Functional and Biochemical Optical Imaging Techniques and Advances in Skin Disease Detection and Assessment

Optical imaging can acquire various types of information from different skin levels, supporting non-invasive diagnosis and dynamic monitoring. This article analyzes typical functional and biochemical optical imaging modalities providing clear interpretable information and reviews their applications in skin disease detection. It compares their information characteristics, unique diagnostic capabilities, clinical status, current limitations, and translational requirements. However, no single modality can fully characterize the complex pathological changes and multidimensional features of skin lesions because imaging depth, spatial resolution, and information specificity cannot be optimized simultaneously. Multimodal imaging is therefore essential for integrating complementary structural, functional, and molecular information and providing a more comprehensive representation of lesion heterogeneity. This review further examines major multimodal fusion strategies and discusses challenges including cross-modal registration, information redundancy, and unified representation. Developing adaptive multimodal imaging and fusion frameworks that effectively capture and integrate multidimensional diagnostic information represents an important direction toward more accurate skin disease assessment.