Improved Visualization of Coronary Arteries Using a New Three-Dimensional Submillimeter MR Coronary Angiography Sequence with Balanced Gradients

Abstract

OBJECTIVE. The goal of our study was to evaluate a new three-dimensional real-time navigator MR coronary angiography sequence to noninvasively visualize the coronary arteries.SUBJECTS AND METHODS. Fifteen healthy volunteers underwent MR coronary angiography with a new balanced turbo field-echo sequence in comparison with the standard turbo field-echo sequence. Signal-to-noise, blood-to-myocardium, blood-to-fat, and blood-topericardial fluid contrast ratios of the left and right coronary artery systems were measured. Image quality was graded, the length and diameter of the coronary arteries were measured, and the number of visible side branches was assessed.RESULTS. The balanced turbo field-echo images yielded a higher blood-to-myocardium and blood-to-pericardial fluid contrast ratio, a similar blood-to-fat contrast ratio, and a lower signal-to-noise ratio than the turbo field-echo images. On a 5-point grading scale (1, nondiagnostic or unreadable; 2, poor; 3, moderate; 4, good; 5, excellent), image quality was rated significantly better for the balanced turbo field-echo sequence than for the turbo field-echo sequence (left coronary artery, 4.0 ± 0.6 vs 3.6 ± 0.5 [ p = 0.015]; right coronary artery, 4.4 ± 0.4 vs 3.6 ± 0.4 [ p < 0.0001], respectively), resulting in a significantly longer segment of the three major coronary arteries visualized (left anterior descending coronary artery, 92 ± 21 mm vs 79 ± 24 mm; left circumflex coronary artery, 70 ± 7 mm vs 60 ± 18 mm; right coronary artery, 112 ± 28 mm vs 95 ± 27 mm) and a significantly higher number of side branches visualized (left anterior descending coronary artery, 2.9 ± 1.3 vs 1.5 ± 1.3; left circumflex coronary artery, 2.1 ± 1.7 vs 1.0 ± 1.2; right coronary artery, 3.7 ± 1.7 vs 2.6 ± 1.5). Mean imaging time per coronary artery was significantly shorter for the balanced turbo field-echo sequence (5.7 ± 1.0 min) than for the turbo field-echo sequence (8.4 ± 1.4 min) ( p < 0.0001).CONCLUSION. Compared with standard turbo field-echo MR coronary angiography, optimized balanced turbo field-echo MR coronary angiography improves the visualization of the coronary arteries and their side branches within a significantly shorter imaging time.oronary artery disease remains one of the leading causes of morbidity and mortality in the industrialized countries. Catheter angiography, currently the gold standard in detecting atheromatous coronary artery disease, is invasive and potentially harmful and necessitates the use of iodinated contrast material and radiation. Therefore, several techniques are under research to depict atheromatous changes in the coronary arteries in a noninvasive or less invasive fashion [1,2]. This technique could be used to screen or select patients for coronary catherization, which would significantly reduce the number of unnecessary diagnostic catherizations and would thus be potentially cost-effective. Three-dimensional (3D) MR coronary angiography techniques, performed either in breath-hold [3][4][5] or during free-breathing using a navigator [6,7...

Feasibility of 4D Flow MR Imaging of the Brain with Either Cartesian y-z Radial Sampling or k-t SENSE: Comparison with 4D Flow MR Imaging using SENSE

“…The so-called "elliptical k-space shutter" reduces scanning time while maintaining spatial resolution. 14 We combined Cartesian y-z radial sampling with SENSE and with a view-sharing technique to reduce the scan time by about 50%. This acceleration scan using y-z radial sampling quantified PSV and BFV precisely, but the pathlines left the blood vessels in some arteries.…”

“…Other acceleration techniques, such as Cartesian y-z radial sampling and k-t SENSE, have been combined with 4D Flow MR imaging or cardiovascular applications. 13,14 For acceleration, Cartesian y-z radial sampling employs k-space correlation, and k-t SENSE uses k-space and time correlation. [13][14][15] To our knowledge, only a few reports validate the use of these acceleration techniques in 4D Flow MR imaging of the brain.…”

“…13,14 For acceleration, Cartesian y-z radial sampling employs k-space correlation, and k-t SENSE uses k-space and time correlation. [13][14][15] To our knowledge, only a few reports validate the use of these acceleration techniques in 4D Flow MR imaging of the brain. 12,16 In this study in healthy volunteers, we applied an acceleration technique, y-z radial sampling or k-t SENSE, to 4D Flow MR imaging of the brain and assessed the technical feasibility of each type of accelerated 4D Flow MR imaging compared to standard 4D flow MR imaging using SENSE for measuring peak systolic velocity (PSV), BFV, and image quality of pathlines.…”

Assessment of qualitative and quantitative features in coronary artery MRA

“…The state-of-art of MR sequences used for clinical studies are those based on steady-state free precession (SSFP) technique [18,19]. Whole-heart acquisition makes the image analysis less operator dependent by including the vessels up to distal vascular parts in a single volume.…”

“…The 10 datasets were acquired on a 1.5T system (Philips Intera and Achieva) using a steady-state free precession (SSFP) MR sequence [18], at end-diastolic phase without contrast agent. The MR sequence parameters are summarized in table 1.…”