Papers Published

1. Barton, J.K. and Rollins, A. and Yazdanfar, S. and Pfefer, T.J. and Westphal, V. and Izatt, J.A., Photothermal coagulation of blood vessels: a comparison of high-speed optical coherence tomography and numerical modelling, Phys. Med. Biol. (UK), vol. 46 no. 6 (2001), pp. 1665 - 78 [306] .
   (last updated on 2007/04/13)

   Abstract:
   Optical-thermal models that can accurately predict temperature rise and damage in blood vessels and surrounding tissue may be used to improve the treatment of vascular disorders. Verification of these models has been hampered by the lack of time- and depth-resolved experimental data. An optical coherence tomography system operating at 4-30 frames per second was used to visualize laser irradiation of cutaneous (hamster dorsal skin flap) blood vessels. An argon laser was utilized with the following parameters: pulse duration 0.1-2.0 s, spot size 0.1-1.0 mm, power 100-400 mW. Video microscopy images were obtained before and after irradiations, and optical-thermal modelling was performed on two irradiation cases. Time-resolved optical coherence tomography and still images were compared with predictions of temperature rise and damage using Monte Carlo and finite difference techniques. In general, predicted damage agreed with the actual blood vessel and surrounding tissue coagulation seen in images. However, limitations of current optical-thermal models were identified, such as the inability to model the dynamic changes in blood vessel diameter that were seen in the optical coherence tomography images

   Keywords:
   blood vessels;coagulation;finite difference methods;hyperthermia;laser applications in medicine;Monte Carlo methods;optical tomography;physiological models;radiation therapy;skin;