Magnetic resonance imaging guidance for laser photothermal therapy

作者：Chen Yichao; Gnyawali Surya C; Wu Feng; Liu Hong; Tesiram Yasvir A; Abbott Andrew; Towner Rheal A; Chen Wei R^*

来源：Journal of Biomedical Optics, 2008, 13(4): 044033.

DOI：10.1117/1.2960020

• laser phototherapy
• selective photothermal interaction
• magnetic resonance imaging (MRI)
• noninvasive temperature measurement
• Indocyanine Green (ICG)

Temperature distribution is a crucial factor in determining the outcome of laser phototherapy in cancer treatment. Magnetic resonance imaging (MRI) is an ideal method for 3-D noninvasive temperature measurement. A 7.1-T MRI was used to determine laser-induced high thermal gradient temperature distribution of target tissue with high spatial resolution. Using a proton density phase shift method, thermal mapping is validated for in vivo thermal measurement with light-absorbing enhancement dye. Tissue-simulating phantom gels, biological tissues, and tumor-bearing animals were used in the experiments. An 805-nm laser was used to irradiate the samples, with laser power in the range of 1 to 3W. A clear temperature distribution matrix within the target and surrounding tissue was obtained with a specially developed processing algorithm. The temperature mapping showed that the selective laser photothermal effect could result in temperature elevation in a range of 10 to 45 degrees C. The temperature resolution of the measurement was about 0.37 degrees C with 0.4-mm spatial resolution. The results of this study provide in vivo thermal information and future reference for optimizing laser dosage and dye concentration in cancer treatment.

• 出版日期2008-8
• 单位重庆医科大学