Metabolic imaging of myocardial triglyceride content: reproducibility of 1H MR spectroscopy with respiratory navigator gating in volunteers.

Institutional review board approval and informed consent were obtained. The purpose of the study was to prospectively compare spectral resolution and reproducibility of hydrogen 1 (1H) magnetic resonance (MR) spectroscopy, with and without respiratory motion compensation based on navigator echoes, in the assessment of myocardial triglyceride content in the human heart. In 20 volunteers (14 men, six women; mean age+/-standard error, 31 years+/-2.8 [range, 19-60 years]; body mass index, 19-30 kg/m2) without history of cardiovascular disease, 1H MR spectroscopy of the myocardium was performed at rest, with and without respiratory motion compensation. Unsuppressed water signal linewidth changed from 11.9 Hz to 10.7 Hz (P<.001) with the use of the navigator, which indicated better spectral resolution. The navigator improved the intraclass correlation coefficient for the assessment of myocardial triglyceride content from 0.32 to 0.81. Therefore, the authors believe that respiratory motion correction is essential for reproducible assessment of myocardial triglycerides. Copyright (c) RSNA, 2007.