Pancreatic extracellular volume fraction using T1 mapping in patients with impaired glucose intolerance.

ABSTRACT

PURPOSE: To evaluate pancreatic T1 mapping and extracellular volume (ECV) fraction's feasibility to assess impaired glucose tolerance (IGT) patients. METHODS: A total of 45 consecutive patients with known or suspected pancreatic disease underwent contrast-enhanced magnetic resonance (MR) imaging, including T1 mapping, using saturation recovery sequence. Patients were classified into three groups based on the American Diabetes Association criteria no-diabetes subjects, HbA1c < 5.7%; pre-diabetes, 5.7% ≤ HbA1c < 6.5%; and type 2 diabetes mellitus (T2DM), HbA1c ≥ 6.5%. Pre-contrast pancreatic T1 value and ECV of the pancreas were computed, and then pre-contrast pancreatic T1 value, ECV and HbA1c values were compared. The present prospective study was approved by our institutional review board. Written informed consent was obtained from all patients. RESULTS: A positive correlation between HbA1c values and both pre-contrast pancreatic T1 value and ECV (r = 0.79, P < 0.001 and r = 0.60, P < 0.001, respectively) were observed. The pre-contrast pancreatic T1 value and ECV were significantly higher in T2DM vs. no-diabetes subjects and pre-diabetes (P < 0.001). No significant difference between two qualitative values (P = 0.14) was found, however, the sensitivity, specificity, and area under the receiver-operating-characteristic curve differentiating no-diabetes subjects and pre-diabetes from T2DM were superior in ECV (100%, 93.5%, and 0.990) vs. pre-contrast pancreatic T1 values (84.6%, 96.8%, and 0.906). CONCLUSIONS: The ECV of the pancreas could serve as a potential imaging biomarker for the assessment of pancreatic fibrosis leading to IGT.