SIMULTANEOUS DETERMINATION OF MUSCLE PERFUSION AND OXYGENATION BY INTERLEAVED NMR PLETHYSMOGRAPHY AND DEOXYMYOGLOBIN SPECTROSCOPY

A novel approach is presented that combines NR IR-plethysmography and NMRS of deoxymyoglobin in real-time, using line-by-line interleaved ac quisitions of both gradient echo images during venous occlusion and of the N-delta proton signal of myoglobin's proximal F8 histidine, This method allowed simultaneous measurement of peripheral regional perfusi on and skeletal muscle oxygen content. During reactive hyperaemia, usi ng our combined NMRI-NMRS protocol, we explored the relationship betwe en muscle reoxygenation (myoglobin resaturation half-time, y in s) and reperfusion (x in ml/100 g tissue/min) and found it to be highly sign ificant (y = 70.83x (-0.94); r(2) = 0.70; F = 64.40; p = 9.73 x 10(-9) ), We also demonstrated that at low how muscle perfusion was a rate-li miting factor to reoxygenation, Making certain hypotheses, muscle oxyg en extraction was derived from perfusion and myoglobin resaturation ra te, Muscle oxygen extraction during early post-ischemic recovery (0.78 +/- 0.11, 0.79 +/- 0.09 and 0.72 +/- 0.05 at 0, 60 and 100 Torr count er-pressure, respectively) was shown to be independent of perfusion an d maximum at each step of the protocol in most volunteers but also to display significant variability among subjects in this supposedly norm al population sample, (C) 1997 John Wiley & Sons, Ltd.