Shear-Wave Based Monitoring of Radiofrequency Ablations at Clinically Relevant Depths

Real-time monitoring of radiofrequency ablation is important to ensure adequate treatment coverage of tumors as well as protection of healthy tissues. The high stiffness contrast between ablated and non-treated tissues has led to the use of ultrasound elastography for coagulation zone visualization but its use has been limited to shallow depths. A shear wave decorrelation mapping approach was developed for ablation boundary detection at clinically relevant depths. The shear wave elastography technique was evaluated using ex vivo bovine liver samples as well as whole livers from fresh cadavers and anesthetized live pigs. Overall the shear wave technique appears feasible for defining and monitoring the progression of thermal lesion boundary.