodine-based contrast media at an iodine K-edge of 33.2 keV. Enhanced angiography was performed by fourfold magnification imaging with a computed radiography system using iodine-based microspheres 15 μm in diameter. In the angiography of nonliving animals, we observed fine blood vessels of approximately 100 μm with high contrast.

  17. Breath-hold two-dimensional MR angiography of coronary arteries. Comparison with conventional coronary angiography in ten cases

    International Nuclear Information System (INIS)

    Purpose: To assess the diagnostic value of two-dimensional coronary magnetic resonance (MR) angiography in patients evaluated for ischemic heart disease. Materials and methods: Ten patients who underwent selective cardiac catheterization with coronary MR angiography were evaluated with two-dimensional coronary MR angiography. Coronary MR angiography was performed with breath-hold fat-suppressed ECG-gated Turbo-FLASH with K-space segmentation using a 1.5 T imager. Results: The left main coronary artery, proximal left anterior descending artery, circumflex artery and right coronary artery were demonstrated in all cases. Continuous segments (mean) of left anterior descending, circumflex and right coronary arteries visualized on MRA were 6.72 +- 3.16 cm, 3.67 +- 4.81 cm and 7.93 +- 3.12 cm respectively. The overall sensitivity for detection of hemodynamically significant coronary artery lesion (≥50%) was 62.5% respectively. Conclusion: Breath-hold two-dimensional coronary MR angiography was useful in showing relatively long segments of the main coronary arteries and also has potential in depicting hemodynamically significant coronary artery lesions

  18. Clinical utility of landiolol for use in coronary CT angiography

    Directory of Open Access Journals (Sweden)

    Tomizawa N

    2015-11-01

    Full Text Available Nobuo Tomizawa,1 Yayoi Hayakawa,1 Shinichi Inoh,1 Takeshi Nojo,1 Sunao Nakamura2 1Department of Radiology, 2Department of Cardiology, New Tokyo Hospital, Matsudo, Chiba, Japan Abstract: Although remarkable advancement in computed tomography (CT has been achieved, heart rate control is important to maintain an optimal image quality in coronary CT angiography. Oral or intravenous β-blockers are used as premedication for this purpose. Landiolol was developed as a β-blocker with very high cardioselectivity (β1/β2 =255 and short half-life (4 minutes. In this review, we report the pharmacological features and usage of landiolol and also its effects on heart rate and image quality in coronary CT angiography. In addition, we discuss the safety of landiolol. Keywords: coronary computed tomography angiography, heart rate, image quality

  19. Cerebral infarction showed hyperperfusion pattern on radionuclide cerebral angiography

    International Nuclear Information System (INIS)

    Four patients of middle cerebral infarctin showed hyperperfusion on radionuclide cerebral angiography and fan-shape accumulation at the area of middle cerebral artery on early and delayed brain scan. In these patients, bone scanning agents such as sup(99m)Tc-EHDP or sup(99m)Tc-MDP also prominently accumulated at the area of infarction. These findings were observed on the study when it was performed within seventeen days after attack, but reexamination tended to show normal or decreased perfusion on radionuclide cerebral angiography and improve abnormal accumulation on brain scans. The clinical diagnosis of these three patients were cerebral embolism with heart disease, but one patient was internal carotid artery occlusion. The prognosis of all patients were very good. The hyperperfusion on radionuclide cerebral angiography of these patients represents the luxury perfusion in the lesion and these infarction has been called hot stroke by Yarnell et al. (author)

  20. Port visualisation before intraperitoneal chemotherapy: Scintigraphy or angiography?

    International Nuclear Information System (INIS)

    For assessing the functioning of intraperitoneal port-catheter systems prior to intraperitoneal chemotherapy, scintigraphy/SPECT and subtraction-angiography were compared. The patient under scrutiny had three port-catheter systems. Two of the three ports were functioning well. However, one port did not function. Via scintigraphy with 99m-Tc-nanocolloid this defective port was detected, but the cause was identified only by angiography. By the angiographic technique, a leakage near the port chamber caused by dislocation of the catheter could be verified. SPECT is a more useful method than angiography, since it shows very clearly intraperitoneal distribution by the possibility of reconstructing various slices. In conclusion, both techniques, the scintigraphic and the angiographic one, complement each other well. (orig.)

  1. Angiography in the investigation of spinal dural arteriovenous fistula

    International Nuclear Information System (INIS)

    The authors present their protocol for spinal angiography in their investigation of dural arteriovenous fistula (DAVF). The protocol has been used in approximately 120 patients from 1983 to the present at Bicetre Hospital. The approach is based on the fact that venous congestion is responsible for the myelopathy of DAVF. If the venous phase of the spinal circulation is normal, this alone rules out DAVF as the cause of the patient's symptoms. If there is stasis in the spinal circulation, this is consistent with DAVF, and thus complete spinal angiography is necessary. Complete angiography includes the selective intercostal arteries, including the lateral sacrals, as well as the supply to the cervical cord and posterior fossa. (orig.)

  2. 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...

  3. Digital subtraction angiography in patients with central vertigo

    International Nuclear Information System (INIS)

    Digital subtraction angiography (DSA) is a recently developed non-invasive intravenous angiography which has become possible through real time digital subtraction of x-ray transmission data from an image intensifier and television system. The output signals of the image intensifier-television camera system are digitized by an analog-digital converter. The digital information, 512x512 pixels and 9 bits deep, is fed into the image processing assembly after logarithmic amplification, where 2-8 frames are added and subtracted from mask images for the final digital images. Intravenous digital subtraction angiography was performed in 21 patients with intractable dizzy spells of central origin resistant to treatment. These patients showed some signs of CNS disturbance, although there were no significant findings on CT scans. Surprisingly, findings were abnormal in 14 of 21 patients (66.7%). DSA is, therefore, considered to be an important aid in the diagnosis of vertigo of the central type. (J.P.N.)

  4. 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

  5. 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.

  6. 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

  7. 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.

  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. 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.

  10. The Breakdown Mechanisms In Electrical Discharges: The Role Of The Field Emission Effect In Direct Current Discharges In Micro gaps

    International Nuclear Information System (INIS)

    This review represents an attempt to sum up the current state of the research in the field of breakdown phenomena in electrical discharges. The paper provides facts and theories concerning different classes of direct current, radio and microwave frequency discharges, in vacuum, in the gas and in liquids, without and in the presence of the magnetic fields. The emphasize was made on the field emission effects and on the fundamental aspects of the breakdown phenomena in micro discharges via discussions and analysis of the experimental, theoretical and simulation results. It was found that the Paschen's law is not applicable for the micron gap sizes, when deviations from the standard scaling law become evident and modified Paschen curve should be used. The explanation of the deviations from the Paschen law was attributed to the secondary electron emission enhanced by the strong field generated in micro gaps. The experiments were carried out in order to establish scaling law in micro gaps. The volt-ampere characteristics were also recorded and compared with the theoretical predictions based on the Fowler-Nordheim theory. The importance of the enhancement factor and the space charge on results was also considered. On the basis of the experimental breakdown voltage curves, the effective yields in micro gaps have been estimated for different gases which can be served as input data in modeling. The effective yields allow analytically produce modified Paschen curves that predicts the deviations from the Paschen law observed in the experiments. In addition, we present results of computer simulations using a Particle-in-cell/Monte Carlo Collisions (PIC/MCC) code with the secondary emission model in order to include the field emission enhanced secondary electron production in micro gaps. The agreement between simulation and experimental results suggest that computer simulations can be used to improve understanding of the plasma physics as an alternative to analytical

  11. 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 ...

  12. 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...

  13. Comparison of fluorescein angiography with microvascular anatomy of macaque retinas.

    Science.gov (United States)

    Weinhaus, R S; Burke, J M; Delori, F C; Snodderly, D M

    1995-07-01

    Recent anatomic work has shown that the capillary network of the fovea is multilaminar. We have identified the elements of this network that are visualized by fluorescein angiography and those that are missed. Fluorescein angiograms of monkey retinas (Macaca fascicularis) with good visualization of individual capillaries were obtained by standard clinical techniques. Retinal whole mounts were prepared from the same animals. Anatomic drawings made from the whole mounts were used to identify which parts of the capillary network were visualized angiographically. Angiographic estimates of dimensions of the foveal avascular zone corresponded closely to the anatomy. Capillary visibility declined rapidly from near perfect visualization at the edge of the foveal avascular zone to less than 40% by 900 microns eccentricity. While all the widest capillary segments (diameter 6.1-7.0 microns) were visualized, only 43% of the modal group of capillary segments (diameter 4.1-4.5 microns) were detected. When a relatively homogeneous population of capillaries was analyzed (diameters limited to the narrow range of 4.0-5.0 microns), visualization declined monotonically with depth in the retina. Capillary segments in the nerve fiber plane were visualized more than four times as effectively as segments of comparable diameter in the deepest vascular plane. High quality angiograms accurately delineate the foveal avascular zone, but they visualize only a fraction of the adjacent multilaminar network. Therefore, current techniques may not detect the earliest nonperfusion of capillaries in vaso-occlusive diseases. Capillary visibility is a joint function of diameter and of retinal depth. The decline in visualization with retinal depth implies that light scattering in the retina degrades the angiographic image. PMID:7556462

  14. Comparison of 64-slice computed tomography angiography and coronary angiography for the detection and assessment of coronary artery disease in patients with angina: A systematic review

    International Nuclear Information System (INIS)

    Background: Coronary artery disease (CAD) is the leading cause of death in Western countries. It presents itself in various ways, the commonest being angina. According to the Royal College of Radiologist referral guidelines, Coronary Angiography (CA) is currently the gold standard for diagnosis and evaluation of CAD. However, due to the invasive nature and expense of CA there is a perceived need for a primary non-invasive imaging modality to supersede it. Computed tomography angiography (CTA), utilising 64-slice technology, may be a less invasive alternative to CA. Aim: To consider the research evidence for the current gold standard diagnostic test for CAD. Specifically, which is more sensitive and specific for detecting CAD in patients with angina; 64-slice CTA or CA? Inclusion Criteria: Prospective, non-randomised control trials and diagnostic accuracy studies comparing 64-slice CTA and CA were included. Participants were adults with angina with suspected or known CAD. Method: An electronic search of the databases; AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE and Science Direct, was conducted between January 2004 and April 2012. Secondary hand-searching of grey literature was undertaken. Two reviewers independently determined studies for inclusion, assessed quality, using SIGN50, and extracted data. Diagnostic value of 64-slice CTA and CA was compared and analysed at patient and segment level. Results: Ten studies were included in the critical review enrolling 1188 patients. At patient level sensitivity for 64-slice CTA ranged from 88% to 100%, specificity 64–92%, PPV 86–97% and NPV 76.9–100%. At segment level sensitivity for 64-slice CTA ranged from 73% to 100%, specificity 83–98%, PPV 47–90% and NPV 89–100% Conclusion: At both patient and segment level, 64-slice CTA is a highly sensitive and specific non-invasive alternative to CA for diagnosis of significant stenosis in patients with angina. For standalone diagnosis of CAD current research would

  15. Digital subtraction angiography for breast diseases

    International Nuclear Information System (INIS)

    We performed digital subtraction angiography (DSA) via arteries (IA-DSA) and veins (IV-DSA) on 42 patients with breast diseases to investigate its availability. The findings by DSA in cases with breast cancer included: tumor stains, hypervascularity and tortuosity, enlarged blood vessels, encasement and pooling. Metastatic lymph nodes and daughter nodules were also recognized by DSA. In benign tumors of the breast, a tumor stain was observed only in one case of fibroadenoma; otherwise no remarkable changes were noticed. The incidence of signs in cases with breast cancer using IA-DSA was 65 % for hypervascularity, 59 % for tumor stain, 41 % for vascular tortuosity and 41 % for enlargement of vessels. IV-DSA, on the contrary, revealed less incidences. However, tumor stain was seen frequently, and hypervascularity was seldom observed. The number of signs out of the abovementioned six appearing in each case was tabulated. With IA-DSA, there were 5 signs noted in 2 cases, but the majority had fewer: 4 cases in 4 cases and only 2 signs in 4 cases. There were no signs evident in 18 % of the cases. The incidence of the appearance of signs with IV-DSA was lower: there were no signs in 36 % of the cases. Therefore, the diagnostic accuracy of IA-DSA seemed to be fairly good in comparison with that of IV-DSA. The rate of appearance of abnormal signs was also examined, according to the size of the tumors. In IA-DSA, T1 breast cancers revealed malignant signs in 80 % of the cases, in T2 there were such signs 75 % and 100 % of the T3 cases exhibited malignant signs, for an overall average of 82 %. In IV-DSA, T1 showed 33 %, T2 showed 70 %, and T3, 1 out of 1 case, showed malignant signs, 64 % altogether. It was the bigger the tumor, the larger the number of signs. The smallest breast cancer that exhibited abnormality in DSA was 1.0 x 0.7 cm in size. (J.P.N.)

  16. The Chironomidae collection at the Zoological Institute (St Petersburg: history, current state and role for further research

    Directory of Open Access Journals (Sweden)

    Andrey Przhiboro

    2012-10-01

    Full Text Available This paper briefly reviews the collection of Chironomidae (Diptera housed at the Zoological Institute of Russian Academy of Sciences in St Petersburg (ZIN. Although it is the oldest and one of the largest Chironomidae collections in Russia, most of the collection has been unknown to specialists for decades. The collection consists of three main parts: dry specimens (about 20000 pinned adults, material in ethanol (over 25000 vials with larvae, pupae and adults and permanent slides (over 12000 slides with larvae, pupae and adults. Based on a study of the collection itself, published sources and archival data, major periods for the formation of the collection are here described. Collectors and expeditions, whose contributions were most important, are listed, as well as the regions where the material was collected. The role of chironomid researchers, who made important contributions to the creation, enrichment or study of the collection, is also described. The contributions by Aleksei Chernovskii and Vera Pankratova are considered in more detail. According to a preliminary estimate, the collection contains type specimens of no less than 150 species described by 24 authors, and thousands of specimens determined by experts. The Chironomidae collection of ZIN is particularly important because it hopefully will enable us to correctly interpret many species names proposed in 1930-1980’s, mostly based on brief descriptions of larvae and currently often considered nomina dubia. In addition, the collection includes the unprocessed material from vast territory of the former Soviet Union, including many distant regions, which are still difficult to access. doi: 10.5324/fn.v31i0.1402.Published online: 17 October 2012.

  17. 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).

  18. A review of the potential therapeutic role of statins in the treatment of Alzheimer’s disease: current research and opinion

    OpenAIRE

    Sánchez-Ferro, Álvaro; Benito-León, Julián; Mitchell, Alex J.; Bermejo-Pareja, Félix

    2013-01-01

    Alzheimer’s disease is one of the most prevalent neurodegenerative disorders. However, there is no current treatment, which definitively influences disease progression over a sustained period. Numerous studies linking an increase in serum cholesterol, mainly during midlife, with the pathogenic process of Alzheimer’s disease have been published. Therefore, the role of statins as a therapy in this disorder may be of great interest. The aim of the present review is to summarize of the role of st...

  19. Single Center Retrospective Analysis of Conventional and Radial TIG Catheters for Transradial Diagnostic Coronary Angiography

    Directory of Open Access Journals (Sweden)

    Marc Vorpahl

    2015-01-01

    Full Text Available Current guidelines favor the radial approach for coronary angiography. Therefore, specialty radial diagnostic catheters were designed to engage both coronary arteries with a single device. However, it is unclear if single catheters are superior to conventional catheters. A retrospective analysis was performed of consecutive right radial coronary angiographies to determine catheter use, fluoroscopy time, radiation dosage, and consumption of contrast. Procedures were performed with a single TIG catheter or conventional catheters (CONV. Procedures with coronary artery bypass grafts or ventricular angiographies were excluded. 273 transradial procedures were performed successfully. 95 procedures were performed with CONV and 178 procedures with a TIG. Crossover to additional catheters was higher in TIG (15.2% compared to CONV (5.3%, p=0.02. Fluoroscopy time was comparable between CONV and TIG, without crossover (2.2±1.2 min versus 2.3±1.2 min; n.s., however, greater in the case of crossover for CONV (5.8±0.7 and TIG (7.6±3.0; p=0.0001. Radiation dosage was similar in CONV and the TIG, without crossover (1419±1075, cGy∗cm2 versus 1690±1138; n.s., however, greater for CONV (2374±620 and TIG (3733±2281, p=0.05 with crossover. Overall, the amount of contrast was greater in TIG (56±13 mL versus CONV (48±3 mL; p=0.0003. CONV femoral catheters may be the primary choice for radial approach.

  20. Symptomatic middle cerebral artery stenosis and occlusion. Comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Motoshi; Yano, Hirohito; Shinoda, Jun; Funakoshi, Takashi (Daiyukai General Hospital, Ichinomiya, Aichi (Japan)); Kumagai, Morio

    1994-10-01

    The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (<1.0cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients. (author).

  1. 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

  2. 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.

  3. 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)

  4. Evaluation of angiography performed by radiographers and nurses

    Energy Technology Data Exchange (ETDEWEB)

    Chalmers, N.; Conway, B.; Andrew, H.; Parkinson, A.; Butterfield, J.S.; Fawcitt, R. A

    2002-04-01

    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)

  5. Magnetic resonance angiography: the state of the art

    International Nuclear Information System (INIS)

    Three-dimensional contrast magnetic resonance angiography has rapidly advanced over recent years. It is now a highly accurate and safe method of diagnosing vascular abnormalities of the thoracic, abdominal and peripheral vessels. We describe techniques for the examination of the thoracic and abdominal aorta, the renal arteries and the lower limb vessels together with strategies to improve their diagnostic accuracy. (orig.)

  6. 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.)

  7. Neurologic complications of cerebral angiography in childhood moyamoya syndrome

    International Nuclear Information System (INIS)

    Purpose. To determine the incidence of neurologic complications of cerebral angiography in children with moyamoya syndrome (MMS) as compared to children without MMS. Materials and methods. One-hundred-ninety consecutive cerebral angiograms obtained in 152 children were evaluated. Sixty of these angiograms were obtained in 40 children with MMS. Patients underwent neurologic evaluation prior to and after the procedure. For this study, a neurologic complication was defined as any new focal neurologic deficit or alteration in mental status occurring during the procedure or within the ensuing 24 hours. Results. There were 2 neurologic complications within 24 hours of angiography, one in the MMS group and one in the non-MMS group. One patient with MMS became mute following angiography. The symptom resolved within 12 hours. One patient without MMS being examined postoperatively for residual arteriovenous malformation developed intracranial hemorrhage requiring reexploration 12 hours after the angiogram. Using a two-tail Fisher's exact test, there was no significant statistical difference in the ischemic (P = 0.3) or hemorrhagic (P = 1.0) complication rates between the group of patients with MMS and the non-MMS groups. Conclusion. The risk of a neurologic complication from cerebral angiography in children with MMS is low and not statistically different from the risk in children with other cerebrovascular disorders. (orig.)

  8. Radiation dose in cardiac CT angiography: Protocols and image quality

    International Nuclear Information System (INIS)

    This paper aims to evaluate the radiation dose exposure of patients submitted to cardiac computed tomography angiography. The effective dose was obtained from the product of dose-length product values and the conversion factor established in the European Working Group for Guidelines on Quality Criteria in CT. The image noise and contrast-and signal-to-noise ratios were obtained for all images. Sixty-four- and 256-slice CT angiographies were used in 211 (68.5 %) and 97 (31.5 %) patients, respectively. The calculated mean effective dose with prospective CT angiography was 6.0±1.0 mSv and the retrospective mode was 8.4±1.2 mSv. The mean image noise values were 38.5±9.5 and 21.4±5.3 for prospective and retrospective modes, respectively. It was observed that the image noise increased by 44.4 % using a prospective mode. Prospective CT angiography reduces radiation dose by ∼29 % compared with the retrospective mode, while maintaining diagnostic image quality and the ability to assess obstructions in patients. (authors)

  9. Digital subtraction angiography in the diagnosis of Fallot's tetralogy

    International Nuclear Information System (INIS)

    The authors analyze the efficacy of digital subtraction angiography (DSA) in the diagnosis of Fallot's tetralogy (FT); this method helps simplity and cut down their scope of investigations but does not deteriorate their informative value. DSA findings in 120 patients with TF are analyzed. 5 refs.; 6 figs

  10. Inferior epigastric artery angiography applied in the transplantation with the deep inferior epigastric perforator free flap

    International Nuclear Information System (INIS)

    Objective: To observe the effect of inferior epigastric artery angiography applied in the transplantation with the deep inferior epigastric perforator free flap. Methods: Seven patients who had undergone the deep inferior epigastric perforator free flap transplantation, received angiography of the inferior epigastric artery. The value of the angiography was discussed. Results: All patients were successful in angiography without any adverse reaction. All patients were successful in transplantation except one because of personal reason. Conclusion: Inferior epigastric artery angiography facilitates the transplantation with the deep inferior epigastric perforator free flap. (authors)

  11. Current intimate relationship status, depression, and alcohol use among bisexual women: The mediating roles of bisexual-specific minority stressors

    OpenAIRE

    Molina, Yamile; Marquez, Jacob H.; Logan, Diane E.; Leeson, Carissa J.; Balsam, Kimberly F.; Kaysen, Debra L.

    2015-01-01

    Current intimate relationship characteristics, including gender and number of partner(s), may affect one's visibility as a bisexual individual and the minority stressors they experience, which may in turn influence their health. The current study tested four hypotheses: 1) minority stressors vary by current intimate relationship status; 2) higher minority stressors are associated with higher depressive symptoms and alcohol-related outcomes; 3) depressive symptoms and alcohol-related outcomes ...

  12. Brachytherapy, diagnostic radiology, mammographic radiology and ophthalmic applicators. An assessment of current and future needs in the UK and the role of NPL

    International Nuclear Information System (INIS)

    Several UK hospitals were visited by NPL staff to discuss the current practises and future developments in brachytherapy, diagnostic and mammographic radiology and ophthalmic applicators. The results of the discussions are presented here, including NPL's role in each of these areas is discussed. (author)

  13. 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

  14. Clinical Assessment of a New Stereoscopic Digital Angiography System

    International Nuclear Information System (INIS)

    Purpose: To assess the clinical feasibility of an experimental modified angiographic system capable of real-time digital stereofluoroscopy and stereography in X-ray angiography, using a twin-focus tube and a stereoscopic monitor. Methods: We report the experience obtained in 37 patients with a well-documented examination. The patients were examined for coronary angiography (11 cases), aortography (7 cases), pulmonary angiography (6 cases), inferior vena cava filter placement (2 cases), and cerebral angiography (11 cases). Six radiologists were asked to use stereoscopic features for fluoroscopy and angiography. A questionnaire was designed to record their subjective evaluation of stereoscopic image quality, ergonomics of the system, and its medical interest. Results: Stereofluoroscopy was successfully used in 25 of 37 cases; diplopia and/or ghost images were reported in 6 cases. It was helpful for aortic catheterization in 10 cases and for selective catheterization in 5 cases. In stereoangiography, depth was easily and accurately perceived in 27 of 37 cases; diplopia and/or ghost images were reported in 4 cases. A certain gain in the three-dimensional evaluation of the anatomy and relation between vessels and lesions was noted. As regards ergonomic considerations, polarized spectacles were not considered cumbersome. Visual fatigue and additional work were variously reported. Stereoshift tuning before X-ray acquisition was not judged to be a limiting factor. Conclusion: A twin-focus X-ray tube and a polarized shutter for stereoscopic display allowed effective real-time three-dimensional perception of angiographic images. Our clinical study suggests no clear medical interest for diagnostic examinations, but the field of interventional radiology needs to be investigated

  15. 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.

  16. Three-dimensional MR angiography for planning of hepatic arterial catheterization

    International Nuclear Information System (INIS)

    The aim of this study is to assess the potential utility of gadolinium-enhanced three-dimensional MR angiography (3D MR angiography) for arterial catheterization of hepatic tumor. Thirty-five consecutive patients with suspected abdominal tumors underwent MR angiography with a gadolinium-enhanced 3D fast gradient echo sequence. Visualization of the vascular tree of visceral arteries, and their variations, the apparent length of common hepatic artery (CHA), and the tilt of celiac trunk were prospectively evaluated by 3D MR angiography. The results were compared with those obtained by the conventional angiography. In 27 patients with hepatic tumors, the prospective planning with 3D MR angiography was compared with the actual catheterization. Celiac trunk, CHA, and superior mesenteric artery (SMA) were visualized on 3D MR angiography in all 35 patients. There was a significant linear correlation of the length of CHA and the tilt of SMA as measured by 3D MR angiography and conventional angiography (r=0.75, r=0.64, respectively). The 3D MR angiography provided useful clinical information for planning of arterial catheterization in all 27 patients with hepatic tumors. Thus gadolinium-enhanced 3D MR angiography is considered to be of value for the planning of arterial catheterization of hepatic tumor. (author)

  17. Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

    International Nuclear Information System (INIS)

    Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

  18. 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.

  19. 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

  20. CT angiography for evaluation of cerebral vasospasm following acute subarachnoid haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Shankar, Jai Jai Shiva [Dalhousie University, Division of Neuroradiology, Department of Diagnostic Imaging, QEII Health Sciences Center, Halifax (Canada); Tan, Irene Y.L.; Krings, Timo; Terbrugge, Karel; Agid, Ronit [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada)

    2012-03-15

    Cerebral vasospasm (CV) is one of the most dreaded complications in patients who survive acute subarachnoid haemorrhage (SAH), and conventional cerebral angiography (DSA) is the gold standard for its diagnosis. We evaluated CT angiography (CTA) as a non-invasive alternative for diagnosis of CV and assessed if CTA could have a role in choosing appropriate treatment. Consecutive patients with SAH and suspected vasospasm were included when DSA was performed within 24 h from CTA. Two neuro-radiologists retrospectively analysed CTA and DSA studies independently. Assessment included presence of central and peripheral vasospasm and grading of severity of central CV. A treatment recommendation based on CTA was compared to actual treatment received. Final analysis included 34 patients. CTA was more accurate for diagnosis of central then for peripheral CV with high sensitivity (reader 1, 91%; reader 2, 92%), specificity (reader 1, 73%; reader 2, 90%), accuracy, positive predictive value and negative predictive value for central vasospasm. For grading the severity of CV CTA's sensitivity, specificity and accuracy were high for most central arteries. The reader's recommendation of angioplasty according to CTA was significantly predictive of actual receipt of angioplasty but overestimated actual receipt of triple H treatment. CTA is adequate for detecting central vasospasm in symptomatic SAH patients. A negative result should not prevent further investigation especially when evaluating arterial segments adjacent to metal artefacts from coils or clips. CTA is helpful in treatment decision making specifically regarding the need for balloon angioplasty. (orig.)