Optimized enhanced acceleration selective arterial spin labeling (eAccASL) for non-gated and non-enhanced MR angiography of the hands

Purpose Enhanced acceleration selective arterial spin labeling (eAccASL) was introduced as non-enhanced and non-gated magnetic resonance angiography (MRA). This technique has not been applied to hand MRA. The objective of this study was to optimize the eAccASL for MRA of the hands and to investigate the factors for MRA visibility of the hands. Methods Twenty healthy volunteers were examined on a 1.5 T MR system. To evaluate arterial visualization, we compared four different acceleration-encoding (AENC) values (i.e., 0.12, 0.29, 0.58, and 0.87 m/s2). Image quality score regarding the MRA depiction of the proximal artery (range, 0–10), the distal artery (0–5), and venous contamination (0–5) was evaluated by three radiologists. We measured the peak to peak arterial blood flow velocity (Vpp) measured by phase contrast cine MRI and hand temperature as the factors for arterial visualization. Qualitative scores were compared with Friedman's tests. Spearman's correlation of qualitative scores with Vpp and hand temperature was performed to analyze influencing factors. Results For the distal arterial depiction, scores at AENC 0.12 (median, 9.0) and AENC 0.29 (8.0) were significantly better (both P 0.05). Conclusion eAccASL MRA of the hands was optimized by using low AENC values (0.12–0.29 m/s2). Venous contamination may increase with elevation of arterial blood flow.