Single-Injection, Semi-Automated Multi-Station Bolus Timing for Optimization of 3D Peripheral MR Angiography

P. Aksit, V. B. Ho, M. L. Hood, P. L. Choyke, M. B. Montequin, T. K. Foo Applied Science Laboratory East, GE Medical Systems, Baltimore, MD, United States, Department of Radiology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, Department of Radiology, National Institutes of Health, Bethesda, MD, United States Introduction: Contrast media travel times can vary widely between patients with peripheral vascular disease. Typically, automatic or fluoroscopic detection methods are used to monitor contrast arrival at the abdominal station and to initiate a 3D multi-station exam. However, in the absence of timing information on contrast bolus travel to the distal vasculature, multi-station peripheral MRA using fixed imaging times will result in wide variation in resultant arterial signal and potentially significant venous contamination at the lowermost station. Timing bolus scans using two separate injections have been shown to improve reliability of arterial depiction and reduce venous contamination in peripheral MRA [1]. Furthermore, Maki, et al. demonstrated the value of twostation bolus timing with manual table translation and fluoroscopic triggering [2]. Since automatic detection of the contrast arrival at the abdominal station is more reproducible, we demonstrate the feasibility of obtaining multi-station contrast timing information using a single injection of contrast media by using a moving table automatic detection algorithm that is capable of detecting contrast arrival in the abdominal aorta, automatically moving the table to the calf, and initiating a 2D projection angiogram. This provided two station timing information that can then be used to optimize spatial resolution and timing for a multi-station 3D MRA.