A	Total lung capacity
BPD	Bronchopulmonary Dysplasia
BW	Body weight
Cst	Static compliance
ED	External diameter
G	Tissue damping
GA	Gestational age
H	Tissue elastance
H&E	Hematoxylin and eosin
ID	Internal diameter
LIS	Lung injury score system
Lm	Mean linear intercept
Lmw	Mean wall transection length
P8	Primewave-8 perturbation
PAAT	Pulmonary artery acceleration time
PAET	Pulmonary artery ejection time
PAAT/PAET ratio	Pulmonary artery acceleration/ejection time ration
PN	Postnatal
PVr-V	Pressure volume perturbation
RAC	Radial alveolar count
Rn	Airway resistance
RVSP	Right ventricular systolic pressure