Purpose: To assess the feasibility of Clariscan, an intravascular contrast agent, for free breathing, navigator assisted, high resolution, three-dimensional-magnetic resonance coronary angiography (MRCA) in patients, as extracellular contrast agents are unfavorable for the improvement of image quality.
Materials And Methods: MRCA was performed in 10 patients with known coronary artery disease (CAD) with (1-5 mg Fe/kg body weight) and without contrast agent.
Results: Compared to unenhanced images, Clariscan did not improve signal-to-noise (SNR) or contrast-to-noise ratios (CNR) compared to fat or myocardium in the proximal parts of the coronary arteries.
Background: In patients with coronary artery stents, no direct noninvasive coronary artery imaging is possible with magnetic resonance (MR). A well-established method for the assessment of the functional significance of a coronary lesion is the measurement of coronary flow reserve by invasive intracoronary Doppler. The purpose of the study was to determine coronary flow velocity reserve (CFVR) with MR after stent deployment.
View Article and Find Full Text PDFThe Medical Outcome Short Form 36 is commonly used as a generic quality of life measure in the assessment of vascular disease. The Claudication Scale CLAU-S, the PAVK-86 Fragebogen, and the Walking Impairment Questionnaire WIQ are validated disease-specific questionnaires for intermittent claudication. A disease specific tool for critical ischaemia is lacking.
View Article and Find Full Text PDFCurrently, adenosine or dipyridamole is commonly used for the assessment of perfusion reserve. With intolerance to these agents, dobutamine can be used alternatively or it can be used for a combined examination of wall motion and perfusion. The aim of the study was to analyze the feasibility of cardiovascular magnetic resonance (CMR) to assess perfusion reserve with dobutamine.
View Article and Find Full Text PDFBackground: Examination of the influence of dorzolamide on the autoregulation of retinal vessel diameter in glaucoma patients.
Patients And Methods: Eleven patients with primary open angle glaucoma (age 60 +/- 11) without medication and four weeks after starting therapy with dorzolamid eye drops three times daily were examined in the study. Short-time rise of intraocular pressure (IOP) was obtained via suction-cup.
In three-dimensional (3D) coronary magnetic resonance angiography (MRA), the in-flow contrast between the coronary blood and the surrounding myocardium is attenuated as compared to thin-slab two-dimensional (2D) techniques. The application of a gadolinium (Gd)-based intravascular contrast agent may provide an additional source of signal and contrast by reducing T(1blood) and supporting the visualization of more distal or branching segments of the coronary arterial tree. In six healthy adults, the left coronary artery (LCA) system was imaged pre- and postcontrast with a 0.
View Article and Find Full Text PDFRetinal Vessel Analysis is a new technique to assess behavior of large retinal vessels based on diameter measurements. The Retinal Vessel Analyzer (RVA) measures continuously on-line obtaining data in relation to time and local position. Possible analysis tools include (a) Time Course Analysis of physiological, pathological, or therapy induced changes; (b) Local Course Analysis to recognize local narrow or wide vessel segments along the vessel; (c) Vasomotoric Analysis to determine vasomotions and blood pressure related diameter changes; (d) Functional Analysis to examine dynamic behavior e.
View Article and Find Full Text PDFThe purpose of this study was to determine whether steady-state free precession (SSFP) could improve accuracy of geometric models for evaluation of left ventricular (LV) function in comparison to turbo gradient echo (TGrE) and thereby reduce the acquisition and post-processing times, which are commonly long by use of the Simpson's Rule. In 25 subjects, cine loops of the complete heart in short and horizontal long-axis planes were acquired using TGrE (TR/TE/flip = 5.0/1.
View Article and Find Full Text PDFPurpose: To compare the accuracy of real-time magnetic resonance (MR) imaging with that of standard echo-planar MR imaging for detecting myocardial wall-motion abnormalities at rest and during dobutamine hydrochloride-induced stress in patients with coronary arterial disease.
Materials And Methods: In 22 patients with coronary arterial disease, left ventricular wall motion was examined at rest and during dobutamine hydrochloride stress, by using echo-planar MR imaging and a new technique with real-time segmented k-space turbo gradient-echo echo-planar MR imaging (repetition time, 16.5 msec; echo time, 6.
Klin Monbl Augenheilkd
July 2002
Background: [corrected] To evaluate the reproducibility of measurements with the Retinal Vessel Analyzer (RVA) in healthy subjects and to describe which measuring conditions should be guaranteed to obtain optimal results.
Methods: The diameter of retinal arteries and veins of 20 healthy subjects (M : F = 11 : 9; mean age: 33 +/- 12 years) were measured with the RVA at baseline, after 2 hours, and after 2 weeks.
Results: No statistically significant differences in the diameter of retinal arteries and veins between the single measurements were present.
Eur J Ophthalmol
August 2002
Purpose: Regulation of ocular blood flow might be impaired in glaucoma patients. We compared the reaction of retinal vessels to a short-term increase of intraocular pressure (IOP), using a retinal vessel analyzer (RVA), in normal volunteers, ocular hypertensive patients (OH) and primary open angle glaucoma patients (POAG).
Methods: Ten healthy subjects (56+/-8 years, IOP 13.
J Cardiovasc Magn Reson
February 2002
For the assessment of myocardial perfusion with cardiac magnetic resonance imaging, different semiquantitative parameters of the first pass signal intensity time curves can be calculated and myocardial perfusion reserve indices can be determined. In this study we evaluated the feasibility of different perfusion parameters and their perfusion reserve indices for the detection of significant coronary artery stenosis. The signal intensity time curves of the first pass of a gadolinium-DTPA bolus injected via a central vein catheter before and after dipyridamole infusion were investigated in 15 patients with single vessel (stenosis > or = 75% area reduction) and five patients without significant coronary artery disease.
View Article and Find Full Text PDFN Engl J Med
December 2001
Background: An accurate, noninvasive technique for the diagnosis of coronary disease would be an important advance. We investigated the accuracy of coronary magnetic resonance angiography among patients with suspected coronary disease in a prospective, multicenter study.
Methods: Coronary magnetic resonance angiography was performed during free breathing in 109 patients before elective x-ray coronary angiography, and the results of the two diagnostic procedures were compared.
The implementation and first in vivo results of a novel coronary magnetic resonance angiography (MRA) protocol allowing simultaneous acquisition of multiple geometrically independent 3D imaging stacks are presented. Each imaging stack is acquired in a separate cardiac phase using an individual magnetization preparation and navigator-based gating and prospective motion correction. Each stack covers one of the main coronary vessels.
View Article and Find Full Text PDFContrast between blood and myocardium in standard turbo gradient echo MR techniques (TFE) used routinely in clinical practice is mainly caused by unsaturated inflowing blood. Steady-state free precession (SSFP) has excellent contrast even in the absence of inflow effects. In 45 subjects cardiac cine loops in two long axis projections were acquired using TFE and compared with SSFP.
View Article and Find Full Text PDFThe aim of this study was the evaluation of new algorithms to measure diameter of segments of retinal branch vessels offline in local dependence and independent by observer. Methods 360 flashed fundus images (camera FF 450 ZEISS Germany, Visualis IMEDOS GmbH Weimar/Germany) of 12 eyes of healthy volunteers (10 independent sessions containing 3 images for every eye) were analysed. Algorithms detect the vessel diameter along the vessel course automatically.
View Article and Find Full Text PDFJ Cardiovasc Magn Reson
October 2001
New ultrafast gradient systems and hybrid imaging sequences make it possible to acquire a complete image in real time, without the need for breathholding or electrocardiogram (ECG) triggering. In 21 patients, left ventricular function was assessed by the use of a turbo-gradient echo technique, an echo-planar imaging (EPI) technique, and a new real-time imaging technique. End-diastolic and end-systolic volumes, left ventricular muscle mass, and ejection fraction of the ultrafast techniques were compared with the turbo-gradient echo technique.
View Article and Find Full Text PDFJ Magn Reson Imaging
September 2001
Ultrafast gradient systems and hybrid imaging sequences offer the opportunity to acquire phase contrast flow data in real time. In a 1.5-Tesla magnetic resonance (MR)-tomograph, peak velocity and volume flow were assessed in 36 large vessels (aorta) and 33 medium-sized vessels (carotid and iliac artery) using a real-time (segmented k-space turbo gradient-echo planar imaging sequence) in comparison with a gradient-echo technique.
View Article and Find Full Text PDFJ Magn Reson Imaging
September 2001
A new magnetic resonance (MR) sequence was developed to acquire real-time images in a multi-slice dynamic imaging mode to cover the complete heart in 15 seconds without the need for electrocardiogram (ECG) triggering and multiple breath holds. In 34 patients, left ventricular function was assessed with the new technique and a standard technique. The new technique proved to be feasible and accurate for functional cardiac examinations.
View Article and Find Full Text PDFWe report on a 58 year-old male who presented with nausea, a painful tumor palpable in the upper right epigastrium, moderate fever without leukocytosis. Both ultrasonic scan and subsequent computerized tomography lead to the primary diagnosis of a malignant tumor of the gall bladder infiltrating the liver and inducing an intrahepatic abscess formation in segments 4b and 3. The patient was scheduled for emergency operation, i.
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