Feasibility of rapid-sequence 31P magnetic resonance spectroscopy in cardiac patients

Purpose: To determine the clinical feasibility of rapid-sequence phosphorus- 31 magnetic resonance spectroscopy (P-31-MRS) of the heart with cardiac patients using a 1.5T clinical MR system. Material and Methods: Twenty cardiac patients, i.e. dilated cardiomyopathy (DCM) 13 cases, hypertrophic cardiomyopathy (HCM) 3 cases, hypertensive heart diseases (HHD) 3 cases, and aortic regurgitation (AR) 1 case were examined using rapid cardiac P-31-MRS. Complete three-dimensional localization was performed using a two-dimensional phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. The rapid-sequence P-31-MRS procedure was phase encoded in arrays of 868 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac P-31-MRS procedure, ranged from 10 to 15 min, depending on the heart rate. Student's t test was used to compare creatine phosphate (PCr)/adenosine triphosphate (ATP) ratios from the cardiac patients with those of the control subjects (n=13). Results: The myocardial PCr/ATP ratio obtained by rapid P-31-MRS was significantly lower (P<0.001) in DCM patients (1.82 +/- 0.33, mean +/- SD), and in patients with global myocardial dysfunction ( combined data for 20 patients: 1.89 +/- 0.32) than in normal volunteers (2.96 +/- 0.59). These results are similar to previous studies. Conclusion: Rapid-sequence P-31-MRS may be a valid diagnostic tool for patients with cardiac disease.