Pulsed-microwave-induced thermoacoustic tomography

Filtered backprojection in a circular measurement configuration

Xu, Minghua
Wang, Lihong V.

Optical Imaging Laboratory, Biomedical Engineering Program, Texas A&M University, 3120 TAMU, College Station, Texas 77843-3120

^a)Author to whom all correspondence should be addressed. Telephone: 979-847-9040; fax: 979-845-4450; electronic mail: [email protected]; URL: http://oilab.tamu.edu.

(Received 12 December 2001; accepted for publication 7 May 2002; published 16 July 2002)

[DOI: 10.1118/1.1493778]

Medical Physics 29(8):p 1661-1669, August 2002.

Our study on pulsed-microwave-induced thermoacoustic tomography in biological tissues is presented. A filtered backprojection algorithm based on rigorous theory is used to reconstruct the cross-sectional image from a thermoacoustic measurement in a circular configuration that encloses the sample under study. Specific details describing the measurement of thermoacoustic waves and the implementation of the reconstruction algorithm are discussed. A two-dimensional (2D) phantom sample with 2 mm features can be imaged faithfully. Through numerical simulation, the full width half-maximum (FWHM) of the point-spread function (PSF) is calculated to estimate the spatial resolution. The results demonstrate that the circular measurement configuration combined with the filtered backprojection method is a promising technique for detecting small tumors buried in biological tissues by utilizing microwave absorption contrast and ultrasound spatial resolution (∼mm).