Improvement in B1-inhomogeneity artifacts in the abdomen at 3T MR imaging using a radiofrequency cushion

Abstract

Purpose: To determine the impact of a radiofrequency (RF) cushion on abdominal image quality at 3T.

Materials and methods: Twenty volunteers were scanned on a 3T system with and without the use of an RF cushion. T2-weighted HASTE and true-FISP sequences were used for coronal imaging, and each sequence was performed with and without integrated parallel acquisition techniques (iPAT). Additionally, axial T2-weighted HASTE and true-FISP imaging without iPAT was performed. The effect on image quality was assessed by subjectively evaluating the presence and severity of RF inhomogeneity artifacts by two independent readers in a side-by-side comparison with a 5-point differential receiver operating characteristics curve.

Results: Both readers considered the quality of HASTE images acquired with the RF cushion to be significantly better in all cases. The quality of true-FISP images did not benefit significantly from the use of the RF cushion in any case.

Conclusion: The RF cushion significantly improves image quality for abdominal imaging at 3T by reducing or eliminating B1-inhomogenity artifacts. This improved image quality is seen on turbo spin echo-based T2-weighted imaging such as HASTE but does not apply to gradient echo-based T2-weighted imaging such as the true-FISP sequence.