[31P-MR spectroscopy of liver diseases with reference to variable pulse recovery times]

The value of 31P-MRS for different types of liver disease and the effect of repetition time (TR) on measurements of relative phosphor metabolite concentrations was studied. Spectroscopy was performed on 26 patients with predominantly focal liver disease and on 14 normals, using a 1.5 Tesla clinical MR system. In all cases, (TR) of 2,400 ms was chosen and in 11 patients and 10 normals additionally shorter (TR) of 600 ms (with T1 weighted spectra) was chosen. The results show that PME/beta-ATP and PDE/beta-ATP are sensitive indicators of liver disease and differ widely from the findings in normal livers. In patients with liver metastases, the long (TR) of 2,400 ms (16 cases) showed an increase of PME/beta-ATP (0.96 +/- 0.32) and significant reduction of PDE/beta-ATP (1.89 +/- 0.47) as compared with normals (PME/beta-ATP = 0.75 +/- 0.26 and PDE/beta-ATP = 2.27 +/- 0.41), for a (TR) of 600 ms, PME/beta-ATP (0.87 +/- 0.47) and PDE/beta-ATP (1.82 +/- 0.67) are significantly increased. T1 weighted spectra showed more significant differences in phosphometabolites between patients and normals than density weighted spectra. The spectra in patients showed a significantly reduced signal to noise ratio independent of the (TR).