Limited angle ultrasonic transmission tomography of the compressed female breast

A modified ultrasonic time-of-flight tomography algorithm which the authors presented before (1996) is implemented in a system composed by a commercially available ultrasound scanner, a PC, and a special applicator which compresses the female breast like in X-ray mammography. An acquisition time of two minutes per frame was obtained and allows the clinical evaluation of the concept. The limited total angle leads to a coarse axial resolution and to artifacts. However, B-mode images which are stained with a color-coded representation of the reconstructed velocity and of the attenuation, respectively, can significantly improve breast diagnostics. In the work the authors present phantom and in vivo results of the time-of-flight mode to demonstrate the potentials of this method which is part of a new imaging concept, “CARISMA” (Computer Assisted Reconstructive Imaging by Sonographic and Mechano-Elastic Analysis)