Quantitative CT characterization of pediatric lung development using routine clinical imaging

Abstract

Background The use of quantitative CT analysis in children is limited by lack of normal values of lung parenchymal attenuation. These characteristics are important because normal lung development yields significant parenchymal attenuation changes as children age. Objective To perform quantitative characterization of normal pediatric lung parenchymal X-ray CT attenuation under routine clinical conditions in order to establish a baseline comparison to that seen in pathological lung conditions. Materials and methods We conducted a retrospective query of normal CT chest examinations in children ages 0–7 years from 2004 to 2014 using standard clinical protocol. During these examinations semi-automated lung parenchymal segmentation was performed to measure lung volume and mean lung attenuation. Results We analyzed 42 CT examinations in 39 children, ages 3 days to 83 months (mean ± standard deviation [SD] = 42±27 months). Lung volume ranged 0.10–1.72 liters (L). Mean lung attenuation was much higher in children younger than 12 months, with values as high as −380 Hounsfield units (HU) in neonates (lung volume 0.10 L). Lung volume decreased to approximately −650 HU by age 2 years (lung volume 0.47 L), with subsequently slower exponential decrease toward a relatively constant value of −860 HU as age and lung volume increased. Conclusion Normal lung parenchymal X-ray CT attenuation decreases with increasing lung volume and age; lung attenuation decreases rapidly in the first 2 years of age and more slowly thereafter. This change in normal lung attenuation should be taken into account as quantitative CT methods are translated to pediatric pulmonary imaging.

Quantitative CT scans of lung parenchymal pathology in premature infants ages 0–6 years

“…Mean lung attenuation did not differ between BPD subjects and controls (P = 0.18); this was corrected for age at imaging in a multivariable regression model, as lung attenuation is known to decrease with age, and remained non-significant (P = 0.16). 33,34 When age was considered as a dichotomous variable (less than or greater than 1 year), the mean attenuation in BPD subjects was lower than controls in the first year (P = 0.015) but not at older ages.…”

Quantitative Assessment of Parenchymal Involvement Using 3D Lung Model in Adolescent With Covid-19 Interstitial Pneumonia

“…We measured density values on healthy right lung with Hounsfield values from −1024Hu to −543Hu similar to typical range values of pediatric lungs (8).…”

Quantification of neonatal lung parenchymal density via ultrashort echo time MRI with comparison to CT

“…We further suspect that the mean whole-lung CT-measured density is slightly lower than UTE-measured image intensity in small part because of the decrease in lung density after birth as infants age 31 ; CT-measured lung density is expected to decrease by $0.01 g/cm 3 between a chronological age of 4 weeks (mean age of the MRI cohort) to 11 weeks (mean age of the CT cohort). 31 Additionally, because structural characteristics of lung disease evolve with time, there was a small degree of subjectivity in manual ROI selections on CTs and UTE MRIs acquired at different timepoints. However, this was mitigated through matching of axial slices and in-plane anatomical positions of CT and UTE ROIs, in addition to a large number of ROIs per patient.…”