CT pulmonary angiography for the detection of pulmonary embolism: interobserver agreement between on-call radiology residents and specialists (CTPA interobserver agreement)

Purpose: The aim of this study was to prospectively determine interobserver agreement between on-call radiology residents and specialists in the interpretation of computed tomographic pulmonary angiography (CTPA).Methods: CTPA examinations obtained between January 2002 and March 2003 were interpreted by a radiology resident on call and by two radiology specialists. Agreement was assessed using percentage of agreement between interpreters and by the kappa coefficient. Sensitivity of residents' interpretations was calculated by relating them to the interpretation of Specialist 1, which served as the gold standard. Results: Of the 81 CTPA examinations evaluated, there was agreement of 93% and 91% for the diagnosis of pulmonary embolism (PE) and of 97% and 85% for the exclusion of PE with Specialist 1 and 2, respectively. The concordance between residents' interpretations and those of Specialist 1 was very high (kappa=.8), and with those of Specialist 2 was high (kappa=.7). In all cases of agreement between the two specialists, there was complete agreement between the specialists' and the residents' intepretations. Conclusions: Our study showed good to very good agreement of residents' interpretations with each of the radiology specialists. Therefore, relying on the residents' preliminary interpretations during after-hour calls is reasonable.