Muscle MRI in Becker muscular dystrophy.

The aim of this study was to evaluate pelvis and lower limb muscle MRI scans of 46 patients affected by Becker muscular dystrophy (BMD), subdivided according to disease severity, ranging from clinically asymptomatic patients to patients who had lost ambulation. We found a distinct pattern on muscle imaging characterized by prominent involvement of the gluteus maximus and medius, adductor magnus, biceps femoris long head, semimembranosus and vasti. This pattern was consistent in all the 25 symptomatic patients. Milder changes in the same muscles were found in 13 of the 21 asymptomatic cases. The other 8 asymptomatic patients had a normal scan. The severity of muscle involvement was significantly correlated with age. Our results suggest that a distinct pattern of muscle involvement can be detected in BMD. The early identification of muscle changes in a proportion of asymptomatic patients may be useful as an additional tool in the diagnostic workup.