Neonatal lung disease of prematurity (bronchopulmonary dysplasia, BPD) is a serious pulmonary condition. However, there is little understanding of the underlying structural pathologies or relationship to disease trajectories. Pulmonary MRI of neonatal BPD is an emerging research technique, with preliminary correlation to clinical outcomes, but assessment of parenchyma has been limited to manual radiological reads. We present quantitative lung-density measures in 55 patients from ultrashort echo-time (UTE) MRI, with strong correlation to clinical BPD severity and a current BPD reader scoring system. This technique distinguishes between patients with varying lung-density phenotypes, which in the future may help inform treatment strategies.