SILO2 (Signal Intensity Lung washOut)

Inclusion criteria

• Male or female adults aged ≥40 years, who have signed an Informed Consent Form prior to initiation of study related procedures.
• Current or exsmokers who have a smoking history of at least 10 pack years. (Ten pack years are defined as 20 cigarettes a day for 10 years, or 10 cigarettes a day for 20 years etc.)
• Clinical diagnosis of COPD with a post bronchodilator FEV1 30-80% of personal predicted, according to GOLD (Global Initiative for Chronic Obstructive Lung Disease) guidelines.

Exclusion criteria

• Patients with a contra-indication to MRI scanning: i.e. patients who are non MRI compatible (ferro-magnetic metallic implants, pacemakers) as per the MRI questionnaire used in clinical practice by the Unit of Academic Radiology, Royal Hallamshire Hospital, or who are unable to tolerate the MRI.
• Patients with renal conditions (as described in the Gd-DTPA (Gadovist) Summary of Product Characteristics) in which administration of Gd-DTPA MR vascular contrast agent would pose a risk.
• Patients contraindicated for treatment with, or having a history of reactions/ hypersensitivity to any of the following inhaled drugs, drugs of a similar class or any component thereof:

• long and short acting beta-2 agonists
• sympathomimetic amines
• lactose or any of the other excipients
• Resting oxygen saturation of <90% on air as determined by pulse oximetry.
• Women of child bearing potential, not using effective methods of contraception.
• Pregnant women or nursing mothers (pregnancy confirmed by positive urine pregnancy test).
• Inability to understand or comply with study procedures; including patients unable to use a dry powder inhaler (e.g. single dose dry powder inhaler Aerolyzer®) device.
• Significant pulmonary pathology other than COPD.
• Previous lung surgery.
• Patients taking oral theophyllines, PDE4 inhibitors or leukotriene antagonists, or on maintenance treatment with oral steroids.
• Patients who are participating in the active phase of a supervised pulmonary rehabilitation program.
• Patients with a history of long QT syndrome or whose QTc measured (Fridericia method) is prolonged (>450 ms for males and females) or a history of dysrhythmia other than established chronic atrial fibrillation.
• Subjects with unstable cardiac disease which in the opinion of the investigator exposes them to significant additional risk. .
• Heart failure which is either unstable or the predominant cause of the subject's dyspnea.
• Patients who, in the judgment of the investigator, had a clinically relevant laboratory abnormality or a clinically significant condition such as (but not limited to):

• Any condition which might compromise patient safety or compliance, interfere with evaluation, or preclude completion of the study.
• Use of other investigational drugs at the time of enrollment, or within 30 days or 5 half-lives of study enrollment (whichever is longer).
• Patients unable to use a dry powder inhaler (e.g. single dose dry powder inhaler Aerolyzer®) device.