Freehand 3D Ultrasound Imaging System with Position Tracking
The research, carried out by Carsten Poulsen, then an MS student in Electrical and Computer Engineering, developed a new and compact type of optical registration system, which tracks the position of the transducer on the skin surface. This is done continuously by acquiring images of the skin at the transducer location with a CCD-array, attached on the side of the transducer. With this position information, a sequence of 2D ultrasound frames, obtained with freehand scanning and thus likely to have unequal spacing and varying lateral position, is interpolated into a sequence of ultrasound frames with equal spacing and fixed lateral position. The implementation uses the Terason ultrasound scanner [1] and Sonocubic 3D software, operating in Windows XP.
To validate the registration method, a phantom with a rod-shaped inclusion was scanned several times along different irregular paths. A reconstruction is shown below. The volume estimations, based on the interpolated scan planes, fell within 96-106% of the actual volume, with a mean around 101%.
Actual image of pure agar rod (left); 3D reconstruction of agar rod, using freehand 3D imaging system (right)
Last modified: March 11, 2008 14:21:21