Automatic quantitative computed tomography measurement of longitudinal lung volume loss in interstitial lung diseases

Abstract

Objectives To compare the lung CT volume (CTvol) and pulmonary function tests in an interstitial lung disease (ILD) population. Then to evaluate the CTvol loss between idiopathic pulmonary fibrosis (IPF) and non-IPF and explore a prognostic value of annual CTvol loss in IPF. Methods We conducted in an expert center a retrospective study between 2005 and 2018 on consecutive patients with ILD. CTvol was measured automatically using commercial software based on a deep learning algorithm. In the first group, Spearman correlation coefficients (r) between forced vital capacity (FVC), total lung capacity (TLC), and CTvol were calculated. In a second group, annual CTvol loss was calculated using linear regression analysis and compared with the Mann–Whitney test. In a last group of IPF patients, annual CTvol loss was calculated between baseline and 1-year CTs for investigating with the Youden index a prognostic value of major adverse event at 3 years. Univariate and log-rank tests were calculated. Results In total, 560 patients (4610 CTs) were analyzed. For 1171 CTs, CTvol was correlated with FVC (r: 0.86) and TLC (r: 0.84) (p < 0.0001). In 408 patients (3332 CT), median annual CTvol loss was 155.7 mL in IPF versus 50.7 mL in non-IPF (p < 0.0001) over 5.03 years. In 73 IPF patients, a relative annual CTvol loss of 7.9% was associated with major adverse events (log-rank, p < 0.0001) in univariate analysis (p < 0.001). Conclusions Automated lung CT volume may be an alternative or a complementary biomarker to pulmonary function tests for the assessment of lung volume loss in ILD. Key Points • There is a good correlation between lung CT volume and forced vital capacity, as well as for with total lung capacity measurements (r of 0.86 and 0.84 respectively, p < 0.0001). • Median annual CT volume loss is significantly higher in patients with idiopathic pulmonary fibrosis than in patients with other fibrotic interstitial lung diseases (155.7 versus 50.7 mL, p < 0.0001). • In idiopathic pulmonary fibrosis, a relative annual CT volume loss higher than 9.4% is associated with a significantly reduced mean survival time at 2.0 years versus 2.8 years (log-rank, p < 0.0001).

GLPG1205 for idiopathic pulmonary fibrosis: a phase 2 randomised placebo-controlled trial

“…This is in line with IPF disease distribution and consistent with numerical trends seen in FVC, supporting treatment potential of GPR84 antagonism. While lung volume by HRCT is not validated in clinical trials, lung volume has been shown to be strongly correlated with HRCT and FVC [ 17 , 19 ]. Results from the PINTA trial support the use of lung volume assessment by HRCT as a measure of IPF disease progression alongside FVC in IPF studies, pending validation as an end-point, which could help further contextualise low or moderate numerical change in FVC in clinical trials with small patient populations.…”

Assessment of COVID-19 lung involvement on computed tomography by deep-learning-, threshold-, and human reader-based approaches—an international, multi-center comparative study

“…To quantify lung involvement using a deep-learning-based approach, an IntelliSpace Discovery Plugin was used. This plugin is a pre-release of the CT Pulmo Auto Results application available in the CE-certified IntelliSpace Portal 11.1.6 and higher releases (Philips Healthcare) ( 16 , 27 , 28 ). No changes have been applied to the final, commercially available software; i.e., the segmentation software used in this publication fully resembles the CT Pulmo Auto Results application release.…”

Interstitial Lung Disease Associated with Systemic Sclerosis

“…57 CT can also contribute to measuring lung volumes as shown in patients with various ILDs, including SSc-ILD. 58 The CT scan may also reveal esophageal dilatation (which is pathological when it exceeds one-third of the height of the thorax) or, more rarely, soft tissue calcifications (which may also be seen in polymyositis), pointing to SSc in the context of unexplained ILD. 59,60 Mediastinal lymph node enlargement may be present but is generally multiple, not bulky, moderately hypermetabolic, and located at the base of the mediastinum lymph node chains.…”