Research On Multimodal Biomedical Imaging Technique In Tissue Oxygenation And Perfusion Detection And Early Screening Of Cervical Cancer

The development of biomedical optics provides new avenues for the detection of biomedical information and disease diagnosis.The multimodal imaging technique can assess the tissues' structural,functional and molecular parameters in an accurate,fast,non-radiative,and non-invasive fashion,which is significant for the comprehensive diagnosis and therapy assessment in clinics.However,current imaging systems are challenged by the lack of traceable standards for performance evaluation and calibration,the difficulty of monitoring dynamic changes,high cost and low imaging speed,lack of clinical evaluation,and the measurement disparities resulting from different imaging scales and inappropriate co-registration.To overcome these limitations,we developed two different multimodal imaging systems towards cutaneous wound assessment and cervical cancer early screening.Both systems share the same imaging module for different imaging modalities,and suit for quantitative and noninvasive assessment of superficial tissues' functional,structural and molecular parameters.We systematically studied the integration between different imaging modalities,system software control,experimental design,and data analysis methods we used.The major study content and contribution of this paper are listed below.(1)We built up a quasi-simultaneous multimodal system for cutaneous tissue oxygenation and perfusion measurement.The system integrated multispectral imaging technique and laser speckle imaging technique into one setup.We developed and validated the algorithms for tissue oxygenation based on spectral analysis and perfusion reconstruction based on laser speckle contrast analysis(LASCA).To test our system,macro and micro skin-simulating phantoms made of Polydimethylsiloxane(PDMS)were designed to mimic the perfusion and oxygenation change in human tissue.In vivo,dynamic detection of cutaneous tissue oxygenation and perfusion was demonstrated by a post-occlusion reactive hyperemia(PORH)procedure in a human project.In addition,a wound model based on mice dorsal skin chamber was established and the wound healing process was assessed by our system.All the results demonstrated the potential use of this system in a lot clinical applications such as chronic wound assessment.(2)We developed a multimodal colposcopy system that combined multispectral reflectance,auto-fluorescence,and RGB imaging for noninvasive characterization of cervical intraepithelial neoplasia(CIN).We studied the optical properties of cervical tissue first;then the imaging system was designed and tested in a clinical trial where comprehensive datasets were acquired and analyzed to differentiate between squamous normal and high grade types of cervical tissue.The custom-designed multimodal colposcopy is capable of acquiring multispectral reflectance images,auto-fluorescence images,and RGB images of cervical tissue consecutively.The classification algorithm was employed on both normal and abnormal cases for image segmentation.The performance characteristics of this system were comparable to the gold standard histopathologic measurements with statistical significance.Our pilot study demonstrated the clinical potential of this multimodal colposcopic system for noninvasive characterization of CIN.The proposed system was simple,noninvasive,cost-effective,and portable,making it a suitable device for deployment in developing countries or rural regions of limited resources.