TY - GEN
T1 - Compensation for air voids in photoacoustic computed tomography image reconstruction
AU - Matthews, Thomas P.
AU - Li, Lei
AU - Wang, Lihong V.
AU - Anastasio, Mark A.
N1 - Publisher Copyright:
© 2016 SPIE.
PY - 2016
Y1 - 2016
N2 - Most image reconstruction methods in photoacoustic computed tomography (PACT) assume that the acoustic properties of the object and the surrounding medium are homogeneous. This can lead to strong artifacts in the reconstructed images when there are significant variations in sound speed or density. Air voids represent a particular challenge due to the severity of the differences between the acoustic properties of air and water. In whole-body small animal imaging, the presence of air voids in the lungs, stomach, and gastrointestinal system can limit image quality over large regions of the object. Iterative reconstruction methods based on the photoacoustic wave equation can account for these acoustic variations, leading to improved resolution, improved contrast, and a reduction in the number of imaging artifacts. However, the strong acoustic heterogeneities can lead to instability or errors in the numerical wave solver. Here, the impact of air voids on PACT image reconstruction is investigated, and procedures for their compensation are proposed. The contributions of sound speed and density variations to the numerical stability of the wave solver are considered, and a novel approach for mitigating the impact of air voids while reducing the computational burden of image reconstruction is identified. These results are verified by application to an experimental phantom.
AB - Most image reconstruction methods in photoacoustic computed tomography (PACT) assume that the acoustic properties of the object and the surrounding medium are homogeneous. This can lead to strong artifacts in the reconstructed images when there are significant variations in sound speed or density. Air voids represent a particular challenge due to the severity of the differences between the acoustic properties of air and water. In whole-body small animal imaging, the presence of air voids in the lungs, stomach, and gastrointestinal system can limit image quality over large regions of the object. Iterative reconstruction methods based on the photoacoustic wave equation can account for these acoustic variations, leading to improved resolution, improved contrast, and a reduction in the number of imaging artifacts. However, the strong acoustic heterogeneities can lead to instability or errors in the numerical wave solver. Here, the impact of air voids on PACT image reconstruction is investigated, and procedures for their compensation are proposed. The contributions of sound speed and density variations to the numerical stability of the wave solver are considered, and a novel approach for mitigating the impact of air voids while reducing the computational burden of image reconstruction is identified. These results are verified by application to an experimental phantom.
KW - Photoacoustic computed tomography
KW - acoustic heterogeneity
KW - image reconstruction
UR - http://www.scopus.com/inward/record.url?scp=84975087394&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84975087394&partnerID=8YFLogxK
U2 - 10.1117/12.2213307
DO - 10.1117/12.2213307
M3 - Conference contribution
AN - SCOPUS:84975087394
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Photons Plus Ultrasound
A2 - Oraevsky, Alexander A.
A2 - Wang, Lihong V.
PB - SPIE
T2 - Photons Plus Ultrasound: Imaging and Sensing 2016
Y2 - 14 February 2016 through 17 February 2016
ER -