@article{oai:repo.qst.go.jp:00057071,
 author = {Nagatsuka, Shin-ichiro and Fukushi, Kiyoshi and Namba, Hiroki and Shinotoh, Hitoshi and Tanaka, Noriko and Tanada, Shuji and Irie, Toshiaki and 長塚 伸一郎 and 福士 清 and 難波 宏樹 and 篠遠 仁 and 田中 典子 and 棚田 修二 and 入江 俊章},
 journal = {Physiological Imaging of the Brain with PET},
 month = {},
 note = {Blood flow linitation of tracer delivery to tissues often affects accuracy and precision of kinetic parameter estimates, particularly in the K3 parameter (tracer conversion rate) of irreverisible tracers in tissues with high K3. As an example of such irreversible radiotracers,[11C] N-methylpiperidinyl-4-acetate, which is metabolically trapped in the brain, was used in the present study. The extent of PET data error in the scanning conditions employed was estimated by analyzing relationships in radioactivity count, standard error of pixel data, and observed PET data error in regiouns of inerest taken in emission images of a homogenous phantom and healthy human subjects. In several cerebral regions with different K3, standard time-radioactivity curves were obtained from one particular subject using three-compartment kinetic model analysis with nonlinear leaast-squares method.The standard time-radioactivity curve and the estimated PET data error were used to generate 100 different time-radioactivity data sets in each region. Two analytical methods for kinetic parameter estimation, i,e., conventional nonlinear least-squares method and shape analysis that estimtes K3 without using input function, were then applied to the sinulated data sets to evaluate the accuracy and precicion of K3 estimates. Both methods gave higher accuracy and precision of K3 in regions with lower K3. The dynamic range of K3 estimation was slightly Wider in the nonlinear least-squares method than in the shape analysis.},
 pages = {139--144},
 title = {Tracer Conversion Rate and Accuracy of Compartmental Model Parameter in Irreversibly Trapped Radiotracer Method},
 year = {2001}
}