Scanning thermoacoustic tomography in biological tissue.
Microwave-induced thermoacoustic tomography was explored to image biological tissue. Short microwave pulses irradiated tissue to generate acoustic waves by thermoelastic expansion. The microwave-induced thermoacoustic waves were detected with a focused ultrasonic transducer. Each time-domain signal from the ultrasonic transducer represented a one-dimensional image along the acoustic axis of the ultrasonic transducer similar to an ultrasonic A-scan. Scanning the system perpendicularly to the acoustic axis of the ultrasonic transducer would generate multi-dimensional images. Two-dimensional tomographic images of biological tissue were obtained with 3-GHz microwaves. The axial and lateral resolutions were characterized. The time-domain piezo-electric signal from the ultrasonic transducer in response to the thermoacoustic signal was simulated theoretically, and the theoretical result agreed with the experimental result very well.
Ku
G
G
Optical Imaging Laboratory, Biomedical Engineering Program, Texas A&M University, College Station 77843-3120, USA.
Wang
L V
LV
D000162:Acoustics; D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008872:Microwaves; D008962:Models, Theoretical; D012815:Signal Processing, Computer-Assisted; D013696:Temperature; D014054:Tomography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data