Non-contrast-enhanced 3D MR portography within a breath-hold using compressed sensing acceleration: A prospective noninferiority study.

PURPOSE

To evaluate images of non-contrast-enhanced 3D MR portography within a breath-hold (BH) using compressed sensing (CS) compared to standard respiratory-triggered (RT) sequences.

MATERIALS AND METHODS

Fifty-nine healthy volunteers underwent MR portography using two sequences of balanced steady-state free-precession (bSSFP) with time-spatial labeling inversion pulses (Time-SLIP): BH bSSFP-CS and RT bSSFP. Two radiologists independently scored the diagnostic acceptability to delineate the portal branches (MPV: main portal vein; RPV: right portal vein; LPV: left portal vein; RPPV: right posterior portal vein; and P4 and P8: portal branch of segment 4 and segment 8, respectively) and the overall image quality on a four-point scale. We assessed noninferiority of BH bSSFP-CS to RT bSSFP. For quantitative analysis, vessel-to-liver contrast (C) was calculated in MPV, RPV and LPV.

RESULTS

BH bSSFP sequence was successfully performed with a 30-second acquisition time. The diagnostic acceptability scores of BH bSSFP-CS compared with RT bSSFP were statistically noninferior: MPV (95% CI for score difference of Reader 1 and Reader 2, respectively: [-0.16, 0.06], [-0.05, 0.02]), RPV ([-0.00, 0.11], [-0.01, 0.08]), LPV ([-0.03, 0.10], [-0.10, 0.03]), RPPV ([-0.03, 0.10], [-0.05, 0.05]), P4 ([-0.13, 0.34], [-0.28, 0.21]) and P8 ([-0.21, 0.11], [-0.25, -0.02]). However, the overall image quality of BH bSSFP-CS did not show noninferiority ([-0.61, -0.24], [-0.54, -0.17]). C values were significantly lower in BH bSSFP-CS (P<0.001).

CONCLUSION

CS enabled non-contrast-enhanced 3D bSSFP MR portography to be performed within a BH while maintaining noninferior diagnostic acceptability compared to standard RT bSSFP MR portography.