1 Respirology Division, University of British Columbia, Vancouver, BC, Canada; St. Paul's Hospital, Vancouver, BC, Canada; University of British Columbia Institute for Heart + Lung Health, Vancouver, BC, Canada. Electronic address: pman@providencehealth.bc.ca.
2 Department of Radiology, University of British Columbia, Vancouver, BC, Canada; St. Paul's Hospital, Vancouver, BC, Canada.
3 Division of Cardiology, University of British Columbia, Vancouver, BC, Canada; St. Paul's Hospital, Vancouver, BC, Canada.
4 Respirology Division, University of British Columbia, Vancouver, BC, Canada; St. Paul's Hospital, Vancouver, BC, Canada; University of British Columbia Institute for Heart + Lung Health, Vancouver, BC, Canada.