Patient respiratory-triggered quantitative T-2 mapping in the pancreas

Background Long acquisition times and motion sensitivity limit T-2 mapping in the abdomen. Accelerated mapping at 3 T may allow for quantitative assessment of diffuse pancreatic disease in patients during free-breathing. Purpose To test the feasibility of respiratory-triggered quantitative T-2 analysis in the pancreas and correlate T-2-values with age, body mass index, pancreatic location, main pancreatic duct dilatation, and underlying pathology. Study Type Retrospective single-center pilot study. Population Eighty-eight adults. Field Strength/Sequence Ten-fold accelerated multiecho-spin-echo 3 T MRI sequence to quantify T-2 at 3 T. Assessment Two radiologists independently delineated three regions of interest inside the pancreatic head, body, and tail for each acquisition. Means and standard deviations for T-2 values in these regions were determined. T-2-value variation with demographic data, intraparenchymal location, pancreatic duct dilation, and underlying pancreatic disease was assessed. Statistical Tests Interreader reliability was determined by calculating the interclass coefficient (ICCs). T-2 values were compared for different pancreatic locations by analysis of variance (ANOVA). Interpatient associations between T-2 values and demographical, clinical, and radiological data were calculated (ANOVA). Results The accelerated T-2 mapping sequence was successfully performed in all participants (mean acquisition time, 2:48 +/- 0:43 min). Low T-2 value variability was observed across all patients (intersubject) (head: 60.2 +/- 8.3 msec, body: 63.9 +/- 11.5 msec, tail: 66.8 +/- 16.4 msec). Interreader agreement was good (ICC, 0.82, 95% confidence interval: 0.77-0.86). T-2-values differed significantly depending on age (P < 0.001), location (P < 0.001), main pancreatic duct dilatation (P < 0.001), and diffuse pancreatic disease (P < 0.03). Data Conclusion The feasibility of accelerated T-2 mapping at 3 T in moving abdominal organs was demonstrated in the pancreas, since T-2 values were stable and reproducible. In the pancreatic parenchyma, T-2-values were significantly dependent on demographic and clinical parameters. Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:410-416.