Characteristics of meningioma scintigraphy with multiple brain imaging agents

Purpose: To clarify the characteristics of meningioma scintigraphy with multiple brain imaging agents and to evaluate their roles in diagnosis of meningiomas. Methods: Blood flow, 99mTc-ECD, 99mTc-DTPA, and/or 99mTc-MIBI brain imagings were performed in 21 patients with meningiomas (3 malignant, 18 benign) proved by surgery and pathology. CT/MRI examinations were also made within one month. Characteristics of meningioma images were analyzed and uptake ratios were calculated. Results: In 16 of 20 patients, increased radioactivity during the arterial phase in the blood flow image was seen. Concave round or oval defects with smooth contour in the cerebral cortex were observed in 17 of 19 patients with 99mTc-ECD, depression of frontoparietal cortex was found in one case and no abnormality in the other. A homogeneous accumulation of radioactivity in area corresponding to the defect in 99mTc-ECD image was found in 17/17 patients with 99mTc-DTPA and in 14/14 patients with 99mTc-MIBI study. No correlation was found between uptake ratios of the three tracers, but 99mTc-ECD uptake ratio was significantly lower in malignant meningioma than in benign one. Conclusions: The combined use of 99mTc-ECD and 99mTc-DTPA and/or 99mTc-MIBI brain imaging is useful in making the diagnosis of meningiomas. Whether the 99mTc-ECD uptake ratio will be valuable to differentiate malignant from benign meningioma needs further studies