Quantification of parenchymal fibrosis in chronic pancreatitis: relation to atrophy and pancreatic function

Abstract

Background Non-invasive modalities for assessing chronic pancreatitis (CP) are needed in clinical practice. Purpose To investigate the correlation between magnetic resonance elastography (MRE)-derived stiffness and T1 relaxation times (as proxies of fibrosis) and explore their relationships to gland volume and pancreatic functions in patients with CP and healthy controls (HCs). Material and Methods In 49 patients with CP and 35 HCs, pancreatic stiffness, T1 relaxation times, and gland volume were assessed. Fecal elastase and the presence of diabetes were used to evaluate pancreatic exocrine and endocrine functions. Uni- and multivariable linear regression models were used to analyze correlations between imaging parameters. Results There was a positive correlation between MRE-derived stiffness and T1 relaxation times in patients with CP (R2 = 0.42; P < 0.001) and HCs (R2 = 0.14; P = 0.028). There was no correlation between MRE-derived stiffness and gland volume in patients (R2 = 0.007; P = 0.065) or HCs (R2 = 0.010; P = 0.57). T1 relaxation time was correlated to gland volume (R2 = 0.19; P = 0.002) in patients with CP but not in the HCs ( P = 0.056). Severity of pancreatic functional impairment was reflected by increased fibrosis-related parameters in patients without functional impairment, followed by a further increase in fibrosis-related parameters and reduction in gland volume in patients with pancreatic functional impairments. Conclusion Pancreatic MRE-derived stiffness and T1 relaxation times might reflect early pathophysiological changes in CP. The dynamic correlation with pancreatic function suggests that these parameters may be useful for the non-invasive and early identification of CP.