Quantitative MRI in muscular dystrophy

In recent years, research into several different therapy approaches for Duchenne muscular dystrophy (DMD) has advanced to the point of clinical trials. A critical issue in designing trials is the choice of appropriate endpoints. To date, assessments of muscle function (such as 6-minute walk distance) or strength (hand-held or integrated chair myometry) have been proposed as primary endpoints. However, the results of these tests depend on patient motivation and engagement, and can involve the recruitment of multiple muscle groups that are affected to different degrees by the dystrophy. This reduces the power of these measures to discriminate change over the relatively short time scales required in trials of novel therapeutics. A number of neuromuscular research groups have proposed that MRI and magnetic resonance spectroscopy (MRS) may provide sensitive, objective measurements of muscle involvement.1–4