MR elastography of pancreatic masses:preliminary results / 中华放射学杂志

ABSTRACT

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 range1.15 to 1.30) kPa and 2.43 kPa (interquantile range1.94 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.