Noncontrast MR angiography (MRA) of infragenual arteries using flow-sensitive dephasing (FSD)-prepared steady-state free precession (SSFP) at 3.0 Tesla: Comparison with contrast-enhanced MRA.

BACKGROUND: To evaluate the feasibility and diagnostic performance 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: Twenty consecutive patients with suspicion of lower extremity arterial disease undergoing routine CE MRA were recruited. FSD MRA was performed at calf before CE MRA. Image quality and stenosis degree of infragenual arteries from both techniques were independently evaluated and compared. Six patients in this study underwent DSA examination.

RESULTS: Three undiagnostic segments were excluded with severe venous contamination in CE MRA. A total of 197 calf arterial segments images were analyzed. No significant difference existed in the relative signal intensity (rSI) of arterial segments between FSD MRA and CE MRA techniques (0.92 ± 0.09 versus 0.93 ± 0.05; P = 0.207). However, the subjective image quality score was slightly higher in FSD MRA (3.66 ± 0.81 versus 3.49 ± 0.87; P = 0.050). With CE MRA images as reference standard, slight overestimation existed in FSD MRA (2.19 ± 1.24 versus 2.09 ± 1.18; P = 0.019), with total agreement of 84.3% on the basis of all arterial segments. The sensitivity, specificity, negative predictive value, and positive predictive value of FSD MRA was 96.4%, 93.0%, 98.5%, and 84.1%. No significant difference in the stenosis degree score was detected between MRA (FSD MRA and CE MRA) and DSA (P > 0.05).

CONCLUSION: FSD MRA performed on at 3.0T without the use of contrast medium provides diagnostic images allowing for arterial stenosis assessment of calf arteries that was highly comparable with CE MRA. Moreover, venous contamination was less problematic with FSD MRA.