Identification of tissue parameters using ultrasound vibro-elastography

With post-doctoral fellow Hani Eskandari (co-supervised with R. Rohling), Ph.D. students Reza Zahiri and Ali Baghani (co-supervised with R. Rohling). Funded by an NSERC Strategi Partnership Grant.

Real-time strain imaging of elastography phantom shown here.

Vibro-elastography is an extension of static elastography and was developed with Emre Turgay and Rob Rohling.  As illustrated below, the method consists of applying broad-band low-frequency (typically <30Hz) compression waves to tissue by a vibrator, measuring tissue displacement, and either fitting a parametric model to the relative tissue motion, or computing a frequency response from the relative tissue motion.

From left to right, the figures below show: the low-frequency asymptotes of these frequency responses in a soft-hard-soft cubic 5cm3 phantom (256x256), the conventional B-mode ultrasound image which does not show any contrast, and the magnitudes of the relative motion responses of tissue at different depths relative to a tissue patch near the vibrator (located at the top of the images), as a function of frequency. Note that in the hard region responses are closer together and change more with frequency. With an 8MHz transducer, stiffness changes of 10% and hard (twice as stiff) inclusions of 0.5mm can be detected [Turgay, Salcudean and Rohling 2006])

We are developing

See papers with Eskandari, Zahiri, Baghani for recent work.