Diffusion Tensor MRI to Assess Damage in Healthy and Dystrophic Skeletal Muscle after Lengthening Contractions

Table 1

Quantitative data between control (wild-type) and dystrophic (mdx) TA muscles without and with injury. Except for RD, all the calculated water diffusion characteristics were significantly altered (𝑃<0.05) after injury, and to a greater extent in mdx muscles. There was a trend toward increased RD, but this was not significant (NS) at 𝑃<0.05.

	mdx noninjured versus wt noninjured	wt injured versus noninjured	mdx injured versus wt injured	mdx injured versus noninjured
Whole MD (mm^2/s)	NS	NS	↑(0.00163±0.00012 versus 0.00143±0.000087)	↑(0.00163±0.00012 versus 0.00140±0.00013)
Proximal MD (mm^2/s)	NS	NS	↑(0.00165±0.00011 versus 0.00143±0.00012)	NS
Middle MD (mm^2/s)	NS	NS	↑(0.00161±0.00013 versus 0.00140±0.00011)	NS
Distal MD (mm^2/s)	NS	NS	NS	NS
Whole AD (mm^2/s)	NS	NS	↑(0.00139±0.00010 versus 0.00118±0.000056)	↑(0.00139±0.00010 versus 0.00113±0.000011)
Proximal AD (mm^2/s)	NS	NS	↑(0.00140±0.000082 versus 0.00117±0.000097)	↑(0.00140±0.000082 versus 0.00115±0.00014)
Middle AD (mm^2/s)	NS	NS	↑(0.00137±0.00011 versus 0.00116±0.000076)	↑(0.00137±0.00011 versus 0.00113±0.00010)
Distal AD (mm^2/s)	NS	NS	NS	NS
Whole FA	NS	NS	↑(0.287±0.013 versus 0.329±0.031)	↑(0.287±0.013 versus 0.349±0.021)
Proximal FA	NS	NS	↑(0.282±0.017 versus 0.333±0.015)	↑(0.282±0.017 versus 0.348±0.040)
Middle FA	NS	NS	↑(0.287±0.018 versus 0.330±0.027)	↑(0.287±0.018 versus 0.341±0.022)
Distal FA	NS	NS	NS	NS
Whole RD (mm^2/s)	NS	NS	NS	NS
Proximal RD (mm^2/s)	NS	NS	NS	NS
Middle RD (mm^2/s)	NS	NS	NS	NS
Distal RD (mm^2/s)	NS	NS	NS	NS
Whole T2 (ms)	NS	NS	NS	NS
Proximal T2 (ms)	NS	NS	↑(38.93±2.57 versus 29.93±5.35)	NS
Middle T2 (ms)	NS	NS	NS	NS
Distal T2 (ms)	NS	NS	NS	NS

Explanation of DTI parameters (apply to all but the last 4 lines, which report data for T2): MD: mean diffusivity; measure of total diffusion within a voxel; AD: axial diffusivity; diffusion along the longitudinal axis; FA: fractional anisotropy; the fraction of unidirectional diffusion; RD: radial diffusivity; diffusion occurring perpendicular to a track; T2: a time constant describing the exponential decay of signal.