Gadolinium diethylenetriamine penta acetic acid

All MR images of the enrolled patients were acquired on 3.0 T MR units (Discovery MR750, GE Healthcare, Milwaukee, WI, United States; Magnetom Trio TIM/Skyra, Siemens Healthcare, Erlangen, Germany) with 8-, 12-, or 20-channel head coil. Briefly, the brain MRI protocol included the following: (a) pre-contrast axial and sagittal T1, (b) axial T2, (c) axial FLAIR, (d) DWI, and (e) axial, sagittal, and coronal T1c acquired immediately after an intravenous administration of a 0.1-mmol/kg dose of a gadolinium-based contrast agent (gadolinium-diethylenetriamine pentaacetic acid, Bayer Healthcare, Leverkusen, Germany, or gadoteric acid meglumine salt injection, Hengrui Healthcare, Jiangsu, China) with the same parameters as the matched pre-contrast sequence. All DWI acquisitions were obtained before injection of the contrast agent and were used as a monopolar spin-echo echo-planar sequence, with diffusion sensitizing gradients encoded in the x, y, and z directions. ADC maps were calculated from acquired DWI with b = 0 and b = 1,000 s/mm² images using the dedicated software (version 4.6, GE Healthcare, Milwaukee, WI, United States; Syngo, Siemens Healthcare, Erlangen, Germany). Details of the parameters for all the sequence acquisitions are available in Supplementary Table 1.

All MRI examinations were performed on a 3.0 T MR scanner (Verio, Siemens, Erlangen, Germany) and a 1.5 T MR scanner (Signa EXCITE HD, GE Healthcare, Milwaukee, WI, USA), equipped with a 12-channel head coil. The following sequences were acquired: axial T₁-weighted image (T₁WI) (repetition time/echo time (TR/TE), 400~2000/9~15 ms; section thickness, 6 mm; number of signals acquired, 2; matrix, 320 × 320; field of view (FOV), 230 × 230 mm), axial T₂-weighted image (T₂WI) ((TR/TE, 3500~6000/95~100 ms; section thickness, 6 mm; number of signals acquired, 1; matrix, 320 × 320; FOV, 230 × 230 mm), and axial T₂-weighted fluid attenuated inversion recovery (T₂_FLAIR) images ((TR/TE, 6000~8000/90~120 ms; section thickness, 6 mm; number of signals acquired, 1; matrix, 320 × 320; FOV, 230 × 230 mm)). In addition, axial, sagittal, and coronal post-contrast T₁WIs were acquired after intravenous administration of 0.1 mmol/kg gadolinium diethylenetriamine penta-acetic acid (Bayer Healthcare, Berlin, Germany).

Images were collected for all patients using a 1.5 T MR scanner (Avanto, Siemens) equipped with an 8-channel body coil. The scanning area ranged from the anteroom-superior iliac spine to the symphysis pubis. The scanning sequence included the coronal, sagittal, and axial oblique fat-saturation (fs) T2WI; axial oblique DWI and axial oblique three-dimensional volumetric interpolated breath-hold examination (3D-VIBE). DWI was acquired by echo-planar imaging (b-value = 0, 800 s/mm²). After DWI scanning, the workstation automatically calculates and generates ADC map. The specific MRI parameters are shown in Table 1. When 3D-VIBE sequence was used to obtain DCEI, patients were instructed to hold their breath at the end of expiratory breath. A high pressure syringe (Spectris MR injection system, Medrad Inc.) was used to administer gadolinium diethylenetriamine penta-acetic acid (Bayer Healthcare Pharmaceuticals) through the cubital vein at a rate of 2 mL/s. The dosage of Gd-DTPA was 0.1 mmol/kg. Images of arterial phase, venous phase and delay phase were obtained by scanning at 25 s, 60 s and 180 s after administration.