Evaluation of the usefulness of modified biological fingerprints in chest radiographs for patient recognition and identification.

We have been developing an image-searching method to identify misfiled images in a PACS server. Developing new biological fingerprints (BFs) that would reduce the influence of differences in positioning and breathing phases to improve the performance of recognition is desirable. In our previous studies, the whole lung field (WLF) that included the shadows of the body and lungs was affected by differences in positioning and/or breathing phases. In this study, we showed the usefulness of a circumscribed lung with a rectangular region of interest and the upper half of a chest radiograph as modified BFs. We used 200 images as hypothetically misfiled images. The cross-correlation identifies the resemblance between the BFs in the misfiled images and the corresponding BFs in the database images. The modified BFs indicated better results than did WLF in a receiver operating characteristic analysis; therefore, they could be used as identifiers for patient recognition and identification.