Subtractionless first-pass single contrast medium dose peripheral MR angiography using two-point Dixon fat suppression.

OBJECTIVE: To investigate the feasibility of subtractionless first-pass single contrast medium dose (0.1 mmol/kg) peripheral magnetic resonance angiography (MRA) at 1.5 T using two-point Dixon fat suppression and compare it with conventional subtraction MRA in terms of image quality.
METHODS: Twenty-eight patients (13 male, 15 female; mean age ± standard deviation, 66 ± 16 years) with known or suspected peripheral arterial disease underwent subtractionless and subtraction first-pass MRA at 1.5 T using two-point Dixon fat suppression. Results were compared with regard to vessel-to-background contrast. A phantom study was performed to assess the signal-to-noise ratio (SNR) of both MRA techniques. Two experienced observers scored subjective image quality. Agreement regarding subjective image quality was expressed in quadratic weighted κ values.
RESULTS: Vessel-to-background contrast improved in all anatomical locations with the subtractionless method versus the subtraction method (all P < 0.001). Subjective image quality was uniformly higher with the subtractionless method (all P < 0.03, except for the aorto-iliac arteries for observer 1, P = 0.052). SNR was 15 % higher with the subtractionless method (31.9 vs 27.6).
CONCLUSION: This study demonstrates the feasibility of subtractionless first-pass single contrast medium dose lower extremity MRA. Moreover, both objective and subjective image quality are better than with subtraction MRA. KEY POINTS: • MRA is increasingly used for vascular applications. • Dixon imaging offers an alternative to image subtraction for fat suppression. • Subtractionless first-pass peripheral MRA is possible using two-point Dixon fat suppression. • Subtractionless peripheral MRA is possible at 1.5 T a single contrast medium dose. • Subtractionless first-pass peripheral MRA provides good image quality with few non-diagnostic studies.