【作者】 陈大朝；

【导师】 许乙凯；

【作者基本信息】 第一军医大学 ， 医学影像学， 2004， 硕士

【摘要】 【目的】 ① 建立兔肝原位炎性假瘤(IPL)模型，并研究其MRI平扫及Gd-DTPA与SPIO增强表现。② 探讨肝脏炎性假瘤的MRI表现并与其病理相对照，并分析其鉴别诊断。 【材料与方法】 ① 将弗氏完全佐剂2.0 ml／只，作兔肝左叶原位注射，14天后行MRI平扫及Gd-DTPA与SPIO增强扫描，观察兔病灶的MRI表现。并取标本做病理检查。 ② 回顾性分析18例肝炎性假瘤的MRI平扫与Gd-DTPA动态增强扫描资料，所有病例经CT引导穿或B超引导穿刺或手术后经病理组织学证实，总结IPL的MRI表现特征，分析其MRI鉴别诊断。 【结果】 ① 10只兔子发现了IPL，发生率为83.3％，大小分别是2.5±1.0cm。IPL的MRI表现为T1WI呈等或略高信号，T2WI为略高信号，Gd-DTPA增强后呈缓慢轻度强化，延迟期SE序列图像最有利于观察病灶。SPIO增强后正常肝实质信号明显降低，病灶信号无明显降低，病灶与正常组织信号比明显提高。病理学证实局部肝组织片状坏死并有纤维组织增生及炎细胞浸润。 ② 18例患者共发现计20个病灶，多位于右叶，呈圆、类圆形、三角形、或不规则形。平扫T1WI为略低或等信号，T2WI为等或稍高信号。增强后动脉期多不强化，而门静脉期及延迟扫描表现为不强化、轻至中度强化、周边环状强化或结节性强化，瘤内可有点片状或条形强化。11例在延迟期有明显包膜强化。IPL的MRI表现及强化方式与其病理表现、分期可能有关。 【结论】 1．本方法所形成的炎性假瘤模型易于建立、容易复制、成功率高、制备周期短，与临床上IPL的病理学特征相似，有坏死无结构组织，纤维组织增生，炎性细胞浸润。可用来作为研究炎性假瘤的病因学及影像学的理想动物模型。 2，Gd一D仰A增强可提高兔肝炎性假瘤与正常组织的信号噪声比，提高病灶的显现性。炎性假瘤表现为少血供占位病灶，增强后缓慢强化，以延迟期最有利于显示病灶的细节显示，同时包膜表现为病灶边缘的带状强化。 3.sPIo不为炎性假瘤所吸收，但能显著地降低正常肝实质在TZWI上的信号强度，大大地提高病灶与正常肝组织的信号比。发现炎性假瘤不具有网状内皮系统，SPIO增强前后，TZWI上病灶信号变化不具有显著性意义。 4.IPL的MRI特征:①IPL多位于右叶，呈圆、类圆形、三角形、或不规则形;②平扫TIWI为略低或等信号，TZWI为等或稍高信号，瘤体内信号相对均匀，增强后亦如此。③动态增强后动脉期多数强化不明显，为少血供模式，少数可轻至中度强化;④静脉期及延迟扫描表现为无强化、轻至中度强化、周边环状强化或结节性强化，瘤内可有点片状或条形强化;⑤延迟期IPL肿瘤实质相对均匀，约半数明显包膜，其包膜规则完整，呈均匀带状强化。⑥由于IPL病灶内存在增生变性的致密胶原纤维及成纤维细胞、组织细胞的局灶性增生形成分隔和核心，故在增强晚期可出现分隔强化及中心核心强化;⑦IPL的平扫MRI表现及强化方式与其病理表现、分期可能有一定的相关性。更多还原

【Abstract】 Objective:1. To eatablish the animals models carrying inflammatory pseudotumor of the liver(IPL) in rabbits with Freund’s complete adjuvant serving for MRI study purpose. And to analyze its MRI manifestations before and after enhanced by Gd-DTPA and SPIO. Then correlating the model’ pathologic finding.2. To investigate MRI features of the inflammatory pseudo tumor of the liver in human, and correlated with the features to the pathologic findings, analyze it’s differential diagnosisMaterials and Methods:12 rabbits were injected with Freund’s complete adjuvant into left lobe of the liver at the dose of 2.0 ml per rabbit (n=12). All animals underwent MRI scan 14 days after the injection. MRI scans involved plain scan, Gd-DTPA enhanced FL2D sequences dynamic scan and SE-T1 sequence delay scan, SPIO enhanced TSE-T2 sequence scan and SE-T1 sequence. Then the lesions were harvested for further pathological examinations.The MRI findings of 18 case of IPL were retrospectively reviewed, and correlated with pathologic findings. The MRI scans involved both plain and Gd-DTPA enhanced MRI scanning. All the cases were proved IPL patho-histologily with aspiration needle biopsy specimens guided by CT or B-ultrasounds or surgery. The IPL’s MRI features were summarized, and it’s differential diagnosis were analysised.Results:1. There were 10 IPL detected in 10 rabbits of all 12 rabbits (incidence rate was 83.3%). With the tumor size of 2.5 +1.0 cm, the lesions were hypo-iso-intensity or slightly hyperintensity on T1 weighted images and hyperintensity on T2 weighted. When enhanced by Gd-DTPA, the lesions showed slowly reinforcement and has the best conspicuous in the delayed phase T1-weighted SE sequence imaging. While enhanced by SPIO, the lesions did not change much but intensity of normal hepatic parenchyma reduced sharply in T2WI. The contrast of intensity between lesion and liver rose apparently. Histologically, there were necrotic areas within the nodulesassociated with fibrous proliferation and inflammatory cells infiltrated.2. There were 20 lesions in 18 cases being detected, most of them located in the right lobes of liver, the lesions were round or round-like, triangle or abnormal in shape All lesions showed slightly-low-intensity signal on plain scanning T1WI and iso-intensity or slightly-high-intensity signal on T2WI. Dynamic enhanced MR imaging revealed that most lesion were not enhanced markedly immediately after gadolinium administration, during portal-venous phase and delay phase scanning, the lesions show no-reinforcement, edge enhanced, slightly to intermediate enhanced, round-ring reinforcement and nodes reinforcements. It also reviewed there are correlation between MRI finding and it’s pathologic features and stages of the IPL.Conclusions:1.The model bearing IPL in rabbits induced by Freund’s complete adjuvant has the advantage of high incidence rate, short latent period, easy duplication, it also have the pathologic feature of necrotic constitution, fibrous proliferation and inflammatory cells infiltrated. The model could be served as ideal experimental animal model for further study of IPL’s etiopathology and imaging features.2.Gd-DPTA could enhance signal to noise ratio of IPL in rabbit, improved it’s conspicuity. IPL were lesions of hypovascularity, it’s signal increased slowly, it’s details manifested best in the delayed phase imaging, the envelope show as bandlike reinforcement outside the lesions.3.SPIO particle can’t be absorbed by IPL. But it reduced normal liver parenchyma significantly, thus increased signal ratio of lesion-to-liver. IPL didn’t possess reticuloendothelial system, when enhanced by SPIO, it’s signal changed little in T2WI.4. The MRI features of the IPL in human were: (1) Most IPL located in the right lobes of the liver, with the shape of roundness, round-like, triangle, poly-nodes confluence or abnormity; (2) All lesions showed low or slightly-low-intensity signal on plain T1WI scanning and high or slightly-high-intensity iso-intensity or signal on T2WI, the更多还原