磁共振弥散加权成像对急性胰腺炎严重性分级的诊断价值

目的 探讨磁共振弥散加权成像（DWI）及表观弥散系数（ADC）值对急性胰腺炎（AP）严重性分级的诊断价值.方法 收集57例AP及13例正常胰腺含有DWI的磁共振成像（MRI）资料.参照Balthazar CT分级标准,将AP的MRI表现分为相应的A、B、C、D、E5级,测量炎症胰腺及正常胰腺的ADC值.应用单因素方差分析（ANOVA）对各级别AP之间、各级别与正常胰腺之间的ADC值进行统计学分析.结果 57例AP的MRI分为A级6例,B级9例,C级11例,D级10例,E级21例.炎症胰腺在DWI图像均呈高信号（100％）.A、B、C、D、E级AP的平均ADC值分别为（1.138 ±0.024）、（1.289±0.179）、（1.513 ±0.156）、（1.554 ±0.248）、（1.938±0.567） ×10-3 mm2/s,正常胰腺的ADC值为（1.687±0.129）×10-3mm2/s.A、B级AP的ADC值显著低于E级（P值均＜0.01）及正常胰腺（P值均＜0.05）,C级的ADC值低于E级（P＜0.05）,其余各级别之间,C、D、E级与正常胰腺之间的ADC值差异均无统计学意义（P值均＞0.05）.结论 磁共振DWI有利于Balthazar分级中形态变化不明显的A级及B级AP的早期诊断,但ADC值对AP严重性的分级诊断无明显价值.

Diffusion-weighted imaging for assessing the severity of acute pancreatitis

Objective To investigate the value of diffusion weighted imaging （DWI） and apparent diffusion coefficient （ADC） for the severity evaluation of acute pancreatitis （AP）. Methods Findings of MRI including DWI in 57 patients with AP and 13 subjects with normal pancreas （NP） were retrospectively reviewed. According to Balthazar＇s CT grading system, the severity of AP was divided into five groups from A to E according to the MRI findings. ADC values were measured at the inflammatory segments and normal segments. Comparison of mean ADC values was performed among each grade of AP, each grade of AP and NP by using ANOVA method. Results Of the 57 AP patients, 6, 9, 11, 10 and 21 patients were graded as A, B, C, D and E on MRI, respectively. The DWI of inflammatory pancreas showed hyperintensity in all AP patients （100%）. The mean ADC values in AP of grade A, B, C, D and E were （1.138±0.024）, （1.289 ±0. 179）, （1.513 ±0. 156）, （1.554 ±0.248） and （1.938 ±0.567） × 10^-3mm2/s, respectively. The mean ADC value of NP was （ 1. 687 ± 0. 129） × 10^-3 mm2/s. The mean ADC value was lower in AP of grade A and B than that in grade E （ P 〈 0.01 ） and NP （P 〈 0.05）. The mean ADC value was lower in grade C than that in grade E （P 〈 0.05）. There was no significant difference of ADC values among other each grade of AP （P 〉 0.05 ）, NP and AP of grade C, D and E （P 〉 0.05）. Conclusions DWI is helpful to diagnose acute pancreatitis of grade A and B with no morphologic change, but ADC value cannot be used to evaluate the severity of acute pancreatitis.