@article{oai:repo.qst.go.jp:00047363,
 author = {Okada, Maki and Kikuchi, Tatsuya and Okamura, Toshimitsu and Ikoma, Yoko and Tsuji, Atsushi and Wakizaka, Hidekatsu and Aoki, Ichio and Zhang, Ming-Rong and Kato, Koichi and Kamakura, Tomoo and 岡田 真希 and 菊池 達矢 and 岡村 敏充 and 生駒 洋子 and 辻 厚至 and 脇坂 秀克 and 青木 伊知男 and 張 明栄 and 加藤 孝一},
 issue = {12},
 journal = {Nuclear Medicine Communications},
 month = {Dec},
 note = {The blood–brain barrier (BBB) limits the entry of some therapeutics into the brain, resulting in reduced efficacy. BBB-opening techniques have been developed to enhance the entry into the brain. However, a non-invasive, highly sensitive and quantitative method for evaluating the changes in BBB permeability induced by such techniques is needed to optimise treatment protocols. We evaluated 2-amino-[3-11C]isobutyric acid ([3-11C]AIB) as a positron emission tomography (PET) probe for quantifying BBB permeability in model rats.
BBB opening was induced by a lipopolysaccharide injection or focused ultrasound (FUS) sonication. [3-11C]AIB distribution in the brain was evaluated by autoradiography and PET and compared with that of Evans blue (EB), a traditional BBB permeability marker. Kinetics of [3-11C]AIB was compared with that of gadolinium–diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging. The unidirectional blood–brain transfer constant (Ki) of [3-11C]AIB was estimated using Patlak plot.
[3-11C]AIB uptake in the lesion area was significantly higher than that in the control area, and radioactivity co-localised with EB in both models. [3-11C]AIB uptake in the FUS-sonicated region decreased over time after sonication. The ratio of [3-11C]AIB accumulation in the FUS-treated to the contralateral side increased during the experiment time, whereas that of Gd-DTPA intensity reached a maximum at 10 min post-injection and decreased thereafter. The [3-11C]AIB Ki values were significantly higher in the lesion area than the control area.
[3-11C]AIB PET is a promising, highly sensitive and quantitative imaging method for assessing BBB permeability.},
 pages = {1239--1248},
 title = {In vivo imaging of blood–brain barrier permeability using positron emission tomography with 2-amino-[3-11C]isobutyric acid},
 volume = {36},
 year = {2015}
}