Proton observed phosphorus editing (POPE) for in vivo detection of phospholipid metabolites

The purpose of this article was to compare the sensitivity of proton observed phosphorus editing (POPE) with direct 31P MRS with Ernst angle excitation for 1H–31P coupled metabolites at 7 T. POPE sequences were developed for detecting phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC), and glycerophosphoethanolamine (GPE) on the 1H channel, thereby using the enhanced sensitivity of the 1H nuclei over 31P detection. Five healthy volunteers were examined with POPE and 31P‐MRS. POPE editing showed a more than doubled sensitivity in an ideal phantom experiment as compared with direct 31P MRS with Ernst angle excitation. In vivo, despite increased relaxation losses, significant gains in signal‐to‐noise ratio (SNR) of 30–40% were shown for PE and GPE + PC levels in the human brain. The SNR of GPC was lower in the POPE measurement compared with the 31P‐MRS measurement. Furthermore, selective narrowband editing on the 31P channel showed the ability to separate the overlapping GPE and PE signals in the 1H spectrum. POPE can be used for enhanced detection of 1H–31P coupled metabolites in vivo. Copyright © 2015 John Wiley & Sons, Ltd. We demonstrate the enhanced sensitivity of proton observed phosphorus editing (POPE) over direct 31P MRS with Ernst angle excitation for 1H–31P coupled metabolites in the human brain at 7 T.