Comparison of ultrasound strain images with multi-modality imaging techniques in liver rf ablation assessment: Initial ex vivo and clinical results

Ultrasound (US) elastography in liver imaging has recently gained interest in the clinical . Various techniques explore the use of elasticity for clinical diagnosis (for fibrosis-cirrhosis staging) assessment of radiofrequency (RF) or High Intensity Focused (HIFU) ablation. In this paper, we conduct based strain imaging for ex vivo and clinical liver ablation (RFA) assessment, using the RFA needle to induce strain (method initially proposed by Varghese et al. [1] in ex porcine). The results are validated against several imaging . Six ex vivo bovine livers were embedded in gelatin . A commercial RFA needle (Rita) was inserted and into each liver sample. Radiofrequency (RF) ultrasound were collected using Philips US systems during RFA needle . Strain images were generated offline using 2D speckle . Post- RFA strain images were compared to T1-weighted (Philips). The livers were then dissected along the US image for caliper measurements. The elasticity images of the exhibit a 40-fold contrast-to-noise Ratio (CNR) as compared to B-mode. The lesion sizes, as on the elasticity images, compared well with the MRI (<10% error). Clinical RF data were acquired on RFA patients with an iU-22 system (Philips). Both patients pre- and post-operative contrast computed tomograpy (CT) imaging, and one also had intra-operative contrastenhanced . . Following RFA, no lesion could be clearly in the US B-mode images. Comparable lesion were measured from the intra-operative elasticity and post-operative contrast CT. Elasticity imaging could similar information as contrast CT or contrast imaging without the need for contrast or additional radiation. It also potentially allows for intra-operative of the RFA procedure, which in turn could lead to efficacy of RFA treatments.