Abstract
Unless the clinical trial is done, it is difficult realistically to obtain the data which has the signature of subject. Furthermore, it is serious for the Japanese manufacturer to obtain the approval of PMDA, when they cannot use the same technique as the American manufacturer acquired the approval of FDA. With the result of our two large-scale reading tests by ROC analysis, the usefulness of CAD was not proven, because the difference of the reading power of among doctors was larger than with or without of CAD, and the reading doctors endeavored in order not to overlook in the reading test. Then, for the approving CAD the definition of CAD and establishment of evaluation method are necessary.