Microwave imaging for thermal therapy monitoring: temperature accuracy and image reconstruction time improvements

Paul M. Meaney; Margaret W. Fanning; Dun Li; Qianqian Fang; Sarah Pendergrass; Keith D. Paulsen

doi:10.1117/12.476644

10 June 2003 Microwave imaging for thermal therapy monitoring: temperature accuracy and image reconstruction time improvements

Paul M. Meaney, Margaret W. Fanning, Dun Li, Qianqian Fang, Sarah Pendergrass, Keith D. Paulsen

Author Affiliations +

Proceedings Volume 4954, Thermal Treatment of Tissue: Energy Delivery and Assessment II; (2003) https://doi.org/10.1117/12.476644
Event: Biomedical Optics, 2003, San Jose, CA, United States

Abstract

Microwave imaging has been investigated as a method of non-invasively estimating tissue electrical properties especially the conductivity, which is highly temperature dependent, as a means of monitoring thermal therapy. The technique we have chosen utilizes an iterative Gauss-Newton approach to converge on the correct property distribution. A previous implementation utilizing the complex form (CF) of the electric fields along with a sub-optimal phantom experimental configuration resulted in imaging temperature accuracy of only 1.6°C. Applying the log-magnitude/phase form (LMPF) of the algorithm has resulted in imaging accuracy on the order of 0.3°C which is a significant advance for the area of treatment monitoring. The LMPF algorithm was originally introduced as a way to reconstruct images of large, high-contrast scatterers as is the case in breast imaging. However, recent analysis of the Jacobian matrices for the comparable implementations has shown that the reconstruction problem in the new formulation more closely resembles a linear task as is the case in x-ray computed tomography. The comparisons were performed by examining plots of the Jacobian matrix terms for fixed transmit and receive antennas which demonstrated higher sensitivity in the center of the imaging zone along with narrower paths of senstivity between the atnenna pair for the LMPF algorithm. Animal model experiments have also been performed to validate these capabilities in a more realistic setting. Finally, the overall computational efficiency has been significantly enhanced through the use of the adjoint image reconstruction approach. This enables us to reconstruct images in roughly one minute which is essential if the approach is to be used as a therapy feedback mechanism.

Citation Download Citation

Paul M. Meaney, Margaret W. Fanning, Dun Li, Qianqian Fang, Sarah Pendergrass, and Keith D. Paulsen "Microwave imaging for thermal therapy monitoring: temperature accuracy and image reconstruction time improvements", Proc. SPIE 4954, Thermal Treatment of Tissue: Energy Delivery and Assessment II, (10 June 2003); https://doi.org/10.1117/12.476644

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
11 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Reconstruction algorithms

Antennas

Image restoration

Microwave imaging

Microwave radiation

Receivers

Thermography

Show All Keywords

Keywords/Phrases

Search In:

Publication Years