Okazawa H, Diksic M
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Quebec, Canada.
J Comput Assist Tomogr. 1998 Sep-Oct;22(5):777-85. doi: 10.1097/00004728-199809000-00021.
We sought to create functional images of the serotonin (5-HT) synthesis rate obtained with alpha-[11C]methyl-L-tryptophan (alpha-MTrp) and PET and standardize them into the stereotaxic coordinate system.
Dynamic PET scans were performed in 11 healthy subjects after an injection of alpha-MTrp. Results obtained by the Patlak plot and nonlinear least-squares methods using arterial plasma as input function were compared. The pixel-by-pixel calculation of functional images of 5-HT synthesis was done by the Patlak plot approach, after results were compared by two methods. Input function obtained by combining venous plasma and sinus radioactivities was also evaluated as an alternative to arterial input function.
There were no significant differences in 5-HT synthesis between the two calculation methods. The normalized venous input functions gave similar results as the arterial input function. The regional rates of 5-HT synthesis from functional images were not significantly different from those obtained by graphical plotting.
alpha-MTrp images could be converted into functional images representing 5-HT synthesis rates in the living brain, facilitating statistical comparison.
我们试图利用α-[11C]甲基-L-色氨酸（α-MTrp）和正电子发射断层扫描（PET）创建血清素（5-HT）合成率的功能图像，并将其标准化到立体定向坐标系中。
对11名健康受试者注射α-MTrp后进行动态PET扫描。比较了使用动脉血浆作为输入函数，通过Patlak图和非线性最小二乘法获得的结果。在两种方法比较结果后，通过Patlak图方法逐像素计算5-HT合成的功能图像。还评估了通过组合静脉血浆和窦放射性获得的输入函数作为动脉输入函数的替代方法。
两种计算方法之间的5-HT合成无显著差异。标准化的静脉输入函数与动脉输入函数给出了相似的结果。功能图像中5-HT合成的区域速率与通过图形绘制获得的速率无显著差异。
α-MTrp图像可以转换为代表活体大脑中5-HT合成率的功能图像，便于进行统计比较。
