Microwave‐induced thermoacoustic scanning CT for high‐contrast and noninvasive breast cancer imaging

Abstract

A fast thermoacoustic computed tomography system with a multielement linear transducer array was developed to image biological tissues with circular scanning. The spatial resolution of the imaging system and the spectra of the thermoacoustic signals were analyzed. A modified integration backprojection algorithm using velocity potential was employed to recover the direct energy deposition distribution, signal processing methods, and reconstruction algorithms were validated by imaging a phantom. The differences of the microwave-frequency dielectric properties between malignant and normal adipose-dominated tissues in the breast are considerable, and the absorption contrast can reach as large as 6:1 at 1.2 GHz. An experiment of human breast tissue with a tumor was performed with this system; the thermoacoustic images reconstructed by a limited-field-filtered backprojection algorithm and a modified integration backprojection algorithm were also compared with a mammogram. Our results show that the system can provide a rapid and noninvasive approach for high-contrast breast cancer imaging.

An Integrated Simulation Approach and Experimental Research on Microwave Induced Thermo-Acoustic Tomography System

“…Some experimental MITAT systems have been developed and been reported [12,13,[15][16][17]. In order to validate the performance of the integrated simulation approach, we have developed a MITAT system.…”

“…In recent years, various thermo-acoustic imaging (TAI) demonstrations have been reported [11][12][13]. Two-and three-dimensional (2-D and 3-D) imaging of breast tissue phantoms or real breast tissue specimens have been investigated [14][15][16][17].…”

System Development of Microwave Induced Thermo-Acoustic Tomography and Experiments on Breast Tumor

“…In recent years, experiments on imaging real human tissue of MITAT have attracted lots of attentions [5,14]. Some thermoacoustic imaging results for various kinds of phantoms were reported to demonstrate MITAT's potential in breast tumor detection [2][3][4][5].…”

“…Some thermoacoustic imaging results for various kinds of phantoms were reported to demonstrate MITAT's potential in breast tumor detection [2][3][4][5]. It requires that the electromagnetic parameters and acoustic properties of a phantom must be similar to a real tissue.…”

“…Microwave induced thermo-acoustic tomography (MITAT) has recently received more and more attentions due to its great potential in early breast cancer detection [1][2][3][4][5]. MITAT has the advantages of both high contrast of microwave imaging [6,7] and fine resolution of ultrasound imaging.…”