肝硬化患者脑常规和扩散加权 MR 成像与门静脉高压测量参数的相关性

Brain conventional MR and DWI in cirrhotic patients：correlated with portal hypertension

目的：探讨肝硬化患者脑常规和扩散加权（ DWI ）磁共振成像（ MRI ）与门静脉高压测量参数之间的相关性。方法回顾分析南京军区南京总医院2009年6月至2014年5月275例肝硬化患者行脑MR检查；计算苍白球指数（ GPI），测量双侧顶叶白质、额叶白质、枕叶白质、尾状核头、壳核、苍白球和丘脑的表观扩散系数（ ADC）；在CT图像测量肝脏体积、门静脉和侧支循环的最大管径值。独立样本t检验用于比较有无T1 WI苍白球高信号组之间以及1.5T和3.0T MR之间GPI之间的差异；采用单因素方差分析按照Child-Pugh分级进行分析；采用配对样本t检验分析比较随访病例前后两次脑MR检查的GPI值；采用Pearson相关检验分析GPI、脑各部位ADC值与门静脉管径、肝脏体积、侧支循环管径及静脉血氨值之间的相关性；采用Spearman等级相关检验分析GPI、各部位ADC值与Child-Pugh分级之间的相关性。结果（1）肝硬化患者T1WI苍白球高信号组的GPI显著高于无高信号组患者（0.128±0.031比0.057±0.021，t＝22.244，P＜0.01）；两组间脑各部位ADC值及静脉血氨值差异无统计学意义；苍白球高信号组的门静脉管径、侧支循环管径明显大于无高信号组[（18±4） mm 比（17±3） mm、（10±6） mm 比（6±4） mm，t 值分别为2.816、5.048，P 值分别为0.005、＜0.01]；高信号组的肝脏体积明显小于无高信号组[（1113±445）ml比（14443±698）ml，t＝-4.280，P＜0.01]；不同Child-Pugh分级组间差异均无统计学意义（均P＞0.05）。（2）1.5T和3.0T MR的肝硬化患者GPI差异有统计学意义（t＝-5.15，P＜0.01）；短期随访患者的GPI差异无统计学意义（t＝-0.271，P＝0.788）；（3）GPI与肝脏体积呈负相关（r＝-0.240，P＜0.01），与门静脉管径和侧支循环管径呈正相关（r值分别为0.296、0.355；均P＜0.01）；顶叶、额叶、尾状核、苍白球和枕叶的ADC值与GPI呈正相关（ r值分别为0.309、0.156、0.174、0.155、0.185；均P＜0.05）；顶叶的ADC值与门静脉管径呈正相关（r＝0.187，P＝0.025）；其他部位ADC值与门静脉高压测量参数之间无显著相关性（均P＞0.05）；GPI、丘脑ADC值与Child-Pugh 分级间呈正相关（ r值分别为0.195、0.217，均P＜0.05），其余部位ADC值与Child-Pugh分级间无显著相关性（均P＞0.05）。结论肝硬化患者GPI与门静脉高压严重程度有关，且与ADC值呈正相关，但ADC值的改变与门静脉高压关系不大，静脉血氨值和Child-Pugh分级对于GPI和ADC值改变影响不大。

Objective To explore the relationship among brain routine magnetic resonance imaging （ MRI） , diffusion weight imaging （ DWI ） , and parameters of portal hypertension of cirrhosis patients.Methods Two hundred and seventy-five patients with cirrhosis underwent routine MRI exams were analyzed retrospectively.Signal intensities of putamen and globus pallidus （ GP） were measured on T 1 WI to compute globus pallidus index （GPI）.In apparent diffusion coefficient （ADC） images, regions of interest （ROIs）were placed on the white matter of parietal lobe , frontal lobe, occipital lobe, caudate head, putamen, GP, and thalamus to get ADC values of each location.In abdomen CT images , liver areas of all slices were drawn to multiply slice thickness to get liver volumes , and maximum portal venous caliber and portosystemic shunting collateral caliber were recorded.Independent-samples t test was performed to explore the significance of GPI between GP hyperintensity group and GP non-hyperintensity group , as well as between cirrhosis groups underwent 1.5T and 3.0T MR exams.One-way ANOVA test was performed to evaluate differences among Child-Pugh classes.The difference between baseline and follow-up MR exams were compared with paired-samples t test.Pearson correlation test was performed to explore the relationships among GPI, ADC values, parameters of portal hypertension , and venous blood ammonia levels.Spearman rank correlation test was performed to explore the relationships among GPI , ADC values, and Child-Pugh classes.Results （ 1 ） The GPI in GP hyperintensity group was significantly higher than GP non-hyperintensity group （0.128 ±0.031 vs 0.057 ±0.021,t =22.244, P〈0.01）.The ADC values and venous blood ammonia levels showed no significant difference between two groups .GP hyperintensity group showed larger portal venous and collateral calibers than GP non-hyperintensity group （（18±4）mm vs （17 ±3）mm,（10±6） mm vs （6 ±4） mm,t was 2.816 and 5.048 respectively; P was 0.005 and〈0.01 respectively）.GP hyperintensity group showed less liver volumes than the other group （（1 113±445）ml vs （14 443 ±698） ml,t=-4.280, P〈0.01）.Child-Pugh classes showed no significant difference among each other （all P〉0.05）.（2）The GPI of 1.5T and 3.0T exams showed significant difference between each other （t=-5.15, P〈0.01）.Short-term follow-up patients showed no significant difference of GPI between two exams （t=-0.271, P=0.788）.（3）GPI showed negative correlation with liver volumes of cirrhosis patients （ r =-0.240;P 〈0.01 ） , and GPI positively correlated with portal venous calibers and portosystemic shunting collateral calibers （ r=0.296, 0.355;both P〈0.01）.ADC values of parietal lobe , frontal lobe, caudate head, GP, and occipital lobe positively correlated with GPI （ r =0.309, 0.156, 0.174, 0.155, 0.185;all P〉0.05）.ADC values of parietal lobe positively correlated with portal venous calibers （r=0.187, P =0.025）, ADC values of other locations showed no significant correlation with parameters of portal hypertension （all P〉0.05）.GPI and thalamus ADC values showed positive correlation with Child-Pugh classes （ r=0.195 and 0.217;both P〈0.05 ） , ADC values of other locations showed no significant correlation with Child-Pugh classes （all P〉0.05）.Conclusions The GPI of cirrhosis patients was correlated with severity of portal hypertension , and showed significant correlation with ADC values , while ADC values had no relationship with portal hypertension.Besides , venous blood ammonia values and Child-Pugh classes have little effect on GPI and ADC values.