Shear-wave elasticity imaging of a @entity1575 XXXX model using high-frequency ultrasound.

@entity1575 @entity82 @entity4314 @entity19
The objective of this study was to develop a high-frequency imaging platform for evaluating @entity1575 in @entity19 based on shear-wave elasticity imaging (SWEI). Although SWEI has been used to diagnose @entity1575 clinically, it is performed at relatively low frequencies (<20 MHz). For preclinical ultrasound imaging in small animals, a high-frequency (>30 MHz) single-element transducer with mechanical scanning is often used. In this study we developed a new SWEI system based on a 40-MHz single-element transducer for imaging and a separate 20-MHz excitation transducer for producing the radiation force and the associated shear waves. @entity1575 was induced in ten C57BL/6 (B6) @entity19 using @entity4314 ; the other ten @entity19 served as the control group. Synchronizing the excitation beam (i.e., the beam from the excitation transducer) and the detection beam sequence (i.e., the beam from the imaging transducer) allows this mechanicalscanning setup to analyze the shear-wave dispersion relation. The liver viscoelastic properties were determined in vivo by measuring the shear-wave dispersion curve followed by fitting to the Voigt model. The @entity19 were then killed and the @entity82 stage was evaluated (from F0 to F4) based on the METAVIR score. The measured mean values of liver elasticity and viscosity, respectively, ranged from 1.06 to 1.89 kPa and from 1.29 to 1.75 Pa   s for normal F0 and @entity82 stages of F3 and F4. The Spearman coefficients for the correlations between the measured elasticity and viscosity at various @entity82 stages as assessed by the METAVIR score were 0.73 (p < 0.001) and 0.634 (p = 0.0013), respectively. We also found that the collagen content in the liver was linearly correlated with the measured elasticity (r(2) = 0.54, p < 0.001) and less strongly with the viscosity (r2 = 0.26, p = 0.022). Finally, the diagnosis performance of high-frequency SWEI was evaluated using multivariate receiver operating characteristic curve (ROC) analysis. The areas under the multivariate ROC curve for diagnosing @entity82 stages of F >=  3, F = 4, F0 vs. F3, F0 vs. F4, and F3 vs. F4 were 0.9, 0.98, 0.83, 1.0, and 0.96, respectively. Compared with traditional ROC analysis, an improved diagnosis performance was found for diagnosing @entity82 stages of F >=  3 and F0 vs. F3. These results demonstrate that the developed high-frequency SWEI platform can yield quantitative viscoelastic properties for diagnosing various @entity82 stages in @entity19 . It is a promising tool for studying the progression of @entity1575 in preclinical animal models both noninvasively and quantitatively.
