Tρ Relaxation of the liver: A potential biomarker of liver function

Purpose To investigate the diagnostic potential of Tρ relaxation for assessing liver function, liver fibrosis, or liver necroinflammation in patients with chronic liver disease (CLD). Materials and Methods We obtained Tρ maps of the liver for 53 patients with or without CLD. We measured the Tρ values of the liver and correlated them with the results of laboratory tests and histological examinations. Pearson's correlation coefficients (r) were calculated between the Tρ values and blood serum parameters including the retention rates at 15 minutes after an injection of indocyanine green (ICG-R15). Spearman's rank correlation coefficients were calculated between the Tρ values and the scores of liver fibrosis or liver necroinflammation. Results The Tρ values showed significant positive correlations with the serum levels of total bilirubin (r=0.31, P<0.05), direct bilirubin (r=0.32, P<0.05), and ICG-R15 (r=0.46, P<0.05), and significant negative correlations with the serum levels of albumin (r=-0.33, P<0.05) and γ-glutamyl transpeptidase (r=-0.28, P<0.05). However, there were no significant correlations between the Tρ value and the scores of liver fibrosis (P=0.95) or liver necroinflammation (P=0.86). Conclusion Tρ relaxation has potential as a biomarker of liver function in patients with CLD. However, it may not be suitable to estimate liver fibrosis or liver necroinflammation.