Utilization of three-dimensional MR angiography in the better demarcation of the renal arteries

To date, conventional breath-hold two-dimensional (2D) acquisition has been used in MR angiography to visualize the renal arteries, but signal overlaps from the adjacent left renal vein often prevented precise detection of the arteries. The purpose of this paper is to acquire better images of the renal arteries with a 3D acquisition technique. 2D and 3D time-of-flight MR angiograms of the renal arteries were obtained in eight normal volunteers with a 1.5-T superconducting system. 2D images were obtained with a sequential breath-hold fast low-angle shot sequence (TR/TE/flip angle (FA) = 40/10/20 degrees; slab thickness, 90 mm; 64 partitions) without breathholding. All images were processed with a maximum-intensity projection algorithm. In all eight cases, 3D imaging increased the signal-to-noise ratio, which enabled sharper margins and better contrast of luminal intensities to the surrounding tissues. The problematic overlaps of the left renal vein with the left renal arteries were also erased by the saturation of the signal. The current study has shown that the 3D acquisition method is better than 2D imaging in delineating the renal artery on MR angiograms