MRI长时间延迟多期增强扫描在肝脏孤立性坏死结节诊断和鉴别诊断中的应用价值

发布时间：2018-05-31 11:50

本文选题：肝脏孤立性坏死结节 + 肝细胞癌　；参考：《山东大学》2017年硕士论文

【摘要】：研究背景肝脏孤立性坏死结节(solitary necrotic nodule of the liver,SNNL)是一种罕见的良性肿瘤样病变。肝脏孤立性坏死结节的病因尚不清楚,可能与创伤、寄生虫感染、肝血管瘤、肿瘤所引起的变态反应和缺血等因素有关。肝脏孤立性坏死结节具有明显的良性生物学行为,病灶大小可长期无明显改变或自发性减小甚至完全消失,且目前没有肝脏孤立性坏死结节发生恶性转化和引起严重并发症的报道,故临床上其治疗以对症治疗为主,因而明确诊断可避免不必要的手术。肝脏孤立性坏死结节患者的临床表现和体征并无特异性,临床上亦无特殊的实验室检查指标可辅助其诊断。影像学检查中MRI被认为是最具诊断价值的检查手段,然而肝脏孤立性坏死结节在MRI上的特征性影像学表现存在争议,有学者认为肝脏孤立性坏死结节在增强MRI上的特征性表现为肝动脉期、门静脉期和延迟期上均无强化,而亦有学者认为病灶边缘在延迟期出现环形强化而病灶中心三期均无强化是病灶的特征性表现。这些相互矛盾的结论以及非特异性的临床资料导致目前基于患者的临床表现、病史、影像学表现和实验室检查肝脏孤立性坏死结节的术前疑诊率仅约7.8%。虽然特征性影像学表现尚存争议,但肝脏孤立性坏死结节的病理表现具有特征性,即病灶中心完全性、凝固性坏死,病灶周围有薄层纤维包膜包绕,包膜内有浆细胞、单核细胞和淋巴细胞等慢性炎症细胞浸润。鉴于纤维组织和延迟强化的密切关系,且常规增强MRI上延迟强化时间不超过5分钟,因此我们推断肝脏孤立性坏死结节边缘无环形强化的原因是因为相对短的延迟时间。故我们用延迟时间达2小时的长延迟增强MRI扫描以获得肝脏孤立性坏死结节的特异性影像学表现,提高肝脏孤立性坏死结节的诊断率。研究目的通过应用MRI长时间延迟多期增强扫描获得肝脏孤立性坏死结节的特征性影像学表现并将这些影像学表现与肝内三种主要相似恶性疾病的影像学表现进行对比,以探究MRI长时间延迟多期增强扫描在肝脏孤立性坏死结节的诊断和鉴别诊断中的应用价值。研究方法对16例临床疑诊为肝脏孤立性坏死结节、后被病理证实的患者进行平扫及三期增强CT扫描以及平扫和动态对比增强MRI成像,MRI的延迟时间分别为对比剂(Gd-DTPA)注射后3分钟、5分钟、10分钟、15分钟、30分钟、1小时和2小时。同时,将23例具有肝内相似恶性病灶的患者设定为对照组,包括7例肝细胞癌患者(8个病灶)、5例肝内胆管细胞癌患者(5个病灶)和11例肝转移癌患者,利用同样的MRI技术进行扫描,但当观察到病灶边缘强化退出后,后续的延迟扫描便不再进行。在CT和MRI上病灶的影像学观测指标包括:病灶的数目、位置、形状、大小、密度、信号强度、增强程度、边缘强化出现时间和消失时间等,图像的分析和评估由两位具有十年以上经验的放射科医师在不知研究内容的情况下进行评估并记录。本研究获得医院伦理委员会批准并获得所有患者或家属的知情同意。研究结果在16例肝脏孤立性坏死结节患者中,影像学检查共发现16个病灶,当延迟时间≤5分钟时,16个病灶中分别有4个(25%)和8个(50%)病灶在常规CT和MRI延迟期上表现为边缘轻度环形强化。随着增强MRI的延迟时间被延长,肿瘤边缘/瘤内间隔的强化逐渐增厚、强化程度逐渐增加。当延迟时间达到1小时时,所有病灶(100%)均表现为中度至明显边缘环形强化伴中心无强化低信号区。在对照组中,当延迟时间≤5分钟时,所有肝细胞癌、肝内胆管细胞癌及大多数肝转移癌病灶在传统MRI延迟期上表现为中度至明显边缘环形强化。然而,当对比剂注射后10分钟-15分钟时,7个(87.5%)肝细胞癌病灶以及除3个外的所有肝转移癌病灶边缘强化退出,当对比剂注射后30分钟时,1个(20%)肝内胆管细胞癌病灶边缘强化退出,对比剂注射后1小时时,其余4个(80%)肝内胆管细胞癌病灶边缘强化退出。另外,肝内胆管细胞癌和肝转移癌病灶在边缘强化退出时通常伴有对比剂向病灶中心弥散,表现为病灶中心斑片状强化。结论延迟时间为1小时或2小时的长延迟增强MRI在肝脏孤立性坏死结节的诊断及其与肝内相似疾病的鉴别诊断中具有重要意义。肝脏孤立性坏死结节在长延迟增强MRI上的特征性影像学表现为病灶边缘/瘤内间隔明显强化伴中心无强化低信号区,而肝癌、胆管癌和转移瘤则在1小时时边缘的对比剂退出。如果在整个长延迟过程中病灶均未表现出强化,则可以排除肝脏孤立性坏死结节的诊断。
[Abstract]:Background hepatic solitary necrotic nodules (solitary necrotic nodule of the liver, SNNL) is a rare benign tumor like lesion. The etiology of solitary necrotic nodules of the liver is unclear. It may be related to the factors such as trauma, parasitic infection, hepatic hemangioma, allergy and ischemia caused by tumors. Solitary necrotic nodules of the liver. With obvious benign biological behavior, the size of the lesion can not be changed or spontaneously decreased for a long time or even completely disappeared, and there is no report on the malignant transformation of the solitary necrotic nodules of the liver and the report of serious complications. Therefore, the clinical treatment is mainly for symptomatic treatment, so the definite diagnosis can avoid unnecessary operation. There is no specific clinical manifestation and physical signs in patients with solitary necrotic nodules. There is no special laboratory test for diagnosis. MRI is considered as the most diagnostic method in imaging examination. However, the characteristic imaging findings of isolated necrotic nodules in the liver are controversial, and some scholars believe the liver is in the liver. The characteristic manifestations of the solitary necrotic nodules on the enhanced MRI were the hepatic arterial phase, the portal venous phase and the delay period were not enhanced, while some scholars believed that the edge of the lesion had a circular enhancement in the delay period and the three stage of the focus was not enhanced. These contradictory conclusions and non specific clinical data were found. The present rate of diagnosis based on the clinical manifestation, history, imaging and laboratory examination of solitary necrotic nodules of the liver is only about 7.8%., although the characteristic imaging manifestations of the liver are still controversial, but the pathological manifestations of the solitary necrotic nodules of the liver are characteristic, that is, the central integrity of the lesion, the coagulation necrosis, and the thin lesions around the focus. There are chronic inflammatory cells, such as plasma cells, mononuclear cells and lymphocytes in the envelope, in the envelope. In view of the close relationship between the fibrous tissue and the delayed enhancement, and the delayed enhancement time of the conventional enhanced MRI is not more than 5 minutes. Therefore, we infer that the reason for the non ring enhancement on the edge of the solitary liver is because it is relatively short. Delay time. Therefore, we use long delay enhanced MRI scan with delayed time of 2 hours to obtain specific imaging findings of solitary necrotic nodules of the liver, and improve the diagnostic rate of solitary necrotic nodules of the liver. Objective to obtain the characteristic image of hepatic solitary necrotic nodules by MRI long time delayed multiphase enhanced scan. The findings were compared with the imaging findings of the three major similar malignant diseases in the liver to explore the value of MRI long time delayed multiphase enhanced scan in the diagnosis and differential diagnosis of solitary necrotic nodules of the liver. 16 cases were clinically suspected as solitary necrotic nodules of the liver, and then pathologically. The confirmed patients underwent plain and three phase enhanced CT scans as well as plain and dynamic contrast enhanced MRI imaging. The delay time of MRI was 3 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 1 hours and 2 hours after the contrast agent (Gd-DTPA). At the same time, 23 patients with intrahepatic similar malignant lesions were set as the control group, including 7 liver fine. Patients with cell carcinoma (8 lesions), 5 cases of intrahepatic cholangiocarcinoma (5 lesions) and 11 patients with liver metastases were scanned with the same MRI technique, but the follow-up delayed scans were no longer carried out when the lesions were fortified. The number, position, shape, size of the focus on CT and MRI were observed. The analysis and evaluation of the image was evaluated and recorded by two radiologists with more than ten years of experience without knowing the content of the study. This study was approved by the hospital ethics committee and obtained the informed consent of all patients or family members. Results in 16 patients with solitary necrotic nodules of the liver, 16 lesions were found in the imaging examination. When the delay time was less than 5 minutes, 4 (25%) and 8 (50%) of the 16 lesions, respectively, showed marginal annular intensification at the conventional CT and MRI delays. With the prolongation of the intensification of MRI, the tumor margin / intratumoral septum was prolonged. When the delay time was 1 hours, all lesions (100%) showed moderate to obvious marginal annular enhancement with central non intensification low signal region. In the control group, all hepatocellular carcinoma, intrahepatic bile duct carcinoma and most liver metastases were in the traditional MR when the delay time was less than 5 minutes. The I delay period showed moderate to obvious marginal annular enhancement. However, when the contrast agent was injected 10 minutes -15 minutes, 7 (87.5%) hepatocellular carcinoma lesions and all the liver metastases except 3 outside were exited, and 1 (20%) of the intrahepatic cholangiocarcinoma were fortified at the edge of the contrast agent at 30 minutes after the contrast injection, and the contrast agent was injected. At the next 1 hours, the other 4 (80%) intrahepatic cholangiocarcinoma lesions were withdrawn. In addition, intrahepatic cholangiocarcinoma and hepatic metastases were usually accompanied by contrast agent diffusion to the center of the lesion, showing central plaque enhancement in the focus. Conclusion the delay time was 1 hours or 2 hours of long delayed enhanced MRI in the liver. The diagnosis of erect necrotic nodules is of great significance in the differential diagnosis of intrahepatic similar diseases. The characteristic imaging of hepatic solitary necrotic nodules on long delayed enhanced MRI shows that the marginal / intratumoral septum is obviously enhanced with the central non enhanced low signal region, while the liver, cholangiocarcinoma and metastatic tumors are at the edge of 1 hours. If the lesion does not show enhancement during the whole long delay, the diagnosis of solitary necrotic nodule of the liver can be ruled out.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R575;R445.2

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