Extracting more for less: multi‐echo MP2RAGE for simultaneous T₁‐weighted imaging, T₁ mapping, mapping, SWI, and QSM from a single acquisition

Abstract

Purpose To demonstrate simultaneous T 1 ‐weighted imaging, T 1 mapping, mapping, SWI, and QSM from a single multi‐echo (ME) MP2RAGE acquisition. Methods A single‐echo (SE) MP2RAGE sequence at 7 tesla was extended to ME with 4 bipolar gradient echo readouts. T 1 ‐weighted images and T 1 maps calculated from individual echoes were combined using sum of squares and averaged, respectively. ME‐combined SWI and associated minimum intensity projection images were generated with TE‐adjusted homodyne filters. A QSM reconstruction pipeline was used, including a phase‐offsets correction and coil combination method to properly combine the phase images from the 32 receiver channels. Measurements of susceptibility, , and T 1 of brain tissue from ME‐MP2RAGE were compared with those from standard ME‐gradient echo and SE‐MP2RAGE. Results The ME combined T 1 ‐weighted, T 1 map, SWI, and minimum intensity projection images showed increased SNRs compared to the SE results. The proposed coil combination method led to QSM results free of phase‐singularity artifacts, which were present in the standard adaptive combination method. T 1 ‐weighted, T 1 , and susceptibility maps from ME‐MP2RAGE were comparable to those obtained from SE‐MP2RAGE and ME‐gradient echo, whereas maps showed increased blurring and reduced SNR. T 1 , , and susceptibility values of brain tissue from ME‐MP2RAGE were consistent with those from SE‐MP2RAGE and ME‐gradient echo. Conclusion High‐resolution structural T 1 weighted imaging, T 1 mapping, mapping, SWI, and QSM can be extracted from a single 8.5‐min ME‐MP2RAGE acquisition using a customized reconstruction pipeline. This method can be applied to replace separate SE‐MP2RAGE and ME‐gradient echo acquisitions to significantly shorten total scan time.