Study Skin Edema Using Optical Coherence Tomography

Optical coherence tomography(OCT)has distinctive advantages in the field of optical imaging.It offers high imaging resolution,no damage to biological tissue,and real-time non-contact imaging.Since its introduction into hospitals,the OCT-based technology has been widely used in ophthalmology.At present,researchers have also tried to apply OCT in dermatology by conducting multi-dimensional research on OCT imaging of normal and diseased skin.An accurate research model is crucial for the research and clinical application of OCT in the field of skin.This research utilized OCT technology to study the dynamic process of skin edema.The changes of multiple parameters of the skin edema process were obtained by establishing a realiable animal models,analyzing and processing OCT imaging and OCT signals.More specifically,changes in the thickness,volume,and tendency of the edema lesion during skin swelling process,as well as the degree of vasodilation and optical attenuation coefficient changes,were analyzed.Multi-dimensional analysis of the dynamic changes of skin edema can provide valuable information in the understanding of the skin edema process.The specific research content and main results of this paper can be summarized as:1.Through building a neural network,training the neural network and performing machine learning to obtain the training model,Super-Resolution Convolutional Neural Network(SRCNN)in artificial intelligence-based convolutional neural network was used to remove noise in OCT images.The results showed that after processing,the image's local signal-to-noise ratio,equivalent view number,signal-to-noise ratio,and cross-correlation value were improved.The super resolution reconstruction technology has an obvious protection effect on the edge information of OCT image,therefore,provides a strong support for the data processing and analysis in this study.2.Use chemical methods to exfoliate the stratum corneum of mouse ear skin.Use OCT to collect images prior to and post exfoliation to quantify the thickness of the stratum corneum layer.This process provided a critical step for establishing edema model for OCT experiment of this study.3.Establish histamine sensitization animal model of skin edema.Based on three-dimensional image data from OCT scans,the dynamic changes in edema volume and thickness were measured and analyzed.A method was also established to monitor the swelling change trend during skin edema.4.Based on OCT imaging and Lambert's law,the dynamic changes of the optical attenuation coefficient were studied in skin edema model and fatty emulsion model.The monitor of optical property of skin might provide an estimation of the severity of skin edema.5.By reproducing and improving the speckle variance and correlation mapping OCT(cm-OCT)angiography algorithms,a two-way blood flow information extraction algorithm was proposed and applied to study histamine-induced skin edema.Quantitative analysis of vasodilation was performed.Speckle variance is susceptible to background noise during angiography.The masking technique in cm-OCT angiography was used to overcome the noise-sensitive problem of speckle variance algorithm.The improved algorithm was more sensitive to the resolution of small-scale blood vessels and can be used in the quantitative experiment of blood vessel dilation during skin edema.