(Color online) The value of the mean error in the attenuation slope for the simulations vs the usable bandwidth and the location along of the section used to obtain the estimates.
(a) Difference between estimated and simulated attenuation slope value of plotted vs location along the echo in the simulations using a bandwidth of . The error bars represent one s.d. above and below the mean as calculated using the 20 independent sets of 50 wave forms. (b) Mean error in attenuation vs location along the echo in the simulations both with and without focusing compensation.
An example of the normalized amplitude spectra from the Plexiglas block both with and without the cervix sample along the propagation path.
An example of the estimated attenuation vs frequency after dividing the spectra shown with a linear fit vs frequency.
Fitting a line through the measured values to obtain an equation of vs wavelength, .
In vivo ultrasound attenuation slope estimates for rat cervix showing the mean and standard deviation for every cervix sample (bars) vs gestational age as well as the mean and standard deviation for all of the cervices at each gestational age (horizontal lines).
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