Acute portal vein thrombosis

The findings in acute portal vein thrombosis in a patient with chronic calcific pancreatitis and two episodes of pancreatic surgery are described. The diagnosis was made by ultrasound, which showed a dilated portal vein filled with low-level echoes, surrounding hepatic oedema, hypertrophy of the hepatic artery, splenomegaly, collateral vessels and ascites. This was confirmed by computed tomography. The ultrasonic differences in appearance between acute and chronic portal vein thrombosis are discussed, in the context of portal hypertension. The diagnosis of acute portal vein thrombosis should be considered in patients in the appropriate situation who suffer a sudden clinical deterioration with right upper quadrant or abdominal pain. Ultrasound is recommended as the imaging modality of first choice because of the flexibility of its scanning plane and its real time and Doppler capabilities. Computed tomography is valuable in patients with an ileus or heavy pancreatic calcification and for its ability to demonstrate patent vessels on intravenous injection of contrast medium.     

Ultrasonographic demonstration of portal vein thrombosis.

For screening patients suspected of having portal vein thrombosis, the ultrasound examination is simple to perform, noninvasive, and can be accomplished rapidly. Three patients were studied in whom ultrasound examination revealed portal vein thrombosis that was subsequently confirmed by angiography or surgery. Ultrasonic findings in a series of 100 randomly selected patients are summarized.     

门静脉和肠系膜上静脉血栓形成的MRI诊断

目的 分析门静脉（PV）和肠系膜上静脉（SMV）血栓形成的MRI特征及其诊断价值。方法 搜集经手术与病理证实的PV和SMV血栓形成患者12例，全部行MR T1WI、T2WI、抑脂T2、血管成像及钆喷替酸葡甲胺（Gd-DTPA）3期动态增强扫描。结果 直接征象为血管内血栓信号（12例），表现为T1WI和T2WI显示PV和SMV流空信号消失。3例急性期血栓T。WI为低或等信号，T2WI为高信号；8例亚急性期血栓T1WI及T2WI均为高信号；1例慢性期血栓T1WI为混杂信号，T2WI为低信号；增强扫描静脉期PV、SMV管腔内无对比剂充盈，PV周围呈轨道样增强，其内无强化的低信号血栓。间接征象包括肠腔扩张积液（10例）、肠管积血（6例）、肠壁增厚（12例）、肠黏膜水肿（11例）、薄纸样肠壁（1例）、缆绳征（11例）、肠系膜积液（2例）、肠壁积气（3例）、腹腔积液（12例）、PV海绵样变（3例）、肝脏异常灌注（6例）。结论 MRI是诊断PV和SMV血栓形成并肠道缺血敏感有效的方法，MR多序列、多轴面成像及增强扫描对病变的显示、定位、范围及血栓的分期等有重要作用。     

Sonographic features of portal vein thrombosis

The ability of real-time sonography to demonstrate the liver venous network is well documented. Sonographic features of 21 cases of unsuspected portal vein thrombosis, detected by a screening sonography of the upper abdomen and subsequently confirmed by computed tomography, angiography, or surgery, are discussed. Sonographic features of portal vein thrombosis were an echogenic thrombus within the lumen of the vein (67%), demonstration of portal vein collateral circulation (48%), enlargement of the thrombosed segment of the vein (38%), and the so-called cavernomatous transformation of the portal vein (19%). Echogenic endoluminal thrombi were observed with the same incidences in malignant and benign disease. Sonography, unlike angiography, was unable to characterize neoplastic thrombi; only the combination of an echogenic thrombus and an adjacent hepatic mass was strongly suggestive of malignancy, especially hepatoma. The extensive use of sonography as a screening test in upper abdomen pathology will probably improve the detection of portal vein thrombosis, a diagnosis until now considered rare.     

MR imaging of portal vein thrombosis

MR imaging is emerging as a potential means of detecting portal venous thrombosis (PVT). Therefore, we attempted to establish specific criteria with which to diagnose PVT on conventional spin-echo images. In a retrospective review of 342 consecutive abdominal MR scans performed with a 0.5-T magnet, we identified nine patients with persistent signal in the portal vein and used the findings in these patients to establish criteria with which to diagnose PVT. We subsequently applied these criteria to 109 additional consecutive abdominal MR scans performed with the same magnet. Fifteen cases were found in which all images showed either (1) signal involving the entire width of the portal vein lumen, which approximated (with T1 weighting) and exceeded (with T2 weighting) the intensity of the hepatic parenchyma in images in which the hepatic veins showed a complete flow void or (2) complete nonvisualization of the portal vein and its major branches in images that showed a flow void in portal venous collaterals and hepatic veins. All patients had unequivocal findings of PVT on at least one other imaging study (CT or sonography) or at surgery. Although the sensitivity of these signs could not be calculated, their specificity was 100%. We conclude that in the presence of these signs, the diagnosis of PVT can be made with confidence.     

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.

门静脉癌栓合并门脉高压症的TIPS姑息治疗

目的 评价门静脉癌栓（portal vein tumor thrombosis,PVTT) 合并门脉高压症患者行经颈静脉肝内门体静脉分流术（transjugular intrahepatic portosystemic shunt,TIPS)姑息治疗的疗效，并讨论其技术特点。方法 本组报告14例终末期肝癌合并门静脉癌栓及门静脉高压症患者，平均年龄53．6％。8例门静脉主干完全堵塞，6例门静脉主干及分支有不同程度栓塞，5例合并门静脉海绵样变。1例单纯上消化道大出血，3例单纯顽固性腹水，10例上消化道大出血合并顽固性腹水。结果 14例中10例患者成功行TIPS治疗，门静脉压力平均从术前37.2mmHg(1mmHg=0.133kPa)降至术后18.2mmHg，平均降低19.0mmHg；腹水减少或消失，消化道出血，腹胀，腹泻等症状缓解，平均生存32.3d。4例失败。结论 TIPS是姑息治疗肝癌合并门静脉癌栓引起的上消化道大出血和顽固性腹水的有效方法。     

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.     

Macronodular hepatic tuberculosis associated with portal vein thrombosis and portal hypertension

Tuberculosis (TB) of the liver is usually associated with miliary spread. Macronodular TB of the liver is rare. A case of macronodular TB of the liver in a 31-year-old woman causing portal vein thrombosis and portal hypertension is presented. Ultrasound and CT appearances are described. There was coexistent ileo-caecal TB with extensive mesenteric and retroperitoneal lymphadenopathy. Macronodular TB should be considered in the differential diagnosis when a patient presents with multiple calcified masses in the liver with portal vein thrombosis and portal hypertension.     

MRI diagnosis of bilateral adrenal vein thrombosis

We report a case of bilateral adrenal vein thrombosis in an adult female who had a history of breast cancer. The patient does not have clinical, serological or imaging evidence of metastatic disease 14 months from the initial diagnosis. Adrenal vein thrombosis is a rare entity. There have been no previous reports specifically stating an association between adrenal vein thrombosis and hypercoaguability, but there are many cases in the literature documenting venous thrombosis elsewhere within the body in patients with hypercoaguable states. Laboratory testing performed to exclude a hypercoaguable state, revealed heterozygosity for the Factor V Leiden mutation/activated protein C resistance and elevated factor VIII levels [3660 IU l(-1) (<1500)]. This is the first reported case of bilateral metachronous adrenal vein thrombosis in which MRI established the diagnosis.     

Diagnosis of portal vein thrombosis: value of color Doppler imaging.

This study was undertaken to determine the accuracy of color Doppler imaging in the diagnosis of portal vein thrombosis. Two hundred fifteen patients were studied with color Doppler imaging to determine patency of the main portal vein. Sonographic findings were confirmed in 75 patients, aged 19 to 66 years. Correlation with angiography was obtained in 13 patients, and surgical correlation was obtained in the remaining 62. Nine patients had portal vein thrombosis on the basis of these gold standards. Sonograms were classified as showing either patency or thrombosis, depending on the ability to show color flow within the main portal vein. Agreement between sonography and angiography or surgery was found in 69 patients (61 patent, eight thrombosed). One patient with a patent portal vein at sonography was found to have a thrombosed vessel at surgery, whereas five patients without portal venous flow at sonography had patent vessels at angiography (one patient) or surgery (four patients). Overall sensitivity and specificity for detection of portal vein thrombosis were 89% and 92%, with an accuracy of 92%, a false-negative rate of 0.11, a negative predictive value of 0.98, and a positive predictive value of 0.62. We postulate that the majority of errors in our study occurred in vessels that, although patent, had only sluggish flow, which could not be resolved because of technical limitations. We conclude that color Doppler imaging is a valuable screening procedure for the assessment of portal vein patency. If the sonogram shows a patent portal vein, no further studies are required. However, a lack of demonstrable flow does not always indicate thrombosis, and other imaging studies should be performed for confirmation.     

Dynamic MR studies of hepatocellular carcinoma with portal vein tumor thrombosis.

Gd-DTPA enhanced dynamic MR studies were evaluated in six patients with hepatocellular carcinoma associated with portal vein tumor thrombus. The portal vein tumor thrombus was clearly visualized as a low intensity lesion. The hepatic segment supplied by the portal vein showed high intensity, probably due to decreased portal blood flow and compensatory arterial blood flow. Tumors located in this segment were shown as areas of relatively low intensity compared with segmental high intensity areas. Thus dynamic MR study was found to be a useful method for differentiating the tumor from the surrounding nontumorous tissue with decreased portal blood flow.     

Sonographic demonstration of a patent umbilical vein in portal vein tumor thrombosis

A patent umbilical vein is a well-known sonographic sign of portal hypertension. We here describe this finding in a patient with extensive tumor thrombosis of the portal vein and its branches.     

Gradient echo sequences in the diagnosis of inferior vena cava thrombosis]

The capability for studying noninvasively vessels has been dramatically improved with the use of gradient echo sequences. Twenty-one patients presenting a suspected inferior vena cava obstruction on cavography underwent MR examination with axial, sagittal and coronal gradient echo images. Eighteen patients were also imaged with ultrasound and/or CT. Gradient echo sequences visualized a thrombus in 19 cases and a normal vein in the remaining 2 cases. The potential MR pitfalls are illustrated and the two cases of false positive on cavography are discussed. Gradient echo sequences allow a fast and performant examination of the vessels.     

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.