Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.
Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
J Magn Reson Imaging. 2021 Jun;53(6):1853-1861. doi: 10.1002/jmri.27487. Epub 2021 Jan 6.
Infants admitted to the neonatal intensive care unit (NICU) often suffer from multifaceted pulmonary morbidities that are not well understood. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) is a promising technique for pulmonary imaging in this population without requiring exposure to ionizing radiation. The aims of this study were to investigate the effect of neonatal pulmonary disease on R * and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R *.This was a prospective study, in which 17 neonatal human subjects (five control, seven with bronchopulmonary dysplasia [BPD], five with congenital diaphragmatic hernia [CDH]) were enrolled. Twelve subjects were male and five were female, with postmenstrual age (PMA) at MRI of 39.7 ± 4.7 weeks. A 1.5T/multiecho three-dimensional UTE MRI was used. Pulmonary R * and tissue density were compared across disease groups over the whole lung and regionally. A spherical shell alveolar model was used to predict the expected R * over a range of tissue densities and tissue susceptibilities. Tests for significantly different mean R * and tissue densities across disease groups were evaluated using analysis of variance, with subsequent pairwise group comparisons performed using t tests. Lung tissue density was lower in the ipsilateral lung in CDH compared to both controls and BPD patients (both p < 0.05), while only the contralateral lung in CDH (CDHc) had higher whole-lung R * than both controls and BPD (both p < 0.05). R * differences were significant between controls and CDHc within all tissue density ranges (all p < 0.05) with the exception of the 80%-90% range (p = 0.17). Simulations predicted an inverse relationship between alveolar tissue density and R * that matches empirical human data. Alveolar wall thickness had no effect on R * independent of density (p = 1). The inverse relationship between R * and tissue density is influenced by the presence of disease globally and regionally in neonates with BPD and CDH in the NICU. LEVEL OF EVIDENCE: 2. TECHNICAL EFFICACY STAGE: 2.
新生儿重症监护病房（NICU）收治的婴儿常患有多种肺部疾病，这些疾病的发病机制尚不清楚。超短回波时间（UTE）磁共振成像（MRI）是一种很有前途的肺部成像技术，它可用于该人群，而无需接触电离辐射。本研究的目的是研究新生儿肺部疾病对 R * 和组织密度的影响，并利用数值模拟评估不同肺泡结构对预测 R * 的影响。这是一项前瞻性研究，共纳入 17 名新生儿受试者（对照组 5 名，支气管肺发育不良[BPD]组 7 名，先天性膈疝[CDH]组 5 名）。其中 12 名男性，5 名女性，MRI 检查时的胎龄为 39.7±4.7 周。使用 1.5T/multiecho 三维 UTE MRI 进行检查。比较了疾病组在整个肺部和区域的肺部 R * 和组织密度。使用球形壳肺泡模型预测了一系列组织密度和组织磁化率下的预期 R *。使用方差分析评估疾病组间 R * 和组织密度的差异，然后使用 t 检验进行组间两两比较。与对照组和 BPD 患者相比，CDH 患者的同侧肺组织密度较低（均 p<0.05），而仅 CDH 的对侧肺（CDHc）的全肺 R * 高于对照组和 BPD（均 p<0.05）。在所有组织密度范围内，对照组和 CDHc 之间的 R * 差异均具有统计学意义（均 p<0.05），但在 80%-90%范围内除外（p=0.17）。模拟预测了肺泡组织密度与 R * 之间的反比关系，这与人类的经验数据相符。肺泡壁厚度与密度无关，对 R * 无影响（p=1）。R * 与组织密度之间的反比关系受 BPD 和 CDH 新生儿整体和局部疾病的影响。证据水平：2。技术功效分期：2。
