胰泌素增强MR胰胆管成像联合常规胰腺MRI对慢性胰腺炎诊断的价值

Combination of secretin-enhanced MR cholangiopancreatography and conventional MRI in the diagnosis of chronic pancreatitis

目的 探讨胰泌素增强MR胰胆管成像（MRCP）联合常规胰腺MRI对慢性胰腺炎（CP）诊断的价值.方法 收集17名健康志愿者和36例CP患者在注射胰泌素前后多期MRCP和冠状面T2 WI、常规胰腺平扫和增强MR资料.观察注射胰泌素前后的胰管变化,胰腺外分泌功能的评估采用十二指肠充盈度分级法,测量平扫时胰腺与同层面左侧腰大肌的信号强度比（SIR）和增强扫描时胰腺实质期和延迟期同层面信号强度比值（A/V）来观察胰腺实质MR特征.将53例受试者按照健康志愿组和CP患者不同剑桥分级进行分组,并按照十二指肠充盈正常和异常进行分组,观察SIR和A/V.采用单因素方差分析比较健康志愿者和CP患者不同剑桥分级各组患者的SIR和A/V值.十二指肠内充盈正常组和异常组SIR和A/V值的比较采用独立样本t检验.剑桥分级、十二指肠充盈度分级与SIR、A/V之间相关性分析采用Spearman秩相关检验.结果 胰泌素注射后所有受试者主胰管和分支胰管均较注射前图像质量提高,17名健康志愿者中均未见分支胰管显示.注射胰泌素11 min后,17名健康志愿者十二指肠充盈均为3级,36例CP患者中十二指肠内充盈3级、2级、1级者分别为23、8和5例.依据剑桥分级,CP轻度、中度和重度患者分别为11、12和13例,健康志愿组、CP轻度组、CP中度组和CP重度组SIR值分别为1.21 ±0.19、1.07 ±0.21、0.98 ±0.21和0.85 ±0.18,A/V值分别为1.15 ±0.11、1.23±0.34、0.97 ±0.16和0.91 ±0.12,差异均有统计学意义（F值分别为8.72和7.72,P值均＜0.01）.十二指肠充盈正常组和异常组患者分别为40和13例,SIR分别为1.09 ±0.20和0.88±0.27,A/V分别为1.15 ±0.11和0.94±0.30,差异均有统计学意义（t值分别为3.10和-2.40,P值均＜0.05）.剑桥分级、十二指肠充盈度分级与SIR值有相关性,r值分别为0.60和0.41,P值均＜0.01;与A/V也均有相关性,r值分别为0.60和0.52,P值均＜0.01.结论 胰泌素增强MRCP联合胰腺常规MR扫描可以从形态和功能方面诊断CP,为临床诊断提供参考.

Objective To discuss the value of combining secretin-enhanced MR cholangiopancreatography （MRCP） and conventional MRI in the evaluation of chronic pancreatitis （CP）.Methods Seventeen normal volunteers,and 36 patients with CP were enrolled in this study.Thick slab two dimension MRCP sequence,coronal T2 weighted sequence and conventional MRI were performed on all subjects.The changes of pancreatic ducts were observed before and after the injection of secretin.The exocrine function of the pancreas was evaluated using duodenal filling （DF） grades.Pancreatic parenchyma was reflected by signal intensity ratio （SIR） between the pancreas and the left psoas muscle on MR plain scan,and the ratio between the pancreatic substance phase and portal phase （A/V） of MR enhanced scan.All subjects were classified based on Cambridge classification and DF grades.The SIR and A/V were compared between all groups of Cambridge classification using the one-way ANOVA test,and between two groups of DF grades using Student＇s t test.Correlations between Cambridge classifications,DF grades and SIR,A/V were tested using Spearman rank correlation coefficients.Results After secretin injection,the visualization of all portions of the main pancreatic ducts and branch ducts were significantly improved in all subjects.Ten minutes after secretin injection,17 volunteers showed grade 3.Grade 3,2 and 1 were seen in 23,8,5 patients,respectively.Mild,moderate and severe CP by Cambridge classification showed in 11,12,13 patients,respectively.The mean SIR values of the volunteers and the three groups were 1.21 ± 0.19,1.07 ±0.21,0.98 ± 0.21 and 0.85 ± 0.18,respectively; the mean A/V values：1.15 ± 0.11,1.23 ± 0.34,0.97 ± 0.16 and 0.91 ± 0.12.There was statistically significant difference of SIR and A/V （F =8.72 and 7.72,P ＜0.01） between volunteers and CP.Normal and abnormal DF were seen in 40 and 13 patients.The mean SIR values of the two groups were 1.09 ± 0.20 and 0.88 ± 0.27 ; the mean A/V values：1.15 ± 0.11 and 0.94 ± 0.30.There was statistically significant difference of SIR and A/V （t =3.10 and -2.40,P ＜ 0.01） between two groups.There were correlations between Cambridge classification,DF grades and SIR （r =0.60 and 0.41,P＜0.01）,A/V （r =0.60 and 0.52,P＜0.01）.Conclusion Secretin-enhanced MRCP combined with conventional MRI can be used to evaluate CP regarding changes of morphology and function,which can provide a useful reference for the clinical diagnosis.