Automated diagnosis system for dental diseases using functions of the humanvisual system

本研究的目的是从普通观察者那里获得人类视觉系统的功能，并将其作为一个半自动系统应用于邻面龋诊断。1.人类视觉系统对邻面龋诊断的影响本实验使用两种类型的记录介质-模拟胶片和数字成像胶片。材料包括27颗从青少年中拔除的第三磨牙，使用这些设备和材料，共获得594个数字图像和189个胶片X线照片。七位口腔放射科医生一次评价一个系列。受试者工作特性（ROC）曲线，在每个曝光的记录system.In这个实验中，它得出的结论是，辐射对比记录介质确定龋齿诊断所需的信息。2.邻面龋半自动诊断系统利用上述实验的结果，我们开发了邻面龋半自动诊断系统，该系统的算法如下：1）提取近端表面的轮廓2）沿着水平轴的灰度级测量3）沿沿着近端表面的灰度级轮廓4）与轮廓拟合的多项式曲线5）从函数中提取参数6）使用上述参数的龋齿判别函数从半自动系统获得的诊断准确性与观察者的诊断准确性相当。特别是，它是最有效的系统中使用自动曝光补偿programmes.ConclusionThe目前的半自动系统可能是有用的邻面龋诊断，特别是在系统与自动曝光补偿。

The purpose of this project was to obtain the function of the human visual system from the average observer and apply it to the proximal caries diagnosis as a semi-automated system.1.Effects of the human visual system on the proximal caries diagnosisTwo types of recording media-the analogue film and the digital imaging films- were used for this experiment. The materials consisted of 27 third molar teeth extracted from young adolescents.Using these equipments and materials, a total of 594 digital images and 189 film radiographs were obtained. Seven oral radiologists evaluated one series at one time. Receiver operating characteristic (ROC) curves were obtained at each exposure of the recording system.In this experiment, it was concluded that radiation contrast registered by the recording medium determines the information required for the caries diagnosis. The effect of human visual system on the caries diagnosis was minimum.2.Semi-automated system for the proximal caries diagnosisUsing the results from the above experiment, we have developed the semi-automated system for the proximal caries diagnosis.In this system, the algorithm for the caries diagnosis is following :1) extraction of the contour of the proximal surface2) gray level measurement along the horizontal axis3) gray level profile along the proximal surface4) polynomial curve fitting to the profile5) extraction of the parameters from the function6) discrimination function for the caries using the above parametersDiagnostic accuracy obtained from the semi-automated system was comparable to that of the observers. Especially, it was most effective in the system using automated exposure compensation program.ConclusionThe present semi-automated system may be useful for the proximal caries diagnosis, especially in the system with automated exposure compensation.