5.4　Reflectance Confocal Microscope

Reflectance confocal microscope（RCM）is a commonly used dermatology clinical imaging technique.It relies on reflectance（back-scattering）of light from structures with endogenous contrast，such as melanin，haemoglobin and some organelles.Reflectance occurs at the boundaries of two structures with different refractive indices，such as membranes，keratohyaline granules and melanosomes.RCM is a non-invasive imaging technique that enables in vivo visualisation of the epidermis down to the papillary dermis in real-time.Resolution is almost comparable to conventional histology.It has the advantage of allowing the clinician to do a“virtual biopsy”of the skin and obtain diagnostic clues while minimizing unnecessary skin biopsies.RCM is widely used in clinical diagnosis of most dermatosis，including inflammatory lesions，infestations and infections，pigmented tumors，epithelial tumors，etc，and cosmetics.Specifically，RCM has received extensive attention from researchers in the diagnosis and application of benign and malignant skin tumors.Compared with regular optical microscopes，RCM has the following features：①ultra-high resolution（up to 1μm）；②non-invasive continuous optical section of the sample to achieve threedimensional reconstruction imaging and obtain the fine structure inside the sample；③optical section of samples with a thickness of less than 1 μm to avoid damage caused by biopsy；④the pinhole placed in front of the detector can effectively decrease stray background scattered light，and greatly improve image contrast and quality.RCM has gradually become an important auxiliary instrument for diagnosis，treatment and follow-up of skin tumor patients in large medical centers.(https://www.daowen.com)