Study of Effect of Adaptive Histogram Equalization on Image Quality in Digital Preapical Image in Pre Apex Area

摘要

Comparing direct digital radiographs before and after processing with Adaptive Histogram Equalization (AHE) in order to detect the effectiveness of this option on diagnostic ability of images in pre apex area. In this study, 28 digital radiographs were evaluated and were scored from 1-5 for three different anatomical areas by three dentists who were expert in reading digital radiographs. Then, we processed the images with adaptive histogram equalization. Each reading was first done on unprocessed radiograph (single view) and then re-done with image processed with adaptive histogram equalization displayed beside the unprocessed version (twin view). Histogram equalization of images by the way of increasing contrast were caused in increasing the diagnostic ability of lamina dura and root apex in maxilla and lamina dura, bone trabeculation and root apex in mandible. But, quality of diagnosing of bone trabeculation in maxilla was decreased by this method. Displaying a dental image processed with adaptive histogram equalization together with unprocessed image may enhance the subjectively evaluated image quality, thereby providing extra information for the dentist. The twin view procedure facilitates the discerning of root apex in preapical images with suboptimal quality.