To investigate the feasibility and image quality of gadofosveset-enhanced steady-state peripheral MR-angiography using Dixon fat saturation in comparison to spectral fat saturation.Materials and Methods:
After Institutional Review Board (IRB) approval, 10 healthy volunteers underwent peripheral MR-angiography at 3.0 T during the steady state 50 minutes after gadofosveset injection. A steady-state-adapted volume interpolated breathhold examination sequence with an isotropic spatial resolution of 1 mm was acquired with 2-point Dixon fat saturation (DixFS, acquisition time 52 seconds) and with conventional, spectral fat saturation (SFS, acquisition time 58 seconds). The quality of the images was rated on an ordinal 4-point scale (4, very good) by 2 radiologists in consensus. The signal-to-noise ratios (SNRs) of the vessels, the fat, and the muscles as well as the contrast-to-noise-ratio (CNR) between vessels, fat, and muscle were determined. Paired P tests were performed for statistical analysis with a significance level of P < 0.05.Results:
Diagnostic image quality was achieved in all examinations. The image quality of the DixFS images was rated superior (median 4) over the SFS images (median 3; P= 0.03). The SNR of muscles and vessels was 40% higher with DixFS (P < 0.008), whereas the SNR of fat was decreased by 40.3% from 40.7 with SFS to 22.4 with DixFS (P < 0.0001). The CNR (fat/muscle) of the DixFS images of 84.1/71.7 was significantly higher than the CNR of the SFS images of 47.7/47.4 (P < 0.001).Discussion:
Two-point Dixon fat suppression for MR-angiography during the steady state after the administration of gadofosveset is feasible with superior image quality and more than 50% increase in CNR (fat/muscle) compared with spectral fat saturation without an additional time penalty.