Subjects male and female aged 50-85 with a clinical diagnosis of chronic obstructive pulmonary disease (COPD) or Bronchiectasis, or those with ≥ 10 pack/years smoking history will be imaged with CT and MRI for the development of tools to quantify and validate longitudinal in vivo magnetic resonance imaging phenotypes of COPD and Bronchiectasis.

COPD patients will be stratified into four groups: Gold Stage 0, Gold Stage I, Gold Stage II, and Gold Stage III. During a single 2-2 ½ hour visit, patient subjects will perform some or all of: 1) spirometry pre-and-post salbutamol and plethysmography, Lung Clearance Index, Airway Oscillometry (Airwave Oscillometry measures the mechanics of the respiratory system by superimposing a gentle multi-frequency airwave onto the patient's respiratory airflow. Measurements take no longer than 16 seconds and the patient simply breathes normally into a disposable mouthpiece for the duration of the test.) 2) 6MWT (including Borg questionnaire pre-and post-walk), 3) health status evaluation using a self-administered SGRQ and MMRC (Modified Medical Research Council dyspnea scale) 4) CT, and, 5) 3He MRI.

Subjects will first provide written informed consent and then be screened for MRI compatibility and will complete: 1) Spirometry pre-salbutamol, SGRQ after inhaling 2-4 puffs (200-400μg) of the short-acting bronchodilator (eg. Salbutamol), 2) MRI, 3) CT. (Subjects will be taken by wheelchair to and from University Hospital, LHSC to decrease the potential for dynamic hyperinflation), 4) plethysmography and spirometry within 1 ½ hours of salbutamol. Vital signs will be performed. Because it is impossible to schedule imaging at the same time-point post-bronchodilator, subjects will be randomized to MR or CT 30 minutes post-salbutamol (1:1 ratio), to minimize bias.

Inclusion Criteria:

• Subjects male and female aged 50-85 with either A) a clinical diagnosis of COPD or Bronchiectais or B) >10 pack/year smoking history
• Subject understands the study procedures and is willing to participate in the study as indicated by signature on the informed consent
• Subject must be able to perform a breathhold for 16s.
• Subject is judged to be in otherwise stable health on the basis of medical history
• Subject is ambulatory and can perform the 6MWT
• Subject able to perform reproducible pulmonary function testing (i.e., the 3 best acceptable spirograms have FEV1 values that do not vary more than 5% of the largest value or more than 100 ml, whichever is greater.)
• FEV1 >25% predicted
• FVC > 25% predicted and >0.5L

Exclusion Criteria:

• Patient is, in the opinion of the investigator, mentally or legally incapacitated, preventing informed consent from being obtained, or cannot read or understand the written material.
• Subject has a daytime room air oxygen saturation <90% while lying supine.
• Patient is unable to perform spirometry or plethysmography maneuvers
• Patient is pregnant
• In the investigator's opinion, subject suffers from any physical, psychological or other condition(s) that might prevent performance of the MRI, such as severe claustrophobia.
• Subject has an implanted mechanically, electrically or magnetically activated device or any metal in their body which cannot be removed, including but not limited to pacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment or foreign body, shunt, surgical staples (including clips or metallic sutures and/or ear implants.)