A Study on the Effects of Depth-Dependent Power Loss on Speckle Statistics Estimation.

Autor:	Christensen A; Department of Medical Physics, University of the Wisconsin, Madison, WI, USA. Electronic address: amchristens4@wisc.edu., Rosado-Mendez I; Department of Medical Physics, University of the Wisconsin, Madison, WI, USA; Department of Radiology, University of the Wisconsin, Madison, WI, USA., Hall TJ; Department of Medical Physics, University of the Wisconsin, Madison, WI, USA.
Jazyk:	angličtina
Zdroj:	Ultrasound in medicine & biology [Ultrasound Med Biol] 2024 Dec; Vol. 50 (12), pp. 1800-1811. Date of Electronic Publication: 2024 Sep 07.
DOI:	10.1016/j.ultrasmedbio.2024.08.001
Abstrakt:	Characterization of the interference patterns observed in B-mode images (i.e., speckle statistics) is a valuable tool in tissue characterization. However, changes in echo amplitudes unrelated to speckle, including power loss due to attenuation and diffraction, can bias these metrics, undermining their utility. Tissue with high attenuation such as the uterine cervix are especially affected. The purpose of this study was to demonstrate and quantify the effects of attenuation and diffraction on speckle statistics and to propose methods of compensation. Analysis was performed on simulated diffuse scattering phantoms of varying attenuation with simulated transducers at 9 and 5 MHz center frequency. Application in the in vivo macaque cervix using a clinical scanner is also presented. Nakagami and homodyned K distribution parameters were calculated in parameter estimation regions (PERs) of varying size within simulations and experiments. Changes in speckle statistics parameters with respect to PER size and depth were compared with and without two different compensation schemes. It has been shown that compensation for attenuation and diffraction is necessary to produce speckle statistics estimates that do not depend on medium attenuation or PER size. Reducing the dependence on these factors connects speckle statistics estimates more closely with the microstructure of the probed medium. Competing Interests: Conflict of interest All of the authors of this work are affiliated with the quantitative ultrasound laboratory (QUL) at the University of Wisconsin Madison, which has a research agreement with Siemens Medical Solutions, Inc. The QUL also provides custom phantom design, fabrication, and calibration services to industry and academic laboratories. (Copyright © 2024 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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