Optimization of Cube-FLAIR 3 D FSE imaging at 7 T

Purpose: Refocusing flip angle modulation schemes like SPACE and Cube [1-2] enable use of longer echo-train-lengths in 3D T2-weighted imaging. For improved lesion conspicuity, an inversion prep is used to null CSF but adds undesirable T1 weighting at 7T due to incomplete T1 recovery at the CSF null point, reducing SNR and contrast. The use of a magnetization preparation (MP) scheme [3] can help mitigate this effect but further increases the already high SAR at 7T. We added an MP-FLAIR module to a Cube sequence and optimized the MP-FLAIR-Cube sequence, taking into account image contrast, SAR, and SNR as well as T1/T2 values of WM/GM at 7T. Whole brain MP-FLAIR-Cube scans were performed on 20 patients at 7T using these modifications.