T₁ρ Relaxation of the liver: A potential biomarker of liver function

Purpose To investigate the diagnostic potential of T₁ρ relaxation for assessing liver function, liver fibrosis, or liver necroinflammation in patients with chronic liver disease (CLD). Materials and Methods We obtained T₁ρ maps of the liver for 53 patients with or without CLD. We measured the T₁ρ 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 T₁ρ 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 T₁ρ values and the scores of liver fibrosis or liver necroinflammation. Results The T₁ρ 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 T₁ρ value and the scores of liver fibrosis (P=0.95) or liver necroinflammation (P=0.86). Conclusion T₁ρ 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.