- 作者：Toshiaki Taoka ; MD ; PhD* ; ttaoka@med.nagoya-u.ac.jp" class="auth_mail" title="E-mail the corresponding author ; Masayuki Fujioka ; MD ; PhD&dagger ; ; &Dagger ; ; Yuto Kashiwagi ; PhD§ ; ; Atsushi Obata ; PhD§ ; ; Takemi Rokugawa ; MSc§ ; ; Masaaki Hori ; MD ; PhD‖ ; Yoshitaka Masutani ; PhD¶ ; ; Shigeki Aoki ; MD ; PhD‖ ; Shinji Naganawa ; MD ; PhD* ; Kohji Abe ; PhD§ ;
- 关键词：Rat ; infarction ; middle cerebral artery occulusion ; MRI ; diffusion ; kurtosis
- 刊名：Journal of Stroke and Cerebrovascular Diseases
- 出版年：2016
- 出版时间：March 2016
- 年：2016
- 卷：25
- 期：3
- 页码：610-617
- 全文大小：930 K
Materials and Methods
Adult male Wistar rats were subjected to 30 or 60 minutes of middle cerebral artery occlusion and imaged with a 7T Magnetic Resonance Imager System (Varian MRI System 7T/210: Agilent Technologies, CA). Diffusion kurtosis images were obtained before middle cerebral artery (MCA) reperfusion and 3, 6, and 24 hours after reperfusion to generate the apparent diffusion coefficient (ADC), fractional anisotropy (FA), mean apparent diffusion kurtosis coefficient (mAKC), AKC axial to the eigenvector (axAKC), and AKC radial to the eigenvector (radAKC) images. The time course of the region/normal ratio was evaluated for the above parameters in the caudoputamen and white matter.
Results
Relative FA and relative ADC values decreased 3 hours after MCA reperfusion and remained decreased until 24 hours. Relative mAKC, axAKC, and radAKC values were increased 3 hours after MCA reperfusion, peaked after 6 hours, and slightly decreased after 24 hours. In the white matter, axAKC showed larger changes than radAKC.
Conclusion
The time course of the diffusion kurtosis value showed earlier pseudonormalization than the ADC value of the lesions. For white matter lesions, the increase in axAKC was larger than that in radAKC, suggesting that the tissue changes after infarction mainly produce reduced diffusivity along the fibers and lead to increased inhomogeneity of the diffusion.