Systems and methods for detecting regions of altered stiffness
An ultrasound imaging method for detecting a target region of altered stiffness is provided. The method comprises delivering at least one reference pulse to the target region to detect an initial position of the target region, delivering a first pushing pulse having a first value of a variable parameter to a target region to displace the target region to a first displaced position, delivering a first tracking pulse to detect the first displaced position of the target region, delivering a second pushing pulse having a second value of the variable parameter to the target region to displace the target region to a second displaced position, and delivering a second tracking pulse to detect the second displaced position of the target region. An ultrasound imaging system for detecting a region of altered stiffness is also provided.
1. An ultrasound imaging method for detecting a target region of altered stiffness, comprising:
delivering at least one reference pulse to the target region to detect an initial position of the target region;
delivering a first pushing pulse having a first value of a variable parameter to the target region to displace the target region to a first displaced position;
delivering a first tracking pulse to detect the first displaced position of the target region;
delivering a second pushing pulse having a second value of the variable parameter to the target region to displace the target region to a second displaced position;
delivering a second tracking pulse to detect the second displaced position of the target region; and
detecting the target region of altered stiffness based on the first displaced position and the second displaced position of the target region.
2. The method of claim 1 , wherein the first pushing pulse and the second pushing pulse are delivered to the target region and at least one other target region.
3. The method of claim 1 , wherein the variable parameter of the pushing pulse comprises an amplitude, a peak power, an average power, a length, a frequency, a waveform, pulse repetition frequency, or combinations thereof.
4. The method of claim 3 , further comprising mapping displacements of the target region with respect to the variable parameter.
5. The method of claim 1 , wherein the first or second tracking pulses are, respectively, delivered after a motion induced by the first or second pushing pulses is reduced to a determined value.
6. The method of claim 1 , further comprising interleaving one or more of the reference pulse, the tracking pulse, or the pushing pulses for the target region and at least one other target region.
7. The method of claim 1 , wherein at least one of the first and second pushing pulses is delivered as a plurality of pulses.
8. The method of claim 7 , wherein the first tracking pulse, or the second tracking pulse, or both, are delivered in between the plurality of pulses of the first or the second pushing pulse.
9. The method of claim 1 , wherein at least one of the first and second pushing pulses is delivered to the target region while varying two or more variable parameters of at least one of the first and second pushing pulses.
10. The method of claim 9 , wherein the first and second pushing pulses are delivered at the target region while successively changing the variable parameter before moving to at least one other target region.
11. The method of claim 10 , further comprising:
delivering the first and second pushing pulses having the first value of the variable parameter to the target region and the at least one other target region and changing the value of the variable parameter of the first and second pushing pulses to the second value; and
delivering the first and second pushing pulses having the second value of the variable parameter to the target region and the at least one other target region.
12. The method of claim 1 , further comprising varying pulse repetition frequency (PRF) of the first tracking pulse, or the second tracking/pushing pulse, or both.
13. The method of claim 1 , further comprising measuring at least one of a maximum displacement, a time-to-peak displacement, a time to recover from peak displacement to a determined value, an integral under the displacement curve, or a displacement at a determined time for the target region as a function of the variable parameter.
14. The method of claim 1 , further comprising delivering another reference pulse prior to delivering the second pushing pulse.
15. The method of claim 1 , further comprising delivering at least a pair of pushing pulses, wherein one of the pair of pushing pulses comprises a first variable parameter, and the other of the pair of pushing pulses comprises a second variable parameter, and wherein one of the first and second variable parameters is taken as a reference.
16. A method of detecting a target region of altered stiffness, comprising:
delivering pushing pulses at the target region while varying a variable parameter of the pushing pulses;
tracking displacements in one or more regions disposed outside the target region; and
detecting the target region of altered stiffness based on the displacements in the one or more regions disposed outside the target region.
17. The method of claim 16 , further comprising measuring at least one of a maximum displacement, a time-to-peak displacement, a time to recover from peak displacement to a determined value, an integral under a displacement curve, or a displacement at a determined time for the target region as a function of the variable parameter of the pushing pulses.