title: Evolution of Cerebral Ischemia Assessed by Amide Proton Transfer-Weighted MRI.
abstract: Amide proton transfer-weighted (APTW) magnetic resonance imaging (MRI) has recently become a potentially important tool for evaluating acidosis in ischemic stroke. The purpose of this study was to evaluate the dynamic pH-related changes in the lesions in patients with ischemia. Thirty-nine patients with ischemic stroke (symptom onset to imaging time ranging 2 h-7 days) were examined with a 3.0-T MRI system. Patients were divided into four groups: at the hyperacute stage (onset time ≤ 6 h), at the acute stage (6 h < onset time ≤ 48 h), at the early subacute stage (48 h < onset time ≤ 96 h), and at the late subacute stage (96 h < onset time ≤ 168 h). The APTW signal intensities were quantitatively measured in multiple ischemic regions for each patient. Compared with the contralateral normal white matter, APTW signals were significantly lower in ischemic tissue for all four stages (P< 0.05). The APTW signal intensities (APTWaveand APTWmin) increased consistently with onset time (R2= 0.11,P= 0.040;R2= 0.13,P= 0.022, respectively). APTWmax-minshowed a continued reduction with onset time (R2= 0.44,P< 0.001). Our results suggest that persistent tissue acidification could occur after ischemia, and as the time from stroke onset increases, the acidotic environment would alleviate. APTW signal intensities could reflect pH-weighted properties in ischemic tissue at different stages and time points.
authors.affiliation: Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China; Graduate School of Peking Union Medical College, Beijing, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Song
authors.affiliation: Department of Radiology, Beijing Hospital, National Center of Gerontology , Beijing , China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Radiology, Beijing Hospital, National Center of Gerontology , Beijing , China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Radiology, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Xuna
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China; Graduate School of Peking Union Medical College, Beijing, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Zhujiang Hospital of Southern Medical University , Guangzhou , China.
authors.forename: Xianlong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neurology, Beijing Hospital, National Center of Gerontology , Beijing , China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Neurology, Beijing Hospital, National Center of Gerontology , Beijing , China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Neurology, Beijing Hospital, National Center of Gerontology , Beijing , China.
authors.forename: Tao
authors.initials: T
authors.lastname: Gong
authors.affiliation: Department of Radiology, Johns Hopkins University , Baltimore, MD , USA.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Radiology, Beijing Hospital, National Center of Gerontology, Beijing, China; Graduate School of Peking Union Medical College, Beijing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
keywords: APT imaging; chemical exchange saturation transfer imaging; magnetization transfer; pH; stroke