Fat fraction measurement in muscular dystrophy is important for therapy trials. Accelerated acquisition reconstructed by combined compressed sensing and parallel imaging (CS-PI) can improve patient compliance. Eight patients with Becker muscular dystrophy were recruited and prospectively undersampled data at ratios of 3.65×, 4.94×, and 6.42× were acquired in addition to fully sampled data. The CS-PI reconstructions were of sufficient quality at 3.65× and 4.94× acceleration. Compared to fully sampled data, non-significant bias and 95% limits of agreement of 1.65%, 1.95% and 2.22% were found for the three CS-PI reconstructions, significantly outperforming conventional parallel imaging alone.