Use of non‐invasive optical imaging techniques in dermatology

Noninvasive imaging of skin diseases is highly valued in both dermatological research and practice. Reflectance confocal microscopy (RCM) is primarily applied to assess melanocytic lesions because of its high resolution, whereas optical coherence tomography (OCT) is particularly used for non-melanocytic skin tumors owing to its greater penetration depth. Line-field confocal optical coherence tomography (LC-OCT) combines the techniques of reflectance confocal microscopy (RCM) and optical coherence tomography (OCT), enabling visualization of the skin down to the superficial dermis while simultaneously providing cellular resolution. The visualization of the skin changes can be done horizontally, vertically, in 3D mode or as a video in real time. The evaluation of the measurement can be supported by artificial intelligence if required. The field of application of LC-OCT includes both melanocytic and non-melanocytic lesions. In addition, preliminary studies show great potential in the diagnosis and therapy control of inflammatory and infectious skin diseases. Nevertheless, RCM and OCT still have their place in special cases such as tumors requiring a particularly high resolution or penetration depth > 500 µm.