Dilated Cardiomyopathy: Phosphorus 31 MR Spectroscopy at 7 T.
Purpose To test whether the increased signal-to-noise ratio of phosphorus 31 (31P) magnetic resonance (MR) spectroscopy at 7 T improves precision in cardiac metabolite quantification in patients with dilated cardiomyopathy (DCM) compared with that at 3 T. Materials and Methods Ethical approval was obtained, and participants provided written informe consent. In a prospective study,31P MR spectroscopy was performed at 3 T and 7 T in 25 patients with DCM. Ten healthy matched control subjects underwent31P MR spectroscopy at 7 T. Paired Student t tests were performed to compare results between the 3-T and 7-T studies. Results The phosphocreatine (PCr) signal-to-noise ratio increased 2.5 times at 7 T compared with that at 3 T. The PCr to adenosine triphosphate (ATP) concentration ratio (PCr/ATP) was similar at both field strengths (mean ± standard deviation, 1.48 ± 0.44 at 3 T vs 1.54 ± 0.39 at 7 T, P = .49), as expected. The Cramér-Rao lower bounds in PCr concentration (a measure of uncertainty in the measured ratio) were 45% lower at 7 T than at 3 T, reflecting the higher quality of 7-T31P spectra. Patients with dilated cardioyopathy had a significantly lower PCr/ATP than did healthy control subjects at 7 T (1.54 ± 0.39 vs 1.95 ± 0.25, P = .005), which is consistent with previous findings. Conclusion 7-T cardiac31P MR spectroscopy is feasible in patients with DCM and gives higher signal-to-noise ratios and more precise quantification of the PCr/ATP than that at 3 T. PCr/ATP was significantly lower in patients with DCM than in control subjects at 7 T, which is consistent with previous findings at lower field strengths.
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Victoria M
VM
Stoll
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
William T
WT
Clarke
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Eylem
E
Levelt
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Alexander
A
Liu
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Saul G
SG
Myerson
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Matthew D
MD
Robson
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Stefan
S
Neubauer
From the Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Level 0, John Radcliffe Hospital, Oxford OX3 9DU, England.
Christopher T
http://orcid.org/0000-0003-1275-1197
CT
Rodgers
D015415:Biomarkers / Q000378:metabolism; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010725:Phosphocreatine / Q000378:metabolism; D010758:Phosphorus; D011446:Prospective Studies; D059629:Signal-To-Noise Ratio
D015415:Biomarkers; D010725:Phosphocreatine; D010758:Phosphorus