INFLAMMATORY LESIONS OF THE SPINAL-CORD A ND THE NERVE ROOTS IN MAGNETIC-RESONANCE-IMAGING

Purpose: TO evaluate characteristic and reliable MRI patterns of diffe rent inflammatory lesions of the spinal cord and the nerve roots in im munologically compromised and immunologically competent patients in or der to be able to establish a correct diagnosis based on MRI findings. Material and methods: The MRI examinations of 52 patients (27 men, 25 women, mean age 38.5 years, range 14-75 years) with proven inflammato ry lesions (39 patients) or tumorous/postactinic lesions of the spinal cord (6 patients) and vascular malformations of the spinal cord (7 pa tients) were retrospectively analyzed. ALI examinations were performed on a 1.5 T MR unit, using bi- or triplanar T1-w pre- and postcontrast as well as T2-w SE sequences. Additionally, a review of the common me dical literature concerning inflammatory lesions of the spinal cord wa s included, Results: Clinical and radiological examinations allow a su bdivision of inflammations of the spinal cord and the nerve roots into (meningoradiculo) myelitis and meningoradiculo (myelitis) in immunolo gically suppressed or competent patients. The MRI patterns of these tw o inflammatory subtypes vary: meningoradiculitis presents with an enha ncement of the nerve roots and the leptomeninges; myelitis itself is c haracterized by single or multiple, diffuse or multifocal, with or wit hout nodular, patchy or diffusely enhancing intramedullary lessions, w ith or without thickening of the cord and leptomeningeal inflammation. This differentiation helps to determine the underlying etiology in so me of the patients. The immunologically suppressed patient suffers fro m viral infections (especially herpes simplex, varicella-zoster virus, cytomegalovirus), bacterial infections (tuberculosis), but rarely fro m parasitic infections. The immunologically competent patient suffers from bacterial (borreliosis), but rarely viral infections, sarcoidosis and demyelinating diseases. Idiopathic myelitis is also common. Concl usion: Secondary ischemic and demyelinating processes result in a comp lex morphology of inflammatory lesions on MRI, and therefore the whole spectrum of demyelinating, ischemic and inflammatory lesions has to b e included in the differential diagnosis. Even tumors may imitate infl ammatory myelitis and radiculitis. Most commonly, meningoradiculitis c an be separated from myelitis. A reliable diagnosis of a specific infl ammatory lesion is difficult and is mostly achieved in patients with m ultiple sclerosis and in patients with HIV-associated cytomegalovirus infection.