Application of digital image analysis in dental radiography for the description of periapical bone lesions: a preliminary study

The use of digital image analysis in dental radiography for the description of periapical bone lesions is described. This technique circumvents the problem of observer variability and can eventually be used for the quantitative assessment of bone lesions. Since periapical bone lesions appear on a radiography as dark areas compared to the surrounding tissues, an edge-detection method was developed to extract the boundaries between anatomy and pathology. The original data were transformed in such a way that only the outlines remained. The lesion was assumed to be demarcated by a continuous outline, so all the contour points not being part of a continuous outline were excluded. With only limited operator interaction, the lesion contour could be projected successfully onto the original image. The result was a simplified diagnostic examination process promising a higher degree of objectivity in periapical bone lesion detection. It is concluded that the results encourage further development of image processing techniques that would yield definitive detection and diagnosis of periapical bone lesions.