Non-invasive assessment of diffuse liver disease by in vivo measurement of proton nuclear magnetic resonance relaxation times at 0.08 T

Abstract

44 patients with a range of parenchymal liver diseases diagnosed by biopsy or laboratory investigations underwent proton nuclear magnetic resonance (NMR) relaxometry of the liver at 0.08 T. T1 maps were produced using an interleaved saturation recovery and inversion recovery sequence and T2 maps using a four echo Carr-Purcell-Meiboom-Gill sequence. Significantly raised relaxation times compared with a previously studied group of 42 normal volunteers were found in groups of patients with alcoholic cirrhosis (p < 0.001 for T1 and T2), chronic active hepatitis (CAH) (p < 0.01 for T1 and T2) and minor liver abnormalities (p < 0.01, T2 only). T1 was significantly higher in cirrhotics than in patients with CAH (p < 0.002) and minor abnormalities (p < 0.001). This suggests a role for relaxometry in the confirmation of the presence of cirrhosis (sensitivity = 75%, specificity approximately 97%, taking T1 > 266 ms as a positivity criterion). Reduced T2 values were found in patients with liver iron overload prior to venesection (p < 0.001 versus normals, p < 0.02 versus venesected patients). Although this latter test has relatively low sensitivity and specificity, it may have a role in the monitoring of treatment for iron overload.