1. From the Centre for Clinical Research in Emergency Medicine, Harry Perkins Institute of Medical Research, Royal Perth Hospital, and the University of Western Australia (S.G.A.B., E.L.B., C.A.R.), Royal Perth Hospital Imaging (K.V.L.) and the Respiratory Department (E.L.B., Q.A.S.), Royal Perth Hospital, the Department of Respiratory Medicine, Sir Charles Gairdner Hospital (Y.C.G.L.), and the Centre for Respiratory Health, School of Medicine and Pharmacology, University of Western Australia (Y.C.G.L.),...