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OP29.07: Non‐invasive in utero measurements of placental oxygen transport using MRI

2016; Wiley; Volume: 48; Issue: S1 Linguagem: Inglês

10.1002/uog.16443

1469-0705

Brahmdeep S. Saini, Meng Yuan Zhu, Sharon Portnoy, Prashob Porayette, Jessie Mei Lim, Abing Duan, John G. Sled, Rachel M. Wald, Rory Windrim, Christopher K. Macgowan, John‏ Kingdom, Mike Seed,

Pregnancy and preeclampsia studies

To investigate the use of MRI to assess placental function in terms of placental-fetal oxygen (O2) transport in utero. Eight women with normal pregnancies were scanned using a 1.5 T Siemens MRI system. To measure placental-fetal O2 transport, blood flow (Q) and oxygen content (C) were measured in blood vessels supplying (uterine arteries and fetal descending aorta) and draining (uterine, ovarian and umbilical veins) the placenta. Phase contrast MRI was used to measure Q. Vascular blood T1 and T2 MRI relaxometry were used to measure oxygen saturation and hematocrit to derive C. The oxygen delivery (Do2) and return (Ro2) were calculated as C*Q. Oxygen consumption (Vo2) was calculated using the arterio-venous difference in C of blood supplied to and drained from an organ and multiplying it by Q. All oxygen transport measures were indexed to fetal weight, which was calculated from the 3D MRI acquisition of the uterus. The mean placental-Vo2 was 4.1 ml/min/kg, which accounted for 33.9% of the total placental-fetal-Vo2. The mean fetal-Vo2 was 8.0 ml/min/kg and the mean placental-to fetal-Vo2 ratio was 0.53 (see table 1).