Tissue temperature is critically related to the success or failure of catheter ablation procedures. Temperature imaging using ultrasound techniques is attractive because of the potential to provide real-time information at low cost. The signal-processing methods used here were developed to investigate the feasibility of monitoring ablative therapy by identifying the point at which the slope of the thermal strain curve changes sign caused primarily by speed of sound variations with temperature. Previously, we have demonstrated the feasibility of this method in-vivo using porcine models. In this paper, we present recent results with temperature validation for this method in-vivo using an integrated intracardiac echocardiography (ICE) probe. Also preliminary results on thermal strain imaging using a cMUT array integrated into the ICE probe are presented.