MPI SIGNS OF NONTUMORAL MYELOPATHIES

We present a retrospective study in order to analyze the abnormalities noted on MRI in 27 cases of myelopathy excluding tumors, explored bet ween 1994 and 1996. The different lesions were : Multiple Sclerosis (n = 11), Spondylotic myelopathy (n = 3), Neurosarcoidosis (n = 4), CMV Myelitis (n = 1), Radiation Myelopathy (n = 1), Spinal Dural Arteriove inous Fistula (n = 1), Intramedullary Cysticercosis (n = 1), Infarct ( n = 5). The exams have been made on 1.5 Tesla Magnetom Vision Siemens or GE Signa machine, All patients have had axial and sagittal views wi th coronal complementary study in 4 eases. Sequences were Spin echo pT 1 (TR: 560, TE: 12). Fast Spin echo pT2 (TR : 3500, TE : 99 or 128), a nd gradient echo pT2 (TR: 700, TE: 22, Angle: 25 degrees). Intravenous injection of Gadolinium has been made in 16 cases (0,1 mmol/kg). We h ave studied the presence or not of a signal abnormality in pT1 and/or in pT2, of enhancement, and its topography (cervical, thoracic, lombar ). We classified lesions in central and/or peripheral and according to their topography in anterior, posterior or lateral type, The form has been classified in four types (nodular, triangular, pen Like,,, plage ), Extension in transversal (superior or inferior to half medullary su rface) and cranio-caudal directions (inferior to one vertebrae. beetwe en one and two vertebrae. superior to two vertebrae) has been also cla ssified, Others intra or perimedullar and encephalic abnormalities hav e been noted, We analyzed the results fur each pathology and underline the essential diagnosis criteria noted (low cranio-caudal and transve rsal extension with frequent triangular form of Multiple Sclerosis les ions, frequent suggestive abnormalities of the encephale (82%) in Mult iple Sclerosis. intra and perimedullar enhancement with deformations o f the surface of the spinal cord in Sarcoidosis' lesions, extended dor solombar ''pen like'' lesions with inconstant enhancement of infarcts, focal plage lesions centered on degenerative changes of the spinal ca nal in spondylotic myelopathy, bony lipomatous involution in front of intramedullary radiation plage lesion...) and also review the literatu re and confront their results to it, We insist on the difficulties in classifying myelopathy (radio-clinical terminology discordances, ident ical signal abnormalities frequently caused by different illness. nece ssity to compare to pathologic results). We propose a MRI study protoc ole that should interest the whole spinal cord and comport TI weighted without and after gadolinium sequences, T2 weighted sequences (with a lways a gradient echo type), 3 or better 3 different plans should be m ade. A complementary study of the brain by MRI is often useful. Clinic al study, biology, evolution, MRI and when possible pathology ail are necessary to better understand myelopathy's mechanisms.