Optistar le

iMRI scans were performed with a mobile MRI system (IMRIS, Innovative Magnetic Resonance Imaging Systems, Inc., Winnipeg, MB, Canada) interfaced to a 3.0T MR system console (Verio, Siemens Medical Systems, Erlangen, Germany) after the STA-MCA anastomosis within one hour for all patients. Time-of-flight (TOF) magnetic resonance angiography (MRA) scans (4 slabs, 40 slices/slab; repetition time, 22 ms; echo time, 4.2 ms; flip angle, 18; matrix size, 365 × 384; slice thickness, 0.5 mm; field of view, 181 × 200 mm²) were obtained to reconstruct the 3-dimensional brain template.
PWI was performed based on the enhanced fat-suppressed T2 single-shot echo-planar imaging sequence with the following acquisition parameters: repetition time, 1500 ms; echo time, 30 ms; filed of view, 230 × 230 mm²; matrix size, 128 × 128; number of layers, 19; slice thickness, 4 mm; interval, 1.2 mm; flip angle, 90°. The contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) (Magnevist, Bayer, Berlin, Germany), was administered into an antecubital vein using a power injector (the OptiStar LE Mallinckrodt, Liebel-Flarsheim Company, USA) with a dosage of 0.2 mmol/kg and an injection rate of 4 ml/s.

MRI examinations were performed on a 3.0-T system (Signa HDXT, General Electric Healthcare, Waukesha, WI, USA), which was equipped with an eight-channel torso array coil. All patients were scanned by conventional sequence and IVIM-DWI with multiple b values. Patients was placed in the supine position and breathed freely during collection. In the chemical shift selective saturation (CHESS) sequence, the axial IVIM-DWI with FS was obtained by using single-shot echo-planar imaging (EPI) pulse sequence, which has 10 b values (0, 10, 20, 50, 100, 200, 400, 800, 1,200 and 1,500 s/mm²), repetition time (TR) = 4000 ms, echo time (TE) =75 ms, FOV 42 cm×42 cm, matrix 96×130, slice thickness/gap: 4 mm/1 mm, number of excitations (NEX) = 6. Liver acquisition with a volume acceleration (LAVA) sequence was used for contrast-enhanced pelvic imaging, and a high-pressure injector (Optistar LE; Mallinckrodt; Cincinnati, Ohio, USA) was used for injection of contrast material (0.1 mmol/kg, Gadodiamide, General Electric Healthcare, USA). The details of the LAVA MR parameters are as follows: TR=4.5 ms, TE =1.3 ms, flip angle =15°, NEX = 1, band width =166.67 kHz. These images were obtained from multiple phases after injection of the contrast agent in the axial and sagittal planes (postcontrast at 20 s, 60 s, and 120 s in axial planes and 150 s in sagittal planes).