Ultrasound systems and methods for real-time noninvasive spatial temperature estimation

Abstract

Ultrasound systems and methods for real-time noninvasive spatial temperature estimation are disclosed herein. A method for noninvasive temperature estimation in accordance with an embodiment of the present technology can include, for example, propagating ultrasound waves into tissue and detecting echoes of the ultrasound waves. The ultrasound waves can become nonlinear as they propagate into the tissue. The method can further include monitoring changes in tissue temperature in real-time using a spectral-based temperature estimation approach, which correlates nonlinear acoustic effects with changes in tissue temperature.

I/We claim: 
     
         1 . A method of noninvasively treating tissue, the method comprising:
 applying targeted energy to tissue at a treatment site;   transmitting ultrasound waves that become nonlinear at a focal region in the tissue;   detecting harmonics of the nonlinear ultrasound waves; and   determining tissue temperature at the focal region in real-time using changes in the magnitudes of detected harmonics to estimate the tissue temperature, wherein greater attenuation of an individual harmonic correlates to an increase in the tissue temperature.   
     
     
         2 . The method of  claim 1  wherein applying targeted energy to the tissue at the treatment site comprises pulsing high-intensity focused ultrasound (HIFU) waves toward the target site. 
     
     
         3 . The method of  claim 1  wherein determining the tissue temperature comprises determining the tissue temperature after the tissue has coagulated. 
     
     
         4 . The method of  claim 1 , further comprising monitoring changes in tissue temperature proximal to the focal region using changes in the sound speed of detected echoes of ultrasound waves to estimate the tissue temperature, wherein faster sound speeds correlate to higher tissue temperatures. 
     
     
         5 . The method of  claim 1  wherein:
 transmitting ultrasound waves comprises transmitting ultrasound waves with a multilayer transducer device, the multilayer transducer device having a first plurality of transducers configured to propagate HIFU waves and a second plurality of transducers; and 
 detecting harmonics of the nonlinear ultrasound waves comprises detecting up to at least the third harmonic with the second plurality of transducers of the multilayer transducer device.