脂肪抑制T_2WI和MRI增强在慢性乙型肝炎活动期中的诊断价值

The Value of Fat Suppressed T_2-Weighted and Contrast-Enhanced MR Imaging in Diagnosing Activity of Chronic Hepatitis B

目的探讨慢性乙型肝炎活动期的MRI表现,提高诊断的准确性。方法回顾性分析经临床证实的75例乙型肝炎活动期患者MRI资料。71例行平扫+增强,4例行平扫;重症组12例,非重症组63例。在脂肪抑制T_2WI序列下测量肝脏信号强度与右侧竖脊肌信号强度之比值(SII)。对照组选择无肝病病史及腹部疾病的正常成人66名,同样测量SII并进行统计学分析。结果慢性乙型肝炎活动期在脂肪抑制T_2WI信号增高,高于右侧竖脊肌信号,慢性乙型肝炎组与正常对照组间的SII值差异有统计学意义(P<0.05);非重症乙型肝炎组和重症乙型肝炎组与正常对照组间的SII值差异均有统计学意义(P<0.05);非重症乙型肝炎组与重症乙型肝炎组间SII值差异无统计学意义(P>0.05)。动脉期肝脏多发斑片状或网格样明显强化区,多分布于门静脉周围及肝包膜下,部分病例出现延迟廓清表现,少数重症病例肝脏散在小斑片状无强化区。61例存在Glisson囊炎性渗出,23例出现胆囊壁水肿增厚,23例存在胆汁淤积,13例出现腹腔积液,63例有肝门区多发小淋巴结。结论乙型肝炎活动期患者的MR表现有一定的特征性,有助于提高诊断的准确性。

Objective To study the manifestation of magnetic resonance imaging（ MRI） on the patients with activity of chronic hepatitis B（ CHB）,in order to improve its diagnostic level. Methods Seventy-five patients（ 65 men and 10women; mean age 37. 7 ± 12. 0,range from 18 to 72） with clinically proved activity of CHB and 66 healthy subjects without history of liver disease were included in this study. The clinical,pathological and MRI materials were collected. In a total of 75 cases proved CHB,there existed 63 cases with non-severe hepatitis B and 12 cases with severe hepatitis B. The imaging characteristics of CHB were retrospectively analyzed. The correlation between imaging features and pathological results were evaluated. 71 cases had underwent non-contrast and contrast-enhanced MR imaging,and 4 cases had only noncontrast MR imaging. The SII was calculated as the signal intensity ratio between the hepatic parenchyma and the right erector spinae muscles in the same MR section for fat-suppressed T_2-weighted images for all included cases. Results The signal intensity of the hepatic parenchyma in patients with CHB in fat-suppressed T_2-weighted images was higher than that of right erector spinae muscle. The difference of mean SII between the hepatitis group and the normal control group was statistically significant（ P〈0. 05）. The difference of mean SII between the control group and non-severe hepatitis group and severe hepatitis group were statistical significance（ P〈0. 05）. But there existed no statistical significance between the nonsevere hepatitis group and severe hepatitis group（ P〈0. 05）. Furthermore,the liver presented multiple patchy or reticular obvious enhancement in the arterial phase after contrast injection. The enhanced regions were distributed around the portal vein and the liver capsule. Some cases also showed delayed clearance,and a few severe CHB cases demonstrated scattered small patchy non-enhanced areas in the liver. Moreover,61 cases（ 81. 3%） exhibited inflammatory exudation within Glisson＇s capsule,and 23 cases（ 30%） appeared edema and thickening in the gallbladder wall,with 23 cases（ 30%） in cholestasis,13 cases（ 17. 3%） appearing seroperitoneum,and 63 cases（ 82. 3%） associated with multiple small lymph nodes in hepatic hilar region. Conclusion Activity of chronic hepatitis B have certain MRI features,which could be helpful for the diagnosis of CHB.