The preservation of the neurovascular bundle (NVB) including cavernous nerves during radical prostatectomy improves the postoperative recovery of sexual potency. At present, the location of NVB is determined by the surgeon's visual estimation. However, NVB is difficult to visualize with simple visual magnification of the surgical field with surgical loupes or laparoscopic lenses due to the periprostatic connective tissue and intraoperative hemorrhage. One approach to better estimate the location of the NVB is to identify a macroscopic landmark to more clearly direct the surgeon to the location of the NVB. The accompanying arteries and veins in the NVB, which are visible with Doppler ultrasound, can serve as a macroscopic landmark to localize the microscopic cavernous nerves in the NVB. Therefore, the use of TRUS imaging during radical prostatectomy can potentially improve the visualization of the NVB and subsequently improve postoperative recovery of potency in men. In addition, the 3-D shape of the prostate gland can potentially be clearly and accurately delineated in ultrasounds imaging, providing direct guidance of landmarks to the surgeon.