Magnetic resonance imaging of boiling induced by high intensity focused ultrasound.

Both mechanically induced acoustic cavitation and thermally induced boiling can occur during high intensity focused ultrasound (HIFU) medical therapy. The goal was to monitor the temperature as boiling was approached using magnetic resonance imaging (MRI). Tissue phantoms were heated for 20 s in a 4.7-T magnet using a 2-MHz HIFU source with an aperture and radius of curvature of 44 mm. The peak focal pressure was 27.5 MPa with corresponding beam width of 0.5 mm. The temperature measured in a single MRI voxel by water proton resonance frequency shift attained a maximum value of only 73 degrees C after 7 s of continuous HIFU exposure when boiling started. Boiling was detected by visual observation, by appearance on the MR images, and by a marked change in the HIFU source power. Nonlinear modeling of the acoustic field combined with a heat transfer equation predicted 100 degrees C after 7 s of exposure. Averaging of the calculated temperature field over the volume of the MRI voxel (0.3 x 0.5 x 2 mm(3)) yielded a maximum of 73 degrees C that agreed with the MR thermometry measurement. These results have implications for the use of MRI-determined temperature values to guide treatments with clinical HIFU systems.

[1]  Ronald A. Roy,et al.  Applications of Acoustics and Cavitation to Noninvasive Therapy and Drug Delivery , 2008 .

[2]  R. Cini,et al.  Temperature Dependence of the Magnetic Susceptibility of Water , 1968 .

[3]  L. Crum,et al.  Physical mechanisms of the therapeutic effect of ultrasound (a review) , 2003 .

[4]  Ronald A. Roy,et al.  Role of acoustic cavitation in the delivery and monitoring of cancer treatment by high-intensity focused ultrasound (HIFU) , 2007, International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group.

[5]  Kullervo Hynynen,et al.  MR imaging-controlled focused ultrasound ablation: a noninvasive image-guided surgery. , 2005, Magnetic resonance imaging clinics of North America.

[6]  Paul C. Lauterbur,et al.  Principles of magnetic resonance imaging : a signal processing perspective , 1999 .

[7]  J. B. Fowlkes,et al.  Acoustic cavitation generated by microsecond pulses of ultrasound , 1986, Nature.

[8]  Padmakar P. Lele,et al.  Effects of Ultrasound on “Solid” Mammalian Tissues and Tumors In Vivo , 1987 .

[9]  J. Chapelon,et al.  Combination of thermal and cavitation effects to generate deep lesions with an endocavitary applicator using a plane transducer: ex vivo studies. , 2004, Ultrasound in medicine & biology.

[10]  D. R. Bacon,et al.  Absorption of finite amplitude focused ultrasound. , 1991, The Journal of the Acoustical Society of America.

[11]  H. Nagawa,et al.  Heating and coagulation volume obtained with high-intensity focused ultrasound therapy: comparison of perflutren protein-type A microspheres and MRX-133 in rabbits. , 2005, Radiology.

[12]  G. ter Haar,et al.  Temperature rise recorded during lesion formation by high-intensity focused ultrasound. , 1997, Ultrasound in medicine & biology.

[13]  W. Fry,et al.  Determination of Absolute Sound Levels and Acoustic Absorption Coefficients by Thermocouple Probes—Theory , 1954 .

[14]  K Hynynen,et al.  MRI-guided gas bubble enhanced ultrasound heating in in vivo rabbit thigh. , 2003, Physics in medicine and biology.

[15]  Lawrence A Crum,et al.  Acoustic characterization of high intensity focused ultrasound fields: a combined measurement and modeling approach. , 2008, The Journal of the Acoustical Society of America.

[16]  Zhen Xu,et al.  Controlled ultrasound tissue erosion: the role of dynamic interaction between insonation and microbubble activity. , 2005, The Journal of the Acoustical Society of America.

[17]  J. Hindman,et al.  Proton Resonance Shift of Water in the Gas and Liquid States , 1966 .

[18]  Wen-Zhi Chen,et al.  Extracorporeal high intensity focused ultrasound ablation in the treatment of 1038 patients with solid carcinomas in China: an overview. , 2004, Ultrasonics sonochemistry.

[19]  Ronald A. Roy,et al.  Measurements of bubble-enhanced heating from focused, MHz-frequency ultrasound in a tissue-mimicking material. , 2001, Ultrasound in medicine & biology.

[20]  L A Crum,et al.  Use of overpressure to assess the role of bubbles in focused ultrasound lesion shape in vitro. , 2001, Ultrasound in medicine & biology.

[21]  W. Dewey,et al.  Thermal dose determination in cancer therapy. , 1984, International journal of radiation oncology, biology, physics.

[22]  N. McDannold.  Quantitative MRI-based temperature mapping based on the proton resonant frequency shift: Review of validation studies , 2005, International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group.

[23]  Peter J. Kaczkowski,et al.  Monitoring formation of high intensity focused ultrasound (HIFU) induced lesions using backscattered ultrasound , 2004 .

[24]  K Hynynen,et al.  Demonstration of enhanced temperature elevation due to nonlinear propagation of focussed ultrasound in dog's thigh in vivo. , 1987, Ultrasound in medicine & biology.

[25]  Charles R. Thomas,et al.  Dynamics and control of cavitation during high-intensity focused ultrasound application , 2005 .

[26]  E. Day.  Equation for the magnetic susceptibility of water , 1980 .

[27]  F. Jolesz,et al.  Current status and future potential of MRI‐guided focused ultrasound surgery , 2008, Journal of magnetic resonance imaging : JMRI.

[28]  L. Crum,et al.  Millisecond initiation of boiling by high‐intensity focused ultrasound in tissue‐mimicking phantoms , 2006 .

[29]  Lawrence A Crum,et al.  Effects of nonlinear propagation, cavitation, and boiling in lesion formation by high intensity focused ultrasound in a gel phantom. , 2006, The Journal of the Acoustical Society of America.

[30]  F V Gleeson,et al.  The safety and feasibility of extracorporeal high-intensity focused ultrasound (HIFU) for the treatment of liver and kidney tumours in a Western population , 2005, British Journal of Cancer.

[31]  P. Callaghan.  Principles of Nuclear Magnetic Resonance Microscopy , 1991 .

[32]  C. Chaussy,et al.  High-intensity focused ultrasound in prostate cancer: results after 3 years. , 2000, Molecular urology.

[33]  J. Philo,et al.  Temperature dependence of the diamagnetism of water , 1980 .

[34]  R. Ehman,et al.  Reliability of water proton chemical shift temperature calibration for focused ultrasound ablation therapy. , 2000, Medical physics.

[35]  Vasant A Salgaonkar,et al.  Acoustic emissions during 3.1 MHz ultrasound bulk ablation in vitro. , 2008, Ultrasound in medicine & biology.

[36]  L A Crum,et al.  Real-time visualization of high-intensity focused ultrasound treatment using ultrasound imaging. , 2001, Ultrasound in medicine & biology.

[37]  J P Felmlee,et al.  MR guided focused ultrasound: technical acceptance measures for a clinical system , 2006, Physics in medicine and biology.

[38]  Vesna Zderic,et al.  Gel phantom for use in high-intensity focused ultrasound dosimetry. , 2005, Ultrasound in medicine & biology.

[39]  K. Kuroda,et al.  A precise and fast temperature mapping using water proton chemical shift , 1995, Magnetic resonance in medicine.

[40]  I. Rivens,et al.  The intensity dependence of the site of maximal energy deposition in focused ultrasound surgery. , 1996, Ultrasound in medicine & biology.