Tc-99m-DTPA aerosol and radioactive gases compared as adjuncts to perfusion scintigraphy in patients with suspected pulmonary embolism. - Alderson,P.O.; Biello,D.R.; Gottschalk,A.; Hoffer,P.B.; Kroop,S.A.; Lee,M.E.; Ramanna,L.; Siegel,B.A.; Waxman,A.D. (Radiology, 1984)