Objective. To investigate the magnetic resonance （MR） features of meningeal carcinomatosis

and to improve the ability in understanding and diagnosing meningeal carcinomatosis by MR findings.Methods. Eleven cases with proven meningeal carcinomatosis were studied by conventional and Gd - DTPA enhanced MR imaging. The enhancement patterns and features

as well as the types of meningeal involvement

were retrospectively analyzed.Results. Conventional MR imaging showed no evident meningeal abnormalities. After the administration of Gd - DTPA

abnormal pia mater enhancement was detected in 9 cases

demonstrating as the continuous

thin

and lineal high signal intensity on the brain surface that could descend into the sulci. The abnormal pial enhancement occurred on the cortical surfaces of cerebellum

brainstem

and cerebrum. No abnormal enhancement in the subarach-noid space was found. Abnormal dura - arachnoid enhancement was seen in 3 cases

showing as the continuous

thick

and curvilineal high signal intensity over the convexities or in the tentorium without extension into the cortical sulci. Cerebral dura - arachnoid involvement was found in all 3 cases and one of them also showed abnormal enhancement in cerebellar dura - arachnoid and tentorium. Of the 11 cases

9 with pial involvement had abnormal cerebrospinal fluid （CSF） results

2 involving only the dura - arachnoid had normal CSF results.Conclusion. Meningeal carcinomatosis could be well demonstrated by Gd - DTPA enhanced MR imaging

and its type could be differentiated by the enhancement features. Combined with the clinical information

Gd - enhanced MR imaging may lead to the diagnosis and guide the therapy of meningeal carcinomatosis.