Fig. 1.
a–c: Longitudinal total brain volume (TBV) measurements. a. Representative images demonstrating the method used for estimation of total brain volume (TBV) in all mice using the polygon tool in ImageJ. The outline of each brain structure from representative T1-w coronal and T2-w -coronal, -axial and -sagittal images are delineated in green. b. Bar graph displaying longitudinal comparison of TBV. MRI derived TBV for mice at 4 months old, 6 months old, 12 months old and 18 months old (n = 8 mice per genotype at each time point). The control mouse brain increased in volume between 4 and 18 months old (p < 0.05). The mdx mice had a larger TBV compared to control mice from 12 months onwards (p < 0.01). Between 12 and 18 months old the mdx mice had a significantly larger TBV compared to control mice (p < 0.05). c. Line graph showing average body weights of mice used for the longitudinal MR imaging study. At 4 months old all mice have a comparable body weight. Between 12 and 18 months mdx mice begin to lose weight whereas control mice gain weight. Data presented as mean ± SEM, *p < 0.05, **p < 0.01 for control vs. mdx, ^p < 0.05, ^^p < 0.01 for changes observed with ageing in mdx mice, $<p.0.05 for changes observed with ageing in control mice. d. Line graph displaying the rate of change in TBV between 4 and 18 months old in control C57BL/10 and mdx mice.