Determination of absolute concentrations of cardiac high-energy phosphatesusing P-31-MR-spectroscopy and SLOOP in healthy and diseased myocardium.

Purpose: A quantitative P-31-MR-spectroscopic technique was used to assess the energy metabolism in healthy and diseased myocardium. Methods: P-31-spe ctra were acquired on a 1.5 T scanner using a 3D-chemical shift imaging tec hnique. Based on the anatomical information provided by H-1-images, SLOOP ( Spatial Localization with Optimal Pointspread Function) allows to obtain sp ectra from defined compartments. With SLOOP a free voxel shape with adaptio n to anatomic structures, e.g. the myocardium, is possible. Absolute values for phosphocreatine (PCr) and adenosine triphosphate (ATP) were determined using an external standard. Results: P-31-spectra showed only minimal cont amination by surrounding tissue. The standard deviation for the determined values of healthy volunteers was low. Compared to healthy volunteers, reduc ed PCr and ATP concentrations were seen for dilative cardiomyopathies and c oronary artery disease and unchanged concentrations were observed for hyper tensive heart disease. Conclusion: P-31-MR-spectroscopy with SLOOP allows a non-invasive, quantitative analysis of cardiac energy metabolism.