背景: 碳-11-raclopride正子電腦斷層造影(positron emission tomography; PET)被用來研究多巴胺神經細胞突觸的功能。本回顧研究之目的探討臨床碳-11-raclopride定量分析比值法(simple ratio method of quantification)中，比較用小(cerebellum)，或用枕葉皮質(occipital cortex)當測量的參考區域(reference region)，與紋狀體(striatum)比值所得結果有無差異。
方法: 11位正常志願者與32位長期服用非傳統抗精神病藥物治療之精神分裂症(schizophrenic)患者接受碳-11-reclopride正子電腦斷層造影檢查，分別計算基底核(basal ganglion)對小腦及基底核對枕葉皮質之放射活性計數密度比值，並分別以皮爾森相關係數檢定及two sample statistics t-test分析。
結果: 全部43位受檢者之定量比值分析，基底核對小腦之放射活性密度比值，以及基底核對枕葉皮質之放射活性密度比值，兩者有顯著的關連性(皮爾森相關係數=0.955; P=0.01)。利用two sample statistics t-test分析基底核對小腦的比值，在常人與精神分裂症患者之間的顯著差異值為T=5.546 (P=0.000，小於預設P=0.01)。而基底核對枕葉皮質的比值，正常人與精神分裂症患者之間的顯著差異值為T=6.531(P=0.000，小於預設P=0.01)。
結論: 臨床碳-11-raclopride PET檢查之定量分析法中，選取枕葉皮質當參考區域，就像選取小腦當參考區域一樣的可靠。

Background: 11C-labeled raclopride has been widely used with PET to study the function of dopaminergic synapses. The purpose of this retrospective study was to compare the cerebellum versus the occipital cortex as a reference region in simple ratio method of quantification of clinical 11C-raclopride studies.
Method: Eleven normal volunteers and 32 schizophrenic patients received 11C-raclopride PET. Specific 11C-raclopride binding in the striatum was defined as the ration between the maximal radioactivity in the basal ganglion and that in either the cerebellum or the occipital cortex. Pearson correlation coefficients were used to examine whether there was any correlation between the cerebellums versus the occipital cortex as a reference region in simple ratio method of quantification.
Results: The cerebellum versus the occipital cortex as a reference region correlated well for all 43 subjects (Pearson correlation coefficients=0.955; correlation was significant at P=0.01 level). Two sample t-test was used to examine the difference between normal subjects and schizophrenic patients. For the basal ganglion-to-cerebellum ratio, the difference was significant at T=5.546 (P=0.000; less than 0.01) for the basal ganglion/occipital cortex ratio, the difference was significant at T=6.531 (P=0.000; less than 0.01)
Conclusion: In the simple ratio method of quantification for clinical 11C-raclopride PET studies, the use of the occipital cortex as a reference region was as reliable as the use of the cerebellum.