Impact of segmental location, fibrosis, and emphysema on predicting volume loss during lung resection

Accurate prediction of postoperative pulmonary function is essential in lung resection, particularly in patients with underlying pulmonary disease. Conventional prediction models assume uniform segmental lung volumes, which may lead to inaccuracies, especially in the presence of emphysema or fibrosis. This study aimed to assess segmental lung volume distributions using 3-dimensional computed tomography (3DCT) volumetry and evaluate the effects of emphysema and fibrosis.

We retrospectively analyzed 354 patients who underwent high-resolution 3DCT imaging before surgery between January 2020 and December 2022. Segmental lung volumes were calculated using dedicated 3-dimensional image-processing software. Patients were classified into 3 groups on the basis of computed tomography findings: normal, fibrosis, and emphysema. Segmental volume distributions were compared across groups. The Goddard score was used to evaluate the severity of emphysematous changes.

Normal lungs exhibited uneven segmental volume distribution, with bilateral S³ and left S¹⁺² being the largest. In fibrosis, lower lobe volumes were significantly reduced with compensatory redistribution to the upper lobes. Emphysema was associated with generalized lung enlargement, particularly affecting upper lobe segments, and correlated with the greater Goddard score.

Segmental lung volumes are inherently asymmetric and are significantly influenced by underlying lung pathologies. Fibrosis results in lower lobe contraction and relative upper lobe expansion, whereas emphysema causes diffuse hyperinflation, predominantly in the upper lobes. These findings highlight the limitations of traditional predictive models and underscore the clinical value of 3DCT volumetry for individualized preoperative assessment and surgical planning.