Preliminary Study of Hydrodynamics in Fetal Mice Using ¹⁷O-MRI [Presidential Award Proceedings]

Abstract

　¹⁷O-MRI is expected to have clinical applications owing to its high biocompatibility and ability to directly track water movement. Fetuses grow with an active exchange of water with the mother ; therefore, understanding the water dynamics of the mother-fetus amniotic fluid cycle is important. However, water movement cannot be measured using echocardiography, and Gd contrast-enhanced MRI is contraindicated in pregnant women. In this study, ¹⁷O-labeled saline was administered to measure fetal water dynamics in pregnant mice. The results were compared with the signal changes induced by Gd administration. Dynamic scans of fetal mice using ¹⁷O-labeled saline were successfully obtained. The images showed signal changes that differed from those obtained using the Gd contrast agent. In the future, efforts will be made to improve the temporal and spatial resolution as well as to investigate the possibility of detecting correlations between the signals observed in various tissues.