Magnetic resonance imaging and spectroscopy of skin and subcutis

Amongst in vivo skin imaging methods, magnetic resonance (MR) imaging and spectroscopy is of high interest not only for its ability to distinguish structures at a submillimetre scale but also for its ability to describe the physiology of the different skin layers through the measurement of their intrinsic MR parameters. High spatial resolution MR imaging allows the differentiation of epidermis, dermis and hypodermis. Cutaneous appendages such as hair follicles are also clearly visible. By measuring proton relaxation times and proton density, it is possible to go a step further in the description of skin physiology in vivo through the analysis of water-macromolecular interactions within the dermis as an example. Finally, quantification of water and lipid components in healthy and diseased adipose tissue by localized spectroscopy is also described. Even if MR imaging is of little interest for dermatological diagnosis, some preliminary studies have shown interesting results for preoperative staging, postoperative follow-up, and assessment of the efficacy of new dermatological products. In healthy skin, MR imaging and spectroscopy is a very promising method for the study of chronological and photoageing effects.