Three-dimensional computed tomography lung volume analysis associates with the presence of pathological usual...

Pathological usual interstitial pneumonia (UIP) is crucial in predicting the prognosis of fibrotic interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis. However, pathological UIP assessment relies solely on lung biopsy, and no simple, non-invasive approach currently exists. In this study, we aimed to investigate its association with pathological UIP using a novel three-dimensional computed tomography (3D-CT) method.

This retrospective study analyzed 120 patients who underwent transbronchial lung cryobiopsy for ILD diagnosis. Clinical data, CT scans, pulmonary function test results, and pathological findings were collected. The bilateral lower lobe volume to total lung volume ratio (hereafter, b-LLV/TLV ratio) was assessed using 3D-CT. Logistic regression analysis evaluated the association between pathological UIP and patient characteristics, including the b-LLV/TLV ratio.

Among the 120 patients, 53 (44 %) had pathological UIP. Univariate analysis showed that UIP was significantly associated with older age (71.0 vs. 65.0 years, P = 0.0033) and b-LLV/TLV ratio (36.9 % vs. 41.6 %, P = 0.0069). Multivariate analysis confirmed that b-LLV/TLV ratio (OR = 0.9053; 95 % CI, 0.8461-0.9596; P = 0.0005) was an independent predictor of UIP, which was unaffected by age (OR = 1.0690; 95 % CI, 1.0224-1.2435; P = 0.0028) or sex (OR = 3.5868; 95 % CI, 1.3106-10.7061; P = 0.0123). Notably, UIP showed no association with the pulmonary function test results, whereas the b-LLV/TLV ratio was more effective in predicting UIP.

A reduced b-LLV/TLV ratio was significantly associated with pathological UIP, suggesting that 3D-CT lung volume analysis may serve as a noninvasive diagnostic tool.