Muscle edema in MR imaging of neuromuscular diseases

The purpose of this study was to examine the frequency of muscle edema and the diagnostic usefulness of Gd-DTPA in neuromuscular diseases. 144 consecutive patients with various generalized neuromuscular diseases were examined by MR imaging. Areas of high signal intensity, relative to normal muscle, were seen in 36% of T2-weighted images, whereas the corresponding T1-weighted images showed normal or lower signal intensities. These edema-like abnormalities -enlargement of the extracellular fluid space-were found more often in inflammatory and metabolic myopathies, but were also seen in degenerative myopathies. Contrast-enhanced T1-weighted images in 25 patients were not more sensitive than plain T2-weighted images. (orig.)