Achieva system

Images of the brain were acquired using a 3 Tesla (3T) Philips Achieva System with an 8-channel head-receiver coil or a 3T Siemens Prisma using a 20-channel head-neck coil. Structural T1-weighted images and T2-weighted fluid attenuated inversion recovery (FLAIR) images were reviewed by a staff neuroradiologist.

MRI explorations were initially performed on a 1.5 Tesla Philips Healthcare Achieva™ system (11/42) (Best, The Netherlands), a 1.5 Tesla Siemens Healthcare Magnetom Aera™ system (21/42) or a 3 Tesla Siemens Healthcare Skyra™ system (10/42) (Erlangen, Germany). The imaging protocol included axial, coronal, and sagittal T2 turbo spin echo, axial T1 turbo spin echo, diffusion MRI with two B-values (0–800 for the first exams, 50–1000 for the next exams), and dynamic T1 contrast-enhanced sequences that were acquired in the axial plane. We collected the following data: T2WI lesion shape (round or oval-shaped nodule versus focal area with irregular boundaries); number of lesions on T2WI (1; 2; >2); T2WI, T1WI and DWI signal (hyposignal; isosignal; hypersignal); apparent diffusion coefficient (ADC) values in the ADC map of the lesion and the normal testis parenchyma using the manual region of interest; enhancement of the nodule compared with that of the normal contralateral parenchyma (hypoperfusion; isoperfusion; hyperperfusion); time–signal-intensity curve type (15) (if available); and the size of the hypo- or hyperperfused area compared to the T2WI lesion, after intravenous injection of gadolinium chelates (Dotarem™, gadoteric acid, 0.2 mL per kg body weight, Guerbet SA, Aulnay-sous-Bois, France).