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Intraocular Water Movement Visualization Using 1 H‐MRI With Eye Drops of O‐17‐Labeled Saline: First‐in‐Human Study
Author(s) -
Tomiyasu Moyoko,
Sahara Yasuka,
Mitsui Etsuko,
Tsuchiya Hiroki,
Maeda Takamasa,
Tomoyori Nobuhiro,
Kawashima Makoto,
Nogawa Toshifumi,
Kishimoto Riwa,
Takado Yuhei,
Higashi Tatsuya,
Mizota Atsushi,
Kudo Kohsuke,
Obata Takayuki
Publication year - 2023
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.28345
Subject(s) - intensity (physics) , saline , nuclear medicine , blood flow , contrast (vision) , outflow , nuclear magnetic resonance , aqueous humor , gadolinium , chemistry , medicine , ophthalmology , physics , optics , meteorology , organic chemistry
Background 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 (H 2 17 O) might be used as an ocular contrast agent. Purpose To observe the distribution of H 2 17 O in the human eye, and its flow in and out of the anterior chamber, using dynamic T2‐weighted MRI. Study Type Prospective. Population Six ophthalmologically normal volunteers (20–37 years, six females). Field Strength/Sequence A 3 T/dynamic T2‐weighted MRI. Assessment H 2 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 H 2 17 O and H 2 17 O concentration were calculated from the nAC. Statistical Tests 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. Results 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 H 2 17 O concentration was 0.078%–0.24%. Data Conclusion H 2 17 O were distributed in the anterior chamber. The H 2 17 O inflow into the anterior chamber was significantly faster than that of the outflow. Level of Evidence 2 Technical Efficacy Stage 2