Assessment of normal pulmonary development using functional magnetic resonance imaging techniques

• Published in: American journal of obstetrics & gynecology MFM 2023-06, Vol.5 (6), p.100935-100935, Article 100935
• Main Authors: Avena-Zampieri, Carla L., Hutter, Jana, Deprez, Maria, Payette, Kelly, Hall, Megan, Uus, Alena, Nanda, Surabhi, Milan, Anna, Seed, Paul T., Rutherford, Mary, Greenough, Anne, Story, Lisa
• Format: Article
• Language: English
• Subjects: Female; fetal magnetic resonance imaging; Gestational Age; Humans; Lung - diagnostic imaging; lung development; Magnetic Resonance Imaging - methods; Original Research; Pregnancy; prenatal prediction
• ISSN: 2589-9333; 2589-9333
• DOI: 10.1016/j.ajogmf.2023.100935

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