Real-time 3D image-guided HIFU therapy.
ABSTRACT Real-time three-dimensional ultrasound imaging (4D US) was utilized to monitor the treatment site during high-intensity focused ultrasound (HIFU) treatment. To obtain real-time monitoring during HIFU sonication, a 4D US imaging system and HIFU were synchronized and interference on the US image adjusted so that the region of interest was visible during treatment. The system was tested using tissue mimicking phantom gels and chicken breast tissue. The 4D US showed hyperechoic spots at the focal region of the HIFU transducer which then slowly faded after HIFU treatment. The hyperechoic regions were used as an indication of coagulative necrosis which occurs at temperatures higher than 60 degrees C. Different intensities of HIFU were applied to observe the difference in lesion formation and to determine the threshold intensity that produced hyperechoic regions due to the thermal and mechanical effects of focused ultrasound waves. The position, orientation, and shape of various lesions were examined in the three dimensional ultrasound images, and the volume of the lesions was measured. These volumes were compared to the volume measurements obtained from dissection of the tissue and phantom gels.
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ABSTRACT: The problem studied in this paper is ultrasound image reconstruction from frequency-domain measurements of the scattered field from an object with contrast in attenuation and sound speed. The case where the object has uniform but unknown contrast in these properties relative to the background is considered. Background clutter is taken into account in a physically realistic manner by considering an exact scattering model for randomly located small scatterers that vary in sound speed. The resulting statistical characteristics of the interference is incorporated into the imaging solution, which includes applying a total-variation minimization based approach where the relative effect of perturbation in sound speed to attenuation is included as a parameter. Convex optimization methods provide the basis for the reconstruction algorithm. Numerical data for inversion examples are generated by solving the discretized Lippman-Schwinger equation for the object and speckle-forming scatterers in the background. A statistical model based on the Born approximation is used for reconstruction of the object profile. Results are presented for a two dimensional problem in terms of classification performance and compared to minimum-l2-norm reconstruction. Classification using the proposed method is shown to be robust down to a signal-to-clutter ratio of less than 1 dB.03/2011;
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ABSTRACT: Image-guided high-intensity focused ultrasound (HIFU) has been used for more than ten years, primarily in the treatment of liver and prostate cancers. HIFU has the advantages of precise cancer ablation and excellent protection of healthy tissue. Breast cancer is one of the most common cancers in women. HIFU, in combination with other therapies, has the potential to improve both oncological and cosmetic outcomes for breast cancer patients by providing a curative therapy that conserves mammary shape. Unfortunately, HIFU therapy is not frequently used in breast cancer treatment currently, and efforts to increase HIFU treatment availability must be made. In this article, we compare different image-guided models for HIFU and review the status, drawbacks and potential of HIFU therapy for breast cancer treatment.Chinese journal of cancer 12/2012;
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ABSTRACT: The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms.Ultrasonography (Seoul, Korea). 07/2014; 33(3):191-199.