All participants underwent an MRI scan of the brain (Siemens Avanto, n = 7; GE Discovery MR750, n = 14; Impax, n = 119; 3T Philips Ingenuity TF PET/MR system, n = 123; 1.5T GE Signa HDxt, n = 21; 3.0T GE Signa HDxt, n = 262; 1.5T Siemens Sonata, n = 27; 3T Toshiba Vantage Titan, n = 119; Vision, n = 1). The protocol included 3D T1-weighted images, 3D T2-weighted images, and 3D T2-weighted fluid-attenuated inversion-recovery (FLAIR) images.18 (link) Visual rating of medial temporal lobe atrophy (MTA) was performed on coronal T1-weighted images averaging scores for the left and right sides (range 0–4).28 (link) Posterior atrophy was rated using sagittal, axial, and coronal planes of T1 and FLAIR-weighted images averaging scores for the left and right sides (range 0–3).29 (link) Global cortical atrophy (GCA) was rated using axial FLAIR images (range 0–3).30 (link) The severity of white matter hyperintensities was determined on the FLAIR sequence using the Fazekas scale (range 0–3).31 (link) Lacunes were defined as deep lesions (3–15 mm) with CSF-like signal on all sequences. They were counted and dichotomized into absent (0) of present (≥1 lacune). Microbleeds were defined as small dot-like hypointense lesions on T2-weighted images. They were also counted and dichotomized into absent (0) or present (≥1 microbleed). An experienced neuroradiologist reviewed all scans.
Discovery mr750
Manufactured by Philips
Sourced in China
The Discovery MR750 is a magnetic resonance imaging (MRI) system manufactured by Philips. It is designed to capture high-quality images of the human body for diagnostic and research purposes. The system utilizes advanced magnetic and radio frequency technologies to generate detailed visualizations of anatomical structures and physiological processes.
Automatically generated - may contain errors
Lab products found in correlation
Signa hdxt, by GE Healthcare (2 mentions)
Prisma, by Siemens (2 mentions)
Signa hdxt, by Siemens (1 mentions)
Vantage titan, by Toshiba (1 mentions)
Prisma fit, by GE Healthcare (1 mentions)
Achieva dstream, by Philips (1 mentions)
Ingenia, by Philips (1 mentions)
Sense body coil, by Philips (1 mentions)
Intellispace portal, by Philips (1 mentions)
Tim trio, by Siemens (1 mentions)
5 protocols using discovery mr750
1
Multimodal MRI Analysis of Brain Structure
2
Multi-site Longitudinal MRI Acquisition
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MR protocols had been harmonized at the start of the study and included a T1-weighted MPRAGE and a T2-weighted isotropic acquisition. Five scanners were used across different sites: 3 subjects were imaged on a GE Discovery MR750, 108 on a Philips Achieva, 51 on a Siemens Prisma, 72 on a Siemens Skyra and 102 on a Siemens Trio. Details of the acquisition protocol across the different scanners are reported as supplementary material (see Supplementary Table 1). The majority of the participants were scanned longitudinally on the same scanner but 32 were not scanned on the same scanner at all time points (24 controls, 9 presymptomatic mutation carriers and 1 symptomatic mutation carrier).
3
Harmonized Multisite MRI Imaging Protocol
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The ABCD Data Analysis and Informatics Center (DAIC) and the ABCD Imaging Acquisition Workgroup developed the imaging protocol used in the present study. These groups harmonized the imaging protocol for all scanner platforms. Imaging data was acquired across 21 sites using the following 3 tesla (3 T) scanner models: Siemens Prisma, Siemens Prisma Fit, General Electric Discovery MR750, Philips Achieva dStream, and Philips Ingenia. Imaging data collection occurred across one to two sessions. Further detail on these methods is documented elsewhere (Casey et al., 2018 (link); Hagler et al., 2019 (link)). Each session included T1‐ and T2‐weighted images of brain structure. Details on the imaging parameters include the following: TR (repetition time) 2400–2500 ms; TE (echo time) 2–2.9 ms; FOV (field of view) 256 × 240 to 256; FOV phase of 93.75%–100%; matrix 256 × 256; 176–225 slices; TI (inversion delay) 1060 ms; flip angle of 8°; voxel resolution of 1 × 1 × 1 mm; total acquisition time from 5 min 38 s to 7 min 12 s.
4
Quantitative MRI Evaluation of Hip Cartilage
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All MRI scans were performed on a 3T MRI unit (GE DISCOVERY MR750, China-Japan Friendship Hospital) with a surface coil wrapped around the hips (SENSE Body Coil, Philips Healthcare, The Netherlands). The patients were imaged in a supine position, with the hips positioned neutrally and legs straight. Imaging sequences included fat-saturated proton-density weighted imaging (PD-FS), three-dimension double echo steady-state sequence (3D-DESS), and quantitative Cube T2 -mapping. The MRI parameters were optimized to achieve the highest signal noise ratio (SNR) and image quality. T2-mapping was conducted using similar imaging parameters to enable comparison. The repetition time (TR) was 1000 ms, while the echo time (TE) was set to 32 ms. The slice thickness was chosen to be 3.5 mm with a spacing of 0.7 mm. The field of view (FOV) was 256 mm × 256 mm. And the number of excitations (NEX) was set to 1. Each participant was required to rest for 30 minutes before the knee scan to ensure that the cartilage was resting.
We used an advanced cartilage analysis application (IntelliSpace Portal, Philips Healthcare) to analyze the reconstructed T2 maps. Local T2 values can be determined through T2 mapping using multiecho (ME) SE methods [29 (link)].
We used an advanced cartilage analysis application (IntelliSpace Portal, Philips Healthcare) to analyze the reconstructed T2 maps. Local T2 values can be determined through T2 mapping using multiecho (ME) SE methods [29 (link)].
5
Harmonized Multi-Site Resting-State fMRI
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Imaging data were acquired using 3 Tesla MRI scanners at six centers across Canada, varying by model and manufacturer (GE Healthcare Signa HDxT (TGH), GE Healthcare Discovery MR750 (CAM, MCU, UCA), Phillips Intera (UBC), Siemens Trio Tim (QNS)). Imaging protocols varied slightly among sites, to accommodate for scanner and manufacturer differences (see MacQueen et al., 2019 (link) for detailed protocols). RS-fMRI was collected over a 10-minute scan (2000 ms repetition time) using a whole-brain T2*-sensitive blood-oxygen-level-dependent echo planar imaging sequence (30 ms echo time, 4 mm × 4 mm × 4 mm resolution). Accompanying whole-brain structural 3D T1-weighted images were acquired with a 1 mm isotropic resolution. In addition to protocol harmonization, substantial quality control and assurance efforts were implemented to ensure consistent high-quality data was collected from all sites. These methods included, but were not limited to, automated file name and imaging protocol adherence checks, manual image quality control rating, and longitudinal monitoring of scanner stability using monthly phantom scans from all sites (see MacQueen et al. 2019 (link)). Details of image pre-processing are included in the Supplementary Materials.
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