Department of Women and Children's Health, King's College London, London, United Kingdom (XX Avena-Zampieri, XX Hall, XX Seed, XX Greenough, and XX Story); Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom (Ms Avena-Zampieri, Dr Hutter, Mr Deprez, Ms Payette, Dr Hall, Ms Uus, Prof Rutherford, and Dr Story).
Centre for the Developing Brain, School of Biomedical Engineering & Imaging Sciences, King's College London, London, United Kingdom (Ms Avena-Zampieri, Dr Hutter, Mr Deprez, Ms Payette, Dr Hall, Ms Uus, Prof Rutherford, and Dr Story).
Am J Obstet Gynecol MFM. 2023 Jun;5(6):100935. doi: 10.1016/j.ajogmf.2023.100935. Epub 2023 Mar 17.
The mainstay of assessment of the fetal lungs in clinical practice is via evaluation of pulmonary size, primarily using 2D ultrasound and more recently with anatomical magnetic resonance imaging. The emergence of advanced magnetic resonance techniques such as T2* relaxometry in combination with the latest motion correction post-processing tools now facilitates assessment of the metabolic activity or perfusion of fetal pulmonary tissue in vivo.
This study aimed to characterize normal pulmonary development using T2* relaxometry, accounting for fetal motion across gestation.
Datasets from women with uncomplicated pregnancies that delivered at term, were analyzed. All subjects had undergone T2-weighted imaging and T2* relaxometry on a Phillips 3T magnetic resonance imaging system antenatally. T2* relaxometry of the fetal thorax was performed using a gradient echo single-shot echo planar imaging sequence. Following correction for fetal motion using slice-to-volume reconstruction, T2* maps were generated using in-house pipelines. Lungs were manually segmented and mean T2* values calculated for the right and left lungs individually, and for both lungs combined. Lung volumes were generated from the segmented images, and the right and left lungs, as well as both lungs combined were assessed.
Eighty-seven datasets were suitable for analysis. The mean gestation at scan was 29.9±4.3 weeks (range: 20.6-38.3) and mean gestation at delivery was 40±1.2 weeks (range: 37.1-42.4). Mean T2* values of the lungs increased over gestation for right and left lungs individually and for both lungs assessed together (P=.003; P=.04; P=.003, respectively). Right, left, and total lung volumes were also strongly correlated with increasing gestational age (P<.001 in all cases).
This large study assessed developing lungs using T2* imaging across a wide gestational age range. Mean T2* values increased with gestational age, which may reflect increasing perfusion and metabolic requirements and alterations in tissue composition as gestation advances. In the future, evaluation of findings in fetuses with conditions known to be associated with pulmonary morbidity may lead to enhanced prognostication antenatally, consequently improving counseling and perinatal care planning.
在临床实践中，评估胎儿肺部的主要方法是通过评估肺的大小，主要使用 2D 超声，最近则使用解剖磁共振成像。随着 T2*弛豫测量等先进磁共振技术的出现，以及最新的运动校正后处理工具的出现，现在可以在体内评估胎儿肺组织的代谢活性或灌注。
本研究旨在通过 T2*弛豫测量来描述正常的肺发育，同时考虑到妊娠期间的胎儿运动。
分析了来自于在足月时分娩的无并发症孕妇的数据集。所有受试者均在产前接受了飞利浦 3T 磁共振成像系统的 T2 加权成像和 T2弛豫测量。胎儿胸部的 T2弛豫测量采用梯度回波单次激发回波平面成像序列进行。使用切片到体积重建对胎儿运动进行校正后，使用内部管道生成 T2图谱。手动分割肺，分别计算右肺和左肺以及双肺的平均 T2值。从分割图像生成肺容积，并评估右肺、左肺和双肺。
87 个数据集适合进行分析。扫描时的平均孕龄为 29.9±4.3 周（范围：20.6-38.3），分娩时的平均孕龄为 40±1.2 周（范围：37.1-42.4）。右肺、左肺和双肺的平均 T2*值随孕龄增加而增加（分别为 P=.003；P=.04；P=.003）。右肺、左肺和双肺容积也与胎龄呈强相关（所有情况下 P<.001）。
本研究使用 T2成像对广泛的胎龄范围进行了发育中的肺部评估。平均 T2值随孕龄增加而增加，这可能反映了灌注和代谢需求的增加以及随着胎龄的增加组织成分的改变。在未来，对已知与肺部发病率相关的胎儿进行评估可能会提高产前预测能力，从而改善咨询和围产期护理计划。
