Effects of neonatal lung abnormalities on parenchymal R

BACKGROUND: Infants admitted to the neonatal intensive care unit (NICU) often suffer from multifaceted pulmonary morbidities that are not well understood. Ultrashort echo time (UTE) MRI is a promising technique for pulmonary imaging in this population without requiring exposure to ionizing radiation. PURPOSE: To investigate the effect of neonatal pulmonary disease on R(2)* and tissue density and to utilize numerical simulations to evaluate the effect of different alveolar structures on predicted R(2)*. STUDY TYPE: Prospective. POPULATION: 17 neonatal human subjects (5 control, 7 with bronchopulmonary dysplasia (BPD), 5 with congenital diaphragmatic hernia (CDH)). 12 male, 5 female, post-menstrual age (PMA) at MRI 39.7±4.7 weeks. FIELD STRENGTH/SEQUENCES: 1.5T/multi-echo 3D UTE MRI. ASSESSMENT: Pulmonary R(2)* 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(2)* over a range of tissue densities and tissue susceptibilities. STATISTICAL TESTS: Tests for significantly different mean R(2)* and tissue densities across disease groups were evaluated using analysis of variance (ANOVA), with subsequent pairwise group comparisons performed using t-tests. RESULTS: Lung tissue density was lower in the ipsilateral lung in CDH compared to both controls and BPD patients (both P