Image Reconstruction in Photoacoustic Computed Tomography with Acoustically Heterogeneous Media

<p>Photoacoustic computed tomography (PACT), also known as optoacoustic or thermoacoustic tomography, is a rapidly emerging hybrid imaging modality that combines optical image contrast with ultrasound detection. The majority of currently available PACT image reconstruction algorithms are based on idealized imaging models that assume a lossless and acoustically homogeneous medium. However, in many applications of PACT these assumptions are violated and the induced photoacoustic (PA) wavefields are scattered and absorbed as they propagate to the receiving transducers. In those applications of PACT, the reconstructed images can contain significant distortions and artifacts if the inhomogeneous acoustic properties of the object are not accounted for in the reconstruction algorithm. In this dissertation, we develop and investigate a full-wave approach to iterative image reconstruction in PACT with acoustically heterogeneous lossy media. A key contribution of this work is the establishment of a discrete imaging model that is based on the exact PA wave equation and a procedure to implement an associated matched discrete forward and backprojection</p> <p>operator pair, which permits application of a variety of modern iterative image reconstruction algorithms that can mitigate the effects of noise, data incompleteness and model errors. Another key contribution is the development of an optimization approach to joint reconstruction (JR) of absorbed optical energy density and speed of sound in PACT, which is utilized to investigate the numerical properties of the JR problem and its feasibility in practice. We also develop a TR-based methodology to compensate for heterogeneous acoustic attenuation that obeys a frequency power law. In addition, we propose a image reconstruction methodology for transcranial PACT that employs detailed subject-specific descriptions of the acoustic properties of the skull to mitigate skull-induced distortions in the reconstructed image.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biomedical Engineering

Year dc:date.available

2014

Author dc:creator

• Huang, Chao

Contributors dc:contributor

• Mark A. Anastasio

• Acoustic heterogeneity
• Image reconstruction
• Iterative reconstruction
• Optoacoustic computed tomography
• Photoacoustic computed tomography
• thermoacoustic computed tomography
• Biomedical Engineering and Bioengineering
• Engineering

Language dc:language

English (en)

DOI

https://doi.org/10.7936/K75B00F2

OAI identifier oai:identifier

oai:openscholarship.wustl.edu:etd-2308