1. A computer aided diagnosis (CAD) apparatus, comprising: an image receiver configured to sequentially receive images; a memory configured to store instructions; and at least one processor, that upon executing the stored instructions, configured to: detect at least one region of interest (ROI) from a current image, determine whether at least one ROI, that is erroneously detected, of the detected at least one ROI exists based on an ROI size transition information, and output visual information indicating the at least one ROI except for the erroneously detected at least one ROI based on a result of the determination.