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

Abstract

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