Abstract
1620
Objectives Simultaneous imaging of cerebral blood flow and central benzodiazepine receptor (BZR) images would help localizing epileptic foci by demonstrating non-specific activities associated with subclinical ictal events. The aim of this study was to test a prototype CdTe SPECT system which has high energy resolution (6.6%) for dual isotope study using Tc-99m ECD and I-123 IMZ in patients with epilepsy.
Methods This study included 12 patients with partial epilepsy. Three hours after injection of 185 MBq of IMZ, BZR images were acquired for 20 minutes using conventional 3 head scintillation gamma camera (GCA-9300, Toshiba, Tokyo, Japan). Immediately after image acquisition, 740Bq of Tc-99m ECD was injected. Five minutes after ECD injection, CBF and BZR images were acquired simultaneously using the new SPECT system. On another day, additional CBF image was acquired at rest with the conventional camera. The images acquired with the new SPECT system were compared with those with the conventional camera
Results There were 12 abnormal uptakes in BZR images and 13 abnormal uptakes in CBF images in conventional camera. There were good agreements between findings of the single isotope study with conventional camera and those of the dual isotope study with semiconductor SPECT in 10 patients. The finding of CBF images were different in two temporal epilepsy patients, however, the findings of BZR were same. The difference was considered to be effect of seizure.
Conclusions Our new SPECT system could allow simultaneous pixel-by-pixel analysis of CBF and BZR information, which may be beneficial particularly in detecting epileptic foci because it allows assessment of two different functions at the same pathophysiological condition.