Quantitative microwave-induced thermoacoustic tomography.
OBJECTIVE
Microwave-induced thermoacoustic tomography (MI-TAT) is an imaging modality that exploits dielectric contrast while producing images with high ultrasound resolution. Existing reconstruction algorithms for MI-TAT are qualitative and can image only the distribution of the absorbed microwave energy or power loss density. Here the authors describe a method for quantitative MI-TAT and obtain the distribution of dielectric property which directly correlates with tissue structural and functional information.


METHODS
The authors implement the quantitative MI-TAT method based on the finite-element (FE) solution to the Helmholtz equation for electromagnetic field coupled with the thermoacoustic wave equation. Regularization techniques are also used in the FE-based reconstruction algorithm.


RESULTS
Simulation results are obtained under various practical scenarios including different noise levels, different contrast levels between the heterogeneity and background region, and multiple targets with various sizes and shapes.


CONCLUSIONS
The quantitative MI-TAT method described can provide accurate recovery of conductivity distribution in heterogeneous media and is insensitive to noise effect.
Yao
Lei
L
Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, USA.
Guo
Gaofeng
G
Jiang
Huabei
H
D000465:Algorithms; D004553:Electric Conductivity; D004574:Electromagnetic Fields; D007091:Image Processing, Computer-Assisted; D008872:Microwaves; D014054:Tomography / Q000379:methods*