Characterization Of Portal Vein Thrombosis Research Articles

Usefulness of Imaging and Biological Tools for the Characterization of Portal Vein Thrombosis in Hepatocellular Carcinoma.

This study aims to evaluate the performance of contrast-enhanced ultrasound (CEUS) and biological tests to characterize portal vein thrombosis (PVT). We retrospectively analyzed 101 patients with PVT, liver cirrhosis, and hepatocellular carcinoma (HCC). In all patients, demographic, biologic, imaging, and endoscopic data were collected. All patients underwent CEUS and a second line imaging technique (CE-CT/MRI) to characterize PVT. Of the 101 cirrhotic subjects, 77 (76.2%) had HCC. CEUS had 98.6% sensitivity (Se) and 89.3% specificity (Sp) for the characterization of PVT type. A significant correlation was found between alpha-fetoprotein (AFP) levels and the PVT characterization at CEUS (r = 0.28, p = 0.0098) and CT/MRI (r = 0.3, p = 0.0057). Using the AFP rule-out cutoff values for HCC (AFP < 20 ng/dL), 78% of the subjects were correctly classified as having benign PVT, while 100% of the subjects were correctly classified as tumor-in-vein (TIV) when the rule-in cutoff value was used (AFP ≥ 200 ng/dL). Using multiple regression analysis, we obtained a score for classifying PVT. The PVT score performed better than CEUS (AUC—0.99 vs. AUC—0.93, p = 0.025) or AFP serum levels (AUC—0.99 vs. AUC—0.96, p = 0.047) for characterizing PVT. In conclusion, CEUS is a sensitive method for the characterization of PVT. The PVT score had the highest performance for PVT characterization.

Differentiation of Malignant from Benign Portal Vein Thrombi on CT Images Using Thrombus Density

AbstractBackground: Portal vein thrombosis described as the presence of a clot in the portal vein lumen or a permanent obliteration of the portal vein as a result of prior thrombosis with replacement by numerous tortuous venous channels (termed cavernoma). Malignant portal vein thrombus, so named for its neoplastic origin, is a common complication of HCC, and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy.Aim of Study: The purpose of this study was to investigate the role of CT thrombus density (measured in Hounsfield Units) in distinguishing between neoplastic and bland portal vein thrombosis on arterial and portal venous phases.Material and Methods: In this study, 30 patients underwent contrast-enhanced CT of abdomen & pelvis were included for characterization of portal vein thrombosis. Assessment of portal vein thrombosis was performed by measuring of CT attenuation values of the thrombi in Hounsfield Units (HU).ROC (Receiver Operating Characteristic) curves were used to identify accuracy and optimal cutoff values.Results: Of the 30 CT studies, 14 neoplastic thrombi and 13 bland thrombi were identified on the images. CT thrombus density (measured in Housinfield Unit) to differentiate neo-plastic from bland thrombus. The AUCs was 0.98 in arterial phase and 0.98 in portovenous phase for thrombus density.The optimal cut off in arterial phase is 47 and in porto-venous phase is 50.Conclusion: CT attenuation values allow reliable differ-entiation between neoplastic and bland thrombi on arterial and portal venous phase CT examination.

Characterization of Portal Vein Thrombosis (Neoplastic Versus Bland) on CT Images Using Software-Based Texture Analysis and Thrombus Density (Hounsfield Units).

The purpose of this study was to investigate the role of CT texture analysis and thrombus density (measured in Hounsfield units) in distinguishing between neoplastic and bland portal vein thrombosis (PVT) on portal venous phase CT. In this retrospective study, 117 contrast-enhanced CT studies of 109 patients were included for characterization of PVT. Assessment of PVT was performed by estimation of CT textural features using CT texture analysis software and measurement of attenuation values. For CT texture analysis, filtered and unfiltered images were assessed to quantify heterogeneity using a set of predefined histogram-based texture parameters. The Mann-Whitney U test and binary logistic regression were applied for statistical significance. ROC curves were used to identify accuracy and optimal cutoff values. Of the 117 CT studies, 63 neoplastic thrombi and 54 bland thrombi were identified on the images. The two most discriminative CT texture analysis parameters to differentiate neoplastic from bland thrombus were mean value of positive pixels (without filtration, p < 0.001) and entropy (with fine filtration, p < 0.001). Mean thrombus density values could also reliably distinguish neoplastic (81.39 HU) and bland (32.88 HU) thrombi (p < 0.001). The AUCs were 0.97 for mean value of positive pixels (p < 0.001), 0.93 for entropy (p < 0.001), 0.99 for the model combining mean value of positive pixels and entropy (p < 0.001), 0.91 for thrombus density (p < 0.001), and 0.61 for the radiologist's subjective evaluation (p = 0.037). The optimal cutoffs values were 56.9 for mean value of positive pixels, 4.50 for entropy, and 54.0 HU for thrombus density. CT texture analysis and CT attenuation values allow reliable differentiation between neoplastic and bland thrombi on a single portal venous phase CT examination.

Portal vein thrombosis in liver cirrhosis - the added value of contrast enhanced ultrasonography.

Portal vein thrombosis (PVT) is a frequent complication of liver cirrhosis and its prevalence increases with the severity of liver disease. Patients with liver cirrhosis and hepatocellular carcinoma may have either malignant or blunt (benign) PVT. In these patients, the diagnosis and characterization of PVT is important for the prognosis and further treatment. Ultrasound (US) is the modality of choice for the diagnosis of PVT. The features of PVT on B-mode (gray-scale) US include: dilatation of the portal vein, visualization of the thrombus and, in chronic PVT- cavernous transformation. Sensitivity of US in the diagnosis of PVT is improved by the use of Doppler US and of ultrasound contrast agents. In the latter years, contrast enhanced ultrasound (CEUS) showed high sensitivity in the differential diagnosis between benign and malignant PVT and could be the diagnostic method of choice for the characterization of PVT. Blunt thrombi are avascular and will not enhance during CEUS examination, while a hyperenhancement pattern of the portal thrombus in the arterial phase, with "wash out" in the portal or late phase is typical for malignant PVT.

Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma: Diagnostic Accuracy of Gadoxetic Acid-enhanced MR Imaging.

Purpose To assess the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging in the evaluation of portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC). Materials and Methods This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. A total of 366 patients with HCC who underwent gadoxetic acid-enhanced MR imaging between January 2007 and May 2013, including 134 with malignant PVT, 49 with benign PVT, and 183 without PVT matched for age and sex, comprised our study population. PVTs were complete in 125 patients and partial in 58 and were located in a major portal vein (n = 159) or segmental portal vein (n = 24). Two radiologists independently reviewed the MR images and assessed the sensitivity, specificity, and accuracy in the detection and characterization of PVT according to location (major vs segmental) and type (complete vs partial). The Fisher exact or χ(2) test was used to evaluate sensitivity difference between the subsets. Results Gadoxetic acid-enhanced MR imaging showed good sensitivity (reviewer 1, 84% [154 of 183 patients]; reviewer 2, 70% [129 of 183 patients]) and high specificity (reviewer 1, 89% [163 of 183 patients]; reviewer 2, 96% [176 of 183 patients]) in the detection of PVT. Diagnostic accuracy for differentiating malignant PVT from benign PVT was high (reviewer 1, 92% [141 of 154 patients]; reviewer 2, 95% [122 of 129 patients]). However, there was slightly lower sensitivity for detecting segmental PVT compared with that of major PVT in the malignant PVT group (reviewer 1, 95% [104 of 110 patients] vs 88% [21 of 24 patients]; reviewer 2, 82% [90 of 110 patients] vs 79% [19 of 24 patients]; P = .203 and .775 for reviewers 1 and 2, respectively). Conclusion Gadoxetic acid-enhanced MR imaging provided good diagnostic performance in the detection of PVT and the differentiation of malignant from benign PVT in patients with HCC. However, caution is needed when evaluating potential candidates for curative treatment because of the low sensitivity for segmental PVT in the malignant PVT group. (©) RSNA, 2016 Online supplemental material is available for this article.

CEUS Na Caracterização Da Trombose De Veia Porta

CEUS Na Caracterização Da Trombose De Veia Porta

Contrast-enhanced Ultrasound for Liver Imaging: Recent Advances

Contrast-enhanced ultrasonography (CEUS), providing relevant informations not available with non-enhanced ultrasonography, greatly impacted the practice of liver imaging. The characterization of focal liver lesions (FLLs), is obtained in a rapid, accurate and safe way and is considered the main hepatic indication; however CEUS offers other established or emergent relevant applications. Metastases detection and assessment of response to locoregional tumor treatment are accepted applications with specific indications. Needle guidance in case of poorly or non visible target lesions at conventional ultrasound is also accepted. The early assessment of response to systemic treatment, and in particular to antiangiogenic ones, by quantification software is an emergent application. The manageability of CEUS determined also its use in the operating theatre, improving the accuracy of intraoperatory US with a significant impact on final surgical strategy. In cirrhotic patients, the role of CEUS was proven highly accurate and sensitive in the characterization of portal vein thrombosis, by identification of contrast arterial enhancement inside the thrombus, that occurs only in case of neoplastic origin. In recent years microbubbles taken up by Kupffer cells, thus possessing a "postvascular" phase, were registered as ultrasound contrast agent in Japan (Sonazoid). During the post-vascular phase tumoral tissue tend to appear as a contrast defect image due to the lack of Kupffer cells, strongly contributing to tumor staging beside characterization. Newly developed techniques, such as fusion imaging or real-time three dimensional US, in addition to other applications of CEUS, in terms of post-transplantation or cholecystitis-related complications, have been recently proposed and will be discussed.

Validation of an extension of the international non‐invasive criteria for the diagnosis of hepatocellular carcinoma to the characterization of macroscopic portal vein thrombosis

We aimed to validate the non-invasive criteria for the characterization of portal vein thrombosis (PVT) in patients with cirrhosis and hepatocellular carcinoma (HCC). In a prospective study, we examined the impact of arterial hypervascularity, as established by the European Association for the Study of the Liver and the American Association for the Study of Liver Diseases recommendations for the non-invasive diagnosis of HCC, as a criterion for characterizing macroscopic PVT (EASL/AASLD extension criteria). A total of 96 cases of PVT detected using ultrasonography in patients with cirrhosis and HCC were included in the study. When coincidental arterial hypervascularity was detected by contrast perfusional ultrasonography and helical computed tomography, the thrombus was considered malignant according to our EASL/AASLD extension criteria. In all cases, an ultrasound-guided biopsy examination of the thrombus was performed. Coincidental hypervascularity was found in 54 of 96 nodules (56.2%), and all were malignant upon biopsy (100% positive predictive value). Twenty-four (25%) had negative results with both techniques (non-vascular thrombus). Biopsies showed HCC in five non-vascular thrombi (5.3% of all thrombi) and in 13 of 18 thrombi with a hypervascularity result from only one technique. The EASL/AASLD extension criteria for non-invasive diagnosis of malignant thrombosis were satisfied in 75.2% of malignant thrombi; thus, a biopsy is frequently required in this setting. However, in the presence of coincidental hypervascularity of a thrombus with both techniques, a biopsy is not required (absolute positive predictive value for malignancy). Relying on imaging techniques in thrombi could miss the diagnosis of malignant portal invasion in up to 24.9% of cases.

Contrast-enhanced ultrasonography and spiral computed tomography in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma

Background and aim: To compare contrast-enhanced (CE) ultrasonography (US) versus tri-phasic spiral computed tomography (CT) for detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma (HCC).

Contrast-enhanced ultrasonography and spiral computed tomography in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma

The aim was to compare the performances of contrast-enhanced (CE) ultrasonography (US) and spiral computed tomography (CT) in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma (HCC). We studied 50 patients with HCC who had biopsy-proven portal vein thrombi that had been detected with US and color Doppler US. Thirteen of the thrombi involved the main portal trunk and 37 the segmental branches. CEUS and CT were performed within a week of thrombus biopsies. For each imaging technique, diagnoses of thrombosis (present/absent) and thrombus nature (malignancy/benignancy) were made by experienced readers under blinded conditions and compared with pathological findings to determine accuracy rates for thrombus detection and characterization. Forty-four of the 50 thrombi were pathologically diagnosed as malignant and the remaining six were benign. CEUS detected 50/50 (100%) thrombi and correctly characterized 49/50 (98%). CT detected 34/50 (68%) thrombi and correctly characterized 23 of these 34 (68%). CEUS outperformed CT in terms of both thrombus detection (P < 0.0001) and characterization (P = 0.0001). CEUS appears to be significantly superior to CT for detection and characterization of portal vein thrombosis complicating HCC, and it should be considered in the staging of these tumors.