Assessment of the accuracy of an ultrasound elastography liver scanning system using a PVA-cryogel phantom with optimal acoustic and mechanical properties
Citation:
S. Cournane, L.M. Cannon, J.E. Browne, A.J. Fagan, Assessment of the accuracy of an ultrasound elastography liver scanning system using a PVA-cryogel phantom with optimal acoustic and mechanical properties, Physics in Medicine and Biology, 55, 19, 2010, 5965-5983Download Item:
Abstract:
The accuracy of a transient elastography liver-scanning ultrasound system was assessed using a
novel application of PVA-cryogel as a tissue-mimicking material with acoustic and shear
elasticity properties optimized to best represent those of liver tissue. Although the
liver-scanning system has been shown to offer a safer alternative for diagnosing liver cirrhosis
through stiffness measurement, as compared to the liver needle biopsy exam, the scanner?s
accuracy has not been fully established. The Young?s elastic modulus values of 5-6wt%
PVA-cryogel phantoms, also containing glycerol and 0.3?m Al2O3 and 3?m Al2O3, were
measured using a `gold standard? mechanical testing technique and transient elastography. The
mechanically measured values and acoustic velocities of the phantoms ranged between
1.6-16.1kPa and 1540-1570m/s, respectively, mimicking those observed in liver tissue. The
values reported by the transient elastography system overestimated the Young?s elastic modulus
values representative of the progressive stages of liver fibrosis by up to 32%. These results were
attributed to the relative rather than absolute nature of the measurement arising from the singlepoint
acoustic velocity calibration of the system, rendering the measurements critically
dependent on the speed of sound of the sample under investigation. Given the wide range of
acoustic velocities which exist in the liver, spanning healthy tissue to cirrhotic pathology,
coupled with the system?s assumption that the liver is approximately elastic when it is rather
highly viscoelastic, care should be exercised when interpreting the results from this system in
patient groups.
Sponsor
Grant Number
Science Foundation Ireland (SFI)
Author's Homepage:
http://people.tcd.ie/fagananDescription:
PUBLISHED
Author: FAGAN, ANDREW
Sponsor:
Science Foundation Ireland (SFI)Type of material:
Journal ArticleCollections
Series/Report no:
Physics in Medicine and Biology55
19
Availability:
Full text availableKeywords:
Bioengineering, highly viscoelasticSubject (TCD):
Next Generation Medical DevicesMetadata
Show full item recordLicences: