While initial observations were made on the larger and less severe Dy/Dy model of MDC1A by Tardif de Gery et. al in 2000, the present study shows for the first time that it is not only possible to detect the underlying DyW pathology, but also that MRI can be used to detect therapeutic improvements in DyW muscles (in this case in response to the Angiotensin II type 1 receptor blocker, Losartan). This evidence concerns the gene AGTR1 and Congenital muscular dystrophy type 1A.