Ultrasound imaging to track the advance of coagulation front in laser irradiated tissue

Several theoretical models have been developed to predict the advance of the coagulation front in a laser irradiated tissue. However, there exists a keen interest in obtaining experimental feedback methods to better understand and monitor the response of tissue to laser irradiation in surgical and therapeutic procedures. In this work, an attempt was made to track the advancement of the coagulation front in beef myocardium tissue using ultrasound imaging. An intravascular ultrasound probe was used to image tissue coagulation while being irradiated by a Nd:YAG laser. Image processing algorithms were developed to track the coagulation front automatically based on a sequence of ultrasound image frames. Parameters of a gaussian function were employed to quantify the coagulation depth. All the algorithms were incorporated into a graphical-user-interface to allow a user-friendly and easy-to-use mechanism for computing the coagulation advancement. Histological information was then utilized to verify the validity of the coagulation depth. The results obtained demonstrate the feasibility of ultrasound imaging as a potentially viable tool for studying or monitoring laser-tissue interaction.