Image analysis for magnetic resonance elastography

Abstract

A newly developed magnetic resonance imaging technique can directly visualize propagating acoustic strain waves in tissue-like materials. By estimating the local wavelength of the acoustic wave pattern, quantitative values of shear modulus can be calculated and images generated that depict tissue elasticity or stiffness. Since tumors are significantly stiffer than normal tissue (the basis of their detection by palpation), this technique may have potential for "palpation by imaging", with possible application to the detection of tumors in breast, liver, kidney, and prostate. We describe the local wavelength estimation algorithm and show a variety of sample "elastograms"-images of elasticity-for both test phantoms and tissue samples.