The utility of I-123-FP-CIT brain SPECT (DAT scan) with three head gamma camera system.

Objectives The three head gamma camera system (GCA-9300R, Toshiba) which was released in 2014 realizes high sensitivity and high resolution image acquisition. The aim of this study is to access the utility of clinical efficiency of high quality scans with this gamma camera system.

Methods In 145 patients who received DAT scans from September 2014 to August 2015, 104 patients (M:F=42:62, age:74±14) who had definite diagnosis and didn't show large ischemic change which seemed to affect the result of accumulation accounts in striatum were included in this study. Each patient was intravenously injected with 167MBq of I-123-FP-CIT. The mean imaging times post injection is 3 hours. Image reconstruction was performed without attenuation and scatter correction. We divided the materials into 4 groups, PD group (n=55), PS group (MSA,DLB,CBD)(n=20),control group (dementia without DLB, essential tremor) (n=23), undivided group which could not be classified in other three group (n=6). The ROC analysis between the abnormal (PR+ PS) group and control group was performed, and the specific banding ratio (SBR) and asymmetry index (AI) measured by the BOLT method were compared statistically. An analysis of SBR t-test was used and the Mann Whitney-U test was used in AI because it didn’t show normal distribution.

Results In the ROC analysis, as to SBR, when threshold between abnormal and control group was defined as 2.94, the sensitivity was 91% and the specificity was 89% (P<0.00001), and the difference between PD group and PS group (P<0.0005), and between PS group and control group (P<0.05) showed apparently significant differences respectively. The difference of AI between PD group and PS group showed significant difference (P<0.05), and there were no statistically significant difference between PS group and the control group.

Conclusions The DAT scan with three head gamma camera system can provide highly sensitive results clinically in diagnosis of PD and PS.