Reference Phantom Method for Ultrasonic Imaging of Thin Dynamic Constructs

Quantitative ultrasound has a great potential for the non-destructive evaluation of tissue engineered constructs, where local attenuation and integrated backscatter coefficient (IBC) can be used monitoring development biological processes. The determination both parameters achieved using reference phantom method (RPM). However, its accuracy affected when evaluating constructs evolving sound speed, thickness, example, biodegradable hydrogels developing neocartilage. To assess feasibility RPM under such dynamic conditions while employing 50-MHz transducer, we conducted series experiments on 3-mm-thick acellular laden with microspheres. ultrasonic procedure was validated by detecting compensating large variations occurring in construct, up to 20-fold respect phantom, estimations errors below 1%. We found that speed mismatch does not affect estimation, but causes strong diffraction effect reducing intensity. Such intensity reduction compensated determining IBC percentage change (IBCΔ) as function (ΔSS), equation IBCΔ = (0.63 ± 0.07) ΔSS + (8.54 0.76) 10–3 ΔSS2. investigated interval 120 m/s two different concentrations microspheres, estimation 7% relative construct's actual IBC. Finally, spectral difference is sufficient measure within few millimetres depth mismatch, combining negligible additional effects. These results pave way use generic thin thus simplifying need phantoms depending properties.