MR imaging of meningeal carcinomatosis by systemic malignancy.

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 subarachnoid 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.