Feasibility of Gadofosveset-Enhanced Steady-State MRA of the Peripheral Vessels at 3 Tesla with Dixon Fat-Saturation

H. J. Michaely; U. I. Attenberger; M. F. Reiser; S. O. Schoenberg

doi:10.1055/s-0028-1124050

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Feasibility of Gadofosveset-Enhanced Steady-State MRA of the Peripheral Vessels at 3 Tesla with Dixon Fat-Saturation

HJ Michaely ¹, UI Attenberger ², MF Reiser ², SO Schoenberg ¹

¹University Medical Center Mannheim, Mannheim/Germany
²University Hospital Munich, Munich/Germany

Abstract

Purpose: The aim of this study was to evaluate the feasibility and image quality of peripheral MRA with two-point Dixon-FatSaturation during the steady state after injection of gadofosveset.

Materials and Methods: In prospective, intraindividual study 10 healthy volunteers (mean age 29.2 years) were examined at 3.0T (Siemens Tim Trio) 1h after the bolus injection of 0.03mmol/kg BW gadofosveset (Vasovist®, Bayerhealthcare) using a dedicated 36-element peripheral MRA-matrix coil. A large field of view ranging from the knee to the ankle volume-interpolated breathhold-exam (VIBE) sequence with two-point Dixon fat-suppression (DixFS) and the a VIBE sequence with spectral fat-saturation (SFS) were acquired in a random order. The VIBE sequences were specifically adapted to steady state conditions with a long TR of 7ms and a low flip angle of 12°. Apart from the different method of fat-suppression the sequence parameters of the VIBE sequences were equal (spatial resolution 1×1x1mm³, TAqc DixFS 0:52min, SFS 0:58min). Image quality was rated by two radiologists in consensus on a 4 point ordinal scale (4-very good –1 poor-non diagnostic). The signal-to-nose ratio (SNR) contrast-to-noise ratio (CNR, vessel-fat) was measured in the volunteers/patients using the difference method at three distinct points over the FOV (knee level +20mm, +210mm, +350mm). T-tests were used for statistical analysis.

Results: Diagnostic image quality was achieved in all exams. 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) while 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).

Conclusion: 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 to spectral fat saturation without an additional time penalty.