Fat-suppressed MR imaging of myositis.

Abstract

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.

Whole-body MRI in the assessment of disease activity in juvenile dermatomyositis

“…The potential of musculoskeletal MRI as a non-invasive imaging procedure for defining the contribution of each of these components to the patient's weakness is well established 8–12. Water-sensitive sequences (ie, T2-weighted or short τ inversion recovery (STIR) sequences) are in fact very sensitive to the presence of inflammation13 and have the potential to support diagnosis, guide muscle biopsy in an area of active disease14 15 and monitor treatment response 10. So far, all MRI studies in JDM focused on pelvic and thigh musculature.…”

Psoriatic arthritis

“…Muscle edema occurring in inflammatory diseases increases the signal intensity of muscle structures in all spin-echo images. Differential diagnosis of such finding using fat-saturation sequence (STIR) includes symptoms of fatty infiltration with increased amount of fat resulting in a high signal intensity [56]. …”

Cyclosporine A versus methotrexate in the treatment of polymyositis and dermatomyositis

“…Muscle MRI at the entry and after 3 months was performed on thigh muscles using T2 weighted image with fat suppression and STIR (short tau inversion recovery) technique (27,28). Changes on MRI were scored semiquantitatively: severe in¯ammation ± 2 points, mild in¯ammation ± 1 point, and no changes ± 0 point.…”