Association with chest CT measured pectoralis muscle area and outcomes of non-tuberculosis mycobacterial pulmonary disease

Background The prevalence and burden of nontuberculous mycobacterial pulmonary disease (NTM-PD) are increasing globally, yet the prognostic factors influencing its progression remain inadequately understood. This study evaluates the prognostic significance of pectoralis muscle area (PMA) in predicting the progression of NTM-PD. Methods From August 2018 to December 2023, we retrospectively collected 237 patients with NTM-PD at a single tertiary referral center. PMA were measured using AI-based software on chest CT images obtained at diagnosis at the level of mid-T4. Radiological progression of NTM-PD was assessed using a segment-based CT scoring system. Uni- and multivariable logistic regression analysis was used to assess the association between PMA and NTM-PD. Results A total of 77 patients (39 male and 38 female) were finally enrolled in the study. Among them, 32 patients (41.2 %) showed radiologic progression. The radiologic progression group exhibited more in females (65.6 % vs. 34.4 %, p = 0.029), higher initial total (10.0 vs. 7.2, p = 0.002) and bronchiectasis CT scores (3.6 vs. 2.2, p = 0.001) and smaller PMA (23.7 vs. 31.2 cm 2 , p Conclusions This study demonstrated that small PMA might be a potential risk factor of the radiological progression of NTM-PD.