[Possibilities of magnetic resonance imaging of lesions in demyelinating diseases of the orbital optic nerve].

By employing the so-called inversion recovery technique, one has a nuclear magnetic resonance method at hand that allow discrete imaging of lesion in the intraorbital portion of the optic nerve in patients with optic neuritis. In our series, signal rich areas were visible in affected optic nerves in 15 of 18 patients. The areas of increased signal intensity involved the middle or the proximal third of the nerve and were still demonstrable following recovery of visual function. On the other hand, inversion recovery studies of the affected optic nerves following long inflammation free periods after an attack were within normal limits. Inflammatory edema or alterations in glial tissue may be considered as the causes of the increased signals.