The Diagnosis of The Stage of Inflammation of Pyogenic Liver Abscess Formation Between CT and MR Scan
　　KANG Su-hai1， ZHANG Hui﹡2， LIU Qi-wang2， XIE Wei， LIANG Hong-qin1
　　（1 Department of Radiology， The 264 Hospital of PLA，Taiyuan，China，030001；2 Department of Imaging of the First Affiliated Hospital of Shan Xi Medical University）
　　Objective： The characteristic findings of pyogenic liver abscess（PLA） were studied through the correlation between three phase enhanced CT scan and MRI plain scan in order to offer the imaging basement for early diagnosis and treatment ，so as to reduce the complication and mortality of this disease. Methods： The study were retrospectively reviewed twenty-one patients with PLA belonged to the stage of inflammation of abscess ， which were confirmed by pathology or clinical treatment. Nineteen patients of them were underwent CT and MRI plain scan ， and then analysis the image of CT/MRI in the same situation. Results： PLA was caused by infection originating in four tracts. Although causes were different， imaging of the stage of inflammation were either similar or different. Their similar imaging showed slight low attenuation or mildly hypointense on T1-weighted and mildly hyperintense on T2–weighted， which their area ranged from less than one segment to more than one liver lobe. In hepatic artery phase（PAH）， transient hepatic attenuation difference （THAD） could be seen . It became iso-attenuation in portal venous phase（PVP） ， and then showed a more slight hyperattenuation than normal liver parenchyma in hepatic late phase（PLH）. There were several different aspects below next contents. ①Infection originating in the biliary tract. Eight patients belonged to it. Cholangitis showed “ring sign” on T2–weighted in plain scan. It showed hyperattenuation “ring sign”in PAH and PVP， and then it became iso-attenuation in PLH. There was no difference （t = 1.43， p= 0.227） between the enhanced CT scan and MRI plain scan in the ability of showing the cholangitis . ② Infection originating in the portal circulation. Seven patients belonged to it. It showed a widely lesion originating the result of pylephlebits. It showed “periportal halo sign” on T2–weighted imaging. It showed a low attenuation ring around portal on the enhanced CT scan. There was a significant difference （t = 3.23， p= 0.014） between the enhanced CT scan and MRI plain scan in the ability of showing the pylephlebits. The former was inferior to the later. ③ Infection originating in the arterial hematogenous spread. Two patients belonged to it. It showed some round and slight patched low attenuation or mildly hypointense on T1-weighted and mildly hyperintense on T2–weighted. ④ Infection originating in the directed extension. Two patients belonged to it. The area of lesion was limited. Conclusion： Making use full of their advantages of three phase enhanced CT scan and MR plain scan ， the process evolution of information stage of pyogenic liver abscess could be disclosed in order to offer a new view for the early diagnosis and treatment of this disease. 　Key word： pyogenic liver abscess ； the stage of inflammation； information stage of abscess； cholangitis； pylephlebits
　　肝脓肿被认为是一种对生命具有威胁的疾病[1]。其早期诊断和迅速治疗对降低与肝脓肿有关的发病率和死亡率是至关重要的[2]。肝脓肿的形成分为三期，即炎症期、成脓早期、成脓期。国外学者把肝脓肿分为：急性期、亚急性期、慢性期[3]。这两种分期从病理上讲大致相似，但前者更准确。据目前的文献显示，学者们对炎症期影像诊断的研究较少。但是，炎症期是肝脓肿演变的初始阶段，认识该期的影像特点对临床治疗有重要意义，可明显缩短疗程，减少并发症，降低死亡率。
　　资料与方法
　　1. 临床资料
　　2005年5月至2010年11月间经证实含有脓肿炎症期病变的患者19例。年龄在26 -79岁之间，平均56岁，病程7天左右，主要临床表现为发热、寒战，最常见实验室检查结果为白细胞升高。病因分析显示胆道源性7例（结石性4例，肿瘤性2例，胰腺炎并发症1例），门静脉源性8例（由胆道或消化道疾病吸收入门静脉），肝动脉源性2例，邻近组织感染2例。经肝穿病理证实5例，血培养证实7例（表皮葡萄球菌1例、大肠埃希氏菌2例、霉菌1例，克雷伯杆菌1例，革兰氏阴性菌与阳性菌混合感染2例），手术证实2例，据临床表现及抗生素治疗后复查MRI或B超，病灶明显缩小或消失、临床症状好转7例。
　　2. 检查技术
　　2.1 CT检查技术
　　采用GE Prospeed F-II螺旋CT机。层厚8mm、层距1.0mm，螺距1.0，19例均行全肝平扫和动态增强三期扫描。对比剂为碘帕醇和碘普罗胺 （300 mgI/ml），总量80～100ml，高压注射器注射，流速为2. 5ml/s，经肘静脉注入对比剂后30 s行动脉期扫描， 60s行静脉期扫描， 3 min行延迟期扫描。
　　2.2 MR检查技术
　　磁共振为GE Signa 0.35T 永磁型扫描仪，层厚8mm、层距2mm，体线圈，矩阵256×192，常规T1WI采用SE序列，TR 400 ms、TE 12 ms；T2WI采用快速恢复快速自旋回波序列（FRFSE），TR 8182 ms、TE 85ms。
　　CT增强与MRI扫描均为隔日检查。
　　2.3图像分析及处理 病灶的各种影像表现
　　由两名放射科高年资医师独立阅片，记录病灶的病因、范围、形态、胆管炎、门静脉或肝静脉炎以及狭窄、血栓的数目，肝段性一过性强化的数目，取其平均值。(责任编辑：南粤论文中心)转贴于南粤论文中心: http://www.nylw.net(南粤论文中心__代写代发论文_毕业论文带写_广州职称论文代发_广州论文网）