Research to Evaluate a Possible Relation Between Values Obtained After Processing CT Images, Lung Function Tests and the Experience of the Patient During an Exacerbation in COPD Patients.

Inclusion Criteria:

• Male or female, ≥ 40 years old
• COPD as defined by the global Initiative on obstructive lung disease4
• Post-bronchodilator FEV1/FVC < 70% AND post-bronchodilator FEV1 <80%pred as documented in the last 5 years.
• Smoking history of at least 10 pack-years
• At entry in the study experiencing an exacerbation defined as an acute change in the patient 's baseline dyspnea, cough, and/or sputum that is beyond normal day to day variations, and that necessitates the administration or doubling of systemic corticosteroid treatment.
• Patients must be able to understand and complete protocol requirements, instructions, questionnaires and protocol-stated restrictions.
• Written and signed informed consent

Exclusion Criteria:

• Pregnant or lactating females
• Patient diagnosed with asthma
• Patient with pneumonia as defined radiologically at the start of the exacerbation
• Patient with a history of or presence of lung cancer
• Patient with an indication for non-invasive ventilation
• Patient unlikely to comply with the protocol or unable to understand the nature, scope and possible consequences of the study.
• Patient who received any investigational new drug within the last 4 weeks prior to visit 1.