Changes in pancreatic exocrine function, fat and fibrosis in diabetes mellitus: Analysis using MR imaging.

OBJECTIVE: To evaluate the relationships between HbA1c levels with exocrine pancreatic function using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) and the pancreatic parenchyma using fat-suppressed T1 mapping and the proton density fat fraction (PDFF).

METHODS: Patients who underwent 3T-MRI and HbA1c measurement were retrospectively recruited. MRI included cine-dynamic MRCP with a spatially selective inversion-recovery (SS-IR) pulse, fat-suppressed Look-Locker T1 mapping and multi echo 3D Dixon based PDFF mapping. The pancreatic exocrine secretion grade on cine-dynamic MRCP, T1 values, and PDFF were analysed in non-diabetic ( n = 32), pre-diabetic ( n = 44) and diabetic ( n = 23) groups defined using HbA1c.

RESULTS: PDFF was weakly correlation with HbA1c (rho = 0.30, p = 0.002). No correlations were detected between HbA1c and secretion grade (rho= - 0.16, p = 0.118) or pancreatic parenchymal T1 (rho = 0.13, p = 0.19). The secretion grade was comparable between the three groups. The T1 value was higher in diabetic (T1 = 1006.2+/- 224.8 ms) than in non-diabetic (T1 = 896.2+/- 86.3 ms, p = 0.010) and pre-diabetic (T1 = 870.1+/- 91.7 ms, p < 0.010) patients. The PDFF was higher in diabetic (FF = 11.8+/- 8.7 %) than in non-diabetic (FF = 6.8+/- 4.2 %, p = 0.014) patients.

CONCLUSION: Pancreatic exocrine function, T1, and FF showed no correlation with HbA1c. Pancreatic T1 and fat fraction is increased in patients with T2DM.

ADVANCES IN KNOWLEDGE: This study demonstrates unaffected exocrine function in pre-diabetes and diabetes and confirms that pancreatic parenchymal T1 and FF are increased in patients with diabetes.