Applications of prostate ultrasonography.
 Transrectal ultrasonography is a relatively new imaging modality that may be useful in the evaluation and management of patients with prostate cancer.
 Although cancer may have a characteristic appearance, it cannot always be reliably differentiated from benign conditions.
 While this technique has clinical applications in staging, monitoring tumor response to therapy, and assisting in biopsy, it is unclear as to whether useful information is obtained in the evaluation of patients with palpable disease.
 The role of transrectal ultrasonography in patients with nonpalpable disease or as a screening tool has yet to be determined.
 Other diagnostic tests in conjunction with ultrasound may in the future prove to be useful.
 Carefully performed prospective investigations with state-of-the-art equipment are still needed to further define the role of this diagnostic modality.
