Patient respiratory‐triggered quantitative T2 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. Level of Evidence : 4 Technical Efficacy : Stage 1 J. Magn. Reson. Imaging 2019;50:410–416.