title: Optical-thermal light-tissue interactions during photoacoustic breast imaging.
abstract: Light-tissue interactions during photoacoustic imaging, including dynamic heat transfer processes in and around vascular structures, are not well established. A three-dimensional, transient, optical-thermal computational model was used to simulate energy deposition, temperature distributions and thermal damage in breast tissue during exposure to pulsed laser trains at 800 and 1064 nm. Rapid and repetitive temperature increases and thermal relaxation led to superpositioning effects that were highly dependent on vessel diameter and depth. For a ten second exposure at established safety limits, the maximum single-pulse and total temperature rise levels were 0.2°C and 5.8°C, respectively. No significant thermal damage was predicted. The impact of tissue optical properties, surface boundary condition and irradiation wavelength on peak temperature location and temperature evolution with time are discussed.
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993, USA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Gould
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993, USA.
authors.forename: Quanzeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993, USA.
authors.forename: T Joshua
authors.initials: TJ
authors.lastname: Pfefer
keywords: (140.3360) Laser safety and eye protection; (170.3660) Light propagation in tissues; (170.3830) Mammography; (170.5120) Photoacoustic imaging; (350.5340) Photothermal effects