TY - JOUR. T1 - Time-of-flight magnetic resonance angiography of the canine brain at 3.0 Tesla and 7.0 Tesla. AU - Martin-Vaquero, Paula. AU - Da Costa, Ronaldo C.. AU - Echandi, Rita L.. AU - Tosti, Christina L.. AU - Knopp, Michael V.. AU - Sammet, Steffen. PY - 2011/3/1. Y1 - 2011/3/1. N2 - Objective - To evaluate the ability of 2-D time-of-flight (ToF) magnetic resonance angiography (MRA) to depict intracranial vasculature and compare results obtained with 3.0- and 7.0-T scanners in dogs. Animals - 5 healthy Beagles. Procedures - 2-D ToF-MRA of the intracranial vasculature was obtained for each dog by use of a 3.0-T and a 7.0-T scanner. Quantitative assessment of the images was obtained by documentation of the visibility of major arteries comprising the cerebral arterial circle and their branches and recording the number of vessels visualized in the dorsal third of the brain. Qualitative assessment was established by evaluation of overall image quality and image artifacts. Results - Use of ...
In this prospective study, the accuracy of whole-heart coronary MR angiography was evaluated in 131 patients with suspected coronary artery disease. The current MR angiography protocol incorporated several improvements over those used in previous studies. First, MR angiograms were acquired on axial 3-dimensional planes that encompassed the entire heart. Second, the image acquisition window in the cardiac cycle was optimized in each patient to minimize motion blurring caused by cardiac contraction. Using this approach, coronary stenoses with a reference diameter of ≥2 mm were detected with an accuracy of 94% for individual segments and 87% for individual patients.. Coronary MR angiography has been acquired in double-oblique 3-dimensional planes that followed the course of one of the major coronary arteries, necessitating repeated MR acquisitions to cover the entire coronary arteries (1). A steady-state, free-precession MR sequence permitted acquisition of a large 3-dimensional volume covering ...
TY - JOUR. T1 - Three-dimensional time-of-flight MR angiography. T2 - Applications in the abdomen and thorax. AU - Lewin, J. S.. AU - Laub, G.. AU - Hausmann, R.. PY - 1991/1/1. Y1 - 1991/1/1. N2 - The application of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiographic techniques to the vasculature of the abdomen and thorax has not, to the authors knowledge, been previously reported; this is possibly due to the large amount of physiologic motion in these regions along with the anticipated sensitivity of the 3D acquisition scheme to image degradation caused by motion artifact. The authors describe an asymmetric short-echo velocity-compensated 3D TOF technique that minimized the effects of physiologic motion on image quality and provided rapid high-resolution 3D MR arteriograms of the abdomen and thorax. Contiguous 3D volumes were often combined to provide sufficient anatomic coverage. Benefits include high spatial resolution and minimization of signal loss; ...
Additional file 1: of Visualization of coronary arteries in paediatric patients using whole-heart coronary magnetic resonance angiography: comparison of image-navigation and the standard approach for respiratory motion compensation
TY - JOUR. T1 - Synergistic role of susceptibility-weighted imaging with diffusion-weighted imaging and magnetic resonance angiography in the evaluation of acute arterial stroke. AU - Rai, Santosh P.V.. AU - Sanyal, Pulastya. AU - Pai, Shivananda. AU - Achappa, Basavaprabhu. AU - Madi, Deepak. AU - MR, Pavan. PY - 2019/5/1. Y1 - 2019/5/1. N2 - Objective: This study was performed to investigate whether diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) are more effective than conventional imaging modalities for evaluation of stroke and selection of candidates for thrombolytic therapy. Methods: Eighty patients who presented within 12 hours of onset of symptoms of brain ischemia underwent 1.5T magnetic resonance imaging. DWI and SWI were compared with conventional sequences (T1, T2, and fluid-attenuated inversion recovery [FLAIR]) and time-of-flight magnetic resonance angiography (TOF-MRA) to assess factors that affect stroke management and prognosis. Results: The volume of ...
Bruehschwein A, Foltin I, Flatz K, et al. Vet Radiol Ultrasound 2010;51:116-121. Computed tomography angiography, sonography, scintigraphy, and portography can be used to evaluate the portal vasculature to evaluate for a portosystemic shunt (PSS). Time-of-flight magnetic resonance angiography (TOF-MRA) and … Read More
TY - JOUR. T1 - Acceleration apportionment. T2 - A method of improved 2D SENSE acceleration applied to 3D contrast-enhanced MR angiography. AU - Weavers, Paul T.. AU - Borisch, Eric A.. AU - Johnson, Casey P.. AU - Riederer, Stephen J.. N1 - Copyright: Copyright 2020 Elsevier B.V., All rights reserved.. PY - 2014/2. Y1 - 2014/2. N2 - Purpose In 2D SENSE-accelerated 3D Cartesian acquisition, the net acceleration factor R is the product of the two individual accelerations, R = RY × RZ. Acceleration Apportionment tailors acceleration parameters (RY, RZ) to improve parallel imaging performance on a patient- and coil-specific basis and is demonstrated in contrast-enhanced MR angiography. Methods A performance metric is defined based on coil sensitivity information which identifies the (RY, R Z) pair that optimally trades off image quality with scan time reduction on a patient-specific basis. Acceleration Apportionment is evaluated using retrospective analysis of contrast-enhanced MR angiography ...
Contrast-enhanced computed tomography angiography is usually valuable for the evaluation of clipped cerebral aneurysm, but it has side effects of contrast medium. Time-of-flight magnetic resonance angiography (MRA) is a non-invasive and fast method. However, clip-induced artifact limits assessment of the artery in the vicinity of a clip. MRA with ultrashort echo time (TE) reduces metal artifact. We use MAGNETOM Aera 1.5T (SIEMENS, München, Germany) and perform pointwise encoding time reduction with radial acquisition (PETRA)-MRA using ultrashort TE for the assessment of the cerebral aneurysm after clipping. We, herein, presented two representative cases with a clipped aneurysm which could be evaluated by PETRA- MRA. Especially in one of them, the neck remnant was revealed by PETRA-MRA. PETRA-MRA can reduce the time and the invasiveness and may be helpful for the usual follow-up of the clipped aneurysm with the development of MRA technology in the future.. Keywords: Cerebral aneurysm, Clipping, ...
TY - JOUR. T1 - High-resolution steady-state free precession coronary magnetic resonance angiography within a breath-hold. T2 - Parallel imaging with extended cardiac data acquisition. AU - Park, Jaeseok. AU - Larson, Andrew C.. AU - Zhang, Qiang. AU - Simonetti, Orlando. AU - Li, Debiao. PY - 2005/11. Y1 - 2005/11. N2 - Coronary artery imaging data are conventionally acquired in a single imaging frame during mid-diastole. The data acquisition window must be sufficiently short to avoid cardiac motion artifacts. A short data acquisition window results in decreased imaging efficiency and limited spatial resolution. Parallel imaging may lessen these limitations, but requires highly accurate coil sensitivity. The purpose of this work was to increase the imaging efficiency and spatial resolution in coronary artery imaging using parallel imaging with an extended acquisition window. External coil calibration data were acquired before and after a short mid-diastolic period of accelerated imaging data ...
Yang Q, Li K, Liu X, Bi X, Liu Z, An J, Zhang A, Jerecic R, Li D. Contrast-enhanced whole-heart coronary magnetic resonance angiography at 3.0-T: a comparative study with X-ray angiography in a single center. J Am Coll Cardiol. 2009 Jun 30;54(1):69-76 ...
Aims For catheter ablation of atrial fibrillation (AF), proper catheter positioning is crucial and depends on knowledge of pulmonary vein (PV) anatomy. The aim of this study was to assess PV spatial orientation and ostial shape by contrast-enhanced magnetic resonance angiography (CE-MRA).. Methods and results In 30 consecutive AF patients, CE-MRA was performed prior to ostial ablation. Using a centre-line technique, the PV ostium was defined perpendicular to this centre-line. Minimal and maximal ostial diameters, ostial perimeter, and angles in the anatomical frontal and transverse planes were measured. Twenty-one patients had four separate PVs. In four patients, there was a distinct right-middle PV and in five a common left common PV was found. Left-sided PV ostia were smaller and more elliptical than right-sided PVs. In the transverse plane, the ostia of both superior PVs were directed anteriorly (LS −15±13°, RS −13±11°) and both inferior PV ostia were directed posteriorly (LI ...
Contrast-enhanced magnetic resonance angiography in rabbits: evaluation of the gadolinium-based agent p846 and the iron-based blood pool agent p904 in compariso
TY - JOUR. T1 - Velocity-coded colour magnetic resonance angiography and perfusion-weighted magnetic resonance imaging for the evaluation of extracranial-to-intracranial arterial bypass surgery. AU - Miyazawa, Nobuhiko. AU - Aoki, Shigeki. AU - Toyama, Keiji. AU - Arbab, Ali Syed. AU - Hori, Masaaki. AU - Umeda, Takako. AU - Araki, Tsutomu. AU - Nukui, Hideaki. PY - 2002/12/1. Y1 - 2002/12/1. N2 - Background and purpose: Velocity-coded colour magnetic resonance angiography (VCCMRA) and perfusion magnetic resonance imaging (pMRI) were evaluated as methods for investigating the efficacy of extracranial-to-intracranial arterial bypass (EC-IC bypass) by comparing the findings of VCCMRA and those of cerebral angiography and by measuring the improvement ratio after EC-IC bypass by pMRI compared to that by single photon emission computed tomography (SPECT) using the autoradiographic technique. Methods: Thirteen patients who underwent VCCMRA, angiography, SPECT, and pMRI before and after surgery were ...
To evaluate the relationship between the flow signal intensity of branch arteries distal to the stenosis on 3-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and the risk of stroke recurrence in patients with severe middle cerebral artery (MCA) trunk stenosis. We prospectively recruited 153 patients (mean age 62.9 ± 13.0 years, 106 males) with a first ischemic stroke or transient ischemic attack caused by a severe MCA trunk stenosis (70 % to 99 %) confirmed by 3D TOF MRA and followed them for one year to determine the stroke recurrence. The MCA branch signal intensity distal to the site of stenosis on 3D TOF MRA was classified as either good (grade A) or poor [mild reduction (grade B) or severe reduction (grade C)] according to the extent to which the MCA could be visualized. The patients were divided into groups A (35), B (58), or C (60) based on the MRA grading of the MCA branch signal intensity distal to the site of stenosis. Poor MCA branch signal intensity was associated
To evaluate the relationship between the flow signal intensity of branch arteries distal to the stenosis on 3-dimensional (3D) time-of-flight (TOF) magnetic resonance angiography (MRA) and the risk of stroke recurrence in patients with severe middle cerebral artery (MCA) trunk stenosis. We prospectively recruited 153 patients (mean age 62.9 ± 13.0 years, 106 males) with a first ischemic stroke or transient ischemic attack caused by a severe MCA trunk stenosis (70 % to 99 %) confirmed by 3D TOF MRA and followed them for one year to determine the stroke recurrence. The MCA branch signal intensity distal to the site of stenosis on 3D TOF MRA was classified as either good (grade A) or poor [mild reduction (grade B) or severe reduction (grade C)] according to the extent to which the MCA could be visualized. The patients were divided into groups A (35), B (58), or C (60) based on the MRA grading of the MCA branch signal intensity distal to the site of stenosis. Poor MCA branch signal intensity was associated
TY - JOUR. T1 - Temporal profile of the vascular anatomy evaluated by 9.4-T magnetic resonance angiography and histopathological analysis in mice lacking RNF213. T2 - A susceptibility gene for moyamoya disease. AU - Sonobe, Shinya. AU - Fujimura, Miki. AU - Niizuma, Kuniyasu. AU - Nishijima, Yasuo. AU - Ito, Akira. AU - Shimizu, Hiroaki. AU - Kikuchi, Atsuo. AU - Arai-Ichinoi, Natsuko. AU - Kure, Shigeo. AU - Tominaga, Teiji. PY - 2014/3/13. Y1 - 2014/3/13. N2 - Moyamoya disease (MMD) is a chronic occlusive cerebrovascular disease with unknown etiology. Recent genome-wide and locus-specific association studies identified RNF213 as an important MMD susceptibility gene. However, the exact mechanism by which an abnormality in RNF213 leads to MMD is unknown. To evaluate the role of RNF213 in the etiology of MMD, we generated RNF213-deficient mice (RNF213-/-) by deleting exon 32 of RNF213 by the Cre-lox system, and investigated whether they developed MMD. The temporal profile of cervical/intracranial ...
TY - JOUR. T1 - Diagnostic value of gadolinium-enhanced 3D magnetic resonance angiography in patients with suspected hepatic arterial complications after liver transplantation. AU - Ishigami, Kousei. AU - Stolpen, Alan H.. AU - Hanna Al-Kass, Faraj M.. AU - Zhang, Yan. AU - Rayhill, Stephen C.. AU - Katz, Daniel A.. AU - Abu-Yousef, Monzer. PY - 2005/7/1. Y1 - 2005/7/1. N2 - Purpose: To evaluate the accuracy and clinical role of gadolinium-enhanced 3D magnetic resonance angiography (MRA) in patients with suspected hepatic arterial complications after liver transplantation. Materials and Methods: Thirty-six consecutive MRA studies were performed in 33 liver transplant recipients after transplantation. MRA image quality was assessed subjectively. Thirty-two MRA studies were retrospectively reviewed and correlated with surgery (n = 2), conventional angiography (n = 18), or clinical follow-up (n = 12). MRA findings were also correlated with those of Doppler sonography in 30 of the cases. In 20 ...
BACKGROUND AND PURPOSE: We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan. METHODS: With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage ...
TY - JOUR. T1 - Intraindividual comparison of high-spatial-resolution abdominal MR angiography at 1.5 T and 3.0 T. T2 - Initial experience. AU - Michaely, Henrik J.. AU - Kramer, Harald. AU - Dietrich, Olaf. AU - Nael, Kambiz. AU - Lodemann, Klaus Peter. AU - Reiser, Maximilian F.. AU - Schoenberg, Stefan O.. PY - 2007/9/1. Y1 - 2007/9/1. N2 - Purpose: To prospectively compare three-dimensional (3D) contrast material-enhanced abdominal magnetic resonance (MR) angiography at 1.5 and 3.0 T intraindividually in healthy volunteers. Materials and Methods: After institutional review board approval and informed consent were obtained, 15 healthy male volunteers (age range, 24-41 years) underwent one abdominal 3D contrast-enhanced MR angiographic examination each at 1.5 and 3.0 T in random order. Fast 3D gradient-echo sequence with parallel imaging acceleration factor of three was used for MR angiography; acquired spatial resolutions were 1 x 0.8 x 1 mm3 (imaging time, 19 seconds) at 1.5 T and 0.9 x 0.8 ...
MRI (Magnetic Resonance Imaging) White Plains - MRI (Magnetic Resonance Imaging), Magnetic Resonance Angiography (MRA), Magnetic Resonance Venography (MRV) and other services which are offered at Hartsdale Imaging serving White Plains, Yonkers and the surrounding area.
TY - JOUR. T1 - Peripheral contrast-enhanced MR angiography at 3.0T, improved spatial resolution and low dose contrast. T2 - Initial clinical experience. AU - Nael, Kambiz. AU - Krishnam, Mayil. AU - Nael, Ali. AU - Ton, Anthony. AU - Ruehm, Stefan G.. AU - Finn, J. Paul. PY - 2008/7/14. Y1 - 2008/7/14. N2 - To investigate a high spatial resolution peripheral contrast-enhanced MR angiography (CE-MRA) protocol, applying a dedicated multi-channel array coil and accelerated parallel acquisition at 3.0T in evaluation of patients with peripheral vascular disease. Twenty patients with peripheral vascular disease underwent multi-station high spatial resolution peripheral CE-MRA at 3T. The image quality, presence of venous contamination, image noise, and artifact were evaluated by 2 radiologists independently. Assessment of arterial disease for 540 arterial segments was performed, and findings were correlated with conventional catheter angiography in 10 patients. All studies were yielded high diagnostic ...
0006] There are many conventional techniques to suppress venous contamination. (See, for example, (1) Lee et al., Distal lower extremity arteries: evaluation with two-dimensional MR digital subtraction angiography, Radiology. 1998 May, 207(2):505-12; (2) Maki et al., Utilizing SENSE to achieve lower station sub-millimeter isotropic resolution and minimal venous enhancement in peripheral MR angiography, JMRI, 2002 April, 15(4):484-91; (3) Ho et al., High-spatial-resolution multistation MR imaging of lower-extremity peripheral vasculature with segmented volume acquisition: feasibility study, Radiology 2001 June, 219(3):835-41; (4) Leiner et al., Three-dimensional contrast-enhanced moving-bed infusion-tracking (MoBi-track) peripheral MR angiography with flexible choice of imaging parameters for each field of view JMRI, 2000 April, 11(4):368-77; (5) Wentz et al., High-resolution magnetic resonance angiography of hands with timed arterial compression (tac-MRA) Lancet 2003, 36149-50; (6) ...
Atherosclerosis of the lower leg arteries is a common disease. Patients with this condition has symptoms of ischemia, for instance intermittent claudication (pain during exercise). Diagnosis of atherosclerosis in the legs is normally done with an interventional x-ray-based angiography (DSA- digital subtraction angiography). This is uncomfortable for the patient, and associated with risks of complications (bleeding, vascular damage, embolism).A novel approach to diagnosing atherosclerosis is the use of magnetic resonance angiography. A variant of this is the whole body magnetic resonance angiography(WB-MRA), that produce a picture of the arteries in almost the whole body (excluding the coronary arteries). WB-MRA has a number of advantages compared to DSA. It does not use ionizing radiation, is not invasive, uses a contrast medium with fewer side affects and finally gives a covers a great deal of the arteries in the body.. This study will compare WB-MRA with DSA in patients with symptoms of ...
Neurosurgery 81:688-695, 2017. Stereoelectroencephalography (SEEG) requires high-quality angiographic studies because avascular trajectory planning is a prerequisite for the safety of this procedure. Some epilepsy surgery groups have begun to use computed tomography angiography and magnetic resonance T1-weighted sequence with contrast enhancement for this purpose.. OBJECTIVE: To present the first series of patients with avascular trajectory planning of SEEG based on magnetic resonance angiography (MRA).. METHODS: Thirty-six SEEG explorations for drug-resistant focal epilepsy were performed from January 2013 to December 2015. A retrospective analysis of this consecutive surgical series was then performed. Magnetic resonance imaging included MRA with a modified contrast-enhanced magnetic resonance venography (MRV) protocol with a short acquisition delay, which allowed simultaneous arterial and venous visualization. Our criteria for satisfactoryMRAwere the visualization of at least first-order ...
Methods and Results-Two-dimensional black-blood coronary wall magnetic resonance imaging and 3-dimensional whole-heart coronary magnetic resonance angiography were performed on 130 participants (65-84 years), including 65 hypertensive patients and 65 healthy controls. Coronary segments derived from hypertensive participants had a higher mean coronary wall thickness, a smaller vessel area, a smaller coronary wall area, a smaller lumen area, a lower coronary distensibility index, and a higher percent of the coronary wall occupying the vessel area (PWOV) than those from healthy controls. When the average PWOV was set as an ad hoc cutoff point, coronary segments with a high PWOV had a significantly higher mean wall thickness, a higher maximum wall thickness, a smaller vessel area, a smaller lumen area, a higher coronary distensibility index, and a lower coronary plaque index compared with coronary segments with a low PWOV.. ...
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TY - JOUR. T1 - 4D radial contrast-enhanced MR angiography with sliding subtraction. AU - Cashen, Ty A.. AU - Jeong, Hyun. AU - Shah, Maulin K.. AU - Bhatt, Hem M.. AU - Shin, Wanyong. AU - Carr, James C.. AU - Walker, Matthew T.. AU - Batjer, H. Hunt. AU - Carroll, Timothy J.. PY - 2007/11/1. Y1 - 2007/11/1. N2 - A method is presented for high spatial and temporal resolution 3D contrast-enhanced magnetic resonance angiography. The overall technique involves a set of interrelated components suited to high-frame-rate angiography, including 3D cylindrical k-space sampling, angular undersampling, asymmetric sampling, sliding window reconstruction, pseudorandom view ordering, and a sliding subtraction mask. Computer simulations and volunteer studies demonstrated the utility of each component of the technique. Angiograms of one hemisphere of the intracranial vasculature were acquired with a pixel size of 1.1 x 1.1 x 2.8 mm and a frame rate of 0.35 sec based on a temporal resolution of 3.5 sec. Such a ...
Twenty-two patients (64 ± 10.2 years) with suspected coronary artery disease underwent cardiac MR examination at 3 T (MAGNETOM Tim Trio, Siemens, Germany) after informed consent was obtained. Coronary arteries were imaged using an ECG-triggered, navigator-gated, inversion-recovery, segmented gradient-echo sequence with isotropic whole-heart coverage. A twelve-element matrix coil (six anterior and six posterior) was used for data acquisition. To speed up data acquisition, parallel acquisition (GRAPPA) was used in the phase-encoding direction with an acceleration factor of two. Imaging parameters included: voxel size 0.65 × 0.65 × 0.65 mm3 (interpolated from 1.3 × 1.3 × 1.3 mm3), TR/TE = 3.3/1.5 msec, flip angle = 20°, bandwidth = 700 Hz/pixel, imaging time = 8.8 ± 1.9 min. Contrast agent (0.2 mmol/kg body weight, Multihance, Bracco Imaging SpA, Italy) was intravenously administered at the rate of 0.3 ml/sec using a Medrad power injector. All patients received x-ray angiography (CAG) within ...
Background The combination of coronary MR angiography (CMRA) with cine- and late gadolinium-enhanced (LGE)-MRI provides a comprehensive assessment of coronary artery disease (CAD). However, prognostic value of CMRA compared to cine- or LGE-MRI has not been evaluated. We sought to study the independent and incremental prognostic value of CMRA over clinical variables, left ventricular ejection fraction (LVEF), and presence of LGE.. Methods Cine-, LGE-MRI, and whole-heart CMRA were acquired by using 1.5T MR system and 32 channel cardiac coils in 196 patients (mean age, 68 ± 11; male 60%) with suspected CAD but without known CAD. LVEF was measured from cine MRI, and LGE and significant coronary stenosis (diameter stenosis ≥ 50%) were determined from LGE-MRI and CMRA, respectively. Major adverse cardiac events (MACEs) were defined as cardiac death, acute myocardial infarction, unstable angina, heart failure, and ventricular arrhythmia.. Results During a median follow-up period of 25 months ...
Carotid and intracranial stenosis are responsible for stroke, which is the third leading cause of death globally. Carotid and intracranial stenting are used in management of stenosis. In-stent stenosis occurs in 25-35% of patients. Stent related artifacts and artificial lumen narrowing are problems during MRI scanning. A potential solution is estimate the flow profile across stenosis. The goal of this project is to optimize and implement quantitative magnetic resonance angiography (QMRA) for flow encoding and flow velocity estimation for better characterizing stenosis and assessing its degrees. We conducted multiple phantom measurements (mimicking normal carotid and middle cerebral anatomy) using phase contrast sequence with implementing different degrees of stenosis. Subsequent volunteer and patients measurements were conducted. In 8 mm tubes, flow was stable till 75 % stenosis while in 4 mm tubes, decline starts at 65% stenosis. In subject measurements, there is flow asymmetry between paired ...
See related article, pages 991-993. Prabhakaran and colleagues describe a promising technique, quantitative MR angiography, as a screening tool for detecting intracranial in-stent stenosis. They looked at 14 patients with intracranial stents and compared quantitative MR angiography and conventional angiography. Using a 20% decrease in quantitative MR angiography vessel flow, they found that low blood flow measured by quantitative MR angiography at sites of intracranial stent placement was significantly associated with in-stent stenosis by catheter-based angiography. The sensitivity, specificity, and negative predictive value are excellent, whereas the positive predictive value was fair. They identified all true cases of in-stent stenosis.1 This article and methodology come at a good time because intracranial stents are increasingly being used for the treatment of aneurysms as well as for treating symptomatic intracranial atherosclerotic disease. Other noninvasive imaging such as MR angiography ...
Coronary MR angiography. Patient with anomalous origin of the right coronary artery from the left aortic sinus of Valsalva. Coronary angiography was performed u
Toda la información sobre las últimas publicaciones científicas de la Clínica Universidad de Navarra. Preoperative planning of DIEP and SGAP flaps: Preliminary experience with magnetic resonance angiography using 3-tesla equipment and blood-pool contrast medium
Magnetic resonance angiography is a test used to discover blocked or abnormal arteries or veins. Learn what to expect during an MRA here at Ohio State.
Magnetic resonance angiography or MRA is a type of imaging test that allows a healthcare provider to look at the bodys blood vessels.
Magnetic resonance angiography or MRA is a type of imaging test that allows a healthcare provider to look at the bodys blood vessels.
Magnetic resonance angiography or MRA is a type of imaging test that allows a healthcare provider to look at the bodys blood vessels.
TY - GEN. T1 - Comparison of automatic vessel segmentation techniques for whole body magnetic resonance angiography with limited ground truth data. AU - McNeil, Andrew. AU - Degano, Giulio. AU - Poole, Ian. AU - Houston, Graeme. AU - Trucco, Emanuele. N1 - © Springer International Publishing AG 2017. PY - 2017. Y1 - 2017. N2 - This work is part of a project aimed at automatically detecting vascular disease in whole body magnetic resonance angiograms (WBMRA). Here we present a comparison of four techniques for automatic artery segmentation in WBMRA data volumes; active contours, two vesselness filter approaches (the Frangi filter and Optimally Oriented Flux (OOF)) and a convolutional neural network (Convnet) trained for voxel-wise classification. Their performance was assessed on three manually segmented WBMRA datasets, comparing the maximum Dice Similarity Coefficient (DSC) achieved by each method. Our results show that, in the presence of limited training data, OOF performs best for our ...
MARACAS (MAgnetic Resonance Angiography Computer ASsisted Analysis) : an interactive software for visualisation and analysis of blood vessels in 3D MRA providing automatic quantification of arterial ...
A 20 year old man was found to be hypertensive on routine screening. Examination revealed an absent right and barely palpable left femoral arterial pulse. Radiofemoral delay was present and pulsations were palpable over both scapulae. Parasaggital gadolinium enhanced magnetic resonance angiography (left) demonstrates a uniform 3 cm narrowing in the proximal descending aorta (d), which terminates in a discrete stricture before returning to a normal calibre (a, ascending aorta). Internal mammary artery hypertrophy is noted in the retrosternal. ...
With the development of medical imaging modalities and image processing algorithms, there arises a need for methods of their comprehensive quantitative evaluation. In particular, this concerns the algorithms for vessel tracking and segmentation in magnetic resonance angiography images. The problem can be approached by using synthetic images, where true geometry of vessels is known. This paper presents a framework for computer modeling of MRA imaging and the results of its validation. A new model incorporates blood flow simulation within MR signal computation kernel. The proposed solution is unique, especially with respect to the interface between flow and image formation processes. Furthermore it utilizes the concept of particle tracing. The particles reflect the flow of fluid they are immersed in and they are assigned magnetization vectors with temporal evolution controlled by MR physics. Such an approach ensures flexibility as the designed simulator is able to reconstruct flow profiles of any ...
Understand the usages of Magnetic Resonance Angiography in various health conditions. Explore other smart treatment options, see research evidence, and find out about peoples experiences with many popular treatments, including feedback from patients and professionals.
Robust motion correction is necessary to minimize respiratory motion artefacts in coronary MR angiography (CMRA). The state-of-the-art method uses a 1D feet-head translational motion correction approach, and data acquisition is limited to a small window in the respiratory cycle, which prolongs the scan by a factor of 2-3. The purpose of this work was to implement 3D affine motion correction for Cartesian whole-heart CMRA using a 3D navigator (3D-NAV) to allow for data acquisition throughout the whole respiratory cycle. ...
Parallel imaging using sophisticated receiver coils has improved the clinical feasibility of magnetic resonance coronary angiography (MRCA). These techniques, however, are not readily available outside advanced imaging centers. Our custom-made 2-element phased array coil is readily and inexpensively assembled to address this limitation and enable the widespread application of MRCA. The 2-element phased array coil, comprised of two 4-inch, overlapping circular coils, is specifically designed for MRCA. We compare our prototype coil to two commercially available coils commonly used for MRCA. MRCA has been performed in 14 normal volunteers. Anatomic coverage, image quality, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) are calculated for each coil. The prototype coil has imaged 92.6% (125/135) of the segments compared to 83.7% (113/135) and 76.3% (103/135) (p = 0.002) using the surface coil and cardiac phased array coil, respectively. Excellent or good (grade 1-2) image quality has ...
TY - JOUR. T1 - Contrast-enhanced MR angiography of the peripheral vasculature with a continuously moving table and modified elliptical centric acquisition. AU - Madhuranthakam, Ananth J.. AU - Hu, Houchun H.. AU - Kruger, David G.. AU - Glockner, James F.. AU - Riederer, Stephen J.. PY - 2006/7. Y1 - 2006/7. N2 - This study was approved by the institutional review board and was HIPAA compliant. All subjects provided written informed consent, and subject confidentiality was protected. The purpose of this study was to prospectively evaluate the feasibility of integrating a modified elliptical centric (EC) acquisition with a continuously moving table technique to acquire high-spatial-resolution contrast material-enhanced magnetic resonance (MR) angiograms of the peripheral vasculature. Incorporation of two-dimensional homodyne reconstruction modified the EC view order, allowing improved spatial resolution per unit time while retaining the advantage of venous suppression intrinsic to the EC ...
It can be argued that magnetic resonance angiography of the aorta and peripheral vessels has undergone more dramatic changes over the last couple decades than any other form of cardiovascular magnetic resonance imaging. The first useful clinical applications primarily used two-dimensional time-of-flight technology. However, in the mid-1990s, this approach was replaced to a large degree by contrast-enhanced techniques using conventional agents in dynamic, multiphase mode. Blood pool agents have also been developed for use in magnetic resonance angiography, but their precise role remains to be determined. Given the risks of gadolinium contrast in patients with renal failure, which is not an unusual concomitant in patients undergoing vascular evaluation, there has been a recent resurgence in interest in the use of non-contrast magnetic resonance angiographic approaches.
Both of these techniques were compared with another imaging technique called X-ray coronary angiography, which acted as the reference standard. In this way, the researchers could directly compare the results of the two scans in a single patient and then turn to X-ray scanning to confirm which was most accurate.. In X-ray coronary angiography, a contrast agent is introduced into the coronary artery and X-ray images are taken. Again, the patient is exposed to ionising radiation and in addition the technique used to introduce the contrast agent is invasive. This is an anatomical test that shows where any narrowed arteries might be.. Patients with suspected disease were randomised into two groups, receiving either CMR before SPECT (prior to confirmation with angiography) or SPECT before CMR (prior to confirmation with angiography). Offering CMR and SPECT in a random order reduces the chances of the results being influenced by bias: for example, the process of performing a scan might potentially ...
RESULTS. There were 27 patients (14 male, 13 female) with a mean age of 62 (range, 44-77) years. There were 10 patients with renal transplants; their native renal arteries were not evaluated. Each of the two experienced interventional and body magnetic resonance radiologists, who were blinded to the results, reviewed the digital subtraction angiography and magnetic resonance angiography images respectively. Digital subtraction angiography was used as the standard of reference. A total of 39 renal arteries from these 27 patients were evaluated. One of the arteries was previously stented and could not be assessed with magnetic resonance angiography due to severe artefacts. Of the remaining 38 renal arteries, two were graded as normal, seven as having mild stenosis (=50% but =75%). Magnetic resonance angiography and digital subtraction angiography were concordant in 89% of the arteries; magnetic resonance angiography overestimated the degree of stenosis in 8% and underestimated it in 3% of them. In ...
A dynamic MR angiography technique, MR digital subtraction angiography (MR DSA), is proposed using fast acquisition, contrast enhancement, and complex subtraction. When a bolus of contrast is injected into a patient, data acquisition begins, dynamically acquiring a thick slab using a fast gradient e …
BACKGROUND AND PURPOSE: Contrast-enhanced MR angiography and extracranial color-coded duplex sonography are noninvasive, preoperative imaging modalities for evaluation of carotid artery stenosis. Innovative techniques and improvements in image quality require frequent reassessment of accuracy, reliability, and diagnostic value compared with those of digital subtraction angiography (DSA). We evaluated contrast-enhanced MR angiography and duplex sonography compared with DSA for detection of high-grade carotid artery stenoses. METHODS: Four readers, blinded to clinical symptoms and the outcome of other studies, independently evaluated stenoses on contrast-enhanced MR angiograms in 71 vessels of 39 symptomatic patients. Duplex sonography was also performed in all vessels. The severity of stenosis was defined according to North American Symptomatic Carotid Endarterectomy Trial criteria (0-29%, 30-69%, 70-99%, 100%). Results of both modalities were compared with the corresponding DSA finding
TY - JOUR. T1 - Peripheral vascular disease. T2 - Blinded study of dedicated calf MR angiography versus standard bolus-chase MR angiography and film hard-copy angiography. AU - Binkert, Christoph A.. AU - Baker, Phillip D.. AU - Petersen, Bryan D.. AU - Szumowski, Jerzy. AU - Kaufman, John A.. PY - 2004/9/1. Y1 - 2004/9/1. N2 - PURPOSE: To compare the accuracy of contrast material-enhanced three-dimensional (3D) dedicated calf magnetic resonance (MR) angiography with that of bolus-chase MR angiography, with conventional angiography as the reference standard, in patients with symptomatic peripheral vascular disease (PVD). MATERIALS AND METHODS: Thirty men with symptomatic PVD were examined. MR angiography was performed at 1.5 T before conventional angiography. MR angiographic examination included 3D contrast-enhanced dedicated calf MR angiography and three-station bolus-chase MR angiography. Two radiologists blinded to conventional angiographic results evaluated the MR angiograms independently. ...
TY - JOUR. T1 - Noninvasive determination of infarct artery patency by cine magnetic resonance angiography. AU - Hundley, W. G.. AU - Clarke, G. D.. AU - Landau, C.. AU - Lange, R. A.. AU - Willard, J. E.. AU - Hillis, L. D.. AU - Peshock, R. M.. PY - 1995. Y1 - 1995. N2 - Background: In survivors of myocardial infarction, restoration of antegrade flow in the infarct artery reduces morbidity and mortality. At present, coronary artery patency must be assessed invasively with contrast angiography. A noninvasive method of evaluating infarct artery patency would be useful in managing survivors of infarction. This study was performed to determine whether magnetic resonance (MR) imaging could reliably assess infarct artery patency in this patient population. Methods and Results: Eighteen survivors of myocardial infarction (11 men and 7 women, aged 35 to 74 years) who were consecutively referred for cardiac catheterization underwent contrast coronary angiography and cine MR coronary angiography. ...
TY - JOUR. T1 - Noninvasive coronary artery imaging. T2 - Magnetic resonance angiography and multidetector computed tomography angiography: A scientific statement from the American Heart Association committee on cardiovascular imaging and intervention of the council on cardiovascular radiology and intervention, and the councils on clinical cardiology and cardiovascular disease in the young. AU - Bluemke, David A.. AU - Achenbach, Stephan. AU - Budoff, Matthew. AU - Gerber, Thomas C.. AU - Gersh, Bernard. AU - Hillis, L. David. AU - Hundley, W. Gregory. AU - Manning, Warren J.. AU - Printz, Beth Feller. AU - Stuber, Matthias. AU - Woodard, Pamela K.. PY - 2008/7/29. Y1 - 2008/7/29. KW - AHA scientific statements. KW - Angiography. KW - Imaging. UR - http://www.scopus.com/inward/record.url?scp=49649104098&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=49649104098&partnerID=8YFLogxK. U2 - 10.1161/CIRCULATIONAHA.108.189695. DO - 10.1161/CIRCULATIONAHA.108.189695. M3 - Review ...
TY - JOUR. T1 - Contrast-enhanced MR angiography for evaluation of vascular complications of the pancreatic transplant. AU - Dobos, Nora. AU - Roberts, David A.. AU - Insko, Erik K.. AU - Siegelman, Evan S.. AU - Naji, Ali. AU - Markmann, James F.. PY - 2005/5. Y1 - 2005/5. N2 - Vascular complications are a common cause of postoperative dysfunction in a pancreatic transplant. Coronal three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography performed with high spatial and temporal resolution is a safe and effective method of assessing these vascular complications. A study was performed of selected patients who had undergone MR imaging and MR angiography during the past 6 years for evaluation of graft dysfunction following pancreatic transplantation. Thrombosis within peripheral stump vessels involving either the arterial or venous segments was a commonly observed vascular complication. Isolated distal arterial stump thrombi are incidental findings that may not require ...
TY - JOUR. T1 - Magnetic resonance angiography in vertebrobasilar ischemia. AU - Verro, Piero. AU - Levine, R. L.. AU - Turski, P. A.. AU - Partington, C.. PY - 1993. Y1 - 1993. UR - http://www.scopus.com/inward/record.url?scp=0027516360&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0027516360&partnerID=8YFLogxK. M3 - Article. C2 - 10148530. AN - SCOPUS:0027516360. VL - 3. SP - 132. EP - 138. JO - Journal of Neuroimaging. JF - Journal of Neuroimaging. SN - 1051-2284. IS - 2. ER - ...
Introduction: Contrast-enhanced MR angiography (CE-MRA) provides highly accurate measurement of carotid stenosis. But non-contrast techniques are desired as contrast agents may lead to anaphylaxis or nephrogenic system fibrosis. Recently, an inversion-recovery gradient echo sequence with phase-sensitive reconstruction was developed for assessment of lumen and intraplaque hemorrhage in one sequence - Simultaneous Noncontrast Angiography and intraPlaque hemorrhage (SNAP).. Hypothesis: We tested the hypothesis that SNAP provides an accurate and reproducible assessment of carotid stenosis compared to CE-MRA.. Methods: Fifty-eight subjects with 16-79% stenosis on ultrasound were scanned using a large-coverage (16 cm), isotropic-resolution (0.8 mm) SNAP sequence. Minimum intensity projections were generated at ten degrees increments to get 3D views of carotid arteries. Carotid stenosis was measured bilaterally according to the NASCET criteria by independent readers to estimate inter-reader ...
Conventional coronary angiography frequently underestimates the true burden of atherosclerosis. As reported by Glagov et al,1 the initial response to endothelial injury and development of atherosclerosis is vessel enlargement, with relative preservation of lumen diameter. Subsequent plaque progression, with lumen-encroachment stenoses, is a later event. Invasive x-ray coronary angiography and bright-blood2 3 coronary magnetic resonance angiography (MRA) only allow for assessment of luminal vessel diameter and do not provide direct information regarding coronary vessel wall thickness or atherosclerotic plaque. Recent intravascular ultrasound (IVUS) studies4 5 have shown that lesion-site cross-sectional area, minimum lesion diameter, cross-sectional narrowing, and area stenosis are good predictors for subsequent acute cardiac events. However, this invasive technique is not appropriate for screening or serial examinations. Apart from plaque burden and luminal encroachment, plaque composition is a ...
In many preliminary and feasibility studies, various contrast-enhanced MR angiorgaphic techniques have been implemented in the assessment of extracranial disease of the carotid artery. Different strategies are used to optimize image quality, including time-resolved and high-resolution techniques. Most of these reports, although based on small numbers of patients, suggest that contrast-enhanced MR angiography could become a diagnostic alternative as a fast, first screening method in patients suspected of having carotid artery disease, independently from the technique employed in the study.. DSA is still considered to be the criterion standard for imaging of arteriosclerotic supraaortic vessel disease. Harboring the risks of thromboembolic events, this technique can reduce the overall benefit of endarterectomy. Noninvasive techniques for imaging supraaortic vessels prevent this risk related to the diagnostic procedure and can be regarded as a safe alternative to DSA whenever possible.. We chose to ...
BACKGROUND: Magnetic resonance (MR)-guided vascular interventions are of increasing interest, and, with the use of contrast-enhanced techniques, intraarterial contrast-enhanced MR angiography (ia-ce-MRA) competes with intraarterial digital subtraction angiography (ia-DSA) for the diagnostic evaluation of the infrainguinal vessel tree. PURPOSE: To assess the diagnostic value of ia-ce-MRA and high-resolution T1-weighted (hr-T1w) imaging compared to the gold-standard ia-DSA for residual stenosis and local dissections after femoropopliteal recanalization in patients with peripheral arterial occlusive disease (PAOD). MATERIAL AND METHODS: Eight patients with PAOD and short vessel occlusion of their femoropopliteal arteries underwent recanalization and balloon positioning under DSA. Patients were transferred to a short-bore MR scanner. Percutaneous transluminal angioplasty (PTA) was accomplished under MR fluoroscopy. Pre- and postinterventional ia-ce three-dimensional (3D) gradient-echo MRA with ...
The authors compared the three-dimensional Fourier transform (3DFT) time-of-flight magnetic resonance (MR) angiograms in 38 patients initially studied with selective intraarterial digital subtraction angiography (DSA) for suspected arteriosclerotic disease of the carotid bifurcation. MR angiograms w …
Transcatheter arterial chemo-embolization (TACE) is a therapeutic procedure to treat primary and metastatic liver cancer. It requires prior delineation of the hepatic arteries on magnetic resonance angiography (MRA) data and identification of the vessels supplying the tumor. Manual segmentation is extremely challenging and time consuming, thereby increasing the risk of wrongfully identifying the feeding vessels. We present a vascular path planning tool for TACE procedures by automatically segmenting the hepatic arteries on MRA. The proposed method first detects the celiac trunk from the aorta, then localizes and tags bifurcations throughout the arterial network for path planning. The algorithm is based on a multiple hypothesis tracking approach used to propagate deformable mesh surfaces. We validated the proposed framework on 20 liver-cancer-patients using abdominal MRA with 20 seconds delay after contrast injection. We show that the algorithm improves the selectivity of the arterial segments ...
Focal damage to the fornices is uncommon and may be due to surgical removal of ventricular cysts and tumours.1 We report a case of bilateral fornix infarction with reduced fractional anisotropy values at 3 T after anterior communicating artery aneurysm clipping.. A healthy 33-year-old woman was admitted to our hospital with the incidental finding of an anterior communicating artery (ACoA) aneurysm on magnetic resonance angiography. Neurological examination was normal. Digital subtraction angiography visualised a broad based, tapered and 4 mm sized aneurysm of the ACoA and a median callosal artery (fig 1C). The ACoA aneurysm was treated with surgical clipping because of its irregular configuration. After surgery, the patient was drowsy with fluctuating impaired vigilance. She was disoriented in time, space and person, and revealed anterograde amnesia and amnesic aphasia. Her relatives noticed personality changes, psychomotor slowing and decreased spontaneity of speech and behaviour. Apart from ...
TY - GEN. T1 - VIDEO REQUIREMENTS FOR DIGITAL SUBTRACTION ANGIOGRAPHY.. AU - Hines, Horace H.. AU - Seibert, J Anthony. AU - Borger, David J.. PY - 1984. Y1 - 1984. N2 - The television camera comprises an important link in the imaging chain of digital subtraction angiography equipment. Various factors including spatial resolution, signal to noise ratio (SNR), progressive and interlaced read out, exposure utilization and camera lag are investigated. Requirements for the video camera for optimized DSA studies include sufficient bandpass to satisfy digitization matrix sizes, an 800:1 camera SNR, progressive read out of the camera target, and bias light to minimize build-up lag response.. AB - The television camera comprises an important link in the imaging chain of digital subtraction angiography equipment. Various factors including spatial resolution, signal to noise ratio (SNR), progressive and interlaced read out, exposure utilization and camera lag are investigated. Requirements for the video ...
Get Digital Subtraction Angiography cost from certified hospitals in Bangalore. Get assistance from medical experts to select best hospital for Digital Subtraction Angiography in Bangalore
I had a stroke back in early 2005. With that, and with my moms death, my neurologist recommended that I have an MRA done of my head. I had that done at the clinic today. The neurologist also wants me to get my homocystine levels checked to make sure my medications are still working. In addition, I saw my cardiologist earlier this week and she wants me to have my choloestrol checked. So, Im going to get blood work done at LabCorp on Friday ...
View details of top cerebral digital subtraction angiography dsa hospitals in New Delhi. Get guidance from medical experts to select best cerebral digital subtraction angiography dsa hospital in New Delhi
Grey-scale and Doppler ultrasound (US) are alternative modalities to diagnose soft-tissue vascular anomalies [16]. However, US has only a limited ability to display the full extent of large lesions and to demonstrate an intra-osseous component [17,18]. Some MRI techniques have been used for classification of peripheral vascular lesions [18,19,20]. Time-of-flight MR angiography can show feeding arteries with high-flow; however, this modality has a limitation regarding smaller vessels [19]. A previous study by van Rijswijk et al. [20] has demonstrated that with the use of the dynamic contrast-enhancement gradient-echo technique, venous malformations were distinguished from non-venous malformations with high specificity. Another study has demonstrated that time-resolved MR projection angiography was useful for the separation of high- and low-flow vascular malformations [18]. Although direct puncture venography is useful for the diagnosis of VMs and also for confirming lymphatic fluid leaks to ...
Coronary artery disease (CAD) is the leading cause of death in the United States. CAD is implicated in 900,000 deaths per year 1.5 million heart attacks occur each year estimated yearly cost of care for patients with CAD is $60 billion dollars More than 1 million cardiac catheterizations are performed each year cardiac catherization is used to define coronary artery anatomy, and also to guide therapy for cardiac patients X-ray coronary angiography is associated with significant radiation exposure and a small risk (1.7%) of serious complications estimated per-patient cost of cardiac catherization is $3000-$5000 Cardiac catheterization has diagnostic limitations X-ray angiography provides little information regarding coronary artery blood flow, and does not address the functional significance of coronary lesions
Purpose: To evaluate the suitability of an improved version of an automatic segmentation method based on geodesic active regions (GAR) for segmenting cerebral vasculature with aneurysms from 3D X-ray reconstruc-tion angiography (3DRA) and time of °ight magnetic resonance angiography (TOF-MRA) images available in the clinical routine.Methods: Three aspects of the GAR method have been improved: execution time, robustness to variability in imaging protocols and robustness to variability in image spatial resolutions. The improved GAR was retrospectively evaluated on images from patients containing intracranial aneurysms in the area of the Circle of Willis and imaged with two modalities: 3DRA and TOF-MRA. Images were obtained from two clinical centers, each using di®erent imaging equipment. Evaluation included qualitative and quantitative analyses ofthe segmentation results on 20 images from 10 patients. The gold standard was built from 660 cross-sections (33 per image) of vessels and aneurysms, ...
MR Angiography (MRA) is an MRI scan that provides pictures of blood vessels inside the body. These tests are used to diagnose blockages, aneurysms, and narrowing of blood vessels. Unlike traditional angiograms, which require an arterial catheter to be placed, MR angiography is completely non-invasive. If you are receiving an IV Contrast MRA, you will be injected with a contrast solution to make images appear brighter on the screen.. MRI doesnt use harmful radiation to create images. Instead, strong magnetic fields and radiofrequency waves (the same kind used in radio transmissions) are used to create images of the body. No harmful side effects have ever been reported from MRI. ...
We tested the hypothesis that differences in proximal and distal contrast bolus arrival times may result in insufficient vascular signal in the distal part of the aortoiliofemoral territory with routinely used timing techniques. The difference in arrival time of the contrast medium bolus between the aorta and the common femoral arteries was measured in 14 patients undergoing magnetic resonance angiography of the aortoiliac arteries. A dual-station test bolus technique adjusting for this difference was evaluated. The variation coefficient of the signal intensity in six defined locations and signal intensities (SI) normalised to fat were calculated. Comparisons were made with findings in 13 patients examined with a fluoroscopically triggered timing technique (BolusTrak, Philips Medical Systems, Best, The Netherlands). The difference in bolus arrival time between proximal and distal vessels was 0-7 s. In 3 of 14 patients it was 5.6-7 s. There was a tendency towards a lower mean variation ...
With Philips Digital Subtraction Angiography (DSA) automatic examination pre-sets support a smooth and efficient workflow in angiography examinations.
Animal models offer a flexible experimental environment for studying atherosclerosis. The mouse is the most commonly used animal, however, the underlying hemodynamics in larger animals such as the rabbit are far closer to that of humans. The aortic arch is a vessel with complex helical flow and highly heterogeneous shear stress patterns which may influence where atherosclerotic lesions form. A better understanding of intraspecies flow variation and the impact of geometry on flow may improve our understanding of where disease forms. In this work, we use magnetic resonance angiography (MRA) and 4D phase contrast magnetic resonance imaging (PC-MRI) to image and measure blood velocity in the rabbit aortic arch. Measured flow rates from the PC-MRI were used as boundary conditions in computational fluid dynamics (CFD) models of the arches. Helical flow, cross flow index (CFI), and time-averaged wall shear stress (TAWSS) were determined from the simulated flow field. Both traditional geometric metrics ...
Millimeter measurements are needed for management decisions and treatment planning of some vascular diseases. Surveying 2 recent issues of the American Journal of Neuroradiology gleaned reports requiring millimeter measurements from digital subtraction angiography (DSA).1-4 These included aneurysm sizes, necks, and devices matched to artery size.. Despite the multiple advantages of DSA, the technology did not, and still does not, include a method of measurement that provides the same ability to measure in millimeters as earlier analog techniques did. C-arm DSA with adjustable intensifiers reduces tube distance and thus increases magnification. Intensifier positional variability and tabletop movements add to millimeter inaccuracy with variable magnification in different projections.5 FOV settings further complicate calibrations. There are challenges to calibrating real millimeters with different positions when scanning the same patient. Manufacturers did not develop millimeter adjustments for ...
Ratering, D; Baltes, C; Lohmann, C; Matter, C M; Rudin, M (2011). Accurate assessment of carotid artery stenosis in atherosclerotic mice using accelerated high-resolution 3D magnetic resonance angiography. Magma, 24(1):9-18.. Baltes, C; Bosshard, S; Mueggler, T; Ratering, D; Rudin, M (2011). Increased blood oxygen level-dependent (BOLD) sensitivity in the mouse somatosensory cortex during electrical forepaw stimulation using a cryogenic radiofrequency probe. NMR in Biomedicine, 24(4):439-446.. Ratering, D. Improving sensitivity per unit time in small animal MRI: Low temperature detection and parallel acquisition. 2010, ETHZ Diss.No 18954, Faculty of Medicine.. Yankam Njiwa, J; Ratering, D; Baltes, C; Rudin, M (2010). Increasing temporal resolution of DSC perfusion MRI using the analytic image concept. Magma, 23(4):251-261.. Ratering, D; Baltes, C; Nordmeyer-Massner, J A; Marek, D; Rudin, M (2008). Performance of a 200-MHz cryogenic RF probe designed for MRI and MRS of the murine brain. Magnetic ...
The digital subtraction angiography method useful for three dimensional (3D) imaging of a selected volume of a body comprises the following steps. Acquiring first and second 3D data sets representative of an image of substantially the same selected volume in the body, the first and second data sets being acquired at different times corresponding to a pre- and a post injection of a contrast medium, respectively. Determining common reference points for spatially corresponding subvolumes in the data sets. Comparing in a 3D spatial manner data in subvolumes of the second data set with data in corresponding subvolumes in the first data set in order to determine a new reference point in each of the subvolumes of the first data set which results in a best match of the spatial similarity of the data in the corresponding subvolumes of the second data set. Spatially interpolating new data for the subvolumes of said first data set using the new reference points determined above and the originally acquired
MRIs are used to scan and examine one part of your body at a time. The scan can focus on many parts of the anatomy. There is even a form of MRI that can look at blood vessels and the flow of the blood as it goes through them. This is called Magnetic Resonance Angiography (MRA). These kinds of scans can help to find arterial and vein problems, such as a blocked vessel, torn vessel lining or aneurysm. The different kinds of MRI scans include, but are not limited to: Abdomen, Adrenal Glands, Ankle (Achilles), Bladder, Brain, Breast, Cervical Spine (C-Spine), Chest, Coccyx (Tailbone), Elbow, Face (Maxillofacial, Parotid Glands), Femur (Thigh, Upper Leg), Fingers, Foot, Forearm (Lower Arm), Hand, Hip, Humerus (Upper Arm), IACs (Inner Ear), Kidneys (Renal, Knee, Liver, Lower Leg (Calf, Tibia, Fibula), Lumbar Spine (L-Spine), Mandible (Jaw), MRA Abdomen (Abdominal Aorta), MRA Brain, MRA Chest, MRA Kidneys, MRA Knee, MRA Neck, Nasopharynx (Tongue), Neck, Orbits (Ears), Pancreas, Pelvis, Pituitary ...
Magnetic resonance perfusion imaging in glioblastoma Indications Magnetic resonance perfusion imaging, may: Provide a noninvasive diagnostic tool for properly grading lesions. Identifying the most malignant region of a tumor for guiding biopsy Monitoring response to therapy that may precede conventionally assessed changes in tumor morphology and enhancement characteristics.
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A 39-year-old man with no known cardiovascular risk factors was hospitalized for chest pain radiating to the side. Type A aortic dissection was diagnosed by transthoracic echocardiography and computed tomography (CT). Urgent surgery was performed, in which the ascending aorta was replaced with a valved tube graft (Bentall-Bono procedure). The patient had a phenotype typical of Marfan disease: height of 190 cm, long limbs, scoliosis and dural ectasia.. Postoperative follow-up included yearly imaging studies with transthoracic echocardiography and magnetic resonance angiography of the aorta. Two years later, after the aorta had reached a diameter of 59 mm in the curve distal to the origin of the supra-aortic trunks (Figure 1), a second operation, consisting of an elephant trunk technique (Figure 2) with on-pump circulation and retrograde cerebral perfusion was performed to repair the arch. The patient was thus prepared for the third and last operation, performed three months later and involving ...
SINAPSE is developing a world class future in medical imaging for Scotland by drawing on the combined expertise of seven Scottish universities.
SINAPSE is developing a world class future in medical imaging for Scotland by drawing on the combined expertise of seven Scottish universities.
Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessels angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to ...
The first part of the book describes the normal anatomy of the cerebral arteries and veins, with attention to morphological aspect, embryological development, function, and vascular territories. Cerebral Angiography: Normal Anatomy and Vascular Pathology di Bradac, Gianni Boris su AbeBooks.it - ISBN 10: 3642156770 - ISBN 13: 9783642156779 - Springer Verlag - 2011 - Rilegato This anatomy module of e-Anatomy was designed and created by MD Micheau Antoine and MD Hoa Denis, radiologists in Montpellier (France). arteriovenous malformation; arteriovenous fistula MR angiography, and especially Gd-enhanced 3D MRA, has recently emerged and offers excellent visualization of venous morphology from multiple orientations. An overview of the current non-invasive MRA methods and their applications has been provided during depiction of normal venous anatomy. CT angiography of the cerebral arteries (also known as a CTA carotids or an arch to vertex angiogram) is a noninvasive technique allows visualization of ...
In addition to expanding our knowledge of the process of HCMV maturation, information from these studies will also be utilized to develop new antiviral therapies. We established founder colonies from West Africa, controlled for diversity, linkage disequilibrium and population stratification. Differential effects of tranylcypromine and imidazole on mammary carcinogenesis in rats fed low and high fat diets. This study reports on a combination of multi-echo acquisition with time-resolved undersampled PR imaging and its application to peripheral magnetic resonance angiography.. Moving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Comparison of cervical os versus vaginal evidentiary findings during sexual assault exam. Resveratrol production in bioreactor: Assessment of cell physiological states and plasmid segregational stability. Germination of Aspergillus fumigatus inside avian respiratory macrophages is associated with ...
BACKGROUND: No golden diagnostic standard is available to diagnose chronic gastrointestinal ischemia (CGI). GOALS: We aimed to establish an accurate prediction model for CGI, based on clinical symptoms and radiologic evaluation of the amount of stenosis in the celiac artery (CA) and superior mesenteric artery (SMA) by means of computed tomography-angiography or magnetic resonance (MR)-angiography. STUDY: We prospectively included 436 consecutive patients with clinical suspicion of CGI in a tertiary referral center. Predictors for CGI were obtained by comparing clinical parameters to the diagnosis of CGI. Multivariable logistic regression was used to combine the strongest predictors in a model. A score chart based on the prediction model was provided to calculate the risk of CGI. RESULTS: CGI was present in 171/436 (39%) patients (67 y; range, 54 to 74 y; 27% male). Strongest predictors for CGI were female gender [odds ratio (OR)=1.44; 95% confidence interval (CI), 0.85-2.43], weight loss ...
Conventional angiography is the diagnostic standard for determining the presence, location and severity of heart disease. An EB, CT, EBT Angiography are different forms of angiographies that offers similar results if a convetional angiography is not necessary. Find an angiography clinic facility in your area.
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