Measurements corrections in quantitative ultrasound-aided image guided radiotherapy: Speed of sound aberration correction

Abstract

To correct speed of sound (SOS) aberrations in ultrasound (US) imaging systems for quantitative image guided radiotherapy (IGRT) applications. US waves travel at different speeds in different human tissues. Conventional qualitative US-based imaging systems assume instead that the SOS is constant in all tissues; 1540 m/s, which is an accepted average value for soft tissues. This assumption is a systematic source of errors and image distortion in quantitative US imaging, whereas in qualitative diagnostic imaging it is usually unimportant