Computerized interpretation of solitary pulmonary nodules

In physicians' interpretation, morphologic characteristics of pulmonary nodules are not only important signs for the discrimination, but also important features for the diagnosis with a reasonable degree of confidence. This paper describes about the computerized interpretation system which is developed to analyze the relation between the measuring values and the morphologic characteristics, and to make clear the logic of physicians' diagnosis. We think that the four basic morphologic characteristics of the discriminative diagnosis between benign and malignant nodules exist which are: 1.the density; 2.the homogeneity; 3.the definition; and 4.the convergence. To obtain each grade of the parameters, we developed an interpretation system. On the other hand, to obtain digital feature values, we used our computer aided diagnosis (CAD) system. Interpretation experiments were performed by using 15 benign and 19 malignant cases of chest X-ray CT images. As the result of a statistical analysis, some digital features have the significant differences between benign and malignant nodules, and the morphologic characteristics have also differences. Therefore the computerized system is feasible to help physicians' interpretation to distinct between malignant and benign nodules by showing digital feature values as some references.