Separating fetal and maternal placenta circulations using multiparametric MRI

• Published in: Magnetic resonance in medicine Vol. 81; no. 1; pp. 350 - 361
• Main Authors: Melbourne, Andrew, Aughwane, Rosalind, Sokolska, Magdalena, Owen, David, Kendall, Giles, Flouri, Dimitra, Bainbridge, Alan, Atkinson, David, Deprest, Jan, Vercauteren, Tom, David, Anna, Ourselin, Sebastien
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.01.2019; John Wiley and Sons Inc
• Subjects: Algorithms; Blood; Blood volume; chorion; DECIDE; diffusion; Exchanging; Female; Fetal Blood; Fetus - blood supply; Fetuses; Flow characteristics; flow‐matching; Full Papers—Imaging Methodology; Humans; Image Processing, Computer-Assisted - methods; Magnetic Resonance Imaging; Maternal-Fetal Exchange; Models, Theoretical; Myometrium; Myometrium - blood supply; Myometrium - diagnostic imaging; Nutrients; Oxygen; Physical properties; Placenta; Placenta - blood supply; Placenta - diagnostic imaging; Placental Circulation; Pregnancy; Prenatal Diagnosis; Relaxation time; relaxometry; Umbilical Arteries - diagnostic imaging; flow-matching; chorion; diffusion; relaxometry; DECIDE
• ISSN: 0740-3194; 1522-2594; 1522-2594
• DOI: 10.1002/mrm.27406

Purpose The placenta is a vital organ for the exchange of oxygen, nutrients, and waste products between fetus and mother. The placenta may suffer from several pathologies, which affect this fetal‐maternal exchange, thus the flow properties of the placenta are of interest in determining the course of pregnancy. In this work, we propose a new multiparametric model for placental tissue signal in MRI. Methods We describe a method that separates fetal and maternal flow characteristics of the placenta using a 3‐compartment model comprising fast and slowly circulating fluid pools, and a tissue pool is fitted to overlapping multiecho T2 relaxometry and diffusion MRI with low b‐values. We implemented the combined model and acquisition on a standard 1.5 Tesla clinical system with acquisition taking less than 20 minutes. Results We apply this combined acquisition in 6 control singleton placentas. Mean myometrial T2 relaxation time was 123.63 (±6.71) ms. Mean T2 relaxation time of maternal blood was 202.17 (±92.98) ms. In the placenta, mean T2 relaxation time of the fetal blood component was 144.89 (±54.42) ms. Mean ratio of maternal to fetal blood volume was 1.16 (±0.6), and mean fetal blood saturation was 72.93 (±20.11)% across all 6 cases. Conclusion The novel acquisition in this work allows the measurement of histologically relevant physical parameters, such as the relative proportions of vascular spaces. In the placenta, this may help us to better understand the physiological properties of the tissue in disease.