Twinspeed

Magnetic resonance imaging images acquisition was performed by an experienced neuroradiologist. MRI sequences were performed on all subjects with a 1.5T clinical MRI scanner manufactured by General Electric Company (Twin speed; Milwaukee, WI, USA) equipped with a birdcage head coil. Supportive foam pads were used to minimize head motion. A rapid sagittal localizer scan was acquired to confirm alignment. Normal T1 and T2 MRI scans were taken to exclude obvious structural abnormalities. In the 98 SLE patients, nine patients were excluded due to brain structural abnormities identified by T1- and T2-weighted MRI (local infarction or ischemia). Data from the remaining 89 patients were included in this study. 11 subjects from the HC group were also excluded due to local ischemia, and thus 84 HC subjects were included in the study. A set of three-dimensional volumetric structural MRI scans was taken on each subject using a fast spoiled gradient echo sequence with the following parameters: repetition time/echo time = 10.5/2 ms, matrix size = 256 × 256, thickness = 1.8 mm with no interslice gap, field of view = 240 mm, and flip angle = 15°. Resolution = 0.94 mm× 0.94 mm× 0.9 mm. Whole brain images were acquired in axial planes parallel to the anterior commissure-posterior commissure line, yielding 172 continuous slices of 0.9 mm thick.

All MR images were obtained by an experienced neuroradiologist using a 1.5T MRI scanner (TwinSpeed; GE Medical Systems, Milwaukee, WI, USA) with cage head coils for MRI data acquisition. Subjects were placed in a supine position and advised to be relaxed, to be motionless, to have their eyes closed during the scan. Foam support pads were used to reduce head movement. Conventional T1-weighted image (T1WI) and T2-weighted image (T2WI) plain scanning was performed first to exclude obvious structural abnormalities. The scanning parameters were as follows: axial T1WI: echo time (TE) = 8.9 ms, repetition time (TR) = 2,056.9 ms, layer thickness = 5 mm, layer spacing = 6 mm, and turning angle = 90°; T2WI: TR = 12,000 ms, TE = 88.4 ms, layer thickness = 6 mm, layer spacing = 6 mm, and turning angle = 90°. No subjects were excluded for the presence of abnormal brain structure; 3D-MRI uses 3D-T1-weighted fast phase disturbance gradient echo sequence (3D-T1-fspgr sequence), and the parameters were as follows: TR = 10.5 ms, TE = 2 ms, inversion time = 350 ms, layer thickness = 1.8 mm and no layer interval, scanning matrix = 256, turning angle = 15°, field of view = 240 mm, spatial resolution = 0.94 mm × 0.94 mm × 0.9 mm, and layer number = 172; scanning range covers the whole brain.

The MRI scans for all subjects were conducted by a highly experienced radiologist, utilizing the same 1.5 T MRI scanner manufactured by General Electric (Twinspeed; GE Medical Systems, Milwaukee, WI, USA). Initially, plain scanning including routine T1-weighted image and T2-weighted image was conducted to rule out any intracranial organic lesions. An echo planner imaging sequence scan was used with the following parameters: repetition time = 2000 ms, echo time = 40 ms, thickness = 5 mm with an interslice gap of 1 mm, field of view = 240 mm × 240 mm, matrix size = 64 × 64, flip angle = 90°, number of excitation = 2.00, number of layers = 24, time point = 160. The total fMRI scan time was 320 s.
The rs-fMRI data was preprocessed on a DPARSF software based on the MatlabR2016a platform. As per the Anatomical Automatic Labeling template from MNI, the gray matter in each subject's brain was segmented into 116 regions. Among these, the initial 90 regions corresponded to the brain's gray matter, while the remaining 26 regions represented the gray matter of the cerebellum. The rs-fMRI data processing toolkit REST V1.8 was used to extract the mean ReHo value, mean ALFF value, and mean fALFF value of each region.

The CMR protocol used for patients with repaired TOF has been previously published [23 (link)]. Briefly, studies were performed with a 1.5-T whole body scanner (Achieva, Phillips Healthcare Systems, Best, the Netherlands or TwinSpeed, GE Healthcare, Milwaukee, Wisconsin, USA) using surface coils selected based on patient size. The scanner manufacturer was different for the pre- and post-PVR CMR study in 4 patients. Imaging included breath-hold, electrocardiographically-gated, balanced steady-state free precession cine CMR acquisitions in 4-chamber and short-axis planes. A total of 12−14 slices were obtained in the short-axis plane to completely cover both ventricles. In all views, 30 images per cardiac cycle were acquired which yielded a temporal resolution of 20–40 ms, depending on heart rate. Ventricular volumes and blood flow were measured using commercially available software (QMASS and QFLOW, Medis, Leiden, the Netherlands) [23 (link)].