Quantitative comparison between optical coherence elastography, ultrasound-based shear wave elastography, and Brillouin imaging

Abstract Optical elastography is rapidly evolving for assessing tissue biomechanical properties, and these techniques are now reaching technical maturity, resulting in large-scale clinical studies. However, a lack of extensive research on intra- and inter-operability across different methods may limit clinical utility and complicate the interpretation of results due to uncertainty in elastographic measurements. This study evaluates the performance of wave-based air-pulse optical coherence elastography (OCE), air-coupled ultrasound (ACUS) OCE, piezoelectric (PZT) OCE, quasistatic compression OCE, ultrasound-based shear wave elastography (USWE), and Brillouin imaging against the benchmark standard of uniaxial mechanical testing. The absolute percentage difference of Young’s modulus was calculated between uniaxial mechanical testing and all elastography methods. Bland–Altman analysis was utilized to identify systematic biases and levels of agreement. The results show that wave-based OCE methods (air-pulse, ACUS, and PZT) agree well with each other and with mechanical testing. The degree of variability was greater in USWE and compression OCE. However, wave-based OCE had a lower degree of variability, while USWE demonstrated the least overall error when compared with uniaxial mechanical testing results. Brillouin imaging showed a strong correlation ( R = 0.96) with uniaxial mechanical testing measurements. However, because its link to Young’s modulus is not direct without knowledge of the refractive index and density, it was not compared. The findings from this comprehensive approach will facilitate further research into optimizing elastography technologies, allowing for more accurate, consistent, and reproducible measurements of tissue elasticity across diverse applications.