Evaluation of competence in the interpretation of chest radiographs.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine relative rates of missed diagnoses for radiologists as a measure of competence in interpreting chest radiographs. MATERIALS AND METHODS: Cases involving differing interpretations of chest radiographs were collected from January 1994 through December 1999 by faculty (chest and nonchest radiology specialists) in an academic radiology department. A quarterly peer-review process designated cases months after the fact, and anonymously, as no miss or as class I (nondiagnosable), class II (very difficult diagnosis), class III (should be diagnosed most of time), or class IV (should almost always be diagnosed) missed diagnoses. The rates and classes of missed diagnoses were compared among chest faculty and for the nonchest radiology specialists as a group. RESULTS: Chest radiologists read 184,977 studies, and nonchest radiologists read 300,684 studies. Of these, 243 missed diagnoses were classified (classes I and II, 184 cases; class III, 50; and class IV, nine). No difference was detected in the rate of class III and IV misses among chest faculty, but nonchest faculty had significantly more class III (P = .022) and class IV misses (P = .016). CONCLUSION: Random sampling of differing interpretations can yield a relative rate of missed diagnoses for radiologists. No difference was detected in clinically important misses (ie, classes III and IV) among chest radiologists, but a statistically significantly higher rate of seemingly obvious misdiagnoses was found for nonchest specialty radiologists. Potential biases may have influenced this analysis, including disease prevalence, sampling, clinical factors, observer variability, and truth-in-diagnosis.

Comparison of upright inspiratory and expiratory chest radiographs for detecting pneumothoraces.

OBJECTIVE: Expiratory films are regarded as being superior to inspiratory films for pneumothorax detection, yet this has not been proved. In the current study, we compared inspiratory versus expiratory chest radiographs for pneumothorax detection. MATERIALS AND METHODS: Eighty-five paired inspiratory and expiratory radiographs with pneumothoraces and 93 pairs without pneumothoraces were randomly arranged and reviewed independently by three radiologists. A score of 1-5 was assigned for each hemithorax (5 = definite pneumothorax, 1 = definitely no pneumothorax). Results were compared for inspiration and expiration using receiver operating characteristic (ROC) analysis. RESULTS: The average area under the ROC curves for all readers was .973 for inspiration and .972 for expiration (nonsignificant). McNemar's test and an alpha level of .05 also yielded no significant difference in sensitivity and specificity. Four of the 85 cases were scored as definite pneumothorax on inspiration and as definitely not on expiration by all readers, and three of the 85 cases were scored as definite pneumothorax on expiration and as definitely not on inspiration. CONCLUSION: Inspiratory and expiratory upright films are equally sensitive for pneumothorax detection. Given the limitations of expiratory films, inspiratory films are recommended as the initial examination of choice for pneumothorax detection.