Intraocular Water Movement Visualization Using 1 H-MRI With Eye Drops of O-17-Labeled Saline: First-in-Human Study.

Journal of magnetic resonance imaging : JMRI 2023 Mar

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Visualization of aqueous humor flow in MR contrast images using gadolinium is challenging because of the delayed contrast effects associated with the blood-retinal and blood-aqueous humor barriers. However, oxygen-17 water (H2 17 O) might be used as an ocular contrast agent. To observe the distribution of H2 17 O in the human eye, and its flow in and out of the anterior chamber, using dynamic T2-weighted MRI. Prospective. Six ophthalmologically normal volunteers (20-37 years, six females). A 3 T/dynamic T2-weighted MRI. H2 17 O eye drops were administered to the right eye. Time-series images were created by subtracting the image before the eye drops from each of the images obtained after the eye drops. The normalized signal intensity of the right anterior chamber (nAC) was obtained by dividing the signal intensity of the right anterior chamber region by that of the left. The inflow and outflow constants of H2 17 O and H2 17 O concentration were calculated from the nAC. A paired t-test was used to compare the flow-related values and temporal changes in signal intensity. P-values < 0.05 were considered statistically significant. Significantly decreased signal intensity was observed in the right anterior chamber but not the right vitreous body (P = 0.39). The nAC signal intensity decreased significantly and then recovered. The inflow and outflow constants were 0.36-0.94 min-1 and 0.023-0.13 min-1 , respectively. The maximum H2 17 O concentration was 0.078%-0.24%. H2 17 O were distributed in the anterior chamber. The H2 17 O inflow into the anterior chamber was significantly faster than that of the outflow. 2 TECHNICAL EFFICACY STAGE: 2. © 2022 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.

Citation

Moyoko Tomiyasu, Yasuka Sahara, Etsuko Mitsui, Hiroki Tsuchiya, Takamasa Maeda, Nobuhiro Tomoyori, Makoto Kawashima, Toshifumi Nogawa, Riwa Kishimoto, Yuhei Takado, Tatsuya Higashi, Atsushi Mizota, Kohsuke Kudo, Takayuki Obata. Intraocular Water Movement Visualization Using 1 H-MRI With Eye Drops of O-17-Labeled Saline: First-in-Human Study. Journal of magnetic resonance imaging : JMRI. 2023 Mar;57(3):845-853