In vivo phosphorus NMR spectroscopy of skin using a crossover surface coil

A modified crossover surface coil with minimal B 1 field penetration was used for collection of skin phosphorus NMR spectra. Projection imaging experiments show that the coilsensitive volume is uniform at the phosphorus frequency, but strikingly nonuniform at s the proton frequency. Experiments with an in vitro phosphorus phantom, designed to simulate skin and underlying tissue, demonstrated that 45.1% (±1.2%) of total signal was derived from Sprague‐Dawley rat skin and 19.3% (±1.4%) of total signal was derived from Fischer‐344 rat skin. 31 P MR spectra of rat skin in vivo permitted resolution of four phosphorus compounds: nucleoside triphosphates, phosphocreatine (PCr), inorganic phosphate (P i ), and phosphomonoester. Spectra collected after skin flap surgery in Fischer‐344 rats showed a 50.1% (±7.6%) reduction in the ratio of PCr/P i within 30 min of surgery, compared to presurgical PCr/P i levels (P < 0.01). Skin phosphorus spectra are potentially useful for assessment of skin flap and skin graft viability. © 1992 Academic Press, Inc.