Imaging features of pathologically confirmed smoking-related interstitial fibrosis: identifying characteristic features to differentiate from combined pulmonary fibrosis and emphysema = 병리적으로 확진된 흡연 연관 간질성 섬유증의 영상의학적 특징: 복합 폐 섬유화와 폐기종과의 감별을 위한 특징 규명

다국어 초록 (Multilingual Abstract)

While smoking-related interstitial fibrosis (SRIF) is known to have a benign clinical course, combined pulmonary fibrosis and emphysema (CPFE) is associated with high morbidity and mortality burden.
The goal of our study is to differentiate SRIF (CPFE-histologic SRIF) from CPFE (CPFE-histologic UIP) using chest computed tomography (CT).
This retrospective study included patients who underwent surgical lung biopsy or resection between January 2015 and January 2025; all had pathologic confirmation of SRIF or UIP. CT features assessed included centrilobular and paraseptal emphysema, multiple thin-walled cysts (MTWC), honeycombing, traction bronchiectasis, subpleural ground-glass opacities (GGO)/reticulation, centrilobular ground-glass nodules, and ratio between the diameter of the pulmonary artery and that of the aorta (PA:Ao). CT features were assessed using univariable and multivariable logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was used to quantify the performance of imaging features.
A total of 106 patients with SRIF (n = 32) and CPFE (n = 74) were included. Among the evaluated CT features, MTWC (75% in SRIF, 25.7% in CPFE) and centrilobular ground-glass nodules (46.9% in SRIF, 32.4% in CPFE) were significantly more prevalent in SRIF than in CPFE, whereas honeycombing (52.7% in CPFE, 6.3% in SRIF) and PA:Ao > 1 (55.4% in CPFE, 25% in SRIF) were more frequently observed in CPFE. Centrilobular and paraseptal emphysema were observed in both groups, with higher frequencies in SRIF. Traction bronchiectasis and subpleural GGO/reticulation were present in all patients in both groups. In both univariable and multivariable analyses comparing SRIF and CPFE, MTWC was a predictive feature of SRIF (p < 0.05), whereas honeycombing and PA:Ao > 1 were predictive features of CPFE (all p < 0.05). ROC analysis of a model including MTWC, honeycombing, and PA:Ao > 1 yielded an area under the curve (AUC) of 0.880 for differentiating SRIF from CPFE.
For differentiating SRIF from CPFE, MTWC, honeycombing, and PA:Ao > 1 may serve as valuable CT features.

국문 초록 (Abstract)

흡연 연관 간질성 섬유증 (smoking-related interstitial fibrosis, SRIF)은 비교적 양호한 임상 경과를 보이는 반면, 복합 폐 섬유화와 폐기종 (combined pulmonary fibrosis and emphysema, CPFE)은 높은 이환율과 사망률을 보인다. 본 연구의 목적은 흉부 컴퓨터 단층촬영 (CT)을 이용하여 병리적으로 확진된 SRIF (CPFE-histologic SRIF)와 CPFE (CPFE-histologic UIP)를 감별하는 것이다.
2015년 1월부터 2025년 1월까지 수술적 폐생검 또는 폐절제를 시행받고 SRIF 또는 UIP로 병리학적으로 확진된 환자를 후향적으로 분석하였다. CT 소견으로는 중심소엽성 및 격막주변 폐기종, 다발성 얇은 벽의 낭종(multiple thin-walled cysts, MTWC), 벌집모양(honeycombing), 견인성 기관지확장증, 흉막하 간유리음영/망상음영, 중심소엽성 간유리결절, 폐동맥과 대동맥 직경비(PA:Ao)를 평가하였다. 단변량 및 다변량 로지스틱 회귀분석과 ROC 분석을 시행하였다.
총 106명(SRIF 32명, CPFE 74명)이 포함되었다. SRIF군에서는 MTWC와 중심소엽성 간유리결절이 CPFE군보다 유의하게 흔하였으며, CPFE군에서는 벌집모양과 PA:Ao > 1이 더 빈번하게 관찰되었다. 단변량 및 다변량 분석에서 MTWC는 SRIF의 예측 인자였고, 벌집모양과 PA:Ao > 1은 CPFE의 예측 인자였다(p < 0.05). MTWC, 벌집모양, PA:Ao > 1을 포함한 모델의 AUC는 0.880이었다.
즉, MTWC, 벌집모양, 그리고 PA:Ao > 1은 CPFE-histologic SRIF와 CPFE-histologic UIP를 감별하는 데 유용한 영상의학적 소견이다. 두 질환은 임상 경과와 예후가 상이하므로, 영상의학과 의사는 이러한 CT 소견을 숙지하면 임상의에게 적절한 정보를 제공함으로써 최적의 환자 관리에 기여할 것으로 기대된다.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• Chapter 2. Material and methods 4
• 1. Patient selection 4
• 2. CT acquisition 5
• 3. Image interpretation 6
• 4. Clinical and pathological analyses 9
• 5. Statistical analysis 9
• Chapter 3. Results 11
• 1. Patient characteristics 11
• 2. CT features of SRIF and CPFE groups 13
• 3. Univariable and multivariable logistic regression analyses for differentiating CT features of SRIF from CPFE group 16
• Chapter 4. Discussion 19
• Chapter 5. Conclusion 22