Clinical application of biological fingerprints extracted from averaged chest radiographs and template-matching technique for preventing left–right flipping mistakes in chest radiography Abstract We aimed to evaluate the identification performance achieved using biological fingerprints extracted from averaged chest radiographs and template-matching techniques for the prevention of left–right flipping mistakes. We produced averaged chest radiographs for each sex by averaging 100 posteroanterior chest radiographs. Further, 400 and 566 chest radiographs were used in consistency and validation tests, respectively, and they were flipped horizontally to produce flipped chest radiographs under the assumption that the left–right flipping mistake occurred. The correlation values obtained with chest radiographs and those obtained with flipped chest radiographs were calculated. When we used correlation indices calculated from the correlation values from four biological fingerprints except for the lung apex, 96.5% (386/400) and 95.8% (542/566) of the left or right sides were identified correctly in the consistency and validation tests, respectively. This result indicates that our proposed method would be promising for the prevention of left–right flipping mistakes.