Fasciculations are brief spontaneous
contractions affecting a small number of muscle fibers. We investigated
how diffusion sensitized MR images were able to detect these contractions in
the lower leg of healthy volunteers. Large intensity decreases were
observed (at random times) in random areas of muscle on images, acquired
repeatedly using single shot (diffusion sensitized) EPI acquisitions over the
course of several minutes. Signal intensity reductions were attributed to
intra-voxel incoherent-like motion due to displacement of tissue.
Quantification compared activated areas to total muscle area and frequency of
activation on a per pixel basis. Results were expressed as a
fasciculation index parameter and in fasciculation frequency maps.