Correlation of quantitative pancreatic T 1 value and HbA1c value in subjects with normal and impaired glucose tolerance

Background Signal intensity on T 1 ‐weighted images (T 1 WI) is associated with pancreatic fibrosis and HbA1c levels. Purpose To evaluate the feasibility of the pancreatic T 1 value for assessment of subjects with normal and impaired glucose tolerance (IGT). Study Type A prospective single‐institution study. Population In all, 95 consecutive patients with a known or suspected pancreatic disease. Field Strength/Sequences 3T/fast pancreatic T 1 mapping using a modified Look–Locker sequence. Assessment 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 T 1 value and signal intensity ratio (SIR = SI pancreas /SI muscle ) using T 1 WI were compared with the HbA1c values. Statistical Tests Quantitative data were assessed with one‐way analysis of variance, Fisher's and Mann–Whitney U tests, and receiver‐operating characteristic analysis. Results The pancreatic T 1 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 T 1 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 T 1 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 T 1 values and 77.8%, 54.4%, and 0.63 in SIR on T 1 WI, respectively. The specificity ( P  < 0.0001) and AUC ( P  = 0.0020) were significantly higher in the pancreatic T 1 values than in SIR on T 1 WI. Data Conclusion Pancreatic T 1 value has the potential of being an imaging biomarker for the assessment of IGT. Level of Evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:711–718.