Comparison of flow-sensitive dephasing-prepared steady-state free precession MR angiography and contrast-enhanced MR angiography in lower leg

Objective: To evaluate the feasibility of flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) MR angiography (MRA) for imaging infragenual arteries at 3.0T, with contrast enhanced MR angiography (CE MRA) as reference. Methods: Totally 20 patients with suspicion of lower extremity arterial disease underwent routine CE MRA and FSD MRA. Image quality and stenosis degree of infragenual arteries from both techniques were independently evaluated and compared. Taking CE MRA as standard, diagnostic performance of FSD MRA were judged. Results: Useful FOV on frequency direction of FSD MRA was (275.93±29.76)mm. Intra-observer consistency was good on image quality assessment (Kappa=0.81, P<0.01). On vascular segments basis, image quality score of FSD MRA (3.66±0.81) was slightly higher than that of CE MRA (3.49±0.87, P=0.05). There was no difference in the number of diagnostic segments between FSD MRA and CE MRA (97.65% [166/170] vs 98.24% [167/170], P=0.32). On patients basis, there was no significant difference of image quality between CE MRA and FSD MRA (2.94±1.06 vs 3.25±1.06, P=0.40). Intra-observer consistency was good on arterial stenosis score assessment (Kappa=0.81, P<0.01). On vascular segmental basis, total agreement of arterial stenosis degree assessment between FSD MRA and CE MRA was 84.34%, the sensitivity, specificity, positive predictive value, and negative predictive value of FSD MRA for the detection of significant stenosis was 96.41%, 93.04%, 84.06%, and 98.53%. On patients basis, there were no significant difference of arterial stenosis degree scores between FSD MRA and CE MRA (3.27±1.10 vs 3.27±1.10, P=1.00). Conclusion: FSD MRA performed on at 3.0T can provide reliable non contrast-enhanced MRA.