Hybrid ultrasonic computed tomography

Ultrasonic computed tomography can provide valuable information on tissue properties. However, the large number of projections required to obtain a high-resolution image renders it impractical for routine clinical use. B-scan imaging, on the other hand is very rapid, but mainly provides information on tissue morphology. An algorithm which fuses information from a compound B-scan image and a limited view speed of sound (SOS) tomographic reconstruction of an object is presented here. The algorithm is iterative and is based on the two-dimensional Taylor series expansion. The algorithm diminishes artifacts caused by tomographic reconstruction from too few projections and produces an image which depicts both tissue morphology and acoustic properties (SOS). Consequently, quantitative images can be acquired in a much shorter time than required by conventional tomography. This method may potentially find application in ultrasonic breast screening. (C) 1997 Academic Press.