Elastographic measurement of the area and volume of thermal lesions resulting from radiofrequency ablation: Pathologic correlation

Tomy Varghese, Udomchai Techavipoo, Wu Liu, James A. Zagzebski, Quan Chen, Gary Frank, Fred T. Lee

Research output: Contribution to journalArticlepeer-review

80 Scopus citations

Abstract

OBJECTIVE. Elastography is a promising tool for visualizing the zone of necrosis in liver tissue resulting from radiofrequency tumor ablation. Because heat-ablated tissues are stiffer than normal untreated tissue, elastography may prove useful for following up patients who undergo radiofrequency ablative therapy. We sought to report the initial evaluations of the reliability of elastography for delineating thermal lesion boundaries in liver tissue by comparing lesion dimensions determined by elastography with the findings at whole-mount pathology. MATERIALS AND METHODS. Radiofrequency ablation was performed in vitro on liver tissue specimens encased in gelatin phantoms. The imaging plane for elastography was perpendicular to the axis of the radiofrequency electrode so that the ablated region was around the center of the plane. To obtain three-dimensional visualization of thermal lesions, we reconstructed the lesions from multiple elastograms by linearly translating the elastographic scanning plane. Pathology photographs were obtained in the same image plane used for elastography by slicing through the gelatin and tissue phantom using external markers. We used digitized gross pathology photographs obtained at a specified slice thickness to compute the areas and volumes of the lesions. These measurements were then compared to the measurements obtained from the elastograms. RESULTS. In a sample of 40 thermal lesions, we obtained a correlation between in vitro elastographic and pathologic measurements of r = 0.9371 (p < 0.00001) for area estimates and r = 0.979 (p < 0.00001) for volume estimates. CONCLUSION. We found excellent correlation between the measurements of the dimensions, areas, and volumes of thermal lesions that were based on elastographic images and the measurements that were based on digitized pathologic images. When compared with digitized pathologic measurements, elastographic measurements showed a tendency to slighly underestimate both the areas and volumes of lesions. Nevertheless, elastography is a reliable technique for delineating thermal lesions resulting from radiofrequency ablation.

Original languageEnglish
Pages (from-to)701-707
Number of pages7
JournalAmerican Journal of Roentgenology
Volume181
Issue number3
DOIs
StatePublished - Sep 1 2003

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Fingerprint

Dive into the research topics of 'Elastographic measurement of the area and volume of thermal lesions resulting from radiofrequency ablation: Pathologic correlation'. Together they form a unique fingerprint.

Cite this