2.5. MRI Data Acquisition
All MRI data were acquired from a 3.0 Tesla scanner (Siemens, Sonata, Germany) at Dongzhimen Hospital, Beijing, China. The parameters of gradient echoplanar imaging (EPI) were as follows: echo time (TE) = 30 ms, repetition time (TR) = 2000 ms, matrix = 64 × 64, field of vision (FOV) = 225 mm × 225 mm, slice thickness = 3.5 mm, and flip angle (FA) = 90°. The functional scan lasted for 6 minutes, and 179 image volumes were obtained. And the T1-weighted imaging (T1WI) scan lasted for 4 minutes and 10 seconds, with the following parameters: TE = 2.53 ms, TR = 1900 ms, matrix = 256 × 256, FOV = 250 mm × 250 mm, slice thickness = 1.0 mm, and FA = 9°.