Fig. 2.

(a)Transaxial scout magnetic resonance image of 52 yr old male HC patient, annotated to show location of 5 adjacent tissue volumes sampled by ³¹P magnetic resonance spectroscopy (b–d) in the chest wall (blue arrows), and anterior myocardium (red arrows). Spectra in (b) were acquired with no saturation applied for the purpose of measuring absolute concentrations. Spectra in (c) and (d) were acquired with control saturation (green arrow) and with γ-ATP saturated (amber arrow). The change in the height of the PCr peak (blue and red lines) is due to the forward flux through CK, and is proportional to the pseudo first-order rate constant. Each magnetic resonance spectroscopy data set was acquired in about 6min.