Research On Key Techniques Of Static And Dynamic Full-field Optical Coherence Tomography

Full field optical coherence tomography(FFOCT)is a kind of non-invasive,non-contact,non-destructive,high resolution imaging mode for biological tissue and it can generate optical sectioning images of biological tissue samples at the resolution of micron level.The en face images obtained by conventional FFOCT can only reveal the static backscattering structures in the sample while image contrast in dynamic full field optical coherence tomography(DFFOCT)is dynamic information of scattering structures in biological tissue samples.It is then expectd that a combination of the two techniques will provide more information about the tissue samples which are helpful for promoting the diagnosis of the cancers.In this thesis the key methods for the clinical diagnostic applications of the en face images obtained with conventional FFOCT and the image reconstruction methods for DFFOCT were investigated.First of all,the common points and the differences between imaging properties of the conventional FFOCT and DFFOCT are analyzed and compared.It is demonstrated that because their differences in imaging signal detection and processing,FFOCT can generate images of the static structures such as collagenous fiber structures and cells and the subcellular metabolic information can be obtained in the images produced by DFFOCT.Second,the images of normal and cencerous human liver were obtained with a FFOCT setup established in our Lab.To solve the problem that it is difficult to distinguish between the normal and early cancerous liver tissues with unaided human eye from the FFOCT images,grayscale characteristics of the high resolution en face tomographic image were extracted and statistical analysis was carried out.The results show that FFOCT image gray feature can be used to the diagnosis of cancer tissues in the actual clinical diagnosis.Finally,the conventional FFOCT system was modified for rapid imaging.The motion of the scatterers inside the sample were used to image moving scatterers by using time correlation and a series of raw images were obtained.DFFOCT images were obtained by processing the original data which can reveal the signal of moving scattering structures.