Umr 770

All MRI examinations were completed within two weeks prior to radical surgery. Patients were scanned in the supine position using a 3.0-T whole-body MRI scanner (uMR770, United Imaging, China) with a sixteen-channel phased-array coil centered over the belly. Before the MRI, all patients were required to fast for a minimum of 8 hours. A T1-weighted volume interpolated breath-hold gradient recall echo sequence was used to provide an unenhanced scan, dynamic contrast-enhanced phase, and hepatobiliary phase (HBP). The dynamic contrast-enhanced scan early arterial (EAP) and late arterial phases (LAP) were used to ensure that we could observe the enhancement of the tumor. A dosage of 0.025 mmol/kg Gd-EOB-DTPA (Primovist; Bayer HealthCare, Berlin, Germany) was administered at a rate of 2.0 mL/s, and then followed by a 30-mL saline flush at the same rate. Using bolus triggering, a dual arterial phase sequence was started 15-25 seconds after the contrast media arrived at the distal thoracic aorta, while the portal venous phase (PVP), delay phase (DP), and HBP were acquired at 1, 3, and 15 minutes after Gd-EOB-DTPA administration, respectively. The HBP images were used to assist in the diagnosis and demarcation of the tumor location.

As our previous studies described, the Gd contrast medium (Omniscan, Xudonghaipu Pharmaceutical Co. Ltd, Shanghai, China) was diluted 8-fold with saline (v/v, 1: 7). Approximately 0.4–0.6 ml of the diluted Gd was injected intratympanically. The injection was performed under a microscope. The patient then was placed in the supine position for 60 min (14 (link)).
Twenty-four hours after the Gd injection, MRI scans were performed with a 3.0 Tesla MR scanner (UMR 770, united-imaging, Shanghai, China), using a 24-channel head coil. 3D-FLAIR imaging was subsequently performed. The scan parameters for the 3D-FLAIR sequence were as follows: time of repetition = 6,500 ms, time of echo = 286.1 ms, time of inversion = 1,950 ms, flip angle = 67°, slice thickness = 0.6 mm, echo train length = 160, field of view = 200 ^* 200 mm, and matrix size = 256 ^* 256, voxel size = 0.78 ^* 0.78 ^* 1.1 mm. The scan time was 6 min 11 s. Three dimensional heavily T2-weighted spectral attenuated inversion recovery (3D-T2-SPAIR) sequence was also performed with the following parameters: voxel size = 0.65 ^* 0.52 ^* 0.76 mm, scan time = 4 min 30 s, TR = 1,300 ms, TE = 254.7 ms, flip angle = 110°, slice thickness = 0.4 mm, field of view = 200 ^* 200 mm, and matrix size = 384 ^* 384 (15 (link)).

All MRI data analyzed in the present study were preoperatively acquired using 3.0 T MRI scanners according to the protocols in each institution, including the Philips instrument (Achieva TX, Philips Medical Systems, The Netherlands) and United imaging instrument (uMR770, United Imaging Healthcare, China), and the parameters are shown in Table S1. Available preoperative MRI images included T1 weighted image (T1WI), T2 weighted image (T2WI), diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) maps, and T1 contrast-enhanced (T1CE) MR images. We eliminated the difference in MRI image brightness caused by the deviation in the scanning process and performed N4 deviation field correction on all MRI images.

MRI was performed 24 h after the application of the contrast agent on a 3.0 Tesla MR scanner (Umr 770, united-imaging, Shanghai, China), using a 24-channel head coil. Three-dimensional heavily T2-weighted spectral attenuated inversion recovery (3D-T2-SPAIR, T2) and 3D T2 fluid-attenuated inversion recovery (3D-FLAIR) imaging were subsequently performed. The scan parameters for the 3D-FLAIR sequence were as follows: voxel size = 0.78 * 0.78 * 1.1 mm, scan time = 6 min and 11 s, time of repetition (TR) = 6500 ms, time of echo (TE) = 286.1 ms, time of inversion = 1950 ms, flip angle = 67°, echo train length = 160 points, slice thickness = 0.6 mm, field of view = 200 * 200 mm, and matrix size = 256 * 256. We used a heavily T2-weighted SPAIR sequence with the detailed scan parameters as follows: voxel size = 0.65 * 0.52 * 0.76 mm, scan time = 4 min and 30 s, TR = 1,300 ms, TE = 254.7 ms, flip angle = 110°, slice thickness = 0.4 mm, field of view = 200 * 200 mm, and matrix size = 384 * 384.

MRI acquisitions, including three-dimensional (3D) T1w, coronal 3D T2w, and a 3D gradient recalled echo (GRE) sequence (3.0 T uMR 770, United Imaging Healthcare, Shanghai, China), were performed on a 3-T MRI scanner several days before the day of the surgery. PD patients with severe tremors at rest were scanned while on medication or were injected with diazepam to reduce the possibility of movement artifacts during MRI examinations. Detailed imaging parameters for T1w, T2w, and GRE sequences, including the repetition time (TR), echo time (TE), bandwidth, field of view (FOV), acquisition matrix, voxel size, and scan time are summarized in Table 1. For QSM map calculation, multiecho GRE data were acquired using the susceptibility-weighted imaging (SWI) + sequence (Ye et al., 2018 ). B0 field maps were extracted using the multidimensional integration method (Ye and Lyu, 2019 ), unwrapped from aliased phases using SPUN (Ye et al., 2019b (link)), and background fields were removed using vSHARP (Li et al., 2014 (link)). QSM maps were obtained by solving the L1 regularization problem, with an extra term for streaking artifact suppression (Ye et al., 2019a ), using the precondition conjugate gradient method. The calculation of B0 and the generation of QSM maps were performed on the postprocessing workstation of the scanner.