Applications of ultrasonic time-reversal in biomedical imaging: from cancer detection to functional imaging

Speaker:Profesor Mathias Fink
Affiliation:école supérieure de physique et de chimie industrielles de la ville de Paris
Location:Lidow Rosen Auditorium (323)
Abstract:This talk will present an overview of the research conducted on ultrasonic time-reversal methods applied to biomedical imaging.
We will first describe iterative time-reversal techniques that allow tracking and focusing ultrasonic waves on reflectors in
tissues (kidney stones, micro-calcifications). Because time reversal is also able to correct for the strong distortions induced
by the skull bone on ultrasonic propagation, this adaptive focusing technique allows non-invasive therapy of brain diseases
and high resolution brain neurostimulation. We will also show that time-reversal focusing does not need the presence of
bright reflectors but it can be achieved only from the speckle noise generated by random distributions of non-resolved
scatterers. We will describe the applications of this concept to correct distortions and aberrations in ultrasonic imaging.
In the second part of the talk we will describe the concept of time-reversal processors to get ultrafast ultrasonic images
with typical frame rates of order of 10.000 F/s. It is the field of ultrafast ultrasonic imaging that have plenty medical
applications. We will focus on two of them: Quantitative Elasticity imaging of tissues by following shear wave
propagation to improve cancer detection and Ultrafast Doppler imaging that allows ultrasonic functional imaging.