Objective To investigate the feasibility of spin-echo echo-planar imaging(SE-EPI) of magnetic resonance elastography (MRE) for the diagnosis of pancreatic mass and to evaluate the difference of stiffness value in different pancreatic mass. Methods In a retrospective study, MRE was performed in 20 healthy volunteer (control group) and 62 patients with surgery-proved pancreatic masses, including pancreatic cystadenoma in 5 cases and solid masses of pancreas in 57 cases (39 with malignant mass and 18 with benign mass) using 3.0 T MRE. The differences of stiffness between two groups were evaluated using non-parametric Mann-Whitney U test. ROC was used to assess the diagnostic ability of elastogram for the detection of pancreatic masses, and to evaluate MRE-determined stiffness for the differentiation of masses from healthy pancreas, and malignancy from benign solid masses. Results The total detection rate of elastogram was 91.9%(57/62),with false positive rate of 5.0%(1/20) and false negative rate of 8.1%(5/62). The median stiffness value in the control group vs patient group were 1.18 kPa (interquantile range:1.15 to 1.30) kPa and 2.43 kPa (interquantile range:1.94 to 3.64 kPa) respectively, with statistically significant differences (Z=-5.967,P<0.01). The sensitivity and specificity of stiffness (≥1.36 kPa) to differentiate pancreatic mass from healthy pancreas was 93.6%and 100.0%, respectively, and to differentiate benign and malignant solid masses (≥2.17 kPa) was 82.1%and 83.3%, respectively. Conclusion MRE is a promising method in detecting and distinguishing different pancreatic masses.

Objective To explore the value of 3.0T MR elastography (MRE) in diagnosis of obstructive chronic pancreatitis.Methods Totally 32 patients (lesion group) with suspected obstructive chronic pancreatitis who underwent pancreaticoduodenectomy and 32 volunteers (normal control group) were enrolled.MRE was performed,and pancreatic stiffness value was measured.The consistency between two observers and the repeatability of the same observer were evaluated.The difference of pancreatic stiffness value was compared between the two groups.The efficacy of pancreatic stiffness value in diagnosis of obstructive chronic pancreatitis was analyzed with ROC curve.Results The consistency between two observers and the repeatability of the same observer were excellent (all ICC＞0.9).The pancreatic stiffness value of normal control group and lesion group was (1.21±0.11)kPa and (1.51±0.24)kPa,respectively (t=-6.077,P ＜0.001).The area under ROC curve of pancreatic stiffness value in diagnosis of chronic pancreatitis,mild and moderate to severe,mild to moderate and severe was 0.900,0.941 and 0.960,respectively (all P＜0.001).Conclusion MRE can objectively measure pancreatic stiffness and noninvasively assess the severity of chronic pancreatitis.