Ultrasonography of the kidney

Office-based renal sonography provides the urologist with cost-effective and noninvasive means of imaging the upper urinary tract. A majority of transrectal sonography units currently on the market can be easily adapted to transabdominal use by the purchase of one additional transducer. This enables the urologist to rule out hydronephrosis sonographically and to follow patients with known upper-tract disease who have previously undergone radiographic studies. In contrast, the differential diagnosis of upper-tract mass lesions requires a much more advanced level of training and experience. For patients at low risk of developing renal tumor, e.g., patients with BPH, renal ultrasound should replace contrast-enhanced imaging studies.