Abstract: High intensity focused ultrasound (HIFU) is registered with imaging. The effects of transmission from a HIFU transducer, such as a rise in temperature, are detected by a separate imaging system. By using multiple transmissions, a plurality of locations of the transmissions from the HIFU transducer are determined within the imaging system coordinates. A transform relating the imaging system coordinates to the HIFU transducer coordinates is determined from the detected effects. The transform may be used to relate locations indicated in images of the imaging system with coordinates of the HIFU transducer for application of HIFU. The imaging system may not have to scan the HIFU transducer or fiducials and a fixed relationship may not be needed.

Abstract: Magnetic resonance and ultrasound parametric image is fused or combined. MRI and ultrasound imaging are used to acquire the same type of parametric images. Fused data is created by combining ultrasound and MRI parametric data at times for which both types of data are available. Rather than sacrificing rate, fused data is created for times for which MRI data is not acquired. A curve representing the values of the parameter over time is fit to the available MRI and ultrasound data of each location, resulting in fused data at times for which MRI data is not available.

Abstract: Sub-aperture control is provided for high intensity focused ultrasound. Test transmissions are made sequentially from different sub-apertures. The tissue response at the focal regions is determined and used to select sub-apertures. For example, one or more sub-apertures are not used where temperature does not rise above certain threshold or tissue displacement is weak, such as associated with intervening bone or attenuating tissue. Other factors may be used instead or in addition to tissue response at the focal region. Relative proximity of the sub-apertures to a lesion, angular distribution of the sub-apertures, shape or size of the sub-aperture focal regions as compared to the tissue to be treated, or combinations thereof may be used. Once selected, the relative weight for each sub-aperture may be adjusted based on measured tissue response for each sub-aperture, such as to provide more equal treatment contribution from different sub-apertures.

Abstract: Magnetic resonance imaging frame rate is increased using ultrasound information. Magnetic resonance (MR) images may be provided at an increased frame rate relative to the MR acquisition. For times between acquisition of MR data, MR data may be created. To account for any change in position of tissue over time, ultrasound is used to track the location of tissue or other imaged structure. The ultrasound-based location information is used to indicate the position of intensities or values of the created MR data. MR images at a higher frame rate than the MR acquisition are generated, but with accuracy of relative position based on the ultrasound data.

Abstract: Therapy control and/or monitoring is performed with an ultrasound scanner. The ultrasound scanner detects temperature to monitor therapy, and perform HIFU beam location refocusing of the therapy system based on the temperature. The monitoring is synchronized with the therapy using a trigger output of the ultrasound scanner. The trigger output responds to a scan sequence of the ultrasound scanner. To meet a given therapy plan, the scan sequence is customized, resulting in the customized trigger sequence. Three dimensional or multi-planar reconstruction rendering is used to represent temperature for monitoring feedback. The temperature at locations not being treated may be monitored. If the temperature has an undesired characteristic (e.g., too high), then the therapy is controlled by ceasing, at least temporarily.

Abstract: Skin temperature is measured during medical ultrasound therapy. The temperature of a standoff between the transducer and skin is monitored. The temperature of the standoff relates to the skin temperature. The temperature, whether skin or standoff temperature, is used to control the therapy. The temperature feedback may allow for increased or optimize therapy levels.

Abstract: Magnetic resonance and ultrasound parametric image is fused or combined. MRI and ultrasound imaging are used to acquire the same type of parametric images. Fused data is created by combining ultrasound and MRI parametric data at times for which both types of data are available. Rather than sacrificing rate, fused data is created for times for which MRI data is not acquired. A curve representing the values of the parameter over time is fit to the available MRI and ultrasound data of each location, resulting in fused data at times for which MRI data is not available.

Abstract: High intensity focused ultrasound (HIFU) is registered with imaging. The effects of transmission from a HIFU transducer, such as a rise in temperature, are detected by a separate imaging system. By using multiple transmissions, a plurality of locations of the transmissions from the HIFU transducer are determined within the imaging system coordinates. A transform relating the imaging system coordinates to the HIFU transducer coordinates is determined from the detected effects. The transform may be used to relate locations indicated in images of the imaging system with coordinates of the HIFU transducer for application of HIFU. The imaging system may not have to scan the HIFU transducer or fiducials and a fixed relationship may not be needed.

Abstract: A viscoelastic property of tissue is measured in vivo. To collect more information and/or estimate viscosity, shear modulus, and/or other shear characteristics, an amplitude and phase modulated waveform is transmitted to the tissue. The displacement caused by the waveform over time includes displacements associated with response to different frequencies. By examining the displacement in the frequency domain, one or more viscoelastic properties may be calculated for different frequencies. The frequency response may indicate the health of the tissue.

Abstract: A viscoelastic property of tissue is measured in vivo. To collect more information and/or estimate viscosity, shear modulus, and/or other shear characteristics, an amplitude and phase modulated waveform is transmitted to the tissue. The displacement caused by the waveform over time includes displacements associated with response to different frequencies. By examining the displacement in the frequency domain, one or more viscoelastic properties may be calculated for different frequencies. The frequency response may indicate the health of the tissue.

Abstract: Sub-aperture control is provided for high intensity focused ultrasound. Test transmissions are made sequentially from different sub-apertures. The tissue response at the focal regions is determined and used to select sub-apertures. For example, one or more sub-apertures are not used where temperature does not rise above certain threshold or tissue displacement is weak, such as associated with intervening bone or attenuating tissue. Other factors may be used instead or in addition to tissue response at the focal region. Relative proximity of the sub-apertures to a lesion, angular distribution of the sub-apertures, shape or size of the sub-aperture focal regions as compared to the tissue to be treated, or combinations thereof may be used. Once selected, the relative weight for each sub-aperture may be adjusted based on measured tissue response for each sub-aperture, such as to provide more equal treatment contribution from different sub-apertures.