Real-time optoacoustic monitoring of temperature in tissues

There is a need to monitor tissue temperature and optical properties during thermotherapy in real time in order to control the boundaries of hyperthermia or coagulation of diseased tissues and minimize the damage to surrounding normal tissues. We propose to use optoacoustic technique for monitoring of tissue temperature. Efficiency of thermoacoustic excitation in water is dependent on temperature. Therefore, the optoacoustic technique may be utilized to monitor tissue temperature if the efficiency of thermoacoustic excitation in tissue is temperature-dependent. We performed experiments on real-time optoacoustic monitoring of temperature in freshly excised canine tissues (liver and myocardium) and aqueous solution during conductive heating. Laser-induced optoacoustic pressure signals were recorded from tissues and the aqueous solution during heating with the use of sensitive wide-band acoustic transducers. Fundamental harmonic of Q-switched Nd:YAG lasers were used for pressure wave generation. Amplitude of the optoacoustic pressure induced in tissues increased linearly with temperature. Good agreement was obtained between the experimental data and theory for the aqueous solution. We demonstrated that laser optoacoustic technique is capable of measuring 1 - 2 degrees Celsius temperature change in tissue and at the distance of up to several centimeters between the investigated tissue volume and the transducer.

[1]  R. Esenaliev,et al.  Sensitivity of laser opto-acoustic imaging in detection of small deeply embedded tumors , 1999 .

[2]  Yoshimi Anzai,et al.  MR imagin—histopathologic correlation of thermal injuries induced with interstitial Nd:YAG laser irradiation in the chronic model , 1992, Journal of magnetic resonance imaging : JMRI.

[3]  R M Henkelman,et al.  Time and temperature dependence of MR parameters during thermal coagulation of ex vivo rabbit muscle , 1998, Magnetic resonance in medicine.

[4]  B. Hooper.  Optical-thermal response of laser-irradiated tissue , 1996 .

[5]  P. VanBaren,et al.  Noninvasive real-time multipoint temperature control for ultrasound phased array treatments , 1996, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[6]  Frank K. Tittel,et al.  Laser optoacoustic tomography for medical diagnostics: principles , 1996, Photonics West.

[7]  Kirill V. Larin,et al.  Optical properties of normal and coagulated tissues: measurements using combination of optoacoustic and diffuse reflectance techniques , 1999, Saratov Fall Meeting.

[8]  René M. Botnar,et al.  Monitoring of radio frequency tissue ablation in an interventional magnetic resonance environment. Preliminary ex vivo and in vivo results. , 1997, Investigative radiology.

[9]  R. Kruger,et al.  Photoacoustic ultrasound (PAUS)--reconstruction tomography. , 1995, Medical physics.

[10]  C. Damianou,et al.  Noninvasive temperature estimation in tissue via ultrasound echo-shifts. Part II. In vitro study. , 1996, The Journal of the Acoustical Society of America.

[11]  F. Duck.  Physical properties of tissue , 1990 .

[12]  C. Damianou,et al.  Noninvasive temperature estimation in tissue via ultrasound echo-shifts. Part I. Analytical model. , 1996, The Journal of the Acoustical Society of America.

[13]  S L Jacques,et al.  Measurement of tissue optical properties by time-resolved detection of laser-induced transient stress. , 1997, Applied optics.

[14]  Frank K. Tittel,et al.  Axial resolution of laser opto-acoustic imaging: influence of acoustic attenuation and diffraction , 1998, Photonics West - Biomedical Optics.

[15]  B. Wilson,et al.  Ultrasound properties of liver tissue during heating. , 1997, Ultrasound in medicine & biology.

[16]  Frank K. Tittel,et al.  Laser optoacoustic tomography for medical diagnostics: experiments with biological tissues , 1996, Photonics West.

[17]  Frank K. Tittel,et al.  Laser optoacoustic imaging for breast cancer diagnostics: limit of detection and comparison with x-ray and ultrasound imaging , 1997, Photonics West - Biomedical Optics.

[18]  T Nakamura,et al.  Gray scale second harmonic imaging of the liver: a preliminary animal study. , 1997, Ultrasound in medicine & biology.

[19]  R. Seip,et al.  Noninvasive estimation of tissue temperature response to heating fields using diagnostic ultrasound , 1995, IEEE Transactions on Biomedical Engineering.

[20]  Alexander A. Karabutov,et al.  Influence of thermal nonlinearity on the thermooptical generation of sound , 1979 .

[21]  Kirill V. Larin,et al.  Laser optoacoustic technique for real-time measurement of thermal damage in tissues , 1999, Photonics West - Biomedical Optics.

[22]  M Essenpreis,et al.  Effect of temperature on the optical properties of ex vivo human dermis and subdermis. , 1998, Physics in medicine and biology.

[23]  M. Sigrist.  Laser generation of acoustic waves in liquids and gases , 1986 .

[24]  Vladimir V. Lozhkarev,et al.  Application of quasi-resonant ultrasonic detectors in the optoacoustic tomography of biological objects , 1999 .

[25]  R Lufkin,et al.  Phase imaging on a .2‐T MR scanner: Application to temperature monitoring during ablation procedures , 1997, Journal of magnetic resonance imaging : JMRI.

[26]  René M. Botnar,et al.  Radio-frequency-induced thermoablation: monitoring with T1-weighted and proton-frequency-shift MR imaging in an interventional 0.5-T environment. , 1998, Radiology.