title: Evaluation of a mobile NMR sensor for determining skin layers and locally estimating the T(2eff) relaxation time in the lower arm.
abstract: OBJECTIVE
  The nuclear magnetic resonance (NMR) mobile-universal-surface-explorer (MOUSE) was evaluated in a pilot study to determine its ability to detect physiological changes in human skin caused by physical or pharmacological interventions.
  
  
  METHODS
  The left lower arm skin thicknesses of ten male subjects were measured five times using a Profile NMR-MOUSE(®) ((1)H, 19 MHz) before and after a venous occlusion manoeuvre. In five of the subjects, the T(2eff) relaxation times were derived from a bi-exponential fitting and were determined in the dermis and subcutis before and after applying a salve containing capsaicin.
  
  
  RESULTS
  The dermis (including the epidermis) showed rather homogeneous signal amplitudes. The subcutis was characterised by higher and more variable amplitudes. The full-skin thickness values were affirmed by ultrasound imaging. The NMR profiles did not show significant skin swelling due to venous occlusion. In the dermis, capsaicin caused significant (p < 0.05) decreases in both components of T(2eff) (100 ± 19 ms-19 ± 10 ms; 9.5 ± 0.5 ms-7.2 ± 1.6 ms). In the subcutis, the T(2eff) was not affected.
  
  
  CONCLUSIONS
  In principle, NMR-MOUSE profiles are capable of detecting skin structure. However, precise measurements are jeopardised by poor reproducibility, long acquisition times, and incompatibility between the geometries of the sensitive area of the instrument and the non-planar structure of the skin. In the dermis, T(2eff) contrast could be used to detect the changes in tissue composition caused by inflammatory reactions.
authors.affiliation: Institute of Aerospace Medicine, Deutsches Zentrum für Luft- und Raumfahrt, DLR eV, Linder Höhe, 51147 Cologne, Germany. darius.kornetka@dlr.de
authors.forename: Darius
authors.initials: D
authors.lastname: Kornetka
authors.forename: Martin
authors.initials: M
authors.lastname: Trammer
authors.forename: Jochen
authors.initials: J
authors.lastname: Zange
mesh_terms: D000328:Adult; D000465:Algorithms; D015992:Body Mass Index; D020405:Dermis / Q000473:pathology; D004817:Epidermis / Q000473:pathology; D004867:Equipment Design; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D008297:Male; D015233:Models, Statistical; D010865:Pilot Projects; D015203:Reproducibility of Results; D012867:Skin / Q000473:pathology*; D013499:Surface Properties; D014463:Ultrasonography / Q000379:methods; D014680:Veins / Q000473:pathology