IN-VIVO PHOSPHORUS SPECTROSCOPY OF HUMAN SKIN

Skin P-31 MRS measurements might detect metabolic damage from irradiat ion, chemotherapy, or ischemia. Although rat and cadaver data have dem onstrated this potential (C. D. Cuono, et al., Plast. Reconstr. Surg. 81, 1-11 (1988), H. W. Klein, ef al., Ann. Plast. Surg. 20, 547-551 (1 988)), few studies of in vivo phosphorus human skin spectra have been published (A. Zemtsov, et al., J. Dermatol. Surg. Oncol. 15, 1207-1211 (1989), A Zemtsov, et al., J. Am. Acad. Dermatol. 30, 959-965 (1994)) , and those likely reflect underlying muscle as much as skin. To separ ate P-31 Skin and muscle spectra, we have developed a unique two-layer ''flotation'' phantom for mapping coil sensitivity and an associated semiempirical two-power RF depth-resolved technique. Phantom and metho d have been applied in a study of 17 normal volunteers to obtain human in vivo P-31 skin spectra uncompromised by muscle contamination and t o quantitate ratios of major phosphometabolites. Skin results consiste ntly showed low ratios of phosphocreatine (PCr) to adenosine triphosph ate (ATP), high levels of phosphomonoester (PME), P-i, and phosphodies ter (PDE) relative to PCr, and demonstrated a shift in pH toward great er alkalinity, compared to that with simultaneous muscle results.