Nishizawa S, Kuwabara H, Ueno M, Shimono T, Toyoda H, Konishi J
Department of Nuclear Medicine and Diagnostic Imaging, Graduate School of Medicine, Kyoto University, Japan.
Ann Nucl Med. 2001 Jun;15(3):203-7. doi: 10.1007/BF02987832.
[18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) may be used to examine changes in cerebral glucose metabolism in two physiological conditions. We proposed and evaluated a double injection-single session FDG method with biological constraints for this purpose.
Simulated brain time-radioactivity curves (TACs) generated by using a plasma TAC from an actual study and physiological combinations of input values in a kinetic model were analyzed to evaluate the accuracy of the proposed method. The reproducibility of the estimated values obtained by this method was tested in five normal volunteers who were studied with a dynamic PET scan and two injections of FDG in a single session while fasting.
The simulation study showed that the estimated values obtained by the proposed method agreed well with the input values. In the human study, plasma glucose levels were 5.3 +/- 0.2 and 5.0 +/- 0.2 mM in the first and second measurements, respectively. The difference between the plasma glucose measurements was small but statistically significant (p < 0.05). Although no systematic deviations were noted in K1 or rCMRglc, there were small deviations in K (less than 10%) and LC (less than 5%) with a statistical significance (p < 0.01).
The deviation between the measurements in K* and LC seemed to relate to the difference in the plasma glucose level. The double-injection FDG method with biological constraints can be used to estimate rCMRglc and LC sequentially in a single PET scanning session.
[18F]氟脱氧葡萄糖（FDG）和正电子发射断层扫描（PET）可用于检查两种生理状态下脑葡萄糖代谢的变化。为此，我们提出并评估了一种具有生物学约束的双注射单时段FDG方法。
使用实际研究中的血浆时间-放射性曲线（TAC）和动力学模型中输入值的生理组合生成模拟脑时间-放射性曲线，以评估所提出方法的准确性。在五名正常志愿者中测试了该方法获得的估计值的可重复性，这些志愿者在禁食状态下进行了动态PET扫描并在单时段内注射了两次FDG。
模拟研究表明，所提出方法获得的估计值与输入值吻合良好。在人体研究中，第一次和第二次测量时血浆葡萄糖水平分别为5.3±0.2和5.0±0.2 mM。血浆葡萄糖测量值之间的差异很小但具有统计学意义（p<0.05）。虽然在K1或rCMRglc中未发现系统偏差，但在K（小于10%）和LC（小于5%）中存在小偏差，具有统计学意义（p<0.01）。
K*和LC测量值之间的偏差似乎与血浆葡萄糖水平的差异有关。具有生物学约束的双注射FDG方法可用于在单次PET扫描时段中依次估计rCMRglc和LC。
