For acquisition of the 3-D ultrasound data the UTC System is equipped with the so-called Tracker. Main function of the Tracker is to displace the ultrasound transducer in very accurate steps of 0.2 mm across the area of interest to collect successive 2-dimensional ultrasound slices for compounding into the 3-D data block. This approach eliminates all variables, including operator skills, ensuring accurate, reliable, and repeatable ultrasound data sets.