Research: Effects of neonatal lung abnormalities on parenchymal R 2 * estimates

J Magn Reson Imaging

. 2021 Jan 6. doi: 10.1002/jmri.27487. Online ahead of print.

Effects of neonatal lung abnormalities on parenchymal R 2 * estimates

Andrew D Hahn 1Annelise Malkus 1Jeffery Kammerman 1Nara Higano 2Laura L Walkup 2 3Jason Woods 2 3Sean B Fain 1 4 5Affiliations expand

Full-text linksCite


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 R2 * and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R2 *.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 R2 * 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 R2 * over a range of tissue densities and tissue susceptibilities. Tests for significantly different mean R2 * 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 R2 * than both controls and BPD (both p < 0.05). R2 * 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 R2 * that matches empirical human data. Alveolar wall thickness had no effect on R2 * independent of density (p = 1). The inverse relationship between R2 * 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.

Keywords: R2*; T2*; bronchopulmonary dysplasia; congenital diaphragmatic hernia; lung; neonatal magnetic resonance imaging.

Recommended Articles

Translate »