Correlation of quantitative pancreatic T1 value and HbA1c value in subjects with normal and impaired glucose tolerance.

Abstract

Signal intensity on T1 -weighted images (T1 WI) is associated with pancreatic fibrosis and HbA1c levels. To evaluate the feasibility of the pancreatic T1 value for assessment of subjects with normal and impaired glucose tolerance (IGT). A prospective single-institution study. In all, 95 consecutive patients with a known or suspected pancreatic disease. 3T/fast pancreatic T1 mapping using a modified Look-Locker sequence. Following the American Diabetes Association criteria, patients were classified into three groups, as follows: no-diabetes subject, HbA1c < 5.7%; prediabetes, 5.7% ≤ HbA1c < 6.5%; and type 2 diabetes mellitus (T2DM), HbA1c ≥ 6.5%. Pancreatic T1 value and signal intensity ratio (SIR = SIpancreas /SImuscle ) using T1 WI were compared with the HbA1c values. Quantitative data were assessed with one-way analysis of variance, Fisher's and Mann-Whitney U tests, and receiver-operating characteristic analysis. The pancreatic T1 value was significantly longer in T2DM than in no-diabetes and prediabetes subjects (P < 0.05) and was significantly longer in prediabetes than in no-diabetes subjects (P < 0.05). The mean pancreatic T1 value was significantly lower in the low-value group (HbA1c < 5.7%) (906.3 msec) compared with the high-value group (HbA1c ≥ 6.5%) (993.8 msec) (P < 0.0001). SIR on T1 WI was significantly higher in the low-value group compared with the high-value group (P = 0.029). The sensitivities, specificities, and area under the receiver-operating characteristic curve (AUCs) for differentiating the low- and high-value groups were 74.1%, 83.8%, and 0.82 in the pancreatic T1 values and 77.8%, 54.4%, and 0.63 in SIR on T1 WI, respectively. The specificity (P < 0.0001) and AUC (P = 0.0020) were significantly higher in the pancreatic T1 values than in SIR on T1 WI. Pancreatic T1 value has the potential of being an imaging biomarker for the assessment of IGT. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:711-718.