Assessment of Structural Heterogeneity and Viscosity in the Cervix Using Shear Wave Elasticity Imaging: Initial Results from a Rhesus Macaque Model
Por:
Rosado-Mendez I.M., Palmeri M.L., Drehfal L.C., Guerrero Q.W., Simmons H., Feltovich H., Hall T.J.
Publicada:
1 ene 2017
Resumen:
Shear wave elasticity imaging has shown promise in evaluation of the pregnant cervix. Changes in shear wave group velocity have been attributed exclusively to changes in stiffness. This assumes homogeneity within the region of interest and purely elastic tissue behavior. However, the cervix is structurally/microstructurally heterogeneous and viscoelastic. We therefore developed strategies to investigate these complex tissue properties. Shear wave elasticity imaging was performed ex vivo on 14 unripened and 13 misoprostol-ripened cervix specimens from rhesus macaques. After tests of significant and uniform shear wave displacement, as well as reliability of estimates, group velocity decreased significantly from the distal (vaginal) to proximal (uterine) end of unripened, but not ripened, specimens. Viscosity was quantified by the slope of the phase velocity versus frequency. Dispersion was observed in both groups (median: 5.5 m/s/kHz, interquartile range: 1.5–12.0 m/s/kHz), also decreasing toward the proximal cervix. This work suggests that comprehensive assessment of complex tissues such as cervix requires consideration of structural heterogeneity and viscosity. © 2016 World Federation for Ultrasound in Medicine & Biology
Filiaciones:
Rosado-Mendez I.M.:
Department of Medical Physics, University of Wisconsin—Madison, Madison, Wisconsin, United States
Palmeri M.L.:
Biomedical Engineering, Duke University, Durham, North Carolina, United States
Drehfal L.C.:
Department of Medical Physics, University of Wisconsin—Madison, Madison, Wisconsin, United States
Guerrero Q.W.:
Department of Medical Physics, University of Wisconsin—Madison, Madison, Wisconsin, United States
Simmons H.:
Wisconsin National Primate Research Center, Madison, Wisconsin, United States
Feltovich H.:
Department of Medical Physics, University of Wisconsin—Madison, Madison, Wisconsin, United States
Maternal Fetal Medicine, Intermountain Healthcare, Provo, Utah, United States
Hall T.J.:
Department of Medical Physics, University of Wisconsin—Madison, Madison, Wisconsin, United States
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