Hyperintensities of the optic radiation on T2-weighted MR images of elderly subjects

BACKGROUND AND PURPOSE: Although abnormal hyperintensities are frequently o bserved at or around the optic radiation in elderly subjects, no previous r eports have mentioned the clinical significance and pathologic changes of t hese hyperintensities. We evaluated the hyperintensity patterns of the opti c radiation and its surrounding structures on T2-weighted MR images and com pared these findings with pathologic observations and visual field measurem ents, METHODS: High-resolution coronal T2-weighted MR images of 102 consecutive p atients (51-84 years old) were evaluated retrospectively for the presence a nd morphology of hyperintensities of the optic radiation (204 sides) and it s surrounding structures. Pathologic specimens were obtained from 25 other patients (60-91 years old) who had died of nonneurologic causes. The histop athologic changes of the optic radiation and its surrounding structures wer e evaluated and correlated with the MR findings, Finally, MR findings and v isual field measurements were correlated in 46 elderly volunteers (70-91 ye ars old). RESULTS: Hyperintensities of the optic radiation or its surrounding structu res or both were observed on 125 sides (93%) of 67 patients (61%), and line ar/laminar hyperintensity of the optic radiation and the tapetum was the ch aracteristic finding. Eleven (44%) of 25 pathologic specimens exhibited pal lor of three anatomic layers (the external sagittal stratum or the optic ra diation, the internal sagittal stratum, and the tapetum). No subjects with hyperintensity of the optic radiation had visual field abnormalities. CONCLUSION: Linear/laminar hyperintensity of the optic radiation and tapetu m on T2-weighted images is common in elderly subjects, and may reflect diff erences in the internal structures and in the water content of three anatom ic structures. Hyperintensities of this region did not cause visual field a bnormalities in a group of elderly volunteers.