Variability of integrated backscatter: simulations and measurements in vitro

Absolute integrated backscatter (IB) levels and other derived parameters such as cyclic variation (CV) have been used for ultrasonic tissue characterization. Ideally, such a parameter would provide information on the scattering structure and would be independent of the acquisition or the equipment used. It is well known however, that the measured reflected signal of a scattering structure depends on the precise position of the individual scatterers. In order to estimate the sensitivity of IB to this stochastical process, the authors analyzed backscattered data from structures with fixed scatterer densities but with a random distribution, Several independent measurements were made and the variability in IB was calculated. In order to produce the radio frequency (RF) data the authors firstly used computer simulations. Secondly, a real-time RF acquisition system was used to acquire RF data from a tissue mimicking phantom. Finally, an adapted imaging approach was evaluated using mathematical simulations in order to see if it can reduce the measured variability of IB.