PB1340 - Effect of near- infrared laser photobiomodulation therapy on biomechanical parameters of healthy human brachial artery using a new ultrasound- based automatic image processing software
Faculty Member Islamic Azad University- Tabriz Branch Tabriz, Azarbayjan-e Sharqi, Iran
Background: Mechanical changes include thickening of arterial wall, alteration of arterial elasticity, contraction of smooth muscle, increase in sensitivity to pharmacological stimulation and increase in arterial viscoelasticity, i.e., arteriosclerosis. Hence, the use of non-invasive clinical tools to evaluate endothelium function and arterial biomechanical parameters is of interest.
Aims: We used a high resolution diagnostic ultrasound imaging equipment in this work to examine the effects of near-infrared (8500 nm, 500 mw, 200 J/cm2) laser irradiation on brachial artery biomechanical characteristics in healthy human volunteers.
Methods: In this study we used a new computerized analysis method for measurement of instantaneous changes in far and near arterial walls in sequential ultrasound images. In this method, two algorithms, i.e., maximum gradient and dynamic programming, were composed and implemented. Approximately 70 sequential ultrasound images spanning three cardiac cycles were analyzed from each examination to detect instantaneous changes in the far and near walls and lumen maximum, minimum, and mean diameters.
Results: Results showed a significant reduction in the mean value for shear elastic modulus and a significant increase in the mean value for radial strain, compliance and distensibility index in the near- infrared laser treatment group compared with the other groups (P < 0.05).
Conclusion(s): Nitric Oxide (NO) is considered the most important endothelial-derived vasodilation factor. Near- infrared laser irradiation can cause to enhance the endothelial NO synthase, resulting in an increase in the arterial diameter and arterial biomechanical parameters improvement. Furthermore, we concluded that our new ultrasound- based computerized automatic method is reliable to accurate and repeated evaluation of arterial biomechanical parameters.
