ISTerre seminar

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Shear-wave focal spot imaging in medicine: theoretical analysis and numerical experiments

Wednesday 29 April 2026 - 11h00

Goulven Le Moign - Postdoc ISTerre (Seiscope)
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When ambient noise correlation is applied to a diffuse wave field recorded by a dense seismic network, a "focal spot" emerges and contains information about the media. The term “focal spot imaging” has first been used, in seismology, with Rayleigh-waves to image the subsurface structure. This methodology can be extended to a completely different context: the human body, with the goal to detect early signs of cancers. In this presentation, the concept of the focal spot imaging will be introduced before talking about "passive elastography", a medical imaging technique for assessing tissue elasticity. Then, two aspects will be presented. First, a mathematical analysis will be exposed to explain an observation: the 3D noise correlation function is related to the 2D Green's function, when both sources and stations are located on a single plan. Then, as viscosity of soft tissues can affect the shape of the focal spot, preliminary results using viscoelastic simulations will be exposed.

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Organizing team : Ondes et structures

Salle Dolomieu, Maison des Géosciences, 38400 Saint Martin d'Hères

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/95348921656?pwd=xp7Cw9bhOjbvoO0TV9rVzAxdcmxxXJ.1
Meeting ID 953 4892 1656
Passcode 927149