title: Ablation monitoring with elastography: 2D in-vivo and 3D ex-vivo studies.
abstract: The clinical feasibility of 2D elastography methods is hindered by the requirement that the operator avoid out-of-plane motion of the ultrasound image during palpation, and also by the lack of volumetric elastography measurements. In this paper, we develop and evaluate a 3D elastography method operating on volumetric data acquired from a 3D probe. Our method is based on minimizing a cost function using dynamic programming (DP). The cost function incorporates similarity of echo amplitudes and displacement continuity. We present, to the best of our knowledge, the first in-vivo patient studies of monitoring liver ablation with freehand DP elastography. The thermal lesion was not discernable in the B-mode image but it was clearly visible in the strain image as well as in validation CT. We also present 3D strain images from thermal lesions in ex-vivo ablation. Good agreement was observed between strain images, CT and gross pathology.
authors.affiliation: ERC for Computer Integrated Surgery, Johns Hopkins University, USA. rivaz@jhu.edu
authors.forename: Hassan
authors.initials: H
authors.lastname: Rivaz
authors.forename: Ioana
authors.initials: I
authors.lastname: Fleming
authors.forename: Lia
authors.initials: L
authors.lastname: Assumpcao
authors.forename: Gabor
authors.initials: G
authors.lastname: Fichtinger
authors.forename: Ulrike
authors.initials: U
authors.lastname: Hamper
authors.forename: Michael
authors.initials: M
authors.lastname: Choti
authors.forename: Gregory
authors.initials: G
authors.lastname: Hager
authors.forename: Emad
authors.initials: E
authors.lastname: Boctor
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome