Prostate cancer can generally be detected through ultrasound, as it reveals nodules in the prostate. By examining the internal echoes of these nodules, one can differentiate between benign and malignant prostate conditions. Thus, in foreign countries, ultrasound, specifically prostate color Doppler ultrasound examinations, are used as a screening method for prostate cancer. In China, screening methods also include traditional digital rectal examinations and generally involve blood tests for specific prostate tumor markers, namely PSA. These tests are combined with prostate ultrasound for a comprehensive assessment.