T 1 ρ Relaxation of the liver: A potential biomarker of liver function

Purpose To investigate the diagnostic potential of T 1 ρ relaxation for assessing liver function, liver fibrosis, or liver necroinflammation in patients with chronic liver disease (CLD). Materials and Methods We obtained T 1 ρ maps of the liver for 53 patients with or without CLD. We measured the T 1 ρ 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 T 1 ρ 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 T 1 ρ values and the scores of liver fibrosis or liver necroinflammation. Results The T 1 ρ 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 T 1 ρ value and the scores of liver fibrosis ( P  = 0.95) or liver necroinflammation ( P  = 0.86). Conclusion T 1 ρ 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. J. Magn. Reson. Imaging 2015;42:188–195 . © 2014 Wiley Periodicals, Inc .