German researchers compared quantitative magnetic resonance imaging (MRI) data of a set of muscles from 19 patients with calpainopathy and 19 healthy subjects. These data were then analysed in relation to other clinical and functional parameters for correlation:
- the study targeted eight muscles of the thigh and seven of the leg;
- selective involvement of the hamstring and medial gastrocnemius muscles was confirmed;
- several algorithms allowed quantification of degenerative muscle damage at a stage where replacement with fat tissue was of little or no significance;
- diffusion parameters and T2 values are, from this point of view, the most relevant parameters in still preserved target muscles.
This study can be used in future natural history protocols for calpainopathies and in the clinical trials that should follow.