A novel photoacoustic tomography based on a time-resolved technique and an acoustic lens imaging system

Abstract

A novel photoacoustic (PA) tomographic method, which is based on a time-resolved technique and an acoustic lens imaging system, is presented in this paper. A YAG laser operating at 532 nm with a 7 ns pulse width and 10 mJ optical pulse is employed as the excitation source to irradiate the tissue. PA signals generated from the tissue are imaged onto a multi-element linear array transducer with an acoustic lens. A 64 electronic switch is efficiently used for changing the parallel PA signals into a series. The proposed method directly provides PA images without any complex reconstruction algorithms. With the time-resolved technique, tomographic imaging can be achieved successfully. The results show that the images agree well with the original samples.

Numerical study of thermoacoustic detection of composite materials

“…According to the direction of energy conversion, the thermoacoustic effect can be divided into the following two categories [1] : first, heat-driven acoustic oscillations, in which heat energy is converted into kinetic energy (acoustic signal); second, sound-driven heat transfer, which uses acoustic oscillations to generate heat. Thermoacoustic imaging, based on the principle of heat-driven acoustic oscillations, has become a hotspot in the field of medical imaging [2,4] , and it is widely used in tumor detection [5] , angiography [6,8] mouse brain structure, functional imaging [9] and molecular imaging [10] . In recent years, the thermoacoustic effect has also been used to detect the thermal properties of materials and test the quality of resistance weld nugget [11] and other directions.…”

3D photoacoustic imaging system with 4F acoustic lens

“…However, this method needs complex algorithm and further image quality improvement. On the other hand, the 4F acoustic lens technology in photoacoustic imaging has been developed recently [13,14]. It can simplify imaging reconstruction algorithm and has the potential of real-time imaging, but this method still suffered from aberration of lens system.…”

Wideband focused transducer array for optoacoustic tomography

“…For the application under consideration (early breast cancer detection) we will consider cylindrical shape of the antenna surface. However, from the technical standpoint, it is better using plane transducers with a focusing acoustic lens [8]. It was shown [3,9] that signal-to-noise ratio and sensitivity increase for such system leading to an improvement of the image contrast.…”