Resumo

MANANA, GABRIEL; ROMERO, EDUARDO  e  FORERO, MARTHA ELENA. AUTOMATIC REGISTRATION METHOD FOR THE EVALUATION OF POST SURGICAL BONE MINERALIZATION. rev.fac.med [online]. 2007, vol.15, n.2, pp.180-191. ISSN 0121-5256.

Digital subtraction is a common technique used in radiological studies of periapical lesions and other dental disorders, where treatment has to be evaluated over time. This paper shows a fast and reliable registration method for subtracting two digitized radiographs showing an unpredicted mismatch. An optimal affine transformation is found using an adaptive Genetic Algorithm (GA) as the optimizing strategy and a correlation ratio as the similarity measure. When processing pairs of standard intra-oral radiographs, the parallel GA implemented takes advantage of the CPU idle cycles of a computational grid, resulting in an application that exploits an existent infrastructure with a computational time of twenty seconds. By using an existing hardware infrastructure and software of free distribution, the proposed approach can be used in public hospitals and other institutions carrying low budget. The validation process shows that there are not significant differences between the automatic system and the manual registration. The results show that in endodontic surgery the technique of digital radiographic subtraction is a determining tool in the evaluation of post-surgical bone mineralization. Furthermore, it will be useful in clinical environments where there is not viable to follow a standardization protocol.

Palavras-chave : bone mineralization; genetics.