Ultrasound is also a method for screening prostate cancer, but it is generally combined with Prostate Specific Antigen (PSA) for a comprehensive consideration in prostate cancer screening. If prostate nodules are found during a prostate color Doppler ultrasound, the differentiation between prostate cancer and benign prostatic nodules can be aided by the variations in internal echoes, but this is only a reference and cannot be 100% certain. Thus, in clinical practice, it is also combined with PSA for a comprehensive evaluation. Generally, a PSA greater than 10 suggests a higher likelihood of malignancy. The diagnosis of prostate cancer requires a biopsy to confirm the pathology.