Optimization of ECG-triggered 3D (23)Na MRI of the human heart

(23)Na MRI may allow distinction of normal and ischemically injured myocardium. The aim of this study was to optimize (23)Na MRI of the human heart by improvement of spatial resolution and ECG-triggering and to measure the signal/noise of blood and myocardium and the myocardium/blood signal ratios in a volunteer study. A spoiled gradient echo sequence was developed on a 1.5T scanner equipped with a (23)Na heart surface coil. 3D short axis ECG-triggered (23)Na MRI was performed in 10 healthy subjects. The signal/noise of myocardium and blood were 8.2 +/- 0.7 and 18.3 +/- 1.3, respectively, signal ratio myocardium/blood was 0.44 +/- 0.03. This value is in good agreement with the theoretical value of 0.45. ECG gated 3D (23)Na MRI of the human heart is feasible with sufficient spatial resolution and signal/noise ratio. Magn Reson Med 45:164-166, 2001.