Background: Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of chronic morbidity and mortality worldwide. There is debate about diagnosis and management of COPD because it was described as complex syndrome accounting for various pulmonary and extrapulmonary abnormalities. As a result, there is consensus that both clinical evaluation and pulmonary function tests (PFTs) data by themselves do not adequately describe the complexity of the disease. The chest radiograph is the sole imaging examination recommended for the routine evaluation of these patients by the physicians guidelines (GOLD guidelines),which, however, are also debating on the utility of computed tomography (CT) in this setting. Indeed, a number of studies reported a dramatic increasing use of CT of the chest for COPD assessment, in both clinical and research settings. COPD assessment by CT seems to improve the accuracy and completeness of the clinical evaluation of these patients. Nevertheless, the clinical utility of CT has yet to be proved by prospective studies or defined by guidelines.

Objectives: To evaluate the change in the diagnosis and management of COPD when multiple CT-derived information is added to pre-test evaluation.

Methods: Four pulmonologists with various expertise in the field will review clinical data, PFTs results, and chest radiographs of 200 consecutive COPD patients diagnosed according to current guidelines. Therefore, after two months from the first evaluation, the pulmonologists will review the clinical and PFTs records with comprehensive information about low-dose CT (LDCT) previously performed in a week from the chest radiograph. Information about LDCT findings will include qualitative assessment by an experienced chest radiologist and quantitative analysis by means of an innovative 3D imaging dedicated software. Phenotype assessment and patient care decisions (e.g. therapeutic and follow-up strategies, need of additional tests etc.) will be recorded before and after assimilation of LDCT data.

Expected results: This evidence-based prospective study will test the impact of chest LDCT on management of COPD patient. In addition, the level of agreement between pulmonologists in terms of diagnosis and therapeutic strategies will be assessed. Furthermore, the study will evaluate the need for additional tests referable to LDCT information and their impact on the health care system (e.g. in terms of additional costs).

Inclusion Criteria:

• COPD diagnosis according to ATS/ERS criteria (post-bronchodilator FEV1 to FVC ratio < 0.7);
• clinical stability, namely no acute exacerbation in the previous 4 weeks;
• clinical indication for low-dose computed tomography (LDCT) to investigate bronchiectasis, interstitial lung disease, or pulmonary hypertension.

Exclusion Criteria:

• pregnancy;
• patients with congenital or acquired immune deficit;
• patients with lung transplantation;
• patients under oxygen therapy;
• patients with diagnosis of asthma or other clinically relevant pulmonary disease other than COPD.