Soft tissue absorption tomography with correction for scattering aberrations.

摘要: Among the many factors involved in ultrasound attenuation phenomena, scattering effects play a major role, even unexpected case of soft tissues. It is proposed this study to quantitatively evaluate affecting measurements before reconstructing absorption parameter alone. The reconstruction procedure involves three steps: (1) Estimating sound speed map using trans-mission tomography algorithm. This estimation provides numerical phantom organ probed, cleared all dissipative components. free mimics (viscoacoustic) tissues imaged except for density and characteristics: priori equals 1000 kg/m 3 not taken into account. impedance fluctuations object are therefore approximated on basis contrast. (2) Synthesing field scattered by phantom; observed here results solely from phenomenon. synthesis carried out finite-element time domain code simulating ultrasonic propagation through phantom. distortion reference introduced log spectral estimator. (3) Reducing distortions integrated measured along ray paths procedure. corrected then processed tomographic that an estimate distribution. Simple simulations show improvement obtained estimates with approach.