Fat-suppressed MR imaging of myositis.

A hybrid fat-suppression sequence in magnetic resonance (MR) imaging was used to evaluate inflammatory muscle disorders in seven children: five patients with dermatomyositis, one patient with vasculitis, and one patient with viral myositis. Fat-suppressed multisection axial images obtained with the same repetition and echo times as those used to obtain standard spin-echo (SE) images enabled direct comparison of images, with little variation of T1 and T2 weighting. In six patients, the contrast on images obtained with T2 fat suppression was 15%-20% greater than contrast on conventional T2-weighted SE images. In all seven patients, the subjective judgment was that T2-weighted fat-suppression sequences improved visualization of muscle abnormalities. It is concluded that T2 fat suppression is useful in evaluation of inflammatory muscle disorders in children because it increases contrast and eliminates fat as a cause of muscle abnormality.