Comparison of Acoustic Radiation Force Impulse (ARFI) Imaging and Shear Wave Imaging (SWI) in Evaluation of Myocardial Ablation Lesions

Radiofrequency ablation (RFA) is commonly used to treat cardiac arrhythmias, by generating a series of discrete RFA lesions in the myocardium to isolate arrhythmogenic conduction pathways. The size of each lesion is controlled by the temperature of the tissue at the surface or the duration of RF power delivery, but feedback on the extent and transmurality of the generated lesion are unavailable with current technology. Intracardiac Echocardiography (ICE) may provide a solution through Acoustic Radiation Force Impulse (ARFI) imaging or Shear Wave Imaging (SWI), which each generate images of local mechanical compliance from very small ultrasonically-induced waves. This work compares ARFI and SWI in an ex-vivo experiment for lesion boundary assessment and lesion gap resolution.