SPECT imaging with [I-123]-beta-CIT in Parkinsonism: comparison of SPECT images obtained by a single-headed and a three-headed gamma camera

Single photon emission computed tomography (SPECT) imaging of dopamine tran sporters by using the cocaine derivative [I-123]-(1R)-2-beta -carbomethoxy- 3-beta-(4-iodophenyl)-tropane ([I-123]-beta -CIT) has been shown to be usef ul in patients with Parkinsonism. The aim of this study was to compare beta -CIT imaging with single-headed (SHS) and three-headed gamma camera system s (THS). In 17 patients with Parkinsonism, SPECT imaging with an SHS and a THS was performed 24 h after injection of 180 MBq of [I-123]-beta -CIT. The SPECT studies were evaluated by visual assessment of the caudate nucleus ( CN) and the putamen (PT) and the calculation of the striatal/cerebellar (S/ C) ratios (with additional comparison to clinical symptoms measured by the Unified Parkinson's Disease Rating Scale (UPDRS)). The S/C ratios measured by the SHS and THS showed highly significant correlation (two-tailed P < 0. 01) with Spearman correlation coefficients (SCCs) of 0.864 for the right si de, 0.676 for the left side, and 0.761 for both sides. By the SHS, a suffic ient visual differentiation between the CN and the PT could not be achieved . A significantly better distinction could be achieved by using the THS (Wi lcoxon P < 0.05). The S/C ratios of the THS only showed a significant (P < 0.05) SCC of - 0.514 comparing to the UPDRS. Pathological alterations in th e <beta>-CIT uptake pattern could be identified by using the SHS, but a sig nificantly better differentiation of CN and the PT was possible by using th e THS. The significant correlation of the S/C ratios measured by THS only e mphasizes the value of THS in beta -CIT imaging. ( (C) 2001 Lippincott Will iams & Williams).