MRI assessments.
LIVER, BRAIN
Head and abdominal MRIs were used to assess regional brain, liver, and spleen volumes at baseline, week 24, and week 48 of Study 250-201. Brain volumetric analysis was performed on 3D T1-weighted images using the FreeSurfer Image Analysis Suite, version 5.3 (Martinos Center, Harvard University) (Brain volumes are noted without normalization, similarly to previous publications (Liver and spleen volumes were calculated by ICON Laboratory Services. Because liver and spleen volumes increased linearly compared with both age and BSA, these volumes were normalized to BSA, calculated using the Mosteller formula to allow for comparison among patients ranging from 2–9 years of age (