Multi-Parameter MRI Analysis of the Time Course of Induced Muscle Damage and Regeneration

Donghoon Lee¹, Shu Feng¹, Daniel Chen¹, Martin Kushmerick¹

We analyzed the time course of changes in mouse hind-limb musculature following localized myotoxin injection by T1, T2, magnetization transfer (MT) and diffusion MRI. Diffusivity and edema increased within the first hours after toxin injection, and faster than the rates of rise of both T2 and MT ratio. Volume decreased faster than T2 and ADC during regeneration. MT returned to control the slowest. Histological analyses confirmed the underlying cellular changes. The kinetics of change in the MRI modalities can be distinguished during muscle damage and regeneration and provide a basis for specific MRI methods to distinguish the underlying cellular processes.