急性门静脉和肠系膜上静脉血栓形成的MRI诊断

目的 分析急性门静脉(PV)和肠系膜上静脉(SMV)血栓形成的临床及MRI表现.资料与方法 回顾性分析经手术及临床综合诊断证实的7例急性PV及SMV血栓形成患者的MRI表现.7例均行MR T1WI、T2WI、脂肪抑制T2WI、血管成像及三期动态增强扫描.结果 直接征象为血管内血栓信号,表现为T1WI和T2WI显示PV和SMV流空信号消失.急性期血栓T1WI为低或等信号,T2WI为高信号;增强扫描静脉期PV、SMV管腔内无对比剂充盈.间接征象包括6例见腹腔积液,5例见小肠管壁增厚、水肿,4例见肠管扩张积液.结论 MRI对诊断急性PV及SMV血栓形成具有重要意义;临床对急性腹痛、不明原因腹腔积液及可疑小肠梗阻者应观察PV系统情况.     

门静脉和肠系膜上静脉血栓形成的相关基础和介入治疗近展

在肠管缺血性疾病中,因门静脉(PV)和肠系膜上静脉(SMV)血栓栓塞所致者占5％～15％,既往报道的病例中多数由剖腹探察或尸检确诊,近年由于影像学技术的发展,使早期诊断病例有所增加。PV和SMV血栓形成可继发于腹腔感染、门脉高压症、腹部外科术(如脾切除、门-腔或脾-肾分流、肝脏移植术)后、血液病等,较常见的临床表现有腹痛、腹胀、厌食、腹泻等,但缺乏特征性,常被延误诊断,急性和亚急性患者可因侧支循环建立不良而发生肠梗死,未经及时治疗的患者病死率高达50％。近年,随着介入微创技术的发展,为治疗PV和SMV广泛血栓形成开辟了新途径。     

急性门静脉和肠系膜上静脉血栓形成的CT诊断

目的:分析急性门静脉及肠系膜上静脉血栓形成的临床及CT表现。方法:回顾性分析9例经手术及临床综合诊断证实的急性门静脉及肠系膜上静脉血栓形成病例的CT表现,9例均行CT平扫,3例行增强扫描。结果:9例CT平扫均显示门静脉或肠系膜上静脉增粗,7例见腔内高密度影,8例见腹腔积液,5例见小肠管壁增厚、水肿;3例强化扫描示静脉内低密度充盈缺损。结论:CT对诊断急性门静脉及肠系膜上静脉血栓形成具有重要意义;临床上对急性腹痛,不明原因腹水及可疑肠梗阻的病例,应注意观察其门脉系统情况。     

急性肠系膜上静脉血栓形成的影像学诊断

目的分析急性肠系膜上静脉血栓形成（SMVT）的临床及影像学表现,以提高对其诊断水平。资料与方法16例均经彩色多普勒超声（彩超）或／和CT检查确诊,10例经手术证实。结果彩超发现SMVT14例,CT诊断SMVT16例,二者均可见到肠管扩张,肠壁增厚,腹腔内游离液体等间接征象。V结论影像学检查对于明确诊断SMVT具有重要价值。     

常规MRI和三维对比增强MR血管成像对门肠系膜静脉血栓的诊断

目的 探讨常规MRI和三维对比增强MR血管成像(3D CE MRA)在门肠系膜静脉血栓诊断中的价值.资料与方法 回顾性分析经临床、手术证实的14例门肠系膜静脉血栓的平扫、增强MRI和3D CE MRA资料.结果 14例中,门肠系膜静脉及分支累及10例,门静脉及分支累及2例,2例仅累及肠系膜上静脉及分支;其中5例并发侧支血管形成.3D CE MRA准确地显示了相应病理解剖改变;平扫MRI能够显示门静脉、肠系膜上静脉主干内的血栓,但难以确切显示门肠系膜静脉属支、门静脉肝内分支血栓和较小血栓;增强后快速扰相稳态梯度回复采集序列(FSPGR)图像由于血管内和血管壁的强化及更高信噪比可更好地显示血栓.结论 平扫时重视对血管形态的观察有利于发现血栓,同时行3D CE MRA及增强后FSPGR,可以准确地诊断门肠系膜静脉血栓,为临床提供重要的诊断信息.     

肠系膜上静脉血栓形成的CT诊断

目的探讨螺旋CT对肠系膜上静脉血栓形成的诊断价值。方法回顾性分析临床证实的13例肠系膜上静脉血栓形成的CT表现特点。13例均行CT平扫及多期增强扫描,其中4例行口服对比剂后延迟扫描。部分图像数据行多平面最大密度投影等后处理。结果所有病例均表现有肠系膜充血水肿,8例于增强扫描后显示有肠系膜上静脉内圆形充盈缺损。其余5例发生于末梢血管的病变。CT未能直接显示血栓,扫描显示了肠管扩张、肠壁增厚、靶征、肠壁强化程度减低、缺失或肠间小气泡影等反映继发肠缺血表现的CT征象。后两者对肠缺血坏死的判断,有较高的特异性。而肠坏死的发生与血栓是否位于主干并无直接关系。结论螺旋CT是诊断肠系膜上静脉血栓形成的重要的检查方法。     

急性肠系膜上静脉血栓形成的CT诊断

目的分析急性肠系膜上静脉血栓形成的临床特点及CT表现，提高认识水平。方法回顾性分析6例经手术证实为肠系膜上静脉血栓形成的CT表现。平扫6例，增强扫描2例。结果6例CT平扫均出现腹腔积液、肠壁增厚、肠腔变窄、肠系膜密度增高模糊、肠系膜上静脉内高密度阴影等征象。4例可见肠系膜上静脉增宽，3例可见肠系膜间游离积液，2例增强扫描可见肠系膜上静脉内低密度血栓影，静脉壁环形强化呈“靶征”。结论CT检查对于早期诊断肠系膜上静脉血栓形成是一种有价值的方法。对于不明原冈所致腹痛应及时行CT检查。     

64层螺旋CT对急性门静脉和肠系膜上静脉血栓的诊断价值

目的 探讨64层螺旋CT对急性门静脉和肠系膜上静脉血栓的诊断价值.资料与方法回顾性分析经手术及临床确诊的19例急性门静脉和肠系膜上静脉血栓形成患者的64层螺旋CT表现.19例均行平扫,14例加行增强扫描,并应用多平面重组(MPR)、曲面重组(CPR)、最大密度投影(MIP)和容积再现(VR)行多层螺旋CT血管成像(MSCTA).结果 19例平扫均显示门静脉和肠系膜上静脉增粗,12例肠系膜周围脂肪密度增高,13例管腔内高密度,10例有不同程度腹腔积液,14例肠管扩张、积气积液,10例肠壁增厚水肿;14例增强扫描均显示静脉内低密度充盈缺损,门静脉和肠系膜上静脉管壁环形强化,肠管管壁强化呈"靶征",3例肠管未强化,5例显示肝脏一过性供血不足,门静脉期供血减少.结论 64层螺旋CT平扫及增强扫描,以及三维重组技术相结合能够早期发现急性门静脉和肠系膜上静脉血栓形成.     

MRI联合磁共振静脉成像诊断脑静脉窦血栓形成的价值

目的:探讨MRI及磁共振静脉成像(MRV)对脑静脉窦血栓形成的诊断价值.方法:回顾性分析37例DSA确诊脑静脉窦血栓形成患者的临床资料及影像表现.37例中有30例行常规MRI检查,29例行MRV(2D TOF)检查.结果:30例常规MRI检查中28例静脉窦有异常信号,其中26例MRI表现为静脉窦T1WI、T2WI高信号,2例T1WI等信号、T2WI低信号,并部分伴有脑组织梗死、出血.29例MRV检查均发现静脉窦充盈缺损或中断.结论:MRI与MRV结合对诊断脑静脉窦血栓形成具有高度敏感性,是诊断静脉窦血栓形成的首选检查方法.     

Aneurysm of the superior mesenteric vein

A superior mesenteric vein aneurysm was diagnosed by ultrasound, computed tomography, and angiography in a 55-year-old woman. It was successfully treated by partial resection and reconstruction of the confluent veins.     

Mesenteric arteriovenous shunt associated with thrombosis of the portal venous system: Case report

We report a rare case of mesenteric arteriovenous shunt associated with thrombosis of the portal venous system. The angiographic features consisted of new vessel formation, thrombosis of the main portal vein, superior mesenteric vein and branches, and early filling of distal mesenteric veins with hepatopetal collateral flow. This phenomenon may be due to new vessel formation within the portal vein thrombosis and active lysis of the thrombus exposing the organizing vessels to the distal superior mesenteric veins.     

A rare pediatric case of portal vein aneurysm thrombosis

Portal vein aneurysm (PVA) is rarely encountered, and published papers describing this etiology in adults and children typically include only case reports or small case series. We present a clinical case of PVA in a child associated with severe complications, including diffuse thrombosis of the portal venous system. A 10-year-old boy presented with abdominal pain and vomiting, resulting in an initial diagnosis of pancreatic head tumor based on suspicious images on abdominal grayscale ultrasound. Contrast-enhanced computed tomography confirmed a diagnosis of occlusive PVA thrombosis (36 × 37 × 95 mm). Lacking drastic symptoms, the patient was treated with conservative anticoagulant therapy. On follow-up, the thrombosis appeared to shrink gradually and disappeared at 6 months based on Doppler ultrasound imaging. The PVA was reduced in size, and hepatopetal flow was restored. Surgeons and radiologists should be aware of this rare entity to ensure that a precise diagnosis can be established and to provide suitable treatment.     

磁共振门静脉血流动力学改变与肝功能相关性

目的：通过磁共振相位对比法成像测量慢性肝病患者门静脉主干的平均血流速度及每分血流量,并将其与肝功能终末期肝病模型（MELD）评分进行相关性研究,探讨磁共振相位对比法成像在评价慢性肝病肝功能的应用价值。方法：60例慢性肝病患者行肝脏磁共振相位对比法成像（包括15例治疗前后的随访复查）,测量病例组60例及15例治疗前、后门静脉主干的平均血流速度及每分血流量,分析它们与MELD评分的相关性。结果：病例组60例门静脉主干的平均血流速度与MELD评分有显著性负相关（R=-0.40,P〈0.05）,每分血流量与MELD评分无显著性相关（R=-0.22,P〉0.05）。治疗前后15例门静脉主干的平均血流速度变化量与MELD评分变化量有显著性负相关（R=-0.69,P〈0.01）,每分血流量变化量与MELD评分变化量也有显著性负相关（R=-0.51,P〈0.05）。结论：门静脉主干的平均血流速度及每分血流量与MELD评分有较密切的相关性,对慢性肝病患者的肝功能评估及疗效观测有较高的临床应用价值。     

Interruption of systemic venous return with portal continuation: Assessment using magnetic resonance imaging

A case of interruption of both the superior and infrahepatic inferior vena cava with portal continuation of the systemic venous return is described. This unusual abnormality is probably acquired and represents the result of earlier, silent thrombosis of the venae cavae. Magnetic resonance imaging provided valuable anatomic information supplementing venography.     

Quantification of portal venous blood flow during fasting and after a standardized meal — a MRI phase-mapping study

Portal venous blood flow was measured with a double-oblique phase-sensitive magnetic resonance imaging (MRI) flow measurement technique in six healthy volunteers after 7 h of fasting. A standard liquid meal with an energy content of 4200 kJ, containing equal parts of carbohydrate, protein and fat was given to the volunteers while in the scanner. Flow measurements were performed 5, 15 and 30 min after intake of the meal. The average portal vein blood flow was 0.88 ± 0.17 l · min^–1 during fasting. After intake of the standard meal, flow increased by 30,67 and 111% after 5, 15 and 30 min, respectively.This study shows that a non-invasive MRI technique can be used for volume flow determinations in the portal vein and that physiological changes in flow can be quantified. The technique may be of clinical value in evaluation of patients with abdominal angina as well as patients with portal hypertension. Correspondence to: C. Thomsen     

A rare Abernethy Ib malformation was initially misdiagnosed as chronic portal vein thrombosis in a 27-year-old female

Abernethy malformation or congenital portosystemic shunt is a rare congenital vascular malformation and anomaly of the splanchnic venous system defined by diverting portal blood away from the liver. It is commonly associated with multiple congenital anomalies. Imaging modalities such as computed tomography or magnetic resonance have a crucial role in prompting diagnosis and determining the prognosis based on the type of malformation and associated anomalies. Misdiagnosis could be harmful and may lead to inappropriate treatment. We present a case of Abernethy malformation with a complete end-to-side shunt of portal venous flow into the systemic venous flow and complete bypass of the liver, which was initially misdiagnosed with portal venous thrombosis.     

Imaging and radiological interventions of portal vein thrombosis

Portal vein thrombosis (PVT) is diagnosed by imaging methods. Once diagnosed by means of ultrasound, Doppler ultrasound can be performed to distinguish between a benign and malignant thrombus. If further information is required, magnetic resonance angiography or contrast-enhanced computed tomography is the next step, and if these tests are unsatisfactory, digital subtraction angiography should be performed. Many papers have been published dealing with alternative methods of treating PVT, but the material is fairly heterogeneous. In symptomatic non-cavernomatous PVT, recanalization using local methods is recommended by many authors. Implantation of transjugular intrahepatic portosystemic shunt is helpful in cirrhotic patients with non-cavernomatous PVT in reducing portal pressure and in diminishing the risk of re-thrombosis. In non-cirrhotic patients with recent PVT, some authors recommend anticoagulation alone. In chronic thrombotic occlusion of the portal vein, local measures may be implemented if refractory symptoms of portal hypertension are evident.     

Discrimination between malignant and bland portal vein thrombosis: Could diffusion weighted MRI help

Objective

To study the role of DWI in the differentiation between bland and malignant portal vein thrombus in HCC patients.