Intravoxel incoherent motion magnetic resonance imaging for assessment of chronic pancreatitis with special focus on its early stage

Abstract

Background It is clinically necessary to validate a new non-invasive and reliable imaging method to detect early chronic pancreatitis. Intravoxel incoherent motion magnetic resonance imaging (MRI) is useful for quantitative assessment in abdominal solid organs. Purpose To investigate the usefulness of intravoxel incoherent motion MRI parameters in the diagnosis of chronic pancreatitis. Material and Methods Sixty patients with early chronic pancreatitis (n = 44) and chronic pancreatitis (n = 16) were assessed with intravoxel incoherent motion imaging. For comparison, a control group of 71 individuals without chronic pancreatitis was also enrolled. The perfusion fraction (f), pseudo-diffusion coefficient (D*), true diffusion coefficient (D), and apparent diffusion coefficient of pancreatic parenchyma were calculated. These measurements were compared between the three groups. The diagnostic accuracy of imaging parameters was assessed. Results The f values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly lower than those of the control group ( P < 0.001 and P < 0.001, respectively). The D* value of the chronic pancreatitis group was significantly lower than that of the early chronic pancreatitis group ( P = 0.0025). The D values of the early chronic pancreatitis group and the chronic pancreatitis group were significantly higher than those of the control group ( P = 0.001 and P = 0.001, respectively). The perfusion fraction showed the highest diagnostic performance with an Az value of 0.76 for discriminating the control group from the early chronic pancreatitis and chronic pancreatitis groups. Conclusion Intravoxel incoherent motion MRI parameters may reflect the minimal histological changes in early chronic pancreatitis.