Cardiac 31 P MRS analysis development: Improved fitting of 2, 3 DPG

Background 31P MRS is an important tool for the measurement of in vivo energetics via the ratio PCr/ATP. Low signal-to-noise (31P molar receptivity is 1/14 that of 1H) coupled with low concentration of high-energy phosphates can result in high measurement variability. 31P MRS of human heart often contains signals originating from blood i.e. 2,3DPG and ATP. Measurement of myocardial PCr/ATP thus requires subtraction of blood derived ATP signal. The aim of this work was to improve blood correction by applying prior knowledge (PK) of molecular spectral parameters to the 2,3DPG signal. We demonstrate that accurate spectral fitting of 2,3DPG prevents proliferation of fitting errors through blood correction, resulting in improved accuracy of PCr/ATP measurement.