Computer model for studying the detection of intraoral pathology using digital radiography.

摘要

Caries and periodontal disease are two major pathological conditions treated by dentists. Intraoral radiography is a widely used method for detecting these diseases. However, conventional radiography can provide a reliable diagnosis only after a substantial mineral loss has occurred. Newer techniques utilizing digital radiography may make it possible to perform a diagnosis at an earlier stage. A mathematical tool that simulates various aspects of intraoral radiography has been developed to study and evaluate these digital techniques as they become available. The five essential components in such a simulation process, namely the x-ray spectrum, the attenuation within relevant materials (enamel, dentin, bone and soft-tissue), scatter, noise, and the response characteristics (grey levels versus exposures) of a digital intraoral detector have been objectively modeled and validated in this research project. These components are inserted into a projection program as different alterable modules to create simulated radiographs from a virtual phantom. The utilization of the program was demonstrated for three selected tasks: (1) to study the effect of scatter on the perceptibility of detail, (2) to simulate the process of digital tomosynthesis, and (3) to evaluate the effect of digital subtraction on the detectability of virtual periodontal lesions created by modifying data from micro CT scans of two hemi-mandibles. This computer model of the radiographic process shows promise for comparing existing techniques and for evaluating any new novel techniques in intraoral digital radiography that may be developed in the future.