Electromagnetic acoustic imaging

Electromagnetic acoustic imaging (EMAI) is a new imaging technique that uses long-wavelength RF electromagnetic (EM) waves to induce ultrasound emission. Signal intensity and image contrast have been found to depend on spatially varying electrical conductivity of the medium in addition to conventional acoustic properties. The resultant conductivity- weighted ultrasound data may enhance the diagnostic performance of medical ultrasound in cancer and cardiovascular applications because of the known changes in conductivity of malignancy and blood-filled spaces. EMAI has a potential advantage over other related imaging techniques because it combines the high resolution associated with ultrasound detection with the generation of the ultrasound signals directly related to physiologically important electrical properties of the tissues. Here, we report the theoretical development of EMAI, implementation of a dual-mode EMAI/ultrasound apparatus, and successful demonstrations of EMAI in various phantoms designed to establish feasibility of the approach for eventual medical applications.

[1]  R A Kruger,et al.  Photoacoustic ultrasound. , 1994, Medical physics.

[2]  David Gur,et al.  A preliminary evaluation of multi-probe resonance-frequency electrical impedance based measurements of the breast. , 2011, Academic radiology.

[3]  A. Jara-Lazaro,et al.  A prospective study to compare the diagnostic performance of breast elastography versus conventional breast ultrasound. , 2010, Clinical radiology.

[4]  Boris Rubinsky,et al.  Electrical impedance characterization of normal and cancerous human hepatic tissue , 2010, Physiological measurement.

[5]  B. Blad,et al.  Impedance spectra of tumour tissue in comparison with normal tissue; a possible clinical application for electrical impedance tomography. , 1996, Physiological measurement.

[6]  Robert A Kruger,et al.  Photoacoustic angiography of the breast. , 2010, Medical physics.

[7]  M. Fink,et al.  Time reversal of ultrasonic fields. I. Basic principles , 1992, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[8]  K J Parker,et al.  Imaging of the elastic properties of tissue--a review. , 1996, Ultrasound in medicine & biology.

[9]  Marc Bodenstein,et al.  Principles of electrical impedance tomography and its clinical application , 2009, Critical care medicine.

[10]  R A Kruger,et al.  Thermoacoustic computed tomography--technical considerations. , 1999, Medical physics.

[11]  A. Manduca,et al.  Magnetic resonance elastography by direct visualization of propagating acoustic strain waves. , 1995, Science.

[12]  S Abboud,et al.  Evaluation of Impedance Technique for Detecting Breast Carcinoma Using a 2‐D Numerical Model of the Torso , 1999, Annals of the New York Academy of Sciences.

[13]  Richard Su,et al.  Real-time optoacoustic monitoring and three-dimensional mapping of a human arm vasculature. , 2010, Journal of biomedical optics.

[14]  J. C. TOZER,et al.  Magnetic Impedance Tomography a , 1999, Annals of the New York Academy of Sciences.

[15]  Young-Tae Lim,et al.  Microwave Tomography Analysis System for Breast Tumor Detection , 2012, Journal of Medical Systems.

[16]  Robert E Lenkinski,et al.  Radiofrequency ablation: importance of background tissue electrical conductivity--an agar phantom and computer modeling study. , 2005, Radiology.

[17]  Mathias Fink.  Time-reversal mirrors , 1993 .

[18]  Stephen Anthony Cerwin.  Electromagnetic-acoustic imaging , 2006 .

[19]  M. Cheney.  Inverse Boundary-Value Problems , 1997 .

[20]  Xu Xiao.  Photoacoustic imaging in biomedicine , 2008 .

[21]  Ryan J Halter,et al.  The correlation of in vivo and ex vivo tissue dielectric properties to validate electromagnetic breast imaging: initial clinical experience , 2009, Physiological measurement.

[22]  A. Tangoku,et al.  Basic study of a diagnostic modality employing a new electrical impedance tomography (EIT) method for noninvasive measurement in localized tissues. , 2010, The journal of medical investigation : JMI.