Feasibility of Rapid‐Sequence ³¹P Magnetic Resonance Spectroscopy in Cardiac Patients

Abstract

Purpose: To determine the clinical feasibility of rapid‐sequence phosphorus‐31 magnetic resonance spectroscopy (³¹P ‐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 ³¹P‐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 ³¹P‐MRS procedure was phase encoded in arrays of 8×8 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac ³¹P‐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 ³¹P‐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 ³¹P‐MRS may be a valid diagnostic tool for patients with cardiac disease.

• Cardiac diseases
• dilated cardiomyopathy
• high‐energy phosphate
• human heart
• MR spectroscopy