Region-of-interest analysis of changes in R1 between the open and closed eye. (a) Axial MR image shows regions of interest. (b) Graph shows changes of R1 over time after closing and covering the eye. Data at time of 0 are eye open. Studies acquired at the following times were binned: 9–12 minutes, 15–23 minutes, and 30–43 minutes. AN = anterior nasal region, AT = anterior temporal region, Mid = midvitreous, PN = posterior nasal region, PT = posterior temporal region.