Volumetric characteristics of idiopathic pulmonary fibrosis lungs: Computational analyses of high-resolution computed tomography images of lung lobes

Bora Sul, Lucia Flors, Joanne Cassani, Michael J. Morris, Jaques Reifman*, Talissa Altes, Anders Wallqvist

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Background: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease involving progressive degeneration of lung capacity. Current diagnosis of IPF heavily relies on visual evaluation of fibrotic features in high-resolution computed tomography (HRCT) images of the lungs. Although the characteristics of this disease have been studied at the molecular and cellular levels, little is known about the mechanical characteristics of IPF lungs inferred from HRCT images. To this end, we performed a pilot study to investigate the radiographic and volumetric characteristics of lungs in subjects with IPF. Methods: We collected HRCT images of healthy (N = 13) and IPF (N = 9) lungs acquired at breath-holds after full inspiration (expanded state) and full expiration (contracted state). We performed statistical analyses on Hounsfield unit (HU) histograms, lobar volumes (V: Lobe volume normalized by the lung volume), and lobar flows (Q: The difference in lobe volume divided by the difference in lung volume between the expanded and contracted states). Results: Parameters characterizing the HU histograms (i.e., mean, median, skewness, and kurtosis) significantly differed between healthy and IPF subjects, for all lobes in both expanded and contracted states. The distribution of V across lobes differed significantly between the groups in both states. The distribution of Q also differed significantly between the groups: Q values of the lower lobes for the IPF group were 33% (right) and 22% (left) smaller than those for the healthy group, consistent with the observation that radiographic scores were highest in the lower lung section in IPF. Notably, the root-mean-squared difference (RMSD) of Q, a measure of distance from the mean value of the healthy group, clearly distinguished the IPF subjects (RMSD of Q > 1.59) from the healthy group (RMSD of Q < 0.67). Conclusion: This study shows that lung volume and flow distribution change heterogeneously across the lung lobes of IPF subjects, with reduced capacity in the lower lobes. These volumetric changes may improve our understanding of the pathophysiology in IPF lungs.

Original languageEnglish
Article number216
JournalRespiratory Research
Issue number1
StatePublished - 11 Oct 2019
Externally publishedYes


  • Idiopathic pulmonary fibrosis
  • Lobar flow distribution
  • Quantitative HRCT analysis


Dive into the research topics of 'Volumetric characteristics of idiopathic pulmonary fibrosis lungs: Computational analyses of high-resolution computed tomography images of lung lobes'. Together they form a unique fingerprint.

Cite this