[31P-MR spectroscopy of all regions of the human heart at 1.5 T with acquisition-weighted chemical shift imaging]. / 31P-MR-Spektroskopie aller Wandabschnitte des menschlichen Herzens bei 1,5 T mit akquisitionsgewichteter Chemical-shift- Bildgebung *

ABSTRACT

AIM: Aim of this study was to show whether or not acquisition-weighted chemical shift imaging (AW-CSI) allows the determination of PCr and ATP in the lateral and posterior wall of the human heart at 1.5 T. METHODS: 12 healthy volunteers were examined using a conventional chemical shift imaging (CSI) and an AW-CSI. The sequences differed only in the number of repetitions for each point in k space. A hanning function was used as filter function leading to 7 repetitions in the center of the k space and 0 in the corners. Thus, AW-CSI had the same resolution as the CSI sequence. The results for both sequences were analyzed using identically positioned voxels in the septal, anterior, lateral and posterior wall. RESULTS: The determined averaged AW-CSI signal to noise ratios were higher for PCr by a factor of 1.3 and for ATP by 1.4 than those of CSI. The PCr/ATP ratios were higher by a factor of 1.2 - 1.3 and showed a smaller standard deviation in all locations for AW-CSI. The mean PCr/ATP ratios determined by AW-CSI of septal, lateral and posterior wall were almost identical (1.72 - 1.76), while it was higher in the anterior wall (1.9). CONCLUSIONS: The reduced contamination in AW-CSI improves the signal to noise ratio and the determination of the PCr/ATP ratio in cardiac (31)P spectroscopy compared to CSI with the same resolution. The results in volunteers indicate that AW-CSI renders (31)P spectroscopy of the lateral and posterior wall of the human heart feasible for patient studies at 1.5 T.