Evaluation of a nondiffracting transducer for tissue characterization

The authors describe a method for estimating backscatter coefficients of excised human liver samples and the RMI413A tissue equivalent phantom, using the J/sub 0/ Bessel nondiffracting transducer. A formula for the calculation of backscatter coefficients that requires only two one-dimensional integrations in addition to one-dimensional Fourier transforms is presented. This equation in combination with backscatter from a J/sub 0/ Bessel nondiffracting beam results in the ability to calculate backscatter coefficients in real time. In addition, estimations of the backscatter coefficients are more distance-independent because of the nonspreading nature of the J/sub 0/ Bessel nondiffracting beam. The present results compare well to those obtained by the conventional focused Gaussian beam transducer.<
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