Date of Award
Master of Science (MS)
While colorectal cancer is the second largest cause of cancer-related deaths in the United States, early detection is a key factor in its survival rate. Compared to conventional imaging modalities, photoacoustic imaging offers benefits in providing angiographic images which are valuable for early-stage tumor detection. This thesis presents the design of a 32-channel 80 MHz photoacoustic image system, whose relatively high frequency offers particular advantages.
The system comprises several modules, including a laser system, ultrasound probe, AD convertor, microcontroller (FPGA), and a computer. The system requires programs for the FPGA and the data receiver on the computer. The data transportation accuracy, signal-noise ratio, and transmission speed are analyzed here to understand the system’s performance.
The system was tested by standard phantoms, like carbon fiber and black tape, and images were reconstructed by the typical delay-and-sum algorithm. As important parameters of this system, the spatial resolution and signal-to-noise ratio were analyzed.
In the future, to improve the lateral resolution of this system and broaden its imaging window, we can expand the 32-channel system up to 256 channels simply by duplicating the 32-channel data acquisition module. This improved system can provide detailed ex-vivo and in-vivo information about colorectal cancer.
Song Hu Chao Zhou