Magnetom avanto

MRI was performed at both 1.5T (Siemens Espree, Siemens Magnetom Avanto, GE Signa Excite, GE Signa HDx) and 3T (GE Signa HDx, GE Signa Excite). Conventional MRI included pre-contrast T1w, T2-weighted, fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging.^{11 (link)} For both pre- and post-contrast T1w imaging, all sites were required to collect the data using a spin-echo sequence with the following parameter ranges: TE/TR = min (<15 ms)/400–600 ms, FOV=220–240 mm, phase FOV = 75%, slice thickness/gap = 5 mm/1 mm, matrix = 256 × 256, NEX = 1. The imaging protocol remained fixed at each site and across all time points. Following i.v. of 0.1 mmol/kg of a standard gadolinium-based contrast agent (The brand used was dictated by each site’s preference.), axial 2D spin-echo (2D-T1) and 3D volumetric T1w post-contrast images were acquired. Patients participating in the optional advanced component of the trial had dynamic contrast-enhanced, dynamic susceptibility contrast (DSC), and/or spectroscopic MRI at baseline, week 2, and after every two cycles of treatment. Results from these advanced imaging cohorts were previously reported.^{12 (link)–14 (link)} A complete listing of all MRI parameters for this protocol can be found on the ACRIN website. (https://www.acrin.org/PROTOCOLSUMMARYTABLE/PROTOCOL6677/6677ImagingMaterials.aspx).