P-31-MR SPECTROSCOPY OF LIVER ABNORMALITI ES WITH REFERENCE TO VARYING PULSE RECOVERY TIMES

The value of P-31-MRS for different types of liver disease and the eff ect of repetition time (T(R)) on measurements of relative phosphor met abolite concentrations was studied. Spectroscopy was performed on 26 p atients with predominantly focal liver disease and on 14 normals, usin g a 1.5 Tesla clinical MR system. In all cases, (T(R)) of 2,400 ms was chosen and in 11 patients and 10 normals additionally shorter (T(R)) 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 disea se and differ widely from the findings in normal livers. In patients w ith liver metastases, the long (T(R)) 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 (T(R)) 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 d ifferences in phosphometabolites between patients and normals than den sity weighted spectra. The spectra in patients showed a significantly reduced signal to noise ratio independent of the (T(R)).