Non-Contrast MRA with Compressed Setting Shortens Acquisition Time

Non-contrast coronary MR angiography (MRA) using compressed sensing (CS) may shorten acquisition time, compared with conventional navigator-gated coronary MRA, according to a study published in the European Journal of Radiology.

Researchers from Japan and Germany sought to evaluate the scan time and image quality of CS coronary MRA compared with conventional coronary MRA. They recruited 20 healthy volunteers who underwent navigator-gated coronary MRA with a CS prototype sequence and conventional navigator-gated coronary MRA on a clinical 3T MRI scanner without contrast medium. The spatial resolutions were 1.33 × 1.33 × 1.20 mm3 for CS and 1.33 × 1.33 × 1.48 mm3 interpolated to 0.70 × 0.70 × 1.20 mm3 for conventional, respectively.

The researchers compared acquisition times, rated image quality on a four-point scale (RCA; proximal, middle, and distal, LAD; main, proximal, middle, and distal, LCX; proximal and distal), and measured the visualized vessel lengths of three vessels.

The results showed mean acceptance rates were 44.9 percent for CS coronary MRA and 48.7 percent for conventional coronary MRA. The CS coronary MRA was quicker, with a mean effective scan time of three minutes, 45 seconds compared to 15 minutes, 6 seconds for conventional coronary MRA. The image quality scores were significantly lower for CS coronary MRA than for conventional coronary MRA. Conventional coronary MRA images were scored >3.4 in all segments on average, while CS coronary MRA images were scored >3.2 (good quality for diagnosis) in almost all segments, with only the distal RCA segment graded 2.9 on average.

The researchers concluded that use of non-contrast coronary MRA using CS could largely shorten acquisition time, compared with conventional navigator-gated coronary MRA, while maintaining acceptable visualization at 3T.