The attenuation coefficient slope (ACS) has the potential to be used for tissue characterization and as
a diagnostic ultrasound tool, hence complementing B-mode images. The ACS can be valuable for estimation
of other ultrasound parameters such as the backscatter coefficient. There is a well-known tradeoff
between the precision of the estimated ACS values and the data block size used in spectral-based
techniques such as the spectral log difference (SLD). This trade-off limits the practical usefulness of
spectral-based attenuation imaging techniques.
In this thesis work, the regularized spectral log difference (RSLD) technique is presented in detail
and evaluated with simulations and experiments with physical phantoms, ex vivo and in vivo. The ACS
values obtained when using the RSLD technique were compared to the ones obtained when using the
SLD technique, as well as the ground truth ACS values obtained with insertion loss techniques. The
results showed that the RSLD technique allowed significantly decreasing estimation variance when
using small data block sizes (i.e., standard deviation of percentage error reduced by more than an order
of magnitude in all cases when using 10 x 10 data blocks) without sacrificing estimation accuracy.
Therefore, the RSLD allows for the reconstruction of attenuation coefficient images with an improved
trade-off between spatial resolution and estimation precision. / Tesis
| Identifer | oai:union.ndltd.org:PUCP/oai:tesis.pucp.edu.pe:20.500.12404/8991 |
| Date | 13 July 2017 |
| Creators | Coila Pacompia, Andres Leonel |
| Contributors | Lavarello Montero, Roberto Janniel |
| Publisher | Pontificia Universidad Católica del Perú, PE |
| Source Sets | Pontificia Universidad Católica del Perú |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, http://creativecommons.org/licenses/by-nc-nd/2.5/pe/ |
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