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
Department of Molecular Imaging and Theranostics, National Institutes for Quantum Science and Technology, Chiba, Japan.
Department of Medical Technology, National Institutes for Quantum Science and Technology, Chiba, Japan.
J Magn Reson Imaging. 2023 Mar;57(3):845-853. doi: 10.1002/jmri.28345. Epub 2022 Jul 15.
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 O) might be used as an ocular contrast agent.
To observe the distribution of H 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).
FIELD STRENGTH/SEQUENCE: A 3 T/dynamic T2-weighted MRI.
H 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 O and H 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 and 0.023-0.13 min , respectively. The maximum H O concentration was 0.078%-0.24%.
H O were distributed in the anterior chamber. The H O inflow into the anterior chamber was significantly faster than that of the outflow.
2 TECHNICAL EFFICACY STAGE: 2.
由于与血视网膜屏障和血房水屏障相关的延迟对比效应，利用钆在磁共振对比图像中观察房水流动具有挑战性。然而，氧-17水（H₂¹⁷O）可作为一种眼部造影剂。
使用动态T2加权磁共振成像观察H₂¹⁷O在人眼中的分布及其进出前房的流动情况。
前瞻性研究。
6名眼科检查正常的志愿者（年龄20 - 37岁，均为女性）。
场强/序列：3T/动态T2加权磁共振成像。
向右眼滴入H₂¹⁷O眼药水。通过将滴眼药水后获得的每张图像减去滴眼药水前的图像来创建时间序列图像。右前房（nAC）的归一化信号强度通过将右前房区域的信号强度除以左前房区域的信号强度获得。根据nAC计算H₂¹⁷O的流入和流出常数以及H₂¹⁷O浓度。
采用配对t检验比较与流动相关的值和信号强度的时间变化。P值<0.05被认为具有统计学意义。
右前房信号强度显著降低，但右玻璃体未出现（P = 0.39）。nAC信号强度显著降低后恢复。流入和流出常数分别为0.36 - 0.94分钟⁻¹和0.023 - 0.13分钟⁻¹。H₂¹⁷O的最大浓度为0.078% - 0.24%。
H₂¹⁷O分布在前房。H₂¹⁷O流入前房的速度明显快于流出速度。
2 技术效能阶段：2
