Pituitary imaging performed for clinical care, including assessment for metastatic disease or of symptoms such as headache, was reviewed by a board-certified neuroradiologist (J.V.M.). Twenty-five subjects had MRI scans in at least 2 time periods defined below. Outside records were reviewed extensively to capture complete imaging data for patients. All patient MRIs were re-reviewed (J.V.M.) blinded to time of onset of hypophysitis for an unbiased approach. The pituitary gland, including the infundibulum, was categorized as being normal in appearance, enlarged, or small (labeled empty or partially empty sella). Categorization was performed on post-contrast T1-weighted images, either small-field-of-view two-dimensional (2D) sagittal and coronal imaging targeted to the pituitary gland or high-resolution isotropic 3D imaging of the brain. The timing of the MRI scans was classified relative to hypophysitis diagnosis (Fig. 2): baseline (at least 40 days prior), diagnosis (within 40 days), and follow-up (over 40 days), using time intervals suggested in the published literature based on time to resolution of imaging changes [16 (link)]. If multiple MRIs were done within the same period of time and were incongruent, the abnormal MRI was selected to represent that time period.