Investigating the Quantitative Fidelity of Prospectively Undersampled Chemical Shift Imaging in Muscular Dystrophy with Compressed Sensing and Parallel Imaging Reconstruction

PurposeFat fraction measurement in muscular dystrophy has an important role to play in future therapy trials. Undersampled data acquisition reconstructed by combined compressed sensing and parallel imaging (CS-PI) can potentially reduce trial cost and improve compliance. These benefits are only gained from prospectively undersampled acquisitions. MethodsEight patients with Becker muscular dystrophy were recruited and prospectively undersampled data at ratios of 3.65x, 4.94x, and 6.42x were acquired in addition to fully sampled data: equivalent coherent undersamplings were acquired for reconstruction with parallel imaging alone (PI). Fat fraction maps and maps of total signal were created using a combined compressed sensing/parallel imaging (CS-PI) reconstruction. ResultsThe CS-PI reconstructions are of sufficient quality to allow muscle delineation at 3.65x and 4.94x undersampling but some muscles were obscured at 6.42x. When plotted against the fat fractions derived from fully sampled data, non-significant bias and 95% limits of agreement of 1.58%, 2.17% and 2.41% were found for the three CS-PI reconstructions, while a 3.36x PI reconstruction yields 2.78%, 1.8 times worse than the equivalent CS-PI reconstruction. ConclusionProspective undersampling and CS-PI reconstruction of muscle fat fraction mapping can be used to accelerate muscle fat fraction measurement in muscular dystrophy. Magn Reson Med 72:1610-1619, 2014. (c) 2013 Wiley Periodicals, Inc.