Satisfaction of Search in Periapical Radiograph Interpretation

Several studies in radiology and medicine have evaluated the satisfaction of search (SOS) error effect in chest radiography, abdominal radiography, osteoradiology, and patients with multiple trauma. No research to date has been published evaluating the possible existence of the SOS error phenomenon made during dental periapical radiograph interpretations. The purpose of the present pilot study was to determine if an SOS error effect exists when dental clinicians interpret periapical radiographs. The null hypothesis was that the detection accuracy will be the same or will improve for the detection of native lesions in the presence of an added abnormality. The alternative hypothesis is that there will be a decrease in detection accuracy for native lesions in the presence of an added abnormality.

Six images were selected to be part of the present experiment. One of the 6 images served as the positive control, and another image served as the negative control. Four images, each including a single subtle carious lesion, were selected to represent the experimental images. The single subtle carious lesion present within the 4 experimental radiographs served as the native pathology, and an abnormality such as a periapical radiolucency, resorption, inadequate nonideal root canal obturation material, or recurrent carious lesion was artificially inserted into the image as the added pathology. Thus, the second set of images consisted of the same 4 images containing the native pathology including an added pathology that was inserted into the image using Adobe Photoshop CS6 (Adobe, Inc, San Jose, CA). Purposive sampling was obtained from 16 examiners including residents from endodontics and periodontics as well as alumni and faculty from the Saint Louis University Center for Advanced Dental Education, St Louis, MO. Each observer participated as a subject during 2 time-separated sessions. Each session was separated by a minimum period of 3 months' duration in order to prevent memory bias. Before starting each interpretation session, the participants were given verbal instructions. Subjects were instructed to provide a location (by tooth number), identify, and rate the presence of all suspected pathology using a Likert scale of 1-5 (1: definitely normal, 2: probably normal, 3: possibly abnormal, 4: probably abnormal, and 5: definitely abnormal). In the second session, the radiographs that were initially presented containing only the native lesion were presented again with the added abnormality, and vice versa. The observers' reports and confidence ratings were recorded and analyzed. Ratings of 3-5 were considered as being positive for the presence of pathology.

A true SOS error occurs when the presence of the native lesion is reported correctly without an added abnormality but is not reported (missed) in the presence of an added abnormality. In our study, a true SOS error occurred in 13 of the 64 interpretation sets (20.31%). There was a total of 64 expected native lesions present within the 4 native images viewed by 16 observers. In the 4 added images, there was a total of 64 expected added findings. In the images containing only native lesions, the observers reported 30 of the 64 expected native lesions. In the images containing an artificially added abnormality, the observers reported 58 of the 64 expected added abnormalities and 25 of the 64 expected native lesions. Observers reported fewer native lesions in the presence of an added abnormality.

The current investigation demonstrated the existence of the SOS effect during periapical radiographic interpretations. In 20.31% of interpretations, a true SOS error occurred. This study is clinically relevant because it can help clinicians in reducing false-negative errors made during radiographic interpretation, thus preventing misdiagnosis.