在 3T 下使用多延迟 3D GRASE 伪连续动脉自旋标记测量人胎盘血流。
Measuring human placental blood flow with multidelay 3D GRASE pseudocontinuous arterial spin labeling at 3T.
机构信息
Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Department of Radiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
出版信息
J Magn Reson Imaging. 2018 Jun;47(6):1667-1676. doi: 10.1002/jmri.25893. Epub 2017 Nov 14.
BACKGROUND
Placenta influences the health of both a woman and her fetus during pregnancy. Maternal blood supply to placenta can be measured noninvasively using arterial spin labeling (ASL).
PURPOSE
To present a multidelay pseudocontinuous arterial spin labeling (pCASL) combined with a fast 3D inner-volume gradient- and spin-echo (GRASE) imaging technique to simultaneously measure placental blood flow (PBF) and arterial transit time (ATT), and to study PBF and ATT evolution with gestational age during the second trimester. The PBF values were compared with uterine arterial Doppler ultrasound to assess its potential clinical utility.
STUDY TYPE
This was a prospective study.
SUBJECTS
Thirty-four pregnant women.
FIELD STRENGTH/SEQUENCE: Multidelay 3D inner-volume GRASE pCASL sequence on 3T MR scanners.
ASSESSMENT
Subjects underwent two longitudinal MRI scans within the second trimester, conducted between 14-16 and 19-22 weeks of gestational age, respectively. Placental perfusion was measured using the free-breathing pCASL sequence at three postlabeling delays (PLDs), followed by offline motion correction and model fitting for estimation of PBF and ATT.
STATISTICAL TESTS
A paired t-test was conducted to evaluate the significance of PBF/ATT variations with placental development. A two-sample t-test was conducted to evaluate the significance of PBF difference in subjects with and without early diastolic notch.
RESULTS
The mean PBF and ATT for the second trimester were 111.4 ± 26.7 ml/100g/min and 1387.5 ± 88.0 msec, respectively. The average PBF increased by 10.4% (P < 0.05), while no significant change in ATT (P = 0.72) was found along gestational ages during the second trimester. PBF decreased 20.3% (P < 0.01) in subjects with early diastolic notches in ultrasound flow waveform patterns.
DATA CONCLUSION
Multidelay pCASL with inner-volume 3D GRASE is promising for noninvasive assessment of PBF during pregnancy. Its clinical use for the detection of aberrations in placental function and prediction of fetal developmental disorders awaits evaluation.
LEVEL OF EVIDENCE
1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1667-1676.
背景
胎盘在女性怀孕期间影响其自身和胎儿的健康。胎盘的母体血液供应可以使用动脉自旋标记（ASL）进行无创测量。
目的
介绍一种多延迟伪连续动脉自旋标记（pCASL）与快速 3D 内体积梯度和自旋回波（GRASE）成像技术相结合的方法，以同时测量胎盘血流（PBF）和动脉通过时间（ATT），并研究妊娠中期 PBF 和 ATT 随妊娠周数的变化。将 PBF 值与子宫动脉多普勒超声进行比较，以评估其潜在的临床应用价值。
研究类型
这是一项前瞻性研究。
受试者
34 名孕妇。
磁场强度/序列：3T 磁共振扫描仪上的多延迟 3D 内体积 GRASE pCASL 序列。
评估
受试者分别在妊娠 14-16 周和 19-22 周时进行了两次纵向 MRI 扫描。使用自由呼吸 pCASL 序列在三个标记后延迟（PLD）测量胎盘灌注，然后进行离线运动校正和模型拟合，以估计 PBF 和 ATT。
统计学检验
采用配对 t 检验评估 PBF/ATT 随胎盘发育的变化的显著性。采用两样本 t 检验评估超声血流波形模式中存在和不存在早期舒张切迹的受试者之间 PBF 差异的显著性。
结果
妊娠中期的平均 PBF 和 ATT 分别为 111.4 ± 26.7 ml/100g/min 和 1387.5 ± 88.0 msec。随着妊娠中期的进展，PBF 平均增加了 10.4%（P < 0.05），而 ATT 没有明显变化（P = 0.72）。在超声血流波形模式中存在早期舒张切迹的受试者中，PBF 下降了 20.3%（P < 0.01）。
数据结论
使用 3D GRASE 的多延迟 pCASL 有望成为一种非侵入性的妊娠期间 PBF 评估方法。其用于检测胎盘功能异常和预测胎儿发育障碍的临床应用尚待评估。
证据水平
1 技术功效：阶段 2 J. Magn. Reson. Imaging 2018;47:1667-1676.
Zotero 插件