Minimum apparent diffusion coefficient for the differential diagnosis of ganglioglioma

OBJECTIVES: The utility of apparent diffusion coefficient (ADC) values was evaluated for the differential diagnosis of ganglioglioma. METHODS: Ten consecutive patients, five men and five women, aged from 14 to 67 years, with histologically proven supratentorial gangliogliomas, underwent diffusion-weighted magnetic resonance imaging with echo planar imaging technique. The minimum ADC (minADC) of each tumor was pre-operatively determined from several regions of interest. The minADC of ganglioglioma was compared with that of low- or high-grade astrocytomas (astrocytoma, anaplastic astrocytoma and glioblastoma). Tumor cellularity of gangliogliomas was compared with the minADC. RESULTS: The mean minADC of the gangliogliomas (1.45 +/- 0.20 x 10(-3) mm(2)/s) was significantly higher than that of the low- or high-grade astrocytomas. Tumor cellularity of ganglioglioma was inversely correlated with the minADC value. DISCUSSION: The minADC value reflects in the low tumor cellularity of gangliogliomas and may provide a method for the differential diagnosis of ganglioglioma.