Reduction in Artifacts in the Liver at 3T Using a 3D T2-Weighted Variable Flip-Angle Sequence (SPACE)

Introduction: 3T MRI systems provide an inherent increase in SNR that can be used for gains in spatial and/or temporal resolution. However, a limitation of imaging at 3T is an increase in specific absorption rate (SAR), particularly in sequences with large flip angles and many refocusing pulses, as occurs with many 180o refocusing pulses of a turbo spin echo sequence. A recently developed sequence termed Sampling Perfection with Application Optimized Contrasts using different Flip Angle Evolutions (SPACE) uses variable flip angles to maintain a low SAR while performing many refocusing pulses. This technique allows a 3D T2-weighted acquisition with high SNR and spatial resolution. In the past year, several studies have demonstrated the benefit of using SPACE at 3T to obtain a 3D MRCP with improved overall image quality, reduced artifact, and improved bile duct visualization. However, to our knowledge, no study has assessed SPACE liver imaging at 3T. In this study, we aim to quantitatively and qualitatively compare image quality of 3D T2W SPACE and 2D T2W TSE for liver imaging at 3T.