Ultrasound attenuation coefficient estimation using aberration compensation and reference phantoms

A method for estimating ultrasound attenuation coefficient using aberration compensation and reference phantom method, comprising the following steps:

• (a) acquiring ultrasound data on a human sample and calculating the central frequencies of echo signals at the depth d after the transmission of a single frequency f0, wherein d is the depth at the top edge of the region of interest;
• (b) acquiring ultrasound data on N reference phantoms with N attenuation coefficients α1, α2, α3, . . . αN after the transmission of a plurality of m frequencies f1, f2, f3 . . . fm on each phantom, and with almost the same settings as in the human study except for the transmit frequencies, and calculating the center frequencies of the echo signals at the depth d;
• (c) selecting a specific reference phantom αi with a specific transmit frequency fj so that the center frequencies of its echo signals are closest to the center frequencies of the echo signals from the human sample at the depth d among the central frequencies of the echo signals at the depth d calculated from the N reference phantoms at a plurality of different transmit frequencies;
• (d) calculating the attenuation coefficient of the human sample according to the reference phantom method, according to the formula
• α
• s
• (
• f
• )
• =
• -
• d
• ⁡
• (
• ln
• ⁡
• (
• S
• s
• (
• f
• ,
• z
• )
• S
• i
• (
• f
• ,
• z
• )
• )
• )
• 4
• ⁢
• dz
• +
• α
• i
• (
• f
• )
• ,
• wherein αs(f) is the attenuation coefficient of the human sample to be estimated, Ss(f, z) is the power spectra of the echo signals of the human sample at the transmit frequency f0, Si(f, z) is the power spectra of the echo signals of the reference phantom at the selected transmit frequency fj,
• d
• ⁡
• (
• ln
• ⁡
• (
• S
• s
• (
• f
• ,
• z
• )
• S
• i
• (
• f
• ,
• z
• )
• )
• )
• 4
• ⁢
• dz
• is the slope or differential value of the logarithm of the power spectra ratio versus the depth in the region of interest, and αi(f) is the attenuation coefficient of the selected reference phantom;
• wherein, when calculating the center frequencies of the echo signals of the human sample and of the reference phantoms at the depth d, using the centroid method by the following formula specifically
• f
• c
• =
• ∫
• 0
• ∞
• f
• ⁢
• ❘
• "\[LeftBracketingBar]"
• X
• ⁡
• (
• f
• )
• ❘
• "\[RightBracketingBar]"
• ⁢
• df
• ∫
• 0
• ∞
• ❘
• "\[LeftBracketingBar]"
• X
• ⁡
• (
• f
• )
• ❘
• "\[RightBracketingBar]"
• ⁢
• df
• ,
• where fc is the center frequency to be estimated, f is the frequency of the echo signals, and X(f) is the spectra of the echo signals at the depth d;
• wherein before calculation of the central frequencies and the power spectra of the acquired ultrasound data, performing noise reduction on the power spectra of the echo signals of the human sample and on the power spectra of the echo signals from each reference phantom.