Diagnosis of bone lesions by subtraction radiography

Examiner diagnostic accuracy and response times were compared using subtraction and conventional radiography in a dog model. Osseous lesions were induced interproximally and through the mandibular buccal bone interradicularly and radicularly. Standardized preoperative and postoperative conventional radiographs of the induced lesions were compared to subtraction images of the same sites by 11 dentists. Examiners using the subtraction technique demonstrated improved diagnostic performance (P less than 0.001) and response times (P less than 0.001). Additionally, this method yielded a 30% reduction in equivocal diagnostic decisions. Data from this study suggest that subtraction radiography is a sensitive and accurate method to detect osseous lesions associated with periodontal diseases.