New real-time strain imaging concepts using diagnostic ultrasound

Two real-time strain imaging concepts and systems are presented. Both syste ms are based on a conventional ultrasound scanner that is connected to a PC with an A/D converter card for real-time data acquisition of rf data. Diff erential strain between successively acquired rf frames are estimated using phase root seeking. The first concept uses a special real-time implementat ion of manual elastography. In the second concept, denoted 'vibrography', t he static compression is replaced by low-frequency axial vibration of the p robe, still operating in quasistatic acquisition mode. The properties of bo th concepts are discussed with regard to noise and motion artefacts, and it is shown, using simulations and phantom experiments, that both imaging con cepts yield the same kind of strain images. Vibrography has the advantage t hat no manual compression has to be applied, total compression can be very low and some motion artefacts are better suppressed.