In vivo ultrasound electrode displacement strain imaging

Nicholas Rubert*, Shyam Bharat, Ryan Dewall, Anita Andreano, Christopher Brace, Jingfeng Jiang, Lisa Sampson, James A. Zagzebski, Fred Lee, Tomy Varghese

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


The incidence of primary and secondary liver tumors has increased significantly over the last two decades. Due to poor liver function and/or distribution of lesions, surgery is often not an option for affected patients. An alternative to surgical resection, percutaneous radiofrequency ablation is often used to thermally destroy the tumor in situ. Radiofrequency ablation is evolving into one of the more popular minimally-invasive treatments for hepatic tumors. Monitoring the treated region is an important factor in the success of radiofrequency ablation, and ultrasound elastography could become a convenient, cost-effective means to delineate the thermal lesion boundaries for clinical personnel during the procedure. This study assesses "electrode displacement" strain imaging for monitoring abdominal radiofrequency ablation procedures. We present results utilizing a novel approach of displacing the ablation electrode itself to introduce the mechanical stimuli required for strain imaging. Utilizing a Siemens Antares clinical ultrasound scanner equipped with a research interface, ultrasound radiofrequency data were acquired immediately following radiofrequency ablation of porcine liver. The porcine liver was excised following the procedure, and the dimensions of the thermal lesion in the imaging plane measured by slicing though the lesion. Strain images of the lesions were produced offline using axial guidance based block-matching and multi-level motion tracking algorithms. The area of the lesion on the strain image was compared to the area of the lesion in pathology images obtained from eight separate lesions. The estimated linear correlation coefficient between the pathology image and the strain image was r = 0.961 (p < .001) for manual segmentation using 4 observers. The area of the lesion in the strain image slightly underestimates the area of the lesion in the pathology image for all slices, agreeing with earlier ex-vivo experiments.

Original languageEnglish (US)
Title of host publication2009 IEEE International Ultrasonics Symposium and Short Courses, IUS 2009
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Print)9781424443895
StatePublished - 2009
Event2009 IEEE International Ultrasonics Symposium, IUS 2009 - Rome, Italy
Duration: Sep 20 2009Sep 23 2009

Publication series

NameProceedings - IEEE Ultrasonics Symposium
ISSN (Print)1051-0117


Other2009 IEEE International Ultrasonics Symposium, IUS 2009


  • Ablation
  • Elasticity
  • Elasticity imaging
  • Elastography
  • Electrode displacement
  • Microwave ablation
  • Radiofrequency ablation
  • Strain
  • Ultrasound

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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