**1. Introduction**

123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) is used to evaluate the cerebral blood flow (CBF) in patients with either cerebrovascular or neurode‐ generative diseases [3, 6]. However, its application for patients with brain tumors has so far only been rarely reported [2, 8, 11]. Primary central nervous system lymphoma (PCNSL) is a rare tumor that shows a delayed IMP uptake [1, 5, 7, 9, 10]. The relatively low spatial resolution of SPECT is a clinical problem when it is used to diagnose brain tumors.

Anatomical standardized statistical mapping is a useful method for improving the diagnostic ability of SPECT. We examined the statistical mapping of IMP SPECT in patients with brain lesions. In this report, we analyzed the diagnostic performance of the usual reconstructed images and statistical mapping of IMP SPECT of patients with brain tumors.
