A FEASIBILITY STUDY OF NA-23 MAGNETIC-RESONANCE-IMAGING OF HUMAN AND RABBIT VITREAL DISORDERS

Purpose. To assess the clinical feasibility of sodium magnetic resonan ce imaging for the visualization and characterization of intraocular t issues. Methods. Na-23 magnetic resonance images were obtained of enuc leated human eyes and of rabbit eyes in vivo. The magnetic resonance i maging 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 d isplay normal anatomic details of the lens and vitreous humor, and imp ortant pathologic details such as intravitreal and subretinal hemorrha ges, ocular melanoma, and retinal detachments. Intraocular tissue iden tifications based on relative spin-spin relaxation time values and pix el intensities correlate with those made by standard diagnostic techni ques. Conclusions. Na-23 magnetic resonance imaging may be used for th e visualization and characterization of intraocular tissues. Different iation among vitreous humor, lens, aqueous humor, subretinal fluid, or hemorrhage and tumor may be based on image intensity and/or spin-spin relaxation times.