Department of Obstetrics and Gynecology, Aalborg University Hospital, Reberbansgade 15, 9000, Aalborg, Denmark.
Department of Pathology, Aalborg University Hospital, Ladegaardsgade 3, 9000, Aalborg, Denmark.
Placenta. 2021 Oct;114:76-82. doi: 10.1016/j.placenta.2021.08.057. Epub 2021 Aug 24.
The antenatal detection of small for gestational age (SGA) pregnancies is a challenge, which may be improved by placental MRI. The longitudinal relaxation time (T1) is a tissue constant related to tissue morphology and tissue oxygenation, thereby placental T1 may be related to placental function. The aim of this study is to investigate placental T1 in appropriate for gestational age (AGA) and SGA pregnancies.
A total of 132 singleton pregnancies were retrieved from our MRI research database. MRI and ultrasound estimated fetal weight (EFW) was performed at gestational week 20.6-41.7 in a 1.5 T system. SGA was defined as BW ≤ -15% of the expected for gestational age (≤10th centile). A subgroup of SGA pregnancies underwent postnatal placental histological examination (PHE) and abnormal PHE was defined as vascular malperfusion. The placental T1 values were converted into Z-scores adjusted for gestational age at MRI. The predictive performance of placental T1 and EFW was compared by receiver operating curves (ROC).
In AGA pregnancies, placental T1 showed a negative linear correlation with gestational age (r = -0.36, p = 0.004) Placental T1 was significantly reduced in SGA pregnancies (mean Z-score = -0.34) when compared to AGA pregnancies, p = 0.03. Among SGA pregnancies placental T1 was not reduced in cases with abnormal PHE, p = 0.84. The predictive performance of EFW (AUC = 0.84, 95% CI, 0.77-0.91) was significantly stronger than placental T1 (AUC = 0.62, 95% CI, 0.52-0.72) (p = 0.002).
A low placental T1 relaxation time is associated with SGA at birth. However, the predictive performance of placental T1 is not as strong as EFW.
产前检测胎儿生长受限（SGA）是一项挑战，胎盘 MRI 可能有助于提高检测的准确性。纵向弛豫时间（T1）是一个与组织形态和组织氧合相关的组织常数，因此胎盘 T1 可能与胎盘功能有关。本研究旨在探讨正常胎龄（AGA）和 SGA 妊娠的胎盘 T1 值。
从我们的 MRI 研究数据库中检索了 132 例单胎妊娠。在 1.5T 系统中，在 20.6 至 41.7 孕周进行 MRI 和超声估计胎儿体重（EFW）。SGA 定义为 BW≤-15%的预期胎龄（≤第 10 百分位数）。SGA 妊娠的亚组接受产后胎盘组织学检查（PHE），异常 PHE 定义为血管灌注不良。将胎盘 T1 值转换为 MRI 时胎龄校正的 Z 分数。通过接收者操作曲线（ROC）比较胎盘 T1 和 EFW 的预测性能。
在 AGA 妊娠中，胎盘 T1 与胎龄呈负线性相关（r=-0.36，p=0.004）。与 AGA 妊娠相比，SGA 妊娠的胎盘 T1 明显降低（平均 Z 分数=-0.34），p=0.03。在 SGA 妊娠中，异常 PHE 病例的胎盘 T1 并未降低，p=0.84。EFW（AUC=0.84，95%CI，0.77-0.91）的预测性能明显强于胎盘 T1（AUC=0.62，95%CI，0.52-0.72）（p=0.002）。
低胎盘 T1 弛豫时间与出生时的 SGA 相关。然而，胎盘 T1 的预测性能不如 EFW。
