Muscular transverse relaxation time measurement by magnetic resonance imaging at 4 Tesla in normal and dystrophic dy/dy and dy(2j)/dy(2j) mice

Muscular transverse relaxation times values were measured in vivo in normal mice (strain C57BL6/J, n = 14) and in murine models of human congenital mu scular dystrophy (dy/dy, n = 9; dy(2j)/dy(2j), n = 8). A single-slice multi -echo sequence was used. Gastrocnemius/soleus complex, thigh and buttock mu scles were studied. Muscular transverse relaxation times values were compar ed between different muscle groups in each type of animal and between anima l groups. Differences were observed between normal and dy(2j)/dy(2j) mice f rom 3 to 12 weeks of age, and between normal and dy/dy mice at 6 weeks. In specific age ranges, the values of muscular transverse relaxation times in two dystrophic models are different from those in normal mice, and could th us be used as an index of modifications in dystrophic muscle to evaluate th erapies. (C) 2000 Elsevier Science B.V. All rights reserved.