Question

Light energy of sufficient intensity can cause materials to emit sound waves depending on their light absorption. Propose a system to make 2D images of these optoacoustic properties of an object

Answer 1

Introduction to System make 2D images of optoacoustic properties of an object :

We describe two optoacoustic imaging systems for an object.

For example , for breast cancer detection based on arrays of acoustic detectors operated manually in a way similar to standard ultrasonic breast imaging. The systems have the advantages of standard light illumination (regardless of the interrogated part of the breast), the ability to visualize any part of the breast, and convenience in operation.

However the second eystem is used for 3D imaging.

The second system was proposed as a circular array of acoustic transducers with an axi-

symmetric laser beam in the center. It was capable of 3D optoacoustic imaging with minimized optoacoustic artifacts

caused by the distribution of the absorbed optical energy within the breast tissue.

In the optoacoustic mode we were also able to visualize blood vessels located in the neighborhood of the tumor. The second system was proposed as a circular array of acoustic transducers with an axisymmetric laser beam in the center. The distribution of optical energy absorbed in the bulk tissue of the breast was removed from the image by implementing the principal component analysis on the measured signals.

It has been over a decade since the first prototypes of the optoacoustic imaging system for visualization of breast cancer were proposed In the following decade two different modifications of the original design based on the stationary array of ultrawide-band acoustic transducers were primarily utilized. The first approach involves an arc-shaped array used to visualize a specific slice of the breast (imaging slice) orthogonal to the incident laser beamLarge acoustic aperturewithin the imaging slice provided high 2D resolution of the images. However, severe low frequency acoustic artifacts,and the necessity to have a tumor within the imaging slice, dramatically limited its performance. Another approach was implemented to visualize multiple breast slices using a planar 2D array working in the forward imaging mode. Althoughacoustic artifacts were less of a problem in this case, the resolution of the system was very poor.