Contrast-enhanced ultrasound in differentiating malignant from benign portal vein thrombosis in hepatocellular carcinoma

Contemporary management of portal vein thromboses in patients with and without cirrhosis

PURPOSE OF REVIEW

Portal vein thromboses (PVT) is a common clotting disorder that can be seen in patients with and without cirrhosis. There are no current clinical guidelines on management of portal vein thromboses in these two distinct populations given most studies are retrospective and comprised of heterogenous cohorts.

RECENT FINDINGS

When evaluating PVT, patients must first be stratified into those with cirrhosis and those without cirrhosis. In addition, a novel nomenclature can help categorize specific PVT types and determine the need and response to anticoagulation. The management of PVT in patients with cirrhosis varies and is primarily dependent on whether the PVT is recent or chronic. In contrast, patients without cirrhosis are almost always anticoagulated to avoid complications of PVT. Direct oral anticoagulants, low-molecular weight heparin, and vitamin-K antagonists have all been used in patients with and without cirrhosis, without clear guidance on optimal treatment duration and surveillance.

SUMMARY

Direct oral anticoagulants are increasingly used for patients with PVT though there is limited data on the safety and efficacy of these medications. The risk/benefit profiles of various anticoagulants must be considered when choosing a therapeutic anticoagulant. There are ongoing studies evaluating outcome measures of different anticoagulants in patients with PVT. Large, multicenter, randomized controlled trials may help elucidate the efficacy of anticoagulants on various outcome measures in PVT, including recanalization, bleeding, and survival.

Imaging in Vascular Liver Diseases

Vascular liver diseases (VLDs) include different pathological conditions that affect the liver vasculature at the level of the portal venous system, hepatic artery, or venous outflow system. Although serological investigations and sometimes histology might be required to clarify the underlying diagnosis, imaging has a crucial role in highlighting liver inflow or outflow obstructions and their potential causes. Cross-sectional imaging provides a panoramic view of liver vascular anatomy and parenchymal patterns of enhancement, making it extremely useful for the diagnosis and follow-up of VLDs. Nevertheless, multiparametric ultrasound analysis provides information useful for differentiating acute from chronic portal vein thrombosis, distinguishing neoplastic invasion of the portal vein from bland thrombus, and clarifying the causes of venous outflow obstruction. Color Doppler analysis measures blood flow velocity and direction, which are very important in the assessment of VLDs. Finally, liver and spleen elastography complete the assessment by providing intrahepatic and intrasplenic stiffness measurements, offering further diagnostic information.

Liver transplantation for advanced hepatocellular carcinoma: Controversy over portal vein tumor thrombosis

Liver transplantation (LT) is considered the ideal treatment for hepatocellular carcinoma (HCC) concurrent with underlying cirrhotic liver disease. As well-known, LT for HCC based on the Milan criteria has shown satisfactory outcomes. However, numerous expanded transplantation criteria were proposed to benefit more patients for LT and showed comparable survivals as well. In addition, a modest expansion of transplantation criteria for HCC may be acceptable on the basis of the consensus within the transplantation community. Nonetheless, LT in patients with advanced HCC and portal vein tumor thrombosis (PVTT) recently has received attention and has been reported by many transplantation centers despite being contraindicated. Of those, the LT outcomes in certain HCC patients with PVTT were favorable. Additionally, the advancement of multimodality treatments and the evolution of systemic therapies have emerged as promising therapeutic options for downstaging advanced HCC prior to LT. Somehow, advanced HCC with PVTT could be downstaged to become eligible for LT through these multidisciplinary approaches. Although the available evidence of LT for HCC with PVTT is limited, it is hoped that LT may soon be more widely indicated for these patients. Nevertheless, several unknown factors associated with LT for HCC remain to be explored. Herein, this review aimed to update the developments in LT for patients with advanced HCC.

Role of contrast-enhanced ultrasound for differentiation of benign vs. malignant portal vein thrombosis in hepatocellular carcinoma - A systematic review a meta-analysis

INTRODUCTION/PURPOSE

Patients with cirrhosis and hepatocellular carcinoma (HCC) can develop both benign and malignant portal vein thrombosis (PVT). Characterising the nature of PVT is important for planning an optimal therapeutic strategy. In the absence of typical findings or contraindications to computed tomography (CT) or magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS) could help in this differentiation. The present meta-analysis aimed to evaluate the performance of CEUS for characterising PVT in patients with HCC.

METHODS

Electronic databases of PubMed, Embase and Scopus were searched from inception to 31 December 2022 for studies analysing the role of CEUS in the differentiation of benign and malignant PVT in HCC. Using the bivariate random effect model, pooled sensitivity and specificity were calculated, and the summary receiver operating characteristic (sROC) curve was plotted.

RESULTS

A total of 12 studies with data from 712 patients were included in the meta-analysis. The pooled sensitivity and specificity of CEUS for the diagnosis of tumour in vein were 97.0% (95% CI: 93.0-98.7) and 96.8% (95% CI: 92.1-98.7), respectively, without significant heterogeneity. A sROC curve was plotted, and the area under the receiver operating characteristic was 0.99 (95% CI: 0.98-1.00). Despite the presence of publication bias, sensitivity analysis did not show any change in sensitivity and specificity.

DISCUSSION

Our meta-analysis summarises the accuracy data from 12 studies, including >700 subjects. Contrast-enhanced ultrasound had excellent diagnostic accuracy with pooled sensitivity and specificity of 97.5% (95% CI: 93.5-99.1) and 98.2% (95% CI: 91.5-99.6), respectively, without any significant heterogeneity. Additionally, the pooled positive LR, negative LR and DOR were 54.6 (95% CI: 11.1-25.6), 0.02 (0.01-0.07) and 2186.8 (318.3-15022.2), respectively. A positive result increases the pretest probability of malignant PVT from 50% to 98%, whereas a negative result decreases it from 50% to 2%. Most of the studies included in our meta-analysis used identical techniques and 6-12-month follow-up scans to check for thrombus progression or regression. Our analysis showed no significant heterogeneity in the studies, and area under receiver operating characteristic curve (AUROC) with 95% CI was 1.00 (95% CI: 0.99-1.00). This critical meta-analysis thus propels CEUS to the forefront for differentiating benign from tumoural PVT and suggests routinely using CEUS in patients presenting with HCC and evidence of thrombus on greyscale ultrasound.

CONCLUSION

Contrast-enhanced ultrasound is an effective diagnostic modality differentiation of benign and malignant PVT in patients with HCC and can be an alternative modality to CT or MRI. Further studies are required to study the role of CEUS as initial diagnostic modality for the characterisation of PVT in HCC.

Value of contrast-enhanced ultrasound for vascular diseases of the liver - current indications and open questions

Contrast-enhanced ultrasonography (CEUS) is a widely available and well-tolerated technique that can expand the diagnosis of a variety of vascular liver diseases. This paper presents an overview of the current possibilities of the use of CEUS in vascular liver diseases. Particularly where Doppler sonography has technical limitations, CEUS provides additional opportunities to visualize vascular thrombosis and other obstructions restricting blood flow. When CT or MRI contrast agents cannot be used because of severe allergy or renal insufficiency, CEUS can be a valuable diagnostic alternative and has demonstrated comparable diagnostic performance in at least some vascular liver diseases, such as portal vein thrombosis. In addition, CEUS works without radiation and, therefore, might be particularly suitable for young patients and children. This may be useful, for example, in congenital disorders such as persistent umbilical vein or preduodenal portal vein. Vascular liver disease is rare and comprehensive data are still lacking, but the available literature provides promising insights into potential new ways to study vascular liver disease. Although most studies are based on small sample sizes or even case reports, the high diagnostic utility is undisputed.

The Role of Contrast-Enhanced Ultrasound (CEUS) in the Detection of Neoplastic Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the principal primary liver cancer and one of the most frequent malignant tumors worldwide in patients with chronic liver disease. When diagnosed at an advanced stage, it is often associated with portal vein tumor thrombosis (PVTT), which heavily affects patients' prognosis. Imaging evaluation is crucial in PVTT detection and staging; computed tomography and magnetic resonance are the principal diagnostic tools. Contrast-enhanced ultrasound (CEUS) is a non-invasive and easily repeatable method that can also be used in patients with impaired renal function. It represents an important means for the identification of PVTT, particularly differentiating neoplastic and non-neoplastic thrombosis through the analysis of ultrasound enhancement characteristics of the thrombosis (arterial hyperenhancement and portal washout), thus allowing more refined disease staging, appropriate treatment planning, and response evaluation, along with prognosis assessment.

Breaking down tumor thrombus: Current strategies for medical management

Tumor thrombus, the intravascular extension of tumor into adjacent blood vessels, is frequently encountered in patients with renal cell carcinoma and hepatocellular carcinoma, and often involves the abdominal vasculature including the renal vein, portal vein, and the inferior vena cava. While a bland thrombus is composed of platelets and fibrin, in contrast, a tumor thrombus refers to an organized collection of tumor cells. Though oftentimes detected incidentally on imaging, tumor thrombus may have significant clinical implications and can be challenging to differentiate from bland thrombus. Additionally, the optimal management of tumor thrombus, including the use of anticoagulation, remains poorly described. This review summarizes common causes of tumor thrombus, as well as its impact on staging, prognosis, and treatment.

The utility of ultrasound and computed tomography in the assessment of carotid artery plaque vulnerability-A mini review

As the burden of cardiovascular and cerebrovascular events continues to increase, emerging evidence supports the concept of plaque vulnerability as a strong marker of plaque rupture, and embolization. Qualitative assessment of the plaque can identify the degree of plaque instability. Ultrasound and computed tomography (CT) have emerged as safe and accurate techniques for the assessment of plaque vulnerability. Plaque features including but not limited to surface ulceration, large lipid core, thin fibrous cap (FC), intraplaque neovascularization and hemorrhage can be assessed and are linked to plaque instability.

Identification of the origin of tumor in vein: comparison between CEUS LI-RADS v2017 and v2016 for patients at high risk

Objectives

To compare the diagnostic performance of the Contrast-Enhanced Ultrasound (CEUS) Liver Imaging Report and Data System (LI-RADS) v2016 and v2017 in identifying the origin of tumor in vein (TIV).

Methods

From April 2014 to December 2018, focal liver lesions (FLLs) accompanied by TIV formation in patients at high risk for hepatocellular carcinoma (HCC) were enrolled. Histologic evaluation or composite imaging reference standard were served as the reference standard. Each case was categorized according to the CEUS LI-RADS v2016 and v2017, respectively. Diagnostic performance of CEUS LI-RADS v2016 and v2017 in identifying the originated tumor of TIV was validated via sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value.

Results

A total of 273 FLLs with TIV were analyzed finally, including 266 HCCs and 7 non-HCCs. In v2016, when adopting all TIV as LR-5V, the accuracy and PPV in identifying the originated tumor were both 97.4%. In v2017, when assigning TIV according to contiguous FLLs CEUS LI-RADS category, the accuracy and PPV were 61.9% and 99.4% in subclass of LR-5 as the diagnostic criteria of HCC, and 64.1% and 99.4% in subclass of LR-4/5 as the criteria of HCC diagnosis. There were significant differences in diagnostic accuracy between CEUS LI-RADS v2016 and v2017 in identifying the originated tumor of TIV (p < 0.001).

Conclusions

CEUS LI-RADS v2016 could be better than v2017 in identifying the originated tumor of TIV.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00912-4.

Small Bowel Perforation Secondary to Portal Vein Thrombosis

Portal vein thrombosis (PVT) is a heterogeneous entity often described as either an acute or chronic occlusion of the portal vein or its tributaries. The clinical presentation is highly variable, and it often mimics other more common causes of abdominal pain. In most patients, imaging studies such as doppler ultrasound, computed tomography, or magnetic resonance imaging are adequate for diagnosis. Occasionally imaging studies may be inadequate, and the diagnosis may not be made until complications such as bowel necrosis and perforation have occurred. We present a case of a morbidly obese 45-year-old female who was initially treated for suspected small bowel enteritis and discharged home on several occasions after nonspecific findings on abdominal imaging were seen and interval improvement in symptoms occurred with intravenous fluids and antibiotics. She then presented with worsening symptoms and was found on abdominal imaging to have a large fluid collection in the peritoneal cavity requiring exploratory laparotomy with peritoneal washout and partial small bowel resection due to perforation. She was diagnosed with PVT with mesenteric extension after samples of the resected mesentery were evaluated in the pathology laboratory. Her treatment included a prolonged course of antibiotics, total parenteral nutrition, and anticoagulation.

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.

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.

Liver Transplant Imaging prior to and during the COVID-19 Pandemic

BACKGROUND

The suspension of the surgical activity, the burden of the infection in immunosuppressed patients, and the comorbidities underlying end-stage organ disease have impacted transplant programs significantly, even life-saving procedures, such as liver transplantation.

METHODS

A review of the literature was conducted to explore the challenges faced by transplant programs and the adopted strategies to overcome them, with a focus on indications for imaging in liver transplant candidates.

RESULTS

Liver transplantation relies on an appropriate imaging method for its success. During the Coronavirus Disease 2019 (COVID-19) pandemic, chest CT showed an additional value to detect early signs of SARS-CoV-2 infection and other screening modalities are less accurate than radiology.

CONCLUSION

There is an emerging recognition of the chest CT value to recommend its use and help COVID-19 detection in patients. This examination appears highly sensitive for liver transplant candidates and recipients, who otherwise would have not undergone it, particularly when asymptomatic.

Comparative the clinical value of contrast-enhanced ultrasonography, enhancement CT and MRI for diagnosing of liver lesions

BACKGROUND

To investigate the accuracy of contrast-enhanced ultrasonography, CT-enhancement and MRI in the diagnosis of liver-occupying lesions.

METHODS

176 patients with suspected liver lesions in our hospital were retrospectively studied from July 2014 to July 2016. All of the 176 patients were diagnosed by contrast-enhanced ultrasonography, enhanced CT and MRI, and the pathological examination was performed. The results of pathological examination were regarded as the results of the diagnosis. The diagnostic accuracywas then compared among contrast-enhanced ultrasound, enhanced CT and MRI of these patients.

RESULTS

The results of contrast-enhanced ultrasonography showed that 164 of the 176 patients had liver-occupying lesions, and the accuracy of the diagnosis was 95.35%, which was significantly higher than that of CT enhancement and MRI (80.23% 84.30%). The accuracy of contrast-enhanced ultrasonography, in the diagnosis of primary liver cancer was significantly higher than that of CT enhancement and MRI (P <  0.05), and the difference was significant difference (P <  0.05).

CONCLUSIONS

The examination of contrast-enhanced ultrasonography is relatively simple, and the patients can get duplicateexamination, so we should choose the contrast-enhanced ultrasonography as the preferred method of diagnosis in liver mass, especially primary liver cancer.

Portal vein thrombosis in patients with chronic liver diseases: From conventional to quantitative imaging

Portal vein thrombosis is a pathological condition characterized by the lumen occlusion of the portal vein and its intrahepatic branches, commonly associated to chronic liver diseases. Portal vein thrombosis is often asymptomatic and discovered as an incidental finding in the follow-up of chronic hepatopathy. Imaging plays a pivotal role in the detection and characterization of portal vein thrombosis in patients with hepatocellular carcinoma. Ultrasound and Color-Doppler ultrasound are usually the first-line imaging modalities for its detection, but they have limits related to operator-experience, patient size, meteorism and the restrained field-of view. Unenhanced cross-sectional imaging doesn't provide specific signs of portal vein thrombosis except under certain specific circumstances. Conventional contrast-enhanced imaging can depict portal vein thrombosis as an endoluminal filling defect best detected in venous phase and can differentiate between non-neoplastic and neoplastic thrombus based on the contrast enhanced uptake, but not always rule-out the malignant nature. Functional and quantitative imaging techniques and software seem to be more accurate. The purpose of this work is to provide the reader with an accurate overview focused on the main imaging features of portal vein thrombosis.

Role of Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Portal Vein Thrombus in the Diagnosis and Staging of Hepatocellular Carcinoma

BACKGROUND/AIMS

Malignant portal vein thrombus (PVT) is found in up to 44% of patients with hepatocellular carcinoma (HCC). The nature of the thrombus influences treatment selection. The aim of this study was to assess the safety and efficacy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in determining the nature of PVT in liver cirrhosis and/or HCC.

METHODS

A prospective study was conducted in 34 patients with liver cirrhosis and/or HCC with PVT. Under EUS guidance, PVT was punctured using a 22 G FNA needle (Cook Medical, Bloomington, IN, USA) followed by monitoring of the puncture tract using color Doppler. Patients were followed for adverse events 2 hours after recovery.

RESULTS

Throughout the 30-month study period, 34 patients, including 24 males with a mean age of 59±8 years, were enrolled. There were 8 patients with known HCC and 26 with no liver masses detected by computed tomography (CT). EUS-FNA from PVT was positive for malignancy in 3 patients (8.8%), of which only 1 patient was diagnosed with HCC by CT and 2 patients were newly diagnosed with HCC after EUS-FNA. No major complications were reported.

CONCLUSION

EUS-FNA is a safe and effective technique for determining the nature of PVT that does not fulfill the malignant criteria via imaging studies in patients with liver cirrhosis and/or HCC.

Role of Ultrasound for Chronic Liver Disease and Hepatocellular Carcinoma Surveillance

Ultrasound plays a vital role in the evaluation of patients with chronic liver disease and in hepatocellular carcinoma (HCC) surveillance in populations at risk for developing HCC. Semiannual ultrasound for HCC surveillance is universally recommended by all liver societies around the world. Advanced ultrasound techniques, such as elastography and contrast-enhanced ultrasound, offer additional benefits in imaging evaluation of chronic liver disease. Major benefits of ultrasound include its high safety profile and relatively low cost.

Contrast-Enhanced Ultrasound in Chronic Liver Diseases

Contrast-enhanced ultrasound (CEUS) is a safe adjunct tool for liver imaging and can be an alternative to computed tomography or MR imaging. CEUS has a proven track record in guiding management for patients with chronic liver disease who need further evaluation of focal liver lesions. CEUS is a dynamic examination with high temporal and spatial resolution. CEUS uses a pure blood pool contrast agent that allows for a unique evaluation of the perfusion kinetics of a region of interest.

Incremental value of three-dimensional and contrast echocardiography in the evaluation of endocardial fibroelastosis and multiple cardiovascular thrombi: A case report

BACKGROUND

Endocardial fibroelastosis (EFE) is a rare heart disease characterized by thickening of the endocardium caused by massive proliferation of collagenous and elastic tissue, usually leading to impaired cardiac function. Multimodality cardiovascular imaging for the evaluation of EFE with thrombi is even rarer.

CASE SUMMARY

We report a rare case of EFE associated with multiple cardiovascular thrombi. Three-dimensional (3D) and contrast echocardiography (CE) were used to assess ventricular thrombi. Anticoagulant therapy was administered to eliminate the thrombi. The peripheral contrast-enhanced thrombi with the highest risk were dissolved with anticoagulant therapy at the time of reexamination, which was consistent with the presumption of fresh loose thrombi.

CONCLUSION

This new echocardiography technique has a great advantage in the diagnosis and treatment of EFE. On the basis of conventional echocardiography, 3D echocardiography is used to display the position, shape, and narrow base of the thrombus. CE does not only help to confirm the diagnosis of thrombus, but also determines its risk.

Contrast-enhanced ultrasound in the diagnosis of infiltrative hepatocellular carcinoma: A report of three cases

Infiltrative hepatocellular carcinoma (HCC) is a challenging imaging diagnosis due to its ill-defined appearance and variable enhancement, which may be difficult to distinguish from background changes from cirrhosis. The literature on the role of contrast-enhanced ultrasound (CEUS) in the diagnosis of infiltrative HCC is currently limited. CEUS has greater sensitivity for contrast enhancement due to its temporal resolution, and can be used when there is contraindication to CT or MRI contrast. We present 3 cases where CEUS aided in the diagnosis of infiltrative HCC in patients with equivocal CT and MRI findings and/or renal failure, with significant implications for management. As current guidelines focus on the role of CEUS in characterizing defined focal liver lesions or discrete observations on precontrast US, further studies are warranted to validate the utility of CEUS in the noninvasive diagnosis of infiltrative HCC and delineate its role in algorithms for imaging workup.

Contrast-enhanced ultrasound applications in liver transplant imaging

Contrast-enhanced ultrasound (CEUS) is gaining ever-increasing acceptance in the preoperative and postoperative evaluation of liver-transplanted patients. While indications are still a matter of research, CEUS is used in tertiary centers to supplement ultrasound (US) and Color Doppler US examination, with the potential of providing a comprehensive first-line ultrasound-based diagnosis. Alternatively, CEUS is used as a problem-solving tool when previous cross-sectional or US imaging was inconclusive, especially in assessing hepatocellular carcinoma, parenchymal perfusion abnormalities, the vascular status, and even the biliary tree. This review describes the potential use for CEUS in the setting of orthotopic liver transplantation (OLT).

Contrast-enhanced ultrasound imaging of the liver: a review of the clinical evidence for SonoVue and Sonazoid

Contrast-enhanced ultrasound (CEUS) has become an established modality in various clinical indications for liver diseases. SonoVue®, a pure blood pure agent, and Sonazoid®, which exhibits an additional Kupffer phase, are contrast agents approved for liver imaging. This review discusses and compares the current clinical evidence for these two ultrasound contrast agents in the characterization and detection of focal liver lesions in the non-cirrhotic and cirrhotic liver, as well as for the use in interventional procedures such as liver biopsy guidance, and local ablation treatment monitoring. Reference is made to clinical studies which evaluated the accuracy of CEUS using a standard of reference, its safety, or to comparative studies of these two agents.

Multimodality Imaging of Abdominopelvic Tumors with Venous Invasion

A broad range of abdominal and pelvic tumors can manifest with or develop intraluminal venous invasion. Imaging features at cross-sectional modalities and contrast-enhanced US that allow differentiation of tumor extension within veins from bland thrombus include the expansile nature of tumor thrombus and attenuation and enhancement similar to those of the primary tumor. Venous invasion is a distinctive feature of hepatocellular carcinoma and renal cell carcinoma with known prognostic and treatment implications; however, this finding remains an underrecognized characteristic of multiple other malignancies-including cholangiocarcinoma, adrenocortical carcinoma, pancreatic neuroendocrine tumor, and primary venous leiomyosarcoma-and can be a feature of benign tumors such as renal angiomyolipoma and uterine leiomyomatosis. Recognition of tumor venous invasion at imaging has clinical significance and management implications for a range of abdominal and pelvic tumors. For example, portal vein invasion is a strong negative prognostic indicator in patients with hepatocellular carcinoma. In patients with rectal cancer, diagnosis of extramural venous invasion helps predict local and distant recurrence and is associated with worse survival. The authors present venous invasion by vascular distribution and organ of primary tumor origin with review of typical imaging features. Common pitfalls and mimics of neoplastic thrombus, including artifacts and anatomic variants, are described to help differentiate these findings from tumor in vein. By accurately diagnosing tumor venous invasion, especially in tumors where its presence may not be a typical feature, radiologists can help referring clinicians develop the best treatment strategies for their patients. ^©RSNA, 2020.

Role of imaging in visceral vascular emergencies

Differential diagnosis in non-traumatic acute abdomen is broad and unrelated diseases may simulate each other from a clinical perspective. Despite the fact that they are not as common, acute abdominal pain due to diseases related to visceral vessels may be life-threating if not detected and treated promptly. Thrombosis, dissection, and aneurysm in the abdominal visceral arteries or thrombosis in visceral veins may cause acute abdominal pain. Imaging with appropriate protocoling plays a fundamental role in both early diagnosis and determination of the treatment approach in these cases where early treatment can be life-saving. Computed tomography (CT) appears to be the most effective modality for the diagnosis as it provides high detail images in a very short time. Patient cooperation is also a less concern as compared to magnetic resonance imaging (MRI). As the imaging findings may sometimes be really subtle, diagnosis may be difficult especially to inexperienced imagers. Correct protocoling is also very critical to detect arterial abnormalities as visceral arterial abnormalities may not be detectable in portal phase only abdominal CT scans. In this article, we aimed to increase awareness among imaging specialists to these not very common causes of acute abdomen.

Contrast-Enhanced Ultrasonography for Screening and Diagnosis of Hepatocellular Carcinoma: A Case Series and Review of the Literature

Background: Contrast-enhanced ultrasound (CEUS) is a safe and noninvasive imaging technique that can characterize and evaluate liver lesions, and has been approved for this use in the Unites States since 2016. CEUS has been shown to be similar in accuracy to computed tomography (CT) and magnetic resonance imaging (MRI) for noninvasive diagnosis of hepatocellular carcinoma (HCC) and offers several advantages in certain patient populations who have contraindications for CT or MRI. However, CEUS has inherent limitations and has not been widely employed for evaluation of HCC. Methods: We present three retrospective cases of liver lesions in patients with cirrhosis, who underwent screening for HCC using concurrent, well-timed CT and CEUS. Results: In these cases, the liver lesions were better visualized and then diagnosed as malignancy via CEUS, whereas the lesions were best appreciated on CT only in retrospect. Conclusions: In some cirrhotic patients, a focal lesion may be more easily identifiable via CEUS than on CT and thus accurately characterized, suggesting an important and complementary role of CEUS with CT or MRI. Further studies are indicated to support the use of CEUS for the diagnosis and characterization of liver lesions in screening patients at risk for developing HCC.

Imaging of acute abdomen in cancer patients

The pattern of disease causing acute abdominal pain has changed over last few decades, some of this has been attributed to intraabdominal cancers. The most common acute abdominal complaints in cancer patients are related to the gastrointestinal system. Abdominal emergencies in cancer patients can result from the underlying malignancy itself, cancer therapy and/or result from the standard pathologies causing acute abdomen in otherwise healthy population. Therapy-related or disease-related immunosuppression or high dose analgesics often blunt many of the findings which are usually expected in non-cancer general population. This complicates the clinical picture rendering the clinical exam less reliable in many cancer patients, and resulting in different pathologies which clinicians and the radiologists should remain aware of. This article focuses on imaging illustrations with differential diagnosis for various emergency scenarios related to acute abdomen specifically in oncologic settings.

Use of contrast ultrasound in differentiating thrombosed pseudoaneurysm from sarcoma, prior to surgery

We describe a case of a 69-year-old male with a right-sided popliteal mass following a motor vehicle accident 15 years ago. The mass was indeterminate via multiple modalities (magnetic resonance imaging, digital subtraction angiography, and vascular ultrasound) with biopsy requested prior to surgical removal to determine the appropriate surgical team – vascular versus sarcoma oncologic surgery. Contrast ultrasound was utilized to determine if biopsy was indicated and if so, to determine the most appropriate target. Contrast ultrasound showed no areas of enhancement, therefore biopsy was not performed and the patient safely proceeded to vascular surgery. Pathology confirmed the mass to be a thrombosed pseudoaneurysm of the popliteal artery. We present the benefits of using contrast ultrasound in the work up and diagnosis of a popliteal neoplasm versus suspected vascular complication.

Contrast-enhanced ultrasonography of intraluminal inferior vena cava leiomyosarcoma: A case report

Primary leiomyosarcoma of the inferior vena cava (IVC) is a rare and fatal disease. Imaging is the main diagnostic method. CT and MRI images of IVC leiomyosarcoma have been published, but ultrasonographic features have been scarcely described, especially with contrast-enhancement. We report the case of a patient in whom ultrasonography incidentally revealed a mass in the IVC. Contrast-enhanced ultrasonography showed heterogeneous enhancement in the arterial phase with some irregular non-enhanced areas, and mild clearance in the venous phase. The location and nature of the lesion as shown by ultrasonography were confirmed by CT and MRI.

Infiltrative non-mass-like hepatocellular carcinoma initially presenting with isolated malignant portal vein thrombosis: A case report and review of the literature

Hepatocellular carcinoma (HCC) shows a rising incidence and mortality rates worldwide. HCC is divided into several distinct subtypes, both morphologically and histopathologically. Among these subtypes, infiltrative HCC may be the most challenging subtype to diagnose, given its characteristic myriad of tumor nodules blended with normal hepatocytes without a distinct mass-like lesion. Herein, we report an unusual case of an infiltrative HCC initially presenting with isolated malignant portal vein thrombosis and provide a brief review of the literature regarding the infiltrative HCC subtype. Additionally, we demonstrate how sonoelastography could aid in detecting the appropriate biopsy area in the infiltrative HCC subtype. To our knowledge, there have not been previously reported cases describing the use of sonoelastography in the evaluation of the appropriate area for the targeted liver biopsy.

Diagnostic accuracy of contrast-enhanced ultrasound for detecting bland thrombus from inferior vena cava tumor thrombus in patients with renal cell carcinoma

PURPOSE

To evaluate the role of contrast-enhanced ultrasound (CEUS) in differentiating bland thrombus from tumor thrombus of the inferior vena cava (IVC) in patients with renal cell carcinoma (RCC).

MATERIALS AND METHODS

We retrospectively investigated 30 consecutive patients who underwent robot-assisted radical nephrectomy with IVC thrombectomy and had pathologically confirmed RCC. All patients underwent US and CEUS examination. Two offline readers observed and recorded thrombus imaging information and enhancement patterns. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for bland thrombus were assessed.

RESULTS

Of the 30 patients, no adverse events occurred during administration of the contrast agent. Early enhancement of the mass within the IVC lumen on CEUS was na indicator of tumor thrombus. Bland thrombus showed no intraluminal flow on CEUS. There were eight (26.7%) patients with bland thrombus, including three level II, two level III, and three level IV. There were three cases with cephalic bland thrombus and five cases with caudal bland thrombus. Three caudal bland thrombi extended to the iliac vein and underwent surgical IVC interruption. Based on no intraluminal flow, for bland thrombus, CEUS had 87.5% sensitivity, 100% specificity, 96.7% accuracy, 100% positive predictive value and 95.6% negative predictive value.

CONCLUSION

Our study demonstrates the potential of CEUS in the differentiation of bland and tumor thrombus of the IVC in patients with RCC. Since CEUS is an effective, inexpensive, and non-invasive method, it could be a reliable tool in the evaluation of IVC thrombus in patients with RCC.

Contrast-enhanced ultrasound of liver lesions in children

Initial pediatric imaging of the liver heavily relies on ultrasonography (US) because it is free of ionizing radiation, easily portable and readily available. Although conventional US (gray-scale and color Doppler) is often an excellent screening tool, its relative low specificity compared to CT/MRI limits liver lesion characterization. The United States Food and Drug Administration's recent approval of an intravenous US contrast agent for pediatric liver lesion characterization (sulfur hexafluoride lipid-type A microspheres) and its excellent safety profile have spurred increased interest in contrast-enhanced US for definitive diagnosis of pediatric liver lesions. This review focuses on the safety of contrast-enhanced US, role of contrast-enhanced US in the evaluation of focal liver lesions, basic contrast-enhanced US technique for liver imaging, and interpretation principles. The authors review common focal liver lesions, with special attention to the role of contrast-enhanced US in the pediatric oncology population.

State of the Art: LI-RADS for Contrast-enhanced US

Contrast material-enhanced (CE) US is a recognized imaging tool in the characterization of focal liver lesions and uses microbubble contrast agents to increase signal backscattering from the blood. The European Federation of Societies for Ultrasound in Medicine and Biology and the World Federation for Ultrasound in Medicine and Biology strongly recommend the use of CE US in the characterization of hepatocellular nodules in individuals with liver cirrhosis. CE US was recently approved by the Food and Drug Administration for liver indications in adult and pediatric patients. CE US Liver Imaging Reporting and Data System (LI-RADS) criteria were recently proposed by the American College of Radiology and include eight distinct diagnostic categories: LR-1 (definitely benign), LR-2 (probably benign), LR-3 (intermediate malignancy probability), LR-4 (probably hepatocellular carcinoma [HCC]), LR-5 (definitely HCC), LR-NC (cannot be categorized due to image degradation), LR-TIV (tumor in vein), and LR-M (probably or definitely malignant but not HCC specific). CE US LI-RADS criteria can be used to produce a structured report for HCC diagnosis. However, the variability of US equipment in terms of sensitivity to microbubble signal, interreader variability, large number of HCC nodules classified as LR-3, and wide washout temporal range for LR-M observations are limitations.

Current concepts in portal vein thrombosis: etiology, clinical presentation and management

OBJECTIVE

The aim of this article is to focus on etiology, risk factors, clinical presentation and classification systems of acute and chronic PVT as well as focusing on current diagnostic and therapeutic options for the management of acute and chronic PVT.

RESULTS

PVT represents a serious clinical concern in cirrhotic patients and in those with specific local or systemic risk factors. The rate and extent of thrombus formation can significantly impact patient presentation and the resulting clinical outcomes. The presentation of acute PVT can range from abdominal pain to intestinal ischemia/infarction and even death, while chronic PVT can remain clinically silent. A number of imaging modalities including US, CT and MRI can be used to confirm the diagnosis. In addition to addressing underlying risk factors, AC therapy forms a cornerstone of treatment and has demonstrated efficacy in both acute and chronic settings. Proper caution should be used when initiating AC therapy in cirrhotic patients given their underlying coagulopathic status with attention now being paid to NOACs and LMWH. For patients with bowel ischemia, extensive thrombosis, contraindications or poor response to AC, or for those with co-morbidities that preclude AC, minimally invasive endovascular techniques offer alternative treatment options.

CONCLUSION

Familiarity with the etiology, clinical presentation and classification of PVT optimize early detection and incorporate effective therapeutic options, the management of these complex patients should be undertaken by a multidisciplinary team. Minimally invasive catheter-based therapies and endovascular portosystemic shunt creation demonstrated efficacy in the treatment of AC-resistant patients and for patients with extensive or complicated disease.

[Comparison of various imaging in the diagnosis of renal cell carcinoma with inferior vena cava tumor thrombus combined with bland thrombus]

OBJECTIVE

To analyse the clinical and imaging data of patients with renal cell carcinoma (RCC) with inferior vena cava tumor thrombus (IVCTT), and to assess the diagnostic efficacy of ultrasound, enhanced computed tomography (CT) and enhanced magnetic resonance imaging (MRI) in the diagnosis of RCC with IVCTT combined with bland thrombus was assessed.

METHODS

We retrospectively analyzed the clinical and imaging data of 56 RCC patients with IVCTT who underwent radical nephrectomy and IVC thrombectomy between January 2014 and July 2018 in Department of Urology, Peking University Third Hospital. All the patients underwent US, enhanced CT and enhanced MRI preoperatively, and all the cases were confirmed with RCC with IVCTT by histological evaluation.

RESULTS

The criteria of RCC with IVCTT combined with bland thrombus was confirmed by intraoperative observation and postoperative pathology. The 56 patients were divided into bland thrombus group (n=18) and non bland thrombus group (n=38). Compared the two groups, it was found that the length of IVCTT was longer [(10.50 ± 5.55) cm vs.(6.66 ± 3.73) cm, P=0.014]; the ratio of diameter of IVCTT to maximum coronal diameter of IVC was closer to 1 [1.0 (0.7, 1.0) vs. 0.9 (0.2, 1.0), P=0.004]; the proportion of lower limb edema was higher [66.7(12/8)% vs.5.3%(2/36), P=0.005]；the proportion of segmental resection or interrupt of IVC was higher [66.7%(12/18) vs.15.8%(6/38), P<0.001], with statistical significance. Compared with the three imaging methods of US, enhanced CT and MRI, the highest sensitivity was MRI (77.8%), the highest specificity was enhanced MRI and enhanced CT (97.4%), the highest accuracy was enhanced CT and enhanced MRI (83.9%), the highest positive predictive value was enhanced CT (90.9%) and the highest negative predictive value was enhanced MRI (89.2%).

CONCLUSION

For the patients that RCC with IVCTT combined with bland thrombus, the length of IVCTT is longer, and the ratio of the diameter of IVCTT to the maximum corona diameter of IVC is closer to 1, and more likely to cause lower limb edema. Preoperative comprehensive evaluation of multiple images is needed to improve the accuracy of diagnosis.

Update on Management of Portal Vein Thrombosis and the Role of Novel Anticoagulants

The clinical management of portal vein thrombosis (PVT) remains ambiguous due to its heterogeneous presentations and its associations with liver disease, malignancy, and hypercoagulable states. The natural history and clinical outcome of PVT are highly variable, dependent upon size, extent and degree of the thrombotic occlusion, as well as the physiological impact of patient comorbidities. While existing clinical guidelines consistently recommend low molecular weight heparin or vitamin K antagonist anticoagulation in cirrhotic patients with symptomatic acute PVT, management of asymptomatic and chronic PVT may need to be determined on a case-by-case basis, factoring in the state of underlying liver disease. In general, patients with PVT and underlying malignancy should be anticoagulated to alleviate symptoms and prevent recurrences that could disrupt the cancer management. However, existing clinical data does not support routine anticoagulation of cirrhotic patients with asymptomatic PVT in the absence of underlying cancer. While low molecular weight heparin and vitamin K antagonist remain the most commonly used agents in PVT, an emerging body of clinical evidence now suggests that direct-acting oral anticoagulants may be used safely and effectively in PVT. As such, direct-acting oral anticoagulants may offer a more convenient anticoagulation alternative for PVT management in future practice.

General principles and overview of vascular contrast-enhanced ultrasonography

Ultrasonography (US) is the first-line modality for the evaluation of vascular pathology. Although well-established for many diseases, US has inherent limitations that can occasionally hinder an accurate diagnosis. The value of US was improved by the introduction of microbubbles as ultrasonographic contrast agents (UCAs) and the emergence of contrast-enhanced ultrasonography (CEUS), following the introduction of second-generation UCAs and the emergence of modern contrast-specific techniques. CEUS offers valuable information about vascular disease, both on a macrovascular and a microvascular level, with well-established applications for carotid disease, post-interventional follow-up of abdominal aortic aneurysms, and the assessment of portal vein thrombosis. The purpose of this review is to discuss the principles of CEUS and to present an overview of its vascular applications.

The ability of the new ALBI scoring in predicting mortality, complications and prognostic comparison among cirrhotics

Introduction

Albumin-bilirubin (ALBI) is a newly devised scoring system for prognostication of liver cirrhosis. The ALBI has recently been validated and found superior to Child-Turcotte-Pugh score (CTP) and Model for End stage Liver Disease (MELD) in assessing severity of liver disease.

Aim

To determine the ALBI score's mortality prediction among cirrhotics, associated complications and to compare its prognostic proficiency to that of MELD and CTP.

Material and methods

The diagnostic accuracy of CTP, MELD and ALBI scores for mortality in hospitalized cirrhotic patients was determined by receiver operating characteristic curve (ROC) analysis. The areas under the ROC curve were calculated, with confidence intervals (CI) of 95%. The best cut-off values were ascertained with the greatest specificity and sensitivity.

Results

The study showed overall in-hospital mortality of 25.5%. Median CTP score was 10.2 (IQR = 3) and area under curve (AUC) was 0.842 (95% CI: 0.817-0.868, p < 0.001) with sensitivity of 75.0% and specificity of 79.2%. Median MELD score was 20.9 (IQR = 7.2) and AUC was 0.836 (95% CI: 0.810-0.863, p < 0.001) with sensitivity of 76.6% and specificity of 76.7%. Median ALBI score was -1.1 (IQR = 1.0), and AUC of ALBI was 0.852 (95% CI: 0.826-0.879, p < 0.001) with sensitivity and specificity of 78.1%.

Conclusions

The objective prognostication and easy utilization of ALBI make it a useful alternative to MELD and CTP and therefore favour its applicability in clinical practice. Further validations in large prospective cohorts are needed for prognostic value of ALBI in cirrhosis and its complications.

Application of Contrast-Enhanced Ultrasound (CEUS) in Lymphomatous Lymph Nodes: A Comparison between PET/CT and Contrast-Enhanced CT

PURPOSE

We described imaging characteristics of different types of lymphomas using contrast-enhanced ultrasound (CEUS) and summarized some simple criteria to distinguish between normal lymph nodes and lymphomatous lymph nodes for clinical diagnosis.

MATERIALS AND METHODS

Sixty-one lymphoma patients from 2014 to 2015 with 140 suspicious lymph nodes, who had been confirmed by histology and underwent chemotherapy, were enrolled in our study. The responses to chemotherapy were recorded by PET/CT, contrast-enhanced CT, or CEUS.

RESULTS

We summarized the CEUS enhancement patterns as two types when detecting lymphomatous lymph nodes, which could be the specific diagnostic criteria: (1) rapid well-distributed hyperenhancement, with 83.1% lesions exhibiting a fast-in hyperenhancement pattern in the arterial phase, and (2) rapid heterogeneous hyperenhancement, with 16.9% lesions exhibiting heterogeneous in the arterial phase. Particularly, we found that all the suspicious lesions of indolent lymphomas were rapid well-distributed hyperenhancement. CEUS successfully identified 117 lymphomatous lymph nodes, while PET/CT and contrast-enhanced CT detected 124 and 113 lymphomatous lymph nodes, respectively. CEUS had an accuracy of 83.57%, and the accuracy of PET/CT and contrast-enhanced CT was 88.57% and 80.71%, respectively (p=0.188). The false-negative rate was 16.43%, 11.43%, and 19.29%, respectively (p=0.188).

CONCLUSION

CEUS could be a useful tool in detecting lymphomatous nodes. A rapid well-distributed hyperenhancement pattern in CEUS could be a useful diagnostic criterion in both aggressive lymphoma and indolent lymphoma. These results can help us distinguish between lymphomatous and benign lymph nodes and make better diagnostic and therapeutic decisions.

Characterization of Malignant Portal Vein Thrombosis with Contrast-Enhanced Ultrasonography

We prospectively evaluated the effectiveness of contrast-enhanced ultrasonography (CEUS) for differentiation of benign versus malignant portal vein thrombosis (PVT). We studied a total of 43 patients with chronic liver disease, hepatocellular carcinoma-suggestive nodules and confirmed PVT, in whom the nature of the PVT was confirmed by follow-up imaging (US, computed tomography and/or magnetic resonance imaging) performed up to 6 mo after CEUS. PVT was assessed by US, Doppler US and CEUS with respect to vessel wall disruption and/or invasion, color Doppler vascularization, pulsed Doppler vascularization pattern and CEUS enhancement and vascularization pattern, and thrombi were classified as benign or malignant based on these findings. Follow-up studies revealed malignant PVT in 22 of the 43 patients (51%) and benign PVT in 21 patients (49%). CEUS findings were consistent with follow-up studies in 41 of the 43 patients (95%), with κ = 0.903 (p < 0.0001), sensitivity = 91% and specificity = 100%, indicating that CEUS can be confidently used to differentiate benign from malignant portal vein thrombosis in the setting of chronic liver disease.

Venous invasion by hepatic tumors: imaging appearance and implications for management

Venous invasion by hepatic tumors most commonly occurs with hepatocellular carcinoma and is associated with worse patient prognosis. Imaging plays an important role in the diagnosis of tumor thrombus in the liver. Moreover, differentiating between bland and tumor thrombus in the liver has important diagnostic, staging, therapeutic, and prognostic implications and may require a multimodal imaging approach including ultrasound, computed tomography, and/or magnetic resonance imaging. Treatment of hepatic malignancies with associated tumor thrombus is dependent on tumor type, disease extent within the liver, liver hemodynamics, and underlying liver function. Treatment of such tumors may involve surgical, locoregional and/or systemic therapies. The current review will focus on the imaging characteristics of venous invasion by hepatic tumors. The imaging findings most useful for differentiating hepatic venous tumor thrombus and bland thrombus will be highlighted and demonstrated with imaging examples. Imaging findings with implications for subsequent patient management will be described.

Macroscopic Portal Vein Thrombosis in HCC Patients

Macroscopic portal vein invasion (PVT) by hepatocellular carcinoma (HCC) in the liver is one of the most important negative prognostic factors for HCC patients. The characteristics of a large cohort of such patients were examined. We found that the percent of patients with PVT significantly increased with increasing maximum tumor diameter (MTD), from 13.7% with tumors of MTD <5cm to 56.4% with tumors of MTD >10cm. There were similar numbers of HCC patients with very large tumors with and without PVT. Thus, MTD alone was insufficient to explain the presence of PVT, as were high AFP levels, since less than 50% of high AFP patients had PVT. However, the percent of patients with PVT was also found to significantly increase with increasing blood alpha-fetoprotein (AFP) levels and tumor multifocality. A logistic regression model that included these 3 factors together showed an odds ratio of 17.9 for the combination of MTD>5.0cm plus tumor multifocality plus elevated AFP, compared to low levels of these 3 parameters. The presence or absence of macroscopic PVT may therefore represent different HCC aggressiveness phenotypes, as judged by a significant increase in tumor multifocality and AFP levels in the PVT positive patients. Factors in addition to MTD and AFP must also contribute to PVT development.

Reduced microperfusion due to portal vein thrombosis: Impact on the outcome of percutaneous thermal tumor ablation

PURPOSE

To determine the influence of pre-interventionally existing portal vein thrombosis on the ablation success of percutaneous tumor ablation of HCC.

MATERIALS AND METHODS

15 patients with HCC and pre-existing portal vein thrombosis underwent thermal tumor ablation. We retrospectively analyzed the pre- and post-interventionally performed CT and MRI scans in terms of technical success as well as the complication rate. The portal vein thrombosis was classified into segmental, lobar and central thrombus.

RESULTS

In 13/15 cases (87%) complete ablation with no evidence of residual tumor tissue was seen 6 weeks after the procedure in contrast-enhanced MRI scans and contrast-enhanced ultrasound (CEUS). No major and 2 minor complications were observed after the ablation procedure.

CONCLUSION

Reduced perfusion due to pre-interventionally existing portal vein thrombosis has no significant impact on the ablation success or the complication rate.

Contrast-enhanced ultrasound (CEUS) of the abdominal vasculature

Vascular diseases account for a significant proportion of abdominal pathology and represent a common referral source for abdominal ultrasonographic examinations. B-mode, color Doppler, and spectral Doppler analyses are well-established in the evaluation of abdominal blood vessels although they may occasionally be limited by lower sensitivity for slow flow visualization or the deeper location of abdominal vascular structures. The introduction of microbubbles as ultrasonographic contrast agents has rendered contrast-enhanced ultrasound (CEUS), a valuable complementary ultrasonographic technique, which is capable of addressing clinically significant problems and guiding patient management. The purpose of this pictorial review is to analyze the use of CEUS in the evaluation of abdominal vascular pathology and illustrate such applications by presenting representative images. Pathology discussed includes abdominal aortic aneurysm, post-endovascular treatment aorta, portal vein thrombosis, abdominal vascular trauma, and organ transplantation along with its complications.

Vascular ultrasound, the potential of integration of multiparametric ultrasound into routine clinical practice

Introduction

Ultrasound has traditionally been regarded as the first-line imaging modality for screening, diagnostic evaluation and monitoring treatment and disease progression of vascular pathology, including both the arterial and the venous branch of the vascular system. Albeit of its well-tolerated nature, wide availability and low cost, ultrasound above all, has the advantage of providing the clinician with clinically significant information related to both intraluminal irregularities and extravascular disease. Ultrasound has the potential not only to anatomically describe tissues but also to assess physiology by evaluating blood flow characteristics in real time.

Discussion

The already fundamental role of ultrasound has been even more expanded with the introduction of newer techniques like contrast-enhanced ultrasound, tissue-elastography and 3D ultrasound and the incorporation of research advances into clinical practice. The purpose of this review is to present and discuss some of the latest advances in the field of vascular ultrasound in attempt to illustrate how the adoption of multiparametric ultrasound into everyday clinical practice could address the patient's needs. Pathology and applications discussed include carotid and aortic disease, portal and peripheral venous abnormalities.

Conclusion

Widespread availability of modern technology in ultrasound devices has made the application of contrast-enhanced ultrasound, tissue elastography and 3D ultrasound feasible options, ready to contribute to the diagnostic performance of the ultrasonographic technique.

The risk of venous thromboembolism in patients with hepatitis C

Some studies suggest that patients with hepatitis C virus (HCV) infection have an increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). Unfortunately, available data on this association are contrasting. A systematic review and meta-analysis of literature studies was performed to evaluate the risk of venous thromboembolism (VTE) associated with HCV. Studies reporting on VTE risk associated with HCV were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases. Six studies (10 data-sets) showed a significantly increased VTE risk in 100,364 HCV patients as compared with 8,471,176 uninfected controls (odds ratio [OR]: 1.900; 95 % confidence interval [CI]: 1.406, 2.570; p<0.0001). These results were confirmed when specifically considering the risk of DVT (6 studies, OR: 1.918; 95 %CI: 1.351, 2.723; p<0.0001), whereas a trend towards an increased risk of PE was documented in HCV patients (4 studies, OR: 1.811; 95 %CI: 0.895, 3.663; p=0.099). The increased VTE risk associated with HCV infection was consistently confirmed when analysing four studies reporting adjusted risk estimates (OR: 1.876; 95 %CI: 1.326, 2.654; P<0.0001), and after excluding studies specifically enrolling populations exposed to transient risk factors for VTE (4 studies, OR: 1.493; 95 %CI: 1.167, 1.910; p=0.001). Meta-regression models suggested that age and male gender may significantly impact on the risk of VTE associated with HCV-positivity. Results of our metaanalysis suggest that HCV-infected subjects may exhibit an increased risk of VTE. However, further high quality studies are needed to extend and confirm our findings.

Supplementary Material to this article is available online at www.thrombosis-online.com.