Journal of Lasers in Medical Sciences

Abstract

Introduction: Vascular occlusion is a chronic condition that impairs blood flow to vital organs. This study developed a novel, low-cost photoacoustic imaging (PAI) system that utilizes phantom modeling to detect this condition. In this study, vascular occlusion was modeled using polyvinyl chloride–dioctyl terephthalate phantoms, which were categorized into healthy and occluded types.
Methods: The PAI system comprised an 808-nm laser diode as the radiation source, a condenser microphone as the detector, and a mechanical stage for sample scanning. The PAI system utilized a modulated continuous-wave diode laser, operating at a frequency of 14 kHz and a 50% duty cycle.
Results: Acoustic intensity analysis revealed that healthy vasculature consistently generated more intense signals than occluded vasculature. At a depth of 1 mm, the average intensities were 76.3 dB (healthy) and 65.2 dB (occluded), which decreased to 46.2 dB and 22.1 dB, respectively, at a 5-mm depth. Because of these differences, the contrast ratio between healthy and occluded regions ranged from 1.4 to 6.6 dB. Furthermore, the signal-to-noise ratio in healthy samples was measured at 16.1 dB (1 mm depth) and 3.2 dB (5 mm depth).
Conclusion: This study demonstrates that a simple PAI system can distinguish between healthy and occluded vasculature.