| Autor: |
Mohanty, Kaustav, Blackwell, John, Masuodi, S. Behrooz, Ali, Mir Hasnain, Egan, Thomas, Muller, Marie |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 7/16/2018, Vol. 113 Issue 3, pN.PAG-N.PAG, 5p, 5 Graphs |
| Abstrakt: |
In this letter, we present a near-field method for mapping the micro-architecture of complex media based on the measurement of the diffusion constant D using multiple backscattering of ultrasound waves. Simulation results are reported and validated with experiments. For both simulations and experiments, a linear array of ultrasound transducers is used. The coherent and incoherent intensities are separated using a matrix manipulation of the inter-element response matrix. We demonstrate that no beamforming is necessary to extract the diffusion constant. Acquiring sub-inter-element response matrices by using subsets of elements and calculating the growth of the diffusive halo for each sub-matrix provides an estimate of a semi-local diffusion constant, enabling a 1-D mapping of the scatterer density or volume fraction in a strongly heterogeneous medium. This methodology is then applied to quantitatively characterize the lung parenchyma and detect the presence of solitary pulmonary nodules. The semi-local diffusion constant is mapped along the transducer axis to search for high D values, which correspond to the nodule/lesion location. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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