Spectral resolution in clinical magnetic resonance spectroscopy

We observe linewidths of 0.1-0.4 ppm in 31P spectra of human muscle, liver, and brain. T2 measurements of muscle phosphocreatine, together with previous brain studies, indicate that further improvements in linewidth to 0.02-0.05 ppm might often be achieved, but in some lesions magnetic susceptibility variations may limit spectral resolution.