Male and female subjects age 18-85 with lung disease will inhale 5ml/kg (patient body weight) hyperpolarized helium and will be scanned using MRI at 3 Tesla, to evaluate the Apparent Diffusion Coefficient (ADC), ventilation defect volume and percent ventilation.

Briefly, during a one to two hour visit, subjects will provide written informed consent and then undergo:

1. brief medical history and vital signs,
2. full pulmonary function tests,
3. proton MRI,
4. spin-density and/or diffusion weighted Helium-3 MRI.

Full pulmonary function tests including spirometry, plethysmography and diffusing capacity of carbon monoxide (DLCO), Lung Clearance Index (LCI) and Airwave Oscillometry (AO) will be performed according to ATS guidelines. MedGraphics Elite Series, MedGraphics Corporation. St. Paul, MN USA and/or nDD EasyOne Spirometer, nDD Medical Technologies Inc. Andover, MA USA will be used. All measurements will be performed in the Pulmonary Function Laboratory at Robarts Research Institute.

Inclusion Criteria:

• Subjects male and female aged 18-75 with diagnosed lung disease including but not limited to: asthma, emphysema, Chronic Obstructive Pulmonary Disease (COPD), bronchiectasis, sarcoidosis, pulmonary fibrosis, alpha 1-anti-trypsin deficiency, lymphangioleiomyomatosis (LAM) and Bronchiolitis obliterans organizing pneumonia (BOOP)
• 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 able to perform reproducible pulmonary function testing (i.e., the 3 best acceptable spirograms have Forced Expiratory Volume in one second (FEV1) values that do not vary more than 5% of the largest value or more than 100 ml, whichever is greater.)
• FEV1 >25% predicted
• Forced Vital Capacity (FVC) > 25% predicted and >0.5Liters

Exclusion Criteria:

• Subject with a contraindication to Magnetic Resonance Imaging (i.e. ferrous implants, cardiac pacemakers). This will be determined through a screening form.
• Subject has a daytime room air oxygen saturation <90% while lying supine.
• Subject unable to tolerate MRI due to patient size and/or known history of claustrophobia.
• Subject previously injured by a metallic object that was not removed.
• 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.)