We present a case of primary brain tumor demonstrating increased uptak
e of Tc-99m-ECD, Astrocytoma (Grade II) showed significantly increased
cerebral blood perfusion on dynamic images and homogeneously increase
d uptake on static images with Tc-99m-ECD brain SPECT. There seems to
be some difference in perfusion and mechanism of tumor uptake among th
e cerebral blood flow imaging agents (Tc-99m-ECD, Tc-99m-HMPAO and [I-
123]IMP) and (TI)-T-201-chloride.