摘要:
Shear waves are detected with ultrasound. The detection of the shear wave is constrained using prior measurements in a more controlled environment (e.g., less noise). For example, shear waves measured in a phantom are used to constrain the detection of shear waves in a patient to avoid false positive detections.
摘要:
A shear wave velocity solution is provided for medical ultrasound imaging. Rather than determining shear wave information for each location based on distance from the origin of the shear wave and time to peak displacement for the location, displacement profiles resulting from different combinations of origin and detection locations are correlated. Shear information is detected using displacements from a diverse spatial combination of transmission locations and detection locations. The correlation combination is used in a same function for simultaneously solving for the delays for multiple lateral locations. Spatial diversity and layered correlation may provide for more accurate shear wave estimation.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Detection of tissue response is provided with a high pulse repetition frequency. A sequence of separable signals is transmitted in one event. For example, pulses at different frequencies are transmitted as separate waveforms, but in rapid succession. As another example, coded transmit pulses are used. After transmission of the pulses, signals are received. Based on the different frequencies or coding, tissue response is measured at different times based on the receive event. Instead of one measure, a plurality of measures are provided for a given transmit and receive event pair, increasing the effective pulse repetition frequency for shear or elasticity imaging.
摘要:
Measurements in diagnostic medical imaging are cross-referenced. A measurement made for one type of data is reflected in an image for another type of data. For example, a length is measured from ultrasound data. A line associated with the length is displayed on the ultrasound image. In a magnetic resonance image (MRI), the same line is displayed at a corresponding location. The same measurement may also be made with the MRI data and reflected in the ultrasound image. Each image shows both measurements in this example. The difference in the same measurements from different types of data may be useful for diagnosis. In the above example, the length is measured from ultrasound and from MRI. The difference between the two measured lengths may provide diagnostically useful information.
摘要:
Complex response of tissue is calculated as function of a convolution relationship associated with measured strain with applied stress. In the Fourier or frequency domain, the convolution is a simple algebraic computation, such as multiplication. The complex response provides elasticity and viscosity information, assisting diagnosis. Complex compliance may be directly calculated from the strain and stress. Complex fluidity may be directly calculated from strain rate and stress.
摘要:
Flow information (e.g., velocity and acceleration) and/or pressure gradient information are determined with ultrasound. Both velocity and acceleration are simultaneously estimated using a model and least squares analysis. Anti-aliasing of velocity information may be provided using the model and least squares analysis. Pressure gradient is calculated from velocity information automatically, more likely providing consistent measurements. Consistency may be increased further by automatically positioning a region of interest in either a multidimensional spatial image or a spatial-temporal image. A parametric image of pressure gradient for each spatial location within the image is generated as well as a delta pressure curve. Any single one or combinations of two or more of the features described above may be used.
摘要:
Shear wave characteristics are estimated from analytic data. Measures of displacement are converted into complex representations. The magnitude and/or phase components of the complex representation may be used for estimating various characteristics, such as velocity, center frequency, attenuation, shear modulus, or shear viscosity. The zero-phase of the phase component represents an occurrence of the shear wave at that location.