Quantitative free-hand 3D ultrasound imaging based on a modified 1D transducer array

Abstract

An approach for acquiring dimensionally accurate 3D ultrasound data, based on a modified 1D transducer array, is presented. The method avoids many of the drawbacks of conventional approaches to 3D ultrasound data acquisition. Scanning is simple and easy to perform in a clinical setting. A modified 1D transducer array is employed comprising a central conventional ID 'Imaging' array and two perpendicular 'Tracking' arrays - each integrally mounted at each end of the 'Imaging' array. As the transducer is scanned in the elevation direction of the central array, the images acquired by the 'Tracking' arrays remain coplanar and hence it is possible to accurately track image motion using any one of several image tracking techniques. Methods for improving the performance and ergonomics of the transducer array are presented. In particular, a crossed electrode transducer structure is proposed for minimizing the total transducer 'footprint' (contact surface area). The versatility of the approach in terms of its suitability for scanning breast, carotid and prostate is discussed. We have acquired both phantom and in-vivo 3D ultrasound data with the prototype imaging approach. Initial studies suggest that the linear dimensional accuracy in the elevation direction (i.e., the reconstructed direction) is approximately 5%.