Peripheral MRA with continuous table movement: Imaging speed and robustness compared to a conventional stepping table technique

Abstract

To investigate the potential of continuous table movement (CTM)-MRA for reduction of acquisition time and to evaluate the image quality in comparison to conventional stepping table (CST) MRA. The data of 82 patients were included in this retrospective, IRB-approved study. All patients underwent peripheral MRA at our institution. 41 consecutive patients were examined with a CST-MRA at a 1.5 T MR system. 41 different consecutive patients were examined with a CTM-MRA at 3.0 T MR system. Image quality was assessed by two independent radiologists in consensus on a 4-point Likert-type scale. Descriptive statistics and t-tests were used to compare image acquisition time of CST-MRA to that of CTM-MRA with and without additional time-resolved imaging of the feet using the TWIST technique. Additionally, acquisition time was compared in a subgroup of the fastest 50%. The mean imaging time for the CTM-MRA was 34% less than with the CST-MRA (18.2 min vs. 27.5 min; p<0.0001). Even with inclusion of the TWIST sequence the combined CTM-/TWIST-MRA protocol was 26% faster (20.3 min vs. 27.5 min; p<0.0001). The image quality was slightly better with CTM-MRA (CTM-MRA mean score 3.3±0.5, mean score CST-MRA 2.9±0.6). Venous overlay was significantly lower using the CTM-MRA approach (CTM-MRA mean score 2.8±0.4; CST-MRA mean score 2.2±0.7; p<0.0001). CTM-MRA is on average 30% faster than a comparable CST-MRA protocol with equal image quality. Even when adding an additional time-resolved-MRA of the calf station the CTM-MRA protocol is still 26% faster. In conclusion, this study proves that CTM-MRA further improves MRA by reducing user interference and image acquisition times and hence allowing to increase the clinical throughput.