Onishi Y, Yonekura Y, Tanaka F, Nishizawa S, Okazawa H, Ishizu K, Fujita T, Konishi J, Mukai T
Nihon Medi-Physics Co. Ltd., Nishinomiya, Japan.
Eur J Nucl Med. 1996 Nov;23(11):1491-7. doi: 10.1007/BF01254474.
"Delayed" single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0-3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [123I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended.
静脉推注碘 - 123 艾司西酞普兰后获得的“延迟”单光子发射断层扫描（SPET）图像已被用作苯二氮䓬受体结合的相对图谱。我们确定了获取此类图谱的最佳扫描时间，并评估了该图谱的误差。使用了来自六名健康志愿者和五名患者的SPET及血液数据。在模拟研究和实际数据分析中采用了三室动力学模型。模拟研究表明，在正常大脑中，单个SPET图像最能代表相对受体结合的扫描时间是注射后3.0 - 3.5小时。志愿者的实际数据支持了这一发现。模拟研究还表明，输入函数的变异性对最佳扫描时间影响不大，并且全脑示踪剂动力学的变化不会增加最佳扫描时间附近SPET图像对比度的误差。注射后3.0小时患者的SPET图像对比度与通过动力学分析估计的参考受体结合情况吻合良好，平均误差为3.6%。这些发现支持将静脉推注[123I]艾司西酞普兰后的单个SPET图像用作苯二氮䓬受体结合的相对图谱。为此，建议注射后3.0 - 3.5小时进行SPET扫描。
