Longitudinal Study of Helium-3 and Xenon-129 Magnetic Resonance Imaging

Inclusion Criteria:

• Subjects male and female aged 50-85 with either A) a clinical diagnosis of COPD orBronchiectais or B) >10 pack/year smoking history

• Subject understands the study procedures and is willing to participate in the studyas 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 bestacceptable spirograms have FEV1 values that do not vary more than 5% of the largestvalue 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 thewritten 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 orother condition(s) that might prevent performance of the MRI, such as severeclaustrophobia.

• Subject has an implanted mechanically, electrically or magnetically activated deviceor any metal in their body which cannot be removed, including but not limited topacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysmclips, bioprosthesis, artificial limb, metallic fragment or foreign body, shunt,surgical staples (including clips or metallic sutures and/or ear implants.)