A feasibility study of 23Na magnetic resonance imaging of human and rabbit vitreal disorders.

PURPOSE To assess the clinical feasibility of sodium magnetic resonance imaging for the visualization and characterization of intraocular tissues. METHODS 23Na magnetic resonance images were obtained of enucleated human eyes and of rabbit eyes in vivo. The magnetic resonance imaging technique used in this study provided slices of < 2 mm thickness and in-plane resolution of < 2 x 2 mm. From each of these slices local values of spin-spin relaxation time (T2*) were calculated from pixel intensities in each of the eight echoes. RESULTS The images clearly display normal anatomic details of the lens and vitreous humor, and important pathologic details such as intravitreal and subretinal hemorrhages, ocular melanoma, and retinal detachments. Intraocular tissue identifications based on relative spin-spin relaxation time values and pixel intensities correlate with those made by standard diagnostic techniques. CONCLUSIONS 23Na magnetic resonance imaging may be used for the visualization and characterization of intraocular tissues. Differentiation among vitreous humor, lens, aqueous humor, subretinal fluid, or hemorrhage and tumor may be based on image intensity and/or spin-spin relaxation times.