A 2ND LOOK AT UNENHANCED SPINAL MAGNETIC-RESONANCE-IMAGING OF MALIGNANT LEPTOMENINGEAL DISEASE

The purpose of this study is to evaluate the use of unenhanced magneti c resonance (MR) imaging in identifying malignant leptomeningeal disea se (MLD). Included in this study were fifty patients with evidence of leptomeningeal enhancement on post-gadolinium MR images and with cytol ogical confirmation of MLD. Unenhanced T1-weighted spin-echo (SE) MR i mages of the spine were analyzed for loss of cerebrospinal fluid (CSF) clarity, poor definition of the conus medullaris, thickened and clump ed nerve roots, and nodules. Patterns of leptomeningeal enhancement on post-gadolinium, T1-weighted SE images were noted. Findings of MLD on unenhanced MR images were observed in 41 (85%) of 48 studies of the l umbar spine, 10 (50%) of 20 studies of the thoracic spine, and two (33 %) of six studies of the cervical spine. in the lumbar spine, thickene d and clumped nerve roots, poor definition of the conus medullaris, lo ss of CSF clarity and nodules were observed with decreasing frequency. The signs of MLD on unenhanced images of the cervicothoracic spine in cluded nodules and clouding of CSF. Patterns of leptomeningeal enhance ment included linear, linear/nodular, nodular, enhancement of nerve ro ots, and stacking, with tumor filling the lumbosacral canal. Findings of MLD were present on 73% of the unenhanced MR images of the spine. R ecognition of MLD on unenhanced MR images can guide the appropriate wo rk-up and therapeutic approach. (C) Elsevier Science Inc., 1997.