absorptiometry dual photon absorptiometry 2013-03-22T16:13:55Z A method used to measure, for instance, bone mineral content in the axial skeleton, particularly the lumbar spine, by comparing transmission of the two separate photoelectric energy peaks (gamma rays) emitted by gadolinium 153 through both soft and bone tissues. Because energy at the two peaks is dissipated differentially the soft-tissue component can be subtracted from the total to determine bone-specific absorption. DPA JSmith MMO:0000384 measurement_method_ontology