Yu S, Kumamaru KK, George E, Dunne RM, Bedayat A, Neykov M, Hunsaker AR, Dill KE, Cai T, Rybicki FJ. Classification of CT pulmonary angiography reports by presence, chronicity, and location of pulmonary embolism with natural language processing. J Biomed Inform. 2014 Dec; 52:386-93.