MR OF OPTIC PAPILLA PROTRUSION IN PATIENTS WITH HIGH INTRACRANIAL-PRESSURE

PURPOSE: To evaluate the signal characteristics of the optic papilla ( optic nerve head) on routine cranial MR images in patients with clinic al evidence of optic papilla elevation caused by high intracranial pre ssure, and to compare these findings with findings in healthy adult vo lunteers. METHODS: We reviewed restropectively the MR imaging examinat ions of 15 patients who were referred with objectively decreased visua l acuity and funduscopic findings of optic papilla elevation. T1-weigh ted and T2-weighted axial MR images were obtained by using conventiona l spin-echo acquisitions on 1.5-T MR imagers. In addition, the MR imag ing studies in 10 healthy adult volunteers without visual impairment w ere reviewed as controls. RESULTS: In 10 (67%) of the 15 patients, vis ual elevation of the optic papilla was shown by MR imaging. In all 15 patients, the MR signal intensity of the optic papilla was hypointense relative to the vitreous of the globe on T2-weighted images. In the h ealthy volunteer group, the optic papillae were all similarly hypointe nse relative to the vitreous of the globe on T2-weighted images; howev er, these optic papillae were flat. CONCLUSION: Clinical examination a nd MR imaging may show elevation of the optic papilla in patients with high intracranial pressure. When chronic, optic papilla elevation has been shown to correlate well with severe loss of vision. Actual edema of the optic papilla seems to play little role in the physical elevat ion observed clinically in the chronic stages of this pathologic proce ss.