skip to main content

Title: CT imaging during microwave ablation: Analysis of spatial and temporal tissue contraction

Purpose: To analyze the spatial distribution and temporal development of liver tissue contraction during high-temperature ablation by using intraprocedural computed tomography (CT) imaging. Methods: A total of 46 aluminum fiducial markers were positioned in a 60 × 45 mm grid, in a single plane, around a microwave ablation antenna in each of six ex vivo bovine liver samples. Ablations were performed for 10 min at 100 W. CT data of the liver sample were acquired every 30 s during ablation. Fiducial motion between acquisitions was tracked in postprocessing and used to calculate measures of tissue contraction and contraction rates. The spatial distribution and temporal evolution of contraction were analyzed. Results: Fiducial displacement indicated that the zone measured postablation was 8.2 ± 1.8 mm (∼20%) smaller in the radial direction and 7.1 ± 1.0 mm (∼10%) shorter in the longitudinal direction than the preablation tissue dimension. Therefore, the total ablation volume was reduced from its preablation value by approximately 45%. Very little longitudinal contraction was noted in the distal portion of the ablation zone. Central tissues contracted more than 60%, which was near an estimated limit of ∼70% based on initial water content. More peripheral tissues contracted only 15% in anymore » direction. Contraction rates peaked during the first 60 s of heating with a roughly exponential decay over time. Conclusions: Ablation zones measured posttreatment are significantly smaller than the pretreatment tissue dimensions. Tissue contraction is spatially dependent, with the greatest effect occurring in the central ablation zone. Contraction rate peaks early and decays over time.« less
Authors:
;  [1]
  1. Departments of Radiology and Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53705 (United States)
Publication Date:
OSTI Identifier:
22318088
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 41; Journal Issue: 11; Other Information: (c) 2014 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ABLATION; ALUMINIUM; ANIMAL TISSUES; ANTENNAS; APPROXIMATIONS; CATTLE; COMPUTERIZED TOMOGRAPHY; CONTRACTION; CONTRACTS; COST; DATA; DECAY; ECONOMICS; EVOLUTION; GRIDS; HEATING; HUMIDITY; LIVER; MICROWAVE RADIATION; PARTICLE TRACKS; PEAKS; PLANT TISSUES; SOCIO-ECONOMIC FACTORS; SPATIAL DISTRIBUTION; SULFUR 30; TEMPERATURE RANGE 0400-1000 K; ZONES