[Value of magnetic resonance imaging in the diagnosis of recurrent postoperative lumbosciatica].

Twelve patients who had a subsequent lumbar sciatica after surgery were evaluated with computerized tomography (C.T.) and magnetic resonance imaging (M.R.I.). The M.R.I. was performed with a 0.35 T whole body superconducting unit using spin echo technique. Two pulse sequences were realized varying the repetition time (TR) from 500 to 2,000 ms and the echo time (TE) from 28 to 60 ms. For the longer pulse, the twice echo were interpreted. The slide obtained with a surface-coil were performed in sagittal plane for the twice pulse sequences and in transaxial plane for the shorter pulse sequence. In seven cases, the results obtained with C.T. and M.R.I. were correlated. In two cases, the C.T. showed a scar formation, the M.R.I. showed a recurrent disk herniation. In three times, C.T. was unable to differentiate clearly between recurrent disk herniation and scar formation, the M.R.I. showed unequivocally on one case a scar formation and on two cases a recurrent disk herniation.